WorldWideScience

Sample records for vapor-particle sampler revision

  1. Revised

    DEFF Research Database (Denmark)

    Johannsen, Vivian Kvist; Nord-Larsen, Thomas; Riis-Nielsen, Torben

    This report is a revised analysis of the Danish data on CO2 emissions from forest, afforestation and deforestation for the period 1990 - 2008 and a prognosis for the period until 2020. Revision have included measurements from 2009 in the estimations. The report is funded by the Ministry of Climate...

  2. An improved bedload sampler

    Science.gov (United States)

    Jack Lewis

    1991-01-01

    Abstract - Improvements upon the Birkbeck bedload sampler (Reid et al., 1980) were implemented in the North Fork of Caspar Creek, a gravel-bedded stream draining 383 ha in northern coastal California. Bedload sediment falls through a slotted plate covering a .125-m3 steel box set within a formed concrete pit in the streambed. In the original Birkbeck design, a water-...

  3. Retained gas sampler visualization guide

    Energy Technology Data Exchange (ETDEWEB)

    Shekarriz, A.

    1994-09-01

    In a series of experiments performed in Phase II of the retained gas sampler visualization task, the effect of sampler tip geometry on waste sampling process has been investigated. From flow visualizations, which were captured on video, it is clear that disturbances on the surrounding fluid and the fluid entering the sampler were reduced as the tip changed from a flat to a sharper truncated cone shape. It has been shown, throughout this report, that deformation and disturbance of the waste is dominated by shape of the sampler tip, which moves the stagnation point, and not by viscosity of the fluid or sampling rate.

  4. A gas sampler

    Energy Technology Data Exchange (ETDEWEB)

    Privalov, N.I.; Romanchuk, A.L.; Zrelyy, N.D.

    1982-01-01

    An addition is proposed to USSR inventor's certificate number 458730. In order to increase the reliability of testing the composition of the atmosphere through multiple sampling from several points, the proposed sampler is equipped with a sampling device made in the form of a body with branch pipes for collecting and outletting the samples, and with a spring loaded rod, positioned inside it, and a bushing, installed with the capability of axial movement. The output opening is connected to the pipeline using a tube.

  5. Isokinetic sampler; Amostrador isocinetico

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Luis Cesar C. de; Santos, Antonio Carlos dos [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Barrio, Lara B.A. del [AZ Armaturen do Brasil Ltda., Itatiba, SP (Brazil); Silva, Claudio B. da C. e; Silva, Ricardo R. da [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2005-07-01

    The Center of Research Leopoldo A. Miguez de Melo - CENPES - in association with AZ Armaturen Company do Brasil and TRANSPETRO developed and tested an Isokinetic sampler. This work presents the sampling principles and the results and performance of the tests realized in the 'Sitio de Testes de Atalaia' and in one of the terminals of bunker transfer of TRANSPETRO - 'Terminal Aquaviario da Baia de Guanabara'. In the 'Sitio de Testes' the products used were oil and water with BSW from 5% to 97% and in the terminal were tested samplings of bunker with ranges viscosities between (MF 180 to 380). (author)

  6. Introduction to SamplerCompare

    Directory of Open Access Journals (Sweden)

    Madeleine B. Thompson

    2011-08-01

    Full Text Available SamplerCompare is an R package for comparing the performance of Markov chain Monte Carlo (MCMC samplers. It samples from a collection of distributions with a collection of MCMC methods over a range of tuning parameters. Then, using log density evaluations per uncorrelated observation as a figure of merit, it generates a grid of plots showing the results of the simulation. It comes with a collection of predefined distributions and samplers and provides R and C interfaces for defining additional ones. It also provides the means to import simulation data generated by external systems. This document provides background on the package and demonstrates the basics of running simulations, visualizing results, and defining distributions and samplers in R.

  7. Remote Sampler Demonstration Isolok Configuration Test

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Steve E. [Washington River Protection Solutions, LLC, Richland, WA (United States)

    2016-06-08

    The accuracy and precision of a new Isolok sampler configuration was evaluated using a recirculation flow loop. The evaluation was performed using two slurry simulants of Hanford high-level tank waste. Through testing, the capability of the Isolok sampler was evaluated. Sample concentrations were compared to reference samples that were simultaneously collected by a two-stage Vezin sampler. The capability of the Isolok sampler to collect samples that accurately reflect the contents in the test loop improved – biases between the Isolok and Vezin samples were greatly reduce for fast settling particles.

  8. A passive sampler for atmospheric ozone

    Energy Technology Data Exchange (ETDEWEB)

    Grosjean, D.; Hisham, M.W.M. (DGA, Inc., Ventura, CA (United States))

    1992-02-01

    A simple, cost-effective passive sampler has been developed for the determination of atmospheric ozone. This passive sampler is based on a colorant which fades upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Direct, on-site measurements are possible, and no chemical analyses are needed. Sampler design and validation studies have been carried out and included quantitative determination of color change vs exposure time (1-8 days), color change vs. ozone concentration (30-350 ppb), and response to changes in sampler configuration that modify the passive sampling rate. With indigo carmine as the colorant, the detection limits are 30 ppb. day and 120 ppb. day using a plastic grid and Teflon filter, respectively, as diffusion barriers. Interferences from nitrogen dioxide, formaldehyde and peroxyacetyl nitrate are 15, 4 and 16%, respectively, thus resulting in a negligible bias when measuring ozone in ambient air.

  9. A new passive sampler for collecting atmospheric tritiated water vapor

    Science.gov (United States)

    Feng, Bin; Chen, Bo; Zhuo, Weihai; Zhang, Weiyuan

    2017-04-01

    A new passive sampler was developed for collecting environmental tritiated water vapor. The construction of the sampler was improved according to computational fluid dynamics (CFD) simulations in which the influence on vapor collection by the turbulence inside the sampler was considered. Through changes in temperature from 5 °C to 35 °C and relative humidity from 45% to 90%, the new sampler revealed stable performance of the sampling rate. Compared with the previous samplers, the new sampler significantly lowered the effect of wind speed. Using the adsorption kinetic curve of the sampler provided in the co-comparison experiments, the quantitative relationship between the mass of adsorbed water and the cumulative absolute humidity exposure was established. Field applications in the vicinity of a nuclear power plant show that the data obtained by the new samplers is consistent with the active measurement. The sampler was preliminarily proven to be reliable and flexible for field investigation of HTO in the atmosphere.

  10. Coalescent genealogy samplers: windows into population history.

    Science.gov (United States)

    Kuhner, Mary K

    2009-02-01

    Coalescent genealogy samplers attempt to estimate past qualities of a population, such as its size, growth rate, patterns of gene flow or time of divergence from another population, based on samples of molecular data. Genealogy samplers are increasingly popular because of their potential to disentangle complex population histories. In the last decade they have been widely applied to systems ranging from humans to viruses. Findings include detection of unexpected reproductive inequality in fish, new estimates of historical whale abundance, exoneration of humans for the prehistoric decline of bison and inference of a selective sweep on the human Y chromosome. This review summarizes available genealogy-sampler software, including data requirements and limitations on the use of each program.

  11. Releasable Asbestos Field Sampler (RAFS) Operation Manual

    Science.gov (United States)

    The Releasable Asbestos Field Sampler (RAFS) is a field instrument that provides an in-situ measurement of asbestos releasability from consistent and reproducible mechanical agitation of the source material such as soil. The RAFS was designed to measure concentration (asbestos st...

  12. Improving suspended sediment measurements by automatic samplers.

    Science.gov (United States)

    Gettel, Melissa; Gulliver, John S; Kayhanian, Masoud; DeGroot, Gregory; Brand, Joshua; Mohseni, Omid; Erickson, Andrew J

    2011-10-01

    Suspended solids either as total suspended solids (TSS) or suspended sediment concentration (SSC) is an integral particulate water quality parameter that is important in assessing particle-bound contaminants. At present, nearly all stormwater runoff quality monitoring is performed with automatic samplers in which the sampling intake is typically installed at the bottom of a storm sewer or channel. This method of sampling often results in a less accurate measurement of suspended sediment and associated pollutants due to the vertical variation in particle concentration caused by particle settling. In this study, the inaccuracies associated with sampling by conventional intakes for automatic samplers have been verified by testing with known suspended sediment concentrations and known particle sizes ranging from approximately 20 μm to 355 μm under various flow rates. Experimental results show that, for samples collected at a typical automatic sampler intake position, the ratio of sampled to feed suspended sediment concentration is up to 6600% without an intake strainer and up to 300% with a strainer. When the sampling intake is modified with multiple sampling tubes and fitted with a wing to provide lift (winged arm sampler intake), the accuracy of sampling improves substantially. With this modification, the differences between sampled and feed suspended sediment concentration were more consistent and the sampled to feed concentration ratio was accurate to within 10% for particle sizes up to 250 μm.

  13. Information on the Arnhem Sampler (BTMA)

    NARCIS (Netherlands)

    De Vries, M.

    1979-01-01

    The Subcommittee 6 of the Technical Committee 113 of the International Standardization Organization (ISO) is dealing with measurements of sediment transport in open channels. As a back-ground paper for TC113 this report is written on the BTMA, internationally named the Arnhem Sampler. The BTMA has

  14. Retained gas sampler system acceptance test report

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, N.S., Westinghouse Hanford

    1996-07-18

    Acceptance test results for the Retained Gas Sampler System (RGSS) obtained in the 306E laboratory are reported. The RGSS will be utilized to retrieve and analyze samples from the Hanford flammable gas watch-list tanks to determine the quantity and chemistry of gases confined within the waste.

  15. Retained Gas Sampler Calibration and Simulant Tests

    Energy Technology Data Exchange (ETDEWEB)

    CRAWFORD, B.A.

    2000-01-05

    This test plan provides a method for calibration of the retained gas sampler (RGS) for ammonia gas analysis. Simulant solutions of ammonium hydroxide at known concentrations will be diluted with isotopically labeled 0.04 M ammonium hydroxide solution. Sea sand solids will also be mixed with ammonium hydroxide solution and diluent to determine the accuracy of the system for ammonia gas analysis.

  16. Research of Relation of Samplers Frequency Characteristics

    Directory of Open Access Journals (Sweden)

    Tomaš Tankeliun

    2016-06-01

    Full Text Available This paper proposes an algorithm to reduce limitations in band-width measurements of sampling oscilloscopes then using a swept sine-wave measurement method. The traditional swept sine-wave method allow measure only magnitude response. Phase response can be computed only if a sampler is a minimal phase circuit. In this paper alternative bandwidth measurement algorithm using the nose-to-nose method with measurements corrections for the non-idle properties of oscilloscope is de-scribed. Algorithm includes for noise, time base distortions and jitter in measurement signals corrections methods. Proposed algorithm allows to measure phase and magnitude responses when only two similar oscilloscopes and the source of sync pulse are used. Algorithm performs as well as the swept sine-wave method in case when both samplers have the same frequency characteristics.

  17. Three-Wheel Brush-Wheel Sampler

    Science.gov (United States)

    Duckworth, Geoffrey A.; Liu, Jun; Brown, Mark G.

    2010-01-01

    A new sampler is similar to a common snow blower, but is robust and effective in sample collection. The brush wheels are arranged in a triangle shape, each driven by a brushless DC motor and planetary gearhead embedded in the wheel shaft. Its speed can be varied from 800 - 2,000 rpm, depending on the surface regolith resistance. The sample-collecting flow path, and internal features, are designed based on flow dynamics, and the sample-collecting rates have consistently exceeded the requirement under various conditions that span the range of expected surface properties. The brush-wheel sampler (BWS) is designed so that the flow channel is the main body of the apparatus, and links the brush-wheel assembly to the sample canister. The combination of the three brush wheels, the sample flow path, and the canister location make sample collection, storage, and transfer an easier task.

  18. A wind tunnel test of newly developed personal bioaerosol samplers.

    Science.gov (United States)

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

    2012-07-01

    In this study the performance of two newly developed personal bioaerosol samplers was evaluated. The two test samplers are cyclone-based personal samplers that incorporate a recirculating liquid film. The performance evaluations focused on the physical efficiencies that a personal bioaerosol sampler could provide, including aspiration, collection, and capture efficiencies. The evaluation tests were carried out in a wind tunnel, and the test personal samplers were mounted on the chest of a full-size manikin placed in the test chamber of the wind tunnel. Monodisperse fluorescent aerosols ranging from 0.5 to 20 microm were used to challenge the samplers. Two wind speeds of 0.5 and 2.0 m/sec were employed as the test wind speeds in this study. The test results indicated that the aspiration efficiency of the two test samplers closely agreed with the ACGIH inhalable convention within the size range of the test aerosols. The aspiration efficiency was found to be independent of the sampling orientation. The collection efficiency acquired from these two samplers showed that the 50% cutoff diameters were both around 0.6 microm. However the wall loss of these two test samplers increased as the aerosol size increased, and the wall loss of PAS-4 was considerably higher than that of PAS-5, especially in the aerosol size larger than 5 microm, which resulted in PAS-4 having a relatively lower capture efficiency than PAS-5. Overall, the PAS-5 is considered a better personal bioaerosol sampler than the PAS-4.

  19. Development of syringe pump assisted headspace sampler.

    Science.gov (United States)

    Go, Un Jeong; Eom, In-Yong

    2014-09-26

    This report describes a new platform for headspace sampling technique, i.e. a syringe pump assisted headspace sampler (SPHS). The stand type pump's syringe itself was used as a sealed sample vial and a needle trap device (NTD) was adopted as a miniaturized sorbent tube. The NTD was directly used to inject trapped VOCs into a gas chromatograph. The proposed sampler was designed to take a whole headspace volume instead of a portion of it so as to enhance easily the extraction efficiency. The performance of the SPHS-NTD system was evaluated and compared with the solid-phase microextraction (SPME) with a static headspace (HS) sampling technique. Calibration curves were obtained for aqueous TEX (toluene, ethylbenzene, and o-xylene) solutions in the concentration range of ∼0.1-45 ng/mL. The calculated limit of detections (LOD, S/N=3) for TEX were 0.13 ng/mL or less. This SPHS-NTD was successfully applied to analyze aqueous TEX in river water samples and showed highly good recovery ranged from 97.2% to 105.8% for all tested VOCs. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. VALIDATION OF A NEW SOIL VOC SAMPLER

    Energy Technology Data Exchange (ETDEWEB)

    Susan S. Sorini; John F. Schabron

    1997-04-01

    The overall objective of this project is to facilitate national acceptance of the EnCore{trademark} sampling/storage device by conducting product tests, method development, and method validation activities. The specific goals for the initial six-month period of the project are listed: (1) Evaluate and become familiar with the stainless steel EnCore{trademark} sampling/storage device for collecting and holding soil samples for determination of volatile organic compounds (VOCs); (2) Initiate interaction with American Society for Testing and Materials (ASTM) Committee D-34 on Waste Management to begin the ASTM standard preparation and approval process; (3) Prepare an ASTM drall practice for using a device fitting the description of the EnCore{trademark} sampler for sampling and storing soil for volatile organic analysis. Under ASTM guidelines, the procedure describing the use of a device, such as the EnCore{trademark} sampler, is referred to as a practice rather than a method because it is a definitive set of instructions for performing one or more specific operations that does not produce a test result (ASTM 1996a); and (4) Plan testing needed to establish maximum storage temperatures and times for inclusion in the ASTM practice.

  1. Designing and testing the representative samplers for sampling a ...

    African Journals Online (AJOL)

    establishing the optimum mesh of grind for the various ores, to achieve effective separation of the cobalt minerals from those of copper. This prompted the designing and testing of representative samplers for sampling the milling circuit at Nkana Concentrator. In the design of the samplers, use was made of the Gy's formula to ...

  2. Assessing the utility of a continuous, underway fish egg sampler ...

    African Journals Online (AJOL)

    The accuracy of using a continuous underway fish egg sampler (CUFES) to sample zooplankton was assessed by comparing CUFES samples with those collected using a vertically towed bongo net. Samples were collected concurrently by the two samplers along four inshore–offshore transects off the south-western coast ...

  3. A novel sampler for limnological investigation in developing world ...

    African Journals Online (AJOL)

    A simple pump sampler for shallow water bodies, constructed with materials that are affordable and readily available in the local market is presented. It is simple to operate and no electric motor is required. The challenge of cost of acquisition of conventional samplers for sampling the lentic habitat, especially small water ...

  4. Performance characteristics of a low-volume PM10 sampler

    Science.gov (United States)

    Four identical PM10 pre-separators, along with four identical low-volume (1m3 hr-1) total suspended particulate (TSP) samplers were tested side-by-side in a controlled laboratory particulate matter (PM) chamber. The four PM10 and four TSP samplers were also tested in an oil pipe-cleaning field to ev...

  5. Siting samplers to minimize expected time to detection.

    Science.gov (United States)

    Walter, Travis; Lorenzetti, David M; Sohn, Michael D

    2012-12-01

    We present a probabilistic approach to designing an indoor sampler network for detecting an accidental or intentional chemical or biological release, and demonstrate it for a real building. In an earlier article, Sohn and Lorenzetti developed a proof of concept algorithm that assumed samplers could return measurements only slowly (on the order of hours). This led to optimal "detect to treat" architectures that maximize the probability of detecting a release. This article develops a more general approach and applies it to samplers that can return measurements relatively quickly (in minutes). This leads to optimal "detect to warn" architectures that minimize the expected time to detection. Using a model of a real, large, commercial building, we demonstrate the approach by optimizing networks against uncertain release locations, source terms, and sampler characteristics. Finally, we speculate on rules of thumb for general sampler placement. © 2012 Society for Risk Analysis.

  6. Calibration of nylon organic chemical integrative samplers and sentinel samplers for quantitative measurement of pulsed aquatic exposures.

    Science.gov (United States)

    Morrison, Shane A; Belden, Jason B

    2016-06-03

    Environmental exposures often occur through short, pulsed events; therefore, the ability to accurately measure these toxicologically-relevant concentrations is important. Three different integrative passive sampler configurations were evaluated under different flow and pulsed exposure conditions for the measurement of current-use pesticides (n=19), polyaromatic hydrocarbons (n=10), and personal care products (n=5) spanning a broad range of hydrophobicities (log Kow 1.5-7.6). Two modified POCIS-style samplers were investigated using macroporous nylon mesh membranes (35μm pores) and two different sorbent materials (i.e. Oasis HLB and Dowex Optipore L-493). A recently developed design, the Sentinel Sampler (ABS Materials), utilizing Osorb media enclosed within stainless steel mesh (145μm pores), was also investigated. Relatively high sampling rates (Rs) were achieved for all sampler configurations during the short eight-day exposure (4300-27mL/d). Under flow conditions, median Rs were approximately 5-10 times higher for POCIS-style samplers and 27 times higher for Sentinel Samplers, as compared to static conditions. The ability of samplers to rapidly measure hydrophobic contaminants may be a trade off with increased flow dependence. Analyte accumulation was integrative under pulsed and continuous exposures for POCIS-style samplers with mean difference between treatments of 11% and 33%; however, accumulation into Sentinel Samplers was more variable. Collectively, results show that reducing membrane limitations allows for rapid, integrative accumulation of a broad range of analytes even under pulsed exposures. As such, these sampler designs may be suitable for monitoring environmental substances that have short aquatic half-lives. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Revising Translations

    DEFF Research Database (Denmark)

    Rasmussen, Kirsten Wølch; Schjoldager, Anne

    2011-01-01

    survey. Results clearly show that most translation companies regard both unilingual and comparative revisions as essential components of professional quality assurance. Data indicate that revision is rarely fully comparative, as the preferred procedure seems to be a unilingual revision followed by a more...... or less comparative rereading. Though questionnaire data seem to indicate that translation companies use linguistic correctness and presentation as the only revision parameters, interview data reveal that textual and communicative aspects are also considered. Generally speaking, revision is not carried...... out by specialised revisers, but by staff translators, who revise the work of colleagues and freelancers on an ad hoc basis. Corrections are mostly given in a peer-to-peer fashion, though the work of freelancers and inexperienced in-house translators is often revised in an authoritative (nonnegotiable...

  8. Field intercomparison of ammonia passive samplers: results and lessons learned.

    Science.gov (United States)

    Stephens, Amy; Leeson, Sarah; Jones, Matthew; van Dijk, Netty; Kentisbeer, John; Twigg, Marsailidh; Simmons, Ivan; Braban, Christine; Martin, Nick; Poskitt, Janet; Ferm, Martin; Seitler, Eva; Sacco, Paolo; Gates, Linda; Stolk, Ariën; Stoll, Jean-Marc; Tang, Sim

    2017-04-01

    Ammonia pollution contributes significantly to eutrophication and acidification of ecosystems with resultant losses of biodiversity and ecosystem changes. Monitoring of ambient ammonia over a wide spatial and long temporal scales is primarily done with low-cost diffusive samplers. Less frequently, surface flux measurements of ammonia can be made using passive samplers at plot scale. This paper will present a field intercomparison conducted within the MetNH3 project to assess the performance of passive samplers for ambient measurements of ammonia. Eight different designs of commercial passive samplers housed in shelters provided by the manufacturer/laboratory were exposed over an 8-week period at the Whim experimental field site in Scotland between August and October 2016. Whim Bog has a facility in place for controlled releases of ammonia (http://www.whimbog.ceh.ac.uk/). Automated conditional release from the line source occurs when the wind direction in the preceding minute is from the northeast (wind sector 180-215°) and wind speed is > 5 m s-1. The passive samplers were exposed at different distances from the release source (16, 32 and 60 m) and also at a background location. Most were exposed for 2 x 4-week long periods and some for 4 x 2-week long periods. At the 32 m position, an active denuder method, the CEH DELTA sampler and a continuous high temporal resolution wet chemistry ammonia instrument (AiRRmonia, Mechatronics, NL.) were also deployed alongside the passive samplers to provide reference measurements of ammonia. Results are presented within the context of the MetNH3 CATFAC controlled laboratory exposure assessments. The results are discussed in terms of typical deployments of passive samplers and quality control. Measurement for policy evidence for both local and regional studies using passive samplers are discussed.

  9. 7 CFR 800.185 - Duties of official personnel and warehouse samplers.

    Science.gov (United States)

    2010-01-01

    ... of § 800.161. (d) Scope of operations. Official personnel and warehouse samplers shall operate only... 7 Agriculture 7 2010-01-01 2010-01-01 false Duties of official personnel and warehouse samplers... official personnel and warehouse samplers. (a) General. Official personnel and warehouse samplers shall...

  10. Automated particulate sampler field test model operations guide

    Energy Technology Data Exchange (ETDEWEB)

    Bowyer, S.M.; Miley, H.S.

    1996-10-01

    The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.

  11. CalCOFI Continuous Underway Fish-Egg Sampler

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Samples collected using the Continuous Underway Fish-Egg Sampler, known as CUFES. The data include numbers of anchovy, sardine, jack mackerel, squid, hake, and...

  12. Fluidized Bed Asbestos Sampler Design and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Karen E. Wright; Barry H. O' Brien

    2007-12-01

    A large number of samples are required to characterize a site contaminated with asbestos from previous mine or other industrial operations. Current methods, such as EPA Region 10’s glovebox method, or the Berman Elutriator method are time consuming and costly primarily because the equipment is difficult to decontaminate between samples. EPA desires a shorter and less costly method for characterizing soil samples for asbestos. The objective of this was to design and test a qualitative asbestos sampler that operates as a fluidized bed. The proposed sampler employs a conical spouted bed to vigorously mix the soil and separate fine particulate including asbestos fibers on filters. The filters are then analyzed using transmission electron microscopy for presence of asbestos. During initial testing of a glass prototype using ASTM 20/30 sand and clay fines as asbestos surrogates, fine particulate adhered to the sides of the glass vessel and the tubing to the collection filter – presumably due to static charge on the fine particulate. This limited the fines recovery to ~5% of the amount added to the sand surrogate. A second prototype was constructed of stainless steel, which improved fines recovery to about 10%. Fines recovery was increased to 15% by either humidifying the inlet air or introducing a voltage probe in the air space above the sample. Since this was not a substantial improvement, testing using the steel prototype proceeded without using these techniques. Final testing of the second prototype using asbestos suggests that the fluidized bed is considerably more sensitive than the Berman elutriator method. Using a sand/tremolite mixture with 0.005% tremolite, the Berman elutriator did not segregate any asbestos structures while the fluidized bed segregated an average of 11.7. The fluidized bed was also able to segregate structures in samples containing asbestos at a 0.0001% concentration, while the Berman elutriator method did not detect any fibers at this

  13. The MAGIC meteoric smoke particle sampler

    Science.gov (United States)

    Hedin, Jonas; Giovane, Frank; Waldemarsson, Tomas; Gumbel, Jörg; Blum, Jürgen; Stroud, Rhonda M.; Marlin, Layne; Moser, John; Siskind, David E.; Jansson, Kjell; Saunders, Russell W.; Summers, Michael E.; Reissaus, Philipp; Stegman, Jacek; Plane, John M. C.; Horányi, Mihály

    2014-10-01

    Between a few tons to several hundred tons of meteoric material enters the Earth's atmosphere each day, and most of this material is ablated and vaporized in the 70-120 km altitude region. The subsequent chemical conversion, re-condensation and coagulation of this evaporated material are thought to form nanometre sized meteoric smoke particles (MSPs). These smoke particles are then subject to further coagulation, sedimentation and global transport by the mesospheric circulation. MSPs have been proposed as a key player in the formation and evolution of ice particle layers around the mesopause region, i.e. noctilucent clouds (NLC) and polar mesosphere summer echoes (PMSE). MSPs have also been implicated in mesospheric heterogeneous chemistry to influence the mesospheric odd oxygen/odd hydrogen (Ox/HOx) chemistry, to play an important role in the mesospheric charge balance, and to be a significant component of stratospheric aerosol and enhance the depletion of O3. Despite their apparent importance, little is known about the properties of MSPs and none of the hypotheses can be verified without direct evidence of the existence, altitude and size distribution, shape and elemental composition. The aim of the MAGIC project (Mesospheric Aerosol - Genesis, Interaction and Composition) was to develop an instrument and analysis techniques to sample for the first time MSPs in the mesosphere and return them to the ground for detailed analysis in the laboratory. MAGIC meteoric smoke particle samplers have been flown on several sounding rocket payloads between 2005 and 2011. Several of these flights concerned non-summer mesosphere conditions when pure MSP populations can be expected. Other flights concerned high latitude summer conditions when MSPs are expected to be contained in ice particles in the upper mesosphere. In this paper we present the MAGIC project and describe the MAGIC MSP sampler, the measurement procedure and laboratory analysis. We also present the attempts to

  14. astroABC: Approximate Bayesian Computation Sequential Monte Carlo sampler

    Science.gov (United States)

    Jennings, Elise

    2017-05-01

    astroABC is a Python implementation of an Approximate Bayesian Computation Sequential Monte Carlo (ABC SMC) sampler for parameter estimation. astroABC allows for massive parallelization using MPI, a framework that handles spawning of processes across multiple nodes. It has the ability to create MPI groups with different communicators, one for the sampler and several others for the forward model simulation, which speeds up sampling time considerably. For smaller jobs the Python multiprocessing option is also available.

  15. Validation of parachlorobenzotrifluoride, benzotrifluoride, and monochlorotoluene on diffusive samplers.

    Science.gov (United States)

    Yost, C; Harper, M

    2000-01-01

    Three solvents (OXSOL 10, monochlorotoluene or mixed isomers of 1- chloro-2-methyl benzene and 1-chloro-4-methyl benzene; OXSOL 100, parachlorobenzotrifluoride or 1-chloro-4-(trifluoromethyl) benzene; and OXSOL 2000, benzotrifluoride or trifluoromethyl benzene) produced by Occidental Chemical Corporation (Niagara Falls, NY) were considered as candidates for SKC, Inc.'s on-going diffusive sampler validation program. The 575-series diffusive sampler contains coconut-shell charcoal (575-001) or Anasorb 747 (575-002). Both samplers were used in this study. Desorption efficiency was tested at loadings equivalent to eight-hour time-weighted average (TWA) exposures to 0.01-2 times the Occidental Chemical Corporation in-house limit values (respectively: 50 ppm, 25 ppm, and 100 ppm,. All results met the National Institute for Occupational Safety and Health (NIOSH) criteria of > 75 percent, and, except for the lower loadings of parachlorobenzotrifluoride, the results were in the range of 90-110 percent. The calculated uptake rates were verified for different periods of exposure, up to eight hours, and found to be within 5 percent of the calculated for all three compounds on both samplers. A detailed comparison of the results from different time periods indicated no significant reverse diffusion effects for any combination of sampler and analyte. Samplers exposed to standard atmospheres of each compound were stored for three weeks at ambient temperatures and reanalyzed with results between 94 and 107 percent of expected. Based on full validation of samplers for the lower homologue (benzene), the bi-level theory of sample validation as endorsed by international validation protocols establishes this as a complete validation of the featured samplers for sampling vapors of these chemicals in air.

  16. Pesticide monitoring in surface water and groundwater using passive samplers

    Science.gov (United States)

    Kodes, V.; Grabic, R.

    2009-04-01

    Passive samplers as screening devices have been used within a czech national water quality monitoring network since 2002 (SPMD and DGT samplers for non polar substances and metals). The passive sampler monitoring of surface water was extended to polar substances, in 2005. Pesticide and pharmaceutical POCIS samplers have been exposed in surface water at 21 locations and analysed for polar pesticides, perfluorinated compounds, personal care products and pharmaceuticals. Pesticide POCIS samplers in groundwater were exposed at 5 locations and analysed for polar pesticides. The following active substances of plant protection products were analyzed in surface water and groundwater using LC/MS/MS: 2,4,5-T, 2,4-D, Acetochlor, Alachlor, Atrazine, Atrazine_desethyl, Azoxystrobin, Bentazone, Bromacil, Bromoxynil, Carbofuran, Clopyralid, Cyanazin, Desmetryn, Diazinon, Dicamba, Dichlobenil, Dichlorprop, Dimethoat, Diuron, Ethofumesate, Fenarimol, Fenhexamid, Fipronil, Fluazifop-p-butyl, Hexazinone, Chlorbromuron, Chlorotoluron, Imazethapyr, Isoproturon, Kresoxim-methyl, Linuron, MCPA, MCPP, Metalaxyl, Metamitron, Methabenzthiazuron, Methamidophos, Methidathion, Metobromuron, Metolachlor, Metoxuron, Metribuzin, Monolinuron, Nicosulfuron, Phorate, Phosalone, Phosphamidon, Prometryn, Propiconazole, Propyzamide, Pyridate, Rimsulfuron, Simazine, Tebuconazole, Terbuthylazine, Terbutryn, Thifensulfuron-methyl, Thiophanate-methyl and Tri-allate. The POCIS samplers performed very well being able to provide better picture than grab samples. The results show that polar pesticides and also perfluorinated compounds, personal care products and pharmaceuticals as well occur in hydrosphere of the Czech republic. Acknowledgment: Authors acknowledge the financial support of grant No. 2B06095 by the Ministry of Education, Youth and Sports.

  17. Transient digitizer with displacement current samplers

    Science.gov (United States)

    McEwan, Thomas E.

    1996-01-01

    A low component count, high speed sample gate, and digitizer architecture using the sample gates is based on use of a signal transmission line, a strobe transmission line and a plurality of sample gates connected to the sample transmission line at a plurality of positions. The sample gates include a strobe pickoff structure near the strobe transmission line which generates a charge displacement current in response to propagation of the strobe signal on the strobe transmission line sufficient to trigger the sample gate. The sample gate comprises a two-diode sampling bridge and is connected to a meandered signal transmission line at one end and to a charge-holding cap at the other. The common cathodes are reverse biased. A voltage step is propagated down the strobe transmission line. As the step propagates past a capacitive pickoff, displacement current i=c(dv/dT), flows into the cathodes, driving the bridge into conduction and thereby charging the charge-holding capacitor to a value related to the signal. A charge amplifier converts the charge on the charge-holding capacitor to an output voltage. The sampler is mounted on a printed circuit board, and the sample transmission line and strobe transmission line comprise coplanar microstrips formed on a surface of the substrate. Also, the strobe pickoff structure may comprise a planar pad adjacent the strobe transmission line on the printed circuit board.

  18. Improved passive flux samplers for measuring ammonia emissions from animal houses, Part 2: Performance of different types of sampler as a function of angle of incidence of airflow

    NARCIS (Netherlands)

    Scholtens, R.; Wagemans, M.J.M.; Phillips, V.R.

    2003-01-01

    The basic principle of the improved passive flux sampler has been reported in a companion paper. In the present paper, the performance of different types of the sampler as a function of angle of incidence of airflow was studied in a wind tunnel. The following types of sampler were examined: a basic

  19. Deep-Sea Hydrothermal-Vent Sampler

    Science.gov (United States)

    Behar, Alberto E.; Venkateswaran, Kasthur; Matthews, Jaret B.

    2008-01-01

    An apparatus is being developed for sampling water for signs of microbial life in an ocean hydrothermal vent at a depth of as much as 6.5 km. Heretofore, evidence of microbial life in deep-sea hydrothermal vents has been elusive and difficult to validate. Because of the extreme conditions in these environments (high pressures and temperatures often in excess of 300 C), deep-sea hydrothermal- vent samplers must be robust. Because of the presumed low density of biomass of these environments, samplers must be capable of collecting water samples of significant volume. It is also essential to prevent contamination of samples by microbes entrained from surrounding waters. Prior to the development of the present apparatus, no sampling device was capable of satisfying these requirements. The apparatus (see figure) includes an intake equipped with a temperature probe, plus several other temperature probes located away from the intake. The readings from the temperature probes are utilized in conjunction with readings from flowmeters to determine the position of the intake relative to the hydrothermal plume and, thereby, to position the intake to sample directly from the plume. Because it is necessary to collect large samples of water in order to obtain sufficient microbial biomass but it is not practical to retain all the water from the samples, four filter arrays are used to concentrate the microbial biomass (which is assumed to consist of particles larger than 0.2 m) into smaller volumes. The apparatus can collect multiple samples per dive and is designed to process a total volume of 10 L of vent fluid, of which most passes through the filters, leaving a total possibly-microbe-containing sample volume of 200 mL remaining in filters. A rigid titanium nose at the intake is used for cooling the sample water before it enters a flexible inlet hose connected to a pump. As the water passes through the titanium nose, it must be cooled to a temperature that is above a mineral

  20. Performance of high flow rate samplers for respirable particle collection.

    Science.gov (United States)

    Lee, Taekhee; Kim, Seung Won; Chisholm, William P; Slaven, James; Harper, Martin

    2010-08-01

    The American Conference of Governmental Industrial hygienists (ACGIH) lowered the threshold limit value (TLV) for respirable crystalline silica (RCS) exposure from 0.05 to 0.025 mg m(-3) in 2006. For a working environment with an airborne dust concentration near this lowered TLV, the sample collected with current standard respirable aerosol samplers might not provide enough RCS for quantitative analysis. Adopting high flow rate sampling devices for respirable dust containing silica may provide a sufficient amount of RCS to be above the limit of quantification even for samples collected for less than full shift. The performances of three high flow rate respirable samplers (CIP10-R, GK2.69, and FSP10) have been evaluated in this study. Eleven different sizes of monodisperse aerosols of ammonium fluorescein were generated with a vibrating orifice aerosol generator in a calm air chamber in order to determine the sampling efficiency of each sampler. Aluminum oxide particles generated by a fluidized bed aerosol generator were used to test (i) the uniformity of a modified calm air chamber, (ii) the effect of loading on the sampling efficiency, and (iii) the performance of dust collection compared to lower flow rate cyclones in common use in the USA (10-mm nylon and Higgins-Dewell cyclones). The coefficient of variation for eight simultaneous samples in the modified calm air chamber ranged from 1.9 to 6.1% for triplicate measures of three different aerosols. The 50% cutoff size ((50)d(ae)) of the high flow rate samplers operated at the flow rates recommended by manufacturers were determined as 4.7, 4.1, and 4.8 microm for CIP10-R, GK2.69, and FSP10, respectively. The mass concentration ratio of the high flow rate samplers to the low flow rate cyclones decreased with decreasing mass median aerodynamic diameter (MMAD) and high flow rate samplers collected more dust than low flow rate samplers by a range of 2-11 times based on gravimetric analysis. Dust loading inside the

  1. The neighborhood MCMC sampler for learning Bayesian networks

    Science.gov (United States)

    Alyami, Salem A.; Azad, A. K. M.; Keith, Jonathan M.

    2016-07-01

    Getting stuck in local maxima is a problem that arises while learning Bayesian networks (BNs) structures. In this paper, we studied a recently proposed Markov chain Monte Carlo (MCMC) sampler, called the Neighbourhood sampler (NS), and examined how efficiently it can sample BNs when local maxima are present. We assume that a posterior distribution f(N,E|D) has been defined, where D represents data relevant to the inference, N and E are the sets of nodes and directed edges, respectively. We illustrate the new approach by sampling from such a distribution, and inferring BNs. The simulations conducted in this paper show that the new learning approach substantially avoids getting stuck in local modes of the distribution, and achieves a more rapid rate of convergence, compared to other common algorithms e.g. the MCMC Metropolis-Hastings sampler.

  2. A mathematics sampler topics for the liberal arts

    CERN Document Server

    Berlinghoff, William P; Skrien, Dale

    2001-01-01

    Now in its fifth edition, A Mathematics Sampler presents mathematics as both science and art, focusing on the historical role of mathematics in our culture. It uses selected topics from modern mathematics-including computers, perfect numbers, and four-dimensional geometry-to exemplify the distinctive features of mathematics as an intellectual endeavor, a problem-solving tool, and a way of thinking about the rapidly changing world in which we live. A Mathematics Sampler also includes unique LINK sections throughout the book, each of which connects mathematical concepts with areas of interest th

  3. Nonwoven textile for use in a nanoparticle respiratory deposition sampler.

    Science.gov (United States)

    Vosburgh, Donna J H; Park, Jae Hong; Mines, Levi W D; Mudunkotuwa, Imali A; Anthony, T Renée; Peters, Thomas M

    2017-05-01

    The nanoparticle respiratory deposition (NRD) sampler is a personal sampler that combines a cyclone, impactor, and a nylon mesh diffusion stage to measure a worker's exposure to nanoparticles. The concentration of titanium in the nylon mesh of the diffusion stage complicates the application of the NRD sampler for assessing exposures to titanium dioxide nanoparticles. This study evaluated commercially available nonwoven textiles for use as an alternative media in the diffusion stage of the NRD sampler. Three textiles were selected as containing little titanium from an initial screening of 11 textiles by field portable x-ray fluorescence (FPXRF). Further evaluation on these three textiles was conducted to determine the concentration of titanium and other metals by inductively coupled plasma-optical emission spectroscopy (ICP-OES), the number of layers required to achieve desired collection characteristics for use as the diffusion stage in the NRD sampler (i.e., the nanoparticulate matter, NPM, criterion), and the pressure drop associated with that number of layers.  Only three (two composed of cotton fibers, C1 and C2; and one of viscose bamboo and cotton fibers, BC) of 11 textiles screened had titanium concentrations below the limit of detection the XRF device (0.15 µg/cm 2 ). Multiple metals, including small amounts of titanium, were found in each of the three nonwoven textiles using ICP-OES. The number of 25-mm-diameter layers required to achieve the collection efficiency by size required for the NRD sampler was three for C1 (R 2 = 0.95 with reference to the NPM criterion), two for C2 (R 2 = 0.79), and three for BC (R 2 = 0.87). All measured pressure drops were less than theoretical and even the greatest pressure drop of 65.4 Pa indicated that a typical personal sampling pump could accommodate any of the three nonwoven textiles in the NRD sampler. The titanium concentration, collection efficiency, and measured pressure drops show there is a potential for

  4. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation,

    Science.gov (United States)

    Objectives. This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Approach/Activities. Fifty-five studies were found where both passive sampler uptake...

  5. Initial field evaluation of the Harvard active ozone sampler for personal ozone monitoring.

    Science.gov (United States)

    Geyh, A S; Roberts, P T; Lurmann, F W; Schoell, B M; Avol, E L

    1999-01-01

    Assessing personal exposure to ozone has only been feasible recently with the introduction of passive ozone samplers. These devices are easy to use, but changes in air velocity across their collection surfaces can affect performance. The Harvard active ozone sampler (AS) was developed in response to problems with the passive methods. This active sampler has been tested extensively as a microenvironmental sampler. To test for personal sampling, 40 children attending summer day-camp in Riverside, California wore the active ozone sampler for approximately 2.6 h on July 19 and 21, 1994, when ozone concentrations were about 100 ppb and 140 ppb, respectively. The children spent 94-100% of the sampling period outside, staying within a well-defined area while participating in normal camp activities. Ambient ozone concentrations across this area were monitored by two UV photometric ozone monitors. The active sampler was worn in a small backpack that was also equipped with a passive ozone sampler. Device precision, reported as the percent difference between duplicate pairs of samplers, was +/- 3.7% and +/- 4.2% for the active and passive samplers, respectively. The active sampler measured, on average, 94.5 +/- 8.2% of the ambient ozone while the passive samplers measured, on average, 124.5 +/- 18.8%. The samplers were worn successfully for the entire sampling period by all participating children.

  6. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Science.gov (United States)

    2010-10-01

    ... must: (1) Notify the sea sampler/observer of any sea turtles, marine mammals, or other specimens taken by the vessel. (2) Provide the sea sampler/observer with sea turtles, marine mammals, or other... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false At-sea sea sampler/observer coverage. 697...

  7. FIELD EVALUATION OF A HIGH-VOLUME DICHOTOMOUS SAMPLER

    Science.gov (United States)

    This study presents the field evaluation of a high-volume dichotomous sampler that collects coarse (PM10-2.5) and fine (PM2.5) particulate matter. The key feature of this device is the utilization of a round-nozzle virtual impactor with a 50% cutpoint at 2.5 5m to split PM10 into...

  8. Grab Samplers for Benthic Macroinvertebrates in the Lower Mississippi River.

    Science.gov (United States)

    1982-07-01

    River 26. AftTRACT (Cfeo do reversn e o if neem mod Identiy by block nuibot) -- he use of any one single type and size of existing grab sampler for...was from the stern of a 40-ft* vessel. The vessel’s bow was tied to a tree on the shoreline. Although the range of water depths during sampling was

  9. Fluidic Sampler. Tanks Focus Area. OST Reference No. 2007

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1999-09-01

    Problem Definition; Millions of gallons of radioactive and hazardous wastes are stored in underground tanks across the U.S. Department of Energy (DOE) complex. To manage this waste, tank operators need safe, cost-effective methods for mixing tank material, transferring tank waste between tanks, and collecting samples. Samples must be collected at different depths within storage tanks containing various kinds of waste including salt, sludge, and supernatant. With current or baseline methods, a grab sampler or a core sampler is inserted into the tank, waste is maneuvered into the sample chamber, and the sample is withdrawn from the tank. The mixing pumps in the tank, which are required to keep the contents homogeneous, must be shut down before and during sampling to prevent airborne releases. These methods are expensive, require substantial hands-on labor, increase the risk of worker exposure to radiation, and often produce nonrepresentative and unreproducible samples. How It Works: The Fluidic Sampler manufactured by AEA Technology Engineering Services, Inc., enables tank sampling to be done remotely with the mixing pumps in operation. Remote operation minimizes the risk of exposure to personnel and the possibility of spills, reducing associated costs. Sampling while the tank contents are being agitated yields consistently homogeneous, representative samples and facilitates more efficient feed preparation and evaluation of the tank contents. The above-tank portion of the Fluidic Sampler and the replacement plug and pipework that insert through the tank top are shown.

  10. Optimisation of the membrane-assisted passive sampler and its ...

    African Journals Online (AJOL)

    In both cases, extraction efficiency was highest for 2,4-dichlorophenol. The low extraction efficiency in the passive sampler supports the idea that it is not an exhaustive extraction technique and does not disturb the chemical equilibrium of the sample. It therefore measures the bioavailable fraction of the compound and can ...

  11. Optimisation of the membrane-assisted passive sampler and its ...

    African Journals Online (AJOL)

    2010-07-20

    Jul 20, 2010 ... extraction technique in terms of the extraction efficiency, enrichment factor, detection limit and selectivity in wastewater. The passive sampler .... compounds such as polar industrial pollutants, pesticides, personal care prod- ... Chlorinated phenols can also form during wastewater treat- ment, since chlorine ...

  12. Scanning SQUID sampler with 40-ps time resolution

    Science.gov (United States)

    Cui, Zheng; Kirtley, John R.; Wang, Yihua; Kratz, Philip A.; Rosenberg, Aaron J.; Watson, Christopher A.; Gibson, Gerald W.; Ketchen, Mark B.; Moler, Kathryn. A.

    2017-08-01

    Scanning Superconducting QUantum Interference Device (SQUID) microscopy provides valuable information about magnetic properties of materials and devices. The magnetic flux response of the SQUID is often linearized with a flux-locked feedback loop, which limits the response time to microseconds or longer. In this work, we present the design, fabrication, and characterization of a novel scanning SQUID sampler with a 40-ps time resolution and linearized response to periodically triggered signals. Other design features include a micron-scale pickup loop for the detection of local magnetic flux, a field coil to apply a local magnetic field to the sample, and a modulation coil to operate the SQUID sampler in a flux-locked loop to linearize the flux response. The entire sampler device is fabricated on a 2 mm × 2 mm chip and can be scanned over macroscopic planar samples. The flux noise at 4.2 K with 100 kHz repetition rate and 1 s of averaging is of order 1 mΦ0. This SQUID sampler will be useful for imaging dynamics in magnetic and superconducting materials and devices.

  13. Developments in Emission Measurements Using Lightweight Sensors and Samplers.

    Science.gov (United States)

    Lightweight emission measurement systems making use of miniaturized sensors and samplers have been developed for portable and aerial sampling for an array of pollutants. Shoebox-sized systems called “Kolibri”, weighing 3-5 kg, have been deployed on NASA-flown unmanned...

  14. Evaluation of IOM personal sampler at different flow rates.

    Science.gov (United States)

    Zhou, Yue; Cheng, Yung-Sung

    2010-02-01

    The Institute of Occupational Medicine (IOM) personal sampler is usually operated at a flow rate of 2.0 L/min, the rate at which it was designed and calibrated, for sampling the inhalable mass fraction of airborne particles in occupational environments. In an environment of low aerosol concentrations only small amounts of material are collected, and that may not be sufficient for analysis. Recently, a new sampling pump with a flow rate up to 15 L/min became available for personal samplers, with the potential of operating at higher flow rates. The flow rate of a Leland Legacy sampling pump, which operates at high flow rates, was evaluated and calibrated, and its maximum flow was found to be 10.6 L/min. IOM samplers were placed on a mannequin, and sampling was conducted in a large aerosol wind tunnel at wind speeds of 0.56 and 2.22 m/s. Monodisperse aerosols of oleic acid tagged with sodium fluorescein in the size range of 2 to 100 microm were used in the test. The IOM samplers were operated at flow rates of 2.0 and 10.6 L/min. Results showed that the IOM samplers mounted in the front of the mannequin had a higher sampling efficiency than those mounted at the side and back, regardless of the wind speed and flow rate. For the wind speed of 0.56 m/s, the direction-averaged (the average value of all orientations facing the wind direction) sampling efficiency of the samplers operated at 2.0 L/min was slightly higher than that of 10.6 L/min. For the wind speed of 2.22 m/s, the sampling efficiencies at both flow rates were similar for particles flow rates follows the inhalable mass curve for particles in the size range of 2 to 20 microm. The test results indicate that the IOM sampler can be used at higher flow rates.

  15. Automated particulate sampler for Comprehensive Test Ban Treaty verification (the DOE radionuclide aerosol sampler/analyzer)

    Science.gov (United States)

    Bowyer, S. M.; Miley, H. S.; Thompson, R. C.; Hubbard, C. W.

    1997-06-01

    The Comprehensive Test Ban Treaty (CTBT) was recently signed by President Clinton and is intended to eliminate all nuclear weapons testing. One way which the treaty seeks to accomplish this is by the establishment of the International Monitoring System. As stated in the latest Working Papers of the Draft CTBT, "The International Monitoring System shall comprise facilities for seismological monitoring, radionuclide monitoring including certified laboratories, hydroacoustic monitoring, infrasound monitoring, and respective means of communication, and shall be supported by the International Data Centre of the Technical Secretariat". Radionuclide monitoring consists of both radionuclides associated with particulates and relevant noble gases. This type of monitoring is quite valuable since indications of a nuclear test in the form of radioactive particulate or radioactive noble gases may be detected at great distances from the detonation site. The system presented here is concerned only with radioactive particulate monitoring and is described as an automated sampler/analyzer which has been developed for the Department of Energy (DoE) at the Pacific Northwest National Laboratory (PNNL).

  16. Beyond Canisters (SUMMAs): Passive and Active Samplers and International Perspective

    Science.gov (United States)

    2010-12-01

    cleanliness . Repeat this clean, store, and clean sequence as many times as necessary. • Bulky - require special storage facilities and transport...Desorption Analysis Procedures for Volatile Organic Compounds in Air ISO 16017-2 Indoor, ambient and workplace air — Sampling and analysis of...Practice for Sampling Workplace Atmospheres to Collect Gases or Vapors with Solid Sorbent Diffusive Samplers Sorbent Sampling Guidance ITALY Approximately

  17. Development and evaluation of an ultrasonic personal aerosol sampler.

    Science.gov (United States)

    Volckens, J; Quinn, C; Leith, D; Mehaffy, J; Henry, C S; Miller-Lionberg, D

    2017-03-01

    Assessing personal exposure to air pollution has long proven challenging due to technological limitations posed by the samplers themselves. Historically, wearable aerosol monitors have proven to be expensive, noisy, and burdensome. The objective of this work was to develop a new type of wearable monitor, an ultrasonic personal aerosol sampler (UPAS), to overcome many of the technological limitations in personal exposure assessment. The UPAS is a time-integrated monitor that features a novel micropump that is virtually silent during operation. A suite of onboard environmental sensors integrated with this pump measure and record mass airflow (0.5-3.0 L/min, accurate within 5%), temperature, pressure, relative humidity, light intensity, and acceleration. Rapid development of the UPAS was made possible through recent advances in low-cost electronics, open-source programming platforms, and additive manufacturing for rapid prototyping. Interchangeable cyclone inlets provided a close match to the EPA PM 2.5 mass criterion (within 5%) for device flows at either 1.0 or 2.0 L/min. Battery life varied from 23 to 45 hours depending on sample flow rate and selected filter media. Laboratory tests of the UPAS prototype demonstrate excellent agreement with equivalent federal reference method samplers for gravimetric analysis of PM 2.5 across a broad range of concentrations. © 2016 The Authors. Indoor Air published by John Wiley & Sons Ltd.

  18. A carbon monoxide passive sampler: Research and development needs

    Energy Technology Data Exchange (ETDEWEB)

    Traynor, G.W.; Apte, M.G.; Diamond, R.C.; Woods, A.L.

    1991-11-01

    In rare instances, carbon monoxide (CO) levels in houses can reach dangerously high concentrations, causing adverse health effects ranging from mild headaches to, under extreme conditions, death. Hundreds of fatal accidental carbon monoxide poisonings occur each year primarily due to the indoor operation of motor vehicles, the indoor use of charcoal for cooking, the operation of malfunctioning vented and unvented combustion appliances, and the misuse combustion appliances. Because there is a lack of simple, inexpensive, and accurate field sampling instrumentation, it is difficult for gas utilities and researchers to conduct field research studies designed to quantify the concentrations of CO in residences. Determining the concentration of CO in residences is the first step towards identifying the high risk appliances and high-CO environments which pose health risks. Thus, there exists an urgent need to develop and field-validate a CO-quantifying technique suitable for affordable field research. A CO passive sampler, if developed, could fulfill these requirements. Existing CO monitoring techniques are discussed as well as three potential CO-detection methods for use in a CO passive sampler. Laboratory and field research needed for the development and validation of an effective and cost-efficient CO passive sampler are also discussed.

  19. Field intercomparison of diffusive samplers for measuring ammonia.

    Science.gov (United States)

    Kirchner, M; Braeutigam, S; Ferm, M; Haas, M; Hangartner, M; Hofschreuder, P; Kasper-Giebl, A; Römmelt, H; Striedner, J; Terzer, W; Thöni, L; Werner, H; Zimmerling, R

    1999-06-01

    Agricultural production systems are recognised as a major source of atmospheric ammonia. Deposition of ammonia and ammonium may contribute to undesired changes in oligotrophic ecosystems. The continuous measurement of atmospheric ammonia requires expensive and sophisticated techniques and is performed only in a very restrict number of ambient air stations in Europe. Therefore, the application of passive samplers, which have the advantage of being easy to handle and cost-efficient, is useful. In the past the comparability of different passive samplers must be considered as rather scarce. In a joint European project under the leadership of the GSF-Forschungszentrum für Umwelt und Gesundheit, Neuherberg, in 1997 a comparison of different passive ammonia monitoring methods was carried out in a prealpine rural site near Garmisch-Partenkirchen. It was considered valuable to include not only well established systems but also methods still being developed. For the comparative test ten working groups with different methods took part. A wet annular denuder system, which has been developed by the Netherlands Energy Research Foundation for on-line measurement of atmospheric ammonia, served as reference of passive methods. The experiment, which started in June and finished in December, showed that most of the passive samplers fulfil the requirements and can be recommended for further measurements. Additional measurements of meteorological parameters were performed to check the influences of different weather conditions on passive sampling.

  20. Comparison of the sampling rates and partitioning behaviour of polar and non-polar contaminants in the polar organic chemical integrative sampler and a monophasic mixed polymer sampler for application as an equilibrium passive sampler.

    Science.gov (United States)

    Jeong, Yoonah; Schäffer, Andreas; Smith, Kilian

    2018-02-02

    In this work, Oasis HLB® beads were embedded in a silicone matrix to make a single phase passive sampler with a higher affinity for polar and ionisable compounds than silicone alone. The applicability of this mixed polymer sampler (MPS) was investigated for 34 aquatic contaminants (log K OW -0.03 to 6.26) in batch experiments. The influence of flow was investigated by comparing uptake under static and stirred conditions. The sampler characteristics of the MPS was assessed in terms of sampling rates (R S ) and sampler-water partition coefficients (K SW ), and these were compared to those of the polar organic chemical integrative sampler (POCIS) as a reference kinetic passive sampler. The MPS was characterized as an equilibrium sampler for both polar and non-polar compounds, with faster uptake rates and a shorter time to reach equilibrium than the POCIS. Water flow rate impacted sampling rates by up to a factor of 12 when comparing static and stirred conditions. In addition, the relative accumulation of compounds in the polyethersulfone (PES) membranes versus the inner Oasis HLB sorbent was compared for the POCIS, and ranged from <1% to 83% depending on the analyte properties. This is indicative of a potentially significant lag-phase for less polar compounds within POCIS. The findings of this study can be used to quantitatively describe the partitioning and kinetic behaviour of MPS and POCIS for a range of aquatic organic contaminants for application in field sampling. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Summary report on the design of the retained gas sampler system (retained gas sampler, extruder and extractor)

    Energy Technology Data Exchange (ETDEWEB)

    Wootan, D.W.; Bolden, R.C.; Bridges, A.E.; Cannon, N.S.; Chastain, S.A.; Hey, B.E.; Knight, R.C.; Linschooten, C.G.; Pitner, A.L.; Webb, B.J.

    1994-09-29

    This document summarizes work performs in Fiscal Year 1994 to develop the three main components of Retained Gas Sampler System (RGSS). These primary components are the Retained Gas Sampler (RGS), the Retained Gas Extruder (RGE), and the Retained Gas Extractor (RGEx). The RGS is based on the Westinghouse Hanford Company (WHC) Universal Sampler design, and includes modifications to reduce gas leakage. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. Significant progress has been made in developing the RGSS. The RGSS is being developed by WHC to extract a representative waste sample from a Flammable Gas Watch List Tanks and to measure both the amount and composition of free and {open_quotes}bound{close_quotes} gases. Sudden releases of flammable gas mixtures are a safety concern for normal waste storage operations and eventual waste retrieval. Flow visualization testing was used to identify important fluid dynamic issues related to the sampling process. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. The safety analysis for the RGSS is being performed by Los Alamos National Laboratory and is more than sixty percent (60%) complete.

  2. Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for Inorganic Analytes

    National Research Council Canada - National Science Library

    Parker, Louise V; Mulherin, Nathan D; Gooch, Gordon E

    2008-01-01

    Laboratory studies and a field demonstration were conducted to determine the ability of the Snap Sampler to recover representative concentrations of inorganic analytes, including metals, from ground water...

  3. Quartz measurement in coal dust with high-flow rate samplers: laboratory study.

    Science.gov (United States)

    Lee, Taekhee; Lee, Eun Gyung; Kim, Seung Won; Chisholm, William P; Kashon, Michael; Harper, Martin

    2012-05-01

    A laboratory study was performed to measure quartz in coal dust using high-flow rate samplers (CIP10-R, GK2.69 cyclone, and FSP10 cyclone) and low-flow rate samplers [10-mm nylon and Higgins-Dewell type (BGI4L) cyclones] and to determine whether an increased mass collection from high-flow rate samplers would affect the subsequent quartz measurement by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analytical procedures. Two different sizes of coal dusts, mass median aerodynamic diameter 4.48 μm (Coal Dust A) and 2.33 μm (Coal Dust B), were aerosolized in a calm air chamber. The mass of coal dust collected by the samplers was measured gravimetrically, while the mass of quartz collected by the samplers was determined by FTIR (NIOSH Manual of Analytical Method 7603) and XRD (NIOSH Manual of Analytical Method 7500) after one of two different indirect preparations. Comparisons between high-flow rate samplers and low-flow rate samplers were made by calculating mass concentration ratios of coal dusts, net mass ratios of coal dusts, and quartz net mass. Mass concentrations of coal dust from the FSP10 cyclone were significantly higher than those from other samplers and mass concentrations of coal dust from 10-mm nylon cyclone were significantly lower than those from other samplers, while the CIP10-R, GK2.69, and BGI4L samplers did not show significant difference in the comparison of mass concentration of coal dusts. The BGI4L cyclone showed larger mass concentration of ∼9% compared to the 10-mm nylon cyclone. All cyclones provided dust mass concentrations that can be used in complying with the International Standard Organization standard for the determination of respirable dust concentration. The amount of coal dust collected from the high-flow rate samplers was found to be higher with a factor of 2-8 compared to the low-flow rate samplers but not in direct proportion of increased flow rates. The high-flow rate samplers collected more quartz compared to

  4. Particle-capturing performance of South African non-corrosive samplers

    CSIR Research Space (South Africa)

    Pretorius, CJ

    2011-10-01

    Full Text Available analysis (PSA) could be carried out. The duration of the sampling was established at ? 30 seconds, so the mass of dust collected per sample ranged from 1 to 2 mg. The flow rates for each sampler were specified by the suppliers. For the X... chain to eliminate pulsation in the air flow. The pressure loss due to air flow resistance was measured with a digital micro manometer for each sampler with 2.2 L/min passing through the sampler (2.5 L/min for the aluminium samplers). PSA...

  5. Soil separator and sampler and method of sampling

    Science.gov (United States)

    O'Brien, Barry H [Idaho Falls, ID; Ritter, Paul D [Idaho Falls, ID

    2010-02-16

    A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

  6. Inexpensive weir and proportional sampler for miniature watershed ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Nabholz, J V; Crossley, Jr, D A; Best, G R

    1979-07-01

    A weir system with proportional sampler for use on miniature water-shed ecosystems is described. Eight weir collection systems were evaluated for their ability to measure and sample the inputs and outputs of soil-island ecosystems which occur on granite outcrops. The proportion of water actually collected by the weir systems was generally less than the proportion the systems were designed to sample, but adequate for supplying data needed for estimating elemental budgets. The weir systems were not able to account for 25 to 50% of the variation in total water passing over the cutoff wall. Several ways of improving overall performance of the weir systems are discussed.

  7. Multimodel parameter optimization with adaptive population importance sampler (APIS)

    Science.gov (United States)

    Mäkelä, Jarmo; Susiluoto, Jouni; Knauer, Jürgen; Aurela, Mika; Mammarella, Ivan; Markkanen, Tiina; Thum, Tea; Zaehle, Sönke; Aalto, Tuula

    2017-04-01

    We are optimizing key parameters in soil hydrology and forest water and carbon exchange related formulations in ecosystem model JSBACH, which is the land surface component of the Earth System model of Max Planck Institute for Meteorology (MPI-ESM). The model has been modified to use multiple stomatal/canopy conductance formulations which will vary during the optimization process. Our previous results have shown that JSBACH is lacking in its response to drought, which is the motivation to test the different conductance formulations. The optimization is done with the adaptive population importance sampler (APIS) algorithm, that provides a global estimation of the selected JSBACH parameters, using all generated samples. Additionally APIS is able to estimate the model evidence (or partition function), which can be used to determine the optimal submodel (conductance formulation). APIS starts with a set of N randomly generated proposals (standard deviations for the parameters), with location parameters spread in the state space. We draw M samples and calculate the partial IS (importance sampler) estimators for each proposal, after which we update the location parameters and each proposal as well as the global estimator for each JSBACH parameter. This process is then repeated a number of times. The study focuses on boreal coniferous evergreen forests. The optimization is based on site level eddy covariance flux measurements on multiple sites across the Northern Hemisphere, where the parameters are estimated by minimizing the model-data mismatch in evapotranspiration and gross primary production.

  8. Hayabusa2 Sampler: Collection of Asteroidal Surface Material

    Science.gov (United States)

    Sawada, Hirotaka; Okazaki, Ryuji; Tachibana, Shogo; Sakamoto, Kanako; Takano, Yoshinori; Okamoto, Chisato; Yano, Hajime; Miura, Yayoi; Abe, Masanao; Hasegawa, Sunao; Noguchi, Takaaki

    2017-07-01

    Japan Aerospace Exploration Agency (JAXA) launched the asteroid exploration probe "Hayabusa2" in December 3rd, 2014, following the 1st Hayabusa mission. With technological and scientific improvements from the Hayabusa probe, we plan to visit the C-type asteroid 162137 Ryugu (1999 JU3), and to sample surface materials of the C-type asteroid that is likely to be different from the S-type asteroid Itokawa and contain more pristine materials, including organic matter and/or hydrated minerals, than S-type asteroids. We developed the Hayabusa2 sampler to collect a minimum of 100 mg of surface samples including several mm-sized particles at three surface locations without any severe terrestrial contamination. The basic configuration of the sampler design is mainly as same as the 1st Hayabusa (Yano et al. in Science, 312(5778):1350-1353, 2006), with several minor but important modifications based on lessons learned from the Hayabusa to fulfill the scientific requirements and to raise the scientific value of the returned samples.

  9. An on-the-go-soil sampler for an automated soil nitrate mapping system

    NARCIS (Netherlands)

    Sibley, K.J.; Adsett, J.F.; Struik, P.C.

    2008-01-01

    An automated on-the-go soil sampler was developed as part of a soil nitrate mapping system that collects data for precisely analyzing small-scale variation in soil NO3-N. An essential requirement of the sampler is the ability to reliably collect a soil sample of known "weight" (mass). It was

  10. Determination of organochlorine pesticides in Indian coastal water using a moored in-situ sampler

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    An attempt has been made to determine the concentration of different organochlorine pesticides in the seawater off the central West Coast of India using an in-situ-sampler. The Seastar in-situ sampler is an instrument, which is designed to pump...

  11. 40 CFR 53.54 - Test for proper sampler operation following power interruptions.

    Science.gov (United States)

    2010-07-01

    ... are to be recorded with an analog recording device, the accuracy of the entire instrument-recorder... Equivalent Methods for PM2.5 or PM10â2.5 § 53.54 Test for proper sampler operation following power... performance parameters tested are: (i) Proper flow rate performance of the sampler. (ii) Accuracy of the...

  12. Effects of Hardness on Pintle Rod Performance in the Universal and Retained Gas Samplers

    Energy Technology Data Exchange (ETDEWEB)

    BOGER, R.M.

    1999-11-18

    Interaction between hardness of the pintle rods and the retainer rings used in the core samplers is investigated. It is found that ordinary Rockwell C measurements are not sufficient and superficial hardness instruments are recommended to verify hardness since in-production hardness of pintle rods is found to vary widely and probably leads to some premature release of pistons in samplers.

  13. Evaluation of Bio-VOC Sampler for Analysis of Volatile Organic Compounds in Exhaled Breath.

    Science.gov (United States)

    Kwak, Jae; Fan, Maomian; Harshman, Sean W; Garrison, Catherine E; Dershem, Victoria L; Phillips, Jeffrey B; Grigsby, Claude C; Ott, Darrin K

    2014-09-29

    Monitoring volatile organic compounds (VOCs) from exhaled breath has been used to determine exposures of humans to chemicals. Prior to analysis of VOCs, breath samples are often collected with canisters or bags and concentrated. The Bio-VOC breath sampler, a commercial sampling device, has been recently introduced to the market with growing use. The main advantage for this sampler is to collect the last portion of exhaled breath, which is more likely to represent the air deep in the lungs. However, information about the Bio-VOC sampler is somewhat limited. Therefore, we have thoroughly evaluated the sampler here. We determined the volume of the breath air collected in the sampler was approximately 88 mL. When sampling was repeated multiple times, with the succeeding exhalations applied to a single sorbent tube, we observed linear relationships between the normalized peak intensity and the number of repeated collections with the sampler in many of the breath VOCs detected. No moisture effect was observed on the Tenax sorbent tubes used. However, due to the limitation in the collection volume, the use of the Bio-VOC sampler is recommended only for detection of VOCs present at high concentrations unless repeated collections of breath samples on the sampler are conducted.

  14. A left-in-place group milk sampler can improve disease monitoring in dairy herds

    NARCIS (Netherlands)

    Clarke, T.; Deveraux, R.S.; Madison, N.; Hannah, M.C.; Ridge, S.E.; Ryan, L.; Wientjes, H.A.

    2007-01-01

    A novel milk sampler (MilkThief) is described. It can collect representative samples of milk to be used for disease monitoring from groups of cows during a milking session. The maximum dilution of each individual cow¿s milk did not exceed a 1 : 45 limit when we tested the sampler in a range of

  15. Guidelines for passive sampling of hydrophobic contaminants in water using silicone rubber samplers

    NARCIS (Netherlands)

    Smedes, F.; Booij, K.

    2012-01-01

    This ICES Techniques in Marine Environmental Sciences provides advice on the use of silicone rubber passive samplers for the determination of freely dissolved non-polar contaminants in seawater. The level of detail offered may be helpful to first-timeusers of passive samplers, who wish to implement

  16. Characteristics of Non-metallic Inclusions in Steel Obtained from Different-Sized Samplers

    Science.gov (United States)

    Liao, Hang; Yang, Shufeng; Li, Jingshe; Feng, Jie

    2017-12-01

    To determine the effect of sampler size on the detection of inclusions in liquid steel, four different-sized samplers were designed for industrial sampling from a continuous casting tundish. The samples were evaluated via scanning electron microscopy and energy-dispersive spectroscopy. With increasing sample size, the cooling rate of the sample and velocity for particle engulfment decreased. The extent of encapsulation of complex inclusions increased from 0 pct with the smallest sampler to 48.2 pct with the largest sampler. In the samplers that cooled at 41.2 and 26.7 K s-1, the major inclusions were calcium aluminates; in the larger samplers, which cooled more slowly at 8.2 and 1.0 K s-1, the complex inclusions predominately comprised Al2O3 + (Ca, Mn)S and Al2O3 + CaS, respectively. The sizes of the sulfides gradually increased with increasing sampler size; for example, the sulfide average diameter increased from 2.5 to 3.5 μm when the sampler inner diameter increased from 50 to 70 mm. The main direction of movement of the inclusions during the sampling process was upward.

  17. Assessment of increased sampling pump flow rates in a disposable, inhalable aerosol sampler.

    Science.gov (United States)

    Stewart, Justin; Sleeth, Darrah K; Handy, Rod G; Pahler, Leon F; Anthony, T Renee; Volckens, John

    2017-03-01

    A newly designed, low-cost, disposable inhalable aerosol sampler was developed to assess workers personal exposure to inhalable particles. This sampler was originally designed to operate at 10 L/min to increase sample mass and, therefore, improve analytical detection limits for filter-based methods. Computational fluid dynamics modeling revealed that sampler performance (relative to aerosol inhalability criteria) would not differ substantially at sampler flows of 2 and 10 L/min. With this in mind, the newly designed inhalable aerosol sampler was tested in a wind tunnel, simultaneously, at flows of 2 and 10 L/min flow. A mannequin was equipped with 6 sampler/pump assemblies (three pumps operated at 2 L/min and three pumps at 10 L/min) inside a wind tunnel, operated at 0.2 m/s, which has been shown to be a typical indoor workplace wind speed. In separate tests, four different particle sizes were injected to determine if the sampler's performance with the new 10 L/min flow rate significantly differed to that at 2 L/min. A comparison between inhalable mass concentrations using a Wilcoxon signed rank test found no significant difference in the concentration of particles sampled at 10 and 2 L/min for all particle sizes tested. Our results suggest that this new aerosol sampler is a versatile tool that can improve exposure assessment capabilities for the practicing industrial hygienist by improving the limit of detection and allowing for shorting sampling times.

  18. Chemistry of the sea surface microlayer. 1. Fabrication and testing of the sampler

    Digital Repository Service at National Institute of Oceanography (India)

    Singbal, S.Y.S.; Narvekar, P.V.

    A screen sampler fabricated to study the sea surface microlayer (SML) has been described. The screen sampler was tested in the Mandovi estuary and adjacent waters. Physico-chemical parameters of the subsurface waters from a depth of 25 cm was also...

  19. A new model for bed load sampler calibration to replace the probability-matching method

    Science.gov (United States)

    Robert B. Thomas; Jack Lewis

    1993-01-01

    In 1977 extensive data were collected to calibrate six Helley-Smith bed load samplers with four sediment particle sizes in a flume at the St. Anthony Falls Hydraulic Laboratory at the University of Minnesota. Because sampler data cannot be collected at the same time and place as ""true"" trap measurements, the ""probability-matching...

  20. Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation (IPSW)

    Science.gov (United States)

    This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) as it relates to organism bioaccumulation in the water column and interstitial water. Fifty-five studies were found where both passive samplers and organism bioaccumulation were used to measur...

  1. Characteristics of Non-metallic Inclusions in Steel Obtained from Different-Sized Samplers

    Science.gov (United States)

    Liao, Hang; Yang, Shufeng; Li, Jingshe; Feng, Jie

    2017-09-01

    To determine the effect of sampler size on the detection of inclusions in liquid steel, four different-sized samplers were designed for industrial sampling from a continuous casting tundish. The samples were evaluated via scanning electron microscopy and energy-dispersive spectroscopy. With increasing sample size, the cooling rate of the sample and velocity for particle engulfment decreased. The extent of encapsulation of complex inclusions increased from 0 pct with the smallest sampler to 48.2 pct with the largest sampler. In the samplers that cooled at 41.2 and 26.7 K s-1, the major inclusions were calcium aluminates; in the larger samplers, which cooled more slowly at 8.2 and 1.0 K s-1, the complex inclusions predominately comprised Al2O3 + (Ca, Mn)S and Al2O3 + CaS, respectively. The sizes of the sulfides gradually increased with increasing sampler size; for example, the sulfide average diameter increased from 2.5 to 3.5 μm when the sampler inner diameter increased from 50 to 70 mm. The main direction of movement of the inclusions during the sampling process was upward.

  2. Convergence of the Equi-Energy Sampler and Its Application to the Ising Model

    Science.gov (United States)

    Hua, Xia; Kou, S. C.

    2010-01-01

    We provide a complete proof of the convergence of a recently developed sampling algorithm called the equi-energy (EE) sampler (Kou, Zhou, and Wong, 2006) in the case that the state space is countable. We show that in a countable state space, each sampling chain in the EE sampler is strongly ergodic a.s. with the desired steady-state distribution. Furthermore, all chains satisfy the individual ergodic property. We apply the EE sampler to the Ising model to test its efficiency, comparing it with the Metropolis algorithm and the parallel tempering algorithm. We observe that the dynamic exponent of the EE sampler is significantly smaller than those of parallel tempering and the Metropolis algorithm, demonstrating the high efficiency of the EE sampler. PMID:21969801

  3. Evaluation of low cost in-line milk samplers for estimating individual cow somatic cell counts.

    Science.gov (United States)

    Clarke, T; Andrews, S P; Moate, P J; Pollino, C A; Schmidt, W L

    1997-02-01

    The Dairy Herd Improvement Fund of Victoria recently identified a requirement for a simple and inexpensive in-line sampler to enable dairy farmers to collect representative milk samples for counting somatic cells. We found that the currently available simple in-line milk samplers, when connected to standard 35 ml collection vessels, terminate sampling early in a milking, and thus provide samples that are unrepresentative of the whole milking. We showed that cell count during a milking varies greatly, tending to be high for the first 1-21. Analyses of resulting samples will thus tend to overestimate cell counts if samplers are used in their traditional way. We found greater sampling rates in high-line compared with low-line milking systems, and consequently developed modified samplers suitable for both situations. Our samplers utilize low sampling rates (approximately 1-3%) and large collection vessels (450 ml). Compared with currently available simple in-line samplers, our type of sampler provided milk samples considerably more representative of the entire milking for the majority of cows. In conjunction with subsampling, they provided samples of appropriate size (12.5 ml minimum to 25 ml maximum) for testing fat, protein, lactose and cell count. Cell count results indicated that errors associated with the use of currently available simple in-line samplers could frequently be > 200%. In contrast, we found that use of our samplers gave an estimate for cell count that was only slightly higher (mean 20%) than that from samples collected by an approved Tru-Test sampler.

  4. Performance of prototype high-flow inhalable dust sampler in a livestock production facility.

    Science.gov (United States)

    Anthony, T Renée; Cai, Changjie; Mehaffy, John; Sleeth, Darrah; Volckens, John

    2017-05-01

    A high-flow inhalable sampler, designed for operational flow rates up to 10 L/min using computer simulations and examined in wind tunnel experiments, was evaluated in the field. This prototype sampler was deployed in collocation with an IOM (the benchmark standard sampler) in a swine farrowing building to examine the sampling performance for assessing concentrations of inhalable particulate mass and endotoxin. Paired samplers were deployed for 24 hr on 19 days over a 3-month period. On each sampling day, the paired samplers were deployed at three fixed locations and data were analyzed to identify agreement and to examine systematic biases between concentrations measured by these samplers. Thirty-six paired gravimetric samples were analyzed; insignificant, unsubstantial differences between concentrations were identified between the two samplers (p = 0.16; mean difference 0.03 mg/m 3 ). Forty-four paired samples were available for endotoxin analysis, and a significant (p = 0.001) difference in endotoxin concentration was identified: the prototype sampler, on average, had 120 EU/m 3 more endotoxin than did the IOM samples. Since the same gravimetric samples were analyzed for endotoxin content, the endotoxin difference is likely attributable to differences in endotoxin extraction. The prototype's disposable thin-film polycarbonate capsule was included with the filter in the 1-hr extraction procedure while the internal plastic cassette of the IOM required a rinse procedure that is susceptible to dust losses. Endotoxin concentrations measured with standard plastic IOM inserts that follow this rinsing procedure may underestimate the true endotoxin exposure concentrations. The maximum concentrations in the study (1.55 mg/m 3 gravimetric, 2328 EU/m 3 endotoxin) were lower than other agricultural or industrial environments. Future work should explore the performance of the prototype sampler in dustier environments, where concentrations approach particulates not otherwise

  5. Silica Measurement with High Flow Rate Respirable Size Selective Samplers: A Field Study.

    Science.gov (United States)

    Lee, Taekhee; Harper, Martin; Kashon, Michael; Lee, Larry A; Healy, Catherine B; Coggins, Marie A; Susi, Pam; O'Brien, Andrew

    2016-04-01

    High and low flow rate respirable size selective samplers including the CIP10-R (10 l min(-1)), FSP10 (11.2 l min(-1)), GK2.69 (4.4 l min(-1)), 10-mm nylon (1.7 l min(-1)), and Higgins-Dewell type (2.2 l min(-1)) were compared via side-by-side sampling in workplaces for respirable crystalline silica measurement. Sampling was conducted at eight different occupational sites in the USA and five different stonemasonry sites in Ireland. A total of 536 (268 pairs) personal samples and 55 area samples were collected. Gravimetric analysis was used to determine respirable dust mass and X-ray diffraction analysis was used to determine quartz mass. Ratios of respirable dust mass concentration, quartz mass concentration, respirable dust mass, and quartz mass from high and low flow rate samplers were compared. In general, samplers did not show significant differences greater than 30% in respirable dust mass concentration and quartz mass concentration when outliers (ratio 3.0) were removed from the analysis. The frequency of samples above the limit of detection and limit of quantification of quartz was significantly higher for the CIP10-R and FSP10 samplers compared to low flow rate samplers, while the GK2.69 cyclone did not show significant difference from low flow rate samplers. High flow rate samplers collected significantly more respirable dust and quartz than low flow rate samplers as expected indicating that utilizing high flow rate samplers might improve precision in quartz measurement. Although the samplers did not show significant differences in respirable dust and quartz concentrations, other practical attributes might make them more or less suitable for personal sampling. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2015.

  6. SAVANNAH RIVER SITE TANK 18 AND TANK 19 WALL SAMPLER PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Leishear, R.; Thaxton, D.; Minichan, R.; France, T.; Steeper, T.; Corbett, J.; Martin, B.; Vetsch, B.

    2009-12-19

    A sampling tool was required to evaluate residual activity ({mu}Curies per square foot) on the inner wall surfaces of underground nuclear waste storage tanks. The tool was required to collect a small sample from the 3/8 inch thick tank walls. This paper documents the design, testing, and deployment of the remotely operated sampling device. The sampler provides material from a known surface area to estimate the overall surface contamination in the tank prior to closure. The sampler consisted of a sampler and mast assembly mast assembly, control system, and the sampler, or end effector, which is defined as the operating component of a robotic arm. The mast assembly consisted of a vertical 30 feet long, 3 inch by 3 inch, vertical steel mast and a cantilevered arm hinged at the bottom of the mast and lowered by cable to align the attached sampler to the wall. The sampler and mast assembly were raised and lowered through an opening in the tank tops, called a riser. The sampler is constructed of a mounting plate, a drill, springs to provide a drive force to the drill, a removable sampler head to collect the sample, a vacuum pump to draw the sample from the drill to a filter, and controls to operate the system. Once the sampler was positioned near the wall, electromagnets attached it to the wall, and the control system was operated to turn on the drill and vacuum to remove and collect a sample from the wall. Samples were collected on filters in removable sampler heads, which were readily transported for further laboratory testing.

  7. Evaluation of Coli-Count Samplers for Possible Use in Standard Counting of Total and Fecal Coliforms in Recreational Waters

    Science.gov (United States)

    Hedberg, Mary; Connor, Douglas A.

    1975-01-01

    Millipore Coli-Count Samplers were used to enumerate colonies of laboratory cultures of coliform bacteria. The samplers gave significantly lower counts than standard membrane-filter procedures for both total and fecal coliforms. Although the samplers are useful for semiquantitative analysis as indicated by the manufacturer, they are not suitable for standard examinations of recreational waters. PMID:1106326

  8. Field tests of nylon-screen diffusion samplers and pushpoint samplers for detection of metals in sediment pore water, Ashland and Clinton, Massachusetts, 2003

    Science.gov (United States)

    Zimmerman, Marc J.; Vroblesky, Don A.; Campo, Kimberly W.; Massey, Andrew J.; Scheible, Walter

    2005-01-01

    Efficient and economical screening methods are needed to detect and to determine the approximate concentrations of potentially toxic trace-element metals in shallow groundwater- discharge areas (pore water) where the metals may pose threats to aquatic organisms; such areas are likely to be near hazardous-waste sites. Pushpoint and nylon-screen diffusion samplers are two complementary options for use in such environments. The pushpoint sampler, a simple well point, is easy to insert manually and to use. Only 1 day is required to collect samples. The nylon-screen diffusion sampler is well suited for use in sediments that do not allow a pump to draw water into a pushpoint sampler. In this study, both types of devices were used in sediments suitable for the use of the pushpoint sampler. Sampling with the nylon-screen diffusion sampler requires at least two site visits: one to deploy the samplers in the sediment, and a second to retrieve the samplers and collect the samples after a predetermined equilibration period. Extensive laboratory quality-control studies, field testing, and laboratory analysis of samples collected at the Nyanza Chemical Waste Dump Superfund site along the Sudbury River in Ashland, Massachusetts, and at a Superfund site-assessment location on Rigby Brook in Clinton, Massachusetts, indicate that these two devices yield comparable results for most metals and should be effective tools for pore-water studies. The nylon-screen diffusion samplers equilibrated within 1-2 days in homogeneous, controlled conditions in the laboratory. Nylon-screen diffusion samplers that were not purged of dissolved oxygen prior to deployment yielded results similar to those that were purged. Further testing of the nylon-screen diffusion samplers in homogeneous media would help to resolve any ambiguities about the data variability from the field studies. Comparison of data from replicate samples taken in both study areas shows that even samples taken from sites within a

  9. Particle-into-Liquid Sampler (PILS) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Thomas B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-03-01

    The Particle-into-Liquid Sampler (PILS) is an aqueous-solution-based online technique for determining bulk chemical composition of ambient aerosol particles. As shown in Figure 1, the instrument consists of two units, briefly described below: 1. An aerosol extraction unit where particles are passed through a growth chamber saturated with water vapor, liquid droplets are grown, and the resulting liquid collected and transferred to the detection system. 2. The detection system that includes ion chromatographs (IC) or a total organic carbon detector (TOC). Ion chromatography is performed using two Metrohm ICs—one for positive ions and one for negative ions—with conductivity detectors. The TOC is detected using a GE TOC analyzer. The instrument can be run in either the ion detection mode or the TOC mode.

  10. Albatrosses as Ocean Samplers of Sea Surface Temperature

    Science.gov (United States)

    Shaffer, S. A.; Kappes, M.; Tremblay, Y.; Costa, D. P.; Weber, R.; Weimerskirch, H.

    2006-12-01

    Albatrosses are unique ocean voyagers because they range so widely and travel at speeds exceeding 90 km per hour. Because they can integrate vast areas of open-ocean, albatrosses are ideal ocean samplers. Between 2003 and 2005 breeding seasons, 21 Laysan and 15 black-footed albatrosses (body mass 2.5 to 3.5 kg) were equipped with 6 g leg-mounted geolocation archival data loggers at Tern Island, French Frigate Shoals, Northwest Hawaiian Islands. The tags sampled environmental temperatures every 480 or 540 s and provided a single location per day for the duration of deployment. Whenever an albatross landed on the sea surface to feed or rest, the tag sampled sea surface temperature (SST). After nearly one year of deployment, 31 albatrosses were recaptured and 29 tags provided complete records. A total of 377,455 SST readings were obtained over 7,360 bird-days at sea. Given the location errors in the geolocation methodology (200 km) and the lack of temporal resolution (1 location per day), the SST measurements can only be used to characterize broad-scale correlates between albatross distribution and the ocean environment. However, in February 2006, we deployed 45 g GPS data loggers on 10 breeding albatrosses for 2-4 day deployments. The GPS loggers were attached to feathers on the albatrosses backs, they sampled every 10 s, and were accurate to within 10 m. One albatross was also equipped with the same leg-mounted archival tag that sampled SST every 8 s. This albatross collected 6,289 SST measurements with complementary GPS quality locations in 3 days at sea. These results highlight the efficacy of albatrosses as ocean samplers. Given that Laysan and black- footed albatrosses range throughout the North Pacific Ocean, it is conceivable that these seabirds could someday become sentinels of changing oceanic conditions. Moreover, these technologies provide exciting new information about the oceanic habitats of North Pacific albatrosses.

  11. The development of an active personal ozone sampler using a diffusion denuder

    Energy Technology Data Exchange (ETDEWEB)

    Geyh, A.S.; Wolfson, J.M.; Koutrakis, P. [Harvard Univ., Boston, MA (United States). School of Public Health; Mulik, J. [Environmental Protection Agency, Research Triangle Park, NC (United States)

    1994-12-31

    Personal, microenvironmental and indoor ozone monitoring is currently carried out using a passive sampling device which is both light-weight and inexpensive. However, the collection properties of these samplers have been found to be sensitive to wind effects and sampler placement, thus limiting their potential use for personal monitoring. In addition, because of their relative insensitivity, these samplers cannot be used for short-term monitoring of ozone at low concentrations. In response to these problems the authors are developing a light-weight active ozone sampler which uses a single tube diffusion denuder for sample collection. The new single tube diffusion denuder (STTD) consists of a 1.4 cm (ID) x 10 cm etched Pyrex tube attached to a very small, low-flow, relatively low-cost personal pump. Tube diameter and length were chosen to maximize collection efficiency at a sampling rate of 65 mL/min. The tube is coated with a nitrite reagent which has been successfully used in the passive ozone samplers. Variations in relative humidity, ozone concentration, and total ozone exposure have relatively small affects on the accuracy and precision of the STTD. In addition, the low limit of detection (LOD) of approximately 20 ppb hrs gives a tenfold increase in sensitivity over the passive samplers for which a 200 ppb hr LOD has been determined. This new active sampler thus makes possible both short-term personal and microenvironmental monitoring.

  12. Evaluation of the polyurethane foam (PUF) disk passive air sampler: Computational modeling and experimental measurements

    Science.gov (United States)

    May, Andrew A.; Ashman, Paul; Huang, Jiaoyan; Dhaniyala, Suresh; Holsen, Thomas M.

    2011-08-01

    Computational fluid dynamics (CFD) simulations coupled with wind tunnel-experiments were used to determine the sampling rate (SR) of the widely used polyurethane foam (PUF) disk passive sampler. In the wind-tunnel experiments, water evaporation rates from a water saturated PUF disk installed in the sampler housing were determined by measuring weight loss over time. In addition, a modified passive sampler designed to collect elemental mercury (Hg 0) with gold-coated filters was used. Experiments were carried out at different wind speeds and various sampler angles. The SRs obtained from wind-tunnel experiments were compared to those obtained from the field by scaling the values by the ratios of air diffusivities. Three-dimensional (3D) CFD simulations were also used to generate SRs for both polychlorinated biphenyls (PCBs) and Hg 0. Overall, the modeled and measured SRs agree well and are consistent with the values obtained from field studies. As previously observed, the SRs increased linearly with increasing wind speed. In addition, it was determined that the SR was strongly dependent on the angle of the ambient wind. The SRs increased when the base was tilted up pointing into the wind and when the base was tilted down (i.e., such that the top of the sampler was facing the wind) the SR decreased initially and then increased. The results suggest that there may be significant uncertainty in concentrations obtained from passive sampler measurements without knowledge of wind speed and wind angle relative to the sampler.

  13. ExperienceSampler: An Open-Source Scaffold for Building Smartphone Apps for Experience Sampling.

    Science.gov (United States)

    Thai, Sabrina; Page-Gould, Elizabeth

    2017-06-15

    Experience sampling methods allow researchers to examine phenomena in daily life and provide various advantages that complement traditional laboratory methods. However, existing experience sampling methods may be costly, require constant Internet connectivity, may not be designed specifically for experience sampling studies, or require a custom solution from a computer programming consultant. In this article, we present ExperienceSampler, an open-source scaffold for creating experience-sampling smartphone apps designed for Android and iOS devices. We designed ExperienceSampler to address the common barriers to using experience sampling methods. First, there is no cost to the user. Second, ExperienceSampler apps make use of local notifications to let participants know when to complete surveys and store the data locally until Internet connection is available. Third, our app scaffold was designed with experience sampling methodological issues in mind. We also demonstrate how researchers can easily customize ExperienceSampler even if they have no programming skills. Furthermore, we evaluate the utility of ExperienceSampler apps with results from one social psychological study conducted using ExperienceSampler (N = 168). Mean response rates averaged 84%, and the median response latency was 9 minutes. Taken together, ExperienceSampler creates cost-effective smartphone apps that can be easily customized by researchers to examine experiences in daily life. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. AN AFFINE-INVARIANT SAMPLER FOR EXOPLANET FITTING AND DISCOVERY IN RADIAL VELOCITY DATA

    Energy Technology Data Exchange (ETDEWEB)

    Hou Fengji; Hogg, David W. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Goodman, Jonathan; Weare, Jonathan [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012 (United States); Schwab, Christian, E-mail: fh417@nyu.edu [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States)

    2012-02-01

    Markov chain Monte Carlo (MCMC) proves to be powerful for Bayesian inference and in particular for exoplanet radial velocity fitting because MCMC provides more statistical information and makes better use of data than common approaches like chi-square fitting. However, the nonlinear density functions encountered in these problems can make MCMC time-consuming. In this paper, we apply an ensemble sampler respecting affine invariance to orbital parameter extraction from radial velocity data. This new sampler has only one free parameter, and does not require much tuning for good performance, which is important for automatization. The autocorrelation time of this sampler is approximately the same for all parameters and far smaller than Metropolis-Hastings, which means it requires many fewer function calls to produce the same number of independent samples. The affine-invariant sampler speeds up MCMC by hundreds of times compared with Metropolis-Hastings in the same computing situation. This novel sampler would be ideal for projects involving large data sets such as statistical investigations of planet distribution. The biggest obstacle to ensemble samplers is the existence of multiple local optima; we present a clustering technique to deal with local optima by clustering based on the likelihood of the walkers in the ensemble. We demonstrate the effectiveness of the sampler on real radial velocity data.

  15. Inverse Problem Optimization Method to Design Passive Samplers for Volatile Organic Compounds: Principle and Application.

    Science.gov (United States)

    Cao, Jianping; Du, Zhengjian; Mo, Jinhan; Li, Xinxiao; Xu, Qiujian; Zhang, Yinping

    2016-12-20

    Passive sampling is an alternative to active sampling for measuring concentrations of gas-phase volatile organic compounds (VOCs). However, the uncertainty or relative error of the measurements have not been minimized due to the limitations of existing design methods. In this paper, we have developed a novel method, the inverse problem optimization method, to address the problems associated with designing accurate passive samplers. The principle is to determine the most appropriate physical properties of the materials, and the optimal geometry of a passive sampler, by minimizing the relative sampling error based on the mass transfer model of VOCs for a passive sampler. As an example application, we used our proposed method to optimize radial passive samplers for the sampling of benzene and formaldehyde in a normal indoor environment. A new passive sampler, which we have called the Tsinghua Passive Diffusive Sampler (THPDS), for indoor benzene measurement was developed according to the optimized results. Silica zeolite was selected as the sorbent for the THPDS. The measured overall uncertainty of THPDS (22% for benzene) is lower than that of most commercially available passive samplers but is quite a bit larger than the modeled uncertainty (4.8% for benzene, the optimized result), suggesting that further research is required.

  16. Influence of Sulfide Nanoparticles on Dissolved Mercury and Zinc Quantification by Diffusive Gradient in Thin-Film Passive Samplers.

    Science.gov (United States)

    Pham, Anh Le-Tuan; Johnson, Carol; Manley, Devon; Hsu-Kim, Heileen

    2015-11-03

    Diffusive gradient in thin-film (DGT) passive samplers are frequently used to monitor the concentrations of metals such as mercury and zinc in sediments and other aquatic environments. The application of these samplers generally presumes that they quantify only the dissolved fraction and not particle-bound metal species that are too large to migrate into the sampler. However, metals associated with very small nanoparticles (smaller than the pore size of DGT samplers) can be abundant in certain environments, yet the implications of these nanoparticles for DGT measurements are unclear. The objective of this study was to determine how the performance of the DGT sampler is affected by the presence of nanoparticulate species of Hg and Zn. DGT samplers were exposed to solutions containing known amounts of dissolved Hg(II) and nanoparticulate HgS (or dissolved Zn(II) and nanoparticulate ZnS). The amounts of Hg and Zn accumulated onto the DGT samplers were quantified over hours to days, and the rates of diffusion of the dissolved metal (i.e., the effective diffusion coefficient D) into the sampler's diffusion layer were calculated and compared for solutions containing varying concentrations of nanoparticles. The results suggested that the nanoparticles deposited on the surface of the samplers might have acted as sorbents, slowing the migration of the dissolved species into the samplers. The consequence was that the DGT sampler data underestimated the dissolved metal concentration in the solution. In addition, X-ray absorption spectroscopy was employed to determine the speciation of the Hg accumulated on the sampler binding layer, and the results indicated that HgS nanoparticles did not appear to directly contribute to the DGT measurement. Overall, our findings suggest that the deployment of DGT samplers in settings where nanoparticles are relevant (e.g., sediments) may result in DGT data that incorrectly estimated the dissolved metal concentrations. Models for metal uptake

  17. The Padua Inventory: Do Revisions Need Revision?

    Science.gov (United States)

    Gonner, Sascha; Ecker, Willi; Leonhart, Rainer

    2010-01-01

    The purpose of the present study was to examine the psychometric properties, factorial structure, and validity of the Padua Inventory-Washington State University Revision and of the Padua Inventory-Revised in a large sample of patients with obsessive-compulsive disorder (n = 228) and with anxiety disorders and/or depression (n = 213). The…

  18. Novel Highly Efficient Compact Rotary-Hammering Planetary Sampler Actuated by a Single Piezoelectric Actuator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We had two objectives in this task: 1. Develop effective single low-mass, low-power piezoelectric drive that can actuate rotary-hammer samplers through walls. 2....

  19. A comparative study between real time monitor KH-3000 and conventional Durham sampler measuring airborne pollen

    National Research Council Canada - National Science Library

    Yoda, Shigetoshi; Enomoto, Tadao; Shibano, Akira; Ikeda, Hiroki; Yajin, Shinji; Dake, Yoshihiro; Harada, Tamotsu

    2005-01-01

    .... A problem arose, however, due to differences between the KH3000 (Yamato Co. Ltd) monitor and the conventional Durham sampler pointed out in results of airborne pollen monitoring in Wakayama in 2004...

  20. AirCore Reusable InSitu Sampler for CO2 and Trace Gas Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The AirCore is a simple and novel atmospheric air column sampler to validate satellite observation data of greenhouse gases, using a lightweight, inexpensive coated...

  1. Evaluation of particle resuspension in young children's breathing zone using stationary and robotic (PIPER) aerosol samplers.

    Science.gov (United States)

    Sagona, Jessica A; Shalat, Stuart L; Wang, Zuocheng; Ramagopal, Maya; Black, Kathleen; Hernandez, Marta; Mainelis, Gediminas

    2015-07-01

    Development of asthma in young children may be associated with high exposure to particulate matter (PM). However, typical stationary samplers may not represent the personal exposure of children ages 3 and younger since they may not detect particles resuspended from the floor as children play, thus reducing our ability to correlate exposure and disease etiology. To address this, an autonomous robot, the Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler, was developed to simulate the movements of children as they play on the floor. PIPER and a stationary sampler took simultaneous measurements of particle number concentration in six size channels using an optical particle counter and inhalable PM on filters in 65 homes in New Jersey, USA. To study particle resuspension, for each sampler we calculated the ratio of particle concentration measured while PIPER was moving to the average concentration of particles measured during a reference period when PIPER remained still. For all investigated particle sizes, higher particle resuspension was observed by PIPER compared to the stationary sampler. In 71% of carpeted homes a more significant (at the α = 0.05 level) resuspension of particles larger than 2.5 μm was observed by PIPER compared to the stationary sampler. Typically, particles larger than 2.5 μm were resuspended more efficiently than smaller particles, over both carpeted and bare floors. Additionally, in carpeted homes estimations of PM10 mass from the particle number concentrations measured on PIPER while it was moving were on average a factor of 1.54 higher compared to reference period when PIPER was not moving. For comparison, the stationary sampler measured an increase of PM2.5 mass by a factor of only 1.08 when PIPER was moving compared to a reference period. This demonstrates that PIPER is able to resuspend particles through movement, and provide a better characterization of the resuspended particles than stationary samplers. Accurate

  2. Loosening After Acetabular Revision

    DEFF Research Database (Denmark)

    Beckmann, Nicholas A.; Weiss, Stefan; Klotz, Matthias C.M.

    2014-01-01

    The best method of revision acetabular arthroplasty remains unclear. Consequently, we reviewed the literature on the treatment of revision acetabular arthroplasty using revision rings (1541 cases; mean follow-up (FU) 5.7 years) and Trabecular Metal, or TM, implants (1959 cases; mean FU 3.7 years)...

  3. Computational fluid dynamics (CFD) simulation of a newly designed passive particle sampler.

    Science.gov (United States)

    Sajjadi, H; Tavakoli, B; Ahmadi, G; Dhaniyala, S; Harner, T; Holsen, T M

    2016-07-01

    In this work a series of computational fluid dynamics (CFD) simulations were performed to predict the deposition of particles on a newly designed passive dry deposition (Pas-DD) sampler. The sampler uses a parallel plate design and a conventional polyurethane foam (PUF) disk as the deposition surface. The deposition of particles with sizes between 0.5 and 10 μm was investigated for two different geometries of the Pas-DD sampler for different wind speeds and various angles of attack. To evaluate the mean flow field, the k-ɛ turbulence model was used and turbulent fluctuating velocities were generated using the discrete random walk (DRW) model. The CFD software ANSYS-FLUENT was used for performing the numerical simulations. It was found that the deposition velocity increased with particle size or wind speed. The modeled deposition velocities were in general agreement with the experimental measurements and they increased when flow entered the sampler with a non-zero angle of attack. The particle-size dependent deposition velocity was also dependent on the geometry of the leading edge of the sampler; deposition velocities were more dependent on particle size and wind speeds for the sampler without the bend in the leading edge of the deposition plate, compared to a flat plate design. Foam roughness was also found to have a small impact on particle deposition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Astronaut Edwin Aldrin on Lunar Surface With Core Sampler

    Science.gov (United States)

    1969-01-01

    The Apollo 11 manned lunar mission launched from the Kennedy Space Center, Florida on July 16, 1969 via a Saturn V launch vehicle, and safely returned to Earth on July 24, 1969. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. The 3-man crew aboard the flight consisted of Neil A. Armstrong, commander; Michael Collins, Command Module pilot; and Edwin E. Aldrin Jr., Lunar Module pilot. Carrying astronauts Neil A. Armstrong and Edwin E. Aldrin, Jr., the Lunar Module (LM) 'Eagle' was the first crewed vehicle to land on the Moon. The LM landed on the moon's surface on July 20, 1969 in the region known as Mare Tranquilitatis (the Sea of Tranquility). Armstrong was the first human to ever stand on the lunar surface. As he stepped off the LM, Armstrong proclaimed, 'That's one small step for man, one giant leap for mankind'. He was followed by Edwin Aldrin, describing the lunar surface as magnificent desolation. This photo is of Edwin Aldrin on the lunar surface using the core sampler, one of the many tools used by the astronauts to collect samples. The crew collected 47 pounds of lunar surface material which was returned to Earth for analysis. The surface exploration was concluded in 2½ hours. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished.

  5. Using structural equation modeling to construct calibration equations relating PM2.5 mass concentration samplers to the federal reference method sampler

    Science.gov (United States)

    Bilonick, Richard A.; Connell, Daniel P.; Talbott, Evelyn O.; Rager, Judith R.; Xue, Tao

    2015-02-01

    The objective of this study was to remove systematic bias among fine particulate matter (PM2.5) mass concentration measurements made by different types of samplers used in the Pittsburgh Aerosol Research and Inhalation Epidemiology Study (PARIES). PARIES is a retrospective epidemiology study that aims to provide a comprehensive analysis of the associations between air quality and human health effects in the Pittsburgh, Pennsylvania, region from 1999 to 2008. Calibration was needed in order to minimize the amount of systematic error in PM2.5 exposure estimation as a result of including data from 97 different PM2.5 samplers at 47 monitoring sites. Ordinary regression often has been used for calibrating air quality measurements from pairs of measurement devices; however, this is only appropriate when one of the two devices (the "independent" variable) is free from random error, which is rarely the case. A group of methods known as "errors-in-variables" (e.g., Deming regression, reduced major axis regression) has been developed to handle calibration between two devices when both are subject to random error, but these methods require information on the relative sizes of the random errors for each device, which typically cannot be obtained from the observed data. When data from more than two devices (or repeats of the same device) are available, the additional information is not used to inform the calibration. A more general approach that often has been overlooked is the use of a measurement error structural equation model (SEM) that allows the simultaneous comparison of three or more devices (or repeats). The theoretical underpinnings of all of these approaches to calibration are described, and the pros and cons of each are discussed. In particular, it is shown that both ordinary regression (when used for calibration) and Deming regression are particular examples of SEMs but with substantial deficiencies. To illustrate the use of SEMs, the 7865 daily average PM2.5 mass

  6. Development of a new passive sampler based on diffusive milligel beads for copper analysis in water

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M.; Reynaud, S.; Lespes, G.; Potin-Gautier, M. [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France); Mignard, E. [CNRS-Solvay-Université Bordeaux, UMR5258, Laboratoire du Futur, 178 Avenue du Dr. A. Schweitzer, 33608 Pessac Cedex (France); Chéry, P. [Bordeaux Science Agro, 1 cours du Général De Gaulle, Gradignan, 33175 (France); Schaumlöffel, D. [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France); Grassl, B., E-mail: bruno.grassl@univ-pau.fr [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France)

    2015-08-26

    A new passive sampler was designed and characterized for the determination of free copper ion (Cu{sup 2+}) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k{sub 0}) and the sampler-water partition coefficient (K{sub sw}), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma – Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). - Highlights: • Controlled geometry of new passive sampler with ellipsoidal shape. • Original manufacturing process based on droplet-based millifluidic device. • Pore size characterization of the sampler. • Mass-transfer and sampler-water partitioning coefficients by static exposure experiments.

  7. Multilevel Samplers to Assess Microbial Community Response to Biostimulation

    Science.gov (United States)

    Baldwin, B. R.; McKinley, J. P.; Peacock, A. D.; Park, M.; Ogles, D.; Istok, J. D.; Resch, C. T.; White, D. C.

    2006-05-01

    Passive multilevel samplers (MLS) containing a solid matrix for microbial colonization were used in conjunction with a push-pull biostimulation experiment designed to promote biological U(VI) and Tc(VII) reduction. MLS were deployed at 24 elevations in the injection well and two down gradient wells to investigate the spatial variability in microbial community composition and growth prior to and following biostimulation. The microbial community was characterized by real-time PCR (Q-PCR) quantification of eubacteria, NO3- reducing bacteria (nirS and nirK), δ-proteobacteria, Geobacter sp., and methanogens (mcrA). Pretest cell densities were low overall but varied substantially with significantly greater eubacterial populations detected at circumneutral pH (T-test, α=0.05) suggesting carbon substrate and low pH limitation of microbial activity. Although pretest cell densities were low, denitrifying bacteria were dominant members of the microbial community. Biostimulation with an ethanol amended groundwater resulted in concurrent NO3- and Tc(VII) reduction followed by U(VI) reduction. Q-PCR analysis of MLS revealed significant (1-2 orders of magnitude, T-test, α=0.05) increases in cell densities of eubacteria, denitrifiers, δ- proteobacteria, Geobacter sp., and methanogens in response to biostimulation. Traditionally characterization of sediment samples has been used to investigate the microbial community response to biostimulation, however, collection of sediment samples is expensive and not conducive to deep aquifers or temporal studies. The results presented demonstrate that push-pull tests with passive MLS provide an inexpensive approach to determine the effect of biostimulation on contaminant concentrations, geochemical conditions, and the microbial community composition and function.

  8. 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.

  9. Formaldehyde passive sampler using an optical chemical sensor: how to limit the humidity interference.

    Science.gov (United States)

    Vignau-Laulhere, Jane; Mocho, Pierre; Plaisance, Hervé; Raulin-Woznica, Katarzyna; Tran-Thi, Thu-Hoa; Desauziers, Valérie

    2017-10-01

    The behaviour of a new formaldehyde diffusive sampler using an optical chemical sensor with respect to high humidity conditions is examined in controlled atmospheres. Five prototypes of the radial diffusion sampler having the same chemical sensor and different designs were tested. In addition, a set of experiments were performed on the chemical sensor to characterise its efficiency of trapping water vapour in the absence and in the presence of the reactants, Fluoral-P and formaldehyde. Differences in humidity interference between the five diffusive sampler prototypes were studied and discussed. From all the results obtained, it was shown that the prototype LDE1.4 combining a small diffusion slot, a reduced internal volume and a sensor shifted upwards from the diffusion slot provided formaldehyde measurements least affected by humidity up to 80% RH at 20 °C. This new type of diffusive sampler with on-site direct reading is intended to ultimately replace conventional passive samplers with DNPH requiring offset laboratory analyses.

  10. The MAGIC Meteoric Smoke Particle Sampler - Description and Results

    Science.gov (United States)

    Hedin, J.

    2013-12-01

    properties is by direct collection followed by detailed laboratory analysis. However, the sounding rocket approach, which is the only practical method to carry out a sampling experiment at the desired mesospheric altitudes, is subject to critical limitations imposed by aerodynamics. As nanometer size particles tend to follow the airflow around the rocket payload structure, their sampling is a substantial experimental challenge. The objective of the MAGIC project (Mesospheric Aerosol - Genesis, Interaction and Composition) was to design and build an instrument to directly sample meteoric smoke particles in the mesosphere and return them to ground for detailed laboratory investigations. Here we describe the MAGIC meteoric smoke particle sampler and present attempts to directly sample MSPs and the challenges and uncertainties in the sampling procedure.

  11. Passive Sampler for Measurements of Atmospheric Nitric Acid Vapor (HNO3 Concentrations

    Directory of Open Access Journals (Sweden)

    Andrzej Bytnerowicz

    2001-01-01

    Full Text Available Nitric acid (HNO3 vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3 concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

  12. Bayesian analysis for exponential random graph models using the adaptive exchange sampler

    KAUST Repository

    Jin, Ick Hoon

    2013-01-01

    Exponential random graph models have been widely used in social network analysis. However, these models are extremely difficult to handle from a statistical viewpoint, because of the existence of intractable normalizing constants. In this paper, we consider a fully Bayesian analysis for exponential random graph models using the adaptive exchange sampler, which solves the issue of intractable normalizing constants encountered in Markov chain Monte Carlo (MCMC) simulations. The adaptive exchange sampler can be viewed as a MCMC extension of the exchange algorithm, and it generates auxiliary networks via an importance sampling procedure from an auxiliary Markov chain running in parallel. The convergence of this algorithm is established under mild conditions. The adaptive exchange sampler is illustrated using a few social networks, including the Florentine business network, molecule synthetic network, and dolphins network. The results indicate that the adaptive exchange algorithm can produce more accurate estimates than approximate exchange algorithms, while maintaining the same computational efficiency.

  13. Chaotic motif sampler: detecting motifs from biological sequences by using chaotic neurodynamics

    Science.gov (United States)

    Matsuura, Takafumi; Ikeguchi, Tohru

    Identification of a region in biological sequences, motif extraction problem (MEP) is solved in bioinformatics. However, the MEP is an NP-hard problem. Therefore, it is almost impossible to obtain an optimal solution within a reasonable time frame. To find near optimal solutions for NP-hard combinatorial optimization problems such as traveling salesman problems, quadratic assignment problems, and vehicle routing problems, chaotic search, which is one of the deterministic approaches, has been proposed and exhibits better performance than stochastic approaches. In this paper, we propose a new alignment method that employs chaotic dynamics to solve the MEPs. It is called the Chaotic Motif Sampler. We show that the performance of the Chaotic Motif Sampler is considerably better than that of the conventional methods such as the Gibbs Site Sampler and the Neighborhood Optimization for Multiple Alignment Discovery.

  14. Porous Polyurethane Foam for Use as a Particle Collection Substrate in a Nanoparticle Respiratory Deposition Sampler.

    Science.gov (United States)

    Mines, Levi W D; Park, Jae Hong; Mudunkotuwa, Imali A; Anthony, T Renée; Grassian, Vicki H; Peters, Thomas M

    2016-01-01

    Porous polyurethane foam was evaluated to replace the eight nylon meshes used as a substrate to collect nanoparticles in the Nanoparticle Respiratory Deposition (NRD) sampler. Cylindrical (25-mm diameter by 40-mm deep) foam with 110 pores per inch was housed in a 25-mm-diameter conductive polypropylene cassette cowl compatible with the NRD sampler. Pristine foam and nylon meshes were evaluated for metals content via elemental analysis. The size-selective collection efficiency of the foam was evaluated using salt (NaCl) and metal fume aerosols in independent tests. Collection efficiencies were compared to the nanoparticulate matter (NPM) criterion and a semi-empirical model for foam. Changes in collection efficiency and pressure drop of the foam and nylon meshes were measured after loading with metal fume particles as measures of substrate performance. Substantially less titanium was found in the foam (0.173 μg sampler -1 ) compared to the nylon mesh (125 μg sampler -1 ), improving the detection capabilities of the NRD sampler for titanium dioxide particles. The foam collection efficiency was similar to that of the nylon meshes and the NPM criterion (R 2 = 0.98, for NaCl), although the semi-empirical model underestimated the experimental efficiency (R 2 = 0.38). The pressure drop across the foam was 8% that of the nylon meshes when pristine and changed minimally with metal fume loading (~ 19 mg). In contrast, the pores of the nylon meshes clogged after loading with ~ 1 mg metal fume. These results indicate that foam is a suitable substrate to collect metal (except for cadmium) nanoparticles in the NRD sampler.

  15. Determining particle size distributions in the inhalable size range for wood dust collected by air samplers.

    Science.gov (United States)

    Harper, Martin; Muller, Brian S; Bartolucci, Al

    2002-10-01

    In the absence of methods for determining particle size distributions in the inhalable size range with good discrimination, the samples collected by personal air sampling devices can only be characterized by their total mass. This parameter gives no information regarding the size distribution of the aerosol or the size-selection characteristics of different samplers in field use conditions. A method is described where the particles collected by a sampler are removed, suspended, and re-deposited on a mixed cellulose-ester filter, and examined by optical microscopy to determine particle aerodynamic diameters. This method is particularly appropriate to wood dust particles which are generally large and close to rectangular prisms in shape. Over 200 wood dust samples have been collected in three different wood-products industries, using the traditional closed-face polystyrene/acrylonitrile cassette, the Institute of Occupational Medicine inhalable sampler, and the Button sampler developed by the University of Cincinnati. A portion of these samples has been analyzed to determine the limitations of this method. Extensive quality control measures are being developed to improve the robustness of the procedure, and preliminary results suggest the method has an accuracy similar to that required of National Institute for Occupational Safety and Health (NIOSH) methods. The results should provide valuable insights into the collection characteristics of the samplers and the impact of these characteristics on comparison of sampler results to present and potential future limit values. The NIOSH Deep South Education and Research Center has a focus on research into hazards of the forestry and associated wood-products industry, and it is hoped to expand this activity in the future.

  16. Composite sampling of a Bacillus anthracis surrogate with cellulose sponge surface samplers from a nonporous surface.

    Directory of Open Access Journals (Sweden)

    Jenia A M Tufts

    Full Text Available A series of experiments was conducted to explore the utility of composite-based collection of surface samples for the detection of a Bacillus anthracis surrogate using cellulose sponge samplers on a nonporous stainless steel surface. Two composite-based collection approaches were evaluated over a surface area of 3716 cm2 (four separate 929 cm2 areas, larger than the 645 cm2 prescribed by the standard Centers for Disease Control (CDC and Prevention cellulose sponge sampling protocol for use on nonporous surfaces. The CDC method was also compared to a modified protocol where only one surface of the sponge sampler was used for each of the four areas composited. Differences in collection efficiency compared to positive controls and the potential for contaminant transfer for each protocol were assessed. The impact of the loss of wetting buffer from the sponge sampler onto additional surface areas sampled was evaluated. Statistical tests of the results using ANOVA indicate that the collection of composite samples using the modified sampling protocol is comparable to the collection of composite samples using the standard CDC protocol (p  =  0.261. Most of the surface-bound spores are collected on the first sampling pass, suggesting that multiple passes with the sponge sampler over the same surface may be unnecessary. The effect of moisture loss from the sponge sampler on collection efficiency was not significant (p  =  0.720 for both methods. Contaminant transfer occurs with both sampling protocols, but the magnitude of transfer is significantly greater when using the standard protocol than when the modified protocol is used (p<0.001. The results of this study suggest that composite surface sampling, by either method presented here, could successfully be used to increase the surface area sampled per sponge sampler, resulting in reduced sampling times in the field and decreased laboratory processing cost and turn-around times.

  17. Mathematical modelling of dust samplers and application of the method to the gravimetric dust sampler RESPICON; Mathematische Modellierung von Staubmessgeraeten und Anwendung der Methode auf das gravimetrische Staubmessgeraet RESPICON

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, L. [Deutsche Montan Technologie GmbH, Essen (Germany). Gas and Fire Div.

    2004-07-01

    The evaluation and assessment of the fractionating particle sampler RESPICON due to the European test standard prEN 13205 has been continued by mathematical modelling of the candidate sampler and its response to different aerosols, characterized by the mean aerodynamic particle size (MMAD) and standard deviation (GSD). The three health related size fractions are sampled by the candidate sampler within the limits given by the standard, but correction factors for each fraction have to be taken into account. This result stands only for the use of the candidate as affixed point sampler. But due to the regulations in the standard it can be used as a personal sampler for windspeeds up to 2/ms. The investigations also have shown some disadvantages of the test standard itself, these should be eliminated in the future. (orig.)

  18. Field testing of three bedload samplers' efficiency in a gravel-bed river, Spitsbergen

    Science.gov (United States)

    Rachlewicz, Grzegorz; Zwoliński, Zbigniew; Kociuba, Waldemar; Stawska, Monika

    2017-06-01

    A comparative study of the three bedload traps was accomplished to determine the effectiveness differences between the devices. The research was carried out in two transverse sections of the proglacial, gravel-bedded Scott River (SW Svalbard) using three devices to perform direct measurements of bedload transport in the river channels. Several samplers are used for field measurements, but none of them has gained widespread acceptance as a standard so far. The paper compares transport rates collected in three bedload samplers that differ in structure and functionality: i) a portable Helley-Smith, pressure-difference bedload sampler (H-S), ii) an anchored River Bedload Trap (RBT), and iii) the portable sampler used by the Polish Hydrological Services (PIHM type C). All three samplers are constructed using the same components: a frame made of thin stainless steel sheet and a nylon bag with the same (2 mm) mesh size (except PIHM). Measurements were conducted within three consecutive days in two cross sections, in the same vertical profiles and at the same time (at intervals of 30 and 60 min). Measurements of bedload transport and water velocity were performed simultaneously. In order to determine the effectiveness and representativeness of short-term measurements using particular devices, the masses of the samples were converted into a specific rate of bedload transport and compared to the results of long-term continuous measurement (24 h measurement cycle). The results confirm that both specific transport indicators and the mass of the samples collected by the tested devices show a significant variation. Generally, the highest mass and specific transport indicators were obtained using the H-S sampler. The RBT produced moderate transport rates, while the PIHM sampler gave the lowest rates. The bedload transport rate in a profile estimated on the short-term measurements was compared to results of the continuous measurements conducted in the same cross sections. In the 7

  19. Silicone passive equilibrium samplers as ‘chemometers’ in eels and sediments of a Swedish lake

    DEFF Research Database (Denmark)

    Jahnke, Annika; Mayer, Philipp; McLachlan, Michael S.

    2014-01-01

    Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemical...... diagenesis and sorption to phytoplankton. The ‘chemometer’ approach has the potential to become a powerful tool to study the thermodynamic controls on persistent organic chemicals in the environment and should be extended to other environmental compartments....

  20. Multispectral Resource Sampler: Proof of concept. Literature survey of bidirectional reflectance

    Science.gov (United States)

    1981-01-01

    A bibliography compiled in order to give a comprehensive review of previous work in scene bidirectional reflectance, particularly those studies relevant to the Multispectral Resource Sampler (MRS) is presented. The bibliography contains 124 abstracts. In addition a synthesis of the literature results is given along with background information concerning MRS.

  1. Development and Calibration of a Passive Sampler for Perfluorinated Alkyl Carboxylates and Sulfonates in Water

    NARCIS (Netherlands)

    Kaserzon, S.L.; Kennedy, K.; Hawker, D.W.; Thompson, J.; Carter, S.; Roach, A.C.; Booij, K.; Mueller, J.F.

    2012-01-01

    Perfluorinated chemicals (PFCs) are emerging environmental contaminants with a global distribution. Due to their moderate water solubility, the majority of the environmental burden is assumed to be in the water phase. This work describes the application of the first passive sampler for the

  2. 40 CFR 53.59 - Aerosol transport test for Class I equivalent method samplers.

    Science.gov (United States)

    2010-07-01

    ... Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II... candidate test sampler shall have its inlet and impactor or impactors removed. The lower end of the down... aerosol is introduced at the top of the downtube. (f) Test procedure. (1) All surfaces of the added or...

  3. Page 1 34 C N R Rao meters, high speed samplers and Voltage ...

    Indian Academy of Sciences (India)

    meters, high speed samplers and Voltage standards based on Josephson effects as well as non-Josephson devices such as Superconducting bolometers and SIS mixers are areas where success is likely. Transistor-like devices compatible with oxide superconductors need to be explored vigorously. The new bismuth ...

  4. Comparative performance of two air samplers for monitoring airborne fungal propagules

    Directory of Open Access Journals (Sweden)

    L.G.F. Távora

    2003-05-01

    Full Text Available Many studies have attempted to evaluate the importance of airborne fungi in the development of invasive fungal infection, especially for immunocompromised hosts. Several kinds of instruments are available to quantitate fungal propagule levels in air. We compared the performance of the most frequently used air sampler, the Andersen sampler with six stages, with a portable one, the Reuter centrifugal sampler (RCS. A total of 84 samples were analyzed, 42 with each sampler. Twenty-eight different fungal genera were identified in samples analyzed with the Andersen instrument. In samples obtained with the RCS only seven different fungal genera were identified. The three most frequently isolated genera in samples analyzed with both devices were Penicillium, Aspergillus and Cladophialophora. In areas supplied with a high efficiency particulate air filter, fungal spore levels were usually lower when compared to areas without these filters. There was a significant correlation between total fungal propagule measurements taken with both devices on each sampling occasion (Pearson coefficient = 0.50. However, the Andersen device recovered a broader spectrum of fungi. We conclude that the RCS can be used for quantitative estimates of airborne microbiological concentrations. For qualitative studies, however, this device cannot be recommended.

  5. Evaluation of a depth proportional intake device for automatic pumping samplers

    Science.gov (United States)

    Rand E. Eads; Robert B. Thomas

    1983-01-01

    Abstract - A depth proportional intake boom for portable pumping samplers was used to collect suspended sediment samples in two coastal streams for three winters. The boom pivots on the stream bed while a float on the downstream end allows debris to depress the boom and pass without becoming trapped. This equipment modifies point sampling by maintaining the intake...

  6. Framing the Problem of Identity in Composition and TESOL Studies: A Sampler

    Science.gov (United States)

    Messekher, Hayat

    2011-01-01

    This article looks at how the intricate issue of identity has been addressed and framed in composition and TESOL studies (C&T). It reviews five articles and a book as a sampler to explore identity research in various contexts ranging from the problematic rise of identity in second-language acquisition (SLA) research in 1997, which represented a…

  7. The use of simple diffusion tube samplers for the measurement of

    African Journals Online (AJOL)

    The use of simple diffusion tube samplers for the measurement of nitrogen dioxide in an operating room using nitrogen oxide as an anaesthetic (July — November 1999). *E. E. Ukpebor and C. 0. lmarengiaye. *Department Qf Chemistry and Department of/1 naesthesiology. University of Benin, Benin City, Nigeria. Summary.

  8. The use of simple diffusion tube samplers for the measurement of

    African Journals Online (AJOL)

    1999-11-01

    Nov 1, 1999 ... The use of simple diffusion tube samplers for the measurement of nitrogen dioxide in an operating room using nitrogen oxide as an anaesthetic (July —. November 1999). *E. E. Ukpebor and C. O. Imarengiaye. *Department of Chemistry and Department of A naesthesiology. University of Benin, Benin City, ...

  9. Sampling of high amounts of bioaerosols using a high-volume electrostatic field sampler

    DEFF Research Database (Denmark)

    Madsen, A. M.; Sharma, Anoop Kumar

    2008-01-01

    and 315 mg dust (net recovery of the lyophilized dust) was sampled during a period of 7 days, respectively. The sampling rates of the electrostatic field samplers were between 1.34 and 1.96 mg dust per hour, the value for the Gravikon was between 0.083 and 0.108 mg dust per hour and the values for the GSP...

  10. Determination of organochlorine pesticides in Indian coastal water using a moored in situ sampler

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    Residues if various organochlorine pesticides were determined in the water off the central west coast of India using an in situ sampler. Y-BHC and the two cyclodiene compounds, Aldrine and Dieldrin were found to be more consistent than the compounds...

  11. Improved Assessment Strategies for Vapor Intrusion Passive Samplers and Building Pressure Control

    Science.gov (United States)

    2013-09-01

    project. Technical collaborators for the demonstration of the use of passive samplers include Mr. Todd McAlary, Ms. Hester Groenevelt, Mr. Todd...in collaboration with Todd McAlary, Hester Groenevelt, Todd Creamer, Paul Nicholson, Rachel Klinger, and David Bertrand of Geosyntec Consultants

  12. The effect of size-selective samplers (cyclones) on XRD response

    CSIR Research Space (South Africa)

    Pretorius, CJ

    2011-07-01

    Full Text Available The study evaluated five size-selective samplers used in the South African mining industry to determine how their performance affects the X-ray powder diffraction (XRD) response when respirable dust samples are analysed for quartz using direct...

  13. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Science.gov (United States)

    2010-10-01

    ... sampler/observer in a timely fashion of when fishing operations are to begin and end. (5) Allow for the... any scallop trip of the time, port of departure, open area or specific Sea Scallop Access Area to be.../NEFOP must be notified by the owner, operator, or vessel manager of any trip plan changes at least 48 hr...

  14. Publishing and Revising Content

    Science.gov (United States)

    Editors and Webmasters can publish content without going through a workflow. Publishing times and dates can be set, and multiple pages can be published in bulk. Making an edit to published content created a revision.

  15. Scar revision - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100098.htm Scar revision - series—Normal anatomy To use the sharing ... entire body, and acts as a protective barrier. Scar tissue forms as skin heals after an injury ( ...

  16. Revised Total Coliform Rule

    Science.gov (United States)

    The Revised Total Coliform Rule (RTCR) aims to increase public health protection through the reduction of potential pathways for fecal contamination in the distribution system of a public water system (PWS).

  17. Katz's revisability paradox dissolved

    NARCIS (Netherlands)

    Tamminga, Allard; Verhaegh, Sander

    2013-01-01

    Quine's holistic empiricist account of scientific inquiry can be characterized by three constitutive principles: noncontradiction, universal revisability and pragmatic ordering. We show that these constitutive principles cannot be regarded as statements within a holistic empiricist's scientific

  18. Letter of Map Revision

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  19. Evaluation of passive samplers for assessment of community exposure to toxic air contaminants and related pollutants.

    Science.gov (United States)

    Mason, J Brooks; Fujita, Eric M; Campbell, David E; Zielinska, Barbara

    2011-03-15

    The precision, accuracy, and sampling rates of Radiello and Ogawa passive samplers were evaluated in the laboratory using a flow-through chamber and under field conditions prior to their use in the 2007 Harbor Community Monitoring Study (HCMS), a saturation monitoring campaign in the communities adjacent to the Ports of Los Angeles and Long Beach. Passive methods included Radiello samplers for volatile organic compounds (benzene, toluene, ethylbenzene, xylenes, 1,3-butadiene), aldehydes (formaldehyde, acetaldehyde, acrolein) and hydrogen sulfide, and Ogawa samplers for nitrogen oxides and sulfur dioxide. Additional experiments were conducted to study the robustness of the passive sampling methods under variable ambient wind speed, sampling duration, and storage time before analysis. Our experimentally determined sampling rates were in agreement with the rates published by Radiello and Ogawa with the following exceptions: we observed a diffusion rate of 22.4 ± 0.1 mL/min for benzene and 37.4 ± 1.5 mL/min for ethylbenzene compared to the Radiello published values of 27.8 and 25.7 mL/min, respectively. With few exceptions, the passive monitoring methods measured one-week average ambient concentrations of selected pollutants with sensitivity and precision comparable to conventional monitoring methods averaged over the same period. Radiello Carbograph 4 VOC sampler is not suitable for the collection of 1,3-butadiene due to backdiffusion. Results for the Radiello aldehyde sampler were inconclusive due to lack of reliable reference methods for all carbonyl compounds of interest.

  20. Monitoring solute fluxes: Integrating electrical resistivity with multi-compartment sampler techniques

    Science.gov (United States)

    Bloem, Esther; Fernandez, Perrine; French, Helen K.

    2016-04-01

    The impact of agriculture, industry, airport activities on soil and water quality is strongly influenced by soil heterogeneity. To improve risk assessment, monitoring, and treatment strategies, we require a better understanding of the effect of soil heterogeneity on contaminant movement and better methods for monitoring heterogeneous contaminated transport. Sufficient characterization of spatial and temporal distribution of contaminant transport requires measurements of water and solute fluxes at multiple locations with a high temporal resolution. During this presentation, we will show a newly developed instrument, which combines multi-compartment sampling with electrical resistivity measurements, to observe spatial and temporal fluxes of contaminants. Solute monitoring is often limited to observations of resident concentrations, while flux concentrations govern the movement of solutes in soils. Bloem et al. (2010) developed a multi-compartment sampler (MCS) which is capable of measuring fluxes at a high spatial resolution under natural conditions. The sampler is divided into 100 separate compartments of 31 by 31 mm. Flux data can be recorded at a high time resolution (every 5 minutes). Tracer leaching can be monitored by frequently sampling the collected leachate while leaving the sampler buried in situ. To optimize the monitoring of tracer leaching and measure real solute fluxes the multi-compartment sampler has been extended with 121 electrodes. The electrodes are mounted at each corner of each compartment to measure the electrical conductivity above each compartment while water percolates through the compartments. By using different electrode couples, the setup can also be used to image above the multi-compartment sampler. The instrument can be used for detailed studies both in the laboratory and in the field. For laboratory experiments a transparent column is used which fits perfect on top of the MCS. We present a selection of the integrated electrical

  1. Influence of wind-speed on short-duration NO2 measurements using Palmes and Ogawa passive diffusion samplers

    Science.gov (United States)

    Masey, Nicola; Gillespie, Jonathan; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

    2017-07-01

    We assessed the precision and accuracy of nitrogen dioxide (NO2) concentrations over 2-day, 3-day and 7-day exposure periods measured with the following types of passive diffusion samplers: standard (open) Palmes tubes; standard Ogawa samplers with commercially-prepared Ogawa absorbent pads (Ogawa[S]); and modified Ogawa samplers with absorbent-impregnated stainless steel meshes normally used in Palmes tubes (Ogawa[P]). We deployed these passive samplers close to the inlet of a chemiluminescence NO2 analyser at an urban background site in Glasgow, UK over 32 discrete measurement periods. Duplicate relative standard deviation was personal exposure monitoring, are likely to benefit from protection of these sampling devices from the effects of wind, for example by use of a mesh or membrane across the open end. The uptake rate of Ogawa[P] samplers was not associated with wind-speed resulting in a high correlation between estimated concentrations and observed analyser concentrations. The use of Palmes meshes in Ogawa[P] samplers reduced the cost of sampler preparation and removed uncertainty associated with the unknown manufacturing process for the commercially-prepared collection pads.

  2. Portable XRF analysis of occupational air filter samples from different workplaces using different samplers: final results, summary and conclusions.

    Science.gov (United States)

    Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Bartley, David L; Slaven, James E; Andrew, Michael E

    2007-11-01

    This paper concludes a five-year program on research into the use of a portable X-ray fluorescence (XRF) analyzer for analyzing lead in air sampling filters from different industrial environments, including mining, manufacturing and recycling. The results from four of these environments have already been reported. The results from two additional metal processes are presented here. At both of these sites, lead was a minor component of the total airborne metals and interferences from other elements were minimal. Nevertheless, only results from the three sites where lead was the most abundant metal were used in the overall calculation of method accuracy. The XRF analyzer was used to interrogate the filters, which were then subjected to acid digestion and analysis by inductively-coupled plasma optical-emission spectroscopy (ICP-OES). The filter samples were collected using different filter-holders or "samplers" where the size (diameter), depth and homogeneity of aerosol deposit varied from sampler to sampler. The aerosol collection efficiencies of the samplers were expected to differ, especially for larger particles. The distribution of particles once having entered the sampler was also expected to differ between samplers. Samplers were paired to allow the between-sampler variability to be addressed, and, in some cases, internal sampler wall deposits were evaluated and compared to the filter catch. It was found, rather surprisingly, that analysis of the filter deposits (by ICP-OES) of all the samplers gave equivalent results. It was also found that deposits on some of the sampler walls, which in some protocols are considered part of the sample, could be significant in comparison to the filter deposit. If it is concluded that wall-deposits should be analyzed, then XRF analysis of the filter can only give a minimum estimate of the concentration. Techniques for the statistical analysis of field data were also developed as part of this program and have been reported

  3. Determination of respirable mass concentration using a high volume air sampler and a sedimentation method for fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.

    1995-12-31

    A preliminary study of a new method for determining respirable mass concentration is described. This method uses a high volume air sampler and subsequent fractionation of the collected mass using a particle sedimentation technique. Side-by-side comparisons of this method with cyclones were made in the field and in the laboratory. There was good agreement among the samplers in the laboratory, but poor agreement in the field. The effect of wind on the samplers` capture efficiencies is the primary hypothesized source of error among the field results. The field test took place at the construction site of a hazardous waste landfill located on the Hanford Reservation.

  4. Carbon Nanotube Integrative Sampler (CNIS) for passive sampling of nanosilver in the aquatic environment.

    Science.gov (United States)

    Shen, Li; Fischer, Jillian; Martin, Jonathan; Hoque, Md Ehsanul; Telgmann, Lena; Hintelmann, Holger; Metcalfe, Chris D; Yargeau, Viviane

    2016-11-01

    Nanomaterials such as nanosilver (AgNP) can be released into the aquatic environment through production, usage, and disposal. Sensitive and cost-effective methods are needed to monitor AgNPs in the environment. This work is hampered by a lack of sensitive methods to detect nanomaterials in environmental matrixes. The present study focused on the development, calibration and application of a passive sampling technique for detecting AgNPs in aquatic matrixes. A Carbon Nanotube Integrative Sampler (CNIS) was developed using multi-walled carbon nanotubes (CNTs) as the sorbent for accumulating AgNPs and other Ag species from water. Sampling rates were determined in the laboratory for different sampler configurations and in different aquatic matrixes. The sampler was field tested at the Experimental Lakes Area, Canada, in lake water dosed with AgNPs. For a configuration of the CNIS consisting of CNTs bound to carbon fiber (i.e. CNT veil) placed in Chemcatcher® housing, the time weighted average (TWA) concentrations of silver estimated from deployments of the sampler in lake mesocosms dosed with AgNPs were similar to the measured concentrations of "colloidal silver" (i.e. <0.22μm in size) in the water column. For a configuration of CNIS consisting of CNTs in loose powder form placed in a custom made housing that were deployed in a whole lake dosed with AgNPs, the estimated TWA concentrations of "CNIS-labile Ag" were similar to the concentrations of total silver measured in the epilimnion of the lake. However, sampling rates for the CNIS in various matrixes are relatively low (i.e. 1-20mL/day), so deployment periods of several weeks are required to detect AgNPs at environmentally relevant concentrations, which can allow biofilms to develop on the sampler and could affect the sampling rates. With further development, this novel sampler may provide a simple and sensitive method for screening for the presence of AgNPs in surface waters. Copyright © 2016 Elsevier B.V. All

  5. Integrated passive flux measurement in groundwater: design and performance of iFLUX samplers

    Science.gov (United States)

    Verreydt, Goedele; Razaei, Meisam; Meire, Patrick; Van Keer, Ilse; Bronders, Jan; Seuntjens, Piet

    2017-04-01

    The monitoring and management of soil and groundwater is a challenge. Current methods for the determination of movement or flux of pollution in groundwater use no direct measurements but only simulations based on concentration measurements and Darcy velocity estimations. This entails large uncertainties which cause remediation failures and higher costs for contaminated site owners. On top of that, the lack of useful data makes it difficult to get approval for a risk-based management approach which completely avoids costly remedial actions. The iFLUX technology is a key development of Dr. Goedele Verreydt at the University of Antwerp and VITO. It is supported by the passive flux measurement technology as invented by Prof. Mike Annable and his team at the University of Florida. The iFLUX technology includes an in situ measurement device for capturing dynamic groundwater quality and quantity, the iFLUX sampler, and an associated interpretation and visualization method. The iFLUX sampler is a modular passive sampler that provides simultaneous in situ point determinations of a time-averaged target compound mass flux and water flux. The sampler is typically installed in a monitoring well where it intercepts the groundwater flow and captures the compounds of interest. The sampler consists of permeable cartridges which are each packed with a specific sorbent matrix. The sorbent matrix of the water flux cartridge is impregnated with known amounts of water soluble resident tracers. These tracers are leached from the matrix at rates proportional to the groundwater flux. The measurements of the contaminants and the remaining resident tracer are used to determine groundwater and target compound fluxes. Exposure times range from 1 week to 6 months, depending on the expected concentration and groundwater flow velocity. The iFLUX sampler technology has been validated and tested at several field projects. Currently, 4 cartridges are tested and available: 1 waterflux cartridge to

  6. Quantifying the Effects of Temperature and Salinity on Partitioning of Hydrophobic Organic Chemicals to Silicone Rubber Passive Samplers

    NARCIS (Netherlands)

    Jonker, Michiel T O; van der Heijden, Stephan A; Kotte, Marcel; Smedes, Foppe

    2015-01-01

    Nowadays, passive sampling is a widely applied technique to determine freely dissolved aqueous concentrations of hydrophobic organic chemicals (HOCs), such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Crucial to the measurements are sampler-water partition

  7. Benthic organisms collected using sediment sampler from the CAPT. BRADY J in the Gulf of Mexico from (NODC Accession 8300082)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the CAPT. BRADY J and CAJUN SPECIAL in the Gulf of Mexico from 03 May 1982 to 13 October 1982....

  8. Side-by-side determination of workers' exposure to wood dust with IOM and open-faced samplers

    National Research Council Canada - National Science Library

    Cavlović, Anka Ozana; Beljo Lučić, Ružica; Jug, Matija; Radmanović, Kristijan; Bešlić, Ivan

    2013-01-01

    ... (OF) filter holder with an IOM head to determine woodworkers' exposure to inhalable dust and establish an IOM/OF sampler ratio that might serve as a reliable factor for converting the existing OF data...

  9. Sample viscosity can be a source of analytical error when discrete sampler-dilutors are used.

    Science.gov (United States)

    Chan, K M; Ladenson, J H

    1981-11-01

    Total protein concentration in the serum of a patient with hyperviscosity syndrome differed as measured by the biuret procedure in the DuPont aca (80 g/L) and the SMA 12/60 (105 g/L), owing to viscosity-dependent errors with the aca sampling system; the magnitude depended on sample temperature and volume of sample aspirated. This kind of error was not observed with the SMA 12/60 and was far less severe when a Micromedic sampler-dilutor was tested. It could be eliminated in the case of the aca by adding sample to test packs with a syringe rather than with the aca automated sampler-dilutor. We thus recommend use of the syringe method when unusually viscous samples (serum or other body fluids) are analyzed in the aca.

  10. WHATS-3: An Improved Flow-Through Multi-bottle Fluid Sampler for Deep-Sea Geofluid Research

    Directory of Open Access Journals (Sweden)

    Junichi Miyazaki

    2017-06-01

    Full Text Available Deep-sea geofluid systems, such as hydrothermal vents and cold seeps, are key to understanding subseafloor environments of Earth. Fluid chemistry, especially, provides crucial information toward elucidating the physical, chemical, and biological processes that occur in these ecosystems. To accurately assess fluid and gas properties of deep-sea geofluids, well-designed pressure-tight fluid samplers are indispensable and as such they are important assets of deep-sea geofluid research. Here, the development of a new flow-through, pressure-tight fluid sampler capable of four independent sampling events (two subsamples for liquid and gas analyses from each is reported. This new sampler, named WHATS-3, is a new addition to the WHATS-series samplers and a major upgrade from the previous WHATS-2 sampler with improvements in sample number, valve operational time, physical robustness, and ease of maintenance. Routine laboratory-based pressure tests proved that it is suitable for operation up to 35 MPa pressure. Successful field tests of the new sampler were also carried out in five hydrothermal fields, two in Indian Ocean, and three in Okinawa Trough (max. depth 3,300 m. Relations of Mg and major ion species demonstrated bimodal mixing trends between a hydrothermal fluid and seawater, confirming the high quality of fluids sampled. The newly developed WHATS-3 sampler is well-balanced in sampling capability, field usability, and maintenance feasibility, and can serve as one of the best geofluid samplers available at present to conduct efficient research of deep-sea geofluid systems.

  11. An Introduction to the DA-T Gibbs Sampler for the Two-Parameter Logistic (2PL) Model and beyond

    Science.gov (United States)

    Maris, Gunter; Bechger, Timo M.

    2005-01-01

    The DA-T Gibbs sampler is proposed by Maris and Maris (2002) as a Bayesian estimation method for a wide variety of "Item Response Theory (IRT) models". The present paper provides an expository account of the DA-T Gibbs sampler for the 2PL model. However, the scope is not limited to the 2PL model. It is demonstrated how the DA-T Gibbs…

  12. WHATS-3: An improved flow-through multi-bottle fluid sampler for deep-sea geofluid research

    Science.gov (United States)

    Miyazaki, Junichi; Makabe, Akiko; Matsui, Yohei; Ebina, Naoya; Tsutsumi, Saki; Ishibashi, Jun-ichiro; Chen, Chong; Kaneko, Sho; Takai, Ken; Kawagucci, Shinsuke

    2017-06-01

    Deep-sea geofluid systems, such as hydrothermal vents and cold seeps, are key to understanding subseafloor environments of Earth. Fluid chemistry, especially, provides crucial information towards elucidating the physical, chemical and biological processes that occur in these ecosystems. To accurately assess fluid and gas properties of deep-sea geofluids, well-designed pressure-tight fluid samplers are indispensable and as such they are important assets of deep-sea geofluid research. Here, the development of a new flow-through, pressure-tight fluid sampler capable of four independent sampling events (two subsamples for liquid and gas analyses from each) is reported. This new sampler, named WHATS-3, is a new addition to the WHATS-series samplers and a major upgrade from the previous WHATS-2 sampler with improvements in sample number, valve operational time, physical robustness, and ease of maintenance. Routine laboratory-based pressure tests proved that it is suitable for operation up to 35 MPa pressure. Successful field tests of the new sampler were also carried out in five hydrothermal fields, two in Indian Ocean and three in Okinawa Trough (max. depth 3,300 m). Relations of Mg and major ion species demonstrated bimodal mixing trends between a hydrothermal fluid and seawater, confirming the high-quality of fluids sampled. The newly developed WHATS-3 sampler is well-balanced in sampling capability, field usability, and maintenance feasibility, and can serve as one of the best geofluid samplers available at present to conduct efficient research of deep-sea geofluid systems.

  13. Active Sampler: Light-weight Accelerator for Complex Data Analytics at Scale

    OpenAIRE

    Gao, Jinyang; Jagadish, H. V.; Ooi, Beng Chin

    2015-01-01

    Recent years have witnessed amazing outcomes from "Big Models" trained by "Big Data". Most popular algorithms for model training are iterative. Due to the surging volumes of data, we can usually afford to process only a fraction of the training data in each iteration. Typically, the data are either uniformly sampled or sequentially accessed. In this paper, we study how the data access pattern can affect model training. We propose an Active Sampler algorithm, where training data with more "lea...

  14. Development of a new passive sampler based on diffusive milligel beads for copper analysis in water.

    Science.gov (United States)

    Perez, M; Reynaud, S; Lespes, G; Potin-Gautier, M; Mignard, E; Chéry, P; Schaumlöffel, D; Grassl, B

    2015-08-26

    A new passive sampler was designed and characterized for the determination of free copper ion (Cu(2+)) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k0) and the sampler-water partition coefficient (Ksw), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma - Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). Copyright © 2015 Elsevier B.V. All rights reserved.

  15. astroABC : An Approximate Bayesian Computation Sequential Monte Carlo sampler for cosmological parameter estimation

    Science.gov (United States)

    Jennings, E.; Madigan, M.

    2017-04-01

    Given the complexity of modern cosmological parameter inference where we are faced with non-Gaussian data and noise, correlated systematics and multi-probe correlated datasets,the Approximate Bayesian Computation (ABC) method is a promising alternative to traditional Markov Chain Monte Carlo approaches in the case where the Likelihood is intractable or unknown. The ABC method is called ;Likelihood free; as it avoids explicit evaluation of the Likelihood by using a forward model simulation of the data which can include systematics. We introduce astroABC, an open source ABC Sequential Monte Carlo (SMC) sampler for parameter estimation. A key challenge in astrophysics is the efficient use of large multi-probe datasets to constrain high dimensional, possibly correlated parameter spaces. With this in mind astroABC allows for massive parallelization using MPI, a framework that handles spawning of processes across multiple nodes. A key new feature of astroABC is the ability to create MPI groups with different communicators, one for the sampler and several others for the forward model simulation, which speeds up sampling time considerably. For smaller jobs the Python multiprocessing option is also available. Other key features of this new sampler include: a Sequential Monte Carlo sampler; a method for iteratively adapting tolerance levels; local covariance estimate using scikit-learn's KDTree; modules for specifying optimal covariance matrix for a component-wise or multivariate normal perturbation kernel and a weighted covariance metric; restart files output frequently so an interrupted sampling run can be resumed at any iteration; output and restart files are backed up at every iteration; user defined distance metric and simulation methods; a module for specifying heterogeneous parameter priors including non-standard prior PDFs; a module for specifying a constant, linear, log or exponential tolerance level; well-documented examples and sample scripts. This code is hosted

  16. Multipurpose Sediment Passive Sampler with Improved Tissue Mimicry to Measure the Bioavailable Fraction

    Science.gov (United States)

    2016-11-01

    Discrete sampling of water and sediment followed by laboratory analysis is a standard practice . Total concentration data provided by discrete...bis(trimethoxysilylethyl)benzene (BTEB) which has an aryl ring flexibility linked to two silicon centers.42 Using acid or base catalysis , the Si-OCH3... heterogeneity in the sediment, however, it is likely that the extraction rate may differ between samplers. Strong binding affinity may magnify small

  17. Assessment of personal exposure to airborne nanomaterials: Evaluation of a novel sampler

    Science.gov (United States)

    Faure, Bertrand; Dozol, Hélène; Brouard, Christophe; Guiot, Arnaud; Clavaguera, Simon

    2017-06-01

    A novel sampler, the NANOBADGE, has been developed to assess personal exposure to nano-objects, agglomerates and aggregates (NOAA) at the workplace. The NANOBADGE collects particles on filters subsequently analyzed by X-Ray Fluorescence spectroscopy (XRF), which provides a mass-based quantification with chemical selectivity. The NANOBADGE was benchmarked against a scanning mobility particle sizer (SMPS) and a DiSCmini by carrying out simultaneous measurements on test aerosols of ZnO or TiO2 for particle sizes between 20 and 400 nm for which the DiSCmini has its highest accuracy. The effective density and shape of the NOAA present in the test aerosols were determined experimentally to compare number-based data obtained with the SMPS and the DiSCmini with mass-based data obtained with the NANOBADGE. The agreement between the SMPS and the NANOBADGE sampler was within ± 25 % on all test aerosols. The converted DiSCmini data matched the SMPS and sampler data for polydisperse aerosols in the specified size range as long as the DiSCmini assumptions meet the aerosol characteristics (i.e. lognormal size distribution with a given geometric standard deviation σg = 1.9). The detection limits of the NANOBADGE sampler were in the order of tens of nanograms per filter, which is low enough to reliably detect exposure levels below the recommended exposure limit (REL) of the National Institute for Occupational Safety and Health (NIOSH) and the Institut National de Recherche et de Sécurité (INRS) for ultrafine ZnO and TiO2 even for short-term exposure situations.

  18. Development of highly sensitive passive sampler for nitrogen dioxide using porous polyethylene membrane filter as turbulence limiting diffuser

    Science.gov (United States)

    Sekine, Yoshika; Watts, Simon F.; Rendell, Andrew; Butsugan, Michio

    2008-06-01

    A new design of passive sampler is described which is appropriate to reduce the sampling resolution of most formats of Palmes' tubes from weeks to 24 h or less. The sampler employs a flat-type porous polyethylene membrane filter as a diffuser, which controls mass transfer of the target analyte from ambient air to impregnated trapping filter. The new design is applicable to any analyte for which there is a paper Palmes' tube method, e.g. H2S, OCS, NO, SO2, O3, organic acids, NH3 and so on. As an example, the sampler for the determination of ambient atmospheric nitrogen dioxide (NO2), employing a trapping filter impregnated with triethanolamine is described. Performance of the new sampler was evaluated in laboratory and field experiments. The sampling rate was measured directly at four kerb-side sites in Oxford, UK and Kanagawa, Japan, by comparing measured concentrations from the samplers with co-located automated NO2 analyzers. Results showed mass transfer rate of NO2 within the diffuser did not change with external wind speed (0.5-2 m s-1). The passive device had relatively higher sampling rate than those of previous samplers and gave equivalent results on NO2 concentrations to the automated NO2 analyzer at 24 h or less sampling duration. LOD and LOQ indicated possible application of these devices to sampling in urban intermediate, urban background and suburban areas.

  19. Accelerated solvent extraction (ASE) for purification and extraction of silicone passive samplers used for the monitoring of organic pollutants.

    Science.gov (United States)

    Brockmeyer, Berit; Kraus, Uta R; Theobald, Norbert

    2015-12-01

    Silicone passive samplers have gained an increasing attention as single-phased, practical and robust samplers for monitoring of organic contaminants in the aquatic environment in recent years. However, analytical challenges arise in routine application during the extraction of analytes as silicone oligomers are co-extracted and interfere severely during chemical analyses (e.g. gas chromatographic techniques). In this study, we present a fast, practical pre-cleaning method for silicone passive samplers applying accelerated solvent extraction (ASE) for the removal of silicone oligomers prior to the water deployment (hexane/dichloromethane, 100 °C, 70 min). ASE was also shown to be a very fast (10 min) and efficient extraction method for non-polar contaminants (non-exposed PRC recoveries 66-101 %) sampled by the silicone membrane. For both applications, temperature, extraction time and the solvent used for ASE have been optimized. Purification of the ASE extract was carried out by silica gel and high-pressure liquid size exclusion chromatography (HPLC-SEC). The silicone oligomer content was checked by total reflection X-ray fluorescence spectroscopy (TXRF) in order to confirm the absence of the silicone oligomers prior to analysis of passive sampler extracts. The established method was applied on real silicone samplers from the North- and Baltic Sea and showed no matrix effects during analysis of organic pollutants. Internal laboratory standard recoveries were in the same range for laboratory, transport and exposed samplers (85-126 %).

  20. A Gibbs sampler for Bayesian analysis of site-occupancy data

    Science.gov (United States)

    Dorazio, Robert M.; Rodriguez, Daniel Taylor

    2012-01-01

    1. A Bayesian analysis of site-occupancy data containing covariates of species occurrence and species detection probabilities is usually completed using Markov chain Monte Carlo methods in conjunction with software programs that can implement those methods for any statistical model, not just site-occupancy models. Although these software programs are quite flexible, considerable experience is often required to specify a model and to initialize the Markov chain so that summaries of the posterior distribution can be estimated efficiently and accurately. 2. As an alternative to these programs, we develop a Gibbs sampler for Bayesian analysis of site-occupancy data that include covariates of species occurrence and species detection probabilities. This Gibbs sampler is based on a class of site-occupancy models in which probabilities of species occurrence and detection are specified as probit-regression functions of site- and survey-specific covariate measurements. 3. To illustrate the Gibbs sampler, we analyse site-occupancy data of the blue hawker, Aeshna cyanea (Odonata, Aeshnidae), a common dragonfly species in Switzerland. Our analysis includes a comparison of results based on Bayesian and classical (non-Bayesian) methods of inference. We also provide code (based on the R software program) for conducting Bayesian and classical analyses of site-occupancy data.

  1. Bioaerosol sampling by a personal rotating cup sampler CIP 10-M.

    Science.gov (United States)

    Görner, Peter; Fabriès, Jean-François; Duquenne, Philippe; Witschger, Olivier; Wrobel, Richard

    2006-01-01

    High concentrations of bioaerosols containing bacterial, fungal and biotoxinic matter are encountered in many workplaces, e.g. solid waste treatment plants, waste water treatment plants and sewage networks. A personal bioaerosol sampler, the CIP 10-M (M-microbiologic), has been developed to measure worker exposure to airborne biological agents. This sampler is battery operated; it is light and easy to wear and offers full work shift autonomy. It can sample much higher concentrations than biological impactors and limits the mechanical stress on the microorganisms. Biological particles are collected in 2 ml of liquid medium inside a rotating cup fitted with radial vanes to maintain an air flow rate of 10 l min(-1) at a rotational speed of approximately 7,000 rpm. The rotating cup is made of sterilisable material. The sampled particles follow a helicoidal trajectory as they are pushed to the surface of the liquid by centrifugal force, which creates a thin vertical liquid layer. Sterile water or another collecting liquid can be used. Three particle size selectors allow health-related aerosol fractions to be sampled according to international conventions. The sampled microbiological particles can be easily recovered for counting, incubation or further biochemical analysis, e.g., for airborne endotoxins. Its physical sampling efficiency was laboratory tested and field trials were carried out in industrial waste management conditions. The results indicate satisfactory collection efficiency, whilst experimental application has demonstrated the usefulness of the CIP 10-M personal sampler for individual bioaerosol exposure monitoring.

  2. Spatial Distribution of Tropospheric Ozone in National Parks of California: Interpretation of Passive-Sampler Data

    Directory of Open Access Journals (Sweden)

    John D. Ray

    2001-01-01

    Full Text Available The National Park Service (NPS has tested and used passive ozone samplers for several years to get baseline values for parks and to determine the spatial variability within parks. Experience has shown that the Ogawa passive samplers can provide ±10% accuracy when used with a quality assurance program consisting of blanks, duplicates, collocated instrumentation, and a standard operating procedure that carefully guides site operators. Although the passive device does not meet EPA criteria as a certified method (mainly, that hourly values be measured, it does provide seasonal summed values of ozone. The seasonal ozone concentrations from the passive devices can be compared to other monitoring to determine baseline values, trends, and spatial variations. This point is illustrated with some kriged interpolation maps of ozone statistics. Passive ozone samplers were used to get elevational gradients and spatial distributions of ozone within a park. This was done in varying degrees at Mount Rainier, Olympic, Sequoia–Kings Canyon, Yosemite, Joshua Tree, Rocky Mountain, and Great Smoky Mountains national parks. The ozone has been found to vary by factors of 2 and 3 within a park when average ozone is compared between locations. Specific examples of the spatial distributions of ozone in three parks within California are given using interpolation maps. Positive aspects and limitations of the passive sampling approach are presented.

  3. Revising and editing for translators

    CERN Document Server

    Mossop, Brian

    2014-01-01

    Revising and Editing for Translators provides guidance and learning materials for translation students learning to edit texts written by others, and professional translators wishing to improve their self-revision ability or learning to revise the work of others. Editing is understood as making corrections and improvements to texts, with particular attention to tailoring them to the given readership. Revising is this same task applied to draft translations. The linguistic work of editors and revisers is related to the professional situations in which they work. Mossop offers in-depth coverage of a wide range of topics, including copyediting, style editing, structural editing, checking for consistency, revising procedures and principles, and translation quality assessment. This third edition provides extended coverage of computer aids for revisers, and of the different degrees of revision suited to different texts. The inclusion of suggested activities and exercises, numerous real-world examples, a proposed gra...

  4. Revision without ordinals

    NARCIS (Netherlands)

    Rivello, Edoardo

    2013-01-01

    We show that Herzberger’s and Gupta’s revision theories of truth can be recast in purely inductive terms, without any appeal neither to the transfinite ordinal numbers nor to the axiom of Choice. The result is presented in an abstract and general setting, emphasising both its validity for a wide

  5. Revision of Meiogyne (Annonaceae)

    NARCIS (Netherlands)

    Heusden, van E.C.H.

    1994-01-01

    In the present revision of Meiogyne (Annonaceae) nine species are recognized, of which one is new, M. glabra; five new combinations are made; M. hainanensis is re-established. Meiogyne in its new sense includes the former genera Ancana, Chieniodendron, Guamia, Meiogyne, Oncodostigma, and Polyaulax.

  6. Revising China's Environmental Law

    NARCIS (Netherlands)

    He, G.; Zhang, L.; Mol, A.P.J.; Lu, Y.; Liu, Wenling; Liu, J.

    2013-01-01

    China's Environmental Protection Law (EPL) is the main national environmental legislative framework. Yet the environmental legal system is incomplete, and implementation and enforcement of environmental laws have shown major shortcomings (1–3). A controversial attempt to revise the EPL could have

  7. Belief and Its Revision

    NARCIS (Netherlands)

    Bewersdorf, Benjamin

    2013-01-01

    The role of experience for belief revision is seldom explicitly discussed. This is surprising as it seems obvious that experiences play a major role for most of our belief changes. In this work, the two most plausible views on the role of experience for belief change are investigated: the view that

  8. Evaluation of personal inhalable aerosol samplers with different filters for use during anthrax responses.

    Science.gov (United States)

    Grinshpun, Sergey A; Weber, Angela M; Yermakov, Michael; Indugula, Reshmi; Elmashae, Yousef; Reponen, Tiina; Rose, Laura

    2017-08-01

    Risk of inhalation exposure to viable Bacillus anthracis (B. anthracis) spores has primarily been assessed using short-term, stationary sampling methods which may not accurately characterize the concentration of inhalable-sized spores reaching a person's breathing zone. While a variety of aerosol sampling methods have been utilized during previous anthrax responses, no consensus has yet been established for personal air sampling. The goal of this study was to determine the best sampler-filter combination(s) for the collection and extraction of B. anthracis spores. The study was designed to (1) evaluate the performance of four filter types (one mixed cellulose ester, MCE (pore size = 3 µm), two polytetrafluoroethylene, PTFE (1 and 3 µm), and one polycarbonate, PC (3 µm)); and (2) evaluate the best performing filters in two commercially available inhalable aerosol samplers (IOM and Button). Bacillus thuringiensis kurstaki [Bt(k)], a simulant for B. anthracis, served as the aerosol challenge. The filters were assessed based on criteria such as ability to maintain low pressure drop over an extended sampling period, filter integrity under various environmental conditions, spore collection and extraction efficiencies, ease of loading and unloading the filters into the samplers, cost, and availability. Three of the four tested collection filters-except MCE-were found suitable for efficient collection and recovery of Bt(k) spores sampled from dry and humid as well as dusty and clean air environments for up to 8 hr. The PC (3 µm) filter was identified as the best performing filter in this study. The PTFE (3 µm) demonstrated a comparable performance, but it is more expensive. Slightly higher concentrations were measured with the IOM inhalable sampler which is the preferred sampler's performance criterion when detecting a highly pathogenic agent with no established "safe" inhalation exposure level. Additional studies are needed to address the effects of

  9. Spatially distributed environmental fate modelling of terbuthylazine in a mesoscale agricultural catchment using passive sampler data

    Science.gov (United States)

    Gassmann, Matthias; Farlin, Julien; Gallé, Tom

    2017-04-01

    Agricultural application of herbicides often leads to significant herbicide losses to receiving rivers. The impact of agricultural practices on water pollution can be assessed by process-based reactive transport modelling using catchment scale models. Prior to investigations of management practices, these models have to be calibrated using sampling data. However, most previous studies only used concentrations at the catchment outlet for model calibration and validation. Thus, even if the applied model is spatially distributed, predicted spatial differences of pesticide loss cannot be directly compared to observations. In this study, we applied the spatially distributed reactive transport model Zin-AgriTra in the mesoscale (78 km2) catchment of the Wark River in Luxembourg in order to simulate concentrations of terbuthylazine in river water. In contrast to former studies, we used six sampling points, equipped with passive samplers, for pesticide model validation. Three samplers were located in the main channel of the river and three in smaller tributaries. At each sampling point, event mean concentration of six events from May to July 2011 were calculated by subtraction of baseflow-mass from total collected mass assuming time-proportional uptake by passive samplers. Continuous discharge measurements and high-resolution autosampling during events allowed for accurate load calculations at the outlet. Detailed information about maize cultivation in the catchment and nation-wide terbuthylazine application statistics (341 g/ha in the 3rd week of May) were used for a definition of the pesticide input function of the model. The hydrological model was manually calibrated to fit baseflow and spring/summer events. Substance fluxes were calibrated using a Latin Hypercube of physico-chemical substance characteristics as provided by the literature: surface soil half-lives of 10-35 d, Freundlich KOC of 150-330 ml/g, Freundlich n of 0.9 - 1 and adsorption/desorption kinetics of 20

  10. Monitoring of jökulhlaups and element fluxes in proglacial Icelandic rivers using osmotic samplers

    Science.gov (United States)

    Jones, Morgan T.; Gałeczka, Iwona M.; Gkritzalis-Papadopoulos, Athanasios; Palmer, Martin R.; Mowlem, Matthew C.; Vogfjörð, Kristín; Jónsson, Þorsteinn; Gislason, Sigurður R.

    2015-01-01

    The quantification of volatile emissions from volcanoes is an integral part of understanding magmatic systems, with the exsolution and extent of volcanic degassing having a large impact on the nature of an eruption. Measurements of volatiles have traditionally focused on gas emissions into the atmosphere, but volatiles can also become dissolved in proximal water bodies en route to the surface. Thus the monitoring of rivers draining active volcanic areas can provide insights to identifying changes in activity. This process is particularly important for sub-glacial volcanoes in Iceland, where much of the volatile release is transported within glacial outbreak floods, termed jökulhlaups. Monitoring and characterising these phenomena is hampered by the dependence on spot sampling of stochastic events under challenging field conditions, which often leads to bias in the collected data. A recent technological advance is the osmotic sampler, an electricity-free pump that continuously collects water that can subsequently be divided into time-averaged samples. This technique allows for continued and unsupervised deployment of a sampler for weeks to months, representing a cost-efficient form of chemical monitoring. In this study we deployed osmotic samplers in two rivers in southern Iceland. Skálm is a proglacial river from Mýrdalsjökull glacier and Katla volcano, while Skaftá is a larger drainage system from the western part of Vatnajökull glacier. Both rivers are prone to jökulhlaups from geothermal and volcanic sources, and a small jökulhlaup of geothermal origin occurred during the second deployment in Skaftá in January 2014. The two deployments show that osmotic samplers are capable of delivering accurate chemical data in turbulent conditions for several key elements. Total dissolved fluxes for the deployment at Skaftá are calculated to be Na = 9.9 tonnes/day, Mg = 10.5 t/d, Si = 34.7 t/d, Cl = 11.0 t/d, Ca = 31.6 t/d, DIC = 50.8 t/d, and SO4 = 28.3 t/d, with

  11. Assessing the influence of confounding biological factors when estimating bioaccumulation of PCBs with passive samplers in aquatic ecosystems.

    Science.gov (United States)

    Figueiredo, Kaisa; Mäenpää, Kimmo; Lyytikäinen, Merja; Taskinen, Jouni; Leppänen, Matti T

    2017-12-01

    Passive samplers are promising surrogates for organisms, mimicking bioaccumulation. However, several biological characteristics disturb the passive partitioning process in organisms by accelerating or restraining bioaccumulation, resulting in species-specific body residues of hydrophobic organic contaminants (HOCs). In addition to site-specific characteristics and HOC concentrations, age, sex, diet, biotransformation capability and habitat-specific characteristics may affect body residues. Two passive sampler types, polyethylene (PE) and polydimethylsiloxane (PDMS) were deployed in a PCB-contaminated freshwater lake water and sediment, respectively, to assess their bioaccumulation prediction capacity. In order to understand the importance of biological characteristics in the bioaccumulation process, we explored bioaccumulation in biota from plants and plankton to mussels and fish. The PCB concentrations in the PE sheet reflected the bioavailable concentration of PCBs slightly better than those in the PDMS samplers. Passive samplers were good predictors of PCB concentrations in fish, whereas concentrations in algae and invertebrates were overestimated. When comparing the measured concentrations in biota to the estimated concentrations using the PE samplers, the average regression slope was 0.87 for all biota and 1.22 for fish, and average modeling efficiency (EF) was 3.02 for all biota and 0.6 for fish. The best model performance was achieved for fish in trophic levels 3-4. Bioaccumulation was species-specific and dependent on the trophic level and diet. Closer examination revealed that metabolic capability changes during the life span, and source of nutrition determined the biomagnification of HOCs, which differed between the fish species. Thus, species composition and available prey selection compose a unique bioaccumulation scenario and the resulting body residues. Due to the existing variation in body residues derived from passive samplers, extrapolating the

  12. Validation of Ammonia Diffusive and Active Samplers in a Controlled Atmosphere Test Facility Using Traceable Primary Standard Gas Mixtures

    Science.gov (United States)

    Martin, N. A.; Ferracci, V.; Cassidy, N.; Hook, J.; Battersby, R. M.; Tang, Y. S.; Stevens, A. C. M.; Jones, M. R.; Braban, C. F.; Gates, L.; Hangartner, M.; Sacco, P.; Pagani, D.; Hoffnagle, J.

    2016-12-01

    Intensive farming, the increased use of fertilizers, and certain industrial processes are believed to be responsible for increases in the amount fraction of ammonia (NH3) found in Europe. NH3 contributes to eutrophication and acidification of land and freshwater, leading to a loss of biodiversity, undesirable changes to the ecosystem, and to secondary particulate matter (PM) formation. Measurements of ambient ammonia over a wide geographical area, are principally carried out with low-cost diffusive samplers or by active sampling with denuders, with each technique delivering time-integrated values over the monitoring period. The goal of this work was to measure the NH3 diffusive sampling rates of five different designs of commercial diffusive samplers (FSM Radiello radial sampler, Gradko diffusion tube, Gradko DIFRAM-400, Passam ammonia sampler, and CEH ALPHA sampler), together with validation tests with a denuder sampler (CEH DELTA denuder). The would deliver validated improvements in the accuracy of ambient measurements of NH3 in the field through the establishment of metrological traceability using new stable ammonia Primary Standard Gas Mixtures (PSMs), developed by gravimetry at NPL. All devices were simultaneously exposed in a controlled atmosphere test facility (CATFAC) containing traceable amount fractions of ammonia applicable to a range of ambient monitoring conditions, with well-defined conditions of temperature, relative humidity and wind speed. Online continuous monitoring of the test atmospheres was carried out with a calibrated cavity ring-down spectrometer modified to account for cross interference by water. Exposed samplers were analysed by individual manufacturers for ammonium using traceable wet chemical techniques. The measured diffusive sampling rates were then applied to field measurements carried out at the Whim Bog experimental station in Scotland, where there is a facility in place for controlled releases of NH3 and also a background site.

  13. Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water.

    Science.gov (United States)

    Liao, Chunyang; Richards, Jaben; Taylor, Allison R; Gan, Jay

    2017-12-01

    Widespread use of insecticides for the control of urban pests such as ants, termites, and spiders has resulted in contamination and toxicity in urban aquatic ecosystems in different regions of the world. Passive samplers are a convenient and integrative tool for in situ monitoring of trace contaminants in surface water. However, the performance of a passive sampler depends closely on its affinity for the target analytes, making passive samplers highly specific to the types of contaminants being monitored. The goal of this study was to develop a passive sampler compatible with a wide range of insecticides, including the strongly hydrophobic pyrethroids and the weakly hydrophobic fipronil and organophosphates. Of six candidate polymeric thin films, polyurethane film (PU) was identified to be the best at enriching the test compounds. The inclusion of stable isotope labeled analogs as performance reference compounds (PRCs) further allowed the use of PU film for pyrethroids under non-equilibrium conditions. The PU sampler was tested in a large aquarium with circulatory water flow, and also deployed at multiple sites in surface streams in southern California. The concentrations of pesticides derived from the PU sampler ranged from 0.5 to 18.5 ng/L, which were generally lower than the total chemical concentration measured by grab samples, suggesting that suspended particles and dissolved organic matter in water rendered them less available. The influence of suspended particles and dissolved organic matter on bioavailability was more pronounced for pyrethroids than for fipronils. The results show that the developed PU film sampler, when coupled with PRCs, may be used for rapid and sensitive in-situ monitoring of a wide range of insecticides in surface water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Cumulative Revision Map

    OpenAIRE

    Kim, Seungyeon; Dillon, Joshua V.; Lebanon, Guy

    2012-01-01

    Unlike static documents, version-controlled documents are edited by one or more authors over a certain period of time. Examples include large scale computer code, papers authored by a team of scientists, and online discussion boards. Such collaborative revision process makes traditional document modeling and visualization techniques inappropriate. In this paper we propose a new visualization technique for version-controlled documents that reveals interesting authoring patterns in papers, comp...

  15. An evaluation of total and inhalable samplers for the collection of wood dust in three wood products industries.

    Science.gov (United States)

    Harper, Martin; Muller, Brian S

    2002-10-01

    In 1998 the American Conference for Governmental Industrial Hygienists (ACGIH) proposed size selective sampling for wood dust based on the inhalable fraction. Thus the proposed threshold limit values (TLVs) require the use of a sampler whose performance matches the inhalable convention. The Institute of Occupational Medicine (IOM) sampler has shown good agreement with the inhalable convention under controlled conditions, and the Button sampler, developed by the University of Cincinnati, has shown reasonable agreement in at least one laboratory study. The Button sampler has not been previously evaluated under wood working conditions, and the IOM has been shown to sample more mass than expected when compared to the standard closed-face cassette, which may be due to the collection of very large particles in wood working environments. Some projectile particles may be > 100 microm aerodynamic diameter and thus outside the range of the convention. Such particles, if present, can bias the estimates of concentration considerably. This study is part of an on-going research focus into selecting the most appropriate inhalable sampler for use in these industries, and to examine the impact of TLV changes. This study compared gravimetric analyses (National Institute of Occupational Safety and Health Method 0500) of side-by-side personal samples using the Button, IOM, and 37 mm closed-face cassette (CFC) under field-use conditions. A total of 51 good sample pairs were collected from three wood products industries involved in the manufacturing of cabinets, furniture, and shutters. Paired t-tests were run on each sample pair using Statistical Package for the Social Sciences (SPSS) version 10. The IOM and the CFC measured statistically different concentrations (p wood dust (p = 0.098, n = 23). Sampler ratios for IOM/CFC pairs ranged from 1.19-19 (median 3.35). Sampler ratios for IOM/Button pairs ranged from 0.49-163 (median 3.15). Sampler ratios for CFC/Button pairs ranged from 0

  16. Development of a portable membrane contactor sampler for noble gas analyses of surface and groundwater samples

    Science.gov (United States)

    Matsumoto, T.; Han, L. H.; Jaklitsh, M.; Aggarwal, P. K.

    2012-04-01

    Noble gas isotopes dissolved in groundwater provide valuable information about climatic conditions during air-water exchange, as well as the residence time of groundwater and its renewal rate. The isotope composition of noble gases can also serve as geochemical fingerprints to decipher the origin of groundwater and its flow system. Conventionally, groundwater is sampled using a copper tube, which is subsequently degassed using a vacuum extraction system for isotope analysis by a mass spectrometer. Although this conventional and well-established way of sampling is widely recognised as being reliable and robust, a major drawback to this method is its size and weight. For example, our sampler consists of a copper tube of 10 mm diameter x 1000 mm length and a metal casing with pinch-off clamps with its total weight to be 2 kg each. A box of 24 samplers well exceeds 40 kg. Considering that sampling fields are not necessarily easily accessible by vehicle, taking hundreds of samples in the field is generally a tough task for everyone. There is a different type of sampler, which is comprised of a much smaller copper tube (6 mm in diameter and 100 mm long for our case) with clamps and a semi-permeable membrane filter. It is sunk into water and left there for dissolved gases to diffuse into the sampler until their concentrations in water become equilibrated with those in the tube. This diffusion sampler is small and easy to handle in the field; it has an advantage over conventional copper tubes, as the diffusion sampler collects gases so that there is no gas extraction process needed before isotope analysis. However, this method requires an equilibration time of 24 hours or more, which could result in lower time-efficiency for sampling work. In order to enable time-efficient and less-painstaking sampling of noble gases dissolved in surface and groundwater, we have developed a portable and self-powered sampling device specified to noble gas analysis by mass spectrometer

  17. Calibration of polydimethylsiloxane and XAD-Pocket passive air samplers (PAS) for measuring gas- and particle-phase SVOCs

    Science.gov (United States)

    Okeme, Joseph O.; Saini, Amandeep; Yang, Congqiao; Zhu, Jiping; Smedes, Foppe; Klánová, Jana; Diamond, Miriam L.

    2016-10-01

    Polydimethylsiloxane (PDMS) has seen wide use as the stationary phase of gas chromatographic columns, a passive sampler in water, and recently as a personal exposure sampler, while styrene divinyl-benzene copolymer (XAD) has been used extensively as a passive air sampler outdoors and indoors. We have introduced PDMS and XAD-Pocket as new indoor passive air samplers (PASs). The XAD-Pocket was designed to maximize the surface area-to-volume ratio of XAD and to minimize obstruction of air flow by the sampler housing. Methods were developed to expedite the use of these PASs for measuring phthalates, novel brominated flame-retardants (NFRs) and polybrominated diphenyl ethers (PBDEs) indoors. Sampling rates, Rs, (m3 day-1), were measured during a 7-week calibration study. Variability within and between analyte groups was not statistically significant. As a result, generic values of 0.8 ± 0.4 and 0.5 ± 0.3 m3 day-1 dm-2 are recommended for PDMS and XAD-Pocket for a 50-day deployment time, respectively. PDMS has a higher uptake rate and is easier to use than XAD-Pocket.

  18. Fast monitoring of indoor bioaerosol concentrations with ATP bioluminescence assay using an electrostatic rod-type sampler.

    Directory of Open Access Journals (Sweden)

    Ji-Woon Park

    Full Text Available A culture-based colony counting method is the most widely used analytical technique for monitoring bioaerosols in both indoor and outdoor environments. However, this method requires several days for colony formation. In this study, our goal was fast monitoring (Sampling: 3 min, Detection: < 1 min of indoor bioaerosol concentrations with ATP bioluminescence assay using a bioaerosol sampler. For this purpose, a novel hand-held electrostatic rod-type sampler (110 mm wide, 115 mm long, and 200 mm tall was developed and used with a commercial luminometer, which employs the Adenosine triphosphate (ATP bioluminescence method. The sampler consisted of a wire-rod type charger and a cylindrical collector, and was operated with an applied voltage of 4.5 kV and a sampling flow rate of 150.7 lpm. Its performance was tested using Staphylococcus epidermidis which was aerosolized with an atomizer. Bioaerosol concentrations were measured using ATP bioluminescence method with our sampler and compared with the culture-based method using Andersen cascade impactor under controlled laboratory conditions. Indoor bioaerosol concentrations were also measured using both methods in various indoor environments. A linear correlation was obtained between both methods in lab-tests and field-tests. Our proposed sampler with ATP bioluminescence method may be effective for fast monitoring of indoor bioaerosol concentrations.

  19. Proof of concept for a passive sampler for monitoring of gaseous elemental mercury in artisanal gold mining.

    Science.gov (United States)

    de Barros Santos, Elias; Moher, Paleah; Ferlin, Stacy; Fostier, Anne Hélène; Mazali, Italo Odone; Telmer, Kevin; Brolo, Alexandre Guimarães

    2017-11-28

    Mercury emissions from artisanal gold mining operations occurring in roughly 80 developing countries are a major workplace health hazard for millions of people as well as the largest contributor to global mercury pollution. There are no portable, cheap, and rapid methods able to inform workers or health practitioners of mercury exposure on site in remote locations. In this work, a proof of concept for a miniaturized mercury sampler, prepared by the direct reduction of gold into the porous nanostructures of Vycor glass (PVG), is introduced. Mercury retention on the PVG/Au sampler induces significant color changes, due to the formation of Au-Hg amalgam that affects the surface plasmon resonance characteristics of the material. The color change can potentially be quantified by the analysis of pictures obtained with a cell phone camera rapidly and onsite. Laboratory experiments showed the viability of using PVG/Au as passive sampler for monitoring of Hg°. PVG/Au samplers were then deployed in an artisanal and small-scale gold mining (ASGM) operations in Burkina Faso and it was able to indicate personal mercury exposures. The amount of mercury quantified in the samplers for all miners was higher than the current personal exposure limit set by the US Occupational Safety & Health Administration (OSHA).

  20. Field performance of the Chemcatcher passive sampler for monitoring hydrophobic organic pollutants in surface water.

    Science.gov (United States)

    Vrana, Branislav; Mills, Graham A; Leonards, Pim E G; Kotterman, Michiel; Weideborg, Mona; Hajslová, Jana; Kocourek, Vladimír; Tomaniová, Monika; Pulkrabová, Jana; Suchanová, Marie; Hájková, Katerina; Herve, Sirpa; Ahkola, Heidi; Greenwood, Richard

    2010-04-01

    Six field trials were carried out to assess the performance of the Chemcatcher passive sampler alongside spot sampling for monitoring priority hydrophobic organic pollutants (polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides) in a wide range of conditions in surface water. The trials were performed in three European rivers: Elbe (Czech Republic), Alna (Norway) and Meuse (Netherlands), in two seasons (April-June 2004, and September-October 2004). Samplers spiked with performance reference compounds (PRCs) were deployed for either 14 or 28 days. Ten spot samples of water were collected over the course of the trial and filtered through a 0.7 microm glass fibre filter. Concentrations of pollutants measured using the Chemcatcher were compared with the average concentrations found in spot samples. This study describes the operational performance of Chemcatcher for measuring hydrophobic (log K(OW) 3.7-6.8) chemicals in surface water. Site specific Chemcatcher sampling rates up to 0.5 L d(-1) were found using the PRC approach that reduced the uncertainty in estimates of sampling kinetics where temperature, local flow conditions and biofouling potential varied between sites and seasons, and with time during sampler exposure. The limits of quantification of sampled analytes ranged from one to tens ng L(-1). Highest sensitivity was achieved for compounds with a favourable combination of low instrument quantification limits and high sampling rates including dieldrin, hexachlorobenzene, lindane, pentachlorobenzene, and PAHs with less than five aromatic rings. The direct comparison of time weighted average (TWA) concentrations (mostly close to method limits of detection) obtained using passive and spot sampling was possible for lindane, hexachlorobenzene, and PAHs < 4 rings. Implications of using the Chemcatcher in regulatory monitoring programmes such as the European Union Water Framework Directive are discussed.

  1. Subsurface Environment Sampler for Improved In Situ Characterization of Subsurface Microbial Communities

    Science.gov (United States)

    Barnhart, E. P.; Ruppert, L. F.; Orem, W. H.; McIntosh, J. C.; Cunningham, A. B.; Fields, M. W.; Hiebert, R.; Hyatt, R.

    2016-12-01

    There is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by the extraction and transport of fossil fuels. This threat increases the need for improved groundwater monitoring and the ability to predict the extent to which microbial activity may remediate such contamination. The characterization of subsurface microbial communities could provide an ideal biomonitoring tool for the assessment of subsurface contamination due to prokaryotes environmental ubiquity, rapidity of response to environmental perturbation and the important role they play in hydrocarbon degradation and bioremediation. New DNA sequencing technologies provide the opportunity to cost-effectively identify the vast subsurface microbial ecosystem, but use of this new technology is restricted due to issues with sampling. Prior subsurface microbiology studies have relied on core samples that are expensive to obtain hard to collect aseptically and/or ground water samples that do not reflect in situ microbial densities or activities. The development of down-well incubation of sterile sediment with a Diffusive Microbial Sampler (DMS) has emerged as an alternative method to sample subsurface microbial communities that minimizes cost and contamination issues associated with traditional methods. We have designed a Subsurface Environment Sampler with a DMS module that could enable the anaerobic transport of the in situ microbial community from the field for laboratory bioremediation studies. This sampler could provide an inexpensive and standard method for subsurface microbial sampling which would make this tool useful for Federal, State, private and local agencies interested in monitoring contamination or the effectiveness of bioremediation activities in subsurface aquifers.

  2. Evaluating the PAS-SIM model using a passive air sampler calibration study for pesticides.

    Science.gov (United States)

    Restrepo, Andrés Ramírez; Hayward, Stephen J; Armitage, James M; Wania, Frank

    2015-07-01

    The main objective of this study was to evaluate the performance of a model for simulating the uptake of various pesticides on passive air samplers (PAS). From 2006-2007 a series of PAS using XAD-resin were deployed at Egbert, a rural agricultural site in southern Ontario, Canada, to measure the uptake of pesticides for time periods ranging from two months to one year. A continuous increase in sequestered amounts was observed for most pesticides, except for trifluralin and pendimethalin, which could conceivably be subject to substantial degradation inside the sampler. Continuous low-volume active air samples taken during the same period, along with data on weather conditions, allowed for the simulation of the uptake of the pesticides using the model (PAS-SIM). The modelled accumulation of pesticides on the PAS over the deployment period was in good agreement with the experimental data in most cases (i.e., within a factor of two) providing insight into the uptake kinetics of this type of sampler in the field. Passive sampling rates (PSR, m(3) d(-1)) were determined from the empirical data generated for this study using three different methods and compared with the PSRs generated by the model. Overall, the PAS-SIM model, which is capable of accounting for the influence of temperature and wind variations on PSRs, provided reasonable results that range between the three empirical approaches employed and well-established literature values. Further evaluation and application of the PAS-SIM model to explore the potential spatial and temporal variability in PAS uptake kinetics is warranted, particularly for established monitoring sites where detailed meteorological data are more likely to be available.

  3. astroABC : An Approximate Bayesian Computation Sequential Monte Carlo sampler for cosmological parameter estimation

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, E. [Fermilab; Madigan, M. [Trinity Coll., Dublin

    2017-01-18

    Given the complexity of modern cosmological parameter inference where we arefaced with non-Gaussian data and noise, correlated systematics and multi-probecorrelated data sets, the Approximate Bayesian Computation (ABC) method is apromising alternative to traditional Markov Chain Monte Carlo approaches in thecase where the Likelihood is intractable or unknown. The ABC method is called"Likelihood free" as it avoids explicit evaluation of the Likelihood by using aforward model simulation of the data which can include systematics. Weintroduce astroABC, an open source ABC Sequential Monte Carlo (SMC) sampler forparameter estimation. A key challenge in astrophysics is the efficient use oflarge multi-probe datasets to constrain high dimensional, possibly correlatedparameter spaces. With this in mind astroABC allows for massive parallelizationusing MPI, a framework that handles spawning of jobs across multiple nodes. Akey new feature of astroABC is the ability to create MPI groups with differentcommunicators, one for the sampler and several others for the forward modelsimulation, which speeds up sampling time considerably. For smaller jobs thePython multiprocessing option is also available. Other key features include: aSequential Monte Carlo sampler, a method for iteratively adapting tolerancelevels, local covariance estimate using scikit-learn's KDTree, modules forspecifying optimal covariance matrix for a component-wise or multivariatenormal perturbation kernel, output and restart files are backed up everyiteration, user defined metric and simulation methods, a module for specifyingheterogeneous parameter priors including non-standard prior PDFs, a module forspecifying a constant, linear, log or exponential tolerance level,well-documented examples and sample scripts. This code is hosted online athttps://github.com/EliseJ/astroABC

  4. Respirable size-selective sampler for end-of-shift quartz measurement: Development and performance.

    Science.gov (United States)

    Lee, Taekhee; Lee, Larry; Cauda, Emanuele; Hummer, Jon; Harper, Martin

    2017-05-01

    Aims of this study were to develop a respirable size-selective sampler for direct-on-filter (DoF) quartz measurement at the end-of-shift (EoS) using a portable Fourier transform infrared (FTIR) spectrometer and to determine its size-selective sampling performance. A new miniaturized sampler has been designed to have an effective particle deposition diameter close to the portable FTIR beam diameter (6 mm). The new sampler (named the EoS cyclone) was constructed using a 3D printer. The sampling efficiency of the EoS cyclone was determined using polydisperse glass sphere particles and a time-of-flight direct reading instrument. Respirable dust mass concentration and quartz absorbance levels of samples collected with the EoS cyclone were compared to those collected with the 10-mm nylon cyclone. The EoS cyclone operated at a flow rate of 1.2 l min -1 showed minimum bias compared to the international standard respirable convention. The use of the EoS cyclone induced respirable dust mass concentration results similar but significantly larger (5%) than those obtained from samples collected with 10-mm nylon cyclones. The sensitivity of the DoF-FTIR analysis in estimating quartz was found increased more than 10 times when the samples were collected with the EoS cyclone. The average particle deposition diameter was 8.8 mm in 60 samples. The newly developed user friendly EoS cyclone may provide a better sampling strategy in quartz exposure assessment with faster feedback.

  5. Implementation of Automated Infiltration Soil Water Sampler: Application to Unsaturated Soil in Dune Fields

    Science.gov (United States)

    Higashi, N.; Inoue, M.; Mori, Y.

    2003-12-01

    Accurate measurement and sampling of infiltration water from root zone are necessary to understand soil and groundwater contamination processes. The traditional instruments for sampling water leaching below the root zone cause divergence or bypass of the water flow around the instrument itself. That results in undesired soil water profile and inaccurate sampling. A suction controlled lysimeter, which consists of porous plate connected to an automated vacuum system and tensiometers has developed. Soil matric pressure heads are measured just above the porous plate that installed horizontally and at the same depth in the natural soil profile. The vacuum system is automatically controlled so that the readings of the matric pressure heads match each other. This instrument does not disturb the water flow and the water sampling flux (qe) is almost similar to that of natural infiltration flux (qd). However, for sandy soils, porous plate would show some resistance to flow and soil water could easily accumulate above the porous plate. We improved the existing automated water sampler in order to measure the unsaturated zone in dune fields. High flow rate glass filters with different pore size; 0.02 to 0.03 mm (G3), 0.005 to 0.01 mm (G4), and 0.002 to 0.005 mm (G5) were studied in laboratory instead of the traditionally used porous plate. In the unsaturated steady-state water flow experiment, the value of vacuum pressure was set manually in reference to retention curve of dune sand. The water sampling flux measured by these samplers corresponded well with the irrigation flux (qi) when a suction of 60 cm H2O was applied to G4 and G5 filters. Four different irrigation fluxes were studied. The average water collecting efficiency (WCE = qe divided by qi) was 118 percent for G4 and 147 percent for G5. We concluded that glass filter, especially, G4 filter was suitable as soil water sampler in dune fields. Finally, the improved sampler using G4 filter was buried into a lysimeter (120

  6. Study of Ozone Tropospheric Levels At The Castellon Area (spain) By Means of Passive Samplers

    Science.gov (United States)

    Delgado, J. M.; Esteve, V.

    Tropospheric ozone is produced by means of pollutants (mainly NOx and VOC's ) emitted by mobile sources like traffic or heating engines. In the case of La Plana de Castellon area, the cities, the industrial area called El Serrallo ( with its oil refinery and power plant), the tile factories and the main roads (A7-E15 and N-340), all they are the main pollutant focus of precursors contaminants. Nevertheless, areas far from these points suffer the harmful effects of oxidants as ozone. The aim of this work is the study of tropospheric ozone levels in far areas from Castellon, mainly in La Plana de Castellon area, by means of a new lower-cost sampling technology:passive sam- plers. The measurement campaign is made during the higher photochemical activity period (from May to September) in order to obtain the necessary data to make an ozone isoconcentration map. It has been divided into sampling periods of one week. Twenty samples are collected each sampling period to cover an interest area of 1400 Km2. Two of these samples are laboratory blanks, four are situated at reference points with two co-located points (beside an automatic ozone sampler) and the rest twelve samples are located around the sampling area of interest, in radial peripheral points around Castellon city an the main precursors pollutants points. Two different kind of passive samplers has been employed: Radielloo samplers developed by Dr. Cocheo at Fondazione Salvatore Maugeri and ozone passive samplers Ogawao developed by Dr. Koutrakis at Harvard University. Samples located by the coast show the lowest levels, 40 ug/m3, about 37% lower than the other measuring points. Levels in the city of Castellon are 50 ug/m3, 25% higher to coast levels. Nevertheless, highest levels are measured in the North area with values raising to 60 ug/m3, about 47% higher than coast values. At the inner area values are about 55 ug/m3 and at the south area values are about 50 ug/m3. We would like to thank Dr. M. Wolfosn

  7. A sub 125 nW sub-threshold analog adaptive sampler in 180 nm CMOS.

    Science.gov (United States)

    Laurenson, Callum; Yuce, Mehmet R; Redoute, Jean-Michel

    2017-07-01

    We present an ultra low power analogue adaptive sampler for extraction of features from an arterial blood pressure signal, prior to ADC operation or conversion. The architecture is implemented and simulated in UMC 180 nm technology. A worst case power consumption across process variation of 124.6 nW was achieved, with a process invariant key-point timing error of approximately 2.31 ms, corresponding to a sample error of magnitude less than 0.1 mmHg, simulated at body temperature of 37°C. This is significantly below the standard clinical recording accuracy of 1 mmHg for electronic measurement tools.

  8. Temperature dependence on the pesticide sampling rate of polar organic chemical integrative samplers (POCIS).

    Science.gov (United States)

    Yabuki, Yoshinori; Nagai, Takashi; Inao, Keiya; Ono, Junko; Aiko, Nobuyuki; Ohtsuka, Nobutoshi; Tanaka, Hitoshi; Tanimori, Shinji

    2016-10-01

    Laboratory experiments were performed to determine the sampling rates of pesticides for the polar organic chemical integrative samplers (POCIS) used in Japan. The concentrations of pesticides in aquatic environments were estimated from the accumulated amounts of pesticide on POCIS, and the effect of water temperature on the pesticide sampling rates was evaluated. The sampling rates of 48 pesticides at 18, 24, and 30 °C were obtained, and this study confirmed that increasing trend of sampling rates was resulted with increasing water temperature for many pesticides.

  9. Estimating the parameters of dynamical systems from Big Data using Sequential Monte Carlo samplers

    Science.gov (United States)

    Green, P. L.; Maskell, S.

    2017-09-01

    In this paper the authors present a method which facilitates computationally efficient parameter estimation of dynamical systems from a continuously growing set of measurement data. It is shown that the proposed method, which utilises Sequential Monte Carlo samplers, is guaranteed to be fully parallelisable (in contrast to Markov chain Monte Carlo methods) and can be applied to a wide variety of scenarios within structural dynamics. Its ability to allow convergence of one's parameter estimates, as more data is analysed, sets it apart from other sequential methods (such as the particle filter).

  10. Modelling and field application of the Chemcatcher passive sampler calibration data for the monitoring of hydrophobic organic pollutants in water.

    Science.gov (United States)

    Vrana, Branislav; Mills, Graham A; Kotterman, Michiel; Leonards, Pim; Booij, Kees; Greenwood, Richard

    2007-02-01

    Passive sampling of dissolved pollutants in water has been gaining acceptance for environmental monitoring. Previously, an integrative passive sampler consisting of a C18 Empore disk receiving phase saturated with n-octanol and fitted with low density polyethylene membrane, was developed and calibrated for the measurement of time weighted average (TWA) concentrations of hydrophobic pollutants in water. In this study, the exchange kinetics were modelled to obtain a better understanding of the mechanism of the accumulation process and to enable the measurement of TWA concentrations of hydrophobic pollutants in the field. An empirical relationship that enables the calculation of in situ sampling rates of chemicals using performance reference compounds was derived and its application was demonstrated in a field study in which TWA aqueous concentrations estimated from sampler data for target analytes were compared with TWA concentrations obtained from spot samples of water collected regularly during the sampler deployment period.

  11. Development and application of a dichotomous vapor/aerosol sampler for HDI-derived total reactive isocyanate group.

    Science.gov (United States)

    Rando, R J; Poovey, H G

    1999-01-01

    A dichotomous vapor/aerosol sampler was developed for measurement of HDI (1,6-hexamethylene diisocyanate)-derived total reactive isocyanate group (TRIG). The sampler consisted of an impactor or cyclone inlet, followed by an annular diffusional denuder, and a glass-fiber filter backup. The denuder walls and backup filter were each coated with 20 mg tributylphosphate and 1 mg MAMA reagent (9-N-methylamino-methylanthracene). After collection, MAMA-derivatized isocyanates were desorbed from the sampler and determined by high-performance liquid chromatography with dual-wavelength ultraviolet absorbance and fluorescence detection. Test atmospheres of HDI vapor and of HDI/HDI-biuret aerosols were generated in the laboratory and sampled with the optimized dichotomous sampler. Vapor phase HDI was completely collected by the diffusional denuder. When a mixture of HDI-biuret and HDI (approximately 30 ppb) was nebulized and collected with the dichotomous sampler, approximately 78% of the HDI was in the vapor phase, whereas about 22% was associated with the aerosol fraction. The dichotomous sampler was then used to measure vapor and condensed phase TRIG in a paint spray booth during application of a polyurethane paint. Measured levels of TRIG during the spraying operation averaged 391 +/- 154 micrograms/m3. Concentrations of HDI monomer averaged only 14 +/- 6.5 micrograms/m3. HDI-biuret was the largest component of TRIG found in these samples and was completely in the condensed aerosol phase. In contrast, the majority of the HDI was in the vapor phase, but significant (15-26%) amounts were measured in the aerosol fraction of the paint overspray. Thus, significant partitioning of HDI between vapor and condensed phases was demonstrated in both the laboratory and field, even when its concentration was well below the vapor saturation point.

  12. A comparison of the performance of samplers for respirable dust in workplaces and laboratory analysis for respirable quartz.

    Science.gov (United States)

    Verpaele, Steven; Jouret, Jonathan

    2013-01-01

    The divergent sampling techniques for respirable dust and the analyses for crystalline silica are an important area of interest and discussion among industrial occupational hygienists in Europe. The variety of equipment for air sampling, methods and instrumentation can cause differences between results for the analysis of respirable crystalline silica (RCS). In this study, a Workplace Atmosphere Multi-sampler (WAM), developed by Adhesia, was used to compare respirable dust samplers in the workplace. This rotating device enables the comparison of 12 samplers in a workplace in each run. Seven laboratories participated in the comparison, using six different respirable dust samplers [British Cast Iron Research Association (BCIRA) to the Higgins Dewell (HD) design, Dorr Oliver, Casella SIMPEDS, SKC HD with a polycarbonate filter and polyvinylchloride filter, and the CIP10-R). Each laboratory analysed samples supplied by the samplers and reported the total respirable dust concentration and the RCS concentration. The techniques used were X-ray diffraction direct-on-filter, X-ray diffraction with deposition, infrared direct-on-filter, and infrared with potassium bromide (KBr) discs. The experiments were carried out in four different industries (enamel, sand extraction, foundry and brickworks). Generally, the SKC conductive black plastic sampler is oversampled (y = 1.52x + 0.008) and the CIP10 is undersampled (y = 0.74x + 0.068) when compared with the median air concentration. A pair-wise comparison of the different industries using t-tests indicated significant differences (P quartz) and showed significant differences for the CIP10 techniques and the SKC conductive plastic cyclone analyses when using a polyvinylchloride filter.

  13. A portable membrane contactor sampler for analysis of noble gases in groundwater.

    Science.gov (United States)

    Matsumoto, Takuya; Han, Liang-Feng; Jaklitsch, Manfred; Aggarwal, Pradeep K

    2013-01-01

    To enable a wider use of dissolved noble gas concentrations and isotope ratios in groundwater studies, we have developed an efficient and portable sampling device using a commercially available membrane contactor. The device separates dissolved gases from a stream of water and collects them in a small copper tube (6 mm in diameter and 100 mm in length with two pinch-off clamps) for noble gas analysis by mass spectrometry. We have examined the performance of the sampler using a tank of homogeneous water prepared in the laboratory and by field testing. We find that our sampling device can extract heavier noble gases (Ar, Kr, and Xe) more efficiently than the lighter ones (He and Ne). An extraction time of about 60 min at a flow rate of 3 L/min is sufficient for all noble gases extracted in the sampler to attain equilibrium with the dissolved phase. The extracted gas sample did not indicate fractionation of helium ((3) He/(4) He) isotopes or other noble gas isotopes. Field performance of the sampling device was tested using a groundwater well in Vienna and results were in excellent agreement with those obtained from the conventional copper tube sampling method. © 2012, National Ground Water Association.

  14. Plant leaves as indoor air passive samplers for volatile organic compounds (VOCs).

    Science.gov (United States)

    Wetzel, Todd A; Doucette, William J

    2015-03-01

    Volatile organic compounds (VOCs) enter indoor environments through internal and external sources. Indoor air concentrations of VOCs vary greatly but are generally higher than outdoors. Plants have been promoted as indoor air purifiers for decades, but reports of their effectiveness differ. However, while air-purifying applications may be questionable, the waxy cuticle coating on leaves may provide a simple, cost-effective approach to sampling indoor air for VOCs. To investigate the potential use of plants as indoor air VOC samplers, a static headspace approach was used to examine the relationship between leaf and air concentrations, leaf lipid contents and octanol-air partition coefficients (Koa) for six VOCs and four plant species. The relationship between leaf and air concentrations was further examined in an actual residence after the introduction of several chlorinated VOC emission sources. Leaf-air concentration factors (LACFs), calculated from linear regressions of the laboratory headspace data, were found to increase as the solvent extractable leaf lipid content and Koa value of the VOC increased. In the studies conducted in the residence, leaf concentrations paralleled the changing air concentrations, indicating a relatively rapid air to leaf VOC exchange. Overall, the data from the laboratory and residential studies illustrate the potential for plant leaves to be used as cost effective, real-time indoor air VOC samplers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Position Weight Matrix, Gibbs Sampler, and the Associated Significance Tests in Motif Characterization and Prediction

    Directory of Open Access Journals (Sweden)

    Xuhua Xia

    2012-01-01

    Full Text Available Position weight matrix (PWM is not only one of the most widely used bioinformatic methods, but also a key component in more advanced computational algorithms (e.g., Gibbs sampler for characterizing and discovering motifs in nucleotide or amino acid sequences. However, few generally applicable statistical tests are available for evaluating the significance of site patterns, PWM, and PWM scores (PWMS of putative motifs. Statistical significance tests of the PWM output, that is, site-specific frequencies, PWM itself, and PWMS, are in disparate sources and have never been collected in a single paper, with the consequence that many implementations of PWM do not include any significance test. Here I review PWM-based methods used in motif characterization and prediction (including a detailed illustration of the Gibbs sampler for de novo motif discovery, present statistical and probabilistic rationales behind statistical significance tests relevant to PWM, and illustrate their application with real data. The multiple comparison problem associated with the test of site-specific frequencies is best handled by false discovery rate methods. The test of PWM, due to the use of pseudocounts, is best done by resampling methods. The test of individual PWMS for each sequence segment should be based on the extreme value distribution.

  16. Auto-Gopher: A Wireline Deep Sampler Driven by Piezoelectric Percussive Actuator and EM Rotary Motor

    Science.gov (United States)

    Badescu, Mircea; Ressa, Aaron; Jae Lee, Hyeong; Bar-Cohen, Yoseph; Sherrit, Stewart; Zacny, Kris; Paulsen, Gale L.; Beegle, Luther; Bao, Xiaoqi

    2013-01-01

    The ability to penetrate subsurfaces and perform sample acquisition at depth of meters may be critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars and Europa. A corer/sampler was developed with the goal of enabling acquisition of samples from depths of several meters where if used on Mars would be beyond the oxidized and sterilized zone. For this purpose, we developed a rotary-hammering coring drill, called Auto-Gopher, which employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor that rotates the bit to remove the powdered cuttings. This sampler is a wireline mechanism that can be fed into and retrieved from the drilled hole using a winch and a cable. It includes an inchworm anchoring mechanism allowing the drill advancement and weight on bit control without twisting the reeling and power cables. The penetration rate is being optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that is driven by piezoelectric stack and that was demonstrated to require low axial preload. The design and fabrication of this device were presented in previous publications. This paper presents the results of laboratory and field tests and lessons learned from this development.

  17. Feasibility of Developing a Passive Sampler for Sampling Heavy Metals in BMPs for Stormwater Runoff Management.

    Science.gov (United States)

    Dou, Yueqin; Klein, Mitch; Zhang, Tian C; Stansbury, John; Moussavi, Massoum; Richter-Egger, Dana L; Zeng, Jing

    2018-01-11

    Structural Best Management Practices (BMPs) have been used for stormwater treatment and management for several decades. How to monitor these BMPs performance reliably and economically is a challenge. This paper reports feasibility of developing a flow through passive sampler (PS) based on Amberlite IRC748 ion exchange resin operated in kinetic regime for sampling heavy metals in BMPs (infiltration systems) for stormwater treatment and management. Tests were conducted using batch reactors and laboratory-scale BMPs (bioretention cells). Batch reactor results indicate that PSs performed desirably with consistent and rapid metal uptake, and thus the resin-based PS is feasible to be used for stormwater sampling. In lab-scale BMPs tests, the resin PSs were employed for sampling influent and effluent of BMPs loaded with synthetic stormwater for storm durations of 0.5, 3, and 12 hours. The removal efficiency of heavy metals in the BMPs as predicted by PSs was very similar to the actual treatment efficiencies obtained from control BMPs, with errors ranging from -5% to 2%, indicating that the PSs can be used for sampling stormwater and monitoring BMPs. The next step for this sampler to be operational will be to develop a method or set-up for evaluating the volume of water passing the PS during the sampling period.

  18. Quantification of herbicide removal in a constructed wetland using passive samplers and composite water quality monitoring.

    Science.gov (United States)

    Page, Declan; Dillon, Peter; Mueller, Jochen; Bartkow, Michael

    2010-09-01

    Constructed wetlands used as treatment for urban stormwater have the potential to improve water quality. This study aimed to estimate the removal of selected herbicides in stormwater by a constructed wetland using composite water quality monitoring and passive samplers. For the four week duration of the study the wetland was effective in reducing the concentrations of diuron, simazine and atrazine. Mean estimated concentrations over a 28 d period were 192, 70 and 5 ng L(-1) at the inlet and 94, 30 and 2 ng L(-1) at the outlet for diuron, simazine and atrazine, respectively. Concentrations of these herbicides generally halved as a result of passage through the constructed wetland with a design hydraulic retention time of 7d. Simple ratios of the inlet and outlet herbicide concentrations as well as hydraulic load-based methods of measuring the wetland's removal efficiency resulted in a range of estimations 33-51% for diuron and 20-60% for simazine. Due to their lower detection limits, the use of passive samplers provides a more efficient technique than conventional sampling for assessment of stormwater wetland treatment. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  19. Validation of ammonia diffusive and active samplers in a controlled atmosphere test facility using traceable Primary Standard Gas Mixtures

    Science.gov (United States)

    Martin, Nicholas A.; Ferracci, Valerio; Cassidy, Nathan; Hook, Josh; Battersby, Ross M.; Tang, Yuk S.; Stevens, Amy C. M.; Jones, Matthew R.; Braban, Christine F.; Gates, Linda; Hangartner, Markus; Stoll, Jean-Marc; Sacco, Paolo; Pagani, Diego; Hoffnagle, John A.

    2017-04-01

    Intensive animal farming, the increased use of fertilizers, and certain industrial processes are believed to be responsible for the observed increases in the amount fraction of ammonia (NH3) found in Europe. NH3 contributes to eutrophication and acidification of land and freshwater, potentially leading to a loss of biodiversity and undesirable changes to the ecosystem. It also contributes to the formation of secondary particulate matter (PM) formation, which is associated with poor air quality and adverse health outcomes. Measurements of ambient ammonia are principally carried out with low-cost diffusive samplers or by active sampling with denuders, with each method delivering time-integrated values over the monitoring period. However, such techniques have not yet been extensively validated. The goal of this work was to provide improvements in the metrological traceability through the determination of NH3 diffusive sampling rates. Five different designs of commercial diffusive samplers (FSM Radiello radial sampler, Gradko diffusion tube, Gradko DIFRAM-400, Passam ammonia sampler, and CEH ALPHA sampler) were employed, together with a pumped denuder sampler (CEH DELTA denuder) for comparison. All devices were simultaneously exposed for either 28 days or 14 days (dependent on sampler type) in a controlled atmosphere test facility (CATFAC) containing traceable amount fractions of humidified ammonia using new stable ammonia Primary Standard Gas Mixtures developed by gravimetry at NPL, under a wide range of conditions that are relevant to ambient monitoring. Online continuous monitoring of the ammonia test atmospheres was carried out by extractive sampling, employing a calibrated cavity ring-down spectrometer, which had been modified to account for cross interference by water vapour. Each manufacturer extracted the captured ammonia on the exposed samplers in the form of ammonium (NH4+) using their own accredited traceable wet chemical techniques, and then reported data

  20. Multimodal Revision Techniques in Webtexts

    Science.gov (United States)

    Ball, Cheryl E.

    2014-01-01

    This article examines how an online scholarly journal, "Kairos: Rhetoric, Technology, Pedagogy," mentors authors to revise their webtexts (interactive, digital media scholarship) for publication. Using an editorial pedagogy in which multimodal and rhetorical genre theories are merged with revision techniques found in process-based…

  1. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C.

    This paper is based on research performed for the Highway Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges" It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....... These WL reliability profiles may be used to establish revised rules for Concrete Bridges....

  2. Emotion Processes in Knowledge Revision

    Science.gov (United States)

    Trevors, Gregory J.; Kendeou, Panayiota; Butterfuss, Reese

    2017-01-01

    In recent years, a number of insights have been gained into the cognitive processes that explain how individuals overcome misconceptions and revise their previously acquired incorrect knowledge. The current study complements this line of research by investigating the moment-by-moment emotion processes that occur during knowledge revision using a…

  3. Surgical scar revision: An overview

    Directory of Open Access Journals (Sweden)

    Shilpa Garg

    2014-01-01

    Full Text Available Scar formation is an inevitable consequence of wound healing from either a traumatic or a surgical intervention. The aesthetic appearance of a scar is the most important criteria to judge the surgical outcome. An understanding of the anatomy and wound healing along with experience, meticulous planning and technique can reduce complications and improve the surgical outcome. Scar revision does not erase a scar but helps to make it less noticeable and more acceptable. Both surgical and non-surgical techniques, used either alone or in combination can be used for revising a scar. In planning a scar revision surgeon should decide on when to act and the type of technique to use for scar revision to get an aesthetically pleasing outcome. This review article provides overview of methods applied for facial scar revision. This predominantly covers surgical methods.

  4. Recent Revisions to PVWATTS

    Energy Technology Data Exchange (ETDEWEB)

    Marion, B.; Anderberg, M.; Gray-Hann, P.

    2005-11-01

    PVWATTS is an Internet-accessible software program that allows the user to easily calculate the energy production and cost savings for grid-connected photovoltaic (PV) systems located throughout the United States. To ensure that PVWATTS continues to meet its users' needs, an online survey form was provided to users to identify areas for improvement. The results of the survey were used to prioritize improvements to PVWATTS in FY2005. PVWATTS was revised by changing the PV system specification input for system size from an AC power rating to a nameplate DC power rating; adding an input for an overall DC to AC derate factor; updating the residential electric rates; adding monthly and yearly solar radiation values for the PV array; and simplifying the user interface for Version 2.

  5. Philippines revises power plans

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, D.

    1988-02-01

    Following an unexpected surge in electricity demand the Philippines has revised its medium term power development programme. The sharp increase in electricity consumption follows three years of slack demand due to civil disturbances before the end of the Macros administration and the election of Corazon Aquino as President in 1986. Originally, the Aquino government's medium term power development plans called for about 500MW of generating capacity to be installed between 1986 and 1992. The three proposed plants were scheduled for commissioning in 1991 and 1992. However, a spurt in power demand growth during the past nine months has caused concern among industrialists that power shortages could occur by the end of the decade. So additional capacity will be installed to prevent an anticipated shortfall in electricity supplies by the early 1990s.

  6. Use of passive samplers to characterize the spatial heterogeneity of coarse particle mass concentration and composition in Cleveland, OH

    Science.gov (United States)

    Sawvel, Eric J.

    The overall goals of this dissertation are: 1) to better quantify the spatial heterogeneity of coarse particulate matter (PM10-2.5) and its chemical composition; and 2) to evaluate the performance (accuracy and precision) of passive samplers analyzed by computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (CCSEM-EDS) for PM10-2.5. For these goals, field studies were conducted over multiple seasons in Cleveland, OH and were the source of data for this dissertation. To achieve the first goal, we characterized spatial variability in the mass and composition of PM10-2.5 in Cleveland, OH with the aid of inexpensive passive samplers. Passive samplers were deployed at 25 optimized sites for three week-long intervals in summer 2008 to characterize spatial variability in components of PM10-2.5. The size and composition of individual particles were determined using CCSEM-EDS. For each sample, this information was used to estimate PM10-2.5 mass and aerosol composition by particle class. The highest PM10-2.5 means were observed at three central industrial urban sites (35.4 mug m-3, 43.4 mug m-3, and 47.6 mug m -3), whereas lower means were observed to the west and east of this area with the lowest means observed at outskirt suburban background sites (12.9 mug m-3 and 14.7 mug m-3). Concentration maps for PM10-2.5 and some compositional components of PM10-2.5 (Fe oxide and Ca rich) show an elongated shape of high values stretching from Lake Erie south through the central industrial area, whereas those for other compositional components (e.g., Si/Al rich) are considerably less heterogeneous. The findings from the spatial variability of coarse particles by compositional class analysis, presented in Chapter II of this dissertation, show that the concentrations of some particle classes were substantially more spatially heterogeneous than others. The data suggest that industrial sources located in The Flats district in particular may contribute

  7. Modelling and field application of the Chemcatcher passive sampler calibration data for the monitoring of hydrophobic organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Vrana, Branislav [School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth PO1 2DY (United Kingdom)]. E-mail: branovrana@googlemail.com; Mills, Graham A. [School of Pharmacy and Biomedical Sciences, University of Portsmouth, St Michael' s Building, White Swan Road, Portsmouth PO1 2DT (United Kingdom); Kotterman, Michiel [Netherlands Institute for Fisheries Research, P.O. Box 68, Haringkade 1, 1970 AB IJmuiden (Netherlands); Leonards, Pim [Netherlands Institute for Fisheries Research, P.O. Box 68, Haringkade 1, 1970 AB IJmuiden (Netherlands); Booij, Kees [Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Texel (Netherlands); Greenwood, Richard [School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth PO1 2DY (United Kingdom)

    2007-02-15

    Passive sampling of dissolved pollutants in water has been gaining acceptance for environmental monitoring. Previously, an integrative passive sampler consisting of a C{sub 18} Empore[reg] disk receiving phase saturated with n-octanol and fitted with low density polyethylene membrane, was developed and calibrated for the measurement of time weighted average (TWA) concentrations of hydrophobic pollutants in water. In this study, the exchange kinetics were modelled to obtain a better understanding of the mechanism of the accumulation process and to enable the measurement of TWA concentrations of hydrophobic pollutants in the field. An empirical relationship that enables the calculation of in situ sampling rates of chemicals using performance reference compounds was derived and its application was demonstrated in a field study in which TWA aqueous concentrations estimated from sampler data for target analytes were compared with TWA concentrations obtained from spot samples of water collected regularly during the sampler deployment period. - The exchange kinetics of hydrophobic organic pollutants between passive sampler and water were modelled to enable the measurement of time weighted average concentrations of pollutants. The applicability of the model was tested in a field study.

  8. Demonstration/Validation of the Snap Sampler Passive Groundwater Sampling Device at the Former McClellan Air Force Base

    Science.gov (United States)

    2011-02-01

    25  5.1  CONCEPTUAL EXPERIMENTAL DESIGN .................................................. 25  5.2  EXPERIMENTAL CONTROLS...Table 5-9. Results for the field duplicate RGC samples. .................................................. 42  Table 5-10. Summary of the recovery of...Percent Difference RPP Rigid Porous Polyethylene sampler RSD Percent Relative Standard Deviation S Sulfur Sb Antimony SI Site Investigation

  9. A comparison of freshwater mussels and passive samplers as indicators of heavy metal pollution in aquatic systems

    DEFF Research Database (Denmark)

    Søberg, Laila C.; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    2013-01-01

    The utility of passive sampling as a tool for determining the ecological state of wet retention ponds was investigated as an alternative to the analysis of living organisms. The accumulation of heavy metals over time in mussels and passive samplers exposed to artificial stormwater was examined...

  10. A Model Using Local Weather Data to Determine the Effective Sampling Volume for PCB Congeners Collected on Passive Air Samplers.

    Science.gov (United States)

    Herkert, Nicholas J; Martinez, Andres; Hornbuckle, Keri C

    2016-07-05

    We have developed and evaluated a mathematical model to determine the effective sampling volumes (Veff) of PCBs and similar compounds captured using polyurethane foam passive air samplers (PUF-PAS). We account for the variability in wind speed, air temperature, and equilibrium partitioning over the course of the deployment of the samplers. The model, provided as an annotated Matlab script, predicts the Veff as a function of physical-chemical properties of each compound and meteorology from the closest Integrated Surface Database (ISD) data set obtained through NOAA's National Centers for Environmental Information (NCEI). The model was developed to be user-friendly, only requiring basic Matlab knowledge. To illustrate the effectiveness of the model, we evaluated three independent data sets of airborne PCBs simultaneously collected using passive and active samplers: at sites in Chicago, Lancaster, UK, and Toronto, Canada. The model provides Veff values comparable to those using depuration compounds and calibration against active samplers, yielding an average congener specific concentration method ratio (active/passive) of 1.1 ± 1.2. We applied the model to PUF-PAS samples collected in Chicago and show that previous methods can underestimate concentrations of PCBs by up to 40%, especially for long deployments, deployments conducted under warming conditions, and compounds with log Koa values less than 8.

  11. Beehold : the colony of the honeybee (Apis mellifera L) as a bio-sampler for pollutants and plant pathogens

    NARCIS (Netherlands)

    Steen, van der J.J.M.

    2016-01-01

    Bio-sampling is a function of bio-indication. Bio-indication with honeybee colonies (Apis mellifera L) is where the research fields of environmental technology and apiculture overlap. The honeybees are samplers of the environment by collecting unintentionally and simultaneously, along with nectar,

  12. 40 CFR Table F-1 to Subpart F of... - Performance Specifications for PM2.5 Class II Equivalent Samplers

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Performance Specifications for PM2.5 Class II Equivalent Samplers F Table F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL..., Subpt. F, Table F-1 Table F-1 to Subpart F of Part 53—Performance Specifications for PM2.5 Class II...

  13. Demonstration of the AGI Universal Samplers (F.K.A. the GORE (registered trademark) Modules) for Passive Sampling of Groundwater

    Science.gov (United States)

    2014-03-01

    conversion of the mass data to concentration values. In September 2010, the Gore Laboratory became accredited to ISO /IEC* 17025 , DOD ELAP, and NELAC...Chromatography/Mass Spectrometry HSE Health and Safety Executive HWEP High Water Entry Pressure IRP Installation Restoration Program ISO /IEC...there will be more than 32 ft of head above the sampler. * ISO /IEC International

  14. Demonstration of the AGI Universal Samplers (F.K.A. the GORE Modules) for Passive Sampling of Groundwater

    Science.gov (United States)

    2014-03-27

    conversion of the mass data to concentration values. In September 2010, the Gore Laboratory became accredited to ISO /IEC* 17025 , DOD ELAP, and NELAC...Chromatography/Mass Spectrometry HSE Health and Safety Executive HWEP High Water Entry Pressure IRP Installation Restoration Program ISO /IEC...there will be more than 32 ft of head above the sampler. * ISO /IEC International

  15. THE POTENTIAL INFLUENCES OF FACE VELOCITY ON PM ARTIFACT LOSSES FOR EXPOSURE SAMPLERS USING TEFLON FILTER COLLECTION SUBSTRATES

    Science.gov (United States)

    The influences of artifact formations and losses on Particulate Matter (PM) sampler collection surfaces are well documented, especially for nitrates (Hering and Cass, 1999), and SVOC's (McDow, 1999), and more recently for speciated carbon (Turpin and Lim, 2001). These artifact...

  16. A Field Evaluation of Performance Reference Compound Based Estimates of Cfree Using Water Column Deployed Passive Samplers

    Science.gov (United States)

    Low-Density polyethylene (LDPE) sheets are often used as passive samplers for aquatic environmental monitoring to measure the freely dissolved concentrations of hydrophobic organic contaminants (HOCs). HOCs that are freely dissolved in water (Cfree) will partition into the LDPE u...

  17. Use of Passive Samplers to Determine the Source of Dissolved PAHs in the Ottawa River, Toledo, Ohio

    Science.gov (United States)

    As part of a larger study on the remedy effectiveness on the Ottawa River, (Ohio, USA), research was focused on the source of PAHs to water and sediment. Polyethylene passive samplers, or polyethylene devices (PEDs), were deployed and analyzed, along with whole water samples and...

  18. Passive sampling of perfluorinated acids and sulfonates using polar organic chemical integrative samplers.

    Science.gov (United States)

    Fedorova, Ganna; Golovko, Oksana; Randak, Tomas; Grabic, Roman

    2013-03-01

    The applicability of a polar organic chemical integrative sampler (POCIS) for detection and determination of perfluorinated acids and sulfonates in water was studied under field conditions. Standard POCIS configurations (i.e., pharmaceutical and pesticide) were deployed in effluent from a wastewater treatment plant for 1, 2, and 3 weeks. Ten of 15 target compounds were found in POCIS, five of which were quantified in wastewater. Pest-POCIS appeared more effective for the sampling, while Pharm-POCIS had a more rapid uptake kinetic, which leads to faster saturation or equilibrium. The results showed that the pesticide configuration is probably more suitable for the sampling of this class of compounds. Based on average concentration in water over the sampling period and amount of compound adsorbed in the POCIS, we calculated sampling rates for five studied compounds and obtained values of 0.034 to 0.222 L day(-1).

  19. Projecting Ammonia Dry Deposition Using Passive Samplers and a Bi-Directional Exchange Model

    Science.gov (United States)

    Robarge, W. P.; Walker, J. T.; Austin, R. E.

    2011-12-01

    Animal agriculture within the United States is known to be a source of ammonia (NH3) emissions. Dry deposition of NH3 to terrestrial ecosystems immediately surrounding large local sources of NH3 emissions (e.g. animal feeding operations) is difficult to measure, and is best estimated via models. Presented here are results for a semi-empirical modeling approach for estimating air-surface exchange fluxes of NH3 downwind of a large poultry facility (~ 3.5 million layers) using a bi-directional air-surface exchange model. The modeling domain is the western section of the Pocosin Lakes National Wildlife Refuge in Tyrrell, Washington, and Hyde Counties of eastern North Carolina in the South Atlantic Coastal Plain physiographic region. Vegetation within the modeling domain is primarily pocosin wetlands, characterized by acid (pH 3.6) peat soils and a thick canopy of shrub vegetation (leatherwood (Cyrilla racemiflora), inkberry (Ilex glabra), wax myrtle (Morella cerifera)). Land surrounding the refuge is primarily used for crop production: ~ 28%, 24%, and 45% agricultural in Tyrell, Hyde, and Washington counties, respectively. Ammonia air-surface exchange (flux) was calculated using a two-layer canopy compensation point model developed by Nemitz et al. (2001. Quart. J. Roy. Met. Soc. 127, 815 - 833.) as implemented by Walker et al. (2008. Atmos. Environ., 42, 3407 - 3418.), in which the competing processes of emission and deposition within the foliage-soil system were taken into account by relating the net canopy-scale NH3 flux to the net emission potential of the canopy (i.e., foliage and soil). Ammonia air concentrations were measured using ALPHA passive samplers (Center for Ecology and Hydrology, Edinburgh) along transects to the north and northeast of the poultry facility at distances of 800, 2000 and 3200 m, respectively. Samplers were deployed in duplicate at each location at a height of 5.8 m from July 2008 to July 2010 weekly during warm months and bi-weekly curing

  20. Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

    Directory of Open Access Journals (Sweden)

    Chaeyoung Lee

    2012-11-01

    Full Text Available Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

  1. Development of a macroporous ceramic passive sampler for the monitoring of cytostatic drugs in water.

    Science.gov (United States)

    Franquet-Griell, Helena; Pueyo, Victor; Silva, Jorge; Orera, Victor M; Lacorte, Silvia

    2017-09-01

    The aim of this study was to develop and calibrate a macroporous ceramic passive sampler (MCPS) for the monitoring of anticancer drugs in wastewater. This system was designed by the Spanish Research Council (CSIC) and consists in a porous ceramic tube to allow a high diffusion of contaminants. The MCPS has been calibrated for 16 cytostatic drugs over time periods up to 9 d in spiked water under controlled laboratory conditions. Optimal uptake was accomplished for 7 compounds, namely ifosfamide, cyclophosphamide, capecitabine, prednisone, megestrol, cyproterone and mycophenolic acid, whereas cytarabine was not adsorbed in the receiving phase and the rest were hydrolyzed over the deployment period. The sampling rate for these 7 compounds was between 0.825 and 3.350 mL day(-1) and the diffusion coefficients varied from 1.01E-07 to 4.12E-07 cm(2) s(-1). To prove the applicability of the MCPSs, samplers (n = 3) were deployed in influent and effluent waters of a WWTP for a period of 6 d and results were compared to grab sampling and extraction with Solid Phase Extraction (SPE). In influent waters, MCPS were clogged due to the high amount of suspended solids in these waters. In effluents, MCPS detected cyclophosphamide and mycophenolic acid at concentrations of 19 ± 3 and 136 ± 28 ng L(-1) with a good agreement with the levels obtained by grab sampling. The study discusses the use and performance of the MCPS for the monitoring of stable cytostatic compounds in a complex matrix such as wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Effect of wind on the chemical uptake kinetics of a passive air sampler.

    Science.gov (United States)

    Zhang, Xianming; Brown, Trevor N; Ansari, Amer; Yeun, Beom; Kitaoka, Ken; Kondo, Akira; Lei, Ying D; Wania, Frank

    2013-07-16

    Passive air samplers (PASs) operate in different types of environment under various wind conditions, which may affect sampling rates and thus introduce uncertainty to PAS-derived air concentrations. To quantify the effect of wind speed and angle on the uptake in cylindrical PASs using XAD-resin as the sampling medium, we measured the uptake kinetics of polychlorinated biphenyls (PCBs) in XAD and of water in silica-gel, both under quasi wind-still condition and with lab-generated wind blowing toward the PASs at various speeds and angles. Passive sampling rates (PSRs) of PCBs under laboratory generated windy conditions were approximately 3-4 times higher than under wind-still indoor conditions. The rate of water uptake by silica-gel increased with wind speed, following a logarithmic function so that PSRs are more strongly influenced at lower wind speed. PSRs of both PCBs and water varied little with wind angle, which is consistent with computational fluid dynamic simulations showing that different angles of wind incidence cause only minor variations of air velocities within the cylindrical sampler housing. Because modifications of the design of the cylindrical PAS were not successful in eliminating the wind speed dependence of PSRs at low wind levels, indoor and outdoor deployments require different sets of PSRs. The effect of wind speed and angle on the PSRs of the cylindrical PAS are much smaller than what has been reported for the double-bowl polyurethane foam PAS. PSRs of the cylindrical XAD-PAS therefore tend to vary much less between sampling sites exposed to different wind conditions.

  3. Electrical Conductivity and Chemical Composition of Soil Solution: Comparison of Solution Samplers in Tropical Soils

    Directory of Open Access Journals (Sweden)

    Davi Lopes do Carmo

    2016-01-01

    Full Text Available ABSTRACT Soil solution samplers may have the same working principle, but they differ in relation to chemical and physical characteristics, cost and handling, and these aspects exert influence on the chemical composition of the soil solution obtained. This study was carried out to evaluate, over time, the chemical composition of solutions extracted by Suolo Acqua, with the hydrophilic membrane (HM as a standard, using soils with contrasting characteristics, and to determine the relationship between electrical conductivity (EC and concentration of ions and pH of soil solution samples. This study was carried out under laboratory conditions, using three soils samples with different clay and organic matter (OM contents. Soil solution contents of F−, Cl−, NO−3, Br−, SO42−, Na+, NH4+, K+, Mg2+, Ca2+, were analyzed, as well as inorganic, organic, and total C contents, pH, and EC, in four successive sampling times. Soil solution chemical composition extracted by the Suolo Acqua sampler is similar to that collected by the HM, but the Suolo Acqua extracted more Na+ and soluble organic C than the HM solution. Solution EC, cation and anion concentrations, and soluble C levels are higher in the soil with greater clay and OM contents (Latossolo and Cambissolo in this case. Soil solution composition varied over time, with considerable changes in pH, EC, and nutrient concentrations, especially associated with soil OM. Thus, single and isolated sampling of the soil solution must be avoided, otherwise composition of the soil solution may not be correctly evaluated. Soil solution EC was regulated by pH, as well as the sum of cation and anion concentrations, and the C contents determined in the soil liquid phase.

  4. A sample-freezing drive shoe for a wire line piston core sampler

    Science.gov (United States)

    Murphy, F.; Herkelrath, W.N.

    1996-01-01

    Loss of fluids and samples during retrieval of cores of saturated, noncohesive sediments results in incorrect measures of fluid distributions and an inaccurate measure of the stratigraphic position of the sample. To reduce these errors, we developed a hollow drive shoe that freezes in place the lowest 3 inches (75 mm) of a 1.88-inch-diameter (48 mm), 5-foot-long (1.5 m) sediment sample taken using a commercial wire line piston core sampler. The end of the core is frozen by piping liquid carbon dioxide at ambient temperature through a steel tube from a bottle at the land surface to the drive shoe where it evaporates and expands, cooling the interior surface of the shoe to about -109??F (-78??C). Freezing a core end takes about 10 minutes. The device was used to collect samples for a study of oil-water-air distributions, and for studies of water chemistry and microbial activity in unconsolidated sediments at the site of an oil spill near Bemidji, Minnesota. Before freezing was employed, samples of sandy sediments from near the water table sometimes flowed out of the core barrel as the sampler was withdrawn. Freezing the bottom of the core allowed for the retention of all material that entered the core barrel and lessened the redistribution of fluids within the core. The device is useful in the unsaturated and shallow saturated zones, but does not freeze cores well at depths greater than about 20 feet (6 m) below water, possibly because the feed tube plugs with dry ice with increased exhaust back-pressure, or because sediment enters the annulus between the core barrel and the core barrel liner and blocks the exhaust.

  5. Human breath metabolomics using an optimized non-invasive exhaled breath condensate sampler.

    Science.gov (United States)

    Zamuruyev, Konstantin O; Aksenov, Alexander A; Pasamontes, Alberto; Brown, Joshua F; Pettit, Dayna R; Foutouhi, Soraya; Weimer, Bart C; Schivo, Michael; Kenyon, Nicholas J; Delplanque, Jean-Pierre; Davis, Cristina E

    2016-12-22

    Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube(™) and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017).

  6. Quartz in coal dust deposited on internal surface of respirable size selective samplers.

    Science.gov (United States)

    Soo, Jhy-Charm; Lee, Taekhee; Kashon, Michael; Kusti, Mohannad; Harper, Martin

    2014-01-01

    The objective of the present study is to quantify quartz mass in coal dust deposited on the internal cassette surface of respirable size-selective samplers. Coal dust was collected with four different respirable size-selective samplers (10 mm Dorr-Oliver nylon [Sensidyne, St. Petersburg, Fla.], SKC Aluminum [SKC Inc., Eighty Four, Pa.], BGI4L [BGI USA Inc., Waltham, Mass.], and GK2.69 cyclones [BGI USA Inc.]) with two different cassette types (polystyrene and static-dissipative polypropylene cassettes). The coal dust was aerosolized in a calm air chamber by using a fluidized bed aerosol generator without neutralization under the assumption that the procedure is similar to field sampling conditions. The mass of coal dust was measured gravimetrically and quartz mass was determined by Fourier transform infrared spectroscopy according to the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods, Method 7603. The mass fractions of the total quartz sample on the internal cassette surface are significantly different between polystyrene and static-dissipative cassettes for all cyclones (p quartz mass on cassette internal surface and coal dust filter mass was observed. The BGI4L cyclone showed a higher (but not significantly) and the GK2.69 cyclone showed a significantly lower (p quartz mass fraction for polystyrene cassettes compared to other cyclones. This study confirms previous observations that the interior surface deposits in polystyrene cassettes attached to cyclone pre-selectors can be a substantial part of the sample, and therefore need to be included in any analysis for accurate exposure assessment. On the other hand, the research presented here supports the position that the internal surface deposits in static-dissipative cassettes used with size-selective cyclones are negligible and that it is only necessary to analyze the filter catch.

  7. Sampling medium side resistance to uptake of semivolatile organic compounds in passive air samplers.

    Science.gov (United States)

    Zhang, Xianming; Tsurukawa, Masahiro; Nakano, Takeshi; Lei, Ying D; Wania, Frank

    2011-12-15

    Current theory of the uptake of semivolatile organic compounds in passive air samplers (PAS) assumes uniform chemical distribution and no kinetic resistance within the passive sampling media (PSM) such as polystyrene-divinylbenzene resin (XAD) and polyurethane foam (PUF). However, these assumptions have not been tested experimentally and are challenged by some recently reported observations. To test the assumptions, we performed kinetic uptake experiments indoors using cylindrical PSM that had been concentrically segmented into three layers. Both XAD and PUF were positioned in the same type of sampler housing to eliminate the variation caused by the different housing designs, which enabled us to quantify differences in uptake caused by the properties of the PSM. Duplicated XAD (PUF) samples were retrieved after being deployed for 0, 1 (0.5), 2 (1), 4 (2), 8 (4), 12 (8), and 24 (12) weeks. Upon retrieval, the PSM layers were separated and analyzed individually for PCBs. Passive sampling rates (R) were lower for heavier PCB homologues. Within a homologue group, R for XAD was higher than that for PUF, from which we infer that the design of the "cylindrical can" housing typically used for XAD PAS lowers the R compared to the "double bowl" shelter commonly used for PUF-disk PAS. Outer layers of the PSM sequestered much higher levels of PCBs than inner layers, indicative of a kinetic resistance to chemical transfer within the PSM. The effective diffusivities for chemical transfer within PSM were derived and were found negatively correlated with the partition coefficients between the PSM and air. Based on the results, we conclude that the PSM-side kinetic resistance should be considered when investigating factors influencing R and when deriving R based on the loss of depuration compounds.

  8. Water-quality data from semipermeable-membrane devices and polar organic chemical integrative samplers deployed in the McKenzie River basin, Oregon

    Science.gov (United States)

    McCarthy, Kathleen A.; Alvarez, David A.

    2012-01-01

    Two types of passive samplers—the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS)—are being used to collect data from the McKenzie River, Oregon. The McKenzie River is the source of drinking water for the City of Eugene, Oregon, and passive-sampler data are part of an ongoing monitoring effort designed to help understand and protect the drinking water source. Data from the passive samplers are reported here. This data report is dynamic and will be appended with additional data as they become available.

  9. Circumcision revision in male children

    Directory of Open Access Journals (Sweden)

    Mohammed A. Al-Ghazo

    2006-08-01

    Full Text Available OBJECTIVE: To determine indications for circumcision revision and to identify the specialty of the person who performed unsatisfactory primary circumcision. MATERIALS AND METHODS: The authors reviewed medical records of 52 cases that underwent circumcision revision over a 6-year period (1998 to 2004. Sleeve surgical technique was used for revision in patients with redundant foreskin or concealed penis, penoplasty for partial or complete degloving of the penis and meatotomy for external meatal stenosis. The mean age of children was 32 months (range 6 months to 9 years. RESULTS: Most of unsatisfactory primary circumcisions (86.7% were performed by laymen. All patients who underwent circumcision revision had good to excellent cosmetic results. CONCLUSION: Primary circumcision performed by laymen carry a high complication rate and serious complications may occur. A period of training and direct supervision by physicians is required before allowing laymen to perform circumcision independently.

  10. Membrane assisted passive sampler for triazine compounds in water bodies--characterization of environmental conditions and field performance.

    Science.gov (United States)

    Nyoni, Hlengilizwe; Chimuka, Luke; Vrana, Branislav; Cukrowska, Ewa

    2011-05-23

    In this work, a simple, inexpensive and very selective membrane assisted passive sampler (MAPS) that does not use organic solvents, based on a thin walled silicone hollow fibre membrane for extraction of ionizable organic compounds in water bodies is reported. The potential for passive sampling of basic compounds is demonstrated. By changing the acceptor solution from acidic to basic conditions, the MAPS can be successfully used to extract acidic organic compound. The influence of environmental factors such as temperature, sample matrix and hydrodynamics on enrichment factors and sampling rates have been investigated in order to calibrate the passive sampler for measurement of TWA concentration of triazines. The selectivity, extraction efficiency and enrichment factor of the developed sampler has been compared to the Chemcatcher passive sampler. It was found that the chemical uptake of basic triazine compounds into the passive sampler remained linear and integrative throughout the 7 days exposure periods. For atrazine, propazine, prometryne and terbutryne a large 3 days time lag was experienced. A plot of natural logarithms of the amount taken up by the sampler against exposure time gave linear relationship for these compounds. The sampling rates for individual triazine compounds increased with change of hydrodynamic conditions from static to turbulent. The presence of 20 mg L(-1) humic substances in solution was found to have no significant effect on the concentration of compounds trapped in the acceptor solution. Once these compounds are trapped in the acceptor solution they do not diffuse back during the deployment period. A strong dependence of the sampling rates on the type of protective cover used was noted. Stainless steel protective cover was found to be the better than the iron mesh as it did not rust during deployment. The detection limits on HPLC with UV detection ranged from 0.50 to 4.50 μg L(-1) for MAPS, 0.40 to 3.50 μg L(-1) for Chemcatcher passive

  11. Diana Reference Manual. Revision 3,

    Science.gov (United States)

    1983-02-28

    private -To be filled in... ead Diana ; External Representation of DIANA Page 145 CHAPTER 5 EXTERNAL REPRESENTATION OF DIANA This chapter describes how a...1 1 mml L.~ 2 .i i .- . .... c7- 0/0 04 TARTAN LABORATOR4IES *dOORPORATED 00 N DIANA REFERENCE MANUAL Revision 3 Arthur Evans Jr. MCC Kenneth J...Butler Tartan Laboratories Incorporated Editors. Revised Diana Reference Manual G0. GOOD Inatitut fuer Informatik 11. Universitmet Karlsruhe Win. A. Wuif

  12. Trust Revision for Conflicting Sources

    Science.gov (United States)

    2017-02-01

    analyst wants to include the realistic possibility that there can be rain and sunshine simultaneously, then the domain would need to include a...tative and idempotent; but it is not associative. IV. TRUST DISCOUNTING The general idea behind trust discounting is to express degrees of trust in an...A:C X is revised. Trust revision consists of increasing distrust at the cost of trust and uncertainty. The idea is that sources found to be unreliable

  13. Revision by comparison as a unifying framework: Severe withdrawal, irrevocable revision and irrefutable revision

    National Research Council Canada - National Science Library

    Rott, Hans

    2006-01-01

    ... has both characteristics of belief contraction (with respect to the ‘reference sentence’) and characteristics of belief revision (with respect to the ‘input sentence’). Using...

  14. Benthic organisms collected using sediment sampler from the EXCELLENCE and other platforms in the Gulf of Mexico from 09 December 1981 to 26 August 1985 (NODC Accession 8400043)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE and other platforms in the Gulf of Mexico from 09 December 1981 to 26 August 1985....

  15. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico from 23 October 1980 to 18 February 1981 (NODC Accession 8100566)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 23 October 1980 to 18 February 1981. Data were submitted...

  16. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico from 26 April 1979 to 19 November 1979 (NODC Accession 8000502)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 26 April 1979 to 19 November 1979. Data were submitted...

  17. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico from 22 May 1980 to 25 July 1980 (NODC Accession 8100456)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 22 May 1980 to 25 July 1980. Data were submitted by the...

  18. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico from 18 January 1980 to 04 November 1980 (NODC Accession 8100223)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 18 January 1980 to 04 November 1980. Data were submitted...

  19. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico for 1979-12-19 (NODC Accession 8000603)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 19 December 1979 to 19 December 1979. Data were...

  20. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico from 30 July 1979 to 16 December 1979 (NODC Accession 8000523)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 30 July 1979 to 16 December 1979. Data were submitted by...

  1. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico for 1980-01-28 (NODC Accession 8000602)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 28 January 1980 to 28 January 1980. Data were submitted...

  2. Benthic organisms collected using sediment sampler from the SW RESEARCHER in the Gulf of Mexico from 22 September 1977 to 16 December 1977 (NODC Accession 8100224)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the SW RESEARCHER in the Gulf of Mexico from 22 September 1977 to 16 December 1977. Data were...

  3. Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico from 31 March 1980 to 02 July 1980 (NODC Accession 8100471)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 31 March 1980 to 02 July 1980. Data were submitted by...

  4. Zooplankton, chemical, and other data collected from net, sediment sampler, and other instruments from 01 July 1970 to 01 March 1972 in the Great Lakes (NODC Accession 7200691)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton, chemical, and other data were collected using net, sediment sampler, and other instruments in the Great Lakes. Data were collected from 01 July 1970 to...

  5. A method for targeting air samplers for facility monitoring in an urban environment

    Science.gov (United States)

    Bieringer, Paul E.; Longmore, Scott; Bieberbach, George; Rodriguez, Luna M.; Copeland, Jeff; Hannan, John

    2013-12-01

    There are a variety of applications that require the use of comprehensive specification of the weather conditions combined with an analysis that uses detailed modeling and simulation. The combination of these two elements can make it difficult to achieve the desired level of fidelity in a logistically feasible way. An example of this type of application is the deployment of surface-based sensors/samplers, which is a common practice for emission, and air quality monitoring purposes where the proper selection of sites for the measurement equipment is critical to an accurate characterization of the emissions. This is particularly true in urban environments where the limited availability of suitable sites and the non-intuitive dispersion patterns associated with the wind flow around the buildings and through the urban canyons make site selection difficult. This article demonstrates an improved methodology for optimally locating for air quality monitoring equipment within this complex and challenging environment. The methodology involves a) the utilization of a longer climatological record of meteorological observations or gridded reanalysis products to better represent the full range of representative meteorological conditions; b) reduction of the full climatological record into a subset of characteristic meteorological patterns and associated frequencies of occurrence, utilizing a multi-dimensional feature extraction and classification technique known as a Self Organizing Map (SOM); c) downscaling and diagnosis of the urban area building-aware wind flow fields for each characteristic meteorological pattern; d) atmospheric transport and dispersion (AT&D) simulations for each downscaled meteorological pattern, utilizing a building aware Lagrangian particle dispersion model; and finally e) the combination of predicted downwind concentrations/dosages for each meteorological pattern with their associated frequency of occurrence are used to generate Probability of Detection

  6. Terahertz-dependent evaluation of water content in high-water-cut crude oil using additive-manufactured samplers

    Science.gov (United States)

    Guan, LiMei; Zhan, HongLei; Miao, XinYang; Zhu, Jing; Zhao, Kun

    2017-04-01

    The evaluation of water content in crude oil is of significance to petroleum exploration and transportation. Terahertz (THz) waves are sensitive to fluctuations in the dipole moment of water. However, due to the strong absorption of water in the THz range, it is difficult for the THz spectrum to determine high water content with the common sampler. In this research, micron-grade samplers for THz detection were designed and manufactured using additive manufacturing (AM) technology. Oil-water mixtures with water content from 1.8% to 90.6% were measured with the THz-TDS system using sample cells. In addition, a detailed analysis was performed of the relationships among THz parameters such as signal peak, time delay, and refractive index as well as absorption coefficient and high water content (>60%). Results suggest that the combination of THz spectroscopy and AM technique is effective for water content evaluation in crude oil and can be further applied in the petroleum industry.

  7. Exploiting lipid-free tubing passive samplers and embryonic zebrafish to link site specific contaminant mixtures to biological responses.

    Science.gov (United States)

    Hillwalker, Wendy E; Allan, Sarah E; Tanguay, Robert L; Anderson, Kim A

    2010-03-01

    The Biological Response Indicator Devices Gauging Environmental Stressors (BRIDGES) bio-analytical tool was developed in response to the need for a quantitative technology for assessing the toxicity of environmentally relevant contaminant mixtures. This tool combines passive samplers with the embryonic zebrafish model. When applied in an urban river it effectively linked site specific, bioavailable contaminant mixtures to multiple biological responses. Embryonic zebrafish exposed to extracts from lipid-free passive samplers that were deployed at five locations, within and outside of the Portland Harbor Superfund Megasite, displayed different responses. Six of the eighteen biological responses observed in 941 exposed zebrafish were significantly different between sites. This demonstrates the sensitivity of the bio-analytical tool for detecting spatially distinct toxicity in aquatic systems; bridging environmental exposure to biological response. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Comparison of speciation sampler and PC-BOSS fine particulate matter organic material results obtained in Lindon, Utah, during winter 2001-2002.

    Science.gov (United States)

    Carter, Cory; Eatough, Norman L; Eatough, Delbert J; Olson, Neal; Long, Russell W

    2008-01-01

    The Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) has been previously verified as being capable of measuring total fine particulate matter (PM2.5), including semi-volatile species. The present study was conducted to determine if the simple modification of a commercial speciation sampler with a charcoal denuder followed by a filter pack containing a quartz filter and a charcoal-impregnated glass (CIG) fiber filter would allow for the measurement of total PM2.5, including semi-volatile organic material. Data were collected using an R&P (Rupprecht and Pastasnik Co., Inc.) Partisol Model 2300 speciation sampler; an R&P Partisol speciation sampler modified with a BOSS denuder, followed by a filter pack with a quartz and a CIG filter; a Met One spiral aerosol speciation sampler (SASS); and the PC-BOSS from November 2001 to March 2002 at a U.S. Environmental Protection Agency (EPA) Science to Achieve Results (STAR) sampling site in Lindon, UT. Total PM2.5 mass, ammonium nitrate (both nonvolatile and semi-volatile), ammonium sulfate, organic carbon (both non-volatile and semi-volatile), and elemental carbon were determined on a 24-hr basis. Results obtained with the individual samplers were compared to determine the capability of the modified R&P speciation sampler for measuring total PM2.5, including semi-volatile components. Data obtained with the modified speciation sampler agreed with the PC-BOSS results. Data obtained with the two unmodified speciation samplers were low by an average of 26% because of the loss of semi-volatile organic material from the quartz filter during sample collection.

  9. Characteristics of Twenty-Nine Aerosol Samplers Tested at U.S. Army Edgewood Chemical Biological Center (2000-2006)

    Science.gov (United States)

    2011-02-01

    polycarbonate membrane type collection filter. The filter where particles are collected is contained on a reel, which automatically advances to the...wetted wall cyclone (or a contactor ) for aerosol collection. The sampler is packaged in a suitcase with a handle for easy carrying. This test was started...wall cyclone ( contactor ). Air enters the contactor through two narrow slits. The unit retains the water in the contactor and does not produce a

  10. WHATS-3: An improved flow-through multi-bottle fluid sampler for deep-sea geofluid research

    OpenAIRE

    Miyazaki, Junichi; Makabe, Akiko; Matsui, Yohei; Ebina, Naoya; Tsutsumi, Saki; Ishibashi, Jun-Ichiro; Chen, Chong; Kaneko, Sho; Takai, Ken; KAWAGUCCI, Shinsuke

    2017-01-01

    Deep-sea geofluid systems, such as hydrothermal vents and cold seeps, are key to understanding subseafloor environments of Earth. Fluid chemistry, especially, provides crucial information toward elucidating the physical, chemical, and biological processes that occur in these ecosystems. To accurately assess fluid and gas properties of deep-sea geofluids, well-designed pressure-tight fluid samplers are indispensable and as such they are important assets of deep-sea geofluid research. Here, the...

  11. WHATS-3: An Improved Flow-Through Multi-bottle Fluid Sampler for Deep-Sea Geofluid Research

    OpenAIRE

    Junichi Miyazaki; Akiko Makabe; Yohei Matsui; Naoya Ebina; Saki Tsutsumi; Jun-ichiro Ishibashi; Chong Chen; Sho Kaneko; Ken Takai; Shinsuke Kawagucci

    2017-01-01

    Deep-sea geofluid systems, such as hydrothermal vents and cold seeps, are key to understanding subseafloor environments of Earth. Fluid chemistry, especially, provides crucial information toward elucidating the physical, chemical, and biological processes that occur in these ecosystems. To accurately assess fluid and gas properties of deep-sea geofluids, well-designed pressure-tight fluid samplers are indispensable and as such they are important assets of deep-sea geofluid research. Here, the...

  12. Using Passive Polyethylene Samplers to Evaluate Chemical Activities Controlling Fluxes and Bioaccumulation of Organic Contaminants in Bed Sediments

    Science.gov (United States)

    2010-11-01

    Figure 10. Profile of pyrene activities (= pore water concentration normalized by pyrene’s liquid solubility of 900 µg/L) across the sediment-water...chemical activities (pore water concentration normalized by pyrene’s liquid solubility ) measured in pore waters using PE passive samplers (green...carbonates before CHN analysis. Three analyses of each sediment sub-sample were performed for each of the two measurements (foc and fbc). Acetanilide

  13. Development of a thoracic personal sampler system for co-sampling of sulfuric acid mist and sulfur dioxide gas.

    Science.gov (United States)

    Chien, Chih-Hsiang; Theodore, Alexandros; Zhou, Chufan; Wu, Chang-Yu; Hsu, Yu-Mei; Birky, Brian

    2017-07-01

    A novel personal sampler was designed to measure inorganic acid mists and gases for determining human exposure levels to these acids in workplaces. This sampler consists of (1) a parallel impactor for classifying aerosol by size following the ISO/CEN/ACGIH defined human thoracic fraction, (2) a cellulose filter to collect the residual acid mist but allowing penetration of sulfur dioxide gas, and (3) an accordion-shaped porous membrane denuder (aPMD) for adsorbing the penetrating sulfur dioxide gas. Acid-resistant PTFE was chosen as the housing material to minimize sampling interference. To test the performance of the parallel impactor, monodisperse aerosol was created by a vibrating orifice aerosol generator. The results showed that the penetration curve of the impactor run at 2 LPM flow rate agreed well with the defined thoracic fraction. Almost all sampling biases were within 10% for particle size distributions with MMAD between 1-25 µm and GSD between 1.75-4, which meets the criteria of the EN 13205 standard. To evaluate the performance of the aPMDs, sulfur dioxide gas was sourced directly from a cylinder. The aPMDs maintained a gas collection efficiency greater than 95% for 4 hr when sampling 8.6 ppm of sulfur dioxide gas. While the aPMD had similar performance to the commonly adopted annular or honeycomb denuders made of glass, this shatterproof aPMD is only half of the volume and 1/25 th the weight of the honeycomb denuder. Testing of the entire sampler with a mixture of sulfuric acid mist and sulfur dioxide gas showed the system could sample both with negligible interference. All the test results illustrate that the new sampler, which is flat, lightweight, and portable, is suitable for personal use and is capable of a more accurate assessment of human exposure to inorganic acid mist and SO 2 gas.

  14. A population-based exposure assessment methodology for carbon monoxide: Development of a carbon monoxide passive sampler and occupational dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G. [Univ. of California, Berkeley, CA (United States)

    1997-09-01

    Two devices, an occupational carbon monoxide (CO) dosimeter (LOCD), and an indoor air quality (IAQ) passive sampler were developed for use in population-based CO exposure assessment studies. CO exposure is a serious public health problem in the U.S., causing both morbidity and mortality (lifetime mortality risk approximately 10{sup -4}). Sparse data from population-based CO exposure assessments indicate that approximately 10% of the U.S. population is exposed to CO above the national ambient air quality standard. No CO exposure measurement technology is presently available for affordable population-based CO exposure assessment studies. The LOCD and IAQ Passive Sampler were tested in the laboratory and field. The palladium-molybdenum based CO sensor was designed into a compact diffusion tube sampler that can be worn. Time-weighted-average (TWA) CO exposure of the device is quantified by a simple spectrophotometric measurement. The LOCD and IAQ Passive Sampler were tested over an exposure range of 40 to 700 ppm-hours and 200 to 4200 ppm-hours, respectively. Both devices were capable of measuring precisely (relative standard deviation <20%), with low bias (<10%). The LOCD was screened for interferences by temperature, humidity, and organic and inorganic gases. Temperature effects were small in the range of 10°C to 30°C. Humidity effects were low between 20% and 90% RH. Ethylene (200 ppm) caused a positive interference and nitric oxide (50 ppm) caused a negative response without the presence of CO but not with CO.

  15. Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods

    Science.gov (United States)

    Coes, Alissa L.; Paretti, Nicholas V.; Foreman, William T.; Iverson, Jana L.; Alvarez, David A.

    2014-01-01

    A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

  16. Rayleigh's Scattering Revised

    Science.gov (United States)

    Kolomiets, Sergey; Gorelik, Andrey

    Mie’s waves while sounding within coincident volumes. Being sensitive to the size of scatters, Mie’s waves can give us additional information about particle size distribution. But how about using several wavelengths corresponding to Rayleigh’s diffraction on scatters only? Can any effects be detected in such a case and what performance characteristics of the equipment are required to detect them? The deceptive simplicity of the negative answer to the first part of the question posed will disappear if one collects different definitions of Rayleigh's scattering and consider them more closely than usually. Several definitions borrowed from the introductory texts and most popular textbooks and articles can be seen as one of the reasons for the research presented in the report. Hopefully, based on the comparison of them all, anyone could easily conclude that Rayleigh's scattering has been analyzed extensively, but despite this extensive analysis made fundamental ambiguities in introductory texts are not eliminated completely to date. Moreover, there may be found unreasonably many examples on how these ambiguities have already caused an error to be foreseen, published on the one article, amplified in another one, then cited with approval in the third one, before being finally corrected. Everything indicated that in the light of all the lesions learned and based on modern experimental data, it is time to address these issues again. After the discussion of ambiguities of Rayleigh's scattering concepts, the development of the corrections to original ideas looks relatively easy. In particular, there may be distinguished at least three characteristic regions of the revised models application from the point of view of the scattered field statistical averaging. The authors of the report suggest naming them Rayleigh’s region, Einstein’s region and the region with compensations of the scattering intensity. The most important fact is that the limits of applicability of all

  17. Effect of housing geometry on the performance of Chemcatcher{sup TM} passive sampler for the monitoring of hydrophobic organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Lobpreis, Tomas [Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, 81237 Bratislava (Slovakia); Vrana, Branislav [Water Research Institute, Nabr. arm. gen. L. Svobodu 7, 81249 Bratislava (Slovakia)], E-mail: branovrana@gmail.com; Dominiak, Ewa [Department of Analytical Chemistry, Chemical Faculty, Gdansk University of Technology, 80 952 Gdansk, G. Narutowicza 11/12 (Poland); Dercova, Katarina [Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, 81237 Bratislava (Slovakia); Mills, Graham A. [School of Pharmacy and Biomedical Sciences, University of Portsmouth, St Michael' s Building, White Swan Road, Portsmouth PO1 2DT (United Kingdom); Greenwood, Richard [School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth PO1 2DY (United Kingdom)

    2008-06-15

    Passive sampling of pollutants in water has been gaining acceptance for environmental monitoring. Previously, an integrative passive sampler (the Chemcatcher{sup TM}) was developed and calibrated for the measurement of time weighted average concentrations of hydrophobic pollutants in water. Effects of physicochemical properties and environmental variables (water temperature and turbulence) on kinetic and thermodynamic parameters characterising the exchange of analytes between the sampler and water have been published. In this study, the effect of modification in sampler housing geometry on these calibration parameters was studied. The results obtained for polycyclic aromatic hydrocarbons show that reducing the depth of the cavity in the sampler body geometry increased the exchange kinetics by approximately twofold, whilst having no effect on the correlation between the uptake and offload kinetics of analytes. The use of performance reference compounds thus avoids the need for extensive re-calibration when the sampler body geometry is modified. - The effect of passive sampler geometry on accumulation kinetics of organic pollutants from water was evaluated.

  18. Pesticide impact on aquatic invertebrates identified with Chemcatcher® passive samplers and the SPEAR(pesticides) index.

    Science.gov (United States)

    Münze, Ronald; Orlinskiy, Polina; Gunold, Roman; Paschke, Albrecht; Kaske, Oliver; Beketov, Mikhail A; Hundt, Matthias; Bauer, Coretta; Schüürmann, Gerrit; Möder, Monika; Liess, Matthias

    2015-12-15

    Pesticides negatively affect biodiversity and ecosystem function in aquatic environments. In the present study, we investigated the effects of pesticides on stream macroinvertebrates at 19 sites in a rural area dominated by forest cover and arable land in Central Germany. Pesticide exposure was quantified with Chemcatcher® passive samplers equipped with a diffusion-limiting membrane. Ecological effects on macroinvertebrate communities and on the ecosystem function detritus breakdown were identified using the indicator system SPEARpesticides and the leaf litter degradation rates, respectively. A decrease in the abundance of pesticide-vulnerable taxa and a reduction in leaf litter decomposition rates were observed at sites contaminated with the banned insecticide Carbofuran (Toxic Units≥-2.8), confirming the effect thresholds from previous studies. The results show that Chemcatcher® passive samplers with a diffusion-limiting membrane reliably detect ecologically relevant pesticide pollution, and we suggest Chemcatcher® passive samplers and SPEARpesticides as a promising combination to assess pesticide exposure and effects in rivers and streams. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Solid phase microextraction devices prepared on plastic support as potential single-use samplers for bioanalytical applications.

    Science.gov (United States)

    Reyes-Garcés, Nathaly; Bojko, Barbara; Hein, Dietmar; Pawliszyn, Janusz

    2015-10-06

    This study presents new thin-film solid phase microextraction (SPME) devices prepared on plastic as potential single-use samplers for bioanalysis. Polybutylene terephthalate (PBT) was selected as a support due to its well-known chemical resistance, low cost, and suitability as a material for different medical grade components. The herein proposed samplers were prepared by applying a hydrophilic-lipophilic balanced (HLB)-polyacrylonitrile (PAN) coating on rounded and flat PBT pieces previously sanded with regular sandpaper. SPME devices prepared on PBT were evaluated in terms of robustness, chemical stability, and possible interferences upon exposure to different solvents and matrixes. Rewarding results were found when these samplers were employed for the quantitative analysis of multiple doping substances in common biological matrixes such as urine, plasma, and whole blood. Finally, the proposed thin-film SPME devices made on a PBT were evaluated by conducting multiple extractions from whole blood and plasma using the Concept 96 system. Results showed that more than 20 extractions from plasma and whole blood can be performed without observed decreases in coating performance or peeling of the extraction phase from the plastic surface. These findings demonstrate the robustness of PAN-based coatings applied on such polymeric substrate and open up the possibility of introducing new alternatives and cost-effective materials as support to manufacture SPME biocompatible devices for a wide range of applications, particularly in the clinical field.

  20. The creation of pollution mapping and measurement of ambient concentration of sulfur dioxide and nitrogen dioxide with passive sampler.

    Science.gov (United States)

    Akdemir, Andaç

    2014-01-01

    Measurements of nitrogen and sulfur dioxide using passive sampler over 12 months in Samsun, Turkey, are compared with SO2 and NO2 concentrations obtained from a co-located chemiluminescence analyzer. The concentrations of Sulfur and nitrogen dioxide in the ambient air during the period from November 2009 to September 2010 are analyzed. The highest value for annual NO2 and SO2 averages of passive sampler was 29.65 μg/m(3) and 21.01 μg/m(3) for exposures of 2-weeks at an industrial site. The maximum monthly concentration for SO2 was observed at the 10(th) measurement station with 44.19 μg/m(3) for August. The maximum monthly concentration for NO2 was observed on the 3(rd) measurement station with 42.83 μg/m(3) for November. A negative correlation between nitrogen dioxide concentrations and temperature (R(2) = -0.5489) was estimated. A positive correlation between nitrogen dioxide measurement with passive sampler and continuous measurement (R(2) = 0.6571) was estimated.

  1. A minimally invasive micro sampler for quantitative sampling with an ultrahigh-aspect-ratio microneedle and a PDMS actuator.

    Science.gov (United States)

    Liu, Long; Wang, Yan; Yao, Jinyuan; Yang, Cuijun; Ding, Guifu

    2016-08-01

    This study describes a novel micro sampler consisting of an ultrahigh-aspect-ratio microneedle and a PDMS actuator. The microneedle was fabricated by a new method which introduced reshaped photoresist technology to form a flow channel inside. The microneedle includes two parts: shaft and pedestal. In this study, the shaft length is 1500 μm with a 45° taper angle on the tip and pedestal is 1000 μm. Besides, the shaft and pedestal are connected by an arc connection structure with a length of 600 μm. The microneedles have sufficient mechanical strength to insert into skin with a wide safety margin which was proved by mechanics tests. Moreover, a PDMS actuator with a chamber inside was designed and fabricated in this study. The chamber, acting as a reservoir in sampling process as well as providing power, was optimized by finite element analysis (FEA) to decrease dead volume and improve sampling precision. The micro sampler just needs finger press to activate the sampling process as well as used for quantitative micro injection to some extent. And a volume of 31.5 ± 0.8 μl blood was successfully sampled from the ear artery of a rabbit. This micro sampler is suitable for micro sampling for diagnose or therapy in biomedical field.

  2. Modeling the transport of organic chemicals between polyethylene passive samplers and water in finite and infinite bath conditions.

    Science.gov (United States)

    Tcaciuc, A Patricia; Apell, Jennifer N; Gschwend, Philip M

    2015-12-01

    Understanding the transfer of chemicals between passive samplers and water is essential for their use as monitoring devices of organic contaminants in surface waters. By applying Fick's second law to diffusion through the polymer and an aqueous boundary layer, the authors derived a mathematical model for the uptake of chemicals into a passive sampler from water, in finite and infinite bath conditions. The finite bath model performed well when applied to laboratory observations of sorption into polyethylene (PE) sheets for various chemicals (polycyclic aromatic hydrocarbons, polychlorinated biphenyls [PCBs], and dichlorodiphenyltrichloroethane [DDT]) and at varying turbulence levels. The authors used the infinite bath model to infer fractional equilibration of PCB and DDT analytes in field-deployed PE, and the results were nearly identical to those obtained using the sampling rate model. However, further comparison of the model and the sampling rate model revealed that the exchange of chemicals was inconsistent with the sampling rate model for partially or fully membrane-controlled transfer, which would be expected in turbulent conditions or when targeting compounds with small polymer diffusivities and small partition coefficients (e.g., phenols, some pesticides, and others). The model can be applied to other polymers besides PE as well as other chemicals and in any transfer regime (membrane, mixed, or water boundary layer-controlled). Lastly, the authors illustrate practical applications of this model such as improving passive sampler design and understanding the kinetics of passive dosing experiments. © 2015 SETAC.

  3. Improved evaluation of measurement uncertainty from sampling by inclusion of between-sampler bias using sampling proficiency testing.

    Science.gov (United States)

    Ramsey, Michael H; Geelhoed, Bastiaan; Wood, Roger; Damant, Andrew P

    2011-04-07

    A realistic estimate of the uncertainty of a measurement result is essential for its reliable interpretation. Recent methods for such estimation include the contribution to uncertainty from the sampling process, but they only include the random and not the systematic effects. Sampling Proficiency Tests (SPTs) have been used previously to assess the performance of samplers, but the results can also be used to evaluate measurement uncertainty, including the systematic effects. A new SPT conducted on the determination of moisture in fresh butter is used to exemplify how SPT results can be used not only to score samplers but also to estimate uncertainty. The comparison between uncertainty evaluated within- and between-samplers is used to demonstrate that sampling bias is causing the estimates of expanded relative uncertainty to rise by over a factor of two (from 0.39% to 0.87%) in this case. General criteria are given for the experimental design and the sampling target that are required to apply this approach to measurements on any material. © The Royal Society of Chemistry 2011

  4. Concentration and movement of neonicotinoids as particulate matter downwind during agricultural practices using air samplers in southwestern Ontario, Canada.

    Science.gov (United States)

    Forero, Luis Gabriel; Limay-Rios, Victor; Xue, Yingen; Schaafsma, Arthur

    2017-12-01

    Atmospheric emissions of neonicotinoid seed treatment insecticides as particulate matter in field crops occur mainly for two reasons: 1) due to abraded dust of treated seed generated during planting using vacuum planters, and 2) as a result of disturbances (tillage or wind events) in the surface of parental soils which release wind erodible soil-bound residues. In the present study, concentration and movement of neonicotinoids as particulate matter were quantified under real conditions using passive and active air samplers. Average neonicotinoid concentrations in Total Suspended Particulate (TSP) using passive samplers were 0.48 ng/cm 2 , trace, trace (LOD 0.80 and 0.04 ng/cm 2 for clothianidin and thiamethoxam, respectively), and using active samplers 16.22, 1.91 and 0.61 ng/m 3 during planting, tillage and wind events, respectively. There was a difference between events on total neonicotinoid concentration collected in particulate matter using either passive or active sampling. Distance of sampling from the source field during planting of treated seed had an effect on total neonicotinoid air concentration. However, during tillage distance did not present an effect on measured concentrations. Using hypothetical scenarios, values of contact exposure for a honey bee were estimated to be in the range from 1.1% to 36.4% of the reference contact LD 50 value of clothianidin of 44 ng/bee. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Side-by-side determination of workers' exposure to wood dust with IOM and open-faced samplers.

    Science.gov (United States)

    Cavlović, Anka Ozana; Beljo Lučić, Ružica; Jug, Matija; Radmanović, Kristijan; Bešlić, Ivan

    2013-09-01

    Woodworkers' exposure to airborne particles is measured with different sampling techniques throughout the world. Due to a great number of exposure data obtained with different samplers, European countries have aimed over the last ten years to find a conversion factor for mass concentrations that would render these measurements comparable. Following the accepted EU standards and regulations, we replaced a 25 mm open-faced (OF) filter holder with an IOM head to determine woodworkers' exposure to inhalable dust and establish an IOM/OF sampler ratio that might serve as a reliable factor for converting the existing OF data to IOM dust mass concentration in the industrial environment. For this side-by-side sampling we used personal 25 mm OF (N=29) and IOM (N=29) sampling heads over eight working hours. The obtained IOM/OF ratios ranged between 0.7 and 2.3. However, mass concentrations obtained by IOM and OF samplers did not significantly differ. Our findings suggest that there is no need for conversion of the existing OF data for workers exposed to wood dust, provided that dust mass concentrations in the working environment range between 1 mg m-3 and 7 mg m-3. Future side-by-side measurements should also involve environments with low wood dust mass concentrations.

  6. Vadose Zone Monitoring of Dairy Green Water Lagoons using Soil Solution Samplers.

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, James R.; Coplen, Amy K

    2005-11-01

    Over the last decade, dairy farms in New Mexico have become an important component to the economy of many rural ranching and farming communities. Dairy operations are water intensive and use groundwater that otherwise would be used for irrigation purposes. Most dairies reuse their process/green water three times and utilize lined lagoons for temporary storage of green water. Leakage of water from lagoons can pose a risk to groundwater quality. Groundwater resource protection infrastructures at dairies are regulated by the New Mexico Environment Department which currently relies on monitoring wells installed in the saturated zone for detecting leakage of waste water lagoon liners. Here we present a proposal to monitor the unsaturated zone beneath the lagoons with soil water solution samplers to provide early detection of leaking liners. Early detection of leaking liners along with rapid repair can minimize contamination of aquifers and reduce dairy liability for aquifer remediation. Additionally, acceptance of vadose zone monitoring as a NMED requirement over saturated zone monitoring would very likely significantly reduce dairy startup and expansion costs. Acknowledgment Funding for this project was provided by the Sandia National Laboratories Small Business Assistance Program

  7. Pine needles as passive bio-samplers to determine polybrominated diphenyl ethers.

    Science.gov (United States)

    Ratola, Nuno; Alves, Arminda; Santos, Lúcia; Lacorte, Silvia

    2011-09-01

    Eight polybrominated diphenyl ethers (PBDEs) were determined in pine needles of three species (Pinus halepensis, Pinus pinea and Pinus nigra) collected in the NE Spain in an attempt to use this matrix for the biomonitoring of airborne PBDEs. The method used was based in ultrasonic extraction followed by alumina and Florisil clean-up and determination by gas chromatography coupled to mass spectrometry in negative chemical ionization. Recoveries were between 99% and 138%, limits of detection between 0.011 and 0.070 ng g(-1)-dw (0.232 ng g(-1)-dw for BDE 209) and repeatability lower than 13%. PBDE levels ranged between 0.027 ng g(-1)-dw and 13.04 ng g(-1)-dw, with predominance of BDE 209, followed by BDEs 47. P. halepensis was the species with the highest PBDE levels and P. nigra, the least, according to their widespread and remote distribution, respectively. The presence of PBDEs in pine needles was attributed to the release of in-use PBDEs, transport through atmosphere and adsorption upon lipid rich pine needles. Given the easy collection of pine needles, its ample distribution and its potential to accumulate airborne contaminants, this matrix is proposed as passive bio-sampler to be used in PBDE monitoring programs. Pine needles can be used to biomonitor airborne PBDEs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Calibration of Passive Samplers for the Monitoring of Pharmaceuticals in Water-Sampling Rate Variation.

    Science.gov (United States)

    Męczykowska, Hanna; Kobylis, Paulina; Stepnowski, Piotr; Caban, Magda

    2017-05-04

    Passive sampling is one of the most efficient methods of monitoring pharmaceuticals in environmental water. The reliability of the process relies on a correctly performed calibration experiment and a well-defined sampling rate (Rs) for target analytes. Therefore, in this review the state-of-the-art methods of passive sampler calibration for the most popular pharmaceuticals: antibiotics, hormones, β-blockers and non-steroidal anti-inflammatory drugs (NSAIDs), along with the sampling rate variation, were presented. The advantages and difficulties in laboratory and field calibration were pointed out, according to the needs of control of the exact conditions. Sampling rate calculating equations and all the factors affecting the Rs value - temperature, flow, pH, salinity of the donor phase and biofouling - were discussed. Moreover, various calibration parameters gathered from the literature published in the last 16 years, including the device types, were tabled and compared. What is evident is that the sampling rate values for pharmaceuticals are impacted by several factors, whose influence is still unclear and unpredictable, while there is a big gap in experimental data. It appears that the calibration procedure needs to be improved, for example, there is a significant deficiency of PRCs (Performance Reference Compounds) for pharmaceuticals. One of the suggestions is to introduce correction factors for Rs values estimated in laboratory conditions.

  9. Design and evaluation of an exhaled breath sampler for biological monitoring of organic solvents.

    Science.gov (United States)

    Periago, J F; Luna, A; Morente, A; Zambudio, A

    1992-04-01

    We designed a breath sampler based on a tube which collects the final portion of exhaled air. The passage of successive fractions through a layer of activated charcoal is controlled by a three-way valve. This system was validated in a controlled atmosphere of n-hexane and toluene at four concentrations between 12 and 110 mg m-3 and 12 and 115 mg m-3, respectively. Uptake volumes of 0.1, 0.2 and 0.31 were tested at relative humidities of 46% and 98%. There were no significant differences in the recoveries obtained under any of the conditions tested. We confirmed the reproducibility between successive samples in volunteers and exposed workers, and found no significant differences between the different sampling conditions studied. Our system enriches the sample in an adsorbent cartridge by collecting successive fractions of end-exhaled breath from one or more exhalations until the amount required by the analytical method has been accumulated. It is portable, economical and highly operative in the field.

  10. [A comparative study between real time monitor KH-3000 and conventional Durham sampler measuring airborne pollen].

    Science.gov (United States)

    Yoda, Shigetoshi; Enomoto, Tadao; Shibano, Akira; Ikeda, Hiroki; Yajin, Shinji; Dake, Yoshihiro; Harada, Tamotsu

    2005-08-01

    Real time monitoring of airborne pollen has gradually increased because monitoring is laborsaving and provides better real-time information. A problem arose, however, due to differences between the KH3000 (Yamato Co. Ltd) monitor and the conventional Durham sampler pointed out in results of airborne pollen monitoring in Wakayama in 2004. We compared the two monitors for airborne pollen in Wakayama in 2004, which less dispersed than usual. The peak monitored by the KH-3000 monitor was not consistent with the prime period of Japanese cedar and cypress pollen dispersion, especially in February and April, although they correlated highly in March. The inconsistency in February is thought to be caused by snow, and that in April by falsely monitoring beech-tree airborne pollen-which is similar in size-in addition to Japanese cedar and cypress pollen. This report points out the need to take these conditions (snow and other plants pollen) into account when a real time monitor is used for collecting pollen information.

  11. Gravimetric Analysis of Particulate Matter using Air Samplers Housing Internal Filtration Capsules.

    Science.gov (United States)

    O'Connor, Sean; O'Connor, Paula Fey; Feng, H Amy; Ashley, Kevin

    2014-10-01

    An evaluation was carried out to investigate the suitability of polyvinyl chloride (PVC) internal capsules, housed within air sampling devices, for gravimetric analysis of airborne particles collected in workplaces. Experiments were carried out using blank PVC capsules and PVC capsules spiked with 0,1 - 4 mg of National Institute of Standards and Technology Standard Reference Material ® (NIST SRM) 1648 (Urban Particulate Matter) and Arizona Road Dust (Air Cleaner Test Dust). The capsules were housed within plastic closed-face cassette samplers (CFCs). A method detection limit (MDL) of 0,075 mg per sample was estimated. Precision S r at 0,5 - 4 mg per sample was 0,031 and the estimated bias was 0,058. Weight stability over 28 days was verified for both blanks and spiked capsules. Independent laboratory testing on blanks and field samples verified long-term weight stability as well as sampling and analysis precision and bias estimates. An overall precision estimate Ŝ rt of 0,059 was obtained. An accuracy measure of ±15,5% was found for the gravimetric method using PVC internal capsules.

  12. Preparation and performance features of wristband samplers and considerations for chemical exposure assessment

    Science.gov (United States)

    Anderson, Kim A; Points, Gary L; Donald, Carey E; Dixon, Holly M; Scott, Richard P; Wilson, Glenn; Tidwell, Lane G; Hoffman, Peter D; Herbstman, Julie B; O'Connell, Steven G

    2017-01-01

    Wristbands are increasingly used for assessing personal chemical exposures. Unlike some exposure assessment tools, guidelines for wristbands, such as preparation, applicable chemicals, and transport and storage logistics, are lacking. We tested the wristband’s capacity to capture and retain 148 chemicals including polychlorinated biphenyls (PCBs), pesticides, flame retardants, polycyclic aromatic hydrocarbons (PAHs), and volatile organic chemicals (VOCs). The chemicals span a wide range of physical–chemical properties, with log octanol–air partitioning coefficients from 2.1 to 13.7. All chemicals were quantitatively and precisely recovered from initial exposures, averaging 102% recovery with relative SD ≤21%. In simulated transport conditions at +30 °C, SVOCs were stable up to 1 month (average: 104%) and VOC levels were unchanged (average: 99%) for 7 days. During long-term storage at −20 °C up to 3 (VOCs) or 6 months (SVOCs), all chemical levels were stable from chemical degradation or diffusional losses, averaging 110%. Applying a paired wristband/active sampler study with human participants, the first estimates of wristband–air partitioning coefficients for PAHs are presented to aid in environmental air concentration estimates. Extrapolation of these stability results to other chemicals within the same physical–chemical parameters is expected to yield similar results. As we better define wristband characteristics, wristbands can be better integrated in exposure science and epidemiological studies. PMID:28745305

  13. Freeze shoe sampler for the collection of hyporheic zone sediments and porewater.

    Science.gov (United States)

    Bianchin, M; Smith, L; Beckie, R

    2015-01-01

    The Starr and Ingleton (1992) drive point piston sampler (DPPS) design was modified by fitting it with a Murphy and Herkelrath (1996) type sample-freezing drive shoe (SFDS), which uses liquid carbon dioxide as a cryogen. Liquid carbon dioxide was used to freeze sediments in the lower 0.1 m of the core and the drive-point piston sealed the core at the top preserving the reductive-oxidation (redox) sensitive sediments from the atmosphere and maintaining natural stratigraphy. The use of nitrogen gas to provide positive pressure on the gas system blocked the ingress of water which froze on contact with the cryogen thus blocking the gas lines with ice. With this adaptation to the gas system cores could be collected at greater depths beneath the static water level. This tool was used to collect intact saturated sediment cores from the hyporheic zone of the tidally influenced Fraser River in Vancouver, British Columbia, Canada where steep geochemical and microbial gradients develop within the interface between discharging anaerobic groundwater and recharging aerobic river water. In total, 25 cores driven through a 1.5 m sampling interval were collected from the river bed with a mean core recovery of 75%. The ability to deploy this method from a fishing vessel makes the tool more cost effective than traditional marine-based drilling operations which often use barges, tug boats, and drilling rigs. © 2014, National Ground Water Association.

  14. Study of the superficial ozone concentrations in the atmosphere of Comunidad de Madrid using passive samplers

    Directory of Open Access Journals (Sweden)

    D. Galán Madruga

    2001-06-01

    Full Text Available The ozone is a secondary atmospheric pollutant which is generated for photochemical reactions of volatil organic compounds (VOC’s and nitrogen oxides (NOx. In Spain the ozone is a big problem as a consequence of the solar radiation to reach high levels. Exposure over a period of time to elevated ozone concentrations can cause damage in the public health and alterations in the vegetation.The aim of this study is to carry out the development and validation of a measurement method to let asses the superficial ozone levels in the Comunidad de Madrid, by identifing the zones more significants, where to measure with UV photometric monitors (automatics methods this pollutant and where the health and the vegetation can be affected. To such effect, passive samplers are used, which have glass fiber filters coated with a solution of sodium nitrite, potassium carbonate, glycerol and water. The nitrite ion in the presence of ozone is oxidized to nitrato ion, which it is extrated with ultrapure water and analyzed for ion chromatography, by seen proportional to the concentration existing in the sampling point.The results of validation from field tests indicate a excellent correlation between the passive and the automatic method.The higher superficial ozone concentrations are placed in rural zones, distanced of emission focus of primary pollutants (nitrogen oxides and volatil organic compounds... principally in direction soutwest and northwest of the Comunidad of Madrid.

  15. Importance of the substrate nature to preserve microorganisms' cultivability in electrostatic air samplers

    Science.gov (United States)

    Roux, Jean-Maxime; Rongier, Anaëlle; Jary, Dorothée

    2015-10-01

    Recent research shows that electrostatic precipitation is a gentle method to collect airborne microorganisms and preserve their cultivability. However, the corona discharge used to charge the particles and the high electric field used to capture them are known to have a germicidal effect. The present paper investigates this paradoxical situation. Vegetative cells of E. coli and B. subtilis and spores of A. fumigatus and B. subtilis were deposited on different media and subjected to electrostatic fields of different strengths and polarities for controlled time periods. Vegetative cells are inactivated on cultivation agar plates, but remain cultivable when exposed on a stainless steel electrode and transferred afterwards onto agar plates. For the investigated conditions, spores were not affected by the corona discharge. Further experiments with a pH indicator show that chemical reactions occur when an aqueous media is exposed to the discharge. Some of these reactions are likely to create hydrogen peroxide which is known to kill a broad range of microorganisms. It is therefore highlighted that collecting electrodes in electrostatic air samplers should rather be dry conductive media.

  16. Comparison of dialysis membrane diffusion samplers and two purging methods in bedrock wells

    Science.gov (United States)

    Imbrigiotta, T.E.; Ehlke, T.A.; Lacombe, P.J.; Dale, J.M.; ,

    2002-01-01

    Collection of ground-water samples from bedrock wells using low-flow purging techniques is problematic because of the random spacing, variable hydraulic conductivity, and variable contamination of contributing fractures in each well's open interval. To test alternatives to this purging method, a field comparison of three ground-water-sampling techniques was conducted on wells in fractured bedrock at a site contaminated primarily with volatile organic compounds. Constituent concentrations in samples collected with a diffusion sampler constructed from dialysis membrane material were compared to those in samples collected from the same wells with a standard low-flow purging technique and a hybrid (high-flow/low-flow) purging technique. Concentrations of trichloroethene, cis-1,2-dichloroethene, vinyl chloride, calcium, chloride, and alkalinity agreed well among samples collected with all three techniques in 9 of the 10 wells tested. Iron concentrations varied more than those of the other parameters, but their pattern of variation was not consistent. Overall, the results of nonparametric analysis of variance testing on the nine wells sampled twice showed no statistically significant difference at the 95-percent confidence level among the concentrations of volatile organic compounds or inorganic constituents recovered by use of any of the three sampling techniques.

  17. Monitoring of 45 pesticides in Lebanese surface water using Polar Organic Chemical Integrative Sampler (POCIS)

    Science.gov (United States)

    Aisha, Al Ashi; Hneine, Wael; Mokh, Samia; Devier, Marie-Hélène; Budzinski, Hélèn; Jaber, Farouk

    2017-09-01

    The aim of this study is to assess the dissolved concentration of 45 pesticides in the surface waters of the Lebanese Republic using Polar Organic Chemical Integrative Sampler "POCIS". All of the sampling sites are located in the major agricultural land areas in Lebanon. POCIS (n = 3) were deployed at Ibrahim River, Qaraoun Lake and Hasbani River for a duration of 14 days. The total concentration of pesticides ranged from not detected (nd) to 137.66 ng.L-1. Chlorpyrifos, DDE-pp, diazinon and Fenpropathrin were the most abundant compounds. Qaraoun Lake and Hasbani River were found to be more polluted than Ibrahim River, since they receive large amounts of waste water derived from nearby agricultural lands and they had the lowest dilution factor. The aqueous average concentration of the target compounds were estimated using sampling rates obtained from the literature. Comparison between Time Weighed Average concentrations "TWA" using POCIS and spot sampling is presented. Results showed that POCIS TWA concentrations are in agreement with spot sampling concentrations for Ibrahim and Hasbani Rivers. The toxicity of the major detected pesticides on three representative aquatic species ( Daphnia magna, Scenedesmus quadricauda and Oncorhynchus mykiss) is also reported.

  18. Evaluation of Passive Samplers as a Monitoring Tool for Early Warning of Dinophysis Toxins in Shellfish

    Science.gov (United States)

    Pizarro, Gemita; Moroño, Ángeles; Paz, Beatriz; Franco, José M.; Pazos, Yolanda; Reguera, Beatriz

    2013-01-01

    From June 2006 to January 2007 passive samplers (solid phase adsorbing toxin tracking, SPATT) were tested as a monitoring tool with weekly monitoring of phytoplankton and toxin content (liquid chromatography–mass spectrometry, LC-MS) in picked cells of Dinophysis and plankton concentrates. Successive blooms of Dinophysis acuminata, D. acuta and D. caudata in 2006 caused a long mussel harvesting closure (4.5 months) in the Galician Rías (NW Spain) and a record (up to 9246 ng·g resin-week−1) accumulation of toxins in SPATT discs. Best fit of a toxin accumulation model was between toxin accumulation in SPATT and the product of cell densities by a constant value, for each species of Dinophysis, of toxin content (average) in picked cells. Detection of Dinophysis populations provided earlier warning of oncoming diarrhetic shellfish poisoning (DSP) outbreaks than the SPATT, which at times overestimated the expected toxin levels in shellfish because: (i) SPATT accumulated toxins did not include biotransformation and depuration loss terms and (ii) accumulation of toxins not available to mussels continued for weeks after Dinophysis cells were undetectable and mussels were toxin-free. SPATT may be a valuable environmental monitoring and research tool for toxin dynamics, in particular in areas with no aquaculture, but does not provide a practical gain for early warning of DSP outbreaks. PMID:24152559

  19. Quantum interaction. Revised selected papers

    Energy Technology Data Exchange (ETDEWEB)

    Song, Dawei; Zhang, Peng; Wang, Lei [Aberdeen Univ. (United Kingdom). School of Computing; Melucci, Massimo [Padua Univ., Padova (Italy). Dept. of Information Engineering; Frommholz, Ingo [Bedfordshire Univ. (United Kingdom); Arafat, Sachi (eds.) [Glasgow Univ. (United Kingdom). School of Computing Science

    2011-07-01

    This book constitutes the thoroughly refereed post-conference proceedings of the 5th International Symposium on Quantum Interaction, QI 2011, held in Aberdeen, UK, in June 2011. The 26 revised full papers and 6 revised poster papers, presented together with 1 tutorial and 1 invited talk were carefully reviewed and selected from numerous submissions during two rounds of reviewing and improvement. The papers show the cross-disciplinary nature of quantum interaction covering topics such as computation, cognition, mechanics, social interaction, semantic space and information representation and retrieval. (orig.)

  20. HEDR modeling approach: Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Shipler, D.B.; Napier, B.A.

    1994-05-01

    This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies.

  1. Development and field application of a 6-bottle serial gas-tight fluid sampler for collecting seafloor cold seep and hydrothermal vent fluids with autonomous operation capability

    Science.gov (United States)

    Wu, S.; Ding, K.; Yang, C.; Seyfried, W. E., Jr.; Tan, C.; Schaen, A. T.; Luhmann, A. J.

    2014-12-01

    A 6-bottle serial gas-tight sampler (so-called "six-shooter") was developed for application with deep-sea vent fluids. The new device is composed of a custom-made 6-channel valve manifold and six sampling bottles which are circularly distributed around the valve manifold. Each valve channel consists of a high-pressure titanium cartridge valve and a motor-driven actuator. A sampling snorkel is connected to the inlet of the manifold that delivers the incoming fluid to different bottles. Each sampling bottle has a 160 ml-volume chamber and an accumulator chamber inside where compressed nitrogen is used to maintain the sample at near in-situ pressure. An electronics chamber that is located at the center of the sampler is used to carry out all sampling operations, autonomously, if desired. The sampler is of a compact circular configuration with a diameter of 26 cm and a length of 54 cm. During the SVC cruise AT 26-12, the sampler was deployed by DSV2 Alvin at a cold seep site MC036 with a depth of 1090 m in the Gulf of Mexico. The sampler collected fluid samples automatically following the tidal cycle to monitor the potential impact of the tide cycle on the fluid chemistry of cold seep in a period of two day. During the cruise AT 26-17, the sampler was used with newly upgraded DSV2 Alvin three times at the hydrothermal vent sites along Axial Seamount and Main Endeavor Field on Juan de Fuca Ridge. During a 4-day deployment at Anemone diffuse site (Axial Caldera), the sampler was set to work in an autonomous mode to collect fluid samples according to the preset interval. During other dives, the sampler was manually controlled via ICL (Inductively Coupled Link) communication through the hull. Gas-tight fluid samples were collected from different hydrothermal vents with temperatures between 267 ℃ and 335 ℃ at the depth up to 2200 m. The field results indicate unique advantages of the design. It can be deployed in extended time period with remote operation or working

  2. Revised Human Health Risk Assessment on Chlorpyrifos

    Science.gov (United States)

    We have revised our human health risk assessment and drinking water exposure assessment for chlorpyrifos that supported our October 2015 proposal to revoke all food residue tolerances for chlorpyrifos. Learn about the revised analysis.

  3. Special Consolidated Checklists for Toxicity Characteristics Revisions

    Science.gov (United States)

    This checklist consolidates the changes to the Federal code addressed by the Toxicity Characteristic (TC) Rule [55 FR 11798; March 29, 1990; Revision Checklist 74] and subsequent revisions which have occurred through December 31, 2002.

  4. [Revised practice guideline 'Anaemia in midwifery practice'

    NARCIS (Netherlands)

    Beentjes, M.; Jans, S.M.P.J.

    2012-01-01

    The practice guideline of the Royal Dutch Organization of Midwives 'Anaemia in primary care midwifery practice' published in 2000, has recently been revised. The revised guideline takes physiological haemodilution during pregnancy into consideration and provides gestation specific reference values

  5. Diet History Questionnaire: Database Revision History

    Science.gov (United States)

    The following details all additions and revisions made to the DHQ nutrient and food database. This revision history is provided as a reference for investigators who may have performed analyses with a previous release of the database.

  6. Air Pollution Primer. Revised Education.

    Science.gov (United States)

    Corman, Rena

    This revised and updated book is written to inform the citizens on the nature, causes, and effects of air pollution. It is written in terms familiar to the layman with the purpose of providing knowledge and motivation to spur community action on clean air policies. Numerous charts and drawings are provided to support discussion of air pollution…

  7. Psychological considerations in revision rhinoplasty.

    Science.gov (United States)

    Ambro, Bryan T; Wright, Richard J

    2008-08-01

    Revision rhinoplasty is a unique challenge. In addition to the technical considerations that are inherently more difficult than those of primary cases, the surgeon must also be mindful of the psychological considerations that revision rhinoplasty presents. These patients are by definition unhappy with their prior rhinoplasty experience, and this perception of a suboptimal result is both legitimate and real, even if the surgeon is not in agreement. Tantamount to any intraoperative technique, the preoperative ability of the surgeon to sift through the myriad psychological and psychosocial issues is critical to achieving satisfactory outcomes for both patient and surgeon. Reasons for dissatisfaction with a primary surgery, reasons for seeking revision surgery, and the psychological profiles of revision rhinoplasty patients can differ from those related to other facial cosmetic procedures. This article attempts to provide the reader with a better understanding of the complex interplay of these issues and with this understanding help the reader to distinguish one who is a favorable surgical candidate from one who is best left unrevised.

  8. BEGINNING IN SOMALI. REVISED EDITION.

    Science.gov (United States)

    PIA, J.J.; AND OTHERS

    THIS COURSE WAS DEVELOPED UNDER A PEACE CORPS CONTRACT TO PROVIDE INSTRUCTION IN SOMALI AT AN ELEMENTARY LEVEL. GRAMMATICAL COVERAGE IS SUFFICIENT TO PERMIT THE STUDENTS TO ACHIEVE S2, AS DEFINED IN THE ABSOLUTE LANGUAGE PROFICIENCY RATINGS OF THE FOREIGN SERVICE INSTITUTE. THE VOLUME IS A REVISION OF AN EARLIER COURSE. THE APPROACH USED IS THE…

  9. A revision of Ichnocarpus (Apocynaceae)

    NARCIS (Netherlands)

    Middleton, D.J.

    1994-01-01

    The genus Ichnocarpus is revised. A total of 12 species are recognised, of which one new species is described. Three new combinations in Ichnocarpus and one in Anodendron are made. Micrechites and Lamechites are treated as synonyms of Ichnocarpus. Nomina nuda and species exclusae have been given as

  10. Revised Industry Projections to 1985

    Science.gov (United States)

    Mooney, Thomas J.; Tschetter, John H.

    1976-01-01

    Revised Bureau of Labor Statistics projections, which reflect assumptions about unemployment, labor productivity, and government taxes and spending, provide information about long-term trends of industry output and employment. One projection made is that health services and computer-related industries will continue to be the leaders in job growth.…

  11. Concise revision of the Sarcospermataceae

    NARCIS (Netherlands)

    Lam, H.J.; Royen, van P.

    1952-01-01

    After the senior writer, together with W. W. Varossieau, had published a revision of this monogeneric family (Blumea III, 1938—’39 and IV, 1941), some more material has been examined by us and, moreover, some new species have been described. Thanks to the courtesy of Prof. F. Gagnepain of Paris, and

  12. Medical writing, revising and editing

    DEFF Research Database (Denmark)

    Pilegaard, Morten

    2006-01-01

    The globalization of science makes medical writing, editing and revision a rapidly growing field of linguistic study and practice. Medical science texts are written according to uniform, general guidelines and medical genres have become highly conventionalized in terms of structure and linguistic...

  13. Molecular dynamics simulation methods revised

    NARCIS (Netherlands)

    Bekker, Hendrik

    1996-01-01

    Korte beschrijving: In this thesis, all the subjects mentioned in the previous section are revised, except neighbor searching and integration. So, the following subjects are discussed: non-bonded force calculations, bonded force calculations, constraint dynamics, and box shapes. Moreover, mapping

  14. Soft tissue trauma and scar revision.

    Science.gov (United States)

    Mobley, Steven R; Sjogren, Phayvanh P

    2014-11-01

    Numerous techniques and treatments have been described for scar revision, with most studies focusing on the adult population. A comprehensive review of the literature reveals a paucity of references related specifically to scar revision in children. This review describes the available modalities in pediatric facial scar revision. The authors have integrated current practices in soft tissue trauma and scar revision, including closure techniques and materials, topical therapy, steroid injection, cutaneous laser therapy, and tissue expanders. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Evaluating the applicability of a semi-continuous aerosol sampler to measure Asian dust particles.

    Science.gov (United States)

    Son, Se-Chang; Park, Seung Shik

    2015-03-01

    A Korean prototype semi-continuous aerosol sampler was used to measure Asian dust particles. During two dust-storm periods, concentrations of crustal and trace elements were significantly enriched. Dust storms are one of the most significant natural sources of air pollution in East Asia. The present study aimed to evaluate use of a Korean semi-continuous aerosol sampler (K-SAS) in observation of mineral dust particles during dust storm events. Aerosol slurry samples were collected at 60 min intervals using the K-SAS, which was operated at a sampling flow rate of 16.7 L min(-1) through a PM10 cyclone inlet. The measurements were made during dust storm events at an urban site, Gwangju in Korea, between April 30 and May 5, 2011. The K-SAS uses particle growth technology as a means of collecting atmospheric aerosol particles. Concentrations of 16 elements (Al, Fe, Mn, Ca, K, Cu, Zn, Pb, Cd, Cr, Ti, V, Ni, Co, As, and Se) were determined off-line in the collected slurry samples by inductively coupled plasma-mass spectrometry (ICP-MS). The sampling periods were classified into two types, based on the source regions of the dust storms and the transport pathways of the air masses reaching the sampling site. The first period "A" was associated with dust particles with high Ca content, originating from the Gobi desert regions of northern China and southern Mongolia. The second period "B" was associated with dust particles with low Ca content, originating from northeastern Chinese sandy deserts. The results from the K-SAS indicated noticeable differences in concentrations of crustal and trace elements in the two sampling periods, as a result of differences in the source regions of the dust storms, the air mass transport pathways, and the impact of smoke from forest fires. The concentrations of the crustal (Al, Ca, Ti, Mn, and Fe) and anthropogenic trace elements (Vi, Ni, Cu, Zn, As, Se, and Pb) were enriched significantly during the two dust storm periods. However, the

  16. Revision Anterior Cruciate Ligament Reconstruction

    Science.gov (United States)

    Wilde, Jeffrey; Bedi, Asheesh; Altchek, David W.

    2014-01-01

    Context: Reconstruction of the anterior cruciate ligament (ACL) is one of the most common surgical procedures, with more than 200,000 ACL tears occurring annually. Although primary ACL reconstruction is a successful operation, success rates still range from 75% to 97%. Consequently, several thousand revision ACL reconstructions are performed annually and are unfortunately associated with inferior clinical outcomes when compared with primary reconstructions. Evidence Acquisition: Data were obtained from peer-reviewed literature through a search of the PubMed database (1988-2013) as well as from textbook chapters and surgical technique papers. Study Design: Clinical review. Level of Evidence: Level 4. Results: The clinical outcomes after revision ACL reconstruction are largely based on level IV case series. Much of the existing literature is heterogenous with regard to patient populations, primary and revision surgical techniques, concomitant ligamentous injuries, and additional procedures performed at the time of the revision, which limits generalizability. Nevertheless, there is a general consensus that the outcomes for revision ACL reconstruction are inferior to primary reconstruction. Conclusion: Excellent results can be achieved with regard to graft stability, return to play, and functional knee instability but are generally inferior to primary ACL reconstruction. A staged approach with autograft reconstruction is recommended in any circumstance in which a single-stage approach results in suboptimal graft selection, tunnel position, graft fixation, or biological milieu for tendon-bone healing. Strength-of-Recommendation Taxonomy (SORT): Good results may still be achieved with regard to graft stability, return to play, and functional knee instability, but results are generally inferior to primary ACL reconstruction: Level B. PMID:25364483

  17. Honey Bees (Apis mellifera, L.) as Active Samplers of Airborne Particulate Matter.

    Science.gov (United States)

    Negri, Ilaria; Mavris, Christian; Di Prisco, Gennaro; Caprio, Emilio; Pellecchia, Marco

    2015-01-01

    Honey bees (Apis mellifera L.) are bioindicators of environmental pollution levels. During their wide-ranging foraging activity, these hymenopterans are exposed to pollutants, thus becoming a useful tool to trace the environmental contaminants as heavy metals, pesticides, radionuclides and volatile organic compounds. In the present work we demonstrate that bees can also be used as active samplers of airborne particulate matter. Worker bees were collected from hives located in a polluted postmining area in South West Sardinia (Italy) that is also exposed to dust emissions from industrial plants. The area is included in an official list of sites of national interest for environmental remediation, and has been characterized for the effects of pollutants on the health of the resident population. The head, wings, hind legs and alimentary canal of the bees were investigated with Scanning Electron Microscopy coupled with X-ray spectroscopy (SEM-EDX). The analyses pointed to specific morphological and chemical features of the particulate, and resulted into the identification of three categories of particles: industry-, postmining-, and soil-derived. With the exception of the gut, all the analyzed body districts displayed inorganic particles, mostly concentrated in specific areas of the body (i.e. along the costal margin of the fore wings, the medial plane of the head, and the inner surface of the hind legs). The role of both past mining activities and the industrial activity close to the study area as sources of the particulate matter is also discussed. We conclude that honey bees are able to collect samples of the main airborne particles emitted from different sources, therefore could be an ideal tool for monitoring such a kind of pollutants.

  18. Monitoring for contaminants of emerging concern in drinking water using POCIS passive samplers.

    Science.gov (United States)

    Metcalfe, Chris; Hoque, M Ehsanul; Sultana, Tamanna; Murray, Craig; Helm, Paul; Kleywegt, Sonya

    2014-03-01

    Contaminants of emerging concern (CEC) have been detected in drinking water world-wide. The source of most of these compounds is generally attributed to contamination from municipal wastewater. Traditional water sampling methods (grab or composite) often require the concentration of large amounts of water in order to detect trace levels of these contaminants. The Polar Organic Compounds Integrative Sampler (POCIS) is a passive sampling technology that has been developed to concentrate trace levels of CEC to provide time-weighted average concentrations for individual compounds in water. However, few studies to date have evaluated whether POCIS is suitable for monitoring contaminants in drinking water. In this study, the POCIS was evaluated as a monitoring tool for CEC in drinking water over a period of 2 and 4 weeks with comparisons to typical grab samples. Seven "indicator compounds" which included carbamazepine, trimethoprim, sulfamethoxazole, ibuprofen, gemfibrozil, estrone and sucralose, were monitored in five drinking water treatment plants (DWTPs) in Ontario. All indicator compounds were detected in raw water samples from the POCIS in comparison to six from grab samples. Similarly, four compounds were detected in grab samples of treated drinking water, whereas six were detected in the POCIS. Sucralose was the only compound that was detected consistently at all five plants. The POCIS technique provided integrative exposures of CECs in drinking water at lower detection limits, while episodic events were captured via traditional sampling methods. There was evidence that the accumulation of target compounds by POCIS is a dynamic process, with adsorption and desorption on the sorbent occurring in response to ambient levels of the target compounds in water. CECs in treated drinking water were present at low ng L(-1) concentrations, which are not considered to be a threat to human health.

  19. Retained gas sampler extractor mixing and mass transfer rate study: Experimental and simulation results

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, K.P.; Bates, J.M.; Shekarriz, A.

    1997-11-01

    Research staff at Pacific Northwest National Laboratory conducted experimental testing and computer simulations of the impeller-stirred Retained Gas Sampler (RGS) gas extractor system. This work was performed to verify experimentally the effectiveness of the extractor at mixing viscous fluids of both Newtonian and non-Newtonian rheology representative of Hanford single- and double-shell wastes, respectively. Developing the computational models and validating their results by comparing them with experimental results would enable simulations of the mixing process for a range of fluid properties and mixing speeds. Five tests were performed with a full-scale, optically transparent model extractor to provide the data needed to compare mixing times for fluid rheology, mixer rotational direction, and mixing speed variation. The computer model was developed and exercised to simulate the tests. The tests demonstrated that rotational direction of the pitched impeller blades was not as important as fluid rheology in determining mixing time. The Newtonian fluid required at least six hours to mix at the hot cell operating speed of 3 rpm, and the non-Newtonian fluid required at least 46 hours at 3 rpm to become significantly mixed. In the non-Newtonian fluid tests, stagnant regions within the fluid sometimes required days to be fully mixed. Higher-speed (30 rpm) testing showed that the laminar mixing time was correlated to mixing speed. The tests demonstrated that, using the RGS extractor and current procedures, complete mixing of the waste samples in the hot cell should not be expected. The computer simulation of Newtonian fluid mixing gave results comparable to the test while simulation of non-Newtonian fluid mixing would require further development. In light of the laboratory test results, detailed parametric analysis of the mixing process was not performed.

  20. [Hip revision arthroplasty (long-term results)].

    Science.gov (United States)

    Tarasevicius, Sarūnas; Zegunis, Vidmantas; Tarasevicius, Rimantas; Kalesinskas, Romas Jonas; Janusonis, Vinsas

    2004-01-01

    To evaluate the risk factors after total hip replacement arthroplasty for rerevision and to analyze complications after hip revision surgery. We obtained data from 117 hip revisions and 12 hip rerevision arthroplasties performed in 1992-2001 in the Department of Orthopedics of Klaipeda Hospital. Special forms were filled in for every patient who participated in the study. Name, operation date, type of implants, operative technique, revision diagnosis, intraoperative and postoperative complications were recorded. All patients were checked for death until 2003. Hip revisions were performed for 77 (66%) women and 50 (44%) men in 1992-2001. We revised 22 (19%) cups, 6 (5%) stems, 86 (74%) total hip revisions; femoral head was exchanged for 3 patients. Revision diagnoses were: aseptic loosening in 106 (90%) cases, recurrent dislocations in 7 (6%) cases, and periprosthetic fractures in 4 (4%) cases. Patients' age varied from 26-82 years, average 63.5 years. In revision group only 8% of patients were less than 50 years old, compared to 33% in rerevision group. Morselized allografts and bone impaction technique for reconstruction of bone defects were used in 70 (60%) of cases. We rerevised one cup only for which revision morselized allografts were used. Eight (67%) rerevisions were performed after first 28 (24%) hip revisions. Patients, who underwent revision surgery being younger than 50 years old, were at higher risk for rerevision surgery. Revision with morselized bone allografts and bone impaction technique decreases number of rerevisions. Learning curve was steep and had great influence to our results.

  1. Evaluation of the use of performance reference compounds in an Oasis-HLB adsorbent based passive sampler for improving water concentration estimates of polar herbicides in freshwater.

    Science.gov (United States)

    Mazzella, Nicolas; Lissalde, Sophie; Moreira, Sylvia; Delmas, François; Mazellier, Patrick; Huckins, James N

    2010-03-01

    Passive samplers such as the Polar Organic Chemical Integrative Sampler (POCIS) are useful tools for monitoring trace levels of polar organic chemicals in aquatic environments. The use of performance reference compounds (PRC) spiked into the POCIS adsorbent for in situ calibration may improve the semiquantitative nature of water concentration estimates based on this type of sampler. In this work, deuterium labeled atrazine-desisopropyl (DIA-d5) was chosen as PRC because of its relatively high fugacity from Oasis HLB (the POCIS adsorbent used) and our earlier evidence of its isotropic exchange. In situ calibration of POCIS spiked with DIA-d5 was performed, and the resulting time-weighted average concentration estimates were compared with similar values from an automatic sampler equipped with Oasis HLB cartridges. Before PRC correction, water concentration estimates based on POCIS data sampling rates from a laboratory calibration exposure were systematically lower than the reference concentrations obtained with the automatic sampler. Use of the DIA-d5 PRC data to correct POCIS sampling rates narrowed differences between corresponding values derived from the two methods. Application of PRCs for in situ calibration seems promising for improving POCIS-derived concentration estimates of polar pesticides. However, careful attention must be paid to the minimization of matrix effects when the quantification is performed by HPLC-ESI-MS/MS.

  2. [Juniper pollen monitoring by Burkard sampler in Galveston, Texas, USA and Japanese cedar pollen counting in Fukuoka, Japan -- introduction of Pan American Aerobiology Association protocol counting technique].

    Science.gov (United States)

    Kishikawa, Reiko; M-Horiuti, Terumi; Togawa, Akihisa; Kondoh, Yasuto; Janzy, Paul D; Goldblum, Randal M; Kotoh, Eiko; Shimoda, Teruhumi; Shoji, Shunsuke; Nishima, Sankei; Brooks, Edward G

    2004-06-01

    We have monitored Juniper pollen which caused winter allergy symptoms by Burkard sampler in Galveston, Texas. We identified and counted Juniper pollen grains by PAAA protocol which was a comprehensive guideline for the operation of Hirst-Type suction bioaerosol sampler, (original of Burkard sampler) in the USA. In Galveston we were able to detect the Mountain Cedar (Juniperus ashei) pollen from December to of January, and Eastern Red Cedar (Juniperus virginiana) which has cross reactivity to MC from almost middle of January to February. There is no MC vegetation in Galveston. We found the pollen grains were transported from west at Edward Plateau in West Texas where it was thickly wooded. Then, we tried to monitor Japanese Cedar (JC) pollen grains in Fukuoka, Japan according with the same method. We found the significant positive correlation between the pollen counts using one single longitudinal traverse counting technique in the PAAA protocol and the JC pollen counting on the whole of Melinex tape per 24 hours (R2=0.9212, p=0.0001), and the gravitational method that is Durham sampler's pollen counting in 2002 (R2=0.489, p=0.0001), and in 2003 (R2=0.948, p=0.0001) respectively. We suggested that we can use the PAAA protocol for airborne pollen investigation in Japan by Burkard sampler.

  3. Field testing of passive diffusion bag samplers for volatile organic compound concentrations in ground water, Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota, November 1999 and May 2000

    Science.gov (United States)

    Vroblesky, Don A.; Petkewich, Matthew D.

    2000-01-01

    Volatile organic compound concentrations from passive diffusion bag samplers were compared with concentrations from conventional purge (three or more casing volumes) sampling and low-flow purge sampling in side-by-side tests in 17 wells at the Naval Industrial Reserve Ordnance Plant, in Fridley, Minnesota. An initial comparison of 1,2-dichloroethene and trichloroethene concentrations obtained by using passive diffusion bag samplers and the conventional purge method in wells where one passive diffusion bag sampler was deployed showed good agreement at several wells but poor agreement at others. Collection of data from multiple diffusion samplers during the conventional purge sampling and during the low-flow sampling, however, suggests that the volatile organic compound concentrations from the passive diffusion bag samplers accurately reflect the volatile organic compound distribution in the screened interval, whereas the conventional purge and low-flow purge samples reflect mixing during pumping. The data also show that contaminant stratification was present in some wells. In one well, trichloroethene concentrations ranged from 470 to 1,600 micrograms per liter over a vertical distance of approximately 6 feet.

  4. Exposure of bakery and pastry apprentices to airborne flour dust using PM2.5 and PM10 personal samplers

    Science.gov (United States)

    Mounier-Geyssant, Estelle; Barthélemy, Jean-François; Mouchot, Lory; Paris, Christophe; Zmirou-Navier, Denis

    2007-01-01

    Background This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma. Methods Questionnaires on work activity were completed by 286 students. Among them, 34 performed a series of two personal exposure measurements using a PM2.5 and PM10 personal sampler during a complete work shift, one during a cold ("winter") period, and the other during a hot ("summer") period. Results Bakery apprentices experience greater average PM2.5 and PM10 exposures than pastry apprentices (p bakery apprentices incur substantial exposure to known airways allergens, a situation that might elicit early induction of airways inflammation. PMID:17976230

  5. Emerging investigator series: development and application of polymeric electrospun nanofiber mats as equilibrium-passive sampler media for organic compounds.

    Science.gov (United States)

    Qian, Jiajie; Jennings, Brandon; Cwiertny, David M; Martinez, Andres

    2017-11-15

    We fabricated a suite of polymeric electrospun nanofiber mats (ENMs) and investigated their performance as next-generation passive sampler media for environmental monitoring of organic compounds. Electrospinning of common polymers [e.g., polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and polystyrene (PS), among others] yielded ENMs with reproducible control of nanofiber diameters (from 50 to 340 nm). The ENM performance was investigated initially with model hydrophilic (aniline and nitrobenzene) and hydrophobic (selected PCB congeners and dioxin) compounds, generally revealing fast chemical uptake into all of these ENMs, which was well described by a one compartment, first-order kinetic model. Typical times to reach 90% equilibrium (t90%) were ≤7 days under mixing conditions for all the ENMs and equilibrium timescales suggest that ENMs may be used in the field as an equilibrium-passive sampler, at least for our model compounds. Equilibrium partitioning coefficients (KENM-W, L kg-1) averaged 2 and 4.7 log units for the hydrophilic and hydrophobic analytes, respectively. PAN, PMMA and PS were prioritized for additional studies because they exhibited not only the greatest capacity for simultaneous uptake of the entire model suite (log KENM-W ∼1.5-6.2), but also fast uptake. For these optimized ENMs, the rates of uptake into PAN and PMMA were limited by aqueous phase diffusion to the nanofiber surface, and the rate-determining step for PS was analyte specific. Sorption isotherms also revealed that the environmental application of these optimized ENMs would occur within the linear uptake regime. We examined the ENM performance for the measurement of pore water concentrations from spiked soil and freshwater sediments. Soil and sediment studies not only yielded reproducible pore water concentrations and comparable values to other passive sampler materials, but also provided practical insights into ENM stability and fouling in such systems. Furthermore

  6. Belief Revision and Argumentation Theory

    Science.gov (United States)

    Falappa, Marcelo Alejandro; Kern-Isberner, Gabriele; Simari, Guillermo Ricardo

    Belief revision is the process of changing beliefs to adapt the epistemic state of an agent to a new piece of information. The logical formalization of belief revision is a topic of research in philosophy, logic, and in computer science, in areas such as databases or artificial intelligence. On the other hand, argumentation is concerned primarily with the evaluation of claims based on premises in order to reach conclusions. Both provide basic and substantial techniques for the art of reasoning, as it is performed by human beings in everyday life situations and which goes far beyond logical deduction. Reasoning, in this sense, makes possible to deal successfully with problems in uncertain, dynamic environments and has been promoting the development of human societies.

  7. Revising Academic Library Governance Handbooks

    Directory of Open Access Journals (Sweden)

    Jen Stevens

    2015-07-01

    Full Text Available Regardless of our status (tenure track, non-tenure track, staff, and/or union, academic librarians at colleges and universities may use a handbook or similar document as a framework for self-governance. These handbooks typically cover rank descriptions, promotion requirements, and grievance rights, among other topics. Unlike employee handbooks used in the corporate world, these documents may be written and maintained by academic librarians themselves1. In 2010, a group of academic librarians at George Mason University was charged with revising our Librarians’ Handbook. Given the dearth of literature about academic librarians’ handbooks and their revision, we anticipate our library colleagues in similar situations will benefit from our experience and recommendations.

  8. Clean Air Act. Revision 5

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-15

    This Reference Book contains a current copy of the Clean Air Act, as amended, and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. This Reference Book has been completely revised and is current through February 15, 1994.

  9. Revised dietary guidelines for Koreans.

    Science.gov (United States)

    Jang, Young Ai; Lee, Haeng Shin; Kim, Bok Hee; Lee, Yoonna; Lee, Hae Jeung; Moon, Jae Jin; Kim, Cho-il

    2008-01-01

    With rapidly changing dietary environment, dietary guidelines for Koreans were revised and relevant action guides were developed. First, the Dietary Guidelines Advisory Committee was established with experts and government officials from the fields of nutrition, preventive medicine, health promotion, agriculture, education and environment. The Committee set dietary goals for Koreans aiming for a better nutrition state of all after a thorough review and analysis of recent information related to nutritional status and/or problems of Korean population, changes in food production/supply, disease pattern, health policy and agricultural policy. Then, the revised dietary guidelines were proposed to accomplish these goals in addition to 6 different sets of dietary action guides to accommodate specific nutrition and health problems of respective age groups. Subsequently, these guidelines and guides were subjected to the focus group review, consumer perception surveys, and a public hearing for general and professional comments. Lastly, the language was clarified in terms of public understanding and phraseology. The revised Dietary guidelines for Koreans are as follows: eat a variety of grains, vegetables, fruits, fish, meat, poultry and dairy products; choose salt-preserved foods less, and use less salt when you prepare foods; increase physical activity for a healthy weight, and balance what you eat with your activity; enjoy every meal, and do not skip breakfast; if you drink alcoholic beverages, do so in moderation; prepare foods properly, and order sensible amounts; enjoy our rice-based diet.

  10. Development of a flexible dialysis pore water sampler placement system: easy handling and related error sources

    Directory of Open Access Journals (Sweden)

    Stephan Hilgert

    2014-02-01

    Full Text Available Investigations in the context of greenhouse gas production measurements in sub-tropical reservoirs brought up the necessity to survey the in situ pore water gas and ion concentrations at many positions within a relatively short time. As several sediment cores were taken, the interest in analyzing the pore water at the same time and at the same positions forced us to develop a cost- and time saving method for the placement of dialysis pore water samplers (DPS. General prerequisites were the ability to place several DPS per day, within a flexible depth range of up to 40 m and with a low cost budget. To meet these requirements, a DPS placing system (DPSPS was developed, which would allow the precise placement of DPS in water with a depth of up to 40 m and assessing the biases of on-board measurements and possible methodological improvements. The DPSPS was transported to Brazil and tested in a measurement campaign for 10 days. The measurements were carried out during two campaigns in December 2012 and March 2013 in the Capivari Reservoir north-east of Curitiba in the State of Paraná. The system worked properly and several DPS could be placed from a 5 m class aluminum boat. The placement was performed with high accuracy regarding the positioning as well as the penetration depth of the DPS. After the recovery of the DPS, the possible biases during sampling were analyzed. Possible back-diffusion was investigated, taking oxygen concentration as one representative parameter for estimation of the sample behavior. Laboratory as well as field results showed that special care has to be taken to minimize the influence of diffusion processes during post-recovery sampling. The results also suggested that the used membranes are affected by clogging which is likely to influence the diffusion times of various ions and gases. It can be stated that the DPSPS was developed successfully as the demands in terms of handling as well as monitoring efficiency and sample

  11. Evaluation and use of a diffusion-controlled sampler for determining chemical and dissolved oxygen gradients at the sediment-water interface

    Science.gov (United States)

    Simon, N.S.; Kennedy, M.M.; Massoni, C.S.

    1985-01-01

    Field and laboratory evaluations were made of a simple, inexpensive diffusion-controlled sampler with ports on two sides at each interval which incorporates 0.2-??m polycarbonate membrane to filter samples in situ. Monovalent and divalent ions reached 90% of equilibrium between sampler contents and the external solution within 3 and 6 hours, respectively. Sediment interstitial water chemical gradients to depths of tens of centimeters were obtained within several days after placement. Gradients were consistent with those determined from interstitial water obtained by centrifugation of adjacent sediment. Ten milliliter sample volumes were collected at 1-cm intervals to determine chemical gradients and dissolved oxygen profiles at depth and at the interface between the sediment and water column. The flux of dissolved species, including oxygen, across the sediment-water interface can be assessed more accurately using this sampler than by using data collected from benthic cores. ?? 1985 Dr W. Junk Publishers.

  12. [Volatile organic compounds (VOCs) emitted from wood furniture--estimation of emission rate by passive flux sampler].

    Science.gov (United States)

    Jinno, Hideto; Tanaka-Kagawa, Toshiko; Furuta, Mitsuko; Shibatsuji, Masayoshi; Nishimura, Tetsuji

    2011-01-01

    The aim of this study was to evaluate aldehydes and other volatile organic compounds (VOCs) emission from furniture, which may cause hazardous influence on human being such as sick building/sick house syndrome. In this study, VOCs emitted from six kinds of wood furniture, including three set of dining tables and three beds, were analyzed by large chamber test method (JIS A 1911). Based on the emission rates of total VOCs (TVOC), the impacts on the indoor TVOC was estimated by the simulation model with volume of 20 m3 and ventilation frequency of 0.5 times/h. The estimated increment of formaldehyde were exceeded the guideline value (100 microg/m3) in one set of dining table and one bed. The estimated TVOC increment values were exceeded the provisional target value for indoor air (400 microg/m3) in two sets of dining tables and two beds. These results revealed that VOC emissions from wood furniture may influence significantly indoor air quality. Also, in this study, to establish the alternative method for large chamber test methods, emission rates from representative five areas of furniture unit were evaluated by passive sampling method using flux sampler and emission rate from full-sized furniture was predicted. Emission rates predicted by flux passive sampler were 10-106% (formaldehyde) and 8-141% (TVOC) of the data measured using large chamber test, respectively.

  13. Estimation of the Human Extrathoracic Deposition Fraction of Inhaled Particles Using a Polyurethane Foam Collection Substrate in an IOM Sampler

    Directory of Open Access Journals (Sweden)

    Darrah K. Sleeth

    2016-03-01

    Full Text Available Extrathoracic deposition of inhaled particles (i.e., in the head and throat is an important exposure route for many hazardous materials. Current best practices for exposure assessment of aerosols in the workplace involve particle size selective sampling methods based on particle penetration into the human respiratory tract (i.e., inhalable or respirable sampling. However, the International Organization for Standardization (ISO has recently adopted particle deposition sampling conventions (ISO 13138, including conventions for extrathoracic (ET deposition into the anterior nasal passage (ET1 and the posterior nasal and oral passages (ET2. For this study, polyurethane foam was used as a collection substrate inside an inhalable aerosol sampler to provide an estimate of extrathoracic particle deposition. Aerosols of fused aluminum oxide (five sizes, 4.9 µm–44.3 µm were used as a test dust in a low speed (0.2 m/s wind tunnel. Samplers were placed on a rotating mannequin inside the wind tunnel to simulate orientation-averaged personal sampling. Collection efficiency data for the foam insert matched well to the extrathoracic deposition convention for the particle sizes tested. The concept of using a foam insert to match a particle deposition sampling convention was explored in this study and shows promise for future use as a sampling device.

  14. Gibbs Sampler-Based λ-Dynamics and Rao-Blackwell Estimator for Alchemical Free Energy Calculation.

    Science.gov (United States)

    Ding, Xinqiang; Vilseck, Jonah Z; Hayes, Ryan L; Brooks, Charles L

    2017-06-13

    λ-dynamics is a generalized ensemble method for alchemical free energy calculations. In traditional λ-dynamics, the alchemical switch variable λ is treated as a continuous variable ranging from 0 to 1 and an empirical estimator is utilized to approximate the free energy. In the present article, we describe an alternative formulation of λ-dynamics that utilizes the Gibbs sampler framework, which we call Gibbs sampler-based λ-dynamics (GSLD). GSLD, like traditional λ-dynamics, can be readily extended to calculate free energy differences between multiple ligands in one simulation. We also introduce a new free energy estimator, the Rao-Blackwell estimator (RBE), for use in conjunction with GSLD. Compared with the current empirical estimator, the advantage of RBE is that RBE is an unbiased estimator and its variance is usually smaller than the current empirical estimator. We also show that the multistate Bennett acceptance ratio equation or the unbinned weighted histogram analysis method equation can be derived using the RBE. We illustrate the use and performance of this new free energy computational framework by application to a simple harmonic system as well as relevant calculations of small molecule relative free energies of solvation and binding to a protein receptor. Our findings demonstrate consistent and improved performance compared with conventional alchemical free energy methods.

  15. Numerical estimation of structure constants in the three-dimensional Ising conformal field theory through Markov chain uv sampler

    Science.gov (United States)

    Herdeiro, Victor

    2017-09-01

    Herdeiro and Doyon [Phys. Rev. E 94, 043322 (2016), 10.1103/PhysRevE.94.043322] introduced a numerical recipe, dubbed uv sampler, offering precise estimations of the conformal field theory (CFT) data of the planar two-dimensional (2D) critical Ising model. It made use of scale invariance emerging at the critical point in order to sample finite sublattice marginals of the infinite plane Gibbs measure of the model by producing holographic boundary distributions. The main ingredient of the Markov chain Monte Carlo sampler is the invariance under dilation. This paper presents a generalization to higher dimensions with the critical 3D Ising model. This leads to numerical estimations of a subset of the CFT data—scaling weights and structure constants—through fitting of measured correlation functions. The results are shown to agree with the recent most precise estimations from numerical bootstrap methods [Kos, Poland, Simmons-Duffin, and Vichi, J. High Energy Phys. 08 (2016) 036, 10.1007/JHEP08(2016)036].

  16. Technical aspects of revision and functional outcome after revision of the Oxford unicompartmental knee arthroplasty.

    Science.gov (United States)

    Somford, Matthijs P; Brouwer, Reinoud W; Haen, Pieter-Stijn W A; van Raay, Jos J A M; van Raaij, Tom M

    2016-12-01

    This study analysed the technical aspects of revision of the Oxford unicompartmental knee arthroplasty (OUKA) and functional results after revision. In a historic cohort study we analysed all revised OUKAs that were primarily implanted at our clinic over a 10-year period (1998-2009). The primary aim was to investigate surgical difficulties encountered during revision surgery of the OUKA. Outcomes were the knee society score (KSS), WOMAC (Western Ontario and McMaster Universities), SF-36, VAS pain and VAS satisfaction after revision. During the study period, 331 OUKAs were inserted. With an average follow-up of six years and five months (range one month to nine years and eight months), there were 44 (13.3%) OUKAs that needed one or more revision surgery procedures. The average time to revision was three years and eight months (range one month to nine years and five months). The main reasons for revision surgery were bearing dislocation, malpositioning or loosening of a component and progression of osteoarthritis. Most revisions, mainly conversion to primary total knee arthroplasty (TKA), gave few surgical problems. Minor bone loss that needed no augmentation was seen most frequently. The functional outcomes after revision surgery were moderate. A limited amount of surgical difficulty during revision of OUKA was found; in all total revision cases a primary TKA was implanted. However, in most patients there were moderate functional results as well as disappointing pain and satisfaction scores after revision. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Revised diagnostic criteria for neurocysticercosis.

    Science.gov (United States)

    Del Brutto, O H; Nash, T E; White, A C; Rajshekhar, V; Wilkins, P P; Singh, G; Vasquez, C M; Salgado, P; Gilman, R H; Garcia, H H

    2017-01-15

    A unified set of criteria for neurocysticercosis (NCC) has helped to standardize its diagnosis in different settings. Cysticercosis experts were convened to update current diagnostic criteria for NCC according to two principles: neuroimaging studies are essential for diagnosis, and all other information provides indirect evidence favoring the diagnosis. Recent diagnostic advances were incorporated to this revised set. This revised set is structured in absolute, neuroimaging and clinical/exposure criteria. Absolute criteria include: histological confirmation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. Neuroimaging criteria are categorized as major (cystic lesions without scolex, enhancing lesions, multilobulated cysts, and calcifications), confirmative (resolution of cysts after cysticidal drug therapy, spontaneous resolution of single enhancing lesions, and migrating ventricular cysts on sequential neuroimaging studies) and minor (hydrocephalus and leptomeningeal enhancement). Clinical/exposure criteria include: detection of anticysticercal antibodies or cysticercal antigens by well-standardized tests, systemic cysticercosis, evidence of a household Taenia carrier, suggestive clinical manifestations, and residency in endemic areas. Besides patients having absolute criteria, definitive diagnosis can be made in those having two major neuroimaging criteria (or one major plus one confirmative criteria) plus exposure. For patients presenting with one major and one minor neuroimaging criteria plus exposure, definitive diagnosis of NCC requires the exclusion of confounding pathologies. Probable diagnosis is reserved for individuals presenting with one neuroimaging criteria plus strong evidence of exposure. This revised set of diagnostic criteria provides simpler definitions and may facilitate its more uniform and widespread applicability in different scenarios. Copyright © 2016 The Authors. Published by Elsevier B.V. All

  18. Revised hypothesis and future perspectives

    DEFF Research Database (Denmark)

    Norsk, P; Drummer, C; Christensen, N J

    2001-01-01

    Results from space have been unexpected and not predictable from the results of ground-based simulations. Therefore, the concept of how weightlessness and gravity modulates the regulation of body fluids must be revised and a new simulation model developed. The main questions to ask in the future...... activated by spaceflight? Why are the renal responses to saline and water stimuli in space attenuated compared with those of ground simulations? How can the effects of weightlessness on fluid and electrolyte regulation be correctly simulated on the ground? The information obtained from space may...

  19. Revision Surgery of Deep Brain Stimulation Leads.

    Science.gov (United States)

    Falowski, Steven M; Bakay, Roy A E

    2016-07-01

    Deep brain stimulation (DBS) is widely used for various movement disorders. DBS lead revisions are becoming more common as the indications and number of cases increases. Patients undergoing DBS lead revisions at a single institution were retrospectively analyzed based on diagnosis, reason for revision, where the lead was relocated, and surgical technique. We reviewed 497 consecutive DBS lead placements and found that there was need for 25 DBS lead revisions with at least six months of follow-up. Loss of efficacy and development of adverse effects over time were the most common reasons for lead revision across all diagnosis. Lead malfunction was the least common. Ten patients requiring 19 DBS lead revisions that underwent their original surgery at another institution were also analyzed. Surgical technique dictated replacing with a new lead while maintaining brain position and tract with the old lead until final placement. Methods to seal exposed wire were developed. Surgical technique, as well as variable options are important in lead revision and can be dictated based on reason for revision. Over time patients who have had adequate relief with DBS placement may experience loss of efficacy and development of adverse effects requiring revision of the DBS lead to maintain its effects. © 2016 International Neuromodulation Society.

  20. Vagus nerve stimulation after lead revision.

    Science.gov (United States)

    Dlouhy, Brian J; Viljoen, Steven V; Kung, David K; Vogel, Timothy W; Granner, Mark A; Howard, Matthew A; Kawasaki, Hiroto

    2012-03-01

    Vagus nerve stimulation (VNS) has demonstrated benefit in patients with medically intractable partial epilepsy. As in other therapies with mechanical devices, hardware failure occurs, most notably within the VNS lead, requiring replacement. However, the spiral-designed lead electrodes wrapped around the vagus nerve are often encased in dense scar tissue hampering dissection and removal. The objective in this study was to characterize VNS lead failure and lead revision surgery and to examine VNS efficacy after placement of a new electrode on the previously used segment of vagus nerve. The authors reviewed all VNS lead revisions performed between October 2001 and August 2011 at the University of Iowa Hospitals and Clinics. Twenty-four patients underwent 25 lead revisions. In all cases, the helical electrodes were removed, and a new lead was placed on the previously used segment of vagus nerve. All inpatient and outpatient records of the 25 lead revisions were retrospectively reviewed. Four cases were second lead revisions, and 21 cases were first lead revisions. The average time to any revision was 5 years (range 1.8-11.1 years), with essentially no difference between a first and second lead revision. The most common reason for a revision was intrinsic lead failure resulting in high impedance (64%), and the most common symptom was increased seizure frequency (72%). The average duration of surgery for the initial implantation in the 15 patients whose VNS system was initially implanted at the authors' institution was much shorter (94 minutes) than the average duration of lead revision surgery (173 minutes). However, there was a significant trend toward shorter surgical times as more revision surgeries were performed. Sixteen of the 25 cases of lead revision were followed up for more than 3 months. In 15 of these 16 cases, the revision was as effective as the previous VNS lead. In most of these cases, both the severity and frequency of seizures were decreased to levels

  1. Revision of IAU Style Manual

    Science.gov (United States)

    Wilkins, G. A.

    The 1989 edition of the "IAU Style Manual" is in need of revision to reflect the changes in practice that have taken place since its preparation. These changes include the use of desk-top systems for the production of high-quality copy, the electronic transmission of text with embedded typesetting codes and the electronic publication of papers and reports, which may contain numerical data and images. The Manual should give advice and recommendations about the new procedures and typographical formats, but it is more important than ever that it should give clear and appropriate recommendations on matters that affect the quality of the content of all astronomical publications. The Manual should provide especially for the needs of astronomers who do not have English as their first language and it should include advice to them on the oral presentation of their papers. The editor. G. A. Wilkins, would be pleased to have the assistance of astronomers and others who are concerned with the quality of astronomical publications and who would be willing to participate in any aspect of the revision.

  2. Main features and possibilities of the new scale module for calculation of sensitivity and uncertainty by sampling: SAMPLER; Principlaes caracteristicas y posibilidades del nuevo modulo de SCALE 6.2 para calculo de sensibilidad e incertidumbre por muestreo: SAMPLER

    Energy Technology Data Exchange (ETDEWEB)

    Mesado, C.; Miro, R.; Barrachina, T.; Verdu, G.

    2014-07-01

    Due to the importance of calculating sensitivity and uncertainty in the calculation of field engineering, and especially in the nuclear world, it has been decided to present the main features of the new module present in the new version of SCALE 6.2 (currently beta 3 version) called SAMPLER. This module allows the calculation of uncertainty in a wide range of effective sections, neutron parameters, composition and physical parameters. However, the calculation of sensitivity is not present in the beta 3 release. Even so, this module can be helpful for participants of the proposed Benchmark by Expert Group on Uncertainty Analysis in Modelling (UAM-LWR), as well as to analysts in general. (Author)

  3. Sensor transition failure in the high flow sampler: Implications for methane emission inventories of natural gas infrastructure.

    Science.gov (United States)

    Howard, Touché; Ferrara, Thomas W; Townsend-Small, Amy

    2015-07-01

    Quantification of leaks from natural gas (NG) infrastructure is a key step in reducing emissions of the greenhouse gas methane (CH4), particularly as NG becomes a larger component of domestic energy supply. The U.S. Environmental Protection Agency (EPA) requires measurement and reporting of emissions of CH4 from NG transmission, storage, and processing facilities, and the high-flow sampler (or high-volume sampler) is one of the tools approved for this by the EPA. The Bacharach Hi-Flow Sampler (BHFS) is the only commercially available high-flow instrument, and it is also used throughout the NG supply chain for directed inspection and maintenance, emission factor development, and greenhouse gas reduction programs. Here we document failure of the BHFS to transition from a catalytic oxidation sensor used to measure low NG (~5% or less) concentrations to a thermal conductivity sensor for higher concentrations (from ~5% to 100%), resulting in underestimation of NG emission rates. Our analysis includes both our own field testing and analysis of data from two other studies (Modrak et al., 2012; City of Fort Worth, 2011). Although this failure is not completely understood, and although we do not know if all BHFS models are similarly affected, sensor transition failure has been observed under one or more of these conditions: (1) Calibration is more than ~2 weeks old; (2) firmware is out of date; or (3) the composition of the NG source is less than ~91% CH4. The extent to which this issue has affected recent emission studies is uncertain, but the analysis presented here suggests that the problem could be widespread. Furthermore, it is critical that this problem be resolved before the onset of regulations on CH4 emissions from the oil and gas industry, as the BHFS is a popular instrument for these measurements. An instrument commonly used to measure leaks in natural gas infrastructure has a critical sensor transition failure issue that results in underestimation of leaks, with

  4. Relative efficiencies of the Burkard 7-Day, Rotorod and Burkard Personal samplers for Poaceae and Urticaceae pollen under field conditions

    DEFF Research Database (Denmark)

    Peel, Robert George; Kennedy, Roy; Smith, Matt

    2014-01-01

    Introduction: In aerobiological studies it is often necessary to compare concentration data recorded with different models of sampling instrument. Sampler efficiency typically varies from device to device, and depends on the target aerosol and local atmospheric conditions. To account for these di...

  5. Development of a soil fugacity sampler for determination of air-soil partitioning of persistent organic pollutants under field controlled conditions.

    Science.gov (United States)

    Cabrerizo, Ana; Dachs, Jordi; Barceló, Damià

    2009-11-01

    Soils are the main reservoir of persistent organic pollutants (POPs) and thus air-soil exchange and partitioning are key processes controlling the fate and transport of POPs at regional and global scales. To date, soil fugacity has been estimated from models of the soil-air partition coefficients, with the associated unavoidable uncertainties; or by experimental procedures in the laboratory with uncertain application in field conditions. The development of an operational soil fugacity sampler is presented here; one which ensures optimal field data of the POP fugacity in soil and environmentally relevant surface (soil+grass, etc.) and therefore ensuring accurate soil-air partition coefficients and surface-air fugacity gradients. The sampler flow rate is optimized, sampler reproducibility is assessed, and equilibrium between the gas and soil concentrations of polychlorinated biphenyls and polycyclic aromatic hydrocarbons is demonstrated. The development and comprehensive validation of a soil fugacity sampler opens the door for the first time to field studies that accurately determine the variables driving the soil-air partitioning and fluxes of POPs.

  6. A multi-variate statistical model integrating passive sampler and meteorology data to predict the frequency distributions of hourly ambient ozone (O3) concentrations.

    Science.gov (United States)

    Krupa, S; Nosal, M; Ferdinand, J A; Stevenson, R E; Skelly, J M

    2003-01-01

    A multi-variate, non-linear statistical model is described to simulate passive O3 sampler data to mimic the hourly frequency distributions of continuous measurements using climatologic O3 indicators and passive sampler measurements. The main meteorological parameters identified by the model were, air temperature, relative humidity, solar radiation and wind speed, although other parameters were also considered. Together, air temperature, relative humidity and passive sampler data by themselves could explain 62.5-67.5% (R(2)) of the corresponding variability of the continuously measured O3 data. The final correlation coefficients (r) between the predicted hourly O3 concentrations from the passive sampler data and the true, continuous measurements were 0.819-0.854, with an accuracy of 92-94% for the predictive capability. With the addition of soil moisture data, the model can lead to the first order approximation of atmospheric O3 flux and plant stomatal uptake. Additionally, if such data are coupled to multi-point plant response measurements, meaningful cause-effect relationships can be derived in the future.

  7. Modeling the uptake of neutral organic chemicals on XAD passive air samplers under variable temperatures, external wind speeds and ambient air concentrations (PAS-SIM).

    Science.gov (United States)

    Armitage, James M; Hayward, Stephen J; Wania, Frank

    2013-01-01

    The main objective of this study was to evaluate the performance and demonstrate the utility of a fugacity-based model of XAD passive air samplers (XAD-PAS) designed to simulate the uptake of neutral organic chemicals under variable temperatures, external wind speeds and ambient air concentrations. The model (PAS-SIM) simulates the transport of the chemical across the air-side boundary layer and within the sampler medium, which is segmented into a user-defined number of thin layers. Model performance was evaluated using data for polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from a field calibration study (i.e., active and XAD-PAS data) conducted in Egbert, Ontario, Canada. With some exceptions, modeled PAS uptake curves are in good agreement with the empirical PAS data. The results are highly encouraging, given the uncertainty in the active air sampler data used as input and other uncertainties related to model parametrization (e.g., sampler-air partition coefficients, the influence of wind speed on sampling rates). The study supports the further development and evaluation of the PAS-SIM model as a diagnostic (e.g., to aid interpretation of calibration studies and monitoring data) and prognostic (e.g., to inform design of future passive air sampling campaigns) tool.

  8. Investigation of the Efficiencies of Bioaerosol Samplers for Collecting Aerosolized Bacteria Using a Fluorescent Tracer. II: Sampling Efficiency and Half-Life Time

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Doornenbal, P.; Huynh, T.T.T.; Groot Koerkamp, P.W.G.; Landman, W.J.M.; Jong, de M.C.M.

    2011-01-01

    Using uranine as a physical tracer, this study assessed the sampling efficiencies of four bioaerosol samplers (Andersen 6-stage impactor, all glass impinger “AGI-30,” OMNI-3000, and Airport MD8 with gelatin filter) for collecting Gram-positive bacteria (Enterococcus faecalis), Gram-negative bacteria

  9. 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

  10. The determination of nitrogen dioxide in ambient air with free hanging filters as passive samplers, and a new calibration method using fritted bubblers

    NARCIS (Netherlands)

    Heeres, P.; Setiawan, R.; Krol, M.C.; Adema, E.H.

    2009-01-01

    This paper describes two new methods for the determination of NO2 in the ambient air. The first method consists of free hanging filters with a diameter of 2.5 cm as passive samplers. The filters are impregnated with triethanolamine to bind NO2. With standard colorimetrical analysis, the amount of

  11. Investigation of the tritium release from Building 324 in which the stack tritium sampler was off, April 14 through 17, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.H.

    1998-06-30

    On April 14, 1998, a Pacific Northwest National Laboratory (PNNL) researcher performing work in the Building 324 facility approached facility management and asked if facility management could turn off the tritium sampler in the main exhaust stack. The researcher was demonstrating the feasibility of treating components from dismantled nuclear weapons in a device called a plasma arc furnace and was concerned that the sampler would compromise classified information. B and W Hanford Company (BWHC) operated the facility, and PNNL conducted research as a tenant in the facility. The treatment of 200 components in the furnace would result in the release of up to about 20 curies of tritium through the facility stack. The exact quantity of tritium was calculated from the manufacturing data for the weapons components and was known to be less than 20 curies. The Notice of Construction (NOC) approved by the Washington State Department of Health (WDOH) had been modified to allow releasing 20 curies of tritium through the stack in support of this research. However, there were irregularities in the way the NOC modification was processed. The researcher was concerned that data performed on the sampler could be used to back-calculate the tritium content of the components, revealing classified information about the design of nuclear weapons. He had discussed this with the PNNZ security organization, and they had told him that data from the sampler would be classified. He was also concerned that if he could not proceed with operation of the plasma arc furnace, the furnace would be damaged. The researcher told BWHC management that the last time the furnace was shut down and restarted it had cost $0.5 million and caused a six month delay in the project`s schedule. He had already begun heating up the furnace before recognizing the security problem and was concerned that stopping the heatup could damage the furnace. The NOC that allowed the research did not have an explicit requirement to

  12. Field evaluation and calibration of a small axial passive air sampler for gaseous and particle bound polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs.

    Science.gov (United States)

    Magnusson, Roger; Arnoldsson, Kristina; Lejon, Christian; Hägglund, Lars; Wingfors, Håkan

    2016-09-01

    Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated analogues (OPAHs) are ubiquitous air pollutants known to cause adverse health effects. PAH air levels are commonly monitored by active sampling but passive sampling has become popular because of its lower cost and simplicity, which facilitate long-term sampling and increased spatial coverage. However, passive samplers are less suitable for short-term sampling and are in general less accurate than active samplers because they require reliable sampling rate (Rs) measurements for individual analytes under diverse environmental conditions. In this study a small passive sampler designed to sample both particle-bound and gaseous compounds was evaluated and calibrated for PAHs and OPAHs in a traffic environment by co-deployment with active samplers for two weeks. Despite the relatively low average air concentrations of PM10 (20 μg/m(3)), PM2.5 (5 μg/m(3)), total PAHs (4.2 ng/m(3)), and OPAHs (2.3 ng/m(3)) at the site, detectable quantities (on average 24 times above blank values) of the full range of PAHs and OPAHs were captured, with low variability (average RSD of 16%). This was accomplished by using a Tenax(®) TA-modified glass fiber substrate that is compatible with highly sensitive thermal desorption GC-MS analysis, which made it possible to achieve detection limits per sample in the pg range. Experiments with inverted samplers revealed that the relative contribution of gravitational settling to the sampling of particles carrying PAHs and OPAHs was around 3.5 times larger than other deposition mechanisms. Average Rs values for individual OPAHs and PAHs were 0.046 ± 0.03 m(3)/day and 0.12 ± 0.07 m(3)/day, respectively, with no appreciable difference between the values for particle-associated and gaseous compounds. Furthermore, the Rs values were competitive with other currently used passive samplers if normalized for substrate area. Overall, the new sampler's performance, simplicity and

  13. Postoperative pain treatment' practice guideline revised

    NARCIS (Netherlands)

    Houweling, P.L.; Molag, M.L.; Boekel, R.L.M. van; Verbrugge, S.J.; Haelst, I.M. van; Hollmann, M.W.

    2013-01-01

    - On the initiative of the Dutch Association of Anaesthesiologists, a multidisciplinary workgroup has revised the 2003 practice guideline on 'Postoperative pain treatment' for adults and children.- The main reason for revision was the availability of new drugs and new methods of administration. The

  14. How to revise a total preorder

    CSIR Research Space (South Africa)

    Booth, R

    2011-02-01

    Full Text Available determining one-step revision. But in those approaches describing a family of operators there is usually little indication of how to proceed uniquely after the first revision step. In this paper we contribute towards addressing that deficiency by providing a...

  15. Taxonimic revision of Endiandra (Lauraceae) in Borneo

    NARCIS (Netherlands)

    Arifiani, Deby

    2001-01-01

    The genus Endiandra R.Br. (Lauraceae) has not been revised since Meissner (1864). Flora treatments and local revisions for this genus of about 100 species have been produced for Peninsular Malaysia (Kochummen, 1989) and Australia (Hyland, 1989) with ten and thirty-eight species, respectively. A

  16. 76 FR 4258 - Occupational Radiation Protection; Revision

    Science.gov (United States)

    2011-01-25

    ...The Department of Energy (DOE) proposes to revise the values in an appendix to its Occupational Radiation Protection requirements. The derived air concentration values for air immersion are calculated using several parameters. One of these, exposure time, is better represented by the hours in the workday, rather than the hours in a calendar day, and is therefore used in the revised calculations.

  17. Revising Matumo's Setswana– English–Setswana Dictionary

    African Journals Online (AJOL)

    rbr

    Abstract: The aim of this article is to design a revision strategy for the Setswana to English side of the Setswana–English–Setswana Dictionary compiled by Z.I. Matumo in 1993. An existing general organic Setswana corpus as well as a dedicated corpus compiled for the purposes of the revision will be used as a basis for ...

  18. Assessing Speaking in the Revised FCE.

    Science.gov (United States)

    Saville, Nick; Hargreaves, Peter

    1999-01-01

    Describes the Speaking Test, which forms part of the revised First Certificate of English (FCE) examination of the University of Cambridge Local Examinations Syndicate. Discusses key revisions, including use of paired-testing format, and notes the role of the oral examiners. Considers why the new design provides improvements in the assessment of…

  19. A taxonomic revision of Harpullia (Sapindaceae)

    NARCIS (Netherlands)

    Leenhouts, P.W.; Vente, Magda

    1982-01-01

    The present taxonomic revision of Harpullia was started by the second author as the main part of her work for a M. Sc. in biology at Leiden University. She concentrated on a revision of the species occurring in New Guinea, paid only a more superficial attention to the rest of the genus. The first

  20. Revising Child Support Orders: The Wisconsin Experience.

    Science.gov (United States)

    Kost, Kathleen A.; And Others

    1996-01-01

    Provides an overview of the Wisconsin child support system. Explores policy and program implications of the child support revision process and makes recommendations for improving revision. Advocates expressing child support orders as a percentage of the noncustodial parents' income to keep the orders updated automatically and replace the need for…

  1. Monitoring polycyclic aromatic hydrocarbons in the Northeast Aegean Sea using Posidonia oceanica seagrass and synthetic passive samplers.

    Science.gov (United States)

    Apostolopoulou, Maria-Venetia; Monteyne, Els; Krikonis, Konstantinos; Pavlopoulos, Kosmas; Roose, Patrick; Dehairs, Frank

    2014-10-15

    The concentrations of 22 polyaromatic hydrocarbons (PAH) in Posidonia oceanica seagrass, sediments, and seawater from the Alexandroupolis Gulf in the Aegean Sea, were investigated from 2007 to 2011. Temporal trends of total PAH contents in P. oceanica and sediments were similar. PAH levels in seawater, sediments, and seagrasses generally decreased with increasing distance from Alexandroupolis Port. Leaves and sheaths of P. oceanica had higher PAH levels than roots and rhizomes. P. oceanica accumulates PAHs and has good potential as a bioindicator of spatiotemporal pollution trends. PAH concentrations were also examined using in situ passive seawater sampling and were compared to results of passive sampling in the laboratory using local sediments and seawater. Levels of high molecular weight PAHs assessed using passive samplers confirmed the decreasing gradient of pollution away from Alexandroupolis Port. Passive sampling also proved useful for investigating sources of PAHs in P. oceanica meadows. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. An alternative method for monitoring carbonyls, and the development of a 24-port fully automated carbonyl sampler for PAMS program

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, S.S.; Ugarova, L. [Atmospheric Analysis and Consulting, Ventura, CA (United States); Fernandes, C.; Guyton, J.; Lee, C.P. [Arizona Dept. of Environmental Quality, Phoenix, AZ (United States)

    1994-12-31

    The authors have investigated the possibility of collecting different aldehydes and ketones on different sorbents such as silica gel, molecular sieve and charcoal followed by solvent extraction, DNPH derivatization and HPLC/UV analysis. Carbonyl collection efficiencies for these sorbents were calculated relative to a DNPH coated C{sub 18} sep-pak cartridge. From a limited number of laboratory experiments, at various concentrations, it appears that silica gel tubes can be used for sampling aldehydes (collection efficiencies {approximately} 1), whereas charcoal tubes are suitable for collecting ketones. Molecular sieve was found to be unsuitable for collecting most of the carbonyl studied. The authors also report the development of a fully automated 24-port carbonyl sampler specially designed for EPA`s PAMS program.

  3. Study of the sealing performance of tubing adapters in gas-tight deep-sea water sampler

    Directory of Open Access Journals (Sweden)

    Haocai Huang

    2014-09-01

    Full Text Available Tubing adapter is a key connection device in Gas-Tight Deep-Sea Water Sampler (GTWS. The sealing performance of the tubing adapter directly affects the GTWS's overall gas tightness. Tubing adapters with good sealing performance can ensure the transmission of seawater samples without gas leakage and can be repeatedly used. However, the sealing performance of tubing adapters made of different materials was not studied sufficiently. With the research discussed in this paper, the materials match schemes of the tubing adapters were proposed. With non-linear finite element contact analysis and sea trials in the South China Sea, it is expected that the recommended materials match schemes not only meet the requirements of tubing adapters’ sealing performance but also provide the feasible options for the following research on tubing adapters in GTWS.

  4. Using performance reference compound-corrected polyethylene passive samplers and caged bivalves to measure hydrophobic contaminants of concern in urban coastal seawaters.

    Science.gov (United States)

    Joyce, Abigail S; Pirogovsky, Mallory S; Adams, Rachel G; Lao, Wenjian; Tsukada, David; Cash, Curtis L; Haw, James F; Maruya, Keith A

    2015-05-01

    Low-density polyethylene (PE) passive samplers containing performance reference compounds (PRCs) were deployed at multiple depths in two urban coastal marine locations to estimate dissolved concentrations of hydrophobic organic contaminants (HOCs), including dichlorodiphenyltrichloroethane (DDT) and its metabolites, polychlorinated biphenyl (PCB) congeners, and polybrominated flame retardants. PE samplers pre-loaded with PRCs were deployed at the surface, mid-column, and near bottom at sites representing the nearshore continental shelf off southern California (Santa Monica Bay, USA) and a mega commercial port (Los Angeles Harbor). After correcting for fractional equilibration using PRCs, concentrations ranged up to 100 pg L(-1) for PCBs and polybrominated diphenyl ethers (PBDEs), 500 pg L(-1) for DDMU and 300 pg L(-1) for DDNU, and to 1000 pg L(-1) for p,p'-DDE. Seawater concentrations of DDTs and PCBs increased with depth, suggesting that bed sediments serve as the source of water column HOCs in Santa Monica Bay. In contrast, no discernable pattern between surface and near-bottom concentrations in Los Angeles Harbor was observed, which were also several-fold lower (DDTs: 45-300 pg L(-1), PCBs: 5-50 pg L(-1)) than those in Santa Monica Bay (DDTs: 2-1100 pg L(-1), PCBs: 2-250 pg L(-1)). Accumulation by mussels co-deployed with the PE samplers at select sites was strongly correlated with PE-estimated seawater concentrations, providing further evidence that these samplers are a viable alternative for monitoring of HOC exposure. Fractional equilibration observed with the PRCs increased with decreasing PRC molar volume indicating the importance of target compound physicochemical properties when estimating water column concentrations using passive samplers in situ. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Calibrated Passive Sampling--Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers.

    Science.gov (United States)

    Pacholski, Andreas

    2016-03-21

    Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% fine dust formation within the EU15. But NH3 emissions also mean a considerable loss of nutrients. Many studies on NH3 emission from organic and mineral fertilizer application have been performed in recent decades. Nevertheless, research related to NH3 emissions after application fertilizers is still limited in particular with respect to relationships to emissions, fertilizer type, site conditions and crop growth. Due to the variable response of crops to treatments, effects can only be validated in experimental designs including field replication for statistical testing. The dominating ammonia loss methods yielding quantitative emissions require large field areas, expensive equipment or current supply, which restricts their application in replicated field trials. This protocol describes a new methodology for the measurement of NH3 emissions on many plots linking a simple semi-quantitative measuring method used in all plots, with a quantitative method by simultaneous measurements using both methods on selected plots. As a semi-quantitative measurement method passive samplers are used. The second method is a dynamic chamber method (Dynamic Tube Method) to obtain a transfer quotient, which converts the semi-quantitative losses of the passive sampler to quantitative losses (kg nitrogen ha(-1)). The principle underlying this approach is that passive samplers placed in a homogeneous experimental field have the same NH3 absorption behavior under identical environmental conditions. Therefore, a transfer co-efficient obtained from single passive samplers can be used to scale the values of all passive samplers used in the same field trial. The method proved valid under a wide range of experimental conditions and is recommended to be used under conditions with bare soil or small canopies (<0.3 m). Results obtained from

  6. SyPRID sampler: A large-volume, high-resolution, autonomous, deep-ocean precision plankton sampling system

    Science.gov (United States)

    Billings, Andrew; Kaiser, Carl; Young, Craig M.; Hiebert, Laurel S.; Cole, Eli; Wagner, Jamie K. S.; Van Dover, Cindy Lee

    2017-03-01

    The current standard for large-volume (thousands of cubic meters) zooplankton sampling in the deep sea is the MOCNESS, a system of multiple opening-closing nets, typically lowered to within 50 m of the seabed and towed obliquely to the surface to obtain low-spatial-resolution samples that integrate across 10 s of meters of water depth. The SyPRID (Sentry Precision Robotic Impeller Driven) sampler is an innovative, deep-rated (6000 m) plankton sampler that partners with the Sentry Autonomous Underwater Vehicle (AUV) to obtain paired, large-volume plankton samples at specified depths and survey lines to within 1.5 m of the seabed and with simultaneous collection of sensor data. SyPRID uses a perforated Ultra-High-Molecular-Weight (UHMW) plastic tube to support a fine mesh net within an outer carbon composite tube (tube-within-a-tube design), with an axial flow pump located aft of the capture filter. The pump facilitates flow through the system and reduces or possibly eliminates the bow wave at the mouth opening. The cod end, a hollow truncated cone, is also made of UHMW plastic and includes a collection volume designed to provide an area where zooplankton can collect, out of the high flow region. SyPRID attaches as a saddle-pack to the Sentry vehicle. Sentry itself is configured with a flight control system that enables autonomous survey paths to low altitudes. In its verification deployment at the Blake Ridge Seep (2160 m) on the US Atlantic Margin, SyPRID was operated for 6 h at an altitude of 5 m. It recovered plankton samples, including delicate living larvae, from the near-bottom stratum that is seldom sampled by a typical MOCNESS tow. The prototype SyPRID and its next generations will enable studies of plankton or other particulate distributions associated with localized physico-chemical strata in the water column or above patchy habitats on the seafloor.

  7. Potentialities of Revised Quantum Electrodynamics

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2013-10-01

    Full Text Available The potentialities of a revised quantum electrodynamic theory (RQED earlier established by the author are reconsidered, also in respect to other fundamental theories such as those by Dirac and Higgs. The RQED theory is characterized by intrinsic linear symmetry breaking due to a nonzero divergence of the electric field strength in the vacuum state, as supported by the Zero Point Energy and the experimentally confirmed Casimir force. It includes the results of electron spin and antimatter by Dirac, as well as the rest mass of elementary particles predicted by Higgs in terms of spontaneous nonlinear symmetry breaking. It will here be put into doubt whether the approach by Higgs is the only theory which becomes necessary for explaining the particle rest masses. In addition, RQED theory leads to new results beyond those being available from the theories by Dirac, Higgs and the Standard Model, such as in applications to leptons and the photon.

  8. Radiological control manual. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Kloepping, R.

    1996-05-01

    This Lawrence Berkeley National Laboratory Radiological Control Manual (LBNL RCM) has been prepared to provide guidance for site-specific additions, supplements and interpretation of the DOE Radiological Control Manual. The guidance provided in this manual is one methodology to implement the requirements given in Title 10 Code of Federal Regulations Part 835 (10 CFR 835) and the DOE Radiological Control Manual. Information given in this manual is also intended to provide demonstration of compliance to specific requirements in 10 CFR 835. The LBNL RCM (Publication 3113) and LBNL Health and Safety Manual Publication-3000 form the technical basis for the LBNL RPP and will be revised as necessary to ensure that current requirements from Rules and Orders are represented. The LBNL RCM will form the standard for excellence in the implementation of the LBNL RPP.

  9. Evaluation of intake efficiencies and associated sediment-concentration errors in US D-77 bag-type and US D-96-type depth-integrating suspended-sediment samplers

    Science.gov (United States)

    Sabol, Thomas A.; Topping, David J.

    2013-01-01

    Accurate measurements of suspended-sediment concentration require suspended-sediment samplers to operate isokinetically, within an intake-efficiency range of 1.0 ± 0.10, where intake efficiency is defined as the ratio of the velocity of the water through the sampler intake to the local ambient stream velocity. Local ambient stream velocity is defined as the velocity of the water in the river at the location of the nozzle, unaffected by the presence of the sampler. Results from Federal Interagency Sedimentation Project (FISP) laboratory experiments published in the early 1940s show that when the intake efficiency is less than 1.0, suspended-sediment samplers tend to oversample sediment relative to water, leading to potentially large positive biases in suspended-sediment concentration that are positively correlated with grain size. Conversely, these experiments show that, when the intake efficiency is greater than 1.0, suspended‑sediment samplers tend to undersample sediment relative to water, leading to smaller negative biases in suspended-sediment concentration that become slightly more negative as grain size increases. The majority of FISP sampler development and testing since the early 1990s has been conducted under highly uniform flow conditions via flume and slack-water tow tests, with relatively little work conducted under the greater levels of turbulence that exist in actual rivers. Additionally, all of this recent work has been focused on the hydraulic characteristics and intake efficiencies of these samplers, with no field investigations conducted on the accuracy of the suspended-sediment data collected with these samplers. When depth-integrating suspended-sediment samplers are deployed under the more nonuniform and turbulent conditions that exist in rivers, multiple factors may contribute to departures from isokinetic sampling, thus introducing errors into the suspended-sediment data collected by these samplers that may not be predictable on the basis

  10. Scar Revision Surgery: The Patient's Perspective

    Directory of Open Access Journals (Sweden)

    Benjamin H Miranda

    2015-11-01

    Full Text Available BackgroundInsufficient satisfaction outcome literature exists to assist consultations for scar revision surgery; such outcomes should reflect the patient's perspective. The aim of this study was to prospectively investigate scar revision patient satisfaction outcomes, according to specified patient-selection criteria.MethodsPatients (250 were randomly selected for telephone contacting regarding scar revisions undertaken between 2007-2011. Visual analogue scores were obtained for scars pre- and post-revision surgery. Surgery selection criteria were; 'presence' of sufficient time for scar maturation prior to revision, technical issues during or wound complications from the initial procedure that contributed to poor scarring, and 'absence' of site-specific or patient factors that negatively influence outcomes. Patient demographics, scar pathogenesis (elective vs. trauma, underlying issue (functional/symptomatic vs. cosmetic and revision surgery details were also collected with the added use of a real-time, hospital database.ResultsTelephone contacting was achieved for 211 patients (214 scar revisions. Satisfaction outcomes were '2% worse, 16% no change, and 82% better'; a distribution maintained between body sites and despite whether surgery was functional/symptomatic vs. cosmetic. Better outcomes were reported by patients who sustained traumatic scars vs. those who sustained scars by elective procedures (91.80% vs. 77.78%, P=0.016 and by females vs. males (85.52% vs. 75.36%, P<0.05, particularly in the elective group where males (36.17% were more likely to report no change or worse outcomes versus females (16.04% (P<0.01.ConclusionsSuccessful scar revision outcomes may be achieved using careful patient selection. This study provides useful information for referring general practitioners, and patient-surgeon consultations, when planning scar revision.

  11. Revision of infected knee arthroplasties in Denmark

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Martin; Jørgensen, Christoffer C; Bagger, Jens

    2016-01-01

    Background and purpose - The surgical treatment of periprosthetic knee infection is generally either a partial revision procedure (open debridement and exchange of the tibial insert) or a 2-stage exchange arthroplasty procedure. We describe the failure rates of these procedures on a nationwide...... basis. Patients and methods - 105 partial revisions (100 patients) and 215 potential 2-stage revision procedures (205 patients) performed due to infection from July 1, 2011 to June 30, 2013 were identified from the Danish Knee Arthroplasty Register (DKR). Failure was defined as surgically related death...

  12. Quantum Field Theory, Revised Edition

    Science.gov (United States)

    Mandl, F.; Shaw, G.

    1994-01-01

    Quantum Field Theory Revised Edition F. Mandl and G. Shaw, Department of Theoretical Physics, The Schuster Laboratory, The University, Manchester, UK When this book first appeared in 1984, only a handful of W± and Z° bosons had been observed and the experimental investigation of high energy electro-weak interactions was in its infancy. Nowadays, W± bosons and especially Z° bosons can be produced by the thousand and the study of their properties is a precise science. We have revised the text of the later chapters to incorporate these developments and discuss their implications. We have also taken this opportunity to update the references throughout and to make some improvements in the treatment of dimen-sional regularization. Finally, we have corrected some minor errors and are grateful to various people for pointing these out. This book is designed as a short and simple introduction to quantum field theory for students beginning research in theoretical and experimental physics. The three main objectives are to explain the basic physics and formalism of quantum field theory, to make the reader fully proficient in theory calculations using Feynman diagrams, and to introduce the reader to gauge theories, which play such a central role in elementary particle physics. The theory is applied to quantum electrodynamics (QED), where quantum field theory had its early triumphs, and to weak interactions where the standard electro-weak theory has had many impressive successes. The treatment is based on the canonical quantization method, because readers will be familiar with this, because it brings out lucidly the connection between invariance and conservation laws, and because it leads directly to the Feynman diagram techniques which are so important in many branches of physics. In order to help inexperienced research students grasp the meaning of the theory and learn to handle it confidently, the mathematical formalism is developed from first principles, its physical

  13. Guidelines for the use of the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS) in environmental monitoring studies

    Science.gov (United States)

    Alvarez, David A.

    2010-01-01

    The success of an environmental monitoring study using passive samplers, or any sampling method, begins in the office or laboratory. Regardless of the specific methods used, the general steps include the formulation of a sampling plan, training of personnel, performing the field (sampling) work, processing the collected samples to recover chemicals of interest, analysis of the enriched extracts, and interpretation of the data. Each of these areas will be discussed in the following sections with emphasis on specific considerations with the use of passive samplers. Water is an extremely heterogeneous matrix both spatially and temporally (Keith, 1991). The mixing and distribution of dissolved organic chemicals in a water body are controlled by the hydrodynamics of the water, the sorption partition coefficients of the chemicals, and the amount of organic matter (suspended sediments, colloids, and dissolved organic carbon) present. In lakes and oceans, stratification because of changes in temperature, water movement, and water composition can occur resulting in dramatic changes in chemical concentrations with depth (Keith, 1991). Additional complications related to episodic events, such as surface runoff, spills, and other point source contamination, can result in isolated or short-lived pulses of contaminants in the water. The application of passive sampling technologies for the monitoring of legacy and emerging organic chemicals in the environment is becoming widely accepted worldwide. The primary use of passive sampling methods for environmental studies is in the area of surface-water monitoring; however, these techniques have been applied to air and groundwater monitoring studies. Although these samplers have no mechanical or moving parts, electrical or fuel needs which require regular monitoring, there are still considerations that need to be understood in order to have a successful study. Two of the most commonly used passive samplers for organic contaminants are

  14. Revision of Khoikhoiinae (Hymenoptera, Braconidae

    Directory of Open Access Journals (Sweden)

    Michael Sharkey

    2009-09-01

    Full Text Available The species of the two genera of Khoikhoiinae (Hymenoptera, Braconidae are revised. Thirteen species are recognized, of which five are new and eight were previously described: Khoikhoia anthelion Sharkey, sp. n., K. lission Mason, 1984, K. oligospilos Sharkey, sp. n., K. semiadusta Mason, 1983, K. solata Mason, 1983, K. townesi Mason, 1983, K. turneri Mason, 1984, Sania browni Sharkey, sp. n., S. capensis Mason, 1983, S. henryi Mason, 1983, S. marjoriae Mason, 1983, S. masneri Sharkey, sp. n., and S. masoni Sharkey, sp. n.. All are from the Cape Region of South Africa, and all but one species are confined to the western Cape. A dichotomous key to species is presented; links to electronic interactive keys and to distribution maps are also included. Based on phylogenetic position and morphological characters, speculations on life history are made, and it is suggested that some species may be parasitoids of wood- or stem-boring Lepidoptera. The DELTA data matrix and images for the key are available at 10.3897/zookeys.20.108.app.1.ik; Intkey files are available at 10.3897/zookeys.20.108.app.2.ik; Lucid files in LIF and SDD format are available at doi:10.3897/zookeys.20.108.app.3.ik and doi:10.3897/zookeys.20.108.app.4.ik. Publishing of DELTA raw data will facilitate future workers to edit keys and to add newly discovered taxa.

  15. Photon Physics of Revised Electromagnetics

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2006-04-01

    Full Text Available Conventional theory, as based on Maxwell’s equations and associated quantum electrodynamical concepts in the vacuum, includes the condition of zero electric field divergence. In applications to models of the individual photon and to dense light beams such a theory exhibits several discrepancies from experimental evidence. These include the absence of angular momentum (spin, and the lack of spatially limited geometry in the directions transverse to that of the propagation. The present revised theory includes on the other hand a nonzero electric field divergence, and this changes the field equations substantially. It results in an extended quantum electrodynamical approach, leading to nonzero spin and spatially limited geometry for photon models and light beams. The photon models thereby behave as an entirety, having both particle and wave properties and possessing wave-packet solutions which are reconcilable with the photoelectric effect, and with the dot-shaped marks and interference patterns on a screen by individual photons in a two-slit experiment.

  16. MOVES Degree Update: Curriculum Revision Proposal

    OpenAIRE

    Darken, Chris

    2012-01-01

    MOVES Research & Education Systems Seminar: Presentation; Session 1: Educational Initiatives and Status, Moderator: Chris Darken; MOVES Degree Update, Speaker Chris Darken Outline: Brief intro to MOVES Masters degree, Pressures driving the proposed curriculum revision, Salient features of the proposal

  17. Revision of the Neotropical genus Pseudoxandra (Annonaceae)

    NARCIS (Netherlands)

    Maas, P.J.M.; Westra, L.Y.Th.

    2003-01-01

    A taxonomic revision is made of the Neotropical genus Pseudoxandra. This genus forms part of the Cremastosperma alliance which consists of Bocageopsis, Cremastosperma, Ephedranthus, Klarobelia, Malmea, Mosannona, Onychopetalum, Oxandra, Pseudephedranthus, Pseudomalmea, Pseudoxandra, Ruizodendron,

  18. Revised Total Coliform Rule Lab Sampling Form

    Science.gov (United States)

    This form should be completed when a water system collects any required Revised Total Coliform Rule (RTCR) samples. It should also be used when collecting “Special” non-compliance samples for the RTCR.

  19. Revised Total Coliform Webinar for Primacy Agencies

    Science.gov (United States)

    This webinar was created to assist Primacy Agencies in the implementation of the Revised Total Coliform Rule. It provides an overview of the requirements in the rule and implementation guidance for Primacy Agencies.

  20. Descriptor revision belief change through direct choice

    CERN Document Server

    Hansson, Sven Ove

    2017-01-01

    This book provides a critical examination of how the choice of what to believe is represented in the standard model of belief change. In particular the use of possible worlds and infinite remainders as objects of choice is critically examined. Descriptors are introduced as a versatile tool for expressing the success conditions of belief change, addressing both local and global descriptor revision. The book presents dynamic descriptors such as Ramsey descriptors that convey how an agent’s beliefs tend to be changed in response to different inputs. It also explores sentential revision and demonstrates how local and global operations of revision by a sentence can be derived as a special case of descriptor revision. Lastly, the book examines revocation, a generalization of contraction in which a specified sentence is removed in a process that may possibly also involve the addition of some new information to the belief set.

  1. Parker River NWR : Revised Hunting Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains revisions to the 1978 Parker River National Wildlife Refuge Hunt Management Plan. Refuge hunters must obtain a permit to use the hunting...

  2. A taxonomic revision of Nephelium (Sapindaceae)

    NARCIS (Netherlands)

    Leenhouts, P.W.

    1986-01-01

    In the present revision of Nephelium 22 species are recognised, 6 of which are new (1 unnamed). Nephelium cuspidatum is subdivided into 6 varieties and 4 subvarieties; N. lappaceum comprises 3 varieties. The systematic connections within the genus are unclear.

  3. Fast-track revision knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Otte, Niels Kristian Stahl; Kristensen, Billy B

    2011-01-01

    Abstract Background and purpose Fast-track surgery has reduced the length of hospital stay (LOS), morbidity, and convalescence in primary hip and knee arthroplasty (TKA). We assessed whether patients undergoing revision TKA for non-septic indications might also benefit from fast-track surgery....... Methods 29 patients were operated with 30 revision arthroplasties. Median age was 67 (34-84) years. All patients followed a standardized fast-track set-up designed for primary TKA. We determined the outcome regarding LOS, morbidity, mortality, and satisfaction. Results Median LOS was 2 (1-4) days...... undergoing revision TKA for non-septic reasons may be included in fast-track protocols. Outcome appears to be similar to that of primary TKA regarding LOS, morbidity, and satisfaction. Our findings call for larger confirmatory studies and studies involving other indications (revision THA, 1-stage septic...

  4. A taxonomic revision of Willughbeia Roxb. (Apocynaceae)

    NARCIS (Netherlands)

    Middleton, D.J.

    1993-01-01

    The genus Willughbeia Roxb. is revised. A total of 15 species are recognised. One new combination is made. Urnularia Stapf is reduced to synonymy within Willughbeia. Species exclusae have been given as well as an index of exsiccatae.

  5. A Revised Measure of Locus of Control

    Science.gov (United States)

    Clifford, Margaret M.

    1976-01-01

    A revised measure of locus of control for children and a summary of its descriptive statistics is presented. The nature of the instrument is discussed in light of Weiner's two-dimensional attribution table. (Author/MS)

  6. Benthic organisms collected using sediment sampler from the SW RESEARCHER and other platforms in the Gulf of Mexico from 03 February 1978 to 19 October 1978 (NODC Accession 8100491)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the SW RESEARCHER in the Gulf of Mexico from 03 February 1978 to 19 October 1978. Data were...

  7. Benthic organisms and marine toxic substances and pollutants collected using net and sediment samplers from the MT MITCHELL and other platforms from 22 May 1974 to 27 May 1974 (NODC Accession 7800886)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms and marine toxic substances and pollutants were collected using sediment sampler and net casts in the coastal waters of the East coast of US. Data...

  8. Benthic organisms and marine toxic substances and pollutants collected using sediment sampler and net casts from the GUS III and EXCELLENCE in the Gulf of Mexico from 1978-05-24 to 1979-02-26 (NODC Accession 7900304)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms and marine toxic substances and pollutants were collected using sediment sampler and net casts in the Gulf of Mexico. Data were submitted by Texas...

  9. Benthic organism and marine toxic substances and pollutants collected using net and sediment sampler casts from NOAA Ship RESEARCHER in Gulf of Mexico from 1979-07-23 to 1980-12-13 (NODC Accession 8200103)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organism and marine toxic substances and pollutants were collected using net, sediment sampler, and other instruments from NOAA Ship RESEARCHER and other...

  10. Benthic organism collected using sediment sampler, BT, and bottle casts from the EASTWARD and other platforms in Georges' Bank from 10 July 1981 to 08 June 1983 (NODC Accession 8500125)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organism were collected using sediment sampler, BT, and bottle casts from the EASTWARD and other platforms in the Georges' Bank from 10 July 1981 to 08 June...

  11. Benthic organisms data collected using sediment sampler and net casts from NOAA Ship DELAWARE II and other platforms in the New York Blight from 1957-06-19 to 1978-07-20 (NCEI Accession 8000013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms data were collected using sediment sampler and net casts from NOAA Ship DELAWARE II and other platforms in the New York Blight from 19 June 1957 to...

  12. Benthic organisms data collected using sediment sampler casts from NOAA Ship OCEANOGRAPHER in the Chukchi Sea from 1986-09-06 to 1987-10-05 (NCEI Accession 8900299)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms data were collected using sediment sampler casts from NOAA Ship OCEANOGRAPHER in the Chukchi Sea from 06 September 1986 to 05 October 1987. Data...

  13. Benthic organisms collected using sediment sampler and net casts from the GUS III and EXCELLENCE in the Gulf of Mexico from 22 May 1978 to 20 April 1979 (NODC Accession 7900332)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler and net casts in the Gulf of Mexico. Data were submitted by Texas A they may have been collected by point...

  14. Benthic organisms and phytoplankton collected using net and sediment sampler casts from the CAPT. BRADY J and other platforms in Gulf of Mexico from 10 October 1982 to 30 November 1983 (NODC Accession 8400200)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms and phytoplankton were collected using sediment sampler and net casts in the Gulf of Mexico. Data were submitted by Texas A bottom depth and...

  15. Bacteria, taxonomic code, and other data collected from G.W. PIERCE in North Atlantic Ocean from sediment sampler; 20 February 1976 to 23 March 1976 (NODC Accession 7601642)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bacteria, taxonomic code, and other data were collected using sediment sampler and other instruments in the North Atlantic Ocean from G.W. PIERCE. Data were...

  16. Revision total knee arthroplasty using a custom tantalum implant in a patient following multiple failed revisions

    Directory of Open Access Journals (Sweden)

    Colin A. McNamara, BS

    2017-03-01

    Full Text Available The number of revision total knee arthroplasty procedures performed annually is increasing and, subsequently, so is the number of patients presenting following a failed revision. Rerevising a total knee arthroplasty after one or more failed revision procedures presents many challenges, including diminished bone stock for prosthetic fixation. “Off the shelf” implants may not offer the best alternative for reconstruction. We present the case of a 55-year-old patient who required a rerevision total knee arthroplasty following multiple failed revisions with severe femoral and tibia bone loss. We describe a novel technique we employed to improve component fixation within the compromised bone stock.

  17. Outcome, revision rate and indication for revision following resurfacing hemiarthroplasty for osteoarthritis of the shoulder

    DEFF Research Database (Denmark)

    Rasmussen, J V; Polk, A; Sorensen, A K

    2014-01-01

    In this study, we evaluated patient-reported outcomes, the rate of revision and the indications for revision following resurfacing hemiarthroplasty of the shoulder in patients with osteoarthritis. All patients with osteoarthritis who underwent primary resurfacing hemiarthroplasty and reported...... to the Danish Shoulder Arthroplasty Registry (DSR), between January 2006 and December 2010 were included. There were 772 patients (837 arthroplasties) in the study. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index was used to evaluate patient-reported outcome 12 months (10 to 14) post.......001), but with no increased risk of revision. There was no significant difference in the mean WOOS or the risk of revision between designs of resurfacing hemiarthroplasty....

  18. Revised data taking schedule with ion beams

    CERN Document Server

    Gazdzicki, Marek; Aduszkiewicz, A; Andrieu, B; Anticic, T; Antoniou, N; Argyriades, J; Asryan, A G; Baatar, B; Blondel, A; Blumer, J; Boldizsar, L; Bravar, A; Brzychczyk, J; Bubak, A; Bunyatov, S A; Choi, K U; Christakoglou, P; Chung, P; Cleymans, J; Derkach, D A; Diakonos, F; Dominik, W; Dumarchez, J; Engel, R; Ereditato, A; Feofilov, G A; Fodor, Z; Ferrero, A; Gazdzicki, M; Golubeva, M; Grebieszkow, K; Grzeszczuk, A; Guber, F; Hasegawa, T; Haungs, A; Igolkin, S; Ivanov, A S; Ivashkin, A; Kadija, K; Katrynska, N; Kielczewska, D; Kikola, D; Kisiel, J; Kobayashi, T; Kolesnikov, V I; Kolev, D; Kolevatov, R S; Kondratiev, V P; Kowalski, S; Kurepin, A; Lacey, R; Laszlo, A; Lyubushkin, V V; Majka, Z; I Malakhov, A; Marchionni, A; Marcinek, A; Maris, I; Matveev, V; Melkumov, G L; Meregaglia, A; Messina, M; Mijakowski, P; Mitrovski, M; Montaruli, T; Mrówczynski, St; Murphy, S; Nakadaira, T; Naumenko, P A; Nikolic, V; Nishikawa, K; Palczewski, T; Pálla, G; Panagiotou, A D; Peryt, W; Planeta, R; Pluta, J; Popov, B A; Posiadala, M; Przewlocki, P; Rauch, W; Ravonel, M; Renfordt, R; Röhrich, D; Rondio, E; Rossi, B; Roth, M; Rubbia, A; Rybczynski, M; Sadovskii, A; Sakashita, K; Schuster, T; Sekiguchi, T; Seyboth, P; Shibata, M; Sissakian, A N; Skrzypczak, E; Slodkowski, M; Sorin, A S; Staszel, P; Stefanek, G; Stepaniak, J; Strabel, C; Ströbele, H; Susa, T; Szentpétery, I; Szuba, M; Tada, M; Taranenko, A; Tsenov, R; Ulrich, R; Unger, M; Vassiliou, M; Vechernin, V V; Vesztergombi, G; Wlodarczyk, Z; Wojtaszek, A; Zipper, W; CERN. Geneva. SPS and PS Experiments Committee; SPSC

    2009-01-01

    This document presents the revised data taking schedule of NA61 with ion beams. The revision takes into account limitations due to the new LHC schedule as well as final results concerning the physics performance with secondary ion beams. It is proposed to take data with primary Ar and Xe beams in 2012 and 2014, respectively, and to test and use for physics a secondary B beam from primary Pb beam fragmentation in 2010, 2011 and 2013.

  19. Nevada Test Site Radiological Control Manual. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2010-02-09

    This document supersedes DOE/NV/25946--801, “Nevada Test Site Radiological Control Manual,” Revision 0 issued in October 2009. Brief Description of Revision: A minor revision to correct oversights made during revision to incorporate the 10 CFR 835 Update; and for use as a reference document for Tenant Organization Radiological Protection Programs.

  20. Adsorption of norovirus and ostreid herpesvirus type 1 to polymer membranes for the development of passive samplers.

    Science.gov (United States)

    Vincent-Hubert, F; Morga, B; Renault, T; Le Guyader, F S

    2017-04-01

    This study was performed to develop a passive sampling methodology for the detection of two viruses in seawater in the area of shellfish production, the norovirus (NoV), a human pathogen implicated in gastroenteritis outbreaks linked to oyster consumption and the ostreid herpesvirus type 1 (OsHV-1), a virus associated with mass mortalities of Pacific oysters. Commercially, membranes were tested for their capacity to adsorb virus: zetapor, gauze, nylon, low-density polyethylene (LDPE) and polyvinylidene difluoride (PVDF). Laboratory exposures of membranes to contaminated water samples (stool, sewage, seawater) were performed. Our data show that the amount of NoV GII genome per membrane measured with qRT-PCR increased with the time of exposure up to 24 h, for all types of membranes except gauze. After 15 days of exposure, the amount of NoV GII per membrane continued to increase only for nylon and LDPE. The amount of OsHV-1 per zetapor membrane was significantly increased as soon as 4 h of exposure, and after 24 h of exposure for all types of membranes. Exposure of membranes to serial dilutions of various samples revealed that the amount of NoV GII and OsHV-1 per membrane is significantly higher in diluted samples. The detection of NoV and OsHV-1, respectively, with zetapor and PVDF membranes was found to be more efficient than the direct analysis of sewage and seawater. All membranes immersed in contaminated samples adsorbed NoV GII and OsHV-1. The amount of both viruses increased with the time of exposure. Zetapor and PVDF membranes seem to be more adapted to NoV GII and OsHV-1 detection respectively. Membranes tested will be used as passive samplers to improve the detection of virus in oyster production areas. Also, passive samplers could be a valuable tool for microbiome analysis with new generation sequencing. © 2017 The Society for Applied Microbiology.

  1. Design and testing of a new sampler for simplified vacuum-assisted headspace solid-phase microextraction.

    Science.gov (United States)

    Yiantzi, Evangelia; Kalogerakis, Nicolas; Psillakis, Elefteria

    2016-07-13

    The design and testing of a new and low-cost experimental setup used for vacuum-assisted headspace solid-phase microextraction (Vac-HSSPME) is reported here. The device consists of a specially designed O-ring seal screw cap offering gas-tight seal to commercially available headspace vials. The new polytetrafluoroethylene (PTFE) cap was molded by a local manufacturer and had a hole that could tightly accommodate a septum. All operations were performed through the septum: air evacuation of the sampler, sample introduction and HSSPME sampling. The analytical performance of the new sampler was evaluated using 22 mL headspace vials with 9 mL water samples spiked with polychlorinated biphenyls (PCBs). Several experimental parameters were controlled and the optimized conditions were: 1000 rpm agitation speed; 30 min extraction time; 40 °C sampling temperature; polydimethylsiloxane-divinylbenzene (PDMS-DVB) fiber. The lack of accurate Henry's law constant (KH) values and information regarding how they change with temperature was a major limitation in predicting the phase location of evaporation resistance during Vac-HSSPME. Nevertheless, the combined effects of system conditions indicated the increasing importance of gas phase resistance with increasing degree of PCBs chlorination. Stirring enhancements were not recorded for the higher chlorinated PCBs suggesting that the hyperhydrophobic gas/water interface was the preferred location for these compounds. Analytically, the developed method was found to yield linear calibration curves with limits of detection in the sub ng L(-1) level and relative standard deviations ranging between 5.8 and 14%. To compensate for the low recoveries of the higher chlorinated PCB congeners in spiked river water the standard addition methodology was applied. Overall, the compact design of the new and reusable sample container allows efficient HSSPME sampling of organic analytes in water within short extraction times and at low sampling

  2. Calibration and field evaluation of the Chemcatcher® passive sampler for monitoring metaldehyde in surface water.

    Science.gov (United States)

    Castle, Glenn D; Mills, Graham A; Bakir, Adil; Gravell, Anthony; Schumacher, Melanie; Townsend, Ian; Jones, Lewis; Greenwood, Richard; Knott, Stuart; Fones, Gary R

    2018-03-01

    Metaldehyde is a potent molluscicide. It is the active ingredient in most slug pellets used for crop protection. This polar compound is considered an emerging pollutant. Due to its environmental mobility, metaldehyde is frequently detected at impacted riverine sites, often at concentrations above the EU Drinking Water Directive limit of 0.1µgL-1 for an individual pesticide. This presents a problem when such waters are abstracted for use in the production of potable water supplies, as this chemical is difficult to remove using conventional treatment processes. Understanding the sources, transport and fate of this pollutant in river catchments is therefore important. We developed a new variant of the Chemcatcher® passive sampler for monitoring metaldehyde comprising a Horizon Atlantic™ HLB-L disk as the receiving phase overlaid with a polyethersulphone membrane. The sampler uptake rate (Rs) was measured in semi-static laboratory (Rs = 15.7mLday-1) and in-field (Rs = 17.8mLday-1) calibration experiments. Uptake of metaldehyde was linear over a two-week period, with no measurable lag phase. Field trials (five consecutive 14day periods) using the Chemcatcher® were undertaken in eastern England at three riverine sites (4th September-12th November 2015) known to be impacted by the seasonal agricultural use of metaldehyde. Spot samples of water were collected regularly during the deployments, with concentrations of metaldehyde varying widely (~ 0.03-2.90µgL-1) and often exceeding the regulatory limit. Time weighted average concentrations obtained using the Chemcatcher® increased over the duration of the trial corresponding to increasing stochastic inputs of metaldehyde into the catchment. Monitoring data obtained from these devices gives complementary information to that obtained by the use of infrequent spot sampling procedures. This information can be used to develop risk assessments and catchment management plans and to assess the effectiveness of any mitigation

  3. Revision of the DELFIC Particle Activity Module

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, David A [ORNL; Jodoin, Vincent J [ORNL

    2010-09-01

    The Defense Land Fallout Interpretive Code (DELFIC) was originally released in 1968 as a tool for modeling fallout patterns and for predicting exposure rates. Despite the continual advancement of knowledge of fission yields, decay behavior of fission products, and biological dosimetry, the decay data and logic of DELFIC have remained mostly unchanged since inception. Additionally, previous code revisions caused a loss of conservation of radioactive nuclides. In this report, a new revision of the decay database and the Particle Activity Module is introduced and explained. The database upgrades discussed are replacement of the fission yields with ENDF/B-VII data as formatted in the Oak Ridge Isotope Generation (ORIGEN) code, revised decay constants, revised exposure rate multipliers, revised decay modes and branching ratios, and revised boiling point data. Included decay logic upgrades represent a correction of a flaw in the treatment of the fission yields, extension of the logic to include more complex decay modes, conservation of nuclides (including stable nuclides) at all times, and conversion of key variables to double precision for nuclide conservation. Finally, recommended future work is discussed with an emphasis on completion of the overall radiation physics upgrade, particularly for dosimetry, induced activity, decay of the actinides, and fractionation.

  4. Using long-term air monitoring of semi-volatile organic compounds to evaluate the uncertainty in polyurethane-disk passive sampler-derived air concentrations.

    Science.gov (United States)

    Holt, Eva; Bohlin-Nizzetto, Pernilla; Borůvková, Jana; Harner, Tom; Kalina, Jiří; Melymuk, Lisa; Klánová, Jana

    2017-01-01

    Much effort has been made to standardise sampling procedures, laboratory analysis, data analysis, etc. for semi volatile organic contaminants (SVOCs). Yet there are some unresolved issues in regards to comparing measurements from one of the most commonly used passive samplers (PAS), the polyurethane foam (PUF) disk PAS (PUF-PAS), between monitoring networks or different studies. One such issue is that there is no universal means to derive a sampling rate (Rs) or to calculate air concentrations (Cair) from PUF-PAS measurements for SVOCs. Cair was calculated from PUF-PAS measurements from a long-term monitoring program at a site in central Europe applying current understanding of passive sampling theory coupled with a consideration for the sampling of particle associated compounds. Cair were assessed against concurrent active air sampler (AAS) measurements. Use of "site-based/sampler-specific" variables: Rs, calculated using a site calibration, provided similar results for most gas-phase SVOCs to air concentrations derived using "default" values (commonly accepted Rs). Individual monthly PUF-PAS-derived air concentrations for the majority of the target compounds were significantly different (Wilcoxon signed-rank (WSR) test; p < 0.05) to AAS regardless of the input values (site/sampler based or default) used to calculate them. However, annual average PUF-PAS-derived air concentrations were within the same order of magnitude as AAS measurements except for the particle-phase polycyclic aromatic hydrocarbons (PAHs). Underestimation of PUF-derived air concentrations for particle-phase PAHs was attributed to a potential overestimation of the particle infiltration into the PUF-PAS chamber and underestimation of the particle bound fraction of PAHs. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  5. Comparison of three high-flow single-stage impaction-based air samplers for bacteria quantification: DUO SAS SUPER 360, SAMPL'AIR and SPIN AIR

    OpenAIRE

    Sánchez-Muñoz, Marta; Muñoz-Vicente, María; Cobas, Guillermo; Portela, Raquel; Amils, Ricardo; Sánchez, Benigno

    2012-01-01

    Indoor Air Quality (IAQ) can be significantly deteriorated by high levels of bioaerosols that may cause adverse health effects in building occupants. There is no standard method for the quantification of this kind of pollutants and several protocols and sampling devices are used. The aim of this work was to compare three commonly used portable air samplers available in the market. DUO SAS SUPER 360, SAMPL'AIR and SPIN AIR units were tested simultaneously for bacteria quantification in a labor...

  6. Personal samplers of bioavailable pesticides integrated with a hair follicle assay of DNA damage to assess environmental exposures and their associated risks in children.

    Science.gov (United States)

    Vidi, Pierre-Alexandre; Anderson, Kim A; Chen, Haiying; Anderson, Rebecca; Salvador-Moreno, Naike; Mora, Dana C; Poutasse, Carolyn; Laurienti, Paul J; Daniel, Stephanie S; Arcury, Thomas A

    2017-10-01

    Agriculture in the United States employs youth ages ten and older in work environments with high pesticide levels. Younger children in rural areas may also be affected by indirect pesticide exposures. The long-term effects of pesticides on health and development are difficult to assess and poorly understood. Yet, epidemiologic studies suggest associations with cancer as well as cognitive deficits. We report a practical and cost-effective approach to assess environmental pesticide exposures and their biological consequences in children. Our approach combines silicone wristband personal samplers and DNA damage quantification from hair follicles, and was tested as part of a community-based participatory research (CBPR) project involving ten Latino children from farmworker households in North Carolina. Our study documents high acceptance among Latino children and their caregivers of these noninvasive sampling methods. The personal samplers detected organophosphates, organochlorines, and pyrethroids in the majority of the participants (70%, 90%, 80%, respectively). Pesticides were detected in all participant samplers, with an average of 6.2±2.4 detections/participant sampler. DNA damage in epithelial cells from the sheath and bulb of plucked hairs follicles was quantified by immunostaining 53BP1-labled DNA repair foci. This method is sensitive, as shown by dose response analyses to γ radiations where the lowest dose tested (0.1Gy) led to significant increased 53BP1 foci density. Immunolabeling of DNA repair foci has significant advantages over the comet assay in that specific regions of the follicles can be analyzed. In this cohort of child participants, significant association was found between the number of pesticide detections and DNA damage in the papilla region of the hairs. We anticipate that this monitoring approach of bioavailable pesticides and genotoxicity will enhance our knowledge of the biological effects of pesticides to guide education programs and

  7. A revision of Bremia graminicola.

    Science.gov (United States)

    Thines, Marco; Göker, Markus; Spring, Otmar; Oberwinkler, Franz

    2006-06-01

    Bremia graminicola (Chromista, Peronosporales) is a common downy mildew pathogen of Arthraxon spp. (Poaceae) in Central to East Asia and the only species of Bremia parasitic on grasses. Despite its widespread occurrence and apparent differences in host range and morphology compared with other species of the genus, its placement in Bremia has not been challenged for the past 90y. Its current taxonomic position is revised based on sporangiophore morphology and ultrastructure, haustorium morphology, and nu-rDNA sequence analysis. Haustorium morphology and sporangiophore ultrastructure indicate that B. graminicola is not a member of the genus Bremia, which shows affinities to Plasmopara and Paraperonospora. Based on haustorium morphology, B. graminicola appears to be more closely related to Viennotia oplismeni, although the sporangiophore morphology is strikingly different between these two taxa. This is supported by molecular analyses based on a near-representative sample of nuLSU rDNA sequences of downy mildew genera, whereby B. graminicola is revealed as the sister taxon of V. oplismeni with 100 % BS support under all phylogenetic optimality criteria applied. Relationships of this clade to other groups are less clear. However, network and reduced-consensus analyses show that this lack of resolution is mainly due to the ambiguous molecular affinities of Sclerospora graminicola. Omitting this highly divergent taxon results in considerable support for a clade comprised of taxa with globose to pyriform haustoria, including B. lactucae, and for the sister-group relationship of B. graminicola and V. oplismeni with Hyaloperonospora. Consequently, a new genus, Graminivora, is described to accommodate B. graminicola.

  8. A study of aerosol entrapment and the influence of wind speed, chamber design and foam density on polyurethane foam passive air samplers used for persistent organic pollutants.

    Science.gov (United States)

    Chaemfa, Chakra; Wild, Edward; Davison, Brian; Barber, Jonathan L; Jones, Kevin C

    2009-06-01

    Polyurethane foam disks are a cheap and versatile tool for sampling persistent organic pollutants (POPs) from the air in ambient, occupational and indoor settings. This study provides important background information on the ways in which the performance of these commonly used passive air samplers may be influenced by the key environmental variables of wind speed and aerosol entrapment. Studies were performed in the field, a wind tunnel and with microscopy techniques, to investigate deployment conditions and foam density influence on gas phase sampling rates (not obtained in this study) and aerosol trapping. The study showed: wind speed inside the sampler is greater on the upper side of the sampling disk than the lower side and tethered samplers have higher wind speeds across the upper and lower surfaces of the foam disk at a wind speed > or = 4 m/s; particles are trapped on the foam surface and within the body of the foam disk; fine (designed to sample gas phase POPs, entrapment of particles ensures some 'sampling' of particle bound POPs species, such as higher molecular weight PAHs and PCDD/Fs. Further work is required to investigate how quantitative such entrapment or 'sampling' is under different ambient conditions, and with different aerosol sizes and types.

  9. Polyoxymethylene passive samplers to monitor changes in bioavailability and flux of PCBs after activated carbon amendment to sediment in the field.

    Science.gov (United States)

    Beckingham, B; Ghosh, U

    2013-06-01

    Field and laboratory exposures of polyoxymethylene passive samplers to sediments and the water column were applied to monitor changes in bioavailability and flux of polychlorinated biphenyls (PCBs) following a pilot-scale amendment of activated carbon in Grasse River. Following amendment, reductions in passive sampler uptake tracked reductions in bioaccumulation in a freshwater invertebrate, which supports a biological basis for utilizing passive samplers for in situ site investigations following a remediation. Freely dissolved concentrations of PCBs were reduced in sediment pore waters compared to untreated sediments indicating reduced bioavailability of PCBs after activated carbon amendment. Freely dissolved PCB concentrations in sediment pore water in treated sites were also lower than overlying water concentrations indicating a reversal of the sediment from being a source to a sink of PCBs from the water column. These observations indicate that activated carbon amendment to sediment limits contaminant exposure to both the benthic and pelagic food webs through reductions in bioavailability and flux of PCBs into the water column. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. How do PDMS-coated stir bars used as passive samplers integrate concentration peaks of pesticides in freshwater?

    Science.gov (United States)

    Assoumani, A; Margoum, C; Lombard, A; Guillemain, C; Coquery, M

    2017-03-01

    Passive samplers are theoretically capable of integrating variations of concentrations of micropollutants in freshwater and providing accurate average values. However, this property is rarely verified and quantified experimentally. In this study, we investigated, in controlled conditions, how the polydimethylsiloxane-coated stir bars (passive Twisters) can integrate fluctuating concentrations of 20 moderately hydrophilic to hydrophobic pesticides (2.18 pesticide accumulation in the passive Twisters during high concentration peaks of various durations in tap water. We then followed their elimination from the passive Twisters placed in non-contaminated water (experiment no. 1) or in water spiked at low concentrations (experiment no. 2) for 1 week. In the third experiment, we assessed the accuracy of the time-weighted average concentrations (TWAC) obtained from the passive Twisters exposed for 4 days to several concentration variation scenarios. We observed little to no elimination of hydrophobic pesticides from the passive Twisters placed in non-contaminated water and additional accumulation when placed in water spiked at low concentrations. Moreover, passive Twisters allowed determining accurate TWAC (accuracy, determined by TWAC-average measured concentrations ratios, ranged from 82 to 127 %) for the pesticides with Log K ow higher than 4.2. In contrast, fast and large elimination was observed for the pesticides with Log K ow lower than 4.2 and poorer TWAC accuracy (ranging from 32 to 123 %) was obtained.

  11. A suspended-particle rosette multi-sampler for discrete biogeochemical sampling in low-particle-density waters

    Energy Technology Data Exchange (ETDEWEB)

    Breier, J. A.; Rauch, C. G.; McCartney, K.; Toner, B. M.; Fakra, S. C.; White, S. N.; German, C. R.

    2010-06-22

    To enable detailed investigations of early stage hydrothermal plume formation and abiotic and biotic plume processes we developed a new oceanographic tool. The Suspended Particulate Rosette sampling system has been designed to collect geochemical and microbial samples from the rising portion of deep-sea hydrothermal plumes. It can be deployed on a remotely operated vehicle for sampling rising plumes, on a wire-deployed water rosette for spatially discrete sampling of non-buoyant hydrothermal plumes, or on a fixed mooring in a hydrothermal vent field for time series sampling. It has performed successfully during both its first mooring deployment at the East Pacific Rise and its first remotely-operated vehicle deployments along the Mid-Atlantic Ridge. It is currently capable of rapidly filtering 24 discrete large-water-volume samples (30-100 L per sample) for suspended particles during a single deployment (e.g. >90 L per sample at 4-7 L per minute through 1 {mu}m pore diameter polycarbonate filters). The Suspended Particulate Rosette sampler has been designed with a long-term goal of seafloor observatory deployments, where it can be used to collect samples in response to tectonic or other events. It is compatible with in situ optical sensors, such as laser Raman or visible reflectance spectroscopy systems, enabling in situ particle analysis immediately after sample collection and before the particles alter or degrade.

  12. Exposure of bakery and pastry apprentices to airborne flour dust using PM2.5 and PM10 personal samplers

    Directory of Open Access Journals (Sweden)

    Paris Christophe

    2007-11-01

    Full Text Available Abstract Background This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma. Methods Questionnaires on work activity were completed by 286 students. Among them, 34 performed a series of two personal exposure measurements using a PM2.5 and PM10 personal sampler during a complete work shift, one during a cold ("winter" period, and the other during a hot ("summer" period. Results Bakery apprentices experience greater average PM2.5 and PM10 exposures than pastry apprentices (p 10 values among bakers = 1.10 mg.m-3 [standard deviation: 0.83] than in summer (0.63 mg.m-3 [0.36]. While complying with current European occupational limit values, these exposures exceed the ACGIH recommendations set to prevent sensitization to flour dust (0.5 mg.m-3. Over half the facilities had no ventilation system. Conclusion Young bakery apprentices incur substantial exposure to known airways allergens, a situation that might elicit early induction of airways inflammation.

  13. Aquatic passive sampling of perfluorinated chemicals with polar organic chemical integrative sampler and environmental factors affecting sampling rate.

    Science.gov (United States)

    Li, Ying; Yang, Cunman; Bao, Yijun; Ma, Xueru; Lu, Guanghua; Li, Yi

    2016-08-01

    A modified polar organic chemical integrative sampler (POCIS) could provide a convenient way of monitoring perfluorinated chemicals (PFCs) in water. In the present study, the modified POCIS was calibrated to monitor PFCs. The effects of water temperature, pH, and dissolved organic matter (DOM) on the sampling rate (R s) of PFCs were evaluated with a static renewal system. During laboratory validation over a 14-day period, the uptake kinetics of PFCs was linear with the POCIS. DOM and water temperature slightly influenced POCIS uptake rates, which is in consistent with the theory for uptake into POCIS. Therefore, within a narrow span of DOM and water temperatures, it was unnecessary to adjust the R s value for POCIS. Laboratory experiments were conducted with water over pH ranges of 3, 7, and 9. The R s values declined significantly with pH increase for PFCs. Although pH affected the uptake of PFCs, the effect was less than twofold. Application of the R s value to analyze PFCs with POCIS deployed in the field provided similar concentrations obtained from grab samples.

  14. Analysis of hydrogen and methane in seawater by "Headspace" method: Determination at trace level with an automatic headspace sampler.

    Science.gov (United States)

    Donval, J P; Guyader, V

    2017-01-01

    "Headspace" technique is one of the methods for the onboard measurement of hydrogen (H2) and methane (CH4) in deep seawater. Based on the principle of an automatic headspace commercial sampler, a specific device has been developed to automatically inject gas samples from 300ml syringes (gas phase in equilibrium with seawater). As valves, micro pump, oven and detector are independent, a gas chromatograph is not necessary allowing a reduction of the weight and dimensions of the analytical system. The different steps from seawater sampling to gas injection are described. Accuracy of the method is checked by a comparison with the "purge and trap" technique. The detection limit is estimated to 0.3nM for hydrogen and 0.1nM for methane which is close to the background value in deep seawater. It is also shown that this system can be used to analyze other gases such as Nitrogen (N2), carbon monoxide (CO), carbon dioxide (CO2) and light hydrocarbons. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Structure Modify of High-pressure Chamber in Pressure-retaining Sampler for Deep-sea Sediment

    Science.gov (United States)

    Chen, Jiawang; Ge, Han; Fu, Mengru

    2017-10-01

    The titanium alloy high-pressure chamber studied in this paper serves as a key component of the manipulator-held sampler, which has an ability of in-situ pressure-retaining and used for deep-sea sediment in manned submersibles. Finite element analysis (FEA) had been used to analyze the burst of the high-pressure chamber with original structure under simulated deep-sea condition. Numerical results showed that the burst was due to stress concentration on the top rounded surface of the lower section of pressure chamber, so the structure of high-pressure chamber was further designed to eliminate this stress concentration. After improvement, the maximum principal stress of the concentration point on modified structure was 396.672 MPa about two times smaller than that on the original structure (809.282 MPa). Moreover, an experimental test was carried out to verify the modified structure. The experiment results showed that the in-situ pressure-retaining ability of modified high-pressure chamber could achieve 93% under an ambient pressure of 60 MPa, and the ability was 86.7% when exposed to 71.5 MPa.

  16. A recirculation aerosol wind tunnel for evaluating aerosol samplers and measuring particle penetration through protective clothing materials.

    Science.gov (United States)

    Jaques, Peter A; Hsiao, Ta-Chih; Gao, Pengfei

    2011-08-01

    A recirculation aerosol wind tunnel was designed to maintain a uniform airflow and stable aerosol size distribution for evaluating aerosol sampler performance and determining particle penetration through protective clothing materials. The oval-shaped wind tunnel was designed to be small enough to fit onto a lab bench, have optimized dimensions for uniformity in wind speed and particle size distributions, sufficient mixing for even distribution of particles, and minimum particle losses. Performance evaluation demonstrates a relatively high level of spatial uniformity, with a coefficient of variation of 1.5-6.2% for wind velocities between 0.4 and 2.8 m s(-1) and, in this range, 0.8-8.5% for particles between 50 and 450 nm. Aerosol concentration stabilized within the first 5-20 min with, approximately, a count median diameter of 135 nm and geometric standard deviation of 2.20. Negligible agglomerate growth and particle loss are suggested. The recirculation design appears to result in unique features as needed for our research.

  17. Possible malfunction in widely used methane sampler deserves attention but poses limited implications for supply chain emission estimates

    Directory of Open Access Journals (Sweden)

    Ramón A. Alvarez

    2016-12-01

    Full Text Available Abstract Estimates of methane emissions from natural gas production sites in the United States based on recent studies have been questioned due to possible malfunction of the Bacharach Hi Flow® Sampler (BHFS, the primary measurement instrument used for two out of five source types examined in those studies (equipment leaks and chemical injection pumps. Without assessing whether the BHFS malfunction occurred in those studies, we constrain the possible underestimation of emissions associated with the BHFS-based results by excluding potentially affected measurements. Assuming leak emission rates are similar for sites with low and high methane content, U.S. methane emissions from equipment leaks and chemical injection pumps in recent studies could be underestimated by up to 40–80% due to a malfunctioning BHFS. We discuss uncertainties associated with this estimate. While a 40–80% underestimation is important when characterizing individual source categories, the potential implications are attenuated when aggregating emissions across the five sources examined in the recent studies (<12–24%, across all sources in the natural gas production segment (<7–14%, or across the entire supply chain (<2–5%. Therefore, potential errors caused by BHFS malfunction in recent studies would not substantially alter estimates of methane emissions from the U.S. natural gas supply chain. The possible malfunction of such a widely-used instrument deserves further attention to ensure that its use in quantifying emissions from individual supply chain components is not compromised.

  18. Field trial and modeling of uptake rates of in situ lipid-free polyethylene membrane passive sampler.

    Science.gov (United States)

    Anderson, K A; Sethajintanin, D; Sower, G; Quarles, L

    2008-06-15

    Lipid-free polyethylene membrane tubing (LFT) has been further developed in response to a growing need for an inexpensive and simple time-integrative sampling device for dissolved hydrophobic contaminants in water. The LFT sampler is based on the diffusion of dissolved hydrophobic target compounds through the aqueous boundary layer and into the polyethylene membrane, mimicking uptake by organisms. We demonstrate through laboratory and field validation studies that LFT provided the same benefits as many other passive sampling devices, withoutthe potential of analytical interference from lipid impurities. A total of 370 LFTs and semipermeable membrane devices were deployed for 21 days in paired studies at highly urbanized, undeveloped, and two Superfund sites, representing several river conditions. A simple internal surrogate spiking method served as an in situ calibration indicator of the effects of environmental conditions on the uptake rates. A modified extraction method for the LFT increased recoveries while decreasing solvent use and labor compared to other organic extraction procedures. LFT sampling rates were estimated using ratios, in situ calibration and modeling for over 45 target analytes, including PAHs, PCBs, and pesticides.

  19. Chemical and isotopic properties and origin of coarse airborne particles collected by passive samplers in industrial, urban, and rural environments

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Dietze, Volke; Gieré, Reto

    2012-12-01

    Passive air samplers have been installed in industrial, urban, rural and remote forested environments in order to collect coarse airborne particles for subsequent chemical characterization. To identify principal polluting sources, isotopic tracers, such as Sr, Nd and Pb isotopic ratios, have been used. The mass deposition rates (MDRs) of trace metals, determined for each of the studied environments, clearly indicate that industrial and traffic sites are especially affected by air pollution. Elements such as V, Pb, Fe, Cr, Co, Mo, Cd, Ni, As, Sb and Zn are notably enriched in samples from industrial zones, whereas V, Mn, Ba, Sr, Al, U, Th, rare earth elements (REE), Zr, Y, Cs, Rb, Sb, Sn and Cu are principal components of the airborne particles collected close to areas influenced by heavy traffic. The chemical/isotopic baseline composition derived from the airborne particles is the result of mixing of particles from different industrial sources, traffic and fertilizers. The monthly analysis of trace-metal MDRs of the collected airborne particle samples from different stations around the industrial zone allows for the detection of distinct atmospheric dust-deposition events during the year, characterized by high MDRs. "Natural" dusts from regional soil re-suspension, including from more distant regions like the Sahara desert, might overprint the regional atmospheric baseline composition, as suggested by trace metal trajectories in ternary diagrams and by Sr, Nd and Pb isotope data.

  20. In situ bioavailability of DDT and Hg in sediments of the Toce River (Lake Maggiore basin, Northern Italy): accumulation in benthic invertebrates and passive samplers.

    Science.gov (United States)

    Pisanello, Francesca; Marziali, Laura; Rosignoli, Federica; Poma, Giulia; Roscioli, Claudio; Pozzoni, Fiorenzo; Guzzella, Licia

    2016-06-01

    DDT and mercury (Hg) contamination in the Toce River (Northern Italy) was caused by a factory producing technical DDT and using a mercury-cell chlor-alkali plant. In this study, DDT and Hg contamination and bioavailability were assessed by using different approaches: (1) direct evaluation of sediment contamination, (2) assessment of bioaccumulation in native benthic invertebrates belonging to different taxonomic/functional groups, and (3) evaluation of the in situ bioavailability of DDT and Hg using passive samplers. Sampling sites were selected upstream and downstream the industrial plant along the river axis. Benthic invertebrates (Gammaridae, Heptageniidae, and Diptera) and sediments were collected in three seasons and analyzed for DDT and Hg content and the results were used to calculate the biota sediment accumulation factor (BSAF). Polyethylene passive samplers (PEs) for DDT and diffusive gradients in thin films (DGTs) for Hg were deployed in sediments to estimate the concentration of the toxicants in pore water. Analysis for (DDx) were performed using GC-MS. Accuracy was within ±30 % of the certified values and precision was >20 % relative standard deviation (RSD). Total mercury concentrations were determined using an automated Hg mercury analyzer. Precision was >5 % and accuracy was within ±10 % of certified values. The results of all the approaches (analysis of sediment, biota, and passive samplers) showed an increasing contamination from upstream to downstream sites. BSAF values revealed the bioavailability of both contaminants in the study sites, with values up to 49 for DDx and up to 3.1 for Hg. No correlation was found between values in sediments and the organisms. Concentrations calculated using passive samplers were correlated with values in benthic invertebrates, while no correlation was found with concentrations in sediments. Thus, direct analysis of toxicant in sediments does not provide a measurement of bioavailability. On the contrary

  1. Revision Surgery after Vertebroplasty or Kyphoplasty

    Science.gov (United States)

    Ha, Kee-Yong; Kim, Ki-Won; Oh, In-Soo; Park, Sang-Won

    2010-01-01

    Background We wanted to investigate the leading cause of failed vertebroplasty or kyphoplasty. Methods Twelve patients (10 females and 2 males) who underwent revision surgery after vertebroplasty or kyphoplasty were included. In 4 cases, vertebroplasty was done for two or more levels. Six cases with kyphoplasty were included. Through the retrospective review of the radiographic studies and medical record, we analyzed the etiology of the revision surgery. Results Uncontrolled back pain was the main clinical presentation. In 4 cases, neurological symptoms were noted, including one case with conus medullaris syndrome. The average time to the revision surgery after vertebroplasty or kyphoplasty was 15 months. Infection (4 cases) and progressive kyphosis with collapse (8 cases) were the causes for the revision. A solid pattern of inserted bone cement and bone resorption around the cement were noted in the all cases with progressive collapse and kyphosis. Conclusions Infection, misdiagnosis and progressive kyphosis were causes of the revision surgery after vertebroplasty and kyphoplasty. A solid pattern of accumulation of bone cement and peri-cement bone resorption might be related with the progressive collapse. PMID:21119935

  2. Comparison of a disposable sorptive sampler with thermal desorption in a gas chromatographic inlet, or in a dedicated thermal desorber, to conventional stir bar sorptive extraction-thermal desorption for the determination of micropollutants in water.

    Science.gov (United States)

    Wooding, Madelien; Rohwer, Egmont R; Naudé, Yvette

    2017-09-01

    The presence of micropollutants in the aquatic environment is a worldwide environmental concern. The diversity of micropollutants and the low concentration levels at which they may occur in the aquatic environment have greatly complicated the analysis and detection of these chemicals. Two sorptive extraction samplers and two thermal desorption methods for the detection of micropollutants in water were compared. A low-cost, disposable, in-house made sorptive extraction sampler was compared to SBSE using a commercial Twister sorptive sampler. Both samplers consisted of polydimethylsiloxane (PDMS) as a sorptive medium to concentrate micropollutants. Direct thermal desorption of the disposable samplers in the inlet of a GC was compared to conventional thermal desorption using a commercial thermal desorber system (TDS). Comprehensive gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS) was used for compound separation and identification. Ten micropollutants, representing a range of heterogeneous compounds, were selected to evaluate the performance of the methods. The in-house constructed sampler, with its associated benefits of low-cost and disposability, gave results comparable to commercial SBSE. Direct thermal desorption of the disposable sampler in the inlet of a GC eliminated the need for expensive consumable cryogenics and total analysis time was greatly reduced as a lengthy desorption temperature programme was not required. Limits of detection for the methods ranged from 0.0010 ng L-1 to 0.19 ng L-1. For most compounds, the mean (n = 3) recoveries ranged from 85% to 129% and the % relative standard deviation (% RSD) ranged from 1% to 58% with the majority of the analytes having a %RSD of less than 30%. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Resource description and access 2013 revision

    CERN Document Server

    2013-01-01

    This e-book contains the 2013 Revision of RDA: Resource Description and Access, and includes the July 2013 Update. This e-book offers links within the RDA text and the capability of running rudimentary searches of RDA, but please note that this e-book does not have the full range of content or functionality provided by the subscription product RDA Toolkit. Included: A full accumulation of RDA- the revision contains a full set of all current RDA instructions. It replaces the previous version of RDA Print as opposed to being an update packet to that version. RDA has gone through many changes sin

  4. Fugacity gradients of hydrophobic organics across the air-water interface measured with a novel passive sampler.

    Science.gov (United States)

    Wu, Chen-Chou; Yao, Yao; Bao, Lian-Jun; Wu, Feng-Chang; Wong, Charles S; Tao, Shu; Zeng, Eddy Y

    2016-11-01

    Mass transfer of hydrophobic organic contaminants (HOCs) across the air-water interface is an important geochemical process controlling the fate and transport of HOCs at the regional and global scales. However, few studies have characterized concentration or fugacity profiles of HOCs near both sides of the air-water interface, which is the driving force for the inter-compartmental mass transfer of HOCs. Herein, we introduce a novel passive sampling device which is capable of measuring concentration (and therefore fugacity) gradients of HOCs across the air-water interface. Laboratory studies indicated that the escaping fugacity values of polycyclic aromatic hydrocarbons (PAHs) from water to air were negatively correlated to their volatilization half-lives. Results for field deployment were consistent between the passive sampler and an active method, i.e., a combination of grab sampling and liquid-liquid extraction. In general, the fugacity profiles of detected PAHs were indicative of an accumulation mechanism in the surface microlayer of the study regions (Haizhu Lake and Hailing Bay of Guangdong Province, China), while p,p'-DDD tended to volatilize from water to the atmosphere in Hailing Bay. Furthermore, the fugacity profiles of the target analytes increased towards the air-water interface, reflecting the complexity of environmental behavior of the target analytes near the air-water interface. Overall, the passive sampling device provides a novel means to better characterize the air-water diffusive transfer of HOCs, facilitating the understanding of the global cycling of HOCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Complex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers.

    Science.gov (United States)

    Van Metre, Peter C; Alvarez, David A; Mahler, Barbara J; Nowell, Lisa; Sandstrom, Mark; Moran, Patrick

    2017-01-01

    The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers (POCIS) in 100 small streams across the Midwest for about 5 weeks during summer 2013 and analyzed the extracts for 227 pesticide compounds. Analysis of water samples collected weekly for pesticides during POCIS deployment allowed for comparison of POCIS results with periodic water-sampling results. The median number of pesticides detected in POCIS extracts was 62, and 141 compounds were detected at least once, indicating a high level of pesticide contamination of streams in the region. Sixty-five of the 141 compounds detected were pesticide degradates. Mean water concentrations estimated using published POCIS sampling rates strongly correlated with means of weekly water samples collected concurrently, however, the POCIS-estimated concentrations generally were lower than the measured water concentrations. Summed herbicide concentrations (units of ng/POCIS) were greater at agricultural sites than at urban sites but summed concentrations of insecticides and fungicides were greater at urban sites. Consistent with these differences, summed concentrations of herbicides correlate to percent cultivated crops in the watersheds and summed concentrations of insecticides and fungicides correlate to percent urban land use. With the exception of malathion concentrations at nine sites, POCIS-estimated water concentrations of pesticides were lower than aquatic-life benchmarks. The POCIS provide an alternative approach to traditional water sampling for characterizing chronic exposure to pesticides in streams across the Midwest region. Published by Elsevier Ltd.

  6. Novel lineage patterns from an automated water sampler to probe marine microbial biodiversity with ships of opportunity

    Science.gov (United States)

    Stern, Rowena F.; Picard, Kathryn T.; Hamilton, Kristina M.; Walne, Antony; Tarran, Glen A.; Mills, David; McQuatters-Gollop, Abigail; Edwards, Martin

    2015-09-01

    There is a paucity of data on long-term, spatially resolved changes in microbial diversity and biogeography in marine systems, and yet these organisms underpin fundamental ecological processes in the oceans affecting socio-economic values of the marine environment. We report results from a new autonomous Water and Microplankton Sampler (WaMS) that is carried within the Continuous Plankton Recorder (CPR). Whilst the CPR with its larger mesh size (270 μm), is designed to capture larger plankton, the WaMS was designed as an additional device to capture plankton below 50 μm and delicate larger species, often destroyed by net sampling methods. A 454 pyrosequencing and flow cytometric investigation of eukaryotic microbes using the partial 18S rDNA from thirteen WaMS samples collected over three months in the English Channel revealed a wide diversity of organisms. Alveolates, Fungi, and picoplanktonic Chlorophytes were the most common lineages captured despite the small sample volumes (200-250 ml). The survey also identified Cercozoa and MAST heterotrophic Stramenopiles, normally missed in microscopic-based plankton surveys. The most common was the likely parasitic LKM11 Rozellomycota lineage which comprised 43.2% of all reads and are rarely observed in marine pelagic surveys. An additional 9.5% of reads belonged to other parasitic lineages including marine Syndiniales and Ichthyosporea. Sample variation was considerable, indicating that microbial diversity is spatially or temporally patchy. Our study has shown that the WaMS sampling system is autonomous, versatile and robust, and due to its deployment on the established CPR network, is a cost-effective monitoring tool for microbial diversity for the detection of smaller and delicate taxa.

  7. The use of passive membrane samplers to assess organic contaminant inputs at five coastal sites in west Maui, Hawaii

    Science.gov (United States)

    Campbell, Pamela L.; Prouty, Nancy G.; Storlazzi, Curt; D'antonio, Nicole

    2017-07-26

    Five passive membrane samplers were deployed for 28 continuous days at select sites along and near the west Maui coastline to assess organic compounds and contaminant inputs to diverse, shallow coral reef ecosystems. Daily and weekly fluctuations in such inputs were captured on the membranes using integrative sampling. The distribution of organic compounds observed at these five coastal sites showed considerable variation; with high concentrations of terrestrially sourced organic compounds such as C29 sterols and high molecular weight n-alkanes at the strongly groundwater-influenced Kahekili vent site. In comparison, the coastal sites were presumably influenced more by seasonal surface and stream water runoff and therefore had marine-sourced organic compounds and fewer pharmaceuticals and personal care products. The direct correlation to upstream land-use practices was not obvious and may require additional wet-season sampling. Pharmaceuticals and personal care products as well as flame retardants were detected at all sites, and the Kahekili vent site had the highest number of detections. Planned future work must also determine the organic compound and contaminant concentrations adsorbed onto water column particulate matter, because it may also be an important vector for contaminant transport to coral reef ecosystems. The impact of contaminants per individual (such as fecundity and metabolism) as well as per community (such as species abundance and diversity) is necessary for an accurate assessment of environmental stress. Results presented herein provide current contaminant inputs to select nearshore environments along the west Maui coastline captured during the dry season, and they can be useful to aid potential future evaluations and (or) comparisons.

  8. Complex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers

    Science.gov (United States)

    Van Metre, Peter C.; Alvarez, David; Mahler, Barbara J.; Nowell, Lisa H.; Sandstrom, Mark W.; Moran, Patrick W.

    2017-01-01

    The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers (POCIS) in 100 small streams across the Midwest for about 5 weeks during summer 2013 and analyzed the extracts for 227 pesticide compounds. Analysis of water samples collected weekly for pesticides during POCIS deployment allowed for comparison of POCIS results with periodic water-sampling results. The median number of pesticides detected in POCIS extracts was 62, and 141 compounds were detected at least once, indicating a high level of pesticide contamination of streams in the region. Sixty-five of the 141 compounds detected were pesticide degradates. Mean water concentrations estimated using published POCIS sampling rates strongly correlated with means of weekly water samples collected concurrently, however, the POCIS-estimated concentrations generally were lower than the measured water concentrations. Summed herbicide concentrations (units of ng/POCIS) were greater at agricultural sites than at urban sites but summed concentrations of insecticides and fungicides were greater at urban sites. Consistent with these differences, summed concentrations of herbicides correlate to percent cultivated crops in the watersheds and summed concentrations of insecticides and fungicides correlate to percent urban land use. With the exception of malathion concentrations at nine sites, POCIS-estimated water concentrations of pesticides were lower than aquatic-life benchmarks. The POCIS provide an alternative approach to traditional water sampling for characterizing chronic exposure to pesticides in streams across the Midwest region.

  9. Taxi Regulatory Revision in Portland, Oregon : A Case Study

    Science.gov (United States)

    1982-09-01

    Interest in taxi regulatory revision stems from the taxicab's potential to complement or to be an alternative to conventional fixed-route transit. Taxi regulatory revision in Portland, Oregon, and other cities reflects the current awareness to reduce...

  10. Revised Total Coliform Rule Assessments and Corrective Actions

    Science.gov (United States)

    EPA has developed the Revised Total Coliform Rule Assessment and Corrective Actions Guidance Manual for public water systems (e.g., owners and operators) to assist in complying with the requirements of the Revised Total Coliform Rule.

  11. Anomalies of Nuclear Criticality, Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, E. D.; Prichard, Andrew W.; Durst, Bonita E.; Erickson, David; Puigh, Raymond J.

    2010-02-19

    This report is revision 6 of the Anomalies of Nuclear Criticality. This report is required reading for the training of criticality professionals in many organizations both nationally and internationally. This report describes many different classes of nuclear criticality anomalies that are different than expected.

  12. 36 CFR 219.9 - Revision.

    Science.gov (United States)

    2010-07-01

    ... System Land and Resource Management Planning The Framework for Planning § 219.9 Revision. (a) Application... is a review of the overall management of a unit of the National Forest System and an opportunity to... be appropriate for consideration (§ 219.4), any relevant inventories, new data, findings and...

  13. Revision of the African genus Annickia (Annonaceae)

    NARCIS (Netherlands)

    Versteegh, C.P.C.; Sosef, M.S.M.

    2007-01-01

    complete revision, including a key to the species, drawings and distribution maps, of the tropical African Annonaceae genus Annickia (= Enantia Oliv., non Falc.) is presented. The exact phylogenetic position of this genus within the family has long been, and in fact still is, unclear. The status of

  14. Facial Scar Revision: Understanding Facial Scar Treatment

    Science.gov (United States)

    ... facial plastic surgeon Facial Scar Revision Understanding Facial Scar Treatment When the skin is injured from a cut ... A facial plastic surgeon has many options for treating and improving facial scars. “After the accident, I thought I would never ...

  15. Revision of the genus Bromheadia (Orchidaceae)

    NARCIS (Netherlands)

    Kruizinga, J.; Scheindelen, van H.J.; Vogel, de E.F.

    1997-01-01

    This paper is a taxonomic revision of the genus Bromheadia. In Bromheadia sect. Bromheadia seven species and two varieties are recognized. One species, B. pendek, and one variety, B. borneensis var. longiflora, are described as new. Bromheadia philippinensis Ames & Quisumb. is here reduced to

  16. Revision of the genus Mediocalcar (Orchidaceae)

    NARCIS (Netherlands)

    Schuiteman, A.

    1997-01-01

    The genus Mediocalcar is revised. Fifteen species and five subspecies are recognized, of which the following are new: Mediocalcar congestion Schuit., M. umboiense Schuit., M. versteegii J.J. Smith subsp. amphigeneum Schuit., M. versteegii J.J. Smith subsp. intermedium Schuit. and M. versteegii J.J.

  17. A revision of Jatropha (Euphorbiaceae) in Malesia

    NARCIS (Netherlands)

    Welzen, van P.C.; Sweet, F.S.T.; Fernández-Casas, F.J.

    2017-01-01

    Jatropha, a widespread, species rich genus, ranges from the Americas and Caribbean to Africa and India. In Malesia five species occur, all of which were introduced and originated in Central and South America. The five species are revised and an identification key, nomenclature, descriptions,

  18. A revision of Omalanthus (Euphorbiaceae) in Malesia

    NARCIS (Netherlands)

    Esser, H.-J.

    1997-01-01

    Omalanthus is revised for Malesia and the Solomon Islands. For this region, 13 species without subspecific taxa are accepted, namely O. arfakiensis, O. caloneurus, O. fastuosus, O. giganteus, O. grandifolius, O. longistylus, O. macradenius, O. nervosus, O. novoguineensis, O. populifolius, O.

  19. Revised definitions of women's sexual dysfunction

    NARCIS (Netherlands)

    Basson, Rosemary; Leiblum, Sandra; Brotto, Lori; Derogatis, Leonard; Fourcroy, Jean; Fugl-Meyer, Kerstin; Graziottin, Alessandra; Heiman, Julia R.; Laan, Ellen; Meston, Cindy; Schover, Leslie; van Lankveld, Jacques; Schultz, Willibrord Weijmar

    2004-01-01

    INTRODUCTION: Existing definitions of women's sexual disorders are based mainly on genitally focused events in a linear sequence model (desire, arousal and orgasm). AIM: To revise definitions based on an alternative model reflecting women's reasons/incentives for sexual activity beyond any initial

  20. Revised Reynolds Stress and Triple Product Models

    Science.gov (United States)

    Olsen, Michael E.; Lillard, Randolph P.

    2017-01-01

    Revised versions of Lag methodology Reynolds-stress and triple product models are applied to accepted test cases to assess the improvement, or lack thereof, in the prediction capability of the models. The Bachalo-Johnson bump flow is shown as an example for this abstract submission.

  1. Achievement Monitoring Via Item Sampling (Revised).

    Science.gov (United States)

    Romberg, Thomas A.

    As a new program is developed, information must be collected to identify weaknesses, to guide the staff in the revision process, and to formulate decision-making procedures, i.e., formative evaluation techniques are essential. A set of criteria for the information needed in formative evaluation is set-up and a practical strategy for meeting these…

  2. Revision of South African pavement design method

    CSIR Research Space (South Africa)

    Kannemeyer, L

    2015-08-01

    Full Text Available an improved mechanistic-empirical design method has been developed, based on the latest available local and international research and design trends. The process followed during revision as well as some of the key outcomes of this process are presented...

  3. Hermann Weyl's intuitionistic mathematics (revised edition)

    NARCIS (Netherlands)

    Dalen, D. van

    1993-01-01

    It is common knowledge that for a short while Hermann Weyl joined Brouwer in his pursuit of a revision of mathematics according to intuitionistic principles. There is, however, little in the literature that sheds light on Weyl's role, and in particular on Brouwer's reaction to Weyl's allegiance

  4. A revision of Boletellus sect. Ixocephali

    Science.gov (United States)

    Roy E. Halling; Beatriz Ortiz-Santana

    2009-01-01

    Taxa included in Boletellus section Ixocephali sensu Singer are re-evaluated and species limits are clarified in a morphological context. In this revision, we recognize four distinct morphological species: B. jalapensis, B. elatus, B. longicollis, and B. singerii. Among these, we have...

  5. Revising incompletely specified convex probabilistic belief bases

    CSIR Research Space (South Africa)

    Rens, G

    2016-04-01

    Full Text Available We propose a method for an agent to revise its incomplete probabilistic beliefs when a new piece of propositional information is observed. In this work, an agent’s beliefs are represented by a set of probabilistic formulae – a belief base...

  6. Revision of the genus Aponogeton (Aponogetonaceae)

    NARCIS (Netherlands)

    Bruggen, van H.W.E.

    1968-01-01

    After the treatment of Jumelle in the Flore de Madagascar fam. 23 (1936) substantial additions were made and much material has accumulated. Instead of 7 species of Aponogeton distinguished by Jumelle, 11 are recognized in the present revision, among which 3 are new to science. Moreover it was found

  7. A revision of the family Leeaceae

    NARCIS (Netherlands)

    Ridsdale, C.E.

    1974-01-01

    A world wide revision of the family with a general discussion of the systematic position, the affinities within the family, the morphology of leaves, flowers, and seeds, the chromosome number, and the geographic distribution. Types of ruminate endosperm of the seed, previously unknown in the family,

  8. 48 CFR 315.307 - Proposal revisions.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Proposal revisions. 315.307 Section 315.307 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING... factors by the Contracting Officer and Project Officer, with assistance from a cost/price analyst, as...

  9. Fast-track revision knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Otte, Niels Kristian Stahl; Kristensen, Billy B

    2011-01-01

    Abstract Background and purpose Fast-track surgery has reduced the length of hospital stay (LOS), morbidity, and convalescence in primary hip and knee arthroplasty (TKA). We assessed whether patients undergoing revision TKA for non-septic indications might also benefit from fast-track surgery...

  10. INDIRECT WRITTEN CORRECTIVE FEEDBACK, REVISION, AND LEARNING

    Directory of Open Access Journals (Sweden)

    Fatemeh Poorebrahim

    2017-01-01

    Full Text Available Corrective feedback, the necessity of providing it, and how it should be provided has been one of the hot topics in the area of ELT. Amid continuing controversies over whether providing feedback helps L2 learners improve their writing accuracy, many research studies have been undertaken to compare the relative effectiveness of different types of feedback. However, the difference between two types of indirect corrective feedback, namely indication and indication plus location, have not been properly examined yet. Motivated to narrow this gap, this study is designed to compare two groups of Iranian learners, each revising their papers based on one of the aforementioned options. For data analysis, a series of independent samples t tests were employed. The results revealed that the difference between the two groups in their reduction of errors from the original draft to the revision of each task followed a growing trend and became significant. Nonetheless, the difference in accuracy of new pieces of writing fell short of significance. Finally, it was found that error reduction in revision stage cannot be considered as learning. The results of the study, discussed in relation to that of others, implicate that the purpose for which feedback is provided is essential in determining the type of feedback; more explicit feedback is better for revising purposes while more implicit feedback is good for learning purposes.

  11. Revised definitions of women's sexual dysfunction

    NARCIS (Netherlands)

    Basson, Rosemary; Leiblum, Sandra; Brotto, Lori; Derogatis, Leonard; Fourcroy, Jean; Fugl-Meyer, Kerstin; Graziottin, Alessandra; Heiman, Julia R.; Laan, Ellen; Meston, Cindy; Schover, Leslie; van Lankveld, Jacques; Schultz, Willibrord Weijmar

    Introduction. Existing definitions of women's sexual disorders are based mainly on genitally focused events in a linear sequence model (desire, arousal and orgasm). Aim. To revise definitions based on an alternative model reflecting women's reasons/incentives for sexual activity beyond any initial

  12. 76 FR 2291 - TRICARE Reimbursement Revisions

    Science.gov (United States)

    2011-01-13

    ... assistant-at-surgery (e.g., home, office or hospital visit), the combined allowable charge for the procedure... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Office of the Secretary 32 CFR Part 199 RIN 0720-AB43 TRICARE Reimbursement Revisions AGENCY: Office of the...

  13. Revision of the genus Phaeanthus (Annonaceae)

    NARCIS (Netherlands)

    Mols, J.B.; Keßler, P.J.A.

    2000-01-01

    A revision of the genus Phaeanthus Hook.f. & Thomson (Annonaceae) is presented. The genus comprises 8 species. A key to the fruiting and/or flowering specimens of the genus is included. The genus consists of shrubs to small-sized trees from Malesia and Vietnam. It is characterised by sepals and

  14. A High-Speed Continuous Recording High Flow Gas Sampler for Measuring Methane Emissions from Pneumatic Devices at Oil and Natural Gas Production Facilities

    Science.gov (United States)

    Ferrara, T.; Howard, T. M.

    2016-12-01

    Studies attempting to reconcile facility level emission estimates of sources at oil and gas facilities with basin wide methane flux measurements have had limited success. Pneumatic devices are commonly used at oil and gas production facilities for process control or liquid pumping. These devices are powered by pressurized natural gas from the well, so they are known methane sources at these sites. Pneumatic devices are estimated to contribute 14% to 25% of the total greenhouse gas emissions (GHG) from production facilities. Measurements of pneumatic devices have shown that malfunctioning or poorly maintained control systems may be emitting significantly more methane than currently estimated. Emission inventories for these facilities use emission factors from EPA that are based on pneumatic device measurements made in the early 1990's. Recent studies of methane emissions from production facilities have attempted to measure emissions from pneumatic devices by several different methods. These methods have had limitations including alteration of the system being measured, the inability to distinguish between leaks and venting during normal operation, or insufficient response time to account of the time based emission events. We have developed a high speed recording high flow sampler that is capable of measuring the transient emissions from pneumatic devices. This sampler is based on the well-established high flow measurement technique used in oil and gas for quantifying component leak rates. In this paper we present the results of extensive laboratory controlled release testing. Additionally, test data from several field studies where this sampler has been used to measure pneumatic device emissions will be presented.

  15. Engineering Design and Testing of a Novel High-Resolution Trace-Metal Clean Sampler for Profiling and Long-term Deployment Applications

    Science.gov (United States)

    Mueller, A. V.; Crusius, J.; Carlson, K.; Chapin, T. P.

    2016-02-01

    Design, assembly, and testing of a novel in-situ sampler for automated high-frequency trace-metal clean sampling at ocean moorings was undertaken with the goal of improving marine data density for iron (and other metals) by up to a factor of ten relative to existing samplers. Target characteristics are: modular, flexible use (profiling, static moorings, AUV-deployed), high capacity (100-200 samples), low power, low cost ($3k per 100-samples), ability to collect filtered + unfiltered samples, and simple assembly. Smaller sample volumes (10mL) are enabled by recent innovations in analysis techniques, while use of off-the-shelf components enables lower cost and faster development time, although attention must be taken to verify trace-metal cleanliness of materials in commercial products. Standard polypropylene syringes (tips with lock fittings) are adapted as sample chambers through fabrication of a dual (viton) o-ring replacement plunger to prevent barrel contamination between acid washing and sample collection. Syringes are mounted along a (pumped) sampling channel machined into a modular custom-designed 7.5in. HDPE ring; successive rings stack, fitted around the central 3 in. PVC pressure housing containing the pump, batteries, and temperature and pressure sensors. Optional filtering (0.45um) is easily added at the inlet to the pumped sampling line. Syringes, pre-filled with acid for sample preservation, are held "closed" using plastic zipties connected to the plunger pull; individual syringes are selected for filling by breaking a 0.003in. wire (e.g., stainless steel, gold-plated tungsten/rhenium) with a pulse of current or by melting the ziptie loop using a nichrome wire. Multiplexed addressing minimizes required microcontroller output pins and wires between the free-flooded collection chamber and the pressure housing. A novel, custom rotating inlet mounting scheme ensures that the pump tubing inlet remains positioned approximately 1m upstream of the sampler.

  16. Characterization of performance reference compound kinetics and analyte sampling rate corrections under three flow regimes using nylon organic chemical integrative samplers.

    Science.gov (United States)

    Morrison, Shane A; Belden, Jason B

    2016-09-30

    Performance reference compounds (PRCs) can be spiked into passive samplers prior to deployment. If the dissipation kinetics of PRCs from the sampler corresponds to analyte accumulation kinetics, then PRCs can be used to estimate in-situ sampling rates, which may vary depending on environmental conditions. Under controlled laboratory conditions, the effectiveness of PRC corrections on prediction accuracy of water concentrations were evaluated using nylon organic chemical integrative samplers (NOCIS). Results from PRC calibrations suggest that PRC elimination occurs faster under higher flow conditions; however, minimal differences were observed for PRC elimination between fast flow (9.3cm/s) and slow flow (5.0cm/s) conditions. Moreover, minimal differences were observed for PRC elimination from Dowex Optipore L-493; therefore, PRC corrections did not improve results for NOCIS configurations containing Dowex Optipore L-493. Regardless, results suggest that PRC corrections were beneficial for NOCIS configurations containing Oasis HLB; however, due to differences in flow dependencies of analyte sampling rates and PRC elimination rates across the investigated flow regimes, the use of multiple PRC corrections was necessary. As such, a "Best-Fit PRC" approach was utilized for Oasis HLB corrections using caffeine-(13)C3, DIA-d5, or no correction based on the relative flow dependencies of analytes and these PRCs. Although PRC corrections reduced the variability when in-situ conditions differed from laboratory calibrations (e.g. static versus moderate flow), applying PRC corrections under similar flow conditions increases variability in estimated values. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Complications after hip rearthroplastics with revision endoprosthesis.

    Science.gov (United States)

    Maricević, Antun; Erceg, Marinko; Gulan, Goran; Srsen, Darko

    2011-09-01

    The stability of the revision endoprosthesis components is more difficult to achieve than in primary endoprosthesis due to large bone defects and/or decreased bone mass quality. That is the reason for more frequent complications for revision than in primary arthroplasty. The aim of this study was to investigate the frequency of complications in 122 patients who were operated with the revision endoprosthesis in the Department of Orthopedics in University Hospital Split in the period of 1998 to 2007 and accepted to participate in this study. There were 3 patients treated on bought hips. The average follow up time was four years (0.6-10.6). There were 32 (26.2%) males and 90 (73.8%) females. The average age was 70.66 +/- 7.63 years. The average time from operation to physical therapy was 3.53 +/- 2.56 days. There were 27 (21.6%) complications. The most common complication was infection in 9 (7.2%) cases. From those cases, 4 (3.2%) had superficial, and 5 (4%) had deep infection. From other complications, there were 5 (4%) endoprosthesis reluxations, 2 (1.6%) periprosthetic femur fractures, 5 (4%) urinary infections, and 6 (4.8%) other complications (lung mycroembolia, heart infarction, lumbal plexus lesion from L2, spinal cord infarction with paraplegia, pneumonia and severe sacral bed-sore). There were 10 (8%) re-interventions following the revision arthroplasty. The result was good or excellent in 80% of operated patients, satisfied in 17%, and bad in 3%. The revision hip procedures are characterized with a high complications incidence rate. Our results are comparable with the results from literature.

  18. Integrating Relational Reasoning and Knowledge Revision during Reading

    Science.gov (United States)

    Kendeou, Panayiota; Butterfuss, Reese; Van Boekel, Martin; O'Brien, Edward J.

    2017-01-01

    Our goal in this theoretical contribution is to connect research on knowledge revision and relational reasoning. To achieve this goal, first, we review the "knowledge revision components framework" (KReC) that provides an account of knowledge revision processes, specifically as they unfold during reading of texts. Second, we review a…

  19. 78 FR 44596 - Minor Boundary Revision at Yosemite National Park

    Science.gov (United States)

    2013-07-24

    ... National Park Service Minor Boundary Revision at Yosemite National Park AGENCY: National Park Service, Interior. ACTION: Notification of Boundary Revision. SUMMARY: The boundary of Yosemite National Park is... boundary of Yosemite National Park. DATES: The effective date of this boundary revision is July 24, 2013...

  20. Primary and Revision Amputation Surgery in a Tertiary Institution in ...

    African Journals Online (AJOL)

    An increasing trend in the prevalence of revision amputation was found. There was a statistically significant association between diabetic amputees and their having a revision amputation done with p =0.002. Conclusion: Diabetic amputees are at a higher risk of a revision amputation. Counseling and appropriate diagnostic ...

  1. 76 FR 1440 - Notice of Revised Child Outcomes Framework

    Science.gov (United States)

    2011-01-10

    ... HUMAN SERVICES Administration for Children and Families Notice of Revised Child Outcomes Framework AGENCY: Office of Head Start (OHS), HHS. ACTION: Notice of Revised Child Outcomes Framework. SUMMARY: This notice announces and informs the public of the revised Head Start Child Outcomes Framework...

  2. A novel method for sampling the suspended sediment load in the tidal environment using bi-directional time-integrated mass-flux sediment (TIMS) samplers

    Science.gov (United States)

    Elliott, Emily A.; Monbureau, Elaine; Walters, Glenn W.; Elliott, Mark A.; McKee, Brent A.; Rodriguez, Antonio B.

    2017-12-01

    Identifying the source and abundance of sediment transported within tidal creeks is essential for studying the connectivity between coastal watersheds and estuaries. The fine-grained suspended sediment load (SSL) makes up a substantial portion of the total sediment load carried within an estuarine system and efficient sampling of the SSL is critical to our understanding of nutrient and contaminant transport, anthropogenic influence, and the effects of climate. Unfortunately, traditional methods of sampling the SSL, including instantaneous measurements and automatic samplers, can be labor intensive, expensive and often yield insufficient mass for comprehensive geochemical analysis. In estuaries this issue is even more pronounced due to bi-directional tidal flow. This study tests the efficacy of a time-integrated mass sediment sampler (TIMS) design, originally developed for uni-directional flow within the fluvial environment, modified in this work for implementation the tidal environment under bi-directional flow conditions. Our new TIMS design utilizes an 'L' shaped outflow tube to prevent backflow, and when deployed in mirrored pairs, each sampler collects sediment uniquely in one direction of tidal flow. Laboratory flume experiments using dye and particle image velocimetry (PIV) were used to characterize the flow within the sampler, specifically, to quantify the settling velocities and identify stagnation points. Further laboratory tests of sediment indicate that bidirectional TIMS capture up to 96% of incoming SSL across a range of flow velocities (0.3-0.6 m s-1). The modified TIMS design was tested in the field at two distinct sampling locations within the tidal zone. Single-time point suspended sediment samples were collected at high and low tide and compared to time-integrated suspended sediment samples collected by the bi-directional TIMS over the same four-day period. Particle-size composition from the bi-directional TIMS were representative of the array of

  3. Field evaluation of the error arising from inadequate time averaging in the standard use of depth-integrating suspended-sediment samplers

    Science.gov (United States)

    Topping, David J.; Rubin, David M.; Wright, Scott A.; Melis, Theodore S.

    2011-01-01

    Several common methods for measuring suspended-sediment concentration in rivers in the United States use depth-integrating samplers to collect a velocity-weighted suspended-sediment sample in a subsample of a river cross section. Because depth-integrating samplers are always moving through the water column as they collect a sample, and can collect only a limited volume of water and suspended sediment, they collect only minimally time-averaged data. Four sources of error exist in the field use of these samplers: (1) bed contamination, (2) pressure-driven inrush, (3) inadequate sampling of the cross-stream spatial structure in suspended-sediment concentration, and (4) inadequate time averaging. The first two of these errors arise from misuse of suspended-sediment samplers, and the third has been the subject of previous study using data collected in the sand-bedded Middle Loup River in Nebraska. Of these four sources of error, the least understood source of error arises from the fact that depth-integrating samplers collect only minimally time-averaged data. To evaluate this fourth source of error, we collected suspended-sediment data between 1995 and 2007 at four sites on the Colorado River in Utah and Arizona, using a P-61 suspended-sediment sampler deployed in both point- and one-way depth-integrating modes, and D-96-A1 and D-77 bag-type depth-integrating suspended-sediment samplers. These data indicate that the minimal duration of time averaging during standard field operation of depth-integrating samplers leads to an error that is comparable in magnitude to that arising from inadequate sampling of the cross-stream spatial structure in suspended-sediment concentration. This random error arising from inadequate time averaging is positively correlated with grain size and does not largely depend on flow conditions or, for a given size class of suspended sediment, on elevation above the bed. Averaging over time scales >1 minute is the likely minimum duration required

  4. [Indoor air pollution by volatile organic compounds in large buildings: pollution levels and remaining issues after revision of the Act on Maintenance of Sanitation in Buildings in 2002].

    Science.gov (United States)

    Sakai, Kiyoshi; Kamijima, Michihiro; Shibata, Eiji; Ohno, Hiroyuki; Nakajima, Tamie

    2010-09-01

    This study aimed to clarify indoor air pollution levels of volatile organic compounds (VOCs), especially 2-ethyl-1-hexanol (2E1H) in large buildings after revising of the Act on Maintenance of Sanitation in Buildings in 2002. We measured indoor air VOC concentrations in 57 (97%) out of a total of 61 large buildings completed within one year in half of the area of Nagoya, Japan, from 2003 through 2007. Airborne concentrations of 13 carbonyl compounds were determined with diffusion samplers and high-performance liquid chromatography, and of the other 32 VOCs with diffusion samplers and gas chromatography with a mass spectrometer. Formaldehyde was detected in all samples of indoor air but the concentrations were lower than the indoor air quality standard value set in Japan (100 microg/m3). Geometric mean concentrations of the other major VOCs, namely toluene, xylene, ethylbenzene, styrene, p-dichlorobenzene and acetaldehyde were also low. 2E1H was found to be one of the predominating VOCs in indoor air of large buildings. A few rooms in a small number of buildings surveyed showed high concentrations of 2E1H, while low concentrations were observed in most rooms of those buildings as well as in other buildings. It was estimated that about 310 buildings had high indoor air pollution levels of 2E1H, with increase during the 5 years from 2003 in Japan. Indoor air pollution levels of VOCs in new large buildings are generally good, although a few rooms in a small number of buildings showed high concentrations in 2E1H, a possible causative chemical in sick building symptoms. Therefore, 2E1H needs particular attention as an important indoor air pollutant.

  5. A gel probe equilibrium sampler for measuring arsenic porewater profiles and sorption gradients in sediments: I. Laboratory development

    Science.gov (United States)

    Campbell, K.M.; Root, R.; O'Day, P. A.; Hering, J.G.

    2008-01-01

    A gel probe equilibrium sampler has been developed to study arsenic (As) geochemistry and sorption behavior in sediment porewater. The gels consist of a hydrated polyacrylamide polymer, which has a 92% water content. Two types of gels were used in this study. Undoped (clear) gels were used to measure concentrations of As and other elements in sediment porewater. The polyacrylamide gel was also doped with hydrous ferric oxide (HFO), an amorphous iron (Fe) oxyhydroxide. When deployed in the field, HFO-doped gels introduce a fresh sorbent into the subsurface thus allowing assessment of in situ sorption. In this study, clear and HFO-doped gels were tested under laboratory conditions to constrain the gel behavior prior to field deployment. Both types of gels were allowed to equilibrate with solutions of varying composition and re-equilibrated in acid for analysis. Clear gels accurately measured solution concentrations (??1%), and As was completely recovered from HFO-doped gels (??4%). Arsenic speciation was determined in clear gels through chromatographic separation of the re-equilibrated solution. For comparison to speciation in solution, mixtures of As(III) and As(V) adsorbed on HFO embedded in gel were measured in situ using X-ray absorption spectroscopy (XAS). Sorption densities for As(III) and As(V) on HFO embedded in gel were obtained from sorption isotherms at pH 7.1. When As and phosphate were simultaneously equilibrated (in up to 50-fold excess of As) with HFO-doped gels, phosphate inhibited As sorption by up to 85% and had a stronger inhibitory effect on As(V) than As(III). Natural organic matter (>200 ppm) decreased As adsorption by up to 50%, and had similar effects on As(V) and As(III). The laboratory results provide a basis for interpreting results obtained by deploying the gel probe in the field and elucidating the mechanisms controlling As partitioning between solid and dissolved phases in the environment. ?? 2008 American Chemical Society.

  6. Correlations between short-term mobile monitoring and long-term passive sampler measurements of traffic-related air pollution

    Science.gov (United States)

    Riley, Erin A.; Schaal, LaNae; Sasakura, Miyoko; Crampton, Robert; Gould, Timothy R.; Hartin, Kris; Sheppard, Lianne; Larson, Timothy; Simpson, Christopher D.; Yost, Michael G.

    2016-05-01

    Mobile monitoring has provided a means for broad spatial measurements of air pollutants that are otherwise impractical to measure with multiple fixed site sampling strategies. However, the larger the mobile monitoring route the less temporally dense measurements become, which may limit the usefulness of short-term mobile monitoring for applications that require long-term averages. To investigate the stationarity of short-term mobile monitoring measurements, we calculated long term medians derived from a mobile monitoring campaign that also employed 2-week integrated passive sampler detectors (PSD) for NOx, Ozone, and nine volatile organic compounds at 43 intersections distributed across the entire city of Baltimore, MD. This is one of the largest mobile monitoring campaigns in terms of spatial extent undertaken at this time. The mobile platform made repeat measurements every third day at each intersection for 6-10 min at a resolution of 10 s. In two-week periods in both summer and winter seasons, each site was visited 3-4 times, and a temporal adjustment was applied to each dataset. We present the correlations between eight species measured using mobile monitoring and the 2-week PSD data and observe correlations between mobile NOx measurements and PSD NOx measurements in both summer and winter (Pearson's r = 0.84 and 0.48, respectively). The summer season exhibited the strongest correlations between multiple pollutants, whereas the winter had comparatively few statistically significant correlations. In the summer CO was correlated with PSD pentanes (r = 0.81), and PSD NOx was correlated with mobile measurements of black carbon (r = 0.83), two ultrafine particle count measures (r = 0.8), and intermodal (1-3 μm) particle counts (r = 0.73). Principal Component Analysis of the combined PSD and mobile monitoring data revealed multipollutant features consistent with light duty vehicle traffic, diesel exhaust and crankcase blow by. These features were more consistent

  7. The effects of dissolved organic matter and pH on sampling rates for polar organic chemical integrative samplers (POCIS).

    Science.gov (United States)

    Li, Hongxia; Helm, Paul A; Paterson, Gordon; Metcalfe, Chris D

    2011-04-01

    The effect of solution pH and levels of dissolved organic matter (DOM) on the sampling rates for model pharmaceuticals and personal care products (PPCPs) and endocrine disrupting substance (EDS) by polar organic chemical integrative samplers (POCIS) was investigated in laboratory experiments. A commercially available POCIS configuration containing neutral Oasis HLB (hydrophilic-lipophilic balance) resin (i.e. pharmaceutical POCIS) and two POCIS configurations prepared in-house containing MAX and MCX anion and cation exchange resins, respectively were tested for uptake of 21 model PPCPs and EDS, including acidic, phenolic, basic and neutral compounds. Laboratory experiments were conducted with dechlorinated tap water over a pH range of 3, 7 and 9. The effects of DOM were studied using natural water from an oligotrophic lake in Ontario, Canada (i.e. Plastic Lake) spiked with different amounts of DOM (the concentration of dissolved organic carbon ranged from 3 to 5mgL(-1) in uptake experiments). In experiments with the commercial (HLB) POCIS, the MCX-POCIS and the MAX-POCIS, the sampling rates generally increased with pH for basic compounds and declined with pH for acidic compounds. However, the sampling rates were relatively constant across the pH range for phenols with high pKa values (i.e. bisphenol A, estrone, estradiol, triclosan) and for the neutral pharmaceutical, carbamazepine. Thus, uptake was greatest when the amount of the neutral species in solution was maximized relative to the ionized species. Although the solution pH affected the uptake of some model ionic compounds, the effect was by less than a factor of 3. There was no significant effect of DOM on sampling rates from Plastic Lake. However, uptake rates in different aqueous matrixes declined in the order of deionized water>Plastic Lake water>dechlorinated tap water, so other parameters must affect uptake into POCIS, although this influence will be minor. MAX-POCIS and MCX-POCIS showed little advantage

  8. 30 CFR 285.617 - What activities require a revision to my SAP, and when will MMS approve the revision?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What activities require a revision to my SAP... OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 285.617 What activities require a revision to my SAP, and when will MMS approve the revision? (a) You must...

  9. Employee Office Sampler

    Data.gov (United States)

    Social Security Administration — Capture/store/manage end-user work activities at designated times as needed for DOWS sampling. The end-user, e.g., CR, receives a desktop alert when a DOWS sample is...

  10. Navsonde Atmospheric Sampler Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a low-cost, retrievable and reusable, autonomously guided dropsonde capable of deploying from a host aircraft and performing in-situ...

  11. Pyramid Comet Sampler Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on the sampling requirements, we propose an Inverted Pyramid sampling system. Each face of the pyramid includes a cutting blade which is independently actuated...

  12. Standards for vision science libraries: 2014 revision.

    Science.gov (United States)

    Motte, Kristin; Caldwell, C Brooke; Lamson, Karen S; Ferimer, Suzanne; Nims, J Chris

    2014-10-01

    This Association of Vision Science Librarians revision of the "Standards for Vision Science Libraries" aspires to provide benchmarks to address the needs for the services and resources of modern vision science libraries (academic, medical or hospital, pharmaceutical, and so on), which share a core mission, are varied by type, and are located throughout the world. Through multiple meeting discussions, member surveys, and a collaborative revision process, the standards have been updated for the first time in over a decade. While the range of types of libraries supporting vision science services, education, and research is wide, all libraries, regardless of type, share core attributes, which the standards address. The current standards can and should be used to help develop new vision science libraries or to expand the growth of existing libraries, as well as to support vision science librarians in their work to better provide services and resources to their respective users.

  13. Robotic left hepatectomy with revision of hepaticojejunostomy

    Directory of Open Access Journals (Sweden)

    Kuo-Hsin Chen

    2014-04-01

    Full Text Available Laparoscopic hepatectomy and hepaticojejunostomy remain a surgical challenge despite the recent advances in minimally invasive surgery. A robotic surgical system has been developed to overcome the inherent limitations of the traditional laparoscopic approach. However, techniques of robotic hepatectomy have not been well described, and a description of robotic major hepatectomy with bilioenteric anastomosis can be found only in two previous reports. Here, we report a 33-year-old man with a history of choledochocyst resection. The patient experienced repeat cholangitis with left hepatolithiasis during follow-up. Robotic left hepatectomy and revision of hepaticojejunostomy were performed smoothly. The patient recovered uneventfully and remained symptoms-free at a follow-up of 20 months. The robotic approach is beneficial in the fine dissection of the hepatic hilum and revision of hepaticojejunostomy in this particular patient.

  14. Sources and distribution of organic compounds using passive samplers in Lake Mead national recreation area, Nevada and Arizona, and their implications for potential effects on aquatic biota.

    Science.gov (United States)

    Rosen, Michael R; Alvarez, David A; Goodbred, Steven L; Leiker, Thomas J; Patiño, Reynaldo

    2010-01-01

    The delineation of lateral and vertical gradients of organic contaminants in lakes is hampered by low concentrationsand nondetection of many organic compounds in water. Passive samplers (semipermeable membrane devices [SPMDs] and polar organic chemical integrative samplers [POCIS]) are well suited for assessing gradients because they can detect synthetic organic compounds (SOCs) at pg L(-1) concentrations. Semi-permeable membrane devices and POCIS were deployed in Lake Mead, at two sites in Las Vegas Wash, at four sites across Lake Mead, and in the Colorado River downstream from Hoover Dam. Concentrations of hydrophobic SOCs were highest in Las Vegas Wash downstream from waste water and urban inputs and at 8 m depth in Las Vegas Bay (LVB) where Las Vegas Wash enters Lake Mead. The distribution of hydrophobic SOCs showed a lateral distribution across 10 km of Lake Mead from LVB to Boulder Basin. To assess possible vertical gradient SOCs, SPMDs were deployed at 4-m intervals in 18 m of water in LVB. Fragrances and legacy SOCs were found at the greatest concentrations at the deepest depth. The vertical gradient of SOCs indicated that contaminants were generally confined to within 6 m of the lake bottom during the deployment interval. The high SOC concentrations, warmer water temperatures, and higher total dissolved solids concentrations at depth are indicative of a plume of Las Vegas Wash water moving along the lake bottom. The lateral and vertical distribution of SOCs is discussed in the context of other studies that have shown impaired health of fish exposed to SOCs.

  15. Combining passive samplers and biomonitors to evaluate endocrine disrupting compounds in a wastewater treatment plant by LC/MS/MS and bioassay analyses

    Energy Technology Data Exchange (ETDEWEB)

    Liscio, C. [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, via Dodecaneso, 31, 16146 Genova (Italy); Magi, E., E-mail: magie@chimica.unige.i [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, via Dodecaneso, 31, 16146 Genova (Italy); Di Carro, M. [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, via Dodecaneso, 31, 16146 Genova (Italy); Suter, M.J.-F.; Vermeirssen, E.L.M. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Uberlandstrasse 133, 8600 Duebendorf (Switzerland)

    2009-10-15

    Two types of integrative sampling approaches (passive samplers and biomonitors) were tested for their sampling characteristics of selected endocrine disrupting compounds (EDCs). Chemical analyses (LC/MS/MS) were used to determine the amounts of five EDCs (nonylphenol, bisphenol A, estrone, 17beta-estradiol and 17alpha-ethinylestradiol) in polar organic chemical integrative samplers (POCIS) and freshwater mussels (Unio pictorum); both had been deployed in the influent and effluent of a municipal wastewater treatment plant (WWTP) in Genoa, Italy. Estrogenicity of the POCIS samples was assessed using the yeast estrogen screen (YES). Estradiol equivalent values derived from the bioassay showed a positive correlation with estradiol equivalents calculated from chemical analyses data. As expected, the amount of estrogens and EEQ values in the effluent were lower than those in the influent. Passive sampling proved to be the preferred method for assessing the presence of these compounds since employing mussels had several disadvantages both in sampling efficiency and sample analyses. - Passive sampling and biomonitoring were used to determine the amounts of endocrine disrupting compounds in wastewaters.

  16. Evaluation of Passive Samplers for Long-Term Monitoring of Organic Compounds in the Untreated Drinking Water Supply for the City of Eugene, Oregon, September-October 2007

    Science.gov (United States)

    McCarthy, Kathleen A.; Alvarez, David A.; Anderson, Chauncey W.; Cranor, Walter L.; Perkins, Stephanie D.; Schroeder, Vickie

    2009-01-01

    Two types of passive samplers, polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs), were deployed at three sites in the McKenzie River basin during September-October 2007. The McKenzie River is the source of drinking water for the city of Eugene, Oregon, and the work presented here was designed to evaluate the use of POCIS and SMPDs as part of a long-term monitoring plan for the river. Various compounds were detected in extracts from the POCIS and SPMDs, indicating that some compounds of concern are present in the McKenzie River basin, including the intake for the drinking water plant. However, most concentrations were near the quantitation limits of the analytical methods used - generally at subnanogram per liter concentrations - and would not have been detectable with conventional water sampling and analysis methods. These results indicate that both POCIS and SPMDs are well suited to monitor organic compounds in the McKenzie River basin.

  17. Comparison of atmospheric concentrations of currently used pesticides between urban and rural areas during intensive application period in Alsace (France) by using XAD-2® based passive samplers.

    Science.gov (United States)

    Liaud, Celine; Schwartz, Jean-Jacques; Millet, Maurice

    2017-07-03

    XAD-2® passive samplers (PAS) have been exposed simultaneously for 14 days on two sites, one rural and one urban, situated in Alsace (East of France) during intensive pesticides application in agriculture (between March and September). PAS have been extracted and analyzed for current-used pesticides and lindane with an analytical method coupling accelerated solvent extraction (ASE), solid-phase microextraction (SPME) and GC/MS/MS. Results show the detection of pesticides is linked to the period of application and spatial and temporal variabilities can be observed with these PAS during the selected sampling period. The spatial and temporal variability is comparable to the one previously observed by comparing data obtained with PAS with data from Hi.-Vol. samplers in an urban area. Sampling rates were calculated for some pesticides and values are comparable to the data already available in the literature. From these sampling rates, concentrations in ng m -3 of pesticides in PAS have been calculated and are in the same order of magnitude as those obtained with Hi.Vol. sampling during the same period of time.

  18. Revision of the genus Bromheadia (Orchidaceae)

    OpenAIRE

    Kruizinga, J.; Scheindelen, van, H.J.; Vogel, de, E.F.

    1997-01-01

    This paper is a taxonomic revision of the genus Bromheadia. In Bromheadia sect. Bromheadia seven species and two varieties are recognized. One species, B. pendek, and one variety, B. borneensis var. longiflora, are described as new. Bromheadia philippinensis Ames & Quisumb. is here reduced to synonymy. Bromheadia sect. Aporodes has 19 species; 12 species (B. cecieliae, B. coomansii, B. devogelii, B. gracilis, B. graminea, B. grandiflora, B. humilis, B. latifolia, B. lohaniensis, B. longifolia...

  19. Revision of the genus Mediocalcar (Orchidaceae)

    OpenAIRE

    Schuiteman, A.

    1997-01-01

    The genus Mediocalcar is revised. Fifteen species and five subspecies are recognized, of which the following are new: Mediocalcar congestion Schuit., M. umboiense Schuit., M. versteegii J.J. Smith subsp. amphigeneum Schuit., M. versteegii J.J. Smith subsp. intermedium Schuit. and M. versteegii J.J. Smith subsp. vulcanicum Schuit. All species are illustrated by line drawings, several also with colour plates. Aspects of the ecology, biogeography, morphology and systematics of Mediocalcar are di...

  20. 78 FR 59982 - Revisions to Radiation Protection

    Science.gov (United States)

    2013-09-30

    ...The U.S. Nuclear Regulatory Commission (NRC) is issuing final revisions to the following sections of NUREG-0800, ``Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition'': Section 12.1, ``Assuring that Occupational Radiation Exposures Are As Low As Is Reasonably Achievable,'' Section 12.2, ``Radiation Sources,'' Section 12.3 -12.4, ``Radiation Protection Design Features,'' and Section 12.5, ``Operational Radiation Protection Program.''

  1. Food miles to assess sustainability: A revision

    OpenAIRE

    Van Passel, Steven

    2013-01-01

    Sustainability assessment is an essential process in our aim to reach a more sustainable production and consumption pattern. This research revises the food miles concept as a guiding tool to assess sustainability. Food miles measure the distance that food travels from where it is grown or raised to where it is consumed. Three different concepts to assess sustainability are described: (i) food miles, (ii) enhanced food miles, (iii) food chain sustainability. An illustrative case study shows th...

  2. Benchmarking i eksternt regnskab og revision

    DEFF Research Database (Denmark)

    Thinggaard, Frank; Kiertzner, Lars

    2001-01-01

    løbende i en benchmarking-proces. Dette kapitel vil bredt undersøge, hvor man med nogen ret kan få benchmarking-begrebet knyttet til eksternt regnskab og revision. Afsnit 7.1 beskæftiger sig med det eksterne årsregnskab, mens afsnit 7.2 tager fat i revisionsområdet. Det sidste afsnit i kapitlet opsummerer...... betragtningerne om benchmarking i forbindelse med begge områder....

  3. Clinical Outcomes Following Revision Anterior Shoulder Stabilization

    Science.gov (United States)

    Frank, Rachel M.; Mellano, Chris; Shin, Jason J.; Feldheim, Terrence F.; Mascarenhas, Randhir; Yanke, Adam Blair; Cole, Brian J.; Nicholson, Gregory P.; Romeo, Anthony A.; Verma, Nikhil N.

    2015-01-01

    Objectives: The purpose of this study was to determine the clinical outcomes following revision anterior shoulder stabilization performed either via all-arthroscopic soft tissue repair or via Latarjet coracoid transfer. Methods: A retrospective review of prospectively collected data on 91 shoulders undergoing revision anterior shoulder stabilization was performed. All patients underwent prior soft tissue stabilization; those with prior open bone grafting procedures were excluded. For patients with 25% glenoid bone loss, Latarjet was performed (n=28). Patients were queried regarding recurrent instability (subluxation or dislocation). Clinical outcomes were evaluated using validated patient reported outcome questionnaires including the American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST), visual analog scale (VAS) for pain, and Western Ontario Shoulder Instability Index (WOSI). Results: A total of 63 shoulders in 62 patients (46 males, 16 females) with an average age of 23.2 ± 6.9 years were included in the revision arthroscopy group. At an average follow-up of 46.9 ± 16.8 months (range, 15 to 78), the mean WOSI score was 80.1 (range, 15.0 to 100), and there were significant improvements (pLatarjet group. Thirteen (46%) had more than one previous stabilization attempt. ), the average WOSI score was 71.9, and there were significant improvements (pLatarjet. Conclusion: Both arthroscopic revision stabilization and Latarjet coracoid transfer result in satisfactory outcomes in patients who have failed previous arthroscopic capsulolabral repair. Recurrent instability rates were higher in the all-arthroscopic group (19% versus 7%). Longer-term studies are required to determine whether similar results are maintained over time, and to provide guidance on focused clinical indications for this challenging patient population.

  4. Revision of ISO 15859 Aerospace Fluid Standards

    Science.gov (United States)

    Greene, Benjamin; McClure, Mark B.

    2012-01-01

    A detailed review of ISO 15859 "Space Systems - Fluid Characteristics, Sampling and Test Methods" was performed An approach to revising Parts 1-9 and 11-13 was developed and concurred by the NASA Technical Standards Program Office. The approach was to align them with the highest level source documents, and not to program-specific requirements. The updated documents were prepared and presented.

  5. A Revision of Melanesian Heliographa (Diptera, Muscidae)

    OpenAIRE

    Satoshi, SHINONAGA; Adrian C., PONT; Department of Medical Zoology, Faculty of Medicine, Tokyo Medical and Dental University; Department of Entomology, British Museum (Natural History)

    1988-01-01

    The species of the genus Heliographa MALLOCH from Papua New Guinea, the Solomon Islands and the Bismarck Archipelago are revised. The genus is defined and discussed, and a key is given to sixteen species, of which twelve are new : H. acumicornis, H. albistriata, H. bicolorata, H. bismarckensis, H. gressitti, H. ismayi, H. nigrolineata, H. papuensis, H. ruficornis, H. solomonensis, H. xanthisma and H. xanthofemina. Heliographa steini nom. nov. (fasciata (STEIN), preocc.), H. excellens (STEIN) ...

  6. Revised Safety Instruction 41 (IS41 REV.)

    CERN Multimedia

    SC Secretariat

    2005-01-01

    Please note that the Revised Safety Instruction No. 41 (IS41 REV.), entitled 'The use of plastic and other non-metallic materials at CERN with respect to fire safety and radiation resistance' is available on the web at the following url: https://edms.cern.ch/document/335806/LAST_RELEASED Paper copies can also be obtained from the SC Unit Secretariat, e-mail: sc.secretariat@cern.ch SC Secretariat

  7. Guidance document for revision of DOE Order 5820.2A, Radioactive Waste Technical Support Program. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Kudera, D.E.; McMurtrey, C.D.; Meagher, B.G.

    1993-04-01

    This document provides guidance for the revision of DOE Order 5820.2A, ``Radioactive Waste Management.`` Technical Working Groups have been established and are responsible for writing the revised order. The Technical Working Groups will use this document as a reference for polices and procedures that have been established for the revision process. The overall intent of this guidance is to outline how the order will be revised and how the revision process will be managed. In addition, this document outlines technical issues considered for inclusion by a Department of Energy Steering Committee.

  8. Rett Syndrome: Revised Diagnostic Criteria and Nomenclature

    Science.gov (United States)

    Neul, Jeffrey L.; Kaufmann, Walter E.; Glaze, Daniel G.; Christodoulou, John; Clarke, Angus J.; Bahi-Buisson, Nadia; Leonard, Helen; Bailey, Mark E. S.; Schanen, N. Carolyn; Zappella, Michele; Renieri, Alessandra; Huppke, Peter; Percy, Alan K.

    2010-01-01

    Objective Rett syndrome (RTT) is a severe neurodevelopmental disease that affects approximately 1 in 10,000 live female births and is often caused by mutations in Methyl-CpG-binding protein 2 (MECP2). Despite distinct clinical features, the accumulation of clinical and molecular information in recent years has generated considerable confusion regarding the diagnosis of RTT. The purpose of this work was revise and clarify 2002 consensus criteria for the diagnosis of RTT in anticipation of treatment trials. Method RettSearch members, representing the majority of the international clinical RTT specialists, participated in an iterative process to come to a consensus on a revised and simplified clinical diagnostic criteria for RTT. Results The clinical criteria required for the diagnosis of classic and atypical RTT were clarified and simplified. Guidelines for the diagnosis and molecular evaluation of specific variant forms of RTT were developed. Interpretation These revised criteria provide clarity regarding the key features required for the diagnosis of RTT and reinforce the concept that RTT is a clinical diagnosis based on distinct clinical criteria, independent of molecular findings. We recommend that these criteria and guidelines be utilized in any proposed clinical research. PMID:21154482

  9. Diffusive gradients in thin films sampler predicts stress in brown trout (Salmo trutta L.) exposed to aluminum in acid fresh waters.

    Science.gov (United States)

    Røyset, Oddvar; Rosseland, Bjørn Olav; Kristensen, Torstein; Kroglund, Frode; Garmo, Oyvind Aaberg; Steinnes, Eiliv

    2005-02-15

    Increased levels of aluminum ions released from nutrient-poor soils affected by acid rain have been the primary cause of fish deaths in the acidified watersheds of southern Norway. The complex aluminum chemistry in water requires speciation methods to measure the gill-reactive species imposing toxic effects toward fish. Previously, aluminum speciation has mainly followed the fractionation principles outlined by Barnes/Driscoll, and several analogues of these fractionation principles have been used both in situ and in the laboratory. Due to rapid transformation processes, aluminum speciation in water samples may change even during short storage times. Thus, results obtained by laboratory fractionation methods might be misleading for the assessment of potentially toxic aluminum species in the water. Until now, all in situ field fractionation methods have been time and labor consuming. The DGT technique (diffusive gradients in thin films) is a new in situ sampler collecting a fraction of dissolved metal weighted according to the rate of diffusion and dissociation kinetics. In a field experiment with acid surface water we studied the DGT sampler as a new prediction tool for the gill accumulation of aluminum in trout (Salmo trutta L.) and the induced physiological stress responses measured as changes in blood glucose and plasma chloride. Aluminum determined with DGT (DGT-AI) was higher than labile monomeric aluminum (Ali) determined with a laboratory aluminum fractionation procedure (PCV--a pyrocatechol violet analogue of Barnes/Driscoll), a difference due to collection of a fraction of organically complexed aluminum by DGT and a reduction of the Ali fraction during sample storage. DGT-AI predicted the gill uptake and the aluminum-induced physiological stress responses (increased blood glucose and decreased plasma chloride, r2 from 0.6 to 0.9). The results indicate that DGT-AI is a better predictor for the stress response than laboratory-determined Ali, because the DGT

  10. Seamus Heaney and the Belfast Group: Revising on His Own

    Directory of Open Access Journals (Sweden)

    Ashby Bland Crowder

    2016-03-01

    Full Text Available It was Seamus Heaney’s practice to submit poems that were to appear in Death of a Naturalist to the Belfast Group. He did not, however, bring all of them for the weekly discussions and published some just as they had appeared in the journals they were first published in. He did some revising independent of the Group, and this essay argues that when Heaney revised on his own the principles of the Group influenced his practice: he was sometimes successful in those independent revisions, sometimes not. Two poems demonstrate his practice. His revisions of “The Barn” eliminated awkward repetition, achieved clarity, and enhanced the emotion of fear experienced by the boy character. The revisions he made on his own for “Ancestral Photograph”, however, were not all successful; after the Group discussed the poem, Heaney made additional effective revisions, correcting all but one of the original missteps.

  11. Revised group classification of the genus Spiroplasma.

    Science.gov (United States)

    Williamson, D L; Whitcomb, R F; Tully, J G; Gasparich, G E; Rose, D L; Carle, P; Bové, J M; Hackett, K J; Adams, J R; Henegar, R B; Konai, M; Chastel, C; French, F E

    1998-01-01

    Significant changes have been made in the systematics of the genus Spiroplasma (class Mollicutes) since it was expanded by revision in 1987 to include 23 groups and eight sub-groups. Since that time, two additional spiroplasmas have been assigned group numbers and species names. More recently, specific epithets have been assigned to nine previously designated groups and three sub-groups. Also, taxonomic descriptions and species names have been published for six previously ungrouped spiroplasmas. These six new organisms are: Spiroplasma alleghenense (strain PLHS-1T) (group XXVI), Spiroplasma lineolae (strain TALS-2T) (group XXVII), Spiroplasma platyhelix (strain PALS-1T) (group XXVIII), Spiroplasma montanense (strain HYOS-1T) (group XXXI), Spiroplasma helicoides (strain TABS-2T) (group XXXII) and Spiroplasma tabanidicola (strain TAUS-1T) (group XXXIII). Also, group XVII, which became vacant when strain DF-1T (Spiroplasma chrysopicola) was transferred to group VIII, has been filled with strain Tab 4c. The discovery of these strains reflects continuing primary search in insect reservoirs, particularly horse flies and deer files (Diptera: Tabanidae). In the current revision, new group designations for 10 spiroplasma strains, including six recently named organisms, are proposed. Three unnamed but newly grouped spiroplasmas are strain TIUS-1 (group XXIX; ATCC 51751) from a typhiid wasp (Hymenoptera: Tiphiidae), strain BIUS-1 (group XXX; ATCC 51750) from floral surfaces of the tickseed sunflower (Bidens sp.) and strain BARC 1901 (group XXXIV; ATCC 700283). Strain BARC 2649 (ATCC 700284) from Tabanus lineola has been proposed as a new sub-group of group VIII. Strains TIUS-1 and BIUS-1 have unusual morphologies, appearing as helices at only certain stages in culture. In this revision, potentially important intergroup serological relationships observed between strain DW-1 (group II) from a neotropical Drosophila species and certain sub-group representatives of group I

  12. Belief Revision in the GOAL Agent Programming Language

    DEFF Research Database (Denmark)

    Spurkeland, Johannes Svante; Jensen, Andreas Schmidt; Villadsen, Jørgen

    2013-01-01

    Agents in a multiagent system may in many cases find themselves in situations where inconsistencies arise. In order to properly deal with these, a good belief revision procedure is required. This paper illustrates the usefulness of such a procedure: a certain belief revision algorithm is consider...... in order to deal with inconsistencies and, particularly, the issue of inconsistencies, and belief revision is examined in relation to the GOAL agent programming language....

  13. The thesaurus review, renaissance, and revision

    CERN Document Server

    Roe, Sandra K

    2013-01-01

    Use this single source to uncover the origin and development of the thesaurus! The Thesaurus: Review, Renaissance, and Revision examines the historical development of the thesaurus and the standards employed for thesaurus construction. This book provides both the history of thesauri and tutorials on usage to increase your understanding of thesaurus creation, use, and evaluation. This reference tool offers essential information on thesauri in the digital environment, including Web sites, databases, and software. For 50 years, the thesaurus has been a core reference book; The Thesaurus: Review,

  14. Tantalum Cones in Revision Total Knee Arthroplasty.

    Science.gov (United States)

    Kim, Eric G; Patel, Nirav K; Chughtai, Morad; Elmallah, Randa D K; Delanois, Ronald E; Harwin, Steven F; Mont, Michael A

    2016-11-01

    The best strategy to address large bony defects in revision total knee arthroplasty has yet to be determined. The relatively recent development of porous tantalum cones and their use to address massive bone loss in knee arthroplasty has shown promising short- and intermediate-term results. The purpose of this review is to present the current literature on: (1) basic science of porous tantalum, (2) classification and treatment for bone loss, (3) clinical results, and (4) evolution of newer generation cones. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. Revision of emmenomma simon (amaurobiidae, macrobuninae).

    Science.gov (United States)

    Almeida-Silva, Lina M; Griswold, Charles E; Brescovit, Antonio D

    2015-03-13

    The genus Emmenomma is revised and now includes three species from Southern Chile, Argentina and Falkland Islands (Islas Malvinas). The type species Emmenomma oculatum is redescribed and considered a senior synonym of E. beauchenicum. Emmenomma oculatum obscurum is removed from synonymy with E. oculatum, raised to the species level and redescribed; the male of this species remains unknown. A new species, Emmenomma joshuabelli sp. nov. is described. The presence of a grate shaped tapetum outside the Lycosoidea clade is described. Detailed images are provided for all known species.

  16. Revised numerical wrapper for PIES code

    Science.gov (United States)

    Raburn, Daniel; Reiman, Allan; Monticello, Donald

    2015-11-01

    A revised external numerical wrapper has been developed for the Princeton Iterative Equilibrium Solver (PIES code), which is capable of calculating 3D MHD equilibria with islands. The numerical wrapper has been demonstrated to greatly improve the rate of convergence in numerous cases corresponding to equilibria in the TFTR device where magnetic islands are present. The numerical wrapper makes use of a Jacobian-free Newton-Krylov solver along with adaptive preconditioning and a sophisticated subspace-restricted Levenberg-Marquardt backtracking algorithm. The details of the numerical wrapper and several sample results are presented.

  17. Actitudes Haci la Enfermedad Mental: Revision Bibliografica (Attitudes toward Mental Illness: Revised Bibliography). Publication No. 40.

    Science.gov (United States)

    Stefani, Dorina

    In this work, some of the most important instruments used to measure attitudes toward mental illness were analysed. A revision of different experimental investigations which studied attitudes toward mental illness among general public, mental health professionals and patients and their relatives was made. Some of the strategies applied to change…

  18. Actitud Hacia las Matematicas: Revision Bibliografica (Attitudes Toward Mathematics: Revised Bibliography). Publication No. 39.

    Science.gov (United States)

    Rodriguez Feijoo, Nelida

    Investigations about attitudes toward mathematics carried out in the past decade were revised. The instruments used to measure attitudes toward mathematics were analysed as well as the attitudes toward different aspects of mathematics, their relation with other school subjects and their stability through time. Opinions about the influence of…

  19. Unforced Revision in Processing Relative Clause Association Ambiguity in Japanese: Evidence against Revision as Last Resort

    Science.gov (United States)

    Yamada, Toshiyuki; Arai, Manabu; Hirose, Yuki

    2017-01-01

    The current study tackles a long standing question of whether comprehenders perform structural revision when it is not forced by grammar or not. Using an eye-tracking reading paradigm, we addressed this issue by making use of global structural ambiguity in Japanese. Our results show that comprehenders initially associate a relative clause with the…

  20. Is Peer Review Training Effective in Iranian EFL Students’ Revision?

    Directory of Open Access Journals (Sweden)

    Hadiseh Esmaeeli

    2014-08-01

    Full Text Available This study aims to investigate the effect of peer review training on the Iranian EFL students’ subsequent revision in an advanced writing class in Larestan Islamic Azad University. After 12 weeks class demonstration, teacher-reviewer conferences with 20 male and female students, the students’ first drafts, revisions, and reviewers’ comments were collected and compared the comments before and after peer review training. The findings revealed that the students incorporated significantly more comments into subsequent revisions after peer review training. Therefore, peer review training had a positive effect on the students’ subsequent revisions.

  1. Evaluation of a CFD-based approach to estimate pollutant distribution within a real urban canopy by means of passive samplers.

    Science.gov (United States)

    Santiago, J L; Borge, R; Martin, F; de la Paz, D; Martilli, A; Lumbreras, J; Sanchez, B

    2017-01-15

    The distribution of pollutants is spatially heterogeneous within urban streets making difficult to build a realistic concentration map. In this paper, a methodology based on computational fluid dynamic modeling with Reynolds-averaged Navier-Stokes approach is used to compute maps of concentration for a period of several weeks. The methodology is evaluated by comparing simulation results against experimental data from two different campaigns where a large number of passive samplers deployed in an area with heavy vehicular traffic in Madrid (Spain). The evaluation shows that the methodology is able to reproduce the general pattern of several-week averaged pollutant distribution in an urban area with heavy vehicular traffic, resolving the spatial variability up to a resolution of 1-2m. In addition, the model results fit satisfactorily the time evolution of the pollutant concentration measured at an air quality station deployed in the studied area. However, problems were detected close to zones with complex emissions patterns (tunnels, street forks, etc.), where the model compared poorly against passive sampler measurements. A preliminary assessment of the uncertainties induced in the numerical methodology due to consider NO2 as non-reactive pollutant under winter conditions indicates that it would be an acceptable approach for this particular case study. Overall, our analysis contributes to raise the confidence in that approached similar to the one presented in this study can be adopted for dealing with several aspects of the air quality management such as air quality assessment, optimization of the location of measurement stations, and the evaluation of air pollution reduction strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Calibration of silicone rubber rods as passive samplers for pesticides at two different flow velocities: Modeling of sampling rates under water boundary layer and polymer control.

    Science.gov (United States)

    Martin, Alexis; Margoum, Christelle; Jolivet, Antoine; Assoumani, Azziz; El Moujahid, Bachir; Randon, Jérôme; Coquery, Marina

    2017-11-28

    There is a need to determine time-weighted average concentrations of polar contaminants such as pesticides by passive sampling in environmental waters. Calibration data for silicone rubber-based passive samplers are lacking for this class of compounds. The calibration data, sampling rate (R s ), and partition coefficient between silicone rubber and water (K sw ) were precisely determined for 23 pesticides and 13 candidate performance reference compounds (PRCs) in a laboratory calibration system over 14 d for 2 water flow velocities, 5 and 20 cm s -1 . The results showed that an in situ exposure duration of 7 d left a silicone rubber rod passive sampler configuration in the linear or curvilinear uptake period for 19 of the pesticides studied. A change in the transport mechanism from polymer control to water boundary layer control was observed for pesticides with a log K sw of approximately 3.3. The PRC candidates were not fully relevant to correct the impact of water flow velocity on R s . We therefore propose an alternative method based on an overall resistance to mass transfer model to adjust R s from laboratory experiments to in situ hydrodynamic conditions. We estimated diffusion coefficients (D s ) and thickness of water boundary layer (δ w ) as adjustable model parameters. Log D s values ranged from -12.13 to -10.07 m 2  s -1 . The estimated δ w value showed a power function correlation with water flow velocity. Environ Toxicol Chem 2018;9999:1-11. © 2017 SETAC. © 2017 SETAC.

  3. The effects of meteorological parameters and diffusive barrier reuse on the sampling rate of a passive air sampler for gaseous mercury

    Science.gov (United States)

    McLagan, David S.; Mitchell, Carl P. J.; Huang, Haiyong; Hussain, Batual Abdul; Duan Lei, Ying; Wania, Frank

    2017-10-01

    Passive air sampling of gaseous mercury (Hg) requires a high level of accuracy to discriminate small differences in atmospheric concentrations. Meteorological parameters have the potential to decrease this accuracy by impacting the sampling rate (SR), i.e., the volume of air that is effectively stripped of gaseous mercury per unit of time. We measured the SR of a recently calibrated passive air sampler for gaseous Hg in the laboratory under varying wind speeds (wind still to 6 m s-1), temperatures (-15 to +35 °C), and relative humidities (44 to 80 %). While relative humidity has no impact on SR, SR increases slightly with both wind speed (0.003 m3 day-1 increase in SR or 2.5 % of the previously calibrated SR for every m s-1 increase for wind speeds > 1 m s-1, typical of outdoor deployments) and temperature (0.001 m3 day-1 increase in SR or 0.7 % for every 1 °C increase). The temperature dependence can be fully explained by the effect of temperature on the molecular diffusivity of gaseous mercury in air. Although these effects are relatively small, accuracy can be improved by adjusting SRs using measured or estimated temperature and wind speed data at or near sampling sites. We also assessed the possibility of reusing Radiello® diffusive barriers previously used in the passive air samplers. The mean rate of gaseous Hg uptake was not significantly different between new and previously used diffusive barriers in both lab and outdoor deployments, irrespective of the applied cleaning procedure. No memory effect from Radiellos® previously deployed in a high Hg atmosphere was observed. However, a loss in replicate precision for the dirtiest Radiellos® in the indoor experiment suggests that cleaning is advisable prior to reuse.

  4. Assessment of polycyclic aromatic hydrocarbon contamination of the Bílina River (Czech Republic using passive water samplers and fish biliary metabolites

    Directory of Open Access Journals (Sweden)

    Jana Blahová

    2011-01-01

    Full Text Available The aim of the study was to assess polycyclic aromatic hydrocarbon (PAH contamination on the Bílina River (the Czech Republic by measurement of three PAH biliary metabolites in fish and 16 PAHs in passive samplers. A total of sixty-one fish were collected; the indicator species were chub (Leuciscus cephalus L.; n = 25, roach (Rutilus rutilus L.; n = 17 and brown trout (Salmo trutta m. fario L.; n = 19. Three biliary PAH metabolites were measured: 1-hydroxypyrene (1-OHP, 2-naphtol, and 1-hydroxyphenanthrene, but only 1-OHP was detected in all fish. The highest median value of 32.3 ng·mg-1of 1-OHP was found at Ústí nad Labem, while the lowest median value of 27.6 ng·mg-1was found in the control site, Březenec. No significant differences (P < 0.05 among the sites were found. The highest concentration of PAH was detected in Litvínov-Záluží (172.0 ng·l-1 and the lowest concentration (7.9 ng·l-1 was detected in Březenec. A positive, but non-significant correlation (rs = 0.8 was confirmed between biliary 1-OHP and total PAH in passive samplers. These results indicate the highest pollution in the middle stretches of the Bílina River, especially at Litvínov-Záluží. We confirmed 1-OHP as the most prevalent PAH biliary metabolite in fish that could be used as a biomarker for assessment of PAH pollution of the aquatic ecosystem. The main importance of the present study is in the combination of biochemical and chemical monitoring that provides complex evaluation of aquatic environment contamination. It was the first study on the Bílina River, in which the assessment of PAH contamination in the aquatic ecosystem was realized using combination of biotic and abiotic monitoring.

  5. Solid-phase extraction of organic compounds in atmospheric aerosol particles collected with the particle-into-liquid sampler and analysis by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Parshintsev, Jevgeni; Hyötyläinen, Tuulia; Hartonen, Kari; Kulmala, Markku; Riekkola, Marja-Liisa

    2010-01-15

    Atmospheric aerosol particles, collected with the particle-into-liquid sampler at SMEARII station in Finland in mid-August 2007, were analysed for biogenic acids. The sample pretreatment method, comprising solid-phase extraction with anion exchange and hydrophilic-lipophilic balance materials, was optimized. Extraction efficiencies of solid-phase extraction from 10 and 20ml samples were about 100%, with average relative standard deviation of 8.9%, in concentration range from 12.5 to 50ng/ml of the acid. Extraction of aldehydes was less successful, with efficiencies from 69 to 163% and average 10% deviation. Pretreated samples were analysed by reversed phase high performance liquid chromatography with ion trap mass spectrometric detection. Limits of detection achieved for organic acids with the analytical procedure developed ranged from 9 to 27microg/l of extracted sample, while limits of quantitation were from 31 to 90microg/l. Oxidation with ozone was used for the preparation of the acid of beta-caryophyllene (beta-caryophyllinic acid), which was also studied in aerosol samples. MS(2) experiments were used to confirm the identification of trans-pinic, trans-pinonic and beta-caryophyllinic acids. Azelaic, hexadecanoic, cis-pinonic, and cis- and trans-pinic acids were quantitated in the samples with use of authentic standards, while the concentrations of trans-pinonic and beta-caryophyllinic acids were determined with cis-pinonic acid as surrogate. Also, the contribution of beta-caryophyllene oxidation products to aerosol organic carbon was evaluated. Aldehydes could not be analysed in real samples due to the insufficient extraction. The particle-into-liquid sampler proved to be suitable for the collection of aerosol particles for the elucidation of daily and diurnal variation of selected species. The optimized sample pretreatment, together with the analysis method, offer a promising approach for the study of aerosol chemical composition, where artifact formation is

  6. Revision of Rubus (Rosaceae in Taiwan

    Directory of Open Access Journals (Sweden)

    Juinn-Yih Huang

    2009-11-01

    Full Text Available The genus Rubus L. in Taiwan is taxonomically revised based on morphological and phytogeographical patterns. Forty taxa (34 species, 3 varieties, and 3 hybrids of the genus are recognized, including two new hybrid species R. croceacanthus × corchorifolius and R. rosifolius × fraxinifolius. Among the Rubus taxa in Taiwan, R. croceacanthus H. Lév. exhibits tremendous variation and we do believe that more investigations are needed in the future. Several taxa described in the Flora of Taiwan, 2nd ed. are treated as synonyms of other species, and several taxa in Taiwan are revised. The existence of R. howii Merr. & Chun, R. linearifoliolus Hayata, and R. parvifraxinifolius Hayata in Taiwan are reconfirmed, we described R. howii fruit information which was absent in original literature; and the third taxon is treated as a natural hydrid R. × parvifraxinifolius Hayata which putatively derived from R. rosifolius Sm. and R. linearifoliolus based on intermediate morphology and the scarcity of fruit set. Rubus pseudoacer Makino ssp. flexuosus (Y.-C. Liu & F.-Y. Lu H. Ohashi & C.-F. Hsieh is treated as synonym of R. pseudoacer Makino and is excluded in Taiwan. A key to the taxa, synonyms and taxonomic descriptions of each taxon are presented. Moreover, information about phenology, chromosome number, distribution and specimens examined for each taxon are also provided.

  7. Taxonomic revision of Parampheres (Arachnida: Opiliones: Gonyleptidae

    Directory of Open Access Journals (Sweden)

    Bruno Jacob Mori

    2014-12-01

    Full Text Available Parampheres Roewer, 1913 is a relatively common genus of South American harvestmen. This genus is easily diagnosed by the remarkable yellow patches on the prosoma. Nonetheless, species determination within this group is challenging due the convoluted taxonomic history of the group and lack of a recent revision. In this study we revise Parampheres and describe a new species, Parampheres tenebris sp. nov., from Parque Nacional da Serra Geral, Rio Grande do Sul, Brazil. The new species can be distinguished from the other species of the genus by having dorsal scutum dark, and apophysis of coxa IV of male elongated. Furthermore, we propose the following new synonymies: Callampheres boliviensis Roewer, 1913, Pertyana ronae Mello-Leitão, 1927 and Parampheres tibialis Roewer, 1917 with Parampheres pectinatus Roewer, 1913. Parampheres now includes four species distributed from southern Brazil to adjacent areas in Argentina and Uruguay. In addition, we present a phylogenetic hypothesis based on morphological characters that supports the transfer of Parampheres from Gonyleptinae to Caelopyginae.

  8. A Way to Revised Quantum Electrodynamics

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2012-04-01

    Full Text Available In conventional theoretical physics and its Standard Model the guiding principle is that the equations are symmetrical. This limitation leads to a number of difficulties, because it does not permit masses for leptons and quarks, the electron tends to “explode” un- der the action of its self-charge, a corresponding photon model has no spin, and such a model cannot account for the “needle radiation” proposed by Einstein and observed in the photoelectric e ff ect and in two-slit experiments. This paper summarizes a revised Lorentz and gauge invariant quantum electrodynamic theory based on a nonzero electric field divergence in the vacuum and characterized by linear intrinsic broken symmetry. It thus provides an alternative to the Higgs concept of nonlinear spontaneous broken sym- metry, for solving the difficulties of the Standard Model. New results are obtained, such as nonzero and finite lepton rest masses, a point-charge-like behavior of the electron due to a revised renormalization procedure, a magnetic volume force which counteracts the electrostatic eigen-force of the electron, a nonzero spin of the photon and of light beams, needle radiation, and an improved understanding of the photoelectric effect, two-slit ex- periments, electron-positron pair formation, and cork-screw-shaped light beams.

  9. Extended porous femoral stems in hip revisions.

    Directory of Open Access Journals (Sweden)

    Pablo Bruno

    2016-08-01

    Full Text Available Introduction: The porous coated cylindrical  stem are one of the most popular option in the set of hip revison surgery. The poupose of this study is present the clinical and radiographic results of a group of patients treated with this stem. Material and Methods: Between 1997 and 2010, we retrospectively evaluated 150 stem in 148 patients. The indication for revisión was aseptic loosening in 88 cases (58.6%, septic loosening in 41 cases (27.3%, periprosthetic fracture in 14 cases (9.3%, failed hip ostesynthesis in 4 cases (2.6% and stem fracture in 3 cases (2%. We followed the patient on average for 7.7 years. Results: We achived bone-ingrowth fixation in 135 patients (90 %,,  fibrous tissue fixation in 12 (8% and unstable fixation in 3 (2 %. The mean Harris hip score improved to 92 points at last follow-up. Three stem were revised (2%. One patient had revisión becouse of stem loosening. The other two becouse of deep infection required a 2 staged revision.  Three patient (2% had dislocation and was treated succesfully with closed reduction. Conclusion:  The porous coated cylindrical stem is a predictable technique with excellent survival rates  in  the set of  revisión hip surgery.

  10. The JFK Coma Recovery Scale--Revised.

    Science.gov (United States)

    Kalmar, Kathleen; Giacino, Joseph T

    2005-01-01

    The JFK Coma Recovery Scale (CRS) was developed to help characterise and monitor patients functioning at Rancho Levels I-IV and has been used widely in both clinical and research settings within the US and Europe. The CRS was recently revised to address a number of concerns emanating from our own clinical experience with the scale, feedback from users and researchers as well as the results of Rasch analyses. Additionally, the CRS did not include all of the behavioural criteria necessary to diagnose the minimally conscious state (MCS), thereby limiting diagnostic utility. The revised JFK Coma Recovery Scale (CRS-R) includes addition of new items, merging of items found to be statistically similar, deletion or modification of items showing poor fit with the scale's underlying construct, renaming of items, more stringent scoring criteria, and quantification of elicited behaviours to improve accuracy of rating. Psychometric properties of the CRS-R appear to meet standards for measurement and evaluation tools for use in clinical and research settings, and diagnostic application suggests that the scale is capable of discriminating patients in the minimally conscious state from those in the vegetative state.

  11. 77 FR 13969 - Revising Standards Referenced in the Acetylene Standard

    Science.gov (United States)

    2012-03-08

    ... the Acetylene Standard AGENCY: Occupational Safety and Health Administration (OSHA), Department of... date of its direct final rule that revises the Acetylene Standard for general industry by updating the... that revised the Acetylene Standard for general industry by updating a reference to the Compressed Gas...

  12. 75 FR 71632 - Revised Medical Criteria for Evaluating Mental Disorders

    Science.gov (United States)

    2010-11-24

    ... ADMINISTRATION 20 CFR Parts 404 and 416 RIN 0960-AF69 Revised Medical Criteria for Evaluating Mental Disorders... mental disorders that we receive during this reopened comment period. DATES: To ensure that your comments..., 2010 the comment period on one aspect of our proposed rules to revise our mental disorders listings...

  13. 40 CFR 281.52 - Revision of approved state programs.

    Science.gov (United States)

    2010-07-01

    ... believe the proposed revision will receive significant negative comment from the public. (1) The..., unless significant negative comment opposing the proposed revision is received during the comment period. If significant negative comment is received, EPA must notify the state and within 60 days after the...

  14. 76 FR 33366 - New Jail Planning Initiative; Review and Revision

    Science.gov (United States)

    2011-06-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE National Institute of Corrections New Jail Planning Initiative; Review and Revision The following funding... Agreement--New Jail Planning Initiative: Review and Revision. Funding Opportunity Number 11JA03, found on...

  15. Perioperative transfusion threshold and ambulation after hip revision surgery

    DEFF Research Database (Denmark)

    Nielsen, Kamilla; Johansson, Pär I; Dahl, Benny

    2014-01-01

    BACKGROUND: Transfusion with red blood cells (RBC) may be needed during hip revision surgery but the appropriate haemoglobin concentration (Hb) threshold for transfusion has not been well established. We hypothesized that a higher transfusion threshold would improve ambulation after hip revision ...

  16. 78 FR 44559 - Effective Date of Revised Company Registration Requirements

    Science.gov (United States)

    2013-07-24

    ... company registration to the new format. Companies required to file using CIDs are urged to register or... Energy Regulatory Commission Effective Date of Revised Company Registration Requirements AGENCY: Federal... of the Revised Company Registration Requirements. The Commission issued a Notice in the Federal...

  17. Is Peer Review Training Effective in Iranian EFL Students' Revision?

    Science.gov (United States)

    Esmaeeli, Hadiseh; Abasi, Maasumeh; Soori, Afshin

    2014-01-01

    This study aims to investigate the effect of peer review training on the Iranian EFL students' subsequent revision in an advanced writing class in Larestan Islamic Azad University. After 12 weeks class demonstration, teacher-reviewer conferences with 20 male and female students, the students' first drafts, revisions, and reviewers' comments were…

  18. The Development of the Revised Peabody Mobility Scale.

    Science.gov (United States)

    Merbler, John B.

    Described are the steps involved in revising the Peabody Mobility Scale (PMS), an instrument for assessing the orientation and mobility skills of multiply handicapped blind children. Among the revision procedures discussed are a redefinition of item content for mobility and prerequisite skills, and alteration of the format to that of an easily…

  19. Merlin C. Wittrock and the Revision of Bloom's Taxonomy

    Science.gov (United States)

    Krathwohl, David R.; Anderson, Lorin W.

    2010-01-01

    Merl Wittrock, a cognitive psychologist who had proposed a generative model of learning, was an essential member of the group that over a period of 5 years revised the "Taxonomy of Educational Objectives," originally published in 1956. This article describes the development of that 2001 revision (Anderson and Krathwohl, Editors) and Merl's…

  20. ISO 9000:2000 revisions and their implications.

    Science.gov (United States)

    Sim, P

    2000-05-01

    The planned revision of the ISO 9000 series of standards means that all medical device companies will have to revise their quality systems to align them with the new ISO 9000:2000 standards. This overview outlines the changes and the factors companies need to consider, and highlights future standards activity.