WorldWideScience

Sample records for air filter samples

  1. Direct analysis of air filter samples for alpha emitting isotopes

    International Nuclear Information System (INIS)

    The traditional method for determination of alpha emitting isotopes on air filters has been to process the samples by radiochemical methods. However, this method is too slow for cases of incidents involving radioactive materials where the determination of personnel received dose is urgent. A method is developed to directly analyze the air filters taken from personal and area air monitors. The site knowledge is used in combination with alpha spectral information to identify isotopes. A mathematical function is developed to estimate the activity for each isotope. The strengths and weaknesses of the method are discussed

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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 of particulate radioactive air samples. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor(regsign) 3000) used at PNNL for self absorption effects. There were two methods used in the study, (1) to compare the radioactivity concentration by direct gas-flow proportional counting of the filter to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection and (2) to evaluate sample filters by high resolution visual/infrared microscopy to determine the depth of material loading on or in the filter fiber material. Sixty samples were selected from the archive for acid digestion in the first method and about 30 samples were selected for high resolution visual/infrared microscopy. Mass loading effects were also considered. From the sample filter analysis, large error is associated with the average self absorption factor, however, when the data is compared directly one-to-one, statistically, there appears to be good correlation between the two analytical methods. The mass loading of filters evaluated was <0.2 mg cm-2 and was also compared against other published results. The microscopy analysis shows the sample material remains on the top of the filter paper and does not imbed into the filter media. Results of the microscopy evaluation lead to the conclusion that there is not a mechanism for significant self absorption. The overall conclusion is that self-absorption is not a significant factor in the analysis of filters used at PNNL for radioactive air stack sampling of radionuclide particulates and that an applied correction factor is conservative in determining overall sample activity. A new self absorption factor of 1.0 is recommended

  4. Study of Filter Media for Air-Sampling Purposes

    International Nuclear Information System (INIS)

    A comparative study of six filter media commonly used m monitoring airborne radioactivity has been carried out. The following characteristics were studied: (1) filtration efficiency for uranyl nitrate aerosol and natural activity, (2) pressure drop at various flow rates, (3) absorption factor for alpha particles, (4) use for alpha pulse-height analysis, and (5) physical properties such as tensile strength, thickness, density and ash content. From the results obtained, the order of preference for use in routine monitoring is found to be CWS-6, HV-70, AGF/F, AGF/A, Whatman-41 and Whatman-42. (author)

  5. Detection of fissile materials in smeared or air filter samples by fission track registration technique

    International Nuclear Information System (INIS)

    The fission track registration technique was investigated for the detection of fissile materials in smeared and air filter samples. The filters taken directly from the nuclear facilities were applied onto the surface of Lexan plate for neutron irradiation in the HANARO research reactor. The fission tracks in the Lexan plate were observed under optical microscope. The optimal conditions for the neutron irradiation and chemical etching were established, where the total neutron irradiation dose was 300x1013n/cm2 and the chemical etching was done in 6.25 M-NaOH solution for 10 min., respectively

  6. Radiological background levels found in glass fiber filters used for low-level environmental surveillance air sampling

    International Nuclear Information System (INIS)

    Environmental surveillance monitoring of low-level radioactive particles in air requires a thorough understanding of low-level techniques and air sample collection media. High-volume air sampling for radioactive particles around Lawrence Livermore National Laboratory (LLNL) currently employs glass-fiber filters that are analyzed for gross alpha and gross beta activity and for specific isotopes. This study was conducted to determine the activities of radionuclides contained in blank glass-fiber filters. Data from this study provided a partial explanation of differences between current reported concentrations of radionuclides in air and those reported historically when cellulose filters were used in the LLNL monitoring effort. (author)

  7. Radiological background levels found on glass fiber filters used for low-level environmental surveillance air sampling

    International Nuclear Information System (INIS)

    Environmental surveillance of low-level radioactive particles in air requires a thorough understanding of low-level techniques and air sample collection media. High-volume air sampling for radioactive particles around Lawrence Livermore National Laboratory (LLNL) employs glass-fiber filters that are analyzed for gross alpha and gross beta activity and for specific isotopes. This study was conducted to determine the activities of radionuclides contained in blank glass-fiber filters. Data from this study provided a partial explanation of differences between current reported concentrations of radionuclides in air and those reported historically when cellulose filters were used in the LLNL monitoring effort

  8. Measurement of gross alpha and beta in air filter samples by using liquid scintillation counter

    International Nuclear Information System (INIS)

    The determination of gross alpha and gross beta in particulate air filter samples was carried out by alpha, beta discrimination method using Liquid Scintillation Analyzer by setting the PSA value at 55 for 5 ml 0.1 HCl plus 15 ml of Ultima Gold AB cocktail by using 241Am and 90Sr/90Y sources. The standardized method was compared with the gross alpha and gross beta activity determined by conventional method of direct counting with end window G.M. counter and ZnS (Ag). The minimum detectable activity of LSA method was found to be 9.3 mBq and 17.7 mBq for gross alpha and gross beta respectively for 6000 sec compared to the conventional method of 9.8 mBq and 189 mBq respectively at the same counting time. The result of analysis by both method indicate that the alpha, beta discrimination set up of LSA method is highly effective in the determination of low level alpha, beta activity in air filter samples. (author)

  9. HEPA air filter (image)

    Science.gov (United States)

    ... 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 ...

  10. The sampling of hydrogen sulfide in air with impregnated filter paper

    NARCIS (Netherlands)

    Huygen, C.

    1964-01-01

    A method is proposed for the quantitative collection of hydrogen sulfide in air on impregnated filter paper. An aqueous solution of potassium hydroxide, potassium zincate and glycerol is used as impregnating fluid. The stability of the collected sulfide and the efficiency of collection at different

  11. PM10 sampler deposited air particulates: Ascertaining uniformity of sample on filter through rotated exposure to radiation

    International Nuclear Information System (INIS)

    For reproducibility of analytical results of samples deposited on filters using PM10 sampler, homogeneity of the sample on the filter is very important especially when the size of the X-ray beam for the analysis is less than the size of filter. It is against this background that the air particulate samples collected on using PM10 samplers are analysed to determine the elemental concentrations. Each sample was divided into four quadrants and each was analysed under same conditions to determine if the particles were deposited uniformly over the filter. Each analysis was done using EDXRF technique. The spectrometer consists of four secondary targets, which are automatically switched to in sequence in analysing each sample. The concentration of various elements detected was determined using TURBOQUANT (a brand name for a SPECTRO method which is used for screening analysis). Sixteen elements were detected in every sample. Results show that there was less than 10% deviation in the concentrations in different quadrants. There were a few elements like Ba, Cs, etc., which have deviation greater than 20%. The concentrations of these latter elements were close to detection limits of the spectrometer. We conclude that the analytical result of particulate samples deposited on filters by the PM10 sampler can be reliable in terms of the homogeneity of the deposition. For such analytes with low concentrations, it would be important that the sampling time be increased to allow for higher mass deposition on the filter

  12. Effect of sample digestion, air filter contamination, and post-adsorption on the analysis of trace elements in air particulate matter

    International Nuclear Information System (INIS)

    Inductively coupled plasma atomic emission spectrometry and inductively coupled plasma MS are the major analytical tools for trace elements in environmental matrices, however, the underestimate of certain trace elements in analysis of air particulate matter by these two techniques has long been observed. This has been attributed to incomplete sample digestion. Here, we demonstrate that the combined effects of sample digestion, air filter impurities, and post-adsorption of the analytes contribute to the interference of the analysis. Particular attention should be paid to post-adsorption of analytes onto air filters after acid digestion. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Methods for detection of fused alumina powder, used as a tracer aerosol, on air sample filters

    International Nuclear Information System (INIS)

    Graded fused aluminia dusts (Aloxite) of mean particle sizes of 6 μm upwards are useful for measuring the effects of particle size on aerosol sampling systems and in dust experiments. Methods are described for the determination of filter loading with Aloxite aerosol using thermoluminescence (TL) and x-ray fluorescence (XRF). The XRF method was found to be almost as precise as direct weighing with a precision microbalance, and presents a useful method of detection where other contaminants are present in the sampled airstream. (author)

  14. Fukushima radionuclides at air filter and rain water samples collected from Istanbul and their atmospheric removal time

    International Nuclear Information System (INIS)

    Accident at Fukushima Daiichi Nuclear Power Plant (FDNPP) is one of the most serious accident in the world after Chernobyl accident. Following the continuing release of radionuclides in air after FDNPP, traces of fission products (131I, 134Cs and 137Cs) were recorded in the air filter and rain water samples collected from the CNAEM area at Istanbul on 4 April 2011. Airborne particle samples were collected daily in air filters and radio assayed with a high purity germanium detector. The fission products 131I, 134Cs and 137Cs were measured with the maximum activity concentrations of 1.03±0.08, 0.25±0.03 and 0.23±0.03 mBq m-3, respectively. For determination of the origin of the releases the 134Cs/137Cs ratio was calculated between 1.09 and 0.85. The authors find removal times for 137Cs of 8.13 d, 134Cs of 7.25 d and 131I of 6.82 d. (authors)

  15. Attempt at in-air PIXE analysis of spot samples on a filter-tape mounted in an automated beta-ray absorption mass monitor

    International Nuclear Information System (INIS)

    We attempted in-air-PIXE analysis of SPM using spot samples on a filter-tape mounted in an automated beta-ray absorption mass monitor. Al, Si, S, Fe and Zn, etc., which are of interest for identifying the behavior and characteristics of SPM, were detected on the SPM spot samples on a glass-fiber filter-tape, but the peaks of these elements were nearly identical to those of blank glass-fiber filter-tape. As such, it was difficult to detect elements present in SPM from the X-ray spectra of the spot samples. On the other hand, in the case of a PTFE membrane filter-tape, the S peak was distinct and the Fe peak was also clear, and peaks for elements Al, Mn and Zn, etc., were also confirmed. Consequently, if a method for determining quantity is established, direct multi-elemental analysis by in-air-PIXE of high time-resolution SPM spot samples collected on a PTFE membrane filter-tape mounted in a SPM monitor will be possible. (author)

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

    Science.gov (United States)

    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 ...

  17. Sample-whitened matched filters

    DEFF Research Database (Denmark)

    Andersen, Ib

    1973-01-01

    A sample-whitened matched filter (SWMF) for a channel with intersymbol interference and additive white Gaussian noise is defined as a linear filter with the properties that its output samples are a sufficient statistic for the MAP estimation of the transmitted sequence and have uncorrelated noise...... components. These filters are shown to exist for ali realistic channels and the complete set of SWMF's for any channel is determined. It is shown that for nonpathological channels there is a unique SWMF which minimizes the amount of intersymbol interference defined as the discrete-time analog to the rms...

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

    OpenAIRE

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

    2014-01-01

    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 an...

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

    Science.gov (United States)

    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

  20. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

    Although the field of radioactive air sampling has matured and evolved over decades, it has lacked a single resource that assimilates technical and background information on its many facets. Edited by experts and with contributions from top practitioners and researchers, Radioactive Air Sampling Methods provides authoritative guidance on measuring airborne radioactivity from industrial, research, and nuclear power operations, as well as naturally occuring radioactivity in the environment. Designed for industrial hygienists, air quality experts, and heath physicists, the book delves into the applied research advancing and transforming practice with improvements to measurement equipment, human dose modeling of inhaled radioactivity, and radiation safety regulations. To present a wide picture of the field, it covers the international and national standards that guide the quality of air sampling measurements and equipment. It discusses emergency response issues, including radioactive fallout and the assets used ...

  1. Ventilation filters as sources of air pollution – Processes occurring on surfaces of used filters

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Halás, Oto; Clausen, Geo; Weschler, Charles J.

    ~ 35 and 55 ppb and slowly increased over time. Within an hour the ozone concentration downstream of the filter had increased to ~ 70 ppb. In contrast, no change in ozone removal efficiency over time was observed for a new filter. The used filter samples were then placed for 24 hours in ambient air...... (ozone concentration <5 ppb); ambient air at an elevated temperature (100°C); or nitrogen. When subsequently placed in the air stream containing 75 ppb of ozone partial regeneration of the filter’s ozone removal capabilities was observed. Regeneration was greatest for the sample that had sat at an...

  2. Sequential isotopic determination of plutonium, thorium, americium and uranium in the air filter and drinking water samples around the WIPP site

    International Nuclear Information System (INIS)

    The simultaneous determination of actinides in air filter and water samples around the WIPP site have been demonstrated. The analytical method is based on the selective separation and purification by anion exchange and Eichrome-TEVA, TRU and DGA-resin followed by determination of actinides by alpha spectrometry. Counting sources for alpha spectrometric measurements were prepared by microcoprecipitation on neodymium fluoride (NdF3). Radiochemical yields were determined using 242Pu, 229Th, 243Am and 232U as tracers. The validation of the method is performed through the analysis of reference materials or participating in laboratory intercomparison programs. The plutonium concentrations in aerosols varied seasonally, being highest in spring and summer due to the spring-time enhanced wind-storm transportation of radioactive aerosols from the stratosphere to the troposphere. The 238Pu/239+240Pu activity ratio in the aerosol samples is typically close to that of global fallout from historic above-ground nuclear weapons testing. The results presented here indicate that the source of plutonium in the WIPP environment results mainly from global nuclear fallout and there is no evidence of increases in radiological contaminants in the region that could be attributed to releases from the WIPP. (author)

  3. Air filters for use at nuclear facilities

    International Nuclear Information System (INIS)

    The ventilation system of a nuclear facility plays a vital role in ensuring that the air in working areas and the environment remains free from radioactive contamination. An earlier IAEA publication, Techniques for Controlling Air Pollution from the Operation of Nuclear Facilities, Safety Series No. 17, deals with the design and operation of ventilation systems at nuclear facilities. These systems are usually provided with air-cleaning devices which remove the contaminants from the air. This publication is intended as a guide to those who are concerned with the design of air-filtering systems and with the testing, operation and maintenance of air-filter installations at nuclear facilities. Emphasis is mainly placed on so-called high-efficiency particulate air filters (HEPA filters) and on providing general information on them. Besides describing the usual filter types, their dimensions and construction materials, the guidebook attempts to explain their properties and behaviour under different operating conditions. It also gives advice on testing and handling the filters so that effective and safe performance is ensured. The guidebook should serve as an introduction to the use of high efficiency particulate air filters in countries where work with radioactive materials has only recently commenced. The list of references at the end of the book indicates sources of more advanced information for those who already have comprehensive experience in this field. It is assumed here that the filters are obtained from a manufacturer, and the guidebook thus contains no information on the design and development of the filter itself, nor does it deal with the cleaning of the intake air to a plant, with gas sorption or protective respiratory equipment

  4. High efficiency particulate air filter experience survey

    International Nuclear Information System (INIS)

    Causes and magnitude of HEPA filter changeouts and failures at DOE sites for the years 1977 to 1979 were evaluated. Conclusions inferred from the data follow: HEPA filters have been generally performing the task they were designed for; most changeouts have been made because of filter plugging, preventive maintenance, or precautionary reasons rather than evidence of filter failure; where failures have been experienced, records generally have not been adequate to determine the cause of failure; where cause of failure has been determined, damage attributed to personnel handling and installation has been substantially more prevalent than that from filter environmental exposure. The need for improved personnel training in handling and installation was stressed. Some reduction in filter failure frequency can be achieved by improving the acid and moisture resistance of filters, and providing adequate pretreatment of air prior to HEPA filtration

  5. Initial studies of oxidation processes on filter surfaces and their impack on perceived air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Halás, Oto; Clausen, Geo;

    2003-01-01

    studies, human subjects assessed air passing through various filter samples. This occurred when samples were first placed in the test rig (each of 3 filters equivalent); immediately after the samples had sat for 48 hours in ozone, nitrogen or air (ozone-treated worse than air-treated worse than nitrogen...

  6. Precision temperature controlled filtered laminar air enclosure

    International Nuclear Information System (INIS)

    We demonstrate a novel temperature controlled filtered laminar air enclosure composed of primarily off-the-shelf components that can be applied to a broad class of systems to significantly enhance their performance. An air mixing method is employed to provide variable cooling of the incoming filtered air, providing a temperature stability of ± 0.02 °C within the enclosure. The method is inexpensive to implement, and is suitable for a wide range of temperature controlled enclosures, with dimensions in the approximate range from 1 m to 5 m, making it ideal for many scientific applications. (technical design note)

  7. Air sampling in the workplace

    International Nuclear Information System (INIS)

    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. Air sampling system for airborne surveys

    International Nuclear Information System (INIS)

    An air sampling system has been designed for installation on the Beechcraft King Air A-100 aircraft as a part of the Aerial Radiological Measuring System (ARMS). It is intended for both particle and whole gas sampling. The sampling probe is designed for isokinetic sampling and is mounted on a removable modified escape hatch cover, behind the co-pilot's seat, and extends about two feet forward of the hatch cover in the air stream lines. Directly behind the sampling probe inside the modified hatch cover is an expansion chamber, space for a 5-inch diameter filter paper cassette, and an optional four-stage cascade impactor for particle size distribution measurements. A pair of motors and blower pumps provide the necessary 0.5 atmosphere pressure across the type MSA 1106 B glass fiber filter paper to allow a flow rate of 50 cfm. The MSA 1106 B filter paper is designed to trap sub-micrometer particles with a high efficiency; it was chosen to enable a quantitative measurement of airborne radon daughters, one of the principal sources of background signals when radiological surveys are being performed. A venturi section and pressure gauges allow air flow rate measurements so that airborne contaminant concentrations may be quantified. A whole gas sampler capable of sampling a cubic meter of air is mounted inside the aircraft cabin. A nuclear counting system on board the aircraft provides capability for α, β and γ counting of filter paper samples. Design data are presented and types of survey missions which may be served by this system are described

  9. Air filtering through the building envelope

    Directory of Open Access Journals (Sweden)

    Petrosova D.V.

    2012-03-01

    Full Text Available Recently, building envelopes with efficient insulation of low thermal conductivity, including light building envelope, which allow to increase thermal protection of buildings, are widely used. This new building envelope require a comprehensive study, because previously considered unimportant features often start to make significant effect on the performance characteristics of structures.To reduce the air permeability in the constructions wind-proof membranes are used. However, the influence of air filtering in such structures has not been researched yet.When the air-permeable building envelopes are used, the heat flow is moved away also due to the air filtering. It is proposed to take into account the convective heat transfer mechanism commensurate with the conductive heat transfer mechanism. In the formula for determining the heat flow due to the air filtering the filtration coefficient of air through the building envelope is used. This coefficient is found experimentally for light building envelopes.Furthermore, the empirical expression for the filtration coefficient, which relates it and the coefficient of heat loss is found.

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

    International Nuclear Information System (INIS)

    This invention relates to an apparatus for testing air having contaminants and radon progeny. 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. The box has a sintered stainless steel filter. Air is drawn from a source into the sampling box using a vacuum pump, passing the air through the filter. The contaminants trapped by the filter are monitored. The apparatus provides 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 through

  11. Ensemble Filtering in Air Quality Models

    Czech Academy of Sciences Publication Activity Database

    Eben, Kryštof; Juruš, Pavel; Resler, Jaroslav; Belda, M.; Pelikán, Emil

    Brno : Masaryk University, 2007 - (Horová, I.; Hřebíček, J.) ISBN 978-80-210-4333-6. [ TIES 2007. Annual Meeting of the International Environmental Society /18./. 16.08.2007-20.08.2007, Mikulov] Institutional research plan: CEZ:AV0Z10300504 Keywords : air quality models * data assimilation * ensemble filtering

  12. Enhancing indoor air quality –The air filter advantage

    Directory of Open Access Journals (Sweden)

    Vannan Kandi Vijayan

    2015-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  14. Adaptive Importance Sampling in Particle Filtering

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav; Hofman, Radek

    Istanbul : ISIF, 2013. ISBN 978-605-86311-1-3. [16th International Conference on Information Fusion. Istanbul (TR), 09.07.2013-12.07.2013] R&D Projects: GA MV VG20102013018; GA ČR(CZ) GAP102/11/0437 Keywords : importance sampling * sequential monte carlo * sufficient statistics Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2013/AS/smidl-adaptive importance sampling in particle filtering.pdf

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

    Science.gov (United States)

    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.

  16. Design and Set up of an Air Filter Testing Unit to Demonstrate Characteristics and Performance of Particulate Air Filters

    OpenAIRE

    Ken Smigielski; Farhang Akbar-Khanzadeh

    2009-01-01

    An air filter is a significant element of any mechanical ventilation system. However, the importance and performance evaluation of air filters have not been well publicized and related scientific reports are scarce. In this study, a transportable, off-line, air filter-testing unit (the Unit) was designed and utilized to simulate the filter housing of a mechanical ventilation system. The Unit was designed, assembled, and operated in a laboratory. To demonstrate the applications of the Unit, a ...

  17. Simulation of the air flows in many industrial pleated filters

    International Nuclear Information System (INIS)

    The study presents results concerning the characterization of the charge loss and the air flow in nuclear and automobile type pleated filters. The experimental studies in correlation with the numerical models showed an homogenous distribution of the air flows in a THE nuclear type filter, whereas the distribution is heterogenous in the case of an automobile filter. (A.L.B.)

  18. Design and Set up of an Air Filter Testing Unit to Demonstrate Characteristics and Performance of Particulate Air Filters

    Directory of Open Access Journals (Sweden)

    Ken Smigielski

    2009-04-01

    Full Text Available An air filter is a significant element of any mechanical ventilation system. However, the importance and performance evaluation of air filters have not been well publicized and related scientific reports are scarce. In this study, a transportable, off-line, air filter-testing unit (the Unit was designed and utilized to simulate the filter housing of a mechanical ventilation system. The Unit was designed, assembled, and operated in a laboratory. To demonstrate the applications of the Unit, a series of air filter handling and installation scenarios was performed to determine the characteristic curve and capture efficiencies of a selected set of HEPA filters. The research project produced a transportable, closed system air filter testing unit. The Unit incorporated a fan, a damper to adjust air flowrate, a filter-housing (consisting of a mixing chamber, a filter-frame, and a pressure-gauge, and ducting with ports to introduce challenge particles and monitor them after filtration. By using the Unit, the detrimental effects of damaged filter-media, damaged filter-gasket, and improper installation of air filters on their capture efficiencies were clearly demonstrated. An air filter testing unit, similar to the Unit presented here, can readily be designed, fabricated, and assembled to simulate the filter-housing of mechanical ventilation systems. The assembled unit can be used (1 to determine capture efficiency of air filters and their characteristic curve, (2 to demonstrate the negative effects of improper handling and installation of air filters, and (3 as an effective investigative and educational tool.

  19. Modification of Air Filter Media with Nylon-6 Nanofibers

    OpenAIRE

    Lei Li; Margaret W. Frey; Thomas B. Green

    2006-01-01

    Nylon-6 fibers with average diameters below 500 nm were electrospun onto conventional air filter media at varying weight coverage levels using a multi-nozzle bank. The initial filtration efficiency of the air filter media was improved significantly with increasing coverage level and decreasing size of nylon-6 fibers. Nylon-6 fibers were very durable on the air filter media at the coverage level of 0.1 g/m2 due to the good adhesion with the air filter fibers. The production efficiency of the c...

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

    International Nuclear Information System (INIS)

    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 137Cs 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, 7Be and 210Pb, continue to be detected in most air filter samples. Variations in the annual mean concentrations of 7Be 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 7Be and 210Pb 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 7Be, 95Zr, 137Cs, 144Ce, and 210Pb measured at sampling sites in SASP during 1990--1993 are presented. The weekly mean surface air concentrations of 7Be, 95Zr, 137Cs, 144Ce, and 210Pb for samples collected during 1990--1993 are given for 17 sites

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Sampling and preparation of air pollutants at the Coal Paiton Power Plant area Probolinggo

    International Nuclear Information System (INIS)

    Sampling has been conducted on April 8 th to 18 th, 2012 at the plant area of Paiton Coal Power Plant using e-sampler for particulated matter PM-2,5 and PM-10, high volume air sampler for total suspended particulate (TSP) at the three sampling locations as the representative pollution. Filter before and after sampling was weighed and extremely guarded contamination. Air filters stored in desiccator filter for 24 hours. Determination of concentration of ambient air pollutants conducted by gravimetric method derived from a reduction in weight the samples on the filter PM-2,5; PM-10 and TSP to the weight of the empty filter. (author)

  3. The high efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    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

  4. High efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    The authors 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-efficiently 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 steel filters, they 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, prototype filters were then built for venting compressed gases and evaluated in their automated filter tester

  5. Efficiency of dust sampling inlets in calm air.

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Ammonia transformation in a biotrickling air filter

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter; Nielsen, Marie Louise; Andersen, Mathias; Nielsen, Anders M.

    outlet / water inlet, and only 8% of the nitrite was turned into nitrate. Water supply only exceeded evaporation by 20% but modelling indicated that additional watering would have limited effect on filter efficiency. The filter was also robust to varying loading, as a 4-fold increase in ammonia inlet...

  8. Electrostatic air filters generated by electric fields

    International Nuclear Information System (INIS)

    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

  9. Air sampling in the workplace. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hickey, E.E.; Stoetzel, G.A.; Strom, D.J.; Cicotte, G.R. [Pacific Northwest Lab., Richland, WA (United States); Wiblin, C.M. [Advanced Systems Technology, Inc., Atlanta, GA (United States); McGuire, S.A. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications

    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.

  10. Report on two intercomparisons on the determination of selected radionuclides in simulated air filters [Air-1/1 and Air-2/1 (1978-1979)

    International Nuclear Information System (INIS)

    The public interest in atmospheric pollution by heavy metals and radioactive contaminants and the need for their reliable determination has convinced the International Atomic Energy Agency of the necessity to continue its programme of intercomparisons of air filter analyses. Several such intercomparison exercises have been organized by the Agency in the past years. The present report deals with a recent intercomparison of activity measurements of air filters spiked with radionuclides. This intercomparison exercise had the aims to provide laboratories dealing with the determination of radionuclides in air filters with an opportunity of checking their analytical performance and, in addition, it was hoped that these simulated air filters would become sufficiently well characterized to be considered later as reference samples with ''recommended'' values for the activities of several radionuclides. The values for 137Cs, 54Mn, 239Pu and 90Sr in Air-1/1 filters seem to be established with a reasonable degree of confidence. The issue of Air-1/1 filters as a reference material for the above radionuclides will follow soon. The comparison of the results of these intercomparison runs with those of the preceding exercises shows on the whole no significant improvement of the quality of analysis. The results of these intercomparison runs show again the difficulties encountered in the determination of radionuclides on air filters. Much effort is still needed to achieve better reliability

  11. Methodology for modeling the microbial contamination of air filters.

    Directory of Open Access Journals (Sweden)

    Yun Haeng Joe

    Full Text Available 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.

  12. Comparison of Endotoxin Exposure Assessment by Bioaerosol Impinger and Filter-Sampling Methods

    OpenAIRE

    Duchaine, Caroline; Thorne, Peter S.; Mériaux, Anne; Grimard, Yan; Whitten, Paul; Cormier, Yvon

    2001-01-01

    Environmental assessment data collected in two prior occupational hygiene studies of swine barns and sawmills allowed the comparison of concurrent, triplicate, side-by-side endotoxin measurements using air sampling filters and bioaerosol impingers. Endotoxin concentrations in impinger solutions and filter eluates were assayed using the Limulus amebocyte lysate assay. In sawmills, impinger sampling yielded significantly higher endotoxin concentration measurements and lower variances than filte...

  13. Magnetic analyses of powders from exhausted cabin air filters

    Science.gov (United States)

    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.

  14. Guidance for air sampling at nuclear facilities

    International Nuclear Information System (INIS)

    The principal uses of air sampling at nuclear facilities are to monitor general levels of radioactive air contamination, identify sources of air contamination, and evaluate the effectiveness of contaminant control equipment, determine exposures of individual workers, and provide automatic warning of hazardous concentrations of radioactivity. These applications of air sampling are discussed with respect to standards of occupational exposure, instrumentation, sample analysis, sampling protocol, and statistical treatment of concentration data. Emphasis is given to the influence of spacial and temporal variations of radionuclide concentration on the location, duration, and frequency of air sampling

  15. Investigation into the behaviour of HEPA filters at high temperature, air humidity, and elevated differential pressure

    International Nuclear Information System (INIS)

    Investigations into the response of full-size HEPA filters to extended operation under high humidity airflows were continued with tests of 47 commercial and 13 prototypical filter units. The parameters studied were relative air humidity or liquid moisture content, temperatures between 20 and 800C, filter loading with dust, exposure time, and filter orientation to airflow. In view of complementary investigations with samples of HEPA-filter media, a laboratory test facility was built and put into operation. Based on the establishment of the main failure mechanisms, new prototype filters, incorporating a filter medium reinforced by glass-fiber cloth and a new separator design with modified corrugations, were built and tested. (orig./DG)

  16. High efficiency particulate air filter behavior under high humidity airflows

    International Nuclear Information System (INIS)

    A loss-of-coolant accident could threaten the integrity of the HEPA filters in the air cleaning systems of a nuclear power reactor with airflows of high humidity, elevated temperature, and greater than design flow rate. It is important that filter reliability be assured during accident situations since a loss of filter integrity could result in a loss of containment. The average failure differential pressure at 1700 m3/h for three commercial filter designs under conditions of high air humidity at 500C were found to lie between 0.7 and 7.6 kPa. The modes and mechanisms of structural failure were determined for wooden frame deep pleat filters, the design with the most potential for improvement. Initial tests of prototype filter units with a glass fiber medium reinforced by fiber glass cloth proved that structural limits could be increased to at least 10 kPa even with significant decreases in the lateral stability of the filter pack. A similar test of a prototype filter equipped with a special arrangement of the separators and a conventional glass fiber medium showed that pack stability could be maintained during fog conditions that cause failure of conventional glass fiber filters within several hours

  17. Mathematical models for changes in HEPA filter pressure drop caused by high air humidity

    International Nuclear Information System (INIS)

    Possible high air humidities resulting from an accident in a nuclear installation threaten the integrity of high-efficiency particulate air (HEPA) filter units in the facility air cleaning systems. Field surveys indicate that filter units continue to be exposed to adverse humidities in routine service despite the development of moisture countermeasures. One of the detrimental consequences of exposure to high air humidity is an increase in filter pressure drop (Δp). Reported failures due to a tearing of the filter medium partly result from elevated structural loadings imposed by Δp increases. The extent to which filter Δp varies with airstream conditions can be used to help calculate safety margins for filter units during normal and upset operations as well as during postulated accidents involving high air humidity. Studies of humidity-related changes in pressure drop were carried out to help explain structural failures in routine service and to obtain the empirical data needed to numerically model flow dynamics in air cleaning systems under accident conditions. Tests were performed on full-scale filter units under fog conditions and on samples of filter media at humidities up to 99% RH. Test results show that typical changes in Δp can be mathematically modeled by a number of time functions having coefficients that can only be determined empirically. Regression analysis is used to establish the coefficients for specific filter units and dust loadings tested under the operating conditions of interest. Comparison of measured and calculated increases in pressure drop for clean filter units under fog conditions show that good agreement can be obtained with coefficients determined as relatively simple functions of the airstream velocity and liquid water content

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

    Science.gov (United States)

    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).

  19. Self-Cleaning Particulate Air Filter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA requires an innovative solution to the serious issue of particulate fouling on air revitalization component surfaces in order to address the potential for...

  20. Enhancing indoor air quality –The air filter advantage

    OpenAIRE

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

    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 in...

  1. PFPSO: An Optimised Filtering Approach Based on Sampling

    Directory of Open Access Journals (Sweden)

    Y. Hernane

    2010-01-01

    Full Text Available Extended Kalman filter is the first algorithm applied to nonlinear state estimation problem and following its limits, other methods based on sampling were developed. We can consider two categories of particle filters: filters which apply a deterministic sampling as the famous unscented Kalman filter and those whose principle is the random sampling as the Particle filter. Furthermore, other approaches that take these two forms of sampling were proposed as Sigma Point Particle filter. The major difficulty of these methods is the computation time which is related to the complexity of sampling. Particle Filter is one among the methods that has attracted particular interest recently; however, PF suffers the problem of degeneration of particles that occurs after re-sampling. We propose to improve PF by the bioinspired algorithm Particle Swarm Optimization as these 2 models have several common. The hybrid method developed in this study is called PFPSO. The PFPSO reduces significantly the degeneracy of the particles; empirical results obtained by applying PFPSO to the problem of estimating the trajectory of a mobile robot illustrate robustness and computational efficiency of our approach.

  2. Studies on filtration theory of high efficiency air filters

    International Nuclear Information System (INIS)

    Filtration theory proposed by Kirsch et al. predicting the collection performance of high efficiency air filters was corrected allowing for the variance in the thickness of filter paper. In order to compare the predicted performance with the actual one, penetrations of dioctyl phthalate (DOP) particles through Whatman GF/A filter were measured by using laser particle spectrometer and condensation nucleus counter (CNC)/diffusion battery (DB) system. The comparison between the theoretical value and the experimental one was made in the following four indexes: the most penetrating particle size, maximum penetration, full width at tenth maximum and pressure drop. The calculated penetration through the GF/A filter is in fair agreement with the experimental data at the air flow velocity of 2.4 cm/s. (author)

  3. Concept of filter-adsorber type integrated air purifier

    Directory of Open Access Journals (Sweden)

    Raos Miomir

    2010-01-01

    Full Text Available In order to prove flow-thermal and operating parameters of air purifiers in a filter-adsorber system, the authors conducted comprehensive experimental examination in the laboratory for air quality control at the Faculty of Occupational Safety in Niš. Experimental examination was carried out on original experimental equipment with the concept of integrated air purifier which includes simultaneous activity of two different filter screens on separating mechanical and chemical test contaminants from a gas mixture. For that purpose, in cooperation with several companies, we designed and produced original filter screens and provided certain conceptual solutions for purifiers. Experimental data were recorded with suitable acquisition equipment in order to identify the processes.

  4. Design and development of high performance panel air filter with experimental evaluation and analysis of filter media pleats

    OpenAIRE

    Sagar R. Patil; Prof. Sachin V. Lomte

    2015-01-01

    In automobile vehicles mostly plastic molded panel filters used for the purpose of engine air filtration. Fibrous structured cellulose media were being used with different permeability’s according to requirement of rated air flow rate required for the engine. To optimize the filter pleat design of automotive panel air filter, it is important to study correlation of pressure drop, dust holding capacity & efficiency. The main role of a filter is to provide least pressure drop with h...

  5. Comparison of aerosol and bioaerosol collection on air filters

    OpenAIRE

    Miaskiewicz-Peska, Ewa; Lebkowska, Maria

    2011-01-01

    Air filters efficiency is usually determined by non-biological test aerosols, such as potassium chloride particles, Arizona dust or di-ethyl-hexyl-sebacate (DEHS) oily liquid. This research was undertaken to asses, if application of non-biological aerosols reflects air filters capacity to collect particles of biological origin. The collection efficiency for non-biological aerosol was tested with the PALAS set and ISO Fine Test Dust. Flow rate during the filtration process was 720 l/h, and par...

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

    Science.gov (United States)

    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...

  7. Local Importance Sampling: A Novel Technique to Enhance Particle Filtering

    Directory of Open Access Journals (Sweden)

    Péter Torma

    2006-04-01

    Full Text Available In the low observation noise limit particle filters become inefficient. In this paper a simple-to- implement particle filter is suggested as a solution to this well-known problem. The proposed Local Importance Sampling based particle filters draw the particles’ positions in a two-step process that makes use of both the dynamics of the system and the most recent observation. Experiments with the standard bearings-only tracking problem indicate that the proposed new particle filter method is indeed very successful when observations are reliable. Experiments with a high-dimensional variant of this problem further show that the advantage of the new filter grows with the increasing dimensionality of the system.

  8. Combined filtering facilities for nuclear air cleaning systems

    International Nuclear Information System (INIS)

    Full text of publication follows: The choice of an optimal cleaning technology and cleaning system design depends on the specificity of the provision of the ecological safety of NPP under operation and accident conditions. The major requirements imposed on such systems are to achieve high efficiency (99,0-99,95 %) and reliability. In this respect, the important problem is to develop combined filtering facilities (CFF) which are able within the same aggregate to provide complex cleaning of air from moisture, radioactive aerosols, iodine in molecular (I2) and organic (CH3I) forms. A great experience accumulated at SSC RF IPPE and other organizations in the course of researches dealing with construction of aerosol filters and iodine filters-sorbers for NPPs and radio-chemical plants made it possible to develop a pilot mock-up facility providing complex cleaning of air from radioactive aerosols and iodine in reference to the real ventilation conditions at the First in the World Nuclear Power Plant. By now complex tests of the mock-up specimen of the UFK-3500 facility have been run with the aim of determining the functional efficiency of its separate filtering sections in terms of droplet moisture, atmospheric and radioactive aerosols and radioiodine and its organic compounds as well as of the filtering facility as a whole. Control over aerosol and radioiodine concentrations and volumetric activity was performed using laser and gamma spectrometry. The obtained data give necessary grounds to formulate the recommendations, how to develop and organize production of combined filtering facilities for flow rates of the medium to be cleaned of 3500, 7000, 10500 m3/h. The production is organized on the basis of OAO PZ 'Signal' in Obninsk. Provision is made for using small capacity small size filters (for radiochemical plants and research test facilities and rigs) and high efficiency sorbers (for commercial NPP) as filters-sorbers. To date the design plans and specifications

  9. Sampling Procedure for a Radionuclide Assessment of a Spent HEPA Filter Waste

    International Nuclear Information System (INIS)

    According to the operation of nuclear facilities and a continuous construction of them, a great amount of used high efficiency particulate air (HEPA) filters which are widely used in a ventilation system in the nuclear industry has been generated as spent filter waste. All these HEPA filter wastes generated at KAERI have been stored in accordance with the original form without any treatment of them. However, to secure space in a waste storage facility approaching saturation, it is desirable to treat them by a compaction in view of a radioactive waste treatment and storage, and finally, to repack the compacted spent filters into a 200 liter drum for sending them to a disposal site. In order to dispose of the HEPA filters, it is first necessary to conduct a radionuclide assessment of them before compacting them. However, it is difficult to directly measure a radioactive concentration level of the nuclides captured in a HEPA filter because of its great bulk and specific shape. Therefore, after taking a representative sample from a HEPA filter, the analysis results for it are regarded as a representative value for the corresponding HEPA filter. To use this method, it is essential to confirm the validity of the sampling procedure and representative value. In this study, the depth distribution of the captured nuclides in a HEPA filter waste was first investigated. From the results, it was possible to obtain a representative sample from the intake part and the outlet part of a HEPA filter without a dismantlement. And then, a punch device with a diameter of 2 inch was developed for taking a representative sample which has a regular size

  10. Sampling Procedure for a Radionuclide Assessment of a Spent HEPA Filter Waste

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young-Yong; Hong, Dae-Seok; Kang, Il-Sik; Kim, Tae-Kuk; Lee, Young-Hee; Shon, Jong-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-10-15

    According to the operation of nuclear facilities and a continuous construction of them, a great amount of used high efficiency particulate air (HEPA) filters which are widely used in a ventilation system in the nuclear industry has been generated as spent filter waste. All these HEPA filter wastes generated at KAERI have been stored in accordance with the original form without any treatment of them. However, to secure space in a waste storage facility approaching saturation, it is desirable to treat them by a compaction in view of a radioactive waste treatment and storage, and finally, to repack the compacted spent filters into a 200 liter drum for sending them to a disposal site. In order to dispose of the HEPA filters, it is first necessary to conduct a radionuclide assessment of them before compacting them. However, it is difficult to directly measure a radioactive concentration level of the nuclides captured in a HEPA filter because of its great bulk and specific shape. Therefore, after taking a representative sample from a HEPA filter, the analysis results for it are regarded as a representative value for the corresponding HEPA filter. To use this method, it is essential to confirm the validity of the sampling procedure and representative value. In this study, the depth distribution of the captured nuclides in a HEPA filter waste was first investigated. From the results, it was possible to obtain a representative sample from the intake part and the outlet part of a HEPA filter without a dismantlement. And then, a punch device with a diameter of 2 inch was developed for taking a representative sample which has a regular size.

  11. A nested sampling particle filter for nonlinear data assimilation

    KAUST Repository

    Elsheikh, Ahmed H.

    2014-04-15

    We present an efficient nonlinear data assimilation filter that combines particle filtering with the nested sampling algorithm. Particle filters (PF) utilize a set of weighted particles as a discrete representation of probability distribution functions (PDF). These particles are propagated through the system dynamics and their weights are sequentially updated based on the likelihood of the observed data. Nested sampling (NS) is an efficient sampling algorithm that iteratively builds a discrete representation of the posterior distributions by focusing a set of particles to high-likelihood regions. This would allow the representation of the posterior PDF with a smaller number of particles and reduce the effects of the curse of dimensionality. The proposed nested sampling particle filter (NSPF) iteratively builds the posterior distribution by applying a constrained sampling from the prior distribution to obtain particles in high-likelihood regions of the search space, resulting in a reduction of the number of particles required for an efficient behaviour of particle filters. Numerical experiments with the 3-dimensional Lorenz63 and the 40-dimensional Lorenz96 models show that NSPF outperforms PF in accuracy with a relatively smaller number of particles. © 2013 Royal Meteorological Society.

  12. Cabin Air Sampling Study Functionality Test.

    OpenAIRE

    Muir, Helen; Walton, Christopher; McKeown, Rebecca

    2008-01-01

    The Department for Transport (DFT), on behalf of the Government’s Aviation Health Working Group (AHWG), commissioned Cranfield University to organise, manage and deliver a functionality test of a variety of air sampling devices capable of detecting a wide range of compounds in a cabin air environment. The functionality test was to be the preliminary stage of a major monitoring study of the cabin air environment, which the Department intends to conduct. Report prepared for the Department f...

  13. East Mountain Area 1995 air sampling results

    Energy Technology Data Exchange (ETDEWEB)

    Deola, R.A. [Sandia National Labs., Albuquerque, NM (United States). Air Quality Dept.

    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.

  14. East Mountain Area 1995 air sampling results

    International Nuclear Information System (INIS)

    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 (PM10) 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

  15. K West Basin Sand Filter Backwash Sample Analysis

    International Nuclear Information System (INIS)

    A sand filter is used to help maintain water clarity at the K West Basin where highly radioactive sludge is stored. Eventually that sand filter will require disposal. The radionuclide content of the solids trapped in the sand filter will affect the selection of the sand filter disposal pathway. The Pacific Northwest National Laboratory (PNNL) was contracted by the K Basin Operations & Plateau Remediation Project (operations contractor CH2M Hill) to analyze the radionuclide content of the solids collected from the backwash of the K West Basin sand filter. The radionuclide composition in the sand filter backwash solids will be used by CH2M Hill to determine if the sand filter media and retained sludge solids will be designated as transuranic waste for disposal purposes or can be processed through less expensive means. On October 19, 2015, K Basin Operations & Plateau Remediation Project staff backwashed the sand filter into the North Load-Out Pit (NLOP) and immediately collected sample slurry from a sampling tube positioned 24 in. above the NLOP floor. The 764 g sand filter backwash slurry sample, KW-105 SFBW-001, was submitted to PNNL for analysis on October 20, 2015. Solids from the slurry sample were consolidated into two samples (i.e., a primary and a duplicate sample) by centrifuging and measured for mass (0.82 g combined – wet centrifuged solids basis) and volume (0.80 mL combined). The solids were a dark brown/orange color, consistent with iron oxide/hydroxide. The solids were dried; the combined dry solids mass was 0.1113 g, corresponding to 0.0146 weight percent (wt%) solids in the original submitted sample slurry. The solids were acid-digested using nitric and hydrochloric acids. Insoluble solids developed upon dilution with 0.5 M HNO3, corresponding to an average 6.5 wt% of the initial dry solids content. The acid digestate and insoluble solids were analyzed separately by gamma spectrometry. Nominally, 7.7% of the 60Co was present in the insoluble solids

  16. Penggunaan Unit Slow Sand Filter, Ozon Generator dan Rapid Sand Filter untuk Meningkatkan Kualitas Air Sumur Dangkal menjadi Air Layak Minum dengan Parameter Kekeruhan, Fe, dan Mn

    Directory of Open Access Journals (Sweden)

    Jami’ah Jami’ah

    2014-09-01

    Full Text Available Air tanah dapat diambil masyarakat untuk keperluan sehari-hari. Air tanah terkadang belum memenuhi standar kualitas air minum karena adanya kadar besi, mangan dan kekeruhan yang tinggi. Dari permasalahan tersebut diperlukan adanya teknologi pengolahan yang efektif dan efisien bagi masyarakat. Slow sand filter, proses ozonisasi dan rapid sand filter dapat menjadi alternatif pengolahan air sumur dangkal tercemar menjadi air layak minum.Tujuan dari penelitian ini yaitu untuk menganalisa kemampuan unit slow sand filter, ozon generator dan rapid sand filter dalam menyisihkan besi, mangan, dan kekeruhan yang terkandung dalam air minum.Hasil penelitian menunjukkan bahwa efisiensi removal pada unit slow sand filter untuk beban besi, mangan dan kekeruhan adalah (84,13%; 4842%; 89,21%, pada proses ozonisasi (75,4%; 47,4%; 35,83%, dan pada unit rapid sand filter (79,63%; 72,2%; 64,94%.

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

    Directory of Open Access Journals (Sweden)

    Petar M. Djurić

    2005-10-01

    Full Text Available 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.

  18. Selection of filter media in alpha air monitors for emergency environmental monitoring

    International Nuclear Information System (INIS)

    We have developed an alpha air monitor which is possible to measure rapidly and sensitively the concentrations of airborne alpha-emitting particles, such as plutonium, for the environmental monitoring at an accident of nuclear reprocessing plant. The monitor is designed to collect airborne alpha-emitting particles by drawing the ambient air through a filter and to detect the activity by alpha spectroscopy. In order to achieve high-sensitive measurements, selection of a suitable filter used in the monitor is considerably important. The most important requirement for the filter is that it has a high surface collection efficiency to obtain the sharpness of the alpha energy spectrum. This makes it easy to distinguish the alpha-ray peak of plutonium from the alpha spectrum of naturally occurring radon decay products in the environment. And the filter is also desired to have low resistance of the air flow so that particles can be collected at a high flowrate. We have made a comparison of the surface collection efficiency and pressure drop for the various filters. Types of the test filters, most of which are commercially available in Japan, were glass fiber, cellulose-glass fiber, membrane and so on. The surface collection efficiency has been evaluated by the following two indices. One was the sharpness of alpha-ray energy peaks of thoron decay products generated in a laboratory and collected in the fibers. The other was the background counts of radon decay products in a plutonium region by measuring alpha-ray energy spectrum of radon decay products collected in the filters by sampling of dust in the atmosphere. It was found that the PTFE (polytetrafluoroethylene) membrane filter with backing had a high surface collection efficiency and low pressure drop. The results of the test are described in detail in this paper. (author)

  19. Report on intercomparison air-3/1 of the determination of trace elements in simulated air filters

    International Nuclear Information System (INIS)

    The report is a sum up of an intercomparison experiment organized by the Analytical Quality Control Service of the IAEA, for simulated air filters (Air-3/1) spiked with 17 trace elements. The purpose was twofold: to assist participating laboratories in controlling their own performance, and to characterize exactly the prepared batch of air filters in order to be able to use them as reference filters for elemental trace analysis. The results submitted by 29 laboratories from 20 countries are presented and statistically processed. The analytical methods used are also specified. Conclusions concerning the use of filters Air-3/1 as certified reference filters are presented

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

    Science.gov (United States)

    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

  1. A study of collector filter for radioactive gas and dust in high altitude air

    International Nuclear Information System (INIS)

    The collector filter for radioactive gas (gaseous radioiodine) and dust in high altitude air was manufactured on trial and its fundamental performances were studied. The newly designed filter is composed of the electret filter to collect air suspended dust and the fibrous activated carbon filter to collect gaseous iodine. By the tests of the collector filter, it was shown that gaseous iodine was effectively collected, even though there are some restrictions for using this filter system in high altitude air. Also the collection performance of the collector filter for air suspended dust was almost the same as that of current filter paper, thus data for air suspended dust obtained by this system are comparable to those obtained by the current filter paper system. (author)

  2. Deposition of carbon nanotubes in commonly used sample filter media

    Directory of Open Access Journals (Sweden)

    B.D. Smith

    2015-07-01

    Full Text Available There is no single standard technique or methodology to characterize the size, structure, number, and chemical composition of airborne carbon nanotubes.  Existing analytical instruments and analytical techniques for evaluating nanoparticle concentrations cannot simultaneously provide morphology, state of agglomeration, surface area, mass, size distribution and chemical composition data critical to making occupational health assessments.  This research utilized scanning electron microscopy and thermogravimetric analysis to assess the morphology and mass of carbon nanotubes collected using various commercial sample filters.  It illustrated carbon nanotube agglomeration, deposition and distribution in commonly used sample filter media.  It also illustrated that a sufficient mass for carbon nanotube analysis by thermogravimetric analysis is uncommon under most current research and production uses of carbon nanotubes.  Individual carbon nanotubes were found to readily agglomerate with diameters ranging from 1 – 63 µm. They were collected at the face of or within the filter.  They were not evenly distributed across the face of the filters.

  3. Measurement of radon daughters in air samples by alpha spectroscopy

    International Nuclear Information System (INIS)

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of polonium 214 and polonium 218. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter (Author)

  4. A comparison of two extended Kalman filter algorithms for air-to-air passive ranging.

    OpenAIRE

    Ewing, Ward Hubert.

    1983-01-01

    Approved for public release; distribution is unlimited Two Extended Kalman Filter algorithms for air-to-air passive ranging are proposed, and examined by computer simulation. One algorithm uses only bearing observations while the other uses both bearing and elevation angles. Both are tested using a flat-Earth model and also using a spherical-Earth model where the benefit of a simple correction for the curvature-of-the-Earth effect on elevation angle is examined. The effects of varied an...

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

    Science.gov (United States)

    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.

  6. Tests on the sampling performance of 3 kinds of filters for α-radioactive aerosol sampling

    International Nuclear Information System (INIS)

    Filter for α-radioactive aerosol sampling is one of the important parts in radioactive aerosol detection. Filter with high efficiency, low self-absorption and high-performed surface collection will improve the speed of monitoring and energy resolution of α. In this study, 3 different types of filters were chosen for sampling of natural radon daughter aerosol. The parameters of collection efficiency, self-absorption, surface collection characteristics and flow rate under the same resistance were measured. In the same condition of the aerosol concentration, sampling flow rate and sampling time, the membrane filter which is made of mixed cellulose ester with the mean pore radius of 0.8 μm, has the highest filter efficiency and less self-absorption; heavy-ion microporous membrane with pore radius of 0.4μm has minimal self-absorption and superior surface collection, which is important in improving the α energy resolution; the glass fiber filter has the lowest resistance, suiting for large flow rate in sampling. (authors)

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

    Science.gov (United States)

    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

  8. Air gap resonant tunneling bandpass filter and polarizer.

    Science.gov (United States)

    Melnyk, A; Bitarafan, M H; Allen, T W; DeCorby, R G

    2016-04-15

    We describe a bandpass filter based on resonant tunneling through an air layer in the frustrated total internal reflection regime, and show that the concept of induced transmission can be applied to the design of thin film matching stacks. Experimental results are reported for Si/SiO2-based devices exhibiting a polarization-dependent passband, with bandwidth on the order of 10 nm in the 1550 nm wavelength range, peak transmittance on the order of 80%, and optical density greater than 5 over most of the near infrared region. PMID:27082360

  9. Particle size of unattached radon progeny in filtered room air

    International Nuclear Information System (INIS)

    The size distribution of the unattached radon progeny in filtered room air was measured with a serial array of wire screens. Nearly all the size distributions of 2 to 3 min air, measured with the graded wire screen samplers were unimodal, with a geometric standard deviation averaging 1.8 ± 0.058. The grand average of the geometric mean and standard error of the mean diffusion coefficient was 0.048 ± 0.0004. The results obtained using different combinations of the graded wire screens were consistent. The measured diffusion coefficient predicts a nasal penetration of 9% to 16% for inspiratory flow rates of 3 1.min-1 to 30 min-1, respectively. The results indicate that about 15% of the inhaled unattached radon progeny penetrate beyond the nose into the tracheobronchial region to deliver a radiation dose to the bronchial epithelium. (author)

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

    Science.gov (United States)

    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

  11. Digital timing: sampling frequency, anti-aliasing filter and signal interpolation filter dependence on timing resolution

    International Nuclear Information System (INIS)

    The main focus of our study is to investigate how the performance of digital timing methods is affected by sampling rate, anti-aliasing and signal interpolation filters. We used the Nyquist sampling theorem to address some basic questions such as what will be the minimum sampling frequencies? How accurate will the signal interpolation be? How do we validate the timing measurements? The preferred sampling rate would be as low as possible, considering the high cost and power consumption of high-speed analog-to-digital converters. However, when the sampling rate is too low, due to the aliasing effect, some artifacts are produced in the timing resolution estimations; the shape of the timing profile is distorted and the FWHM values of the profile fluctuate as the source location changes. Anti-aliasing filters are required in this case to avoid the artifacts, but the timing is degraded as a result. When the sampling rate is marginally over the Nyquist rate, a proper signal interpolation is important. A sharp roll-off (higher order) filter is required to separate the baseband signal from its replicates to avoid the aliasing, but in return the computation will be higher. We demonstrated the analysis through a digital timing study using fast LSO scintillation crystals as used in time-of-flight PET scanners. From the study, we observed that there is no significant timing resolution degradation down to 1.3 Ghz sampling frequency, and the computation requirement for the signal interpolation is reasonably low. A so-called sliding test is proposed as a validation tool checking constant timing resolution behavior of a given timing pick-off method regardless of the source location change. Lastly, the performance comparison for several digital timing methods is also shown.

  12. K West Basin Sand Filter Backwash Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smoot, Margaret R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Deborah S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pool, Karl N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    A sand filter is used to help maintain water clarity at the K West Basin where highly radioactive sludge is stored. Eventually that sand filter will require disposal. The radionuclide content of the solids trapped in the sand filter will affect the selection of the sand filter disposal pathway. The Pacific Northwest National Laboratory (PNNL) was contracted by the K Basin Operations & Plateau Remediation Project (operations contractor CH2M Hill) to analyze the radionuclide content of the solids collected from the backwash of the K West Basin sand filter. The radionuclide composition in the sand filter backwash solids will be used by CH2M Hill to determine if the sand filter media and retained sludge solids will be designated as transuranic waste for disposal purposes or can be processed through less expensive means. On October 19, 2015, K Basin Operations & Plateau Remediation Project staff backwashed the sand filter into the North Load-Out Pit (NLOP) and immediately collected sample slurry from a sampling tube positioned 24 in. above the NLOP floor. The 764 g sand filter backwash slurry sample, KW-105 SFBW-001, was submitted to PNNL for analysis on October 20, 2015. Solids from the slurry sample were consolidated into two samples (i.e., a primary and a duplicate sample) by centrifuging and measured for mass (0.82 g combined – wet centrifuged solids basis) and volume (0.80 mL combined). The solids were a dark brown/orange color, consistent with iron oxide/hydroxide. The solids were dried; the combined dry solids mass was 0.1113 g, corresponding to 0.0146 weight percent (wt%) solids in the original submitted sample slurry. The solids were acid-digested using nitric and hydrochloric acids. Insoluble solids developed upon dilution with 0.5 M HNO3, corresponding to an average 6.5 wt% of the initial dry solids content. The acid digestate and insoluble solids were analyzed separately by gamma spectrometry. Nominally, 7.7% of the 60Co was present

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

    Science.gov (United States)

    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. Elemental analysis of dust trapped in air conditioner filters for the assessment of Lahore city's air quality

    International Nuclear Information System (INIS)

    A study was undertaken to assess the air quality of Lahore by the elemental analysis of air conditioner (AC) filter dust samples collected from 15 different commercial sites. Samples were prepared using the Leeds Public Analyst Method and were analyzed using instrumental neutron activation analysis (INAA) for up to 31 elements. The elements Al, As, Ba, Ce, Co, Cr, Cs, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sc, Sm, Sn, Ta, Th, Yb and Zn were detected in all 15 samples whereas the remaining elements have been detected in fewer samples; i.e. Mg, Sb and Tb were detected in 14 samples, Br and V in ten samples, U in nine samples and Ca and Ti in eight samples only. Al, Ca, Fe, K, Mg and Na were determined in all samples at percentage levels. The concentrations of most elements were found to lie around the mean values for the 15 samples studied and were not orders of magnitude different. However the concentrations of Ca, Mg, Sn and Zn were found to be more variable and were found to be dependant on activities such as construction, fruit and vegetable handling, tin plating and transport, respectively. (author)

  15. Resistance of HEPA filter separator materials to humid air--hydrogen fluoride--fluorine environments

    International Nuclear Information System (INIS)

    The U. S. Energy Research and Development Administration (ERDA) is interested in the development of a high-efficiency particulate air (HEPA) filter that is resistant to such corrosive reagents as hydrogen fluoride (HF) and fluorine (F2) in air environments of normal relative humidity (about 50% RH). Several types of separator materials are used in the fabrication of commercial filters. The basic types of separator materials are asbestos, Kraft paper, plastic, and aluminum. At the request of the ERDA Division of Operational Safety, the different types of separator materials have been evaluated for their resistance to corrosive attack by HF and F2. The separator materials were dynamically tested in the 4-stage multiunit tester located in the Oak Ridge Gaseous Diffusion Plant laboratories. This is the system previously used in the evaluation of the Herty Foundation filter paper samples. Concurrent with the testing of filter media for its resistance to HF and F2, another component of the completed filter, the separator, was tested. All samples were exposed to a constant air flow (50% RH) of 32 liters/min, at 1000F, containing 900 ppM HF and 300 ppM F2. Exposure periods varied from 2 to 1000 h; however, the longer exposures were made only on the stronger candidates. Test results show the plastic and aluminum separator materials to be superior to the other types in resistance to HF and F2. The asbestos separators disintegrated after a relatively short exposure time; the Kraft paper types were the next weakest. The Clear Plastic S was the best performer of the plastics tested

  16. Design and development of high performance panel air filter with experimental evaluation and analysis of filter media pleats

    Directory of Open Access Journals (Sweden)

    Sagar R. Patil

    2015-11-01

    Full Text Available In automobile vehicles mostly plastic molded panel filters used for the purpose of engine air filtration. Fibrous structured cellulose media were being used with different permeability’s according to requirement of rated air flow rate required for the engine. To optimize the filter pleat design of automotive panel air filter, it is important to study correlation of pressure drop, dust holding capacity & efficiency. The main role of a filter is to provide least pressure drop with high dust holding and efficiency. A channel made for the testing of different pleat designs. This research comprises of experimental design & evaluation of filter element with variable pleat depth and pleat density. This assessment offers the selection of pleat design according to the performance requirements.

  17. Antimicrobial Air Filters Using Natural Euscaphis japonica Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Gi Byoung Hwang

    Full Text Available 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

  18. Preliminary enviromagnetic comparison of the moss, lichen, and filter fabric bags to air pollution monitoring

    Directory of Open Access Journals (Sweden)

    Hanna Salo

    2014-08-01

    Full Text Available Air quality and anthropogenic air pollutants are usually investigated by passive biomonitoring which utilizes native species. Active biomonitoring, instead, refers to the use of transplants or bags in areas lacking native species. In Finland, the standardized moss bag technique SFS 5794 is commonly applied in active monitoring but there is still need for simpler and labor-saving sample material even on international scale. This article focuses on a preliminary comparison of the usability and collection efficiency of bags made of moss Sphagnum papillosum, lichen Hypogymnia physodes, and filter fabric (Filtrete™ in active biomonitoring of air pollutants around an industrial site in Harjavalta, SW Finland. The samples are analyzed with magnetic (i.e. magnetic susceptibility, isothermal remanent magnetization, hysteresis loop and hysteresis parameters methods highly suitable as a first-step tool for pollution studies. The results show that the highest magnetic susceptibility of each sample material is measured close to the industrial site. Furthermore, moss bags accumulate more magnetic material than lichen bags which, on the contrary, perform better at further distances. Filter fabric bags are tested only at 1 km sites indicating a good accumulation capability near the source. Pseudo-single-domain (PSD magnetite is identified as the main magnetic mineral in all sample materials and good correlations are found between different bag types. To conclude, all three materials effectively accumulate air pollutants and are suitable for air quality studies. The results of this article provide a base for later studies which are needed in order to fully determine a new, efficient, and easy sample material for active monitoring.

  19. Proposed retrofit of HEPA filter plenums with injection and sampling manifolds for in-place filter testing

    International Nuclear Information System (INIS)

    The importance of testing HEPA filter exhaust plenums with consideration for As Low as Reasonably Achievable (ALARA) will require that new technology be applied to existing plenum designs. HEPA filter testing at Rocky Flats has evolved slowly due to a number of reasons. The first plenums were built in the 1950's, preceding many standards. The plenums were large, which caused air dispersal problems. The systems were variable air flow. Access to the filters was difficult. The test methods became extremely conservative. Changes in methods were difficult to make. The acceptance of new test methods has been made in recent years with the change in plant mission and the emphasis on worker safety

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

    Science.gov (United States)

    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)

  1. Effectiveness of Air Filters and Air Cleaners in Allergic Respiratory Diseases: A Review of the Recent Literature

    OpenAIRE

    Sublett, James L.

    2011-01-01

    Air filtration is frequently recommended as a component of environmental control measures for patients with allergic respiratory disease. Residential air filtration can be provided by whole house filtration via the home’s heating, ventilation, or air conditioning system, by portable room air cleaners, or a combination of the two. Appliances to filter the sleep breathing zone also have been developed. High-efficiency whole house filtration, high-efficiency particulate air sleep zone air filtra...

  2. Formation and evolution of aerosols in filtered air and in natural air. Effect of radioactivity

    International Nuclear Information System (INIS)

    Results are presented concerning the formation, the evolution, the coagulation and the electrical charge of aerosols which form in natural filtered air containing only gaseous impurities, under the influence of solar light (photolysis) and of radioactive disintegrations (radiolysis). The modifications brought about in the aerosol by an increase in the sulphur dioxide content and in the natural radioactive gas content are studied. The work is then repeated with non-filtered natural atmospheric air. A comparison is also made of the behaviour of non-radioactive and radioactive particles (active thoron deposit). In conclusion, the possible consequences of these phenomena on the origin and the size distribution of particles occurring in the atmosphere is considered. (author)

  3. Improvement of the equipment for air sampling and enriching air samples with radionuclides

    International Nuclear Information System (INIS)

    The air liquefaction and cryogenic distillation methods were used to inverse the concentration of gaseous radionuclides in the air samples. For this purpose the air liquefaction equipment ZIF-1002 was applied. Gaseous radionuclides which liquefy at the temperature higher than -200 degrees Celsius are concentrated in liquid oxygen. In the work an equipment model allowing to increase the volume of pumping and the liquefied air 2-3 times by ZIF is proposed. For this purpose an air drying and preliminary cooling equipment were constructed, and a pump was applied. Having shortened the sampling time, it became possible to measure the volumetric activity of short-lived radionuclides in the environment of their sources. The activity of 131J, 41Ar, krypton and xenon radioisotope is measured in liquid oxygen in a special disk. For determining tritium volumetric activity, samples of air humidity (water) or a mixture of hydrogen and other undissolved gases are taken and finally prepared in the laboratory. For 14C sampling, a special equipment allowing to obtain about 60 I of CO2 gas per day was constructed. The ZIF-1002 equipment with supplements was installed in a car and in a container. Using the refrigerating unit MVT-20-1-0, a fresh water cooling system of the ZIF was constructed. The equipment was tested on land and sea. (author)

  4. 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)

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  6. Penurunan Kandungan Zat Kapur dalam Air Tanah dengan Menggunakan Filter Media Zeolit Alam dan Pasir Aktif Menjadi Air Bersih

    OpenAIRE

    Qorry Nugrahayu; Alfan Purnomo

    2013-01-01

    Salah satu syarat yang harus terpenuhi dalam kualitas air minum dalam parameter kimia adalah kesadahan. Salah satu kesadahan adalah kesadahan kalsium atau yang lebih sering dikenal dengan air kapur. Pada umumnya air tanah atau air sumur mempunyai tingkat kesadahan yang tinggi. Masalah lain yang timbul dari air tanah adalah kandungan Fe dan Mn yang tinggi. Penelitian ini bertujuan untuk memperoleh komposisi media filter yang efektif dan efisien untuk mereduksi kesadahan Kalsium, Fe dan Mn dala...

  7. Long term performance of particulate air-filter in an office environment

    DEFF Research Database (Denmark)

    Afshari, Alireza; Iqbal, Ahsan; Bergsøe, Niels Christian

    2015-01-01

    The present article is based on initial findings of an ongoing study. The objective of present study is to analyse the long term performance of an air particulate filter with and without ionizer. To study the performance of the air filters, a test rig was built in the Danish Building Research Ins...

  8. Relative solubiolity in simulated biological fluids of PuO2 on air sampler filters

    International Nuclear Information System (INIS)

    An ultrafiltration method was developed to estimate the solubility of PuO2 on an air filter in simulated lung fluid (SLF), simulated gastric juice (SGJ), and in 1% DTPA. After a very rapid early appearance in the filtrate, both 238Pu and 239Pu showed similar rates of low ultrafilterability. The amount of 239Pu appearing during the first day of ultrafiltration was 10 times less in SLF than in SGJ or DTPA, although the amount of 238Pu was similar for the three solvents. The method used to estimate solubility requires only about 1000 dpm of plutonium alpha radiation per sample

  9. High-efficiency particulate air (HEPA) filter performance following service and radiation exposure

    International Nuclear Information System (INIS)

    Small HEPA filters were exposed to a 60Co source with a radiation strength of 3 x 107 rads per hour and then exposed to steam--air mixtures at several times filter design flow, followed by extended exposure to steam and air at reduced flow. Additional filters were exposed to air flow in a reactor confinement system and then similarly tested with steam--air mixture flows. The test data and calculated effects of filter pluggage with moisture on confinement system performance following potential reactor accidents are described. Gamma radiation exposure impaired the performance of new filters only slightly and temporarily improved performance of service aged filters. Normal confinement system service significantly impaired filter performance although not sufficiently to prevent adequate performance of the SRP confinement system following an unlikely reactor accident. Calculations based on measured filter pluggage indicate that during an accident air flow could be reduced approximately 50 percent with service-degraded HEPA filters present, or approximately 10 percent with new filters damaged by the radiation exposure. (U.S.)

  10. 40 CFR 53.57 - Test for filter temperature control during sampling and post-sampling periods.

    Science.gov (United States)

    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... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test for filter temperature...

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

    Science.gov (United States)

    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

  12. Comparison of concentrations of ions sampled on cellulose and teflon filters

    OpenAIRE

    Kořínková, Alena

    2012-01-01

    Determination of chloride, fluoride, nitrate, sulfate, oxalate and ammonium bounded to aerosol by sampling on cellulose filters is influenced by positive and negative interferences of gaseous pollutants. Interferences of gaseous pollutants during sampling of aerosols on teflon filters were eliminated by including of annular diffusion denuder in front of the filter.

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

    Science.gov (United States)

    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

  14. Radiological results for samples collected on paired glass- and cellulose-fiber filters at the Sandia complex, Tonopah Test Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Mizell, Steve A. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Shadel, Craig A. [Desert Research Inst. (DRI), Las Vegas, NV (United States)

    2016-03-01

    Airborne particulates are collected at U.S. Department of Energy sites that exhibit radiological contamination on the soil surface to help assess the potential for wind to transport radionuclides from the contamination sites. Collecting these samples was originally accomplished by drawing air through a cellulose-fiber filter. These filters were replaced with glass-fiber filters in March 2011. Airborne particulates were collected side by side on the two filter materials between May 2013 and May 2014. Comparisons of the sample mass and the radioactivity determinations for the side-by-side samples were undertaken to determine if the change in the filter medium produced significant results. The differences in the results obtained using the two filter types were assessed visually by evaluating the time series and correlation plots and statistically by conducting a nonparametric matched-pair sign test. Generally, the glass-fiber filters collect larger samples of particulates and produce higher radioactivity values for the gross alpha, gross beta, and gamma spectroscopy analyses. However, the correlation between the radioanalytical results for the glass-fiber filters and the cellulose-fiber filters was not strong enough to generate a linear regression function to estimate the glass-fiber filter sample results from the cellulose-fiber filter sample results.

  15. Radiological results for samples collected on paired glass- and cellulose-fiber filters at the Sandia complex, Tonopah Test Range, Nevada

    International Nuclear Information System (INIS)

    Airborne particulates are collected at U.S. Department of Energy sites that exhibit radiological contamination on the soil surface to help assess the potential for wind to transport radionuclides from the contamination sites. Collecting these samples was originally accomplished by drawing air through a cellulose-fiber filter. These filters were replaced with glass-fiber filters in March 2011. Airborne particulates were collected side by side on the two filter materials between May 2013 and May 2014. Comparisons of the sample mass and the radioactivity determinations for the side-by-side samples were undertaken to determine if the change in the filter medium produced significant results. The differences in the results obtained using the two filter types were assessed visually by evaluating the time series and correlation plots and statistically by conducting a nonparametric matched-pair sign test. Generally, the glass-fiber filters collect larger samples of particulates and produce higher radioactivity values for the gross alpha, gross beta, and gamma spectroscopy analyses. However, the correlation between the radioanalytical results for the glass-fiber filters and the cellulose-fiber filters was not strong enough to generate a linear regression function to estimate the glass-fiber filter sample results from the cellulose-fiber filter sample results.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. NUMERICAL SIMULATION FOR AIR AND AIR-PM FLOW IN WALL FLOW DIESEL PARTICULATE FILTERS

    Institute of Scientific and Technical Information of China (English)

    Zhao Binjuan; Yuan Shouqi; Seizo Kato; Akira Nishimura

    2005-01-01

    Numerical simulations are performed both for the single airflow and air-PM two-phase flow in wall flow diesel particulate filters (DPF) for the first time. The calculation domain is divided into two regions. In the inlet and outlet flow channels, the simulations are performed for the steady and laminar flow; In the porous filtration walls, the calculation model for flow in porous media is used. The Lagrange two-phase flow model is used to calculate the air-PM flow in DPF, for the dispersed phase (PM), its flow tracks are obtained by the integrating of the Lagrange kinetic equation. The calculated velocity, pressure distribution and PM flow tracks in DPF are obtained, which exhibits the main flow characteristics in wall flow DPF and will be help for the optimal design and performance prediction of wall flow DPF.

  18. The Brookhaven National Laboratory filter pack system for collection and determination of air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Leahy, D.F.; Klotz, P.J.; Springston, S.R.; Daum, P.H.

    1995-04-01

    A filter pack system for sampling trace constituents in the atmosphere from aircraft and ground-based measurement platforms has been developed. The system simultaneously and quantitatively collects atmospheric aerosol, nitric acid, and sulfur dioxide using three sequential filter stages. The quartz aerosol filter is routinely analyzed for sulfate, nitrate, ammonium, and hydrogen ions, and specifically for sulfuric acid. The sodium chloride filter is analyzed for nitrate ion (from collected nitric acid), and the carbonate-glycerine filter for sulfate ion (from collected sulfur dioxide). Details of the procedures used for filter preparation, sampling, extraction and analysis are given.

  19. Membrane filter contact technique for bacteriological sampling of moist surfaces.

    OpenAIRE

    Craythorn, J M; Barbour, A G; Matsen, J M; Britt, M R; Garibaldi, R A

    1980-01-01

    We used a membrane filter contact technique to pick up and grow bacteria from artificially contaminated surfaces. We were able to recover individual colony-forming units (CFU) of Staphylococcus aureus from a moist agar surface more efficiently with 3- and 5- micron membrane filters than with Rodac plates, velvet pads, velveteen pads, or smaller-pore membrane filters. The effective transfer of bacteria with the 3- and 5-micron membrane filters was 0.96 +/- 0.04 (standard error of the mean) and...

  20. Feasibility for the medium efficiency filter as a postfilter in the air cleaning unit

    International Nuclear Information System (INIS)

    The Air Cleaning Unit (ACU) is provided in a nuclear facility to filter the radioactive materials in gaseous effluents released from the facility during normal operation and during a postulated accident. The Air Cleaning Unit (ACU) consists of pre-HEPA filters, charcoal adsorber, post HEPA filters, fans, etc. The charcoal filters keep on-site dose and off-site effluents ALARA, consistent with regulatory requirements. The function of HEPA filter downstream of charcoal(carbon) adsorber in ACU is to catch potential radioactive carbon dust and to be a backup in the event of failure of upstream HEPA. Previous Regulatory Guide use only post HEPA filter of charcoal adsorber downstream but the Regulatory Guide of current revisions allows use of 95% dust spot efficiency filters in lieu of HEPA at the downstream of the carbon adsorber. In this paper is described that the background information of filters, Current Regulatory Guide of revised by the United States Nuclear Regulatory Commission and the feasibility for the medium efficiency filter as a carbon adsorber post filter in the Air Cleaning Unit

  1. Comparison of polycarbonate and cellulose acetate membrane filters for isolation of Campylobacter concisus from stool samples

    DEFF Research Database (Denmark)

    Linde Nielsen, Hans; Engberg, Jørgen; Ejlertsen, Tove;

    2013-01-01

    One thousand seven hundred ninety-one diarrheic stool samples were cultivated for Campylobacter spp. We found a high prevalence of Campylobacter concisus with use of a polycarbonate filter (n = 114) compared to a cellulose acetate filter (n = 79) (P ... to the commonly used cellulose acetate filter for detection of C. concisus....

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

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, R.L.; Jessop, B.H.; McDowell, B.L. [Radiation Safety Engineering, Inc., Chandler, AZ (United States)

    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.

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

    International Nuclear Information System (INIS)

    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 U3O8. Profiles developed for U3O8 samples show good agreement with in vitro and in vivo tests performed by other investigators on samples from the same uranium mills

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Removal of viable bioaerosol particles with a low-efficiency HVAC filter enhanced by continuous emission of unipolar air ions

    Energy Technology Data Exchange (ETDEWEB)

    Huang, R.; Agranovski, I.; Pyankov, O. (Griffith Univ., Nathan, Qld (AU)); Grinshpun, S. (Univ. of Cincinnati, Dept. of Environmental Health, Cincinnati, OH (US))

    2008-04-15

    Continuous emission of unipolar ions has been shown to improve the performance of respirators and stationary filters challenged with non-biological particles. In this study, we investigated the ion-induced enhancement effect while challenging a low-efficiency heating, ventilation and air-conditioning (HVAC) filter with viable bacterial cells, bacterial and fungal spores, and viruses. The aerosol concentration was measured in real time. Samples were also collected with a bioaerosol sampler for viable microbial analysis. The removal efficiency of the filter was determined, respectively, with and without an ion emitter. The ionization was found to significantly enhance the filter efficiency in removing viable biological particles from the airflow. For example, when challenged with viable bacteria, the filter efficiency increased as much as four- to fivefold. For viable fungal spores, the ion-induced enhancement improved the efficiency by a factor of approx 2. When testing with virus-carrying liquid droplets, the original removal efficiency provided by the filter was rather low: 9.09 +- 4.84%. While the ion emission increased collection about fourfold, the efficiency did not reach 75-100% observed with bacteria and fungi. These findings, together with our previously published results for non-biological particles, demonstrate the feasibility of a new approach for reducing aerosol particles in HVAC systems used for indoor air quality control. (au)

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

    International Nuclear Information System (INIS)

    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 20o, (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.

  7. Modelling of air flows in pleated filters and of their clogging by solid particles

    International Nuclear Information System (INIS)

    The devices of air cleaning against particles are widely spread in various branches of industry: nuclear, motor, food, electronic,...; among these devices, numerous are constituted by pleated porous media to increase the surface of filtration and thus to reduce the pressure drop, for given air flow. The objective of our work is to compensate a lack evident of knowledge on the evolution of the pressure drop of pleated filter during the clogging and to deduct a modelling from it, on the basis of experiments concerning industrial filters of nuclear and car types. The obtained model is a function of characteristics of the filtering medium and pleats, of the characteristics of solid particles deposited on the filter, of the mass of particles and of the aeraulic conditions of air flow. It also depends on data on the clogging of flat filters of equivalent medium. To elaborate this model of pressure drop, an initial stage was carried out in order to characterize, experimentally and numerically, the pressure drop and the distribution of air flow in clean pleated filters of nuclear (high efficiency particulate air filter, in fiberglasses) and car (mean efficiency filter, in fibers of cellulose) types. The numerical model allowed to understand the fundamental role played by the aeraulic resistance of the filtering medium. From an non-dimensional approach, we established a semi-empirical model of pressure drop for a clean pleated filter valid for both studied types of medium; this model is used of first base for the development of the final model of clogging. The study of the clogging of the filters showed the complexity of the phenomenon dependent mainly on a reduction of the surface of filtration. This observation brings us to propose a clogging of pleated filters in three phases. Both first phases are similar in those observed for flat filters, while last phase corresponds to a reduction of the surface of filtration and leads a strong increase of the filter pressure drop

  8. Experimental Investigations on Electrospun Mat Production: For Use in High-Performance Air Filters

    OpenAIRE

    SOMAYEH FARHANG DEHGHAN; FARIDEH GOLBAAEI; BOZORGMEHR MADDAH; RASOUL YARAHMADI; ASGHAR SEDIGH ZADEH

    2015-01-01

    Electrospun nanofibrous filter media have attracted considerable attention in the last decade. The present study aimed to develop the electrospun PAN (polyacrylonitrile) filter media through experimental investigations for application in high-performance air filters. For this purpose, an experimental design was proposed to assess the effect of electrospinning process conditions including solution concentration, electric voltage and nozzle-collector distance on the structural properties of fil...

  9. AFA and AFAS analytical filter packets for studying radioactive iodine component composition in air medium

    International Nuclear Information System (INIS)

    To analyse radioactive iodine content in gaseous effluents air the AFAS-I and AFAS-SKI filter packets are used. It is shown that, when trapping molecular 131I vapors, very sharp sorption wave front is formed. Difficulty sorbed iodine fraction in the AFAS-I filter packet forms a gently sloping sorption wave front, which slope slightly varies in time. In the AFAS-SKI filter packet quick sorbent saturation takes place, sorption wave front is extended along the layer

  10. Realistic Air Filter Media Performance Simulation. Part I: Navier-Stokes / Finite-Volume CFD Procedures

    OpenAIRE

    Tronville, Paolo Maria

    2013-01-01

    A review of published studies of numerical techniques for air filter performance simulation shows that there are two general approaches to such simulations. One describes gases flowing through filter media as continuous fluids, influenced by themacro properties viscosity, density, and pressure. The alternate approach treats gases as molecules in random motion, impacting their own kind and solid surfaces on a micro-scale. The appropriate form for a given filter medium and operating condition d...

  11. Controls of nitrite oxidation in ammonia-removing biological air filters

    DEFF Research Database (Denmark)

    Juhler, Susanne; Ottosen, Lars Ditlev Mørck; Nielsen, Lars Peter;

    2008-01-01

    In biological air filters ammonia is removed due to the action of Ammonia Oxidizing Bacteria (AOB) resulting in nitrite accumulation exceeding 100 mM. Among filters treating exhaust air from pig facilities successful establishment of Nitrite Oxidizing Bacteria (NOB) sometimes occurs, resulting in...... accumulation of nitrate rather than nitrite and a significant decline in pH. As a consequence, ammonia is removed more efficiently, but heterotrophic oxidation of odorous compounds might be inhibited.  To identify the controlling mechanisms of nitrite oxidation, full-scale biological air filters were...... analysis. Furthermore, the effect of varying air load and water exchange was investigated. Absence of NOB in many filters was explained by the inhibitory effect of Free Ammonia (FA). When first established, NOB induced a self-perpetuating effect through oxidation of nitrite which allowed increased AOB...

  12. Air and smear sample calculational tool for Fluor Hanford Radiological control

    International Nuclear Information System (INIS)

    A spreadsheet calculation tool was developed to automate the calculations performed for determining the concentration of airborne radioactivity and smear counting as outlined in HNF--13536, Section 5.2.7, ''Analyzing Air and Smear Samples''. This document reports on the design and testing of the calculation tool. Radiological Control Technicians (RCTs) will save time and reduce hand written and calculation errors by using an electronic form for documenting and calculating work place air samples. Current expectations are RCTs will perform an air sample and collect the filter or perform a smear for surface contamination. RCTs will then survey the filter for gross alpha and beta/gamma radioactivity and with the gross counts utilize either hand calculation method or a calculator to determine activity on the filter. The electronic form will allow the RCT with a few key strokes to document the individual's name, payroll, gross counts, instrument identifiers; produce an error free record. This productivity gain is realized by the enhanced ability to perform mathematical calculations electronically (reducing errors) and at the same time, documenting the air sample

  13. Characterization of depth filter media for gas turbine intake air filtration: From flat sheet media to cartridge filter assembly

    International Nuclear Information System (INIS)

    Depth filter media should be able to contain a certain amount of dust within the barrier layer without excessive contribution to pressure drop increase and have acceptable particulate collection efficiency during a certain period of service. To satisfy all these preconditions, a depth filter media consisting of more than one layer is considered to be an appropriate structure. Three samples of the filter media of multiple-layer structure are designed and manufactured. Also samples of cartridge assembly were made for each media. The tests with flat sheet media were conducted using the standard test units. Test with cartridges were conducted in a recently developed test unit which can accommodate one single cartridge inside its chamber. Tests with filter media TFM2 and TFM3 missed at least one of the above mentioned targets. Based on the results from the tests with two previous media, the depth filter media TFM4 was developed to achieve greater holding capacity but did not exhibit satisfactory results. The shortcomings of three previously developed filter media were remedied by combining the advantages in a modified media TFM5 which, according to the test results, could be a good match for an efficient depth filtration media. The tests with flat sheet media and cartridge with pleated filter media TFM5 have shown satisfactory filtration performance with low initial pressure drop, high dust holding capacity and high particulate collection efficiency. (author)

  14. Simultaneous removal of formaldehyde and benzene in indoor air with a combination of sorption- and decomposition-type air filters.

    Science.gov (United States)

    Sekine, Yoshika; Fukuda, Mitsuru; Takao, Yosuke; Ozano, Takahiro; Sakuramoto, Hikaru; Wang, Kuan Wei

    2011-12-01

    Urgent measures for indoor air pollution caused by volatile organic compounds are required in urban areas of China. Considering indoor air concentration levels and hazardous properties, formaldehyde and benzene should be given priority for pollution control in China. The authors proposed the use of air-cleaning devices, including stand-alone room air cleaners and in-duct devices. This study aimed to find the best combination of sorption and decomposition filters for the simultaneous removal of formaldehyde and benzene, employing four types of air filter units: an activated charcoal filter (ACF), an ACF impregnated with a trapping agent for acidic gases (ACID), a MnO2 filter (MDF) for oxidative decomposition of formaldehyde at room temperature and a photocatalyst filter (PHOTO) coupled with a parallel beam ultraviolet (UV) irradiation device. The performance of the combined systems under air flow rates of 35-165 m3 h(-1) was evaluated in a test chamber (2 m3) with a constant gas generation system. The experimental results and data analysis using a kinetic approach showed the combined system of ACF, PHOTO and MDF significantly reduced both concentrations of formaldehyde and benzene in air without any unpleasant odours caused by the UV-induced photocatalytic reaction. The system was then evaluated in a full-size laboratory (22 m3). This test proved the practical performance of the system even at full scale, and also suggested that the filters should be arranged in the order of PHOTO/ACF/MDF from upstream to downstream. The proposed system has the potential of being used for improving indoor air quality of houses and buildings in China. PMID:22439587

  15. Energy Efficient Indoor VOC Air Cleaning with Activated Carbon Fiber (ACF) Filters

    OpenAIRE

    Sidheswaran, Meera

    2012-01-01

    This study explores the potential environmental and energy benefits of using activated carbon fiber (ACF) filters for air cleaning in HVAC systems. The parallel aims for the air cleaning system were to enable reduced indoor exposures to volatile organic compounds (VOCs) and to simultaneously allow reduced rates and energy consumption for outdoor-air ventilation. We evaluated the use of ACF media to adsorb VOCs from indoor air during repeated simulated 12-hour to 24-hour periods of occupancy. ...

  16. Nuclear and atomic techniques in air pollution studies by transplant lichens and air dust collection on filters in Romania

    International Nuclear Information System (INIS)

    Lichen transplants from relatively unpolluted sites are successfully used as heavy metal bioaccumulators for air pollution monitoring, significant element accumulations being generally revealed after 6 to 12 months of exposure. The simultaneous collection of bulk (wet and dry) deposition and airborne particulate matter on filters supplies information on the atmospheric availability of trace elements. The potential of the lichen transplant technique and the high effectiveness of nuclear and atomic methods (INAA, XRFA and ICP-MS) applied to air pollution studies in Romania are presented. The paper is mainly based on the study entitled 'Air pollution monitoring by sampling airborne particulate matter combined with lichen bioaccumulator exposure', which is in progress at IDRANAP (Inter-Disciplinary Research and Applications based on Nuclear and Atomic Physics) Center of Excellence of IFIN-HH as part of the EU project ICA1-CT-2000-70023. In this study, Evernia prunastri and Pseudevernia furfuracea lichen species from the Prealps, northeastern Italy, were exposed during 6 and 12 months at six locations with different degrees and types of industrial activity, as well as on a background site with relatively clean air. Bulk deposition was collected for the same periods, while airborne particulate matter was collected for 2 months at each investigated location. The accumulating capacity of Evernia prunastri and Pseudevernia furfuracea corresponding to these specific environmental conditions was compared with those of Cetraria islandica, Evernia prunastri, and Ramalina farinacea used in a previous comparative air pollution study involving exposure sites in Germany, Italy, and Romania (Project No. RUM-020-96, partly supported by the German Federal Ministry of Education and Research). The lichen material was analyzed by INAA, XRFA, and ICP-MS, while the aerosol filters were analyzed by INAA and XRFA, and the bulk deposition by INAA. The main elements determined were: As, Br, Ca

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

    Science.gov (United States)

    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)

  18. Path sampling for particle filters with application to multi-target tracking

    CERN Document Server

    Maroulas, Vasileios

    2010-01-01

    In recent work (arXiv:1006.3100v1), we have presented a novel approach for improving particle filters for multi-target tracking. The suggested approach was based on Girsanov's change of measure theorem for stochastic differential equations. Girsanov's theorem was used to design a Markov Chain Monte Carlo step which is appended to the particle filter and aims to bring the particle filter samples closer to the observations. In the current work, we present an alternative way to append a Markov Chain Monte Carlo step to a particle filter to bring the particle filter samples closer to the observations. Both current and previous approaches stem from the general formulation of the filtering problem. We have used the currently proposed approach on the problem of multi-target tracking for both linear and nonlinear observation models. The numerical results show that the suggested approach can improve significantly the performance of a particle filter.

  19. Sampling strong tracking nonlinear unscented Kalman filter and its application in eye tracking

    International Nuclear Information System (INIS)

    The unscented Kalman filter is a developed well-known method for nonlinear motion estimation and tracking. However, the standard unscented Kalman filter has the inherent drawbacks, such as numerical instability and much more time spent on calculation in practical applications. In this paper, we present a novel sampling strong tracking nonlinear unscented Kalman filter, aiming to overcome the difficulty in nonlinear eye tracking. In the above proposed filter, the simplified unscented transform sampling strategy with n + 2 sigma points leads to the computational efficiency, and suboptimal fading factor of strong tracking filtering is introduced to improve robustness and accuracy of eye tracking. Compared with the related unscented Kalman filter for eye tracking, the proposed filter has potential advantages in robustness, convergence speed, and tracking accuracy. The final experimental results show the validity of our method for eye tracking under realistic conditions. (classical areas of phenomenology)

  20. Sampling strong tracking nonlinear unscented Kalman filter and its application in eye tracking

    Science.gov (United States)

    Zhang, Zu-Tao; Zhang, Jia-Shu

    2010-10-01

    The unscented Kalman filter is a developed well-known method for nonlinear motion estimation and tracking. However, the standard unscented Kalman filter has the inherent drawbacks, such as numerical instability and much more time spent on calculation in practical applications. In this paper, we present a novel sampling strong tracking nonlinear unscented Kalman filter, aiming to overcome the difficulty in nonlinear eye tracking. In the above proposed filter, the simplified unscented transform sampling strategy with n + 2 sigma points leads to the computational efficiency, and suboptimal fading factor of strong tracking filtering is introduced to improve robustness and accuracy of eye tracking. Compared with the related unscented Kalman filter for eye tracking, the proposed filter has potential advantages in robustness, convergence speed, and tracking accuracy. The final experimental results show the validity of our method for eye tracking under realistic conditions.

  1. Determining the retention capacity of technical aerosol-air filters in the submicroscopic range

    International Nuclear Information System (INIS)

    Using an aerosol generator and the short-lived radiotracer Na-24, discharge distributions of a maximum of 0.1 μm have been made. Technical aerosol-air filters of the size of 1 dm2 have been charged with such a particle stream that the permeability data that could be determined by measurement of the activities of the aerosol-air filter and the subsequent analytical filters go down to 10-7. The method is very precise and allows proof of permeability with the parameters required, such as free stream velocity and differential pressure. (orig.)

  2. Simulation of the air flows in many industrial pleated filters; Modelisation des ecoulements d'air dans differents filtres industriels plisses

    Energy Technology Data Exchange (ETDEWEB)

    Del Fabbro, L.; Brun, P. [FILTRAUTO, 78 - Saint-Quentin-en-Yvelines (France); Laborde, J.C.; Lacan, J.; Ricciardi, L. [CEA/Saclay, Inst. de Protection et de Surete Nucleaire, IPSN/DPEA/SERAC, 91 - Gif-sur-Yvette (France); Renoux, A. [Paris-12 Univ., Lab. de Physique des Aerosols et de Transfert des Contaminations, 94 - Creteil (France)

    2000-07-01

    The study presents results concerning the characterization of the charge loss and the air flow in nuclear and automobile type pleated filters. The experimental studies in correlation with the numerical models showed an homogenous distribution of the air flows in a THE nuclear type filter, whereas the distribution is heterogenous in the case of an automobile filter. (A.L.B.)

  3. Development of a Sampling Method for a Radionuclide Assessment of a Spent HEPA Filter Waste

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young-Yong; Hong, Dae-Seok; Kang, Il-Sig; Kim, Tae-Kuk; Lee, Young-Hee; Shon, Jong-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    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 a storage space, it is necessary to make a volume reduction of the stored radioactive wastes through a compression treatment or a regulatory clearance. These methods are considered in view of a reduction of a management cost and disposal cost and the security of a 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 for obtaining the representative sample in the spent filter. As for conducting a nuclide analysis for this representative sample, a corresponding spent filter can be sorted as either a regulatory clearance waste or a radioactive waste. In this study, the spent filter wastes were classified according to their generating facilities, their generation date and their surface dose rate. After selecting several HEPA filters, they were dismantled into a frame part and a filter medium part. And then, a quantitative analysis of the nuclide existing in the filter medium was conducted. From the analysis results, it was possible to divide the filter medium into three specific regions in respect of the nuclide distribution. As a result, these three regions could be a sampling guide to take a representative sample of a spent HEPA filter waste for treating it.

  4. Development of a Sampling Method for a Radionuclide Assessment of a Spent HEPA Filter Waste

    International Nuclear Information System (INIS)

    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 a storage space, it is necessary to make a volume reduction of the stored radioactive wastes through a compression treatment or a regulatory clearance. These methods are considered in view of a reduction of a management cost and disposal cost and the security of a 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 for obtaining the representative sample in the spent filter. As for conducting a nuclide analysis for this representative sample, a corresponding spent filter can be sorted as either a regulatory clearance waste or a radioactive waste. In this study, the spent filter wastes were classified according to their generating facilities, their generation date and their surface dose rate. After selecting several HEPA filters, they were dismantled into a frame part and a filter medium part. And then, a quantitative analysis of the nuclide existing in the filter medium was conducted. From the analysis results, it was possible to divide the filter medium into three specific regions in respect of the nuclide distribution. As a result, these three regions could be a sampling guide to take a representative sample of a spent HEPA filter waste for treating it

  5. HEPA filters of high structural strength for nuclear air cleaning systems

    International Nuclear Information System (INIS)

    HEPA-filter media, though having excellent particle-removal efficiencies, remain characterized as rather brittle, fragile, and weak materials. As a result, undesired structural damage, followed by significant losses in filtration efficiency, can easily occur in handling, transport, and even normal operation of filter units. In recent years, extensive investigations into the structural limits of HEPA filters in dry air and under extended exposure to high-humidity airflow have been carried out. In the course of this work, the failure modes and the underlying failure mechanisms were thoroughly studied. On the basis of the information obtained, considerable improvements in the structural strength of HEPA filters could be achieved. As verified by removal efficiency tests, differential pressures up to 56 kPA in dry air and 15 kPA after extended operation under fog conditions were proved to be sustainable without mechanical damage to the filter medium

  6. VHF/UHF filters and multicouplers application of air resonators

    CERN Document Server

    Piette, Bernard

    2013-01-01

    This book describes the various devices used in radio communication and broadcasting to achieve high selectivity filtering and coupling. After providing a background in the basics of microwave theory and more detailed material - including a special chapter on precision and errors in measurement - the reader will find detailed descriptions, manufacturing processes, and, for the most useful instances, a number of worked-through formulas, which will allow engineers and technicians to design circuits or components for filtering or coupling applications. Content is covered in this format across a b

  7. Performances of pleated HEPA filters as a function of relative humidity of air

    International Nuclear Information System (INIS)

    Pleated High Efficiency Particulate Air (HEPA) filters are used for maintaining the containment of radioactive substances in nuclear plants; thus, they are sensitive elements of nuclear safety. Some accidental situations, such as the emergence of a hole on a pipe with release of steam, can lead to a high increase of the air humidity. This work can overcome the lack of analytical data in the literature regarding the behaviour of pleated HEPA filters, in terms of changes in pressure drop and efficiency, in presence of humidity (unsaturated air). Experimental clogging tests have been performed on a test bench with two aerosols: non hygroscopic micron-size alumina particles and hygroscopic sub-micron sodium chloride particles. The results showed that the influence of humidity during the clogging of a HEPA filter depends on several parameters: the geometry of the filter (plane or pleated), the size distribution and hygroscopicity of the aerosol clogging and finally the interaction time between the aerosol and humid air. Measurements of efficiency of clean and clogged filters (at different degrees of clogging), performed with the normalized soda fluorescein aerosol, are also sensitive to the presence of more or less relative humidity in the air. Finally, all results helped to develop an empirical model for estimating the evolution of the pressure drop of HEPA filters; this model is applicable during the formation of the particulate cake in presence of humidity without reducing of the surface area filtration. (author)

  8. Performance Analysis of Upsample Filter for Sample Rate Converter

    OpenAIRE

    Manish Sabraj,; Vipan Kakkar

    2012-01-01

    Now a days many signal processing tasks are performed in the digital domain. Various sample rates are used on the basis of required signal quality and the available bandwidth. Sample-rate conversion is therefore inevitable to interface systems with different sample rates. The aim of digital sample rate conversion is to bring a digital audio signal from one sample frequency to another. Some information is lost while sampling.The distortion of the audio signal introduced by the sample rat...

  9. In-situ continuous scanning high efficiency particulate air (HEPA) filter monitoring system

    International Nuclear Information System (INIS)

    The testing and replacement of HEPA filters, which are widely used in the nuclear industry to purify process air before it is ventilated to the atmosphere, is a costly and labor-intensive undertaking. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow for determination of overall filter performance but preclude detection of symptoms of incipient filter failure, such as small holes in the filters themselves. Using current technology, a continual in-situ monitoring system has been designed which provides three major improvements over current methods of filter testing and replacement. This system (1) realizes a cost savings by reducing the number of intact filters which are currently being replaced unnecessarily, (2) provides a more accurate and quantitative measurement of filter performance than is currently achieved with existing testing methods, and (3) reduces personnel exposure to a radioactive environment by automatically performing most testing operations. The operation and performance of the HEPA filter monitoring system are discussed

  10. Conditions for using outdoor-air inlet filter for removing UFP in residential buildings

    DEFF Research Database (Denmark)

    Afshari, Alireza; Ardkapan, Siamak Rahimi; Bergsøe, Niels Christian;

    2012-01-01

    The purpose of this project is to study the possibility of achieving a reduction of ultrafine particles in the indoor air by placing a filter at the outdoor-air inlet in residential buildings with exhaust ventilation or natural ventilation. This paper presents field measurements of airflow rates ...

  11. Asymptotically optimal linear shrinkage of sample LMMSE and MVDR filters

    OpenAIRE

    Serra, Jordi; Nájar Martón, Montserrat

    2014-01-01

    Conventional implementations of the linearminimum mean-square (LMMSE) and minimum variance distortionless response (MVDR) estimators rely on the sample matrix inversion (SMI) technique, i.e., on the sample covariance matrix (SCM). This approach is optimal in the large sample size regime. Nonetheless, in small sample size situations, those sample estimators suffer a large performance degradation. Thus, the aim of this paper is to propose corrections of these sample methods that counteract thei...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    K. E. Yttri

    2014-07-01

    Full Text Available 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

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

    Science.gov (United States)

    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

  15. Development of Air Sampling Technology by the Atomic Energy Research Establishment, Harwell

    International Nuclear Information System (INIS)

    For many years the Health Physics and Medical Division of the Atomic Energy Research Establishment, Harwell, has pursued a vigorous programme of investigation and development in the field of air-sampling technology. The programme has made important contributions to the development of sampling media, the design of sampling equipment, the characterization of environmental airborne contamination and the interpretation of air-sampling data in terms of personal exposure. These developments form the basis for the present operational and research programmes in this field in the United Kingdom Atomic Energy Authority (U.K.A.E.A). . This paper, which summarizes the advances made in the Harwell laboratories in the above fields, is divided into three sections: 1. Sampling techniques. The development and characterization of glass-fibre filter papers (Stevens and Hounam) with improved surface collection properties has simplified counting procedures and has made ' possible detailed autoradiographic examination of the dust collected. The problem of energy degradation of alpha radiation by absorption in particles and paper has been studied (Stevens and Toureau). Development of charcoal-impregnated papers (Stevens and Hounam) has facilitated the detection and measurement of airborne contamination by iodine vapour. The combination of these papers with granular characoal in the May Pack (May) has given a sampling device which is now in common use for the determination and characterization of atmospheric iodine contamination. The concept and development of the personal air sampler (Sherwood and Greenhalgh) led to a better appreciation of the uncertainties of conventional air sampling and to the first quantitative demonstration of the problems of interpreting air samples in terms of personal inhalation exposure. Work on the design of a size selective head for the personal air sampler has not yet resolved the difficulties. The drawbacks of the cascade impactor as a continuous size

  16. CFD simulation of nanofiber-enhanced air filter media

    OpenAIRE

    Tronville, Paolo Maria

    2015-01-01

    The first step in a CFD analysis of filter media flow is to create a computational domain geometry which imitates the simulated media as closely as is practical. The media in the present study combined a relatively flat web of nanofibers with a cellulosic fiber support media. A CFD grid suited to calculating the flow patterns through the cellulosic media structure would be far too coarse to simulate flow around the nanofiber web elements. This scale difference forces some assumption about the...

  17. Farrow-structure-based reconfigurable bandpass linear-phase FIR filters for integer sampling rate conversion

    OpenAIRE

    Johansson, Håkan

    2011-01-01

    A class of Farrow-structure-based reconfigurable bandpass finite-length impulse response (FIR) filters for integer sampling rate conversion is introduced. The converters are realized in terms of a number of fixed linear-phase FIR subfilters and two sets of reconfigurable multipliers that determine the passband location and conversion factor, respectively. Both Mth-band and general FIR filters can be realized, and the filters work equally well for any integer factor and passband location. Desi...

  18. Flexible Analog Front Ends of Reconfigurable Radios Based on Sampling and Reconstruction with Internal Filtering

    Directory of Open Access Journals (Sweden)

    Poberezhskiy Gennady Y

    2005-01-01

    Full Text Available Bandpass sampling, reconstruction, and antialiasing filtering in analog front ends potentially provide the best performance of software defined radios. However, conventional techniques used for these procedures limit reconfigurability and adaptivity of the radios, complicate integrated circuit implementation, and preclude achieving potential performance. Novel sampling and reconstruction techniques with internal filtering eliminate these drawbacks and provide many additional advantages. Several ways to overcome the challenges of practical realization and implementation of these techniques are proposed and analyzed. The impact of sampling and reconstruction with internal filtering on the analog front end architectures and capabilities of software defined radios is discussed.

  19. Element analysis of atmospheric particles collected on polytetrafluoroetylene (PTFE) filter using in-air helium ion induced X-ray emission method

    International Nuclear Information System (INIS)

    In order to confirm the availability of an in-air Helium ion induced X-ray emission method for multi-elemental analysis of polytetrafluoroetylene (PTFE) filter sample containing atmospheric particles, NIST urban particulate matter (SRM 1648) collected on PTFE filter using a special small chamber was analyzed by an in-air PIXE method with Helium ions and a proton beam. In addition, we analyzed 10 elements, mixing a standard solution with different concentrations to confirm detection sensitivity of characteristic X-ray peaks. As a result, it is suggested that 1) elements that are lighter than Zn and Pb can be satisfactorily measured using the in-air Helium ion induced X-ray emission method if the amount contained in the filter sample is at least 0.1 mg/L, i.e., 15 ng/cm2, 2) the in-air Helium ion induced X-ray emission method is useful as a method for quantitatively analyzing the light elements such as Mg, Al, Si, S and Cl that are important for identifying the behavior and characteristics of atmospheric particles from the PTFE filter sample containing atmospheric particles, and 3) in the case of the PTFE filter sample containing atmospheric particles, it is possible to measure elements from Mg to Pb by means of analysis using Helium ions and protons. (author)

  20. Workplace air monitoring and sampling practices at DOE facilities

    International Nuclear Information System (INIS)

    The Pacific Northwest Laboratory (PNL) surveyed the current air monitoring and sampling practices at U.S. Department of Energy (DOE) facilities as a part of an air monitoring upgrade task. A comprehensive questionnaire was developed and distributed to DOE contractors through the DOE field offices. Twenty-six facilities returned a completed questionnaire. Questionnaire replies indicate a large diversity in air sampling and monitoring practices among DOE facilities. The differences among the facilities exist in monitoring and sampling instrumentation, procedures, calibration, analytical methods, detection levels, and action levels. Many of these differences could be attributed to different operational needs. 5 references, 2 figures, 2 tables

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

    International Nuclear Information System (INIS)

    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. (orig.)

  2. Depth profiling of hydrogen in amorphous media and applicable to quartz air filters

    International Nuclear Information System (INIS)

    We have explored the use of proton-proton coincidence, at proton energy of 6.35 MeV, for hydrogen determination and depth profiling in amorphous media. The method has been applied to quartz air filters. This non-destructive method is highly specific to hydrogen, depending only on the energy-loss distribution in p-p scattering events. The method, combined with other techniques, can be used to measure the total amount and depth distribution of particulate organic matter in aerosols on quartz air. The results for ambient air quartz filters show that the technique can separate several kinds of gaseous organic artifact, one of which cannot be corrected through the standard use of tandem quartz filters. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Clogging of industrial pleated high efficiency particulate air (HEPA) filters in the event of fire

    International Nuclear Information System (INIS)

    Research highlights: → Study of the clogging of pleated HEPA filters in case of fire in a nuclear installation. → Influence of fuels, filtration velocity and burnings conditions on aerosol characteristics and filter clogging. → Development of an empirical way to predict the clogging behaviour of HEPA filters in the event of fire. - Abstract: The IRSN and AREVA NC are currently conducting a common interest fire research programme with the aim, among other things, of improving knowledge of clogging of high efficiency particulate air (HEPA) filters and developing an empirical model for clogging of such filters by combustion aerosols. This model must - insofar as possible - be independent of the nature of the fuel and be able to be integrated in a calculation code covering the interaction between the ventilation and the fire. This paper discusses the influence of various 'direct' factors such as the filtration velocity, the mass of deposited aerosol per filter area, the diameter and morphology of the combustion particles, the condensate content of the aerosols, and 'indirect' factors such as the air flow feeding the fire and its oxygen content, which influence the evolution of the aeraulic resistance of a clogged filter.

  4. Clogging of industrial pleated high efficiency particulate air (HEPA) filters in the event of fire

    Energy Technology Data Exchange (ETDEWEB)

    Mocho, V.M. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Saclay, BP 68, 91192 Gif-sur-Yvette cedex (France); Ouf, F.-X., E-mail: francois-xavier.ouf@irsn.f [Institut de Radioprotection et de Surete Nucleaire (IRSN), Saclay, BP 68, 91192 Gif-sur-Yvette cedex (France)

    2011-05-15

    Research highlights: Study of the clogging of pleated HEPA filters in case of fire in a nuclear installation. Influence of fuels, filtration velocity and burnings conditions on aerosol characteristics and filter clogging. Development of an empirical way to predict the clogging behaviour of HEPA filters in the event of fire. - Abstract: The IRSN and AREVA NC are currently conducting a common interest fire research programme with the aim, among other things, of improving knowledge of clogging of high efficiency particulate air (HEPA) filters and developing an empirical model for clogging of such filters by combustion aerosols. This model must - insofar as possible - be independent of the nature of the fuel and be able to be integrated in a calculation code covering the interaction between the ventilation and the fire. This paper discusses the influence of various 'direct' factors such as the filtration velocity, the mass of deposited aerosol per filter area, the diameter and morphology of the combustion particles, the condensate content of the aerosols, and 'indirect' factors such as the air flow feeding the fire and its oxygen content, which influence the evolution of the aeraulic resistance of a clogged filter.

  5. Tritium monitoring in air, optimization of a sampling method

    International Nuclear Information System (INIS)

    An air humidity sampling method using dry silica gel and its application to tritium activity concentration monitoring in air humidity are described. The method was used to monitor tritium in the surroundings of Czech nuclear power plants. The problem of elimination of cross-contamination is discussed

  6. ALMERA Proficiency Test: Determination of Gamma Emitting Radionuclides in Simulated Air Filters

    International Nuclear Information System (INIS)

    The activity concentration of radionuclides in air is a critical factor in assessing the air quality and the potential impact of possible pollutants. Air is in fact one of the main pathways for human exposure to radioactivity. Radioactivity may be present in the atmosphere due to natural processes; intentional (low level) anthropogenic release; or as a consequence of nuclear or radiological incident. The resulting environmental impact should be considered carefully to ensure safety and compliance with environmental regulations. A reliable determination of radionuclides in air is necessary for regular monitoring of air quality to comply with radiation protection and environmental regulations. This proficiency test (PT) is one of the series of the ALMERA network proficiency tests organised on regular basis by the Terrestrial Environment Laboratory in Seibersdorf, designed to assess the technical capacity of ALMERA Members in analysing radionuclides to identify any analytical problems and to support ALMERA laboratories to maintain their preparedness to provide rapid and reliable analytical results. The range of simulated air filters used in this PT for analysis has been mainly at environmental level. The PT set consisted of four filters. The participating laboratories were requested to analyze Mn-54, Co-57, Fe-59, Co-60, Zn-65, Cd-109, Ba-133, Cs-134, Cs-137, Eu-152 and Am-241 in filters 01, 02 and 03. The participants were informed that only some of the listed radionuclides were present in the filters and the levels of the radionuclides were such that they could be measured within a 6-hour measurement period using a conventional HPGe gammaspectrometer of 35% relative efficiency. Filter 04, was containing only Co-60 and Ba-133 with known activities to the participants, had to be used as a control for the efficiency calibration. The tasks of IAEA were to prepare and distribute the simulated air filters to the participating laboratories, to collect and interpret

  7. Robust H-infinity filtering on uncertain systems under sampled measurements

    Institute of Scientific and Technical Information of China (English)

    Ping SUN; Yuanwei JING

    2006-01-01

    This paper is concerned with the problem of robust H-infinity filtering on uncertain systems under sampled measurements, both continuous disturbance and discrete disturbance are considered in the systems. The parameter uncertainty is assumed to be time-varying norm-bounded. The aim is to design an asymptotically stable filter, using the locally sampled measurements, which ensures both the robust asymptotic stability and a prescribed level of H-infinity performance for the filtering error dynamics for all admissible uncertainties. The derivation process is simplified by introducing auxiliary systems and the sufficient condition for the existence of such a filter is proposed. During the study, the main results were expressed as LMIs by employing various matrix techniques. Using LMI toolbox of Matlab software, it is very convenient to obtain the appropriate filter. Finally, a numerical example shows that the method is effective and feasible.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Presence of organophosphorus pesticide oxygen analogs in air samples

    OpenAIRE

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

    2013-01-01

    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 lab...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

  14. Recent development in uranium mining air sampling programs

    International Nuclear Information System (INIS)

    Licensees planning to operate in-situ uranium mining facilities must demonstrate compliance with USNRC Regulatory Guide 4.14 regarding the facility's impact on the local ambient air quality. Regulatory compliance includes a pre-operational baseline study with a subsequent operational air monitoring program. Compliance with the air monitoring requirements is being aided by utilization of advanced-technology AC/DC air sampling systems operable from batteries charged by solar power or wind turbine systems. These modern air sampling systems employ low power brushless motors, automatic flow control, in addition to normalization of flow rates and volumes to a standard temperature and pressure. These high tech features enable a licensee to demonstrate more accurately compliance with the MDA requirements of Req. Guide 4.14 for specific isotopes of Th, Ra, Pb and U.

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

    Science.gov (United States)

    2010-07-01

    ... the mean mass of each sample medium (e.g., filter). Use good engineering judgment to exclude outliers... the sample medium's mass. However, it may not be advantageous when net PM masses exceed 1% of the sample medium's mass. If you utilize substitution weighing, it must be used for both pre-test and...

  16. Looking for the minimum efficiency of fibrous air filters during their service life

    OpenAIRE

    Tronville, Paolo Maria

    2012-01-01

    Electret fibrous air filter media achieve high efficiencies while maintaining low air flow resistance by incorporating electrostatic charges on their fibers. However, captured ultrafine particles reduce this electrostatic enhancement. It is important to evaluate the behavior of such media when their electrostatic enhancement has been completely suppressed, leaving only "mechanical" effects such as sieving, impaction, interception and diffusion. Existing standards EN779:2002 and ASHRAE 52.2-20...

  17. The comparison of pollen abundance in air and honey samples

    Directory of Open Access Journals (Sweden)

    Ingrida Šaulienė

    2015-12-01

    Full Text Available Honey as a food has long been used in human nutrition and is still popular. Honey is important because of its therapeutic, prophylactic and strengthening value. Pollen is one of the most decisive components that ensure the quality and type of honey. Modern society becomes more and more sensitive to airborne pollen. Therefore, it is crucial to determine the composition of allergenic plant pollen in natural honey. For this purpose, we studied and compared pollen abundance in honey and air samples collected in Lithuania. Standard methods for pollen investigation in air and honey were used in this study. The botanical diversity of pollen identified in honey and air samples indicates 10 morphotypes: 8 of woody plants and 2 of herbaceous plants, in both the honey and air samples. Salix pollen counts in the honey were found to be highest among airborne pollen from May to September. The anemophilous allergenic pollen constituted 44 % of the total pollen detected in the honey.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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.

  20. Determination of plutonium from air filters for the detection of undeclared nuclear activities

    International Nuclear Information System (INIS)

    In Finland analytical development in being carried out to support the IAEA Action Team which has the UN's mission to detect undeclared nuclear activities in Iraq. A research consortium Finnish Nuclear Verification (FINUVE), which combines the analytical surveys of the Laboratory of Radiochemistry, Technical Research Centre of Finland and the Finnish Radiation and Nuclear Safety Authority, has carried out air filter testing in Kazakhstan in the years 2000-2001. In the Laboratory of Radiochemistry weekly filters have been first wet-ashed and then Pu separated by extraction chromatography using Eichrom's UTEVA and TRU resins. Finally the plutonium activity and isotopic composition have been determined by alpha spectrometry. Development of the analytical procedures, especially the features concerning air filters, are described in this paper. (author)

  1. Standard specification for high efficiency particulate air filters. Revision No. 2

    International Nuclear Information System (INIS)

    This specification covers the requirements for four types and four sizes of high efficiency particulate air filters, assembled with or without separators and gaskets. Types include Fire Resistant and Moisture Resistant; Hydrogen Fluoride Fume (HF) Resistant; Fire Resistant and Moisture Resistant and Chemical Resistant; and Fire Resistant and Moisture Resistant, High Temperature and High Humidity

  2. FLOW CHARACTERISTICS OF WALL-FLOW DIESEL PARTICULATE FILTER SYSTEM WITH REVERSE PULSE AIR REGENERATION

    Institute of Scientific and Technical Information of China (English)

    Yao Chunde; Shao Yuping; Zhang Chunrun; Zi XinYun; Jiang Dahai; Deng Chenglin

    2005-01-01

    To simulate steady airflows inside of wall-flow diesel particulate filters (DPF) with different reverse blowing pipes collocation, a mathematical model of the flow in a DPF is established by an equivalent continuum approach. The experimental results agree well with the theoretical values calculated from the model. Simulation shows that the velocity and the pressure distribution of the filters in the regenerative process are key factors to the filter's regeneration. How to decrease the mal-distribution of the flow in the filter and how to achieve the better regenerative performance at the least cost of air consumption in the regenerative process are the ultimate goals of the study. Calculation and experiments show that the goals can be realized through adjusting the angle of two reverse blowing pipes and their relative location suitably.

  3. Call-centre occupant response to new and used filters at two outdoor air supply rates

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David; Nielsen, J.; Fanger, Povl Ole

    2002-01-01

    A 2x2 replicaterd field intervention experiment was conducted in a call-centre providing a public telephone directory service: outdoor air supply rate was 8% or 80% of the total airflow of 430 L/s providing 3.5 h-1; and the supply air filters were either new or used (i.e. used in place for 6 mont......). Each of these 4 conditions was maintained for a full working week at a time. Room temperature and humidity averaged 24 deg.C and 27% RH. The 26 operators were blind to conditions and assessed perceived air quality (PAQ), the intensity of Sick Building Syndrome (SBS) symnptoms and self...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Passive sampling of polychlorinated biphenyls (PCB) in indoor air

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Mayer, Philipp

    PCBs were widely used in construction materials in the 1906s and 1970s, a period of high building activity in Denmark. The objective of this study was therefore to use passive sampling techniques to develop a simple and cost-effective screening tool for PCBs in indoor air. The study proceeded in...... three phases combining a literature review, laboratory experiments and measurements in buildings potentially containing PCBs in indoor air. The laboratory experiments showed a strong influence of air velocity on the PCB partitioning between air and the passive sampler. Based on the results of the first...... two phases and comments from experts in the field of PCB containing construction materials, a kinetic sampler (petri dish with silicone) and a potential equilibrium sampler (silicone-coated paper) were tested in buildings. Calibration and validation were based on conventional active sampling, for both...

  6. Polyphase Filter Banks for Embedded Sample Rate Changes in Digital Radio Front-Ends

    DEFF Research Database (Denmark)

    Awan, Mehmood-Ur-Rehman; Le Moullec, Yannick; Koch, Peter; Harris, Fred

    2011-01-01

    This paper presents efficient processing engines for software-defined radio (SDR) front-ends. These engines, based on a polyphase channelizer, perform arbitrary sample-rate changes, frequency selection, and bandwidth control. This paper presents an M-path polyphase filter bank based on a modified N......-path polyphase filter. Such a system allows resampling by arbitrary ratios while performing baseband aliasing from center frequencies at Nyquist zones that are not multiples of the output sample rate. This resampling technique is based on sliding cyclic data load interacting with cyclic-shifted coefficients. A...... non-maximally-decimated polyphase filter bank (where the number of data loads is not equal to the number of M subfilters) processes M subfilters in a time period that is less than or greater than the M data loads. A polyphase filter bank with five different resampling modes is used as a case study for...

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

    Science.gov (United States)

    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

  8. Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

    International Nuclear Information System (INIS)

    Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

  9. Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Eui-seok; Hwang, Gi Byoung [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Nho, Chu Won [Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do 210-340 (Korea, Republic of); Kwon, Bo Mi [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Jung Eun [Biosafety Research Team, National Institute of Environmental Research, Kyungseo-Dong, Seo-Gu, Incheon 404-170 (Korea, Republic of); Seo, SungChul [Department of Environmental Health, College of Medicine, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Bae, Gwi-Nam, E-mail: gnbae@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Jung, Jae Hee, E-mail: jaehee@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2013-02-01

    Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

  10. Air Monitoring: New Advances in Sampling and Detection

    Directory of Open Access Journals (Sweden)

    Nicola Watson

    2011-01-01

    Full Text Available 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.

  11. Realistic air filter media performance simulation. Part II: Beyond finite-volume computational fluid dynamics procedures

    OpenAIRE

    Tronville, Paolo Maria

    2013-01-01

    One form of numerical simulation of flow and particle capture by air filter media sees gases as continuous fluids, influenced by the macro-properties viscosity, density, and pressure. The alternate approach treats gases as atoms or molecules in random motion, impacting their own kind and solid surfaces on a micro-scale. The appropriate form for analysis of flow through a given filter medium at a given operating condition depends on the gas condition and the Knudsen number (Kn) of the finest f...

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

    Science.gov (United States)

    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

  13. On the structurization of coal dust precipitations and their influence on aerodynamic resistance by granulated mediums in air filters at nuclear power plants

    CERN Document Server

    Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

    2012-01-01

    The processes of structurization of dust precipitations in granulated filtering mediums, formed by the monolithic glass spherical granules with the diameters of 2mm and 3mm, are re-searched. The distinctions between the distributions of filtered coal dust masses in the air filters with cylindrical granules and the air filters with spherical granules, are found. The influences by the filtered dust masses on the air resistance of both the air filters with the cylindrical granules and the air filters with the spherical granules are described. The conclusions on a possibility of the use of various chemical adsorbents with different geometric forms and volumetric dimensions to improve the filtering properties of granulated filtering mediums in air filters at nuclear power plants are formulated.

  14. Sampling density for the quantitative evaluation of air trapping

    Energy Technology Data Exchange (ETDEWEB)

    Goris, Michael L. [Stanford University School of Medicine, Division of Nuclear Medicine, Stanford, CA (United States); Robinson, Terry E. [Stanford University School of Medicine, Center of Excellence in Pulmonary Biology, Pulmonary Division, Department of Pediatrics, Stanford, CA (United States)

    2009-03-15

    Concerns have been expressed recently about the radiation burden on patient populations, especially children, undergoing serial radiological testing. To reduce the dose one can change the CT acquisition settings or decrease the sampling density. In this study we determined the minimum desirable sampling density to ascertain the degree of air trapping in children with cystic fibrosis. Ten children with cystic fibrosis in stable condition underwent a volumetric spiral CT scan. The degree of air trapping was determined by an automated algorithm for all slices in the volume, and then for 1/2, 1/4, to 1/128 of all slices, or a sampling density ranging from 100% to 1% of the total volume. The variation around the true value derived from 100% sampling was determined for all other sampling densities. The precision of the measurement remained stable down to a 10% sampling density, but decreased markedly below 3.4%. For a disease marker with the regional variability of air trapping in cystic fibrosis, regardless of observer variability, a sampling density below 10% and even more so, below 3.4%, apparently decreases the precision of the evaluation. (orig.)

  15. Sampling density for the quantitative evaluation of air trapping

    International Nuclear Information System (INIS)

    Concerns have been expressed recently about the radiation burden on patient populations, especially children, undergoing serial radiological testing. To reduce the dose one can change the CT acquisition settings or decrease the sampling density. In this study we determined the minimum desirable sampling density to ascertain the degree of air trapping in children with cystic fibrosis. Ten children with cystic fibrosis in stable condition underwent a volumetric spiral CT scan. The degree of air trapping was determined by an automated algorithm for all slices in the volume, and then for 1/2, 1/4, to 1/128 of all slices, or a sampling density ranging from 100% to 1% of the total volume. The variation around the true value derived from 100% sampling was determined for all other sampling densities. The precision of the measurement remained stable down to a 10% sampling density, but decreased markedly below 3.4%. For a disease marker with the regional variability of air trapping in cystic fibrosis, regardless of observer variability, a sampling density below 10% and even more so, below 3.4%, apparently decreases the precision of the evaluation. (orig.)

  16. Penggunaan Unit Slow Sand Filter, Ozon Generator dan Rapid Sand Filter Skala Rumah Tangga Untuk Meningkatkan Kualitas Air Sumur Dangkal Menjadi Air Layak Minum (Parameter Zat Organik dan Deterjen

    Directory of Open Access Journals (Sweden)

    Anindya Prawita Sari

    2014-09-01

    Full Text Available Air sumur merupakan air tanah yang sering kali digunakan masyarakat untuk aktivitas sehari-hari. Air sumur dengan kadar organik dan deterjen tinggi tidak layak dikonsumsi masyarakat karena dapat menyebabkan berbagai macam penyakit. Selain itu, adanya zat organik dan deterjen mempengaruhi warna dan bau air sumur sehingga tidak layak konsumsi. Slow sand filter merupakan unit pengolahan yang mampu meremoval zat organik pada air. Slow sand filter dan rapid sand filter tidak menggunakan bahan kimia dalam proses pengolahan sehingga lebih ekonomis dan efektif. Sedangkan ozon, efektif digunakan untuk meremoval zat organik yang ada dalam air dengan mengubah rantai zat organik menjadi lebih sederhana. Tujuan penelitian ini adalah untuk mengetahui keefektifan penggunaan slow sand filter, ozon generator dan rapid sand filter dalam menyisihkan beban deterjen dan zat organik pada air sumur. Hasil penelitian menunjukkan bahwa efisiensi removal pada unit slow sand filter untuk beban organik dan deterjen sebesar 57,6% dan 60,5 %, pada unit ozonasi sebesar 47,4% dan 17,5%, dan pada unit rapid sand filter sebesar 50,0% dan 50,9 %.

  17. CAS-H3 type device for sampling tritium from air

    International Nuclear Information System (INIS)

    CAS-H3 type devices is designed for sampling tritiated water vapors and H3 inside nuclear power plants or outside, within a 30 km radius. The devices is supplied by means of two 1.25 Vcc batteries while to ensure an independent long operation it is provided with two photocells for recharge the batteries. The device is conceived to retain integrally both tritiated water vapors and free tritium from the air flow passing through it. The principal components are: - mechanical filter; - oxidizing catalyst; - photocell; - bag; - minipump; - shaking box; - 2.5 V battery; - flowmeter. Technical characteristics are: - air sampling flowrate, 12 l/min; - minipump motor power, 3 W / 3 V; - supply voltage 2.5 Vcc; - size 450 x 350 x 120 mm; - weight 5 kg

  18. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    International Nuclear Information System (INIS)

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3σ), based on ten atomizations of an unexposed filter, was 40 ng g-1, corresponding to 0.12 ng m-3 in the air for a typical air volume of 1440 m3 collected within 24 h. The limit of quantification was 150 ng g-1, equivalent to 0.41 ng m-3 in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between -1 and 381 ± 24 ng g-1. These values correspond to a mercury concentration in the air between -3 and 1.47 ± 0.09 ng m-3. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  19. Comparison of quartz and Teflon filters for simultaneous collection of size-separated ultrafine aerosol particles and gas-phase zero samples.

    Science.gov (United States)

    Parshintsev, Jevgeni; Ruiz-Jimenez, Jose; Petäjä, Tuukka; Hartonen, Kari; Kulmala, Markku; Riekkola, Marja-Liisa

    2011-07-01

    In this research, the two most common filter media, quartz and Teflon, were tested to obtain information about the possible adsorption of gas-phase compounds onto filters during long sample collection of atmospheric aerosols. Particles of nanometer-size for off-line chemical characterization were collected using a recently introduced differential mobility analyzer for size separation. Samples were collected at an urban site (Helsinki, SMEARIII station) during spring 2010. Sampling time was 4 to 10 days for particles 50, 40, or 30 nm in diameter. Sample air flow was 4 L/min. The sampling setup was arranged so that two samples were obtained for each sampling period almost simultaneously: one containing particles and adsorbed gas-phase compounds and one containing adsorbed gas-phase compounds only. Filters were extracted and analyzed for the presence of selected carboxylic acids, polyols, nitrogen-containing compounds, and aldehydes. The results showed that, in quartz filter samples, gas-phase adsorption may be responsible for as much as 100% of some compound masses. Whether quartz or Teflon, simultaneous collection of gas-phase zero samples is essential during the whole sampling period. The dependence of the adsorption of gas-phase compounds on vapor pressure and the effect of adsorption on the deposited aerosol layer are discussed. PMID:21533796

  20. Sampling frequency guidance for ambient air toxics monitoring.

    Science.gov (United States)

    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

  1. Gaussian Filter based on Deterministic Sampling for High Quality Nonlinear Estimation

    OpenAIRE

    Huber, Marco F.; Hanebeck, Uwe D.

    2008-01-01

    In this paper, a Gaussian filter for nonlinear Bayesian estimation is introduced that is based on a deterministic sample selection scheme. For an effective sample selection, a parametric density function representation of the sample points is employed, which allows approximating the cumulative distribution function of the prior Gaussian density. The computationally demanding parts of the optimization problem formulated for approximation are carried out off-line for obtaining an efficient filt...

  2. Some observations on the results of personal air samples

    International Nuclear Information System (INIS)

    Results of personal air samples taken in plutonium and uranium handling areas at Harwell Laboratory during 1986 were examined on a statistical basis. The distribution of concentrations shown by samples is of log-normal form, and similar in all plutonium handling areas in having a median concentration of 0.026 DAC and a geometric standard deviation of ∼6.0. A computer program was used to demonstrate large variation in sample results could be wholly due to statistics of sampling radioactive particles at very low concentration. This variation would mask all but the largest changes due to other causes (e.g. different work methods or ventilation patterns). In uranium handling areas particle sampling statistics do not play an important part in variation between samples as the concentration of particles is high. The geometric standard deviation of the samples was 3.5 and attributable to changes in work, work methods or ventilation patterns. Radiometric analysis of the personal air samples is discussed. Errors due to counting statistics are considered to be relatively small compared with other sources of sample variation. (author)

  3. Polycyclic aromatic hydrocarbons in air samples of meat smokehouses

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Olsen, I L; Poulsen, O M

    In a screening programme nine Danish meat smokehouses were randomly selected for measurements on concentration of airborne polycyclic aromatic hydrocarbons (PAH). A total of 23 stationary air samples were collected during the entire working period of the kiln either above the kiln doors or...

  4. Development of a high-efficiency, high-performance air filter medium

    International Nuclear Information System (INIS)

    A unique high-efficiency particulate air (HEPA) filter medium has been developed for applications in high temperature and high pressure environments. This filter medium is a composite made from quartz and stainless-steel fibers that have been sintered together. The composite medium has the same efficiency and pressure drop as standard HEPA glass media, but has four times the tensile strength and can operate continuously at temperatures up to 500/degree/C. In a conventional HEPA, the binder burns out above 250/degree/C and the medium loses its strength; our composite filter medium has no comparable loss of strength even at 500/degree/C. 8 refs., 8 figs., 1 tab

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

    Science.gov (United States)

    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

  6. Aging assessment of nuclear air-treatment system HEPA filters and adsorbers

    International Nuclear Information System (INIS)

    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

  7. Development of local air blower for removing radioactive iodine using the carbon fiber filter

    International Nuclear Information System (INIS)

    Boiling water type nuclear power plant (BWR) conducts overhaul of the condenser and the turbine regularly. The radioactive iodine dissipation in the turbine system, that occurs in the reactor during plant operation, need to implement safeguards against radioactive iodine. Carbon particle filter type local air blower is conventionally used in order to eliminate the radioactive iodine before during maintenance, but has the problem in mobility due to size of the device. We developed the new type of local air blower using carbon fiber to improve mobility of device. (author)

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

    Science.gov (United States)

    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.

  9. High-efficiency particulate air filter test activities at the Department of Energy

    International Nuclear Information System (INIS)

    For the past 2 years, test activities at the three Department of Energy HEPA Filter Test Facilities (FTFs) have been conducted under a unified set of operating standards intended to help achieve consistency in test methods and test results. Reviews of test operations are conducted at each FTF annually, and technical support and guidance are provided on request. Round Robin tests are conducted twice a year to compare penetration and resistance test results among the three FTFs. The FTFs prepare summary test data twice a year, and the data is analyzed for trends with respect to ongoing quality of HEPA filters in nuclear facilities. Data and conclusions from both the Round Robin tests and semiannual reports are discussed, the latter without reference to specific manufacturers. The new DOE standards include provisions for consideration and approval of new test aerosols or test methods, under closely controlled change procedures. Progress in obtaining DOE approval for DOS as a new aerosol, and for the Alternative Test System (ATS) developed by, and reported on by the LANL, as an approved new test method are discussed, as are 2 significant changes in standard NE-F-3-43, related to (a) toxicology test alternatives, and (b) the test aerosol definition. Finally, the emergence of new, higher flow rated HEPA filters and Ultra Low Particulate Air (ULPA) filters will impact DOE's design, procurement, testing and use of HEPA filters in the near future

  10. Methods for Sampling and Measurement of Compressed Air Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L.

    1976-10-15

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  11. In-air micro-pixe analysis of tissue samples

    International Nuclear Information System (INIS)

    Micro-PIXE is capable of providing spatial distributions of elements in the micro-meter scale and its application to biology is useful to elucidate the cellular metabolism. Since, in this method, a sample target is usually irradiated with proton or α-particle beams in vacuum, beam heating results in evaporation of volatile elements an shrinking of the sample. In order to avoid these side effects, we previously developed a technique of in-air micro-PIXE analysis for samples of cultured cells. In addition to these, analysis of exposed tissue samples from living subjects is highly desirable in biological and medical research. Here, we describe a technique of in-air micro-PIXE analysis of such tissue samples. The target samples of exposed tissue slices from a Donryu rat, in which a tumor had been transplanted, were analyzed with proton micro-beams of 2.6 MeV. We report that the shape of cells and the distribution of volatile elements in the tissue sample remain uncharged when using a target preparation based on a freeze-drying method. (author)

  12. Methods for Sampling and Measurement of Compressed Air Contaminants

    International Nuclear Information System (INIS)

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  13. Size-Resolved Penetration Through High-Efficiency Filter Media Typically Used for Aerosol Sampling

    Czech Academy of Sciences Publication Activity Database

    Zíková, Naděžda; Ondráček, Jakub; Ždímal, Vladimír

    2015-01-01

    Roč. 49, č. 4 (2015), s. 239-249. ISSN 0278-6826 R&D Projects: GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 Keywords : filters * size-resolved penetration * atmospheric aerosol sampling Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.413, year: 2014

  14. Generation of concentration density maxima of small dispersive coal dust particles in horizontal iodine air filter at air-dust aerosol blow

    OpenAIRE

    Neklyudov, I. M.; Ledenyov, O. P.; Fedorova, L. I.; Poltinin, P. Ya.

    2013-01-01

    The spatial distributions of the small dispersive coal dust particles with the nano and micro sizes in the granular filtering medium with the cylindrical coal granules in the absorber in the horizontal iodine air filter during its long term operation at the nuclear power plant are researched. It is shown that the concentration density maxima of the small dispersive coal dust particles appear in the granular filtering medium with the cylindrical coal absorbent granules in the horizontal iodine...

  15. Validation of analysis results of ground air samples - using different sampling and analysis methods

    International Nuclear Information System (INIS)

    In the laboratory different techniques for ground air sampling were compared to each other. For this purpose constant mixtures of gases were produced with gas mixing systems and the samples were taken using different sampling techniques in the same way as usually done in situ. A mixture of different chlorinated hydrocarbons in three different concentrations was analysed. It resulted that all sampling methods testes can be considered as equally suited with regard to the quality of the measuring results. But with regard to other evaluation criteria such as e.g. the limit of determination or sample volume they differ considerably. (orig.)

  16. Design of an online spot air sampling system

    International Nuclear Information System (INIS)

    In all the alpha handling facilities spot air sampling is essential while clearing a lab consequent to week end ventilation shut down or subsequent to completion of work/operations goes inside the facility. The sampling head is designed for 5 micron particles. Following pints are noticed over a period of such operational activities: Health Physicist goes inside a lab with a half face mask whose protection factor is 10, thereby useful for lab air activity up to ten DACs. Many times HP goes inside the lab when activity is more which is highly unsafe. On many occasions simultaneously a number of samples have to be taken by HP from a large number of laboratories inside the facility or for any special job where continuous radiological protection is required. Based on this it is proposed to design a sampling system which will overcome the above limitations. The design of the sampling head has been carried out which is for 5 micron particle size. The pump which is available in the existing facilities can be utilized. An innovative way of counting for large number of samples is fabricated in the RHC wing, RMD which can count ten samples at a time. Removal and counting of the sample may be carried out in a similar sampling carousel which is being used in RHC Unit, Radiometallurgy wing successfully with a little modification. In the proposed system, three samples can be operated in-line such that health physics intervention during the active operation would be minimum and during alarm situations (i.e. on the DAC level) proper protective equipment shall be advised by health physicist or he may suggest any other protective action. This type of online monitors will help in establishing the airborne activity inside the lab where special jobs are being carried out which will provide maximum protection to the lab personnel as well as to the health physicist who supervises the entire operation

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

    Science.gov (United States)

    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

  18. Features of adsorbed radioactive chemical elements and their isotopes distribution in iodine air filters AU-1500 at nuclear power plants

    CERN Document Server

    Neklyudov, I M; Dikiy, N P; Ledenyov, O P; Lyashko, Yu V

    2013-01-01

    The main aim of research is to investigate the physical features of spatial distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU1500 in the forced exhaust ventilation systems at the nuclear power plant. The gamma activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU1500 iodine air filter, which was exposed to the bremsstrahlung gamma quantum irradiation, produced by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granule...

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

    Science.gov (United States)

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

    Science.gov (United States)

    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.

  1. The Recent Development of the Test Standards for Ventilation air filters and Cabin Air Filters%通风和座舱空气过滤器试验标准的最新进展

    Institute of Scientific and Technical Information of China (English)

    丰兰

    2011-01-01

    The test standards and methods for two different air filters of ventilation air filters and cabin air filters were introduced,especially the difference of the test standards and methods between the ventilation air filters and cabin air filters.And the international present situation and the problem existed internal were also pointed,finally the development of cabin air filters were analyzed.%主要介绍了通风用空气过滤器和座舱式空气过滤器两个不同类型的空气过滤器的试验方法和标准,重点介绍了各试验方法和标准的区别,阐述分析了目前国际的现状和国内普遍存在的问题,最后介绍了目前座舱式空气过滤器的发展,为进一步研究提供参考。

  2. Audio-Visual Based Multi-Sample Fusion to Enhance Correlation Filters Speaker Verification System

    Directory of Open Access Journals (Sweden)

    Dzati Athiar Ramli

    2010-07-01

    Full Text Available In this study, we propose a novel approach for speaker verification system that uses a spectrogram image as features and Unconstrained Minimum Average Correlation Energy (UMACE filters as classifiers. Since speech signal is a behavioral signal, the speech data has a tendency not to consistently reproduce due to the change of speaking rates, health, emotional conditions, temperature and humidity. In order to overcome this problem, a modification of UMACE filters architecture is proposed by executing a multi-sample fusion using speech and lipreading data. So as to evaluate the outstanding fusion scheme, five multisample fusion strategies, i.e. maximum, minimum, median, average and majority vote are first experimented using thespeech signal data. Afterward, the performance of the audiovisualsystem using the enhanced UMACE filters is then tested. Here, lipreading data is combined to the audio samples pool and the outstanding fusion scheme that found in prior experiment is used as multi-sample fusion scheme. The Digit Database had been used for performance evaluation and the performance up to 99.64% is achieved by using the enhanced UMACE filters for the speech only system which is 6.89% improvement compared with the base line approach. Subsequently, the implementation of the audio-visual system is observed to be significant in order to broaden the PSR score interval between the authentic and imposter data as well as to further improve the performance of audio only system that offer toward a robust verification system.

  3. Calculation software for efficiency and penetration of a fibrous filter medium based on the mathematical models of air filtration

    OpenAIRE

    Kouropoulos, Giorgos

    2014-01-01

    At this article will be created a software written in visual basic for efficiency and penetration calculation in a fibrous filter medium for given values of particles diameter that are retained in the filter. Initially, will become report of mathematical models of air filtration in fibrous filters media and then will develop the code and the graphical interface of application, that are the base for software creation in the visual basic platform.

  4. The comparison of pollen abundance in air and honey samples

    OpenAIRE

    Ingrida Šaulienė; Laura Šukienė; Auste Noreikaite-Merkeliene; Vidmantas Pileckas

    2015-01-01

    Honey as a food has long been used in human nutrition and is still popular. Honey is important because of its therapeutic, prophylactic and strengthening value. Pollen is one of the most decisive components that ensure the quality and type of honey. Modern society becomes more and more sensitive to airborne pollen. Therefore, it is crucial to determine the composition of allergenic plant pollen in natural honey. For this purpose, we studied and compared pollen abundance in honey and air sampl...

  5. Aerosol sampler with remote air flow control and online radioactivity measurement above the filter

    International Nuclear Information System (INIS)

    The Czech national Radiation Monitoring Network is equipped with JL-150 aerosol samplers 150 m3/h air flow rate. An upgraded design of this system is proposed. The features of the upgraded aerosol sampler include remote air flow rate control via pump power, maintaining the adjusted flow rate constant, sending status information either on demand or automatically on any change, online gamma spectra acquisition above the aerosol filter and their automatic evaluation, comparison of selected regions of a spectrum with the reference levels and automatic signalling when they are exceeded. The minimum detectable activities of 131I and 137Cs, which may be present in the air in case of NPP accident, are at tenths of Bq/m3 for 1 hour measuring time. (orig.)

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Prediction of HEPA filter collection efficiency with a bimodal fiber size distribution; Koseino air filter no nihosei sen`ikei bunpu wo koryoshita hoshu koritsu no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Bao, L.; Otani, Y.; Namiki, N.; Emi, H. [Kanazawa University, Ishikawa (Japan); Mori, J. [Toyama National College of Technology, Toyama (Japan)

    1998-09-05

    Estimation of particle penetration through HEPA (High Efficiency Particulate Air) filters with the conventional filtration theory requires accurate measurements of average fiber size and variance of fiber diameters. However, it is not an easy task to obtain these properties because fiber size distribution varies to a large extent from point to point in a HEPA filter. In the present work, measurements of representative fiber size distribution from scanning electron micrographs of HEPA filter cross-section are performed and the particle penetrations are predicted with the measured fiber size distribution. They are compared with those from the conventional method (measurement from filter surfaces) and experimental data. As a result, even for filters with inhomogeneity factor {delta}p < 1 by the conventional method, the present method gave {delta}p > 1, suggesting that {delta}p < 1 is caused by the failure in measurement for representative fiber size distribution. However, the improvement in prediction with more reliable filter properties is not satisfactory because the conventional filtration theory cannot account for the contribution of fine fibers properly. Introduction of bimodal fiber size distribution together with the measurement of fiber size distribution in a cross-section of a filter is found to give comparable prediction results with the conventional method without resorting the inhomogeneity factor of filter packing. 3 refs., 6 figs., 1 tab.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  14. A filter enhanced sampling and combinatorial scoring study for protein docking in CAPRI.

    Science.gov (United States)

    Gong, Xin Qi; Chang, Shan; Zhang, Qing Hua; Li, Chun Hua; Shen, Long Zhu; Ma, Xiao Hui; Wang, Ming Hui; Liu, Bin; He, Hong Qiu; Chen, Wei Zu; Wang, Cun Xin

    2007-12-01

    Protein-protein docking is usually exploited with a two-step strategy, i.e., conformational sampling and decoy scoring. In this work, a new filter enhanced sampling scheme was proposed and added into the RosettaDock algorithm to improve the conformational sampling efficiency. The filter term is based on the statistical result that backbone hydrogen bonds in the native protein structures are wrapped by more than nine hydrophobic groups to shield them from attacks of water molecules (Fernandez and Scheraga, Proc Natl Acad Sci USA 2003;100:113-118). A combinatorial scoring function, ComScore, specially designed for the other-type protein-protein complexes was also adopted to select the near native docked modes. ComScore was composed of the atomic contact energy, van der Waals, and electrostatic interaction energies, and the weight of each item was fit through the multiple linear regression approach. To analyze our docking results, the filter enhanced sampling scheme was applied to targets T12, T20, and T21 after the CAPRI blind test, and improvements were obtained. The ligand least root mean square deviations (L_rmsds) were reduced and the hit numbers were increased. ComScore was used in the scoring test for CAPRI rounds 9-12 with good success in rounds 9 and 11. PMID:17803223

  15. Mediterranean Region proficiency test on the determination of radionuclides in air filters. IAEA-CU--2008-02

    International Nuclear Information System (INIS)

    The IAEA helps the Member States laboratories to maintain their readiness and improving the quality of the analytical results by producing reference materials, by development of standardized methods for sample collection and analysis, and by conducting interlaboratory comparisons and proficiency tests as a tool for external quality control of analytical results. The Chemistry Unit of the Physics, Chemistry and Instrumentation Laboratory in the International Atomic Energy Agency's Seibersdorf Laboratories in Austria, has the programmatic responsibility to support global radionuclide measurement systems. To fulfil this obligation and ensure a reliable worldwide, rapid and consistent response, the Chemistry Unit organises interlaboratory studies and proficiency tests. The activity concentration of radionuclides in the air is a critical factor in assessing the air quality and the potential impact of possible pollutants. Air is in fact one of the main pathways for human exposure to pollutants. Radioactivity may be present in the atmosphere due to natural processes; intentional (low level) anthropogenic release; or as a consequence of nuclear or radiological incident. Within the frame of the IAEA Technical Cooperation project RER/8/009 'Air Pollution Monitoring in the Mediterranean Region', several Member States expressed their interest in establishing close cooperation among Mediterranean countries in the field of harmonization of air pollution monitoring systems and creation of a common database, since they share geographical position and mutual interest in the environmental conditions of the Mediterranean region. Such cooperation will also promote and enhance the exchange of experience/information. This report summarizes the results of the IAEA-CU-2008-02 Mediterranean Region proficiency test on the determination of radionuclides in air filters

  16. The performance and subjective responses of call-center operators with new and used supply air filters at two outdoor air supply rates

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David; Fanger, Povl Ole

    2004-01-01

    A 2X2 replicated field intervention experiment was conducted in a call-center providing a telephone directory service: outdoor air supply rate was adjusted to be 8% of the total airflow of 430 l/s (3.5/h)and the supply air filters were either new or had been in place for 6 months. One of these...

  17. Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

    International Nuclear Information System (INIS)

    This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ15PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM10 (Particulate Matter up to 10 μm in size) bounded Σ15PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ15PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: → Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. → PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. → The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. → Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

  18. Portable Filtered Air Suction System for Released Radioactive Gases Prevention under a Severe Accident of NPPs

    International Nuclear Information System (INIS)

    In this paper, the portable filtered air suction system (PoFASS) for released radioactive gases prevention under a severe accident of NPP is proposed. This technology can prevent the release of the radioactive gases to the atmosphere and it can be more economical than FVCS because PoFASS can cover many NPPs with its high mobility. The conceptual design of PoFASS, which has the highest cost effectiveness and robustness to the environment condition such as wind velocity and precipitation, is suggested and the related previous research is introduced in this paper. The portable filtered air suction system (PoFASS) for released radioactive gases prevention can play a key role to mitigate the severe accident of NPP with its high cost effectiveness and robustness to the environment conditions. As further works, the detail design of PoFASS to fabricate a prototype for a demonstration will be proceeded. When released radioactive gases from the broken containment building in the severe accident of nuclear power plants (NPPs) such as the Chernobyl and Fukushima accidents occur, there are no ways to prevent the released radioactive gases spreading in the air. In order to solve this problem, several European NPPs have adopted the filtered vented containment system (FVCS), which can avoid the containment failure through a pressure relief capability to protect the containment building against overpressure. However, the installation cost of FVCS for a NPP is more than $10 million and this system has not been widely welcomed by NPP operating companies due to its high cost

  19. Portable Filtered Air Suction System for Released Radioactive Gases Prevention under a Severe Accident of NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Beom W.; Choi, Su Y.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, the portable filtered air suction system (PoFASS) for released radioactive gases prevention under a severe accident of NPP is proposed. This technology can prevent the release of the radioactive gases to the atmosphere and it can be more economical than FVCS because PoFASS can cover many NPPs with its high mobility. The conceptual design of PoFASS, which has the highest cost effectiveness and robustness to the environment condition such as wind velocity and precipitation, is suggested and the related previous research is introduced in this paper. The portable filtered air suction system (PoFASS) for released radioactive gases prevention can play a key role to mitigate the severe accident of NPP with its high cost effectiveness and robustness to the environment conditions. As further works, the detail design of PoFASS to fabricate a prototype for a demonstration will be proceeded. When released radioactive gases from the broken containment building in the severe accident of nuclear power plants (NPPs) such as the Chernobyl and Fukushima accidents occur, there are no ways to prevent the released radioactive gases spreading in the air. In order to solve this problem, several European NPPs have adopted the filtered vented containment system (FVCS), which can avoid the containment failure through a pressure relief capability to protect the containment building against overpressure. However, the installation cost of FVCS for a NPP is more than $10 million and this system has not been widely welcomed by NPP operating companies due to its high cost.

  20. Thyroxine and thyrotropin radioimmunoassays using dried blood samples on filter paper for screening of neonatal hypothyroidism

    International Nuclear Information System (INIS)

    A routine and automatized methodology for thyroxine (T4) and thyrotropin (TSH) radioimmunoassay (RIA) using dried blood samples on filter paper is described. Five mm diameter dots were prepared. One eluted dot, corresponding to 4 μl of plasma, was used for T4-RIA while two were necessary for TSH-RIA. Reference filter papers were introduced in each assay for quality control. In a preliminary study on 1903 newborns, samples were obtained, generally between the 5th-7th day. Mean dot T4 was 7.38 +- 2.5 μg/dl. Mean dot TSH was 11.83 +- 9.1 μU/ml, the equation of the regression line between dot TSH (y) and serum TSH (x) being Y = 10.29 + 0.623x. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  3. Life cycle cost reduction through high efficiency membrane based air intake filters; Reduzierung der Lebensdauerzykluskosten durch hocheffiziente Zuluftfilter auf Membranbasis

    Energy Technology Data Exchange (ETDEWEB)

    Krah, Helmut [W.L. Gore and Associates GmbH, Putzbrunn (Germany)

    2011-07-01

    The use of highly efficient, membrane-based air intake filters means that massive savings can be made in the operation of gas turbines: on the one hand, a higher degree of efficiency can be achieved, which leads to lower fuel consumption and better turbine performance, and on the other, maintenance costs can be reduced thanks to the avoidance of erosion and corrosion. EPA (Efficient Particulate Air) filters based on fibreglass have the disadvantage that they exhibit a relatively high differential pressure, and they can frequently only be used by converting the filter house. This is where the tremendous advantage of membrane-based EPA filters comes in. Its core, a micro-porous PTFE membrane with excellent air permeability. (orig.)

  4. A fast responding continuous tritium-in-air monitor with multi stream sampling for area monitoring

    International Nuclear Information System (INIS)

    A fast responding Tritium-in-Air monitor with multi stream sampling up to a maximum of 8 lines has been developed and field tested for continuous area monitoring in Pressurised Heavy Water Reactors (PHWR) and other tritium handling facilities. The instrument has built in electronic compensation for external gamma and gaseous radionuclide 133Xe (FPNG). The monitor is based on plastic scintillator detector prepared from 5μm thick scintillator film of surface area (each side) of about 250 cm2. Four such films of each weighing 150 mg are packed in a flow cell of 6.3 cm3 volume, made of stainless steel body and Teflon window. The flow cell is coupled face to face to a matched pair of photomultipliers. Measurement is made in coincidence mode of counting. The complete monitor consists of electronic counting system, the detector probe assembly, a diaphragm type of air sampling pump, a particulate filter trap and a rotometer for controlling the air flow rate. For multi stream sampling an external solenoid driver cum isolation unit has been integrated with the system. The efficiency for Tritium vapour for direct passage of sample air through the detector is ∼22%. The instrument records 0.2 cps under normal gamma background of 0.1 - 0.2 μSv/hr, without shielding. With the detector fully shielded (∼ 10 cm thick lead), the instrument does not register significant increase in the background counts with 200 μSv/hr ambient gamma field. Under conditions of gaseous radionuclide interference such as 133Xe (26 MBq/m3 concentrations) the MDA rises to ∼1 DAC for a counting time of 300 s. The MDA under ideal conditions is found to be 0.2 DAC for Tritium vapour. The sensitivity of the system is 0.4 CPS per DAC. The instrument response time is 10 minutes. (author)

  5. Investigation of Gas Turbine Intake Air Cooling Via Evaporative Media and Its Effects on Cartridge Filters Pressures Drop

    Directory of Open Access Journals (Sweden)

    Ehsan Farvaresh

    2015-10-01

    Full Text Available  The Aim of this study was to evaluate the effect of Evaporative Media as gas turbine intake air cooling method on pressure drop of cartridge air filters. This study performed under the laboratory condition, using stainless steel test rig with specified dimensions to investigate the role of evaporative media in air cooling as well as its effects on new and used cartridge filters (as representative of clean and loaded filters. Tests were carried out at three five hours consecutive stages including, warm -dry stage (Ta=35-40°C and relative humidity ([RH] =10-15%, cold - humid stage (Ta=22-27°C and RH=80 to 85%, and, warm-dry stage (Ta=35-40 °C and RH=10-15% for 3 consecutive days. Findings showed that using evaporative media caused air intake temperature reduction was equal to 12.5 °C. Total pressure drop of cartridge filters was 5.13±0.84 and 3.86±0.14 mbar for used and new filters, respectively. Results of repeated measure test showed that the differences between new and used filters pressure drop was significant (P=0.001. Combined effects of humidity and dust loading on filters pressure drop demonstrated that cartridge filters were not affected by humidity (P=0.75 and the main reason of pressure drop was due to collected dust on filters. It is concluded that using evaporative media systems is suitable method for cooling gas turbine intake and increase turbine efficiency without any significant increase of filter pressure drop in hot-dry climate.  

  6. Radioiodine deposition losses from sample air containing particulate and gaseous iodine in nuclear reactor sample lines

    International Nuclear Information System (INIS)

    Mechanisms of radioiodine deposition from sample air containing both gaseous and particulate radioiodine in reactor sample lines are studied, and experimental methods are developed. A short half-lived radioiodine tracer, 128I (t1/2 = 25 min), is used in the chemical forms of molecular iodine and methyl iodide. An effort is made to investigate the type of particles for particulate iodine. Of the various types of particles tested, only tobacco smoke particles have a sufficiently high iodination rate to be used in these studies. The 609.6-cm (20-ft)-long sample lines of Types 316 and 304 stainless steel tube (2.29 cm i.d.) were tested for the sample flow rates of 28.3 ell/min (1 ft3/min) and 56.6 ell/min (2 ft3/min). In-tube measurements using a calibrated thin-walled Geiger tube are conducted to determine the penetration factor and space-dependent deposition velocity profile of radioiodine. Methyl iodide is not reactive for either the tube surfaces or aerosol particles. The overall deposition velocity of the mixture of the smoke particles and molecular iodine is higher than that of molecular iodine alone for similar sampling conditions. It is concluded that the high deposition rate of radioiodine in the sample air mixed with smoke particles and molecular iodine is caused by the different sample line surfaces that are contaminated with smoke particles

  7. Shot noise reduced terahertz detection via spectrally post-filtered electro-optic sampling

    CERN Document Server

    Porer, Michael; Huber, Rupert

    2016-01-01

    In ultrabroadband terahertz electro-optic sampling, spectral filtering of the gate pulse can strongly reduce the quantum noise while the signal level is only weakly affected. The concept is tested for phase-matched electro-optic detection of field transients centered at 45 THz with 12-fs near-infrared gate pulses in AgGaS2. Our new approach increases the experimental signal-to-noise ratio by a factor of 3 compared to standard electro-optic sampling. Under certain conditions an improvement factor larger than 5 is predicted by our theoretical analysis.

  8. Phase I aging assessment of nuclear air-treatment system HEPA filters and adsorbers

    International Nuclear Information System (INIS)

    A Phase I aging assessment of high-efficiency particulate air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the U.S. Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. Information was compiled concerning design features; failure experience; aging mechanisms, effects, and stressors; and monitoring methods. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a U.S. Department of Energy survey. Investigators from other laboratories have suggested that aging could have contributed to over 80 percent of these failures. Several instances of impaired performance as the result of the premature aging of carbon were reported. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of gaskets. Mechanisms that can lead to impaired adsorber performance include the loss of potentially available active sites as a result of the adsorption of moisture or pollutants. Stressors include heat, moisture, radiation and airborne particles and contaminants

  9. Adaptive Kalman Filter Based on Adjustable Sampling Interval in Burst Detection for Water Distribution System

    Directory of Open Access Journals (Sweden)

    Doo Yong Choi

    2016-04-01

    Full Text Available Rapid detection of bursts and leaks in water distribution systems (WDSs can reduce the social and economic costs incurred through direct loss of water into the ground, additional energy demand for water supply, and service interruptions. Many real-time burst detection models have been developed in accordance with the use of supervisory control and data acquisition (SCADA systems and the establishment of district meter areas (DMAs. Nonetheless, no consideration has been given to how frequently a flow meter measures and transmits data for predicting breaks and leaks in pipes. This paper analyzes the effect of sampling interval when an adaptive Kalman filter is used for detecting bursts in a WDS. A new sampling algorithm is presented that adjusts the sampling interval depending on the normalized residuals of flow after filtering. The proposed algorithm is applied to a virtual sinusoidal flow curve and real DMA flow data obtained from Jeongeup city in South Korea. The simulation results prove that the self-adjusting algorithm for determining the sampling interval is efficient and maintains reasonable accuracy in burst detection. The proposed sampling method has a significant potential for water utilities to build and operate real-time DMA monitoring systems combined with smart customer metering systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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

  11. Effect of an Air Cleaner with Electrostatic Filter on the Removal of Airborne House Dust Mite Allergens

    OpenAIRE

    Agrawal, Santosh Rani; Kim, Hak-Joon; Lee, Yong Won; Sohn, Jung-Ho; Lee, Jae Hyun; Kim, Yong-Jin; Lee, Sung-Hwa; Hong, Chein-Soo; Park, Jung-Won

    2010-01-01

    Purpose The effects of air cleaners on the removal of airborne indoor allergens, especially house dust mites (HDM), are still controversial. The objective of this study is to evaluate the effect of an air cleaner with an electrostatic filter on the removal of airborne mite allergens. Materials and Methods A dried HDM culture medium that contained mite body particles and excretions was dispersed in a chamber equipped with an electrostatic air cleaner. The number of airborne particles was recor...

  12. Experimental data required for the design and analysis of emergency filtered air discharge sytems

    International Nuclear Information System (INIS)

    The radiological consequences of an accident in a CANDU nuclear generating station are mitigated by special safety systems which include an Emergency Filtered Air Discharge (EFAD) system. EFAD systems are designed to provide a controlled leakage path following an accident. They remove radioiodine and particulates from the air discharge required, to inhibit uncontrolled emissions by maintaining containment sub-atmospheric in the long term. The design and analysis of an EFAD system requires an accurate data base comprised of the numerous parameters involved in the simulation of fission product behaviour within containment. This paper emphasizes the data requirements of EFAD system design with regard to those parameters which preliminary sensitivity analyses have shown to most effect environmental releases. These include the source term radioisotopes; their chemical behaviour and distribution within containment; the repressurization time during the vacuum hold-up period; and parameters effecting the long term releases through the EFAD system. The net radioiodine trapping efficiency of charcoal filters in the long term is dependent on the adsorption efficiency and desorption of the deep charcoal bed. These are a function of many parameters such as impregnate, aging, humidity, temperature, radiation, recirculation, etc. Although the effect of these parameters on charcoal filters has been individually investigated, generally at ideal or extreme values, there is little applicable data to determine their combined effect under expected post accident operating conditions. As a consequence, designers tend to overdesign by using unduly conservative parameters. A summary comparison is presented to illustrate the information gap between the experimental data from the literature and the data required for optimal design and analysis of the EFAD systems

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

    Energy Technology Data Exchange (ETDEWEB)

    Wright, S.R.; Crouch, H.S.; Bond, J.H. [Micro Composite Materials Corp., Durham, NC (United States)

    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.

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

    International Nuclear Information System (INIS)

    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+ μm 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 μm 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

  15. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Rennan G.O., E-mail: rgoa01@terra.com.br [Laboratorio de Quimica Analitica Ambiental, Departamento de Quimica, Universidade Federal de Sergipe, Campus Sao Cristovao, 49.100-000, Sao Cristovao, SE (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Vignola, Fabiola; Castilho, Ivan N.B. [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borges, Daniel L.G.; Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti R. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Smichowski, Patricia [Comision Nacional de Energia Atomica (CNEA) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, 40170-290, Salvador, BA (Brazil); Becker-Ross, Helmut [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Department Berlin, 12489 Berlin (Germany)

    2011-05-15

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3{sigma}), based on ten atomizations of an unexposed filter, was 40 ng g{sup -1}, corresponding to 0.12 ng m{sup -3} in the air for a typical air volume of 1440 m{sup 3} collected within 24 h. The limit of quantification was 150 ng g{sup -1}, equivalent to 0.41 ng m{sup -3} in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between < 40 ng g{sup -1} and 381 {+-} 24 ng g{sup -1}. These values correspond to a mercury concentration in the air between < 0.12 ng m{sup -3} and 1.47 {+-} 0.09 ng m{sup -3}. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

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

    Science.gov (United States)

    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

  17. Effectiveness of photocatalytic filter for removing volatile organic compounds in the heating, ventilation, and air conditioning system.

    Science.gov (United States)

    Yu, Kuo-Pin; Lee, Grace Whei-May; Huang, Wei-Ming; Wu, Chih-Cheng; Lou, Chia-ling; Yang, Shinhao

    2006-05-01

    Nowadays, the heating, ventilation, and air conditioning (HVAC) system has been an important facility for maintaining indoor air quality. However, the primary function of typical HVAC systems is to control the temperature and humidity of the supply air. Most indoor air pollutants, such as volatile organic compounds (VOCs), cannot be removed by typical HVAC systems. Thus, some air handling units for removing VOCs should be added in typical HVAC systems. Among all of the air cleaning techniques used to remove indoor VOCs, photocatalytic oxidation is an attractive alternative technique for indoor air purification and deodorization. The objective of this research is to investigate the VOC removal efficiency of the photocatalytic filter in a HVAC system. Toluene and formaldehyde were chosen as the target pollutants. The experiments were conducted in a stainless steel chamber equipped with a simplified HVAC system. A mechanical filter coated with Degussa P25 titania photocatalyst and two commercial photocatalytic filters were used as the photocatalytic filters in this simplified HVAC system. The total air change rates were controlled at 0.5, 0.75, 1, 1.25, and 1.5 hr(-1), and the relative humidity (RH) was controlled at 30%, 50%, and 70%. The ultraviolet lamp used was a 4-W, ultraviolet-C (central wavelength at 254 nm) strip light bulb. The first-order decay constant of toluene and formaldehyde found in this study ranged from 0.381 to 1.01 hr(-1) under different total air change rates, from 0.34 to 0.433 hr(-1) under different RH, and from 0.381 to 0.433 hr(-1) for different photocatalytic filters. PMID:16739804

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

    Energy Technology Data Exchange (ETDEWEB)

    Dewalle, Pascale; Sirven, Jean-Baptiste [CEA Saclay, DEN, Department of Physical Chemistry, F-91191 Gif-sur-Yvette (France); Roynette, Audrey; Gensdarmes, Francois [IRSN, DSU, Aerosol Physics and Metrology Laboratory, F-91192 Gif-sur-Yvette (France); Golanski, Luana; Motellier, Sylvie, E-mail: jean-baptiste.sirven@cea.fr [CEA Grenoble, DRT, LITEN, Laboratory of Nanomaterial Chemistry and Security, F-38054 Grenoble (France)

    2011-07-06

    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 Fe{sub 2}O{sub 3} and TiO{sub 2} 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 cm{sup 2} filter during 1 min, we obtained detection limits of 56 {mu}g/m{sup 3} for Fe and 22 {mu}g/m{sup 3} 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.

  19. Improvement of self-cleaning type air filter%自洁式空气过滤器的改进

    Institute of Scientific and Technical Information of China (English)

    王鹏

    2012-01-01

    The self-cleaning type air filter is fitted before air inlet pipe of air compressor completed for air separation plant. The domestic-made carriage has low service life, and in case of highly wet air the filter paper is liable to stick, which lowers the filtering efficiency, results in frequent repair of air compressor repair, and seriously impairs prolonged stable run of air separation plant. The service life of carriage of self-cleaning type air filter is extended and the filtering efficiency is improved through use of the non-woven filtering cotton blended with compound fiber, the carriage made of compound fiber, and the imported filter paper, adjustment of its programmable controller, and change of its back-blowing pressure and air supply. Here, the work principle of self- cleaning type air filter is briefed, the problems during its operation process are analyzed, and the implementation process and economic benefits of the improvement measures are described.%空分设备配套空压机进气管前设置自洁式空气过滤器,由于国内生产的滤筒使用寿命短,遇含湿量大的空气时滤纸易黏连,进而影响过滤效率,导致空压机检修频繁,严重影响了空分设备长周期稳定运行。通过增加复合纤维无纺滤棉,选用复合纤维滤筒和进口滤纸,调整自洁式空气过滤器的编程控制仪,以及改变反吹压力和反吹气源,达到延长自洁式空气过滤器的滤筒寿命和提高过滤效率的目的。简述自洁式空气过滤器的工作原理,分析其使用过程中存在的问题,阐述改进措施的实施过程及取得的经济效益。

  20. The performance and subjective responses of call-center operators with new and used supply air filters at two outdoor air supply rates

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David; Fanger, Povl Ole

    2004-01-01

    . Their performance was continuously monitored by recording the average talk-time every 30 min. Replacing a used filter with a clean filter reduced talk-time by about 10% at the high ventilation rate but had no significant effect at the low rate. Increasing the outdoor air supply rate reduced talk-time by......A 2X2 replicated field intervention experiment was conducted in a call-center providing a telephone directory service: outdoor air supply rate was adjusted to be 8% of the total airflow of 430 l/s (3.5/h)and the supply air filters were either new or had been in place for 6 months. One of these...... effects on health, comfort and performance....

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

    Science.gov (United States)

    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)...

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

    Science.gov (United States)

    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.

  3. Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

    CERN Document Server

    Rhinow, Daniel; Weber, Nils-Eike; Beyer, André; Gölzhäuser, Armin; Kühlbrandt, Werner; Hampp, Norbert; Turchanin, Andrey; 10.1016/j.ultramic.2011.01.028

    2011-01-01

    Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ~ 1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, sus...

  4. Relation between γ-ray detection efficiency and the source size of prepared aerosol filter sample

    International Nuclear Information System (INIS)

    By adding revolution of know activity, six disk sources with different diameters are prepared with the filter of 22.5 cm x 45 cm. Several HPGe detectors with different crystal dimensions are employed to detect the nuclides in the disk sources and the relative detection efficiencies are calculated from the experiments. The result indicates that the source with the highest efficiency has the diameter between 50 mm and 60 mm within the energy range from 60 keV to 1116 keV. It is also found that the diameter of optimum source increases slightly with the crystal diameter of detector. Besides, a relatively thicker source disk with smaller diameter is preferred for lower energy rays, compared with higher energy rays. But this tendency is not as obvious for planar HPGe detector as that for coaxial HPGe detector. For above samples, Monte Carlo Simulations for the measurement of one detector are carried out and the result accords with the experiments. Also, by Monte Carlo Simulating for other different area filters, it is known that the diameter of source with optimum efficiencies increases with the area of filter

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

    Science.gov (United States)

    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

  6. Measurements of Fission Products from the Fukushima Daiichi Incident in San Francisco Bay Area Air Filters, Automobile Filters, Rainwater, and Food

    CERN Document Server

    Smith, A R; Norman, E B; Hurley, D L; Lo, B T; Chan, Y D; Guillaumon, P V; Harvey, B G

    2013-01-01

    A variety of environmental media were analyzed for fallout radionuclides resulting from the Fukushima nuclear accident by the Low Background Facility (LBF) at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA. Monitoring activities in air and rainwater began soon after the onset of the March 11, 2011 tsunami and are reported here through the end of 2012. Observed fallout isotopes include $^{131}$I, $^{132}$I,$^{132}$Te,$^{134}$Cs, $^{136}$Cs, and $^{137}$Cs. Isotopes were measured on environmental air filters, automobile filters, and in rainwater. An additional analysis of rainwater in search of $^{90}$Sr is also presented. Last, a series of food measurements conducted in September of 2013 are included due to extended media concerns of $^{134, 137}$Cs in fish. Similar measurements of fallout from the Chernobyl disaster at LBNL, previously unpublished publicly, are also presented here as a comparison with the Fukushima incident. All measurements presented also include natural radionuclides found...

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

    Science.gov (United States)

    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...

  8. The proton induced X-ray emission (PIXE) for the quantitative analysis of elements in thin samples, in surface layers of thick samples, and in aerosol filters

    International Nuclear Information System (INIS)

    The PIXE analysis method for the determination of elements in thick samples was investigated. The text of the present thesis is arranged under the following headings: physical fundamentals and measuring equipment, quantitative analysis of thin samples, matrix effects at the PIXE analysis of thick samples, matrix correction methods, analysis of 'infinite thick' model substances, PIXE analysis of aerosol filters. (GSCH)

  9. Dispersion modeling of selected PAHs in urban air: A new approach combining dispersion model with GIS and passive air sampling

    Czech Academy of Sciences Publication Activity Database

    Sáňka, O.; Melymuk, L.; Čupr, P.; Dvorská, Alice; Klánová, J.

    2014-01-01

    Roč. 90, oct (2014), s. 88-95. ISSN 1352-2310 Institutional support: RVO:67179843 Keywords : passive air sampling * air dispersion modeling * GIS * polycyclic aromatic hydrocarbons * emission inventories Subject RIV: DI - Air Pollution ; Quality Impact factor: 3.281, year: 2014

  10. Low-cost monitoring of campylobacter in poultry houses by air sampling and quantitative PCR

    DEFF Research Database (Denmark)

    Søndergaard, Mette Sofie Rousing; Josefsen, Mathilde Hasseldam; Löfström, Charlotta;

    2014-01-01

    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......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...

  11. Screening for neonatal hypothyroidism by thyroxine and thyrotrophin radioimmunoassays using dried blood samples on filter paper

    International Nuclear Information System (INIS)

    A routine and automated methodology for thyroxine (T4) and thyrotrophin (TSH) radioimmunoassay (RIA) using dried blood samples on filter paper is described. T4-RIA was performed on one single dot (5 mm diameter equivalent to 4 μl of serum) while two dots were necessary for TSH-RIA. Reference filter papers were introduced in each assay for quality control. In a preliminary study on 4,155 neonates, samples generally obtained between the 5th-7th day gave a mean 'dot-T4' of 97.95 +- 36.04 nmol/l and a mean 'dot-TSH' of 10.19 mU/l +- 8.25, corresponding to 2.47 mU/l of serum. Within an 18-month period (November 1976 - April 1978), a total of 16,522 neonates have been screened allowing detection of three cases of congenital hypothyroidism (incidence 1:5507), two cases of congenitally low TBG and thirty-three cases of transient hypothyroidism. (author)

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

    Science.gov (United States)

    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.

  13. Influence by small dispersive coal dust particles of different fractional consistence on characteristics of iodine air filter at nuclear power plant

    CERN Document Server

    Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

    2013-01-01

    The main purpose of research is to determine the influence by the small dispersive coal dust particles of the different fractional consistence on the technical characteristics of the vertical iodine air filter at nuclear power plant. The research on the transport properties of the small dispersive coal dust particles in the granular filtering medium of absorber in the vertical iodine air filter is completed in the case, when the modeled aerodynamic conditions are similar to the real aerodynamic conditions. It is shown that the appearance of the different fractional consistence of small dispersive coal dust particles with the decreasing dimensions down to the micro and nano sizes at the action of the air dust aerosol stream normally results in a significant change of distribution of the small dispersive coal dust particles masses in the granular filtering medium of an absorber in the vertical iodine air filter, changing the vertical iodine air filter aerodynamic characteristics. The precise characterization of...

  14. THE EFFECT OF THE REYNOLDS NUMBER OF AIR FLOW TO THE PARTICLE COLLECTION EFFICIENCY OF A FIBROUS FILTER MEDIUM WITH CYLINDRICAL SECTION

    Directory of Open Access Journals (Sweden)

    George P. Kouropoulos

    2014-01-01

    Full Text Available At this study an attempt for the theoretical approach of the Re ynolds number effect of air flow to the particle collection efficiency of a fibrous fil ter with cylindrical section will be made. Initially, a report of the air filtration models to fibrous filter media will be presented along with an explanation of both the parameters and the physical quantities which govern the air filtration process. Furthermore, the resul ting equation from the mathematical model will be applied to a real filter medium and the characteristic curves of filter efficiency will be drawn. The change of a filter medi um efficiency with regard to the Reynolds number of air flow that passes through the filt er, derived from the curves, will be studied. The general conclusion that we have is that as the Reynolds number of filtered air increases, the collection efficiency of the filter decreases.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Gorji-Bandpy Mofid

    2012-04-01

    Full Text Available 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.

  17. 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.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Huan Ma

    2016-01-01

    Full Text Available 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

  20. Radiochemical analysis of aerosol filters and precipitation samples by the German Weather Service

    International Nuclear Information System (INIS)

    The German Weather Service routinely analyses air and precipitation samples for the isotopes U-234, U-235, U-238, Am-241, Pu-238, Pu-239/240, Sr-89 and Sr-90. In the presented method, the separation of alpha emitters and strontium isotopes from the same sample is done by a multi-stage extraction chromatography procedure. Alpha-emitting nuclides are electrodeposited and measured by alpha spectrometry, Sr-89 and Sr-90 will be simultaneously determined using a three-window LSC-method. The analysis procedure is used in routine operation, as well, with minor modifications in the intensive operation.

  1. The effects of outdoor air supply rate and supply air filter condition in classrooms on the performance of schoolwork by children (RP-1257)

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David Peter

    2007-01-01

    Two independent field intervention experiments were carried out in mechanically ventilated classrooms receiving 100% outdoor air. Outdoor air supply rate and filter condition were manipulated to modify indoor air quality, and the performance of schoolwork was measured The conditions were establis......Two independent field intervention experiments were carried out in mechanically ventilated classrooms receiving 100% outdoor air. Outdoor air supply rate and filter condition were manipulated to modify indoor air quality, and the performance of schoolwork was measured The conditions were...... scales to indicate their environmental perceptions and the intensity of any symptoms. The children indicated that the air was fresher but otherwise perceived little difference when the outdoor air supply rate increased from 3.0 to 8.5 L/s (6.4-18 cfm) per person, while the speed at which they performed...... classrooms as judged by a sensory panel of adults blind to conditions, as perceived by children, and as indicated by the reduction in the average CO2 concentration from 1300 to 900 ppm, taking this as a marker of reduced bioeffluent concentration. It was not possible to test the effect of replacing a soiled...

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

    Science.gov (United States)

    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

  3. Report on the quality control study NAT-7 for the determination of trace and minor elements in dust artificially loaded on air filters

    International Nuclear Information System (INIS)

    A quality control study was organized on two air filters artificially loaded with urban dust. One dust material was collected from the air intake ducts of the Vienna General Hospital, the second material was collected from the main ventilation shaft of a road tunnel in Prague. 49 laboratories from 40 countries participated in the study, providing 53 sets of results. The following analytical methods were used: neutron activation analysis (NAA), inductive coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), particle induced X-ray emission spectrometry (PDCE), atomic absorption spectrometry (AAS), and X-ray fluorescence spectrometry (XRF). The results were evaluated following the standard LEA procedures for (1) an interlaboratory comparison exercise and (2) a proficiency test using established target values. For the air filter sample V, 754 laboratory mean values for 38 elements were reported. More than 4 mean values were obtained for 26 measurands and these were statistically evaluated. Only 10 % 71 values) of the results were detected as outliers by the statistical data evaluation. The results and statistical parameters are listed in the appendices I and II. The results were also evaluated as a proficiency test using established target values. Precision and accuracy criteria were applied to 15 elements. 534 laboratory mean values were reported for those elements, 114 values (20%) did not pass the set proficiency test criteria. The individual laboratory results are listed in appendix IV. For the air filter sample P, 694 laboratory mean values for 38 elements were reported. More than 4 mean values were obtained for 26 measurands and these were statistically evaluated. Only 9% (60 values) of the results were detected as outliers by the statistical data evaluation. The results and statistical parameters are listed in the appendices I and II. The results were also evaluated as a proficiency test using target values

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

    Science.gov (United States)

    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

  5. Identification of sources of heavy metals in the Dutch atmosphere using air filter and lichen analysis

    International Nuclear Information System (INIS)

    Aerosol samples collected in an industrialized region were analyzed by instrumental neutron activation analysis. Correlation with wind direction and factor analysis were applied to the concentration data to obtain information on the nature and position of the sources. Epiphytic lichens were sampled over the country and analyzed for heavy metals (As, Cd, Sc, Zn, Sb). The data were interpreted by geographically plotting element concentrations and enrichment factors, and by factor analysis. Some pitfalls are discussed which are associated with the use of aerosol and lichen data in studies of heavy metal air pollution. 14 references, 8 figures, 3 tables

  6. Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

    International Nuclear Information System (INIS)

    Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ∼1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, suspended over the holes of a conventional holey carbon film, while backed by ultrathin cCNM. -- Research highlights: → We examine ultrathin carbon nanomembranes (CNM) as supports for biological TEM. → CNM comprise crosslinked biphenyl precursors. → CNM supports enable background-free elemental mapping of heavy and light elements. → We perform cryoEM of ice-embedded biological samples on graphene-like conductive CNM.

  7. Towards "Intelligent Compression" in Streams: A Biased Reservoir Sampling based Bloom Filter Approach

    CERN Document Server

    Dutta, Sourav; Narang, Ankur

    2011-01-01

    With the explosion of information stored world-wide,data intensive computing has become a central area of research.Efficient management and processing of this massively exponential amount of data from diverse sources,such as telecommunication call data records,online transaction records,etc.,has become a necessity.Removing redundancy from such huge(multi-billion records) datasets resulting in resource and compute efficiency for downstream processing constitutes an important area of study. "Intelligent compression" or deduplication in streaming scenarios,for precise identification and elimination of duplicates from the unbounded datastream is a greater challenge given the realtime nature of data arrival.Stable Bloom Filters(SBF) address this problem to a certain extent.However,SBF suffers from a high false negative rate(FNR) and slow convergence rate,thereby rendering it inefficient for applications with low FNR tolerance.In this paper, we present a novel Reservoir Sampling based Bloom Filter,(RSBF) data struc...

  8. Automated Sampling and Extraction of Krypton from Small Air Samples for Kr-85 Measurement Using Atom Trap Trace Analysis

    International Nuclear Information System (INIS)

    Atom-Trap-Trace-Analysis (ATTA) provides the capability of measuring the Krypton-85 concentration in microlitre amounts of krypton extracted from air samples of about 1 litre. This sample size is sufficiently small to allow for a range of applications, including on-site spot sampling and continuous sampling over periods of several hours. All samples can be easily handled and transported to an off-site laboratory for ATTA measurement, or stored and analyzed on demand. Bayesian sampling methodologies can be applied by blending samples for bulk measurement and performing in-depth analysis as required. Prerequisite for measurement is the extraction of a pure krypton fraction from the sample. This paper introduces an extraction unit able to isolate the krypton in small ambient air samples with high speed, high efficiency and in a fully automated manner using a combination of cryogenic distillation and gas chromatography. Air samples are collected using an automated smart sampler developed in-house to achieve a constant sampling rate over adjustable time periods ranging from 5 minutes to 3 hours per sample. The smart sampler can be deployed in the field and operate on battery for one week to take up to 60 air samples. This high flexibility of sampling and the fast, robust sample preparation are a valuable tool for research and the application of Kr-85 measurements to novel Safeguards procedures. (author)

  9. HEPAFIL - a program for the calculation of the fluid dynamics of high efficiency particulate air filter units

    International Nuclear Information System (INIS)

    With HEPAFIL, LAF II provides a FORTRAN program for the calculation of various parameters associated with the fluid dynamics of high efficiency particulate air filter units. Most of the currently available commercial deep pleat designs have been taken into consideration, e.g., high strength nuclear grade units employing separators with inclined corrugations, units for clean room applications, as well as low and medium efficiency EU 6 and EU 8 types having very low pressure drops. The flow resistance curves obtained from HEPAFIL could be verified in extensive experimental test. A user-friendly PC version with the integrated program library HEPAGAS can serve as a useful tool to the researcher in filter development as well as to the filter manufacturer for cost reduction analyses. Knowledge of the distributions of airstream, pressures and velocities within the flow channels of the filter pack allows more precise investigations of failure mechanisms and filtration characteristics for a wide range of flow conditions. The newest scientific application involves fundamental investigations into the cleanability of HEPA filter units. HEPAFIL offers filter manufacturers the opportunity to improve and optimize filter performance with respect to pressure drop, burst strength, and material costs, with a minimum of prototype fabrication and testing. (orig.)

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

    Science.gov (United States)

    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

  11. Pemanfaatan Limbah Kulit Kakao Dan Tanah Lempung Sebagai Material Filter Dalam Pengolahan Air Sumur Menjadi Air Bersih

    OpenAIRE

    Sani, Abd

    2016-01-01

    The research has been conducted about utilization of cocoa rind waste and clay as filter material in the processing of deep well into clean water. Research conducted in two step. The first step was manufacture of filter and the second step was application of filter for deep well processing. The cocoa rind waste used as activated carbon mixed with clay in variation of composition activated carbon from cocoa rind : clay 85%:15%, 80%:20%, 75%:25%, 70%:30% and 65%:35%. Futhermore, the filter is b...

  12. Zooplankton filtering rates: error due to loss of radioisotopic label in chemically preserved samples

    International Nuclear Information System (INIS)

    Zooplankton fed 32P-labeled yeast or 14C-labeled algae were preserved with Formalin, ethanol, or Lugol's iodine and the subsequent loss of labeled materials was followed by analysis of sample filtrates. The commonly used combination of 32P-labeled yeast and Formalin preservation produced maximal loss in both magnitude and duration, reaching a value of 73% loss after 3 days; ethanol preservation resulted in only 5% loss for the same food. Lugol's iodine yielded the best results for animals fed 14C-labeled algae, resulting in a 40% loss that stabilized within 3 h. Nonchemical preservation (heat-killing and drying) produced filtering rates comparable with those of the best chemical preservative

  13. XANES speciation of P in environmental samples: an assessment of filter media for on-site wastewater treatment.

    Science.gov (United States)

    Eveborn, David; Gustafsson, Ion Petter; Hesterberg, Dean; Hillier, Stephen

    2009-09-01

    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. PMID:19764210

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

  16. Physical features of accumulation and distribution processes of small disperse coal dust precipitations and absorbed radioactive chemical elements in iodine air filter at nuclear power plant

    CERN Document Server

    Ledenyov, Oleg P; Poltinin, P Ya; Fedorova, L I

    2012-01-01

    The physical features of absorption process of radioactive chemical elements and their isotopes in the iodine air filters of the type of AU-1500 at the nuclear power plants are researched. It is shown that the non-homogenous spatial distribution of absorbed radioactive chemical elements and their isotopes in the iodine air filter, probed by the gamma-activation analysis method, is well correlated with the spatial distribution of small disperse coal dust precipitations in the iodine air filter. This circumstance points out to an important role by the small disperse coal dust fractions of absorber in the absorption process of radioactive chemical elements and their isotopes in the iodine air filter. The physical origins of characteristic interaction between the radioactive chemical elements and the accumulated small disperse coal dust precipitations in an iodine air filter are considered. The analysis of influence by the researched physical processes on the technical characteristics and functionality of iodine ...

  17. Physical features of small disperse coal dust fraction transportation and structurization processes in iodine air filters of absorption type in ventilation systems at nuclear power plants

    CERN Document Server

    Ledenyov, Oleg P; Poltinin, P Ya; Fedorova, L I

    2012-01-01

    The research on the physical features of transportation and structurization processes by the air-dust aerosol in the granular filtering medium with the cylindrical coal adsorbent granules in an air filter of the adsorption type in the heating ventilation and cooling (HVAC) system at the nuclear power plant is completed. The physical origins of the coal dust masses distribution along the absorber with the granular filtering medium with the cylindrical coal granules during the air-dust aerosol intake process in the near the surface layer of absorber are researched. The quantitative technical characteristics of air filtering elements, which have to be considered during the optimization of air filters designs for the application in the ventilation systems at the nuclear power plants, are obtained.

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

    Science.gov (United States)

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

    OpenAIRE

    Eveborn, David; Gustafsson, Jon Petter; Hesterberg, Dean; Hillier, Stephen

    2009-01-01

    X-ray absorption near edge structure (XANES) spectroscopyis a useful technique for characterization of chemical speciesof phosphorus in complex environmental samples. To developand 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 selectionof promising filter materials: Filtralite P, Filtra P, Polonite, Absol, blast furnace slag, and wollastonite. Full-scale operational was...

  20. Innovative HEPA [high-efficiency particulate air] filter designs to reduce waste generation and simplify waste treatment

    International Nuclear Information System (INIS)

    The treatment and disposal of spent high-efficiency particulate air (HEPA) filters has presented a problem at some defense production plants and could be a problem at potential future spent-fuel consolidation or fuel reprocessing facilities. During studies of transuranic (TRU) waste treatment options conducted by Pacific Northwest Laboratory, it was concluded that treatment of spent HEPA filters would become easier and less costly if some modifications were made to the present materials of construction and design. This study was undertaken to develop and evaluate alternative materials and innovative designs for HEPA filters, making them more compatible with volume reduction technology. The following treatment options were selected for this study: (1) no treatment; (2) compaction; (3) supercompaction; (4) incinerate and melt; and (5) separate the frame from the media and dispose of the frame as low-level waste, and incinerate and melt the filter media and sealant. Forty HEPA design concepts were identified and evaluated by means of a figure-of-merit methodology for technical performance and an economic evaluation that considered filter fabrication and disposal costs. Results of the study indicate that if improved HEPA designs are combined with volume reduction treatments, the costs of filter disposal can be reduced substantially over the use of standard-flow filter designs with no volume reduction treatment. It is estimated that by combining the new design concepts with waste volume reduction treatments, manufacturing and disposal costs can be reduced by $290 or more per filter if classified as low-level waste (LLW) and up to $23,000 per filter if it is high-activity waste (containing activity greater than class-C LLW) and requires repository disposal

  1. Radioactive Air Emissions Notice of Construction for 105-KW filter vessel sparging vent

    International Nuclear Information System (INIS)

    This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.07, for the Integrated Water Treatment System (IWTS) Filter Vessel Sparging Vent at 105-KW Basin. Additionally, the following description, and references are provided as the notices of startup, pursuant to 40 CFR 61.09(a)(1) and (2) in accordance with Title 40 Code of Federal Regulations, Part 61, National Emission Standards for Hazardous Air Pollutants. The 105-K West Reactor and its associated spent nuclear fuel (SNF) storage basin were constructed in the early 1950s and are located on the Hanford Site in the 100-K Area about 1,400 feet from the Columbia River. The 105-KW Basin contains 964 Metric Tons of SNF stored under water in approximately 3,800 closed canisters. This SNF has been stored for varying periods of time ranging from 8 to 17 years. The 105-KW Basin is constructed of concrete with an epoxy coating and contains approximately 1.3 million gallons of water with an asphaltic membrane beneath the pool. The IWTS, which has been described in the Radioactive Air Emissions NOC for Fuel Removal for 105-KW Basin (DOE/RL-97-28 and page changes per US Department of Energy, Richland Operations Office letter 97-EAP-814) will be used to remove radionuclides from the basin water during fuel removal operations. The purpose of the modification described herein is to provide operational flexibility for the IWTS at the 105-KW basin. The proposed modification is scheduled to begin in calendar year 1998

  2. Radioactivity in the furnace air-cleaning filter from a house with an unusually high level of airborne radon

    International Nuclear Information System (INIS)

    The amounts of the three short-lived daughters of radon on the furnace air-cleaning filter from a house with a high level of radon were estimated to be 8.2, 33, and 38 kBq (0.22, 0.89, and 1.03 μCi) for 218Po, 214Pb, and 214Bi, respectively, at the time of removal from the furnace. These data were used to calculate the airborne concentrations of the three, and the results indicated that about 70% of the daughters were lost to surfaces in the house and by impaction in the air ducts. The filter's content of 210Pb was found to be 4.4 kBg (0.12 μCi); from this the average concentration of radon-producing filterable daughters during the time the furnace blower operated, was estimated to be 860 Bq m-3. This indicated that there was no significant loss to surfaces or in air ducts. Possible reasons for the difference are given. The filter was also found to contain 1 kBq (27 nCi) of 212Bi from the thorium series

  3. Studies on sand-bed air filters for the treatment of fuel reprocessing dissolver off-gases

    International Nuclear Information System (INIS)

    Off-gases being released from the dissolver in fuel reprocessing plants contain not only high specific activity but also a large amount of water in the form of vapour and entrained droplets. In addition, considerable amounts of corrosive fumes of nitric acid and nitrogen oxides are also present. For the treatment of this gas stream a train of equipment consisting of an alkali gas-washer, a de-entrainer, a demister, a chiller, a heater and a deep-bed filter is being used in most of the fuel reprocessing plants. The final filter is generally a deep-bed glass-fibre filter (DBGF). Experience has shown that this type of system suffers owing to the inherent difficulties in operational control of this multiple equipment under surging operational conditions. DBGF filters have invariably not performed according to design expectations. This is due to fibre coalescence and sagging when the efficiency of the filter decreases and the pressure drop increases. In addition, they also require frequent replacement, resulting in high costs and large radiation exposures. Our search for more dependable equipment for the treatment of dissolver off-gases indicated that properly designed sand-bed air filters (SBAFs) may be better suited for this purpose. Further investigations on the characteristics of a sand bed as a gas washer for absorption of nitrogen oxides, as a device for the de-entrainment of water droplets, and as an efficient particulate air filter have proved that it fulfils all the basic requirements of cleaning dissolver off-gases in fuel reprocessing plants. This paper covers the results of laboratory- and pilot-plant studies carried out on the suitability of an SBAF for the above purpose. (author)

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

    Science.gov (United States)

    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

  5. Sampling and analysis plan for ORNL filter press cake waste from the Liquid and Gaseous Waste Operations Department

    International Nuclear Information System (INIS)

    This document defines the sampling and analytical procedures needed for the initial characterization of the filter press cake waste from the Process Waste Treatment Plant (PWTP) at the Oak Ridge National Laboratory (ORNL). It is anticipated that revisions to this document will occur as operating experience and sample results suggest appropriate changes be made. Application of this document will be controlled through the ORNL Waste Management and Remedial Action Division. The sampling strategy is designed to ensure that the samples collected present an accurate representation of the waste process stream. Using process knowledge and preliminary radiological activity screens, the filter press cake waste is known to contain radionuclides. Chemical characterization under the premise of this sampling and analysis plan will provide information regarding possible treatments and ultimately, disposal of filter press cake waste at an offsite location. The sampling strategy and analyses requested are based on the K-25 waste acceptance criteria and the Nevada Test Site Defense Waste Acceptance Criteria, Certification, and Transfer Requirements [2, NVO-325, Rev. 1]. The sampling strategy will demonstrate that for the filter press cake waste there is (1) an absence of RCRA and PCBs wastes, (2) an absence of transuranic (TRU) wastes, and (3) a quantifiable amount of radionuclide activity

  6. HPLC-UV-FL PAH analysis in air particulates. Application to La Coruna (Spain) air samples

    Energy Technology Data Exchange (ETDEWEB)

    Pineiro Iglesias, M.; Vasquez Blanco, E.; Lopez Mahia, P.; Muniategui Lorenzo, S.; Prada Rodriguez, D. [A Coruna Univ., A Coruna (Spain). Dept. of Analytical Chemistry

    2000-06-01

    In this paper, a procedure for the determination of airborne polycyclic aromatic hydrocarbons (PAHs) is described. Airborne particulate samples were collected on glass fiber filters which were microwave assisted extracted using hexane/acetone (1:1). The extractable organic matter was submitted to several steps of clean-up procedure by solid phase extraction. The PAH fraction was analyzed by high performance liquid chromatography with ultraviolet (UV) at two fixed wavelengths (254 and 300 nm) and wavelength programmable fluorescence (FL) detection. Analytical method detection limits were in the range from 0.30 to 9.5 pg/m{sup 3} with ultraviolet detection ({lambda}=254 nm) and from 0.035 to 0.86 pg/m{sup 3} with fluorescence detection. Also, the effect of the temperature on the retention of the PAHs is described. [Italian] In questo lavoro e' descritta una procedura per la determinazione degli idrocarburi policiclici aromatici (PAHs) nel particolato atmosferico. I campioni sono stati raccolti su filtri di fibra di vetro dai quali sono stati estratti con l'impiego delle microonde utilizzando esano-acetone (1:1). La materia organica estraibile e' stata sottoposta a vari stadi di una procedura di pulizia mediante cromatografia liquida ad elevata pressione e rivelazione ultravioletta a due lunghezze d'onda fisse (254 e 300 nm) e di fluorescenza a lunghezza d'onda programmabile. I limiti di rivelabilita' del metodo analitico sono nell'intervallo di 0.30-9.5 pg/m{sup 3} per la rilevazione UV (254 nm) e di 0.035-0.86 pg/m{sup 3} per la rivelazione in fluorescenza. E' inoltre descritto l'effetto della temperatura sul trattenimento dei PAHs.

  7. Air sampling system for evaluating the thyroid dose commitment due to fission products released from reactor containment. Final report

    International Nuclear Information System (INIS)

    Accidental releases of radioactivity from fission reactors will consist of active vapors and aerosols. Composition of the released plume or cloud will depend on the energy of release and fission product volatility. In accidents at Windscale and SL-1, 131I was the predominant isotope present in both the initial cloud and later release. Thus an air sampling system was developed for efficient radioiodine collection. The air sampling, readout, and dose assessment system was developed to be used in the environment after loss of containment accidents. The system can detect less than 1 rem dose commitments to thyroids of 5 year old children for immersion times of 10 hours or less. The air mover can be operated on either 110V ac power or 12V dc power available from vehicles with cigar lighter sockets. An inorganic silver loaded silica gel adsorber was developed for high mehyl iodine, HOI, and elemental iodine efficiency and low noble gas efficiency. A peal away high efficiency particulate filter permits the gaseous and particulate sample fractions to be evaluated separately. Predicted particulate iodine is combined with the adsorbed component to account for the total radioiodine in a given sample

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    2010-07-01

    ... review will require policy determinations from different Air Force elements; records describe law... 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...

  10. Influence of mathematical filters in the volume measurement of a travertine sample using high resolution x-ray microtomography

    International Nuclear Information System (INIS)

    X-ray transmission micro-computed tomography technique is a reality for characterization of pores spaces and fractures. Imaging rocks in three-dimensions this technique enables routine visualization of structures in samples, which can be spatially resolved down to the sub-micron scale. The image of micro-computed tomography is a mapping of the linear attenuation coefficient of one cross section of the sample in study. The main objective of this work is to describe the importance of using mathematical filters in the volume measurement of a travertine sample as, well as to evaluate the relevance of the filters, which were: Gaussian Blur, Unsharp Mask, Median, Uniform and Kuwahara. The results showed interesting differences both among the different filters and, mainly, in the same filter when using different radius and, also, for analysis of 2D space, as well as the resulting histograms. However the study showed that even with the evolution of the 'upgrades' of the image there is not a technique capable of solving 100% of the problems that a digital image might present and that the choice of filters must always determine the characteristics of the image emphasizing them within a specific application, always taking into consideration the image processing time. (author)

  11. Development of a modular Kalman Filter based sensor fusion algorithm for air vehicles

    OpenAIRE

    López Milla, Javier

    2013-01-01

    [ANGLÈS] Kalman Filter is nowadays one of the most used tool to perform sensor fusion in navigation environments, i.e. combine information from several different sensors to obtain the optimal navigation solution. However, there is no single algorithm for Kalman Filter and each of them must be adapted to the concrete problem. This implies that there are no two Kalman Filters that are exactly the same, complicating an objective comparison between them, mainly if implemented by different people....

  12. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    International Nuclear Information System (INIS)

    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. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Thyroxine (T4) radioimmunoassay using filter paper dried blood sample: an attempt for screening of neonates for hypothyroidism

    International Nuclear Information System (INIS)

    This paper describes a sensitive but simple and less expensive method suitable for estimation of thyroxine (T4) level. Deficiency of iodine during fetal life results in neonatal hypothyroidism and critinism. Frequency of neonatal hypothyroidism is 1 in 5000 to 7000 in countries having iodine deficiency. It is therefore important to diagnose the neonatal hypothyroidism as soon as possible after birth. The estimation of thyroxine has been found to the a reliable index for diagnosis of hypothyroidism and has long been used for screening of neonatal hypothyroidism. In the present study, instead of serum sample, a 6 mm disc of filter paper containing dried blood sample was used. The test was carried out in the laboratory with 40 samples. As compared to the sensitivity of serum sample technique which is 15.19 n mol/L, the filter paper technique has the sensitivity of 17.23 n mol/L. The work revealed that the T4 concentration do not depend upon the amount of blood on the filter paper. Effect of temperature on filter paper disc was evaluated at 4o c, at 25o c and at 37o c. Results obtained showed significant variation and the best result was obtained for the sample kept at 4o c. The method is simple, rapid, less expensive and needs a small amount of blood and is, therefore, a useful technique for mass screening of neonatal hypothyroidism. 6 refs., 4 tables (author)

  15. PM2.5 analog forecast and Kalman filter post-processing for the Community Multiscale Air Quality (CMAQ) model

    Science.gov (United States)

    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.

  16. Pemanfaatan Zeolit Alam Pahae Modifikasi sebagai Filter Uap Air pada Proses Elektrolisa

    OpenAIRE

    Zebua, Fynnisa

    2016-01-01

    The water vapour filter based on natural pahae zeolite has been succesfully manufactured by pouring the zeolit powder in 6 % H2SO4 solution and followed by heating it at 7000C, 8000C, and 9000C respectively. To improve the water vapour filter absorbility of zeolite, rind cocoa was used as filler. Whole to increase the chemical bonding between the matrik and filler, the clay was mixed with zeolite and rind cocoa. In this case, water vapour filtered come from an electrolysis process. The filter...

  17. Baseline air mass selection at Cape Point, South Africa: application of 222Rn and other filter criteria to CO2

    International Nuclear Information System (INIS)

    Concentrations of 222Rn (March 1999-August 2002) from a recently installed analyser at the station Cape Point (34oS, 18oE), South Africa, were analysed statistically. The combination of 222Rn with information on wind direction and carbon monoxide (CO) permitted a classification of air masses into continental, marine, and mixtures of both. The ability to select trace gas data representing purely maritime conditions is shown through application to carbon dioxide (CO2) data. 222Rn levels at Cape Point ranged from near zero to above 5000 mBq m-3. Monthly percentiles show practically no seasonal dependence for values up to the 25th percentile (P25), corresponding to 222Rn -3 which is considered typical for marine air. In contrast, 222Rn percentiles exceeding P50 reveal an austral winter maximum, related to a higher incidence of continental air at that time of the year. The wind sector pattern for 222Rn concentrations largely coincides with that observed for CO, but covers a wider sector to the east, reflecting continental source areas. Air masses with 222Rn levels between 100 and 250 mBq m-3 were found to be still affected by terrestrial sources. Our routinely used percentile-based statistical filter applied to CO2 accepted 222Rn -3), which only yielded 18%, but is more stringent in excluding terrestrial influences. CO2 data filtered by using a combination of various selection parameters agreed well with data obtained for 222Rn -3, confirming that this 222Rn threshold is a suitable criterion for purely maritime data. Nonetheless, for CO2 the statistical filter, which does not depend on other species and has better data coverage, still retains its applicability for routine trace gas filtering with respect to baseline concentrations. (author)

  18. Early air sampling in Higashi-Hiroshima after the Fukushima Daiichi Nuclear Power Plant accident and subsequent sampling in Minami-Souma City from October 2011 to September 2012

    International Nuclear Information System (INIS)

    Soon after the accident that occurred at the Fukushima Daiichi Nuclear Power Plant on March 11, 2011, air sampling was performed in Higashi-Hiroshima (about 800 km from Fukushima). The sampling began on March 20, and a high-volume air sampler was used. The first radionuclide observed was 131I (on March 30), and 137Cs, 134Cs, 136Cs, and 132Te were observed thereafter. According to the sampling, the maximum concentration in the air occurred on April 7 and again on April 18. After April 30, no radionuclides released due to the accident were observed. Since 137Cs and 134Cs have a long half-life (30 and 2 y, respectively), all of the air filters were measured again in February through March of 2012 using a well-type Ge detector. The results of these measurements showed that 137Cs was already observed on March 21. Later on, air sampling was performed at Minami-Souma City, Fukushima (October 2011 to September 2012). The purpose of this sampling was to investigate whether any radionuclides were released from the forest and flew up into the air from the ground, or were carried by the wind in winter or via pollen in spring. Results showed that the radioactive concentration was quite low and no seasonal variation occurred, indicating that no radionuclides flew up into the air from the ground, nor were any released from the forest via wind or pollen. (author)

  19. Adjustable virtual pore-size filter for automated sample preparation using acoustic radiation force

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Sampling strategies for the analysis of reactive low-molecular weight compounds in air

    OpenAIRE

    Henneken, Hartmut

    2006-01-01

    Within this thesis, new sampling and analysis strategies for the determination of airborne workplace contaminants have been developed. Special focus has been directed towards the development of air sampling methods that involve diffusive sampling. In an introductory overview, the current state-of-the-art of sampling and analysis of airborne isocyanates is reviewed. The most important derivatization reagents are introduced, and their application for air analysis with special emphasis on sampli...

  1. Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

    Science.gov (United States)

    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

  2. Standard Practice for Processing Aerospace Liquid Samples for Particulate Contamination Analysis Using Membrane Filters

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice covers the processing of liquids in preparation for particulate contamination analysis using membrane filters and is limited only by the liquid-to-membrane filter compatibility. 1.2 The practice covers the procedure for filtering a measured volume of liquid through a membrane filter. When this practice is used, the particulate matter will be randomly distributed on the filter surface for subsequent contamination analysis methods. 1.3 The practice describes procedures to allow handling particles in the size range between 2 and 1000 μm with minimum losses during handling. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  3. Technical assessment of compliance with work place air sampling requirements at T Plant. Revision No. 1

    International Nuclear Information System (INIS)

    The US DOE requires its contractors to conduct air sampling to detect and evaluate airborne radioactive material in the workplace. Hanford Reservation T Plant compliance with workplace air sampling requirements has been assessed. Requirements, basis for determining compliance and recommendations are included

  4. Low-cost monitoring of Campylobacter in poultry houses by air sampling and quantitative PCR.

    Science.gov (United States)

    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

  5. CO2 isotope analyses using large air samples collected on intercontinental flights by the CARIBIC Boeing 767.

    Science.gov (United States)

    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

  6. Qualitative analysis by X ray fluorescence of impurities in materials used as air filters; Analisis cualitativo por fluorescencia de rayos X de impurezas en materiales utilizados como filtros de aire

    Energy Technology Data Exchange (ETDEWEB)

    Lartigue G, J; Munoz M, G; Navarrete T, M [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1995-06-01

    A qualitative analysis of impurities in 5 materials commonly used as air filters was performed with 2 aims: to compare them, in regard to their impurities and to set a methodology to identify spectroscopically, in a short time (1000 seconds), those impurities in order to subtract the blanks signal from that one generated by the collected sample. Some papers on air filters impurities (cellulose, polycarbonate and glass fiber) were found in literature. In one case, the analysis was performed by energy-dispersive X ray fluorescence, tube generated method. In this work it was employed the same method but a radioisotope (Cd-109) was used as primary source. This was applied to 2 of the above mentioned materials as well as to nylon, teflon and quartz. The glass fiber filter had the highest impurity level: Ca, Ba, Pb, Zn, Sr, Rb, and Fe (0.5 {mu}gFe/cm{sup 2}, measured by Atomic Absorption Spectroscopy). The teflon filter had the lowest impurity level. The developed procedure is fast, precise and reproducible and it may be applied also to wastewaters filters. [Spanish] Se realizo el analisis cualitativo de impurezas en cinco materiales comunmente utilizados como filtros de aire, con dos propositos: compararlos en base a sus impurezas y establecer una metodologia que permitiera, en muy corto tiempo (1000 segundos), identificar espectroscopicamente las impurezas a fin de restar la senal del blanco de aquella que genera eventualmente la muestra. En la bibliografia se encontraron algunas publicaciones acerca de impurezas en filtros de aire (celulosa, pollicarbonato y fibra de vidrio), determinadas principalmente por Absorcion Atomica. En un caso, tal determinacion se realizo por Fluorescencia de Rayos X generados en tubo de descargas y detectados por dispersion de energia. En este trabajo se empleo el mismo metodo de Fluorescencia de Rayos X detectados por dispersion de energia pero generados por un radioisotopo (Cd-109) y se aplico a dos de los tres materiales antes

  7. A study of the oxidation hydrolysis of CsI radioaerosols in a steam-air medium using filtering units

    International Nuclear Information System (INIS)

    A study of the oxidation hydrolysis of radioaerosols is an issue of acute importance from both scientific and practical points of view. This can be explained by the facts that there is currently virtually no experimental data on this process and that the problem of the localization of CsI radioaerosols during accidents at nuclear power enterprises still remains unsolved. We carried out a study of the oxidation hydrolysis of 137CS131I radioaerosols in a steam-vapor medium during their localization on a column with filtering units, specifically: (1) 'Bekipor WB12' metal fiber (Cr-Ni-Mo alloy, fiber thickness ∼12 μm, density ∼0.05 g/cm3, specific surface area ∼450 cm2/g; (2) spiral filtering unit made of a wire measuring 8.0 m in length and 0.6 mm in diameter (working area parameters: length ∼115 mm, diameter ∼14 mm, and specific surface area ∼0.01 cm2/g; (3) 'TRUMEM stainless steel membrane filter (diameter ∼20 mm, thickness 0.2 mm, specific surface area ∼5000 cm2/g, pore size ∼2 μm; (4) three-layer de-ashed paper filter known as 'white band' (pore diameter 3.5 μm and specific surface ∼8000 cm2/g). The results of the study allowed us to suggest that the sublimation of 137CS131I from a platinum heater under specific conditions can lead to the formation of the following compounds 137CsOH, 137CS131I - 137CsOH, 137CS131I3, and 131I2. The oxidation hydrolysis of 13lCS131I radioaerosols and the interaction of hydrolysis products with the surfaces of the metal and paper filtering units took place under the following conditions: air-flow temperature 403-423 Κ, steam content in the air flow about 3-4 to 90 vol.%, and the linear velocity of the flow in the sorption column from 6 to 24 cm/s. The filtering units managed to localize from ∼5 to ∼98 % of the initial amount of 137CS131I (0:17-70 mg) supplied to the filtering system, which depended on the filtering material, the size of its inner surface, and the conditions of the experiment.

  8. Air filters and air cleaners: Rostrum by the American Academy of Allergy, Asthma & Immunology Indoor Allergen Committee

    OpenAIRE

    Sublett, James L.; Seltzer, James; Burkhead, Robert; Williams, P. Brock; Wedner, H. James; Phipatanakul, Wanda

    2009-01-01

    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.

  9. Retrieval and treatment of spent high efficiency particulate air filters. India. Annex V

    International Nuclear Information System (INIS)

    The use of ventilation systems in a nuclear facility results in active HEPA filters and pre-filters as radioactive solid waste. This waste is categorized as category I (<2 mGy/h). In the past, in the absence of volume reduction and disposal treatment processes for such waste, it was stored in engineered trenches with the intention of its retrieval and treatment at a later date. Retrieval of the stored HEPA filters was required for volume reduction, packaging and disposal in order to conserve storage space. The spent HEPA filter waste interim stored in engineered storage trenches was retrieved by trained workers wearing protective clothing and mask respirators. The waste was handled by mobile cranes and dedicated gantry cranes over the engineered storage trenches using suitable grapplers and material movement devices such as forklift trucks and mobile trailers. A hydraulically operated vertical ram compactor was installed at the site and commissioned for radioactive operations. A volume reduction of five has uniformly been obtained after compaction of HEPA filters. The surface dose on compacted filters was observed to be very low. The spread of contamination was fully controlled and exposure was minimal. The compacted filters are placed in a secondary steel container and disposed of in trenches

  10. Measurement of overall uptake coefficients for HO2 radicals by aerosol particles sampled from ambient air at Mts. Tai and Mang (China)

    OpenAIRE

    Taketani, F.; Y. Kanaya; P. Pochanart; Liu, Y; Li, J.; K. Okuzawa; K. Kawamura; Z. Wang; H. Akimoto

    2012-01-01

    HO2 uptake coefficients for ambient aerosol particles, collected on quartz fiber filter using a high-volume air sampler in China, were measured using an aerosol flow tube coupled with a chemical conversion/laser-induced fluorescence technique at 760 Torr and 298 K, with a relative humidity of 75%. Aerosol particles were regenerated with an atomizer using the water extracts from the aerosol particles. Over 10 samples, the measured HO2 uptake coefficients for the aerosol parti...

  11. Measurement of overall uptake coefficients for HO2 radicals by aerosol particles sampled from ambient air at Mts. Tai and Mang, China

    OpenAIRE

    H. Akimoto; Z. Wang; K. Okuzawa; K. Kawamura; Li, J.; Liu, Y; P. Pochanart; Taketani, F.; Y. Kanaya

    2012-01-01

    HO2 uptake coefficients for ambient aerosol particles, collected on quartz filter using a high-volume air sampler in China, were measured using an aerosol flow tube coupled with a chemical conversion/laser-induced fluorescence technique at 760 Torr and 298 K, with a relative humidity of 75%. Aerosol particles were regenerated with an atomizer using the water extracts from the aerosol particles. Over 10 samples, the measured HO2 uptake coefficients for the aerosol particles at the Mt. ...

  12. Branchfall as a Demographic Filter for Epiphyte Communities: Lessons from Forest Floor-Based Sampling.

    Directory of Open Access Journals (Sweden)

    Juliano Sarmento Cabral

    Full Text Available 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 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 important

  13. Branchfall as a Demographic Filter for Epiphyte Communities: Lessons from Forest Floor-Based Sampling.

    Science.gov (United States)

    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 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 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 important demographic filter structuring epiphyte communities. PMID:26083417

  14. The effect of electrostatic force on air filtration by polypropylene filter media

    International Nuclear Information System (INIS)

    In this paper, the effect of irradiation with 60Co on the efficiency and strength of the polypropylene filter media is mainly researched. The charge density of polypropylene fibre is evaluated by radiation discharge method. Based on isolated cylinder model, the efficiency of the polypropylene filter media, which takes account of the effect of impaction, interception, diffusion and electrostatic, is calculated. A better agreement between theoretical analysis and experimental results is obtained. The results indicate that electrostatic force is the most important factor in solid aerosol filtration of the polypropylene filter media

  15. The impact of air pollution from used ventilation filters on human comfort and health

    DEFF Research Database (Denmark)

    Clausen, Geo; Alm, O.; Fanger, Povl Ole

    2002-01-01

    The comfort and health of 30 women was studied during 4 hours´ exposure in an experimental room with either a used or a new filter present in the ventilation system. All other environmental parameters were kept constant. The presence of the used filter in the ventilation system had a significant ...... adverse impact on several perceptions and symptoms, both immediately upon entering the office and throughout the exposure period. None of the perceptions or symptoms were better when the used filter was in the system....

  16. Comparison of stationary and personal air sampling with an air dispersion model for children's ambient exposure to manganese.

    Science.gov (United States)

    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

  17. Penentuan Nilai pH dan Alkalinitas pada Air Filter HM. Yamin di Laboratorium PDAM Tirtanadi Medan

    OpenAIRE

    Ramahdani

    2015-01-01

    Water is a chemical compound that is essential for the process of life, a lot of water is used for cooking, washing, bathing, and so on. In the provision of drinking water, and the pH value of the water alkalintas is one factor to be considered in the drinking water quality standards. Experiment goal is to determine the pH and alkalinity of the water filter HM.Yamin used as drinking water. Sample taken from the water faucet filter derived from the production wellbore Tritanadi PDAM Medan. ...

  18. imFASP: An integrated approach combining in-situ filter-aided sample pretreatment with microwave-assisted protein digestion for fast and efficient proteome sample preparation.

    Science.gov (United States)

    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

  19. Development of glass-fiber high-efficiency particulate air filters of high structural strength on the basis of the establishment of failure mechanisms

    International Nuclear Information System (INIS)

    Practical experience from routine operation in nuclear installations as well as extensive bench and laboratory testing proved the structural limits of HEPA filters to be very low thus demonstrating the need for improvement of their structural strength. Detailed analysis of the courses and modes of filter failure under the challenge of dry air at high velocities and ambient temperature, together with additional measurements, allowed the establishment of the dominating mechanisms of filter failure. Based on this information, the following three options for effective and economical improvements in filter structural limits exist: (1) an increase in the tensile strength of the filter medium; (2) an increase in the stability of the pack to prevent the swelling of individual pleats; and (3) an increase in the area moment of inertia of the separators and a decrease in the sharpness of their edges. By using a reinforced glass fiber filter medium, the structural strength of standard size HEPA filters was increased to 31 kPa with dry air and beyond 10 kPa with air at high humidity. Prototype filters built with standard glass-fiber media and separators with inclined corrugations exhibited failure pressures of approximately 50 kPa under high velocity airflows. The combination of both types of improvements, together with other measures, will soon lead to even higher HEPA-filter structural strength

  20. Impact of HVAC filter on indoor air quality in terms of ozone removal and carbonyls generation

    Science.gov (United States)

    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.

  1. Sample and injection manifolds used to in-place test of nuclear air-cleaning system

    International Nuclear Information System (INIS)

    Objective: According to the regulations of nuclear safety rules and related standards, in-place test of the nuclear air-cleaning systems should be carried out before and during operation of the nuclear facilities, which ensure them to be in good condition. In some special conditions, the use of sample and injection manifolds is required to make the test tracer and ventilating duct air fully mixed, so as to get the on-spot typical sample. Methods: This paper introduces the technology and application of the sample and injection manifolds in nuclear air-cleaning system. Results: Multi point injection and multi point sampling technology as an effective experimental method, has been used in a of domestic and international nuclear facilities. Conclusion: The technology solved the problem of uniformly of on-spot injection and sampling,which plays an important role in objectively evaluating the function of nuclear air-cleaning system. (authors)

  2. Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

    International Nuclear Information System (INIS)

    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

  3. PRODUCTION OF ACTIVATED CHARCOAL SAMPLER TUBES FOR SAMPLING AIR CONTAMINANTS

    OpenAIRE

    P Nassiri; F Golbabaie; S. Nasseri; M. Mahmoodi; K. Mehrain

    1988-01-01

    The importance of the use of activated charcoal tubes for sampling gases and vapors is very well-known. For producing these tubes in the country, their production started in the laboratory of the department of occupation al health using activated charcoal, polyurethane foam and glass wool and consequently two types of foamed and foamless tubes were produced. To investigate the quality of the raw materials used, 186 tubes were exposed to various proportions of solutions of different volumes of...

  4. PRODUCTION OF ACTIVATED CHARCOAL SAMPLER TUBES FOR SAMPLING AIR CONTAMINANTS

    Directory of Open Access Journals (Sweden)

    P.Nassiri

    1988-08-01

    Full Text Available The importance of the use of activated charcoal tubes for sampling gases and vapors is very well-known. For producing these tubes in the country, their production started in the laboratory of the department of occupation al health using activated charcoal, polyurethane foam and glass wool and consequently two types of foamed and foamless tubes were produced. To investigate the quality of the raw materials used, 186 tubes were exposed to various proportions of solutions of different volumes of known percentages of four compounds of benzene, toluene, O-xylene and P-xlene. The adsorption of various parts of sampler tubes was done by a chemical method using CS2 and the final analysis was done by gas chromatography. The results obtained show that the amount of the above named compounds adsorbed by glass wool and foam in comparison to the activated charcoal isn’t significant (respectively P<0.001 & P,0.05. Also the experiments don’s show any significant differences between the total amount of adsorbed chemicals by charcoal in the back-up layer and the sample layer of the foamed tube and the amount adsorbed in the foamless tube, when treated with various compounds (P,0.001. Considering the equal adsorption of both types of tubes and the advantage of foamed tubes in controlling the time duration and the flow rate of sampling, the foamed type was recommended for production and use.

  5. Suitability of Semiconductor Heterostructure over SiO2-Air Composition for One-Dimensional Photonic Crystal based Bandpass Filter

    Directory of Open Access Journals (Sweden)

    Arka Karmakar

    2013-05-01

    Full Text Available Bandpass filter characteristics is numerically computed for semiconductor heterostructure based onedimensional photonic crystal at different optical wavelengths by varying the structural parameters taking GaAs/AlxGa1-xAs as a suitable composition subject to normal incidence of electromagnetic wave. Transfer matrix technique is used for numerical analysis. Results are compared with conventionally used SiO2-air material system and significance improvements are observed at few desired spectra. Heterostructure provides larger passbandwidth with almost negligible ripple than conventional material system at 1330 nm or 1550 nm, which is required for present day optical communication network. Efficient tuning can be achieved by varying different layer dimensions for the preferred material composition which effectively changes the filter bandwidth in either side of the central wavelength, but it cost generation of ripples for the conventional system.

  6. Modelling of air flows in pleated filters and of their clogging by solid particles; Modelisation des ecoulements d'air et du colmatage des filtres plisses par des aerosols solides

    Energy Technology Data Exchange (ETDEWEB)

    Del Fabbro, L

    2002-07-01

    The devices of air cleaning against particles are widely spread in various branches of industry: nuclear, motor, food, electronic,...; among these devices, numerous are constituted by pleated porous media to increase the surface of filtration and thus to reduce the pressure drop, for given air flow. The objective of our work is to compensate a lack evident of knowledge on the evolution of the pressure drop of pleated filter during the clogging and to deduct a modelling from it, on the basis of experiments concerning industrial filters of nuclear and car types. The obtained model is a function of characteristics of the filtering medium and pleats, of the characteristics of solid particles deposited on the filter, of the mass of particles and of the aeraulic conditions of air flow. It also depends on data on the clogging of flat filters of equivalent medium. To elaborate this model of pressure drop, an initial stage was carried out in order to characterize, experimentally and numerically, the pressure drop and the distribution of air flow in clean pleated filters of nuclear (high efficiency particulate air filter, in fiberglasses) and car (mean efficiency filter, in fibers of cellulose) types. The numerical model allowed to understand the fundamental role played by the aeraulic resistance of the filtering medium. From an non-dimensional approach, we established a semi-empirical model of pressure drop for a clean pleated filter valid for both studied types of medium; this model is used of first base for the development of the final model of clogging. The study of the clogging of the filters showed the complexity of the phenomenon dependent mainly on a reduction of the surface of filtration. This observation brings us to propose a clogging of pleated filters in three phases. Both first phases are similar in those observed for flat filters, while last phase corresponds to a reduction of the surface of filtration and leads a strong increase of the filter pressure drop

  7. Sampling strategies for the analysis of reactive low-molecular weight compounds in air

    NARCIS (Netherlands)

    Henneken, Hartmut

    2006-01-01

    Within this thesis, new sampling and analysis strategies for the determination of airborne workplace contaminants have been developed. Special focus has been directed towards the development of air sampling methods that involve diffusive sampling. In an introductory overview, the current state-of-th

  8. Green Ocean Amazon 2014/15 High-Volume Filter Sampling: Atmospheric Particulate Matter of an Amazon Tropical City and its Relationship to Population Health Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Machado, C. M. [Federal Univ. of Amazonas (Brazil); Santos, Erickson O. [Federal Univ. of Amazonas (Brazil); Fernandes, Karenn S. [Federal Univ. of Amazonas (Brazil); Neto, J. L. [Federal Univ. of Amazonas (Brazil); Souza, Rodrigo A. [Univ. of the State of Amazonas (Brazil)

    2016-08-01

    Manaus, the capital of the Brazilian state of Amazonas, is developing very rapidly. Its pollution plume contains aerosols from fossil fuel combustion mainly due to vehicular emission, industrial activity, and a thermal power plant. Soil resuspension is probably a secondary source of atmospheric particles. The plume transports from Manaus to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility ARM site at Manacapuru urban pollutants as well as pollutants from pottery factories along the route of the plume. Considering the effects of particulate matter on health, atmospheric particulate matter was evaluated at this site as part of the ARM Facility’s Green Ocean Amazon 2014/15 (GoAmazon 2014/15) field campaign. Aerosol or particulate matter (PM) is typically defined by size, with the smaller particles having more health impact. Total suspended particulate (TSP) are particles smaller than 100 μm; particles smaller than 2.5 μm are called PM2.5. In this work, the PM2.5 levels were obtained from March to December of 2015, totaling 34 samples and TSP levels from October to December of 2015, totaling 17 samples. Sampling was conducted with PM2.5 and TSP high-volume samplers using quartz filters (Figure 1). Filters were stored during 24 hours in a room with temperature (21,1ºC) and humidity (44,3 %) control, in order to do gravimetric analyses by weighing before and after sampling. This procedure followed the recommendations of the Brazilian Association for Technical Standards local norm (NBR 9547:1997). Mass concentrations of particulate matter were obtained from the ratio between the weighted sample and the volume of air collected. Defining a relationship between particulate matter (PM2.5 and TSP) and respiratory diseases of the local population is an important goal of this project, since no information exists on that topic.

  9. Large-scale generic test stand for testing of multiple configurations of air filters utilizing a range of particle size distributions.

    Science.gov (United States)

    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

  10. Comparison of concentration of ions in PM1 aerosol sampled on nitrate cellulose and teflon filters

    Czech Academy of Sciences Publication Activity Database

    Kořínková, Alena; Mikuška, Pavel; Večeřa, Zbyněk

    Aligarh: Aligarh Muslim University, 2013. s. 73-73. ISBN N. [International Conferenceon Chemistry: Frontiers and challenges. 02.03.2013-03.03.2013, Aligarh] Institutional support: RVO:68081715 Keywords : aerosol * ions * nitrate cellulose and teflon filter Subject RIV: CB - Analytical Chemistry, Separation

  11. LARGE SAMPLE PROPERTIES OF THE SIR IN CDMA WITH MATCHED FILTER RECEIVERS

    Institute of Scientific and Technical Information of China (English)

    PAN GUANGMING; MIAO BAIQI; ZHU CHUNHUA

    2005-01-01

    The output signal-to-interference (SIR) of conventional matched filter receiver in random environment is considered. When the number of users and the spreading factors tend to infinity with their ratio fixed, the convergence of SIR is showed to be with probability one under finite fourth.moment of the spreading sequences. The asymptotic distribution of the SIR is also obtained.

  12. Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.

    Science.gov (United States)

    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

  13. High-efficiency particulate air filter behavior at high-speed flows

    International Nuclear Information System (INIS)

    This paper presents a filter model based on the principle of fluid flow through porous media. The model includes both laminar and turbulent effects. The coefficients used in the model are determined empirically based on existing data. Deviation from the model is discussed

  14. A fast image retrieval method based on SVM and imbalanced samples in filtering multimedia message spam

    Science.gov (United States)

    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.

  15. Comparison of Filters for Concentrating Microbial Indicators and Pathogens in Lake Water Samples

    OpenAIRE

    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, Vicente; 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 p...

  16. ANALYSIS OF EFFECT OF APPROXIMATING OUTPUT SAMPLES USING RANDOM SUB-SAMPLING OF INPUT FOR COMPUTATION REDUCTION IN FILTERING OPERATION

    Directory of Open Access Journals (Sweden)

    AMANPREET SINGH

    2006-12-01

    Full Text Available Communication plays a significant role in today’s life. Integration of computing and communicating devices, wide-spread internet access through World Wide Web (WWW, and wireless links are an increasing demand for mobile cellular services at the consumer end, so it has led to new signal processing technologies. Signal processing and communications are tightly inter-woven and immensely influence each other. As the need for sophisticated signal processing algorithms and hardware increase, their potential to make contributions to the communication revolution appears unbounded. Digital signal processing (DSP technology is widely used in numerous familiar products, peripherals of computers and the electronics world. This paper deals with the optimization of DSP environment for communication applications. Emphasis is given to the receiver part of the communication system; more specifically the channel separation aspect is discussed. No such algorithm for the computational saving for receiver part of communication system has been reported earlier. In this paper an attempt has been made to optimize the filtering operation.

  17. Effectiveness evaluation of sources of supply and systems filter in production process of breathing air

    Directory of Open Access Journals (Sweden)

    Woźniak Arkadiusz

    2015-12-01

    Full Text Available The determination of how efficiently filtration systems used for the production of breathing air used in hyperbaric environments are operating is significant both from theoretical and practical points of view. The quality of breathing air and the breathing mixes based on air is crucial with regard to divers' safety. Paradoxically, a change in regulations regarding quality requirements for breathing mixes has imposed the necessity to verify both the technical equipment and laboratory procedures used in their production and verification. The following material, which is a continuation of previous publications, presents results of the conducted research along with the evaluation of effectiveness of the filtration systems used by the Polish Navy.

  18. Contamination of the air and other environmental samples of the Ulm region by radioactive fission products after the accident of the Chernobyl reactor

    International Nuclear Information System (INIS)

    Since April 30, 1986, the radioactivity of the fission products released by the accident of the Chernobyl reactor has been measured in the air of the city of Ulm. The airborne dust samples were collected with flow calibrated samplers on cellulose acetate membrane filters and counted with a high resolution gamma ray spectrometer. Later on, the radioactivity measurements were expanded to other relevant environmental samples contaminated by radioactive atmospheric precipitates including grass, spruce needles, mosses, lichens, various kinds of food, drinking water, asphalt and concrete surface layers, municipal sewage sludge and sewage sludge ash. This paper reports the obtained results. (orig.)

  19. Performances of pleated HEPA filters as a function of relative humidity of air; Performances des filtres plisses a Tres Haute Efficacite en fonction de l'humidite relative de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, A.

    2009-11-15

    Pleated High Efficiency Particulate Air (HEPA) filters are used for maintaining the containment of radioactive substances in nuclear plants; thus, they are sensitive elements of nuclear safety. Some accidental situations, such as the emergence of a hole on a pipe with release of steam, can lead to a high increase of the air humidity. This work can overcome the lack of analytical data in the literature regarding the behaviour of pleated HEPA filters, in terms of changes in pressure drop and efficiency, in presence of humidity (unsaturated air). Experimental clogging tests have been performed on a test bench with two aerosols: non hygroscopic micron-size alumina particles and hygroscopic sub-micron sodium chloride particles. The results showed that the influence of humidity during the clogging of a HEPA filter depends on several parameters: the geometry of the filter (plane or pleated), the size distribution and hygroscopicity of the aerosol clogging and finally the interaction time between the aerosol and humid air. Measurements of efficiency of clean and clogged filters (at different degrees of clogging), performed with the normalized soda fluorescein aerosol, are also sensitive to the presence of more or less relative humidity in the air. Finally, all results helped to develop an empirical model for estimating the evolution of the pressure drop of HEPA filters; this model is applicable during the formation of the particulate cake in presence of humidity without reducing of the surface area filtration. (author)

  20. Development of a multicopter-carried whole air sampling apparatus and its applications in environmental studies.

    Science.gov (United States)

    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

  1. Biofiltration of toluene-contaminated air using an agro by-product-based filter bed.

    Science.gov (United States)

    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

  2. Supplementary test method for carbon filters

    International Nuclear Information System (INIS)

    A test method for carbon filters using freon to detect leakage is described. The filters are used in nuclear power plants and in air-raid shelters to separate radioactive iodine.Sampling and detection limits are described and a proposal for a complete equipment is made.(G.B.)

  3. A rapid method for the autoradiography of alpha active air sample filters

    International Nuclear Information System (INIS)

    The report describes an improved version of a technique using a phosphor screen and an optical photographic emulsion to detect alpha-active particles. The sensitivity of the technique when using 'instant' high speed polaroid film is reported. The equipment has been designed to produce rapid results and does not need 'darkroom' conditions. (author)

  4. External calibration strategy for trace element quantification in botanical samples by LA-ICP-MS using filter paper.

    Science.gov (United States)

    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

  5. Assessing the impact of water filters and improved cook stoves on drinking water quality and household air pollution: a randomised controlled trial in Rwanda.

    Directory of Open Access Journals (Sweden)

    Ghislaine Rosa

    Full Text Available 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.Clinicaltrials.gov; NCT01882777; http://clinicaltrials.gov/ct2/results?term=NCT01882777&Search=Search.

  6. Determination of radiocarbon in stratospheric CO2, obtained through AirCore sampling.

    Science.gov (United States)

    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

  7. Effects of statistical quality, sampling rate and temporal filtering techniques on the extraction of functional parameters from the left ventricular time-activity curves

    International Nuclear Information System (INIS)

    Several techniques for the processing of a series of curves derived from two left ventricular time-activity curves acquired at rest and during exercise with a nuclear stethoscope were evaluated. They were three and five point time smoothing. Fourier filtering preserving one to four harmonics (H), truncated curve Fourier filtering, and third degree polynomial curve fitting. Each filter's ability to recover, with fidelity, systolic and diastolic function parameters was evaluated under increasingly 'noisy' conditions and at several sampling rates. Third degree polynomial curve fittings and truncated Fourier filters exhibited very high sensitivity to noise. Three and five point time smoothing had moderate sensitivity to noise, but were highly affected by sampling rate. Fourier filtering preserving 2H or 3H produced the best compromise with high resilience to noise and independence of sampling rate as far as the recovery of these functional parameters is concerned. (author)

  8. Effects of statistical quality, sampling rate and temporal filtering techniques on the extraction of functional parameters from the left ventricular time-activity curves

    Energy Technology Data Exchange (ETDEWEB)

    Guignard, P.A.; Chan, W. (Royal Melbourne Hospital, Parkville (Australia). Dept. of Nuclear Medicine)

    1984-09-01

    Several techniques for the processing of a series of curves derived from two left ventricular time-activity curves acquired at rest and during exercise with a nuclear stethoscope were evaluated. They were three and five point time smoothing. Fourier filtering preserving one to four harmonics (H), truncated curve Fourier filtering, and third degree polynomial curve fitting. Each filter's ability to recover, with fidelity, systolic and diastolic function parameters was evaluated under increasingly 'noisy' conditions and at several sampling rates. Third degree polynomial curve fittings and truncated Fourier filters exhibited very high sensitivity to noise. Three and five point time smoothing had moderate sensitivity to noise, but were highly affected by sampling rate. Fourier filtering preserving 2H or 3H produced the best compromise with high resilience to noise and independence of sampling rate as far as the recovery of these functional parameters is concerned.

  9. Pesticide detection in air samples from contrasted houses and in their inhabitants' hair.

    Science.gov (United States)

    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

  10. Ammonia and ammonium over the southern Baltic Sea. Part 1. Preparation of aerosol and air samples for the determination of ammonia by the indophenol method

    Directory of Open Access Journals (Sweden)

    Lucyna Falkowska

    2004-06-01

    Full Text Available 1997 saw the start of a study into the spatial and temporal changes in the chemical composition of the atmosphere over the littoral and offshore waters of the Baltic Sea. Collection of samples and their subsequent chemical analysis was preceded by meticulous laboratory experiments concerning the validation and adaptation of the analytical procedures. The colorimetric indophenol blue technique was used to analyse the aerosol samples for the concentration of ammonium ions and the air samples for their gaseous ammonia. The samples were collected with PTFE-filters and Whatman 41 filters coated with 5% orthophosphoric acid. This acid enhances the aerosol sampling efficacy but reduces the pH of the reaction in which indophenol is formed. The pH of the aerosol samples thus had to be raised, and this in turn required an alteration to the original procedure prior to ammonia determination. It was demonstrated that the addition of 0.1 N KOH to the filters coated with H3PO4 increases the pH of the reaction medium to the required level of pH = 8-11.5 and does not substantially influence the precision of the determination; the error of the modified procedure was of the order of 5.2%.      Air samples for the determination of gaseous ammonia were collected with annular denuders. Oxalic acid and citric acid are the usual impregnating agents. In the present experiments oxalic acid was used for denuder impregnation; it turned out to be more effective than citric acid under the conditions of the southern Baltic Sea.      The detection limit of the indophenol blue method in these laboratory experiments was 0.045 mmol dm-3. The respective relative standard deviations (RSD within the range of higher and lower concentrations were 0.64% and 4.53%.

  11. Radial line-scans as representative sampling strategy in dried-droplet laser ablation of liquid samples deposited on pre-cut filter paper disks

    International Nuclear Information System (INIS)

    conventional liquid measurements, and by analyzing IAEA-153 reference material (Trace Elements in Milk Powder); a good agreement with the certified value for phosphorus was obtained. - Highlights: • Sample preparation via deposition of liquids on pre-cut filter disks. • Sample introduction via laser ablation of dried filters. • Representative sampling avoids bias. • Signal quantification via external calibration and aqueous standard solutions. • Alternative approach for quantifying P in challenging matrix

  12. Radial line-scans as representative sampling strategy in dried-droplet laser ablation of liquid samples deposited on pre-cut filter paper disks

    Energy Technology Data Exchange (ETDEWEB)

    Nischkauer, Winfried [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna (Austria); Department of Analytical Chemistry, Ghent University, Ghent (Belgium); Vanhaecke, Frank [Department of Analytical Chemistry, Ghent University, Ghent (Belgium); Bernacchi, Sébastien; Herwig, Christoph [Institute of Chemical Engineering, Vienna University of Technology, Vienna (Austria); Limbeck, Andreas, E-mail: Andreas.Limbeck@tuwien.ac.at [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna (Austria)

    2014-11-01

    conventional liquid measurements, and by analyzing IAEA-153 reference material (Trace Elements in Milk Powder); a good agreement with the certified value for phosphorus was obtained. - Highlights: • Sample preparation via deposition of liquids on pre-cut filter disks. • Sample introduction via laser ablation of dried filters. • Representative sampling avoids bias. • Signal quantification via external calibration and aqueous standard solutions. • Alternative approach for quantifying P in challenging matrix.

  13. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Science.gov (United States)

    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).

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

    OpenAIRE

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

    2001-01-01

    Integrated air sampling and PCR-based methods for detecting airborne fungal spores, using Penicillium roqueforti as a model fungus, are described. P. roqueforti spores were collected directly into Eppendorf tubes using a miniature cyclone-type air sampler. They were then suspended in 0.1% Nonidet P-40, and counted using microscopy. Serial dilutions of the spores were made. Three methods were used to produce DNA for PCR tests: adding untreated spores to PCRs, disrupting spores (fracturing of s...

  15. 容积式空压机用空气滤清器技术水平现状综述%Overview of Current Technical Level of Air Filter for Displacement Air Compressor

    Institute of Scientific and Technical Information of China (English)

    谭强

    2012-01-01

    评述空压机用空气滤清器的作用,对压缩机机组能效水平\\辅助部件的性能和寿命的影响;对比国内空气压缩机产品技术标准中对空气滤清器的性能和技术要求;概述当前空气滤清器主导产品的使用现状,以及空气滤清器产品标准和试验标准的现状;列出压缩机用空气滤清器要求进行规范化管理的技术条款.期望建立健全压缩机行业空气滤清器产品的技术标准和验收准则,满足压缩机制造厂和最终用户的要求.%This paper reviews the function of air filter for air compressor,the effect on compressor unit energy efficiency level,and the effect on performance and service life of auxiliary parts of the compressor, and contrasts the performance and technical requirements of air filter in domestic air compressor product technical standards and summarizes the current application situation of leading air filter products and the present situation of air filter product standards and test standards.This paper lists the technical items for standardized management of compressor air filter.It is expected to establish and perfect the air filter product technical standards and acceptance criteria of the compressor industry,to meet the compressor manufacturers and end-users requirements.

  16. k0-INAA performance in the measurement of filters sampled in an industry with high loadings of metals

    International Nuclear Information System (INIS)

    Foundry industry has important environmental and occupational health impacts. More information is needed to properly assess occupational health risks presented by this industrial sector. This works aims at (1) characterizing the workers exposure to particulate matter in the foundry industry using k0-Instrumental Neutron Activation Analysis (k0-INAA) and Particle-Induced X-Ray Emission (PIXE) and (2) identifying some weakness of the k0-INAA technique when high concentrations of particulate matter and metals are involved. Filters were collected in a foundry industry which processes Pb and were analysed by k0-INAA and PIXE. In INAA, the incomplete deposition of gamma-rays in the germanium crystal due to Compton scattering elevated the spectra baseline, thus increased the background, and hindered the identification of some photopeaks. The problem was particularly important due to the high Sb contents existing in the sampled filters. The application of the Compton Suppression System for the analysis of these filters was successfully used in order to ascertain potential improvements on the detection limits for Zn and Fe. Results obtained showed that in this foundry industry workers were exposed to high concentrations of Pb, Sb, Fe, Sn, As, Ni, Br, Na and Cl.

  17. Determination of metals in air samples using X-Ray fluorescence associated the APDC preconcentration technique

    International Nuclear Information System (INIS)

    Air pollution has become one of the leading quality degradation factors of life for people in large urban centers. Studies indicate that the suspended particulate matter in the atmosphere is directly associated with risks to public health, in addition, it can cause damage to fauna, flora and public / cultural patrimonies. The inhalable particulate materials can cause the emergence and / or worsening of chronic diseases related to respiratory system and other diseases, such as reduced physical strength. In this study, we propose a new method to measure the concentration of total suspended particulate matter (TSP) in the air using an impinger as an air cleaning apparatus, preconcentration with APDC and Total Reflection X-ray Fluorescence technique (TXRF) to analyze the heavy metals present in the air. The samples were collected from five random points in the city of Rio de Janeiro/Brazil. Analyses of TXRF were performed at the Brazilian Synchrotron Light Laboratory (LNLS). The technique proved viable because it was able to detect five important metallic elements to environmental studies: Cr, Fe, Ni, Cu and Zn. This technique presented substantial efficiency in determining the elementary concentration of air pollutants, in addition to low cost. It can be concluded that the metals analysis technique in air samples using an impinger as sample collection instrument associated with a complexing agent (APDC) was viable because it is a low-cost technique, moreover, it was possible the detection of five important metal elements in environmental studies associated with industrial emissions and urban traffic. (author)

  18. Determination of metals in air samples using X-Ray fluorescence associated the APDC preconcentration technique

    Energy Technology Data Exchange (ETDEWEB)

    Nardes, Raysa C.; Santos, Ramon S.; Sanches, Francis A.C.R.A.; Gama Filho, Hamilton S.; Oliveira, Davi F.; Anjos, Marcelino J., E-mail: rc.nardes@gmail.com, E-mail: ramonziosp@yahoo.com.br, E-mail: francissanches@gmail.com, E-mail: hamiltongamafilho@hotmail.com, E-mail: davi.oliveira@uerj.br, E-mail: marcelin@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Instituto de Fisica. Departamento de Fisica Aplicada e Termodinamica

    2015-07-01

    Air pollution has become one of the leading quality degradation factors of life for people in large urban centers. Studies indicate that the suspended particulate matter in the atmosphere is directly associated with risks to public health, in addition, it can cause damage to fauna, flora and public / cultural patrimonies. The inhalable particulate materials can cause the emergence and / or worsening of chronic diseases related to respiratory system and other diseases, such as reduced physical strength. In this study, we propose a new method to measure the concentration of total suspended particulate matter (TSP) in the air using an impinger as an air cleaning apparatus, preconcentration with APDC and Total Reflection X-ray Fluorescence technique (TXRF) to analyze the heavy metals present in the air. The samples were collected from five random points in the city of Rio de Janeiro/Brazil. Analyses of TXRF were performed at the Brazilian Synchrotron Light Laboratory (LNLS). The technique proved viable because it was able to detect five important metallic elements to environmental studies: Cr, Fe, Ni, Cu and Zn. This technique presented substantial efficiency in determining the elementary concentration of air pollutants, in addition to low cost. It can be concluded that the metals analysis technique in air samples using an impinger as sample collection instrument associated with a complexing agent (APDC) was viable because it is a low-cost technique, moreover, it was possible the detection of five important metal elements in environmental studies associated with industrial emissions and urban traffic. (author)

  19. Technical basis and evaluation criteria for an air sampling/monitoring program

    International Nuclear Information System (INIS)

    Air sampling and monitoring programs at DOE facilities need to be reviewed in light of revised requirements and guidance found in, for example, DOE Order 5480.6 (RadCon Manual). Accordingly, the Oak Ridge National Laboratory (ORNL) air monitoring program is being revised and placed on a sound technical basis. A draft technical basis document has been written to establish placement criteria for instruments and to guide the ''retrospective sampling or real-time monitoring'' decision. Facility evaluations are being used to document air sampling/monitoring needs, and instruments are being evaluated in light of these needs. The steps used to develop this program and the technical basis for instrument placement are described

  20. Effectiveness of heating, ventilation and air conditioning system with HEPA filter unit on indoor air quality and asthmatic children's health

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ying; Raja, Suresh; Ferro, Andrea R.; Jaques, Peter A.; Hopke, Philip K. [Clarkson University, 8 Clarkson Avenue, Center for Air Resources Engineering and Science, Potsdam, NY 13699 (United States); Gressani, Cheryl; Wetzel, Larry E. [Air Innovations, Inc, 7000 Performance Drive, North Syracuse, NY 13212 (United States)

    2010-02-15

    Poor indoor air quality has been linked to the exacerbation of asthma symptoms in children. Because people spend most of their time indoors, improving indoor air quality may provide some relief to asthma sufferers. A study was conducted to assess whether operating an air cleaning/ventilating unit (HEPAiRx {sup registered}) in a child's bedroom can improve his/her respiratory health. Thirty children diagnosed with asthma were randomly split into two groups. For the first six weeks, group A had the air cleaning/ventilating unit (HEPAiRx {sup registered}) running in the bedrooms of the participants and group B did not; for the second six weeks, both groups had the cleaners running in the bedrooms; and, for the final six weeks, group A turned the cleaners off and group B kept theirs running. Indoor air quality parameters, including temperature, relative humidity, particulate matter (PM 0.5-10 {mu}m), carbon monoxide, carbon dioxide and total volatile organic compound (TVOC) concentrations, were monitored in each bedroom using an AirAdvice indoor air quality multi-meter. As a measure of pulmonary inflammation, exhaled breath condensate (EBC) was collected every sixth day and analyzed for nitrate and pH. Peak expiratory flow (PEF) was also measured. PM and TVOC concentrations decreased with operation of the HEPAiRx an average of 72% and 59%, respectively. The EBC nitrate concentrations decreased significantly and the EBC pH and PEF values increased significantly with operation of the unit (p < 0.001 when comparing on/off sample means). These results indicate that air cleaning in combination with ventilation can effectively reduce symptoms for asthma sufferers. (author)

  1. Sodium chloride aerosol generation method for high efficiency particulate air filter testing

    International Nuclear Information System (INIS)

    A method for submicron aerosol generation from aqueous sodium chloride solutions is presented. The results are discussed with regard to generation capacity and aerosol particle characterization as a function of the experimental conditions, especially of the flow rate of compressed air through the nozzle, of changes of the NaCl concentration and of the nozzle diameter. (author)

  2. Odour and ammonia removal from pig house exhaust air using a biotrickling filter

    NARCIS (Netherlands)

    Melse, R.W.; Mol, G.

    2004-01-01

    Odour from agricultural activities, such as the spreading of manure and the housing of animals, is increasingly being considered a nuisance in densely populated countries like the Netherlands. The objective of this research was to study the odour removal from pig house exhaust air by a biotrickling

  3. Comparison of concentration of ions in PM1 aerosol sampled on nitrate cellulose and teflon filters

    Czech Academy of Sciences Publication Activity Database

    Kořínková, Alena; Mikuška, Pavel; Večeřa, Zbyněk; Křůmal, Kamil

    Brno : Ústav analytické chemie AV ČR, v. v. i, 2012 - (Foret, F.; Křenková, J.; Guttman, A.; Klepárník, K.; Boček, P.), s. 248-249 ISBN 978-80-904959-1-3. [CECE 2012. International Interdisciplinary Meeting on Bioanalysis /9./. Brno (CZ), 01.11.2012-02.11.2012] R&D Projects: GA ČR(CZ) GAP503/11/2315; GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:68081715 Keywords : aerosol * nitrate cellulose and teflon filter * ions Subject RIV: CB - Analytical Chemistry, Separation http://hdl.handle.net/11104/0214234

  4. A sample holder for measuring the magnetic properties of air-sensitive compounds

    Science.gov (United States)

    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.

  5. Analysis of tree bark samples for air pollution biomonitoring of an urban area

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Ana Paula G.; Negri, Elnara M.; Saldiva, Paulo H.N., E-mail: paulista@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Patologia; Saiki, Mitiko; Scapin, Marcos A.; Ribeiro, Andreza P.; Salvador, Vera L., E-mail: mitiko@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Air pollution is receiving much attention as a public health problem around the world due to its adverse health effects from exposures by urban populations. Within this context, the use of vegetal biomonitoring to evaluate air quality has been investigated throughout the world. Air pollutant levels are high in the city of Sao Paulo, SP, Brazil and being the vehicle emissions its main source. The aim of this study was to evaluate concentrations of As, Ba, Br, Ca, Co, Cr, Cu, Fe, Mn, Pb, S, Sb and Zn in tree bark samples used as biomonitor of urban air pollution. Concentrations of these elements were determined in barks collected in trees of the Ibirapuera Park, one of the biggest and most visited parks of the city of Sao Paulo city. Samples of tree barks were also collected in a site outside the city of Sao Paulo, in a rural area of Embu-Guacu, considered as a control site. The element concentrations were determined by the methods of Instrumental Neutron Activation Analysis (INAA) and of Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF). The findings of this study showed that tree bark samples may be used as biomonitors of urban air pollution in a micro scale, and both techniques, INAA and EDXRF, can be used to evaluate element concentrations in tree bark samples. (author)

  6. Analysis of tree bark samples for air pollution biomonitoring of an urban area

    International Nuclear Information System (INIS)

    Air pollution is receiving much attention as a public health problem around the world due to its adverse health effects from exposures by urban populations. Within this context, the use of vegetal biomonitoring to evaluate air quality has been investigated throughout the world. Air pollutant levels are high in the city of Sao Paulo, SP, Brazil and being the vehicle emissions its main source. The aim of this study was to evaluate concentrations of As, Ba, Br, Ca, Co, Cr, Cu, Fe, Mn, Pb, S, Sb and Zn in tree bark samples used as biomonitor of urban air pollution. Concentrations of these elements were determined in barks collected in trees of the Ibirapuera Park, one of the biggest and most visited parks of the city of Sao Paulo city. Samples of tree barks were also collected in a site outside the city of Sao Paulo, in a rural area of Embu-Guacu, considered as a control site. The element concentrations were determined by the methods of Instrumental Neutron Activation Analysis (INAA) and of Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF). The findings of this study showed that tree bark samples may be used as biomonitors of urban air pollution in a micro scale, and both techniques, INAA and EDXRF, can be used to evaluate element concentrations in tree bark samples. (author)

  7. Optimization and standardization of directly inserted air dust samples into an inductively coupled plasma (AES-ICP) by evaporating material with a solid state laser. Optimierung und Standardisierung der direkten Zufuehrung von Staubproben zur AES-ICP mittels Laserverdampfung

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, G.; Suehs, K.; Rieskamp, H.

    1990-09-01

    Investigations were made to determine metals and half metals in air dust samples gathered on flat filters of glass fibre. It could be shown that Atomic Emission Spectrometr combined with laser evaporation of dust material will give detection limits similar to conventional methods using acid solutions. The developed technique was applicated to the elements antimony, arsenic, lead, cadmium, chromium, cobalt, copper, manganese, nickel, vanadium and zinc. It is ncessary to prepare standard filters with a thin layer of homogeneously distributed elements. A simple preparation technique was developed using synthetic solutions of dust material. Satisfactory results were obtained in case of glass fibre filters. Application to quartz filters seems to be possible so far as high performance laser systems are taken. In this way the difficulty of imaginary components will decrease. Application of laser evaporation technique avoids time expensive staps of sample preparation. (orig.) With 112 refs., 80 tabs., 67 figs.

  8. Results of Inspection and Cleaning of Two Radionuclide Air-Sampling Systems Based on the Requirements of ANSI/HPS N13.1-1999

    International Nuclear Information System (INIS)

    The Pacific Northwest National Laboratory (PNNL) conducted inspection and cleaning activities at two radionuclide air-sampling systems that continuously monitor radioactive air emissions from research and development (RandD) facilities. The inspection and cleaning was performed to evaluate effective methods and potential cost impacts of maintenance requirements in the revised American National Standard Institute (ANSI) standard Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities (ANSI/HPS N13.1-1999). The standard requires at least annual inspections of sampling systems followed by cleaning if deposits are visible. During 2001 and 2002, inspections were performed leaving the sampling systems in place and inserting videoscope cables into different access points to allow viewing of the inside and outside of sampling manifolds and transport lines. Cleaning was performed on one of the systems by disconnecting and extracting the sampling manifold, then washing it with de-ionized water and scrub brushes. The wash water was analyzed for radioactivity and solids. Results of the inspection showed greater deposition in one of the systems than would be expected by a High Efficiency Particulate Air (HEPA) filtered exhaust stream; the second system was also downstream of HEPA filters and appeared much cleaner. The videoscope was a useful and cost-effective tool and provided a better view than could be obtained with the naked eye. However, because even small amounts of deposition were made visible with the videoscope, clarification is needed in defining when probe washing is merited, particularly in existing sampling systems whose design is not conducive to easy removal and cleaning

  9. Validation of the integrity of a HEPA filter system.

    Science.gov (United States)

    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. Study of Mass Oxygen Transfer in a Biotrickling Filter for Air Pollution Control

    OpenAIRE

    San-Valero, Pau; Gabaldón García, Carmen; Peñarrocha Oltra, Josep Manuel; Pérez Gil, María del Carmen

    2012-01-01

    Biotrickling filtration is a potential and cost effective alternative for the treatment of volatile organic compound (VOC) emissions in air, so it is necessary to deepen into the key aspects of design and operation for the optimization of this technology. One of these factors is the oxygen mass transfer of the process. This study would facilitate the selection of the packing material and the mathematical modelling and simulation of bioreactors. Four plastic packing materials with ...

  11. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    International Nuclear Information System (INIS)

    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

  12. Passive air sampling of PCBs, PBDEs, and organochlorine pesticides across Europe.

    Science.gov (United States)

    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

  13. Distribution of small dispersive coal dust particles and absorbed radioactive chemical elements in conditions of forced acoustic resonance in iodine air filter at nuclear power plant

    CERN Document Server

    Ledenyov, Oleg P

    2013-01-01

    The physical features of distribution of the small dispersive coal dust particles and the adsorbed radioactive chemical elements and their isotopes in the absorber with the granular filtering medium with the cylindrical coal granules were researched in the case of the intensive air dust aerosol stream flow through the iodine air filter (IAF). It was shown that, at the certain aerodynamic conditions in the IAF, the generation of the acoustic oscillations is possible. It was found that the acoustic oscillations generation results in an appearance of the standing acoustic waves of the air pressure (density) in the IAF. In the case of the intensive blow of the air dust aerosol, it was demonstrated that the standing acoustic waves have some strong influences on both: 1) the dynamics of small dispersive coal dust particles movement and their accumulation in the IAF; 2) the oversaturation of the cylindrical coal granules by the adsorbed radioactive chemical elements and their isotopes in the regions, where the antin...

  14. Comparison of air samples, nasal swabs, ear-skin swabs and environmental dust samples for detection of Methicillin Resistant Staphylococcus aureus (MRSA) in pig herds

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Vigre, Håkan; Cavaco, Lina;

    2014-01-01

    To identify a cost-effective and practical method for detection of methicillin-resistant Staphylococcus aureus (MRSA) in pig herds, the relative sensitivity of four sample types: nasal swabs, ear-skin (skin behind the ears) swabs, environmental dust swabs and air was compared. Moreover, dependency...... conclusion, MRSA detection by air sampling is easy to perform, reduces costs and analytical time compared to existing methods, and is recommended for initial testing of herds. Ear-skin swab sampling may be more sensitive for MRSA detection than air sampling or nasal swab sampling....

  15. Development and calibration of real-time PCR for quantification of airborne microorganisms in air samples

    Science.gov (United States)

    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.

  16. Development of Air Sampling and Analytical Methods for Acetoin, Diacetyl, and 2,3-Pentanedione

    OpenAIRE

    Takaku-Pugh, Sayaka

    2012-01-01

    Acetoin, diacetyl, and 2,3-pentanedione are artificial butter flavoring ingredients. Occupational exposures to diacetyl are associated with severe respiratory disease including bronchiolitis obliterans. Dynamic and passive air sampling and analytical methods were developed for simultaneous sampling of these ketones using 10 % (w/w) O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) on Tenax TA (80/100 mesh). PFBHA O-oximes of the ketones were synthesized with above 95 % pur...

  17. Air sampling in the workplace to meet the new part 20 requirements

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission is developing a Regulatory Guide on air sampling in the workplace to meet the requirements of the revised Part 20. The guide will be accompanied by a technical manual describing and giving examples of how to meet the recommendations in the guide. Draft versions of the guide and manual are scheduled to be published for public comment this year. A final guide and manual, revised to consider the public comments, are scheduled to be published in 1992. This talk will summarize some of the more important features of the guide and manual. In particular, the talk will discuss how to demonstrate that samples taken to estimate worker intakes are representative of the air inhaled by workers and what measurements are necessary if a licensee wants to adjust derived air concentrations to account for particle size

  18. Technical assessment of compliance with workplace air sampling requirements in the 300 Area

    International Nuclear Information System (INIS)

    The purpose of this Technical Work Document is to satisfy HSRCM-1, the ''Hanford Site Radiological Control Manual.'' Article 551.4 of that manual states a requirement for a documented study of facility workplace air sampling programs (WPAS). This first revision of the original Supporting Document covers the period from January 1, 1995 to December 31, 1995. HSRCM-1 is the primary guidance for radiological control at Westinghouse Hanford Company (WHC). It was written to implement DOE/EH-0256T ''US Department of Energy Radiological Control Manual'' as it applies to programs at Hanford. As such, it complies with Title 10, Part 835 of the Code of Federal Regulations. There are also several Department of Energy (DOE) Orders, national consensus standards, and reports that provide criteria, standards, and requirements for workplace air sampling programs. This document provides a summary of these, as they apply to WHC facility workplace air sampling programs. This document also provides an evaluation of the compliance of 300 Areas' workplace air sampling program to the criteria, standards, and requirements and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance. The areas evaluated were the 340 Facility, the Advanced Reactor Operations Division Facilities, the N Reactor Fuels Supply Facility, and The Geotechnical Engineering Laboratory

  19. Technical assessment of workplace air sampling requirements at tank farm facilities. Revision 2

    International Nuclear Information System (INIS)

    Tank Farm facilities compliance with the workplace air sampling (WPAS) program has been assessed. Requirements bases for determining compliance and recommendations are included. In the current condition all buildings are in compliance with the WPAS program. This document also supersedes WHC-SD-SQA-TA-20012, revision 0

  20. CLEANLINESS OF COMMON AIR SAMPLING SORBENTS FOR APPLICATION TO PHENOLIC COMPOUNDS MEASUREMENT USING SUPERCRITICAL FLUID EXTRACTION

    Science.gov (United States)

    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...

  1. the nature of air flow near the inlets of blunt dust sampling probes

    Science.gov (United States)

    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.

  2. Measurement of the carbon 14 activity at natural level in air samples

    International Nuclear Information System (INIS)

    The aim of the study was to measure the carbon 14 activity at natural level in air samples using classical methods of radiochemistry and beta counting. Three different methods have been tested in order to minimise the detection limit. In the three methods, the first step consists in trapping the atmospheric carbon 14 into NaOH (1N) using a bubbling chamber. The atmospheric carbon dioxide reacts with NaOH to form Na2CO3. In the first method the Na2CO3 solution is mixed with a liquid scintillate and is directly analysed by liquid scintillation counting (LSC). The detection limit is approximately 1 Bq/m3 of air samples. The second method consists in evaporating the carbonate solution and then counting the solid residue with a proportional gas circulation counter. The detection limit obtained is lower than the first method (0.4 Bq/m3 of air samples). In the third method, Na2CO3 is precipitated into CaCO3 in presence of CaCl2. CaCO3 is then analysed by LSC. This method appear to be the most appropriate, the detection limit is 0.05 Bq/m3 of air samples. (author)

  3. Conceptual Design of Portable Filtered Air Suction Systems For Prevention of Released Radioactive Gas under Severe Accidents of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Beom W.; Choi, Su Y.; Yim, Man S.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    It becomes evident that severe accidents may occur by unexpected disasters such as tsunami, heavy flood, or terror. Once radioactive material is released from NPP through severe accidents, there are no ways to prevent the released radioactive gas spreading in the air. As a remedy for this problem, the idea on the portable filtered air suction system (PoFASS) for the prevention of released radioactive gas under severe accidents was proposed. In this paper, the conceptual design of a PoFASS focusing on the number of robot fingers and robot arm rods are proposed. In order to design a flexible robot suction nozzle, mathematical models for the gaps which represent the lifted heights of extensible covers for given convex shapes of pipes and for the covered areas are developed. In addition, the system requirements for the design of the robot arms of PoFASS are proposed, which determine the accessible range of leakage points of released radioactive gas. In this paper, the conceptual designs of the flexible robot suction nozzle and robot arm have been conducted. As a result, the minimum number of robot fingers and robot arm rods are defined to be four and three, respectively. For further works, extensible cover designs on the flexible robot suction nozzle and the application of the PoFASS to the inside of NPP should be studied because the radioactive gas may be released from connection pipes between the containment building and auxiliary buildings.

  4. Conceptual Design of Portable Filtered Air Suction Systems For Prevention of Released Radioactive Gas under Severe Accidents of NPP

    International Nuclear Information System (INIS)

    It becomes evident that severe accidents may occur by unexpected disasters such as tsunami, heavy flood, or terror. Once radioactive material is released from NPP through severe accidents, there are no ways to prevent the released radioactive gas spreading in the air. As a remedy for this problem, the idea on the portable filtered air suction system (PoFASS) for the prevention of released radioactive gas under severe accidents was proposed. In this paper, the conceptual design of a PoFASS focusing on the number of robot fingers and robot arm rods are proposed. In order to design a flexible robot suction nozzle, mathematical models for the gaps which represent the lifted heights of extensible covers for given convex shapes of pipes and for the covered areas are developed. In addition, the system requirements for the design of the robot arms of PoFASS are proposed, which determine the accessible range of leakage points of released radioactive gas. In this paper, the conceptual designs of the flexible robot suction nozzle and robot arm have been conducted. As a result, the minimum number of robot fingers and robot arm rods are defined to be four and three, respectively. For further works, extensible cover designs on the flexible robot suction nozzle and the application of the PoFASS to the inside of NPP should be studied because the radioactive gas may be released from connection pipes between the containment building and auxiliary buildings

  5. ELISA-based assay for IP-10 detection from filter paper samples

    DEFF Research Database (Denmark)

    Drabe, Camilla Heldbjerg; Blauenfeldt, Thomas; Ruhwald, Morten

    2014-01-01

    IP-10 is a small pro-inflammatory chemokine secreted primarily from monocytes and fibroblasts. Alterations in IP-10 levels have been associated with inflammatory conditions including viral and bacterial infections, immune dysfunction, and tumor development. IP-10 is increasingly recognized as a b...... biomarker that predicts severity of various diseases and can be used in the immunodiagnostics of Mycobacterium tuberculosis and cytomegalovirus infection. Here, we describe an ELISA-based method to detect IP-10 from dried blood and plasma spot samples....

  6. Estimating occupancy and abundance of stream amphibians using environmental DNA from filtered water samples

    Science.gov (United States)

    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.

  7. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    International Nuclear Information System (INIS)

    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

  9. Report on sampling and analysis of exhaust air at the 221-T and 2706-T buildings

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. CAF-30H1 air cleaner with inverter motor and HEPA filter; `Inverter and HEPA` kuki seijoki CAF-30H1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    An air cleaner series CAF-30H1, equipped with an inverter motor and HEPA filter, has been developed. It has the following major feature: long-life HEPA filter, a special, highly functional filter having a dust-collection efficiency of 99.97% or more for particles of 0.3 {mu}m or more in size; noise of 15.5 dB in the breeze mode, which is the lowest level in the industry; power consumption of 3.5 W in the breeze mode, which is the lowest level in the industry; automatic operational function with a W sensor system incorporating a `dust sensor` and `odor sensor;` and powerful deodorizing filter to adsorb odor of tobacco smoke, to begin with, and that caused by nitrogen oxides and formaldehyde. (translated by NEDO)

  11. CAF-30H1 air cleaner with inverter motor and HEPA filter. 'Inverter and HEPA' kuki seijoki CAF-30H1

    Energy Technology Data Exchange (ETDEWEB)

    1999-03-01

    An air cleaner series CAF-30H1, equipped with an inverter motor and HEPA filter, has been developed. It has the following major feature: long-life HEPA filter, a special, highly functional filter having a dust-collection efficiency of 99.97% or more for particles of 0.3 [mu]m or more in size; noise of 15.5 dB in the breeze mode, which is the lowest level in the industry; power consumption of 3.5 W in the breeze mode, which is the lowest level in the industry; automatic operational function with a W sensor system incorporating a 'dust sensor' and 'odor sensor;' and powerful deodorizing filter to adsorb odor of tobacco smoke, to begin with, and that caused by nitrogen oxides and formaldehyde. (translated by NEDO)

  12. Sampling technologies and air pollution control devices for gaseous and particulate arsenic: a review

    International Nuclear Information System (INIS)

    Direct measurement of arsenic release requires a good sampling and analysis procedure in order to capture and detect the total amount of metals emitted. The literature is extensively reviewed in order to evaluate the efficiency of full field-scale and laboratory scale techniques for capturing particulate and gaseous emissions of arsenic from the thermo-chemical treatment of different sources of arsenic. Furthermore, trace arsenic concentrations in ambient air, national standard sampling methods and arsenic analysis methods are considered. Besides sampling techniques, the use of sorbents is also reviewed with respect to both approaches (1) to prevent the metals from exiting with the flue gas and (2) to react or combine with the metals in order to be collected in air pollution control systems. The most important conclusion is that submicron arsenic fumes are difficult to control in conventional air pollution control devices. Complete capture of the arsenic species requires a combination of particle control and vapour control devices. - Submicron arsenic fumes are difficult to control in conventional air pollution control devices

  13. Water and entrapped air redistribution in heterogeneous sand sample: Quantitative neutron imaging of the process

    Science.gov (United States)

    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.

  14. Electronic Nose and Use of Bags to Collect Odorous Air Samples in Meat Quality Analysis

    Science.gov (United States)

    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.

  15. Diffusive sampling and measurement of microbial volatile organic compounds in indoor air.

    Science.gov (United States)

    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

  16. Excess-air incineration with high temperature filtering for efficient off-gas cleaning

    International Nuclear Information System (INIS)

    When SGN started work on volume reduction of low-level and intermediate-level radioactive wastes in the early 1960s, in collaboration with the French Atomic Energy Commission (CEA), incineration was relatively undeveloped but its potential efficiency was immediately recognized. The incinerators then available divided more or less into proven designs used in municipal refuse incineration and so-called advanced systems: SGN's initial impression was that systems for municipal refuse incineration could be readily adapted to handle combustible nuclear wastes. These systems mainly employed excess-air fixed-bed combustion, rotary furnaces or fluidized-bed combustion, sometimes with partial or total pyrolysis. The ''advanced'' systems proposed by various inventors were far more sophisticated but, due to a lack of industrial experience, were often designed with inadequate regard to human safety. The result was a number of serious accidents, including some deaths. Nuclear-grade incineration was a rather esoteric subject at the time. Standard incinerators were not designed to handle radioactive wastes. They lacked essential safety features (e.g. leaktightness) and did not provide for repair and maintenance after contamination nor for affordable dismantling at end of life. Off-gas cleaning had neither the efficiency nor safety required in the nuclear industry. Extensive automation of control and monitoring was not envisaged, because unnecessary in traditional applications

  17. Monitoring Airborne Fungal Spores in an Experimental Indoor Environment To Evaluate Sampling Methods and the Effects of Human Activity on Air Sampling

    OpenAIRE

    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 sam...

  18. Polyurethane foam (PUF) disks passive air samplers: Wind effect on sampling rates

    Energy Technology Data Exchange (ETDEWEB)

    Tuduri, Ludovic [Equipe Perigourdine de Chimie Appliquee, Laboratoire de Physico-toxicochimie des systemes naturels, Universite Bordeaux I, Site universitaire, 24019 Perigueux cedex (France)]. E-mail: l.tuduri@epca.u-bordeaux1.fr; Harner, Tom [Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada); Hung, Hayley [Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada)

    2006-11-15

    Different passive sampler housings were evaluated for their wind dampening ability and how this might translate to variability in sampler uptake rates. Polyurethane foam (PUF) disk samplers were used as the sampling medium and were exposed to a PCB-contaminated atmosphere in a wind tunnel. The effect of outside wind speed on PUF disk sampling rates was evaluated by exposing polyurethane foam (PUF) disks to a PCB-contaminated air stream in a wind tunnel over air velocities in the range 0 to 1.75 m s{sup -1}. PUF disk sampling rates increased gradually over the range 0-0.9 m s{sup -1} at {approx}4.5-14.6 m{sup 3} d{sup -1} and then increased sharply to {approx}42 m{sup 3} d{sup -1} at {approx}1.75 m s{sup -1} (sum of PCBs). The results indicate that for most field deployments the conventional 'flying saucer' housing adequately dampens the wind effect and will yield approximately time-weighted air concentrations. - Passive sampler housings dampen wind speed and reduce the variability in sampling rates.

  19. Greenhouse gas analysis of air samples collected onboard the CARIBIC passenger aircraft

    Science.gov (United States)

    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.

  20. Polyurethane foam (PUF) disks passive air samplers: Wind effect on sampling rates

    International Nuclear Information System (INIS)

    Different passive sampler housings were evaluated for their wind dampening ability and how this might translate to variability in sampler uptake rates. Polyurethane foam (PUF) disk samplers were used as the sampling medium and were exposed to a PCB-contaminated atmosphere in a wind tunnel. The effect of outside wind speed on PUF disk sampling rates was evaluated by exposing polyurethane foam (PUF) disks to a PCB-contaminated air stream in a wind tunnel over air velocities in the range 0 to 1.75 m s-1. PUF disk sampling rates increased gradually over the range 0-0.9 m s-1 at ∼4.5-14.6 m3 d-1 and then increased sharply to ∼42 m3 d-1 at ∼1.75 m s-1 (sum of PCBs). The results indicate that for most field deployments the conventional 'flying saucer' housing adequately dampens the wind effect and will yield approximately time-weighted air concentrations. - Passive sampler housings dampen wind speed and reduce the variability in sampling rates

  1. Studies on radioactivities of dust samples in the air at high-altitudes

    International Nuclear Information System (INIS)

    The radioactivity concentrations of airborne dust samples were studied. The samples had been collected at high altitude by the Japan Air Self-Defense Force in June 2011 and from September 2011 to March 2012. The obtained data were gross beta radioactivity analysis and gamma nuclide analysis. It is shown that cesium 137 and cesium 134 were detected at the 10 km and 3 km altitude of central area of Japan in almost all the samples. Also, those nuclides were detected around north and west areas of Japan in some samples. Radioactive gases (gaseous radioiodine and radioactive xenon gas) are not detected in all the samples. Refer the report already submitted with regard to the results on radionuclide measurements of Technical Research and Development Institute executed for examining 'the nuclear emergency situation at Fukushima Daiichi and Daini nuclear power plants' after 'Tohoku Region Pacific Ocean Earthquake' on March 11, 2011. (author)

  2. Detection of Legionella spp. by a nested-PCR assay in air samples of a wastewater treatment plant and downwind distances in Isfahan

    Science.gov (United States)

    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

  3. Evaluation of HEPA filter service life

    International Nuclear Information System (INIS)

    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

  4. Evaluation of HEPA filter service life

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Portable monitors for measuring radon and its progenies air by intergrated sampling method

    International Nuclear Information System (INIS)

    Two kinds of portable monitors have been developed, which can be used to measure the concentration of radon or potential energy concentration of radon or potential energy concentration of radon progenies in air. The thermoluminescent material CaSO4(Tm) is used as a detecting element for both of them. The lowest detectable limit of the passive radon monitor is about 1.5 Bq/m3 for radon in air, as the exposure time being one week. Its main advantages are high reliability and convenient manipulation. The working level monitor for radon progenies in air consists of a mini membrane pump and an integrating probe. The lowest detectable limit is about 6.2 x 10-9 J/m3, as the sampling time being 6 hours. It weights only about 0.35 kg

  6. Study of Air Filters in Evaporative Cooling Ventilation and Air-conditioning Unit Used in Power Plants%发电厂蒸发冷却通风空调机组空气过滤器的探讨

    Institute of Scientific and Technical Information of China (English)

    张鑫; 黄翔; 董晓杰

    2015-01-01

    通过对空气过滤器过滤机理、过滤材料以及分类的介绍,并根据蒸发冷却通风空调机组在发电厂中的应用现状,阐释了科学合理选用空气过滤器的重要性。提出为了减缓室外环境中污染物对直接(间接)蒸发冷却器换热性能的影响,应正确选择空气过滤器的类别和级数。%The air filtration theory, air filtration material and classification of air filters are introduced. Based on the current situation of evaporative cooling ventilation and air-conditioning unit used in power plants, these give a explanation of the importance of choose air filters scientifically. In order to slow the effect of evaporative cooler’s heat exchange performance by pollutant in outdoor, the classification and stage of air filters should choose correctly.

  7. Detection of Infectious Cryptosporidium parvum Oocysts in Surface and Filter Backwash Water Samples by Immunomagnetic Separation and Integrated Cell Culture-PCR

    OpenAIRE

    Di Giovanni, George D.; Hashemi, F. Helen; Shaw, Nancy J.; Abrams, Felicia A.; LeChevallier, Mark W.; Abbaszadegan, Morteza

    1999-01-01

    A new strategy for the detection of infectious Cryptosporidium parvum oocysts in water samples, which combines immunomagnetic separation (IMS) for recovery of oocysts with in vitro cell culturing and PCR (CC-PCR), was field tested with a total of 122 raw source water samples and 121 filter backwash water grab samples obtained from 25 sites in the United States. In addition, samples were processed by Percoll-sucrose flotation and oocysts were detected by an immunofluorescence assay (IFA) as a ...

  8. Improving a Single Down-Sampled Image Using Probability-Filtering-Based Interpolation and Improved Poisson Maximum A Posteriori Super-Resolution

    OpenAIRE

    Pan Min-Cheng

    2006-01-01

    We present a novel hybrid scheme called "hyper-resolution" that integrates image probability-filtering-based interpolation and improved Poisson maximum a posteriori (MAP) super-resolution to respectively enhance high spatial and spatial-frequency resolutions of a single down-sampled image. A new approach to interpolation is proposed for simultaneous image interpolation and smoothing by exploiting the probability filter coupled with a pyramidal decomposition and the Poisson MAP super-resoluti...

  9. 14C AMS measurements of tree leaf samples to monitor air pollution induced by city traffic

    International Nuclear Information System (INIS)

    In the past, many radiocarbon measurement have been made for environmental studies such as source apportionment of air-borne particulates, and studies of the anthropogenic effects of nuclear power plants. In this presentation we report our accelerator mass spectrometry (AMS) measurements of radiocarbon on tree leaf samples to investigate the impact of city traffic on our living-environment. The fossil-burning vehicles emit carbon dioxide (CO2) free of 14C content and, when mixed with the clean air CO2, lower 14C ratio compared to the normal reservoir value. This so-called Suess effect can be incorporated to monitor air quality in our living environments, since metabolic processes maintain the 14C content of living organism in equilibrium with atmospheric 14C. In other words, dead CO2 is admixed to the normal atmospheric CO2 and then photo-synthetically assimilated by the plants. Two kinds of tree leaf samples; pine tree needles and Ginkgo tree leaves were collected during a one-week period in the summer 1996 at five different locations with various traffic conditions in the region, within a 10-km diameter circle, south of the River Han, Seoul. The AMS targets were made by a simple sample-making procedure. The leaves have been pretreated by a standard acid-alkali treatment and then charred in a vacuum evaporator by applying ca. 800 deg C heat. The charred samples were mixed with Ag powder and pressed into the Al target holder for the AMS measurement.The AMS measurements were made using the accelerator mass spectrometry facilities of the Leibniz-Labor at the Christian-Albrecht University, Kiel,Germany. The observed Δ14C values, which ranged from 60TM to 158TM, have a good correlation with the traffic conditions in the places where the sampling took place and show a remarkable capability of 14C AMS measurements to monitor our fossil burning environment. The volume ratios of clean air to air from fossil-burn origin in the environmental CO2 reached to a level of 8

  10. Release of Free DNA by Membrane-Impaired Bacterial Aerosols Due to Aerosolization and Air Sampling

    OpenAIRE

    Zhen, Huajun; Han, Taewon; Fennell, Donna E.; Mainelis, Gediminas

    2013-01-01

    We report here that stress experienced by bacteria due to aerosolization and air sampling can result in severe membrane impairment, leading to the release of DNA as free molecules. Escherichia coli and Bacillus atrophaeus bacteria were aerosolized and then either collected directly into liquid or collected using other collection media and then transferred into liquid. The amount of DNA released was quantified as the cell membrane damage index (ID), i.e., the number of 16S rRNA gene copies in ...

  11. Optimal Media for Use in Air Sampling To Detect Cultivable Bacteria and Fungi in the Pharmacy

    OpenAIRE

    Weissfeld, Alice S.; Joseph, Riya Augustin; Le, Theresa V.; Trevino, Ernest A.; Schaeffer, M. Frances; Vance, Paula H.

    2013-01-01

    Current guidelines for air sampling for bacteria and fungi in compounding pharmacies require the use of a medium for each type of organism. U.S. Pharmacopeia (USP) chapter (http://www.pbm.va.gov/linksotherresources/docs/USP797PharmaceuticalCompoundingSterileCompounding.pdf) calls for tryptic soy agar with polysorbate and lecithin (TSApl) for bacteria and malt extract agar (MEA) for fungi. In contrast, the Controlled Environment Testing Association (CETA), the professional organization for in...

  12. Isotopic air sampling in a tallgrass prairie to partition net ecosystem CO2 exchange

    Science.gov (United States)

    Lai, Chun-Ta; Schauer, Andrew J.; Owensby, Clenton; Ham, Jay M.; Ehleringer, James R.

    2003-09-01

    Stable isotope ratios of various ecosystem components and net ecosystem exchange (NEE) CO2 fluxes were measured in a C3-C4 mixture tallgrass prairie near Manhattan, Kansas. The July 2002 study period was chosen because of contrasting soil moisture contents, which allowed us to address the effects of drought on photosynthetic CO2 uptake and isotopic discrimination. Significantly higher NEE fluxes were observed for both daytime uptake and nighttime respiration during well-watered conditions when compared to a drought period. Given these differences, we investigated two carbon-flux partitioning questions: (1) What proportions of NEE were contributed by C3 versus C4 species? (2) What proportions of NEE fluxes resulted from canopy assimilation versus ecosystem respiration? To evaluate these questions, air samples were collected every 2 hours during daytime for 3 consecutive days at the same height as the eddy covariance system. These air samples were analyzed for both carbon isotope ratios and CO2 concentrations to establish an empirical relationship for isoflux calculations. An automated air sampling system was used to collect nighttime air samples to estimate the carbon isotope ratios of ecosystem respiration (δR) at weekly intervals for the entire growing season. Models of C3 and C4 photosynthesis were employed to estimate bulk canopy intercellular CO2 concentration in order to calculate photosynthetic discrimination against 13C. Our isotope/NEE results showed that for this grassland, C4 vegetation contributed ˜80% of the NEE fluxes during the drought period and later ˜100% of the NEE fluxes in response to an impulse of intense precipitation. For the entire growing season, the C4 contribution ranged from ˜68% early in the spring to nearly 100% in the late summer. Using an isotopic approach, the calculated partitioned respiratory fluxes were slightly greater than chamber-measured estimates during midday under well-watered conditions. In addition, time series

  13. Technical assessment of TRUSAF for compliance with work place air sampling. Revision 1

    International Nuclear Information System (INIS)

    The purpose of this Technical Work Document is to satisfy WHC-CM-1-6, the ''WHC Radiological Control Manual.'' This first revision of the original Supporting Document covers the period from January 1, 1994 to December 31, 1994. WHC-CM-1-6 is the primary guidance for radiological control at Westinghouse Hanford Company (WHC). As such, it complies with Title 10, Part 835 of the Code of Federal Regulations. In addition to WHC-CM-1-6, there is HSRCM-1, the ''Hanford Site Radiological Control Manual'' and several Department of Energy (DOE) Orders, national consensus standards, and reports that provide criteria, standards, and requirements for workplace air sampling programs. This document provides a summary of these, as they apply to WHC facility workplace air sampling programs. this document also provides an evaluation of the compliance of the TRUSAF workplace air sampling program to the criteria, standards, and requirements and documents. Where necessary, it also indicates changes needed to bring specific locations into compliance

  14. Technical assessment of workplace air sampling requirements at tank farm facilities. Revision 1

    International Nuclear Information System (INIS)

    WHC-CM-1-6 is the primary guidance for radiological control at Westinghouse Hanford Company (WHC). It was written to implement DOE N 5480.6 ''US Department of Energy Radiological Control Manual'' as it applies to programs at Hanford which are now overseen by WHC. As such, it complies with Title 10, Part 835 of the Code of Federal Regulations. In addition to WHC-CM-1-6, there is HSRCM-1, the ''Hanford Site Radiological Control Manual'' and several Department of Energy (DOE) Orders, national consensus standards, and reports that provide criteria, standards, and requirements for workplace air sampling programs. This document provides a summary of these, as they apply to WHC facility workplace air sampling programs. This document also provides an evaluation of the compliance of Tank Farms' workplace air sampling program to the criteria, standards, and requirements and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance

  15. Measurement of the Tracer Gradient and Sampling System Bias of the Hot Fuel Examination Facility Stack Air Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A.; Flaherty, Julia E.

    2011-07-20

    This report describes tracer gas uniformity and bias measurements made in the exhaust air discharge of the Hot Fuel Examination Facility at Idaho National Laboratory. The measurements were a follow-up on earlier measurements which indicated a lack of mixing of the two ventilation streams being discharged via a common stack. The lack of mixing is detrimental to the accuracy of air emission measurements. The lack of mixing was confirmed in these new measurements. The air sampling probe was found to be out of alignment and that was corrected. The suspected sampling bias in the air sample stream was disproved.

  16. A new device for magnetic stirring-assisted dispersive liquid-liquid microextraction of UV filters in environmental water samples.

    Science.gov (United States)

    Zhang, Ping-Ping; Shi, Zhi-Guo; Yu, Qiong-Wei; Feng, Yu-Qi

    2011-02-15

    A new method based on dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography (HPLC) has been developed for the analysis of UV filters. A specially designed flask, which has two narrow open necks with one of them having a capillary tip, was employed to facilitate the DLLME process. By adopting such a device, the extraction and subsequent phase separation were conveniently achieved. A binary solvent system of water sample and low-density extraction solvent (1-octanol) was used for the DLLME and no disperser solvent was involved. The extraction was accelerated by magnetic agitation of the two phases. After extraction, phase separation of the extraction solvent from the aqueous sample was easily achieved by leaving the extraction system statically for a while. No centrifugation step involving in classical DLLME was necessary. The analyte-enriched phase, floating above the sample solution, was elevated and concentrated into the narrow open tip of the flask by adding pure water into it via the other port, which was withdrawn with a microsyringe for the subsequent HPLC analysis. Under the optimized conditions, the limits of detection for the analytes were in range of 0.2-0.8ngmL(-1) .The linearity ranges were 8-20,000 ng mL(-1) for HB, 7-20,000 ng mL(-1) for DB, 8-10,000 ng mL(-1) for BP and 5-20,000 ng mL(-1) for HMB, respectively. Enrichment factors ranging from 59 to 107 folders were obtained for the analytes. The relative standard deviations (n=3) at a spiked level of 80 ng mL(-1) were between 1.4 and 4.8%. The proposed magnetic stirring-assisted DLLME method was successfully applied to the analysis of lake water samples. PMID:21238773

  17. Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air Part 1: Sorbent-based air monitoring options.

    Science.gov (United States)

    Woolfenden, Elizabeth

    2010-04-16

    Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions, etc. Levels can range from low percent concentrations in stack and vent emissions to low part per trillion (ppt) levels in ultra-clean outdoor locations. Hundreds, even thousands of different compounds may be present in any given atmosphere. GC is commonly used in combination with mass spectrometry (MS) detection especially for environmental monitoring or for screening uncharacterised workplace atmospheres. Given the complexity and variability of organic vapours in air, no one sampling approach suits every monitoring scenario. A variety of different sampling strategies and sorbent media have been developed to address specific applications. Key sorbent-based examples include: active (pumped) sampling onto tubes packed with one or more sorbents held at ambient temperature; diffusive (passive) sampling onto sorbent tubes/cartridges; on-line sampling of air/gas streams into cooled sorbent traps; and transfer of air samples from containers (canisters, Tedlar) bags, etc.) into cooled sorbent focusing traps. Whichever sampling approach is selected, subsequent analysis almost always involves either solvent extraction or thermal desorption (TD) prior to GC(/MS) analysis. The overall performance of the air monitoring method will depend heavily on appropriate selection of key sampling and analytical parameters. This comprehensive review of air monitoring using sorbent tubes/traps is divided into 2 parts. (1) Sorbent-based air sampling option. (2) Sorbent selection and other aspects of optimizing sorbent-based air monitoring methods. The paper presents

  18. CARBONIZED FIBROUS RESIN AS A NEW SORBENT FOR SAMPLING POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN AMBIENT AIR

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new sampling method of ambient air analysis using carbonized fibrous resin as asorbent for polycyclic aromatic hydrocarbons (PAHs) was reported.The physical and chemical properties of the carbonized fibrous resins were measured. Thesample pretreatment with ultrasonic extraction and subsequent clean-up ehition through a silica gelcolumn was optimized. The suitable ultrasonic extraction conditions were selected as follows: resinweight was 1.5 g, ultrasonic extraction time 20 min, volume of extraction solvent 100 mi andextraction operation times 2~3. The concentrated extractable organic matter was submitted to nextstep of clean-up procedure of adsorption chromatography on silica gel column/n-hexane and amixture of dichloromethene:n-hexane solution 2:3 (v/v). The PAHs fractions in the real samplesfrom Changzhou, China were particularly analyzed using GC-MS data system and the data of massspectra, retention times and scan numbers of the real samples were compared with that of thestandards of 16 PAHs listed by the US EPA as "priority pollutants" of the environment. Theanalysis of the real samples indicates that the carbonized fibrous resin is a good sorbent. Thepretreatment of samples of ambient air with carbonized fibrous resin as a sorbent for P,AHs isproved to be reliable and might be used for the procedure of the determination of PAHs inatmospheric environment.

  19. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    Science.gov (United States)

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-06-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning. PMID:26942452

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

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Robert Clark

    2003-12-01

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

  1. Analysis of air particulate matter in Teflon trademark and quartz filters by short-irradiation, epithermal-neutron activation with Compton suppression

    International Nuclear Information System (INIS)

    This work aimed at developing methodologies to characterize the elemental composition of air particulate matter (APM) collected in Portugal, at an urban area (Lisboa, mainland Portugal) and at a remote location (Terceira island, Azores, Portugal). The Azores' collections were based on quartz filters; Teflon trademark filters were used at the urban area. The main components of Teflon trademark and quartz filters are fluorine and silica, respectively, the latter featuring higher levels of elements in the blanks. Al and Ti are reduced to null values when the blanks are subtracted. Epithermal short irradiation associated to Compton suppression in the measurement allowed the determination of a set of elements potentially representative of important emission sources: seaspray (Cl, Br, Na, Mg), fuel burning (V), incineration (Cl), soil resuspension (Mg, Mn, Na, U, V), and traffic (Br, Mn). The analysis was fast due to the use of an automatic system. In some cases, the same element had different origins in the urban and remote oceanic areas. (orig.)

  2. Atmospheric trace gas measurements with a new clean air sampling system

    International Nuclear Information System (INIS)

    The development of a new clean air sampling system for the Department of Energy's WB-57F aircraft has allowed the analysis of CCl3F (Fluorocarbon-11), CCl2F2 (Fluorocarbon-12), CHClF2 (Fluorocarbon-22), C2Cl3F3 (Fluorocarbon-113), CH4, CO, CO2, N2O, CH3Cl, CCl4, CH3CCl3, OCS and SF6 in tropospheric and stratospheric samples. Samples collected during the interception of the plume from the eruption of Mount St. Helens indicate that OCS was injected into the stratosphere during the eruption. A large CO2 gradient was found at 19.2 km on this flight

  3. Size selective isocyanate aerosols personal air sampling using porous plastic foams

    International Nuclear Information System (INIS)

    As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

  4. Estimating surface CO2 fluxes from space-borne CO2 dry air mole fraction observations using an ensemble Kalman Filter

    Directory of Open Access Journals (Sweden)

    S. Dance

    2008-11-01

    Full Text Available We have developed an ensemble Kalman Filter (EnKF to estimate 8-day regional surface fluxes of CO2 from space-borne CO2 dry-air mole fraction observations (XCO2 and evaluate the approach using a series of synthetic experiments, in preparation for data from the NASA Orbiting Carbon Observatory (OCO. The 32-day duty cycle of OCO alternates every 16 days between nadir and glint measurements of backscattered solar radiation at short-wave infrared wavelengths. The EnKF uses an ensemble of states to represent the prior error covariance to estimate 8-day CO2 surface fluxes over 144 geographical regions. We use a 12×8-day lag window, recognising that XCO2 measurements include surface flux information from prior time windows. The observation operator that relates surface CO2 fluxes to atmospheric distributions of XCO2 includes: a the GEOS-Chem transport model that relates surface fluxes to global 3-D distributions of CO2 concentrations, which are sampled at the time and location of OCO measurements that are cloud-free and have aerosol optical depths 2 profiles to XCO2, accounting for differences between nadir and glint measurements, and the associated scene-dependent observation errors. We show that OCO XCO2 measurements significantly reduce the uncertainties of surface CO2 flux estimates. Glint measurements are generally better at constraining ocean CO2 flux estimates. Nadir XCO2 measurements over the terrestrial tropics are sparse throughout the year because of either clouds or smoke. Glint measurements provide the most effective constraint for estimating tropical terrestrial CO2 fluxes by accurately sampling fresh continental outflow over neighbouring oceans. We also present results from sensitivity experiments that investigate how flux estimates change with 1 bias and unbiased errors, 2 alternative duty cycles, 3 measurement density and correlations, 4 the spatial resolution of estimated flux estimates, and 5 reducing the length of the lag window

  5. Preparation and characterization of a new set of IAEA reference air filters using instrumental neutron activation analysis, proton-induced X-ray emission and Rutherford backscattering

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Havránek, Vladimír; Krausová, Ivana

    2009-01-01

    Roč. 281, č. 1 (2009), s. 123-129. ISSN 0236-5731. [9th International Conference on Nuclear Analytical Methods in the Life Sciences. Lisbon, 07.09.2008-12.09.2008] Institutional research plan: CEZ:AV0Z10480505 Keywords : Reference air filters * instrumental neutron activation analysis * Proton induced X-ray emission Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.631, year: 2009

  6. Accurate quantification of tio2 nanoparticles collected on air filters using a microwave-assisted acid digestion method.

    Science.gov (United States)

    Mudunkotuwa, Imali A; Anthony, T Renée; Grassian, Vicki H; Peters, Thomas M

    2016-01-01

    Titanium dioxide (TiO(2)) particles, including nanoparticles with diameters smaller than 100 nm, are used extensively in consumer products. In a 2011 current intelligence bulletin, the National Institute of Occupational Safety and Health (NIOSH) recommended methods to assess worker exposures to fine and ultrafine TiO(2) particles and associated occupational exposure limits for these particles. However, there are several challenges and problems encountered with these recommended exposure assessment methods involving the accurate quantitation of titanium dioxide collected on air filters using acid digestion followed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Specifically, recommended digestion methods include the use of chemicals, such as perchloric acid, which are typically unavailable in most accredited industrial hygiene laboratories due to highly corrosive and oxidizing properties. Other alternative methods that are used typically involve the use of nitric acid or combination of nitric acid and sulfuric acid, which yield very poor recoveries for titanium dioxide. Therefore, given the current state of the science, it is clear that a new method is needed for exposure assessment. In this current study, a microwave-assisted acid digestion method has been specifically designed to improve the recovery of titanium in TiO(2) nanoparticles for quantitative analysis using ICP-OES. The optimum digestion conditions were determined by changing several variables including the acids used, digestion time, and temperature. Consequently, the optimized digestion temperature of 210°C with concentrated sulfuric and nitric acid (2:1 v/v) resulted in a recovery of >90% for TiO(2). The method is expected to provide for a more accurate quantification of airborne TiO(2) particles in the workplace environment. PMID:26181824

  7. A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates

    Science.gov (United States)

    Maurice, P.A.; Pullin, M.J.; Cabaniss, S.E.; Zhou, Q.; Namjesnik-Dejanovic, K.; Aiken, G.R.

    2002-01-01

    This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the most common techniques used to isolate natural organic matter (NOM) for studies of composition and reactivity; therefore, it is important to understand how the isolates differ from bulk (unisolated) samples and from one another. Although, any comparison between the isolation methods needs to consider that XAD-8 is specifically designed to isolate the humic fraction, whereas RO concentrates a broad range of organic matter and is not specific to humics. The comparison included for all samples: weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity (??), absorbance at 280nm normalized to moles C (??280) (RFW and isolates); and for isolates only: elemental analysis, % carbon distribution by 13C NMR, and aqueous FTIR spectra. As expected, RO isolation gave higher yield of NOM than XAD-8, but also higher ash content, especially Si and S. Mw decreased in the order: RO>XAD-8>RFW>XAD-4. The Mw differences of isolates compared with RFW may be due to selective isolation (fractionation), or possibly in the case of RO to condensation or coagulation during isolation. 13C NMR results were roughly similar for the two methods, but the XAD-8 isolate was slightly higher in 'aromatic' C and the RO isolate was slightly higher in heteroaliphatic and carbonyl C. Infrared spectra indicated a higher carboxyl content for the XAD-8 isolates and a higher ester:carboxyl ratio for the RO isolates. The spectroscopic data thus are consistent with selective isolation of more hydrophobic compounds by XAD-8, and also with potential ester hydrolysis during that process, although further study is needed to determine whether ester hydrolysis does indeed occur. Researchers choosing between XAD and RO

  8. Flow resistance of HEPA filters in supersaturated airstreams

    International Nuclear Information System (INIS)

    A loss of coolant accident or fire suppression with water sprays would release free moisture into the air within the containment building of a nuclear reactor. The resulting high air humidity could be expected to unfavorably affect the behavior of the HEPA filters in the facility air cleaning systems. Still to be found in the literature are instances of moisture related deterioration in filter performance during less serious incidents, and even during normal operations. One phenomenon which contributes to filter failure, and which also causes air-cleaning system malfunction characterized by drastically reduced flow rates, is the increase in filter differential pressure resulting from supersaturated airflow. In order to better evaluate the performance and the reliability of filters exposed to fog, a study of the factors which influence filter pressure drop was carried out in tests of clean and dust loaded full scale HEPA-filter units. Investigated were the effects of several airstream parameters and such filter characteristics as manufacturer, design, pack geometry, extent and type of dust loading, as well as pleat orientation to the airflow. A discontinuous gravimetric method employing full-size filter units as sampling filters was successfully implemented to determine the average liquid moisture content of the airstream with an uncertainty of ≤10%. The dust loading in filters removed from service and the liquid moisture content of the air proved to most adversely affect the rate and extent of the pressure drop increase. Reductions in the susceptibility of clean filters to pressure drop increases can be obtained by changes in filter geometry, design or orientation to the airflow that enhance the drainage of water from the filter medium. However, the predominance of the adverse influence of dust loading appears to be able to counteract the effectiveness of the improvements studied

  9. Impact of Filter Paper Multilayering on Air Permeability%滤纸多层复合对透气率的影响

    Institute of Scientific and Technical Information of China (English)

    黄铖; 曾靖山; 梁云; 沈栋

    2011-01-01

    The relationship of the air permeability between the single-layer and multi-layer composite filter paper was studied. The multi-layer composite filter paper was made by placed the single-layer wet sheet close together in a certain order and dried in the Arc dryer, and the relationship of the air permeability between the double(triple) composite filter paper and its every single-layer at the case that each layer was composed of a single fiber or various fibers was researched. By the research we deduce the relationship between the air permeability of multi-layer composite filter paper and the air permeability of single-layer filter paper as follows: 1/T=1/T1+1/T2 +... +1/T11, which would provide instructional information for the study of multi-layer composite filter paper.%研究多层复合滤纸和单层滤纸间透气率的关系:通过将单层湿纸页按一定顺序紧密叠合在一起并放入弧形干燥器内干燥的方法形成多层复合滤纸,探讨当各层纤维为单一纤维和多种纤维复配两种情况下的2层和3层复合滤纸的透气率与各单层滤纸透气率之间的关系,并从理论上推导出多层复合滤纸和单层滤纸间透气率存在如下关系:1/T=1/T1+1/T2+…+1/T11,这对多层复合滤纸的研究有一定的指导意义。

  10. Estimation of sampling error uncertainties in observed surface air temperature change in China

    Science.gov (United States)

    Hua, Wei; Shen, Samuel S. P.; Weithmann, Alexander; Wang, Huijun

    2016-06-01

    This study examines the sampling error uncertainties in the monthly surface air temperature (SAT) change in China over recent decades, focusing on the uncertainties of gridded data, national averages, and linear trends. Results indicate that large sampling error variances appear at the station-sparse area of northern and western China with the maximum value exceeding 2.0 K2 while small sampling error variances are found at the station-dense area of southern and eastern China with most grid values being less than 0.05 K2. In general, the negative temperature existed in each month prior to the 1980s, and a warming in temperature began thereafter, which accelerated in the early and mid-1990s. The increasing trend in the SAT series was observed for each month of the year with the largest temperature increase and highest uncertainty of 0.51 ± 0.29 K (10 year)-1 occurring in February and the weakest trend and smallest uncertainty of 0.13 ± 0.07 K (10 year)-1 in August. The sampling error uncertainties in the national average annual mean SAT series are not sufficiently large to alter the conclusion of the persistent warming in China. In addition, the sampling error uncertainties in the SAT series show a clear variation compared with other uncertainty estimation methods, which is a plausible reason for the inconsistent variations between our estimate and other studies during this period.

  11. Extreme 13C depletion of CCl2F2 in firn air samples from NEEM, Greenland

    Directory of Open Access Journals (Sweden)

    T. Blunier

    2012-07-01

    Full Text Available A series of 12 high volume air samples collected from the S2 firn core during the North Greenland Eemian Ice Drilling (NEEM 2009 campaign have been measured for mixing ratio and stable carbon isotope composition of the chlorofluorocarbon CFC-12 (CCl2F2. While the mixing ratio measurements compare favorably to other firn air studies, the isotope results show extreme 13C depletion at the deepest measurable depth (65 m, to values lower than δ13C = −80‰ vs. VPDB (the international stable carbon isotope scale, compared to present day surface tropospheric measurements near −40‰. Firn air modeling was used to interpret these measurements. Reconstructed atmospheric time series indicate even larger depletions (to −120‰ near 1950 AD, with subsequent rapid enrichment of the atmospheric reservoir of the compound to the present day value. Mass-balance calculations show that this change must have been caused by a large change in the isotopic composition of anthropogenic CFC-12 emissions, probably due to technological changes in the CFC production process over the last 80 yr. Propagating the mass-balance calculations into the future demonstrates that as emissions decrease to zero, isotopic fractionation by the stratospheric sinks will lead to continued 13C enrichment in atmospheric CFC-12.

  12. Extreme 13C depletion of CCl2F2 in firn air samples from NEEM, Greenland

    Directory of Open Access Journals (Sweden)

    T. Blunier

    2013-01-01

    Full Text Available A series of 12 high volume air samples collected from the S2 firn core during the North Greenland Eemian Ice Drilling (NEEM 2009 campaign have been measured for mixing ratio and stable carbon isotope composition of the chlorofluorocarbon CFC-12 (CCl2F2. While the mixing ratio measurements compare favorably to other firn air studies, the isotope results show extreme 13C depletion at the deepest measurable depth (65 m, to values lower than δ13C = −80‰ vs. VPDB (the international stable carbon isotope scale, compared to present day surface tropospheric measurements near −40‰. Firn air modeling was used to interpret these measurements. Reconstructed atmospheric time series indicate even larger depletions (to −120‰ near 1950 AD, with subsequent rapid enrichment of the atmospheric reservoir of the compound to the present day value. Mass-balance calculations show that this change is likely to have been caused by a large change in the isotopic composition of anthropogenic CFC-12 emissions, probably due to technological advances in the CFC production process over the last 80 yr, though direct evidence is lacking.

  13. Cast Stone Oxidation Front Evaluation: Preliminary Results For Samples Exposed To Moist Air

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C. A.; Almond, P. M.

    2013-11-26

    The rate of oxidation is important to the long-term performance of reducing salt waste forms because the solubility of some contaminants, e.g., technetium, is a function of oxidation state. TcO{sub 4}{sup -} in the salt solution is reduced to Tc(IV) and has been shown to react with ingredients in the waste form to precipitate low solubility sulfide and/or oxide phases. Upon exposure to oxygen, the compounds containing Tc(IV) oxidize to the pertechnetate ion, Tc(VII)O{sub 4}{sup -}, which is very soluble. Consequently the rate of technetium oxidation front advancement into a monolith and the technetium leaching profile as a function of depth from an exposed surface are important to waste form performance and ground water concentration predictions. An approach for measuring contaminant oxidation rate (effective contaminant specific oxidation rate) based on leaching of select contaminants of concern is described in this report. In addition, the relationship between reduction capacity and contaminant oxidation is addressed. Chromate (Cr(VI) was used as a non-radioactive surrogate for pertechnetate, Tc(VII), in Cast Stone samples prepared with 5 M Simulant. Cast Stone spiked with pertechnetate was also prepared and tested. Depth discrete subsamples spiked with Cr were cut from Cast Stone exposed to Savannah River Site (SRS) outdoor ambient temperature fluctuations and moist air. Depth discrete subsamples spiked with Tc-99 were cut from Cast Stone exposed to laboratory ambient temperature fluctuations and moist air. Similar conditions are expected to be encountered in the Cast Stone curing container. The leachability of Cr and Tc-99 and the reduction capacities, measured by the Angus-Glasser method, were determined for each subsample as a function of depth from the exposed surface. The results obtained to date were focused on continued method development and are preliminary and apply to the sample composition and curing / exposure conditions described in this report. The

  14. The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis

    OpenAIRE

    Weiyi Sun; Jian Sun; Lili Zou; Kaini Shen; Dingrong Zhong; Daobin Zhou; Wei Sun; Jian Li

    2015-01-01

    Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove ...

  15. Comparison of Hollow-Fiber Ultrafilters with Pleated Capsule Filters for Surface and Tap Water Samples Using U.S. EPA Method 1623

    OpenAIRE

    Kimble, Gina H.; Amburgey, James E.; Hill, Vincent R.

    2012-01-01

    The EPA method 1623 is designed specifically for the detection of Cryptosporidium and Giardia, but the method has some issues with low and variable recoveries. Ultrafiltration has been used effectively for microorganism recovery from water samples but is not approved by the EPA. To determine the efficacy of using ultrafiltration, 10-L tap water and surface water samples were seeded with Cryptosporidium and Giardia and concentrated with either a pleated capsule filter or a hollow-fiber ultrafi...

  16. Atmospheric aerosol studies using the 'Gent' stacked filter unit and other aerosol collectors, with multi-elemental analysis of the samples by nuclear-related analytical techniques. Appendix 4

    International Nuclear Information System (INIS)

    Our research within the core programme of the Co-ordinated Research Programme (CRP) on Air Pollution is described. This included the analysis of the analytical quality control Nuclepore filter samples, work on the calibration of the PM10 inlet of the 'Gent' stacked filter unit (SFU) sampler, and an aerosol study with this SFU sampler at an urban residential site in Gent. The calibration of the Gent PM10 inlet was done through intercomparisons with commercially available PM10 samplers, and quite reasonable agreement was obtained. For the study at the urban residential site, a total of 118 SFU samples were collected. The samples were analyzed for the particulate mass, black carbon and up to 29 elements. The elements were measured by PIXE and short-irradiation INAA. Median atmospheric concentrations and enrichment factors were calculated for the fine and coarse size fractions, and average FINE/COARSE ratios were derived. The median concentrations were compared with those from a study, done at the same site in the fall of 1986. The levels of the automotive elements Pb and Br had decreased by a factor of about three relative to 1986, but most other elements exhibited very similar concentrations. A brief overview is given of the status in our various regional and global scale aerosol studies. Finally, our plans for future work are given. (author)

  17. Soil separator and sampler and method of sampling

    Science.gov (United States)

    O'Brien, Barry H [Idaho Falls, ID; Ritter, Paul D [Idaho Falls, ID

    2010-02-16

    A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

  18. Evaluation of sampling methods for toxicological testing of indoor air particulate matter.

    Science.gov (United States)

    Tirkkonen, Jenni; Täubel, Martin; Hirvonen, Maija-Riitta; Leppänen, Hanna; Lindsley, William G; Chen, Bean T; Hyvärinen, Anne; Huttunen, Kati

    2016-09-01

    There is a need for toxicity tests capable of recognizing indoor environments with compromised air quality, especially in the context of moisture damage. One of the key issues is sampling, which should both provide meaningful material for analyses and fulfill requirements imposed by practitioners using toxicity tests for health risk assessment. We aimed to evaluate different existing methods of sampling indoor particulate matter (PM) to develop a suitable sampling strategy for a toxicological assay. During three sampling campaigns in moisture-damaged and non-damaged school buildings, we evaluated one passive and three active sampling methods: the Settled Dust Box (SDB), the Button Aerosol Sampler, the Harvard Impactor and the National Institute for Occupational Safety and Health (NIOSH) Bioaerosol Cyclone Sampler. Mouse RAW264.7 macrophages were exposed to particle suspensions and cell metabolic activity (CMA), production of nitric oxide (NO) and tumor necrosis factor (TNFα) were determined after 24 h of exposure. The repeatability of the toxicological analyses was very good for all tested sampler types. Variability within the schools was found to be high especially between different classrooms in the moisture-damaged school. Passively collected settled dust and PM collected actively with the NIOSH Sampler (Stage 1) caused a clear response in exposed cells. The results suggested the higher relative immunotoxicological activity of dust from the moisture-damaged school. The NIOSH Sampler is a promising candidate for the collection of size-fractionated PM to be used in toxicity testing. The applicability of such sampling strategy in grading moisture damage severity in buildings needs to be developed further in a larger cohort of buildings. PMID:27569522

  19. Determination of Ra-226 in Soil Samples Collected from Filters of Underground Water Treatment Stations by Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    An analytical procedure has been proposed for the determination of 226Ra at the low picogram per gram concentration level in soil samples using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). 226Ra is pre-concentrated from sand filters using inorganic acids after optimizing different parameters. Sand filters are used in underground water treatment stations to remove particulate matter from underground water, where iron and manganese are collected and form thin films covers sands. Iron and manganese oxides adsorb radium from underground water. By time, radium concentrations increase in the filters, and consequently the level of radioactivity increases in the station. Separation of radium from Barium, lanthanum, cerium and strontium soils is obtained by using dowex 50w-X8 and Eichrom Sr-resin. The limit of detection for 226Ra determination is 0.02 ppt. 226Ra concentrations are found between 17.9-198 ppt. In addition, uranium concentration and uranium isotope ratios are measured.

  20. Study on DOP substitutes for leaking rate testing of HEPA filter used in nuclear air cleaning systems

    International Nuclear Information System (INIS)

    Based on an extensive investigation over available literatures concerning HEPA filter testing, PEG400, SHELL on dina oil 15 and P.a. were chosen as candidates for Dop substitutes, and on which a series of tests were conducted about their aerosol conversion rate, particle size distribution, Dop detector response and leaking rate in H EPA filter. With consideration of technical properties, safety performance and economy, homemade P.a. is finally selected as the best substitute for Dop among the three. (authors)

  1. HEPA filter monitoring program

    Science.gov (United States)

    Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

    1986-07-01

    The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

  2. Air-deployable oil spill sampling devices review phase 2 testing. Volume 1

    International Nuclear Information System (INIS)

    SAIC Canada tested air deployable oil sampling devices for the Emergencies Science and Technology Division of Environment Canada in order to determine the applicability and status of these devices. The 3 devices tested were: Canada's SABER (sampling autonomous buoy for evidence recovery), the United States' POPEIE (probe for oil pollution evidence in the environment); and, Sweden's SAR Floatation 2000. They were tested for buoyancy properties, drift behaviour and sampler sorbent pickup ratios. The SAR and SABER both had lesser draft and greater freeboard, while the POPEIE had much greater draft than freeboard. All 3 devices could be used for oil sample collection in that their drift characteristics would allow for the SABER and SAR devices to be placed upwind of the slick while the POPEIE device could be placed downwind of an oil spill. The sorbent testing revealed that Sefar sorbent and Spectra sorbent used in the 3 devices had negative pickup ratios for diesel but performance improved as oil viscosity increased. Both sorbents are inert and capable of collecting oil in sufficient volumes for consistent fingerprinting analysis. 10 refs., 8 tabs., 8 figs

  3. Unmanned platform for long-range remote analysis of volatile compounds in air samples.

    Science.gov (United States)

    da Costa, Eric T; Neves, Carlos A; Hotta, Guilherme M; Vidal, Denis T R; Barros, Marcelo F; Ayon, Arturo A; Garcia, Carlos D; do Lago, Claudimir Lucio

    2012-09-01

    This paper describes a long-range remotely controlled CE system built on an all-terrain vehicle. A four-stroke engine and a set of 12-V batteries were used to provide power to a series of subsystems that include drivers, communication, computers, and a capillary electrophoresis module. This dedicated instrument allows air sampling using a polypropylene porous tube, coupled to a flow system that transports the sample to the inlet of a fused-silica capillary. A hybrid approach was used for the construction of the analytical subsystem combining a conventional fused-silica capillary (used for separation) and a laser machined microfluidic block, made of PMMA. A solid-state cooling approach was also integrated in the CE module to enable controlling the temperature and therefore increasing the useful range of the robot. Although ultimately intended for detection of chemical warfare agents, the proposed system was used to analyze a series of volatile organic acids. As such, the system allowed the separation and detection of formic, acetic, and propionic acids with signal-to-noise ratios of 414, 150, and 115, respectively, after sampling by only 30 s and performing an electrokinetic injection during 2.0 s at 1.0 kV. PMID:22965708

  4. Assessment of estrogenic activity in PM₁₀ air samples with the ERE-CALUX bioassay: Method optimization and implementation at an urban location in Flanders (Belgium).

    Science.gov (United States)

    Croes, Kim; Debaillie, Pieterjan; Van den Bril, Bo; Staelens, Jeroen; Vandermarken, Tara; Van Langenhove, Kersten; Denison, Michael S; Leermakers, Martine; Elskens, Marc

    2016-02-01

    Endocrine disrupting chemicals represent a broad class of compounds, are widespread in the environment and can pose severe health effects. The objective of this study was to investigate the overall estrogen activating potential of PM10 air samples at an urban location with high traffic incidence in Flanders, using a human in vitro cell bioassay. PM10 samples (n = 36) were collected on glass fiber filters every six days between April 2013 and January 2014 using a high-volume sampler. Extraction was executed with a hexane/acetone mixture before analysis using a recombinant estrogen-responsive human ovarian carcinoma (BG1Luc4E2) cell line. In addition, several samples and procedural blanks were extracted with ultra-pure ethanol or acetonitrile to compare extraction efficiencies. Results were expressed as bioanalytical equivalents (BEQs) in femtogram 17β-estradiol equivalent (fg E2-Eq) per cubic meter of air. High fluctuations in estrogenic activity were observed during the entire sampling period, with mean and median BEQs of 50.7 and 35.9 fg E2-Eq m(-)(3), respectively. Estrogenic activity was measured in more than 70% of the samples and several sample extracts showed both high BEQs and high cytotoxicity, which could not be related to black carbon, PM10 or heavy metal concentrations. At this moment, it remains unclear which substances cause this toxicity, but comparison of results obtained with different extraction solvents indicated that acetone/hexane extracts contained more compounds that were cytotoxic and suppressive of responses than those extracted using ultra-pure ethanol. Although more research is needed, the use of a more polar extraction solvent seems to be advisable. PMID:26383266

  5. Genotoxicity, inflammation and physico-chemical properties of fine particle samples from an incineration energy plant and urban air

    DEFF Research Database (Denmark)

    Sharma, Anoop Kumar; Jensen, Keld Alstrup; Rank, Jette;

    2007-01-01

    Airborne particulate matter (PM) was sampled by use of an electrostatic sampler in an oven hall and a receiving hall in a waste-incineration energy plant, and from urban air in a heavy-traffic street and from background air in Copenhagen. PM was sampled for 1-2 weeks, four samples at each site. The......), but the distribution was completely different in the oven hall (maximum mode at about 150 nm). Also chemically, the samples from the oven hall were highly different from the other samples. PM extracts from the receiving hall, street and background air were more mutagenic than the PM extracts from the...... locations in particle size distribution, chemical composition and the resulting biological effects when A549 cells were incubated with the PM. These characteristics and observations in the oven hall indicated that the PM source was oven exhaust, which was well combusted. (c) 2007 Elsevier B.V. All rights...

  6. Temporal-spatial analysis of U.S.-Mexico border environmental fine and coarse PM air sample extract activity in human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Particulate matter less than 10 μm (PM10) has been shown to be associated with aggravation of asthma and respiratory and cardiopulmonary morbidity. There is also great interest in the potential health effects of PM2.5. Particulate matter (PM) varies in composition both spatially and temporally depending on the source, location and seasonal condition. El Paso County which lies in the Paso del Norte airshed is a unique location to study ambient air pollution due to three major points: the geological land formation, the relatively large population and the various sources of PM. In this study, dichotomous filters were collected from various sites in El Paso County every 7 days for a period of 1 year. The sampling sites were both distant and near border crossings, which are near heavily populated areas with high traffic volume. Fine (PM2.5) and Coarse (PM10-2.5) PM filter samples were extracted using dichloromethane and were assessed for biologic activity and polycyclic aromatic (PAH) content. Three sets of marker genes human BEAS2B bronchial epithelial cells were utilized to assess the effects of airborne PAHs on biologic activities associated with specific biological pathways associated with airway diseases. These pathways included in inflammatory cytokine production (IL-6, IL-8), oxidative stress (HMOX-1, NQO-1, ALDH3A1, AKR1C1), and aryl hydrocarbon receptor (AhR)-dependent signaling (CYP1A1). Results demonstrated interesting temporal and spatial patterns of gene induction for all pathways, particularly those associated with oxidative stress, and significant differences in the PAHs detected in the PM10-2.5 and PM2.5 fractions. Temporally, the greatest effects on gene induction were observed in winter months, which appeared to correlate with inversions that are common in the air basin. Spatially, the greatest gene expression increases were seen in extracts collected from the central most areas of El Paso which are also closest to highways and border crossings.

  7. Sampling of power plant stacks for air toxic emissions: Topical report for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-21

    Under contract with the US Department of Energy (DE-AC22-92PCO0367), Pittsburgh Energy Technology Center, Radian Corporation has conducted a test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPS). Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical charactization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions.

  8. Molecular beam mass spectrometric sampling of minor species from coal dust-air flames

    International Nuclear Information System (INIS)

    It has been demonstrated that unaugmented, unconfined, premixed coal dust-air flames can be stabilized on small conical or flat, Meeker type burners. Since these flames are laminar, they can be used to study the kinetics of various processes in coal combustion and related areas such as understanding mechanisms of fireside corrosion and of flame and explosive inhibition. Some of the current work with these flames is directed toward identification and measurement of minor alkali metal and other species responsible for fireside corrosion. In order to make these measurements, molecular beam mass spectrometric sampling techniques have been adpated for use with these heterogeneous flames. In this paper, the equipment and techniques used are reviewed and some preliminary results presented

  9. Sensory Pollution from Bag Filters, Carbon Filters and Combinations

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    Used ventilation filters are a major source of sensory pollutants in air handling systems. The objective of the present study was to evaluate the net effect that different combinations of filters had on perceived air quality after 5 months of continuous filtration of outdoor suburban air. A panel...... that contained AC and a synthetic fiber cartridge filter that contained AC. Air that had passed through used filters was most acceptable for those sets in which an AC filter was used downstream of the particle filter. Comparable air quality was achieved with the stand-alone bag filter that contained AC....... Furthermore, its pressure drop changed very little during the 5 months of service, and it had the added benefit of removing a large fraction of ozone from the airstream. If similar results are obtained over a wider variety of soiling conditions, such filters may be a viable solution to a long recognized...

  10. GUIDE TO CALCULATING TRANSPORT EFFICIENCY OF AEROSOLS IN OCCUPATIONAL AIR SAMPLING SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Hogue, M.; Hadlock, D.; Thompson, M.; Farfan, E.

    2013-11-12

    This report will present hand calculations for transport efficiency based on aspiration efficiency and particle deposition losses. Because the hand calculations become long and tedious, especially for lognormal distributions of aerosols, an R script (R 2011) will be provided for each element examined. Calculations are provided for the most common elements in a remote air sampling system, including a thin-walled probe in ambient air, straight tubing, bends and a sample housing. One popular alternative approach would be to put such calculations in a spreadsheet, a thorough version of which is shared by Paul Baron via the Aerocalc spreadsheet (Baron 2012). To provide greater transparency and to avoid common spreadsheet vulnerabilities to errors (Burns 2012), this report uses R. The particle size is based on the concept of activity median aerodynamic diameter (AMAD). The AMAD is a particle size in an aerosol where fifty percent of the activity in the aerosol is associated with particles of aerodynamic diameter greater than the AMAD. This concept allows for the simplification of transport efficiency calculations where all particles are treated as spheres with the density of water (1g cm-3). In reality, particle densities depend on the actual material involved. Particle geometries can be very complicated. Dynamic shape factors are provided by Hinds (Hinds 1999). Some example factors are: 1.00 for a sphere, 1.08 for a cube, 1.68 for a long cylinder (10 times as long as it is wide), 1.05 to 1.11 for bituminous coal, 1.57 for sand and 1.88 for talc. Revision 1 is made to correct an error in the original version of this report. The particle distributions are based on activity weighting of particles rather than based on the number of particles of each size. Therefore, the mass correction made in the original version is removed from the text and the calculations. Results affected by the change are updated.

  11. AMS Measurements in National Parks of Aerosol Mass, Size and Composition, Comparison with Filter Samples and Correlation with Particle Hygroscopicity and Optical Extinction Properties

    Science.gov (United States)

    Alexander, M.; Taylor, N. F.; Collins, D. R.; Kumar, N.; Allen, J.; Newburn, M.; Lowenthal, D. H.; Zielinska, B.

    2011-12-01

    We report a comparison of results from aerosol studies at Great Smoky Mountain National Park (2006), Mt. Rainier National Park (2009) and Acadia National Park (2011), all class I visibility areas associated with IMPROVE (Interagency Monitoring of Protected Visual Environments) sites. This collaborative study was sponsored by the Electric Power Research Institute (EPRI) and was done with the cooperation of the National Park Service and the EPA. The atmospheric aerosol composition in these sites is influenced by a number of anthropogenic as well as biogenic sources, providing a rich environment for fundamental aerosol studies. The primary purpose of these studies was to add state-of-the-art aerosol instrumentation to the standard light extinction and aerosol measurements at the site, used to determine parameters for the IMPROVE light extinction reconstruction equation, adopted by the EPA to estimate light extinction from atmospheric aerosol concentrations and Rayleigh scattering. The combination of these diverse measurements also provides significant insight into fundamental aerosol properties such as aging and radiative forcing. New instrumentation included a quadrupole aerosol mass spectrometer (Aerodyne Q-AMS-Smoky Mountain Study), a high resolution aerosol time-of-flight mass spectrometer (Aerodyne HR-ToF-AMS - Mt. Rainier and Acadia studies) for real time measurements that directly address the relationship between sulfate, nitrate, and OC size and concentration, which is related to cloud and dry gas-to-particle conversion as air masses age during transport, the relationship between WSOC hygroscopic growth and oxygenated organic (OOA) composition, the OCM/OC ratio, and the chemical composition that determines the ambient hygroscopic state. The OCM/OC ratio and organic water uptake was addressed with high-volume and medium volume PM2.5 aerosol samples. Aerosols were collected daily on Teflon coated glass fiber filters (TGFF) in four high-volume PM2.5 samplers

  12. Use of "Parasep filter fecal concentrator tubes" for the detection of intestinal parasites in stool samples under routine conditions.

    Science.gov (United States)

    Zeeshan, Mohammad; Zafar, Afia; Saeed, Zeb; Irfan, Seema; Sobani, Zain A; Shakoor, Sadia; Beg, Mohammad Asim

    2011-01-01

    Parasitic gastrointestinal infections are a major cause of morbidity and mortality in the developing world, with stool microscopy being the mainstay of diagnostic practice. Both direct microscopy and concentration techniques can be utilized; direct microscopy may be time consuming and tedious; however clinical laboratories in developing countries lack trained staff who can effectively use concentration methods. In our practice we used the Parasep O and P filter concentrator tubes (manufactured by DiaSys Ltd, Berkshire, England. Product Code 146000) along with direct microscopic techniques and found that Parasep filters enhanced the ability to detect intestinal parasites that would have been missed on routine microscopy. We found the Parasep filter concentration method to be easy, cost-effective and reliable for routine stool examinations. PMID:21393892

  13. Use of "Parasep filter fecal concentrator tubes" for the detection of intestinal parasites in stool samples under routine conditions

    Directory of Open Access Journals (Sweden)

    Mohammad Zeeshan

    2011-01-01

    Full Text Available Parasitic gastrointestinal infections are a major cause of morbidity and mortality in the developing world, with stool microscopy being the mainstay of diagnostic practice. Both direct microscopy and concentration techniques can be utilized; direct microscopy may be time consuming and tedious; however clinical laboratories in developing countries lack trained staff who can effectively use concentration methods. In our practice we used the Parasep O and P filter concentrator tubes (manufactured by DiaSys Ltd, Berkshire, England. Product Code 146000 along with direct microscopic techniques and found that Parasep filters enhanced the ability to detect intestinal parasites that would have been missed on routine microscopy. We found the Parasep filter concentration method to be easy, cost-effective and reliable for routine stool examinations.

  14. Bionics: prcise color tuning by interference in nature and technology-applications in surface-micromachined 1.55μm vertical air-cavity filters

    Science.gov (United States)

    Hillmer, Hartmut; Daleiden, Juergen; Prott, Cornelia; Irmer, Soeren; Roemer, Friedhard; Ataro, Edwin; Tarraf, Amer; Ruehling, H.; Maniak, Markus; Strassner, Martin

    2003-01-01

    Bionics transfers the principles of success of nature into natural science, engineering disciplines and applications. Often generation and detection of different spectral colors play key roles in communication in both, nature and technology. The latter one refers e.g. to dense wavelength division multiplex optical communication systems. This paper shows interesting parallels in tunable spectral light filtering by butterfly wings and by tunable optical filters used in optical communication systems. In both cases light interferes constructively and destructively with nano- and microstructures of appropriate shape, dimensions and materials. In this paper methodology is strongly emphasized. We demonstrate that tailored scaling allows the effectiveness of physical effects to be enhanced in nature and technology. These principles are rigorously applied in micromachined 1.55μm vertical-resonator-based filters, capable of wide, continuous, monotonic and kink-free tuning by a single control parameter. Tuning is achieved by mechanically actuating one or several membranes embedded by air-gaps in a vertical resonator including two ultra-highly reflective DBR mirrors. The layers of mirrors reveal a very strong refractive index contrast. Filters including InP/air-gap DBR's (3.5 periods) using GaInAs sacrificial layers reveal a continuous tuning of >9% of the absolute wavelength. Varying a reverse voltage (U=0 .. -3.2V) between the membranes, a tuning range up to 142nm was obtained due to electrostatic actuation. Appropriate miniaturization is shown to increase the mechanical stability and the effectiveness of spectral tuning by electrostatic actuation since the relative significance of the fundamental physical forces can be shifted considerably by appropriate scaling.

  15. The decrease of the energy performance for the soiling of the air filters in gas turbines; Disminucion de la eficiencia energetica por ensuciamiento de filtros de aire en turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J. J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Mexico D. F. (Mexico)

    1995-12-31

    The object of this paper is to study the effect in the turbine output of a gas turbine of the conditions of the compressor air inlet in going through a series of filters. The algorithm for the calculation of the energy losses due to the variation of the pressure drop caused by the filters according to their cleanliness condition. In the first part the series of variables that affect the gas turbines performance are exemplified, afterwards the characteristics of the air flow into a turbine are presented as well as their effects on the system. Later on, the results obtained of the system simulation are presented and compared with a real case. From the results it can be determined, that depending on the system and on the environment conditions the efficiency drop might be up to 3%, in accordance with the filters cleanliness. The maintenance periods strongly depend on the air quality variations at the filter house inlet in the zone where the power plant is located. [Espanol] El presente trabajo tiene por objetivo estudiar el efecto en la potencia generada en una turbina de gas de las condiciones de entrada del aire al compresor de una turbina de gas al pasar por un conjunto de filtros. Se presenta el algoritmo para la determinacion de las perdidas energeticas debidas a la variacion de la caida de presion generada por los filtros de acuerdo con su estado de limpieza. En la primera parte se ejemplifica el conjunto de variables que influyen en la eficiencia de las turbinas de gas, posteriormente se mencionan las caracteristicas de flujo de aire hacia una turbina y se muestran los efectos sobre el sistema. A continuacion se presentan los resultados obtenidos de la simulacion del sistema y se comparan con un caso real. De los resultados se puede apreciar que, dependiendo del sistema y de las condiciones ambientales el decremento en la eficiencia puede ser hasta del 3% en funcion del nivel de limpieza de los filtros. Los periodos de mantenimiento dependen fuertemente de las

  16. Influence of filter thickness on PESA calibration

    International Nuclear Information System (INIS)

    Elemental analysis of air particulate matter collected on Teflon filters using ion beam analysis (IBA) allows simultaneous analysis of the hydrogen content. Hydrogen is determined by a method known as particle elastic scattering analysis (PESA). The hydrogen concentration in the air particulate matter samples is determined by comparing the ratio of the hydrogen peak yield to the yields from standards of known hydrogen composition. The study presented in this paper shows that this process can be inaccurate if the calibration standards used are of different thicknesses compared to the air pollution samples. A series of experiments were undertaken to investigate the effect of sample and standard thickness on the determination of hydrogen concentrations. It was found that the filter thickness and the distribution of the air particulate matter within the filter significantly affected the yield of the hydrogen peak in the PESA spectra. Therefore, it is important to consider the effect of thickness and the distribution of the hydrogen in both the calibration standards and the sample filters for PESA analysis

  17. 5. Sampling

    International Nuclear Information System (INIS)

    The sampling is described for radionuclide X-ray fluorescence analysis. Aerosols are captured with various filter materials whose properties are summed up in the table. Fine dispersed solid and liquid particles and gaseous admixtures may be captured by bubbling air through a suitable absorption solution. The concentration of small amounts of impurities from large volumes of air is done by adsorbing impurities on surfactants, e.g., activated charcoal, silica gel, etc. Aerosols may be captured using an electrostatic precipitator and aerosol fractions may be separated with a cascade impactor. Water sampling differs by the water source, i.e., ground water, surface water, rain or waste water. Soil samples are taken by probes. (ES)

  18. Estimating surface CO2 fluxes from space-borne CO2 dry air mole fraction observations using an ensemble Kalman Filter

    Directory of Open Access Journals (Sweden)

    S. Dance

    2009-04-01

    Full Text Available We have developed an ensemble Kalman Filter (EnKF to estimate 8-day regional surface fluxes of CO2 from space-borne CO2 dry-air mole fraction observations (XCO2 and evaluate the approach using a series of synthetic experiments, in preparation for data from the NASA Orbiting Carbon Observatory (OCO. The 32-day duty cycle of OCO alternates every 16 days between nadir and glint measurements of backscattered solar radiation at short-wave infrared wavelengths. The EnKF uses an ensemble of states to represent the error covariances to estimate 8-day CO2 surface fluxes over 144 geographical regions. We use a 12×8-day lag window, recognising that XCO2 measurements include surface flux information from prior time windows. The observation operator that relates surface CO2 fluxes to atmospheric distributions of XCO2 includes: a the GEOS-Chem transport model that relates surface fluxes to global 3-D distributions of CO2 concentrations, which are sampled at the time and location of OCO measurements that are cloud-free and have aerosol optical depths 2 profiles to XCO2, accounting for differences between nadir and glint measurements, and the associated scene-dependent observation errors. We show that OCO XCO2 measurements significantly reduce the uncertainties of surface CO2 flux estimates. Glint measurements are generally better at constraining ocean CO2 flux estimates. Nadir XCO2 measurements over the terrestrial tropics are sparse throughout the year because of either clouds or smoke. Glint measurements provide the most effective constraint for estimating tropical terrestrial CO2 fluxes by accurately sampling fresh continental outflow over neighbouring oceans. We also present results from sensitivity experiments that investigate how flux estimates change with 1 bias and unbiased errors, 2 alternative duty cycles, 3 measurement density and correlations, 4 the spatial resolution of estimated flux estimates, and 5 reducing the length of the lag window and the

  19. The use of nylon and glass fiber filter separators with different pore sizes in air-cathode single-chamber microbial fuel cells

    KAUST Repository

    Zhang, Xiaoyuan

    2010-01-01

    Separators are needed in microbial fuel cells (MFCs) to reduce electrode spacing and preventing electrode short circuiting. The use of nylon and glass fiber filter separators in single-chamber, air-cathode MFCs was examined for their effect on performance. Larger pore nylon mesh were used that had regular mesh weaves with pores ranging from 10 to 160 μm, while smaller pore-size nylon filters (0.2-0.45 μm) and glass fiber filters (0.7-2.0 μm) had a more random structure. The pore size of both types of nylon filters had a direct and predictable effect on power production, with power increasing from 443 ± 27 to 650 ± 7 mW m-2 for pore sizes of 0.2 and 0.45 μm, and from 769 ± 65 to 941 ± 47 mW m-2 for 10 to 160 μm. In contrast, changes in pore sizes of the glass fiber filters resulted in a relatively narrow change in power (732 ± 48 to 779 ± 43 mW m-2) for pore sizes of 0.7 to 2 μm. An ideal separator should increase both power density and Coulombic efficiency (CE). However, CEs measured for the different separators were inversely correlated with power production, demonstrating that materials which reduced the oxygen diffusion into the reactor also hindered proton transport to the cathode, reducing power production through increased internal resistance. Our results highlight the need to develop separators that control oxygen transfer and facilitate proton transfer to the cathode. © 2010 The Royal Society of Chemistry.

  20. Evaluation of Rn equilibrium factor using charcoal filter

    International Nuclear Information System (INIS)

    A simple and new evaluation system for radon equilibrium factor has been developed. Radon equilibrium factor is defined as a ratio between radon progeny concentration and radon concentration in air. Radon progeny in air becomes one of the main factors of public dose. However radon concentration itself in air has usually been estimated, because its detection is much easier than that of its progeny. In this dosimetry technique, radon equilibrium becomes the most important parameter we must adequately evaluate in advance. In this study, a new system using a charcoal filter for evaluation of radon equilibrium factor using charcoal filter was discussed. Two filters are combined to sample the airborne radioactivity of radon family. One of them is the charcoal filter, where is the main point of this study. Radon concentration is estimated based on the radioactivity sampled on a charcoal filter, and radon progeny concentration is based on the radioactivity on a glass-fiber filter. We have already fully known the characteristics of the glass-fiber filter for radon progeny. Therefore we tested charcoal filters here and obtained some characteristics on its sampling ability for radon. Especially we focused on the variety of sample abilities based on sampling flow-rate (L/min) and sampling duration (min). As a result, the most optimum sampling flow-rate was determined as 20 L/min and sampling duration was 10 min, based on the results gained by several experiments. According to this new evaluation system, we can calculate more adequate radon equilibrium factor easily because both concentrations of radon and its progeny in a same sample air can be determined at the same time. We can well adopt this system in special environments like in mines and undergrounds. (author)

  1. A quantitative study of air-borne particulate matter collected on membrane filters by means of X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    The capability of X-ray photoelectron spectroscopy, XPS or ESCA, in analysing oxidation states and measuring the concentration of elements present in air pollution particulates collected on membrane filters is evaluated. Semi-quantitative data are compared with those from XRF and wet chemical analysis. Differences of about a factor of 2.0-2.5 are found which are critically discussed in relation to particle size and the distribution of ionic species. The importance of intrinsic properties of matrix materials and instrumental factors is also discussed. (orig.)

  2. Ship-Borne Phased Array Radar Using GA Based Adaptive α-β-γ Filter for Beamforming Compensation and Air Target Tracking

    OpenAIRE

    J. Mar; Chen-Chih Liu; Basnet, M. B.

    2015-01-01

    Beam pointing error caused by ship motion over the ocean affects the tracking performance of the ship-borne phased array radar. Due to the dynamic nature of the sea environments, the ship-borne phased array radar must be able to compensate for the ship’s motion adaptively. In this paper, the adaptive α-β-γ filter is proposed for the ship-borne phased array radar to compensate for the beam pointing error and to track the air target. The genetic algorithm (GA) and the particle swarm optimizatio...

  3. Precise determination of 13C/12C and CO2 concentration in small samples of soil air by mass spectrometry

    International Nuclear Information System (INIS)

    Studies of soil CO2 concentration and its isotopic composition have been carried out. The sample size of soil air was about 100 cm3 only. The isotope analysis of such small CO2 samples were performed by a dynamic flow mass spectrometer. The air samples were taken from the depth of 10 to 75 cm at two points of a grass field at a distance of a few meters. The measured δ13C values were very consistent for both points ranging from -21.53 to -22.37 per mill, while the corresponding CO2 concentration ranged from 0.24 to 0.55%. (author)

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

    Science.gov (United States)

    EPA's National Risk Management Research Laboratory, through its Environmental Technology Verification Program, evaluated the performance of a bag house filtration product for use controlling PM2.5. The product was BWF America, Inc., filter fabric Grade 700 Polyester Felt. All tes...

  5. Uncertainties in Air Exchange using Continuous-Injection, Long-Term Sampling Tracer-Gas Methods

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; Walker, Iain S.; Lunden, Melissa M.

    2013-12-01

    The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring air exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term Sampling (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs. In this article we will conduct a first-principles error analysis to estimate the uncertainties and then compare that analysis to CILTS measurements that were over-sampled, through the use of multiple tracers and emitter and sampler distribution patterns, in three houses. We find that the CILTS method can have an overall uncertainty of 10-15percent in ideal circumstances, but that even in highly controlled field experiments done by trained experimenters expected uncertainties are about 20percent. In addition, there are many field conditions (such as open windows) where CILTS is not likely to provide any quantitative data. Even avoiding the worst situations of assumption violations CILTS should be considered as having a something like a ?factor of two? uncertainty for the broad field trials that it is typically used in. We provide guidance on how to deploy CILTS and design the experiment to minimize uncertainties.

  6. Sampling of power plant stacks for air toxic emissions: Final report for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-28

    A test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPs) was conducted . Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical characterization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions. Field testing was conducted in two phases. The Phase I field program was performed over the period of August 24 through September 20, 1992, at the Tennessee Valley Authority Widows Creek Unit 8 Power Station, located near Stevenson (Jackson County), Alabama, on the Tennessee River. Sampling activities for Phase II were conducted from September 11 through October 14, 1993. Widows Creek Unit 8 is a 575-megawatt plant that uses bituminous coal averaging 3.7% sulfur and 13% ash. Downstream of the boiler, a venture wet scrubbing system is used for control of both sulfur dioxide and particulate emissions. There is no electrostatic precipitator (ESP) in this system. This system is atypical and represents only about 5% of the US utility industry. However, this site was chosen for this study because of the lack of information available for this particulate emission control system.

  7. Design of complex-valued variable FIR digital filters and its application to the realization of arbitrary sampling rate conversion for complex signals

    OpenAIRE

    Tsui, KM; Chan, SC; Tse, KW

    2005-01-01

    This brief studies the design of complex-valued variable digital filters (CVDFs) and their applications to the efficient arbitrary sample rate conversion for complex signals. The design of CVDFs using either the minimax or least-squares criteria is formulated as a convex optimization problem and solved using the second-order cone programming (SOCP). In addition, linear and convex quadratic inequality constraints can be readily incorporated. Design examples are given to demonstrate the effecti...

  8. Evaluation of Trapper-Collected Nobuto Filter-Paper Blood Samples for Distemper and Parvovirus Antibody Detection in Coyotes (Canis latrans) and Raccoons (Procyon lotor).

    Science.gov (United States)

    Kamps, Amanda J; Dubay, Shelli A; Langenberg, Julie; Maes, Roger K

    2015-07-01

    Blood samples are often collected from free-ranging wildlife for antibody detection. However, filter-paper (FP) strips are more cost efficient and easy to collect and store. We evaluated trapper-collected FP strips and body-cavity blood for canine distemper (CDV) and parvovirus (CPV-2) antibody detection in raccoons (Procyon lotor) and coyotes (Canis latrans). From 2008 to 2010, licensed trappers near Madison and Milwaukee, Wisconsin, US collected paired samples from harvested animals. Canine distemper antibodies were detected using virus neutralization and parvovirus antibodies were detected using hemagglutination inhibition. Titers ≥ 1:32 for CDV and ≥ 1:25 for CPV-2 were considered evidence of exposure. Using Cohen's kappa test of agreement, FP strip titers agreed with sera for CDV in coyotes (n = 28, K = 0.772) and raccoons (n = 29, K = 0.858) and for CPV-2 in coyotes (n = 40, K = 0.775) and raccoons (n = 70, K = 0.646). However, raccoons determined to be exposed to CPV-2 from sera were unexposed by FP strips in 35% of the samples. Titer results may be affected by quality and volume of blood samples, interval between collection and processing, small sample sizes, and diagnostic testing procedures. Filter-paper strips can be useful for detecting CDV and CPV-2 exposure in coyotes and raccoons with correct field sample collection and appropriate diagnostic testing procedures. PMID:25973631

  9. Seroepidemiological study of human cysticercosis with blood samples collected on filter paper, in Lages, State of Santa Catarina, Brazil, 2004-2005

    Directory of Open Access Journals (Sweden)

    Maria Márcia Imenes Ishida

    2011-06-01

    Full Text Available INTRODUCTION: Human serofrequency of antibodies against Taenia solium antigens was determined and risk factors for cysticercosis transmission were identified. METHODS: Individuals (n=878 from periurban and rural locations of Lages, SC, were interviewed to gather demographic, sanitary and health information. Interviews and blood sample collections by finger prick on Whatman filter paper were performed from August 2004 to May 2005. Observation determined that 850 samples were suitable for analysis and were tested by ELISA using vesicular fluid of Taenia crassiceps heterologous antigen. To ensure the reliability of the results, 77 samples of the dried blood were matched with sera. The reactive samples were submitted to a serum confirmatory immunoblot (IB test using purified Taenia crassiceps glycoproteins. RESULTS: The ELISA results for the dried blood and serum samples were statistically consistent. ELISA was positive in 186 (21.9% out of 850 individuals. A group of 213 individuals were asked to collect vein blood for IB (186 with positive result in ELISA and 27 with inappropriate whole blood samples and 130 attended the request. The IB was positive in 29 (3.4% out of 850 individuals. A significant correlation (p = 0.0364 was determined among individuals who tested positive in the IB assay who practiced both pig rearing and kitchen gardening. CONCLUSIONS: ELISA with dried blood eluted from filter paper was suitable for cysticercosis population surveys. In Lages, human infection was associated with pig rearing and kitchen gardening. The prevalence index was compatible with other Latin American endemic areas.

  10. Solutions for Dioctyl Phthalate (DOP) tested high efficiency particulate air (HEPA) filters destined for disposal at Hanford, Washington

    International Nuclear Information System (INIS)

    In January 1992, Argonne National Laboratory East, Environmental and Waste Management Program, learned that a chemical material used for testing of all HEPA filters at the primary source, Flanders Filter, Inc. in Washington, NC, was considered a hazardous chemical by Washington State Dangerous Waste Regulations. These regulations are under the jurisdiction of the Washington Administration Code, Chapter 173-303, and therefore directly under impact the Hanford Site Solid Waste Acceptance Criteria. Dioctyl Phthalate, ''DOP'' as it is referred to in chemical abbreviation form, is added in small test quantities at the factory, at three Department of Energy (DOE) operated HEPA filter test facilities, and in the installed duct work at various operating laboratories or production facilities. When small amounts of radioactivity are added to the filter media in operation, the result is a mixed waste. This definition would normally only develop in the state of Washington since their acceptance criteria is ten times more stringent then the US Environmental Protection Agencys' (US EPA). Methods of Processing will be discussed, which will include detoxification, physical separation, heat and vacuum separation, and compaction. The economic impact of a mixed waste definition in the State of Washington, and an Low Level Waste (LLW) definition in other locations, may lend this product to be a prime candidate for commercial disposal in the future, or a possible de-listing by the State of Washington

  11. Cryogenic separation of oxygen-argon mixture in natural air samples for isotopic and molecular ratios

    Science.gov (United States)

    Habeeb Rahman, Keedakkadan; Abe, Osamu

    2014-05-01

    The discovery of mass independent isotope fractionation in oxygen during the formation of ozone in the stratosphere has initiated a wide application in isotope geochemistry field. Separation of oxygen-argon mixture has become the foundation of high precision analysis of Δ17O and δ(O2/Ar) for geochemical applications. Here we present precise and simplified cryogenic separation of argon oxygen mixture from the atmospheric and dissolved air using 30/60 mesh 5A molecular sieve zeolite. A pioneer study of this method was conducted by Thiemens and Meagher in 1984. The column which is made of glass tube contains about 1.1 grams of molecular sieve zeolite and both ends of column was filled with glass wools. The experimental set up was tested for different combination of molecular sieves and slurry temperatures. We found the most efficient condition for the separation was at a column temperature of -103°C. For complete transfer of O2 and Ar mixture usually takes in 15-20 minutes time. The isotopic ratios of oxygen were analyzed using mass spectrometer (Thermo Fischer Delta Plus) relative to reference oxygen-argon mixture at 3V of m/z 32 for both sample and reference side. The signals of m/z 28, 32, and 40 were measured by dynamically to determine oxygen -argon ratio and to check nitrogen contamination. Repeated measurements of atmospheric air yielded a reproducibility (SE n=80) of 0.006, 0.004 and 0.19‰ for δ17O, δ18O and δO2/Ar respectively. The isotopic and molecular fractionation of argon- oxygen mixture during gas adsorption and desorption while using molecular sieve under liquid nitrogen temperature was studied. We have established a linear relationship governing the effect of 13X and 5A molecular sieves on molecular fractionation. And suggested the use of single 1/8" pellet 13X molecular sieve provided a negligible fractionation.

  12. Indoor Air Quality in Selected Samples of Primary Schools in Kuala Terengganu, Malaysia

    OpenAIRE

    Marzuki Ismail

    2010-01-01

    Studies have found out that indoor air quality affects human especially children and the elderly more compared to ambient atmospheric air. This study aims to investigate indoor air pollutants concentration in selected vernacular schools with different surrounding human activities in Kuala Terengganu, the administrative and commercial center of Terengganu state. Failure to identify and establish indoor air pollution status can increase the chance of long-term and short-term health problems for...

  13. Occurrence and quantitative microbial risk assessment of Cryptosporidium and Giardia in soil and air samples

    Directory of Open Access Journals (Sweden)

    Ana Paola Balderrama-Carmona

    2014-09-01

    Conclusions: Soil and air inhalation and/or ingestion are important vehicles for these parasites. To our knowledge, the results obtained in the present study represent the first QMRAs for cryptosporidiosis and giardiasis due to soil and air inhalation/ingestion in Mexico. In addition, this is the first evidence of the microbial air quality around these parasites in rural zones.

  14. Utilizing the partitioning properties of silicone for the passive sampling of polychlorinated biphenyls (PCBs) in indoor air.

    Science.gov (United States)

    Vorkamp, Katrin; Odsbjerg, Lisbeth; Langeland, Majbrith; Mayer, Philipp

    2016-10-01

    The former use of polychlorinated biphenyls (PCBs) in construction materials can lead to elevated indoor air concentrations. We studied the partitioning of PCB congeners between indoor air and silicone with a view to establish passive sampling of PCBs. The release of PCB congeners from silicone followed first order kinetics and confirmed air-side rate-limited mass transfer. Logarithmic elimination rate constants decreased linearly with the logKOA values of the PCB congeners, but varied in a non-linear way with air velocity. Linear uptake of PCBs was found for silicone disks (0.5 mm thickness) in a petri dish, while PCBs reached equilibrium in silicone-coated paper sheets (0.001 mm silicone on each side) exposed to indoor air for 1-2 weeks. The ratios of equilibrium concentrations in silicone and conventionally measured air concentrations were roughly comparable with silicone-air partition coefficients, but further research is required for the determination of silicone-air partition coefficients. Avoiding performance reference compounds (PRCs) because of the indoor setting, the two formats were calibrated against conventional active measurements. Comparisons of air concentrations derived from active and kinetic passive sampling showed a divergence by factors of 2.4 and 2.0 (median values) for the petri dishes and the silicone-coated paper, respectively. With promising results for sensitivity and precision, the calibration of kinetic passive samplers remains the main challenge and will need suitable, non-hazardous PRCs. Equilibrium sampling indicated promising alternatives. PMID:27389945

  15. Aircraft Cabin Air Sampling Study; Part 2 of the Final Report

    OpenAIRE

    Crump, Derrick; Harrison, Paul; Walton, Christopher

    2011-01-01

    This is the second part of the report on aircraft cabin air quality prepared by Cranfield University for the Department for Transport. The study was set up in light of concerns about possible adverse impacts on the health and well-being of air crew resulting from exposure to substances in cabin air. Part 1 of the report describes in detail the methodology used in the study, summarises the results obtained and assesses cabin air quality against available exposure limits and the quality of air ...

  16. Air filtration in HVAC systems

    CERN Document Server

    Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

    2010-01-01

    Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

  17. Filters in nuclear facilities

    International Nuclear Information System (INIS)

    The topics of the nine papers given include the behavior of HEPA filters during exposure to air flows of high humidity as well as of high differential pressure, the development of steel-fiber filters suitable for extreme operating conditions, and the occurrence of various radioactive iodine species in the exhaust air from boiling water reactors. In an introductory presentation the German view of the performance requirements to be met by filters in nuclear facilities as well as the present status of filter quality assurance are discussed. (orig.)

  18. Use of "Parasep filter fecal concentrator tubes" for the detection of intestinal parasites in stool samples under routine conditions

    OpenAIRE

    Mohammad Zeeshan; Afia Zafar; Zeb Saeed; Seema Irfan; Sobani, Zain A.; Sadia Shakoor; Mohammad Asim Beg

    2011-01-01

    Parasitic gastrointestinal infections are a major cause of morbidity and mortality in the developing world, with stool microscopy being the mainstay of diagnostic practice. Both direct microscopy and concentration techniques can be utilized; direct microscopy may be time consuming and tedious; however clinical laboratories in developing countries lack trained staff who can effectively use concentration methods. In our practice we used the Parasep O and P filter concentrator tubes (manufacture...

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

    Science.gov (United States)

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

    2015-11-01

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

  20. High resolution alpha-particle-spectrometry for radium analysis -the effects of sample thickness and filter pore size

    International Nuclear Information System (INIS)

    In the α-particle spectrometric technique for radium isotope analysis, the effects of the barium carrier thickness and pore size of the membrane filter (used for the main Ba-Ra sulphate filtration) on the resolution of the α-particle energy peaks were investigated. With 0.45 μm Millipore membrane filters, the full width at half maximum (FWHM) for 4.78 MeV α-decay peak of 226Ra decreased from 221.7 to 121.3 keV with reduction in barium carrier additions from 320 to 20 μg Ba. The resolution further improved to 67.0 keV for 20 μg Ba carrier when 0.2 μm Nucleopore filters were used. There was also a significant decrease (20-50%) in the retention of radon and its daughters compared to their equilibrium concentrations as the barium carrier thickness was reduced. A correlation study between 133Ba tracer and 226Ra isotopes recovery factors gave a recovery factor 226Ra/133Ba ratio of 0.93 ± 0.08 in the main Ba-Ra sulphate precipitate under various pH and sulphate concentration conditions. (author)