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Sample records for air stack sampling

  1. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2009-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6 - 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  2. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2008-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6- 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  3. An assessment of air sampling location for stack monitoring in nuclear facility

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Bok [University of Science and Technology, Daejeon (Korea, Republic of); Kim, Tae Hyoung; Lee, Jong Il; Kim, Bong Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    In this study, air sampling locations in the stack of the Advanced Fuel Science Building (AFSB) at the Korea Atomic Energy Research Institute (KAERI) were assessed according to the ANSI/HPS N13.1-1999 specification. The velocity profile, flow angle and 10 μm aerosol particle profile at the cross-section as functions of stack height L and stack diameter D (L/D) were assessed according to the sampling location criteria using COMSOL. The criteria for the velocity profile were found to be met at 5 L/D or more for the height, and the criteria for the average flow angle were met at all locations through this assessment. The criteria for the particle profile were met at 5 L/D and 9 L/D. However, the particle profile at the cross-section of each sampling location was found to be non-uniform. In order to establish uniformity of the particle profile, a static mixer and a perimeter ring were modeled, after which the degrees of effectiveness of these components were compared. Modeling using the static mixer indicated that the sampling locations that met the criteria for the particle profile were 5-10 L/D. When modeling using the perimeter ring, the sampling locations that met the criteria for particle profile were 5 L/D and 7-10 L/D. The criteria for the velocity profile and the average flow angle were also met at the sampling locations that met the criteria for the particle profile. The methodologies used in this study can also be applied during assessments of air sampling locations when monitoring stacks at new nuclear facilities as well as existing nuclear facilities.

  4. 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.

  5. 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.

  6. 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.

  7. 40 CFR 61.44 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack sampling. (a) Sources subject to § 61.42(b) shall be continuously sampled, during...

  8. 40 CFR 61.53 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.53 Section 61.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Mercury ore processing facility. (1) Unless a waiver of emission testing is obtained under...

  9. 40 CFR 61.33 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.33 Section 61.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Unless a waiver of emission testing is obtained under § 61.13, each owner or operator...

  10. CAM and stack air sampler design guide

    International Nuclear Information System (INIS)

    Phillips, T.D.

    1994-01-01

    About 128 air samplers and CAMs presently in service to detect and document potential radioactive release from 'H' and 'F' area tank farm ventilation stacks are scheduled for replacement and/or upgrade by Projects S-5764, S-2081, S-3603, and S-4516. The seven CAMs scheduled to be upgraded by Project S-4516 during 1995 are expected to provide valuable experience for the three remaining projects. The attached document provides design guidance for the standardized High Level Waste air sampling system

  11. Forced Air-Breathing PEMFC Stacks

    Directory of Open Access Journals (Sweden)

    K. S. Dhathathreyan

    2012-01-01

    Full Text Available Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

  12. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Malá, Zdeňka; Pantůčková, Pavla; Gebauer, Petr; Boček, Petr

    2013-01-01

    Roč. 34, č. 1 (2013), s. 3-18 ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional support: RVO:68081715 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.161, year: 2013

  13. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Šlampová, Andrea; Křivánková, Ludmila; Gebauer, Petr; Boček, Petr

    2015-01-01

    Roč. 36, č. 1 (2015), s. 15-35 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.482, year: 2015

  14. 296-B-10 stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1995-01-01

    B Plant Administration Manual, requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with stack 296-B-10 at B Plant. The ventilation system of WESF (Waste Encapsulation and Storage Facility) is designed to provide airflow patterns so that air movement throughout the building is from areas of lesser radioactivity to areas of greater radioactivity. All potentially contaminated areas are maintained at a negative pressure with respect to the atmosphere so that air flows into the building at all times. The exhaust discharging through the 296-B-10 stack is continuously monitored and sampled using a sampling and monitoring probe assembly located approximately 17.4 meters (57 feet) above the base of the stack. The probe assembly consists of 5 nozzles for the sampling probe and 2 nozzles to monitor the flow. The sampling and monitoring system associated with Stack 296-B-10 is functional and performing satisfactorily

  15. Testing the sampling efficiency of a nuclear power station stack monitor

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L.H. [Instrumentinvest, Nykoeping (Sweden)

    1997-08-01

    The test method comprises the injection of known amounts of monodisperse particles in the stack air stream, at a suitable point upstream of the sampling installation. To find a suitable injection polls, the gas flow was mapped by means of a tracer gas, released in various points in the stack base. The resulting concentration distributions at the stack sampler level were observed by means of an array of gas detectors. An injection point that produced symmetrical distribution over the stack area, and low concentrations at the stack walls was selected for the particle tests. Monodisperse particles of 6, 10, and 19 {mu}m aerodynamic diameter, tagged with dysprosium, were dispersed in the selected injection point. Particle concentration at the sampler level was measured. The losses to the stack walls were found to be less than 10 %. The particle concentrations at the four sampler inlets were calculated from the observed gas distribution. The amount calculated to be aspirated into the sampler piping was compared with the quantity collected by the sampling train ordinary filter, to obtain the sampling line transmission efficiency. 1 ref., 2 figs.

  16. Operational air sampling report

    International Nuclear Information System (INIS)

    Lyons, C.L.

    1994-03-01

    Nevada Test Site vertical shaft and tunnel events generate beta/gamma fission products. The REECo air sampling program is designed to measure these radionuclides at various facilities supporting these events. The current testing moratorium and closure of the Decontamination Facility has decreased the scope of the program significantly. Of the 118 air samples collected in the only active tunnel complex, only one showed any airborne fission products. Tritiated water vapor concentrations were very similar to previously reported levels. The 206 air samples collected at the Area-6 decontamination bays and laundry were again well below any Derived Air Concentration calculation standard. Laboratory analyses of these samples were negative for any airborne fission products

  17. 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 ...

  18. Rain Sensor with Stacked Light Waveguide Having Tilted Air Gap

    Directory of Open Access Journals (Sweden)

    Kyoo Nam Choi

    2014-01-01

    Full Text Available Vehicle sensor to detect rain drop on and above waveguide utilizing light deflection and scattering was realized, keeping wide sensing coverage and sensitivity to detect mist accumulation. Proposed sensor structure under stacked light wave guide consisted of light blocking fixture surrounding photodetector and adjacent light source. Tilted air gap between stacked light waveguide and light blocking fixture played major role to increase sensitivity and to enhance linearity. This sensor structure eliminated complex collimating optics, while keeping wide sensing coverage using simple geometry. Detection algorithm based on time-to-intensity transformation process was used to convert raining intensity into countable raining process. Experimental result inside simulated rain chamber showed distinct different response between light rain and normal rain. Application as automobile rain sensor is expected.

  19. Image transfer by cascaded stack of photonic crystal and air layers

    NARCIS (Netherlands)

    Shen, C.; Michielsen, K.; Raedt, H. De

    2006-01-01

    We demonstrate image transfer by a cascaded stack consisting of two and three triangular-lattice photonic crystal slabs separated by air. The quality of the image transfered by the stack is sensitive to the air/photonic crystal interface termination and the frequency. Depending on the frequency and

  20. Simulation and Optimization of Air-Cooled PEMFC Stack for Lightweight Hybrid Vehicle Application

    Directory of Open Access Journals (Sweden)

    Jingming Liang

    2015-01-01

    Full Text Available A model of 2 kW air-cooled proton exchange membrane fuel cell (PEMFC stack has been built based upon the application of lightweight hybrid vehicle after analyzing the characteristics of heat transfer of the air-cooled stack. Different dissipating models of the air-cooled stack have been simulated and an optimal simulation model for air-cooled stack called convection heat transfer (CHT model has been figured out by applying the computational fluid dynamics (CFD software, based on which, the structure of the air-cooled stack has been optimized by adding irregular cooling fins at the end of the stack. According to the simulation result, the temperature of the stack has been equally distributed, reducing the cooling density and saving energy. Finally, the 2 kW hydrogen-air air-cooled PEMFC stack is manufactured and tested by comparing the simulation data which is to find out its operating regulations in order to further optimize its structure.

  1. Air sampling in the workplace

    International Nuclear Information System (INIS)

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

    1993-09-01

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

  2. Stack air-breathing membraneless glucose microfluidic biofuel cell

    International Nuclear Information System (INIS)

    Galindo-de-la-Rosa, J; Moreno-Zuria, A; Vallejo-Becerra, V; Guerra-Balcázar, M; Ledesma-García, J; Arjona, N; Arriaga, L G

    2016-01-01

    A novel stacked microfluidic fuel cell design comprising re-utilization of the anodic and cathodic solutions on the secondary cell is presented. This membraneless microfluidic fuel cell employs porous flow-through electrodes in a “V”-shape cell architecture. Enzymatic bioanodic arrays based on glucose oxidase were prepared by immobilizing the enzyme onto Toray carbon paper electrodes using tetrabutylammonium bromide, Nafion and glutaraldehyde. These electrodes were characterized through the scanning electrochemical microscope technique, evidencing a good electrochemical response due to the electronic transference observed with the presence of glucose over the entire of the electrode. Moreover, the evaluation of this microfluidic fuel cell with an air-breathing system in a double-cell mode showed a performance of 0.8951 mWcm -2 in a series connection (2.2822mAcm -2 , 1.3607V), and 0.8427 mWcm -2 in a parallel connection (3.5786mAcm -2 , 0.8164V). (paper)

  3. Sample Stacking in capillary zone electrophoresis : Principles, advantages and limitations

    NARCIS (Netherlands)

    Beckers, J.L.; Bocek, P.

    2000-01-01

    The principles of stacking procedures are described and their properties are discussed, including the fundamentals of the behavior of zone boundaries and the consequences of the self-correcting properties of boundaries in moving boundary electrophoresis, isotachophoresis, and zone electrophoresis.

  4. 296-B-5 Stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1995-02-01

    The B Plant Administration Manual requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with Stack 296-B-5 at B Plant. The sampling and monitoring system associated with stack 296-B-5 is functional and performing satisfactorily. This document is an annual assessment report of the systems associated with the 296-B-5 stack

  5. Some important results from the air pollution distribution model STACKS (1988-1992)

    International Nuclear Information System (INIS)

    Erbrink, J.J.

    1993-01-01

    Attention is paid to the results of the study on the distribution of air pollutants by high chimney-stacks of electric power plants. An important product of the study is the integrated distribution model STACKS (Short Term Air-pollutant Concentrations Kema modelling System). The improvements and the extensions of STACKS are described in relation to the National Model, which has been used to estimate the environmental effects of individual chimney-stacks. The National Model shows unacceptable variations for high pollutant sources. Based on the results of STACKS revision of the National model has been taken into consideration. By means of the revised National Model a more realistic estimation of the environmental effects of electric power plants can be carried out

  6. Assessment of the LV-C2 Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    This document reports on a series of tests conducted to assess the proposed air sampling location for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste (LAW) C2V (LV-C2) exhaust stack with respect to the applicable criteria regarding the placement of an air sampling probe. Federal regulations require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream. The tests were conducted on the LV-C2 scale model system. Based on the scale model tests, the location proposed for the air sampling probe in the scale model stack meets the requirements of the ANSI/HPS N13.1-1999 standard for velocity uniformity, flow angle, gas tracer and particle tracer uniformity. Additional velocity uniformity and flow angle tests on the actual stack will be necessary during cold startup to confirm the validity of the scale model results in representing the actual stack.

  7. Tank exhaust comparison with 40 CFR 61.93, Subpart H, and other referenced guidelines for Tank Farms National Emission Standards for Hazardous Air Pollutant (NESHAP) designated stacks

    International Nuclear Information System (INIS)

    Bachand, D.D.; Crummel, G.M.

    1994-07-01

    The US Environmental Protection Agency (EPA) promulgated National Emission Standards other than Radon from US Department of Energy (DOE) Facilities (40 CFR 61, Subpart H) on December 15, 1989. The regulations specify procedures, equipment, and test methods that.are to be used to measure radionuclide emissions from exhaust stacks that are designated as National Emission Standards for Hazardous Air Pollutant (NESHAP) stacks. Designated NESHAP stacks are those that have the potential to cause any member of the public to receive an effective dose equivalent (EDE) greater than or equal to 0.1 mrem/year, assuming all emission controls were removed. Tank Farms currently has 33 exhaust stacks, 15 of which are designated NESHAP stacks. This document assesses the compliance status of the monitoring and sampling systems for the designated NESHAP stacks

  8. Tank exhaust comparison with 40 CFR 61.93, Subpart H, and other referenced guidelines for Tank Farms National Emission Standards for Hazardous Air Pollutant (NESHAP) designated stacks

    Energy Technology Data Exchange (ETDEWEB)

    Bachand, D.D.; Crummel, G.M.

    1994-07-01

    The US Environmental Protection Agency (EPA) promulgated National Emission Standards other than Radon from US Department of Energy (DOE) Facilities (40 CFR 61, Subpart H) on December 15, 1989. The regulations specify procedures, equipment, and test methods that.are to be used to measure radionuclide emissions from exhaust stacks that are designated as National Emission Standards for Hazardous Air Pollutant (NESHAP) stacks. Designated NESHAP stacks are those that have the potential to cause any member of the public to receive an effective dose equivalent (EDE) greater than or equal to 0.1 mrem/year, assuming all emission controls were removed. Tank Farms currently has 33 exhaust stacks, 15 of which are designated NESHAP stacks. This document assesses the compliance status of the monitoring and sampling systems for the designated NESHAP stacks.

  9. Determination of sulfur dioxide in ambient air and in industrial stack using X-ray fluorescence technique

    International Nuclear Information System (INIS)

    Sumitra, T.; Chankow, N.; Punnachaiya, S.; Laopaibul, R.

    1988-01-01

    Sulfur dioxide is a major air pollutant of concern. The gas has to be monitored both in ambient air and in industrial stacks. There are several methods of measuring sulfur dioxide. Standard methods adopted for Thailand are based on chemical methods. These are normally sensitive to light and temperature changes. Therefore a method of collecting air sample and determination of SO 2 by X-ray fluorescence technique was developed. Air sampling was done by an in-house low cost air sampler using automobile battery, dependency on a.c. source was thus avoided. The air pump has a flow rate between 0.2-1.5 liters/minute and draw about 0.6 A from a 12 V battery. SO 2 was collected on 37 mm filters impregnated with 5% sodium carbonate. This method could detect SO 2 from 10 μg up. The method has been checked by interlaboratory comparison. Field test has also been performed at some tobacco curing plants in Amphoe Sansai, Changwat Chiengmai, both in ambient air and in stacks. The results were found to be satisfactory and comparable with the standard methods

  10. Isopleths of surface air concentration and surface air kerma rate due to a radioactive cloud released from a stack (3)

    International Nuclear Information System (INIS)

    Tachibana, Haruo; Kikuchi, Masamitsu; Sekita, Tsutomu; Yamaguchi, Takenori

    2004-06-01

    This report is a revised edition of 'Isopleths of Surface Air Concentration and Surface Air Absorbed Dose Rate due to a Radioactive Cloud Released from a Stack(II) '(JAERI-M 90-206) and based on the revised Nuclear Safety Guidelines reflected the ICRP1990 Recommendation. Characteristics of this report are the use of Air Karma Rate (Gy/h) instead of Air Absorbed Dose Rate (Gy/h), and the record of isopleths of surface air concentration and surface air karma rate on CD-ROM. These recorded data on CD-ROM can be printed out on paper and/or pasted on digital map by personal computer. (author)

  11. Performance Analysis of Air Breathing Proton Exchange Membrane Fuel Cell Stack (PEMFCS) At Different Operating Condition

    Science.gov (United States)

    Sunil, V.; Venkata siva, G.; Yoganjaneyulu, G.; Ravikumar, V. V.

    2017-08-01

    The answer for an emission free power source in future is in the form of fuel cells which combine hydrogen and oxygen producing electricity and a harmless by product-water. A proton exchange membrane (PEM) fuel cell is ideal for automotive applications. A single cell cannot supply the essential power for any application. Hence PEM fuel cell stacks are used. The effect of different operating parameters namely: type of convection, type of draught, hydrogen flow rate, hydrogen inlet pressure, ambient temperature and humidity, hydrogen humidity, cell orientation on the performance of air breathing PEM fuel cell stack was analyzed using a computerized fuel cell test station. Then, the fuel cell stack was subjected to different load conditions. It was found that the stack performs very poorly at full capacity (runs only for 30 min. but runs for 3 hours at 50% capacity). Hence, a detailed study was undertaken to maximize the duration of the stack’s performance at peak load.

  12. Experimental performance evaluation of two stack sampling systems in a plutonium facility

    International Nuclear Information System (INIS)

    Glissmeyer, J.A.

    1992-04-01

    The evaluation of two routine stack sampling systems at the Z-Plant plutonium facility operated by Rockwell International for USERDA is part of a larger study, sponsored by Rockwell and conducted by Battelle, Pacific Northwest Laboratories, of gaseous effluent sampling systems. The gaseous effluent sampling systems evaluated are located at the main plant ventilation stack (291-Z-1) and at a vessel vent stack (296-Z-3). A preliminary report, which was a paper study issued in April 1976, identified many deficiencies in the existing sampling systems and made recommendations for corrective action. The objectives of this experimental evaluation of those sampling systems were as follows: Characterize the radioactive aerosols in the stack effluents; Develop a tracer aerosol technique for validating particulate effluent sampling system performance; Evaluate the performance of the existing routine sampling systems and their compliance with the sponsor's criteria; and Recommend corrective action where required. The tracer aerosol approach to sampler evaluation was chosen because the low concentrations of radioactive particulates in the effluents would otherwise require much longer sampling times and thus more time to complete this evaluation. The following report describes the sampling systems that are the subject of this study and then details the experiments performed. The results are then presented and discussed. Much of the raw and finished data are included in the appendices

  13. Directional dependency of air sampling

    International Nuclear Information System (INIS)

    1994-01-01

    A field study was performed by Idaho State University-Environmental Monitoring Laboratory (EML) to examine the directional dependency of low-volume air samplers. A typical continuous low volume air sampler contains a sample head that is mounted on the sampler housing either horizontally through one of four walls or vertically on an exterior wall 'looking down or up.' In 1992, a field study was undertaken to estimate sampling error and to detect the directional effect of sampler head orientation. Approximately 1/2 mile downwind from a phosphate plant (continuous source of alpha activity), four samplers were positioned in identical orientation alongside one sampler configured with the sample head 'looking down'. At least five consecutive weekly samples were collected. The alpha activity, beta activity, and the Be-7 activity collected on the particulate filter were analyzed to determine sampling error. Four sample heads were than oriented to the four different horizontal directions. Samples were collected for at least five weeks. Analysis of the alpha data can show the effect of sampler orientation to a know near source term. Analysis of the beta and Be-7 activity shows the effect of sampler orientation to a ubiquitous source term

  14. Assessment of the National Research Universal Reactor Proposed New Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-02-29

    This document reports on a series of tests conducted to assess the proposed air sampling location for the National Research Universal reactor (NRU) complex exhaust stack, located in Chalk River, Ontario, Canada, with respect to the applicable criteria regarding the placement of an air sampling probe. Due to the age of the equipment in the existing monitoring system, and the increasing difficulty in acquiring replacement parts to maintain this equipment, a more up-to-date system is planned to replace the current effluent monitoring system, and a new monitoring location has been proposed. The new sampling probe should be located within the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream. The internal Pacific Northwest National Laboratory (PNNL) project for this task was 65167, Atomic Energy Canada Ltd. Chalk River Effluent Duct Flow Qualification. The testing described in this document was guided by the Test Plan: Testing of the NRU Stack Air Sampling Position (TP-STMON-032).

  15. Hanford Site radionuclide national emission standards for hazardous air pollutants registered stack source assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.; Barnett, J.M.

    1994-07-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency,, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site . The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified a total of 16 stacks as having potential emissions that,would cause an effective dose equivalent greater than 0.1 mrem/yr.

  16. Hanford Site radionuclide national emission standards for hazardous air pollutants registered stack source assessment

    International Nuclear Information System (INIS)

    Davis, W.E.; Barnett, J.M.

    1994-01-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency,, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site . The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified a total of 16 stacks as having potential emissions that,would cause an effective dose equivalent greater than 0.1 mrem/yr

  17. Hanford Site radionuclide national emission standards for hazardous air pollutants unregistered stack (power exhaust) source assessment

    International Nuclear Information System (INIS)

    Davis, W.E.

    1994-01-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. This evaluation provides an assessment of the 39 unregistered stacks, under Westinghouse Hanford Company's management, and their potential radionuclide emissions, i.e., emissions with no control devices in place. The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified three stacks, 107-N, 296-P-26 and 296-P-28, as having potential emissions that would cause an effective dose equivalent greater than 0.1 mrem/yr. These stacks, as noted by 40 CFR 61.93, would require continuous monitoring

  18. Hanford Site radionuclide national emission standards for hazardous air pollutants unregistered stack (power exhaust) source assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.

    1994-08-04

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. This evaluation provides an assessment of the 39 unregistered stacks, under Westinghouse Hanford Company`s management, and their potential radionuclide emissions, i.e., emissions with no control devices in place. The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified three stacks, 107-N, 296-P-26 and 296-P-28, as having potential emissions that would cause an effective dose equivalent greater than 0.1 mrem/yr. These stacks, as noted by 40 CFR 61.93, would require continuous monitoring.

  19. Development and Characterization of an Electrically Rechargeable Zinc-Air Battery Stack

    Directory of Open Access Journals (Sweden)

    Hongyun Ma

    2014-10-01

    Full Text Available An electrically rechargeable zinc-air battery stack consisting of three single cells in series was designed using a novel structured bipolar plate with air-breathing holes. Alpha-MnO2 and LaNiO3 severed as the catalysts for the oxygen reduction reaction (ORR and oxygen evolution reaction (OER. The anodic and cathodic polarization and individual cell voltages were measured at constant charge-discharge (C-D current densities indicating a uniform voltage profile for each single cell. One hundred C-D cycles were carried out for the stack. The results showed that, over the initial 10 cycles, the average C-D voltage gap was about 0.94 V and the average energy efficiency reached 89.28% with current density charging at 15 mA·cm−2 and discharging at 25 mA·cm−2. The total increase in charging voltage over the 100 C-D cycles was ~1.56% demonstrating excellent stability performance. The stack performance degradation was analyzed by galvanostatic electrochemical impedance spectroscopy. The charge transfer resistance of ORR increased from 1.57 to 2.21 Ω and that of Zn/Zn2+ reaction increased from 0.21 to 0.34 Ω after 100 C-D cycles. The quantitative analysis guided the potential for the optimization of both positive and negative electrodes to improve the cycle life of the cell stack.

  20. Assessment of the LV-S2 & LV-S3 Stack Sampling Probe Locations for Compliance with ANSI/HPS N13.1-1999

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A.; Antonio, Ernest J.; Flaherty, Julia E.; Amidan, Brett G.

    2014-09-30

    This document reports on a series of tests conducted to assess the proposed air sampling locations for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Group 1-2A exhaust stacks with respect to the applicable criteria regarding the placement of an air sampling probe. The LV-C2, LV-S2, and LV-S3 exhaust stacks were tested together as a group (Test Group 1-2A). This report only covers the results of LV-S2 and LV-S3; LV-C2 will be reported on separately. Federal regulations1 require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. 2 These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream.

  1. Project W420 Air Sampler Probe Placement Qualification Tests for Four 6-Inch Diameter Stacks: 296-A-25, 296-B-28, 296-S-22, and 296-T-18

    International Nuclear Information System (INIS)

    Maughan, A.D.; Glissmeyer, J.A.

    1998-01-01

    The W420 project covers the upgrading of effluent monitoring systems at six ventilation exhaust stacks in tank-farm facilities at the U.S. Department of Energy's Hanford Site. The discharge stacks of five of the six systems will be completely replaced. Four of these (296-A-25, 296-B-28, 296-S-22, and 296-T-18) will be of the same size, 6-inches in diameter and about 12-ft high. This report documents tests that were conducted to verify that these four stacks meet the applicable regulatory criteria regarding the placement of the air sampling probe. These criteria ensure that the contaminants in the stack are well mixed with the airflow at the location of the probe such that the extracted sample represents the whole. There are also criteria addressing the transport of the sample to the collection device. These are not covered in this report, but will need to be addressed later. These tests were conducted by Pacific Northwest National Laboratory on a full-scale model of the 6-inch stick. The sequence of tests addresses the acceptability of the flow angle relative to the probe and the uniformity of air velocity and gaseous and particle tracers in the cross section of the stack. All tests were successful, and all acceptance criteria were met

  2. Single point aerosol sampling: Evaluation of mixing and probe performance in a nuclear stack

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, J.C.; Fairchild, C.I.; Wood, G.O. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-02-01

    Alternative Reference Methodologies (ARMs) have been developed for sampling of radionuclides from stacks and ducts that differ from the methods required by the U.S. EPA. The EPA methods are prescriptive in selection of sampling locations and in design of sampling probes whereas the alternative methods are performance driven. Tests were conducted in a stack at Los Alamos National Laboratory to demonstrate the efficacy of the ARMs. Coefficients of variation of the velocity tracer gas, and aerosol particle profiles were determined at three sampling locations. Results showed numerical criteria placed upon the coefficients of variation by the ARMs were met at sampling stations located 9 and 14 stack diameters from flow entrance, but not at a location that is 1.5 diameters downstream from the inlet. Experiments were conducted to characterize the transmission of 10 {mu}m aerodynamic equivalent diameter liquid aerosol particles through three types of sampling probes. The transmission ratio (ratio of aerosol concentration at the probe exit plane to the concentration in the free stream) was 107% for a 113 L/min (4-cfm) anisokinetic shrouded probe, but only 20% for an isokinetic probe that follows the EPA requirements. A specially designed isokinetic probe showed a transmission ratio of 63%. The shrouded probe performance would conform to the ARM criteria; however, the isokinetic probes would not.

  3. Planar array stack design aided by rapid prototyping in development of air-breathing PEMFC

    Science.gov (United States)

    Chen, Chen-Yu; Lai, Wei-Hsiang; Weng, Biing-Jyh; Chuang, Huey-Jan; Hsieh, Ching-Yuan; Kung, Chien-Chih

    The polymer electrolyte membrane fuel cell (PEMFC) is one of the most important research topics in the new and clean energy area. The middle or high power PEMFCs can be applied to the transportation or the distributed power system. But for the small power application, it is needed to match the power requirement of the product generally. On the other hand, the direct methanol fuel cell (DMFC) is one of the most common type that researchers are interested in, but recently the miniature or the micro-PEMFCs attract more attention due to their advantages of high open circuit voltage and high power density. The objective of this study is to develop a new air-breathing planar array fuel cell stacked from 10 cells made by rapid prototyping technology which has potential for fast commercial design, low cost manufacturing, and even without converters/inverters for the system. In this paper, the main material of flow field plates is acrylonitrile-butadiene-styrene (ABS) which allows the fuel cell be mass-manufactured by plastic injection molding technology. The rapid prototyping technology is applied to construct the prototype and verify the practicability of the proposed stack design. A 10-cell air-breathing miniature PEMFC stack with a volume of 6 cm × 6 cm × 0.9 cm is developed and tested. Its segmented membrane electrode assembly (MEA) is designed with the active surface area of 1.3 cm × 1.3 cm in each individual MEA. The platinum loading at anode and cathode are 0.2 mg cm -2 and 0.4 mg cm -2, respectively. Results show that the peak power densities of the parallel connected and serial connected stack are 99 mW cm -2 at 0.425 V and 92 mW cm -2 at 4.25 V, respectively under the conditions of 70 °C relative saturated humidity (i.e., dew point temperature), ambient temperature and free convection air. Besides, the stack performance is increased under forced convection. If the cell surface air is blown by an electric fan, the peak power densities of parallel connected and

  4. Treatability test of a stacked-tray air stripper for VOC in water

    Energy Technology Data Exchange (ETDEWEB)

    Pico, T., LLNL

    1998-04-01

    A common strategy for hydraulic containment and mass removal at VOC contaminated sites is `pump and treat (P&T)`. In P&T operations, contaminated ground water is pumped from wells, treated above ground, and discharged. Many P&T remediation systems at VOC sites rely on air stripping technology because VOCs are easily transferred to the vapor phase. In stacked-tray air strippers, contaminated water is aerated while it flows down through a series of trays. System operations at LLNL are strictly regulated by the California and federal Environmental Protection Agencies (Cal/EPA and EPA), the Bay Area Air Quality Management District (BAAQMD), the California Regional Water Quality Control Board (RWQCB) and the Department of Toxic Substances Control (DTSC). These agencies set discharge limits, require performance monitoring, and assess penalties for non-compliance. National laboratories are also subject to scrutiny by the public and other government agencies. This extensive oversight makes it necessary to accurately predict field treatment performance at new extraction locations to ensure compliance with all requirements prior to facility activation. This paper presents treatability test results for a stacked- tray air stripper conducted at LLNL and compares them to the vendor`s modeling software results.

  5. Guidance for air sampling at nuclear facilities

    International Nuclear Information System (INIS)

    Breslin, A.J.

    1976-11-01

    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

  6. MODIFYING A 60-YEAR-OLD STACK-SAMPLING SYSTEM TO MEET ANSI N13.1-1999 EQUIVALENCY

    International Nuclear Information System (INIS)

    SIMMONS, F.M.

    2006-01-01

    The 291-T-1 stack was constructed in 1944 to support ongoing missions associated with the Hanford Project. Recent changes in the plant mission required a revision to the existing license of the stack that was operating as a minor emission unit. The Environmental Protection Agency (EPA) and the Washington Department of Health (WDOH) deemed this revision to be a significant modification, thereby requiring the stack to operate to the ANSI N13.1-1999 sampling and monitoring requirements. Because the stack is similar to other stacks on the Hanford site, allowance was made by EPA to demonstrate equivalency to the ANSI standard via calculations in lieu of actual testing. Calculations were allowed for determining the deposition, nozzle transmission and aspiration ratios, but measurements were required for the stack flow coefficient of variation (COV). The equivalency determination was to be based on the requirements of Table 6 of the ANSI N13.1-1999 Standard

  7. 40 CFR 61.34 - Air sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Air sampling. 61.34 Section 61.34... sampling. (a) Stationary sources subject to § 61.32(b) shall locate air sampling sites in accordance with a... concentrations calculated within 30 days after filters are collected. Records of concentrations at all sampling...

  8. 291-B-1 stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1994-01-01

    The B Plant 291-B-1 main stack exhausts gaseous effluents to the atmosphere from the 221-B Building canyon and cells, the No. 1 Vessel Ventilation System (VVS1), the 212-B Cask Station cell ventilation system, and, to a limited capacity, the 224-B Building. VVS1 collects offgases from various process tanks in 221-B Building, while the 224-B system maintains a negative pressure in out-of-service, sealed process tanks. B Plant Administration Manual, WHC-CM-7-5, Section 5.30 requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with Stack 291-B-1 (System Number B977A) at B Plant. The system is functional and performing satisfactorily

  9. Separation of arsenic species by capillary electrophoresis with sample-stacking techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zu Liang; Naidu, Ravendra [Adelaide Laboratory, CSIRO Land and Water, PMB2, 5064, Glen Osmond, SA (Australia); Lin, Jin-Ming [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 100085, Beijing (China)

    2003-03-01

    A simple capillary zone electrophoresis procedure was developed for the separation of arsenic species (AsO{sub 2}{sup 2-}, AsO{sub 4}{sup 2-}, and dimethylarsinic acid, DMA). Both counter-electroosmotic and co-electroosmotic (EOF) modes were investigated for the separation of arsenic species with direct UV detection at 185 nm using 20 mmol L{sup -1} sodium phosphate as the electrolyte. The separation selectivity mainly depends on the separation modes and electrolyte pH. Inorganic anions (Cl{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -} and SO{sub 4}{sup 2-}) presented in real samples did not interfere with arsenic speciation in either separation mode. To improve the detection limits, sample-stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were investigated for the preconcentration of As species in co-CZE mode. Less than 1 {mu}mol L{sup -1} of detection limits for As species were achieved using FASI. The proposed method was demonstrated for the separation and detection of As species in water. (orig.)

  10. Evaluation of personal air sampling pumps

    International Nuclear Information System (INIS)

    Ritter, P.D.; Novick, V.J.; Alvarez, J.L.; Huntsman, B.L.

    1987-01-01

    Personal air samplers are used to more conveniently obtain breathing zone samples from individuals over periods of several hours. Personal air sampling pumps must meet minimum performance levels under all working conditions to be suitable for use in radiation protection programs. In addition, the pumps should be simple to operate and as comfortable to wear as possible. Ten models of personal air sampling pumps were tested to evaluate their mechanical performance and physical characteristics. The pumps varied over a wide range in basic performance and operating features. Some of the pumps were found to have adequate performance for use in health physics air sampling applications. 3 references, 2 figures, 5 tables

  11. Performance evaluation of a stack cooling system using CO{sub 2} air conditioner in fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Chul; Won, Jong Phil [Thermal Management Research Center, Korea Automotive Technology Institute, Chungnam 330-912 (Korea); Park, Yong Sun; Lim, Tae Won [Corporate Research and Development Division, Hyundai-Kia Motors, Gyeonggi 449-912 (Korea); Kim, Min Soo [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea)

    2009-01-15

    A relation between the heat release from a fuel cell stack and an air conditioning system's performance was investigated. The air conditioning system installed in a fuel cell vehicle can be used for stack cooling when additional stack heat release is required over a fixed radiator capacity during high vehicle power generation. This study investigated the performance of a stack cooling system using CO{sub 2} air conditioner at various operating conditions. Also, the heat releasing effectiveness and mutual interference were analyzed and compared with those for the conventional radiator cooling system with/without cabin cooling. When the radiator coolant inlet temperature and flow rate were 65 C and 80 L/min, respectively, for the outdoor air inlet speed of 5 m/s, the heat release of the stack cooling system with the aid of CO{sub 2} air conditioner increased up to 36% more than that of the conventional radiator cooling system with cabin cooling. Furthermore, this increased by 7% versus the case without cabin cooling. (author)

  12. Experimental study of convective heat transfer during cooling with low air velocity in a stack of objects

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amara, Sami; Laguerre, Onrawee [Cemagref - Refrigeration Processes Engineering Research Unit, parc de Tourvoie, BP 44, 92163 cedex, Antony (France); Flick, Denis [National Agronomic Institute - INAPG, 16 rue Claude Bernard, 75231 cedex 05, Paris (France)

    2004-12-01

    During cooling with low air velocity (u{<=}0.2 m.s{sup -1}) of a stack of foodstuffs (a few centimeters dimension), the radiation and conduction between products can be of the same order of magnitude as convection. A method was developed to quantify these various transfer modes. The experiment was carried out using an in-line spherical arrangement; however, the same methodology can be applied to other product shapes. The results confirm that the heat transfers by radiation and conduction cannot be neglected. In addition, the convective heat transfer coefficient varies not only with air velocity but also with the product position in the stack. (authors)

  13. Development and characterization of a novel air-breathing micro direct methanol fuel cell stack for portable applications

    International Nuclear Information System (INIS)

    Liu, Xiaowei; Zhang, Bo; Zhang, Yufeng; He, Hong; Li, Jianmin; Wang, Shibo; Yuan, Zhenyu; Deng, Huichao

    2010-01-01

    An air-breathing 10-cell micro direct methanol fuel cell (µDMFC) stack with four anode feeding patterns is designed, fabricated and tested. For a better understanding of the operational characteristics of both the single cell and the stack, a two-dimensional numerical model is established and calculated. Employing micro-stamping technology, the current collectors of each single cell are microfabricated on the stainless steel plate with a thickness of 300 µm. The single µDMFC is first tested under various operating parameters. On the basis of the simulation and experimental observation of the single cell performance, the µDMFC stack performance is thoroughly analyzed with different anode feeding patterns. The results indicate that the µDMFC stack with pattern B can ensure the uniform performance of each single cell and generate the highest power output. With pattern B, further experiments are carried out to investigate the influence of the anode flow rate on the stack performance. As a result, the µDMFC stack achieves the best performance with the maximum power density of about 24.75 mW cm −2 at 5.0 ml min −1 . Finally, the stack is successfully applied to two electronic devices of different rated power

  14. Preliminary evaluation of the gaseous effluent sampling and monitoring systems at the 291-Z-1 and 296-Z-3 stacks

    International Nuclear Information System (INIS)

    Schwendiman, L.C.; Glissmeyer, J.A.

    1992-04-01

    The 291-Z-1 and 296-Z-3 stack effluent particulate sampling and monitoring systems are being evaluated for compliance with Atlantic Richfield Hanford Company's Interim Criteria for such systems. This evaluation is part of a study by Battelle-Northwest of gaseous effluent sampling systems in ARHCO facilities. This letter report presents a preliminary evaluation of the mentioned facilities and the indicated improvements needed to meet the Interim Criteria so that conceptual design work for improved systems can be initiated. There is currently underway a detailed study at the two stacks including a series of sampling experiments, the findings of which will not be included in this report. The gaseous effluent sampling system at the 291-Z-1 and 296-Z-3 stacks are very dissimilar and will be treated in separate sections of this report. The discussions for each sampling system will include a brief description and a preliminary evaluation of the systems

  15. Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy,

    Directory of Open Access Journals (Sweden)

    Tanyse Bahia Carvalho Marques

    2014-10-01

    Full Text Available OBJECTIVE: Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD. The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA and in patients with congenital muscular dystrophy (CMD, as well as to identify associations between spinal deformities and the effects of the maneuvers. METHODS: Eighteen NMD patients (ten with CMD and eight with SMA were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC; and assisted and unassisted peak cough flow (APCF and UPCF, respectively with insufflations. RESULTS: After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis. CONCLUSIONS: Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis.

  16. The physico-chemical 131I species in the stack exhaust air of a boiling water reactor

    International Nuclear Information System (INIS)

    Deuber, H.

    1982-07-01

    In the stack exhaust air of a German boiling water reactor, the fractions of elemental, particulate and organic 131 I were determined over a period of three years. The average fraction of elemental 131 I, which is decisive for the ingestion dose, was about 20% during the first two years and about 50% during the third year. (orig.) [de

  17. Air sampling with solid phase microextraction

    Science.gov (United States)

    Martos, Perry Anthony

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

  18. [Analysis of phthalate esters in plastic-packaging bags on-line sample stacking-microemulsion electrokinetic chromatography].

    Science.gov (United States)

    Xiao, Jia; Huang, Ying; Wang, Minyi; Chen, Guonan

    2012-09-01

    Two convenient, effective, and reproducible methods using microemulsion electrokinetic chromatography (MEEKC)-normal stacking mode (NSM) and reversed electrode polarity stacking mode (REPSM) were developed for the on-line sample stacking of phthalate esters (PAEs). REPSM coupled with MEEKC increased the sensitivity of 937.5 to 7,143 times for four PAEs compared to the conventional MEEKC. The separating conditions in the MEEKC method were studied, and many factors influencing the two sample stacking processes were investigated in detail. The optimum sample matrices for the two stacking methods were as follows: 30 mmol/L sodium cholate (SC) and 30.0 mmol/L borate (pH 8.5). Additionally, sample injections as large as 3.45 kPa x 40 s and 3.45 kPa x 90 s were applied for NSM-MEEKC and REPSM-MEEKC, respectively. The linear relationship and reproducibility were also examined. Under the optimum conditions, the detection limits (S/N = 3) of the PAEs were in the ranges of 0.021 - 0.33 mg/L and 0.7 - 4 microg/L for NSM-MEEKC and REPSM-MEEKC, respectively. The proposed REPSM-MEEKC has been successfully applied to determine PAEs in plastic-packaging bags, and the spiked recoveries were in the range of 89.1% - 105.6% with satisfactory results.

  19. Disinfection of indoor air microorganisms in stack room of university library using gaseous chlorine dioxide.

    Science.gov (United States)

    Hsu, Ching-Shan; Lu, Ming-Chun; Huang, Da-Ji

    2015-02-01

    As with all indoor public spaces in Taiwan, the stack rooms in public libraries should meet the air quality guidelines laid down by the Taiwan Environmental Protection Administration. Accordingly, utilizing a university library in Taiwan for experimental purposes, this study investigates the efficiency of gaseous chlorine dioxide (ClO2) as a disinfection agent when applied using three different treatment modes, namely a single-daily disinfection mode (SIM), a twice-daily disinfection mode (TWM), and a triple-daily disinfection mode (TRM). For each treatment mode, the ClO2 is applied using an ultrasonic aerosol device and is performed both under natural lighting conditions and under artificial lighting conditions. The indoor air quality is evaluated before and after each treatment session by measuring the bioaerosol levels of bacteria and fungi. The results show that for all three disinfection modes, the application of ClO2 reduces the indoor bacteria and fungi concentrations to levels lower than those specified by the Taiwan EPA (i.e., bacteria <1500 CFU/m(3), fungi <1000 CFU/m(3)), irrespective of the lighting conditions under which the disinfection process is performed. For each disinfection mode, a better disinfection efficiency is obtained under natural lighting conditions since ClO2 readily decomposes under strong luminance levels. Among the three treatment modes, the disinfection efficiencies of the TWM and TRM modes are very similar under natural lighting conditions and are significantly better than that of the SIM mode. Thus, overall, the results suggest that the TWM treatment protocol represents the most cost-effective and efficient method for meeting the indoor air quality requirements of the Taiwan EPA.

  20. Air Pollution Modelling to Predict Maximum Ground Level Concentration for Dust from a Palm Oil Mill Stack

    Directory of Open Access Journals (Sweden)

    Regina A. A.

    2010-12-01

    Full Text Available The study is to model emission from a stack to estimate ground level concentration from a palm oil mill. The case study is a mill located in Kuala Langat, Selangor. Emission source is from boilers stacks. The exercise determines the estimate the ground level concentrations for dust to the surrounding areas through the utilization of modelling software. The surround area is relatively flat, an industrial area surrounded by factories and with palm oil plantations in the outskirts. The model utilized in the study was to gauge the worst-case scenario. Ambient air concentrations were garnered calculate the increase to localized conditions. Keywords: emission, modelling, palm oil mill, particulate, POME

  1. Sampling for Air Chemical Emissions from the Life Sciences Laboratory II

    Energy Technology Data Exchange (ETDEWEB)

    Ballinger, Marcel Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lindberg, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-03-30

    Sampling for air chemical emissions from the Life Science Laboratory II (LSL-II) ventilation stack was performed in an effort to determine potential exposure of maintenance staff to laboratory exhaust on the building roof. The concern about worker exposure was raised in December 2015 and several activities were performed to assist in estimating exposure concentrations. Data quality objectives were developed to determine the need for and scope and parameters of a sampling campaign to measure chemical emissions from research and development activities to the outside air. The activities provided data on temporal variation of air chemical concentrations and a basis for evaluating calculated emissions. Sampling for air chemical emissions was performed in the LSL-II ventilation stack over the 6-week period from July 26 to September 1, 2016. A total of 12 sampling events were carried out using 16 sample media. Resulting analysis provided concentration data on 49 analytes. All results were below occupational exposure limits and most results were below detection limits. When compared to calculated emissions, only 5 of the 49 chemicals had measured concentrations greater than predicted. This sampling effort will inform other study components to develop a more complete picture of a worker’s potential exposure from LSL-II rooftop activities. Mixing studies were conducted to inform spatial variation in concentrations at other rooftop locations and can be used in conjunction with these results to provide temporal variations in concentrations for estimating the potential exposure to workers working in and around the LSL-II stack.

  2. Field-amplified sample stacking-sweeping of vitamins B determination in capillary electrophoresis.

    Science.gov (United States)

    Dziomba, Szymon; Kowalski, Piotr; Bączek, Tomasz

    2012-12-07

    A capillary electrophoretic method for determination of five water soluble vitamins B along with baclofen as an internal standard has been developed and assessed in context of precision, accuracy, sensitivity, freedom from interference, linearity, detection and quantification limits. On-line preconcentration technique, namely field-amplified sample stacking (FASS)-sweeping, has been employed in respect to obtain more sensitive analysis. Separation conditions received after optimization procedure were as following background electrolyte (BGE), 10 mM NaH(2)PO(4), 80 mM SDS, (pH 7.25); sample matrix (SM), 10 mM NaH(2)PO(4) (pH 4.60); uncoated fused silica capillary (50 μm i.d. × 67 cm length); UV spectrophotometric detection at 200 nm; injection times: 10s and 30s at 3.45 kPa; applied voltage 22 kV; temperature 22°C. Validation parameters, namely precision, accuracy and linearity, were considered as satisfactory. Under the optimized conditions, it has been also successfully applied for vitamins B determination in bacterial growth medium and commercially available Ilex paraguariensis leaves. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Characterization of cotton gin PM10 emissions based on EPA stack sampling methodologies and particle size distributions

    Science.gov (United States)

    A project to characterize cotton gin emissions in terms of stack sampling was conducted during the 2008 through 2011 ginning seasons. The impetus behind the project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. EPA AP-42 emission factors ar...

  4. Air sampling system for airborne surveys

    International Nuclear Information System (INIS)

    Jupiter, C.; Tipton, W.J.

    1975-01-01

    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

  5. Combination syringe provides air-free blood samples

    Science.gov (United States)

    Pool, S. L.

    1970-01-01

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

  6. Anionic microemulsion to solvent stacking for on-line sample concentration of cationic analytes in capillary electrophoresis.

    Science.gov (United States)

    Kukusamude, Chunyapuk; Srijaranai, Supalax; Quirino, Joselito P

    2014-05-01

    The common SDS microemulsion (i.e. 3.3% SDS, 0.8% octane, and 6.6% butanol) and organic solvents were investigated for the stacking of cationic drugs in capillary zone electrophoresis using a low pH separation electrolyte. The sample was prepared in the acidic microemulsion and a high percentage of organic solvent was included in the electrolyte at anodic end of capillary. The stacking mechanism was similar to micelle to solvent stacking where the micelles were replaced by the microemulsion for the transport of analytes to the organic solvent rich boundary. This boundary is found between the microemulsion and anodic electrolyte. The effective electrophoretic mobility of the cations reversed from the direction of the anode in the microemulsion to the cathode in the boundary. Microemulsion to solvent stacking was successfully achieved with 40% ACN in the anodic electrolyte and hydrodynamic sample injection of 21 s at 1000 mbar (equivalent to 30% of the effective length). The sensitivity enhancement factors in terms of peak height and corrected peak area were 15 to 35 and 21 to 47, respectively. The linearity R(2) in terms of corrected peak area were >0.999. Interday precisions (%RSD, n = 6) were 3.3-4.0% for corrected peak area and 2.0-3.0% for migration time. Application to spiked real sample is also presented. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Development of a method to measure the concentration of 14C in the stack air of nuclear power plants by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Stenstroem, K.; Erlandsson, B.; Hellborg, R.; Haakansson, K.; Wiebert, A.; Skog, G.

    1993-04-01

    C-14, a pure low-energetic beta-emitter, is produced through various nuclear reactions in nuclear power plants. Some of this C-14 is air-borne and is transported via the ventilation system through the stack of the power station and is integrated in living matter in the surroundings of the plant. The long half-life of the isotope (T1/2=5730 years) and the biological importance of carbon may lead to a not negligible contribution of the radiation dose for those living in the neighbourhood of nuclear power plants. C-14 has earlier been measured radiometrically with mainly two different methods, using proportional counters or liquid scintillators. In this report a new method is described, using an accelerator based technique. accelerator mass spectrometry (AMS). This technique has at least three advantages over the radiometrical methods. It requires only a few litres of gas per sample, which is 100-1000 times less compared to the radiometrical methods. It is insensitive to the beta and gamma rays from other radioactive isotopes in the stack air. The measuring time with AMS, about 20 minutes per sample, is considerably shorter compared to the radiometrical methods, which demand several hours per sample. The integrity of the AMS method is high and it might be convenient for regulatory supervision. (22 refs.)

  8. Ambient krypton-85 air sampling at Hanford

    International Nuclear Information System (INIS)

    Trevathan, M.S.; Price, K.R.

    1985-01-01

    In the fall of 1982, the Environmental Evaluations Section of Pacific Northwest Laboratory (PNL) initiated a network of continuous 85 Kr air samplers located on and around the Hanford Site. This effort was in response to the resumption of operations at a nuclear fuel reprocessing plant located onsite where 85 Kr was to be released during fuel dissolution. Preoperational data were collected using noble gas samplers designed by the Environmental Protection Agency-Las Vegas (EPA-LV). The samplers functioned erratically resulting in excessive maintenance costs and prompted a search for a new sampling system. State-of-the-art 85 Dr sampling methods were reviewed and found to be too costly, too complex and inappropriate for field application, so a simple bag collection system was designed and field tested. The system is composed of a reinforced, heavy plastic bag, connected to a variable flow pump and housed in a weatherproof enclosure. At the end of the four week sampling period the air in the bag is transferred by a compressor into a pressure tank for easy transport to the laboratory for analysis. After several months of operation, the air sampling system has proven its reliability and sensitivity to ambient levels of 85 Kr

  9. Ambient krypton-85 air sampling at Hanford

    International Nuclear Information System (INIS)

    Trevathan, M.S.; Price, K.R.

    1984-10-01

    In the fall of 1982, the Environmental Evaluations Section of Pacific Northwest Laboratory (PNL) initiated a network of continuous krypton-85 air samplers located on and around the Hanford Site. This effort was in response to the resumption of operations at a nuclear fuel reprocessing plant located onsite where krypton-85 was to be released during fuel dissolution. Preoperational data were collected using noble gas samplers designed by the Environmental Protection Agency-Las Vegas (EPA-LV). The samplers functioned erratically resulting in excessive maintenance costs and prompted a search for a new sampling system. State of the art krypton-85 sampling methods were reviewed and found to be too costly, too complex and inappropriate for field application, so a simple bag collection system was designed and field tested. The system is composed of a reinforced, heavy plastic bag, connected to a variable flow pump and housed in a weatherproof enclosure. At the end of the four week sampling period the air in the bag is transferred by a compressor into a pressure tank for easy transport to the laboratory for analysis. After several months of operation, the air sampling system has proven its reliability and sensitivity to ambient levels of krypton-85. 3 references, 3 figures, 1 table

  10. Radon discrimination for work place air samples

    International Nuclear Information System (INIS)

    Bratvold, T.

    1994-01-01

    Gross alpha/beta measurement systems are designed solely to identify an incident particle as either an alpha or a beta and register a count accordingly. The tool of choice for radon identification, via decay daughters, is an instrument capable of identifying the energy of incident alpha particles and storing that information separately from detected alpha emissions of different energy. In simpler terms, the desired instrument is an alpha spectroscopy system. K Basins Radiological Control (KBRC) procured an EG ampersand G ORTEC OCTETE PC alpha spectroscopy system to facilitate radon identification on work place air samples. The alpha spectrometer allows for the identification of any alpha emitting isotope based on characteristic alpha emission energies. With this new capability, KBRC will explicitly know whether or not there exists a true airborne concern. Based on historical air quality data, this new information venue will reduce the use of respirators substantially. Situations where an area remains ''on mask'' due solely to the presence of radon daughters on the grab air filter will finally be eliminated. This document serves to introduce a new method for radon daughter detection at the 183KE Health Physics Analytical Laboratory (HPAL). A new work place air sampling analysis program will be described throughout this paper. There is no new technology being introduced, nor any unproven analytical process. The program defined over the expanse of this document simply explains how K Basins Radiological Control will employ their alpha spectrometer

  11. Recent progress of sample stacking in capillary electrophoresis (2014–2016)

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2017-01-01

    Roč. 38, č. 1 (2017), s. 20-32 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : stacking * zone electrophoresis * trace analysis * review Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

  12. Permeability of gypsum samples dehydrated in air

    Science.gov (United States)

    Milsch, Harald; Priegnitz, Mike; Blöcher, Guido

    2011-09-01

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

  13. Numerical model for stack gas diffusion in terrain with buildings. Variations in air flow and gas concentration with additional building near stack

    International Nuclear Information System (INIS)

    Sada, Koichi; Michioka, Takenobu; Ichikawa, Yoichi; Komiyama, Sumito; Numata, Kunio

    2009-01-01

    A numerical simulation method for predicting atmospheric flow and stack gas diffusion using a calculation domain of several km around a stack under complex terrain conditions containing buildings has been developed. The turbulence closure technique using a modified k-ε-type model without a hydrostatic approximation was used for flow calculation, and some of the calculation grids near the ground were treated as buildings using a terrain-following coordinate system. Stack gas diffusion was predicted using the Lagrangian particle model, that is, the stack gas was represented by trajectories of released particles. The developed numerical model was applied to a virtual terrain and building conditions in this study prior to the applications of a numerical model for real terrain and building conditions. The height of the additional building (H a ), located about 200 m leeward from the stack, was varied (i.e., H a =0, 20, 30 and 50 m), and its effects on airflow and the concentration of stack gas at a released height of 75 m were calculated. Furthermore, effective stack height, which was used in the safety analysis of atmospheric diffusion for nuclear facilities in Japan, was evaluated from the calculated ground-level concentration of stack gas. The cavity region behind the additional building was calculated, and turbulence near the cavity was observed to decrease when the additional building was present. According to these flow variations with the additional building, tracer gas tended to diffuse to the ground surface rapidly with the additional building at the leeward position of the cavity, and the ground-level stack gas concentration along the plume axis also increased with the height of the additional building. However, the variations in effective stack height with the height of the additional building were relatively small and ranged within several m in this study. (author)

  14. System effects in sample self-stacking CZE: Single analyte peak splitting of salt-containing samples

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2009-01-01

    Roč. 30, č. 5 (2009), s. 866-874 ISSN 0173-0835 R&D Projects: GA ČR GA203/08/1536; GA AV ČR IAA400310609; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : CZE * peak splitting * self-stacking Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.077, year: 2009

  15. Enhanced water desalination efficiency in an air-cathode stacked microbial electrodeionization cell (SMEDIC)

    KAUST Repository

    Chehab, Noura A.

    2014-11-01

    A microbial desalination cell was developed that contained a stack of membranes packed with ion exchange resins between the membranes to reduce ohmic resistances and improve performance. This new configuration, called a stacked microbial electro-deionization cell (SMEDIC), was compared to a control reactor (SMDC) lacking the resins. The SMEDIC+S reactors contained both a spacer and 1.4±0.2. mL of ion exchange resin (IER) per membrane channel, while the spacer was omitted in the SMEDIC-S reactors and so a larger volume of resin (2.4±0.2. mL) was used. The overall extent of desalination using the SMEDIC with a moderate (brackish water) salt concentration (13. g/L) was 90-94%, compared to only 60% for the SMDC after 7 fed-batch cycles of the anode. At a higher (seawater) salt concentration of 35. g/L, the extent of desalination reached 61-72% (after 10 cycles) for the SMEDIC, compared to 43% for the SMDC. The improved performance was shown to be due to the reduction in ohmic resistances, which were 130. Ω (SMEDIC-S) and 180. Ω (SMEDIC+S) at the high salt concentration, compared to 210. Ω without resin (SMDC). These results show that IERs can improve performance of stacked membranes for both moderate and high initial salt concentrations. © 2014 Elsevier B.V.

  16. Effects of Air Stacking Maneuver on Cough Peak Flow and Chest Wall Compartmental Volumes of Subjects With Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Sarmento, Antonio; Resqueti, Vanessa; Dourado-Júnior, Mario; Saturnino, Lailane; Aliverti, Andrea; Fregonezi, Guilherme; de Andrade, Armele Dornelas

    2017-11-01

    To assess the acute effects of air stacking on cough peak flow (CPF) and chest wall compartmental volumes of persons with amyotrophic lateral sclerosis (ALS) versus healthy subjects positioned at 45° body inclination. Cross-sectional study with a matched-pair design. University hospital. Persons (N=24) with ALS (n=12) and age-matched healthy subjects (n=12). CPF, chest wall compartmental inspiratory capacity, chest wall vital capacity, chest wall tidal volume and operational volumes, breathing pattern, and percentage of contribution of the compartments to the inspired volume were measured by optoelectronic plethysmography. Compared with healthy subjects, significantly lower CPF (P=.007), chest wall compartmental inspiratory capacity (Pprotocol in the healthy subjects, mainly because of end-inspiratory (P<.001) and abdominal volumes (P=.008). No significant differences were observed in percentage of contribution of the compartments to the inspired volume and end-expiratory volume of both groups. No significant differences were found in chest wall tidal volume, operational volume, and breathing pattern in persons with ALS. Air stacking is effective in increasing CPF, chest wall compartmental inspiratory capacity, and chest wall vital capacity of persons with ALS with no hyperinflation. Differences in compartmental volume contributions are probably because of lung and chest wall physiological changes. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  17. Confirmation of vanadium complex formation using electrospray mass spectrometry and determination of vanadium speciation by sample stacking capillary electrophoresis

    International Nuclear Information System (INIS)

    Chen Zuliang; Owens, Gary; Naidu, Ravendra

    2007-01-01

    Capillary zone electrophoresis (CZE) with UV detection was used to determine vanadium species. Nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylene glycol-bis(2-aminoethylether)-tetraacetic acid (EGTA) and 2,6-pyridinedicarboxylic acid (PDCA) were investigated to determine whether these ligands formed stable anionic complexes with vanadium. Of all the ligands studied HEDTA was the most suitable ligand because it gave the largest UV response with reasonable migration time. Electrospray mass spectrometry (ES-MS) was used to confirm the formation of [VO 2 (HEDTA)] 2- and [VO(HEDTA)] 1- in solution. An electrolyte containing 25 mM phosphate, 0.25 mM tetradecyltrimethylammonium bromide (TTAB) at pH 5.5 was optimum for the separation of these anionic vanadium complexes. Sample stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were tested to improve the sensitivity. Best sensitivity was obtained using FASI, with detection limits of 0.001 μM, equivalent to 0.4 μg L -1 , for [VO 2 (HEDTA)] 2- and 0.01 μM, equivalent to 3.4 μg L -1 for [VO(HEDTA)] 1- . The utility of the method for the speciation of V(IV) and V(V) was demonstrated using ground water samples

  18. Confirmation of vanadium complex formation using electrospray mass spectrometry and determination of vanadium speciation by sample stacking capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zuliang [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia)]. E-mail: zuliang.chen@unisa.edu.au; Owens, Gary [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Naidu, Ravendra [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); CRC for Contamination Assessment and Remediation of Environments, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia)

    2007-02-28

    Capillary zone electrophoresis (CZE) with UV detection was used to determine vanadium species. Nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylene glycol-bis(2-aminoethylether)-tetraacetic acid (EGTA) and 2,6-pyridinedicarboxylic acid (PDCA) were investigated to determine whether these ligands formed stable anionic complexes with vanadium. Of all the ligands studied HEDTA was the most suitable ligand because it gave the largest UV response with reasonable migration time. Electrospray mass spectrometry (ES-MS) was used to confirm the formation of [VO{sub 2}(HEDTA)]{sup 2-} and [VO(HEDTA)]{sup 1-} in solution. An electrolyte containing 25 mM phosphate, 0.25 mM tetradecyltrimethylammonium bromide (TTAB) at pH 5.5 was optimum for the separation of these anionic vanadium complexes. Sample stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were tested to improve the sensitivity. Best sensitivity was obtained using FASI, with detection limits of 0.001 {mu}M, equivalent to 0.4 {mu}g L{sup -1}, for [VO{sub 2}(HEDTA)]{sup 2-} and 0.01 {mu}M, equivalent to 3.4 {mu}g L{sup -1} for [VO(HEDTA)]{sup 1-}. The utility of the method for the speciation of V(IV) and V(V) was demonstrated using ground water samples.

  19. Sampling and identification of gaseous and particle bounded air pollutants

    International Nuclear Information System (INIS)

    Kettrup, A.

    1993-01-01

    Air pollutants are gaseous, components of aerosols or particle bounded. Sampling, sample preparation, identification and quantification of compounds depend from kind and chemical composition of the air pollutants. Quality assurance of analytical data must be guaranted. (orig.) [de

  20. The use of cryogenic air sampling in the spectroscopy of airborne gamma-ray emitters

    International Nuclear Information System (INIS)

    Perdue, P.T.; Haywood, F.F.

    1982-01-01

    Wet air can be sampled over a period of four to twelve hours and, with a transfer into a special Marinelli-dewar, can be counted in a spectrometer for several hours. The present minimum detectable amount is about 4 Bq/m 3 for 222 Rn and 220 Rn with liquid air in the counting dewar equivalent to one cubic meter of ambient air. The amount of ambient air sampled can be determined from ambient pressure, temperature, and absolute humidity determinations. Standard meteorological tables are used to determine the weight of ambient air in grams/litre. This quantity divided into the net weight of liquid yields the total litres of ambient air sampled. Tests run so far with 85 Kr indicate that the noble fission gases behave in a manner similar to radon, allowing measurements of stack gases, reactor plumes, etc. The minimum detectable quantity of 85 Kr appears to be about 300 Bq/m 3 , depending upon the 222 Rn and 220 Rn content of the air

  1. Analysis of plant hormones by microemulsion electrokinetic capillary chromatography coupled with on-line large volume sample stacking.

    Science.gov (United States)

    Chen, Zongbao; Lin, Zian; Zhang, Lin; Cai, Yan; Zhang, Lan

    2012-04-07

    A novel method of microemulsion electrokinetic capillary chromatography (MEEKC) coupled with on-line large volume sample stacking was developed for the analysis of six plant hormones including indole-3-acetic acid, indole-3-butyric acid, indole-3-propionic acid, 1-naphthaleneacetic acid, abscisic acid and salicylic acid. Baseline separation of six plant hormones was achieved within 10 min by using the microemulsion background electrolyte containing a 97.2% (w/w) 10 mM borate buffer at pH 9.2, 1.0% (w/w) ethyl acetate as oil droplets, 0.6% (w/w) sodium dodecyl sulphate as surfactant and 1.2% (w/w) 1-butanol as cosurfactant. In addition, an on-line concentration method based on a large volume sample stacking technique and multiple wavelength detection was adopted for improving the detection sensitivity in order to determine trace level hormones in a real sample. The optimal method provided about 50-100 fold increase in detection sensitivity compared with a single MEEKC method, and the detection limits (S/N = 3) were between 0.005 and 0.02 μg mL(-1). The proposed method was simple, rapid and sensitive and could be applied to the determination of six plant hormones in spiked water samples, tobacco leaves and 1-naphthylacetic acid in leaf fertilizer. The recoveries ranged from 76.0% to 119.1%, and good reproducibilities were obtained with relative standard deviations (RSDs) less than 6.6%.

  2. Stack gas treatment

    Science.gov (United States)

    Reeves, Adam A.

    1977-04-12

    Hot stack gases transfer contained heat to a gravity flow of pebbles treated with a catalyst, cooled stacked gases and a sulfuric acid mist is withdrawn from the unit, and heat picked up by the pebbles is transferred to air for combustion or other process. The sulfuric acid (or sulfur, depending on the catalyst) is withdrawn in a recovery unit.

  3. Sensitive determination of pyrrolizidine alkaloids in Tussilago farfara L. by field-amplified, sample-stacking, sweeping micellar electrokinetic chromatography.

    Science.gov (United States)

    Cao, Kun; Xu, Yi; Mu, Xiuni; Zhang, Qing; Wang, Renjie; Lv, Junjiang

    2016-11-01

    Pyrrolizidine alkaloids are the toxic components in Tussilago farfara L. Due to the lack of standard substances for quantitative analysis and traces of pyrrolizidine alkaloids in total alkaloids, the full quality control of Tussilago farfara L has been limited. In this study, we aimed to solve the difficulty of determination of pyrrolizidine alkaloids and identify more components in the total alkaloids. An on-line preconcentration method has been applied to improve determining sensitivity of pyrrolizidine alkaloids in Tussilago farfara L. in which included field-amplified sample stacking and sweeping in micellar electrokinetic capillary chromatography. The main parameters that affected separation and stacking efficiency were investigated in details. Under the optimal conditions, the sensitivity enhancement factors obtained by the developed method for the analytes were from 15- to 12-fold, the limits of detection of senkirkine and senecionine were 2∼5 μg/L. Senkirkine and senecionine have been detected in alkaloids (c) of Tussilago farfara L, along ferulic acid methyl ester and methyl caffeate. The developed method was also applied to the analysis of acid extraction (a) of Tussilago farfara L, and senkirkine could be detected directly. The results indicated that the developed method is feasible for the analysis of pyrrolizidine alkaloids in Tussilago farfara L with good recoveries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Systematic Evaluation of Aggressive Air Sampling for Bacillus ...

    Science.gov (United States)

    Report The primary objectives of this project were to evaluate the Aggressive Air Sampling (AAS) method compared to currently used surface sampling methods and to determine if AAS is a viable option for sampling Bacillus anthracis spores.

  5. Field-amplified sample stacking capillary electrophoresis with electrochemiluminescence applied to the determination of illicit drugs on banknotes.

    Science.gov (United States)

    Xu, Yuanhong; Gao, Ying; Wei, Hui; Du, Yan; Wang, Erkang

    2006-05-19

    Capillary electrophoresis (CE) with Ru(bpy)3(2+) electrochemiluminescence (ECL) detection system was established to the determination of contamination of banknotes with controlled drugs and a high efficiency on-column field-amplified sample stacking (FASS) technique was also optimized to increase the ECL intensity. The method was illustrated using heroin and cocaine, which are two typical and popular illicit drugs. Highest sample stacking was obtained when 0.01 mM acetic acid was chosen for sample dissolution with electrokinetical injection for 6 s at 17 kV. Under the optimized conditions: ECL detection at 1.2 V, separation voltage 10.0 kV, 20 mM phosphate-acetate (pH 7.2) as running buffer, 5 mM Ru(bpy)3(2+) with 50 mM phosphate-acetate (pH 7.2) in the detection cell, the standard curves were linear in the range of 7.50x10(-8) to 1.00x10(-5) M for heroin and 2.50x10(-7) to 1.00x10(-4) M for cocaine and detection limits of 50 nM for heroin and 60 nM for cocaine were achieved (S/N = 3), respectively. Relative standard derivations of the ECL intensity and the migration time were 3.50 and 0.51% for heroin and 4.44 and 0.12% for cocaine, respectively. The developed method was successfully applied to the determination of heroin and cocaine on illicit drug contaminated banknotes without any damage of the paper currency. A baseline resolution for heroin and cocaine was achieved within 6 min.

  6. Crossett Hydrogen Sulfide Air Sampling Report

    Science.gov (United States)

    This report summarizes the results of the EPA’s hydrogen sulfide air monitoring conducted along Georgia Pacific’s wastewater treatment system and in surrounding Crossett, AR, neighborhoods in 2017.

  7. Domestic wastewater treatment and power generation in continuous flow air-cathode stacked microbial fuel cell: Effect of series and parallel configuration.

    Science.gov (United States)

    Estrada-Arriaga, Edson Baltazar; Hernández-Romano, Jesús; García-Sánchez, Liliana; Guillén Garcés, Rosa Angélica; Bahena-Bahena, Erick Obed; Guadarrama-Pérez, Oscar; Moeller Chavez, Gabriela Eleonora

    2018-05-15

    In this study, a continuous flow stack consisting of 40 individual air-cathode MFC units was used to determine the performance of stacked MFC during domestic wastewater treatment operated with unconnected individual MFC and in series and parallel configuration. The voltages obtained from individual MFC units were of 0.08-1.1 V at open circuit voltage, while in series connection, the maximum power and current density were 2500 mW/m 2 and 500 mA/m 2 (4.9 V), respectively. In parallel connection, the maximum power and current density was 5.8 mW/m 2 and 24 mA/m 2 , respectively. When the cells were not connected to each other MFC unit, the main bacterial species found in the anode biofilms were Bacillus and Lysinibacillus. After switching from unconnected to series and parallel connections, the most abundant species in the stacked MFC were Pseudomonas aeruginosa, followed by different Bacilli classes. This study demonstrated that when the stacked MFC was switched from unconnected to series and parallel connections, the pollutants removal, performance electricity and microbial community changed significantly. Voltages drops were observed in the stacked MFC, which was mainly limited by the cathodes. These voltages loss indicated high resistances within the stacked MFC, generating a parasitic cross current. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Up the stack : coal-fired electricity's toxic impact : an OCAA air quality report

    International Nuclear Information System (INIS)

    Rang, S.

    2002-07-01

    Ontario Power Generation (OPG) must report annually its releases and transfers of 268 chemicals to the federal National Pollutant Release Inventory (NPRI). Each OPG facility reports the amount of chemicals released to the air, land, water and injected under ground at the facility site. The facilities must also report the amount of chemicals that are transferred off-site for treatment, sewage, disposal, recycling or energy recovery. In 1999 and 2000, atmospheric releases from OPG's coal-fired plants accounted for a significant percentage of the total pollutants released for Ontario and Canada. OPG's facilities are often in the top 5 in Ontario and Canada for releases of various chemicals, including persistent toxic chemicals. In 1999, the Nanticoke coal-fired power plant on Lake Erie was ranked first in Canada for releases to the air. Data reported for the 1999 and 2000 reporting period for dioxins and furans, hexachlorobenzene, mercury, metals (chromium, nickel and arsenic), and acid gases such as hydrochloric acid, hydrogen fluoride, and sulphuric acid clearly indicates that OPG coal-fired plants are a leading source of air pollution in Canada and Ontario. The Ontario Clean Air Alliance suggests the data is sufficient to phase-out the use of coal for power generation in Ontario. It recommends conserving energy and replacing coal-fired power with renewable energy sources such as wind and water power. Converting coal facilities to high-efficiency natural gas units would also reduce the toxic impacts of OPG's coal-fired power plants. As an immediate first step, it was recommended that the government should ban non-emergency exports of coal-fired electricity during smog-alert periods in Ontario. 11 tabs

  9. Solid-Phase Extraction and Large-Volume Sample Stacking-Capillary Electrophoresis for Determination of Tetracycline Residues in Milk

    Directory of Open Access Journals (Sweden)

    Gabriela Islas

    2018-01-01

    Full Text Available Solid-phase extraction in combination with large-volume sample stacking-capillary electrophoresis (SPE-LVSS-CE was applied to measure chlortetracycline, doxycycline, oxytetracycline, and tetracycline in milk samples. Under optimal conditions, the proposed method had a linear range of 29 to 200 µg·L−1, with limits of detection ranging from 18.6 to 23.8 µg·L−1 with inter- and intraday repeatabilities < 10% (as a relative standard deviation in all cases. The enrichment factors obtained were from 50.33 to 70.85 for all the TCs compared with a conventional capillary zone electrophoresis (CZE. This method is adequate to analyze tetracyclines below the most restrictive established maximum residue limits. The proposed method was employed in the analysis of 15 milk samples from different brands. Two of the tested samples were positive for the presence of oxytetracycline with concentrations of 95 and 126 µg·L−1. SPE-LVSS-CE is a robust, easy, and efficient strategy for online preconcentration of tetracycline residues in complex matrices.

  10. Analysis of Three Compounds in Flos Farfarae by Capillary Electrophoresis with Large-Volume Sample Stacking

    Directory of Open Access Journals (Sweden)

    Hai-xia Yu

    2017-01-01

    Full Text Available The aim of this study was to develop a method combining an online concentration and high-efficiency capillary electrophoresis separation to analyze and detect three compounds (rutin, hyperoside, and chlorogenic acid in Flos Farfarae. In order to get good resolution and enrichment, several parameters such as the choice of running buffer, pH and concentration of the running buffer, organic modifier, temperature, and separation voltage were all investigated. The optimized conditions were obtained as follows: the buffer of 40 mM NaH2P04-40 mM Borax-30% v/v methanol (pH 9.0; the sample hydrodynamic injection of up to 4 s at 0.5 psi; 20 kV applied voltage. The diode-array detector was used, and the detection wavelength was 364 nm. Based on peak area, higher levels of selective and sensitive improvements in analysis were observed and about 14-, 26-, and 5-fold enrichment of rutin, hyperoside, and chlorogenic acid were achieved, respectively. This method was successfully applied to determine the three compounds in Flos Farfarae. The linear curve of peak response versus concentration was from 20 to 400 µg/ml, 16.5 to 330 µg/mL, and 25 to 500 µg/mL, respectively. The regression coefficients were 0.9998, 0.9999, and 0.9991, respectively.

  11. A simple air sampling technique for monitoring nitrous oxide pollution

    Energy Technology Data Exchange (ETDEWEB)

    Austin, J C; Shaw, R; Moyes, D; Cleaton-Jones, P E

    1981-01-01

    A simple, inexpensive device for the continuous low-flow sampling of air was devised to permit monitoring of pollution by gaseous anaesthetics. The device consisted of a water-filled Perspex cylinder in which a double-walled flexible-film gas sample collection bag was suspended. Air samples could be aspirated into the collection bag at flow rates of as low as 1 ml min-1 by allowing the water to drain from the cylinder at a controlled rate. The maintenance of sample integrity with aspiration and storage of samples of nitrous oxide in air at concentrations of 1000, 100 and 30 p.p.m. v/v was examined using gas chromatography. The sample bags retained a mean 94% of the nitrous oxide in air samples containing nitrous oxide 25 p.p.m. over a 72-h storage period.

  12. Water recovery and air humidification by condensing the moisture in the outlet gas of a proton exchange membrane fuel cell stack

    International Nuclear Information System (INIS)

    Wan, Z.M.; Wan, J.H.; Liu, J.; Tu, Z.K.; Pan, M.; Liu, Z.C.; Liu, W.

    2012-01-01

    Humidification is one of the most important factors for the operation of proton exchange membrane fuel cell (PEMFC). To maintain the membrane at hydrated state, plenty of water is needed for the state-of-the-art of PEMFC technology, especially in large power applications or long time operation. A condenser is introduced to separate liquid water from the air outlet for air self-sufficient in water of the stack in this study. The condensed temperature at the outlet of the condenser and water recovered amount for air self-sufficient in water are investigated theoretically and experimentally. It is shown that the condensed temperature for air self-sufficient in water is irrelevant with the working current of the stack. When the condenser outlet temperature was above the theoretical line, recovery water was not sufficient for the air humidification. On the contrary, it is sufficient while the temperature was below the theoretical line. It is also shown that when the moisture is sufficiently cooled, large amount water can be separated from the outlet gas, and it increased almost linearly with the time. With the introduction of the condenser, the recovered amount of water can easily satisfy the air self-sufficient in water by condensing the outlet gas to a proper temperature. - Highlights: ► We introduce a condenser to separate liquid water from the air outlet in the stack. ► The mechanism of air self-sufficient in water by condensing gas is presented. ► The condensed temperature and water recovered amount are investigated. ► An experiment is present to validate simplicity and feasibility of the criterion. ► The criterion for air humidification is used for choosing the condenser.

  13. Venturi Air-Jet Vacuum Ejector For Sampling Air

    Science.gov (United States)

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

    1990-01-01

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

  14. An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

    International Nuclear Information System (INIS)

    Aris, M.S.; McGlen, R.; Owen, I.; Sutcliffe, C.J.

    2011-01-01

    Forced air convection heat pipe cooling systems play an essential role in the thermal management of electronic and power electronic devices such as microprocessors and IGBT's (Integrated Gate Bipolar Transistors). With increasing heat dissipation from these devices, novel methods of improving the thermal performance of fin stacks attached to the heat pipe condenser section are required. The current work investigates the use of a wing type surface protrusions in the form of 3-D delta wing tabs adhered to the fin surface, thin wings punched-out of the fin material and TiNi shape memory alloy delta wings which changed their angles of attack based on the fin surface temperature. The longitudinal vortices generated from the wing designs induce secondary mixing of the cooler free stream air entering the fin stack with the warmer fluid close to the fin surfaces. The change in angle of the attack of the active delta wings provide heat transfer enhancement while managing flow pressure losses across the fin stack. A heat transfer enhancement of 37% compared to a plain fin stack was obtained from the 3-D tabs in a staggered arrangement. The punched-out delta wings in the staggered and inline arrangements provided enhancements of 30% and 26% respectively. Enhancements from the active delta wings were lower at 16%. However, as these devices reduce the pressure drop through the fin stack by approximately 19% in the de-activate position, over the activated position, a reduction in fan operating cost may be achieved for systems operating with inlet air temperatures below the maximum inlet temperature specification for the device. CFD analysis was also carried out to provide additional detail of the local heat transfer enhancement effects. The CFD results corresponded well with previously published reports and were consistent with the experimental findings. - Highlights: → Heat transfer enhancements of heat pipe fin stacks was successfully achieved using fixed and active delta

  15. Application of particle size distributions to total particulate stack samples to estimate PM2.5 and PM10 emission factors for agricultural sources

    Science.gov (United States)

    Particle size distributions (PSD) have long been used to more accurately estimate the PM10 fraction of total particulate matter (PM) stack samples taken from agricultural sources. These PSD analyses were typically conducted using a Coulter Counter with 50 micrometer aperture tube. With recent increa...

  16. Workplace air monitoring and sampling practices at DOE facilities

    International Nuclear Information System (INIS)

    Swinth, K.L.; Kenoyer, J.L.; Selby, J.M.

    1987-01-01

    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

  17. Automated bar coding of air samples at Hanford (ABCASH)

    International Nuclear Information System (INIS)

    Troyer, G.L.; Brayton, D.D.; McNeece, S.G.

    1992-10-01

    This article describes the basis, main features and benefits of an automated system for tracking and reporting radioactive air particulate samples. The system was developed due to recognized need for improving the quality and integrity of air sample data related to personnel and environmental protection. The data capture, storage, and retrieval of air sample data are described. The automation aspect of the associated and data input eliminates a large potential for human error. The system utilizes personal computers, handheld computers, a commercial personal computer database package, commercial programming languages, and complete documentation to satisfy the system's automation objective

  18. Development of a New Microextraction Fiber Combined to On-Line Sample Stacking Capillary Electrophoresis UV Detection for Acidic Drugs Determination in Real Water Samples.

    Science.gov (United States)

    Espina-Benitez, Maria; Araujo, Lilia; Prieto, Avismelsi; Navalón, Alberto; Vílchez, José Luis; Valera, Paola; Zambrano, Ana; Dugas, Vincent

    2017-07-07

    A new analytical method coupling a (off-line) solid-phase microextraction with an on-line capillary electrophoresis (CE) sample enrichment technique was developed for the analysis of ketoprofen, naproxen and clofibric acid from water samples, which are known as contaminants of emerging concern in aquatic environments. New solid-phase microextraction fibers based on physical coupling of chromatographic supports onto epoxy glue coated needle were studied for the off-line preconcentration of these micropollutants. Identification and quantification of such acidic drugs were done by capillary zone electrophoresis (CZE) using ultraviolet diode array detection (DAD). Further enhancement of concentration sensitivity detection was achieved by on-line CE "acetonitrile stacking" preconcentration technique. Among the eight chromatographic supports investigated, Porapak Q sorbent showed higher extraction and preconcentration capacities. The screening of parameters that influence the microextraction process was carried out using a two-level fractional factorial. Optimization of the most relevant parameters was then done through a surface response three-factor Box-Behnken design. The limits of detection and limits of quantification for the three drugs ranged between 0.96 and 1.27 µg∙L -1 and 2.91 and 3.86 µg∙L -1 , respectively. Recovery yields of approximately 95 to 104% were measured. The developed method is simple, precise, accurate, and allows quantification of residues of these micropollutants in Genil River water samples using inexpensive fibers.

  19. Partition/Ion-Exclusion Chromatographic Ion Stacking for the Analysis of Trace Anions in Water and Salt Samples by Ion Chromatography.

    Science.gov (United States)

    Akter, Fouzia; Saito, Shingo; Tasaki-Handa, Yuiko; Shibukawa, Masami

    2018-01-01

    A new analytical methodology for a simple and efficient on-line preconcentration of trace inorganic anions in water and salt samples prior to ion chromatographic determination is proposed. The preconcentration method is based on partition/ion-exclusion chromatographic ion stacking (PIEC ion stacking) with a hydrophilic polymer gel column containing a small amount of fixed anionic charges. The developed on-line PIEC ion stacking-ion chromatography method was validated by recovery experiments for the determination of nitrate in tap water in terms of both accuracy and precision, and the results showed the reliability of the method. The method proposed was also successfully applied to the determination of trace impurity nitrite and nitrate in reagent-grade salts of sodium sulfate. A low background level can be achieved since pure water is used as the eluant for the PIEC ion stacking. It is possible to reach sensitive detection at sub-μg L -1 levels by on-line PIEC ion stacking-ion chromatography.

  20. Determination of plutonium in air and smear samples

    International Nuclear Information System (INIS)

    Hinton, E.R. Jr.; Tucker, W.O.

    1981-01-01

    A method has been developed for the determination of plutonium in air samples and smear samples that were collected on filter papers. The sample papers are digested in nitric acid, extracted into 2-thenoyltrifluoroacetone (TTA)-xylene, and evaporated onto stainless steel disks. Alpha spectrometry is employed to determine the activity of each plutonium isotope. Each sample is spiked with plutonium-236. All glassware used in the procedure is disposable. The detection limits are 3 and 5 dpm (disintegrations per minute) for air and smear samples, respectively, with an average recovery of 87%

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

    International Nuclear Information System (INIS)

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

  3. Operational air sampling report, January--June 30, 1992

    International Nuclear Information System (INIS)

    Lyons, C.L.

    1992-09-01

    Nevada Test Site postshot and tunnel events generate beta/gamma fission products. The Reynolds Electrical ampersand Engineering Co., Inc. air sampling program is designed for measurement of these radionuclides at various facilities supporting these events. Monthly radon sampling is done for documentation of working levels in the tunnel complexes, which would be expected to hove the highest radon levels for on-site facilities. Out of a total of 281 air samples taken in the tunnel complexes, 25 showed airborne fission products with concentrations well below their respective Derived Air Concentrations (DAC). All of these were related to event reentry or mineback operations. Tritiated water vapor and radon levels were very similar to previously reported levels. The 975 air samples taken at the Area-6 decontamination bays and laundry were again well below any DAC calculation standard and negative for any airborne fission products from laboratory analyses

  4. Operational air sampling report, July 1--December 31, 1992

    International Nuclear Information System (INIS)

    Lyons, C.L.

    1993-04-01

    Nevada Test Site postshot and tunnel events generate beta/gamma fission products. The REECo air sampling program is designed for measurement of these radionuclides at various facilities supporting these events. Monthly radon sampling is done for documentation of working levels in the tunnel complexes, which would be expected to have the highest radon levels for on-site facilities. Out of a total of 628 air samples taken in the tunnel complexes, 24 showed airborne fission products with concentrations well below their respective Derived Air Concentrations (DAC). All of these were related to event reentry or mineback operations. Tritiated water vapor concentrations were very similar to previously reported levels. The 838 air samples taken at the Area-6 decontamination bays and laundry were again well below any DAC calculation standard and negative for any airborne fission products from laboratory analyses

  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...

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

    International Nuclear Information System (INIS)

    Barnett, J.M.

    2008-01-01

    Since the mid-1980s the Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as a correction factor for the self absorption of activity of particulate radioactive air samples. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor(reg s ign) 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

  7. Printed Self-Powered Miniature Air Sampling Sensors

    Directory of Open Access Journals (Sweden)

    Joseph Birmingham

    2017-07-01

    Full Text Available The recent geo-political climate has increased the necessity for autonomous, chip-sized, lightweight, air sampling systems which can quickly detect and characterize chemical, biological, radiological, nuclear, and high explosive (CBRNE hazardous materials and relay the results. To address these issues, we have developed a self-powered 3-D chip architecture that processes air to produce concentrated size- sorted particle (and vapor samples that could be integrated with on-chip nanoelectronic detectors for the discovery of weapons of mass destruction (WMD. The unique air movement approach is composed of a nanoscale energy harvester that provides electricity to a printed ion-drag pump to push air through coated-microstructured arrays. The self-powered microstructured array air sampler was designed using computational fluid dynamics (CFD modeling to collect particles from 1-10 microns at greater than 99.9999 % efficiency with less than 100 Pascal [Pa] pressure drop at a specified air flow rate. Surprisingly, even at minimum air flow rates below specifications, these CFD predictions were matched by experimental results gathered in a Government aerosol chamber. The microstructured array engineered filter equaled the collection capability of a membrane or a high efficiency particle air (HEPA filter at a fraction of the filter pressure drop.

  8. Algebraic stacks

    Indian Academy of Sciences (India)

    Deligne, Mumford and Artin [DM, Ar2]) and consider algebraic stacks, then we can cons- truct the 'moduli ... the moduli scheme and the moduli stack of vector bundles. First I will give ... 1–31. © Printed in India. 1 ...... Cultura, Spain. References.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

    Lyons, C.L.

    1992-11-01

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

  11. Method for monitoring stack gases for uranium activity

    International Nuclear Information System (INIS)

    Beverly, C.R.; Ernstberger, H.G.

    1988-01-01

    A method for sampling stack gases emanating from the purge cascade of a gaseous diffusion cascade system utilized to enrich uranium for determining the presence and extent of uranium in the stack gases in the form of gaseous uranium hexafluoride, is described comprising the steps of removing a side stream of gases from the stack gases, contacting the side stream of the stack gases with a stream of air sufficiently saturated with moisture for reacting with and converting any gaseous uranium hexafluroide contracted thereby in the side stream of stack gases to particulate uranyl fluoride. Thereafter contacting the side stream of stack gases containing the particulate uranyl fluoride with moving filter means for continuously intercepting and conveying the intercepted particulate uranyl fluoride away from the side stream of stack gases, and continually scanning the moving filter means with radiation monitoring means for sensing the presence and extent of particulate uranyl fluoride on the moving filter means which is indicative of the extent of particulate uranyl fluoride in the side stream of stack gases which in turn is indicative of the presence and extent of uranium hexafluoride in the stack gases

  12. Regular control of monitors for effluents from nuclear power plant stacks

    International Nuclear Information System (INIS)

    Stroem, L.

    1979-01-01

    The report describes a test procedure for emission monitoring devices for nuclear power plants. The follosing procedures are described, inspection, determination of the air flow through the stack, measurement and adjustment of the flow in the stack loop, measurement and adjustment of flow and density in the measuring loop, calibration of the gas detector, efficiency of sampling of methyliodide and aerosol. (K.K.)

  13. Effect of NaOH on large-volume sample stacking of haloacetic acids in capillary zone electrophoresis with a low-pH buffer.

    Science.gov (United States)

    Tu, Chuanhong; Zhu, Lingyan; Ang, Chay Hoon; Lee, Hian Kee

    2003-06-01

    Large-volume sample stacking (LVSS) is an effective on-capillary sample concentration method in capillary zone electrophoresis, which can be applied to the sample in a low-conductivity matrix. NaOH solution is commonly used to back-extract acidic compounds from organic solvent in sample pretreatment. The effect of NaOH as sample matrix on LVSS of haloacetic acids was investigated in this study. It was found that the presence of NaOH in sample did not compromise, but rather help the sample stacking performance if a low pH background electrolyte (BGE) was used. The sensitivity enhancement factor was higher than the case when sample was dissolved in pure water or diluted BGE. Compared with conventional injection (0.4% capillary volume), 97-120-fold sensitivity enhancement in terms of peak height was obtained without deterioration of separation with an injection amount equal to 20% of the capillary volume. This method was applied to determine haloacetic acids in tap water by combination with liquid-liquid extraction and back-extraction into NaOH solution. Limits of detection at sub-ppb levels were obtained for real samples with direct UV detection.

  14. 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.

  15. Sample design considerations of indoor air exposure surveys

    International Nuclear Information System (INIS)

    Cox, B.G.; Mage, D.T.; Immerman, F.W.

    1988-01-01

    Concern about the potential for indoor air pollution has prompted recent surveys of radon and NO 2 concentrations in homes and personal exposure studies of volatile organics, carbon monoxide and pesticides, to name a few. The statistical problems in designing sample surveys that measure the physical environment are diverse and more complicated than those encountered in traditional surveys of human attitudes and attributes. This paper addresses issues encountered when designing indoor air quality (IAQ) studies. General statistical concepts related to target population definition, frame creation, and sample selection for area household surveys and telephone surveys are presented. The implications of different measurement approaches are discussed, and response rate considerations are described

  16. Polycyclic aromatic hydrocarbons in air samples of meat smokehouses

    DEFF Research Database (Denmark)

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

    1992-01-01

    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 approx......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...

  17. Air sampling program at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Hulett, S.H.

    1975-01-01

    An extensive air sampling program has been developed at the Portsmouth Gaseous Diffusion Plant for monitoring the concentrations of radioactive aerosols present in the atmosphere on plantsite as well as in the environs. The program is designed to minimize exposures of employees and the environment to airborne radioactive particulates. Five different air sampling systems, utilizing either filtration or impaction, are employed for measuring airborne alpha and beta-gamma activity produced from 235 U and 234 Th, respectively. Two of the systems have particle selection capabilities: a personal sampler with a 10-mm nylon cyclone eliminates most particles larger than about 10 microns in diameter; and an Annular Kinetic Impactor collects particulates greater than 0.4 microns in diameter which have a density greater than 12-15 gm/cm 3 . A Hi-Volume Air Sampler and an Eberline Model AIM-3 Scintillation Air Monitor are used in collecting short-term samples for assessing compliance with ''ceiling'' standards or peak concentration limits. A film-sort aperture IBM card system is utilized for continuous 8-hour samples. This sampling program has proven to be both practical and effective for assuring accurate monitoring of the airborne activity associated with plant operations

  18. Sampling density for the quantitative evaluation of air trapping

    International Nuclear Information System (INIS)

    Goris, Michael L.; Robinson, Terry E.

    2009-01-01

    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.)

  19. Computerized plutonium laboratory-stack monitoring system

    International Nuclear Information System (INIS)

    Stafford, R.G.; DeVore, R.K.

    1977-01-01

    The Los Alamos Scientific Laboratory has recently designed and constructed a Plutonium Research and Development Facility to meet design criteria imposed by the United States Energy Research and Development Administration. A primary objective of the design criteria is to assure environmental protection and to reliably monitor plutonium effluent via the ventilation exhaust systems. A state-of-the-art facility exhaust air monitoring system is described which establishes near ideal conditions for evaluating plutonium activity in the stack effluent. Total and static pressure sensing manifolds are incorporated to measure average velocity and integrated total discharge air volume. These data are logged at a computer which receives instrument data through a multiplex scanning system. A multipoint isokinetic sampling assembly with associated instrumentation is described. Continuous air monitors have been designed to sample from the isokinetic sampling assembly and transmit both instantaneous and integrated stack effluent concentration data to the computer and various cathode ray tube displays. The continuous air monitors also serve as room air monitors in the plutonium facility with the primary objective of timely evacuation of personnel if an above tolerance airborne plutonium concentration is detected. Several continuous air monitors are incorporated in the ventilation system to assist in identification of release problem areas

  20. Methods for Sampling and Measurement of Compressed Air Contaminants

    International Nuclear Information System (INIS)

    Stroem, L.

    1976-10-01

    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

  1. 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

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

    International Nuclear Information System (INIS)

    Tanaka, A.; Ishii, K.; Komori, Y.

    2002-01-01

    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)

  3. Combination of micelle collapse and field-amplified sample stacking in capillary electrophoresis for determination of trimethoprim and sulfamethoxazole in animal-originated foodstuffs.

    Science.gov (United States)

    Liu, Lihong; Wan, Qian; Xu, Xiaoying; Duan, Shunshan; Yang, Chunli

    2017-03-15

    An on-line preconcentration method combining micelle to solvent stacking (MSS) with field-amplified sample stacking (FASS) was employed for the analysis of trimethoprim (TMP) and sulfamethoxazole (SMZ) by capillary zone electrophoresis (CZE). The optimized experimental conditions were as followings: (1) sample matrix, 10.0mM SDS-5% (v/v) methanol; (2) trapping solution (TS), 35mM H 3 PO 4 -60% acetonitrile (CH 3 CN); (3) running buffer, 30mM Na 2 HPO 4 (pH=7.3); (4) sample solution volume, 168nL; TS volume, 168nL; and (5) 9kV voltage, 214nm UV detection. Under the optimized conditions, the limits of detection (LODs) for SMZ and TMP were 7.7 and 8.5ng/mL, and they were 301 and 329 times better compared to a typical injection, respectively. The contents of TMP and SMZ in animal foodstuffs such as dairy products, eggs and honey were analyzed, too. Recoveries of 80-104% were acquired with relative standard deviations of 0.5-5.4%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Programmable automatic alpha--beta air sample counter

    International Nuclear Information System (INIS)

    Howell, W.P.

    1978-01-01

    A programmable automatic alpha-beta air sample counter was developed for routine sample counting by operational health physics personnel. The system is composed of an automatic sample changer utilizing a large silicon diode detector, an electronic counting system with energy analysis capability, an automatic data acquisition controller, an interface module, and a teletypewriter with paper tape punch and paper tape reader. The system is operated through the teletypewriter keyboard and the paper tape reader, which are used to instruct the automatic data acquisition controller. Paper tape programs are provided for background counting, Chi 2 test, and sample counting. Output data are printed by the teletypewriter on standard continuous roll or multifold paper. Data are automatically corrected for background and counter efficiency

  5. Remaining Sites Verification Package for the 100-F-46, 119-F Stack Sampling French Drain. Attachment to Waste Site Reclassification Form 2008-021

    International Nuclear Information System (INIS)

    Capron, J.M.

    2008-01-01

    The 100-F-46 french drain consisted of a 1.5 to 3 m long, vertically buried, gravel-filled pipe that was approximately 1 m in diameter. Also included in this waste site was a 5 cm cast-iron pipeline that drained condensate from the 119-F Stack Sampling Building into the 100-F-46 french drain. In accordance with this evaluation, the confirmatory sampling results support a reclassification of this site to No Action. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  6. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  7. Study on sampling conditions for the monitoring of waste air

    International Nuclear Information System (INIS)

    Moeller, T.J.; Buetefisch, K.A.

    1998-01-01

    The technical codes for radiological monitoring of the waste air released from a radwaste repository demand that sampling for determination of aerosol-borne radioactivity is to be made with a screener equipped with a suitable number of measuring probes extending over the entire cross-sectional surface of the vent. Another requirement is to ensure that the waste air stream passing through the measuring channel is representative, containing the typical, operation-induced distribution of aerosols across the surface to be scanned. The study reported was intended to determine in a scaled-down model (1:10) of a repository ventilating duct the typical spatial distribution of aerosols (3D particulate density) in order to establish information on the type of typical distributions of aerosols, to be used for optimisation of the measuring site and monitoring instruments. (orig./CB) [de

  8. Using silver nano particles for sampling of toxic mercury vapors from industrial air sample

    Directory of Open Access Journals (Sweden)

    M. Osanloo

    2014-05-01

    .Conclusion: The presented adsorbent is very useful for sampling of the trace amounts of mercury vapors from air. Moreover, it can be regenerated easily is suitable or sampling at 25 to 70 °C. Due to oxidation of silver and reduction in uptake of nanoparticles, oven temperature of 245 °C is used for the recovery of metallic silver. Low amount of adsorbent, high absorbency, high repeatability for sampling, low cost and high accuracy are of the advantages of the presented method.

  9. Joint Polish–Finnish sampling of surface waters around the phosphogypsum waste stacks in Gdańsk and Police from 1 to 3 July 2013 – Results of the expedition

    OpenAIRE

    Räike, Antti; Koskela, Jarkko; Knuuttila, Seppo; Lehtoranta, Jouni; Pitkänen, Heikki; Risto, Maarit; Vuorinen, Jyrki

    2015-01-01

    The report describes the results of the joint Polish–Finnish sampling expedition aimed at estimating the possible effects of the two Polish phosphogypsum stacks located in Wislinka (Gdańsk) and Police on the loading of the Baltic Sea and the nearby watercourses. The joint expedition was based on the agreement between the Polish and Finnish Ministers of the Environment in June 2013. The results indicate a clear effect of the phosphogypsum stack on phosphate and total phosphorus concentratio...

  10. 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)

    Maenhaut, Willy; Francois, Filip; Cafmeyer, Jan; Okunade, Olusola

    1995-01-01

    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)

  11. Start-Stop Test Procedures on the PEMFC Stack Level

    DEFF Research Database (Denmark)

    Mitzel, Jens; Nygaard, Frederik; Veltzé, Sune

    The test is addressed to investigate the influence on stack durability of a long stop followed by a restart of a stack. Long stop should be defined as a stop in which the anodic compartment is fully filled by air due to stack leakages. In systems, leakage level of the stack is low and time to fil...

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

    Science.gov (United States)

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

    2017-10-01

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

  13. Environmental assessment of phosphogypsum stacks

    International Nuclear Information System (INIS)

    Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

    2009-01-01

    Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

  14. Environmental assessment of phosphogypsum stacks

    International Nuclear Information System (INIS)

    Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

    2008-03-01

    Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

  15. Gas dispersion concentration of trace inorganic contaminants from fuel gas and analysis using head-column field-amplified sample stacking capillary electrophoresis.

    Science.gov (United States)

    Yang, Jianmin; Li, Hai-Fang; Li, Meilan; Lin, Jin-Ming

    2012-08-21

    The presence of inorganic elements in fuel gas generally accelerates the corrosion and depletion of materials used in the fuel gas industry, and even leads to serious accidents. For identification of existing trace inorganic contaminants in fuel gas in a portable way, a highly efficient gas-liquid sampling collection system based on gas dispersion concentration is introduced in this work. Using the constructed dual path gas-liquid collection setup, inorganic cations and anions were simultaneously collected from real liquefied petroleum gas (LPG) and analyzed by capillary electrophoresis (CE) with indirect UV absorbance detection. The head-column field-amplified sample stacking technique was applied to improve the detection limits to 2-25 ng mL(-1). The developed collection and analytical methods have successfully determined existing inorganic contaminants in a real LPG sample in the range of 4.59-138.69 μg m(-3). The recoveries of cations and anions with spiked LPG samples were between 83.98 and 105.63%, and the relative standard deviations (RSDs) were less than 7.19%.

  16. 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

  17. Ultra-sensitive speciation analysis of mercury by CE-ICP-MS together with field-amplified sample stacking injection and dispersive solid-phase extraction.

    Science.gov (United States)

    Chen, YiQuan; Cheng, Xian; Mo, Fan; Huang, LiMei; Wu, Zujian; Wu, Yongning; Xu, LiangJun; Fu, FengFu

    2016-04-01

    A simple dispersive solid-phase extraction (DSPE) used to extract and preconcentrate ultra-trace MeHg, EtHg and Hg(2+) from water sample, and a sensitive method for the simultaneous analysis of MeHg, EtHg and Hg(2+) by using capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) with field-amplified sample stacking injection (FASI) were first reported in this study. The DSPE used thiol cotton particles as adsorbent, and is simple and effective. It can be used to extract and preconcentrate ultra-trace mercury compounds in water samples within 30 min with a satisfied recovery and no mercury species alteration during the process. The FASI enhanced the sensitivity of CE-ICP-MS with 25-fold, 29-fold and 27-fold for MeHg, EtHg and Hg(2+) , respectively. Using FASI-CE-ICP-MS together with DSPE, we have successfully determined ultra-trace MeHg, EtHg and Hg(2+) in tap water with a limits of quantification (LOQs) of 0.26-0.45 pg/mL, an RSD (n = 3) mercury. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 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...

  19. Continuous air monitor correlation to fixed air sample data at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Whicker, J.J.

    1993-01-01

    Continuous air monitoring instruments (CAMS) deployed in laboratories in the TA-55 plutonium facility at Los Alamos National Laboratory (LANL) alarmed less than 33 percent of the time when fixed air sample measurements in the same laboratory showed integrated concentrations exceeding 500 DAC-hrs. The purpose of this study was to explore effects of non-instrument variables on alarm sensitivities for properly working CAMS. Non-instrument variables include air flow patterns, particle size of released material, and the energy of the release. Dilution Factors (DFs) for 21 airborne releases in various rooms and of different magnitudes were calculated and compared. The median DF for releases where the CAM alarmed was 13.1 while the median DF for releases where the CAM did not alarm was 179. Particle sizes ranged considerably with many particles larger than 10 μm. The cause of the release was found to be important in predicting if a CAM would alarm with releases from bagouts resulting in the greatest percentage of CAM alarms. The results of this study suggest that a two-component strategy for CAM placement at LANL be utilized. The first component would require CAMs at exhaust points in the rooms to provide for reliable detection for random release locations. The second component would require placing CAMs at locations where releases have historically been seen. Finally, improvements in CAM instrumentation is needed

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

    International Nuclear Information System (INIS)

    Hebel, S.; Hands, J.; Goering, F.; Kirchner, G.; Purtschert, R.

    2015-01-01

    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)

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

    International Nuclear Information System (INIS)

    Acena, M.L.; Crespo, M.T.

    1989-01-01

    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)

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

    NARCIS (Netherlands)

    Henneken, H.

    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

  3. Development of a New Microextraction Fiber Combined to On-Line Sample Stacking Capillary Electrophoresis UV Detection for Acidic Drugs Determination in Real Water Samples

    Science.gov (United States)

    Araujo, Lilia; Prieto, Avismelsi; Navalón, Alberto; Vílchez, José Luis; Valera, Paola; Zambrano, Ana; Dugas, Vincent

    2017-01-01

    A new analytical method coupling a (off-line) solid-phase microextraction with an on-line capillary electrophoresis (CE) sample enrichment technique was developed for the analysis of ketoprofen, naproxen and clofibric acid from water samples, which are known as contaminants of emerging concern in aquatic environments. New solid-phase microextraction fibers based on physical coupling of chromatographic supports onto epoxy glue coated needle were studied for the off-line preconcentration of these micropollutants. Identification and quantification of such acidic drugs were done by capillary zone electrophoresis (CZE) using ultraviolet diode array detection (DAD). Further enhancement of concentration sensitivity detection was achieved by on-line CE “acetonitrile stacking” preconcentration technique. Among the eight chromatographic supports investigated, Porapak Q sorbent showed higher extraction and preconcentration capacities. The screening of parameters that influence the microextraction process was carried out using a two-level fractional factorial. Optimization of the most relevant parameters was then done through a surface response three-factor Box-Behnken design. The limits of detection and limits of quantification for the three drugs ranged between 0.96 and 1.27 µg∙L−1 and 2.91 and 3.86 µg∙L−1, respectively. Recovery yields of approximately 95 to 104% were measured. The developed method is simple, precise, accurate, and allows quantification of residues of these micropollutants in Genil River water samples using inexpensive fibers. PMID:28686186

  4. Development of a New Microextraction Fiber Combined to On-Line Sample Stacking Capillary Electrophoresis UV Detection for Acidic Drugs Determination in Real Water Samples

    Directory of Open Access Journals (Sweden)

    Maria Espina-Benitez

    2017-07-01

    Full Text Available A new analytical method coupling a (off-line solid-phase microextraction with an on-line capillary electrophoresis (CE sample enrichment technique was developed for the analysis of ketoprofen, naproxen and clofibric acid from water samples, which are known as contaminants of emerging concern in aquatic environments. New solid-phase microextraction fibers based on physical coupling of chromatographic supports onto epoxy glue coated needle were studied for the off-line preconcentration of these micropollutants. Identification and quantification of such acidic drugs were done by capillary zone electrophoresis (CZE using ultraviolet diode array detection (DAD. Further enhancement of concentration sensitivity detection was achieved by on-line CE “acetonitrile stacking” preconcentration technique. Among the eight chromatographic supports investigated, Porapak Q sorbent showed higher extraction and preconcentration capacities. The screening of parameters that influence the microextraction process was carried out using a two-level fractional factorial. Optimization of the most relevant parameters was then done through a surface response three-factor Box-Behnken design. The limits of detection and limits of quantification for the three drugs ranged between 0.96 and 1.27 µg∙L−1 and 2.91 and 3.86 µg∙L−1, respectively. Recovery yields of approximately 95 to 104% were measured. The developed method is simple, precise, accurate, and allows quantification of residues of these micropollutants in Genil River water samples using inexpensive fibers.

  5. Lightweight Stacks of Direct Methanol Fuel Cells

    Science.gov (United States)

    Narayanan, Sekharipuram; Valdez, Thomas

    2004-01-01

    An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

  6. Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug

    Czech Academy of Sciences Publication Activity Database

    Šesták, Jozef; Thormann, W.

    2017-01-01

    Roč. 1512, AUG (2017), s. 124-132 ISSN 0021-9673 Institutional support: RVO:68081715 Keywords : head- column field-amplified sample stacking * capillary electrophoresis * water plug Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  7. Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug

    Czech Academy of Sciences Publication Activity Database

    Šesták, Jozef; Thormann, W.

    2017-01-01

    Roč. 1512, AUG (2017), s. 124-132 ISSN 0021-9673 Institutional support: RVO:68081715 Keywords : head-column field-amplified sample stacking * capillary electrophoresis * water plug Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  8. Stratospheric Air Sub-sampler (SAS) and its application to analysis of Delta O-17(CO2) from small air samples collected with an AirCore

    NARCIS (Netherlands)

    Mrozek, Dorota Janina; van der Veen, Carina; Hofmann, Magdalena E. G.; Chen, Huilin; Kivi, Rigel; Heikkinen, Pauli; Rockmann, Thomas

    2016-01-01

    We present the set-up and a scientific application of the Stratospheric Air Sub-sampler (SAS), a device to collect and to store the vertical profile of air collected with an AirCore (Karion et al., 2010) in numerous sub-samples for later analysis in the laboratory. The SAS described here is a 20m

  9. Modeling fuel cell stack systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J H [Los Alamos National Lab., Los Alamos, NM (United States); Lalk, T R [Dept. of Mech. Eng., Texas A and M Univ., College Station, TX (United States)

    1998-06-15

    A technique for modeling fuel cell stacks is presented along with the results from an investigation designed to test the validity of the technique. The technique was specifically designed so that models developed using it can be used to determine the fundamental thermal-physical behavior of a fuel cell stack for any operating and design configuration. Such models would be useful tools for investigating fuel cell power system parameters. The modeling technique can be applied to any type of fuel cell stack for which performance data is available for a laboratory scale single cell. Use of the technique is demonstrated by generating sample results for a model of a Proton Exchange Membrane Fuel Cell (PEMFC) stack consisting of 125 cells each with an active area of 150 cm{sup 2}. A PEMFC stack was also used in the verification investigation. This stack consisted of four cells, each with an active area of 50 cm{sup 2}. Results from the verification investigation indicate that models developed using the technique are capable of accurately predicting fuel cell stack performance. (orig.)

  10. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Science.gov (United States)

    2010-07-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-06-22

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

  13. Stack Flow Rate Changes and the ANSI/N13.1-1999 Qualification Criteria: Application to the Hanford Canister Storage Building Stack

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-02-29

    The Canister Storage Building (CSB), located in the 200-East Area of the Hanford Site, is a 42,000 square foot facility used to store spent nuclear fuel from past activities at the Hanford Site. Because the facility has the potential to emit radionuclides into the environment, its ventilation exhaust stack has been equipped with an air monitoring system. Subpart H of the National Emissions Standards for Hazardous Air Pollutants requires that a sampling probe be located in the exhaust stack in accordance with criteria established by the American National Standards Institute/Health Physics Society Standard N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities.

  14. Molecular Biological Characterization of Air Samples: A Survey of Four Strategically Important Regions

    National Research Council Canada - National Science Library

    Francesconi, Stephen

    2003-01-01

    .... In support of this requirement, the Joint Program Office for Biological Defense initiated an aggressive program incorporating the development of air-sampling and agent detecting devices, coined...

  15. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Science.gov (United States)

    2010-07-01

    ... ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA processing... determination within 20 workdays, we have instituted multitrack processing of requests. Based on the information... source; responsive records were part of the Air Force's decision-making process, and the prerelease...

  16. Development of activated charcoal impregnated air sampling filter media : their characteristics and use

    International Nuclear Information System (INIS)

    Khan, A.A.; Ramarathinam, K.; Gupta, S.K.; Deshingkar, D.S.; Kishore, A.G.

    1975-01-01

    Because of its low maximum permissible concentration in air, air-borne radioiodine must be accurately monitored in contaminated air streams, in the working environment and handling facilities, before release to the environment from the nuclear facilities. Activated charcoal impregnated air sampling filter media are found to be most suitable for monitoring airborne iodine-131. Because of its simplicity and reproducible nature in assessment of air-borne radioactive iodine, the work on the development of such media was undertaken in order to find a suitable substitute for imported activated charcoal impregnated air sampling filter media. Eight different media of such type were developed, evaluated and compared with two imported media. Best suitable medium is recommended for its use in air-borne iodine sampling which was found to be even better suited than imported media of such type. (author)

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

    International Nuclear Information System (INIS)

    Hackworth, M.F.

    1995-01-01

    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

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

    Science.gov (United States)

    Mullins, Garrett R; Bruns, David E

    2017-10-01

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

  19. 400 W High Temperature PEM Fuel Cell Stack Test

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2006-01-01

    This work demonstrates the operation of a 30 cell high temperature PEM (HTPEM) fuel cell stack. This prototype stack has been developed at the Institute of Energy Technology, Aalborg University, as a proof-of-concept for a low pressure cathode air cooled HTPEM stack. The membranes used are Celtec...

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

    International Nuclear Information System (INIS)

    Iswantoro; Sutanto, W.W

    2013-01-01

    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)

  1. Comparison of indoor air sampling and dust collection methods for fungal exposure assessment using quantitative PCR

    Science.gov (United States)

    Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample ...

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

    International Nuclear Information System (INIS)

    Qiu Dangui; Li Xinzhi; Hou Jianrong; Qiao Taifei; Wu Tao; Zhang Jirong; Han Lihong

    2012-01-01

    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)

  3. Air sampling by pumping through a filter: effects of air flow rate, concentration, and decay of airborne substances

    OpenAIRE

    Šoštarić, Marko; Petrinec, Branko; Babić, Dinko

    2016-01-01

    This paper tackles the issue of interpreting the number of airborne particles adsorbed on a filter through which a certain volume of sampled air has been pumped. This number is equal to the product of the pumped volume and particle concentration in air, but only if the concentration is constant over time and if there is no substance decomposition on the filter during sampling. If this is not the case, one must take into account the inconstancy of the concentration and the decay law for a give...

  4. Assessment for potential radionuclide emissions from stacks and diffuse and fugitive sources on the Hanford Site

    International Nuclear Information System (INIS)

    Davis, W.E.; Schmidt, J.W.; Gleckler, B.P.; Rhoads, K.

    1995-06-01

    By using the six EPA-approved methods, instead of only the original back calculation method for assessing the 84 WHC registered stacks, the number of stacks requiring continuous monitoring was reduced from 32 to 19 stacks. The intercomparison between results showed that no correlation existed between back calculations and release fractions. Also the NDA, upstream air samples, and powder release fraction method results were at least three orders of magnitude lower then the back calculations results. The most surprising results of the assessment came from NDA. NDA was found to be an easy method for assessing potential emissions. For the nine stacks assessed by NDA, all nine of the stacks would have required continuous monitoring when assessed by back calculations. However, when NDA was applied all stacks had potential emissions that would cause an EDE below the > 0.1 mrem/y standard. Apparent DFs for the HEPA filter systems were calculated for eight nondesignated stacks with emissions above the detection limit. These apparent DFs ranged from 0.5 to 250. The EDE dose to the MEI was calculated to be 0.028 mrem/y for diffuse and fugitive emissions from the Hanford Sited. This is well below the > 0.1 mrem/y standard

  5. Gas-chromatographic quantitative determination of argon in air samples, by elimination of oxigen

    International Nuclear Information System (INIS)

    Sofronie, E.

    1982-08-01

    A method of gas-chromatographic quantitative determination of argon in air samples, by elimination of oxygen, is presented. Experiments were carried out in a static system. Conditions for the application of the method in dynamic systems are specified. Sensibility of the method: 5 10 -4 cm 3 Ar per cm 3 of air. (author)

  6. Mixed species radioiodine air sampling readout and dose assessment system

    International Nuclear Information System (INIS)

    Distenfeld, C.H.; Klemish, J.R. Jr.

    1978-01-01

    This invention provides a simple, reliable, inexpensive and portable means and method for determining the thyroid dose rate of mixed airborne species of solid and gaseous radioiodine without requiring highly skilled personnel, such as health physicists or electronics technicians. To this end, this invention provides a means and method for sampling a gas from a source of a mixed species of solid and gaseous radioiodine for collection of the mixed species and readout and assessment of the emissions therefrom by cylindrically, concentrically and annularly molding the respective species around a cylindrical passage for receiving a conventional probe-type Geiger-Mueller radiation detector

  7. Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

    cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes, runs on pure hydrogen in a dead end anode configuration with a purge valve. The cooling of the stack is managed by running......The present work involves the development of a model for predicting the dynamic temperature of a high temperature PEM (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system consists of a prototype...... the stack at a high stoichiometric air flow. This is possible because of the PBI fuel cell membranes used, and the very low pressure drop in the stack. The model consists of a discrete thermal model dividing the stack into three parts: inlet, middle and end and predicting the temperatures in these three...

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

    Science.gov (United States)

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

    2011-09-01

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

  9. Elemental analysis of air particulate samples in Jakarta area by x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Yumiarti; Yusuf, M.; Mellawati, June; Menry, Yulizon; Surtipanti S

    1998-01-01

    Determination of elements in air particulate samples collected from Jakarta, especially from industrial area Pulo Gadung, also from residence, office, and recreation sites had been carried out. The samples collected periodically from August through December 1996. The elements were analyzed by X-ray fluorescence spectrometry method. Quantitative and qualitative analyses were done using QXAS AXIL (Quantitative X-ray Analysis System of x-ray Spectra by Iterative Least squares fitting) and QAES (Quantitative Analyses of Environmental Samples) package program. Results of the analyses showed that the content of heavy metal elements in air particulate samples from all areas studied were still below the maximum permissible concentration. (authors)

  10. Fabrication and characterization of buckypapers for use in air sampling

    Science.gov (United States)

    Oh, Jonghwa

    Occupational exposure to volatile organic compounds (VOCs) is a concern from a public health perspective. In many industrial activities, workers' exposure to VOCs can be sufficiently high to induce adverse health effects, so their monitoring is necessary. In exposure assessment, post sampling extraction and quantification are the typical analytical procedures. Recently, our group developed the photothermal desorption (PTD) technique in which a pulse of light thermally desorbs an analyte directly from a sorbent. Advantages of this technique are; it is solvent free, repeated analysis is possible, sorbents are reusable, and no high cost of equipment is required. PTD overcomes almost all drawbacks of current extraction methods. This study was aimed to develop and test a new sorbent which will efficiently work with PTD. Single-walled carbon nanotubes (SWNTs) were examined as potential sorbents because of their high surface area, great thermal conductivity, and efficient light absorption. SWNTs were fabricated into a self-supporting form (i.e., buckypaper (BP)) which will preserve its physical integrity under normal working conditions. Largely two types of SWNTs were used, arc discharge (AD) and high-pressure carbon monoxide (HiPco), and different fabrication methods were examined. Upon fabrication, their adsorption properties were characterized in terms of Brunauer, Emmett, and Teller (BET) surface area, pore size, and toluene adsorption capacity. HiPco BP and methanol-cleaned AD BP (suspended/rinsed with methanol) were the top two materials, showing the highest surface area (649 and 387 m²/g, respectively) and adsorption capacity (106 and 46 mg/g, respectively) with relatively small mean pore diameter (7.7 and 8.8 nm, respectively). To further improve the adsorption properties, specific heat treatment conditions for each type of BPs were employed. After initial treatments only HiPco BP and acetone-cleaned AD BP (suspended/rinsed with acetone) were selected for further

  11. Design of modified annulus air sampling system for the detection of leakage in waste transfer line

    International Nuclear Information System (INIS)

    Deokar, U.V; Khot, A.R.; Mathew, P.; Ganesh, G.; Tripathi, R.M.; Srivastava, Srishti

    2018-01-01

    Various liquid waste streams are generated during the operation of reprocessing plant. The High Level (HL), Intermediate Level (IL) and Low Level (LL) liquid wastes generated, are transferred from reprocessing plant to Waste Management Facility. These respective waste streams are transferred through pipe-in-pipe lines along the shielded concrete trench. For detection of radioactive leakage from primary waste transfer line into secondary line, sampling of the annulus air between the two pipes is carried out. The currently installed pressurized annulus air sampling system did not have online leakage detection provision. Hence, there are chances of personal exposure and airborne activity in the working area. To overcome these design flaws, free air flow modified online annulus air sampling system with more safety features is designed

  12. High-resolution real-time optical studies of radiological air sample filtration processes in an environmental continuous air monitor

    Science.gov (United States)

    Rodgers, John C.; Wasiolek, Piotr T.; Schery, Stephen D.; Alcantara, Raul E.

    1999-01-01

    The need for a continuous air monitor capable of quick and accurate measurements of airborne radioactivity in close proximity to the work environment during waste management, site restoration, and D&D operations led to the Los Alamos National Laboratory development of an environmental continuous air monitor (ECAM). Monitoring the hostile work environment of waste recovery, for example, presents unique challenges for detector design for detectors previously used for the clean room conditions of the typical plutonium laboratory. The environmental and atmospheric conditions (dust, high wind, etc.) influence aerosol particle penetration into the ECAM sampling head as well as the build-up of deposits on the ECAM filter.

  13. Loss of collected particles from the filter of the stack monitor, the Ringhals-1 power reactor

    International Nuclear Information System (INIS)

    Stroem, L.

    1993-01-01

    The function of the filter holder was examined in the laboratory and in the Ringhals measurement installation. It was concluded that a loss of sample could occur, if the filter has a heavy particle deposit. An approximate relation between deposits thickness and loss of sample could be determined. Particle concentration in the stack air is sometimes so high, that loss of sample can occur. The test have also revealed that the sample air stream can by-pass the filter, without proper indication of the defect. Control instrumentation is proposed

  14. Zirconia coated stir bar sorptive extraction combined with large volume sample stacking capillary electrophoresis-indirect ultraviolet detection for the determination of chemical warfare agent degradation products in water samples.

    Science.gov (United States)

    Li, Pingjing; Hu, Bin; Li, Xiaoyong

    2012-07-20

    In this study, a sensitive, selective and reliable analytical method by combining zirconia (ZrO₂) coated stir bar sorptive extraction (SBSE) with large volume sample stacking capillary electrophoresis-indirect ultraviolet (LVSS-CE/indirect UV) was developed for the direct analysis of chemical warfare agent degradation products of alkyl alkylphosphonic acids (AAPAs) (including ethyl methylphosphonic acid (EMPA) and pinacolyl methylphosphonate (PMPA)) and methylphosphonic acid (MPA) in environmental waters. ZrO₂ coated stir bar was prepared by adhering nanometer-sized ZrO₂ particles onto the surface of stir bar with commercial PDMS sol as adhesion agent. Due to the high affinity of ZrO₂ to the electronegative phosphonate group, ZrO₂ coated stir bars could selectively extract the strongly polar AAPAs and MPA. After systematically optimizing the extraction conditions of ZrO₂-SBSE, the analytical performance of ZrO₂-SBSE-CE/indirect UV and ZrO₂-SBSE-LVSS-CE/indirect UV was assessed. The limits of detection (LODs, at a signal-to-noise ratio of 3) obtained by ZrO₂-SBSE-CE/indirect UV were 13.4-15.9 μg/L for PMPA, EMPA and MPA. The relative standard deviations (RSDs, n=7, c=200 μg/L) of the corrected peak area for the target analytes were in the range of 6.4-8.8%. Enhancement factors (EFs) in terms of LODs were found to be from 112- to 145-fold. By combining ZrO₂ coating SBSE with LVSS as a dual preconcentration strategy, the EFs were magnified up to 1583-fold, and the LODs of ZrO₂-SBSE-LVSS-CE/indirect UV were 1.4, 1.2 and 3.1 μg/L for PMPA, EMPA, and MPA, respectively. The RSDs (n=7, c=20 μg/L) were found to be in the range of 9.0-11.8%. The developed ZrO₂-SBSE-LVSS-CE/indirect UV method has been successfully applied to the analysis of PMPA, EMPA, and MPA in different environmental water samples, and the recoveries for the spiked water samples were found to be in the range of 93.8-105.3%. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Stack Monitoring System At PUSPATI TRIGA Reactor

    International Nuclear Information System (INIS)

    Zamrul Faizad Omar; Mohd Sabri Minhat; Zareen Khan Abdul Jalil Khan; Ridzuan Abdul Mutalib; Khairulezwan Abdul Manan; Nurfarhana Ayuni Joha; Izhar Abu Hussin

    2014-01-01

    This paper describes the current Stack Monitoring System at PUSPATI TRIGA Reactor (RTP) building. A stack monitoring system is a continuous air monitor placed at the reactor top for monitoring the presence of radioactive gaseous in the effluent air from the RTP building. The system consists of four detectors that provide the reading for background, particulate, Iodine and Noble gas. There is a plan to replace the current system due to frequent fault of the system, thus thorough understanding of the current system is required. Overview of the whole system will be explained in this paper. Some current results would be displayed and moving forward brief plan would be mentioned. (author)

  16. 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).

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

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Matthias, E-mail: matthias.schindler@physik.uni-erlangen.de; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-15

    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 CO{sub 2} and reduced to graphite to determine {sup 14}C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  18. Monte Carlo simulation of air sampling methods for the measurement of radon decay products.

    Science.gov (United States)

    Sima, Octavian; Luca, Aurelian; Sahagia, Maria

    2017-08-01

    A stochastic model of the processes involved in the measurement of the activity of the 222 Rn decay products was developed. The distributions of the relevant factors, including air sampling and radionuclide collection, are propagated using Monte Carlo simulation to the final distribution of the measurement results. The uncertainties of the 222 Rn decay products concentrations in the air are realistically evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Actinide nuclides in environmental air and precipitation samples after the Chernobyl accident

    International Nuclear Information System (INIS)

    Rosner, G.; Hoetzl, H.; Winkler, R.

    1988-01-01

    The present paper describes the analysis of isotopes of uranium, neptunium, plutonium, americium and curium, in air and deposition samples taken at our laboratory site 10 km north of Munich, subsequent to the Chernobyl accident. Uranium-234, 237 U, 238 U, 239 Np, 238 Pu, 239+240 Pu and 242 Cm have been identified and upper limits of detection have been established for 241 Am and 244 Cm. Deposition and air concentration values are discussed. 12 refs., 1 fig., 2 tabs

  20. OpenStack essentials

    CERN Document Server

    Radez, Dan

    2015-01-01

    If you need to get started with OpenStack or want to learn more, then this book is your perfect companion. If you're comfortable with the Linux command line, you'll gain confidence in using OpenStack.

  1. Mastering OpenStack

    CERN Document Server

    Khedher, Omar

    2015-01-01

    This book is intended for system administrators, cloud engineers, and system architects who want to deploy a cloud based on OpenStack in a mid- to large-sized IT infrastructure. If you have a fundamental understanding of cloud computing and OpenStack and want to expand your knowledge, then this book is an excellent checkpoint to move forward.

  2. Stacking with stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

    Caspers, Fritz E-mail: Fritz.Caspers@cern.ch; Moehl, Dieter

    2004-10-11

    Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles 'seen' by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly 'protected' from the Schottky noise of the stack. Vice versa the stack has to be efficiently 'shielded' against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 10{sup 5} the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters). In the 'old AA', where the antiproton collection and stacking was done in one single ring, the injected beam was further shielded during cooling by means of a movable shutter. The complexity of these systems is very high. For more modest stacking ratios, one might use azimuthal rather than radial separation of stack and injected beam. Schematically half of the circumference would be used to accept and cool new beam and the remainder to house the stack. Fast gating is then required between the high gain cooling of the injected beam and the low gain stack cooling. RF-gymnastics are used to merge the pre-cooled batch with the stack, to re-create free space for the next injection, and to capture the new batch. This scheme is less demanding for the storage ring lattice, but at the expense of some reduction in stacking rate. The talk reviews the 'radial' separation schemes and also gives some

  3. 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)

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

    International Nuclear Information System (INIS)

    Nardes, Raysa C.; Santos, Ramon S.; Sanches, Francis A.C.R.A.; Gama Filho, Hamilton S.; Oliveira, Davi F.; Anjos, Marcelino J.

    2015-01-01

    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)

  5. Remote tritium-in-air sampling in reactor building at NAPS

    International Nuclear Information System (INIS)

    Mitra, S.R.; Lal Chand

    2000-01-01

    Tritium-in-air activity is an important parameter in PHW reactors from the point of view of internal exposure and heavy water escape from the system. The sampling technique in vogue in PHWRs, for measurement of tritium-in-air activity, requires collection of on the spot sample from different areas using a portable sampler. This sampler uses the bubbler method of sampling. As the areas of sampling are numerous, this technique is time consuming, laborious and can lead to significant internal exposure in areas where tritium-in-air activity is high. This technique is also error prone due to the heavy workload involved. A new scheme, in which the sampling of all the areas of reactor building is done through a sampling station, has been introduced for the first time in NAPS. This sampling station facilitates collection of samples from all the areas of reactor building, remotely and simultaneously at one place thereby reducing time, labour, exposure and error. This paper gives the details of the sampling system installed at NAPS. (author)

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

    International Nuclear Information System (INIS)

    Gregory, D.C.; Bryan, W.L.; Falter, K.G.

    1993-01-01

    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

  7. Recommended radiological air sampling and internal contamination control at nuclear power plants

    International Nuclear Information System (INIS)

    Rich, B.L.; Ritter, P.D.; Martz, D.E.

    1984-01-01

    It has long been recognized by the NRC Technical Staffs that estimating the quantity of radioactivity inhaled by an individual worker involved large uncertainties. General air samples usually produce concentrations lower than those in the workers Breathing Zone (BZ). NRC guides have recognized this problem by specifying air monitoring programs which sample the Breathing Zone or concentrations known to be higher than that actually inhaled. In addition the availability of suitable samplers to obtain BZ samples and the practicality of requiring their use was somewhat in question to the NRC technical staff. AN NRC development contract was issued to provide a detailed review of the technical aspects of the problems and recommendations for practical upgrade of federal guidance. This project accomplished a review of the nuclear industry experience and knowledge through a literature search, site visits to representative licensed facilities, telephone surveys of many others, laboratory testing of personal air samplers (lapel samplers) and aerosol diffusion experiments to verify key conclusions and assumptions

  8. Known volume air sampling pump. Final summary report Jun 1975--Nov 1976

    International Nuclear Information System (INIS)

    McCullough, J.E.; Peterson, A.

    1976-11-01

    The purpose of this development program was to design and develop a known volume air sampling pump for use in measuring the amount of radioactive material in the atmosphere of an underground uranium mine. The principal nuclear radiation hazard to underground uranium mines comes from the mine atmosphere. Daughter products of radon-222 are inhaled by the miner resulting in a relatively high lung cancer rate among these workers. Current exposure control practice employs spot sampling in working areas to measure working level values. Currently available personal air sampling pumps fail to deliver known volumes of air under widely changing differential pressures. A unique type of gas pump known as the scroll compressor, developed by Arthur D. Little, Inc., that has no values and few moving parts is expected to provide a practical, efficient, and dependable air pump for use in dosimeters. The three deliverable known volume air sampling pumps resulting from this work incorporate a scroll pump, drive motor, speed control electronics, and battery pack in a container suitable for attachment to a miner's belt

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

    International Nuclear Information System (INIS)

    Martins, Ana Paula G.; Negri, Elnara M.; Saldiva, Paulo H.N.

    2009-01-01

    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)

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

    International Nuclear Information System (INIS)

    Hayes, Robert

    2009-01-01

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

  11. Profiling quinones in ambient air samples collected from the Athabasca region (Canada).

    Science.gov (United States)

    Wnorowski, Andrzej; Charland, Jean-Pierre

    2017-12-01

    This paper presents new findings on polycyclic aromatic hydrocarbon oxidation products-quinones that were collected in ambient air samples in the proximity of oil sands exploration. Quinones were characterized for their diurnal concentration variability, phase partitioning, and molecular size distribution. Gas-phase (GP) and particle-phase (PM) ambient air samples were collected separately in the summer; a lower quinone content was observed in the PM samples from continuous 24-h sampling than from combined 12-h sampling (day and night). The daytime/nocturnal samples demonstrated that nighttime conditions led to lower concentrations and some quinones not being detected. The highest quinone levels were associated with wind directions originating from oil sands exploration sites. The statistical correlation with primary pollutants directly emitted from oil sands industrial activities indicated that the bulk of the detected quinones did not originate directly from primary emission sources and that quinone formation paralleled a reduction in primary source NO x levels. This suggests a secondary chemical transformation of primary pollutants as the origin of the determined quinones. Measurements of 19 quinones included five that have not previously been reported in ambient air or in Standard Reference Material 1649a/1649b and seven that have not been previously measured in ambient air in the underivatized form. This is the first paper to report on quinone characterization in secondary organic aerosols originating from oil sands activities, to distinguish chrysenequinone and anthraquinone positional isomers in ambient air, and to report the requirement of daylight conditions for benzo[a]pyrenequinone and naphthacenequinone to be present in ambient air. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Measurement of actinides in samples from effluent air, primary coolant and effluent water of nuclear power stations in the Federal Republic of Germany

    International Nuclear Information System (INIS)

    Winkler, R.; Hoetzl, H.; Rosner, G.

    1977-01-01

    Since the middle of 1973 the alpha radioactivity of a number of aerosol filters from the stack monitoring systems of some nuclear power stations, of water effluent samples from all german nuclear power stations and of samples from the primary coolant water of one nuclear power reactor was measured. Essentially, the following procedures of sample preparation for alpha spectrometry of the samples in large area gridded ionization chambers were used; cold ashing of the aerosol samples in 'excited' oxygen, coprecipitation of the alpha emitters from the effluent water samples with iron hydroxide and subsequent cold ashing of the precipitate, and evaporation of the samples from the primary cycle on stainless steel plates. The following transuranium nuclides, or some of them, were found in the samples of the primary coolant and in several aerosol filter samples: Pu-239/240, Pu-238 and/or Am-241, Cm-242 and Cm-244. Cm-242 contributes most to the alpha radioactivity in fresh samples. In the effluent water samples Cm-242, Pu-239/240 and Pu-238 and/or Am-241 were identified in some cases, in one case also Cm-244. Detection limits of the procedures used for the analysis of the above stated transuranium nuclides were in the order of 0,1 fCi per m 3 for the aerosol samples and of 0.2 pCi per 1 for the liquid samples. For the effluent air and water samples in most cases specific activities near the detection limit or somewhat higher were found. On the basis of the measurements, an estimation of the annual actinides releases from nuclear power stations in the Federal Republic of Germany is given

  13. An advanced computer-controlled automatic alpha-beta air sample counter

    International Nuclear Information System (INIS)

    Howell, W.P.; Bruinekool, D.J.; Stapleton, E.E.

    1984-01-01

    An improved computer-controlled automatic alpha-beta air sample counter was developed, based upon an earlier automatic air sample counter design. The system consists of an automatic sample changer, an electronic counting system utilizing a large silicon diode detector, a small desk-type microcomputer, a high-speed matrix printer and the necessary data interfaces. The system is operated by commands from the keyboard and programs stored on magnetic tape cassettes. The programs provide for background counting, Chi 2 test, radon subtraction and sample counting for sample periods of one day to one week. Output data are printed by the matrix printer on standard multifold paper. The data output includes gross beta, gross alpha and plutonium results. Data are automatically corrected for background, counter efficiency, and in the gross alpha and plutonium channels, for the presence of radon

  14. Advanced computer-controlled automatic alpha-beta air sample counter

    International Nuclear Information System (INIS)

    Howell, W.P.; Bruinekool, D.J.; Stapleton, E.E.

    1983-01-01

    An improved computer controlled automatic alpha-beta air sample counter was developed, based upon an earlier automatic air sample counter design. The system consists of an automatic sample changer, an electronic counting system utilizing a large silicon diode detector, a small desk-type microcomputer, a high speed matrix printer, and the necessary data interfaces. The system is operated by commands from the keyboard and programs stored on magnetic tape cassettes. The programs provide for background counting, Chi 2 test, radon subtraction, and sample counting for sample periods of one day to one week. Output data are printed by the matrix printer on standard multifold paper. The data output includes gross beta, gross alpha, and plutonium results. Data are automatically corrected for background, counter efficiency, and in the gross alpha and plutonium channels, for the presence of radon

  15. Stack Monitor Operating Experience Review

    International Nuclear Information System (INIS)

    Cadwallader, L.C.; Bruyere, S.A.

    2009-01-01

    Stack monitors are used to sense radioactive particulates and gases in effluent air being vented from rooms of nuclear facilities. These monitors record the levels and types of effluents to the environment. This paper presents the results of a stack monitor operating experience review of the U.S. Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS) database records from the past 18 years. Regulations regarding these monitors are briefly described. Operating experiences reported by the U.S. DOE and in engineering literature sources were reviewed to determine the strengths and weaknesses of these monitors. Electrical faults, radiation instrumentation faults, and human errors are the three leading causes of failures. A representative 'all modes' failure rate is 1E-04/hr. Repair time estimates vary from an average repair time of 17.5 hours (with spare parts on hand) to 160 hours (without spare parts on hand). These data should support the use of stack monitors in any nuclear facility, including the National Ignition Facility and the international ITER project.

  16. Ambient air sampling of organic pollutants and heavy metals within the EU/93/AIR/22 PHARE Project

    International Nuclear Information System (INIS)

    Kocan, A.

    1997-01-01

    Within the framework of the project the concentrations of eight heavy metals, vapour mercury, seven polychlorinated dibenzo-p-dioxin's, ten polychlordibenzofuran congeners, eighteen polychlorinated biphenyls, two chlorinated pesticides (hexachlorobenzene, p,p'-DDE and p,p'-DDT), fourteen polycyclic aromatic hydrocarbons, forty-two volatile organic compounds, total suspended particles were analysed. The morphology characterization of collected airborne particles and bioassays aimed at the evaluation of the mutagenic potency of pollutants present in collected air were also performed. Ambient air heavy metals were caught on cellulose filters using the same type of the sampler used for semi-volatile compounds sampling and analysed by atomic spectrometry. Vapour mercury was trapped on gold sand packed in a tube through which about 280 L of ambient air during 24 hours were drawn. On-site analysis was performed by an atomic fluorescence analyzer. Inhalable air particles, i.e particles less than 10 μm in diameter were collected by a sampler equipped with a cascade impactor fractionating into five size fractions involving respirable (<3 μm) fractions. The morphology and composition of the respirable fractions was investigated by scanning electron microscopy and X-ray microanalysis

  17. Ambient air sampling for radioactive air contaminants at Los Alamos National Laboratory: A large research and development facility

    International Nuclear Information System (INIS)

    Eberhart, C.F.

    1998-01-01

    This paper describes the ambient air sampling program for collection, analysis, and reporting of radioactive air contaminants in and around Los Alamos National Laboratory (LANL). Particulate matter and water vapor are sampled continuously at more than 50 sites. These samples are collected every two weeks and then analyzed for tritium, and gross alpha, gross beta, and gamma ray radiation. The alpha, beta, and gamma measurements are used to detect unexpected radionuclide releases. Quarterly composites are analyzed for isotopes of uranium ( 234 U, 235 U, 238 U), plutonium ( 238 Pu, 239/249 Pu), and americium ( 241 Am). All of the data is stored in a relational database with hard copies as the official records. Data used to determine environmental concentrations are validated and verified before being used in any calculations. This evaluation demonstrates that the sampling and analysis process can detect tritium, uranium, plutonium, and americium at levels much less than one percent of the public dose limit of 10 millirems. The isotopic results also indicate that, except for tritium, off-site concentrations of radionuclides potentially released from LANL are similar to typical background measurements

  18. Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

    Science.gov (United States)

    Condon, E. P.; Vedder, J. F.

    1984-01-01

    Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

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

    International Nuclear Information System (INIS)

    MULKEY, C.H.

    1999-01-01

    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

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

    International Nuclear Information System (INIS)

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

    1996-02-01

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

  1. Dose assessment from potential radionuclide emissions from stacks on the Hanford Site

    International Nuclear Information System (INIS)

    Davis, W.E.; Barnett, J.M.

    1995-04-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office (RL), received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency (EPA), Region 10. The Compliance Order required RL to (1) evaluate all radionuclide emission points at the Hanford Site to determine which points are subject to the continuous emission sampling requirements of Title 40, Code of Federal Regulations, Part 61 (40 CFR 61), Subpart H, and (2) continuously sample radionuclide emissions in accordance with requirements in 40 CFR 61.93. The Information Request required RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. A Compliance Plan was submitted to EPA, Region 10, on April 30, 1993. The Compliance Plan specified that a dose assessment would be performed for 84 Westinghouse Hanford Company (WHC) stacks registered with the Washington State Department of Health on the Hanford Site. Any stack identified in the assessment as having potential emissions to cause an effective dose equivalent (EDE) to a maximum exposed individual (MEI) greater than 0.1 mrem y -1 must have a compliant sampling system. In addition, a Federal Facility Compliance Agreement (FFCA) was signed on. February 7, 1994. The FFCA required that all unregistered stacks on the Hanford Site be assessed. This requirement increased the number of stacks to be assessed to 123 stacks. Six methods for performing the assessments are described. An initial assessment using only the HEPA filtration factor for back calculations identified 32 stacks that would have emissions which would cause an EDE to the MEI greater than 0.1 mrem y -1 . When the other methods were applied the number was reduced to 20 stacks. The paper discusses reasons for these overestimates

  2. Dioxin emission factors for automobiles from tunnel air sampling in Northern Taiwan.

    Science.gov (United States)

    Chang, Moo Been; Chang, Shu Hao; Chen, Yuan Wu; Hsu, Hsuan Chien

    2004-06-05

    This study measured PCDD/F concentrations in tunnel air and vehicle exhaust. The ambient air samples were collected with air samplers (Tisch PS-1) complying with USEPA TO-9A. The results indicate that the tunnel air had a PCDD/F TEQ concentration about two times as high as that of outside air (47.3 and 57.1 fg-I-TEQ/m3 for tunnel air vs. 37.1 fg-I-TEQ/m3 and 23.3 fg-I-TEQ/m3 for outside air, respectively). This provides the direct evidence that PCDD/F compounds are emitted from the combustion processes in gasoline- and diesel-fueled engines. According to the tunnel study, the emission factors ranged from 5.83 to 59.2 pg I-TEQ/km for gasoline vehicles and 23.32 to 236.65 pg I-TEQ/km of diesel vehicles. This indicates that the dioxin emission factor in Taiwan is lower than that measured in USA, Norway and Germany. When the speed of the diesel vehicle was set at 40 km/h, the dioxin concentration emitted from diesel vehicle was 278 pg/m3 (6.27 pg-I-TEQ/m3) from tailpipe testing. However, when the diesel vehicle was idled, the dioxin concentration increased greatly to 4078 pg/m3 (41.9 pg-I-TEQ/m3). From the results of tunnel air sampling, the PCDD/Fs emission from automobiles in Taiwan was estimated as 3.69 g I-TEQ per year. Copryright 2003 Elsevier B.V.

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

    International Nuclear Information System (INIS)

    Kohara, Eri; Muronoi, Naohiro

    2015-01-01

    The radioactivity concentrations of airborne dust samples were studied. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2013 to March 2014. The obtained data were used for gross beta radioactivity analysis and gamma nuclide analysis. It is shown that cesium 137 was mainly detected at the 10 km and 3 km altitude of central area of Japan in several samples. Gaseous radioiodine was not detected in all the samples. Radioactive xenon was detected but the concentration did not show significant difference to the background level. (author)

  4. Simple and rapid measurement of α-rays on smear samples using air luminescence

    International Nuclear Information System (INIS)

    Takiue, M.

    1980-01-01

    The α-activity collected on smear samples has been measured indirectly using an air luminescence counting method and a liquid scintillation spectrometer. In this method, air luminescence, attributed to the fluorescence emitted by nitrogen molecules excited by α-rays in air, serves to detect α-rays. Thus, sample preparation and α-ray measurement are simple and rapid, and moreover, no radioactive waste solution is produced. Taking into account a low background and a counting efficiency between 10 and 20%, it is estimated that the detectable limit for α-ray measurement is about 1 x 10 -7 μCi/cm 2 for loose contamination. This method is convenient to use in the routine analysis of α-ray-emitting nuclides on smear paper. (author)

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

    International Nuclear Information System (INIS)

    McGuire, S.; Hickey, E.E.; Knox, W.

    1991-01-01

    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

  6. ENVIRONMENTAL SAMPLING USING LOCATION SPECIFIC AIR MONITORING IN BULK HANDLING FACILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, L.; Hanks, D.; Degange, J.; Brant, H.; Hall, G.; Cable-Dunlap, P.; Anderson, B.

    2011-06-07

    Since the introduction of safeguards strengthening measures approved by the International Atomic Energy Agency (IAEA) Board of Governors (1992-1997), international nuclear safeguards inspectors have been able to utilize environmental sampling (ES) (e.g. deposited particulates, air, water, vegetation, sediments, soil and biota) in their safeguarding approaches at bulk uranium/plutonium handling facilities. Enhancements of environmental sampling techniques used by the IAEA in drawing conclusions concerning the absence of undeclared nuclear materials or activities will soon be able to take advantage of a recent step change improvement in the gathering and analysis of air samples at these facilities. Location specific air monitoring feasibility tests have been performed with excellent results in determining attribute and isotopic composition of chemical elements present in an actual test-bed sample. Isotopic analysis of collected particles from an Aerosol Contaminant Extractor (ACE) collection, was performed with the standard bulk sampling protocol used throughout the IAEA network of analytical laboratories (NWAL). The results yielded bulk isotopic values expected for the operations. Advanced designs of air monitoring instruments such as the ACE may be used in gas centrifuge enrichment plants (GCEP) to detect the production of highly enriched uranium (HEU) or enrichments not declared by a State. Researchers at Savannah River National Laboratory in collaboration with Oak Ridge National Laboratory are developing the next generation of ES equipment for air grab and constant samples that could become an important addition to the international nuclear safeguards inspector's toolkit. Location specific air monitoring to be used to establish a baseline environmental signature of a particular facility employed for comparison of consistencies in declared operations will be described in this paper. Implementation of air monitoring will be contrasted against the use of smear

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

    International Nuclear Information System (INIS)

    Olsen, P.A.

    1995-01-01

    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

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

    International Nuclear Information System (INIS)

    BAUMANN, B.L.

    2003-01-01

    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

  9. Probe sampling measurements and modeling of nitric oxide formation in ethane + air flames

    NARCIS (Netherlands)

    Dyakov, I.V.; Ruyck, de J.; Konnov, A.A.

    2007-01-01

    Burning velocity and probe sampling measurements of the concentrations of O2, CO2, CO and NO in the post-flame zone of ethane + air flames are reported. The heat flux method was used for stabilization of laminar, premixed, non-stretched flames on a perforated plate burner at 1 atm. Axial profiles of

  10. The sampling of sulfur dioxide in air with impregnated filter paper

    NARCIS (Netherlands)

    Huygen, C.

    1963-01-01

    A method is suggested for the sampling of sulfur dioxide in air with impregnated filter paper instead of bubblers. The best aqueous impregnating solution contained potassium hydroxide with glycerol or triethanolamine. The possibilities and limitations of the method are discussed. High collection

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

    International Nuclear Information System (INIS)

    Olivier, A.; Tenailleau, L.; Baron, Y.; Maro, D.

    2004-01-01

    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 Na 2 CO 3 . In the first method the Na 2 CO 3 solution is mixed with a liquid scintillate and is directly analysed by liquid scintillation counting (LSC). The detection limit is approximately 1 Bq/m 3 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/m 3 of air samples). In the third method, Na 2 CO 3 is precipitated into CaCO 3 in presence of CaCl 2 . CaCO 3 is then analysed by LSC. This method appear to be the most appropriate, the detection limit is 0.05 Bq/m 3 of air samples. (author)

  12. Stacking the Equiangular Spiral

    OpenAIRE

    Agrawal, A.; Azabi, Y. O.; Rahman, B. M.

    2013-01-01

    We present an algorithm that adapts the mature Stack and Draw (SaD) methodology for fabricating the exotic Equiangular Spiral Photonic Crystal Fiber. (ES-PCF) The principle of Steiner chains and circle packing is exploited to obtain a non-hexagonal design using a stacking procedure based on Hexagonal Close Packing. The optical properties of the proposed structure are promising for SuperContinuum Generation. This approach could make accessible not only the equiangular spiral but also other qua...

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-11

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

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

    Science.gov (United States)

    Zaromb, Solomon

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    2000-01-01

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

  16. 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.

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

    International Nuclear Information System (INIS)

    MULKEY, C.H.

    1999-01-01

    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

  18. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis; FINAL

    International Nuclear Information System (INIS)

    MULKEY, C.H.

    1999-01-01

    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

  19. Quantitative analysis of untreated oil samples in in-air PIXE

    International Nuclear Information System (INIS)

    Sera, K.; Goto, S.; Takahashi, C.; Saitoh, Y.

    2010-01-01

    The method of quantitative analysis of oil samples in in-air PIXE has been developed on the basis of a standard-free method. The components of the continuous X-rays originated from air and backing film can be exactly subtracted using a blank spectrum after normalization by the yields of Ar K-α X-rays. The method was developed using nine oil samples including standard oils and its accuracy was confirmed by comparing the results with those obtained by the internal-standard method. Validity of the method for practical oil samples was confirmed for various kinds of oils such as engine, machine and cooking oils. It was found that the method is effective for various kinds of oils whatever elements we designate as an index element. (author)

  20. Mathematical estimation of the level of microbial contamination on spacecraft surfaces by volumetric air sampling

    Science.gov (United States)

    Oxborrow, G. S.; Roark, A. L.; Fields, N. D.; Puleo, J. R.

    1974-01-01

    Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.

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

    International Nuclear Information System (INIS)

    Helsen, Lieve

    2005-01-01

    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

  2. Passive air sampling for persistent organic pollutants: Introductory remarks to the special issue

    International Nuclear Information System (INIS)

    Harner, Tom; Bartkow, Michael; Holoubek, Ivan; Klanova, Jana; Wania, Frank; Gioia, Rosalinda; Moeckel, Claudia; Sweetman, Andrew J.; Jones, Kevin C.

    2006-01-01

    There have been a number of developments in the need, design and use of passive air samplers (PAS) for persistent organic pollutants (POPs). This article is the first in a Special Issue of the journal to review these developments and some of the data arising from them. We explain the need and benefit of developing PAS for POPs, the different approaches that can be used, and highlight future developments and needs. - The context, needs and state-of-the-art of passive air sampling techniques for atmospheric persistent organic pollutants are discussed

  3. Actinide nuclides in environmental air and precipitation samples after the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Rosner, G.; Hoetzl, H.; Winkler, R. (Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen (West Germany))

    1988-01-01

    The present paper describes the analysis of isotopes of uranium, neptunium, plutonium, americium and curium, in air and deposition samples taken at our laboratory site 10 km north of Munich, subsequent to the Chernobyl accident. Uranium-234, {sup 237}U, {sup 238}U, {sup 239}Np, {sup 238}Pu, {sup 239+240}Pu and {sup 242}Cm have been identified and upper limits of detection have been established for {sup 241}Am and {sup 244}Cm. Deposition and air concentration values are discussed. 12 refs., 1 fig., 2 tabs.

  4. The application of x-ray fluorescence spectrometry for multielemental analysis of air particulate samples

    International Nuclear Information System (INIS)

    Mohamad Rashid Mohamad Yusoff

    1986-01-01

    The performance of XRF spectrometer as a tool for multielemental analysis of air pollution samples was discussed. The non-destructive couples with multielemental nature of the technique satisfactory sensitivity for most elements were the most important characteristics for its popularity as a method of analysis. Thus, the technique promises a significant reduction in cost and time of analysis. As a result, more extensive and revealing air particulates survey should be possible, with consequent improvements in the discovery and positive identification of particulate pollution sources. (author)

  5. Annex I.G. Demolition of the G1 stack at Marcoule by toppling

    International Nuclear Information System (INIS)

    2005-01-01

    The G1 stack at Marcoule was constructed during the first half of 1956 as a ventilation outlet for the G1 reactor, which is cooled by air. After the G1 reactor was decommissioned, the G1 stack served as a ventilation outlet for two new nuclear facilities on the site. Being no longer in compliance with regulations and having many inadequacies and uncertainties in terms of the prestressed concrete, the stack posed a potential damage risk in extreme wind or in the event of an earthquake. In 1994 it was decided that a new stack would be built to act as an outlet for the existing nuclear facilities, and that the old one would be demolished. The G1 stack was 100 m in height, 10 m in diameter and constructed with 24 vertically stacked concrete rings consisting of nine prefabricated sections, each 3.6 m in height. It was capped by a metal deflector (about 6 m in height and weighing 50 t). The inside consisted of nine semicircular tubes constructed of steel sheet metal weighing 120 t. The base of the stack consisted of the foundation, a plate and a base plate which were constructed at the site. The barrel sections were prefabricated. Construction lasted from January 1956 to June 1956. At the base, the cylindrical portion of the stack widened to form three feet extending to a depth of 7.5 m. The base plate of the stack was formed onsite to the height of 16.7 m and then prestressed using cables. A repair carried out in 1964 included adding a concrete lining of the initial rings of the cylinder up to a level of 22.1 m. Additional prestressing with the base plate and repair of the horizontal and vertical prestressing of the barrel were also carried out, leaving only 22 rings and 43 visible cables. The total mass of the stack was 2170 t, including: - Concrete: cylinder 800 t, base plate 1200 t; - Steel: internal structures 120 t, deflector 50 t. The main radiological risk was the presence of traces of tritium. The radioactive inventory for the entire stack was estimated in 2000

  6. A newly developed grab sampling system for collecting stratospheric air over Antarctica

    Directory of Open Access Journals (Sweden)

    Hideyuki Honda

    1996-07-01

    Full Text Available In order to measure the concentrations of various minor constituents and their isotopic ratios in the stratosphere over Antarctica, a simple grab sampling system was newly developed. The sampling system was designed to be launched by a small number of personnel using a rubber balloon under severe experimental conditions. Special attention was paid to minimize the contamination of sample air, as well as to allow easy handling of the system. The sampler consisted mainly of a 15l sample container with electromagnetic and manual valves, control electronics for executing the air sampling procedures and sending the position and status information of the sampler to the ground station, batteries and a transmitter. All these parts were assembled in an aluminum frame gondola with a shock absorbing system for landing. The sampler was equipped with a turn-over mechanism of the gondola to minimize contamination from the gondola, as well as with a GPS receiver and a rawinsonde for its tracking. Total weight of the sampler was about 11kg. To receive, display and store the position and status data of the sampling system at the ground station, a simple data acquisition system with a portable receiver and a microcomputer was also developed. A new gas handling system was prepared to simplify the injection of He gas into the balloon. For air sampling experiments, three sampling systems were launched at Syowa Station (69°00′S, 39°35′E, Antarctica and then recovered on sea ice near the station on January 22 and 25,1996.

  7. Management Aspects of Implementing the New Effluent Air Monitoring Standard

    International Nuclear Information System (INIS)

    Glissmeyer, John A.; Davis, William E.

    2000-01-01

    The revision to ANSI/HPS N13.1,'Sampling and Monitoring Releases of Airborne Radioactive substances From the Stacks and Ducts of Nuclear Facilities,' went into effect in January 1999 - replacing the 1969 version of the standard. There are several significant changes from the old version of the standard. The revised standard provides a new paradigm where representative air samples can be collected by extracting the sample from a single point in air streams where the contaminants are well mixed. The revised standard provides specific performance criteria and requirements for the various air sampling processes - program structure, sample extraction, transport, collection, effluent and sample flow measurement, and quality assurance. A graded approach to sampling is recommended with more stringent requirements for stacks with a greater potential to emit. These significant changes in the standard will impact the air monitoring programs at some sites and facilities. The impacts on the air monitor design, operation, maintenance, and quality control processes are discussed.

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

    International Nuclear Information System (INIS)

    Zhang Huaiqin; Su Jingling; Yao Wanyuan; Liu Jinhua

    1989-01-01

    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 CaSO 4 (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/m 3 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/m 3 , as the sampling time being 6 hours. It weights only about 0.35 kg

  9. Ten-year mortality in a sample of an adult population in relation to air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Krzyzanowski, M; Wojtyniak, B

    1982-12-01

    The 10-year mortality in a sample of adult inhabitants of Cracow, Poland, was analysed according to the levels of air pollution in the area of residence. Smoking habit and several social and occupational factors were considered in the analysis, which was carried out with the use of a multivariate method for categorical variables. Among men the main effect of air pollution was marginally significant, but there was a significant interaction between air pollution and smoking. Among women no such relation could be detected. Also, the association between female mortality and smoking was not significant. From other factors considered in the analysis, only exposure at work to dust, high humidity, and variable temperature was related to mortality in both men and women. In addition among women higher mortality was related to a lower level of education.

  10. Air exposure and sample storage time influence on hydrogen release from tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Moshkunov, K.A., E-mail: moshkunov@gmail.co [National Research Nuclear University ' MEPhI' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation); Schmid, K.; Mayer, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Kurnaev, V.A.; Gasparyan, Yu.M. [National Research Nuclear University ' MEPhI' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation)

    2010-09-30

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D{sub 2}O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of {approx}300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  11. Air exposure and sample storage time influence on hydrogen release from tungsten

    International Nuclear Information System (INIS)

    Moshkunov, K.A.; Schmid, K.; Mayer, M.; Kurnaev, V.A.; Gasparyan, Yu.M.

    2010-01-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2 O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ∼300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  12. Air exposure and sample storage time influence on hydrogen release from tungsten

    Science.gov (United States)

    Moshkunov, K. A.; Schmid, K.; Mayer, M.; Kurnaev, V. A.; Gasparyan, Yu. M.

    2010-09-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ˜300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

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

    Science.gov (United States)

    Lee, Kil Yong; Burnett, William C

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

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

    International Nuclear Information System (INIS)

    Kil Yong Lee; Burnett, W.C.

    2013-01-01

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

  15. Environmental and emergency response capabilities of Los Alamos Scientific Laboratory's radiological air sampling program

    International Nuclear Information System (INIS)

    Gunderson, T.C.

    1980-05-01

    Environmental and emergency response radiological air sampling capabilities of the Environmental Surveillance Group at Los Alamos Scientific Laboratory are described. The air sampling program provides a supplementary check on the adequacy of containment and effluent controls, determines compliance with applicable protection guides and standards, and assesses potential environmental impacts on site environs. It also allows evaluation of potential individual and total population doses from airborne radionuclides that may be inhaled or serve as a source of external radiation. The environmental program is sufficient in scope to detect fluctuations and long-term trends in atmospheric levels of radioactivity originating onsite. The emergency response capabilities are designed to respond to both onsite unplanned releases and atmospheric nuclear tests

  16. Towards stacked zone plates

    International Nuclear Information System (INIS)

    Werner, S; Rehbein, S; Guttman, P; Heim, S; Schneider, G

    2009-01-01

    Fresnel zone plates are the key optical elements for soft and hard x-ray microscopy. For short exposure times and minimum radiation load of the specimen the diffraction efficiency of the zone plate objectives has to be maximized. As the efficiency strongly depends on the height of the diffracting zone structures the achievable aspect ratio of the nanostructures determines these limits. To reach aspect ratios ≥ 20:1 for high efficient optics we propose to superimpose zone plates on top of each other. With this multiplication approach the final aspect ratio is only limited by the number of stacked zone plate layers. For the stack process several nanostructuring process steps have to be developed and/or improved. Our results show for the first time two layers of zone plates stacked on top of each other.

  17. Stochastic stacking without filters

    International Nuclear Information System (INIS)

    Johnson, R.P.; Marriner, J.

    1982-12-01

    The rate of accumulation of antiprotons is a critical factor in the design of p anti p colliders. A design of a system to accumulate higher anti p fluxes is presented here which is an alternative to the schemes used at the CERN AA and in the Fermilab Tevatron I design. Contrary to these stacking schemes, which use a system of notch filters to protect the dense core of antiprotons from the high power of the stack tail stochastic cooling, an eddy current shutter is used to protect the core in the region of the stack tail cooling kicker. Without filters one can have larger cooling bandwidths, better mixing for stochastic cooling, and easier operational criteria for the power amplifiers. In the case considered here a flux of 1.4 x 10 8 per sec is achieved with a 4 to 8 GHz bandwidth

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

    International Nuclear Information System (INIS)

    Olsen, P.A.

    1994-01-01

    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

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

    International Nuclear Information System (INIS)

    Butler, J.D.

    1995-01-01

    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

  20. Laser pulse stacking method

    Science.gov (United States)

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  1. Potential radionuclide emissions from stacks on the Hanford site, Part 2: Dose assessment methodology using portable low-resolution gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, J.M. [Westinghouse Hanford Company, Richland, WA (United States)

    1995-02-01

    In September 1992, the Westinghouse Hanford Company began developing an in situ measurement method to assess gamma radiation emanating from high-efficiency particulate air filters using portable low-resolution gamma spectroscopy. The purpose of the new method was to assess radioactive exhaust stack air emissions from empirical data rather than from theoretical models and to determine the potential unabated dose to an offsite theoretical maximally exposed individual. In accordance with Title 40, Code of Federal Regulations, Part 61, Subpart H, {open_quotes}National Emission Standards for Hazardous Air Pollutants{close_quotes}, stacks that have the potential to emit {ge} 1 {mu}Sv y{sup {minus}1} (0.1 mrem y{sup {minus}1}) to the maximally exposed individual are considered {open_quotes}major{close_quotes} and must meet the continuous monitoring requirements. After the method was tested and verified, the U.S. Environmental Protection Agency, Region 10, approved its use in June 1993. Of the 125 stacks operated by the Westinghouse Hanford Company, 22 were targeted for evaluation by this method, and 15 were assessed. (The method could not be applied at seven stacks because of excessive background radiation or because no gamma emitting particles appear in the emission stream.) The most significant result from this study was the redesignation of the T Plant main stack. The stack was assessed as being {open_quotes}minor{close_quotes}, and it now only requires periodic confirmatory measurements and meets federally imposed sampling requirements.

  2. 2017 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Stacy R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The 2017 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base has been prepared in accordance with the “Letter of Agreement Between Department of Energy, National Nuclear Security Administration, Sandia Field Office (DOE/NNSA/SFO) and 377th Air Base Wing (ABW), Kirtland Air Force Base (KAFB) for Terrestrial Sampling” (signed January 2017), Sandia National Laboratories, New Mexico (SNL/NM). The Letter of Agreement requires submittal of an annual terrestrial sampling plan.

  3. 2018 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base.

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Stacy R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-01-01

    The 2018 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base has been prepared in accordance with the “Letter of Agreement Between Department of Energy, National Nuclear Security Administration, Sandia Field Office (DOE/NNSA/SFO) and 377th Air Base Wing (ABW), Kirtland Air Force Base (KAFB) for Terrestrial Sampling” (signed January 2017), Sandia National Laboratories, New Mexico (SNL/NM). The Letter of Agreement requires submittal of an annual terrestrial sampling plan.

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

    NARCIS (Netherlands)

    Assonov, S.S.; Brenninkmeijer, C.A.M.; Koeppel, C.; Röckmann, T.

    2009-01-01

    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

  5. Comparison of Passive and Active Air Sampling (PAAS) Methods for PCBs – A Pilot Study in New York City Schools

    Science.gov (United States)

    PCBs were used extensively in school building materials (caulk and lighting fixture ballasts) during the approximate period of 1950-1978. Most of the schools built nationwide during this period have not had indoor air sampling conducted for PCBs. Passive air sampling holds promi...

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

    Directory of Open Access Journals (Sweden)

    Cesar A Corzo

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

  7. Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug.

    Science.gov (United States)

    Šesták, Jozef; Thormann, Wolfgang

    2017-08-25

    Part I on head-column field-amplified sample stacking comprised a detailed study of the electrokinetic injection of a weak base across a short water plug into a phosphate buffer at low pH. The water plug is converted into a low conductive acidic zone and cationic analytes become stacked at the interface between this and a newly formed phosphoric acid zone. The fundamentals of electrokinetic processes occurring thereafter were studied experimentally and with computer simulation and are presented as part II. The configuration analyzed represents a discontinuous buffer system. Computer simulation revealed that the phosphoric acid zone at the plug-buffer interface becomes converted into a migrating phosphate buffer plug which corresponds to the cationically migrating system zone of the phosphate buffer system. Its mobility is higher than that of the analytes such that they migrate behind the system zone in a phosphate buffer comparable to the applied background electrolyte. The temporal behaviour of the current and the conductivity across the water plug were monitored and found to reflect the changes in the low conductivity plug. Determination of the buffer flow in the capillary revealed increased pumping caused by the mismatch of electroosmosis within the low conductivity plug and the buffer. This effect becomes elevated with increasing water plug length. For plug lengths up to 1% of the total column length the flow quickly drops to the electroosmotic flow of the buffer and simulations with experimentally determined current and flow values predict negligible band dispersion and no loss of resolution for both low and large molecular mass components. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-18

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

  9. 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......-herd prevalence ⩾25%]. The results indicate that taking swabs of skin behind the ears (ten pools of five) was even more sensitive than taking nasal swabs (ten pools of five) at the herd level and detected significantly more positive samples. spa types t011, t034 and t4208 were observed. In 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....

  10. Independent determination of the accuracy of the OSTR stack gas monitor and its operational application

    International Nuclear Information System (INIS)

    Pickett, B.D.; Johnson, A.G.

    1982-01-01

    This study was undertaken to determine the accuracy of the stack gas monitor, using techniques which were independent of the monitoring system itself. Samples of argon-41 to be used as the standards in this study were carefully produced in the thermal column of the OSTR and counted on a Ge(Li) detector which was connected to a multichannel analyzer (MCA). As the argon-41 standard in the gas sample flask decayed, the concentration of the argon-41 was compared to the output of the Ge(Li)/MCA system. This established a calibration curve for the counting system, whereby a sample with an unknown concentration of argon-41 could be counted and the subsequent count rate from the sample converted to a concentration expressed in mCi per milliliter. Gas samples were extracted from various points in the reactor exhaust system and the concentrations of argon-41 were determined by counting on the Ge(Li)/MCA system. Each sample concentration was then compared to the argon-41 concentration indicated by the stack gas monitor. The initial results indicated that, although possibly intermittent, the argon-41 concentrations displayed by the stack gas monitor were often approximately 50% of those predicted by analysis of individual samples from the exhaust system. Several possible sources for the discrepancy were checked, including the method of SGM calibration, uneven mixing of exhaust air and argon-41 in the reactor building exhaust stream, and dilution of the gas concentration in the SGM system by air leakage into the system. After considerable effort, the latter cause was found to be the culprit, due to an aging gasket around the stack monitor's moving particulate-filter-paper housing

  11. Stacking by electroinjection with discontinuous buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Shihabi, Zak K

    2002-08-01

    The work presented here demonstrates that electroinjection can be performed using discontinuous buffers, which can result in better stacking than that obtained by hydrodynamic injection. The sample can be concentrated at the tip of the capillary leaving practically the whole capillary for sample separation. This results in several advantages, such as better sample concentration, higher plate number and shorter time of stacking. However, sample introduction by electromigration is suited for samples free or low in salt content. Samples, which are high in salt content, are better introduced by the hydrodynamic injection for stacking by the discontinuous buffers. Different simple methods to introduce the discontinuity in the buffer for electroinjection are discussed.

  12. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  13. 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

    2016-01-01

    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.

  14. High efficiency mixed species radioiodine air sampling, readout, and dose assessment system

    International Nuclear Information System (INIS)

    Distenfeld, C.; Klemish, J.

    1976-05-01

    Reactor accidents require monitoring to assess the impact to persons in the environment. This implies methods and apparatus to accurately and economically sample and evaluate possible released activity. The development of a prototype iodine air sampling system that can differentiate against noble gas activity and be evaluated by standard Civil Defense instrumentation is reported. The apparatus can efficiently (95 percent) collect organic or inorganic, particulate or gaseous radioiodine in concentrations below stable atmospheric iodine, and under severe ambient conditions. Response to noble fission gases was reduced to less than 4 x 10 -4 of an equal iodine airborne activity by heating the collector to approximately 100 0 C. Reliable sample size, +-5 percent, was achieved by using a simple air flow regulator. Thyroid dose commitment was mathematically and graphically related to the iodine isotope distribution expected in the environment and to the response of the Civil Defense CDV-700 instrument used to evaluate the sample. Sensitivity of the method allows dose assessment of 1 to 2 rads to a child's thyroid

  15. Radiological air monitoring and sample analysis research and development progress report

    International Nuclear Information System (INIS)

    1992-01-01

    Sponsored by a Department Of Energy (DOE) research and development grant, the State of Idaho INEL Oversight Program (OP) personnel designed an independent air monitoring system that provides detection of the presence of priority airborne contaminants potentially migrating beyond INEL boundaries. Initial locations for off-site ambient air monitoring stations were chosen in consultation with: DOE and NOAA reports; Mesodif modeling; review of the relevant literature; and communication with private contractors and experts in pertinent fields. Idaho State University (ISU) has initiated an Environmental Monitoring Program (EMP). The EMP provides an independent monitoring function as well as a training ground for students. Students learn research techniques dedicated to environmental studies and learn analytical skills and rules of compliance related to monitoring. ISU-EMP assisted OP in specific aspects of identifying optimum permanent monitoring station locations, and in selecting appropriate sample collection equipment for each station. The authorization to establish, prepare and install sampling devices on selected sites was obtained by OP personnel in conjunction with ISU-EMP personnel. All samples described in this program are collected by OP or ISU-EMP personnel and returned to the ISU for analysis. This report represents the summary of results of those samples collected and analyzed for radioactivity during the year of 1992

  16. Mass spectrometry of solid samples in open air using combined laser ionization and ambient metastable ionization

    International Nuclear Information System (INIS)

    He, X.N.; Xie, Z.Q.; Gao, Y.; Hu, W.; Guo, L.B.; Jiang, L.; Lu, Y.F.

    2012-01-01

    Mass spectrometry of solid samples in open air was carried out using combined laser ionization and metastable ionization time-of-flight mass spectrometry (LI-MI-TOFMS) in ambient environment for qualitative and semiquantitative (relative analyte information, not absolute information) analysis. Ambient metastable ionization using a direct analysis in realtime (DART) ion source was combined with laser ionization time-of-flight mass spectrometry (LI-TOFMS) to study the effects of combining metastable and laser ionization. A series of metallic samples from the National Institute of Standards and Technology (NIST 494, 495, 498, 499, and 500) and a pure carbon target were characterized using LI-TOFMS in open air. LI-MI-TOFMS was found to be superior to laser-induced breakdown spectroscopy (LIBS). Laser pulse energies between 10 and 200 mJ at the second harmonic (532 nm) of an Nd:YAG laser were applied in the experiment to obtain a high degree of ionization in plasmas. Higher laser pulse energy improves signal intensities of trace elements (such as Fe, Cr, Mn, Ni, Ca, Al, and Ag). Data were analyzed by numerically calculating relative sensitivity coefficients (RSCs) and limit of detections (LODs) from mass spectrometry (MS) and LIBS spectra. Different parameters, such as boiling point, ionization potential, RSC, LOD, and atomic weight, were shown to analyze the ionization and MS detection processes in open air.

  17. Glyphosate–rich air samples induce IL–33, TSLP and generate IL–13 dependent airway inflammation

    Science.gov (United States)

    Kumar, Sudhir; Khodoun, Marat; Kettleson, Eric M.; McKnight, Christopher; Reponen, Tiina; Grinshpun, Sergey A.; Adhikari, Atin

    2014-01-01

    Several low weight molecules have often been implicated in the induction of occupational asthma. Glyphosate, a small molecule herbicide, is widely used in the world. There is a controversy regarding a role of glyphosate in developing asthma and rhinitis among farmers, the mechanism of which is unexplored. The aim of this study was to explore the mechanisms of glyphosate induced pulmonary pathology by utilizing murine models and real environmental samples. C57BL/6, TLR4−/−, and IL-13−/− mice inhaled extracts of glyphosate-rich air samples collected on farms during spraying of herbicides or inhaled different doses of glyphosate and ovalbumin. The cellular response, humoral response, and lung function of exposed mice were evaluated. Exposure to glyphosate-rich air samples as well as glyphosate alone to the lungs increased: eosinophil and neutrophil counts, mast cell degranulation, and production of IL-33, TSLP, IL-13, and IL-5. In contrast, in vivo systemic IL-4 production was not increased. Co-administration of ovalbumin with glyphosate did not substantially change the inflammatory immune response. However, IL-13-deficiency resulted in diminished inflammatory response but did not have a significant effect on airway resistance upon methacholine challenge after 7 or 21 days of glyphosate exposure. Glyphosate-rich farm air samples as well as glyphosate alone were found to induce pulmonary IL-13-dependent inflammation and promote Th2 type cytokines, but not IL-4 for glyphosate alone. This study, for the first time, provides evidence for the mechanism of glyphosate-induced occupational lung disease. PMID:25172162

  18. Simultaneous multicopter-based air sampling and sensing of meteorological variables

    Science.gov (United States)

    Brosy, Caroline; Krampf, Karina; Zeeman, Matthias; Wolf, Benjamin; Junkermann, Wolfgang; Schäfer, Klaus; Emeis, Stefan; Kunstmann, Harald

    2017-08-01

    The state and composition of the lowest part of the planetary boundary layer (PBL), i.e., the atmospheric surface layer (SL), reflects the interactions of external forcing, land surface, vegetation, human influence and the atmosphere. Vertical profiles of atmospheric variables in the SL at high spatial (meters) and temporal (1 Hz and better) resolution increase our understanding of these interactions but are still challenging to measure appropriately. Traditional ground-based observations include towers that often cover only a few measurement heights at a fixed location. At the same time, most remote sensing techniques and aircraft measurements have limitations to achieve sufficient detail close to the ground (up to 50 m). Vertical and horizontal transects of the PBL can be complemented by unmanned aerial vehicles (UAV). Our aim in this case study is to assess the use of a multicopter-type UAV for the spatial sampling of air and simultaneously the sensing of meteorological variables for the study of the surface exchange processes. To this end, a UAV was equipped with onboard air temperature and humidity sensors, while wind conditions were determined from the UAV's flight control sensors. Further, the UAV was used to systematically change the location of a sample inlet connected to a sample tube, allowing the observation of methane abundance using a ground-based analyzer. Vertical methane gradients of about 0.3 ppm were found during stable atmospheric conditions. Our results showed that both methane and meteorological conditions were in agreement with other observations at the site during the ScaleX-2015 campaign. The multicopter-type UAV was capable of simultaneous in situ sensing of meteorological state variables and sampling of air up to 50 m above the surface, which extended the vertical profile height of existing tower-based infrastructure by a factor of 5.

  19. Radiation damage of paper samples in in-air PIXE analysis

    International Nuclear Information System (INIS)

    Matsuyama, S.; Endo, H.; Ishii, K.; Yamazaki, H.; Tokai, Y.; Sugimoto, A.; Yamamoto, K.; Satoh, T.; Orihara, H.

    1999-01-01

    Degradation of paper caused by beam irradiation was investigated from a viewpoint of discoloration in PIXE analysis and its application to the paper samples of archaeology. Two types of paper (Japanese paper and fine quality paper) were tested in in-air PIXE analysis with 3 MeV protons. The degree of discoloration was quantitatively measured by the use of a colorimeter. The degree of discoloration was different for each tested paper and corresponded to the radiation dose of ions. It is resulted that even the in-air PIXE analysis should be carefully applied to archaeological treasures. Because discoloration of all tested paper decreased gradually at first but then increased after a few weeks. However, this phenomenon can be used to develop a technique of funny coloration. (author)

  20. Radiation damage of paper samples in in-air PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, S.; Endo, H.; Ishii, K.; Yamazaki, H.; Tokai, Y.; Sugimoto, A.; Yamamoto, K.; Satoh, T. [Department of Quantum Science and Energy Engineering, Tohoku University, Sendai, Miyagi (Japan); Orihara, H. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center

    1999-07-01

    Degradation of paper caused by beam irradiation was investigated from a viewpoint of discoloration in PIXE analysis and its application to the paper samples of archaeology. Two types of paper (Japanese paper and fine quality paper) were tested in in-air PIXE analysis with 3 MeV protons. The degree of discoloration was quantitatively measured by the use of a colorimeter. The degree of discoloration was different for each tested paper and corresponded to the radiation dose of ions. It is resulted that even the in-air PIXE analysis should be carefully applied to archaeological treasures. Because discoloration of all tested paper decreased gradually at first but then increased after a few weeks. However, this phenomenon can be used to develop a technique of funny coloration. (author)

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

    International Nuclear Information System (INIS)

    Cong Khanh Huynh; Trinh Vu Duc

    2009-01-01

    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.

  2. The role of multiple regression and exploratory data analysis in the development of leukemia incidence risk models for comparison of radionuclide air stack emissions from nuclear and coal power industries

    International Nuclear Information System (INIS)

    Prybutok, V.R.

    1995-01-01

    Risk associated with power generation must be identified to make intelligent choices between alternate power technologies. Radionuclide air stack emissions for a single coal plant and a single nuclear plant are used to compute the single plant leukemia incidence risk and total industry leukemia incidence risk. Leukemia incidence is the response variable as a function of radionuclide bone dose for the six proposed dose response curves considered. During normal operation a coal plant has higher radionuclide emissions than a nuclear plant and the coal industry has a higher leukaemia incidence risk than the nuclear industry, unless a nuclear accident occurs. Variation of nuclear accident size allows quantification of the impact of accidents on the total industry leukemia incidence risk comparison. The leukemia incidence risk is quantified as the number of accidents of a given size for the nuclear industry leukemia incidence risk to equal the coal industry leukemia incidence risk. The general linear model is used to develop equations that relate the accident frequency required for equal industry risks to the magnitude of the nuclear emission. Exploratory data analysis revealed that the relationship between the natural log of accident number versus the natural log of accident size is linear. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiao Jin [Department of Environment and Climate Change, Environmental Forensic and Analytical Science Section, New South Wales (Australia); Department of Applied Chemistry, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing (China); Wan, Pingyu [Department of Applied Chemistry, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing (China); Foley, Roy [Department of Environment and Climate Change, Environmental Forensic and Analytical Science Section, New South Wales (Australia)

    2012-11-15

    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)

  4. 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)

    Yang, Xiao Jin; Wan, Pingyu; Foley, Roy

    2012-01-01

    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)

  5. Passive air sampling of polychlorinated biphenyls, organochlorine compounds, and polybrominated diphenyl ethers across Asia.

    Science.gov (United States)

    Jaward, Foday M; Zhang, Gan; Nam, Jae Jak; Sweetman, Andrew J; Obbard, Jeffrey P; Kobara, Yuso; Jones, Kevin C

    2005-11-15

    Asia is of global importance economically, yet data on ambient persistent organic pollutant levels are still sparse for the region, despite international efforts under the Stockholm Convention to identify and reduce emissions. A large-scale passive air sampling survey was therefore conducted in Asia, specifically in China, Japan, South Korea, and Singapore. Polyurethane foam disks were deployed simultaneously at 77 sites, between Sept 21 and Nov 16, 2004, and analyzed for polychlorinated biphenyls (PCBs), organochlorine compounds (hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), chlordane), and polybrominated diphenyl ethers (PBDEs). The meteorological conditions prevailing in the region at this time facilitated the assessment of local/regional differences in atmospheric emissions, because large-scale advection effects due to monsoons or dust storms did not occur. Air concentrations estimated assuming an average sampler uptake rate of 3.5 m3/day ranged as follows (pg m(-3)): PCBs, 5-340; HCB, 10-460; DDTs, 0.4-1800; chlordanes, 1-660; PBDEs, < 0.13-340. South Korea and Singapore generally had regionally low concentrations. Elevated concentrations of PCBs, DDTs, and HCB occurred at sites in China, higher than reported in a similar recent sampling campaign in Europe. Chlordane was highest in samples from Japan (which also had elevated levels of PCBs and DDTs) and was also elevated in some Chinese locations. PBDE levels were generally low in the region.

  6. HPLC determination of chlorine in air and water samples following precolumn derivatization to 4-bromoacetanilide

    Energy Technology Data Exchange (ETDEWEB)

    Jain, A. (Rani Durgavati Univ., Jabalpur (India). Dept. of Chemistry); Verma, K.K. (Rani Durgavati Univ., Jabalpur (India). Dept. of Chemistry)

    1993-11-01

    Chlorine has been determined in air and water samples by a rapid and sensitive method entailing precolumn derivatization to 4-bromoacetanilide. A mixed potassium bromide - acetanilide reagent was used as a trapping agent for chlorine in air, and for its derivatization. The 4-bromoacetanilide formed was determined by reversed-phase HPLC on an ODS column, using methanol-water, 65:35 (v/v) as mobile phase; detection was at 240 nm. A rectilinear calibration graph was obtained for the range 0.1-30 [mu]g mL[sup -1] chlorine; the limit of detection found to be 0.01 [mu]g mL[sup -1]. The precolumn derivative has been found to have a shelf-life of at least 21 days; this enables the use of the method for samples transported from the field to the analytical laboratory, or the testing of a variety of conditions for chlorine scrubbing studies without the need for immediate analysis of samples. Humic substances do not cause any interference with the proposed method and the presence of nitrite does not lead to artificially high results and consequent misleading conclusions of the presence of high levels of chlorine. (orig.)

  7. HPLC determination of chlorine in air and water samples following precolumn derivatization to 4-bromoacetanilide

    International Nuclear Information System (INIS)

    Jain, A.; Verma, K.K.

    1993-01-01

    Chlorine has been determined in air and water samples by a rapid and sensitive method entailing precolumn derivatization to 4-bromoacetanilide. A mixed potassium bromide - acetanilide reagent was used as a trapping agent for chlorine in air, and for its derivatization. The 4-bromoacetanilide formed was determined by reversed-phase HPLC on an ODS column, using methanol-water, 65:35 (v/v) as mobile phase; detection was at 240 nm. A rectilinear calibration graph was obtained for the range 0.1-30 μg mL -1 chlorine; the limit of detection found to be 0.01 μg mL -1 . The precolumn derivative has been found to have a shelf-life of at least 21 days; this enables the use of the method for samples transported from the field to the analytical laboratory, or the testing of a variety of conditions for chlorine scrubbing studies without the need for immediate analysis of samples. Humic substances do not cause any interference with the proposed method and the presence of nitrite does not lead to artificially high results and consequent misleading conclusions of the presence of high levels of chlorine. (orig.)

  8. Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

    Science.gov (United States)

    Grover, R; Kerr, L A; Wallace, K; Yoshida, K; Maybank, J

    1976-01-01

    Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts.

  9. Evaluation of active sampling strategies for the determination of 1,3-butadiene in air

    Science.gov (United States)

    Vallecillos, Laura; Maceira, Alba; Marcé, Rosa Maria; Borrull, Francesc

    2018-03-01

    Two analytical methods for determining levels of 1,3-butadiene in urban and industrial atmospheres were evaluated in this study. Both methods are extensively used for determining the concentration of volatile organic compounds in the atmosphere and involve collecting samples by active adsorptive enrichment on solid sorbents. The first method uses activated charcoal as the sorbent and involves liquid desorption with carbon disulfide. The second involves the use of a multi-sorbent bed with two graphitised carbons and a carbon molecular sieve as the sorbent, with thermal desorption. Special attention was paid to the optimization of the sampling procedure through the study of sample volume, the stability of 1,3-butadiene once inside the sampling tube and the humidity effect. In the end, the thermal desorption method showed better repeatability and limits of detection and quantification for 1,3-butadiene than the liquid desorption method, which makes the thermal desorption method more suitable for analysing air samples from both industrial and urban atmospheres. However, sampling must be performed with a pre-tube filled with a drying agent to prevent the loss of the adsorption capacity of the solid adsorbent caused by water vapour. The thermal desorption method has successfully been applied to determine of 1,3-butadiene inside a 1,3-butadiene production plant and at three locations in the vicinity of the same plant.

  10. The determination of volatile chlorinated hydrocarbons in air. Sampling rate and efficiency of diffuse samplers

    Energy Technology Data Exchange (ETDEWEB)

    Giese, U.; Stenner, H.; Kettrup, A.

    1989-05-01

    When applicating diffusive sampling-systems to workplace air-monitoring it is necessary to know the behaviour of the diffusive-rate and the efficiency in dependence of concentration, exposition time and the type of pollutant. Especially concerning mixtures of pollutants there are negative influences by competition and mutual displacement possible. Diffusive-rate and discovery for CH/sub 2/Cl/sub 2/ and CHCl/sub 3/ were investigated using two different types of diffuse samplers. For this it was necessary to develop suitable defices for standard gas generation and for the exposition of diffusive-samplers to a standard gas mixture. (orig.).

  11. OpenStack cloud security

    CERN Document Server

    Locati, Fabio Alessandro

    2015-01-01

    If you are an OpenStack administrator or developer, or wish to build solutions to protect your OpenStack environment, then this book is for you. Experience of Linux administration and familiarity with different OpenStack components is assumed.

  12. Stacked magnet superconducting bearing

    International Nuclear Information System (INIS)

    Rigney, T.K. II; Saville, M.P.

    1993-01-01

    A superconducting bearing is described, comprising: a plurality of permanent magnets magnetized end-to-end and stacked side-by-side in alternating polarity, such that flux lines flow between ends of adjacent magnets; isolating means, disposed between said adjacent magnets, for reducing flux leakage between opposing sides of said adjacent magnets; and a member made of superconducting material having at least one surface in communication with said flux lines

  13. Iridium Interfacial Stack (IRIS)

    Science.gov (United States)

    Spry, David James (Inventor)

    2015-01-01

    An iridium interfacial stack ("IrIS") and a method for producing the same are provided. The IrIS may include ordered layers of TaSi.sub.2, platinum, iridium, and platinum, and may be placed on top of a titanium layer and a silicon carbide layer. The IrIS may prevent, reduce, or mitigate against diffusion of elements such as oxygen, platinum, and gold through at least some of its layers.

  14. 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

    2017-08-01

    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.

  15. BIBLE A whole-air sampling as a window on Asian biogeochemistry

    Science.gov (United States)

    Elliott, Scott; Blake, Donald R.; Blake, Nicola J.; Dubey, Manvendra K.; Rowland, F. Sherwood; Sive, Barkley C.; Smith, Felisa A.

    2003-02-01

    Asian trace gas and aerosol emissions into carbon, nitrogen, and other elemental cycles will figure prominently in near term Earth system evolution. Atmospheric hydrocarbon measurements resolve numerous chemical species and can be used to investigate sourcing for key geocarriers. A recent aircraft study of biomass burning and lightning (BIBLE A) explored the East Asian atmosphere and was unique in centering on the Indonesian archipelago. Samples of volatile organics taken over/between the islands of Japan, Saipan, Java, and Borneo are here examined as a guide to whole-air-based studies of future Asian biogeochemistry. The midlatitude onshore/offshore pulse and tropical convection strongly influence concentration distributions. As species of increasing molecular weight are considered, rural, combustion, and industrial source regimes emerge. Methane-rich inputs such as waste treatment and rice cultivation are evidenced in the geostrophic outflow. The Indonesian atmosphere is rich in biomass burning markers and also those of vehicular activity. Complexity of air chemistry in the archipelago is a direct reflection of diverse topography, land use, and local economies in a rapidly developing nation. Conspicuous in its absence is the fingerprint for liquefied petroleum gas leakage, but it can be expected to appear as demand for clean fossil fuels rises along with per capita incomes. Combustion tracers indicate high nitrogen mobilization rates, linking regional terrestrial geocycles with open marine ecosystems. Sea to air fluxes are superimposed on continental and marine backgrounds for the methyl halides. However, ocean hot spots are not coordinated and suggest an intricate subsurface kinetics. Levels of long-lived anthropogenic halocarbons attest to the success of international environmental treaties while reactive chlorine containing species track industrial air masses. The dozens of hydrocarbons resolvable by gas chromatographic methods will enable monitoring of

  16. [An AIDS-related cognitive map in a sample of drug abusers in Buenos Aires City].

    Science.gov (United States)

    Kornblit, A L; Bilyk, A

    1990-01-01

    This paper is an approach to AIDS as a topic among a drug abusers sample of the city of Buenos Aires. Research was carried out on the basis of a qualitative methodology. In an attempt at surveying opinions and attitudes of such a sample as regards AIDS (i.e. subjects' cognitive map), 21 drug abusers from three different rehabilitation programs operating in the B.A. area were interviewed. On the basis of the research performed, the authors elaborate communication strategies among drug abusers that would be helpful for authorities engaged in AIDS prevention to adopt. To boost a strategy likely to break up the AIDS-drug association existing in the mind of many an abuser would be highly advisable so that a separation be settled between both representations, thus giving drug abusers a higher motivation for self-care practice.

  17. Ram-air sample collection device for a chemical warfare agent sensor

    Science.gov (United States)

    Megerle, Clifford A.; Adkins, Douglas R.; Frye-Mason, Gregory C.

    2002-01-01

    In a surface acoustic wave sensor mounted within a body, the sensor having a surface acoustic wave array detector and a micro-fabricated sample preconcentrator exposed on a surface of the body, an apparatus for collecting air for the sensor, comprising a housing operatively arranged to mount atop the body, the housing including a multi-stage channel having an inlet and an outlet, the channel having a first stage having a first height and width proximate the inlet, a second stage having a second lower height and width proximate the micro-fabricated sample preconcentrator, a third stage having a still lower third height and width proximate the surface acoustic wave array detector, and a fourth stage having a fourth height and width proximate the outlet, where the fourth height and width are substantially the same as the first height and width.

  18. Air-segmented continuous-flow analysis for molybdenum in various geochemical samples

    International Nuclear Information System (INIS)

    Harita, Y.; Sugiyama, M.; Hori, T.

    2003-01-01

    An air-segmented continuous-flow method has been developed for the determination of molybdenum at ultra trace levels using the catalytic effect of molybdate during the oxidation of L-ascorbic acid by hydrogen peroxide. Incorporation of an on-line ion exchange column improved the tolerance limit for various ions. The detection limits with and without the column were 64 pmol L m1 and 17 pmol L m1 , and the reproducibilities at 10 nmol L m1 were 2.1 % and 0.2 %, respectively. The proposed method was applied to the determination of molybdenum in seawater and lake water as well as in rock and sediment samples. This method has the highest sensitivity among the available literature to our knowledge, and is also convenient for routine analysis of molybdenum in various natural samples. (author)

  19. Cast Stone Oxidation Front Evaluation: Preliminary Results For Samples Exposed To Moist Air

    International Nuclear Information System (INIS)

    Langton, C. A.; Almond, P. M.

    2013-01-01

    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 4 - 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 4 - , 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 Cr oxidation front

  20. EPA's Response to the February 2014 Release of Radioactive Material from the Waste Isolation Pilot Plant (WIPP): EPA's WIPP Air Sampling Data from April 2014

    Science.gov (United States)

    In April 2014, U.S. Environmental Protection Agency (EPA) environmental monitoring and assessment team members reviewed DOE's air sampling plan, visited DOE's air samplers and placed air samplers onsite near existing DOE samplers to corroborate results.

  1. Evaluation of physical sampling efficiency for cyclone-based personal bioaerosol samplers in moving air environments.

    Science.gov (United States)

    Su, Wei-Chung; Tolchinsky, Alexander D; Chen, Bean T; Sigaev, Vladimir I; Cheng, Yung Sung

    2012-09-01

    The need to determine occupational exposure to bioaerosols has notably increased in the past decade, especially for microbiology-related workplaces and laboratories. Recently, two new cyclone-based personal bioaerosol samplers were developed by the National Institute for Occupational Safety and Health (NIOSH) in the USA and the Research Center for Toxicology and Hygienic Regulation of Biopreparations (RCT & HRB) in Russia to monitor bioaerosol exposure in the workplace. Here, a series of wind tunnel experiments were carried out to evaluate the physical sampling performance of these two samplers in moving air conditions, which could provide information for personal biological monitoring in a moving air environment. The experiments were conducted in a small wind tunnel facility using three wind speeds (0.5, 1.0 and 2.0 m s(-1)) and three sampling orientations (0°, 90°, and 180°) with respect to the wind direction. Monodispersed particles ranging from 0.5 to 10 μm were employed as the test aerosols. The evaluation of the physical sampling performance was focused on the aspiration efficiency and capture efficiency of the two samplers. The test results showed that the orientation-averaged aspiration efficiencies of the two samplers closely agreed with the American Conference of Governmental Industrial Hygienists (ACGIH) inhalable convention within the particle sizes used in the evaluation tests, and the effect of the wind speed on the aspiration efficiency was found negligible. The capture efficiencies of these two samplers ranged from 70% to 80%. These data offer important information on the insight into the physical sampling characteristics of the two test samplers.

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

    International Nuclear Information System (INIS)

    Sudheendran, V.; Baburajan, A.; Gaikwad, R.H.; Ravi, P.M.; Tripathi, R.M.

    2015-01-01

    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 241 Am and 90 Sr/ 90 Y 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)

  3. Exhaust stack monitoring issues at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Rodgers, J.C.

    1987-11-01

    This report outlines the problems of obtaining valid, representative samples of, and continuously monitoring for, radioactive particulates in the discharge air from the underground disposal facilities at WIPP. There appears to be serious problems with the presently installed systems. Chapter 1 of the report provides an overview of current perspective on the major issues. Principal conclusions of the overview are that the present sampling locations are not optimum for the intended purpose; that the chosen probe design is not capable of meeting requirements for delivery of a representative sample to the detectors; and that the proposed test plan for the flow conditioning and monitoring system is seriously flawed. Chapter 2 is a summary of the major findings and recommendations of a peer review. The review suggested that the proposed flow conditioning concepts were likely to be an unworkable substitute for having adequate duct length between major disturbances in flow and the sampling or monitoring locations; that the use of probes of simpler design with large diameter inlet nozzles feeding short transmission lines would provide superior performance; and that conditions for monitoring discharge air would be far better ahead of the collar in the exhaust shaft than any location downstream. Chapter 3 contains the detailed technical basis for a conceptual design, and a proposed sample extraction system for the stack discharge location. 36 refs., 23 figs., 4 tabs

  4. Levitation characteristics of HTS tape stacks

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovskiy, S. V.; Ermolaev, Y. S.; Rudnev, I. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-03-15

    Due to the considerable development of the technology of second generation high-temperature superconductors and a significant improvement in their mechanical and transport properties in the last few years it is possible to use HTS tapes in the magnetic levitation systems. The advantages of tapes on a metal substrate as compared with bulk YBCO material primarily in the strength, and the possibility of optimizing the convenience of manufacturing elements of levitation systems. In the present report presents the results of the magnetic levitation force measurements between the stack of HTS tapes containing of tapes and NdFeB permanent magnet in the FC and ZFC regimes. It was found a non- linear dependence of the levitation force from the height of the array of stack in both modes: linear growth at small thickness gives way to flattening and constant at large number of tapes in the stack. Established that the levitation force of stacks comparable to that of bulk samples. The numerical calculations using finite element method showed that without the screening of the applied field the levitation force of the bulk superconductor and the layered superconductor stack with a critical current of tapes increased by the filling factor is exactly the same, and taking into account the screening force slightly different.

  5. Calculation of tritium release from reactor's stack

    International Nuclear Information System (INIS)

    Akhadi, M.

    1996-01-01

    Method for calculation of tritium release from nuclear to environment has been discussed. Part of gas effluent contain tritium in form of HTO vapor released from reactor's stack was sampled using silica-gel. The silica-gel was put in the water to withdraw HTO vapor absorbed by silica-gel. Tritium concentration in the water was measured by liquid scintillation counter of Aloka LSC-703. Tritium concentration in the gas effluent and total release of tritium from reactor's stack during certain interval time were calculated using simple mathematic formula. This method has examined for calculation of tritium release from JRR-3M's stack of JAERI, Japan. From the calculation it was obtained the value of tritium release as much as 4.63 x 10 11 Bq during one month. (author)

  6. 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.

  7. MEAN STACK WEB DEVELOPMENT

    OpenAIRE

    Le Thanh, Nghi

    2017-01-01

    The aim of the thesis is to provide a universal website using JavaScript as the main programming language. It also shows the basic parts anyone need to create a web application. The thesis creates a simple CMS using MEAN stack. MEAN is a collection of JavaScript based technologies used to develop web application. It is an acronym for MongoDB, Express, AngularJS and Node.js. It also allows non-technical users to easily update and manage a website’s content. But the application also lets o...

  8. Die-stacking architecture

    CERN Document Server

    Xie, Yuan

    2015-01-01

    The emerging three-dimensional (3D) chip architectures, with their intrinsic capability of reducing the wire length, promise attractive solutions to reduce the delay of interconnects in future microprocessors. 3D memory stacking enables much higher memory bandwidth for future chip-multiprocessor design, mitigating the ""memory wall"" problem. In addition, heterogenous integration enabled by 3D technology can also result in innovative designs for future microprocessors. This book first provides a brief introduction to this emerging technology, and then presents a variety of approaches to design

  9. Potential radionuclide emissions from stacks on the Hanford Site, Part 2: Dose assessment methodology using portable low-resolution gamma spectroscoy

    International Nuclear Information System (INIS)

    Barnett, J.M.

    1994-07-01

    In September 1992, the Westinghouse Hanford Company began developing an in situ measurement method to assess gamma radiation emanating from high-efficiency particulate air filters using portable low-resolution gamma spectroscopy. The purpose of the new method was to assess radioactive exhaust stack air emissions from empirical data rather than from theoretical models and to determine the potential unabated dose to an offsite theoretical maximally exposed individual. In accordance with Title 40, Code of Federal Regulations, Part 61, Subpart H, ''National Emission Standards for Hazardous Air Pollutants'', stacks that have the potential to emit ≥ 0.1 mrem per year to the maximally exposed individual are considered ''major'' and must meet the continuous monitoring requirements. After the method was tested and verified, the US Environmental Protection Agency, Region 10, approved its use in June 1993. Of the 125 stacks operated by the Westinghouse Hanford Company, 22 were targeted for evaluation by this method; and 15 were assessed. The most significant,result from this study was the redesignation. of the T Plant main stack. The stack was assessed as being ''minor'', and it now only requires periodic confirmatory measurements and meets federally imposed sampling requirements

  10. Sources of present Chernobyl-derived caesium concentrations in surface air and deposition samples

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Rosner, G.; Winkler, R. (Gesellschaft fuer Strahlen-und Umweltforschung Munich, Neuherberg (Germany). Forschungszentrum fuer Umwelt und Gesundheit Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany). Inst. fuer Strahlenschutz)

    1992-06-01

    The sources of Chernobyl-derived caesium concentrations in air and deposition samples collected from mid-1986 to end-1990 at Munich- Neuherberg, Germany, were investigated. Local resuspension has been found to be the main source. By comparison with deposition data from other locations it is estimated that within a range from 20 Bq m[sup -2] to 60 kBq m[sup -2] of initially deposited [sup 137]Cs activity [approx]2% is re-deposited by the process of local resuspension in Austria, Germany, Japan and United Kingdom, while significantly higher total resuspension is to be expected for Denmark and Finland. Stratospheric contribution to present concentrations is shown to be negligible. This is confirmed by cross correlation analysis between the time series of [sup 137]Cs in air and precipitation before and after the Chernobyl accident and the respective time series of cosmogenic [sup 7]Be, which is an indicator of stratospheric input. Seasonal variations of caesium concentrations with maxima in winter were observed. (author). 32 refs.; 5 figs.; 1 tab.

  11. Sources of present Chernobyl-derived caesium concentrations in surface air and deposition samples

    International Nuclear Information System (INIS)

    Hoetzl, H.; Rosner, G.; Winkler, R.; Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg

    1992-01-01

    The sources of Chernobyl-derived caesium concentrations in air and deposition samples collected from mid-1986 to end-1990 at Munich- Neuherberg, Germany, were investigated. Local resuspension has been found to be the main source. By comparison with deposition data from other locations it is estimated that within a range from 20 Bq m -2 to 60 kBq m -2 of initially deposited 137 Cs activity ∼2% is re-deposited by the process of local resuspension in Austria, Germany, Japan and United Kingdom, while significantly higher total resuspension is to be expected for Denmark and Finland. Stratospheric contribution to present concentrations is shown to be negligible. This is confirmed by cross correlation analysis between the time series of 137 Cs in air and precipitation before and after the Chernobyl accident and the respective time series of cosmogenic 7 Be, which is an indicator of stratospheric input. Seasonal variations of caesium concentrations with maxima in winter were observed. (author). 32 refs.; 5 figs.; 1 tab

  12. Enhancement of stack ventilation in hot and humid climate using a combination of roof solar collector and vertical stack

    Energy Technology Data Exchange (ETDEWEB)

    Yusoff, Wardah Fatimah Mohammad; Salleh, Elias [Department of Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Adam, Nor Mariah [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapian, Abdul Razak [Department of Architecture, Kulliyyah of Architecture and Environmental Design, International Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur (Malaysia); Yusof Sulaiman, Mohamad [Solar Energy Research Institute, 3rd Floor, Tun Sri Lanang Library Building, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2010-10-15

    In the hot and humid climate, stack ventilation is inefficient due to small temperature difference between the inside and outside of naturally ventilated buildings. Hence, solar induced ventilation is a feasible alternative in enhancing the stack ventilation. This paper aims to investigate the effectiveness of a proposed solar induced ventilation strategy, which combines a roof solar collector and a vertical stack, in enhancing the stack ventilation performance in the hot and humid climate. The methodology selected for the investigation is physical experimental modelling which was carried out in the actual environment. The results are presented and discussed in terms of two performance variables: air temperature and air velocity. The findings indicate that the proposed strategy is able to enhance the stack ventilation, both in semi-clear sky and overcast sky conditions. The highest air temperature difference between the air inside the stack and the ambient air (T{sub i}-T{sub o}) is achieved in the semi-clear sky condition, which is about 9.9 C (45.8 C-35.9 C). Meanwhile, in the overcast sky condition, the highest air temperature difference (T{sub i}-T{sub o}) is 6.2 C (39.3 C-33.1 C). The experimental results also indicate good agreement with the theoretical results for the glass temperature, the air temperature in the roof solar collector's channel and the absorber temperature. The findings also show that wind has significant effect to the induced air velocity by the proposed strategy. (author)

  13. Modelling and Evaluating Air Quality with Fuzzy Logic Algorithm-Ankara-Cebeci Sample

    OpenAIRE

    Atacak, Ismail; Arici, Nursal; Guner, Dilem

    2017-01-01

    Air is one of the most important life sources for all living things. Gases that are present and absent in the composition of clean air also considered as pollutants in the atmosphere. If the pollutants rise above a certain concentration level, air pollution occurs. Air pollution damages all living things, especially human health. Accurate estimation of pollutant concentrations through air pollution modeling has an important effect in reducing the adverse effects of pollution and taking necess...

  14. Air-deployable oil spill sampling devices review phase 2 testing. Volume 1

    International Nuclear Information System (INIS)

    Hawke, L.; Dumouchel, A.; Fingas, M.; Brown, C.E.

    2007-01-01

    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

  15. Impact of preferential sampling on exposure prediction and health effect inference in the context of air pollution epidemiology.

    Science.gov (United States)

    Lee, A; Szpiro, A; Kim, S Y; Sheppard, L

    2015-06-01

    Preferential sampling has been defined in the context of geostatistical modeling as the dependence between the sampling locations and the process that describes the spatial structure of the data. It can occur when networks are designed to find high values. For example, in networks based on the U.S. Clean Air Act monitors are sited to determine whether air quality standards are exceeded. We study the impact of the design of monitor networks in the context of air pollution epidemiology studies. The effect of preferential sampling has been illustrated in the literature by highlighting its impact on spatial predictions. In this paper, we use these predictions as input in a second stage analysis, and we assess how they affect health effect inference. Our work is motivated by data from two United States regulatory networks and health data from the Multi-Ethnic Study of Atherosclerosis and Air Pollution. The two networks were designed to monitor air pollution in urban and rural areas respectively, and we found that the health analysis results based on the two networks can lead to different scientific conclusions. We use preferential sampling to gain insight into these differences. We designed a simulation study, and found that the validity and reliability of the health effect estimate can be greatly affected by how we sample the monitor locations. To better understand its effect on second stage inference, we identify two components of preferential sampling that shed light on how preferential sampling alters the properties of the health effect estimate.

  16. Impact of preferential sampling on exposure prediction and health effect inference in the context of air pollution epidemiology

    Science.gov (United States)

    Lee, A.; Szpiro, A.; Kim, S.Y.; Sheppard, L.

    2018-01-01

    Summary Preferential sampling has been defined in the context of geostatistical modeling as the dependence between the sampling locations and the process that describes the spatial structure of the data. It can occur when networks are designed to find high values. For example, in networks based on the U.S. Clean Air Act monitors are sited to determine whether air quality standards are exceeded. We study the impact of the design of monitor networks in the context of air pollution epidemiology studies. The effect of preferential sampling has been illustrated in the literature by highlighting its impact on spatial predictions. In this paper, we use these predictions as input in a second stage analysis, and we assess how they affect health effect inference. Our work is motivated by data from two United States regulatory networks and health data from the Multi-Ethnic Study of Atherosclerosis and Air Pollution. The two networks were designed to monitor air pollution in urban and rural areas respectively, and we found that the health analysis results based on the two networks can lead to different scientific conclusions. We use preferential sampling to gain insight into these differences. We designed a simulation study, and found that the validity and reliability of the health effect estimate can be greatly affected by how we sample the monitor locations. To better understand its effect on second stage inference, we identify two components of preferential sampling that shed light on how preferential sampling alters the properties of the health effect estimate. PMID:29576734

  17. Asymmetric Flexible Supercapacitor Stack

    Directory of Open Access Journals (Sweden)

    Leela Mohana Reddy A

    2008-01-01

    Full Text Available AbstractElectrical double layer supercapacitor is very significant in the field of electrical energy storage which can be the solution for the current revolution in the electronic devices like mobile phones, camera flashes which needs flexible and miniaturized energy storage device with all non-aqueous components. The multiwalled carbon nanotubes (MWNTs have been synthesized by catalytic chemical vapor deposition technique over hydrogen decrepitated Mischmetal (Mm based AB3alloy hydride. The polymer dispersed MWNTs have been obtained by insitu polymerization and the metal oxide/MWNTs were synthesized by sol-gel method. Morphological characterizations of polymer dispersed MWNTs have been carried out using scanning electron microscopy (SEM, transmission electron microscopy (TEM and HRTEM. An assymetric double supercapacitor stack has been fabricated using polymer/MWNTs and metal oxide/MWNTs coated over flexible carbon fabric as electrodes and nafion®membrane as a solid electrolyte. Electrochemical performance of the supercapacitor stack has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

  18. 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.

  19. Chemosorption sampling and analysis of formaldehyde in air. Influence on recovery during the simultaneous sampling of formaldehyde, phenol, furfural and furfuryl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, K.; Hallgren, C.; Levin, J.O.; Nilsson, C.A.

    1981-12-01

    A method based on trapping formaldehyde on a 2,4-dinitrodinitrophenylhydrazine-coated porous polymer (Amberlite XAD-2) was evaluated for air sampling in occupational environments. The aldehyde is converted to its 2,4-dinitrophenylhydrazone on the adsorbent. The influence of some organic compounds which often occur together with formaldehyde-furfural, phenol and furfuryl alcohol--was studied. The results show that the method allows the sampling of formaldehyde in the range 0.01--1.0 mg/m3 of air, based on a 3-1 (15 min) sample and a coating of 1%. Furfural, phenol, and furfuryl alcohol do not interfere and may be conveniently sampled at the same time. Formaldehyde and furfural hydrazones were analyzed by high-performance liquid chromatography, phenol and furfuryl alcohol by gas chromatography.

  20. Modelling and Evaluation of Heating Strategies for High Temperature Polymer Electrolyte Membrane Fuel Cell Stacks

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2008-01-01

    Experiments were conducted on two different cathode air cooled high temperature PEM (HTPEM) fuel cell stacks; a 30 cell 400W prototype stack using two bipolar plates per cell, and a 65 cell 1 kW commercial stack using one bipolar plate per cell. The work seeks to examine the use of different...... model to simulate the temperature development of a fuel cell stack during heating can be used for assistance in system and control design. The heating strategies analyzed and tested reduced the startup time of one of the fuel cell stacks from 1 h to about 6 min....

  1. Sampling problems and the determination of mercury in surface water, seawater, and air

    International Nuclear Information System (INIS)

    Das, H.A.; van der Sloot, H.A.

    1976-01-01

    Analysis of surface water for mercury comprises the determination of both ionic and organically bound mercury in solution and that of the total mercury content of the suspended matter. Eventually, metallic mercury has to be determined too. Requirements for the sampling procedure are given. A method for the routine determination of mercury in surface water and seawater was developed and applied to Dutch surface waters. The total sample volume is 2500 ml. About 500 ml is used for the determination of the content of suspended matter and the total amount of mercury in the water. The sample is filtered through a bed of previously purified active charcoal at a low flow-rate. The main portion ca. 2000 ml) passes a flow-through centrifuge to separate the solid fraction. One liter is used to separate ''inorganic'' mercury by reduction, volatilization in an airstream and adsorption on active charcoal. The other liter is led through a column of active charcoal to collect all mercury. The procedures were checked with 197 Hg radiotracer both as an ion and incorporated in organic compounds. The mercury is determined by thermal neutron activation, followed by volatilization in a tube furnace and adsorption on a fresh carbon bed. The limit of determination is approximately equal to 1 ng 1 -1 . The rate of desorption from and adsorption on suspended material has been measured as a function of a pH of the solution for Hg +2 and various other ions. It can be concluded that only the procedure mentioned above does not disturb the equilibrium. The separation of mercury from air is obtained by suction of 1 m 3 through a 0.22 μm filter and a charcoal bed. The determination is then performed as in the case of the water samples

  2. Application of the CaF2(Eu) scintillator to 85Kr monitoring in atmospheric air samples

    International Nuclear Information System (INIS)

    Wilhelmova, Ludmila; Dvorak, Zdenek; Tomasek, Milan; Stukheil, Karel

    1986-01-01

    A detection system with a CaF 2 (Eu) scintillator has been developed for monitoring β-radiation of 85 Kr in atmospheric air samples. The geometry of the detector chamber was optimized to achieve maximum detection efficiency. The design of the detector is described and values of the detection efficiency are presented for various compositions and pressures of the gaseous samples. The conditions for calibration of the detector used for monitoring of 85 Kr in enriched air samples have been established. (author)

  3. Air sampling to assess potential generation of aerosolized viable bacteria during flow cytometric analysis of unfixed bacterial suspensions

    Science.gov (United States)

    Carson, Christine F; Inglis, Timothy JJ

    2018-01-01

    This study investigated aerosolized viable bacteria in a university research laboratory during operation of an acoustic-assisted flow cytometer for antimicrobial susceptibility testing by sampling room air before, during and after flow cytometer use. The aim was to assess the risk associated with use of an acoustic-assisted flow cytometer analyzing unfixed bacterial suspensions. Air sampling in a nearby clinical laboratory was conducted during the same period to provide context for the existing background of microorganisms that would be detected in the air. The three species of bacteria undergoing analysis by flow cytometer in the research laboratory were Klebsiella pneumoniae, Burkholderia thailandensis and Streptococcus pneumoniae. None of these was detected from multiple 1000 L air samples acquired in the research laboratory environment. The main cultured bacteria in both locations were skin commensal and environmental bacteria, presumed to have been disturbed or dispersed in laboratory air by personnel movements during routine laboratory activities. The concentrations of bacteria detected in research laboratory air samples were reduced after interventional cleaning measures were introduced and were lower than those in the diagnostic clinical microbiology laboratory. We conclude that our flow cytometric analyses of unfixed suspensions of K. pneumoniae, B. thailandensis and S. pneumoniae do not pose a risk to cytometer operators or other personnel in the laboratory but caution against extrapolation of our results to other bacteria and/or different flow cytometric experimental procedures. PMID:29608197

  4. Determination of biomass burning tracers in air samples by GC/MS

    Directory of Open Access Journals (Sweden)

    Janoszka Katarzyna

    2018-01-01

    Full Text Available Levoglucosan (LG as a main cellulose burning product at 300°C is a biomass burning tracer. LG characterize by relatively high molar mass and it is sorbed by particulate matter. In the study of air pollution monitoring LG is mainly analyzed in particulate matter, PM1 and PM2,5. The tracer create relatively high O-H…O bond and weaker C-H…O bond. Due to the hydrogen bond, LG dissolves very well in water. Analytical procedure of LG determination include: extraction, derivatization and analysis by gas chromatography coupled with mass spectrometry detector. In water samples levoglucosan is determined by liquid chromatography. The paper presents a methodology for particulate matter samples determination their analysis by gas chromatography coupled with a mass spectrometry detector. Determination of LG content in particulate matter was performed according to an analytical method based on simultaneous pyridine extraction and derivatization using N,O-bis (trimethylsilyl trifluoroacetamide and trimethylchlorosilane mixture (BSTFA: TMCS, 99: 1.

  5. Determination of biomass burning tracers in air samples by GC/MS

    Science.gov (United States)

    Janoszka, Katarzyna

    2018-01-01

    Levoglucosan (LG) as a main cellulose burning product at 300°C is a biomass burning tracer. LG characterize by relatively high molar mass and it is sorbed by particulate matter. In the study of air pollution monitoring LG is mainly analyzed in particulate matter, PM1 and PM2,5. The tracer create relatively high O-H…O bond and weaker C-H…O bond. Due to the hydrogen bond, LG dissolves very well in water. Analytical procedure of LG determination include: extraction, derivatization and analysis by gas chromatography coupled with mass spectrometry detector. In water samples levoglucosan is determined by liquid chromatography. The paper presents a methodology for particulate matter samples determination their analysis by gas chromatography coupled with a mass spectrometry detector. Determination of LG content in particulate matter was performed according to an analytical method based on simultaneous pyridine extraction and derivatization using N,O-bis (trimethylsilyl) trifluoroacetamide and trimethylchlorosilane mixture (BSTFA: TMCS, 99: 1).

  6. Remote control air sampling and fast chemical analysis of the composition

    Energy Technology Data Exchange (ETDEWEB)

    Kukuczka, A; Golisz, T

    1981-01-01

    In 1979 the Central mine rescue station in Bytom (Poland) developed and introduced into use a new method of remote control air and gas (from fires) sampling and swift chemical analysis of the samples' composition. The device in this method includes: a probe (situated beyond the fire detector directly in the control zone), thick-walled elastic hose, direr, piston pump, rotameter, chromatograph and minicomputer. The basic technical data included in the set: the capacity of the pump 8 1/min, 2.5 kg mass. run on 12 V current (built at the Main Mining Affairs Inst. in Poland); the chromatograph is VARIAN 1420-10 (USA produced),the working gas is helium (balloon volume 40 1), feed--alternating 220V, capacity--1.5 kW, time for measuring gas from fires-- 15 to 20 min (as apposed to the 1.5h spent before when the SRC device was being used) at an accuracy of /sup + -/ 0.05% (volume); the chromatograph works with a mini-computer (model CDS-111C) with a 20 kg mass.and a size of 16 x 46 x 56 cm. As tests in Moszczenica coal mines, where a fire in 504/2 occurred, showed (the chromatograph was located 750m from the probe for burning gases), the method proved to be a good one although the VARIAN 1420-10 was insufficiently reliable and the VARIAN-1400-AEROGRAF proved to be better.

  7. Forecasting Urban Air Quality via a Back-Propagation Neural Network and a Selection Sample Rule

    Directory of Open Access Journals (Sweden)

    Yonghong Liu

    2015-07-01

    Full Text Available In this paper, based on a sample selection rule and a Back Propagation (BP neural network, a new model of forecasting daily SO2, NO2, and PM10 concentration in seven sites of Guangzhou was developed using data from January 2006 to April 2012. A meteorological similarity principle was applied in the development of the sample selection rule. The key meteorological factors influencing SO2, NO2, and PM10 daily concentrations as well as weight matrices and threshold matrices were determined. A basic model was then developed based on the improved BP neural network. Improving the basic model, identification of the factor variation consistency was added in the rule, and seven sets of sensitivity experiments in one of the seven sites were conducted to obtain the selected model. A comparison of the basic model from May 2011 to April 2012 in one site showed that the selected model for PM10 displayed better forecasting performance, with Mean Absolute Percentage Error (MAPE values decreasing by 4% and R2 values increasing from 0.53 to 0.68. Evaluations conducted at the six other sites revealed a similar performance. On the whole, the analysis showed that the models presented here could provide local authorities with reliable and precise predictions and alarms about air quality if used at an operational scale.

  8. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  9. 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.

  10. Early Detection of Foot-And-Mouth Disease Virus from Infected Cattle Using A Dry Filter Air Sampling System.

    Science.gov (United States)

    Pacheco, J M; Brito, B; Hartwig, E; Smoliga, G R; Perez, A; Arzt, J; Rodriguez, L L

    2017-04-01

    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 the aerogenous nature of the virus. In the current study, air from rooms housing individual (n = 17) or two groups (n = 4) of cattle experimentally infected with FDMV A24 Cruzeiro of different virulence levels was sampled to assess the feasibility of applying air sampling as a non-invasive, screening tool to identify sources of FMDV infection. Detection of FMDV RNA in air was compared with first detection of clinical signs and FMDV RNA levels in serum and oral fluid. FMDV RNA was detected in room air samples 1-3 days prior (seven animals) or on the same day (four animals) as the appearance of clinical signs in 11 of 12 individually housed cattle. Only in one case clinical signs preceded detection in air samples by one day. Overall, viral RNA in oral fluid or serum preceded detection in air samples by 1-2 days. Six individually housed animals inoculated with attenuated strains did not show clinical signs, but virus was detected in air in one of these cases 3 days prior to first detection in oral fluid. In groups of four cattle housed together, air detection always preceded appearance of clinical signs by 1-2 days and coincided more often with viral shedding in oral fluid than virus in blood. These data confirm that air sampling is an effective non-invasive screening method for detecting FMDV infection in confined to enclosed spaces (e.g. auction barns, milking parlours). This technology could be a useful tool as part of a surveillance strategy during FMD prevention, control or eradication efforts. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  11. Experimental 1 kW 20 cell PEFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F N; Marmy, C A; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

    1999-08-01

    A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

  12. High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

    International Nuclear Information System (INIS)

    Ping, Mao; Zhi-Gang, Zhang; Li-Yang, Pan; Jun, Xu; Pei-Yi, Chen

    2009-01-01

    Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3 × 10 12 cm −2 ), small size (2–4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs

  13. Assessing Elementary Algebra with STACK

    Science.gov (United States)

    Sangwin, Christopher J.

    2007-01-01

    This paper concerns computer aided assessment (CAA) of mathematics in which a computer algebra system (CAS) is used to help assess students' responses to elementary algebra questions. Using a methodology of documentary analysis, we examine what is taught in elementary algebra. The STACK CAA system, http://www.stack.bham.ac.uk/, which uses the CAS…

  14. Spherical Torus Center Stack Design

    International Nuclear Information System (INIS)

    C. Neumeyer; P. Heitzenroeder; C. Kessel; M. Ono; M. Peng; J. Schmidt; R. Woolley; I. Zatz

    2002-01-01

    The low aspect ratio spherical torus (ST) configuration requires that the center stack design be optimized within a limited available space, using materials within their established allowables. This paper presents center stack design methods developed by the National Spherical Torus Experiment (NSTX) Project Team during the initial design of NSTX, and more recently for studies of a possible next-step ST (NSST) device

  15. Trace interpolation by slant-stack migration

    International Nuclear Information System (INIS)

    Novotny, M.

    1990-01-01

    The slant-stack migration formula based on the radon transform is studied with respect to the depth steep Δz of wavefield extrapolation. It can be viewed as a generalized trace-interpolation procedure including wave extrapolation with an arbitrary step Δz. For Δz > 0 the formula yields the familiar plane-wave decomposition, while for Δz > 0 it provides a robust tool for migration transformation of spatially under sampled wavefields. Using the stationary phase method, it is shown that the slant-stack migration formula degenerates into the Rayleigh-Sommerfeld integral in the far-field approximation. Consequently, even a narrow slant-stack gather applied before the diffraction stack can significantly improve the representation of noisy data in the wavefield extrapolation process. The theory is applied to synthetic and field data to perform trace interpolation and dip reject filtration. The data examples presented prove that the radon interpolator works well in the dip range, including waves with mutual stepouts smaller than half the dominant period

  16. Potential contamination of shipboard air samples by diffusive emissions of PCBs and other organic pollutants: implications and solutions.

    Science.gov (United States)

    Lohmann, Rainer; Jaward, Foday M; Durham, Louise; Barber, Jonathan L; Ockenden, Wendy; Jones, Kevin C; Bruhn, Regina; Lakaschus, Soenke; Dachs, Jordi; Booij, Kees

    2004-07-15

    Air samples were taken onboard the RRS Bransfield on an Atlantic cruise from the United Kingdom to Halley, Antarctica, from October to December 1998, with the aim of establishing PCB oceanic background air concentrations and assessing their latitudinal distribution. Great care was taken to minimize pre- and post-collection contamination of the samples, which was validated through stringent QA/QC procedures. However, there is evidence that onboard contamination of the air samples occurred,following insidious, diffusive emissions on the ship. Other data (for PCBs and other persistent organic pollutants (POPs)) and examples of shipboard contamination are presented. The implications of these findings for past and future studies of global POPs distribution are discussed. Recommendations are made to help critically appraise and minimize the problems of insidious/diffusive shipboard contamination.

  17. Detection of Campylobacter Bacteria in Air Samples for Continuous Real-Time Monitoring of Campylobacter Colonization in Broiler Flocks

    DEFF Research Database (Denmark)

    Olsen, Katja Nyholm; Lund, Marianne; Skov, J.

    2009-01-01

    Improved monitoring tools are important for the control of Campylobacter bacteria in broiler production. In this study, we compare the sensitivities of detection of Campylobacter by PCR with feces, dust, and air samples during the lifetimes of broilers in two poultry houses and conclude that the ......Improved monitoring tools are important for the control of Campylobacter bacteria in broiler production. In this study, we compare the sensitivities of detection of Campylobacter by PCR with feces, dust, and air samples during the lifetimes of broilers in two poultry houses and conclude...... that the sensitivity of detection of Campylobacter in air is comparable to that in other sample materials. Profiling of airborne particles in six poultry houses revealed that the aerodynamic conditions were dependent on the age of the chickens and very comparable among different poultry houses, with low proportions...

  18. Air sampling procedures to evaluate microbial contamination: a comparison between active and passive methods in operating theatres.

    Science.gov (United States)

    Napoli, Christian; Marcotrigiano, Vincenzo; Montagna, Maria Teresa

    2012-08-02

    Since air can play a central role as a reservoir for microorganisms, in controlled environments such as operating theatres regular microbial monitoring is useful to measure air quality and identify critical situations. The aim of this study is to assess microbial contamination levels in operating theatres using both an active and a passive sampling method and then to assess if there is a correlation between the results of the two different sampling methods. The study was performed in 32 turbulent air flow operating theatres of a University Hospital in Southern Italy. Active sampling was carried out using the Surface Air System and passive sampling with settle plates, in accordance with ISO 14698. The Total Viable Count (TVC) was evaluated at rest (in the morning before the beginning of surgical activity) and in operational (during surgery). The mean TVC at rest was 12.4 CFU/m3 and 722.5 CFU/m2/h for active and passive samplings respectively. The mean in operational TVC was 93.8 CFU/m3 (SD = 52.69; range = 22-256) and 10496.5 CFU/m2/h (SD = 7460.5; range = 1415.5-25479.7) for active and passive samplings respectively. Statistical analysis confirmed that the two methods correlate in a comparable way with the quality of air. It is possible to conclude that both methods can be used for general monitoring of air contamination, such as routine surveillance programs. However, the choice must be made between one or the other to obtain specific information.

  19. Air sampling procedures to evaluate microbial contamination: a comparison between active and passive methods in operating theatres

    Directory of Open Access Journals (Sweden)

    Napoli Christian

    2012-08-01

    Full Text Available Abstract Background Since air can play a central role as a reservoir for microorganisms, in controlled environments such as operating theatres regular microbial monitoring is useful to measure air quality and identify critical situations. The aim of this study is to assess microbial contamination levels in operating theatres using both an active and a passive sampling method and then to assess if there is a correlation between the results of the two different sampling methods. Methods The study was performed in 32 turbulent air flow operating theatres of a University Hospital in Southern Italy. Active sampling was carried out using the Surface Air System and passive sampling with settle plates, in accordance with ISO 14698. The Total Viable Count (TVC was evaluated at rest (in the morning before the beginning of surgical activity and in operational (during surgery. Results The mean TVC at rest was 12.4 CFU/m3 and 722.5 CFU/m2/h for active and passive samplings respectively. The mean in operational TVC was 93.8 CFU/m3 (SD = 52.69; range = 22-256 and 10496.5 CFU/m2/h (SD = 7460.5; range = 1415.5-25479.7 for active and passive samplings respectively. Statistical analysis confirmed that the two methods correlate in a comparable way with the quality of air. Conclusion It is possible to conclude that both methods can be used for general monitoring of air contamination, such as routine surveillance programs. However, the choice must be made between one or the other to obtain specific information.

  20. 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

  1. Comparison of halocarbon measurements in an atmospheric dry whole air sample.

    Science.gov (United States)

    Rhoderick, George C; Hall, Bradley D; Harth, Christina M; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K; Weiss, Ray F

    The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.

  2. Comparison of halocarbon measurements in an atmospheric dry whole air sample

    Directory of Open Access Journals (Sweden)

    George C. Rhoderick

    2015-11-01

    Full Text Available Abstract The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs dichlorodifluoromethane (CFC-12, trichlorofluoromethane (CFC-11, and 1,1,2-trichlorotrifluoroethane (CFC-113; the hydrochlorofluorocarbons (HCFCs chlorodifluoromethane (HCFC-22 and 1-chloro-1,1-difluoroethane (HCFC-142b; and the hydrofluorocarbon (HFC 1,1,1,2-tetrafluoroethane (HFC-134a, all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.

  3. Comparison of halocarbon measurements in an atmospheric dry whole air sample

    Science.gov (United States)

    Hall, Bradley D.; Harth, Christina M.; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A.; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K.; Weiss, Ray F.

    2015-01-01

    The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. PMID:26753167

  4. Mathematical solutions to problems in radiological protection involving air sampling and biokinetic modelling

    International Nuclear Information System (INIS)

    Birchall, A.

    1989-04-01

    Intakes of radionuclides are estimated with the personal air sampler (PAS) and by biological monitoring techniques: in the case of plutonium, there are problems with both methods. The statistical variation in activity collected when sampling radioactive aerosols with low number concentrations was investigated. It was shown that the PAS is barely adequate for monitoring plutonium at annual limit of intake (ALI) levels in typical workplace conditions. Two algorithms were developed, enabling non-recycling and recycling compartmental models to be solved. Their accuracy and speed were investigated, and methods of dealing with partitioning, continuous intake, and radioactive progeny were discussed. Analytical, rather than numerical, methods were used. These are faster, and thus ideally suited for implementation on microcomputers. The algorithms enable non-specialists to solve quickly and easily any first order compartmental model, including all the ICRP metabolic models. Non-recycling models with up to 50 compartments can be solved in seconds: recycling models take a little longer. A biokinetic model for plutonium in man following systemic uptake was developed. The proposed ICRP lung model (1989) was represented by a first order compartmental model. These two models were combined, and the recycling algorithm was used to calculate urinary and faecal excretion of plutonium following acute or chronic intake by inhalation. The results indicate much lower urinary excretion than predicted by ICRP Publication 54. (author)

  5. Air and Surface Sampling Method for Assessing Exposures to Quaternary Ammonium Compounds Using Liquid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    LeBouf, Ryan F; Virji, Mohammed Abbas; Ranpara, Anand; Stefaniak, Aleksandr B

    2017-07-01

    This method was designed for sampling select quaternary ammonium (quat) compounds in air or on surfaces followed by analysis using ultraperformance liquid chromatography tandem mass spectrometry. Target quats were benzethonium chloride, didecyldimethylammonium bromide, benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, and benzyldimethylhexadecylammonium chloride. For air sampling, polytetrafluoroethylene (PTFE) filters are recommended for 15-min to 24-hour sampling. For surface sampling, Pro-wipe® 880 (PW) media was chosen. Samples were extracted in 60:40 acetonitrile:0.1% formic acid for 1 hour on an orbital shaker. Method detection limits range from 0.3 to 2 ng/ml depending on media and analyte. Matrix effects of media are minimized through the use of multiple reaction monitoring versus selected ion recording. Upper confidence limits on accuracy meet the National Institute for Occupational Safety and Health 25% criterion for PTFE and PW media for all analytes. Using PTFE and PW analyzed with multiple reaction monitoring, the method quantifies levels among the different quats compounds with high precision (detection limits to capture quats on air sampling filters with only a 15-min sample duration with a maximum assessed storage time of 103 days before sample extraction. This method will support future exposure assessment and quantitative epidemiologic studies to explore exposure-response relationships and establish levels of quats exposures associated with adverse health effects. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  6. Active AirCore Sampling: Constraining Point Sources of Methane and Other Gases with Fixed Wing Unmanned Aerial Systems

    Science.gov (United States)

    Bent, J. D.; Sweeney, C.; Tans, P. P.; Newberger, T.; Higgs, J. A.; Wolter, S.

    2017-12-01

    Accurate estimates of point source gas emissions are essential for reconciling top-down and bottom-up greenhouse gas measurements, but sampling such sources is challenging. Remote sensing methods are limited by resolution and cloud cover; aircraft methods are limited by air traffic control clearances, and the need to properly determine boundary layer height. A new sampling approach leverages the ability of unmanned aerial systems (UAS) to measure all the way to the surface near the source of emissions, improving sample resolution, and reducing the need to characterize a wide downstream swath, or measure to the full height of the planetary boundary layer (PBL). The "Active-AirCore" sampler, currently under development, will fly on a fixed wing UAS in Class G airspace, spiraling from the surface to 1200 ft AGL around point sources such as leaking oil wells to measure methane, carbon dioxide and carbon monoxide. The sampler collects a 100-meter long sample "core" of air in an 1/8" passivated stainless steel tube. This "core" is run on a high-precision instrument shortly after the UAS is recovered. Sample values are mapped to a specific geographic location by cross-referencing GPS and flow/pressure metadata, and fluxes are quantified by applying Gauss's theorem to the data, mapped onto the spatial "cylinder" circumscribed by the UAS. The AirCore-Active builds off the sampling ability and analytical approach of the related AirCore sampler, which profiles the atmosphere passively using a balloon launch platform, but will add an active pumping capability needed for near-surface horizontal sampling applications. Here, we show design elements, laboratory and field test results for methane, describe the overall goals of the mission, and discuss how the platform can be adapted, with minimal effort, to measure other gas species.

  7. An analytical method for trifluoroacetic Acid in water and air samples using headspace gas chromatographic determination of the methyl ester.

    Science.gov (United States)

    Zehavi, D; Seiber, J N

    1996-10-01

    An analytical method has been developed for the determination of trace levels of trifluoroacetic acid (TFA), an atmospheric breakdown product of several of the hydrofluorocarbon (HFC) and hydrochlorofluorocarbon (HCFC) replacements for the chlorofluorocarbon (CFC) refrigerants, in water and air. TFA is derivatized to the volatile methyl trifluoroacetate (MTFA) and determined by automated headspace gas chromatography (HSGC) with electron-capture detection or manual HSGC using GC/MS in the selected ion monitoring (SIM) mode. The method is based on the reaction of an aqueous sample containing TFA with dimethyl sulfate (DMS) in concentrated sulfuric acid in a sealed headspace vial under conditions favoring distribution of MTFA to the vapor phase. Water samples are prepared by evaporative concentration, during which TFA is retained as the anion, followed by extraction with diethyl ether of the acidified sample and then back-extraction of TFA (as the anion) in aqueous bicarbonate solution. The extraction step is required for samples with a relatively high background of other salts and organic materials. Air samples are collected in sodium bicarbonate-glycerin-coated glass denuder tubes and prepared by rinsing the denuder contents with water to form an aqueous sample for derivatization and analysis. Recoveries of TFA from spiked water, with and without evaporative concentration, and from spiked air were quantitative, with estimated detection limits of 10 ng/mL (unconcentrated) and 25 pg/mL (concentrated 250 mL:1 mL) for water and 1 ng/m(3) (72 h at 5 L/min) for air. Several environmental air, fogwater, rainwater, and surface water samples were successfully analyzed; many showed the presence of TFA.

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

    Science.gov (United States)

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

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments. © The Author 2015

  9. Estimating Sampling Biases and Measurement Uncertainties of AIRS-AMSU-A Temperature and Water Vapor Observations Using MERRA Reanalysis

    Science.gov (United States)

    Hearty, Thomas J.; Savtchenko, Andrey K.; Tian, Baijun; Fetzer, Eric; Yung, Yuk L.; Theobald, Michael; Vollmer, Bruce; Fishbein, Evan; Won, Young-In

    2014-01-01

    We use MERRA (Modern Era Retrospective-Analysis for Research Applications) temperature and water vapor data to estimate the sampling biases of climatologies derived from the AIRS/AMSU-A (Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A) suite of instruments. We separate the total sampling bias into temporal and instrumental components. The temporal component is caused by the AIRS/AMSU-A orbit and swath that are not able to sample all of time and space. The instrumental component is caused by scenes that prevent successful retrievals. The temporal sampling biases are generally smaller than the instrumental sampling biases except in regions with large diurnal variations, such as the boundary layer, where the temporal sampling biases of temperature can be +/- 2 K and water vapor can be 10% wet. The instrumental sampling biases are the main contributor to the total sampling biases and are mainly caused by clouds. They are up to 2 K cold and greater than 30% dry over mid-latitude storm tracks and tropical deep convective cloudy regions and up to 20% wet over stratus regions. However, other factors such as surface emissivity and temperature can also influence the instrumental sampling bias over deserts where the biases can be up to 1 K cold and 10% wet. Some instrumental sampling biases can vary seasonally and/or diurnally. We also estimate the combined measurement uncertainties of temperature and water vapor from AIRS/AMSU-A and MERRA by comparing similarly sampled climatologies from both data sets. The measurement differences are often larger than the sampling biases and have longitudinal variations.

  10. Tracer gas experiment to verify the dispersion from a tall stack

    International Nuclear Information System (INIS)

    Sivertsen, B.; Irwin, J.S.

    1996-01-01

    At the request of the Ministerios de Obras Publicas y Urbanismo (MOPU) in Madrid, the Norwegian Institute for Air Research (NILU) planned and carried out a comprehensive field experiment at the Andorra (Teruel) power plant in Spain. All together, eleven releases of sulfur hexafluoride (SF6) tracer were carried out at the 1,200 MW electric coal fired power plant. The tracer was emitted into the atmosphere from the 343 m high stack, stack exit diameter of 9 m. The stack gas emission characteristics were nearly constant during the period having an exit temperature of 175.1 C (1.9), exit velocity of 35.5 m/s (0.14) and sulfur dioxide (SO 2 ) emission rate of 46.1 x 10 3 kg/hr (5.15 x 10 3 ); standard deviations are listed in parentheses. Samples were taken at the surface along sampling arcs located approximately 8, 23, 43 and 75 km downwind. The releases were undertaken during typical late spring daytime conditions. The synoptic weather conditions were dominated by a large high pressure system on the Atlantic, west of Spain. Fronts were passing the area from the north and a low pressure system was developing over central Europe (Germany). Winds at the surface were generally brisk from the northwest at 7 to 12 m/s

  11. The sampling of hydrogen fluoride in air with impregnated filter paper

    NARCIS (Netherlands)

    Huygen, C.

    1963-01-01

    A method isproposed for the quantitative collection of hydrogen fluoride in air by drawing a known quantity of the air through filter paper impregnated with solutions of potassium hydroxide and glycerol or triethanolamine. Somu possibilities and limitations of the method are discussed.

  12. Dynamic Model of the High Temperature Proton Exchange Membrane Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2009-01-01

    The present work involves the development of a model for predicting the dynamic temperature of a high temperature proton exchange membrane (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system co...... elements for start-up, heat conduction through stack insulation, cathode air convection, and heating of the inlet gases in the manifold. Various measurements are presented to validate the model predictions of the stack temperatures....

  13. Determination of gamma emitting radionuclides in environmental air and precipitation samples with a Ge(Li) detector

    International Nuclear Information System (INIS)

    Hoetzl, H.; Rosner, G.; Winkler, R.; Sansoni, B.

    1977-01-01

    The concentrations of the radionuclides 7 Be, 54 Mn, 95 Zr, 95 Nb, 103 Ru, 106 Ru, 125 Sb, 137 Cs, 140 Ba/ 140 La, 141 Ce and 144 Ce in ground level air and of 7 Be, 95 Zr, 137 Cs and 144 Ce in precipitation were determined since 1970 and 1971 respectively at Neuherberg, 10 km north of Munich, by gamma spectrometry using a 60 cm 3 Ge(Li) detector. Dust samples were collected twice a month 1 m above ground from about 40,000 m 3 of air on 46 cm x 28 cm microsorbane filters and pressed to small cylinders of 35 cm 3 in size. Sensitivity of the procedure is of the order of 1 fCi/m 3 for air and of 10 pCi/m 2 per month for precipitation samples at a counting time of 1500 min. (author)

  14. The Comparative Study Of Saprophytic Fungi In Air Canal, Air, Hospital Instruments And Clinical Samples From Patients With Bone Marrow Transplantation

    Directory of Open Access Journals (Sweden)

    Hashemi S J

    2004-08-01

    Full Text Available Background: Bone Marrow Transplantation is one of the most important therapeutic methods in much malignant and nonmalignant disease. Patients with Bone Marrow Transplantation (BMT following radiotherapy and chemotherapy will suffer from immuno-suppression. Therefore they are susceptible to get saprophytic fungi infection that sometimes are killer. Materials and Methods: The purpose of this cross-sectional survey is isolation of saprophytic fungi from patients with BMT and wards space and instruments. Therefore sampling from ventilator system (HEPA filter and common filter, air canal, air, hospital instruments and clinical samples (nasal discharge, sputum, urine were done and cultured in sabouro dextrose agar with choloramphenicol (SC. In assessing total frequency from 4838 plates of wards space and instruments, 985 fungi colonies includes 21 genus were isolated. Results and Conclusion: Most fungi colonies present were Penicillium , Aspergillus and Cladosporium and low present were Trichoderma ,Stereptomyses, Chrysosporium, Rhizopus.

  15. Description and evaluation of a peracetic acid air sampling and analysis method.

    Science.gov (United States)

    Nordling, John; Kinsky, Owen R; Osorio, Magdalena; Pechacek, Nathan

    2017-12-01

    Peracetic acid (PAA) is a corrosive chemical with a pungent odor, which is extensively used in occupational settings and causes various health hazards in exposed workers. Currently, there is no US government agency recommended method that could be applied universally for the sampling and analysis of PAA. Legacy methods for determining airborne PAA vapor levels frequently suffered from cross-reactivity with other chemicals, particularly hydrogen peroxide (H 2 O 2 ). Therefore, to remove the confounding factor of cross-reactivity, a new viable, sensitive method was developed for assessment of PAA exposure levels, based on the differential reaction kinetics of PAA with methyl p-tolylsulfide (MTS), relative to H 2 O 2 , to preferentially derive methyl p-tolysulfoxide (MTSO). By quantifying MTSO concentration produced in the liquid capture solution from an air sampler, using an internal standard, and utilizing the reaction stoichiometry of PAA and MTS, the original airborne concentration of PAA is determined. After refining this liquid trap high-performance liquid chromatography (HPLC) method in the laboratory, it was tested in five workplace settings where PAA products were used. PAA levels ranged from the detection limit of 0.013 parts per million (ppm) to 0.4 ppm. The results indicate a viable and potentially dependable method to assess the concentrations of PAA vapors under occupational exposure scenarios, though only a small number of field measurements were taken while field testing this method. However, the low limit of detection and precision offered by this method makes it a strong candidate for further testing and validation to expand the uses of this liquid trap HPLC method.

  16. Assessment of the Idaho National Laboratory Hot Fuel Examination Facility Stack Monitoring Site for Compliance with ANSI/HPS N13.1 1999

    International Nuclear Information System (INIS)

    Glissmeyer, John A.; Flaherty, Julia E.

    2010-01-01

    This document reports on a series of tests to determine whether the location of the air sampling probe in the Hot Fuels Examination Facility (HFEF) heating, ventilation and air conditioning (HVAC) exhaust duct meets the applicable regulatory criteria regarding the placement of an air sampling probe. Federal regulations require that a sampling probe be located in the exhaust stack according to the criteria of the ANSI/HPS N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that is representative of the effluent stream. The tests conducted by PNNL during July 2010 on the HFEF system are described in this report. The sampling probe location is approximately 20 feet from the base of the stack. The stack base is in the second floor of the HFEF, and has a building ventilation stream (limited potential radioactive effluent) as well as a process stream (potential radioactive effluent, but HEPA-filtered) that feeds into it. The tests conducted on the duct indicate that the process stream is insufficiently mixed with the building ventilation stream. As a result, the air sampling probe location does not meet the criteria of the N13.1-1999 standard. The series of tests consists of various measurements taken over a grid of points in the duct cross section at the proposed sampling-probe location. The results of the test series on the HFEF exhaust duct as it relates to the criteria from ANSI/HPS N13.1-1999 are desribed in this report. Based on these tests, the location of the air sampling probe does not meet the requirements of the ANSI/HPS N13.1-1999 standard, and modifications must be made to either the HVAC system or the air sampling probe for compliance. The recommended approaches are discussed and vary from sampling probe modifications to modifying the junction of the two air exhaust streams.

  17. Free radicals of an aromatic nature in air samples from iron foundries

    Energy Technology Data Exchange (ETDEWEB)

    Westerberg, L M

    1982-01-01

    Free radicals of relatively long life were identified as spin adducts of phenyl-N-tert-butylnitrone. Pyrolysis studies showed the radicals were oxy-radicals. The hyperfine splitting constants of spin adducts of radicals from the pyrolysis in air of benzo(a)pyrene, coal tar pitch, and moulding sand containing hard coal dust were the same as those of the radicals found in foundry air. Since these radicals can bind to DNA, they must be considered when estimating the hazardous effects of polluted air.

  18. Electrochemical Detection in Stacked Paper Networks.

    Science.gov (United States)

    Liu, Xiyuan; Lillehoj, Peter B

    2015-08-01

    Paper-based electrochemical biosensors are a promising technology that enables rapid, quantitative measurements on an inexpensive platform. However, the control of liquids in paper networks is generally limited to a single sample delivery step. Here, we propose a simple method to automate the loading and delivery of liquid samples to sensing electrodes on paper networks by stacking multiple layers of paper. Using these stacked paper devices (SPDs), we demonstrate a unique strategy to fully immerse planar electrodes by aqueous liquids via capillary flow. Amperometric measurements of xanthine oxidase revealed that electrochemical sensors on four-layer SPDs generated detection signals up to 75% higher compared with those on single-layer paper devices. Furthermore, measurements could be performed with minimal user involvement and completed within 30 min. Due to its simplicity, enhanced automation, and capability for quantitative measurements, stacked paper electrochemical biosensors can be useful tools for point-of-care testing in resource-limited settings. © 2015 Society for Laboratory Automation and Screening.

  19. Regional and global atmospheric aerosol studies using the ''Gent'' stacked filter unit sampler and other aerosol collectors, with multi-elemental analysis of the samples by nuclear-related analytical techniques

    International Nuclear Information System (INIS)

    Maenhaut, W.; Francois, F.; Salma, I.; Cafmeyer, J.; Gilot, C.

    1994-01-01

    The ''Gent'' staked filter unit sampler and other collection devices are used in regional and global scale studies on the tropospheric atmospheric aerosols, its composition, sources and fate. The aerosol samples are analyzed by particle-induced X-ray emission analysis, instrumental neutron activation analysis, ion chromatography, a light reflectance technique (for determining black carbon), and gravimetry (for measuring the particular mass). In evaluating the data, use is made of receptor modelling techniques, transport models and wind sector analysis, and also of air mass trajectories and other meteorological information. Preliminary results from a long-term study in southern Norway are presented. It is suggested that the anthropogenic and soil dust aerosol components are mainly adverted to southern Norway by long-range transport and that the major fraction of the submicrometer particle mass is from anthropogenic origin. Preliminary results are also presented for an intensive study in southern Africa. On the basis of the data for two sites (about 40 km apart) in the Kruger National Park it was concluded that regionally representative aerosol samples were collected and that the biomass burning products account for more than 50% of the fine particle mass. Finally, our plans for future work are given. (author). 70 refs, 4 figs, 1 tab

  20. Air sampling methods to evaluate microbial contamination in operating theatres: results of a comparative study in an orthopaedics department.

    Science.gov (United States)

    Napoli, C; Tafuri, S; Montenegro, L; Cassano, M; Notarnicola, A; Lattarulo, S; Montagna, M T; Moretti, B

    2012-02-01

    To evaluate the level of microbial contamination of air in operating theatres using active [i.e. surface air system (SAS)] and passive [i.e. index of microbial air contamination (IMA) and nitrocellulose membranes positioned near the wound] sampling systems. Sampling was performed between January 2010 and January 2011 in the operating theatre of the orthopaedics department in a university hospital in Southern Italy. During surgery, the mean bacterial loads recorded were 2232.9 colony-forming units (cfu)/m(2)/h with the IMA method, 123.2 cfu/m(3) with the SAS method and 2768.2 cfu/m(2)/h with the nitrocellulose membranes. Correlation was found between the results of the three methods. Staphylococcus aureus was detected in 12 of 60 operations (20%) with the membranes, five (8.3%) operations with the SAS method, and three operations (5%) with the IMA method. Use of nitrocellulose membranes placed near a wound is a valid method for measuring the microbial contamination of air. This method was more sensitive than the IMA method and was not subject to any calibration bias, unlike active air monitoring systems. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  1. [Measurement of Chemical Compounds in Indoor and Outdoor Air in Chiba City Using Diffusive Sampling Devices].

    Science.gov (United States)

    Sakamoto, Hironari; Uchiyama, Shigehisa; Kihara, Akiko; Tsutake, Toyoshige; Bekki, Kanae; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2015-01-01

    Indoor air quality (IAQ) is a major concern, because people on average spend the vast majority of their time indoors and they are repeatedly exposed to indoor air pollutants. In this study, to assess indoor air quality in Chiba City, gaseous chemical compounds were surveyed using four types of diffusive sampler. Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 50 houses throughout Chiba City in winter and summer. Four types of diffusive sampler were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenyl hydrazine and trans-1,2-bis(2-pyridyl)ethylene-coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine-impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid-impregnated silica for basic gases. Almost all compounds in indoor air were detected at higher concentrations in summer than in winter. However, the nitrogen dioxide concentration in indoor air particularly increased only in winter, which well correlated with the formic acid concentration (correlation coefficient=0.974). The compound with the highest concentrations in indoor air was p-dichlorobenzene, with recorded levels of 13,000 μg m(-3) in summer and 1,100 μg m(-3) in winter in indoor air. p-Dichlorobenzene in summer and nitrogen dioxide in winter are detected at markedly high concentrations. Pollution control and continuous monitoring of IAQ are indispensable for human health.

  2. 40 CFR 63.307 - Standards for bypass/bleeder stacks.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards for bypass/bleeder stacks. 63.307 Section 63.307 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1) Except as otherwise...

  3. New approach for dynamic flow management within the PEMFC stack

    International Nuclear Information System (INIS)

    Varlam, Mihai; Culcer, Mihai; Carcadea, Elena; Stefanescu, Ioan; Iliescu, Mariana; Enache, Adrian

    2009-01-01

    An adequate gas and water flow management is a key issue to reach and maintain a higher output power for a PEM fuel cell stack. One of the main aspects which could limit the performance of a PEM fuel cell stack is the weak capability for a non-uniform water distribution management within the fuel cell. The produced water could become a handicap to attain the best working performance by blocking the catalytic surfaces and by preventing the mass transport process. Usually, the excess water is removed in one cell, comparatively to others from the stack and taking into account that all the cells are supplied in parallel from a common air admission pipe, a limitation of gas flow rate within that cell is created. Consequently, this constraint will reduce further the water removal speed. This feedback process will generate finally a drastic decrease of the fuel cell stack performance. A new practical solution to this water and gas non-uniformity of distributions problem is to use a sequential purge procedure of several fuel cell groups inside the stack which could guarantee a right management of water. An experimental setup has been built based on four fuel cell stack. Every fuel cell was connected to a single removal pipe via a solenoid valve. A computer-controlled hardware and software system has been designed and built, in order to generate a given opening-closing sequence for the automatic valve system. (authors)

  4. Scheduling whole-air samples above the Trade Wind Inversion from SUAS using real-time sensors

    Science.gov (United States)

    Freer, J. E.; Greatwood, C.; Thomas, R.; Richardson, T.; Brownlow, R.; Lowry, D.; MacKenzie, A. R.; Nisbet, E. G.

    2015-12-01

    Small Unmanned Air Systems (SUAS) are increasingly being used in science applications for a range of applications. Here we explore their use to schedule the sampling of air masses up to 2.5km above ground using computer controlled bespoked Octocopter platforms. Whole-air sampling is targeted above, within and below the Trade Wind Inversion (TWI). On-board sensors profiled the TWI characteristics in real time on ascent and, hence, guided the altitudes at which samples were taken on descent. The science driver for this research is investigation of the Southern Methane Anomaly and, more broadly, the hemispheric-scale transport of long-lived atmospheric tracers in the remote troposphere. Here we focus on the practical application of SUAS for this purpose. Highlighting the need for mission planning, computer control, onboard sensors and logistics in deploying such technologies for out of line-of-sight applications. We show how such a platform can be deployed successfully, resulting in some 60 sampling flights within a 10 day period. Challenges remain regarding the deployment of such platforms routinely and cost-effectively, particularly regarding training and support. We present some initial results from the methane sampling and its implication for exploring and understanding the Southern Methane Anomaly.

  5. Early detection of sugar beet pathogen Ramularia beticola in leaf and air samples using qPCR

    DEFF Research Database (Denmark)

    Wieczorek, Thies Marten; Jørgensen, Lise Nistrup; Hansen, Anne Lisbet

    2014-01-01

    A quantitative PCR method (qPCR) was developed for the detection and quantification of Ramularia beticola causing Ramularia leaf spot in sugar beet. R. beticola specific primers were designed based on the internal transcribed spacer region 2 (ITS2). The assay was applied on DNA extracted from...... spores trapped on tape from Burkard spore traps placed in an artificially inoculated sugar beet field trial and in two sugar beet fields with natural infections. R. beticola DNA was detected at variable amounts in the air samples 14 to 16 days prior to first visible symptoms. R. beticola DNA was detected...... in air samples from fields with natural infection at significant and increasing levels from development of the first symptoms, indicating that spore production within the crop plays a major role in the epidemic development of the disease. Sugar beet leaves sampled from the inoculated field trial were...

  6. Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro

    International Nuclear Information System (INIS)

    Jia Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2005-01-01

    During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bq kg -1 for 238 U, 0.48-93.9 Bq kg -1 for 234 U and 0.02-12.2 Bq kg -1 for 235 U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, 236 U was detectable in some of the samples. The isotopic ratios of 234 U/ 238 U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 μBq m -3 for 238 U, 0.96-38.0 μBq m -3 for 234 U, and 0.05-1.83 μBq m -3 for 235 U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBq l -1 for 238 U, 0.27-28.1 mBq l -1 for 234 U, and 0.01-0.88 mBq l -1 for 235 U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of

  7. Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro.

    Science.gov (United States)

    Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2005-09-01

    During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bqkg(-1) for (238)U, 0.48-93.9 Bqkg(-1) for (234)U and 0.02-12.2 Bqkg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, (236)U was detectable in some of the samples. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 microBqm(-3) for (238)U, 0.96-38.0 microBqm(-3) for (234)U, and 0.05-1.83 microBqm(-3) for (235)U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBql(-1) for (238)U, 0.27-28.1 mBql(-1) for (234)U, and 0.01-0.88 mBql(-1) for (235)U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated

  8. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  9. Power sources involving ~ 300W PEMFC fuel cell stacks cooled by different media

    Directory of Open Access Journals (Sweden)

    Dudek Magdalena

    2017-01-01

    Full Text Available Two constructions of ~300W PEMFC stacks, cooled by different media, were analysed. An open-cathode ~300W PEMFC stack cooled by air (Horizon, Singapore and a PEMFC F-42 stack cooled by a liquid medium (Schunk, Germany were chosen for all of the investigations described in this paper. The potential for the design and construction of power sources involving fuel cells, as well as of a hybrid system (fuel cell-lithium battery for mobile and stationary applications, is presented and discussed. The impact of certain experimental parameters on PEMFC stack performance is analysed and discussed.

  10. Cryogenic separation of an oxygen-argon mixture in natural air samples for the determination of isotope and molecular ratios.

    Science.gov (United States)

    Keedakkadan, Habeeb Rahman; Abe, Osamu

    2015-04-30

    The separation and purification of oxygen-argon mixtures are critical in the high-precision analysis of Δ(17) O and δ(O2 /Ar) for geochemical applications. At present, chromatographic methods are used for the separation and purification of oxygen-argon mixtures or pure oxygen, but these methods require the use of high-purity helium as a carrier gas. Considerable interest has been expressed in the development of a helium-free cryogenic separation of oxygen-argon mixtures in natural air samples. The precise and simplified cryogenic separation of oxygen-argon mixtures from natural air samples presented here was made possible using a single 5A (30/60 mesh) molecular sieve column. The method involves the trapping of eluted gases using molecular sieves at liquid nitrogen temperature, which is associated with isotopic fractionation. We tested the proposed method for the determination of isotopic fractionations during the gas exchange between water and atmospheric air at equilibrium. The dependency of fractionation was studied at different water temperatures and for different methods of equilibration (bubbling and stirring). Isotopic and molecular fractionations during gas desorption from molecular sieves were studied for different amounts and types of molecular sieves. Repeated measurements of atmospheric air yielded a reproducibility (±SD) of 0.021 ‰, 0.044 ‰, 15 per meg and 1.9 ‰ for δ(17) O, δ(18) O, Δ(17) O and δ(O2 /Ar) values, respectively. We applied the method to determine equilibrium isotope fractionation during gas exchange between air and water. Consistent δ(18) O and Δ(17) O results were obtained with the latest two studies, whereas there was a significant difference in δ(18) O values between seawater and deionized water. We have revised a helium-free, cryogenic separation of oxygen-argon mixtures in natural air samples for isotopic and molecular ratio analysis. The use of a single 13X (1/8" pellet) molecular sieve yielded the smallest isotopic

  11. A new CF-IRMS system for quantifying stable isotopes of carbon monoxide from ice cores and small air samples

    Directory of Open Access Journals (Sweden)

    Z. Wang

    2010-10-01

    Full Text Available We present a new analysis technique for stable isotope ratios (δ13C and δ18O of atmospheric carbon monoxide (CO from ice core samples. The technique is an online cryogenic vacuum extraction followed by continuous-flow isotope ratio mass spectrometry (CF-IRMS; it can also be used with small air samples. The CO extraction system includes two multi-loop cryogenic cleanup traps, a chemical oxidant for oxidation to CO2, a cryogenic collection trap, a cryofocusing unit, gas chromatography purification, and subsequent injection into a Finnigan Delta Plus IRMS. Analytical precision of 0.2‰ (±1δ for δ13C and 0.6‰ (±1δ for δ18O can be obtained for 100 mL (STP air samples with CO mixing ratios ranging from 60 ppbv to 140 ppbv (~268–625 pmol CO. Six South Pole ice core samples from depths ranging from 133 m to 177 m were processed for CO isotope analysis after wet extraction. To our knowledge, this is the first measurement of stable isotopes of CO in ice core air.

  12. Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling.

    Science.gov (United States)

    Kim, Taehong; O'Neal, Dennis L; Ortiz, Carlos

    2006-09-01

    Air duct systems in nuclear facilities must be monitored with continuous sampling in case of an accidental release of airborne radionuclides. The purpose of this work is to identify the air sampling locations where the velocity and contaminant concentrations fall below the 20% coefficient of variation required by the American National Standards Institute/Health Physics Society N13.1-1999. Experiments of velocity and tracer gas concentration were conducted on a generic "T" mixing system which included combinations of three sub ducts, one main duct, and air velocities from 0.5 to 2 m s (100 to 400 fpm). The experimental results suggest that turbulent mixing provides the accepted velocity coefficients of variation after 6 hydraulic diameters downstream of the T-junction. About 95% of the cases achieved coefficients of variation below 10% by 6 hydraulic diameters. However, above a velocity ratio (velocity in the sub duct/velocity in the main duct) of 2, velocity profiles were uniform in a shorter distance downstream of the T-junction as the velocity ratio went up. For the tracer gas concentration, the distance needed for the coefficients of variation to drop 20% decreased with increasing velocity ratio due to the sub duct airflow momentum. The results may apply to other duct systems with similar geometries and, ultimately, be a basis for selecting a proper sampling location under the requirements of single point representative sampling.

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

    Science.gov (United States)

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

    2015-11-01

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

  14. Measurements of CO2 Mole Fractionand δ13C in Archived Air Samples from Cape Meares, Oregon (USA) 1977 - 1998

    Science.gov (United States)

    Clark, O.; Rice, A. L.

    2017-12-01

    Carbon dioxide (CO2) is the most abundant, anthropogenically forced greenhouse gas (GHG) in the global atmosphere. Emissions of CO2 account for approximately 75% of the world's total GHG emissions. Atmospheric concentrations of CO2 are higher now than they've been at any other time in the past 800,000 years. Currently, the global mean concentration exceeds 400 ppm. Today, global networks regularly monitor CO2 concentrations and isotopic composition (δ13C and δ18O). However, past data is sparse. Over 200 ambient air samples from Cape Meares, Oregon (45.5°N, 124.0°W), a coastal site in Western United States, were obtained by researchers at Oregon Institute of Science and Technology (OGI, now Oregon Health & Science University), between the years of 1977 and 1998 as part of a global monitoring program of six different sites in the polar, middle, and tropical latitudes of the Northern and Southern Hemispheres. Air liquefaction was used to compress approximately 1000L of air (STP) to 30bar, into 33L electropolished (SUMMA) stainless steel canisters. Select archived air samples from the original network are maintained at Portland State University (PSU) Department of Physics. These archived samples are a valuable look at changing atmospheric concentrations of CO2 and δ13C, which can contribute to a better understanding of changes in sources during this time. CO2 concentrations and δ13C of CO2 were measured at PSU, with a Picarro Cavity Ringdown Spectrometer, model G1101-i analytical system. This study presents the analytical methods used, calibration techniques, precision, and reproducibility. Measurements of select samples from the archive show rising CO2 concentrations and falling δ13C over the 1977 to 1998 period, compatible with previous observations and rising anthropogenic sources of CO2. The resulting data set was statistically analyzed in MATLAB. Results of preliminary seasonal and secular trends from the archive samples are presented.

  15. Maturing of SOFC cell and stack production technology and preparation for demonstration of SOFC stacks. Part 2

    Energy Technology Data Exchange (ETDEWEB)

    2006-07-01

    The TOFC/Riso pilot plant production facility for the manufacture of anode-supported cells has been further up-scaled with an automated continuous spraying process and an extra sintering capacity resulting in production capacity exceeding 15,000 standard cells (12x12 cm2) in 2006 with a success rate of about 85% in the cell production. All processing steps such as tape-casting, spraying, screen-printing and atmospheric air sintering in the cell production have been selected on condition that up-scaling and cost effective, flexible, industrial mass production are feasible. The standard cell size is currently being increased to 18x18 cm2, and 150 cells of this size have been produced in 2006 for our further stack development. To improve quality and lower production cost, a new screen printing line is under establishment. TOFC's stack design is an ultra compact multilayer assembly of cells (including contact layers), metallic interconnects, spacer frames and glass seals. The compactness ensures minimized material consumption and low cost. Standard stacks with cross flow configuration contains 75 cells (12x12cm2) delivering about 1.2 kW at optimal operation conditions with pre-reformed NG as fuel. Stable performance has been demonstrated for 500-1000 hours. Significantly improved materials, especially concerning the metallic interconnect and the coatings have been introduced during the last year. Small stacks (5-10 cells) exhibit no detectable stack degradation using our latest cells and stack materials during test periods of 500-1000 hours. Larger stacks (50-75 cells) suffer from mal-distribution of gas and air inside the stacks, gas leakage, gas cross-over, pressure drop, and a certain loss of internal electrical contact during operation cycles. Measures have been taken to find solutions during the following development work. The stack production facilities have been improved and up-scaled. In 2006, 5 standard stacks have been assembled and burned in based on

  16. Role of stacking disorder in ice nucleation.

    Science.gov (United States)

    Lupi, Laura; Hudait, Arpa; Peters, Baron; Grünwald, Michael; Gotchy Mullen, Ryan; Nguyen, Andrew H; Molinero, Valeria

    2017-11-08

    The freezing of water affects the processes that determine Earth's climate. Therefore, accurate weather and climate forecasts hinge on good predictions of ice nucleation rates. Such rate predictions are based on extrapolations using classical nucleation theory, which assumes that the structure of nanometre-sized ice crystallites corresponds to that of hexagonal ice, the thermodynamically stable form of bulk ice. However, simulations with various water models find that ice nucleated and grown under atmospheric temperatures is at all sizes stacking-disordered, consisting of random sequences of cubic and hexagonal ice layers. This implies that stacking-disordered ice crystallites either are more stable than hexagonal ice crystallites or form because of non-equilibrium dynamical effects. Both scenarios challenge central tenets of classical nucleation theory. Here we use rare-event sampling and free energy calculations with the mW water model to show that the entropy of mixing cubic and hexagonal layers makes stacking-disordered ice the stable phase for crystallites up to a size of at least 100,000 molecules. We find that stacking-disordered critical crystallites at 230 kelvin are about 14 kilojoules per mole of crystallite more stable than hexagonal crystallites, making their ice nucleation rates more than three orders of magnitude higher than predicted by classical nucleation theory. This effect on nucleation rates is temperature dependent, being the most pronounced at the warmest conditions, and should affect the modelling of cloud formation and ice particle numbers, which are very sensitive to the temperature dependence of ice nucleation rates. We conclude that classical nucleation theory needs to be corrected to include the dependence of the crystallization driving force on the size of the ice crystallite when interpreting and extrapolating ice nucleation rates from experimental laboratory conditions to the temperatures that occur in clouds.

  17. Development and preliminary experimental study on micro-stacked insulator

    International Nuclear Information System (INIS)

    Ren Chengyan; Yuan Weiqun; Zhang Dongdong; Yan Ping; Wang Jue

    2009-01-01

    High gradient insulating technology is one of the key technologies in new type dielectric wall accelerator(DWA). High gradient insulator, namely micro-stacked insulator, was developed and preliminary experimental study was done. Based on the finite element and particle simulating method, surface electric field distribution and electron movement track of micro-stacked insulator were numerated, and then the optimized design proposal was put forward. Using high temperature laminated method, we developed micro-stacked insulator samples which uses exhaustive fluorinated ethylene propylene(FEP) as dielectric layer and stainless steel as metal layer. Preliminary experiment of vacuum surface flashover in nanosecond pulse voltage was done and micro-stacked insulator exhibited favorable vacuum surface flashover performance with flashover field strength of near 180 kV/cm. (authors)

  18. Direct Trace Element Analysis of Liquid Blood Samples by In-Air Ion Beam Analytical Techniques (PIXE-PIGE).

    Science.gov (United States)

    Huszank, Robert; Csedreki, László; Török, Zsófia

    2017-02-07

    There are various liquid materials whose elemental composition is of interest in various fields of science and technology. In many cases, sample preparation or the extraction can be complicated, or it would destroy the original environment before the analysis (for example, in the case of biological samples). However, multielement direct analysis of liquid samples can be realized by an external PIXE-PIGE measurement system. Particle-induced X-ray and gamma-ray emission spectroscopy (PIXE, PIGE) techniques were applied in external (in-air) microbeam configuration for the trace and main element determination of liquid samples. The direct analysis of standard solutions of several metal salts and human blood samples (whole blood, blood serum, blood plasma, and formed elements) was realized. From the blood samples, Na, P, S, Cl, K, Ca, Fe, Cu, Zn, and Br elemental concentrations were determined. The focused and scanned ion beam creates an opportunity to analyze very small volume samples (∼10 μL). As the sample matrix consists of light elements, the analysis is possible at ppm level. Using this external beam setup, it was found that it is possible to determine elemental composition of small-volume liquid samples routinely, while the liquid samples do not require any preparation processes, and thus, they can be analyzed directly. In the case of lower concentrations, the method is also suitable for the analysis (down to even ∼1 ppm level) but with less accuracy and longer measurement times.

  19. Comparison of Air Sampling Methods for Organophosphate Flame Retardants in Small Environmental Chambers

    Science.gov (United States)

    Organophosphorus flame retardants (OPFRs), such as tris(2-chloroethyl) phosphate (TCEP), tris(1-chlor-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP), used as additives in industrial and consumer products are being detected in indoor air, house dust,...

  20. 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

  1. Sampling Studies at an Air Force Live-Fire Bombing Range Impact Area

    National Research Council Canada - National Science Library

    Jenkins, Thomas F; Hewitt, Alan D; Ramsey, Charles A; Bjella, Kevin L; Bigl, Susan R; Lambert, Dennis J

    2006-01-01

    .... The main objective was to assess the effectiveness of using a systematic-random, multi-increment sampling strategy for the collection of representative surface soil samples in areas where bombing...

  2. Results of Soil Vapor Sampling at SA 6, McClellan Air Force Base, California

    National Research Council Canada - National Science Library

    1998-01-01

    ...) and total petroleum hydrocarbon (TPH) contamination in site soil. The soil vapor sampling event was performed in accordance with the Final Sampling and Analysis Plan to Support Recommendation for No Further Investigation at SA 6 (Parsons ES, 1998...

  3. Draught regulator with control flap lowers dew point, keeps stacks dry

    Energy Technology Data Exchange (ETDEWEB)

    Dreizler, U.; Dreizler, W.

    1982-11-30

    Draught regulators for auxiliary air are particularly important in older stacks operated with new boilers and burners. Owing to better ventilation during burner operation and standstill, the dew point of flue gases will be lowered so that water vapour condensation will be prevented. Postfitting of draught regulators will also help in stacks already damaged by condensation water. The draught regulator has a control flap for better control of auxiliary air supply.

  4. A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices.

    Science.gov (United States)

    Armstrong, Jenna L; Dills, Russell L; Yu, Jianbo; Yost, Michael G; Fenske, Richard A

    2014-01-01

    A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.

  5. Glassy carbon based supercapacitor stacks

    Energy Technology Data Exchange (ETDEWEB)

    Baertsch, M; Braun, A; Koetz, R; Haas, O [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Considerable effort is being made to develop electrochemical double layer capacitors (EDLC) that store relatively large quantities of electrical energy and possess at the same time a high power density. Our previous work has shown that glassy carbon is suitable as a material for capacitor electrodes concerning low resistance and high capacity requirements. We present the development of bipolar electrochemical glassy carbon capacitor stacks of up to 3 V. Bipolar stacks are an efficient way to meet the high voltage and high power density requirements for traction applications. Impedance and cyclic voltammogram measurements are reported here and show the frequency response of a 1, 2, and 3 V stack. (author) 3 figs., 1 ref..

  6. Time-predictable Stack Caching

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar

    completely. Thus, in systems with hard deadlines the worst-case execution time (WCET) of the real-time software running on them needs to be bounded. Modern architectures use features such as pipelining and caches for improving the average performance. These features, however, make the WCET analysis more...... addresses, provides an opportunity to predict and tighten the WCET of accesses to data in caches. In this thesis, we introduce the time-predictable stack cache design and implementation within a time-predictable processor. We introduce several optimizations to our design for tightening the WCET while...... keeping the timepredictability of the design intact. Moreover, we provide a solution for reducing the cost of context switching in a system using the stack cache. In design of these caches, we use custom hardware and compiler support for delivering time-predictable stack data accesses. Furthermore...

  7. Magnesium, Iron and Aluminum in LLNL Air Particulate and Rain Samples with Reference to Magnesium in Industrial Storm Water

    Energy Technology Data Exchange (ETDEWEB)

    Esser, Bradley K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bibby, Richard K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fish, Craig [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-25

    Storm water runoff from the Lawrence Livermore National Laboratory’s (LLNL’s) main site and Site 300 periodically exceeds the Discharge Permit Numeric Action Level (NAL) for Magnesium (Mg) under the Industrial General Permit (IGP) Order No. 2014-0057-DWQ. Of particular interest is the source of magnesium in storm water runoff from the site. This special study compares new metals data from air particulate and precipitation samples from the LLNL main site and Site 300 to previous metals data for storm water from the main site and Site 300 and alluvial sediment from the main site to investigate the potential source of elevated Mg in storm water runoff. Data for three metals (Mg, Iron {Fe}, and Aluminum {Al}) were available from all media; data for additional metals, such as Europium (Eu), were available from rain, air particulates, and alluvial sediment. To attribute source, this study compared metals concentration data (for Mg, Al, and Fe) in storm water and rain; metal-metal correlations (Mg with Fe, Mg with Al, Al with Fe, Mg with Eu, Eu with Fe, and Eu with Al) in storm water, rain, air particulates, and sediments; and metal-metal ratios ((Mg/Fe, Mg/Al, Al/Fe, Mg/Eu, Eu/Fe, and Eu/Al) in storm water, rain, air particulates and sediments. The results presented in this study are consistent with a simple conceptual model where the source of Mg in storm water runoff is air particulate matter that has dry-deposited on impervious surfaces and subsequently entrained in runoff during precipitation events. Such a conceptual model is consistent with 1) higher concentrations of metals in storm water runoff than in precipitation, 2) the strong correlation of Mg with Aluminum (Al) and Iron (Fe) in both storm water and air particulates, and 3) the similarity in metal mass ratios between storm water and air particulates in contrast to the dissimilarity of metal mass ratios between storm water and precipitation or alluvial sediment. The strong correlation of Mg with Fe and Al

  8. Thermoacoustic design using stem of goose down stack

    Science.gov (United States)

    Farikhah, Irna; Ristanto, Sigit; Idrus, Hadiyati; Kaltsum, Ummi; Faisal, Affandi; Setiawan, Ihsan; Setio Utomo, Agung Bambang

    2012-09-01

    Many refrigerators using CFC as a refrigerant are seen as the cause of the depletion of ozone. Hence, thermoacoustic was chosen as an alternative refrigerator that safe for environment. There are many variable that influenced the optimization of thermoacoustic design. One of them is thermal conductivity of material of stack. The Stack material must have a low thermal conductivity. In this research we used organic stack made of stem of goose down. It has superior thermal insulating. It means that they have the lowest thermal conductivity. The system uses no refrigerant or compressor, and the only mechanical moving part is the loudspeaker connected to a signal generator that produces the acoustic. The working fluid is air and the material of resonator is stainless steel. A series test on the laboratory found that there is a decrease of 5°C in temperature for about 2 minutes.

  9. Passive air sampling of organochlorine pesticides in a northeastern state of India, Manipur

    Institute of Scientific and Technical Information of China (English)

    Ningombam Linthoingambi Devi; Shihua Qi; Paromita Chakraborty; Gan Zhang; Ishwar Chandra Yadav

    2011-01-01

    Thirty-six polyurethane foam disk passive air samplers (PUF-PAS) were deployed over a year during January to December, 2009 at three locations, i.e., Imphal (urban site), Thoubal (rural site) and Waithou (alpine site) of Manipur, to assess the seasonal local atrnospheric emission of selected organochlorine pesticides (OCPs).The average concentration of HCHs monitored at mountain site during hot season (Mar, Apr, and May) and rainy seasons (Jun, Jul, Aug, and Sep) were 403 and 349 pg/m3, respectively.DDTs had a high concentration with 384 pg/m3 at rural site and 379 pg/m3 at urban site during hot seasons.Endosulfans and chlordane were found high in concentration during hot seasons (260 pg/m3) and low during retreating monsoon seasons (44 pg/m3) at rural site.Most of the OCPs concentrations were high during cultivation period.The OCP concentrations of rainy season were highly correlated (p < 0.01) with OCPs of hot seasons.Further, positive correlation (p < 0.05) was also obtained between cold seasons and retreating monsoon.Principal component analysis showed a significant correlation among the four seasons and distribution pattern of OCPs in air.Back trajectory analysis by using HYPSLIT model showed a long range air transport of OCPs to the present study area.Present OCP levels at Manipur is an outcome of both local emission and also movement of air mass by long range atmospheric transport.

  10. Final work plan : indoor air and ambient air sampling near the former CCC/USDA grain storage facility in Everest, Kansas.

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, L. M. (Environmental Science Division)

    2010-05-24

    The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at the western edge of Everest, Kansas, from the early 1950s to the early 1970s. Sampling by the Kansas Department of Health and Environment (KDHE) in 1997 resulted in the detection of carbon tetrachloride in one domestic well (the Nigh well) northwest of the former facility. On behalf of the CCC/USDA, Argonne National Laboratory subsequently conducted a series of investigations to characterize the contamination (Argonne 2003, 2006a,b,c). Automatic, continuous monitoring of groundwater levels began in 2002 and is ongoing at six locations. The results have consistently indicated groundwater flow toward the north-northwest from the former CCC/USDA property to the Nigh property, then west-southwest from the Nigh property to the intermittent creek. Sitewide periodic groundwater and surface water sampling with analysis for volatile organic compounds (VOCs) began in 2008. Argonne's combined data indicate no significant downgradient extension of contamination since 2000. At present, the sampling is annual, as approved by the KDHE (2009) in response to a plan developed for the CCC/USDA (Argonne 2009). This document presents a plan for collecting indoor air samples in homes located along and adjacent to the defined extent of the carbon tetrachloride contamination. The plan was requested by the KDHE. Ambient air samples to represent the conditions along this pathway will also be taken. The purpose of the proposed work is to satisfy KDHE requirements and to collect additional data for assessing the risk to human health due to the potential upward migration of carbon tetrachloride and its primary degradation product (chloroform) into homes located in close proximity to the former grain storage facility, as well as along and within 100 ft laterally from the currently defined plume emanating from the former Everest facility. Investigation of the indoor air

  11. Develop of a system of sampling of condensable species with the vapor of water in the air

    International Nuclear Information System (INIS)

    Gonzalez Beermann, P. A.

    1999-01-01

    Implements a method for the determination of the dioxide of dissolved sulfur when condensing the vapor of water in samples of air. To carry out this project it was necessary to design, to build and to gauge the sampling system, a generating SO 2 , a meter of relative humidity, a system of dilution of gases and the system to make the laundries of the glassware, as well as a device to carry out the mensuration of the flow of air. The determination of the anions dissolved in those condensed one carries out for ionic chromatography. The calibration test made to the system of designed sampling demonstrated that behaves of stable form and reproducible for flows between 0,3 and 1,0 L/min. Of the tests of efficiency in the gathering of dioxide of sulfur, it was found that this it reached a maximum of 93% for a sampling flow 0,6 L/min. Lower conditions of relative humidity of 66%. It was found that using this sampling method and the later analysis of the one condensed by ionic chromatography is possible to detect the anions fluoride, chloride, saltpeter, nitrate and sulfate dissolved in concentrations of approximately 1 μg/m 3 . the limit of detection obtained for the soluble species in μg/m 3 of air it was of 1,0 for the fluoride, 4,0 for chloride, 5,0 for saltpeter, 8,0 for nitrate and 8,0 for dioxide of sulfur (reported as sulfate) [es

  12. The Reproducibility of Indoor Air Pollution (IAP Measurement: A Test Case for the Measurement of Key Air Pollutants from the Pan Frying of Fish Samples

    Directory of Open Access Journals (Sweden)

    Ki-Hyun Kim

    2014-01-01

    Full Text Available To assess the robustness of various indoor air quality (IAQ indices, we explored the possible role of reproducibility-induced variability in the measurements of different pollutants under similar sampling and emissions conditions. Polluted indoor conditions were generated by pan frying fish samples in a closed room. A total of 11 experiments were carried out to measure a list of key variables commonly used to represent indoor air pollution (IAP indicators such as particulate matter (PM: PM1, PM2.5, PM10, and TSP and a set of individual volatile organic compounds (VOCs with some odor markers. The cooking activity conducted as part of our experiments was successful to consistently generate significant pollution levels (mean PM10: 7110 μg m−3 and mean total VOC (TVOC: 1400 μg m−3, resp.. Then, relative standard error (RSE was computed to assess the reproducibility between different IAP paramters measured across the repeated experiments. If the results were evaluated by an arbitrary criterion of 10%, the patterns were divided into two data groups (e.g., 10% for the remainders. Most noticeably, TVOC had the most repeatable results with a reproducibility (RSE value of 3.2% (n=11.

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

    International Nuclear Information System (INIS)

    Owoade, Oyediran K.; Olise, Felix S.; Obioh, Imoh B.; Olaniyi, Hezekiah B.; Bolzacchini, Ezio; Ferrero, Luca; Perrone, Grazia

    2006-01-01

    For reproducibility of analytical results of samples deposited on filters using PM 10 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 PM 10 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 PM 10 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

  14. PM{sub 10} sampler deposited air particulates: Ascertaining uniformity of sample on filter through rotated exposure to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Owoade, Oyediran K. [Environmental Research Laboratory (ERL), Physics Department, Obafemi Awolowo University, Ile-Ife (Nigeria)]. E-mail: oowoade2001@yahoo.com; Olise, Felix S. [Environmental Research Laboratory (ERL), Physics Department, Obafemi Awolowo University, Ile-Ife (Nigeria); Obioh, Imoh B. [Centre for Energy Research, Development (Cerd), Obafemi Awolowo University, Ile-Ife (Nigeria); Olaniyi, Hezekiah B. [Environmental Research Laboratory (ERL), Physics Department, Obafemi Awolowo University, Ile-Ife (Nigeria); Bolzacchini, Ezio [Universita Milano-Bicocca, Dipartimento di Scienze-Ambientali, Pizza della Scienza, Milan (Italy); Ferrero, Luca [Universita Milano-Bicocca, Dipartimento di Scienze-Ambientali, Pizza della Scienza, Milan (Italy); Perrone, Grazia [Universita Milano-Bicocca, Dipartimento di Scienze-Ambientali, Pizza della Scienza, Milan (Italy)

    2006-08-01

    For reproducibility of analytical results of samples deposited on filters using PM{sub 10} 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 PM{sub 10} 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 PM{sub 10} 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.

  15. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  16. Validation of a HT-PEMFC stack for CHP applications

    Energy Technology Data Exchange (ETDEWEB)

    Pasupathi, S.; Ulleberg, Oe. [Western Cape Univ. (South Africa). HySA Systems, SAIAMC; Bujlo, P. [Western Cape Univ. (South Africa). HySA Systems, SAIAMC; Electrotechnical Institute Wroclaw Division (Poland); Scholta, J. [Centre for Solar Energy and Hydrogen Research (ZSW) (Germany)

    2010-07-01

    Fuel cell systems are very attractive for stationary co-generation applications as they can produce heat and electricity efficiently in a decentralized and environmentally friendly manner. PEMFC stacks operating at temperatures above 120 C, specifically in the range of 140-180 C, are ideal for co-generation purposes. In this study, preliminary results from a HTPEMFC stack designed for CHP applications is presented and discussed. A short, five-cell, HT-PEMFC stack was assembled with Celtec- P-2100 MEAs and validated in terms of electrical performance. The stack was operated with hydrogen and air at 160 C and the utilization curves for anode and cathode were recorded for a wide range of gas utilization at a current density of 0.52 A/cm{sup 2}. The current voltage characteristic was measured at optimal utilization values at 160 C. A 1kW stack is assembled and is currently being validated for its performance under various operating conditions for use in CHP applications. (orig.)

  17. Evaluation of an ambient air sampling system for tritium (as tritiated water vapor) using silica gel adsorbent columns

    International Nuclear Information System (INIS)

    Patton, G.W.; Cooper, A.T.; Tinker, M.R.

    1995-08-01

    Ambient air samples for tritium analysis (as the tritiated water vapor [HTO] content of atmospheric moisture) are collected for the Hanford Site Surface Environmental Surveillance Project (SESP) using the solid adsorbent silica gel. The silica gel has a moisture sensitive indicator which allows for visual observation of moisture movement through a column. Despite using an established method, some silica gel columns showed a complete change in the color indicator for summertime samples suggesting that breakthrough had occurred; thus a series of tests was conducted on the sampling system in an environmental chamber. The purpose of this study was to determine the maximum practical sampling volume and overall collection efficiency for water vapor collected on silica gel columns. Another purpose was to demonstrate the use of an impinger-based system to load water vapor onto silica gel columns to provide realistic analytical spikes and blanks for the Hanford Site SESP. Breakthrough volumes (V b ) were measured and the chromatographic efficiency (expressed as the number of theoretical plates [N]) was calculated for a range of environmental conditions. Tests involved visual observations of the change in the silica gel's color indicator as a moist air stream was drawn through the column, measurement of the amount of a tritium tracer retained and then recovered from the silica gel, and gravimetric analysis for silica gel columns exposed in the environmental chamber

  18. Near-IR laser-based spectrophotometer for comparative analysis of isotope content of CO2 in exhale air samples

    International Nuclear Information System (INIS)

    Stepanov, E V; Glushko, A N; Kasoev, S G; Koval', A V; Lapshin, D A

    2011-01-01

    We present a laser spectrophotometer aimed at high-accuracy comparative analysis of content of 12 CO 2 and 13 CO 2 isotope modifications in the exhale air samples and based on a tunable near-IR diode laser (2.05 μm). The two-channel optical scheme of the spectrophotometer and the special digital system for its control are described. An algorithm of spectral data processing aimed at determining the difference in the isotope composition of gas mixtures is proposed. A few spectral regions (near 4880 cm -1 ) are determined to be optimal for analysis of relative content of 12 CO 2 and 13 CO 2 in the exhale air. The use of the proposed spectrophotometer scheme and the developed algorithm makes the results of the analysis less susceptible to the influence of the interference in optical elements, to the absorption in the open atmosphere, to the slow drift of the laser pulse envelope, and to the offset of optical channels. The sensitivity of the comparative analysis of the isotope content of CO 2 in exhale air samples, achieved using the proposed scheme, is estimated to be nearly 0.1‰.

  19. Stack semantics of type theory

    DEFF Research Database (Denmark)

    Coquand, Thierry; Mannaa, Bassel; Ruch, Fabian

    2017-01-01

    We give a model of dependent type theory with one univalent universe and propositional truncation interpreting a type as a stack, generalizing the groupoid model of type theory. As an application, we show that countable choice cannot be proved in dependent type theory with one univalent universe...

  20. Multilayer Piezoelectric Stack Actuator Characterization

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  1. V-stack piezoelectric actuator

    Science.gov (United States)

    Ardelean, Emil V.; Clark, Robert L.

    2001-07-01

    Aeroelastic control of wings by means of a distributed, trailing-edge control surface is of interest with regards to maneuvers, gust alleviation, and flutter suppression. The use of high energy density, piezoelectric materials as motors provides an appealing solution to this problem. A comparative analysis of the state of the art actuators is currently being conducted. A new piezoelectric actuator design is presented. This actuator meets the requirements for trailing edge flap actuation in both stroke and force. It is compact, simple, sturdy, and leverages stroke geometrically with minimum force penalties while displaying linearity over a wide range of stroke. The V-Stack Piezoelectric Actuator, consists of a base, a lever, two piezoelectric stacks, and a pre-tensioning element. The work is performed alternately by the two stacks, placed on both sides of the lever. Pre-tensioning can be readily applied using a torque wrench, obviating the need for elastic elements and this is for the benefit of the stiffness of the actuator. The characteristics of the actuator are easily modified by changing the base or the stacks. A prototype was constructed and tested experimentally to validate the theoretical model.

  2. Open stack thermal battery tests

    Energy Technology Data Exchange (ETDEWEB)

    Long, Kevin N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grillet, Anne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Headley, Alexander J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fenton, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wong, Dennis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingersoll, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-04-17

    We present selected results from a series of Open Stack thermal battery tests performed in FY14 and FY15 and discuss our findings. These tests were meant to provide validation data for the comprehensive thermal battery simulation tools currently under development in Sierra/Aria under known conditions compared with as-manufactured batteries. We are able to satisfy this original objective in the present study for some test conditions. Measurements from each test include: nominal stack pressure (axial stress) vs. time in the cold state and during battery ignition, battery voltage vs. time against a prescribed current draw with periodic pulses, and images transverse to the battery axis from which cell displacements are computed. Six battery configurations were evaluated: 3, 5, and 10 cell stacks sandwiched between 4 layers of the materials used for axial thermal insulation, either Fiberfrax Board or MinK. In addition to the results from 3, 5, and 10 cell stacks with either in-line Fiberfrax Board or MinK insulation, a series of cell-free “control” tests were performed that show the inherent settling and stress relaxation based on the interaction between the insulation and heat pellets alone.

  3. Adding large EM stack support

    KAUST Repository

    Holst, Glendon

    2016-12-01

    Serial section electron microscopy (SSEM) image stacks generated using high throughput microscopy techniques are an integral tool for investigating brain connectivity and cell morphology. FIB or 3View scanning electron microscopes easily generate gigabytes of data. In order to produce analyzable 3D dataset from the imaged volumes, efficient and reliable image segmentation is crucial. Classical manual approaches to segmentation are time consuming and labour intensive. Semiautomatic seeded watershed segmentation algorithms, such as those implemented by ilastik image processing software, are a very powerful alternative, substantially speeding up segmentation times. We have used ilastik effectively for small EM stacks – on a laptop, no less; however, ilastik was unable to carve the large EM stacks we needed to segment because its memory requirements grew too large – even for the biggest workstations we had available. For this reason, we refactored the carving module of ilastik to scale it up to large EM stacks on large workstations, and tested its efficiency. We modified the carving module, building on existing blockwise processing functionality to process data in manageable chunks that can fit within RAM (main memory). We review this refactoring work, highlighting the software architecture, design choices, modifications, and issues encountered.

  4. Technical assessment of compliance with workplace air sampling requirements at WRAP

    International Nuclear Information System (INIS)

    HACKWORTH, M.F.

    1999-01-01

    The purpose of this Technical Assessment is to satisfy HSRCM-1, ''Hanford Site Radiological Control Manual'' Article 551.4 for a documented study of facility Workplace Air Monitoring (WAM) programs. HSRCM-1 is the primary guidance for radiological control at Waste Management Federal Services of Hanford, Inc. (WMH). The HSRCM-1 complies with Title 10. Part 835 of the Code of Federal Regulations (10CFR835). This document provides an evaluation of the compliance of the Waste Receiving and Processing facility (WRAP) WAM program to the criteria standards, requirements, and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance

  5. Saharan dust particles in snow samples of Alps and Apennines during an exceptional event of transboundary air pollution.

    Science.gov (United States)

    Telloli, Chiara; Chicca, Milvia; Pepi, Salvatore; Vaccaro, Carmela

    2017-12-21

    Southern European countries are often affected in summer by transboundary air pollution from Saharan dust. However, very few studies deal with Saharan dust pollution at high altitudes in winter. In Italy, the exceptional event occurred on February 19, 2014, colored in red the entire mountain range (Alps and Apennines) and allowed to characterize the particulate matter deposited on snow from a morphological and chemical point of view. Snow samples were collected after this event in four areas in the Alps and one in the Apennines. The particulate matter of the melted snow samples was analyzed by scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) and by inductively coupled plasma mass spectrometry (ICP-MS). These analyses confirmed the presence of Saharan dust particle components in all areas with similar percentages, supported also by the positive correlations between Mg-Ca, Al-Ca, Al-Mg, and Al-K in all samples.

  6. Measuring PM2.5, Ultrafine Particles, Nicotine Air and Wipe Samples Following the Use of Electronic Cigarettes.

    Science.gov (United States)

    Melstrom, Paul; Koszowski, Bartosz; Thanner, Meridith Hill; Hoh, Eunha; King, Brian; Bunnell, Rebecca; McAfee, Tim

    2017-09-01

    Few studies have examined the extent of inhalation or dermal contact among bystanders following short-term, secondhand e-cigarette exposure. Measure PM2.5 (particles e-cigarette exposure. E-cigarettes were used ad libitum by three experienced users for 2 hours during two separate sessions (disposable e-cigarettes, then tank-style e-cigarettes, or "tanks") in a 1858 ft3 room. We recorded: uncorrected PM2.5 (using SidePak); UF (using P-Trak); air nicotine concentrations (using air samplers; SKC XAD-4 canisters); ambient air exchange rate (using an air capture hood). Wipe samples were taken by wiping 100 cm2 room surfaces pre- and post- both sessions, and clean cloth wipes were worn during the exposure and collected at the end. Uncorrected PM2.5 and UF were higher (p e-cigarette use can produce: elevated PM2.5; elevated UF; nicotine in the air; and accumulation of nicotine on surfaces and clothing. Short-term indoor e-cigarette use produced accumulation of nicotine on surfaces and clothing, which could lead to dermal exposure to nicotine. Short-term e-cigarette use produced elevated PM2.5 and ultrafine particles, which could lead to secondhand inhalation of these particles and any chemicals associated with them by bystanders. We measured significant differences in PM2.5 and ultrafine particles between disposable e-cigarettes and tank-style e-cigarettes, suggesting a difference in the exposure profiles of e-cigarette products. Published by Oxford University Press on behalf of Society for Research on Nicotine and Tobacco 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  7. Use of respondent driven sampling (RDS generates a very diverse sample of men who have sex with men (MSM in Buenos Aires, Argentina.

    Directory of Open Access Journals (Sweden)

    Alex Carballo-Diéguez

    Full Text Available Prior research focusing on men who have sex with men (MSM conducted in Buenos Aires, Argentina, used convenience samples that included mainly gay identified men. To increase MSM sample representativeness, we used Respondent Driven Sampling (RDS for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited sample, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior.500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI.In contrast with prior studies, RDS generated a very diverse sample of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as "other." Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49% reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size.

  8. Comparison of dioxin-like PCBs in passive air and vegetation samples surrounding a metal reclamation incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Lucaciu, C.M.; Fayez, L.; Reiner, E.J.; Kolic, T.M.; MacPherson, K.A.; Crozier, P.W.; Emerson, R. [Ontario Ministry of the Environment, Toronto, ON (Canada); Wania, F. [Toronto Univ., Scarborough, ON (Canada). Dept. of Physical and Environmental Sciences

    2004-09-15

    In 1998 the WHO identified 12 PCBs to be dioxin-like (DLPCB). This list includes 4 coplanar: 77, 81, 126, 169 and 8 mono-ortho: 105, 114, 118, 123, 156, 157, 167 and 189 congeners. Determination of DLPCBs allows results to be converted into TEQ (toxic equivalent quantity of 2,3,7,8-TCDD) values and enables data comparison at very low (sub ppt (pg/g)) levels. Vegetation and air samples were collected from an area surrounding a metal recovery incinerator in order to assess spatial and temporal trends for DLPCBs stemming from the long term operation of the incinerator. Foliage samples were harvested in September (1999 - 2 sets, 2000 to 2003) from maple and ash trees surrounding the incinerator at varying distances. Mature tree leaves are exposed to atmospheric deposition of PCBs for about 4 months (June to September) and the levels determined in foliage are representative of DLPCBs in the atmosphere surrounding each tree. Additionally, a passive air sampling technique based on the sorption of gaseous pollutants on XAD-2 (a styrene-divinylbenzene co-polymer) resin was used for measuring long-term average gas-phase concentrations in the area surrounding the incinerator. Ten passive samplers were placed adjacent to trees previously sampled for DLPCBs at locations presented in Figure 1. The deployment period, lasting approximately 4 month (June to September 2003), corresponds to the time that mature leaves were present on the adjacent trees. Four other air samplers were placed close to a main highway in Toronto in order to compare the concentration of DLPCB in the urban area with the concentration in the rural area surrounding the incineration facility. Passive air samplers allow the characterization of the gaseous distribution of DLPCBs in the atmosphere. The advantages of using this technique are that it is independent of the atmospheric conditions (winds, precipitation, UV exposure) and can be used for sampling year round. Atmospheric deposition is expected to control

  9. A whole-air relaxed eddy accumulation measurement system for sampling vertical vapour exchange of elemental mercury

    Directory of Open Access Journals (Sweden)

    Jonas Sommar

    2013-11-01

    Full Text Available An apparatus relying on relaxed eddy accumulation (REA methodology has been designed and developed for continuous-field measurements of vertical Hg0 fluxes over cropland ecosystems. This micro-meteorological technique requires sampling of turbulent eddies into up- and downdraught channels at a constant flow rate and accurate timing, based on a threshold involving the sign of vertical wind component (w. The fully automated system is of a whole-air type drawing air at a high velocity to the REA sampling apparatus and allowing for the rejection of samples associated with w-fluctuations around zero. Conditional sampling was executed at 10-Hz resolution on a sub-stream by two fast-response three-way solenoid switching valves connected in parallel to a zero Hg0 air supply through their normally open ports. To suppress flow transients resulting from switching, pressure differentials across the two upstream ports of the conditional valves were minimised using a control unit. The Hg0 concentrations of the up- and downdraught channel were sequentially (each by two consecutive 5-minute gas samples determined after enhancement collection onto gold traps by an automated cold vapour atomic fluorescence spectrophotometer (CVAFS instrument. A protocol of regular reference sampling periods was implemented during field campaigns to continuously adjust for bias that may exist between the two conditional sampling channels. Using a 5-minute running average was conditional threshold, nearly-constant relaxation coefficients (β s of ~0.56 were determined during two bi-weekly field deployments when turbulence statistics were assured for good quality, in accordance with previously reported estimates. The fully developed REA-CVAFS system underwent Hg0 flux field trial runs at a winter wheat cropland located in the North China Plain. Over a 15-d period during early May 2012, dynamic, often bi-directional, fluxes were observed during the course of a day with a tendency of

  10. Auditing of sampling methods for air toxics at coal-fired power plants

    International Nuclear Information System (INIS)

    Agbede, R.O.; Clements, J.L.; Grunebach, M.G.

    1995-01-01

    Advanced Technology Systems, Inc. (ATS) with subcontract assistance from international Technology Corporation (IT) has provided external audit activities for Phase II of the Department of Energy-Pittsburgh Energy Technology Center's air emission test program. The objective of the audits is to help ensure that the data obtained from the emission tests are precise, accurate, representative, scientifically sound and legally defensible. This paper presents the criteria that were used to perform the external audits of the emission test program. It also describes the approach used by ATS and It in performing their audits. Examples of findings of the audits along with the actions take to correct problems and the subsequent effect of those actions on the test data are presented. The results of audit spikes performed at the Plant 1 test site are also discussed

  11. Performance assessment of refractory samples in the Los Alamos Controlled Air Incinerator

    International Nuclear Information System (INIS)

    Hutchins, D.A.; Borduin, L.C.; Koenig, R.A.; Vavruska, J.S.; Warner, C.L.

    1986-01-01

    A refractory evaluation project was initiated in 1979 to study the performance of six selected refractory materials within the Los Alamos Controlled Air Incinerator (CAI). Determining refractory resistance to thermal shock, chemical attack, and plutonium uptake was of particular interest. The experimental refractories were subjected to a variety of waste materials, including transuranic (TRU) contaminated wastes, highly chlorinated compounds and alkaline metal salts of perchlorate, chlorate, nitrate and oxylate, over the six year period of this study. Results of this study to date indicate that the use of high alumina, and possibly specialty plastic refractories, is advisable for the lining of incinerators used for the thermal destruction of diverse chemical compounds. 12 refs., 4 tabs

  12. Auditing of sampling methods for air toxics at coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Agbede, R.O.; Clements, J.L.; Grunebach, M.G. [Advanced Technology Systems, Inc., Monroeville, PA (United States)] [and others

    1995-11-01

    Advanced Technology Systems, Inc. (ATS) with subcontract assistance from international Technology Corporation (IT) has provided external audit activities for Phase II of the Department of Energy-Pittsburgh Energy Technology Center`s air emission test program. The objective of the audits is to help ensure that the data obtained from the emission tests are precise, accurate, representative, scientifically sound and legally defensible. This paper presents the criteria that were used to perform the external audits of the emission test program. It also describes the approach used by ATS and It in performing their audits. Examples of findings of the audits along with the actions take to correct problems and the subsequent effect of those actions on the test data are presented. The results of audit spikes performed at the Plant 1 test site are also discussed.

  13. Quantitative analysis of semivolatile organic compounds in selected fractions of air sample extracts by GC/MI-IR spectrometry

    International Nuclear Information System (INIS)

    Childers, J.W.; Wilson, N.K.; Barbour, R.K.

    1990-01-01

    The authors are currently investigating the capabilities of gas chromatography/matrix isolation infrared (GC/MI-IR) spectrometry for the determination of semivolatile organic compounds (SVOCs) in environmental air sample extracts. Their efforts are focused on the determination of SVOCs such as alkylbenzene positional isomers, which are difficult to separate chromatographically and to distinguish by conventional electron-impact ionization GC/mass spectrometry. They have performed a series of systematic experiments to identify sources of error in quantitative GC/MI-IR analyses. These experiments were designed to distinguish between errors due to instrument design or performance and errors that arise from some characteristic inherent to the GC/MI-IR technique, such as matrix effects. They have investigated repeatability as a function of several aspects of GC/MI IR spectrometry, including sample injection, spectral acquisition, cryogenic disk movement, and matrix deposition. The precision, linearity, dynamic range, and detection limits of a commercial GC/MI-IR system for target SVOCs were determined and compared to those obtained with the system's flame ionization detector. The use of deuterated internal standards in the quantitative GC/MI-IR analysis of selected fractions of ambient air sample extracts will be demonstrated. They will also discuss the current limitations of the technique in quantitative analyses and suggest improvements for future consideration

  14. Air modelling as an alternative to sampling for low-level radioactive airborne releases

    International Nuclear Information System (INIS)

    Morgenstern, M.Y.; Hueske, K.

    1995-01-01

    This paper describes our efforts to assess the effect of airborne releases at one DOE laboratory using air modelling based on historical data. Among the facilities affected by these developments is Los Alamos National Laboratory (LANL) in New Mexico. RCRA, as amended by the Hazardous and Solid Waste Amendments (HSWA) in 1984, requires all facilities which involve the treatment, storage, and disposal of hazardous waste obtain a RCRA/HSWA waste facility permit. LANL complied with CEARP by initiating a process of identifying potential release sites associated with LANL operations prior to filing a RCRA/HSWA permit application. In the process of preparing the RCRA/HSWA waste facility permit application to the U.S. Environmental Protection Agency (EPA), a total of 603 Solid Waste Management Units (SWMUs) were identified as part of the requirements of the HSWA Module VIH permit requirements. The HSWA Module VIII permit requires LANL to determine whether there have been any releases of hazardous waste or hazardous constituents from SWMUs at the facility dating from the 1940's by performing a RCRA Facility Investigation to address known or suspected releases from specified SWMUs to affected media (i.e. soil, groundwater, surface water, and air). Among the most troublesome of the potential releases sites are those associated with airborne radioactive releases. In order to assess health risks associated with radioactive contaminants in a manner consistent with exposure standards currently in place, the DOE and LANL have established Screening Action Levels (SALs) for radioactive soil contamination. The SALs for each radionuclide in soil are derived from calculations based on a residential scenario in which individuals are exposed to contaminated soil via inhalation and ingestion as well as external exposure to gamma emitters in the soil. The applicable SALs are shown

  15. Vertical melting of a stack of membranes

    Science.gov (United States)

    Borelli, M. E. S.; Kleinert, H.; Schakel, A. M. J.

    2001-02-01

    A stack of tensionless membranes with nonlinear curvature energy and vertical harmonic interaction is studied. At low temperatures, the system forms a lamellar phase. At a critical temperature, the stack disorders vertically in a melting-like transition.

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

    Science.gov (United States)

    Demange, Martine; Oury, Véronique; Rousset, Davy

    2011-11-01

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

  17. Crystallite size effects in stacking faulted nickel hydroxide and its electrochemical behaviour

    International Nuclear Information System (INIS)

    Ramesh, T.N.

    2009-01-01

    β-Nickel hydroxide comprises a long range periodic arrangement of atoms with a stacking sequence of AC AC AC-having an ideal composition Ni(OH) 2 . Variation in the preparative conditions can lead to the changes in the stacking sequence (AC AC BA CB AC AC or AC AC AB AC AC). This type of variation in stacking sequence can result in the formation of stacking fault in nickel hydroxide. The stability of the stacking fault depends on the free energy content of the sample. Stacking faults in nickel hydroxide is essential for better electrochemical activity. Also there are reports correlating particle size to the better electrochemical activity. Here we present the effect of crystallite size on the stacking faulted nickel hydroxide samples. The electrochemical performance of stacking faulted nickel hydroxide with small crystallite size exchanges 0.8e/Ni, while the samples with larger crystallite size exchange 0.4e/Ni. Hence a right combination of crystallite size and stacking fault content has to be controlled for good electrochemical activity of nickel hydroxide

  18. Stack monitor for the Proof-of-Breeding Project

    International Nuclear Information System (INIS)

    Fergus, R.W.

    1985-01-01

    This stack monitor system is a coordinated arrangement of hardware and software to monitor four hot cells (8 stacks) during the fuel dissection for the Proof-of-Breeding Project. The cell monitors, which are located in fan lofts, contain a microprocessor, radiation detectors, air flow sensors, and air flow control equipment. Design criteria included maximizing microprocessor control while minimizing the hardware complexity. The monitors have been programmed to produce concentration and total activity release data based on several detector measurements and flow rates. Although each monitor can function independently, a microcomputer can also be used to control each cell monitor including reprogramming if necessary. All programming is software, as opposed to firmware, with machine language for compactness in the cell monitors and Basic language for adaptability in the microcomputer controller

  19. USDA Forest Service national protocols for sampling air pollution-sensitive waters

    Science.gov (United States)

    T. J. Sullivan

    2012-01-01

    The first step in designing a surface water sampling program is identifying one or more problems or questions that require information on water quality. Common water quality problems include nutrient enrichment (from a variety of causes), effects of atmospheric deposition (acidification, eutrophication, toxicity), and effects of major disturbances such as fire or pest...

  20. Tank vapor sampling and analysis data package for tank 241-C-106 waste retrieval sluicing system process test phase III, sampled March 28, 1999

    International Nuclear Information System (INIS)

    LOCKREM, L.L.

    1999-01-01

    This data package presents sampling data and analytical results from the March 28, 1999, vapor sampling of Hanford Site single-shell tank 241-C-106 during active sluicing. Samples were obtained from the 296-C-006 ventilation system stack and ambient air at several locations. Characterization Project Operations (CPO) was responsible for the collection of all SUMMATM canister samples. The Special Analytical Support (SAS) vapor team was responsible for the collection of all triple sorbent trap (TST), sorbent tube train (STT), polyurethane foam (PUF), and particulate filter samples collected at the 296-C-006 stack. The SAS vapor team used the non-electrical vapor sampling (NEVS) system to collect samples of the air, gases, and vapors from the 296-C-006 stack. The SAS vapor team collected and analyzed these samples for Lockheed Martin Hanford Corporation (LMHC) and Tank Waste Remediation System (TWRS) in accordance with the sampling and analytical requirements specified in the Waste Retrieval Sluicing System Vapor Sampling and Analysis Plan (SAP) for Evaluation of Organic Emissions, Process Test Phase III, HNF-4212, Rev. 0-A, (LMHC, 1999). All samples were stored in a secured Radioactive Materials Area (RMA) until the samples were radiologically released and received by SAS for analysis. The Waste Sampling and Characterization Facility (WSCF) performed the radiological analyses. The samples were received on April 5, 1999

  1. Helping Students Design HyperCard Stacks.

    Science.gov (United States)

    Dunham, Ken

    1995-01-01

    Discusses how to teach students to design HyperCard stacks. Highlights include introducing HyperCard, developing storyboards, introducing design concepts and scripts, presenting stacks, evaluating storyboards, and continuing projects. A sidebar presents a HyperCard stack evaluation form. (AEF)

  2. Evaluation of a passive sampling system of CPVC for nitrogen dioxide in the air

    International Nuclear Information System (INIS)

    Rojas-Bolanos, Omar; Jimenez-Barrantes, Irene

    2012-01-01

    Passive diffusion tubes have been built to determine the concentration of NO 2 in the air with poly tubes (vinyl chloride) chloride (CPVC). The performance has been evaluated during the 2008, through comparisons of their results with the results obtained, using the method modified Griess-Saltzman, recommended by the World Health Organization. The comparison results have shown good agreement between the two methodologies with respect to NO 2 concentrations of 45-85 μg/m''3. Linear regression when used by minimum simple square and ranges test and Wilcoxon signs, no significant differences found between the results provided by both methods. Relative bias calculated in 7 comparisons has varied from -19,05% to 24,44% with an average of 5,76%. The results have indicated that the passive tubes overestimated the concentration of NO 2 ; without however, this bias has not been higher than those reported by other authors. The precision the passive system has been in the field of 5,2% to 10,6%, measured in four tubes through the coefficient of variation, similar to reported by other researchers. (author) [es

  3. Availability Analysis of the Ventilation Stack CAM Interlock System

    CERN Document Server

    Young, J

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

  4. Basic design parameters for the new PRR-1 stack

    International Nuclear Information System (INIS)

    Leopando, L.S.

    1994-01-01

    This report presents the results of work done to establish the basic design parameters of the new stack of the Philippine Research Reactor-1 (PRR-1). The work was undertaken to assure that the radioactive air emissions of the PRR-1, under both accident and normal operating conditions, will comply with modern safety practices. The work was done during June and July 1994. (author). 6 refs., 13 figs., 13 tabs

  5. Review of the stack discharge active particle contamination problem

    Energy Technology Data Exchange (ETDEWEB)

    Parker, H M

    1948-03-22

    Quantities of the order of ten million to 100 million radioactive particles per month were emitted from the stacks over a period of several months. High activity in the range 0.1 to 3..mu..c was probably confined to large carrier particles of corrosion debris from iron ductwork in the separations plant ventilation air system. This report discusses chemical, physical and radiochemical properties of the particles, and possible biological and health effects of exposure to them. (ACR)

  6. PRECISION COSMOGRAPHY WITH STACKED VOIDS

    International Nuclear Information System (INIS)

    Lavaux, Guilhem; Wandelt, Benjamin D.

    2012-01-01

    We present a purely geometrical method for probing the expansion history of the universe from the observation of the shape of stacked voids in spectroscopic redshift surveys. Our method is an Alcock-Paczyński (AP) test based on the average sphericity of voids posited on the local isotropy of the universe. It works by comparing the temporal extent of cosmic voids along the line of sight with their angular, spatial extent. We describe the algorithm that we use to detect and stack voids in redshift shells on the light cone and test it on mock light cones produced from N-body simulations. We establish a robust statistical model for estimating the average stretching of voids in redshift space and quantify the contamination by peculiar velocities. Finally, assuming that the void statistics that we derive from N-body simulations is preserved when considering galaxy surveys, we assess the capability of this approach to constrain dark energy parameters. We report this assessment in terms of the figure of merit (FoM) of the dark energy task force and in particular of the proposed Euclid mission which is particularly suited for this technique since it is a spectroscopic survey. The FoM due to stacked voids from the Euclid wide survey may double that of all other dark energy probes derived from Euclid data alone (combined with Planck priors). In particular, voids seem to outperform baryon acoustic oscillations by an order of magnitude. This result is consistent with simple estimates based on mode counting. The AP test based on stacked voids may be a significant addition to the portfolio of major dark energy probes and its potentialities must be studied in detail.

  7. Docker on OpenStack

    OpenAIRE

    Agarwal, Nitin; Moreira, Belmiro

    2014-01-01

    Project Specification CERN is establishing a large scale private cloud based on OpenStack as part of the expansion of the computing infrastructure for storing the data coming out of the Large Hadron Collider (LHC) experiments. As the data coming out of the detectors is increasing continuously that needs to be stored in the data center, we need more physical resources (more money) and since Virtual machines takes lot of CPU and memory overhead and minutes for creating the images, booting u...

  8. Escherichia coli in settled-dust and air samples collected in residential environments in Mexico City.

    OpenAIRE

    Rosas, I; Salinas, E; Yela, A; Calva, E; Eslava, C; Cravioto, A

    1997-01-01

    Escherichia coli, an important indicator of the presence of fecal material, was isolated from indoor and outdoor environments in Mexico City. The heterogeneity of E. coli was represented by 89 serotypes, most of them coming from settled-dust indoor samples; 21% of them presented antibiotic multiresistance. The numbers of plasmids were higher among the antibiotic-resistant strains. The results of this study suggest that intestinal infections produced by environmental strains could be of more e...

  9. U.S. Air Force School of Aerospace Medicine Laboratory Sampling and Analysis Guide

    Science.gov (United States)

    2016-11-15

    Clay Sand Gravel Page | 63 DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. Cleared, 88PA, # 2014-0577...solid/liquid, media will collect semi-liquid only. Not for high viscosity liquids. Dipper (or “pond sampler”) ASTM D5358 ASTM D5013 USEPA...decontamination may be difficult. Limited by length of sampler, small volume of sample collected, and viscosity of fluids. Page | 71

  10. Study of lead pollution in air, soil and water samples of Quetta city

    International Nuclear Information System (INIS)

    Khan, M.; Khan, G.M.; Akbar, S.; Panezai, M.A.; Haq, Z.U.

    2011-01-01

    This study briefly presents the collected data of lead pollution in the environment of Quetta City in Balochistan, Pakistan. The samples were collected from different sites. The analysis of lead was carried out in underground water samples, the exhaust of different vehicles, roadside and sewage soils from selected points of Quetta City. The average discharge resulted in deposition by motorcycles (29.12 g/h), cars (44.47 g/h), wagons (176.54 g/h) and buses (141.52 g/h). The maximum deposition was 222.96 g/h from auto-rickshaws. The value for lead in smoke of different vehicles seems quite high when extrapolated to the large number of such vehicles for a longer time. The concentration of lead in roadside soil varied from 73.3 mg/kg (T and T closed colony) to 731.9 mg/kg (Sirki road bus-stop). The average content of lead in sewage soil of City Nala is 1250.6 mg/kg. The level of lead was more than WHO standards for such soils. The lead quantity in all 24 tube- well water samples, was slightly above the WHO standards (10 macro g/L).The results of this study were comparable to similar study in twin cities of Rawalpindi and islamabad. (author)

  11. Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

    Directory of Open Access Journals (Sweden)

    C. Romero-Trigueros

    2017-10-01

    Full Text Available Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID is studied. Two reference gas mixtures (40 and 5 µg m−3 nominal concentration benzene in air were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C. When measuring a concentration of 0.5 µg m−3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m−3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m−3, biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm−3 – corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

  12. Occurrence of commonly used pesticides in personal air samples and their associated health risk among paddy farmers.

    Science.gov (United States)

    Hamsan, Hazwanee; Ho, Yu Bin; Zaidon, Siti Zulfa; Hashim, Zailina; Saari, Nazamid; Karami, Ali

    2017-12-15

    Tanjung Karang, Selangor, is widely known for its paddy cultivation activity and hosts the third largest paddy field in Malaysia. Pesticides contamination in agriculture fields has become an unavoidable problem, as pesticides are used to increase paddy productivity and reduce plant disease. Human exposure to agrichemicals is common and could results in both acute and chronic health effects, such as acute and chronic neurotoxicity. This study aims to determine the concentrations of commonly used pesticides (azoxystrobin, buprofezin, chlorantraniliprole, difenoconazole, fipronil, imidacloprid, isoprothiolane, pretilachlor, propiconazole, pymetrozine, tebuconazole, tricyclazole, and trifloxystrobin) in personal air samples and their associated health risks among paddy farmers. Eighty-three farmers from Tangjung Karang, Selangor were involved in this study. A solid sorbent tube was attached to the farmer's breathing zone with a clip, and an air pump was fastened to the belt to collect personal air samples. Pesticides collected in the XAD-2 resin were extracted with acetone, centrifuged, concentrated via nitrogen blowdown and reconstituted with 1mL of 3:1 ultrapure water/HPLC-grade methanol solution. The extract was analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The target compounds were detected with a maximum concentration reaching up to 462.5ngm -3 (fipronil). The hazard quotient (HQ) was less than 1 and the hazard index (HI) value was 3.86×10 -3 , indicating that the risk of pesticides related diseases was not significant. The lifetime cancer risk (LCR) for pymetrozine was at an acceptable level (LCR<10 -6 ) with 4.10×10 -8 . The results reported in this study can be beneficial in terms of risk management within the agricultural community. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Radon and thoron progeny levels in air samples at Udagamandalam region of Nilgiris in India

    International Nuclear Information System (INIS)

    Manikandan, N.M.; Selvasekarapandian, S.; Sivakumar, R.; Raghunath, V.M.; Sundaram, V.M.; Santhanam, S.

    2002-01-01

    Measurement of concentration of radon and thoron daughter products in various indoor environment covering four seasons of a year in Udagamandalam Taluk of Nilgiris biosphere has been carried out using a high volume air sampler to assess the inhalation dose to the population which delivers higher dose than the radon and thoron gas alone. The potential alpha-energy concentrations of the radon and thoron progeny ranged from 0.97 to 12.72 mWL and from 1.63 to 15.83 mWL with a geometric mean of 6.02 and 7.89 mWL, respectively, taking all seasons into account. These measurements have yielded a wealth of data on the variation among the indoor radon and thoron progeny in various places during different seasons. The radon and thoron progeny levels are higher in winter seasons and are less in summer season with autumn and spring data lie in between winter and summer. Using the dose conversion factor for indoor exposures given in UNSCEAR 93 report the internal equivalent dose to the inhalation of radon progeny is evaluated to be 1357 μSv x y -1 and the corresponding annual effective dose equivalent value has been found to be 2.13 mSv x y -1 . It can be observed that the mean value of radon is higher than the Indian average. Also it is found the radon and thoron progeny levels are higher in the case of houses built with rock and granite and in tiled type houses of nearly 100 years old. The levels are less in the case of houses built with brick and cement. The observed results for different types of houses and seasons are discussed in this paper. (author)

  14. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds.

    Science.gov (United States)

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks' air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.

  15. A small mono-polar direct methanol fuel cell stack with passive operation

    Science.gov (United States)

    Chan, Y. H.; Zhao, T. S.; Chen, R.; Xu, C.

    A passive direct methanol fuel cell (DMFC) stack that consists of six unit cells was designed, fabricated, and tested. The stack was tested with different methanol concentrations under ambient conditions. It was found that the stack performance increased when the methanol concentration inside the fuel tank was increased from 2.0 to 6.0 M. The improved performance is primarily due to the increased cell temperature as a result of the exothermic reaction between the permeated methanol and oxygen on the cathode. Moreover, the increased cell temperature enhanced the water evaporation rate on the air-breathing cathode, which significantly reduced water flooding on the cathode and further improved the stack performance. This passive DMFC stack, providing 350 mW at 1.8 V, was successfully applied to power a seagull display kit. The seagull display kit can continuously run for about 4 h on a single charge of 25 cm 3 4.0-M methanol solution.

  16. A study on elemental composition in epiphytic lichen samples used as bioindicator of air pollution in Sao Paulo city

    International Nuclear Information System (INIS)

    Montezani, Edmila

    2010-01-01

    Studies on air pollution have intensified in recent years, due to the diversity of emissions and the effect caused to the health of populations. Consequently, several techniques have been investigated for air pollution evaluation and among them one that has gained considerable attention is that of biomonitoring. In this study chemical elemental levels in the atmosphere of Sao Paulo city were evaluated, by means of passive biomonitoring, using epiphytic Canoparmelia texana species, in order to compare between the results obtained in samples from different sites of Sao Paulo city and in a reference site of Ubatuba city, SP. Neutron activation analysis (NAA) procedure applied in the analyses consisted of irradiating aliquots of samples along with synthetic standards of elements in the nuclear reactor IEA-R1 for 16 hours under a thermal neutron flux of about 5.0 x 10 12 n cm -2 s -1 , followed by gamma ray spectrometry for the determination of As, Br, Ca, Co, Cr, Cs, Fe, K, La, Rb, Sc, Se and Zn. Results obtained in the analyses of lichens samples in replicates presented good reproducibility indicating homogeneity of the prepared samples. The precision and accuracy of the results were evaluated by the analyses of certified reference materials IAEA-336 Lichen and INCT-TL-1 Tea Leaves. Results obtained in the reference materials presented, in general, good precision, with relative standard deviations between 0.4 and 14.8% and good accuracy with relative errors between 0.2 and 8.7%. In Sao Paulo city, the lichens were collected in the following sites: Parque Dom Pedro II, Congonhas, Cidade Universitaria, Lapa, Mooca, Morumbi, Nossa Senhora do O, Parque Ibirapuera, Pinheiros, Santana, Santo Amaro and Taboao da Serra. Element concentrations found in lichens indicated a great variability depending on the sites where the samples were collected. The results obtained in the lichens submitted to the cluster analysis indicated three groups of sampling sites according to the

  17. Summertime PAH assembly in Mediterranean air: the Herceg Novi sampling station as an example

    Directory of Open Access Journals (Sweden)

    VLADIMIR Z. JOVANOVIC

    2007-02-01

    Full Text Available The results of an analysis of the total suspended particles (TSP, total solvent organic extracts (TSOE, and polycyclic aromatic hydrocarbons (PAHs in aerosol samples collected from the atmosphere of Herceg Novi from 17th June to 15th September in 1998 and 1999 are presented. The TSP and TSOE concentrations were determined by the standard gravimetric method, whereas the PAHs from the organic part of the aerosol were analysed by the GC-MS method. The difference found in the TSP and TSOE contents between the two consecutive years (before and after the bombing of Yugoslavia was attributed to changes in the intensity and origin of emissions from dominant sources, specific to the summer period of this region. The content and nature of the PAHs identified in the samples of 1998 and 1999 were also different, indicating the significance of traffic as the source of PAHs, which was of significantly lower intensity in 1999 (immediately after the war due to the lower influx of tourists. Factor analysis showed that the PAH distribution at the measuring site in 1999 was largely determined by meteorological parameters, mainly by the average daily temperature and wind direction. In 1998, the dominant impact on the PAH distribution was attributed to traffic, both local and from a wider region, without an explicit impact of meteorological parameters.

  18. Evidence of a non-dimensional parameter controlling the flooding of PEMFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buaud, Fabrice; Lelandais, Damien [Heat and Energy Department, Polytech' Nantes, Nantes University, Rue Christian Pauc, BP50609, 44 306 Nantes Cedex 3 (France); Auvity, Bruno [Heat and Energy Department, Polytech' Nantes, Nantes University, Rue Christian Pauc, BP50609, 44 306 Nantes Cedex 3 (France); Laboratoire de Thermocinetique de Nantes (CNRS-UMR 6607) (France)

    2008-06-15

    Water management is a key issue to get satisfactory and stable Polymer exchange membrane fuel cell (PEMFC) performances. The work reported in the present paper focuses on the determination of the operational conditions when using PEMFC stack working with ambient air without extra humidification. The objectives are to reduce as much as possible the auxiliaries consumptions. As far as the reaction air blower is concerned, the specific goal of the present tests is to find the minimum air flow rate to feed the PEMFC stack in order to prevent flooding. Our particular interest concerns the control of a PEMFC stack to power a prototype vehicle for the Shell Eco Marathon race. Tests are then conducted on a wide range of stoichiometry, for different values of current and stack temperature using ambient air. Flooding is shown to depend on all these parameters. A water balance calculation is developed comparing the amount of water produced by the electrochemical reaction to the amount of water transported as vapour in the exit air flow minus the amount of water incoming the stack in the ambient air. A non-dimensional number called the Flooding Number is constructed. This balance is first considered in the ideal case with the theoretical flow rate of reactants and products. It is shown that the stack temperature and the stoichiometry are the main order parameters and that conditions of ambient air have only secondary effects on the water balance. In a second step, the Flooding Number is evaluated for all the experimental tests. A critical Flooding Number appears clearly delimiting the range of operational conditions for which stack flooding appears. This result allows us to control the air blower and the cooling fan during the runs at the Shell Eco Marathon 2007 race in order to reduce hydrogen consumption due to auxiliaries. The non-dimensional number exhibited in the present paper is believed to be relevant to stack flooding. It can be used for any PEMFC stack to make clear

  19. Air, hand wipe, and surface wipe sampling for Bisphenol A (BPA) among workers in industries that manufacture and use BPA in the United States.

    Science.gov (United States)

    Hines, Cynthia J; Jackson, Matthew V; Christianson, Annette L; Clark, John C; Arnold, James E; Pretty, Jack R; Deddens, James A

    2017-11-01

    For decades, bisphenol A (BPA) has been used in making polycarbonate, epoxy, and phenolic resins and certain investment casting waxes, yet published exposure data are lacking for U.S. manufacturing workers. In 2013-2014, BPA air and hand exposures were quantified for 78 workers at six U.S. companies making BPA or BPA-based products. Exposure measures included an inhalable-fraction personal air sample on each of two consecutive work days (n = 146), pre- and end-shift hand wipe samples on the second day (n = 74 each), and surface wipe samples (n = 88). Potential determinants of BPA air and end-shift hand exposures (after natural log transformation) were assessed in univariate and multiple regression mixed models. The geometric mean (GM) BPA air concentration was 4.0 µg/m 3 (maximum 920 µg/m 3 ). The end-shift GM BPA hand level (26 µg/sample) was 10-times higher than the pre-shift level (2.6 µg/sample). BPA air and hand exposures differed significantly by industry and job. BPA air concentrations and end-shift hand levels were highest in the BPA-filled wax manufacturing/reclaim industry (GM Air = 48 µg/m 3 , GM Hand-End = 130 µg/sample) and in the job of working with molten BPA-filled wax (GM Air = 43 µg/m 3 , GM Hand-End = 180 µg/sample), and lowest in the phenolic resins industry (GM Air = 0.85 µg/m 3 , GM Hand-End = 0.43 µg/sample) and in the job of flaking phenolic resins (GM AIR = 0.62 µg/m 3 , GM Hand-End = 0.38 µg/sample). Determinants of increased BPA air concentration were industry, handling BPA containers, spilling BPA, and spending ≥50% of the shift in production areas; increasing age was associated with lower air concentrations. BPA hand exposure determinants were influenced by high values for two workers; for all other workers, tasks involving contact with BPA-containing materials and spending ≥50% of the shift in production areas were associated with increased BPA hand levels. Surface wipe BPA levels were significantly lower in

  20. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    As SOFC technology is moving closer to a commercial break through, methods to measure the “state-of-health” of operating stacks are becoming of increasing interest. This requires application of advanced methods for detailed electrical and electrochemical characterization during operation....... An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

  1. Occurrence of benzothiazole, benzotriazole and benzenesulfonamide derivates in outdoor air particulate matter samples and human exposure assessment.

    Science.gov (United States)

    Maceira, Alba; Marcé, Rosa Maria; Borrull, Francesc

    2018-02-01

    Benzothiazole (BTHs), benzotriazole (BTRs) and benzenesulfonamide (BSAs) derivates are high production volume chemicals and they are used in several industrial and household applications, therefore it is expected their occurrence in various environments, especially water and air. In this study we developed a method based on gas chromatography-mass spectrometry (GC-MS) combined with pressurised liquid extraction (PLE) to simultaneously determine four BTR, five BTH and six BSA derivates in the particulate matter (PM 10 ) of outdoor air samples collected in quartz fibre filters (QFFs). To the best of our knowledge, this is the first time these compounds have been determined in open ambient environments. Under optimised conditions, method recoveries at the lower and upper concentration levels (0.8 and 4.2 ng m -3 ) ranged from 70 to 120%, except for 1-H-benzothiazole and 2-chlorobenzothiazole, which were about 50%. The repeatability of the method was usually below 20% (n = 3, %RSD) for both concentration levels. This method enables the contaminants to be detected at pg m -3 concentration levels. Several samples from two different sites influenced by local industries showed that BTRs, followed by BTHs, were the most detected compounds, whereas BSAs were hardly found. The most frequently determined compounds were 1-H-benzothiazole, 2-chlorobenzothiazole, 1-H-benzotriazole, 2-hydroxibenzothiazole, 5,6-dimethyl-1-H-benzotriazole and the isomers 4- and 5-methyl-1-H-benzotriazole. With the concentrations found, the human exposure assessment and health risk characterization via ambient inhalation were also evaluated taking into account different subpopulation groups classified by age for the two sampling points. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Stacking and discontinuous buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Shihabi, Z K

    2000-08-01

    Discontinuous buffers for capillary zone electrophoresis (CZE) can be used under less rigid conditions compared to those for isotachophoresis for stacking. They can be prepared simply by modifying the sample itself, either by addition of small inorganic ions, low conductivity diluents, or both, and also by adjusting its pH, meanwhile injecting a large volume on the capillary. Zwitterionic and organic-based buffers such as triethanolamine and tris(hydroxymethyl)aminomethane (Tris) are well suited for stacking due to their low conductivity, provided the buffer is discontinuous as demonstrated here. A simple mechanism based on discontinuous buffers is described to explain many of the observed stacking types in CZE, pointing out the many similarities to transient isotachophoresis.

  3. Investigation of type and density of bio-aerosols in air samples from educational hospital wards of Kerman city, 2014

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2016-10-01

    Full Text Available Background: Bio-aerosols in the air of hospital wards have an important role in the development of infections. It is important to make quantitative and qualitative estimations of microorganisms in the air of these wards as an index for environmental hygiene applicable to different hospital wards. The aim of the study was to investigate degrees of diversity and density of bio-aerosols in the education hospitals of Kerman city. Methods: This study applied a descriptive-cross-sectional methodology in the second half of 2014 in the education hospitals of Kerman city, with bed capacity of over 300. As many as 200 samples were collected from the air in different wards of each hospital using the standard method of the National Occupational Health and Safety Institute. Following collection, samples were placed in an incubator for 48 hours and then bio-aerosol detections were made for and resulting data reported as colonies/m3. Results: Results indicated that maximum and minimum degrees of bacterial density were observed in operation rooms and in the intensive care unit (ICU of Shafa hospital. Furthermore, comparison showedthat the operating room at Afzalipour hospital had the lowest level of fungal contamination, while ICU at Bahonar hospital had the highest level of fungal contamination. The emitted fungi of Aspergillus and Penicillium along with the bacteria, staphylococci and Acinetobacter had greater frequencies. The means of bacterial density and fungal density were not equal across the studied hospitals and significant statistical, difference was observed between means of bacterial and fungal density (P ≤ 0.001. Conclusion: Amounts of bacterial and fungal density were greater than those proposed in the American Industrial Health State Conference in 73.3% of the wards in the educational hospitals of Kerman city sampled in this study. Therefore it is suggested that implementation of some, necessary measures for continuous monitoring, promotion of

  4. Formaldehyde exposure in U.S. industries from OSHA air sampling data.

    Science.gov (United States)

    Lavoue, Jerome; Vincent, Raymond; Gerin, Michel

    2008-09-01

    National occupational exposure databanks have been cited as sources of exposure data for exposure surveillance and exposure assessment for occupational epidemiology. Formaldehyde exposure data recorded in the U.S Integrated Management Information System (IMIS) between 1979 and 2001 were collected to elaborate a multi-industry retrospective picture of formaldehyde exposures and to identify exposure determinants. Due to the database design, only detected personal measurement results (n = 5228) were analyzed with linear mixed-effect models, which explained 29% of the total variance. Short-term measurement results were higher than time-weighted average (TWA) data and decreased 18% per year until 1987 (TWA data 5% per year) and 5% per year (TWA data 4% per year) after that. Exposure varied across industries with maximal estimated TWA geometric means (GM) for 2001 in the reconstituted wood products, structural wood members, and wood dimension and flooring industries (GM = 0.20 mg/m(3). Highest short-term GMs estimated for 2001 were in the funeral service and crematory and reconstituted wood products industries (GM = 0.35 mg/m(3). Exposure levels in IMIS were marginally higher during nonprogrammed inspections compared with programmed inspections. An increasing exterior temperature tended to cause a decrease in exposure levels for cold temperatures (-5% per 5 degrees C for T 15 degrees C). Concentrations measured during the same inspection were correlated and varied differently across industries and sample type (TWA, short term). Sensitivity analyses using TOBIT regression suggested that the average bias caused by excluding non-detects is approximately 30%, being potentially higher for short-term data if many non-detects were actually short-term measurements. Although limited by availability of relevant exposure determinants and potential selection biases in IMIS, these results provide useful insight on formaldehyde occupational exposure in the United States in the last

  5. Large area gridded ionisation chamber and electrostatic precipitator. Application to low-level alphaspectrometry of environmental air samples

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1978-01-01

    A high-resolution, parallel plate Frisch grid ionisation chamber with an efficient area of 300 cm 2 and a large area electrostatic precipitator were developed and applied to direct alpha-particle spectrometry of air dust. The aerosols were deposited on circular tin-plate dishes of 300 cm 2 by the electrostatic precipitator, which was constructed for continuous operation at an air flow rate of 2 m 3 /h. Collection efficiency is found to be 0.78 for the natural Rn- and Tn-daughter products. Using an argon-methane mixture (P-10 gas) at atmospheric pressure, the resolution of the detector system is 22 keV fwhm at 5.15 MeV. The integral background is typically 15.7 counts/h between 4 and 6 MeV. After sampling for one week and decay of short-lived natural activity, the sensitivity of the procedure for long-lived alpha-emitters is about 0.1 fCi/m 3 based on 3s of background as detection limit and 1000 min counting time. (Auth.)

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

    Directory of Open Access Journals (Sweden)

    O. Membrive

    2017-06-01

    Full Text Available An original and innovative sampling system called AirCore was presented by NOAA in 2010 (Karion et al., 2010. It consists of a long (>  100 m and narrow (<  1 cm stainless steel tube that can retain a profile of atmospheric air. The captured air sample has then to be analyzed with a gas analyzer for trace mole fraction. In this study, we introduce a new AirCore aiming to improve resolution along the vertical with the objectives to (i better capture the vertical distribution of CO2 and CH4, (ii provide a tool to compare AirCores and validate the estimated vertical resolution achieved by AirCores. This (high-resolution AirCore-HR consists of a 300 m tube, combining 200 m of 0.125 in. (3.175 mm tube and a 100 m of 0.25 in. (6.35 mm tube. This new configuration allows us to achieve a vertical resolution of 300 m up to 15 km and better than 500 m up to 22 km (if analysis of the retained sample is performed within 3 h. The AirCore-HR was flown for the first time during the annual StratoScience campaign from CNES in August 2014 from Timmins (Ontario, Canada. High-resolution vertical profiles of CO2 and CH4 up to 25 km were successfully retrieved. These profiles revealed well-defined transport structures in the troposphere (also seen in CAMS-ECMWF high-resolution forecasts of CO2 and CH4 profiles and captured the decrease of CO2 and CH4 in the stratosphere. The multi-instrument gondola also carried two other low-resolution AirCore-GUF that allowed us to perform direct comparisons and study the underlying processing method used to convert the sample of air to greenhouse gases vertical profiles. In particular, degrading the AirCore-HR derived profiles to the low resolution of AirCore-GUF yields an excellent match between both sets of CH4 profiles and shows a good consistency in terms of vertical structures. This fully validates the theoretical vertical resolution achievable by AirCores. Concerning CO2 although a

  7. Vertically stacked nanocellulose tactile sensor.

    Science.gov (United States)

    Jung, Minhyun; Kim, Kyungkwan; Kim, Bumjin; Lee, Kwang-Jae; Kang, Jae-Wook; Jeon, Sanghun

    2017-11-16

    Paper-based electronic devices are attracting considerable attention, because the paper platform has unique attributes such as flexibility and eco-friendliness. Here we report on what is claimed to be the firstly fully integrated vertically-stacked nanocellulose-based tactile sensor, which is capable of simultaneously sensing temperature and pressure. The pressure and temperature sensors are operated using different principles and are stacked vertically, thereby minimizing the interference effect. For the pressure sensor, which utilizes the piezoresistance principle under pressure, the conducting electrode was inkjet printed on the TEMPO-oxidized-nanocellulose patterned with micro-sized pyramids, and the counter electrode was placed on the nanocellulose film. The pressure sensor has a high sensitivity over a wide range (500 Pa-3 kPa) and a high durability of 10 4 loading/unloading cycles. The temperature sensor combines various materials such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), silver nanoparticles (AgNPs) and carbon nanotubes (CNTs) to form a thermocouple on the upper nanocellulose layer. The thermoelectric-based temperature sensors generate a thermoelectric voltage output of 1.7 mV for a temperature difference of 125 K. Our 5 × 5 tactile sensor arrays show a fast response, negligible interference, and durable sensing performance.

  8. Nitrogen and triple oxygen isotopes in near-road air samples using chemical conversion and thermal decomposition.

    Science.gov (United States)

    Smirnoff, Anna; Savard, Martine M; Vet, Robert; Simard, Marie-Christine

    2012-12-15

    The determination of triple oxygen (δ(18)O and δ(17)O) and nitrogen isotopes (δ(15)N) is important when investigating the sources and atmospheric paths of nitrate and nitrite. To fully understand the atmospheric contribution into the terrestrial nitrogen cycle, it is crucial to determine the δ(15)N values of oxidised and reduced nitrogen species in precipitation and dry deposition. In an attempt to further develop non-biotic methods and avoid expensive modifications of the gas-equilibration system, we have combined and modified sample preparation procedures and analytical setups used by other researchers. We first chemically converted NO(3)(-) and NH(4)(+) into NO(2)(-) and then into N(2)O. Subsequently, the resulting gas was decomposed into N(2) and O(2) and analyzed by isotope ratio mass spectrometry (IRMS) using a pre-concentration system equipped with a gold reduction furnace. The δ(17)O, δ(18)O and δ(15)N values of nitrate and nitrite samples were acquired simultaneously in one run using a single analytical system. Most importantly, the entire spectrum of δ(17)O, δ(18)O and/or δ(15)N values was determined from atmospheric nitrate, nitric oxide, ammonia and ammonium. The obtained isotopic values for air and precipitation samples were in good agreement with those from previous studies. We have further advanced chemical approaches to sample preparation and isotope analyses of nitrogen-bearing compounds. The proposed methods are inexpensive and easily adaptable to a wide range of laboratory conditions. This will substantially contribute to further studies on sources and pathways of nitrate, nitrite and ammonium in terrestrial nitrogen cycling. Copyright © 2012 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.

  9. Establishment of effective maintenance method based on the superior inspection technique for the deteriorating hot laboratory exhaust stack

    International Nuclear Information System (INIS)

    Mizukoshi, Yasutaka; Yasu, Tetsunori

    2012-06-01

    The Materials Monitoring Facility is equipped with an exhaust stack to emit air from a controlled area (the hot laboratory) into the atmosphere. Cracks and exfoliation have been observed for the surface of the exhaust stack, which is made of reinforced concrete and was constructed on the seacoast about 25 years ago, so exposed to a salt-corrosive condition. In order to get details of the present condition of the exhaust stack, an inspection was carried out using an electromagnetic wave radar method and chloride content method. Cracks and exfoliation were observed for the whole stack surface, especially for high positions. Moreover, salt damage was observed for the outer surface of the exhaust stack, and it was estimated that the infiltration of the chloride content was about 17 mm. Based on this detailed inspection of the exhaust stack, maintenance and repair work were carried out. (author)

  10. Sorption tubes packed with polydimethylsiloxane: a new and promising technique for the preconcentration of volatiles and semi-volatiles from air and gaseous samples

    NARCIS (Netherlands)

    Baltussen, H.A.; David, F.; Sandra, P.J.F.; Janssen, J.G.M.; Cramers, C.A.M.G.

    1998-01-01

    This paper is concerned with the determination of volatile and semi-volatile organic components in air and gaseous (headspace) samples, focusing primarily on polar analytes. Samples were analyzed by preconcentration on different (ad)sorbents followed by thermal desorption and analysis by capillary

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

    Science.gov (United States)

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

    1985-01-01

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

  12. A new stack effluent monitoring system at the Risoe Hot Cell plant

    International Nuclear Information System (INIS)

    Boetter-Jensen, L.; Hedemann Jensen, P.; Lauridsen, B.

    1984-06-01

    This report describes a new stack effluent monitoring system that has been installed at the Hot Cell facility. It is an integrating iodine/particulate system consisting of a γ-shielded flow house in which a continous air sample from the ventilation channel ia sucked through coal and glass filter papers. Activity is accumulated on the filter papers and a thin plastic scintillator detects the β-radiation from the trapped iodine or particulate activity. The stack effluent monitoring system has a two-step regulating function as applied to the ventilation system, first switching it to a recirculating mode, and finally to building-seal after given releases of 131 I. The collection efficiency for iodine in form of elementary iodine (I 2 ) and methyliodide (CH 3 I) has been determined experimentally. The unwanted response from a noble gas release has also been determined from experiments. The noble gas response was determined from puff releases of the nuclide 41 Ar in the concrete cells. It is concluded that the iodine/particulate system is extremely sensitive and that it can easily detect iodine or particulate releases as low as a few MBq. A gamma monitor placed in connection with the iodine/particulate system detects Xe/Kr-releases as low as a few tens of MBq per second. (author)

  13. From the components to the stack. Developing and designing 5kW HT-PEFC stacks; Von der Komponente zum Stack. Entwicklung und Auslegung von HT-PEFC-Stacks der 5 kW-Klasse

    Energy Technology Data Exchange (ETDEWEB)

    Bendzulla, Anne

    2010-12-22

    The aim of the present project is to develop a stack design for a 5-kW HTPEFC system. First, the state of the art of potential materials and process designs will be discussed for each component. Then, using this as a basis, three potential stack designs with typical attributes will be developed and assessed in terms of practicality with the aid of a specially derived evaluation method. Two stack designs classified as promising will be discussed in detail, constructed and then characterized using short stack tests. Comparing the stack designs reveals that both designs are fundamentally suitable for application in a HT-PEFC system with on-board supply. However, some of the performance data differ significantly for the two stack designs. The preferred stack design for application in a HT-PEFC system is characterized by robust operating behaviour and reproducible high-level performance data. Moreover, in compact constructions (120 W/l at 60 W/kg), the stack design allows flexible cooling with thermal oil or air, which can be adapted to suit specific applications. Furthermore, a defined temperature gradient can be set during operation, allowing the CO tolerance to be increased by up to 10 mV. The short stack design developed within the scope of the present work therefore represents an ideal basis for developing a 5-kW HT-PEFC system. Topics for further research activities include improving the performance by reducing weight and/or volume, as well as optimizing the heat management. The results achieved within the framework of this work clearly show that HTPEFC stacks have the potential to play a decisive role in increasing efficiency in the future, particularly when combined with an on-board supply system. (orig.) [German] Ziel der vorliegenden Arbeit ist die Entwicklung eines Stackkonzeptes fuer ein 5 kW-HT-PEFC System. Dazu wird zunaechst fuer jede Komponente der Stand der Technik moeglicher Materialien und Prozesskonzepte diskutiert. Darauf aufbauend werden drei

  14. Measurement of volatile organic compounds during start-up of bioremediation of French limited superfund site in Crosby Texas using wind dependent whole-air sampling

    International Nuclear Information System (INIS)

    Pleil, J.D.; Fortune, C.R.; Yoong, M.; Oliver, K.D.

    1993-01-01

    Whole-air sampling was performed before and after the start-up of the bioremediation of an industrial (primarily petrochemical) waste lagoon in Crosby Texas, near Houston. Four 'Sector Samplers' were deployed at the four corners of the French Limited Superfund Site. These samplers collect air into one of two SUMMA polished canisters depending upon wind direction and speed. When the wind blows at the sampler from across the waste lagoon, air is routed to the 'IN' sector canister, otherwise sample is collected in the 'OUT' sector canister. As such, each sampler provides its own background sample, and, upon gas chromatographic analysis, individual compounds can be associated with the waste lagoon. Five sets of 24-hour sector samples were taken; the first set was collected prior to the start of the bioremediation effort and the remaining four sets were taken sequentially for four 24-hour periods after the start-up of the procedure

  15. The untyped stack calculus and Bohm's theorem

    Directory of Open Access Journals (Sweden)

    Alberto Carraro

    2013-03-01

    Full Text Available The stack calculus is a functional language in which is in a Curry-Howard correspondence with classical logic. It enjoys confluence but, as well as Parigot's lambda-mu, does not admit the Bohm Theorem, typical of the lambda-calculus. We present a simple extension of stack calculus which is for the stack calculus what Saurin's Lambda-mu is for lambda-mu.

  16. Flexural characteristics of a stack leg

    International Nuclear Information System (INIS)

    Cook, J.

    1979-06-01

    A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

  17. ooi: OpenStack OCCI interface

    Directory of Open Access Journals (Sweden)

    Álvaro López García

    2016-01-01

    Full Text Available In this document we present an implementation of the Open Grid Forum’s Open Cloud Computing Interface (OCCI for OpenStack, namely ooi (Openstack occi interface, 2015  [1]. OCCI is an open standard for management tasks over cloud resources, focused on interoperability, portability and integration. ooi aims to implement this open interface for the OpenStack cloud middleware, promoting interoperability with other OCCI-enabled cloud management frameworks and infrastructures. ooi focuses on being non-invasive with a vanilla OpenStack installation, not tied to a particular OpenStack release version.

  18. ooi: OpenStack OCCI interface

    Science.gov (United States)

    López García, Álvaro; Fernández del Castillo, Enol; Orviz Fernández, Pablo

    In this document we present an implementation of the Open Grid Forum's Open Cloud Computing Interface (OCCI) for OpenStack, namely ooi (Openstack occi interface, 2015) [1]. OCCI is an open standard for management tasks over cloud resources, focused on interoperability, portability and integration. ooi aims to implement this open interface for the OpenStack cloud middleware, promoting interoperability with other OCCI-enabled cloud management frameworks and infrastructures. ooi focuses on being non-invasive with a vanilla OpenStack installation, not tied to a particular OpenStack release version.

  19. 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)

    Shizuma, Kiyoshi; Kajimoto, Tsuyoshi; Endo, Satoru

    2013-01-01

    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 "1"3"1I (on March 30), and "1"3"7Cs, "1"3"4Cs, "1"3"6Cs, and "1"3"2Te 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 "1"3"7Cs and "1"3"4Cs 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 "1"3"7Cs 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)

  20. Performance evaluation of an open-cathode PEM fuel cell stack under ambient conditions: Case study of United Arab Emirates

    International Nuclear Information System (INIS)

    Al-Zeyoudi, Hend; Sasmito, Agus P.; Shamim, Tariq

    2015-01-01

    Highlights: • Performance evaluation of open-cathode PEM fuel cell stacks with forced air-convection. • Stack performance can vary up to 40% from winter to summer. • Hot and arid condition leads to membrane drying and performance deterioration. • Anode humidification improves the stack performance up to 40% during summer. - Abstract: The open-cathode polymer electrolyte membrane (PEM) fuel cell stack has been a promising candidate as a sustainable energy conversion system for replacing fossil fuel-based energy conversion devices in portable and automotive applications. As the ambient air is directly used to provide both oxidant and cooling, the complex cooling loop can be avoided which reduces the complexity and cost. However, the stack performance is highly affected by ambient conditions, i.e., ambient temperature and humidity. In this study, the effect of monthly ambient air conditions (temperature and humidity) is evaluated with respect to the stack’s power production performance as well as thermal, water and gas management by employing a validated three-dimensional open-cathode PEM fuel cell stack model. The annual climate data from the hot and arid environment of Abu Dhabi, United Arab Emirates (UAE) are used as a case study. The objective is to develop a better fundamental understanding of the interactions of physical phenomena in a fuel cell stack, which can assist in improving the performance and operation of an open-cathode PEM fuel cell-powered vehicle. The results indicate that the stack performance can vary significantly (up to 40%) from winter to summer, especially at high operating currents, with significant changes in the stack temperature and the water content at the membrane. Moreover, the anode humidification results in a significant improvement in the stack performance (up to 40%) in hot and dry conditions. However, a careful balance has to be struck between the humidifier parasitic load and the stack power.

  1. Direct measurements of sample heating by a laser-induced air plasma in pre-ablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Register, Janna; Scaffidi, Jonathan; Angel, S Michael

    2012-08-01

    Direct measurements of temperature changes were made using small thermocouples (TC), placed near a laser-induced air plasma. Temperature changes up to ~500 °C were observed. From the measured temperature changes, estimates were made of the amount of heat absorbed per unit area. This allowed calculations to be made of the surface temperature, as a function of time, of a sample heated by the air plasma that is generated during orthogonal pre-ablation spark dual-pulse (DP) LIBS measurements. In separate experiments, single-pulse (SP) LIBS emission and sample ablation rate measurements were performed on nickel at sample temperatures ranging from room temperature to the maximum surface temperature that was calculated using the TC measurement results (500 °C). A small, but real sample temperature-dependent increase in both SP LIBS emission and the rate of sample ablation was found for nickel samples heated up to 500 °C. Comparison of DP LIBS emission enhancement values for bulk nickel samples at room temperature versus the enhanced SP LIBS emission and sample ablation rates observed as a function of increasing sample temperature suggests that sample heating by the laser-induced air plasma plays only a minor role in DP LIBS emission enhancement.

  2. Distribution of Gas Phase Polycyclic Aromatic Hydrocarbons (PAHs in Selected Indoor and Outdoor Air Samples of Malaysia: a Case Study in Serdang, Selangor and Bachang, Malacca

    Directory of Open Access Journals (Sweden)

    Haris Hafizal Abd Hamid

    2017-07-01

    Full Text Available Distribution of 10 polycyclic aromatic hydrocarbons (PAHs in the gas phase of air from selected indoor and outdoor areas of Selangor and Malacca, Malaysia has been investigated. A locally designed Semi Permeable Membrane Device (SPMD was applied for passive air sampling for 37 days at selected locations. Cleanup was carried out with Gas Purge - Micro Syringe Extraction (GP-MSE and the final analysis was using Gas Chromatography-Mass Spectrometry (GC-MS. In this study, 6 indoor and 12 outdoor locations were selected for air sampling. A total of 10 compounds of PAHs (Ʃ10PAHs were determined in the range of 0.218 ng/m3 - 1.692 ng/m3 and 0.378 ng/m3 - 1.492 ng/m3 in outdoor and indoor samples respectively. In the outdoor samples, locations such as near a petrol station and heavy traffic showed the maximum levels of Ʃ10PAHs, while rooftop samples showed the lowest Ʃ10PAHs. The distribution of gas phase Ʃ10PAHs was influenced by vehicular emission. Low molecular weight (LMW compounds (2-3 rings were dominant in all samples (>70% indicating that SPMD has successfully sampled the gas phase of the air.

  3. The ''Gent'' stacked filter unit (SFU) sampler for the collection of atmospheric aerosols in two size fractions: Description and instructions for installation and use

    International Nuclear Information System (INIS)

    Maenhaut, W.; Francois, F.; Cafmeyer, J.

    1994-01-01

    This report contains a description and general instructions for the installation and use of the ''Gent'' Stacked Filter Unit (SFU) PM10 sampler. The sampler operates at a flow rate of 16 litres per min. It collects particulates which have an equivalent aerodynamic diameter (EAD) of less than 10 μm in separate ''coarse'' (2-10 μm EAD) and ''fine'' ( 10 μm EAD particles is accomplished by a PM10 pre-impaction stage upstream of the stacked filter cassette. The air is drawn through the sampler by means of a diaphragm vacuum pump, which is enclosed in a special housing together with a needle valve, vacuum gauge, flow meter, volume meter, time switch (for interrupted sampling) and hour meter. A list of manufacturers of the various components of the sampler is also given. (author). 4 figs, 1 tab

  4. Methyl iodide trapping efficiency of aged charcoal samples from Bruce-A emergency filtered air discharge systems

    International Nuclear Information System (INIS)

    Wren, J.C.; Moore, C.J.; Rasmussenn, M.T.; Weaver, K.R.

    1999-01-01

    Charcoal filters are installed in the emergency filtered air discharge system (EFADS) of multiunit stations to control the release of airborne radioiodine in the event of a reactor accident. These filters use highly activated charcoal impregnated with triethylenediamine (TEDA). The TEDA-impregnated charcoal is highly efficient in removing radioiodine from flowing airstreams. The iodine-removal efficiency of the charcoal is presumed to deteriorate slowly with age, but current knowledge of this effect is insufficient to predict with confidence the performance of aged charcoal following an accident. Experiments were performed to determine the methyl iodide removal efficiency of aged charcoal samples taken from the EFADS of Ontario Hydro's Bruce-A nuclear generating station. The charcoal had been in service for ∼4 yr. The adsorption rate constant and capacity were measured under post-loss-of-coolant accident conditions to determine the efficiency of the aged charcoal. The adsorption rate constants of the aged charcoal samples were observed to be extremely high, yielding a decontamination factor (DF) for a 20-cm-deep bed of the aged charcoal >1 X 10 15 . The results show that essentially no CH 3 I would escape from a 20-cm-deep bed of the aged charcoal and that the requirement for a DF of 1000 for organic iodides in the EFADS filters would be exceeded by a tremendous margin. With such high DFs, the release of iodine from a 20-cm-deep bed would be virtually impossible to detect. The adsorption capacities observed for the aged charcoal samples approach the theoretical chemisorption capacity of 5 wt% TEDA charcoal, indicating that aging in the EFADS for 4 yr has had a negligible impact on the adsorption capacity. The results indicate that the short- and long-term performances of the aged charcoal in the EFADS of Bruce-A following an accident would still far exceed performance requirements. (author)

  5. Toxic air pollutants notice of construction for rotary mode core sampling systems three and four and modification system two

    International Nuclear Information System (INIS)

    Dyekman, D.L.

    1998-01-01

    The Washington State Department of Ecology (Ecology) approved the construction and operation of Rotary Mode Core Sampling (RMCS) System Two on November 22, 1993 (NOC-93-04). This approval supported the characterization of waste in the single-shell tanks (SSTS) and double-shell tanks (DSTS) on the Hanford Site. The waste tank characterization sampling and analysis effort is vital to the safe operations of the Hanford Site tank farms, and the timely collection of the information necessary to support retrieval, pretreatment, disposal planning, and final closure strategy. This is based on the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 93-05 Implementation Plan (DOE-RL-94-001), US Department of Energy, Richland Operations Office (DOE-RL) proposed the expedited construction and operation of two additional RMCS systems to support characterization of waste stored in SSTs and DSTS. RMCS currently is scheduled for approximately 50 (active or passively ventilated) of the 149 SSTs in the 200 East and 200 West Areas. If necessary, the RMCS will be used to sample other tanks currently not scheduled, subject to the requirements of this document and any applicable Ecology approval order. The typical components of the RMCS systems are shown in Figure 1. It should be noted that the Flammable Gas Detector cart is not being used during RMCS at this time. RMCS is scheduled for approximately 40 tanks that are not actively ventilated. These tanks operate at atmospheric pressure with passive (breather) high-efficiency particulate air (HEPA) filters. The RMCS system uses nitrogen gas to cool and purge the drill bit assembly. Without the use of a portable ventilation system, the additional gas from RMCS might unsafely pressurize tanks that are not actively ventilated. The RMCS system also will generate aerosols and dust in the tank vapor head space. HEPA filters will be required on the portable exhauster during rotary mode core drilling to control radionuclide

  6. Assessment of natural radioactivity in soil samples and comparison of direct and indirect measurement of environmental air kerma rate

    International Nuclear Information System (INIS)

    Chinnaesakki, S.; Manish Chopra; Sartandel, S.J.; Bara, S.V.; Tripathi, R.M.; Puranik, V.D.; Sanjeev Kumar; Vishal Arora; Bajwa, B.S.

    2011-01-01

    This study presents the high purity germanium (HPGe) gamma spectrometric measurement of natural radioactivity mainly due to 226 Ra, 232 Th and 40 K in soil samples collected in Ferozepur and Faridkot district of Punjab, India. 226 Ra activity varied from 28.6 to 51.1 Bq kg -1 with the mean of 39.7 Bq kg -1 . The range and mean activity of 232 Th were 42.9 - 73.2 and 58.2 Bq kg -1 , respectively. 40 K activity was in the range of 470.9 - 754.9 Bq kg -1 with the mean of 595.2 Bq kg -1 . The air kerma rate (AKR) at 1 m height from the ground was also measured using gamma survey meter in all the sampling locations, which was ranging from 92.1 to 122.8 nGy h -1 with the mean of 110.6 nGy h -1 . The radiological parameters such as Raeq and activity index of the soil samples were also evaluated, which are the tools to assess the external radiation hazard due to building materials. The mean and range of the Raeq values were 168.7 and 132.9 - 210.4 Bq kg -1 , respectively, whereas the activity index varied from 0.5 to 0.8 with the mean value of 0.62. These indices show that the indoor external dose due to natural radioactivity in the soil used for the construction will not exceed the dose criteria. The AKR was also evaluated from soil activity concentration and altitude correction of cosmic radiation contribution. The statistical tests such as Pearson correlation, spearman rank correlation, box and whisker plot, the Wilcoxon/Mann-Whitney test and chi-square test, were used to compare the measured AKR with evaluated AKR, which indicates good correlation. (author)

  7. Stacks of SPS Dipole Magnets

    CERN Multimedia

    1974-01-01

    Stacks of SPS Dipole Magnets ready for installation in the tunnel. The SPS uses a separated function lattice with dipoles for bending and quadrupoles for focusing. The 6.2 m long normal conducting dipoles are of H-type with coils that are bent-up at the ends. There are two types, B1 (total of 360) and B2 (384). Both are for a maximum field of 1.8 Tesla and have the same outer dimensions (450x800 mm2 vxh) but with different gaps (B1: 39x129 mm2, B2: 52x92 mm2) tailored to the beam size. The yoke, made of 1.5 mm thick laminations, consists of an upper and a lower half joined together in the median plane once the coils have been inserted.

  8. California dreaming?[PEM stacks

    Energy Technology Data Exchange (ETDEWEB)

    Crosse, J.

    2002-06-01

    Hyundai's Santa Fe FCEV will be on sale by the end of 2002. Hyundai uses PEM stacks that are manufactured by International Fuel Cells (IFC), a division of United Technologies. Santa Fe is equipped with a 65 kW electric powertrain of Enova systems and Shell's new gasoline reformer called Hydrogen Source. Eugene Jang, Senior Engineer - Fuel Cell and Materials at Hyundai stated that the compressor related losses on IFC system are below 3%. The maximum speed offered by the vehicle is estimated as 123km/hr while the petrol equivalent fuel consumption is quoted between 5.6L/100 km and 4.8L/100 km. Santa Fe is a compact vehicle offering better steering response and a pleasant drive. (author)

  9. Effect of a disinfectant powder on methicillin-resistant Staphylococcus aureus in pigs, bedding and air samples under simulated farm conditions

    DEFF Research Database (Denmark)

    Gongora, Carmen Espinosa; Damborg, Peter Panduro; Nielsen, Søren Saxmose

    2013-01-01

    applications of the disinfectant. MRSA load was measured in samples from pigs, bedding material and air and analysed statistically. While pigs remained positive with variable MRSA counts, the amount of MRSA in the air and bedding material increased significantly during the first week and then was gradually...... reduced in both groups. MRSA couldn’t be isolated from air and bedding material in the treatment group after seven applications and the load of MRSA increased immediately after discontinuation of treatment. This study suggests that this type of disinfectant is not able to eradicate LA-MRSA from animals...

  10. A persisting secondhand smoke hazard in urban public places: results from fine particulate (PM2.5) air sampling.

    Science.gov (United States)

    Wilson, Nick; Edwards, Richard; Parry, Rhys

    2011-03-04

    To assess the need for additional smokefree settings, by measuring secondhand smoke (SHS) in a range of public places in an urban setting. Measurements were made in Wellington City during the 6-year period after the implementation of legislation that made indoor areas of restaurants and bars/pubs smokefree in December 2004, and up to 20 years after the 1990 legislation making most indoor workplaces smokefree. Fine particulate levels (PM2.5) were measured with a portable real-time airborne particle monitor. We collated data from our previously published work involving random sampling, purposeful sampling and convenience sampling of a wide range of settings (in 2006) and from additional sampling of selected indoor and outdoor areas (in 2007-2008 and 2010). The "outdoor" smoking areas of hospitality venues had the highest particulate levels, with a mean value of 72 mcg/m3 (range of maximum values 51-284 mcg/m3) (n=20 sampling periods). These levels are likely to create health hazards for some workers and patrons (i.e., when considered in relation to the WHO air quality guidelines). National survey data also indicate that these venues are the ones where SHS exposure is most frequently reported by non-smokers. Areas inside bars that were adjacent to "outdoor" smoking areas also had high levels, with a mean of 54 mcg/m3 (range of maximum values: 18-239 mcg/m3, for n=13 measurements). In all other settings mean levels were lower (means: 2-22 mcg/m3). These other settings included inside traditional style pubs/sports bars (n=10), bars (n=18), restaurants (n=9), cafes (n=5), inside public buildings (n=15), inside transportation settings (n=15), and various outdoor street/park settings (n=22). During the data collection in all settings made smokefree by law, there was only one occasion of a person observed smoking. The results suggest that compliance in pubs/bars and restaurants has remained extremely high in this city in the nearly six years since implementation of the

  11. Tank vapor sampling and analysis data package for tank 241-C-106 waste retrieval sluicing system process test phase III

    Energy Technology Data Exchange (ETDEWEB)

    LOCKREM, L.L.

    1999-08-13

    This data package presents sampling data and analytical results from the March 28, 1999, vapor sampling of Hanford Site single-shell tank 241-C-106 during active sluicing. Samples were obtained from the 296-C-006 ventilation system stack and ambient air at several locations. Characterization Project Operations (CPO) was responsible for the collection of all SUMMATM canister samples. The Special Analytical Support (SAS) vapor team was responsible for the collection of all triple sorbent trap (TST), sorbent tube train (STT), polyurethane foam (PUF), and particulate filter samples collected at the 296-C-006 stack. The SAS vapor team used the non-electrical vapor sampling (NEVS) system to collect samples of the air, gases, and vapors from the 296-C-006 stack. The SAS vapor team collected and analyzed these samples for Lockheed Martin Hanford Corporation (LMHC) and Tank Waste Remediation System (TWRS) in accordance with the sampling and analytical requirements specified in the Waste Retrieval Sluicing System Vapor Sampling and Analysis Plan (SAP) for Evaluation of Organic Emissions, Process Test Phase III, HNF-4212, Rev. 0-A, (LMHC, 1999). All samples were stored in a secured Radioactive Materials Area (RMA) until the samples were radiologically released and received by SAS for analysis. The Waste Sampling and Characterization Facility (WSCF) performed the radiological analyses. The samples were received on April 5, 1999.

  12. Application of two analytic techniques of sampling for the determination of aldehydes in air and in rain water in three areas of Costa Rica

    International Nuclear Information System (INIS)

    Vega Montero, D. I

    2001-01-01

    The aldehydes are of supreme interest in the quality of the air of Costa Rica; reason why it is very important to determine them qualitative and quantitatively. This study has as objectives the identification and quantification of aldehydes in samples of air and of rain water in three areas of Costa Rica, to compare two methods of taking of samples of air and to correlate the concentration of the aldehydes in the different points of taking of samples. The sampling one carries out in three located stations, in the Hill of the Piroclasticos (3 km. To the Northeast of the active crater of the Volcano Irazu), Escazu (it plants potabilizadora of water) and in Turrucares (facilities of the Rural Watch). The used sampling devices, denuders and cartridges, they were recovered with a breakup of 2,4-dinitrofenilhidrazina o'clock like absorbent reagent, which I form the corresponding hidrazonas in presence of the aldehydes. The identification and quantification of the aldehydes, one carries out by means of chromatography it liquidates of high resolution. The comparison among the concentrations of the aldehydes in air gathered by the two used sampling methods indicates that a significant difference exists among them, at a level of trust of 95% [es

  13. Study on component interface evolution of a solid oxide fuel cell stack after long term operation

    Science.gov (United States)

    Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

    2018-05-01

    A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

  14. Numerical Study on the Cooling Characteristics of a Passive-Type PEMFC Stack

    International Nuclear Information System (INIS)

    Lee, Jae Hyuk; Kim, Bo Sung; Lee, Yong Taek; Kim, Yong Chan

    2010-01-01

    In a passive-type PEMFC stack, axial fans operate to supply both oxidant and coolant to cathode side of the stack. It is possible to make a simple system because the passive-type PEMFC stack does not require additional cooling equipment. However, the performance of a cooling system in which water is used as a coolant is better than that of the air-cooling system. To ensure system reliability, it is essential to make cooling system effective by adopting an optimal stack design. In this study, a numerical investigation has been carried out to identify an optimum cooling strategy. Various channel configurations were applied to the test section. The passive-type PEMFC was tested by varying airflow rate distribution at the cathode side and external heat transfer coefficient of the stack. The best cooling performance was achieved when a channel with thick ribs was used, and the overheating at the center of the stack was reduced when a case in which airflow was concentrated at the middle of the stack was used

  15. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cell Stacks

    Science.gov (United States)

    Valdez, Thomas I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    Dissolution of ruthenium was observed in the 80-cell stack. Duration testing was performed in single cell MEAs to determine the pathway of cell degradation. EDAX analysis on each of the single cell MEAs has shown that the Johnson Matthey commercial catalyst is stable in DMFC operation for 250 hours, no ruthenium dissolution was observed. Changes in the hydrophobicity of the cathode backing papers was minimum. Electrode polarization analysis revealed that the MEA performance loss is attributed to changes in the cathode catalyst layer. Ruthenium migration does not seem to occur during cell operation but can occur when methanol is absent from the anode compartment, the cathode compartment has access to air, and the cells in the stack are electrically connected to a load (Shunt Currents). The open-to-air cathode stack design allowed for: a) The MEAs to have continual access to oxygen; and b) The stack to sustain shunt currents. Ruthenium dissolution in a DMFC stack can be prevented by: a) Developing an internally manifolded stacks that seal reactant compartments when not in operation; b) Bringing the cell voltages to zero quickly when not in operation; and c) Limiting the total number of cells to 25 in an effort to limit shunt currents.

  16. Operating manual for Ford's Farm Range air samplers

    International Nuclear Information System (INIS)

    Glissmeyer, J.A.; Halverson, M.A.

    1980-10-01

    An air-sampling program was designed for a target enclosure at the Ford's Farm Range, Aberdeen Proving Ground, Maryland, where the Army test-fires tungsten and depleted-uranium armor penetrators. The primary potential particle inhalation hazard is depleted uranium. The sampling program includes workplace and filtered exhaust air sampling. Conventional isokinetic stack sampling was employed for the filtered exhaust air. Because of the need for rapid monitor response to concentration increases and decreases, conventional radioactive particle monitors were not used. Instead, real-time aerosol monitors employing a light-scattering technique were used for monitors requiring a fast response. For other monitoring functions, piezoelectric and beta-attenuation respirable-particle sampling techniques were used. The application of these technologies to the monitoring of airborne radioactive contaminants is addressed. Sampler installation and operation are detailed

  17. Vector Fields and Flows on Differentiable Stacks

    DEFF Research Database (Denmark)

    A. Hepworth, Richard

    2009-01-01

    This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... of vector fields....

  18. Project W-420 stack monitoring system upgrades

    International Nuclear Information System (INIS)

    CARPENTER, K.E.

    1999-01-01

    This project will execute the design, procurement, construction, startup, and turnover activities for upgrades to the stack monitoring system on selected Tank Waste Remediation System (TWRS) ventilation systems. In this plan, the technical, schedule, and cost baselines are identified, and the roles and responsibilities of project participants are defined for managing the Stack Monitoring System Upgrades, Project W-420

  19. On the "stacking fault" in copper

    NARCIS (Netherlands)

    Fransens, J.R.; Pleiter, F

    2003-01-01

    The results of a perturbed gamma-gamma angular correlations experiment on In-111 implanted into a properly cut single crystal of copper show that the defect known in the literature as "stacking fault" is not a planar faulted loop but a stacking fault tetrahedron with a size of 10-50 Angstrom.

  20. Learning OpenStack networking (Neutron)

    CERN Document Server

    Denton, James

    2014-01-01

    If you are an OpenStack-based cloud operator with experience in OpenStack Compute and nova-network but are new to Neutron networking, then this book is for you. Some networking experience is recommended, and a physical network infrastructure is required to provide connectivity to instances and other network resources configured in the book.

  1. Quantitative trace analysis of polyfluorinated alkyl substances (PFAS) in ambient air samples from Mace Head (Ireland): A method intercomparison

    Science.gov (United States)

    Jahnke, Annika; Barber, Jonathan L.; Jones, Kevin C.; Temme, Christian

    A method intercomparison study of analytical methods for the determination of neutral, volatile polyfluorinated alkyl substances (PFAS) was carried out in March, 2006. Environmental air samples were collected in triplicate at the European background site Mace Head on the west coast of Ireland, a site dominated by 'clean' westerly winds coming across the Atlantic. Extraction and analysis were performed at two laboratories active in PFAS research using their in-house methods. Airborne polyfluorinated telomer alcohols (FTOHs), fluorooctane sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) as well as additional polyfluorinated compounds were investigated. Different native and isotope-labelled internal standards (IS) were applied at various steps in the analytical procedure to evaluate the different quantification strategies. Field blanks revealed no major blank problems. European background concentrations observed at Mace Head were found to be in a similar range to Arctic data reported in the literature. Due to trace-levels at the remote site, only FTOH data sets were complete and could therefore be compared between the laboratories. Additionally, FOSEs could partly be included. Data comparison revealed that despite the challenges inherent in analysis of airborne PFAS and the low concentrations, all methods applied in this study obtained similar results. However, application of isotope-labelled IS early in the analytical procedure leads to more precise results and is therefore recommended.

  2. Status of MCFC stack technology at IHI

    Energy Technology Data Exchange (ETDEWEB)

    Hosaka, M.; Morita, T.; Matsuyama, T.; Otsubo, M. [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan)

    1996-12-31

    The molten carbonate fuel cell (MCFC) is a promising option for highly efficient power generation possible to enlarge. IHI has been studying parallel flow MCFC stacks with internal manifolds that have a large electrode area of 1m{sup 2}. IHI will make two 250 kW stacks for MW plant, and has begun to make cell components for the plant. To improve the stability of stack, soft corrugated plate used in the separator has been developed, and a way of gathering current from stacks has been studied. The DC output potential of the plant being very high, the design of electric insulation will be very important. A 20 kW short stack test was conducted in 1995 FY to certificate some of the improvements and components of the MW plant. These activities are presented below.

  3. Modular fuel-cell stack assembly

    Science.gov (United States)

    Patel, Pinakin

    2010-07-13

    A fuel cell assembly having a plurality of fuel cells arranged in a stack. An end plate assembly abuts the fuel cell at an end of said stack. The end plate assembly has an inlet area adapted to receive an exhaust gas from the stack, an outlet area and a passage connecting the inlet area and outlet area and adapted to carry the exhaust gas received at the inlet area from the inlet area to the outlet area. A further end plate assembly abuts the fuel cell at a further opposing end of the stack. The further end plate assembly has a further inlet area adapted to receive a further exhaust gas from the stack, a further outlet area and a further passage connecting the further inlet area and further outlet area and adapted to carry the further exhaust gas received at the further inlet area from the further inlet area to the further outlet area.

  4. A stacking method and its applications to Lanzarote tide gauge records

    Science.gov (United States)

    Zhu, Ping; van Ruymbeke, Michel; Cadicheanu, Nicoleta

    2009-12-01

    A time-period analysis tool based on stacking is introduced in this paper. The original idea comes from the classical tidal analysis method. It is assumed that the period of each major tidal component is precisely determined based on the astronomical constants and it is unchangeable with time at a given point in the Earth. We sum the tidal records at a fixed tidal component center period T then take the mean of it. The stacking could significantly increase the signal-to-noise ratio (SNR) if a certain number of stacking circles is reached. The stacking results were fitted using a sinusoidal function, the amplitude and phase of the fitting curve is computed by the least squares methods. The advantage of the method is that: (1) an individual periodical signal could be isolated by stacking; (2) one can construct a linear Stacking-Spectrum (SSP) by changing the stacking period Ts; (3) the time-period distribution of the singularity component could be approximated by a Sliding-Stacking approach. The shortcoming of the method is that in order to isolate a low energy frequency or separate the nearby frequencies, we need a long enough series with high sampling rate. The method was tested with a numeric series and then it was applied to 1788 days Lanzarote tide gauge records as an example.

  5. Development of the novel control algorithm for the small proton exchange membrane fuel cell stack without external humidification

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Hoon; Kim, Sang-Hyun; Kim, Wook; Lee, Jong-Hak; Cho, Kwan-Seok; Choi, Woojin [Department of Electrical Engineering, Soongsil University, 1-1 Sangdo-dong, Dongjak-gu, Seoul 156-743 (Korea); Park, Kyung-Won [Department of Chemical/Environmental Engineering, Soongsil University, 1-1 Sangdo-dong, Dongjak-gu, Seoul 156-743 (Korea)

    2010-09-15

    Small PEM (proton exchange membrane) fuel cell systems do not require humidification and have great commercialization possibilities. However, methods for controlling small PEM fuel cell stacks have not been clearly established. In this paper, a control method for small PEM fuel cell systems using a dual closed loop with a static feed-forward structure is defined and realized using a microcontroller. The fundamental elements that need to be controlled in fuel cell systems include the supply of air and hydrogen, water management inside the stack, and heat management of the stack. For small PEM fuel cell stacks operated without a separate humidifier, fans are essential for air supply, heat management, and water management of the stack. A purge valve discharges surplus water from the stack. The proposed method controls the fan using a dual closed loop with a static feed-forward structure, thereby improving system efficiency and operation stability. The validity of the proposed method is confirmed by experiments using a 150-W PEM fuel cell stack. We expect the proposed algorithm to be widely used for controlling small PEM fuel cell stacks. (author)

  6. Probing Temperature Inside Planar SOFC Short Stack, Modules, and Stack Series

    Science.gov (United States)

    Yu, Rong; Guan, Wanbing; Zhou, Xiao-Dong

    2017-02-01

    Probing temperature inside a solid oxide fuel cell (SOFC) stack lies at the heart of the development of high-performance and stable SOFC systems. In this article, we report our recent work on the direct measurements of the temperature in three types of SOFC systems: a 5-cell short stack, a 30-cell stack module, and a stack series consisting of two 30-cell stack modules. The dependence of temperature on the gas flow rate and current density was studied under a current sweep or steady-state operation. During the current sweep, the temperature inside the 5-cell stack decreased with increasing current, while it increased significantly at the bottom and top of the 30-cell stack. During a steady-state operation, the temperature of the 5-cell stack was stable while it was increased in the 30-cell stack. In the stack series, the maximum temperature gradient reached 190°C when the gas was not preheated. If the gas was preheated and the temperature gradient was reduced to 23°C in the stack series with the presence of a preheating gas and segmented temperature control, this resulted in a low degradation rate.

  7. airGR: an R-package suitable for large sample hydrology presenting a suite of lumped hydrological models

    Science.gov (United States)

    Thirel, G.; Delaigue, O.; Coron, L.; Perrin, C.; Andreassian, V.

    2016-12-01

    Lumped hydrological models are useful and convenient tools for research, engineering and educational purposes. They propose catchment-scale representations of the precipitation-discharge relationship. Thanks to their limited data requirements, they can be easily implemented and run. With such models, it is possible to simulate a number of hydrological key processes over the catchment with limited structural and parametric complexity, typically evapotranspiration, runoff, underground losses, etc. The Hydrology Group at Irstea (Antony) has been developing a suite of rainfall-runoff models over the past 30 years with the main objectives of designing models as efficient as possible in terms of streamflow simulation, applicable to a wide range of catchments and having low data requirements. This resulted in a suite of models running at different time steps (from hourly to annual) applicable for various issues including water balance estimation, forecasting, simulation of impacts and scenario testing. Recently, Irstea has developed an easy-to-use R-package (R Core Team, 2015; Coron et al., 2016), called airGR, to make these models widely available. It includes: - the water balance annual GR1A (Mouehli et al., 2006), - the monthly GR2M (Mouehli, 2003) models, - three versions of the daily model, namely GR4J (Perrin et al., 2003), GR5J (Le Moine, 2008) and GR6J (Pushpalatha et al., 2011), - the hourly GR4H model (Mathevet, 2005), - a degree-day snow module CemaNeige (Valéry et al., 2014). The airGR package has been designed to facilitate the use by non-expert users and allow the addition of evaluation criteria, models or calibration algorithm selected by the end-user. Each model core is coded in FORTRAN to ensure low computational time. The other package functions (i.e. mainly the calibration algorithm and the efficiency criteria) are coded in R. The package is already used for educational purposes. It allows for convenient implementation of model inter-comparisons and

  8. The impact of stack geometry and mean pressure on cold end temperature of stack in thermoacoustic refrigeration systems

    Science.gov (United States)

    Wantha, Channarong

    2018-02-01

    This paper reports on the experimental and simulation studies of the influence of stack geometries and different mean pressures on the cold end temperature of the stack in the thermoacoustic refrigeration system. The stack geometry was tested, including spiral stack, circular pore stack and pin array stack. The results of this study show that the mean pressure of the gas in the system has a significant impact on the cold end temperature of the stack. The mean pressure of the gas in the system corresponds to thermal penetration depth, which results in a better cold end temperature of the stack. The results also show that the cold end temperature of the pin array stack decreases more than that of the spiral stack and circular pore stack geometry by approximately 63% and 70%, respectively. In addition, the thermal area and viscous area of the stack are analyzed to explain the results of such temperatures of thermoacoustic stacks.

  9. Five stacks over the Danube

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Following the departure of Communism, Hungary adopted the most ambitious privatisation programme of all the eastern European countries. Within a year the state electricity company, MVM, and the oil and gas company, MOL, were prepared for sale and a consequent injection of foreign capital. Control of prices by central government inhibited investment initially but a new legal framework put in place in 1995 introduced a pricing regime more attractive to external investors. Particular interest was shown in the 2,200MW mixed heavy oil and natural gas power plant at Dunamenti on the Danube, characterised by its five stacks of varying height which reflect the changing technology employed at the plant. The bid was won by Tractabel of Belgium who have been highly successful in improving plant efficiency. However, the impact of privatisation is now being felt in uncertainty over fuel supply. Removing such uncertainty in order to maintain existing investment and provide the additional 4000MW of generating capacity needed to keep pace with demand, is a major problem which the incoming government faces. (UK)

  10. Background air pollution studies in urban and rural areas in Bangladesh. Appendix 3

    International Nuclear Information System (INIS)

    Khaliquzzaman, M.; Biswas, S.K.; Tarafdar, S.A.; Islam, A.; Khan, A.H.

    1995-01-01

    Air particulate matter at two size fractions have been collected at an urban station (Dhaka) in Bangladesh for one year using a 'Gent' PM-10 stacked filter unit (SFU). Of the samples collected, 73 sets of samples (coarse and fine fractions) extending over a period of six months have been analyzed to find elemental concentrations using PIXE. These results of the analyses are presented and discussed. (author)

  11. Comprehensive Study of Human External Exposure to Organophosphate Flame Retardants via Air, Dust, and Hand Wipes: The Importance of Sampling and Assessment Strategy.

    Science.gov (United States)

    Xu, Fuchao; Giovanoulis, Georgios; van Waes, Sofie; Padilla-Sanchez, Juan Antonio; Papadopoulou, Eleni; Magnér, Jorgen; Haug, Line Småstuen; Neels, Hugo; Covaci, Adrian

    2016-07-19

    We compared the human exposure to organophosphate flame retardants (PFRs) via inhalation, dust ingestion, and dermal absorption using different sampling and assessment strategies. Air (indoor stationary air and personal ambient air), dust (floor dust and surface dust), and hand wipes were sampled from 61 participants and their houses. We found that stationary air contains higher levels of ΣPFRs (median = 163 ng/m(3), IQR = 161 ng/m(3)) than personal air (median = 44 ng/m(3), IQR = 55 ng/m(3)), suggesting that the stationary air sample could generate a larger bias for inhalation exposure assessment. Tris(chloropropyl) phosphate isomers (ΣTCPP) accounted for over 80% of ΣPFRs in both stationary and personal air. PFRs were frequently detected in both surface dust (ΣPFRs median = 33 100 ng/g, IQR = 62 300 ng/g) and floor dust (ΣPFRs median = 20 500 ng/g, IQR = 30 300 ng/g). Tris(2-butoxylethyl) phosphate (TBOEP) accounted for 40% and 60% of ΣPFRs in surface and floor dust, respectively, followed by ΣTCPP (30% and 20%, respectively). TBOEP (median = 46 ng, IQR = 69 ng) and ΣTCPP (median = 37 ng, IQR = 49 ng) were also frequently detected in hand wipe samples. For the first time, a comprehensive assessment of human exposure to PFRs via inhalation, dust ingestion, and dermal absorption was conducted with individual personal data rather than reference factors of the general population. Inhalation seems to be the major exposure pathway for ΣTCPP and tris(2-chloroethyl) phosphate (TCEP), while participants had higher exposure to TBOEP and triphenyl phosphate (TPHP) via dust ingestion. Estimated exposure to ΣPFRs was the highest with stationary air inhalation (median =34 ng·kg bw(-1)·day(-1), IQR = 38 ng·kg bw(-1)·day(-1)), followed by surface dust ingestion (median = 13 ng·kg bw(-1)·day(-1), IQR = 28 ng·kg bw(-1)·day(-1)), floor dust ingestion and personal air inhalation. The median dermal exposure on hand wipes was 0.32 ng·kg bw(-1)·day(-1) (IQR

  12. Characterization of plutonium isotopes in air samples retrospectives techniques ultrasensitive; Caracterizacion de isotopos de plutonio en muestras de aire mediante tecnicas restrospectiva ultrasensibles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This paper presents preliminary results for the determination of plutonium isotope ratios that characterize the natural background for later comparison with that obtained during the dismantling operations. In this manner can be performed retrospective analysis of radiation from the air quality.

  13. Density of oxidation-induced stacking faults in damaged silicon

    NARCIS (Netherlands)

    Kuper, F.G.; Hosson, J.Th.M. De; Verwey, J.F.

    1986-01-01

    A model for the relation between density and length of oxidation-induced stacking faults on damaged silicon surfaces is proposed, based on interactions of stacking faults with dislocations and neighboring stacking faults. The model agrees with experiments.

  14. Biomassa microbiana em amostras de solos secadas ao ar e reumedecidas Microbial biomass in air dried and rewetted soil samples

    Directory of Open Access Journals (Sweden)

    Antônio Samarão Gonçalves

    2002-05-01

    Full Text Available O objetivo do trabalho foi avaliar a viabilidade do condicionamento de amostras como terra fina secada ao ar (TFSA por curto período, para a determinação do carbono da biomassa microbiana (BMS-C, pelo método da fumigaçãoextração, e verificar a respiração microbiana basal (RB do solo. O condicionamento como TFSA, procedendo-se à fumigação para a análise da BMS-C imediatamente ou 24 horas após o reumedecimento, proporcionou valores de BMS-C para os solos Podzólicos, Latossolo Vermelho-Amarelo álico e Orgânico, semelhantes aos valores dos seus controles. Os solos Glei Pouco Húmico e Vertissolo apresentaram valores de BMS-C similares aos do controle a partir de 24 horas de incubação; o solo Planossolo arenoso apresentou valores similares aos do controle com 72 horas, e a Rendizina, com 168 horas de incubação. Na maioria dos solos, a RB determinada na TFSA apresentou valores maiores do que os do tratamento-controle, quando avaliada imediatamente ou 24 horas após o reumedecimento a 60% da capacidade máxima de retenção de água, seguida de queda e manutenção em níveis semelhantes ao do controle nos períodos subseqüentes. O précondicionamento, de curta duração, como TFSA, é promissor para a determinação da BMS-C, quando níveis e períodos adequados de reumedecimento são adotados.The objective of this work was to evaluate the utilization of short term air dried soil samples in a determination of soil microbial biomass (SMB-C, by a fumigationextraction method, and soil microbial basal respiration (BR. Zero time or 24 hours rewetting incubation period before fumigation procedure gave values of SMB-C similar to those of the control for the Podzolic soils, Allic RedYellow Latosol and Organic soil. Low Humic Gley and Vertisol soils gave values of SMB-C similar to those of the control for periods of incubation equal or higher than 24 hours. Planosol (sandy soil and Rendzina soils gave values of SMB-C similar to the

  15. Trace Analysis in End-Exhaled Air Using Direct Solvent Extraction in Gas Sampling Tubes: Tetrachloroethene in Workers as an Example

    Directory of Open Access Journals (Sweden)

    Chris-Elmo Ziener

    2014-01-01

    Full Text Available Simple and cost-effective analytical methods are required to overcome the barriers preventing the use of exhaled air in routine occupational biological monitoring. Against this background, a new method is proposed that simplifies the automation and calibration of the analytical measurements. End-exhaled air is sampled using valveless gas sampling tubes made of glass. Gaseous analytes are transferred to a liquid phase using a microscale solvent extraction performed directly inside the gas sampling tubes. The liquid extracts are analysed using a gas chromatograph equipped, as usual, with a liquid autosampler, and liquid standards are used for calibration. For demonstration purposes, the method’s concept was applied to the determination of tetrachloroethene in end-exhaled air, which is a biomarker for occupational tetrachloroethene exposure. The method’s performance was investigated in the concentration range 2 to 20 μg tetrachloroethene/L, which corresponds to today’s exposure levels. The calibration curve was linear, and the intra-assay repeatability and recovery rate were sufficient. Analysis of real samples from dry-cleaning workers occupationally exposed to tetrachloroethene and from nonexposed subjects demonstrated the method’s utility. In the case of tetrachloroethene, the method can be deployed quickly, requires no previous experiences in gas analysis, provides sufficient analytical reliability, and addresses typical end-exhaled air concentrations from exposed workers.

  16. Concentration of the 241Pu in air samples from Chernobyl at Belgrade site estimated by a 241Am in growth method

    International Nuclear Information System (INIS)

    Vukanac, I.; Novkovic, D.; Djurasevic, M.; Obradovic, Z.; Kandi, A.

    2006-01-01

    The surface air samples collected in the first half of May 1986 at Vinca- Belgrade site were prepared and measured at the end of the 1991 and beginning of the 1992. year. Activity concentrations of the 137 Cs immediately after the Chernobyl accident were determined by means of gamma spectrometry, while the air activity concentration of 238 Pu and 239,240 Pu were determined by alpha spectrometry, after the plutonium radiochemical separation. The 236 Pu was used as a tracer. The same samples were remeasured after 13 years, during the 2004. The surface air activity concentrations of 241 Pu were estimated by a 241 Am in-growth method. The built up activities of 236 Pu progenies were determined from the recorded spectra and also calculated using the Bateman equations. The 241 Am activity in the remeasured samples, obtained by complex spectral analysis was confirmed by gamma spectrometry. The 241 Pu activity concentration in measured air samples ranged from 240 μBq/m3 to 7800 μBq/m3. The average activity concentration ratio 241 Pu/ 239,240 Pu originated from Chernobyl accident was approximately 100. (authors)

  17. Passive air sampling of polybrominated diphenyl ethers in New Delhi, Kolkata, Mumbai and Chennai: Levels, homologous profiling and source apportionment.

    Science.gov (United States)

    Chakraborty, Paromita; Zhang, Gan; Cheng, Hairong; Balasubramanian, Prithiviraj; Li, Jun; Jones, Kevin C

    2017-12-01

    Several studies in the recent past reported new sources for industrial persistent organic pollutants (POPs) from metropolitan cities of India. To fill the data gap for atmospheric polybrominated diphenyl ethers (PBDEs), polyurethane foam disk passive air sampling (PUF-PAS) was conducted along urban-suburban-rural transects in four quadrilateral cities viz., New Delhi, Kolkata, Mumbai and Chennai from northern, eastern, western and southern India respectively. Average concentration of Σ 8 PBDEs in pg/m 3 for New Delhi, Kolkata, Mumbai and Chennai were 198, 135, 264 and 144 respectively. We observed a distinct urban > suburban > rural trend for atmospheric PBDEs in Mumbai. Principal component analysis (PCA) attributed three different source types. BDE-47, -99, -100, -153 and -154 loaded in the first component were relatively high in the sites where industrial and informal electronic waste (e-waste) recycling activities were prevalent. Penta congener, BDE-99 and tetra congener, BDE-47 contributed 50%-75% of total PBDEs. Ratio of BDE-47 and -99 in Indian cities reflected the usage of penta formulations like Bromkal -70DE and DE-71 in the commercial and electrical products. PC-2 was loaded with BDE-28 and -35. Percentage of BDE-28 and BDE-35 (>10%) were comparatively much higher than commercial penta products. Abundance of BDE-28 in majority sites can be primarily due to re-emission from surface soil. PC-3 was loaded with BDE-183 and elevated levels were observed mostly in the industrial corridor of Indian cities. BDE-183 was notably high in the urban industrial sites of New Delhi. We suspect this octa-BDE congener resulted from recycling process of plastic products containing octa-BDE formulation used as flame retardants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method.

    Science.gov (United States)

    Miyake, Yuichi; Tokumura, Masahiro; Iwazaki, Yuta; Wang, Qi; Amagai, Takashi; Horii, Yuichi; Otsuka, Hideyuki; Tanikawa, Noboru; Kobayashi, Takeshi; Oguchi, Masahiro

    2017-06-16

    An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method. With this method, we were able to detect Cr(VI) in air at concentrations of 5.3ng/m 3 (assuming a sampling volume of 1m 3 and a final solution volume of 10mL). Recovery tests at three different concentrations of Cr(VI) (50, 250, 1000ng) were performed with or without fly ash; recovery rates at all the concentrations of Cr(VI), with or without fly ash, ranged from 68% to 110% (mean±relative standard deviation, 96%±11%), and there were no differences in recovery rates with respect to the presence or absence of fly ash. Finally, we used the developed method to determine the concentration of Cr(VI) in stack gases collected from eight industrial waste incinerators located in Japan. The concentration of Cr(VI) in the stack gases ranged from below the method quantification limit to 3100ng/m 3 . The highest concentrations of Cr(VI) detected in the stack gases were two to three orders of magnitude higher than that in ambient air in Japan. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Dynamical stability of slip-stacking particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey; Zwaska, Robert

    2014-09-01

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  20. Text-Filled Stacked Area Graphs

    DEFF Research Database (Denmark)

    Kraus, Martin

    2011-01-01

    -filled stacked area graphs; i.e., graphs that feature stacked areas that are filled with small-typed text. Since these graphs allow for computing the text layout automatically, it is possible to include large amounts of textual detail with very little effort. We discuss the most important challenges and some...... solutions for the design of text-filled stacked area graphs with the help of an exemplary visualization of the genres, publication years, and titles of a database of several thousand PC games....

  1. Tunable electro-optic filter stack

    Science.gov (United States)

    Fontecchio, Adam K.; Shriyan, Sameet K.; Bellingham, Alyssa

    2017-09-05

    A holographic polymer dispersed liquid crystal (HPDLC) tunable filter exhibits switching times of no more than 20 microseconds. The HPDLC tunable filter can be utilized in a variety of applications. An HPDLC tunable filter stack can be utilized in a hyperspectral imaging system capable of spectrally multiplexing hyperspectral imaging data acquired while the hyperspectral imaging system is airborne. HPDLC tunable filter stacks can be utilized in high speed switchable optical shielding systems, for example as a coating for a visor or an aircraft canopy. These HPDLC tunable filter stacks can be fabricated using a spin coating apparatus and associated fabrication methods.

  2. Integrated sampling and analysis unit for the determination of sexual pheromones in environmental air using fabric phase sorptive extraction and headspace-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Alcudia-León, M Carmen; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel; Kabir, Abuzar; Furton, Kenneth G

    2017-03-10

    This article presents a novel unit that integrates for the first time air sampling and preconcentration based on the use of fabric phase sorptive extraction principles. The determination of Tuta absoluta sexual pheromone traces in environmental air has been selected as analytical problem. For this aim, a novel laboratory-built unit made up of commercial brass elements as holder of the sol-gel coated fabric extracting phase has been designed and optimized. The performance of the integrated unit was evaluated analyzing environmental air sampled in tomato crops. The unit can work under sampling and analysis mode which eliminates any need for sorptive phase manipulation prior to instrumental analysis. In the sampling mode, the unit can be connected to a sampling pump to pass the air through the sorptive phase at a controlled flow-rate. In the analysis mode, it is placed in the gas chromatograph autosampler without any instrumental modification. It also diminishes the risk of cross contamination between sampling and analysis. The performance of the new unit has been evaluated using the main components of the sexual pheromone of Tuta absoluta [(3E,8Z,11Z)-tetradecatrien-1-yl acetate and (3E,8Z)-tetradecadien-1-yl acetate] as model analytes. The limits of detection for both compounds resulted to be 1.6μg and 0.8μg, respectively, while the precision (expressed as relative standard deviation) was better than 3.7%. Finally, the unit has been deployed in the field to analyze a number of real life samples, some of them were found positive. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Iridium Interfacial Stack - IrIS

    Science.gov (United States)

    Spry, David

    2012-01-01

    Iridium Interfacial Stack (IrIS) is the sputter deposition of high-purity tantalum silicide (TaSi2-400 nm)/platinum (Pt-200 nm)/iridium (Ir-200 nm)/platinum (Pt-200 nm) in an ultra-high vacuum system followed by a 600 C anneal in nitrogen for 30 minutes. IrIS simultaneously acts as both a bond metal and a diffusion barrier. This bondable metallization that also acts as a diffusion barrier can prevent oxygen from air and gold from the wire-bond from infiltrating silicon carbide (SiC) monolithically integrated circuits (ICs) operating above 500 C in air for over 1,000 hours. This TaSi2/Pt/Ir/Pt metallization is easily bonded for electrical connection to off-chip circuitry and does not require extra anneals or masking steps. There are two ways that IrIS can be used in SiC ICs for applications above 500 C: it can be put directly on a SiC ohmic contact metal, such as Ti, or be used as a bond metal residing on top of an interconnect metal. For simplicity, only the use as a bond metal is discussed. The layer thickness ratio of TaSi2 to the first Pt layer deposited thereon should be 2:1. This will allow Si from the TaSi2 to react with the Pt to form Pt2Si during the 600 C anneal carried out after all layers have been deposited. The Ir layer does not readily form a silicide at 600 C, and thereby prevents the Si from migrating into the top-most Pt layer during future anneals and high-temperature IC operation. The second (i.e., top-most) deposited Pt layer needs to be about 200 nm to enable easy wire bonding. The thickness of 200 nm for Ir was chosen for initial experiments; further optimization of the Ir layer thickness may be possible via further experimentation. Ir itself is not easily wire-bonded because of its hardness and much higher melting point than Pt. Below the iridium layer, the TaSi2 and Pt react and form desired Pt2Si during the post-deposition anneal while above the iridium layer remains pure Pt as desired to facilitate easy and strong wire-bonding to the Si

  4. Characterization of Piezoelectric Stacks for Space Applications

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher; Aldrich, Jack; Blodget, Chad; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to actuate mechanisms to precision levels in the nanometer range and below. Co-fired multilayer piezoelectric stacks offer the required actuation precision that is needed for such mechanisms. To obtain performance statistics and determine reliability for extended use, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and high temperatures and voltages. In order to study the lifetime performance of these stacks, five actuators were driven sinusoidally for up to ten billion cycles. An automated data acquisition system was developed and implemented to monitor each stack's electrical current and voltage waveforms over the life of the test. As part of the monitoring tests, the displacement, impedance, capacitance and leakage current were measured to assess the operation degradation. This paper presents some of the results of this effort.

  5. The stack on software and sovereignty

    CERN Document Server

    Bratton, Benjamin H

    2016-01-01

    A comprehensive political and design theory of planetary-scale computation proposing that The Stack -- an accidental megastructure -- is both a technological apparatus and a model for a new geopolitical architecture.

  6. Development of Auto-Stacking Warehouse Truck

    Directory of Open Access Journals (Sweden)

    Kuo-Hsien Hsia

    2018-03-01

    Full Text Available Warehouse automation is a very important issue for the promotion of traditional industries. For the production of larger and stackable products, it is usually necessary to operate a fork-lifter for the stacking and storage of the products by a skilled person. The general autonomous warehouse-truck does not have the ability of stacking objects. In this paper, we develop a prototype of auto-stacking warehouse-truck that can work without direct operation by a skill person. With command made by an RFID card, the stacker truck can take the packaged product to the warehouse on the prior-planned route and store it in a stacking way in the designated storage area, or deliver the product to the shipping area or into the container from the storage area. It can significantly reduce the manpower requirements of the skilled-person of forklift technician and improve the safety of the warehousing area.

  7. 40 CFR 60.1300 - What test methods must I use to stack test?

    Science.gov (United States)

    2010-07-01

    ... to the Administrator for approval under § 60.8(b) to use a reference method with minor changes in... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What test methods must I use to stack test? 60.1300 Section 60.1300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

  8. Determination of Source Term for an Annual Stack Release of Gas Reactor G.A. Siwabessy

    International Nuclear Information System (INIS)

    Sudiyati; Syahrir; Unggul Hartoyo; Nugraha Luhur

    2008-01-01

    Releases of radionuclide from the reactor are noble gases, halogenides and particulates. The measurements were carried out directly on the air monitoring system of the stack. The results of these measurements are compared with the annual Source-Term data from the Safety Analyses report (SAR) of RSG-GAS. The measurement results are smaller than the data reported in SAR document. (author)

  9. Determination of Glycol Ethers in Ambient Air by Adsorption Sampling and Thermal Desorption with GC/MS Analysis: Performance Evaluation and Field Application

    Directory of Open Access Journals (Sweden)

    Young-Kyo Seo

    2012-01-01

    Full Text Available Some of glycol ethers, such as 2-methoxyethanol (2-ME and 2-ethoxyethanol (2-EE are known to be toxic and classified as hazardous air pollutants in USA, Japan and Germany. In Korea, however, there has been no study conducted so far for these compounds in ambient air. In addition, no clear methodologies for the measurement of glycol ethers have been yet established. We carried out this study to evaluate a sampling and analytical method for the determination of glycol ethers, in ambient air samples collected in specific industrial areas of South Korea. To measure glycol ethers, adsorption sampling and thermal desorption with GC/MS analysis were used in this study. The analytical method showed good repeatability, linearity and sensitivity. The lower detection limits were estimated to be approximately 0.3∼0.5 ppb. Based on storage tests, it was suggested that samples should be analyzed within two weeks. It was also demonstrated that this method can be used for the simultaneous measurement of glycol ethers and other aromatic VOCs such as benzene, toluene, and xylenes. Field sampling campaign was carried out at 2 sites, located in a large industrial area, from October 2006 to June 2007, and a total of 480 samples were collected seasonally. Among them, 2-ME was not detected from any samples, while 2-EE and 2-Ethyloxyethylacetate (2-EEA were found in 7 and 70 samples, respectively. The measured concentrations of 2-EE and 2-EEA for samples were ranged from 0.7-2.5 ppb and from 0.5-10.5 ppb, respectively. To our knowledge, this is the first measurement report for glycol ethers in the ambient atmosphere not only in Korea but also the rest of the world.

  10. Exploring online evolution of network stacks

    OpenAIRE

    Imai, Pierre

    2013-01-01

    Network stacks today follow a one-size-fits-all philosophy. They are mostly kept unmodified due to often prohibitive costs of engineering, deploying and administrating customisation of the networking software, with the Internet stack architecture still largely being based on designs and assumptions made for the ARPANET 40 years ago. We venture that heterogeneous and rapidly changing networks of the future require, in order to be successful, run-time self-adaptation mechanisms at different tim...

  11. Radionuclide characterization of graphite stacks from plutonium production reactors of the Siberian group of chemical enterprises

    International Nuclear Information System (INIS)

    Bushuev, A.V.; Verzilov, Yu.M.; Zubarev, V.N.

    2001-01-01

    The residual radionuclide concentrations and distributions in graphite from moderator stack of plutonium production reactors at Tomsk-7 have been investigated. It was found that the dominant activity of graphite is 14 C. To gain information on surface and volume contamination of graphite blocks from the moderator stack, the special sets of samples were collected and assayed. The schemes are proposed for evaluation of individual radionuclide inventories together with results of the evaluations performed. (author)

  12. A Time-predictable Stack Cache

    DEFF Research Database (Denmark)

    Abbaspour, Sahar; Brandner, Florian; Schoeberl, Martin

    2013-01-01

    Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to le...... of a cache for stack allocated data. Our port of the LLVM C++ compiler supports the management of the stack cache. The combination of stack cache instructions and the hardware implementation of the stack cache is a further step towards timepredictable architectures.......Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to less...... precise results of the cache analysis part of the WCET analysis. Splitting the data cache for different data areas enables composable data cache analysis. The WCET analysis tool can analyze the accesses to these different data areas independently. In this paper we present the design and implementation...

  13. StackGAN++: Realistic Image Synthesis with Stacked Generative Adversarial Networks

    OpenAIRE

    Zhang, Han; Xu, Tao; Li, Hongsheng; Zhang, Shaoting; Wang, Xiaogang; Huang, Xiaolei; Metaxas, Dimitris

    2017-01-01

    Although Generative Adversarial Networks (GANs) have shown remarkable success in various tasks, they still face challenges in generating high quality images. In this paper, we propose Stacked Generative Adversarial Networks (StackGAN) aiming at generating high-resolution photo-realistic images. First, we propose a two-stage generative adversarial network architecture, StackGAN-v1, for text-to-image synthesis. The Stage-I GAN sketches the primitive shape and colors of the object based on given...

  14. Design and experimental characterization of a 350 W High Temperature PEM fuel cell stack

    Directory of Open Access Journals (Sweden)

    Nicola Zuliani

    2011-01-01

    Full Text Available High Temperature Proton Exchange Membrane (HT PEM fuel cell based on polybenzimidazole (PBI polymer and phosphoric acid, can be operated at temperature between 120 °C and 180 °C. Reactants humidification is not required and CO content up to 2% in the fuel can be tolerated, affecting only marginally performance. This is what makes HT PEM very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. Till nowadays, from experimental point of view, only few studies relate to the development and characterization of high temperature stacks. The aim of this work is to present the main design features and the performance curves of a 25 cells HT PEM stack based on PBI and phosphoric acid membranes. Performance curves refer to the stack operating with two type of fuels: pure hydrogen and a gas mixture simulating a typical steam reformer output. The stack voltage distribution analysis and the stack temperature distribution analysis suggest that cathode air could be used as coolant leading to a better thermal management. This could simplify stack design and system BOP, thus increasing system performance.

  15. Stack and area tritium monitoring systems for the tokamak fusion test reactor (TFTR)

    International Nuclear Information System (INIS)

    Pearson, G.G.; Meixler, L.D.; Sirsingh, R.A.P.

    1992-01-01

    This paper reports on the TFTR Tritium Stack and Area Monitoring Systems which have been developed to provide the required level of reliability in a cost effective manner consistent with the mission of the Tritium Handling System on TFTR. Personnel protection, environmental responsibility, and tritium containing system integrity have been the considerations in system design. During the Deuterium-Tritium (D-T) experiments on TFTR, tritium will be used for the first time as one of the fuels. Area monitors provide surveillance of the air in various rooms at TFTR. Stack monitors monitor the air at the TFTR test site that is exhausted through the HVAC systems, from the room exhaust stacks and the tritium systems process vents. The philosophies for the implementation of the Stack and Area Tritium Monitoring Systems at TFTR are to use hardwired controls wherever personnel protection is involved, and to take advantage of modern intelligent controllers to provide a distributed system to support the functions of tracking, displaying, and archiving concentration levels of tritium for all of the monitored areas and stacks

  16. The importance of building downwash in assessing the need to heighten stacks of existing small and medium sized industries

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, J.F.P. [Centro de Tecnologias Ambientais, ISQ - Inst. de Soldadura e Qualidade, Oeiras (Portugal); Duarte, R. [Escola Superior de Tecnologia - Inst. Politecnico de Setubal (Portugal)

    2004-07-01

    This extended abstract intends to share the authors experience on the modelling of atmospheric pollutant dispersal and on the importance of building downwash considerations when assessing the need to heighten stacks of small and medium sized industrial enterprises (SME's). In order to understand the reasons that make industrial companies, especially SME's, consider stack heightening, in section 2 the existing Portuguese legislation on air quality and the stack heightening rules are briefly commented. New legislation that ought to appear soon (new Portuguese Air Act) is also commented and compared critically with the existing one. Then, section 3 characterizes Portuguese industry in terms of the ambient quality problems related to stack height. The adequacy of the stack heightening legislation to the particularities of the Portuguese case is discussed. In section 4 the authors experience in the specific study of stack heightening is presented. The methodology considered in these studies is discussed and compared with the application of existing and soon to appear legislation on stack height calculation. Finally, section 5 presents the conclusions and the need for an increased awareness on the pollutant dispersal problem is discussed. (orig.)

  17. Passive air sampling of organochlorine pesticides and polychlorinated biphenyls in the Yangtze River Delta, China: Concentrations, distributions, and cancer risk assessment

    International Nuclear Information System (INIS)

    Zhang, Lifei; Dong, Liang; Yang, Wenlong; Zhou, Li; Shi, Shuangxin; Zhang, Xiulan; Niu, Shan; Li, Lingling; Wu, Zhongxiang; Huang, Yeru

    2013-01-01

    The Yangtze River Delta (YRD) has been quickly industrialized and urbanized. Passive air sampling of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) was carried out in the YRD in 2010–2011 to investigate their spatiotemporal distributions and estimate the risk of cancer from their inhalation. Annual concentrations were 151, 168, 18.8, 110, 17.9, and 35.0 pg m −3 for HCB, ∑DDTs, ∑HCHs, ∑chlordane, mirex, and PCBs, respectively. The highest OCP and PCB concentrations were generally detected in the autumn and winter. The average concentrations of OCPs and PCBs for the different site groups followed the order urban ≈ urban–rural transition > rural. The lifetime excess cancer risks from the inhalation of OCPs and PCBs were −6 . The predicted cancer cases per lifetime associated with the inhalation of OCPs and PCBs are 12, 7, and 4 per ten thousand people for urban, urban–rural transition, and rural areas, respectively. Highlights: •Organochlorine pollutants were measured in the air in the Yangtze River Delta area. •Air PCB concentration declined in recent years comparing with previous results. •HCB and DDEs predominated, with the highest values in winter and autumn, respectively. •OCPs and PCBs followed the order: urban ≈ urban–rural transition > rural. -- A detailed study of organochlorine pesticides and polychlorinated biphenyls in air across the Yangtze River Delta area using passive air samplers

  18. Principles for Instructional Stack Development in HyperCard.

    Science.gov (United States)

    McEneaney, John E.

    The purpose of this paper is to provide information about obtaining and using HyperCard stacks that introduce users to principles of stack development. The HyperCard stacks described are available for downloading free of charge from a server at Indiana University South Bend. Specific directions are given for stack use, with advice for beginners. A…

  19. The potential effect of differential ambient and deployment chamber temperatures on PRC derived sampling rates with polyurethane foam (PUF) passive air samplers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Karen, E-mail: k.kennedy@uq.edu.a [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Hawker, Darryl W. [Griffith University, School of Environment, Nathan QLD 4111 (Australia); Bartkow, Michael E. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Carter, Steve [Queensland Health Forensic and Scientific Services, Coopers Plains QLD 4108 (Australia); Ishikawa, Yukari; Mueller, Jochen F. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia)

    2010-01-15

    Performance reference compound (PRC) derived sampling rates were determined for polyurethane foam (PUF) passive air samplers in both sub-tropical and temperate locations across Australia. These estimates were on average a factor of 2.7 times higher in summer than winter. The known effects of wind speed and temperature on mass transfer coefficients could not account for this observation. Sampling rates are often derived using ambient temperatures, not the actual temperatures within deployment chambers. If deployment chamber temperatures are in fact higher than ambient temperatures, estimated sampler-air partition coefficients would be greater than actual partition coefficients resulting in an overestimation of PRC derived sampling rates. Sampling rates determined under measured ambient temperatures and estimated deployment chamber temperatures in summer ranged from 7.1 to 10 m{sup 3} day{sup -1} and 2.2-6.8 m{sup 3} day{sup -1} respectively. These results suggest that potential differences between ambient and deployment chamber temperatures should be considered when deriving PRC-based sampling rates. - Internal deployment chamber temperatures rather than ambient temperatures may be required to accurately estimate PRC-based sampling rates.

  20. VOC SAMPLING IN THE WATER TABLE/CAPILLARY FRINGE AREA FOR ASSESSING IMPACT ON VAPOR INTRUSION AND INDOOR AIR QUALITY

    Science.gov (United States)

    Vapor intrusion has been determined to be a major pathway for increased indoor air contamination from volatile organic contaminants (VOCs) at certain contaminated sites. In order to properly assess vapor intrusion, it is important to adequately evaluate VOC concentrations in the...