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Sample records for wipe surface sample

  1. Sampling for Beryllium Surface Contamination using Wet, Dry and Alcohol Wipe Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Kent [Central Missouri State Univ., Warrensburg, MO (United States)

    2004-12-01

    This research project was conducted at the National Nuclear Security Administration's Kansas City Plant, operated by Honeywell Federal Manufacturing and Technologies, in conjunction with the Safety Sciences Department of Central Missouri State University, to compare relative removal efficiencies of three wipe sampling techniques currently used at Department of Energy facilities. Efficiencies of removal of beryllium contamination from typical painted surfaces were tested by wipe sampling with dry Whatman 42 filter paper, with water-moistened (Ghost Wipe) materials, and by methanol-moistened wipes. Test plates were prepared using 100 mm X 15 mm Pyrex Petri dishes with interior surfaces spray painted with a bond coat primer. To achieve uniform deposition over the test plate surface, 10 ml aliquots of solution containing 1 beryllium and 0.1 ml of metal working fluid were transferred to the test plates and subsequently evaporated. Metal working fluid was added to simulate the slight oiliness common on surfaces in metal working shops where fugitive oil mist accumulates over time. Sixteen test plates for each wipe method (dry, water, and methanol) were processed and sampled using a modification of wiping patterns recommended by OSHA Method 125G. Laboratory and statistical analysis showed that methanol-moistened wipe sampling removed significantly more (about twice as much) beryllium/oil-film surface contamination as water-moistened wipes (p< 0.001), which removed significantly more (about twice as much) residue as dry wipes (p <0.001). Evidence for beryllium sensitization via skin exposure argues in favor of wipe sampling with wetting agents that provide enhanced residue removal efficiency.

  2. Determination of Metal Impurities in Carbon Nanotubes Sampled Using Surface Wipes

    Directory of Open Access Journals (Sweden)

    Mary-Luyza Avramescu

    2016-01-01

    Full Text Available Residual metal impurities in carbon nanotubes (CNTs provide a means to distinguish CNT from non-CNT sources of elemental carbon in environmental samples. A practical and cost-effective analytical approach is needed to support routine surface monitoring of CNT metal tracers using wipe sampling. Wipe sampling for CNT metal tracers is considered a qualitative indicator of the presence of CNTs, not a quantitative exposure metric. In this study, two digestion approaches (microwave-assisted nitric acid/H2O2 digestion and ultrasonic nitric/HF acid digestion in conjunction with Inductively Coupled Plasma Mass Spectrometry (ICP-MS determination were evaluated for their ability to extract metal impurities from CNT particles captured on wipe substrates. Aliquots of different carbon nanotubes (including NIST 2483 single-wall CNT with and without GhostWipes™ (ASTM E-1792 compliant were used to compare the performance of the digestion methods. The microwave digestion method accommodated the bulky wipe sample and also eliminated potential ICP-MS signal interferences related to incomplete digestion. Although quantitative recoveries requiring lengthy multistep digestion protocols may be necessary in other applications, the near-total recoveries achieved in the present study for CNT catalyst elements were adequate for identifying surface contamination of CNTs in the workplace using wipe sampling.

  3. Surface wipe sampling for antineoplastic (chemotherapy) and other hazardous drug residue in healthcare settings: Methodology and recommendations.

    Science.gov (United States)

    Connor, Thomas H; Zock, Matthew D; Snow, Amy H

    2016-09-01

    Surface wipe sampling for various hazardous agents has been employed in many occupational settings over the years for various reasons such as evaluation of potential dermal exposure and health risk, source determination, quality or cleanliness, compliance, and others. Wipe sampling for surface residue of antineoplastic and other hazardous drugs in healthcare settings is currently the method of choice to determine surface contamination of the workplace with these drugs. The purpose of this article is to review published studies of wipe sampling for antineoplastic and other hazardous drugs, to summarize the methods in use by various organizations and researchers, and to provide some basic guidance for conducting surface wipe sampling for these drugs in healthcare settings.  Recommendations on wipe sampling methodology from several government agencies and organizations were reviewed. Published reports on wipe sampling for hazardous drugs in numerous studies were also examined. The critical elements of a wipe sampling program and related limitations were reviewed and summarized.  Recommendations and guidance are presented concerning the purposes of wipe sampling for antineoplastic and other hazardous drugs in the healthcare setting, technical factors and variables, sampling strategy, materials required, and limitations. The reporting and interpretation of wipe sample results is also discussed.  It is recommended that all healthcare settings where antineoplastic and other hazardous drugs are handled consider wipe sampling as part of a comprehensive hazardous drug "safe handling" program. Although no standards exist for acceptable or allowable surface concentrations for these drugs in the healthcare setting, wipe sampling may be used as a method to characterize potential occupational dermal exposure risk and to evaluate the effectiveness of implemented controls and the overall safety program. A comprehensive safe-handling program for antineoplastic drugs may

  4. Colling Wipe Samples for VX Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koester, C; Hoppes, W G

    2010-02-11

    This standard operating procedure (SOP) provides uniform procedures for the collection of wipe samples of VX residues from surfaces. Personnel may use this procedure to collect and handle wipe samples in the field. Various surfaces, including building materials (wood, metal, tile, vinyl, etc.) and equipment, may be sampled based on this procedure. The purpose of such sampling is to determine whether or not the relevant surfaces are contaminated, to determine the extent of their contamination, to evaluate the effectiveness of decontamination procedures, and to determine the amount of contaminant that might present as a contact hazard.

  5. Air, hand wipe, and surface wipe sampling for Bisphenol A (BPA) among workers in industries that manufacture and use BPA in the United States.

    Science.gov (United States)

    Hines, Cynthia J; Jackson, Matthew V; Christianson, Annette L; Clark, John C; Arnold, James E; Pretty, Jack R; Deddens, James A

    2017-11-01

    For decades, bisphenol A (BPA) has been used in making polycarbonate, epoxy, and phenolic resins and certain investment casting waxes, yet published exposure data are lacking for U.S. manufacturing workers. In 2013-2014, BPA air and hand exposures were quantified for 78 workers at six U.S. companies making BPA or BPA-based products. Exposure measures included an inhalable-fraction personal air sample on each of two consecutive work days (n = 146), pre- and end-shift hand wipe samples on the second day (n = 74 each), and surface wipe samples (n = 88). Potential determinants of BPA air and end-shift hand exposures (after natural log transformation) were assessed in univariate and multiple regression mixed models. The geometric mean (GM) BPA air concentration was 4.0 µg/m 3 (maximum 920 µg/m 3 ). The end-shift GM BPA hand level (26 µg/sample) was 10-times higher than the pre-shift level (2.6 µg/sample). BPA air and hand exposures differed significantly by industry and job. BPA air concentrations and end-shift hand levels were highest in the BPA-filled wax manufacturing/reclaim industry (GM Air = 48 µg/m 3 , GM Hand-End = 130 µg/sample) and in the job of working with molten BPA-filled wax (GM Air = 43 µg/m 3 , GM Hand-End = 180 µg/sample), and lowest in the phenolic resins industry (GM Air = 0.85 µg/m 3 , GM Hand-End = 0.43 µg/sample) and in the job of flaking phenolic resins (GM AIR = 0.62 µg/m 3 , GM Hand-End = 0.38 µg/sample). Determinants of increased BPA air concentration were industry, handling BPA containers, spilling BPA, and spending ≥50% of the shift in production areas; increasing age was associated with lower air concentrations. BPA hand exposure determinants were influenced by high values for two workers; for all other workers, tasks involving contact with BPA-containing materials and spending ≥50% of the shift in production areas were associated with increased BPA hand levels. Surface wipe BPA levels were significantly lower in

  6. Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels.

    Science.gov (United States)

    Quintana, Penelope J E; Matt, Georg E; Chatfield, Dale; Zakarian, Joy M; Fortmann, Addie L; Hoh, Eunha

    2013-09-01

    Secondhand smoke contains a mixture of pollutants that can persist in air, dust, and on surfaces for months or longer. This persistent residue is known as thirdhand smoke (THS). Here, we detail a simple method of wipe sampling for nicotine as a marker of accumulated THS on surfaces. We analyzed findings from 5 real-world studies to investigate the performance of wipe sampling for nicotine on surfaces in homes, cars, and hotels in relation to smoking behavior and smoking restrictions. The intraclass correlation coefficient for side-by-side samples was 0.91 (95% CI: 0.87-0.94). Wipe sampling for nicotine reliably distinguished between private homes, private cars, rental cars, and hotels with and without smoking bans and was significantly positively correlated with other measures of tobacco smoke contamination such as air and dust nicotine. The sensitivity and specificity of possible threshold values (0.1, 1, and 10 μg/m(2)) were evaluated for distinguishing between nonsmoking and smoking environments. Sensitivity was highest at a threshold of 0.1 μg/m(2), with 74%-100% of smoker environments showing nicotine levels above threshold. Specificity was highest at a threshold of 10 μg/m(2), with 81%-100% of nonsmoker environments showing nicotine levels below threshold. The optimal threshold will depend on the desired balance of sensitivity and specificity and on the types of smoking and nonsmoking environments. Surface wipe sampling for nicotine is a reliable, valid, and relatively simple collection method to quantify THS contamination on surfaces across a wide range of field settings and to distinguish between nonsmoking and smoking environments.

  7. 40 CFR 761.243 - Standard wipe sample method and size.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Standard wipe sample method and size... Natural Gas Pipeline: Selecting Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.243 Standard wipe sample method and size. (a) Collect a surface sample from a natural gas...

  8. False negative rate and other performance measures of a sponge-wipe surface sampling method for low contaminant concentrations.

    Energy Technology Data Exchange (ETDEWEB)

    Einfeld, Wayne; Krauter, Paula A.; Boucher, Raymond M.; Tezak, Mathew; Amidan, Brett G. (Pacific Northwest National Laboratory, Richland, WA); Piepel, Greg F. (Pacific Northwest National Laboratory, Richland, WA)

    2011-05-01

    Recovery of spores from environmental surfaces is known to vary due to sampling methodology, techniques, spore size and characteristics, surface materials, and environmental conditions. A series of tests were performed to evaluate a new, validated sponge-wipe method. Specific factors evaluated were the effects of contaminant concentrations and surface materials on recovery efficiency (RE), false negative rate (FNR), limit of detection (LOD) - and the uncertainties of these quantities. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show a roughly linear dependence of surface roughness on RE, where the smoothest surfaces have the highest mean RE values. REs were not influenced by the low spore concentrations tested (3 x 10{sup -3} to 1.86 CFU/cm{sup 2}). The FNR data were consistent with RE data, showing a trend of smoother surfaces resulting in higher REs and lower FNRs. Stainless steel generally had the lowest mean FNR (0.123) and plastic had the highest mean FNR (0.479). The LOD{sub 90} varied with surface material, from 0.015 CFU/cm{sup 2} on stainless steel up to 0.039 on plastic. Selecting sampling locations on the basis of surface roughness and using roughness to interpret spore recovery data can improve sampling. Further, FNR values, calculated as a function of concentration and surface material, can be used pre-sampling to calculate the numbers of samples for statistical sampling plans with desired performance, and post-sampling to calculate the confidence in characterization and clearance decisions.

  9. A surface wipe sampling and LC-MS/MS method for the simultaneous detection of six antineoplastic drugs commonly handled by healthcare workers.

    Science.gov (United States)

    Jeronimo, Matthew; Colombo, Manuel; Astrakianakis, George; Hon, Chun-Yip

    2015-09-01

    An effective wipe sampling and LC-MS/MS method was developed to simultaneously analyze six commonly administered antineoplastic drugs in stainless steel surface. The analyzed drugs were methotrexate, paclitaxel, cyclophosphamide, 5-fluorouracil, vincristine, and oxaliplatin, a frequently prepared antineoplastic drug that has not been included among any of the published simultaneous detection methods. The established method was used to evaluate the recoveries of antineoplastic drugs on brand new and worn stainless steel surfaces by wiping the plates with a Whatman filter paper wetted with 0.5 mL of water/methanol (20:80) with 0.1% formic acid followed by LC-MS/MS before desorbing the filter with a water/methanol (50:50) solution. A significant decrease in the recovery of all evaluated drugs was found when worn plates were used. Additionally, the inter-personnel variability on drug recoveries during wiping procedures was evaluated. Significantly higher recoveries were achieved by the personnel with more training and experience versus personnel without prior experience. Finally, a laboratory stability test was developed to assess the degradation of the antineoplastic drugs during replicated shipping conditions. With the exception of vincristine sulfate which exhibited a significant (p < 0.05) degradation after 48 h, all evaluated drugs were stable during the first 24-48 h. However, after 144 h, an increase in the degradation of all evaluated drugs was observed, with oxaliplatin and 5-fluorouracil exhibiting the most degradation.

  10. New approaches to wipe sampling methods for antineoplastic and other hazardous drugs in healthcare settings

    Science.gov (United States)

    Connor, Thomas H.; Smith, Jerome P.

    2017-01-01

    Purpose At the present time, the method of choice to determine surface contamination of the workplace with antineoplastic and other hazardous drugs is surface wipe sampling and subsequent sample analysis with a variety of analytical techniques. The purpose of this article is to review current methodology for determining the level of surface contamination with hazardous drugs in healthcare settings and to discuss recent advances in this area. In addition it will provide some guidance for conducting surface wipe sampling and sample analysis for these drugs in healthcare settings. Methods Published studies on the use of wipe sampling to measure hazardous drugs on surfaces in healthcare settings drugs were reviewed. These studies include the use of well-documented chromatographic techniques for sample analysis in addition to newly evolving technology that provides rapid analysis of specific antineoplastic Results Methodology for the analysis of surface wipe samples for hazardous drugs are reviewed, including the purposes, technical factors, sampling strategy, materials required, and limitations. The use of lateral flow immunoassay (LFIA) and fluorescence covalent microbead immunosorbent assay (FCMIA) for surface wipe sample evaluation is also discussed. Conclusions Current recommendations are that all healthcare settings where antineoplastic and other hazardous drugs are handled include surface wipe sampling as part of a comprehensive hazardous drug-safe handling program. Surface wipe sampling may be used as a method to characterize potential occupational dermal exposure risk and to evaluate the effectiveness of implemented controls and the overall safety program. New technology, although currently limited in scope, may make wipe sampling for hazardous drugs more routine, less costly, and provide a shorter response time than classical analytical techniques now in use. PMID:28459100

  11. Dermal Transfer of Chlorpyrifos Residues from Residential Surfaces: Comparison of Hand Press, Hand Drag, Wipe, and Polyurethane Foam Roller Measurements after Broadcast and Aerosol Pesticide Applications

    National Research Council Canada - National Science Library

    Chensheng Lu; Richard A. Fenske

    1999-01-01

    .... This research compared surface sampling techniques [wipe and polyurethane foam (PUF) roller] with the removal ability of human skin following broadcast and total aerosol release applications of Dursban...

  12. Wipe sampling of amphetamine-type stimulants and recreational drugs on selected household surfaces with analysis by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Madireddy, Sri Bharat; Bodeddula, Vanaja Reddy; Mansani, Sravan Kumar; Wells, Martha J.M.; Boles, Jeffrey O., E-mail: jboles@tntech.edu

    2013-06-15

    Highlights: • Degree of sorption of eight drugs on eleven countertop surfaces was investigated. • Surface composition, volatility and solvent composition played a role in sorption. • Solvent-dependent migration was a key factor of consideration during remediation. • SPME-assisted volatility studies provided evidence for varying degrees of recovery. • Rapid three minute UPLC-QTOF method was developed to quantify the eight compounds. -- Abstract: Sorption characteristics of eight drugs related to recreational and clandestine activity—amphetamine, cocaine, heroin, N-formyl amphetamine, N-formyl methamphetamine, methamphetamine, 3, 4-methylenedioxymethamphetamine (MDMA), and pseudoephedrine—were evaluated on selected kitchen countertop surfaces. Methanol-dampened Whatman™ 40 filter paper wipes were used to collect samples from eleven surfaces including alkyd resin, ceramic tiles, glass, granite, laminate, limestone, marble, quartz compac, quartz real, soap stone, and stainless steel. The filter paper wipes were analyzed by a rapid three-minute UPLC-QTOF method, following ammonium acetate buffer (pH 5.8–6.2) extraction. The average percentage recoveries after 15 h of exposure to the surface materials tested, was found to be highest for cocaine and MDMA and lowest for amphetamine and methamphetamine. Among the eleven countertop surfaces, overall recoveries for marble were observed to be the least, whereas soapstone, quartz compac and stainless steel were among the highest. Scanning electron microscopic images of the surfaces provided a unique view of surface irregularities that potentially influenced drug recovery. Aging, migration, solvent composition, and volatility were examined. The variation in recovery of drugs was attributed to four key factors: compound volatility, surface composition, surface—compound interaction, and solvent composition.

  13. Role of surface energy and nano-roughness in the removal efficiency of bacterial contamination by nonwoven wipes from frequently touched surfaces.

    Science.gov (United States)

    Edwards, Nicholas W M; Best, Emma L; Connell, Simon D; Goswami, Parikshit; Carr, Chris M; Wilcox, Mark H; Russell, Stephen J

    2017-01-01

    Healthcare associated infections (HCAIs) are responsible for substantial patient morbidity, mortality and economic cost. Infection control strategies for reducing rates of transmission include the use of nonwoven wipes to remove pathogenic bacteria from frequently touched surfaces. Wiping is a dynamic process that involves physicochemical mechanisms to detach and transfer bacteria to fibre surfaces within the wipe. The purpose of this study was to determine the extent to which systematic changes in fibre surface energy and nano-roughness influence removal of bacteria from an abiotic polymer surface in dry wiping conditions, without liquid detergents or disinfectants. Nonwoven wipe substrates composed of two commonly used fibre types, lyocell (cellulosic) and polypropylene, with different surface energies and nano-roughnesses, were manufactured using pilot-scale nonwoven facilities to produce samples of comparable structure and dimensional properties. The surface energy and nano-roughness of some lyocell substrates were further adjusted by either oxygen (O 2 ) or hexafluoroethane (C 2 F 6 ) gas plasma treatment. Static adpression wiping of an inoculated surface under dry conditions produced removal efficiencies of between 9.4% and 15.7%, with no significant difference ( p  nonwoven wipe substrates with a surface energy closest to that of the contaminated surface produced the highest E. coli removal efficiency, while the associated increase in fibre nano-roughness abrogated this trend with S. aureus and E. faecalis .

  14. False-Negative Rate and Recovery Efficiency Performance of a Validated Sponge Wipe Sampling Method

    Energy Technology Data Exchange (ETDEWEB)

    Krauter, Paula; Piepel, Gregory F.; Boucher, Raymond; Tezak, Matthew S.; Amidan, Brett G.; Einfeld, Wayne

    2012-02-01

    Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on recovery efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10x10^-3 to 1.86 CFU/cm^2). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD90 (>1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm^2 on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions.

  15. A MULTI-RESIDUE METHOD FOR THE ANALYSIS OF INSECTICIDES COLLECTED ON COTTON SURFACE WIPES

    Science.gov (United States)

    A method was developed for the extraction, clean-up, and analysis of multiple pesticides from cotton wipe media used in human exposure studies to collect residues from residential hard surfaces. Measurements of pesticides are critical for estimating dermal and indirect ingestion ...

  16. Measuring PM2.5, Ultrafine Particles, Nicotine Air and Wipe Samples Following the Use of Electronic Cigarettes.

    Science.gov (United States)

    Melstrom, Paul; Koszowski, Bartosz; Thanner, Meridith Hill; Hoh, Eunha; King, Brian; Bunnell, Rebecca; McAfee, Tim

    2017-09-01

    Few studies have examined the extent of inhalation or dermal contact among bystanders following short-term, secondhand e-cigarette exposure. Measure PM2.5 (particles cigarette exposure. E-cigarettes were used ad libitum by three experienced users for 2 hours during two separate sessions (disposable e-cigarettes, then tank-style e-cigarettes, or "tanks") in a 1858 ft3 room. We recorded: uncorrected PM2.5 (using SidePak); UF (using P-Trak); air nicotine concentrations (using air samplers; SKC XAD-4 canisters); ambient air exchange rate (using an air capture hood). Wipe samples were taken by wiping 100 cm2 room surfaces pre- and post- both sessions, and clean cloth wipes were worn during the exposure and collected at the end. Uncorrected PM2.5 and UF were higher (p cigarette use can produce: elevated PM2.5; elevated UF; nicotine in the air; and accumulation of nicotine on surfaces and clothing. Short-term indoor e-cigarette use produced accumulation of nicotine on surfaces and clothing, which could lead to dermal exposure to nicotine. Short-term e-cigarette use produced elevated PM2.5 and ultrafine particles, which could lead to secondhand inhalation of these particles and any chemicals associated with them by bystanders. We measured significant differences in PM2.5 and ultrafine particles between disposable e-cigarettes and tank-style e-cigarettes, suggesting a difference in the exposure profiles of e-cigarette products.

  17. Effects of surface contamination and cleaning with hypochlorite wipes on the antibacterial activity of copper-alloyed antibacterial stainless steel.

    Science.gov (United States)

    Kawakami, Hiroshi; Hayashi, Takatsuna; Nishikubo, Hideyuki; Morikawa, Akifumi; Suzuki, Satoshi; Sato, Yoshihiro; Kikuchi, Yasushi

    2014-01-01

    Effects of surface contamination and cleaning with hypochlorite wipes on the antibacterial activity of copper-alloyed stainless steel were studied. The antibacterial activity of copper alloyed stainless steel decreased with the increase in the amount of surface contaminant, and the bacterial counts from specimens contaminated with a contaminant, e.g. 1.6 × 10(-2) μg/mm(2) of bovine serum albumin, were not significantly different from those from ordinary stainless steel specimens. The once contaminated surface could regain its antibacterial activity when it was sufficiently wiped clean with sterile wipes loaded with sodium hypochlorite solution.

  18. Surface Wipe Test Monitoring for the Toxicant Analysis Center

    Science.gov (United States)

    ... 1 56 3 71 .2 8 .2 97.2 112.3 132.2 16 .2 207.2 29.4 I ii .••j •I • 1 • I • I • I • IJI • I • I•I'J•I• I- U i 50 100 150 200 250 ... RIC for sample E508—Hhl—4901A48 ...

  19. Mechanics of the Removal of Thickened Chemical Agents from Contaminated Surfaces by Wiping

    Science.gov (United States)

    1985-01-20

    TyPE O" REPORT & PERIOD COVERED "MECHANICS OF THE REMOVAL OF THICKENED CHEMICAL Final Report AGENTS FROM CONTAMINATED SURFACES BY WIPING 6. PERFORMING...of 8lade Claplocamant (X2) R-2.75 inX.-O5I L-0.5 in 0 dog angle X2--0. 25 in x 30 x X2-0 in ’A’.x X2-0.25 in 10 Data for Gly#cerine aufl 1/2 20. blod

  20. Disinfectant wipes are appropriate to control microbial bioburden from surfaces: use of a new ASTM standard test protocol to demonstrate efficacy.

    Science.gov (United States)

    Sattar, S A; Bradley, C; Kibbee, R; Wesgate, R; Wilkinson, M A C; Sharpe, T; Maillard, J-Y

    2015-12-01

    The use of disinfectant pre-soaked wipes (DPW) to decontaminate high-touch environmental surfaces (HTES) by wiping is becoming increasingly widespread in the healthcare environment. However, DPW are rarely tested using conditions simulating their field use, and the label claims of environmental surface disinfectants seldom include wiping action. To evaluate the new E2967-15 standard test specific to wipes, particularly their ability to decontaminate surfaces and to transfer acquired contamination to clean surfaces. ASTM Standard E2967-15 was used by three independent laboratories to test the efficacy of five types of commercially available wipe products. All data generated were pulled together, and reproducibility and repeatability of the standard were measured. All the commercial DPW tested achieved a >4log10 (>99.99%) reduction in colony-forming units (CFU) of Staphylococcus aureus and Acinetobacter baumanii with 10s of wiping, but only one DPW containing 0.5% accelerated H2O2 prevented the transfer of bacteria to another surface. This newly introduced standard method represents a significant advance in assessing DPW for microbial decontamination of HTES, and should greatly assist research and development, and in making more relevant and reliable claims on marketed DPW. Copyright © 2015. Published by Elsevier Ltd.

  1. Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Krauter, Paula [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Einfeld, Wayne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2010-12-16

    Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the probability of correct detection (PCD) (or equivalently the false negative rate FNR = 1 - PCD). The PCD/FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not PCD/FNR (which left a major gap in available information). Quantifying the PCD/FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in PCD/FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The study will investigate the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination

  2. Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

    2011-05-01

    Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the false negative rate (FNR). The FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not FNR (which left a major gap in available information). Quantifying the FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The testing was performed by SNL and is now completed. The study investigated the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge-wipe

  3. Broad spectrum infrared thermal desorption of wipe-based explosive and narcotic samples for trace mass spectrometric detection.

    Science.gov (United States)

    Forbes, Thomas P; Staymates, Matthew; Sisco, Edward

    2017-08-07

    Wipe collected analytes were thermally desorbed using broad spectrum near infrared heating for mass spectrometric detection. Employing a twin tube filament-based infrared emitter, rapid and efficiently powered thermal desorption and detection of nanogram levels of explosives and narcotics was demonstrated. The infrared thermal desorption (IRTD) platform developed here used multi-mode heating (direct radiation and secondary conduction from substrate and subsequent convection from air) and a temperature ramp to efficiently desorb analytes with vapor pressures across eight orders of magnitude. The wipe substrate experienced heating rates up to (85 ± 2) °C s(-1) with a time constant of (3.9 ± 0.2) s for 100% power emission. The detection of trace analytes was also demonstrated from complex mixtures, including plastic-bonded explosives and exogenous narcotics, explosives, and metabolites from collected artificial latent fingerprints. Manipulation of the emission power and duration directly controlled the heating rate and maximum temperature, enabling differential thermal desorption and a level of upstream separation for enhanced specificity. Transitioning from 100% power and 5 s emission duration to 25% power and 30 s emission enabled an order of magnitude increase in the temporal separation (single seconds to tens of seconds) of the desorption of volatile and semi-volatile species within a collected fingerprint. This mode of operation reduced local gas-phase concentrations, reducing matrix effects experienced with high concentration mixtures. IRTD provides a unique platform for the desorption of trace analytes from wipe collections, an area of importance to the security sector, transportation agencies, and customs and border protection.

  4. Nanoengineered cotton wipes

    Science.gov (United States)

    Advances in nanotechnology are creating synergy with nonwoven technology in cleaning and/or disinfecting power for the next generation of wipe products. However, there is little known about the use of cotton fiber in wipes as a nanoengineering tool, which self-produces silver nanoparticles -- one of...

  5. Apparatus for Sampling Surface Contamination

    Science.gov (United States)

    Wells, Mark

    2008-01-01

    An apparatus denoted a swab device has been developed as a convenient means of acquiring samples of contaminants from surfaces and suspending the samples in liquids. (Thereafter, the liquids can be dispensed, in controlled volumes, into scientific instruments for analysis of the contaminants.) The swab device is designed so as not to introduce additional contamination and to facilitate, simplify, and systematize the dispensing of controlled volumes of liquid into analytical instruments. The swab device is a single apparatus into which are combined all the equipment and materials needed for sampling surface contamination. The swab device contains disposable components stacked together on a nondisposable dispensing head. One of the disposable components is a supply cartridge holding a sufficient volume of liquid for one complete set of samples. (The liquid could be clean water or another suitable solvent, depending on the application.) This supply of liquid is sealed by Luer valves. At the beginning of a sampling process, the user tears open a sealed bag containing the supply cartridge. A tip on the nondisposable dispensing head is engaged with a Luer valve on one end of the supply cartridge and rotated, locking the supply cartridge on the dispensing head and opening the valve. The swab tip includes a fabric swab that is wiped across the surface of interest to acquire a sample. A sealed bag containing a disposable dispensing tip is then opened, and the swab tip is pushed into the dispensing tip until seated. The dispensing head contains a piston that passes through a spring-loaded lip seal. The air volume displaced by this piston forces the liquid out of the supply cartridge, over the swab, and into the dispensing tip. The piston is manually cycled to enforce oscillation of the air volume and thereby to cause water to flow to wash contaminants from the swab and cause the resulting liquid suspension of contaminants to flow into the dispensing tip. After several cycles

  6. Sampling by sponge wipe or skin excision for recovery of inoculated Salmonella and Campylobacter from defeathered broiler carcasses

    Science.gov (United States)

    Broilers may carry Salmonella and Campylobacter on inner and outer surfaces upon arrival at the slaughter plant and carcasses can be further contaminated during commercial processing. A sensitive, non-destructive, repeatable sampling method would be useful to test carcasses for levels of bacteria b...

  7. Sampling by sponge wipe or skin excision for recovery of inoculated Salmonella and Campylobacter from defeathered broiler carcasses.

    Science.gov (United States)

    Berrang, Mark E; Cox, Nelson A; Oakley, Brian B

    2014-05-01

    Broilers may carry Salmonella and Campylobacter on inner and outer surfaces upon arrival at the slaughter plant, and carcasses can be further contaminated during commercial processing. A sensitive, nondestructive, repeatable sampling method would be useful to test carcasses for levels of bacteria before and after specific processing steps to measure either contamination or efficacy of intervention techniques. Blending of excised skin is accepted as an effective sampling method but requires damage to the carcass; this makes repeated measurements on the same carcass difficult. Herein we compare sponge sampling to skin excision to recover inoculated Salmonella and Campylobacter from broiler carcasses. In each of three replications, broiler carcass breast skin was inoculated with approximately 6.0 log antimicrobial-resistant Salmonella and Campylobacter, allowed to dry for 60 s, and sampled by either sponge, skin excision, or sponge followed by skin excision. Antimicrobial-resistant Salmonella and Campylobacter were enumerated from all samples. Skin excision allowed recovery of 0.1 to 0.2 log more inoculated bacteria than did sponge sampling. When excision was used on the same skin previously sampled by sponging, the combination of both methods did not significantly improve recovery compared with sponging alone. Skin excision is slightly more sensitive than sponge sampling; however, for repeated nondestructive sampling of broiler carcasses during processing, sponge sampling may be preferable to recover Salmonella and Campylobacter within 60 s of a contamination event.

  8. Arsenic levels in wipe samples collected from play structures constructed with CCA-treated wood: Impact on exposure estimates

    Energy Technology Data Exchange (ETDEWEB)

    Barraj, Leila M. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States)], E-mail: lbarraj@exponent.com; Scrafford, Carolyn G. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States); Eaton, W. Cary [RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709 (United States); Rogers, Robert E.; Jeng, Chwen-Jyh [Toxcon Health Sciences Research Centre Inc., 9607 - 41 Avenue, Edmonton, Alberta, T6E 5X7 (Canada)

    2009-04-01

    Lumber treated with chromated copper arsenate (CCA) has been used in residential outdoor wood structures and playgrounds. The U.S. EPA has conducted a probabilistic assessment of children's exposure to arsenic from CCA-treated structures using the Stochastic Human Exposure and Dose Simulation model for the wood preservative scenario (SHEDS-Wood). The EPA assessment relied on data from an experimental study using adult volunteers and designed to measure arsenic in maximum hand and wipe loadings. Analyses using arsenic handloading data from a study of children playing on CCA-treated play structures in Edmonton, Canada, indicate that the maximum handloading values significantly overestimate the exposure that occurs during actual play. The objective of our paper is to assess whether the dislodgeable arsenic residues from structures in the Edmonton study are comparable to those observed in other studies and whether they support the conclusion that the values derived by EPA using modeled maximum loading values overestimate hand exposures. We compared dislodgeable arsenic residue data from structures in the playgrounds in the Edmonton study to levels observed in studies used in EPA's assessment. Our analysis showed that the dislodgeable arsenic levels in the Edmonton playground structures are similar to those in the studies used by EPA. Hence, the exposure estimates derived using the handloading data from children playing on CCA-treated structures are more representative of children's actual exposures than the overestimates derived by EPA using modeled maximum values. Handloading data from children playing on CCA-treated structures should be used to reduce the uncertainty of modeled estimates derived using the SHEDS-Wood model.

  9. Arsenic levels in wipe samples collected from play structures constructed with CCA-treated wood: impact on exposure estimates.

    Science.gov (United States)

    Barraj, Leila M; Scrafford, Carolyn G; Eaton, W Cary; Rogers, Robert E; Jeng, Chwen-Jyh

    2009-04-01

    Lumber treated with chromated copper arsenate (CCA) has been used in residential outdoor wood structures and playgrounds. The U.S. EPA has conducted a probabilistic assessment of children's exposure to arsenic from CCA-treated structures using the Stochastic Human Exposure and Dose Simulation model for the wood preservative scenario (SHEDS-Wood). The EPA assessment relied on data from an experimental study using adult volunteers and designed to measure arsenic in maximum hand and wipe loadings. Analyses using arsenic handloading data from a study of children playing on CCA-treated play structures in Edmonton, Canada, indicate that the maximum handloading values significantly overestimate the exposure that occurs during actual play. The objective of our paper is to assess whether the dislodgeable arsenic residues from structures in the Edmonton study are comparable to those observed in other studies and whether they support the conclusion that the values derived by EPA using modeled maximum loading values overestimate hand exposures. We compared dislodgeable arsenic residue data from structures in the playgrounds in the Edmonton study to levels observed in studies used in EPA's assessment. Our analysis showed that the dislodgeable arsenic levels in the Edmonton playground structures are similar to those in the studies used by EPA. Hence, the exposure estimates derived using the handloading data from children playing on CCA-treated structures are more representative of children's actual exposures than the overestimates derived by EPA using modeled maximum values. Handloading data from children playing on CCA-treated structures should be used to reduce the uncertainty of modeled estimates derived using the SHEDS-Wood model.

  10. Sampling scheme for pyrethroids on multiple surfaces on commercial aircrafts

    Science.gov (United States)

    MOHAN, KRISHNAN R.; WEISEL, CLIFFORD P.

    2015-01-01

    A wipe sampler for the collection of permethrin from soft and hard surfaces has been developed for use in aircraft. “Disinsection” or application of pesticides, predominantly pyrethrods, inside commercial aircraft is routinely required by some countries and is done on an as-needed basis by airlines resulting in potential pesticide dermal and inhalation exposures to the crew and passengers. A wipe method using filter paper and water was evaluated for both soft and hard aircraft surfaces. Permethrin was analyzed by GC/MS after its ultrasonication extraction from the sampling medium into hexane and volume reduction. Recoveries, based on spraying known levels of permethrin, were 80–100% from table trays, seat handles and rugs; and 40–50% from seat cushions. The wipe sampler is easy to use, requires minimum training, is compatible with the regulations on what can be brought through security for use on commercial aircraft, and readily adaptable for use in residential and other settings. PMID:19756041

  11. EVALUATING COMMERCIALLY AVAILABLE DERMAL WIPES, COTTON SUITES, AND ALTERNATIVE URINARY COLLECTION MATERIALS FOR PESTICIDE SAMPLING FROM INFANTS

    Science.gov (United States)

    As the Human Exposure Program focuses on the exposure of children to pesticides, there are concerns about the effect, or perceived effect, of components of the sampling procedure on the health and well-being of the infant and the ability to collect pesticide residues. One...

  12. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  13. Hand wash and manual skin wipes

    NARCIS (Netherlands)

    Brouwer, D.H.; Boeniger, M.F.; Hemmen, J. van

    2000-01-01

    Hand wash and skin wipes are major techniques that have been used for dermal exposure sampling. Both techniques remove chemicals either deposited on or transferred to the skin contaminant layer by a combination of chemical and mechanical actions. The paper overviews identified methods and

  14. Evaluation of surface sampling method performance for Bacillus Spores on clean and dirty outdoor surfaces.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Einfeld, Wayne; Boucher, Raymond M.; Brown, Gary Stephen; Tezak, Matthew Stephen

    2011-06-01

    Recovery of Bacillus atrophaeous spores from grime-treated and clean surfaces was measured in a controlled chamber study to assess sampling method performance. Outdoor surfaces investigated by wipe and vacuum sampling methods included stainless steel, glass, marble and concrete. Bacillus atrophaeous spores were used as a surrogate for Bacillus anthracis spores in this study designed to assess whether grime-coated surfaces significantly affected surface sampling method performance when compared to clean surfaces. A series of chamber tests were carried out in which known amounts of spores were allowed to gravitationally settle onto both clean and dirty surfaces. Reference coupons were co-located with test coupons in all chamber experiments to provide a quantitative measure of initial surface concentrations of spores on all surfaces, thereby allowing sampling recovery calculations. Results from these tests, carried out under both low and high humidity conditions, show that spore recovery from grime-coated surfaces is the same as or better than spore recovery from clean surfaces. Statistically significant differences between method performance for grime-coated and clean surfaces were observed in only about half of the chamber tests conducted.

  15. Surface Sampling Techniques

    Science.gov (United States)

    1982-09-01

    their suitability for use for qualitative analysis of explosiveu/ explosivo residues oil the surface types of interest. Tables 11-5 and 11-6 list spot teot...below: Analytes Tested NG Nitroglycerin PETN Pentaerythritetetranitrate RDX Cyclotrimethylenetrinitramine TNT 2,4,6-trinitrotoluene TNB 1,3,5...acetonitrile had evaporated, the paper was examined under 254 nm UV illumination. All of the analytes except NG and PETN were detecr.ed at the 10OX

  16. Study on the wiping gas jet in continuous galvanizing line

    Science.gov (United States)

    Kweon, Yong-Hun; Kim, Heuy-Dong

    2011-09-01

    In the continuous hot-dip galvanizing process, the gas-jet wiping is used to control the coating thickness of moving steel strip. The high speed gas-jet discharged from the nozzle slot impinges on the strip, and at this moment, wipes the liquid coating layer dragged by a moving strip. The coating thickness is generally influenced on the flow characteristics of wiping gas-jet such as the impinging pressure distribution, pressure gradient and shear stress distribution on the surface of strip. The flow characteristics of wiping gas-jet mentioned above depends upon considerably both the process operating conditions such as the nozzle pressure, nozzle-to-strip distance and line speed, and the geometry of gas-jet wiping apparatus such as the height of nozzle slot. In the present study, the effect of the geometry of nozzle on the coating thickness is investigated with the help of a computational fluid dynamics method. The height of nozzle slot is varied in the range of 0.6mm to 1.7mm. A finite volume method (FVM) is employed to solve two-dimensional, steady, compressible Navier-Stokes equations. Based upon the results obtained, the effect of the height of nozzle slot in the gas-jet wiping process is discussed in detail. The computational results show that for a given standoff distance between the nozzle to the strip, the effective height of nozzle slot exists in achieving thinner coating thickness.

  17. Quat co-formulations optimized for use with cotton nonwoven disposable wipes

    Science.gov (United States)

    Quaternary ammonium compounds, commonly referred to as quats, are cationic surfactants widely used as the active biocidal ingredient for disposable disinfecting wipes. The cationic nature of quats results in a strong ionic interaction and adsorption onto wipes materials that have an anionic surface...

  18. Comparison of Two Surface Contamination Sampling Techniques Conducted for the Characterization of Two Pajarito Site Manhattan Project National Historic Park Properties

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Tammy Ann [Montana Tech of the Univ. of Montana, Butte, MT (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-29

    Technical Area-18 (TA-18), also known as Pajarito Site, is located on Los Alamos National Laboratory property and has historic buildings that will be included in the Manhattan Project National Historic Park. Characterization studies of metal contamination were needed in two of the four buildings that are on the historic registry in this area, a “battleship” bunker building (TA-18-0002) and the Pond cabin (TA-18-0029). However, these two buildings have been exposed to the elements, are decades old, and have porous and rough surfaces (wood and concrete). Due to these conditions, it was questioned whether standard wipe sampling would be adequate to detect surface dust metal contamination in these buildings. Thus, micro-vacuum and surface wet wipe sampling techniques were performed side-by-side at both buildings and results were compared statistically. A two-tail paired t-test revealed that the micro-vacuum and wet wipe techniques were statistically different for both buildings. Further mathematical analysis revealed that the wet wipe technique picked up more metals from the surface than the microvacuum technique. Wet wipes revealed concentrations of beryllium and lead above internal housekeeping limits; however, using an yttrium normalization method with linear regression analysis between beryllium and yttrium revealed a correlation indicating that the beryllium levels were likely due to background and not operational contamination. PPE and administrative controls were implemented for National Park Service (NPS) and Department of Energy (DOE) tours as a result of this study. Overall, this study indicates that the micro-vacuum technique may not be an efficient technique to sample for metal dust contamination.

  19. Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Amidan, Brett G.; Hu, Rebecca

    2011-11-28

    This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the (1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and (2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed and recommendations are given for future studies.

  20. Wipes coated with a singlet-oxygen-producing photosensitizer are effective against human influenza virus but not against norovirus

    NARCIS (Netherlands)

    Verhaelen, Katharina; Bouwknegt, Martijn; Rutjes, Saskia; de Roda Husman, Ana Maria; Duizer, Erwin

    2014-01-01

    Transmission of enteric and respiratory viruses, including human norovirus (hNoV) and human influenza virus, may involve surfaces. In food preparation and health care settings, surfaces are cleaned with wipes; however, wiping may not efficiently reduce contamination or may even spread viruses,

  1. Ball assisted device for analytical surface sampling

    Science.gov (United States)

    ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

    2015-11-03

    A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.

  2. The Case for Cotton Wipes and Nonwovens

    Science.gov (United States)

    The significant growth in the volume and number of wipe-based products for a wide variety of applications is consuming ever increasing amounts of fiber as raw material in wipes and other nonwoven products. The United States Department of Agriculture and Cotton Incorporated recognize both the economi...

  3. Genital region cleansing wipes: Effects on urine culture contamination.

    Science.gov (United States)

    Selek, Mehmet Burak; Bektöre, Bayhan; Sezer, Ogün; Kula Atik, Tuğba; Baylan, Orhan; Özyurt, Mustafa

    2017-01-30

    Urine culture is the gold standard test for revealing the microbial agent causing urinary tract infection (UTI). Culture results are affected by sampling techniques; improper sampling leads to contamination of urine and thus contamination of the culture with urogenital flora. We aimed to evaluate the effect of urogenital cleansing, performed with chlorhexidine-containing genital region cleansing wipes (GRCW) on contamination rates. A total of 2,665 patients with UTI-related complaints and with urine culture requests from various outpatient clinics were enrolled in the study. Of the patients, 1,609 in the experimental group used GRCW before sampling, while 1,046 in the control group did not use any wipes. The contamination rate in the experimental group patients was 7.7%, while it was 15.8% in the control group. Contamination rates were significantly higher in the control group than in the experimental group for both women and men. Contamination rates for children and adults were also significantly lower in the experimental group than in the control group. Our study, conducted in a large population, showed that the use of chlorhexidine-containing cleansing wipes significantly reduced urine culture contamination rates in both genders, in both child and adult age groups. Using GRCW, collection of urine after urogenital area cleansing will decrease the contamination problem.

  4. Efficacy of surface sampling methods for different types of beryllium compounds.

    Science.gov (United States)

    Dufresne, A; Mocanu, T; Viau, S; Perrault, G; Dion, C

    2011-01-01

    The objective of the research work was to evaluate the efficiency of three different sampling methods (Ghost Wipe™, micro-vacuum, and ChemTest®) in the recovery of Be dust by assessing: (1) four Be compounds (beryllium acetate, beryllium chloride, beryllium oxide and beryllium aluminium), (2) three different surfaces (polystyrene, glass and aluminium) and (3) inter-operator variation. The three sampling methods were also tested on site in a laboratory of a dental school for validation purposes. The Ghost Wipe™ method showed recovery ranging from 43.3% to 85.8% for all four Be compounds and for all three quantities of Be spiked on Petri dishes, while recovery with the micro-vacuum method ranged from 0.1% to 12.4%. On polystyrene dishes with 0.4 µg Be, the recovery ranged from 48.3% to 81.7%, with an average recovery of 59.4% for Operator 1 and 68.4% for Operator 2. The ChemTest® wipe method with beryllium acetate, beryllium chloride, and AlBeMet® showed analogous results that are in line with the manufacturer's manual, but collection of beryllium oxide was negative. In the dental laboratory, Ghost Wipe™ samplings showed better recovery than the micro-vacuum method. The ratios between the recovered quantities of Be in each location where the Ghost Wipe™ was tested differed substantially, ranging from 1.45 to 64. In the dental laboratory, a faint blue color indicating the presence of Be was observed on the ChemTest® wipes used in two locations out of six. In summary, the Ghost Wipe™ method was more efficient than micro-vacuuming in collecting the Be dust from smooth, non-porous surfaces such as Petri dishes by a factor of approximately 18. The results obtained on site in a dental laboratory also showed better recovery with Ghost Wipes™. However, the ratio of Be recovered by Ghost Wipes™ versus micro-vacuuming was much lower for surfaces where a large amount of dust was present. Wet wiping is preferred over micro-vacuuming for beryllium forms, but

  5. MESERAN Test Results for Elimination of Flammable Solvents in Wipe Applications at Pantex

    Energy Technology Data Exchange (ETDEWEB)

    M. G. Benkovich

    2005-03-30

    In recent years, efforts have been made within the nuclear weapons complex (National Nuclear Security Administration) of the Department of Energy (DOE) to replace Resource Conservation and Recovery Act (RCRA) regulated solvents (i.e., flammable, toxic, corrosive, and reactive) and ozone-depleting chemicals (ODC) with more benign alternatives. Within the National Nuclear Security Administration (NNSA) and the Department of Defense (DoD) sectors, these solvents are used for cleaning hardware during routine maintenance operations. A primary goal of this study is to replace flammable solvents for wiping applications. Two cleaners, including a hydrofluoroether (HFE) and an azeotrope of the HFE and isopropyl alcohol (IPA), have been studied as potential replacements for flammable solvents. Cleaning efficacy, short-term and longterm materials compatibility, corrosion, drying times, flammability, environment, safety and health (ES&H) issues and accelerated aging studies are among the tests that are being conducted and that are used to screen candidate solvents by the interagency team performing this work. The results are compared to the traditionally used isopropyl alcohol, which serves as the baseline cleaner. This report details the results of MESERAN (Measurement and Evaluation of Surfaces by Evaporative Rate ANalysis) testing performed at the Kansas City Plant (KCP) to quantify the cleaning efficacy on samples contaminated with the various contaminants and cleaned by wiping with the various solvents being evaluated.

  6. Sampling the Uppermost Surface of Airless Bodies

    Science.gov (United States)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.

    2011-01-01

    The uppermost surface of an airless body is a critical source of ground-truth information for the various remote sensing techniques that only penetrate nanometers to micrometers into the surface. Such samples will also be vital for understanding conditions at the surface and acquiring information about how the body interacts with its environment, including solar wind interaction, grain charging and levitation [1]. Sampling the uppermost surface while preserving its structure (e.g. porosity, grain-to-grain contacts) however, is a daunting task that has not been achieved on any sample return mission to date.

  7. Evaluation of a New Environmental Sampling Protocol for Detection of Human Norovirus on Inanimate Surfaces

    Science.gov (United States)

    Lee, David; Treffiletti, Aimee; Hrsak, Mario; Shugart, Jill; Vinjé, Jan

    2015-01-01

    Inanimate surfaces are regarded as key vehicles for the spread of human norovirus during outbreaks. ISO method 15216 involves the use of cotton swabs for environmental sampling from food surfaces and fomites for the detection of norovirus genogroup I (GI) and GII. We evaluated the effects of the virus drying time (1, 8, 24, or 48 h), swab material (cotton, polyester, rayon, macrofoam, or an antistatic wipe), surface (stainless steel or a toilet seat), and area of the swabbed surface (25.8 cm2 to 645.0 cm2) on the recovery of human norovirus. Macrofoam swabs produced the highest rate of recovery of norovirus from surfaces as large as 645 cm2. The rates of recovery ranged from 2.2 to 36.0% for virus seeded on stainless-steel coupons (645.0 cm2) to 1.2 to 33.6% for toilet seat surfaces (700 cm2), with detection limits of 3.5 log10 and 4.0 log10 RNA copies. We used macrofoam swabs to collect environmental samples from several case cabins and common areas of a cruise ship where passengers had reported viral gastroenteritis symptoms. Seventeen (18.5%) of 92 samples tested positive for norovirus GII, and 4 samples could be sequenced and had identical GII.1 sequences. The viral loads of the swab samples from the cabins of the sick passengers ranged from 80 to 31,217 RNA copies, compared with 16 to 113 RNA copies for swab samples from public spaces. In conclusion, our swab protocol for norovirus may be a useful tool for outbreak investigations when no clinical samples are available to confirm the etiology. PMID:26116675

  8. Comet Odyssey: Comet Surface Sample Return

    Science.gov (United States)

    Weissman, Paul R.; Bradley, J.; Smythe, W. D.; Brophy, J. R.; Lisano, M. E.; Syvertson, M. L.; Cangahuala, L. A.; Liu, J.; Carlisle, G. L.

    2010-10-01

    Comet Odyssey is a proposed New Frontiers mission that would return the first samples from the surface of a cometary nucleus. Stardust demonstrated the tremendous power of analysis of returned samples in terrestrial laboratories versus what can be accomplished in situ with robotic missions. But Stardust collected only 1 milligram of coma dust, and the 6.1 km/s flyby speed heated samples up to 2000 K. Comet Odyssey would collect two independent 800 cc samples directly from the surface in a far more benign manner, preserving the primitive composition. Given a minimum surface density of 0.2 g/cm3, this would return two 160 g surface samples to Earth. Comet Odyssey employs solar-electric propulsion to rendezvous with the target comet. After 180 days of reconnaissance and site selection, the spacecraft performs a "touch-and-go” maneuver with surface contact lasting 3 seconds. A brush-wheel sampler on a remote arm collects up to 800 cc of sample. A duplicate second arm and sampler collects the second sample. The samples are placed in a return capsule and maintained at colder than -70 C during the return flight and at colder than -30 C during re-entry and for up to six hours after landing. The entire capsule is then refrigerated and transported to the Astromaterials Curatorial Facility at NASA/JSC for initial inspection and sample analysis by the Comet Odyssey team. Comet Odyssey's planned target was comet 9P/Tempel 1, with launch in December 2017 and comet arrival in June 2022. After a stay of 300 days at the comet, the spacecraft departs and arrives at Earth in May 2027. Comet Odyssey is a forerunner to a flagship Cryogenic Comet Sample Return mission that would return samples from deep below the nucleus surface, including volatile ices. This work was supported by internal funds from the Jet Propulsion Laboratory.

  9. Rapid surface sampling and archival record system

    Energy Technology Data Exchange (ETDEWEB)

    Barren, E.; Penney, C.M.; Sheldon, R.B. [GE Corporate Research and Development Center, Schenectady, NY (United States)] [and others

    1995-10-01

    A number of contamination sites exist in this country where the area and volume of material to be remediated is very large, approaching or exceeding 10{sup 6} m{sup 2} and 10{sup 6} m{sup 3}. Typically, only a small fraction of this material is actually contaminated. In such cases there is a strong economic motivation to test the material with a sufficient density of measurements to identify which portions are uncontaminated, so extensively they be left in place or be disposed of as uncontaminated waste. Unfortunately, since contamination often varies rapidly from position to position, this procedure can involve upwards of one million measurements per site. The situation is complicated further in many cases by the difficulties of sampling porous surfaces, such as concrete. This report describes a method for sampling concretes in which an immediate distinction can be made between contaminated and uncontaminated surfaces. Sample acquisition and analysis will be automated.

  10. Surface sampling concentration and reaction probe

    Science.gov (United States)

    Van Berkel, Gary J; Elnaggar, Mariam S

    2013-07-16

    A method of analyzing a chemical composition of a specimen is described. The method can include providing a probe comprising an outer capillary tube and an inner capillary tube disposed co-axially within the outer capillary tube, where the inner and outer capillary tubes define a solvent capillary and a sampling capillary in fluid communication with one another at a distal end of the probe; contacting a target site on a surface of a specimen with a solvent in fluid communication with the probe; maintaining a plug volume proximate a solvent-specimen interface, wherein the plug volume is in fluid communication with the probe; draining plug sampling fluid from the plug volume through the sampling capillary; and analyzing a chemical composition of the plug sampling fluid with an analytical instrument. A system for performing the method is also described.

  11. A new wiping device for detecting removable contamination.

    Science.gov (United States)

    Furuta, Etsuko; Watanabe, Yasuo; Yokota, Shigeaki

    2012-06-01

    A new wiping device for detecting removable contamination was developed. A cylindrical plastic scintillator (PS) is applied to a roller device. A wiping material wraps around the cylindrical PS roller, and then the roller is used for wiping to detect removable contamination (PS method). After contamination on the floor is wiped off using the roller, the wrapped PS is removed from the roller and placed in a glass vial for use in a liquid scintillation counter (LSC). The vial is measured by LSC without liquid scintillation cocktail. When the PS method was used by wrapping with NUC-Wipe™, the wiping efficiencies, except for the measurement efficiencies, were almost 15% for H and 40% for C. Also a repositionable tape (Double Stick Tape™) could be used for wiping material. The device has three main advantages: 1) Though the wiping efficiency is not very high when using the PS method, the variability observed is lower than that for hand wiping; 2) even when it is contaminated with nuclides whose maximum beta ray energies (Emax) are very close, for example C (Emax; 156 keV) and S (Emax; 167 keV), the contaminated radioisotopes are identified with their spectra by using PS; and 3) the PS method is environmentally friendly, as post-processing time is vastly shortened because it does not use a liquid scintillator. Some issues that were previously considered unavoidable in the wiping method were improved using a plastic scintillator as a roller.

  12. Effect on skin hydration of using baby wipes to clean the napkin area of newborn babies: assessor-blinded randomised controlled equivalence trial.

    Science.gov (United States)

    Lavender, Tina; Furber, Christine; Campbell, Malcolm; Victor, Suresh; Roberts, Ian; Bedwell, Carol; Cork, Michael J

    2012-06-01

    Some national guidelines recommend the use of water alone for napkin cleansing. Yet, there is a readiness, amongst many parents, to use baby wipes. Evidence from randomised controlled trials, of the effect of baby wipes on newborn skin integrity is lacking. We conducted a study to examine the hypothesis that the use of a specifically formulated cleansing wipe on the napkin area of newborn infants (babies (n=280), recruited within 48 hours of birth, were randomly assigned to have their napkin area cleansed with an alcohol-free baby wipe (140 babies) or cotton wool and water (140 babies). Primary outcome was change in hydration from within 48 hours of birth to 4 weeks post-birth. Secondary outcomes comprised changes in trans-epidermal water loss, skin surface pH and erythema, presence of microbial skin contaminants/irritants at 4 weeks and napkin dermatitis reported by midwife at 4 weeks and mother during the 4 weeks. Complete hydration data were obtained for 254 (90.7 %) babies. Wipes were shown to be equivalent to water and cotton wool in terms of skin hydration (intention-to-treat analysis: wipes 65.4 (SD 12.4) vs. water 63.5 (14.2), p=0.47, 95% CI -2.5 to 4.2; per protocol analysis: wipes 64.6 (12.4) vs. water 63.6 (14.3), p=0.53, 95% CI -2.4 to 4.2). No significant differences were found in the secondary outcomes, except for maternal-reported napkin dermatitis, which was higher in the water group (p=0.025 for complete responses). Baby wipes had an equivalent effect on skin hydration when compared with cotton wool and water. We found no evidence of any adverse effects of using these wipes. These findings offer reassurance to parents who choose to use baby wipes and to health professionals who support their use. Current Controlled Trials ISRCTN86207019.

  13. System and method for extracting a sample from a surface

    Science.gov (United States)

    Van Berkel, Gary; Covey, Thomas

    2015-06-23

    A system and method is disclosed for extracting a sample from a sample surface. A sample is provided and a sample surface receives the sample which is deposited on the sample surface. A hydrophobic material is applied to the sample surface, and one or more devices are configured to dispense a liquid on the sample, the liquid dissolving the sample to form a dissolved sample material, and the one or more devices are configured to extract the dissolved sample material from the sample surface.

  14. A NEAR REAL-TIME BERYLLIUM MONITOR WITH CAM AND WIPE ANALYSIS CAPABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    D.T. Kendrick; Steven Saggese

    2002-12-01

    Science & Engineering Associates, Inc. (SEA), under contract No. DE-AC26-00NT40768, was tasked by the US Department of Energy--National Energy Technology Laboratory to develop and test a near real-time beryllium monitor for airborne and surface measurements. Recent public awareness of the health risks associated with exposure to beryllium has underscored the need for better, faster beryllium monitoring capabilities within the DOE. A near real-time beryllium monitor will offer significant improvements over the baseline monitoring technology currently in use. Whereas the baseline technology relies upon collecting an air sample on a filter and the subsequent analysis of the filter by an analytical laboratory, this effort developed a monitor that offers near real-time measurement results while work is in progress. Since the baseline typically only offers after-the-fact documentation of exposure levels, the near real-time capability provides a significant increase in worker protection. The beryllium monitor developed utilizes laser induced breakdown spectroscopy, or LIBS as the fundamental measurement technology. LIBS has been used in a variety of laboratory and field based instrumentation to provide real-time, and near-real-time elemental analysis capabilities. LIBS is an analytical technique where a pulsed high energy laser beam is focused to a point on the sample to be interrogated. The high energy density produces a small high temperature plasma plume, sometimes called a spark. The conditions within this plasma plume result in the constituent atoms becoming excited and emitting their characteristic optical emissions. The emission light is collected and routed to an optical spectrometer for quantitative spectral analysis. Each element has optical emissions, or lines, of a specific wavelength that can be used to uniquely identify that element. In this application, the intensity of the beryllium emission is used to provide a quantitative measure of the abundance of the

  15. Effectiveness of tooth wipes in removing babies' dental biofilm.

    Science.gov (United States)

    Abanto, Jenny; Rezende, Karla Mayra; Carvalho, Thiago Saads; Correa, Fernanda Nahas; Vilela, Tamara; Bönecker, Marcelo; Salete, Maria; Correa, Nahas Pires

    2012-01-01

    To assess the effectiveness of tooth wipes in removing dental biofilm from babies' anterior teeth, as well as to evaluate the babies' behaviour and the guardians' preference concerning hygiene methods. In this random blind cross-over study, 50 high caries risk babies, from 8 to 15 months old, were divided into two groups: babies with oral hygiene performed by caregivers (n = 25) or by their mothers (n = 25). The caregivers and mothers removed biofilm using three methods of oral hygiene (tooth wipes, toothbrushes and gauze), one in each experimental phase. Professional cleaning was done before each phase, which had 2 days of biofilm accumulation and 1 experimental day, when caregivers and mothers used one method to remove biofilm. Examiners blinded to the study design assessed the biofilm index at baseline, prior to and following biofilm removal using each method. The babies' behaviour and the mothers'/caregivers' preference were assessed. The tooth wipes, toothbrushes and gauze significantly reduced the amount of biofilm (P < 0.001). The mothers' group removed more biofilm than the caregivers' group, using toothbrushes or tooth wipes (P < 0.05). Babies in the mothers' group had better behaviour using tooth wipes than toothbrushes (P < 0.05). Mothers and caregivers preferred to use tooth wipes. Tooth wipes are effective in removing biofilm from babies' anterior teeth and are the method best accepted by mothers, caregivers and babies.

  16. Broad Spectrum Sanitizing Wipes with Food Additives Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcide proposes to develop novel multipurpose non-toxic sanitizing wipes that are aqueous based, have shelf life of 3-5 years, have broad spectrum microbicidal...

  17. A Comet Surface Sample Return System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase II investigation will focus on the development of spacecraft systems required to obtain a sample from the nucleus of a comet, hermetically seal...

  18. A Comet Surface Sample Return System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase I investigation will focus on the development of spacecraft systems required to obtain a sample from the nucleus of a comet, hermetically seal the...

  19. Mathematical modeling of wiped-film evaporators. [MAIN codes

    Energy Technology Data Exchange (ETDEWEB)

    Sommerfeld, J.T.

    1976-05-01

    A mathematical model and associated computer program were developed to simulate the steady-state operation of wiped-film evaporators for the concentration of typical waste solutions produced at the Savannah River Plant. In this model, which treats either a horizontal or a vertical wiped-film evaporator as a plug-flow device with no backmixing, three fundamental phenomena are described: sensible heating of the waste solution, vaporization of water, and crystallization of solids from solution. Physical property data were coded into the computer program, which performs the calculations of this model. Physical properties of typical waste solutions and of the heating steam, generally as analytical functions of temperature, were obtained from published data or derived by regression analysis of tabulated or graphical data. Preliminary results from tests of the Savannah River Laboratory semiworks wiped-film evaporators were used to select a correlation for the inside film heat transfer coefficient. This model should be a useful aid in the specification, operation, and control of the full-scale wiped-film evaporators proposed for application under plant conditions. In particular, it should be of value in the development and analysis of feed-forward control schemes for the plant units. Also, this model can be readily adapted, with only minor changes, to simulate the operation of wiped-film evaporators for other conceivable applications, such as the concentration of acid wastes.

  20. Surface reconstruction through poisson disk sampling.

    Directory of Open Access Journals (Sweden)

    Wenguang Hou

    Full Text Available This paper intends to generate the approximate Voronoi diagram in the geodesic metric for some unbiased samples selected from original points. The mesh model of seeds is then constructed on basis of the Voronoi diagram. Rather than constructing the Voronoi diagram for all original points, the proposed strategy is to run around the obstacle that the geodesic distances among neighboring points are sensitive to nearest neighbor definition. It is obvious that the reconstructed model is the level of detail of original points. Hence, our main motivation is to deal with the redundant scattered points. In implementation, Poisson disk sampling is taken to select seeds and helps to produce the Voronoi diagram. Adaptive reconstructions can be achieved by slightly changing the uniform strategy in selecting seeds. Behaviors of this method are investigated and accuracy evaluations are done. Experimental results show the proposed method is reliable and effective.

  1. Effect on skin hydration of using baby wipes to clean the napkin area of newborn babies: assessor-blinded randomised controlled equivalence trial

    Directory of Open Access Journals (Sweden)

    Lavender Tina

    2012-06-01

    Full Text Available Abstract Background Some national guidelines recommend the use of water alone for napkin cleansing. Yet, there is a readiness, amongst many parents, to use baby wipes. Evidence from randomised controlled trials, of the effect of baby wipes on newborn skin integrity is lacking. We conducted a study to examine the hypothesis that the use of a specifically formulated cleansing wipe on the napkin area of newborn infants ( Methods A prospective, assessor-blinded, randomised controlled equivalence trial was conducted during 2010. Healthy, term babies (n = 280, recruited within 48 hours of birth, were randomly assigned to have their napkin area cleansed with an alcohol-free baby wipe (140 babies or cotton wool and water (140 babies. Primary outcome was change in hydration from within 48 hours of birth to 4 weeks post-birth. Secondary outcomes comprised changes in trans-epidermal water loss, skin surface pH and erythema, presence of microbial skin contaminants/irritants at 4 weeks and napkin dermatitis reported by midwife at 4 weeks and mother during the 4 weeks. Results Complete hydration data were obtained for 254 (90.7 % babies. Wipes were shown to be equivalent to water and cotton wool in terms of skin hydration (intention-to-treat analysis: wipes 65.4 (SD 12.4 vs. water 63.5 (14.2, p = 0.47, 95 % CI -2.5 to 4.2; per protocol analysis: wipes 64.6 (12.4 vs. water 63.6 (14.3, p = 0.53, 95 % CI -2.4 to 4.2. No significant differences were found in the secondary outcomes, except for maternal-reported napkin dermatitis, which was higher in the water group (p = 0.025 for complete responses. Conclusions Baby wipes had an equivalent effect on skin hydration when compared with cotton wool and water. We found no evidence of any adverse effects of using these wipes. These findings offer reassurance to parents who choose to use baby wipes and to health professionals who support their use. Trial registration Current Controlled

  2. Sampling procedure for lake or stream surface water chemistry

    Science.gov (United States)

    Robert Musselman

    2012-01-01

    Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

  3. 49 CFR 393.78 - Windshield wiping and washing systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Windshield wiping and washing systems. 393.78 Section 393.78 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION...

  4. Assessment of arsenic surface contamination in a museum anthropology department.

    Science.gov (United States)

    Gribovich, Andrey; Lacey, Steven; Franke, John; Hinkamp, David

    2013-02-01

    To assess potential arsenic (As) contamination of work surfaces to improve upon the control strategy at an anthropology department in a large natural history museum. Work practices were observed and control strategy reviewed to inform an occupational hygiene assessment strategy utilizing surface wipe sampling. A total of 35 sampling targets were identified, focusing on surfaces that receive high touch traffic, including workstations, artifact transport carts, and elevator buttons. Arsenic sampling and analysis were performed using reference method Occupational Safety and Health Administration ID-125G. Four of the sampling areas returned detectable levels of As, ranging from 0.052 to 0.350 μg/100 cm. Workplace observations and wipe sampling data enabled the development of recommendations to help to further reduce potential occupational exposure to As. Continuous reduction of surface contamination is prudent for known human carcinogens.

  5. Efficient maximal Poisson-disk sampling and remeshing on surfaces

    KAUST Repository

    Guo, Jianwei

    2015-02-01

    Poisson-disk sampling is one of the fundamental research problems in computer graphics that has many applications. In this paper, we study the problem of maximal Poisson-disk sampling on mesh surfaces. We present a simple approach that generalizes the 2D maximal sampling framework to surfaces. The key observation is to use a subdivided mesh as the sampling domain for conflict checking and void detection. Our approach improves the state-of-the-art approach in efficiency, quality and the memory consumption.

  6. Effectiveness of cleaning-disinfection wipes and sprays against multidrug-resistant outbreak strains.

    Science.gov (United States)

    Kenters, Nikki; Huijskens, Elisabeth G W; de Wit, Sophie C J; van Rosmalen, Joost; Voss, Andreas

    2017-08-01

    Hospital rooms play an important role in the transmission of several health care-associated pathogens. During the last few years, a number of innovative cleaning-disinfecting products have been brought to market. In this study, commercially available products combining cleaning and disinfection were compared, using 2 different application methods. The aim was to determine which product was most effective in simultaneous cleaning and disinfection of surfaces. Seven cleaning-disinfecting wipes and sprays based on different active ingredients were tested for their efficacy in removal of microbial burden and proteins. Efficacy was tested with known Dutch outbreak strains: vancomycin-resistant enterococci (VRE), Klebsiella pneumoniae OXA-48, or Acinetobacter baumannii. For all bacteria, ready-to-use cleaning-disinfecting products reduced the microbial count with a log10 reduction >5 with a 5-minute exposure time, with the exception of a spray based on hydrogen peroxide. Omitting the aforementioned hydrogen peroxide spray, there were no significant differences between use of a wipe or spray in bacterial load reduction. Using adenosine triphosphate (ATP) measurements, a significant difference in log10 relative light units (RLU) reduction between various bacteria (P ≤ .001) was observed. In general, a >5 log10 reduction of colony forming units (CFU) for tested wipes and sprays was obtained for all tested bacteria strains, with exception of hydrogen peroxide spray and VRE. Although ATP may show a difference between pre- and postcleaning, RLU reduction does not correlate with actual CFU reductions. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  7. Surface sampling techniques for 3D object inspection

    Science.gov (United States)

    Shih, Chihhsiong S.; Gerhardt, Lester A.

    1995-03-01

    While the uniform sampling method is quite popular for pointwise measurement of manufactured parts, this paper proposes three novel sampling strategies which emphasize 3D non-uniform inspection capability. They are: (a) the adaptive sampling, (b) the local adjustment sampling, and (c) the finite element centroid sampling techniques. The adaptive sampling strategy is based on a recursive surface subdivision process. Two different approaches are described for this adaptive sampling strategy. One uses triangle patches while the other uses rectangle patches. Several real world objects were tested using these two algorithms. Preliminary results show that sample points are distributed more closely around edges, corners, and vertices as desired for many classes of objects. Adaptive sampling using triangle patches is shown to generally perform better than both uniform and adaptive sampling using rectangle patches. The local adjustment sampling strategy uses a set of predefined starting points and then finds the local optimum position of each nodal point. This method approximates the object by moving the points toward object edges and corners. In a hybrid approach, uniform points sets and non-uniform points sets, first preprocessed by the adaptive sampling algorithm on a real world object were then tested using the local adjustment sampling method. The results show that the initial point sets when preprocessed by adaptive sampling using triangle patches, are moved the least amount of distance by the subsequently applied local adjustment method, again showing the superiority of this method. The finite element sampling technique samples the centroids of the surface triangle meshes produced from the finite element method. The performance of this algorithm was compared to that of the adaptive sampling using triangular patches. The adaptive sampling with triangular patches was once again shown to be better on different classes of objects.

  8. Adaptive maximal poisson-disk sampling on surfaces

    KAUST Repository

    Yan, Dongming

    2012-01-01

    In this paper, we study the generation of maximal Poisson-disk sets with varying radii on surfaces. Based on the concepts of power diagram and regular triangulation, we present a geometric analysis of gaps in such disk sets on surfaces, which is the key ingredient of the adaptive maximal Poisson-disk sampling framework. Moreover, we adapt the presented sampling framework for remeshing applications. Several novel and efficient operators are developed for improving the sampling/meshing quality over the state-of-theart. © 2012 ACM.

  9. Identifying trace evidence in data wiping application software

    OpenAIRE

    Gregory H. Carlton; Gary C. Kessler

    2012-01-01

    One area of particular concern for computer forensics examiners involves situations in which someone utilized software applications to destroy evidence. There are products available in the marketplace that are relatively inexpensive and advertised as being able to destroy targeted portions of data stored within a computer system. This study was undertaken to identify these tools and analyze them to determine the extent to which each of the evaluated data wiping applications perform their task...

  10. Analysis of the Touch-And-Go Surface Sampling Concept for Comet Sample Return Missions

    Science.gov (United States)

    Mandic, Milan; Acikmese, Behcet; Bayard, David S.; Blackmore, Lars

    2012-01-01

    This paper studies the Touch-and-Go (TAG) concept for enabling a spacecraft to take a sample from the surface of a small primitive body, such as an asteroid or comet. The idea behind the TAG concept is to let the spacecraft descend to the surface, make contact with the surface for several seconds, and then ascend to a safe location. Sampling would be accomplished by an end-effector that is active during the few seconds of surface contact. The TAG event is one of the most critical events in a primitive body sample-return mission. The purpose of this study is to evaluate the dynamic behavior of a representative spacecraft during the TAG event, i.e., immediately prior, during, and after surface contact of the sampler. The study evaluates the sample-collection performance of the proposed sampling end-effector, in this case a brushwheel sampler, while acquiring material from the surface during the contact. A main result of the study is a guidance and control (G&C) validation of the overall TAG concept, in addition to specific contributions to demonstrating the effectiveness of using nonlinear clutch mechanisms in the sampling arm joints, and increasing the length of the sampling arms to improve robustness.

  11. Capacity constrained blue-noise sampling on surfaces

    KAUST Repository

    Zhang, Sen

    2015-11-27

    We present a novel method for high-quality blue-noise sampling on mesh surfaces with prescribed cell-sizes for the underlying tessellation (capacity constraint). Unlike the previous surface sampling approach that only uses capacity constraints as a regularizer of the Centroidal Voronoi Tessellation (CVT) energy, our approach enforces an exact capacity constraint using the restricted power tessellation on surfaces. Our approach is a generalization of the previous 2D blue noise sampling technique using an interleaving optimization framework. We further extend this framework to handle multi-capacity constraints. We compare our approach with several state-of-the-art methods and demonstrate that our results are superior to previous work in terms of preserving the capacity constraints.

  12. 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.

  13. Computer simulation of RBS spectra from samples with surface roughness

    Energy Technology Data Exchange (ETDEWEB)

    Malinský, P., E-mail: malinsky@ujf.cas.cz [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v. v. i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J. E. Purkinje University, Ceske mladeze 8, 400 96 Usti nad Labem (Czech Republic); Hnatowicz, V., E-mail: hnatowicz@ujf.cas.cz [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v. v. i., 250 68 Rez (Czech Republic); Macková, A., E-mail: mackova@ujf.cas.cz [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v. v. i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J. E. Purkinje University, Ceske mladeze 8, 400 96 Usti nad Labem (Czech Republic)

    2016-03-15

    A fast code for the simulation of common RBS spectra including surface roughness effects has been written and tested on virtual samples comprising either a rough layer deposited on a smooth substrate or smooth layer deposited on a rough substrate and simulated at different geometries. The sample surface or interface relief has been described by a polyline and the simulated RBS spectrum has been obtained as the sum of many particular spectra from randomly chosen particle trajectories. The code includes several procedures generating virtual samples with random and regular (periodical) roughness. The shape of the RBS spectra has been found to change strongly with increasing sample roughness and an increasing angle of the incoming ion beam.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-11-01

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

  15. Chapter 5: Surface water quality sampling in streams and canals

    Science.gov (United States)

    Surface water sampling and water quality assessments have greatly evolved in the United States since the 1970s establishment of the Clean Water Act. Traditionally, water quality referred to only the chemical characteristics of the water and its toxicological properties related to drinking water or ...

  16. Effective sampling of random surfaces by baby universe surgery

    NARCIS (Netherlands)

    Ambjørn, J.; Białas, P.; Jurkiewicz, J.; Burda, Z.; Petersson, B.

    1994-01-01

    We propose a new, very efficient algorithm for sampling of random surfaces in the Monte Carlo simulations, based on so-called baby universe surgery, i.e. cutting and pasting of baby universe. It drastically reduces slowing down as compared to the standard local flip algorithm, thereby allowing

  17. Identifying potential surface water sampling sites for emerging ...

    African Journals Online (AJOL)

    The occurrence and concentrations of ECPs in South African water bodies are largely unknown, so monitoring is required in order to determine the potential threat that these ECPs may pose. Relevant surface water sampling sites in the Gauteng Province of South Africa were identified utilising a geographic information ...

  18. A remote controlled freeze corer for sampling unconsolidated surface sediments

    NARCIS (Netherlands)

    Lotter, A.F.; Renberg, I.; Hansson, H.; Stöckli, R.; Sturm, M.

    1997-01-01

    A new coring device is presented which allows the recovery of loose watery surface sediments and the water/sediment interface by in situ freezing, resulting in well preserved samples. The instrument consists of a tripod with adjustable legs, a hydraulic system, an insulated thermos (with

  19. The effect of wiping on skin resurfacing in a pig model using a high energy pulsed CO2 laser system.

    Science.gov (United States)

    Ross, E V; Mowlavi, A; Barnette, D; Glatter, R D; Grevelink, J M

    1999-02-01

    The impact of wiping in laser skin resurfacing has not been systematically studied. We examined the effects of wiping during single- and multiple-pass high energy pulsed CO2 laser skin resurfacing in a farm pig. Consequences of wiping were evaluated with regard to depth of residual thermal damage, tissue necrosis, and fibroplasia. Also, the impact of wiping on gross wound healing was observed. Wounds were followed for 21 days and biopsies were obtained on postoperative days 0, 1, and 21. Immediate postoperative biopsies of single-pass wounds showed equivalent residual thermal damage regardless of wiping; in contrast, biopsies from multiple-pass sites without wiping showed more extensive and variable residual thermal damage than wiped sites. On postoperative day one, single pass sites without wiping were grossly less erythematous than wiped sites, and biopsies showed less extensive necrosis and inflammation. In contrast, multiple pass sites without wiping were grossly more erythematous than corresponding wiped sites, and biopsies revealed significantly increased and variable necrosis. After 21 days, multiple pass sites without wiping were grossly more erythematous and showed a thicker band of fibroplasia microscopy. For single pass wounds, not wiping decreased the level of wounding. In contrast, not wiping in multiple pass wounds significantly increased the depth and variability of residual thermal damage and necrosis, resulting in prolonged healing.

  20. Rapid extraction and assay of uranium from environmental surface samples

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Christopher A.; Chouyyok, Wilaiwan; Speakman, Robert J.; Olsen, Khris B.; Addleman, Raymond Shane

    2017-10-01

    Extraction methods enabling faster removal and concentration of uranium compounds for improved trace and low-level assay are demonstrated for standard surface sampling material in support of nuclear safeguards efforts, health monitoring, and other nuclear analysis applications. A key problem with the existing surface sampling swipes is the requirement for complete digestion of sample and sampling matrix. This is a time-consuming and labour-intensive process that limits laboratory throughput, elevates costs, and increases background levels. Various extraction methods are explored for their potential to quickly and efficiently remove different chemical forms of uranium from standard surface sampling material. A combination of carbonate and peroxide solutions is shown to give the most rapid and complete form of uranyl compound extraction and dissolution. This rapid extraction process is demonstrated to be compatible with standard inductive coupled plasma mass spectrometry methods for uranium isotopic assay as well as screening techniques such as x-ray fluorescence. The general approach described has application beyond uranium to other analytes of nuclear forensic interest (e.g., rare earth elements and plutonium) as well as heavy metals for environmental and industrial hygiene monitoring.

  1. Modelling nanofluidic field amplified sample stacking with inhomogeneous surface charge

    Science.gov (United States)

    McCallum, Christopher; Pennathur, Sumita

    2015-11-01

    Nanofluidic technology has exceptional applications as a platform for biological sample preconcentration, which will allow for an effective electronic detection method of low concentration analytes. One such preconcentration method is field amplified sample stacking, a capillary electrophoresis technique that utilizes large concentration differences to generate high electric field gradients, causing the sample of interest to form a narrow, concentrated band. Field amplified sample stacking has been shown to work well at the microscale, with models and experiments confirming expected behavior. However, nanofluidics allows for further concentration enhancement due to focusing of the sample ions toward the channel center by the electric double layer. We have developed a two-dimensional model that can be used for both micro- and nanofluidics, fully accounting for the electric double layer. This model has been used to investigate even more complex physics such as the role of inhomogeneous surface charge.

  2. Spiraling Edge: Fast Surface Reconstruction from Partially Organized Sample Points

    Energy Technology Data Exchange (ETDEWEB)

    Angel, Edward; Crossno, Patricia

    1999-07-12

    Many applications produce three-dimensional points that must be further processed to generate a surface. Surface reconstruction algorithms that start with a set of unorganized points are extremely time-consuming. Sometimes, however, points are generated such that there is additional information available to the reconstruction algorithm. We present Spiraling Edge, a specialized algorithm for surface reconstruction that is three orders of magnitude faster than algorithms for the general case. In addition to sample point locations, our algorithm starts with normal information and knowledge of each point's neighbors. Our algorithm produces a localized approximation to the surface by creating a star-shaped triangulation between a point and a subset of its nearest neighbors. This surface patch is extended by locally triangulating each of the points along the edge of the patch. As each edge point is triangulated, it is removed from the edge and new edge points along the patch's edge are inserted in its place. The updated edge spirals out over the surface until the edge encounters a surface boundary and stops growing in that direction, or until the edge reduces to a small hole that is filled by the final triangle.

  3. Spiraling Edge: Fast Surface Reconstruction from Partially Organized Sample Points

    Energy Technology Data Exchange (ETDEWEB)

    Angel, E.; Crossno, P.

    1999-01-06

    Many applications produce three-dimensional points that must be further processed to generate a surface. Surface reconstruction algorithms that start with a set of unorganized points are extremely time-consuming. Often, however, points are generated such that there is additional information available to the reconstruction algorithm. We present a specialized algorithm for surface reconstruction that is three orders of magnitude faster than algorithms for the general case. In addition to sample point locations, our algorithm starts with normal information and knowledge of each point's neighbors. Our algorithm produces a localized approximation to the surface by creating a star-shaped triangulation between a point and a subset of its nearest neighbors. This surface patch is extended by locally triangulating each of the points along the edge of the patch. As each edge point is triangulated, it is removed from the edge and new edge points along the patch's edge are inserted in its place. The updated edge spirals out over the surface until the edge encounters a surface boundary and stops growing in that direction, or until the edge reduces to a small hole that fills itself in.

  4. Examples of Optical Assessment of Surface Cleanliness of Genesis Samples

    Science.gov (United States)

    Rodriquez, Melissa C.; Allton, J. H.; Burkett, P. J.; Gonzalez, C. P.

    2013-01-01

    Optical microscope assessment of Genesis solar wind collector surfaces is a coordinated part of the effort to obtain an assessed clean subset of flown wafer material for the scientific community. Microscopic survey is typically done at 50X magnification at selected approximately 1 square millimeter areas on the fragment surface. This survey is performed each time a principle investigator (PI) returns a sample to JSC for documentation as part of the established cleaning plan. The cleaning plan encompasses sample handling and analysis by Genesis science team members, and optical survey is done at each step in the process. Sample surface cleaning is performed at JSC (ultrapure water [1] and UV ozone cleaning [2]) and experimentally by other science team members (acid etch [3], acetate replica peels [4], CO2 snow [5], etc.). The documentation of each cleaning method can potentially be assessed with optical observation utilizing Image Pro Plus software [6]. Differences in particle counts can be studied and discussed within analysis groups. Approximately 25 samples have been identified as part of the cleaning matrix effort to date.

  5. Sampling free energy surfaces as slices by combining umbrella sampling and metadynamics.

    Science.gov (United States)

    Awasthi, Shalini; Kapil, Venkat; Nair, Nisanth N

    2016-06-15

    Metadynamics (MTD) is a very powerful technique to sample high-dimensional free energy landscapes, and due to its self-guiding property, the method has been successful in studying complex reactions and conformational changes. MTD sampling is based on filling the free energy basins by biasing potentials and thus for cases with flat, broad, and unbound free energy wells, the computational time to sample them becomes very large. To alleviate this problem, we combine the standard Umbrella Sampling (US) technique with MTD to sample orthogonal collective variables (CVs) in a simultaneous way. Within this scheme, we construct the equilibrium distribution of CVs from biased distributions obtained from independent MTD simulations with umbrella potentials. Reweighting is carried out by a procedure that combines US reweighting and Tiwary-Parrinello MTD reweighting within the Weighted Histogram Analysis Method (WHAM). The approach is ideal for a controlled sampling of a CV in a MTD simulation, making it computationally efficient in sampling flat, broad, and unbound free energy surfaces. This technique also allows for a distributed sampling of a high-dimensional free energy surface, further increasing the computational efficiency in sampling. We demonstrate the application of this technique in sampling high-dimensional surface for various chemical reactions using ab initio and QM/MM hybrid molecular dynamics simulations. Further, to carry out MTD bias reweighting for computing forward reaction barriers in ab initio or QM/MM simulations, we propose a computationally affordable approach that does not require recrossing trajectories. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. MALDI Imaging of Liquid Extraction Surface Analysis Sampled Tissue.

    Science.gov (United States)

    Randall, Elizabeth C; Race, Alan M; Cooper, Helen J; Bunch, Josephine

    2016-09-06

    Combined mass spectrometry imaging methods in which two different techniques are executed on the same sample have recently been reported for a number of sample types. Such an approach can be used to examine the sampling effects of the first technique with a second, higher resolution method and also combines the advantages of each technique for a more complete analysis. In this work matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) was used to study the effects of liquid extraction surface analysis (LESA) sampling on mouse brain tissue. Complementary multivariate analysis techniques including principal component analysis, non-negative matrix factorization, and t-distributed stochastic neighbor embedding were applied to MALDI MS images acquired from tissue which had been sampled by LESA to gain a better understanding of localized tissue washing in LESA sampling. It was found that MALDI MS images could be used to visualize regions sampled by LESA. The variability in sampling area, spatial precision, and delocalization of analytes in tissue induced by LESA were assessed using both single-ion images and images provided by multivariate analysis.

  7. Identifying trace evidence in data wiping application software

    Directory of Open Access Journals (Sweden)

    Gregory H. Carlton

    2012-06-01

    Full Text Available One area of particular concern for computer forensics examiners involves situations in which someone utilized software applications to destroy evidence. There are products available in the marketplace that are relatively inexpensive and advertised as being able to destroy targeted portions of data stored within a computer system. This study was undertaken to identify these tools and analyze them to determine the extent to which each of the evaluated data wiping applications perform their tasks and to identify trace evidence, if any, left behind on disk media after executing these applications. We evaluated five Windows 7 compatible software products whose advertised features include the ability for users to wipe targeted files, folders, or evidence of selected activities. We conducted a series of experiments that involved executing each application on systems with identical data, and we then analyzed the results and compared the before and after images for each application. We identified information for each application that is beneficial to forensics examiners when faced with similar situations. This paper describes our application selection process, our application evaluation methodology, and our findings. Following this, we describe limitations of this study and suggest areas of additional research that will benefit the study of digital forensics.

  8. Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis

    Science.gov (United States)

    Kovač Viršek, Manca; Palatinus, Andreja; Koren, Špela; Peterlin, Monika; Horvat, Petra; Kržan, Andrej

    2016-01-01

    Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of scientific publications address microplastic pollution of the sea surface. The protocol below describes the methodology for sampling, sample preparation, separation and chemical identification of microplastic particles. A manta net fixed on an »A frame« attached to the side of the vessel was used for sampling. Microplastic particles caught in the cod end of the net were separated from samples by visual identification and use of stereomicroscopes. Particles were analyzed for their size using an image analysis program and for their chemical structure using ATR-FTIR and micro FTIR spectroscopy. The described protocol is in line with recommendations for microplastics monitoring published by the Marine Strategy Framework Directive (MSFD) Technical Subgroup on Marine Litter. This written protocol with video guide will support the work of researchers that deal with microplastics monitoring all over the world. PMID:28060297

  9. Organic analysis of lunar samples and the Martian surface.

    Science.gov (United States)

    Oro, J; Flory, D

    1973-01-01

    In addition to the organogenic elements (H, C, N, O, S, P) which are necessary for the synthesis of organic molecules, the lunar samples from Apollo 11, 12, 14 and 15 contain substantial amounts (approximately equal to 10 to 100 microgram/g) of CO, N2 and CO2, which are released at relatively high temperatures and smaller amounts (approximately equal to 0.1 to 10 microgram/g) of more complex organic compounds (e.g. benzene). Most of these analyses have been performed by mass spectrometry or by combined gas chromatography-mass spectrometry after appropriate volatilization. The release of very small amounts of water has also been observed and is consistent with the findings of goethite (FeO.OH) and with measurements by the suprathermal ion detector. The lunar surface provides one of the less favorable solar system models for the synthesis of organic compounds yet small amounts of these compounds have been detected in the returned samples. It is reasonable to assume that the different physical and developmental features of the planet Mars (increased gravitational field, presence of an atmosphere with CO2, CO and H2O, recent volcanic and tectonic activity, etc.) would favor an increased organic content of the surface of this planet relative to the moon. Therefore the organic molecules present in the Martian soil should be measurable by miniaturized mass spectrometers after fractional distillation or gas chromatographic separation of the volatiles released by moderate heating.

  10. Micro Unmanned Surface Vehicle for Shallow Littoral Data Sampling

    Science.gov (United States)

    Murphy, R. R.; Wilde, G.

    2016-02-01

    This paper describes the creation of an autonomous air boat that can be carried by one person, called a micro unmanned surface vehicle (USV), for sensor sampling in shallow littoral areas such as inlets and creeks. A USV offers advantages over other types of unmanned marine vehicles. Unlike an autonomous underwater vehicle, the Challenge 1.0 air boat can operate in shallow water of less than 15 cm depth and maintain network connectivity for control and data sampling. A USV does not require a tether, like a remotely operated marine vehicle (ROV), which would limit the distance and mobility. However, a USV operating in shallow littoral areas poses several challenges. Navigation is a challenge since rivers and bays may have semi-submerged obstacles and there may be no depth maps; the approach taken in the Challenge 1.0 project is to let the operator specify a safe area of the water by visual inspection and then the USV autonomously creates a path to optimally sample the collision free area. Navigation is also a challenge because of platform dynamics-the USV we describe is a non-holonomic vehicle; this paper explores spiral paths rather than boustrophedon paths. Another challenge is the quality of sensing. Water-based sensing is noisy and thus a reading at a single point may not reflect the overall value. In practice, areas are sampled rather than a single point, but the noise in the point values within the sampled area produce a survey with widely varying numbers and are difficult for humans to interpret. This paper implements an inverse distance weighting interpolation algorithm to produce a visual "heatmap" that reliably portrays the smoothed data.

  11. Effects of Xylitol Wipes on Cariogenic Bacteria and Caries in Young Children

    OpenAIRE

    Zhan, L.; Cheng, J; Chang, P.; Ngo, M.; DenBesten, P.K.; Hoover, C I; Featherstone, J.D.B.

    2012-01-01

    The aim of the study was to investigate the efficacy of the use of xylitol-containing tooth-wipes in preventing dental caries in young children. In a double-blinded randomized controlled clinical trial, 44 mothers with active caries and their 6- to 35-month-old children were randomized to xylitol-wipe or placebo-wipe groups. The children’s caries scores were recorded at baseline and 1 year. Salivary levels of mutans streptococci and lactobacilli were enumerated at baseline, 3, 6, and 12 month...

  12. Low surface contamination by cis/oxaliplatin during hyperthermic intraperitoneal chemotherapy (HIPEC).

    Science.gov (United States)

    Schierl, R; Novotna, J; Piso, P; Böhlandt, A; Nowak, D

    2012-01-01

    The aim of this study was to evaluate contamination by platinum drugs in the operating room during hyperthermic intraperitoneal chemotherapy (HIPEC). Environmental sampling of 151 wipe samples from surfaces on the HIPEC devices and operating room floors was performed for platinum in six German hospitals during 19 HIPEC procedures. Additionally, 45 wipe samples from surgeons' and perfusionists' protective gloves were analyzed. Platinum concentrations from the HIPEC devices and operating room floors ranged from 0.07 to 110,000 pg/cm(2) (Median: 1.5 pg/cm(2)) with high contamination on the regulation knob and reservoir after HIPEC procedure, particularly when injecting the cytostatic drug into the reservoir via syringe. Samples from perfusionists' and surgeons' protective gloves ranged between 0.01 and 729 ng/pair. Although sporadically high platinum concentrations on surfaces on the HIPEC device and operating room floor were detected, our study revealed that low surface loads are definitely possible and can be documented by wipe samples. Important factors for achieving low surface contamination are the use of infusion bags instead of syringes for injection of the cytostatic solution, careful cleaning of the device after HIPEC and wearing of two pairs of gloves. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Pseudospectral Gaussian quantum dynamics: Efficient sampling of potential energy surfaces.

    Science.gov (United States)

    Heaps, Charles W; Mazziotti, David A

    2016-04-28

    Trajectory-based Gaussian basis sets have been tremendously successful in describing high-dimensional quantum molecular dynamics. In this paper, we introduce a pseudospectral Gaussian-based method that achieves accurate quantum dynamics using efficient, real-space sampling of the time-dependent basis set. As in other Gaussian basis methods, we begin with a basis set expansion using time-dependent Gaussian basis functions guided by classical mechanics. Unlike other Gaussian methods but characteristic of the pseudospectral and collocation methods, the basis set is tested with N Dirac delta functions, where N is the number of basis functions, rather than using the basis function as test functions. As a result, the integration for matrix elements is reduced to function evaluation. Pseudospectral Gaussian dynamics only requires O(N) potential energy calculations, in contrast to O(N(2)) evaluations in a variational calculation. The classical trajectories allow small basis sets to sample high-dimensional potentials. Applications are made to diatomic oscillations in a Morse potential and a generalized version of the Henon-Heiles potential in two, four, and six dimensions. Comparisons are drawn to full analytical evaluation of potential energy integrals (variational) and the bra-ket averaged Taylor (BAT) expansion, an O(N) approximation used in Gaussian-based dynamics. In all cases, the pseudospectral Gaussian method is competitive with full variational calculations that require a global, analytical, and integrable potential energy surface. Additionally, the BAT breaks down when quantum mechanical coherence is particularly strong (i.e., barrier reflection in the Morse oscillator). The ability to obtain variational accuracy using only the potential energy at discrete points makes the pseudospectral Gaussian method a promising avenue for on-the-fly dynamics, where electronic structure calculations become computationally significant.

  14. Estimation of surface heat flux and surface temperature during inverse heat conduction under varying spray parameters and sample initial temperature.

    Science.gov (United States)

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong; Zubair, Muhammad

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m(2) was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa.

  15. Estimation of Surface Heat Flux and Surface Temperature during Inverse Heat Conduction under Varying Spray Parameters and Sample Initial Temperature

    Directory of Open Access Journals (Sweden)

    Muhammad Aamir

    2014-01-01

    Full Text Available An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck’s sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa.

  16. Estimation of Surface Heat Flux and Surface Temperature during Inverse Heat Conduction under Varying Spray Parameters and Sample Initial Temperature

    Science.gov (United States)

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa. PMID:24977219

  17. Hand hygiene with soap and water is superior to alcohol rub and antiseptic wipes for removal of Clostridium difficile.

    Science.gov (United States)

    Oughton, Matthew T; Loo, Vivian G; Dendukuri, Nandini; Fenn, Susan; Libman, Michael D

    2009-10-01

    To evaluate common hand hygiene methods for efficacy in removing Clostridium difficile. Randomized crossover comparison among 10 volunteers with hands experimentally contaminated by nontoxigenic C. difficile. Interventions included warm water with plain soap, cold water with plain soap, warm water with antibacterial soap, antiseptic hand wipes, alcohol-based handrub, and a control involving no intervention. All interventions were evaluated for mean reduction in colony-forming units (CFUs) under 2 contamination protocols: "whole hand" and "palmar surface." Results were analyzed according to a Bayesian approach, by using hierarchical models adjusted for multiple observations. Under the whole-hand protocol, the greatest adjusted mean reductions were achieved by warm water with plain soap (2.14 log(10) CFU/mL [95% credible interval (CrI), 1.74-2.54 log(10) CFU/mL]), cold water with plain soap (1.88 log(10) CFU/mL [95% CrI, 1.48-2.28 log(10) CFU/mL), and warm water with antibacterial soap (1.51 log(10) CFU/mL [95% CrI, 1.12-1.91 log(10) CFU/mL]), followed by antiseptic hand wipes (0.57 log(10) CFU/mL [95% CrI, 0.17-0.96 log(10) CFU/mL]). Alcohol-based handrub (0.06 log(10) CFU/mL [95% CrI, -0.34 to 0.45 log(10) CFU/mL]) was equivalent to no intervention. Under the palmar surface protocol, warm water with plain soap, cold water with plain soap, and warm water with antibacterial soap again yielded the greatest mean reductions, followed by antiseptic hand wipes (26.6, 26.6, 26.6, and 21.9 CFUs per plate, respectively), when compared with alcohol-based handrub. Hypothenar (odds ratio, 10.98 [95% CrI, 1.96-37.65]) and thenar (odds ratio, 6.99 [95% CrI, 1.25-23.41]) surfaces were more likely than fingertips to remain heavily contaminated after handwashing. Handwashing with soap and water showed the greatest efficacy in removing C. difficile and should be performed preferentially over the use of alcohol-based handrubs when contact with C. difficile is suspected or likely.

  18. Sample collection of virulent and non-virulent B. anthracis and Y. pestis for bioforensics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hong-geller, Elizabeth [Los Alamos National Laboratory; Valdez, Yolanda E [Los Alamos National Laboratory; Shou, Yulin [Los Alamos National Laboratory; Yoshida, Thomas M [Los Alamos National Laboratory; Marrone, Babetta L [Los Alamos National Laboratory; Dunbar, John [Los Alamos National Laboratory

    2009-01-01

    Validated sample collection methods are needed for recovery of microbial evidence in the event of accidental or intentional release of biological agents into the environment. To address this need, we evaluated the sample recovery efficiencies of two collection methods -- swabs and wipes -- for both non-virulent and virulent strains of B. anthracis and Y. pestis from four types of non-porous surfaces: two hydrophilic surfaces, stainless steel and glass, and two hydrophobic surfaces, vinyl and plastic. Sample recovery was quantified using Real-time qPCR to assay for intact DNA signatures. We found no consistent difference in collection efficiency between swabs or wipes. Furthermore, collection efficiency was more surface-dependent for virulent strains than non-virulent strains. For the two non-virulent strains, B. anthracis Sterne and Y. pestis A1122, collection efficiency was approximately 100% and 1 %, respectively, from all four surfaces. In contrast, recovery of B. anthracis Ames spores and Y. pestis C092 from vinyl and plastic was generally lower compared to collection from glass or stainless steel, suggesting that surface hydrophobicity may playa role in the strength of pathogen adhesion. The surface-dependent collection efficiencies observed with the virulent strains may arise from strain-specific expression of capsular material or other cell surface receptors that alter cell adhesion to specific surfaces. These findings contribute to validation of standard bioforensics procedures and emphasize the importance of specific strain and surface interactions in pathogen detection.

  19. [DNA Extraction of Cast-off Cells of Fingerprints from 502 Glue Fumigated Contact Samples].

    Science.gov (United States)

    Wang, Xian-wen; Leng, Xue-feng; Wang, Shou-yu

    2015-12-01

    To establish a method of fingerprint position, sample transfer and fingerprint DNA extraction in contact samples. Sixty-six cases were visualized by 502 glue fingerprint fumigation. Two methods, ordinary wipe and acetone wipe, were used to transfer cast-off cells of fingerprints from testing samples, respectively. DNA was extracted and purified by ultramicro magnetic bead kit. The data was resolved on genetic analysis after amplification. In 33 samples, 30 samples got better STR analysis by acetone wipe method. The peak range was 1,000-4,000 RFU and peak shapes were equable. It was hard to get ideal STR typing by ordinary wipe method. The samples are visualized by 502 glue fingerprint fumigation and the case-off cells are transferred by acetone wipe method. The method shows better STR analysis result, which might be a better method for forensic science practice.

  20. Surface Sampling and Detection Investigations at the CDC

    Science.gov (United States)

    Rose, L. J.; Coulliette, A. D.

    2015-03-01

    The Environmental and Applied Microbiology Team is tasked with investigating disease outbreaks in healthcare settings. We will summarize and discuss applied research endeavors to understand and optimize sampling and detection of microorganisms.

  1. chemical and microbiological assessment of surface water samples ...

    African Journals Online (AJOL)

    PROF EKWUEME

    are to assess, ascertain and evaluate the level, degree and type of pollution that characterize the surface water resources of Enugu area of southeastern Nigeria in terms of physico-chemical and bacterialogical constituents. Field measurements of ... suggest possible solutions to the problems of water supply. THE STUDY ...

  2. Chemical and microbiological assessment of surface water samples ...

    African Journals Online (AJOL)

    The objectives of the study are to assess, ascertain and evaluate the level, degree and type of pollution that characterize the surface water resources of Enugu area of southeastern Nigeria in terms of physico-chemical and bacterialogical constituents. Field measurements of physical parameters were preceded by chemical ...

  3. Wipe testing of sealed radiation sources using a radiation protection assistant robot

    Directory of Open Access Journals (Sweden)

    Zeb Jahan

    2009-01-01

    Full Text Available Sealed radiation sources are commonly used in different research institutes, industries, and hospitals. The sources of various strengths are manufactured in different sizes and shapes. It is a regulatory requirement that these sources must be monitored frequently for their integrity and to avoid any radiological contamination hazard. Mainly, a wipe test is recommended for the contamination detection due to the leakage of sealed radiation sources. A radiation protection assistant robot has been fabricated to execute different tasks in a hazardous radiation environment. In this study, the robot was used to conduct the wipe test of five sealed radiation sources. The sealed radiation sources were tested safely and securely without giving any radiation dose to the radiation worker. The radiation doses received by the robot gripper and waist during the wipe test were 3.4 Gy and 208.9 mGy, respectively.

  4. A Geostatistical Approach to Indoor Surface Sampling Strategies

    DEFF Research Database (Denmark)

    Schneider, Thomas; Petersen, Ole Holm; Nielsen, Allan Aasbjerg

    1990-01-01

    contamination, sampled from small areas on a table, have been used to illustrate the method. First, the spatial correlation is modelled and the parameters estimated from the data. Next, it is shown how the contamination at positions not measured can be estimated with kriging, a minimum mean square error method...

  5. Data Set for the manuscript entitled, "Sample Processing Approach for Detection of Ricin in Surface Samples."

    Data.gov (United States)

    U.S. Environmental Protection Agency — Figure. This dataset is associated with the following publication: Shah, S., S. Kane, A.M. Erler, and T. Alfaro. Sample Processing Approach for Detection of Ricin in...

  6. Development of a One-Handed, Environmental Surface-Sampling Device

    Science.gov (United States)

    2016-05-01

    2015 4. TITLE AND SUBTITLE Development of a One-Handed, Environmental Surface-Sampling Device 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...the Mano sampling device is capable of collecting a Bacillus anthracis simulant in a laboratory setting with greater efficiency than the BiSKit device...incorporated into regular field use. 15. SUBJECT TERMS Environmental surface sampling Biological sampling kit (BiSKit) Bacillus anthracis 16

  7. 49 CFR 571.104 - Standard No. 104; Windshield wiping and washing systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 104; Windshield wiping and washing systems. 571.104 Section 571.104 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle Safety...

  8. Forced Suffocation of Infants with Baby Wipes: A Previously Undescribed Form of Child Abuse

    Science.gov (United States)

    Krugman, Scott D.; Lantz, Patrick E.; Sinal, Sara; De Jong, Allan R.; Coffman, Kathryn

    2007-01-01

    Background: Foreign body aspiration in children is commonly seen in emergency departments and carries a significant mortality. Abusive foreign body suffocation is not well described. Methods: We present a case-series of four infants who presented with aspiration of a baby wipe. Results: Each child was found to be a victim of child physical abuse…

  9. 78 FR 46447 - Conditional Exclusions From Solid Waste and Hazardous Waste for Solvent-Contaminated Wipes

    Science.gov (United States)

    2013-07-31

    ... and their containers must contain no free liquids as determined by the Paint Filter Liquids Test (EPA... the Alliance of Textile Care Associations requesting that solvent-contaminated reusable wipes be... determined that the Paint Filter Liquids Test (Method 9095B) is most appropriate to determine whether solvent...

  10. A simple method for determination of natural and depleted uranium in surface soil samples.

    Science.gov (United States)

    Vukanac, I; Novković, D; Kandić, A; Djurasević, M; Milosević, Z

    2010-01-01

    A simple and efficient method for determination of uranium content in surface soil samples contaminated with depleted uranium, by gamma ray spectrometry is presented. The content of natural uranium and depleted uranium, as well as the activity ratio (235)U/(238)U of depleted uranium, were determined in contaminated surface soil samples by application of this method. Copyright 2009 Elsevier Ltd. All rights reserved.

  11. Wiping away the dirt-a safe option for plastics?

    DEFF Research Database (Denmark)

    Shashoua, Yvonne; Segel, Kathrine

    ´ vulnerable surfaces. This article presents the results of extensive research into the risks associated with cleaning flexible and rigid plastics. Mechanical cleaning tools were evaluated for their potential to damage plastic surfaces. Examination of PMMA, PVC, HDPE, HIPS, CA and EPS before and after cleaning...

  12. Method and system for formation and withdrawal of a sample from a surface to be analyzed

    Science.gov (United States)

    Van Berkel, Gary J.; Kertesz, Vilmos

    2017-10-03

    A method and system for formation and withdrawal of a sample from a surface to be analyzed utilizes a collection instrument having a port through which a liquid solution is conducted onto the surface to be analyzed. The port is positioned adjacent the surface to be analyzed, and the liquid solution is conducted onto the surface through the port so that the liquid solution conducted onto the surface interacts with material comprising the surface. An amount of material is thereafter withdrawn from the surface. Pressure control can be utilized to manipulate the solution balance at the surface to thereby control the withdrawal of the amount of material from the surface. Furthermore, such pressure control can be coordinated with the movement of the surface relative to the port of the collection instrument within the X-Y plane.

  13. AFM fluid delivery/liquid extraction surface sampling/electrostatic spray cantilever probe

    Science.gov (United States)

    Van Berkel, Gary J.

    2015-06-23

    An electrospray system comprises a liquid extraction surface sampling probe. The probe comprises a probe body having a liquid inlet and a liquid outlet, and having a liquid extraction tip. A solvent delivery conduit is provided for receiving solvent liquid from the liquid inlet and delivering the solvent liquid to the liquid extraction tip. An open liquid extraction channel extends across an exterior surface of the probe body from the liquid extraction tip to the liquid outlet. An electrospray emitter tip is in liquid communication with the liquid outlet of the liquid extraction surface sampling probe. A system for analyzing samples, a liquid junction surface sampling system, and a method of analyzing samples are also disclosed.

  14. Viking GC/MS mechanisms design and performance. [for analyzing samples of Martian surface

    Science.gov (United States)

    Chase, C. P.; Weilbach, A. O.

    1976-01-01

    The Viking Lander gas chromatograph/mass spectrometer will analyze pyrolyzed samples of the Martian surface for organic content. The surface-sample loader and pyrolyzer assembly (SSPLA) is described, along with the major problems encountered during design and testing. Three mechanisms were developed to implement the required SSLPA functions: (1) a soil loader that forces soil from a filled rotating funnel into each of three ovens located on a carriage, (2) a Geneva drive for rotating and precisely indexing the ovens to receive sample, and (3) a toggle-clamp mechanism for sealing the ovens by forcing circular double knife edges into gold sealing surfaces.

  15. Multicenter evaluation of a new closed system drug-transfer device in reducing surface contamination by antineoplastic hazardous drugs.

    Science.gov (United States)

    Bartel, Sylvia B; Tyler, Timothy G; Power, Luci A

    2018-01-16

    Results of a study to evaluate the effectiveness of a recently introduced closed system drug-transfer device (CSTD) in reducing surface contamination during compounding and simulated administration of antineoplastic hazardous drugs (AHDs) are reported. Wipe samples were collected from 6 predetermined surfaces in compounding and infusion areas of 13 U.S. cancer centers to establish preexisting levels of surface contamination by 2 marker AHDs (cyclophosphamide and fluorouracil). Stainless steel templates were placed over the 6 previously sampled surfaces, and the marker drugs were compounded and infused per a specific protocol using all components of the CSTD. Wipe samples were collected from the templates after completion of tasks and analyzed for both marker AHDs. Aggregated results of wipe sampling to detect preexisting contamination at the 13 study sites showed that overall, 66.7% of samples (104 of 156) had detectable levels of at least 1 marker AHD; subsequent testing after CSTD use per protocol found a sample contamination rate of 5.8% (9 of 156 samples). In the administration areas alone, the rate of preexisting contamination was 78% (61 of 78 samples); with use of the CSTD protocol, the contamination rate was 2.6%. Twenty-six participants rated the CSTD for ease of use, with 100% indicating that they were satisfied or extremely satisfied. A study involving a rigorous protocol and 13 cancer centers across the United States demonstrated that the CSTD reduced surface contamination by cyclophosphamide and fluorouracil during compounding and simulated administration. Participants reported that the CSTD was easy to use. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  16. Front-to-back & dabbing wiping behaviour post-toilet associated with anal neoplasia & HR-HPV carriage in women with previous HPV-mediated gynaecological neoplasia.

    Science.gov (United States)

    Simpson, Steve; Blomfield, Penny; Cornall, Alyssa; Tabrizi, Sepehr N; Blizzard, Leigh; Turner, Richard

    2016-06-01

    Anal cancer is a human papillomavirus (HPV)-mediated neoplasia of the anal squamous epithelium. Anal cancer is much more common among women, particularly those with a previous high-grade gynaecological neoplasia. Cross-sectional study of women with a previous HPV-mediated gynaecological neoplasia in Tasmania, Australia. Women presenting for follow-up gynaecological care had anal swab samples taken for anal cytology by Hologic Liquid ThinPrep, followed by HPV genotyping. Women with abnormal anal cytology were invited for high-resolution anoscopy. Potential risk factors, including post-toilet wiping behaviours, were queried by questionnaire while clinical covariates were extracted from medical records. Covariates of anal outcomes evaluated by log-binomial and log-multinomial regression. From 163 women enrolled in the study, 65 (39.9%) had abnormal cytology, with 46 (28.2%) being high-grade. Of the 50 women with abnormal anal cytology having high-resolution anoscopy, 32 (64.0%) had abnormal histology with 13 (26.0%) being high-grade. Of the 123 women tested for HR-HPV DNA, 48 (39.0%) had HR-HPV detected, the most common genotypes being 16 and 51 (14/123, 11.4% for both). In addition to some known anal cancer risk factors, we found front-to-back wiping was associated with significantly increased (Prevalence ratio (PR) range: 1.99-3.60) prevalence of cytological and histological abnormality and HR-HPV carriage/co-carriage, while dabbing post-toilet was significantly associated with decreased prevalences (PR range: 0.50-0.62). Post-toilet wiping behaviours were significantly associated with the prevalence of anal cytological, histological and HR-HPV carriage outcomes. This suggests a biologically plausible mechanism for HR-HPV introduction and the higher frequencies of anal neoplasia in women. Copyright © 2016. Published by Elsevier Ltd.

  17. Contact dermatitis in a child from methlychloroisothiazolinone and methylisothiazolinone in moist wipes.

    Science.gov (United States)

    Kazandjieva, Jana; Gergovska, Malena; Darlenski, Razvigor

    2014-01-01

    Contact allergic reactions to methlychloroisothiazolinone/methylisothiazolinone also widely known as Kathon CG have been reported extensively reported. It is one of the most commonly used preservatives in rinse-off products, cosmetics, and others. Herein, a case of a 50-year-old girl is presented with chronic dermatitis in the anogenital area. The patient was patch tested and had positive reaction to Kathon CG. The detailed history taking revealed that the allergen was present in the moist cleaning wipes used instead of dry toilet paper. The presented case serves as a basis for a appraisal of the use of this preservative in wet wipes. In addition, the duration of the patch test protocol in children has also been discussed. © 2012 Wiley Periodicals, Inc.

  18. Cavitation Erosion Tests Performed by Indirect Vibratory Method on Stainless Steel Welded Samples with Hardened Surface

    Directory of Open Access Journals (Sweden)

    Marian-Dumitru Nedeloni

    2012-09-01

    Full Text Available The paper presents the results of cavitation erosion tests performed on two types of samples. The materials of the samples are frequently used for manufacturing and repairs of the hydro turbines components submitted to cavitation. The first sample was made by welding of an austenitic stainless steel on austenito-feritic base material. The second sample was made similarly with the first but with a martensitic base material. After the welding processes, on both samples was applied a hardening treatment by surface peening. The cavitation erosion tests were performed on vibratory equipment using the indirect method with stationary specimen. The results show a good cavitation erosion resistance on both samples.

  19. Rapid Surface Sampling and Archival Record (RSSAR) System. Topical report, October 1, 1993--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    This report describes the results of Phase 1 efforts to develop a Rapid Surface Sampling and Archival Record (RSSAR) System for the detection of semivolatile organic contaminants on concrete, transite, and metal surfaces. The characterization of equipment and building surfaces for the presence of contaminants as part of building decontamination and decommissioning activities is an immensely large tacks of concern to both government and industry. Contaminated and clean materials must be clearly identified and segregated so that the clean materials can be recycled or reused, if possible, or disposed of more cheaply as nonhazardous waste. Characterization of building and equipment surfaces will be needed during initial investigations, during cleanup operations, and during the final confirmatory process, increasing the total number of samples well beyond that needed for initial characterization. This multiplicity of information places a premium on the ability to handle and track data as efficiently as possible. Aware of the shortcomings of traditional surface characterization technology, GE, with DOE support has undertaken a 12-month effort to complete Phase 1 of a proposed four-phase program to develop the RSSAR system. The objectives of this work are to provide instrumentation to cost-effectively sample concrete and steel surfaces, provide a quick-look indication for the presence or absence of contaminants, and collect samples for later, more detailed analysis in a readily accessible and addressable form. The Rapid Surface Sampling and Archival Record (RSSAR) System will be a modular instrument made up of several components: (1) sampling heads for concrete surfaces, steel surfaces, and bulk samples; (2) quick-look detectors for photoionization and ultraviolet; (3) multisample trapping module to trap and store vaporized contaminants in a manner suitable for subsequent detailed lab-based analyses.

  20. Wipe testing of sealed radiation sources using a radiation protection assistant robot

    OpenAIRE

    Zeb Jahan; Rashid Farooq; Iqbal Naeem; Ahmad Nasir

    2009-01-01

    Sealed radiation sources are commonly used in different research institutes, industries, and hospitals. The sources of various strengths are manufactured in different sizes and shapes. It is a regulatory requirement that these sources must be monitored frequently for their integrity and to avoid any radiological contamination hazard. Mainly, a wipe test is recommended for the contamination detection due to the leakage of sealed radiation sources. A radiation protection assistant robot has bee...

  1. Preparation of well-defined samples of AlPdMn quasicrystals for surface studies

    Science.gov (United States)

    Jenks, C. J.; Delaney, D. W.; Bloomer, T. E.; Chang, S.-L.; Lograsso, T. A.; Shen, Z.; Zhang, C.-M.; Thiel, P. A.

    1996-12-01

    We have developed a method for preparing single-grain, quasicrystalline AlPdMn samples for surface studies in ultrahigh vacuum. The main issues of concern are phase purity, the quality of the surface structure, and the surface, and the surface composition. Phase purity is enhanced by annealing the sample in ultra-pure Ar in a sealed quartz ampoule for several days before polishing. Polishing with colloidal silica allows secondary phases to be detected readily with an optical microscope. As a final precaution, phase purity can be checked sensitively with scanning Auger microscopy. After this stage, the sample can be cleaned in ultrahigh vacuum with ion bombardment. Annealing is required after bombardment to restore surface structure and to obtain a low-energy electron diffraction (LEED) pattern of an oriented sample. However, both ion bombardment and heating to temperatures above 870 K in vacuum, produce Pd-rich surfaces. As a final step, for the five-fold surface, we recommend heating briefly to 1050-1100 K and then annealing at 870 K for several hours. This produces both an excellent LEED pattern, and a surface composition close to that of the bulk.

  2. Body wiping behaviors associated with cutaneous lipids in hylid tree frogs of Florida.

    Science.gov (United States)

    Barbeau, Tamatha R; Lillywhite, Harvey B

    2005-06-01

    Body wiping behavior, integumentary secretions and rates of evaporative water loss (EWL) were examined in six species of Florida tree frogs (Anura: Hylidae). Additionally, morphology of the integument and dermal glands were compared among these and one other Florida tree frog (Hyla andersonii), an arid-adapted tree frog (Phyllomedusa hypochondrialis), and a highly aquatic frog (Rana utricularia). An extra-epidermal layer of lipid and mucus, presumably secreted from dermal granular glands, was detected on the skin of all Florida hylid frogs examined. Distinct body wiping behaviors were observed in the hylid frogs, but these were less complex than those described previously in phyllomedusine frogs, which occupy arid habitats, secrete lipids onto their skin, and are regarded as relatively 'waterproof'. Florida hylids occupy seasonally arid habitats and appear to have reduced rates of EWL. The suite of traits we observed in these frogs have been previously documented in a rhacophorid tree frog from seasonally arid regions of India and likely represent an evolutionary convergent response to periodic dehydration stress. The presence of lipids that are spread by simple wiping behaviors to form an extra-epidermal water barrier may represent an early stage of the more advanced adaptations described in more waterproof arboreal frogs.

  3. Path integral molecular dynamics with surface hopping for thermal equilibrium sampling of nonadiabatic systems.

    Science.gov (United States)

    Lu, Jianfeng; Zhou, Zhennan

    2017-04-21

    In this work, a novel ring polymer representation for a multi-level quantum system is proposed for thermal average calculations. The proposed representation keeps the discreteness of the electronic states: besides position and momentum, each bead in the ring polymer is also characterized by a surface index indicating the electronic energy surface. A path integral molecular dynamics with surface hopping (PIMD-SH) dynamics is also developed to sample the equilibrium distribution of the ring polymer configurational space. The PIMD-SH sampling method is validated theoretically and by numerical examples.

  4. The photoload sampling technique: estimating surface fuel loadings from downward-looking photographs of synthetic fuelbeds

    Science.gov (United States)

    Robert E. Keane; Laura J. Dickinson

    2007-01-01

    Fire managers need better estimates of fuel loading so they can more accurately predict the potential fire behavior and effects of alternative fuel and ecosystem restoration treatments. This report presents a new fuel sampling method, called the photoload sampling technique, to quickly and accurately estimate loadings for six common surface fuel components (1 hr, 10 hr...

  5. Comparative geochemistry of Apollo 16 surface soils and samples from cores 64002 and 60002 through 60007

    Science.gov (United States)

    Korotev, R. L.

    1982-01-01

    New data are presented for the concentrations of 23 to 27 elements in nine Apollo 16 surface soil samples, two subsplits each of 12 splits of core 60002-7, and one subsplit each of 10 splits of drive tube 64002. The surface soils are generally similar to other surface soils collected at their respective stations. All ten 64002 samples are similar to each other and to the station 4 surface soils and distinctly different from soils at other stations. High iron concentrations previously reported for these same subsplits of 60002-7 result primarily from meteoritic metal. One sample from each core is contaminated by stainless steel. The recently proposed ferroan anorthositic norites are required to explain the soil compositions. A yet uncharacterized component with high concentrations of Na, Sr, and Eu is also needed.

  6. Operable Unit 3-13, Group 3, Other Surface Soils (Phase II) Field Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    G. L. Schwendiman

    2006-07-27

    This Field Sampling Plan describes the Operable Unit 3-13, Group 3, Other Surface Soils, Phase II remediation field sampling activities to be performed at the Idaho Nuclear Technology and Engineering Center located within the Idaho National Laboratory Site. Sampling activities described in this plan support characterization sampling of new sites, real-time soil spectroscopy during excavation, and confirmation sampling that verifies that the remedial action objectives and remediation goals presented in the Final Record of Decision for Idaho Nuclear Technology and Engineering Center, Operable Unit 3-13 have been met.

  7. May 2013 Groundwater and Surface Water Sampling at the Rio Blanco, Colorado, Site (Data Validation Package)

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, Rick [S.M. Stoller Corporation, Broomfield, CO (United States)

    2013-10-01

    Annual sampling was conducted at the Rio Blanco, Colorado, site for the Long-Term Hydrologic Monitoring Program May 14-16, 2013, to monitor groundwater and surface water for potential radionuclide contamination. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for the U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). A duplicate sample was collected from location CER #1 Black Sulphur. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional and enrichment methods.

  8. Optical Formation of Waveguide Elements in Photorefractive Surface Layer of a Lithium Niobate Sample

    Science.gov (United States)

    Bezpaly, A. D.; Shandarov, V. M.

    Formation of channel optical waveguides due to the sequential point-to-point exposure of local stripe-like regions of Y-cut lithium niobate sample surface is experimentally investigated. The surface layer of the sample is thermally doped with Cu ions to increase its photorefractive sensitivity. The laser radiation with wavelength of 532 nm and optical power of 10 mW is used for the crystal exposure in experiments. The optical inhomogeneities formed during the sample exposure are studied with their probing by laser beams with wavelength of 633 nm.

  9. Validation and comparison of two sampling methods to assess dermal exposure to drilling fluids and crude oil.

    Science.gov (United States)

    Galea, Karen S; McGonagle, Carolyn; Sleeuwenhoek, Anne; Todd, David; Jiménez, Araceli Sánchez

    2014-06-01

    Dermal exposure to drilling fluids and crude oil is an exposure route of concern. However, there have been no published studies describing sampling methods or reporting dermal exposure measurements. We describe a study that aimed to evaluate a wipe sampling method to assess dermal exposure to an oil-based drilling fluid and crude oil, as well as to investigate the feasibility of using an interception cotton glove sampler for exposure on the hands/wrists. A direct comparison of the wipe and interception methods was also completed using pigs' trotters as a surrogate for human skin and a direct surface contact exposure scenario. Overall, acceptable recovery and sampling efficiencies were reported for both methods, and both methods had satisfactory storage stability at 1 and 7 days, although there appeared to be some loss over 14 days. The methods' comparison study revealed significantly higher removal of both fluids from the metal surface with the glove samples compared with the wipe samples (on average 2.5 times higher). Both evaluated sampling methods were found to be suitable for assessing dermal exposure to oil-based drilling fluids and crude oil; however, the comparison study clearly illustrates that glove samplers may overestimate the amount of fluid transferred to the skin. Further comparison of the two dermal sampling methods using additional exposure situations such as immersion or deposition, as well as a field evaluation, is warranted to confirm their appropriateness and suitability in the working environment. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  10. Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning and household bleach

    NARCIS (Netherlands)

    Kusumaningrum, H.D.; Paltinaite, R.; Koomen, A.J.; Hazeleger, W.C.; Rombouts, F.M.; Beumer, R.R.

    2003-01-01

    Effective cleaning and sanitizing of food preparation sites is important because pathogens are readily spread to food contact surfaces after preparation of contaminated raw products. Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning by wiping with regular, microfiber,

  11. Recycle Experience of Dismantled Cask Handling Crane by Surface Removal Sampling at Kori Unit No.1

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. D.; Baeg, C. Y.; Son, J. K.; Kim, H. S.; Ha, J. A.; Song, M. J.

    2002-02-25

    The Kori No.1, which began operation in 1978, replaced its cask handling crane in 2000. To prove the safety of recycling and reuse of crane scrap, a particular calculation method for surface contamination was used. Because surface radioactive contamination of steel is limited to a few-microns-thick layer, we can calculate the total(removable and fixed contamination) activity of the sample conservatively by this surface removal sampling means. If we multiply the ratio of total surface and the area of the selected surface by its activity, total activity of the scrap can be estimated. Conservatively, the sampled portion can be used as a representative sample of the scrap. Both the inner and outer part of the scrap was sampled separately, and gamma spectra were analyzed to check whether activation had occurred. Before sampling, the entire surface of the steel is scan surveyed by several kinds of GM and GP detectors. Contaminated parts were segregated, or decontaminated to the background. Almost one sample per one ton of steel was collected. Gamma spectra of 62 samples were analyzed by 100% efficiency HP Ge detector. Only 60Co was detected, and its highest activity was 0.01 Bq/g,. This level of activity is much lower than the ''clearance levels'' outlined in IAEA TecDoc-855.(4). The total alpha and total beta for 6 samples were measured in the laboratory by low background alpha, using a beta gas proportional counter. Activities were much lower than 0.005 Bq/g. A representative sample was taken from the complete mixture of 62 samples. Gamma activities of nuclides were measured to estimate the dose to the public. This study revealed that activities of nuclides were lower than 'clearance levels' if decontaminated until the lower limit of detection level of the portable field instrument. New surface removal sampling method was tested. This method allows us to easily calculate the specific activity for the solid material.

  12. Differential efficiencies of dip-net sampling versus sampling surface-floating pupal exuviae in a biodiversity survey of Chironomidae

    Directory of Open Access Journals (Sweden)

    Leonard Charles Ferrington Jr

    2014-12-01

    Full Text Available Relative efficiencies of standard dip-net sampling (SDN versus collections of surface-floating pupal exuviae (SFPE were determined for detecting Chironomidae at catchment and site scales and at subfamily/tribe-, genus- and species-levels based on simultaneous, equal-effort sampling on a monthly basis for one year during a biodiversity assessment of Bear Run Nature Reserve. Results showed SFPE was more efficient than SDN at catchment scales for detecting both genera and species. At site scales, SDN sampling was more efficient for assessment of a first-order site. No consistent pattern, except for better efficiency of SFPE to detect Orthocladiinae genera, was observed at genus-level for two second-order sites. However, SFPE was consistently more efficient at detecting species of Orthocladiinae, Chironomini and Tanytarsini at the second order sites. SFPE was more efficient at detecting both genera and species at two third-order sites. The differential efficiencies of the two methods are concluded to be related to stream order and size, substrate size, flow and water velocity, depth and habitat heterogeneity, and differential ability to discriminate species among pupal exuviae specimens versus larval specimens. Although both approaches are considered necessary for comprehensive biodiversity assessments of Chironomidae, our results suggest that there is an optimal, but different, allocation of sampling effort for detecting Chironomidae across stream orders and at differing spatial and taxonomic scales.Article submitted 13. August 2014, accepted 31. October 2014, published 22. December 2014.

  13. Cracks and nanodroplets produced on tungsten surface samples by dense plasma jets

    Science.gov (United States)

    Ticoş, C. M.; Galaţanu, M.; Galaţanu, A.; Luculescu, C.; Scurtu, A.; Udrea, N.; Ticoş, D.; Dumitru, M.

    2018-03-01

    Small samples of 12.5 mm in diameter made from pure tungsten were exposed to a dense plasma jet produced by a coaxial plasma gun operated at 2 kJ. The surface of the samples was analyzed using a scanning electron microscope (SEM) before and after applying consecutive plasma shots. Cracks and craters were produced in the surface due to surface tensions during plasma heating. Nanodroplets and micron size droplets could be observed on the samples surface. An energy-dispersive spectroscopy (EDS) analysis revealed that the composition of these droplets coincided with that of the gun electrode material. Four types of samples were prepared by spark plasma sintering from powders with the average particle size ranging from 70 nanometers up to 80 μm. The plasma power load to the sample surface was estimated to be ≈4.7 MJ m-2 s-1/2 per shot. The electron temperature and density in the plasma jet had peak values 17 eV and 1.6 × 1022 m-3, respectively.

  14. May 2012 Groundwater and Surface Water Sampling at the Rio Blanco, Colorado, Site (Data Validation Package)

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, Rick [S.M. Stoller Corporation, Broomfield, CO (United States)

    2012-12-01

    Annual sampling was conducted at the Rio Blanco, Colorado, site for the Long-Term Hydrologic Monitoring Program May 9-10, 2012, to monitor groundwater and surface water for potential radionuclide contamination. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for the U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). A duplicate sample was collected from location Johnson Artesian WL. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional and enrichment methods. Results of this monitoring at the Rio Blanco site demonstrate that groundwater and surface water outside the site boundaries have not been affected by project-related contaminants.

  15. Visual Assessment of Surface Fuel Loads Does Not Align with Destructively Sampled Surface Fuels

    Directory of Open Access Journals (Sweden)

    Sarah C. McColl-Gausden

    2017-10-01

    Full Text Available Fuel load and structure are fundamental drivers of fire behaviour. Accurate data is required for managers and researchers to better understand our ability to alter fire risk. While there are many ways to quantify fuel, visual assessment methods are generally considered the most efficient. Visual hazard assessments are commonly used by managers, government agencies and consultants to provide a fuel hazard score or rating but not a quantity of fuel. Many systems attempt to convert the hazard score or rating to a fuel load for use in fire behaviour models. Here we investigate whether the conversion table in the widely used Overall Fuel Hazard Guide (OFHG matches destructively sampled fuel loads from 116 sites across five forest types. We specifically examine whether there are quantifiable differences that can be attributed to forest type. We found there is overlap between the two methods for low, moderate and high hazard categories, however for the very high and extreme hazard categories, visual assessment overestimated fuel load in four of the five forest types. Using a commonly applied fire behaviour model, we found that the overestimation of fuel load in very high and extreme hazard categories leads to an overestimation of fire behavior in these hazard categories.

  16. Surface AFM microscopy of unworn and worn samples of silicone hydrogel contact lenses.

    Science.gov (United States)

    González-Méijome, J M; López-Alemany, A; Almeida, J B; Parafita, M A

    2009-01-01

    To evaluate the qualitative and quantitative topographic changes in the surface of worn contact lenses (CLs) of different materials using atomic force microscopy (AFM). The topography of five different CL materials was evaluated with AFM over a surface of 25 microm(2) according to previously published experimental setup. Average roughness (R(a)) and root mean square (Rms) values were obtained for unworn and worn samples. The R(a) value increased for balafilcon A (11.62-13.68 nm for unworn and worn samples, respectively), lotrafilcon A (3.67-15.01 nm for unworn and worn samples, respectively), lotrafilcon B (4.08-8.42 nm for unworn and worn samples, respectively), galyfilcon A (2.81-14.6 nm for unworn and worn samples, respectively), and comfilcon A (2.87-4.63 nm for unworn and worn samples, respectively). Differences were statistically significant for all lenses except Rms and R(a) for comfilcon A, and R(a) parameter for balafilcon A (p > 0.05). The least relative increase was observed for some balafilcon A samples and for some of these samples the roughness decreased after the lenses had been worn. The changes in surface roughness between unworn and worn lenses are different for different silicone-hydrogel materials. Overall all CLs increased the degree of surface roughness after being worn, even for very short periods of time. However, for samples of balafilcon A, roughness increases at a lower extent or even can decrease as compared to unworn samples of the same material due to filling of the macropores. (c) 2008 Wiley Periodicals, Inc.

  17. Assessment of Progressive Product Innovation on Key Environmental Indicators: Pampers® Baby Wipes from 2007–2013

    Directory of Open Access Journals (Sweden)

    Gert Van Hoof

    2014-08-01

    Full Text Available Companies are increasingly conducting life cycle assessments (LCA of their products to understand potential product impacts on the environment, prioritize areas of innovation to create more sustainable products, and determine valid claims. This case study shows the results of product innovation by comparing an older (2007 and new (2013 version of a common hygiene product in Europe and the U.S. The standard methodology follows the ISO 14040/44 Guidelines for LCA. Results are reported for the impact indicators with high relevance for the product category: primary energy, global warming, particulates, agricultural land occupation, fossil fuel depletion, and solid waste generation. Generally, raw material supply chains for product and packaging contribute most (up to 82% to the calculated environmental impact indicators. Improvements vs. the 2007 baby wipe range between 4% and 14% in Europe and between 15% and 36% in the U.S. The improvement is driven by a new substrate technology that provides more surface area for cleaning, which results in lower use of resources. This case study illustrates three key environmental drivers behind this innovation: the corporate focus on R&D capability to design for environmentally improved products, the increased interest from retailers and consumers requiring accurate and relevant information on the performance and sustainability of products, and the company’s interest in deeper technical understanding of contributions from upstream material and process innovations on a product’s environmental profile.

  18. Novel field sampling procedure for the determination of methiocarb residues in surface waters from rice fields.

    Science.gov (United States)

    Primus, T M; Kohler, D J; Avery, M; Bolich, P; Way, M O; Johnston, J J

    2001-12-01

    Methiocarb was extracted from surface water samples collected at experimental rice field sites in Louisiana and Texas. The sampling system consisted of a single-stage 90-mm Empore extraction disk unit equipped with a battery-powered vacuum pump. After extraction, the C-18 extraction disks were stored in an inert atmosphere at -10 degrees C and shipped overnight to the laboratory. The disks were extracted with methanol and the extracts analyzed by reversed-phase high-performance liquid chromatography with a methanol/water mobile phase. Methiocarb was detected by ultraviolet absorption at 223 nm and quantified with the use of calibration standards. Recoveries from control surface water samples fortified at 5.0, 10, 50, and 100 ng/mL methiocarb averaged 92 +/- 7%. A method limit of detection for methiocarb in rice field surface water was estimated to be 0.23 ng/mL at 223 nm.

  19. Effect on skin hydration of using baby wipes to clean the napkin area of newborn babies: assessor-blinded randomised controlled equivalence trial

    OpenAIRE

    Lavender, T.; Furber, C.; Campbell, M; Victor, S.; Roberts, I.; Bedwell, C; Cork, M.J.

    2012-01-01

    Abstract Background Some national guidelines recommend the use of water alone for napkin cleansing. Yet, there is a readiness, amongst many parents, to use baby wipes. Evidence from randomised controlled trials, of the effect of baby wipes on newborn skin integrity is lacking. We conducted a study to examine the hypothesis that the use of a specifically formulated cleansing wipe on the napkin area of newborn infants (

  20. New technique to take samples from environmental surfaces using flocked nylon swabs.

    Science.gov (United States)

    Hedin, G; Rynbäck, J; Loré, B

    2010-08-01

    Environmental surfaces near infected and/or colonised patients in hospitals are commonly contaminated with potentially pathogenic micro-organisms. At present, however, there is no standardised method for taking samples from surfaces in order to perform quantitative cultures. Usually contact plates or swabs are used, but these methods may give different results. The recovery rate of traditional swabbing, e.g. cotton or rayon, is poor. With a new type of swab utilising flocked nylon, the recovery may be enhanced up to three times compared with a rayon swab. In this study, we inoculated reference strains of Staphylococcus aureus and Enterococcus hirae onto a bedside table and took samples 1h later when inocula were dry. Sequential samples were taken from the same surface. A new sampling technique using two sequential nylon swabs for each sample was validated. The efficiency of the sampling, percentage recovery of the inoculum and the variation of culture results obtained from repeated experiments are described. Enhanced efficiency and higher recovery of inoculum were demonstrated using two sequential flocked nylon swabs for sampling. Copyright 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

  1. Effects of Spatial Sampling Interval on Roughness Parameters and Microwave Backscatter over Agricultural Soil Surfaces

    Directory of Open Access Journals (Sweden)

    Matías Ernesto Barber

    2016-06-01

    Full Text Available The spatial sampling interval, as related to the ability to digitize a soil profile with a certain number of features per unit length, depends on the profiling technique itself. From a variety of profiling techniques, roughness parameters are estimated at different sampling intervals. Since soil profiles have continuous spectral components, it is clear that roughness parameters are influenced by the sampling interval of the measurement device employed. In this work, we contributed to answer which sampling interval the profiles needed to be measured at to accurately account for the microwave response of agricultural surfaces. For this purpose, a 2-D laser profiler was built and used to measure surface soil roughness at field scale over agricultural sites in Argentina. Sampling intervals ranged from large (50 mm to small ones (1 mm, with several intermediate values. Large- and intermediate-sampling-interval profiles were synthetically derived from nominal, 1 mm ones. With these data, the effect of sampling-interval-dependent roughness parameters on backscatter response was assessed using the theoretical backscatter model IEM2M. Simulations demonstrated that variations of roughness parameters depended on the working wavelength and was less important at L-band than at C- or X-band. In any case, an underestimation of the backscattering coefficient of about 1-4 dB was observed at larger sampling intervals. As a general rule a sampling interval of 15 mm can be recommended for L-band and 5 mm for C-band.

  2. Rapid Surface Sampling and Archival Record (RSSAR) system. Final report, October 1995--May 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This report describes the results of Phase 2 efforts to develop a Rapid Surface Sampling and Archival Record (RSSAR) System for the detection of semivolatile organic contaminants on concrete, transite, and metal surfaces. The characterization of equipment and building surfaces for the presence of contaminants as part of building decontamination and decommissioning activities is an immensely large task of concern to both government and industry. Because of the high cost of hazardous waste disposal, old, contaminated buildings cannot simply be demolished and scrapped. Contaminated and clean materials must be clearly identified and segregated so that the clean material can be recycled or reused, if possible, or disposed of more cheaply as nonhazardous waste. DOE has a number of sites requiring surface characterization. These sites are large, contain very heterogeneous patterns of contamination (requiring high sampling density), and will thus necessitate an enormous number of samples to be taken and analyzed. Characterization of building and equipment surfaces will be needed during initial investigations, during cleanup operations, and during the final confirmation process, increasing the total number of samples well beyond that needed for initial characterization. This multiplicity of information places a premium on the ability to handle and track data as efficiently as possible.

  3. Benthic foraminiferal census data from Mobile Bay, Alabama--counts of surface samples and box cores

    Science.gov (United States)

    Richwine, Kathryn A.; Osterman, Lisa E.

    2012-01-01

    A study was undertaken in order to understand recent environmental change in Mobile Bay, Alabama. For this study a series of surface sediment and box core samples was collected. The surface benthic foraminiferal data provide the modern baseline conditions of the bay and can be used as a reference for changing paleoenvironmental parameters recorded in the box cores. The 14 sampling locations were chosen in the bay to cover the wide diversity of fluvial and marine-influenced environments on both sides of the shipping channel.

  4. Allergic contact dermatitis to methylisothiazolinone: exposure from baby wipes causing hand dermatitis.

    Science.gov (United States)

    Boyapati, Ann; Tam, Mei; Tate, Bruce; Lee, Adriene; Palmer, Amanda; Nixon, Rosemary

    2013-11-01

    Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) is a preservative used in both cosmetic and industrial settings. In Europe it is allowed to be used in rinse-off cosmetics only because of its propensity to cause allergic contact dermatitis (ACD). No such legislation exists in Australia. In recent years MI without MCI has been used. In August 2010 the first cases of MI causing non-occupational ACD were reported in Europe. The objective here was to present a case series of ACD to MI occurring in the Australian setting.  : We retrospectively reviewed positive reactions to MI and MCI/MI from the Skin and Cancer Foundation patch test clinical database. MI was added to our baseline test series in January 2011.  : In total 653 patients were tested for MI and there were 43 reactions, of which 23 were relevant, based on a history of exposure to MI. Seven were parents of young children with hand dermatitis caused by ACD to MI contained in baby wipes. The remaining patients reacted to MI in shampoos, conditioners, deodorants, moisturisers, a skin cleanser and a facial wipe. Three patients had ACD to MI associated with occupational exposure to hand cleansers. These data demonstrate for the first time that MI is an emerging, important allergen in both cosmetic and occupational settings in Australia. An important source of exposure was baby wipes, which was predominantly associated with hand dermatitis in parents. We believe that it is important to test for MI, not just MCI/MI, in the baseline series. © 2013 The Authors. Australasian Journal of Dermatology © 2013 The Australasian College of Dermatologists.

  5. Blastocystis surface antigen is stable in chemically preserved stool samples for at least 1 year.

    Science.gov (United States)

    Gould, Rick; Boorom, Kenneth

    2013-07-01

    Blastocystis spp. refer to a group of prevalent enteric protists found in humans and animals. Detection of Blastocystis spp. in fecal samples is often performed by clinicians with direct microscopy, which provides low sensitivity, or with culture and polymerase chain reaction testing, a method which is problematic when used with formalin-preserved stool samples. Prior study of Blastocystis and other enteric protists suggests that immunofluorescence antibody (IFA) stain could provide sensitivity and compatibility with formalin, but no information is available on the longevity of Blastocystis sp.'s surface antigens in formalin. We collected fecal samples from animals at a country fair held in the summer of 2009 in Oregon, USA. Samples were tested for the presence of Blastocystis infection using an IFA stain shortly after collection, and again after 1 year, with samples stored refrigerated at 4-8 °C. Most samples collected from steer, pigs, and goats were found to be Blastocystis positive. All fecal samples that were Blastocystis positive initially remained positive after 1 year. Blastocystis-negative samples remained negative. Minimal degradation was observed in stained slides. Blastocystis surface antigens detected by a polyclonal stain remained stable in formalin for a period of at least 1 year.

  6. Contributions of Paint and Soil to Pb in Household Dust Wipes: An XAS Study

    Science.gov (United States)

    Pingitore, N. E.; Clague, J. W.; Amaya, M. A.

    2010-12-01

    Speciation of Pb by X-ray absorption spectroscopy (XAS) indicated that Pb compounds associated with lead-based paint accounted for perhaps half of the Pb in 24 household dust wipes collected in El Paso, Texas. Soil-derived, sorbed Pb, likely Pb-humate, was also a major Pb species in many of the dust wipes. Household dust wipes are a standard technique for evaluating health risks of Pb to children, particularly toddlers, in public and private housing. The level of Pb in the wipes does not, however, indicate whether the source of the Pb is the house itself (peeling or powdering interior or exterior paint) or external, from contaminated soil or airborne particulate matter brought into the house by wind or foot traction. Understanding the origin of Pb in household dust is important in remediation: cover the old paint or remove the yard soil. XAS speciation can assist in understanding the source of Pb in household dust. The presence of significant Pb-humate requires a soil source, and suggests the need for soil remediation. Such species of Pb as hydrocerussite, lead sulfate, lead silicate, and lead chromate can be presumed to be components of lead-based paint. These may represent interior and/or exterior paint and thus do not uniquely identify the locus of the Pb source(s). Pb L-III edge XAFS data were collected on beam lines 7-3, 10-2, and 11-2 at SSRL at typical conditions of 3 GeV field and 80-200 mA current, using Si(220) water- or liquid-nitrogen-cooled monochromator crystals. Data were collected at ambient temperature in fluorescence mode using a 13- or 30-element Ge detector with a Se 3 or 6 filter and Soller slits to reduce scattered radiation. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-01A1 from the National Institute of Environmental Health Sciences (NIEHS), NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. Portions of this research were

  7. USING OF LASER EMISSION FOR ALLOYING SURFACE ALLOYS’ SAMPLES BY TYPE 38XN3MFA

    Directory of Open Access Journals (Sweden)

    V. D. Shelyagin

    2014-09-01

    Full Text Available The process of laser and laser-plasma methods of surface alloying of steel samples is investigated. It si determined that in the absence of cracks the structural state of the doped layer is characterized by the formation of dispersed phases in their uniform distribution, a low density of dislocations without any sharp gradients and low level of internal stresses.

  8. Surface chemical characterization of PM{sub 10} samples by XPS

    Energy Technology Data Exchange (ETDEWEB)

    Atzei, Davide, E-mail: datzei@unica.it [Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, S.S. 554 Bivio per Sestu, I-09042 Monserrato, Cagliari (Italy); Fantauzzi, Marzia; Rossi, Antonella [Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, S.S. 554 Bivio per Sestu, I-09042 Monserrato, Cagliari (Italy); Fermo, Paola [Dipartimento di Chimica, Università degli Studi Milano, Via Golgi 19, I-20133 Milano (Italy); Piazzalunga, Andrea [Dipartimento di Chimica, Università degli Studi Milano, Via Golgi 19, I-20133 Milano (Italy); Dipartimento di Scienze dell’Ambiente e del territorio, Università degli Studi di Milano-Bicocca, Piazza della Scienza 1, I-20122 Milano (Italy); Valli, Gianluigi; Vecchi, Roberta [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy)

    2014-07-01

    Samples of particulate matter (PM) collected in the city of Milan during wintertime were analyzed by X-ray photoelectron spectroscopy (XPS), thermal optical transmittance (TOT), ionic chromatography (IC) and X-ray fluorescence (XRF) in order to compare quantitative bulk analysis and surface analysis. In particular, the analysis of surface carbon is here presented following a new approach for the C1s curve fitting aiming this work to prove the capability of XPS to discriminate among elemental carbon (EC) and organic carbon (OC) and to quantify the carbon-based compounds that might be present in the PM. Since surface of urban PM is found to be rich in carbon it is important to be able to distinguish between the different species. XPS results indicate that aromatic and aliphatic species are adsorbed on the PM surface. Higher concentrations of (EC) are present in the bulk. Also nitrogen and sulfur were detected on the surfaces and a qualitative and quantitative analysis is provided. Surface concentration of sulfate ion is equal to that found by bulk analysis; moreover surface analysis shows an additional signal due to organic sulfur not detectable by the other methods. Surface appears to be also enriched in nitrogen.

  9. Local surface sampling step estimation for extracting boundaries of planar point clouds

    Science.gov (United States)

    Brie, David; Bombardier, Vincent; Baeteman, Grégory; Bennis, Abdelhamid

    2016-09-01

    This paper presents a new approach to estimate the surface sampling step of planar point clouds acquired by Terrestrial Laser Scanner (TLS) which is varying with the distance to the surface and the angular positions. The local surface sampling step is obtained by doing a first order Taylor expansion of planar point coordinates. Then, it is shown how to use it in Delaunay-based boundary point extraction. The resulting approach, which is implemented in the ModiBuilding software, is applied to two facade point clouds of a building. The first is acquired with a single station and the second with two stations. In both cases, the proposed approach performs very accurately and appears to be robust to the variations of the point cloud density.

  10. Influence of surface topography on the secondary electron yield of clean copper samples.

    Science.gov (United States)

    Hu, Xiao-Chuan; Cao, Meng; Cui, Wan-Zhao

    2016-11-01

    Secondary electron yield (SEY) due to electron impact depends strongly on surface topography. The SEY of copper samples after Ar-ion bombardment is measured in situ in a multifunctional ultrahigh vacuum system. Increasing the ion energy or duration of ion bombardment can even enlarge the SEY, though it is relatively low under moderate bombardment intensity. The results obtained with scanning electron microscopy and atomic force microscopy images demonstrate that many valley structures of original sample surfaces can be smoothed due to ion bombardment, but more hill structures are generated with stronger bombardment intensity. With increasing the surface roughness in the observed range, the maximum SEY decreases from 1.2 to 1.07 at a surface characterized by valleys, while it again increases to 1.33 at a surface spread with hills. This phenomenon indicates that hill and valley structures are respectively effective in increasing and decreasing the SEY. These obtained results thus provide a comprehensive insight into the surface topography influence on the secondary electron emission characteristics in scanning electron microscopy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. An Intrinsic Algorithm for Parallel Poisson Disk Sampling on Arbitrary Surfaces.

    Science.gov (United States)

    Ying, Xiang; Xin, Shi-Qing; Sun, Qian; He, Ying

    2013-03-08

    Poisson disk sampling plays an important role in a variety of visual computing, due to its useful statistical property in distribution and the absence of aliasing artifacts. While many effective techniques have been proposed to generate Poisson disk distribution in Euclidean space, relatively few work has been reported to the surface counterpart. This paper presents an intrinsic algorithm for parallel Poisson disk sampling on arbitrary surfaces. We propose a new technique for parallelizing the dart throwing. Rather than the conventional approaches that explicitly partition the spatial domain to generate the samples in parallel, our approach assigns each sample candidate a random and unique priority that is unbiased with regard to the distribution. Hence, multiple threads can process the candidates simultaneously and resolve conflicts by checking the given priority values. It is worth noting that our algorithm is accurate as the generated Poisson disks are uniformly and randomly distributed without bias. Our method is intrinsic in that all the computations are based on the intrinsic metric and are independent of the embedding space. This intrinsic feature allows us to generate Poisson disk distributions on arbitrary surfaces. Furthermore, by manipulating the spatially varying density function, we can obtain adaptive sampling easily.

  12. Technical Note: Comparison of storage strategies of sea surface microlayer samples

    Directory of Open Access Journals (Sweden)

    K. Schneider-Zapp

    2013-07-01

    Full Text Available The sea surface microlayer (SML is an important biogeochemical system whose physico-chemical analysis often necessitates some degree of sample storage. However, many SML components degrade with time so the development of optimal storage protocols is paramount. We here briefly review some commonly used treatment and storage protocols. Using freshwater and saline SML samples from a river estuary, we investigated temporal changes in surfactant activity (SA and the absorbance and fluorescence of chromophoric dissolved organic matter (CDOM over four weeks, following selected sample treatment and storage protocols. Some variability in the effectiveness of individual protocols most likely reflects sample provenance. None of the various protocols examined performed any better than dark storage at 4 °C without pre-treatment. We therefore recommend storing samples refrigerated in the dark.

  13. Control of the positional relationship between a sample collection instrument and a surface to be analyzed during a sampling procedure with image analysis

    Science.gov (United States)

    Van Berkel, Gary J.; Kertesz, Vilmos

    2011-08-09

    A system and method utilizes an image analysis approach for controlling the collection instrument-to-surface distance in a sampling system for use, for example, with mass spectrometric detection. Such an approach involves the capturing of an image of the collection instrument or the shadow thereof cast across the surface and the utilization of line average brightness (LAB) techniques to determine the actual distance between the collection instrument and the surface. The actual distance is subsequently compared to a target distance for re-optimization, as necessary, of the collection instrument-to-surface during an automated surface sampling operation.

  14. Surface Sampling Collection and Culture Methods for Escherichia coli in Household Environments with High Fecal Contamination

    Science.gov (United States)

    Kosek, Margaret N.; Schwab, Kellogg J.

    2017-01-01

    Empiric quantification of environmental fecal contamination is an important step toward understanding the impact that water, sanitation, and hygiene interventions have on reducing enteric infections. There is a need to standardize the methods used for surface sampling in field studies that examine fecal contamination in low-income settings. The dry cloth method presented in this manuscript improves upon the more commonly used swabbing technique that has been shown in the literature to have a low sampling efficiency. The recovery efficiency of a dry electrostatic cloth sampling method was evaluated using Escherichia coli and then applied to household surfaces in Iquitos, Peru, where there is high fecal contamination and enteric infection. Side-by-side measurements were taken from various floor locations within a household at the same time over a three-month period to compare for consistency of quantification of E. coli bacteria. The dry cloth sampling method in the laboratory setting showed 105% (95% Confidence Interval: 98%, 113%) E. coli recovery efficiency off of the cloths. The field application demonstrated strong agreement of side-by-side results (Pearson correlation coefficient for dirt surfaces was 0.83 (p < 0.0001) and 0.91 (p < 0.0001) for cement surfaces) and moderate agreement for results between entrance and kitchen samples (Pearson (0.53, p < 0.0001) and weighted Kappa statistic (0.54, p < 0.0001)). Our findings suggest that this method can be utilized in households with high bacterial loads using either continuous (quantitative) or categorical (semi-quantitative) data. The standardization of this low-cost, dry electrostatic cloth sampling method can be used to measure differences between households in intervention and non-intervention arms of randomized trials. PMID:28829392

  15. Results of Testing the Relative Oxidizing Hazard of Wipes and KMI Zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Ams, Bridget Elaine [Los Alamos National Laboratory

    2017-05-09

    This report includes the results from testing performed on the relative oxidizing hazard of a number of organic sorbing wipe materials, as well as KMI zeolite. These studies were undertaken to address a need by the Los Alamos National Laboratory (LANL) Hazardous Materials Management group, which requires a material that can sorb small spills in a glovebox without creating a disposal hazard due to the potential for oxidation reactions, as requested in Request for Testing of Wipes and Zeolite for Los Alamos National Laboratory Hazardous Materials Group (NPl-7) (NPl-7-17-002) and Request for Testing of Chamois Material for Los Alamos National Laboratory Hazardous Materials Group (NPl-7) (NPl-7-17-005). This set oftests is a continuation of previous testing described in Results from Preparation and Testing of Sorbents Mixed with (DWT-RPT-003), which provided data for the Waste Isolation Pilot Plant's Basis of Knowledge. The Basis of Knowledge establishes criteria for evaluating transuranic (TRU) waste that contains oxidizing chemicals.

  16. Scrubbing the hub of intravenous catheters with an alcohol wipe for 15 sec reduced neonatal sepsis.

    Science.gov (United States)

    Björkman, Louise; Ohlin, Andreas

    2015-03-01

    The aim of this study was to investigate whether scrubbing the hub of intravenous catheters with an alcohol wipe for 15 sec could reduce the incidence of neonatal sepsis in a level-three neonatal intensive care unit. We studied the incidence of neonatal sepsis caused by coagulase-negative staphylococci (CoNS) for 16.5 months before the initiative was launched on May 15, 2012 and then for a further 8.5 months after it was introduced. The hub routine was applied to all intravenous catheters. During the control period before the initiative was launched, there were nine cases of CoNS sepsis compared with no cases after it was introduced, resulting in a decrease in sepsis incidence from 1.5% to 0% with a risk reduction of 1.5% (0.53-2.58%) (p = 0.06). In the preterm infant population, the incidence of sepsis decreased from 3.6% to 0% (1.1-6.0%) (p = 0.11). Scrubbing the hub of intravenous catheters with an alcohol wipe for 15 sec seemed to be an efficient way of preventing sepsis caused by CoNS in newborn infants. However, the evidence for the benefits will remain weak until a large randomised trial has been completed. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  17. Terra Firma-Forme Dermatosis in Singaporean Patients: The "Alcohol Wipe" Sign.

    Science.gov (United States)

    Oh, Choon Chiat; Oon, Hazel H; Ng, See Ket; Tee, Shang Ian; Jhingan, Anjali; Chong, Wei-Sheng

    2016-01-01

    The term terra firma-forme dermatosis arises from the Latin phrase terra firma , meaning dry land (dirt), thus implying dirt-like dermatosis. The authors highlight five cases of patients with terra firma-forme dermatosis presenting to our dermatology center between 2012 and 2013. All patients presented to the dermatologist for persistent reticulated brown patches on the skin. These patients ranged in age from 6 to 22 years. All patients had tried various cleansing soaps and agents but were unable to remove the patches. The condition was cosmetically unacceptable to the patients and parents. Clinically, these patients had reticulated brown patches. Rubbing 70% isopropyl alcohol wipes on the affected areas demonstrated clearance of the brown pigmented patches in all cases. The diagnosis of terra firma-forme dermatosis (TFFD) was confirmed by forceful rubbing with a gauze pad immersed in 70% isopropyl alcohol or ethyl alcohol. Patients should be reassured about the benign nature of TFFD and educated about the cleaning procedure. Recognition of this condition can assist physicians in making a diagnosis and therapy with a simple alcohol wipe, preventing further unnecessary tests for patients.

  18. Picogram per liter detections of pyrethroids and organophosphates in surface waters using passive sampling.

    Science.gov (United States)

    Moschet, Christoph; Vermeirssen, Etiënne L M; Seiz, Remo; Pfefferli, Hildegard; Hollender, Juliane

    2014-12-01

    Pyrethroids and organophosphates are among the most toxic insecticides for aquatic organisms, leading to annual-average environmental quality standards (AA-EQS) in the picogram per liter range in surface waters. For monitoring purposes, it is therefore crucial to develop very sensitive analytical methods. Until now, it is very difficult to reach detection limits at or below given AA-EQSs. Here, we present a passive sampling method using silicone rubber (SR) sheets for the sampling of ten pyrethroids and two organophosphates in surface waters. An analytical method was developed, optimized and validated for the extraction of the insecticides from the SR sheets by accelerated solvent extraction followed by clean-up on C18 and silica gel and detection with GC-MS/MS in positive ionization mode. Good precision (50%) was observed for all substances, accuracy was between 66% and 139%. Limits of detection between 6 and 200 pg/L were achieved for all substances in surface waters using average sampling rates for PCBs and PAHs. The lack of substance-specific sampling rates and missing performance reference compounds led to an uncertainty in the concentration estimation of factor three in both directions. In a large field study, comprising 40 environmental samples from nine Swiss rivers, eight out of 12 substances were detected (most frequently: chlorpyrifos, cypermethrin). Most of the estimated organophosphate concentrations were between 0.1 and 1 ng/L, most pyrethroid detections below 0.1 ng/L. Four substances (chlorpyrifos-methyl, cypermethrin, deltamethrin and lambda-cyhalothrin) showed exceedances of their respective AA-EQS in multiple samples, also when the uncertainties in the concentration estimation were considered. As pyrethroid and organophosphate detection by SR passive sampling is very practicable and allows sensitive analysis, it has the potential to become a new tool in the monitoring of non-polar pesticides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Cyclophosphamide identification in wipe test by GC-MS and solid phase extraction Identificação de ciclofosfamida em wipe teste por CG-EM com prévia extração em fase sólida

    Directory of Open Access Journals (Sweden)

    Isarita Martins

    2004-03-01

    Full Text Available In this study cyclophosphamide was quantified after adapting a prior analytical method using gas chromatography-mass spectrometry after solid phase purification and derivatization with trifluoroacetic anhydride. The analyte was measured by analysis in wipe test from infusion bags, which may be contaminated by contact with the gloves used during preparation of the drugs. Surface of bag contaminated may be an important source of contamination for workers in the others chemoterapy handling areas, such as administration rooms. This drug, in fact, is one of the most frequently used alkylating antineoplastic agents for different types of tumors and it is furthermore classified as a human carcinogen by IARC. Ifosfamide was used as internal standard and the quantification was carried out by reference to calibration curves within a range from 1 to 100 ng/mL. The limit of detection was 0.4 ng/mL. The values of the variation coefficient varied from 0.5 to 10% (intra-assay and from 0 to 19% (interassay. Frozen reference wipe samples containing cyclophosphamide were analysed over one month and no significant loss was observed. The range obtained for bias assay was 83-116% and the recovery was 98.9%. Cyclophosphamide was measured in 36 of 42 infusion bags collected from different hospitals with values ranging from 90 to 41874 ng (median= 607.5 ng. The results, well related to those reported in the literature, suggest that this method can be used to identify cyclophosphamide from wipe samples and can be considered useful in exposure assessment to this drug.A ciclofosfamida é uma agente alquilante freqüentemente utilizado na prática clínica para diferentes tipos de tumores e, é classificado como carcinógeno para humanos pelo IARC. Neste estudo, o fármaco foi quantificado, após adaptação de um método analítico, utilizando a cromatografia gasosa acoplada à espectrometria de massa com prévia extração em fase sólida e derivação com anidrido

  20. The variation in surface morphology and hardness of human deciduous teeth samples after laser irradiation

    Science.gov (United States)

    Khalid, Arooj; Bashir, Shazia; Akram, Mahreen; Salman Ahmed, Qazi

    2017-11-01

    The variation in surface morphology and hardness of human deciduous teeth samples has been investigated after laser irradiation at different wavelengths and energies. Nd:YAG was employed as a source of irradiation for IR (1064 nm) and visible (532 nm) radiation, whereas an excimer laser was used as the source of UV (248 nm) radiation. Scanning electron microscope (SEM) analysis was carried out to reveal the surface morphological evolution of teeth samples. Vickers microhardness tester was employed to investigate the modifications in the hardness of the laser-treated samples. It is observed from SEM analysis that IR wavelength is responsible for ablation of collagen matrix and intertubular dentine. For visible radiation, the ablation of collagen along with hydroxypatite is observed. With UV radiation, the ablation of peritubular dentine is dominant and is responsible for the sealing of tubules. The decrease in hardness at lower energy for both wavelengths is due to the evaporation of carbon content. With increasing energy, evaporation of water along with carbon content, and resolidification and re-organization of inorganic content causes the increase in hardness of the treated dentine. SEM as well as microhardness analyses reveal that laser wavelengths and energy of laser radiation significantly influence the surface morphology and hardness of samples.

  1. Utilization of Sanitizing Wipes on Selected Coated Nonstick Food Contact Surfaces

    National Research Council Canada - National Science Library

    Powers, Edmund

    2002-01-01

    The objective of this study was to find alternatives to military field sanitation methods that will reduce the amount of greywater produced during sanitation operations and the logistical requirements...

  2. Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples

    Science.gov (United States)

    Lusher, Amy L.; Tirelli, Valentina; O’Connor, Ian; Officer, Rick

    2015-01-01

    Plastic, as a form of marine litter, is found in varying quantities and sizes around the globe from surface waters to deep-sea sediments. Identifying patterns of microplastic distribution will benefit an understanding of the scale of their potential effect on the environment and organisms. As sea ice extent is reducing in the Arctic, heightened shipping and fishing activity may increase marine pollution in the area. Microplastics may enter the region following ocean transport and local input, although baseline contamination measurements are still required. Here we present the first study of microplastics in Arctic waters, south and southwest of Svalbard, Norway. Microplastics were found in surface (top 16 cm) and sub-surface (6 m depth) samples using two independent techniques. Origins and pathways bringing microplastic to the Arctic remain unclear. Particle composition (95% fibres) suggests they may either result from the breakdown of larger items (transported over large distances by prevailing currents, or derived from local vessel activity), or input in sewage and wastewater from coastal areas. Concurrent observations of high zooplankton abundance suggest a high probability for marine biota to encounter microplastics and a potential for trophic interactions. Further research is required to understand the effects of microplastic-biota interaction within this productive environment. PMID:26446348

  3. Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples

    Science.gov (United States)

    Lusher, Amy L.; Tirelli, Valentina; O'Connor, Ian; Officer, Rick

    2015-10-01

    Plastic, as a form of marine litter, is found in varying quantities and sizes around the globe from surface waters to deep-sea sediments. Identifying patterns of microplastic distribution will benefit an understanding of the scale of their potential effect on the environment and organisms. As sea ice extent is reducing in the Arctic, heightened shipping and fishing activity may increase marine pollution in the area. Microplastics may enter the region following ocean transport and local input, although baseline contamination measurements are still required. Here we present the first study of microplastics in Arctic waters, south and southwest of Svalbard, Norway. Microplastics were found in surface (top 16 cm) and sub-surface (6 m depth) samples using two independent techniques. Origins and pathways bringing microplastic to the Arctic remain unclear. Particle composition (95% fibres) suggests they may either result from the breakdown of larger items (transported over large distances by prevailing currents, or derived from local vessel activity), or input in sewage and wastewater from coastal areas. Concurrent observations of high zooplankton abundance suggest a high probability for marine biota to encounter microplastics and a potential for trophic interactions. Further research is required to understand the effects of microplastic-biota interaction within this productive environment.

  4. Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples.

    Science.gov (United States)

    Lusher, Amy L; Tirelli, Valentina; O'Connor, Ian; Officer, Rick

    2015-10-08

    Plastic, as a form of marine litter, is found in varying quantities and sizes around the globe from surface waters to deep-sea sediments. Identifying patterns of microplastic distribution will benefit an understanding of the scale of their potential effect on the environment and organisms. As sea ice extent is reducing in the Arctic, heightened shipping and fishing activity may increase marine pollution in the area. Microplastics may enter the region following ocean transport and local input, although baseline contamination measurements are still required. Here we present the first study of microplastics in Arctic waters, south and southwest of Svalbard, Norway. Microplastics were found in surface (top 16 cm) and sub-surface (6 m depth) samples using two independent techniques. Origins and pathways bringing microplastic to the Arctic remain unclear. Particle composition (95% fibres) suggests they may either result from the breakdown of larger items (transported over large distances by prevailing currents, or derived from local vessel activity), or input in sewage and wastewater from coastal areas. Concurrent observations of high zooplankton abundance suggest a high probability for marine biota to encounter microplastics and a potential for trophic interactions. Further research is required to understand the effects of microplastic-biota interaction within this productive environment.

  5. Semi-automatic surface sediment sampling system - A prototype to be implemented in bivalve fishing surveys

    Science.gov (United States)

    Rufino, Marta M.; Baptista, Paulo; Pereira, Fábio; Gaspar, Miguel B.

    2018-01-01

    In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data, possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

  6. Concept Study For A Near-term Mars Surface Sample Return Mission

    Science.gov (United States)

    Smith, M. F.; Thatcher, J.; Sallaberger, C.; Reedman, T.; Pillinger, C. T.; Sims, M. R.

    The return of samples from the surface of Mars is a challenging problem. Present mission planning is for complex missions to return large, focused samples sometime in the next decade. There is, however, much scientific merit in returning a small sample of Martian regolith before the end of this decade at a fraction of the cost of the more ambitious missions. This paper sets out the key elements of this concept that builds on the work of the Beagle 2 project and space robotics work in Canada. The paper will expand the science case for returning a regolith sample that is only in the range of 50-250g but would nevertheless include plenty of interesting mate- rial as the regolith comprises soil grains from a wide variety of locations i.e. nearby rocks, sedimentary formations and materials moved by fluids, winds and impacts. It is possible that a fine core sample could also be extracted and returned. The mission concept is to send a lander sized at around 130kg on the 2007 or 2009 opportunity, immediately collect the sample from the surface, launch it to Mars orbit, collect it by the lander parent craft and make an immediate Earth return. Return to Earth orbit is envisaged rather than direct Earth re-entry. The lander concept is essen- tially a twice-size Beagle 2 carrying the sample collection and return capsule loading equipment plus the ascent vehicle. The return capsule is envisaged as no more than 1kg. An overall description of the mission along with methods for sample acquisition, or- bital rendezvous and capsule return will be outlined and the overall systems budgets presented. To demonstrate the near term feasibility of the mission, the use of existing Canadian and European technologies will be highlighted.

  7. TRITIUM UNCERTAINTY ANALYSIS FOR SURFACE WATER SAMPLES AT THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, R.

    2012-07-31

    Radiochemical analyses of surface water samples, in the framework of Environmental Monitoring, have associated uncertainties for the radioisotopic results reported. These uncertainty analyses pertain to the tritium results from surface water samples collected at five locations on the Savannah River near the U.S. Department of Energy's Savannah River Site (SRS). Uncertainties can result from the field-sampling routine, can be incurred during transport due to the physical properties of the sample, from equipment limitations, and from the measurement instrumentation used. The uncertainty reported by the SRS in their Annual Site Environmental Report currently considers only the counting uncertainty in the measurements, which is the standard reporting protocol for radioanalytical chemistry results. The focus of this work is to provide an overview of all uncertainty components associated with SRS tritium measurements, estimate the total uncertainty according to ISO 17025, and to propose additional experiments to verify some of the estimated uncertainties. The main uncertainty components discovered and investigated in this paper are tritium absorption or desorption in the sample container, HTO/H{sub 2}O isotopic effect during distillation, pipette volume, and tritium standard uncertainty. The goal is to quantify these uncertainties and to establish a combined uncertainty in order to increase the scientific depth of the SRS Annual Site Environmental Report.

  8. Experimental Evaluation of the Surface Alteration of Gasket Samples under Operative Conditions

    Directory of Open Access Journals (Sweden)

    M.C. Bignozzi

    2015-12-01

    Full Text Available This paper investigates the surface alteration of gasket samples commercialized by two alternative producers. These gaskets, in polymeric materials, are installed in process plants used for cleaning tires molds by a pioneering ultrasonic process. They are exposed to a combination of ultrasonic waves, temperature, humidity and acid attack causing several erosion phenomena. Their surface degradation under ordinary operative conditions was investigated using mechanical and tribological tests. The experimental characterization was performed by optical microscopy, scanning electron microscopy, thermograms, differential scanning calorimetry curves and infrared spectra aiming at defining the specific mechanics of wearing. As a conclusion, it was possible to state that even if samples exhibit similar chemical structures, their thermal and mechanical properties as well as their geometric dimensions are different. Such differences in the materials might cause various unexpected wear behaviors when gaskets are employed in the same working conditions.


  9. Established and emerging atmospheric pressure surface sampling/ionization techniques for mass spectrometry.

    Science.gov (United States)

    Van Berkel, Gary J; Pasilis, Sofie P; Ovchinnikova, Olga

    2008-09-01

    The number and type of atmospheric pressure techniques suitable for sampling analytes from surfaces, forming ions from these analytes, and subsequently transporting these ions into vacuum for interrogation by MS have rapidly expanded over the last several years. Moreover, the literature in this area is complicated by an explosion in acronyms for these techniques, many of which provide no information relating to the chemical or physical processes involved. In this tutorial article, we sort this vast array of techniques into relatively few categories on the basis of the approaches used for surface sampling and ionization. For each technique, we explain, as best known, many of the underlying principles of operation, describe representative applications, and in some cases, discuss needed research or advancements and attempt to forecast their future analytical utility.

  10. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

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

  11. Variation of surface water spectral response as a function of in situ sampling technique

    Science.gov (United States)

    Davis, Bruce A.; Hodgson, Michael E.

    1988-01-01

    Tests were carried out to determine the spectral variation contributed by a particular sampling technique. A portable radiometer was used to measure the surface water spectral response. Variation due to the reflectance of objects near the radiometer (i.e., the boat side) during data acquisition was studied. Consideration was also given to the variation due to the temporal nature of the phenomena (i.e., wave activity).

  12. Stereochemistry of amino acids in surface samples of a marine sediment

    Science.gov (United States)

    Pollock, G. E.; Kvenvolden, K. A.

    1978-01-01

    In two surface samples of marine sediment, the percentages of D-alanine and D-aspartic acid are significantly higher than the other D-amino acids and are similar to the range found in soils. The percentage of D-glutamic acid is also higher than the other amino acids but less than D-alanine and D-aspartic acid. These D-amino acids may come mainly from bacteria.

  13. Elemental Analyses of Hanford Surface Neutron Moisture Measurement Calibration Standard Samples

    Energy Technology Data Exchange (ETDEWEB)

    Watson, W.T., Westinghouse Hanford

    1996-07-31

    Elemental analyses have been performed on twenty samples taken from the moisture standards prepared to use in performing experimental calibrations of the surface neutron moisture measurement system. These standards consisted of mixtures of sand, hydrated alumina, and boron carbide. Elemental analyses were performed primarily to discover the quantities of any strong thermal neutron absorbers that may have been present in the mixture in unknown trace quantities.

  14. Microbiological Sampling Methods and Sanitation of Edible Plants Grown on ISS

    Science.gov (United States)

    Parrish, Charles H. II; Khodadad, Christina L.; Garland, Nathaniel T.; Larson, Brian D.; Hummreick, Mary E.

    2013-01-01

    Pathogenic microbes on the surfaces of salad crops and growth chambers pose a threat to the health of crew on International Space Station. For astronauts to safely consume spacegrown vegetables produced in NASA's new vegetable production unit, VEGGIE, three technical challenges must be overcome: real-time sampling, microbiological analysis, and sanitation. Raphanus sativus cultivar Cherry Bomb II and Latuca sativa cultivar Outredgeous, two saled crops to be grown in VEGGIE, were inoculated with Salmonella enterica serovar Typhimurium (S. Typhimurium), a bacterium known to cause food-borne illness Tape- and swab-based sampling techniques were optimized for use in microgravity and assessed for effectiveness in recovery of bacteria from crop surfaces: Rapid pathogen detection and molecular analyses were performed via quantitative real-time polymerase chain reactiop using LightCycler® 480 and RAZOR® EX, a scaled-down instrument that is undergoing evaluation and testing for future flight hardware. These methods were compared with conventional, culture-based methods for the recovery of S. Typhimurium colonies. A sterile wipe saturated with a citric acid-based, food-grade sanitizer was applied to two different surface materials used in VEGGIE flight hardware that had been contaminated with the bacterium Pseudomonas aeruginosa,. another known human pathogen. To sanitize surfaces, wipes were saturated with either the sanitizer or sterile deionized water and applied to each surface. Colony forming units of P. aeruginosa grown on tryptic soy agar plates were enumerated from surface samples after sanitization treatments. Depending on the VEGGIE hardware material, 2- to 4.5-log10 reductions in colony-forming units were observed after sanitization. The difference in recovery of S. Typhimurium between tape- and swab- based sampling techniques was insignificant. RAZOR® EX rapidly detected S. Typhimurium present in both raw culture and extracted DNA samples.

  15. Sampling and Low-Rank Tensor Approximation of the Response Surface

    KAUST Repository

    Litvinenko, Alexander

    2013-01-01

    Most (quasi)-Monte Carlo procedures can be seen as computing some integral over an often high-dimensional domain. If the integrand is expensive to evaluate-we are thinking of a stochastic PDE (SPDE) where the coefficients are random fields and the integrand is some functional of the PDE-solution-there is the desire to keep all the samples for possible later computations of similar integrals. This obviously means a lot of data. To keep the storage demands low, and to allow evaluation of the integrand at points which were not sampled, we construct a low-rank tensor approximation of the integrand over the whole integration domain. This can also be viewed as a representation in some problem-dependent basis which allows a sparse representation. What one obtains is sometimes called a "surrogate" or "proxy" model, or a "response surface". This representation is built step by step or sample by sample, and can already be used for each new sample. In case we are sampling a solution of an SPDE, this allows us to reduce the number of necessary samples, namely in case the solution is already well-represented by the low-rank tensor approximation. This can be easily checked by evaluating the residuum of the PDE with the approximate solution. The procedure will be demonstrated in the computation of a compressible transonic Reynolds-averaged Navier-Strokes flow around an airfoil with random/uncertain data. © Springer-Verlag Berlin Heidelberg 2013.

  16. Mass spectrometer-pyrolysis experiment for atmospheric and soil sample analysis on the surface of Mars

    Science.gov (United States)

    Mauersberger, Konrad; Mahaffy, Paul; Niemann, Hasso

    1992-01-01

    Results from the Viking mission will form the foundation for future in-depth investigations of atmosphere-surface interactions on Mars. The two Viking landers carried impressive instrumentation to obtain and analyze soil samples: the sites were observed by cameras, and the collector head was located on a long boom and allowed the collection of large samples at various depths. A selection of grain sizes was possible and a distribution system supplied a number of experiments with soil material. Despite stationary vehicles, a wide sampling field was reachable. The GCMS system, responsible for atmospheric as well as surface soil analysis, worked well on both landers. Atmospheric measurements resulted in the determination of the abundance of noble gases as well as of other molecular species. Isotopic composition measurements included the important ratios of C-13/C-12, N-15/N-14, and Ar-36/Ar-40. To verify these past results and to advance detailed studies of noble gas isotope ratios and minor constituents, better instrument sensitivities, higher precision, and lower background contributions are required in future Mars missions. Soil analysis during the Viking mission concentrated on organic material. Heating cycles were performed to 500 C and only water and carbon dioxide were identified. Higher pyrolysis temperatures are of primary importance to advance our understanding of the mineralogy and gas loading of surface material and atmospheric exchange.

  17. Slanted support window-based stereo matching for surface reconstruction of microscopic samples.

    Science.gov (United States)

    Baghaie, Ahmadreza; Zhang, Chi; Bakhshinejad, Ali; Owen, Heather A; Chao, Hongyang; D'Souza, Roshan M; Yu, Zeyun

    2017-12-01

    This work is to address the limitations of 2D Scanning Electron Microscopy (SEM) micrographs in providing 3D topographical information necessary for various types of analysis in biological and biomedical sciences as well as mechanical and material engineering by investigating modern stereo vision methodologies for 3D surface reconstruction of microscopic samples. To achieve this, micrograph pairs of the microscopic samples are acquired by utilizing an SEM equipped with motor controlled specimen stage capable of precise translational, rotational movements and tilting of the specimen stage. After pre-processing of the micrographs by SIFT feature detection/description followed by RANSAC for matching outlier removal and stereo rectification, a dense stereo matching methodology is utilized which takes advantage of slanted support window formulation for sub-pixel accuracy stereo matching of the input images. This results in a dense disparity map which is used to determine the true depth/elevation of individual surface points. This is a major improvement in comparison to previous matching methodologies which require additional post-processing refinement steps to reduce the negative effects of discrete disparity assignment or the blurring artifacts in near the edge regions. The provided results are great representatives of the superior performance of the slanted support window assumption employed here for surface reconstruction of microscopic samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Automated Mars surface sample return mission concepts for achievement of essential scientific objectives

    Science.gov (United States)

    Weaver, W. L.; Norton, H. N.; Darnell, W. L.

    1975-01-01

    Mission concepts were investigated for automated return to Earth of a Mars surface sample adequate for detailed analyses in scientific laboratories. The minimum sample mass sufficient to meet scientific requirements was determined. Types of materials and supporting measurements for essential analyses are reported. A baseline trajectory profile was selected for its low energy requirements and relatively simple implementation, and trajectory profile design data were developed for 1979 and 1981 launch opportunities. Efficient spacecraft systems were conceived by utilizing existing technology where possible. Systems concepts emphasized the 1979 launch opportunity, and the applicability of results to other opportunities was assessed. It was shown that the baseline missions (return through Mars parking orbit) and some comparison missions (return after sample transfer in Mars orbit) can be accomplished by using a single Titan III E/Centaur as the launch vehicle. All missions investigated can be accomplished by use of Space Shuttle/Centaur vehicles.

  19. In-Situ XRF Measurements in Lunar Surface Exploration Using Apollo Samples as a Standard

    Science.gov (United States)

    Young, Kelsey E.; Evans, C.; Allen, C.; Mosie, A.; Hodges, K. V.

    2011-01-01

    Samples collected during the Apollo lunar surface missions were sampled and returned to Earth by astronauts with varying degrees of geological experience. The technology used in these EVAs, or extravehicular activities, included nothing more advanced than traditional terrestrial field instruments: rock hammer, scoop, claw tool, and sample bags. 40 years after Apollo, technology is being developed that will allow for a high-resolution geochemical map to be created in the field real-time. Handheld x-ray fluorescence (XRF) technology is one such technology. We use handheld XRF to enable a broad in-situ characterization of a geologic site of interest based on fairly rapid techniques that can be implemented by either an astronaut or a robotic explorer. The handheld XRF instrument we used for this study was the Innov-X Systems Delta XRF spectrometer.

  20. Concept study for a low cost near-term Mars surface sample return mission

    Science.gov (United States)

    Draper, C.; Kemble, S.; Parkinson, R.; Smith, M.; Thatcher, J.; Reedman, T.; Sallaberger, C.; Pillinger, C.; Sims, M.

    Man has always had a fascination with the red planet and the quest to reveal its secrets. Although in the past this ques t has been confined to observation from afar and in-situ analysis by dated technology, the chance now exists to extract far more from the Martian surface than ever before - by bringing it home. The idea of a Mars Sample Return mission is not a new phenomenon and plans have been in existence for the last 30 years. The trouble is that these have always been restricted on the grounds of technology, politics and, more predominantly, cost. Many such missions have been estimated at well over 1billion, with huge development times and multiple launches for various mission stages. Plans for direct return missions from the Martian surface had the drawbacks of (a) being too expensive in terms of the launch costs required to lift the propellant needed for return and (b) being too slow if an in-situ resource propellant production technique was used. The alternative solution was to return via a rendezvous in Mars orbit, thus reducing the mass to be transported to and from the Martian surface. The most popular of the orbital rendezvous options involved the launch of a combined Mars Ascent Vehicle/Mars Rover mission to gather samples in readiness for a subsequent return to Earth via a second mission that would deliver an Earth Return Vehicle into Mars orbit with which to transport the samples back. This method had the disadvantages of incurring large costs from the prolonged stay at Mars and high launch costs due to the necessity of two separate launches. The concept of this study is to utilise the orbital rendezvous method but incorporate each of the elements into a single mission (i.e. one launch) using mature and affordable lander technology to return a small regolith core sample. This not only reduces launch and development costs, making the mission more `affordable', but also lowers the risk of mission failure compared to the two-launch method. An

  1. THE SELF-WIPING CO-ROTATING TWIN-SCREW EXTRUDER AS A POLYMERIZATION REACTOR FOR METHACRYLATES

    NARCIS (Netherlands)

    Jongbloed, H.A.; Kiewiet, J.A.; van Dijk, J.H.; Janssen, L.P.B.M.

    1995-01-01

    The self-wiping co-rotating twin-screw extruder was studied as a reactor for two polymerizations in bulk: the homopolymerization of n-butylmethacrylate and the copolymerization of n-butylmethacrylate with 2-hydroxypropylmethacrylate. The influence of the extrusion parameters on the product was

  2. Upgraded Technology for Contingent Stimulation of Mouth Wiping by Two Persons with Drooling and Profound Developmental Disabilities

    Science.gov (United States)

    Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Pichierri, Sabrina; Oliva, Doretta

    2009-01-01

    Many persons with developmental and physical disabilities experience drooling (i.e., loss of saliva from the mouth). Technology was recently developed to help two of these persons reduce the negative effects of drooling by increasing mouth-wiping responses. This study upgraded our initial approach and tested it with the two persons who we…

  3. Experimental estimation of migration and transfer of organic substances from consumer articles to cotton wipes: Evaluation of underlying mechanisms

    NARCIS (Netherlands)

    Clausen, P.A.; Spaan, S.; Brouwer, D.H.; Marquart, H.; Feber, M. le; Engel, R.; Geerts, L.; Jensen, K.A.; Kofoed-Sørensen, V.; Hansen, B.; Brouwere, K. de

    2016-01-01

    The aim of this work was to identify the key mechanisms governing transport of organic chemical substances from consumer articles to cotton wipes. The results were used to establish a mechanistic model to improve assessment of dermal contact exposure. Four types of PVC flooring, 10 types of textiles

  4. Reduction of artifacts in fluorescence correlation spectroscopy due to sample adsorption on optical glass surfaces.

    Science.gov (United States)

    Turner, Daniel K; Wayman, Ashley E; Rolando, Chelsey N; Dande, Prasad; Carter, Phillip W; Remsen, Edward E

    2013-06-01

    The preparation of glass cell surfaces that are chemically functionalized with poly(ethylene glycol) (PEG) chains to reduce sample adsorption and their use in fluorescence correlation spectroscopy (FCS) is described. Optical glass coverslips were acid etched and reacted with either 750 Mr PEG (PEG-750) or 5000 Mr PEG (PEG-5000) to produce adsorption-resistant optical surfaces. FCS data for Nile red-loaded Triton X-100 micelles (NR-TX-100) and Alexa Fluor 555-labeled proteins, bovine serum albumin (BSA-A555), lipidized BSA (lipid-BSA-A555), and three low molecular weight dyes deposited on PEGylated coverslips were evaluated. Measurement artifacts due to sample adsorption on the PEG-5000 functionalized coverslips were reduced significantly for the majority of test materials. Calculations of translational diffusion coefficients and Stokes radii confirmed the effectiveness of this approach. PEG-5000 functionalized coverslips were demonstrated as more effective in inhibiting adsorption than PEG-750 functionalized coverslips. Neither of the functionalized coverslips inhibited the adsorption of one test compound, rhodamine B, a dye that adsorbs strongly on glass surfaces. The use of longer PEG chains in conjunction with chemical cross-linking is proposed for producing a denser, less porous PEG layer for the prevention of strongly glass-adsorbing fluorophores that do not interact with the PEG layer.

  5. Microjetting from grooved surfaces in metallic samples subjected to laser driven shocks

    Science.gov (United States)

    de Rességuier, T.; Lescoute, E.; Sollier, A.; Prudhomme, G.; Mercier, P.

    2014-01-01

    When a shock wave propagating in a solid sample reflects from a free surface, geometrical effects predominantly governed by the roughness and defects of that surface may lead to the ejection of tiny jets that may breakup into high velocity, approximately micrometer-size fragments. This process referred to as microjetting is a major safety issue for engineering applications such as pyrotechnics or armour design. Thus, it has been widely studied both experimentally, under explosive and impact loading, and theoretically. In this paper, microjetting is investigated in the specific loading conditions associated to laser shocks: very short duration of pressure application, very high strain rates, small spatial scales. Material ejection from triangular grooves in the free surface of various metallic samples is studied by combining transverse optical shadowgraphy and time-resolved velocity measurements. The influences of the main parameters (groove angle, shock pressure, nature of the metal) on jet formation and ejection velocity are quantified, and the results are compared to theoretical estimates.

  6. Microjetting from grooved surfaces in metallic samples subjected to laser driven shocks

    Energy Technology Data Exchange (ETDEWEB)

    Rességuier, T. de, E-mail: resseguier@ensma.fr [Institut PPRIME, UPR 3346, CNRS, ENSMA, Université de Poitiers, 1 ave. Clément Ader, 86961 Futuroscope Cedex (France); Lescoute, E.; Sollier, A.; Prudhomme, G.; Mercier, P. [CEA, DAM, DIF, 91297 Arpajon (France)

    2014-01-28

    When a shock wave propagating in a solid sample reflects from a free surface, geometrical effects predominantly governed by the roughness and defects of that surface may lead to the ejection of tiny jets that may breakup into high velocity, approximately micrometer-size fragments. This process referred to as microjetting is a major safety issue for engineering applications such as pyrotechnics or armour design. Thus, it has been widely studied both experimentally, under explosive and impact loading, and theoretically. In this paper, microjetting is investigated in the specific loading conditions associated to laser shocks: very short duration of pressure application, very high strain rates, small spatial scales. Material ejection from triangular grooves in the free surface of various metallic samples is studied by combining transverse optical shadowgraphy and time-resolved velocity measurements. The influences of the main parameters (groove angle, shock pressure, nature of the metal) on jet formation and ejection velocity are quantified, and the results are compared to theoretical estimates.

  7. Nasal photodisinfection and chlorhexidine wipes decrease surgical site infections: a historical control study and propensity analysis.

    Science.gov (United States)

    Bryce, E; Wong, T; Forrester, L; Masri, B; Jeske, D; Barr, K; Errico, S; Roscoe, D

    2014-10-01

    Pre-operative decolonization therapy (DcTx) using chlorhexidine (CHG) body washes and/or intranasal mupirocin can reduce surgical site infections (SSIs), but compliance is often suboptimal. To assess the effectiveness of immediate DcTx using a novel approach of intranasal antimicrobial photodisinfection therapy (PDT) combined with CHG body wipes for the reduction of SSIs. Between 1(st) September 2011 and 31(st) August 2012, 3068 elective cardiac, orthopaedic, spinal, vascular, thoracic and neurosurgical patients were treated with CHG in the 24h preceding surgery, and received intranasal PDT in the pre-operative area. SSI surveillance methodology remained unchanged from previous years and patients were followed for one year. Results were compared with those for a four-year historical control group of 12,387 patients as well as those for a concurrent control group of 206 untreated patients. A significant reduction in the SSI rate was observed between treated patients and the historical control group [1.6% vs 2.7%, P = 0.0004, odds ratio (OR) 1.73, 95% confidence interval (CI) 1.2815-2.3453]. This significant reduction was maintained on intent-to-treat analysis (P = 0.021, OR 1.37, 95% CI 1.0476−1.7854) [corrected]. Overall compliance with DcTx was 94%. A 1:4 propensity score analysis of matched treated and untreated patients demonstrated that DcTx reduced the risk of SSIs significantly (P = 0.00026, z = 3.65). The combination of CHG wipes and PDT immediately before surgery reduced SSIs, achieved excellent compliance, and was easily integrated into the pre-operative routine. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  8. Applications of magnetic surface imprinted materials for solid phase extraction of levofloxacin in serum samples.

    Science.gov (United States)

    Xiao, Deli; Wang, Cuixia; Dai, Hao; Peng, Jun; He, Jia; Zhang, Kai; Kong, Sumei; Qiu, Panzi; He, Hua

    2015-05-01

    In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Asteroid surface impact sampling: dependence of the cavity morphology and collected mass on projectile shape.

    Science.gov (United States)

    Cheng, Bin; Yu, Yang; Baoyin, Hexi

    2017-08-30

    In-situ exploration and remote thermal infrared observation revealed that a large fraction of Solar System small bodies should be covered with granular regolith. The complex and varied geology of the regolith layer may preserve the historical records of the surface modification and topographic evolution experienced by asteroids, especially cratering processes, in which the projectile shape plays a crucial role. Regarding the impact sampling scheme, the projectile-shape dependence of both the cavity morphology and the collected mass remains to be explored. This paper studies the process of the low-speed impact sampling on granular regolith using projectiles of different shapes. The results demonstrate that the projectile shape significantly influences the excavation stage, forming cavities with different morphologies, i.e., cone-shaped, bowl-shaped and U-shaped. We further indicate that the different velocity distributions of the ejecta curtains due to the various projectile shapes result in various amounts of collected mass in sampler canister, regarding which the 60° conical projectile exhibits preferable performance for impact sampling scheme. The results presented in this article are expected to reveal the dependence of the excavation process on projectile shape under micro gravity and provide further information on the optimal designs of impact sampling devices for future sample-return space missions.

  10. Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

    KAUST Repository

    Schrittwieser, Stefan

    2017-06-30

    Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essence.

  11. Fabrication of SERS Active Surface on Polyimide Sample by Excimer Laser Irradiation

    Directory of Open Access Journals (Sweden)

    T. Csizmadia

    2014-01-01

    Full Text Available A possible application of excimer laser irradiation for the preparation of surface enhanced Raman spectroscopy (SERS substrate is demonstrated. A polyimide foil of 125 μm thickness was irradiated by 240 pulses of focused ArF excimer laser beam (λ = 193 nm, FWHM = 20 ns. The applied fluence was varied between 40 and 80 mJ/cm2. After laser processing, the sample was coated with 40 nm silver by PLD in order to create a conducting layer required for the SERS application. The SERS activity of the samples was tested by Raman microscopy. The Raman spectra of Rhodamine 6G aqueous solution (c=10−3 mol/dm3 were collected from the patterned and metalized areas. For areas prepared at 40–60 mJ/cm2 laser fluences, the measured Raman intensities have shown a linear dependence on the applied laser fluence, while above 60 mJ/cm2 saturation was observed. The morphology of the SERS active surface areas was investigated by scanning electron microscopy. Finite element modeling was performed in order to simulate the laser-absorption induced heating of the polyimide foil. The simulation resulted in the temporal and spatial distribution of the estimated temperature in the irradiated polyimide sample, which are important for understanding the structure formation process.

  12. Evaluation of wastewater contaminant transport in surface waters using verified Lagrangian sampling

    Science.gov (United States)

    Antweiler, Ronald C.; Writer, Jeffrey H.; Murphy, Sheila F.

    2014-01-01

    Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. Lagrangian sampling, which in theory samples the same water parcel as it moves downstream (the Lagrangian parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise Lagrangian sampling is difficult, and small deviations – such as missing the Lagrangian parcel by less than 1 h – can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed “verified Lagrangian” sampling, which can be used to determine if the Lagrangian parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the Lagrangian parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2–4 h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we

  13. Quantitative Caffeine Analysis Using a Surface Sampling Probe Electrospray Ionization Tandem Mass Spectrometry System

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Michael J [ORNL; Deibel, Michael A. [Earlham College; Tomkins, Bruce A [ORNL; Van Berkel, Gary J [ORNL

    2005-01-01

    Quantitative determination of caffeine on reversed-phase C8 thin-layer chromatography plates using a surface sampling electrospray ionization system with tandem mass spectrometry detection is reported. The thin-layer chromatography/electrospray tandem mass spectrometry method employed a deuterium-labeled caffeine internal standard and selected reaction monitoring detection. Up to nine parallel caffeine bands on a single plate were sampled in a single surface scanning experiment requiring 35 min at a surface scan rate of 44 {mu}m/s. A reversed-phase HPLC/UV caffeine assay was developed in parallel to assess the mass spectrometry method performance. Limits of detection for the HPLC/UV and thin-layer chromatography/electrospray tandem mass spectrometry methods determined from the calibration curve statistics were 0.20 ng injected (0.50 {mu}L) and 1.0 ng spotted on the plate, respectively. Spike recoveries with standards and real samples ranged between 97 and 106% for both methods. The caffeine content of three diet soft drinks (Diet Coke, Diet Cherry Coke, Diet Pepsi) and three diet sport drinks (Diet Turbo Tea, Speed Stack Grape, Speed Stack Fruit Punch) was measured. The HPLC/UV and mass spectrometry determinations were in general agreement, and these values were consistent with the quoted values for two of the three diet colas. In the case of Diet Cherry Coke and the diet sports drinks, the determined caffeine amounts using both methods were consistently higher (by 8% or more) than the literature values.

  14. Control of the positional relationship between a sample collection instrument and a surface to be analyzed during a sampling procedure using a laser sensor

    Science.gov (United States)

    Van Berkel, Gary J [Clinton, TN; Kertesz, Vilmos [Knoxville, TN

    2012-02-21

    A system and method utilizes distance-measuring equipment including a laser sensor for controlling the collection instrument-to-surface distance during a sample collection process for use, for example, with mass spectrometric detection. The laser sensor is arranged in a fixed positional relationship with the collection instrument, and a signal is generated by way of the laser sensor which corresponds to the actual distance between the laser sensor and the surface. The actual distance between the laser sensor and the surface is compared to a target distance between the laser sensor and the surface when the collection instrument is arranged at a desired distance from the surface for sample collecting purposes, and adjustments are made, if necessary, so that the actual distance approaches the target distance.

  15. Clostridium difficile from food and surface samples in a Belgian nursing home: an unlikely source of contamination.

    Science.gov (United States)

    Rodriguez, C; Korsak, N; Taminiau, B; Avesani, V; Van Broeck, J; Brach, P; Delmée, M; Daube, G

    2015-04-01

    This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested surfaces. These results indicate that food and surfaces are an unlikely source of C. difficile infection in this setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites.

    Science.gov (United States)

    Kurashige, E Jessica Ohashi; Oie, Shigeharu; Furukawa, H

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7-14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4cm×8cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0-255)colony-forming units (cfu)/100cm(2), respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0-1620)cfu/100cm(2), respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary. Copyright © 2016. Published by Elsevier Editora Ltda.

  17. Evaluation of Δ(9) -tetrahydrocannabinol detection using DrugWipe5S(®) screening and oral fluid quantification after Quantisal™ collection for roadside drug detection via a controlled study with chronic cannabis users.

    Science.gov (United States)

    Wille, Sarah M R; Di Fazio, Vincent; Toennes, Stefan W; van Wel, Janelle H P; Ramaekers, Johannes G; Samyn, Nele

    2015-03-01

    Oral fluid (OF) is potentially useful to detect driving under the influence of drugs because of its ease of sampling. While cannabis is the most prevalent drug in Europe, sensitivity issues for Δ(9) -tetrahydrocannabinol (THC) screening and problems during OF collection are observed. The ability of a recently improved OF screening device - the DrugWipe5S(®) , to detect recent THC use in chronic cannabis smokers, was studied. Ten subjects participated in a double-blind placebo-controlled study. The subjects smoked two subsequent doses of THC; 300 µg/kg and 150 µg/kg with a pause of 75 min using a Volcano vapourizer. DrugWipe5S(®) screening and OF collection using the Quantisal™ device were performed at baseline, 5 min after each administration and 80 min after the last inhalation. Blood samples were drawn simultaneously. The screening devices (n = 80) were evaluated visually after 8 min, while the corresponding OF and serum samples were analyzed respectively with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) or gas chromatography-mass spectrometry (GC-MS). Neat OF THC concentrations ranged from 12 361 ng/g 5 min after smoking down to 34 ng/g 80 min later. Under placebo conditions, a median THC concentration of 8 ng/g OF (0-746 ng/g) and < 1 ng/ mL serum (0-7.8 ng/mL) was observed. The DrugWipe5S(®) was positive just after smoking (90%); however, sensitivity rapidly decreased within 1.5 h (50%). Sensitivity of DrugWipe5S(®) should be improved. As chronic cannabis users have high residual THC concentrations in their serum and OF, confirmation cut-offs should be set according to the aim of detecting recent drug use or establishing zero tolerance. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Evaluation of Two Surface Sampling Methods for Microbiological and Chemical Analyses To Assess the Presence of Biofilms in Food Companies.

    Science.gov (United States)

    Maes, Sharon; Huu, Son Nguyen; Heyndrickx, Marc; Weyenberg, Stephanie van; Steenackers, Hans; Verplaetse, Alex; Vackier, Thijs; Sampers, Imca; Raes, Katleen; Reu, Koen De

    2017-12-01

    Biofilms are an important source of contamination in food companies, yet the composition of biofilms in practice is still mostly unknown. The chemical and microbiological characterization of surface samples taken after cleaning and disinfection is very important to distinguish free-living bacteria from the attached bacteria in biofilms. In this study, sampling methods that are potentially useful for both chemical and microbiological analyses of surface samples were evaluated. In the manufacturing facilities of eight Belgian food companies, surfaces were sampled after cleaning and disinfection using two sampling methods: the scraper-flocked swab method and the sponge stick method. Microbiological and chemical analyses were performed on these samples to evaluate the suitability of the sampling methods for the quantification of extracellular polymeric substance components and microorganisms originating from biofilms in these facilities. The scraper-flocked swab method was most suitable for chemical analyses of the samples because the material in these swabs did not interfere with determination of the chemical components. For microbiological enumerations, the sponge stick method was slightly but not significantly more effective than the scraper-flocked swab method. In all but one of the facilities, at least 20% of the sampled surfaces had more than 102 CFU/100 cm2. Proteins were found in 20% of the chemically analyzed surface samples, and carbohydrates and uronic acids were found in 15 and 8% of the samples, respectively. When chemical and microbiological results were combined, 17% of the sampled surfaces were contaminated with both microorganisms and at least one of the analyzed chemical components; thus, these surfaces were characterized as carrying biofilm. Overall, microbiological contamination in the food industry is highly variable by food sector and even within a facility at various sampling points and sampling times.

  19. The Pseudomonas aeruginosa chemotaxis methyltransferase CheR1 impacts on bacterial surface sampling.

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    Full Text Available The characterization of factors contributing to the formation and development of surface-associated bacterial communities known as biofilms has become an area of intense interest since biofilms have a major impact on human health, the environment and industry. Various studies have demonstrated that motility, including swimming, swarming and twitching, seems to play an important role in the surface colonization and establishment of structured biofilms. Thereby, the impact of chemotaxis on biofilm formation has been less intensively studied. Pseudomonas aeruginosa has a very complex chemosensory system with two Che systems implicated in flagella-mediated motility. In this study, we demonstrate that the chemotaxis protein CheR1 is a methyltransferase that binds S-adenosylmethionine and transfers a methyl group from this methyl donor to the chemoreceptor PctA, an activity which can be stimulated by the attractant serine but not by glutamine. We furthermore demonstrate that CheR1 does not only play a role in flagella-mediated chemotaxis but that its activity is essential for the formation and maintenance of bacterial biofilm structures. We propose a model in which motility and chemotaxis impact on initial attachment processes, dispersion and reattachment and increase the efficiency and frequency of surface sampling in P. aeruginosa.

  20. Detection of complex molecular samples by low-cost surface enhanced raman spectroscopy (SERS) substrate

    Science.gov (United States)

    Hou, Hsuan-Chao; Banadaki, Yaser Mohammadi; Sharifi, Safura

    2017-04-01

    Raman scattering is a well-known technique for detecting and identifying complex molecular samples. The weak Raman signals are enormously enhanced in the presence of a nano-patterned metallic surface next to the specimen. This paper reports new techniques to obtain the nanostructures required for Surface Enhanced Raman Scattering (SERS) without costly and sophisticated fabrication steps, which are nanoimprint lithography (NIL), electrochemical deposition, electron beam induced deposition, and focus ion beam (FIB). 20 nm Au thicknesses of sputtered Au were deposited on etched household aluminum foil (base substrate) for vitro application. The Raman signal were caused by the Aluminum pre-etched times. In preliminary results, enhancement factors of 106 times were observed from SERS substrate for in vitro measurements. Moreover, the ability to perform in vivo measurements was demonstrated after removing the base aluminum foil substrate. This application allows Raman signals to be obtained from the surface or interior of opaque specimens. The nano-patterned gold may also be coupled in a probe to a remote spectrometer via an articulated arm. This opens up Raman spectroscopy for use in a clinical environment.

  1. Surface-sampling and analysis of TATP by swabbing and gas chromatography/mass spectrometry.

    Science.gov (United States)

    Romolo, Francesco Saverio; Cassioli, Luigi; Grossi, Silvana; Cinelli, Giuseppe; Russo, Mario Vincenzo

    2013-01-10

    The method of sample recovery for trace detection and identification of explosives plays a critical role in several criminal investigations. After bombing, there can be difficulties in sending big objects to a laboratory for analysis. Traces can also be searched for on large surfaces, on hands of suspects or on surfaces where the explosive was placed during preparatory phases (e.g. places where an IED was assembled, vehicles used for transportation, etc.). In this work, triacetone triperoxide (TATP) was synthesized from commercial precursors following reported methods. Several portions of about 6mg of TATP were then spread on different surfaces (e.g. floors, tables, etc.) or used in handling tests. Three different swabbing systems were used: a commercial swab, pre-wetted with propan-2-ol (isopropanol) and water (7:3), dry paper swabs, and cotton swabs wetted with propan-2-ol. Paper and commercial swabs were also used to sample a metal plate, where a small charge of about 4g of TATP was detonated. Swabs were sealed in small glass jars with screw caps and Parafilm(®) M and sent to the laboratory for analysis. Swabs were extracted and analysed several weeks later by gas chromatography/mass spectrometry. All the three systems gave positive results, but wetted swabs collected higher amounts of TATP. The developed procedure showed its suitability for use in real cases, allowing TATP detection in several simulations, including a situation in which people wash their hands after handling the explosive. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Satisfaction and convenience of using terpenoid-impregnated eyelid wipes and teaching method in people without blepharitis

    Directory of Open Access Journals (Sweden)

    Qiu TY

    2018-01-01

    Full Text Available Tian Yu Qiu,1 Sharon Yeo,2 Louis Tong1–4 1Yong Loo Lin School of Medicine, National University of Singapore, 2Singapore Eye Research Institute, 3Singapore National Eye Centre, 4Duke-NUS Medical School, Singapore Purpose: Demodex infestations cause blepharitis and are difficult to treat. Recently, a new type of eyelid wipes with terpenoids has been found effective. We aim to evaluate patient satisfaction after short-term use and compare two teaching modalities on the techniques of use.Patients and methods: Eligible participants were taught to use eyelid wipes (Cliradex® by either live or online video demonstration based on random allocation. Participants used the wipes twice daily for a week. All participants had prior evaluation of socioeconomic status, dry eye symptoms, and meibomian gland features. After 1 week, competence of use was assessed by participants showing their technique to the investigator, and a questionnaire on comfort, ease, and convenience of use was administered. Higher scores indicate greater satisfaction, and these levels are compared among the two teaching modalities using chi square.Results: A total of 50 participants were recruited, with a mean age of 42±16 years, and 88% of the participants were females. Overall, median comfort level was 4.0 (range: 1–6, ease level was 5.0 (3–6, and convenience level was 5.0 (2–6. Median stinging was 2.0 (1–4, which corresponded to some but mild stinging. The median competence level was 4.0 (2–4, which corresponded to excellent competence. These satisfactory levels (ease, comfort, and convenience experienced were not significantly associated with different socioeconomic indicators, that is, housing type, income, highest education level, and were not different between teaching methods (p>0.05.Conclusion: Short-term use of Cliradex eyelid wipes seems to be acceptable to most people. The teaching instructions before using these wipes were equally effective – whether live or

  3. Data Validation Package October 2016 Groundwater and Surface Water Sampling at the Monticello, Utah, Disposal and Processing Sites January 2017

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Jason [USDOE Office of Legacy Management (LM), Washington, DC (United States); Smith, Fred [Navarro Research and Engineering, Inc., Grand Junction, CO (United States)

    2017-02-01

    Sampling Period: October 10–12, 2016. This semiannual event includes sampling groundwater and surface water at the Monticello Disposal and Processing Sites. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated) and Program Directive MNT-2016-01. Samples were collected from 54 of 64 planned locations (16 of 17 former mill site wells, 15 of 18 downgradient wells, 7 of 9 downgradient permeable reactive barrier wells, 3 of 3 bedrock wells, 4 of 7 seeps and wetlands, and 9 of 10 surface water locations).

  4. Evaluation of surface sampling techniques for collection of Bacillus spores on common drinking water pipe materials.

    Science.gov (United States)

    Packard, Benjamin H; Kupferle, Margaret J

    2010-01-01

    Drinking water utilities may face biological contamination of the distribution system from a natural incident or deliberate contamination. Determining the extent of contamination or the efficacy of decontamination is a challenge, because it may require sampling of the wetted surfaces of distribution infrastructure. This study evaluated two sampling techniques that utilities might use to sample exhumed pipe sections. Polyvinyl chloride (PVC), cement-lined ductile iron, and ductile iron pipe coupons (3 cm x 14 cm) cut from new water main piping were conditioned for three months in dechlorinated Cincinnati, Ohio tap water. Coupons were spiked with Bacillus atrophaeus subsp. globigii, a surrogate for Bacillus anthracis. Brushing and scraping were used to recover the inoculated spores from the coupons. Mean recoveries for all materials ranged from 37 +/- 30% to 43 +/- 20% for brushing vs. 24 +/- 10% to 51 +/- 29% for scraping. On cement-lined pipe, brushing yielded a significantly different recovery than scraping. No differences were seen between brushing and scraping the PVC and iron pipe coupons. Mean brushing and scraping recoveries from PVC coupons were more variable than mean recoveries from cement-lined and iron coupons. Spore retention differed between pipe materials and the presence of established biofilms also had an impact. Conditioned PVC coupons (with established biofilms) had significantly lower spore retention (31 +/- 11%) than conditioned cement-lined coupons (61 +/- 14%) and conditioned iron coupons (71 +/- 8%).

  5. Analysis of microcystins in cyanobacteria blooms and surface water samples from Meiliang Bay, Taihu Lake, China.

    Science.gov (United States)

    Shen, P P; Shi, Q; Hua, Z C; Kong, F X; Wang, Z G; Zhuang, S X; Chen, D C

    2003-08-01

    Taihu Lake is the third largest freshwater lake in China. In recent years, the water pollution of cyanobacteria blooms has become a severe problem in this area. Microcystins (MCs) are an important group of toxic compounds mainly produced by some cyanobacteria species and have both acute and chronic hepatotoxic effects on animals and humans. This paper presents the first data on the identification and detection of MCs in both natural occurring cyanobacteria blooms and surface water samples (0-0.5 m), collected from Meiliang Bay, Taihu Lake, China. A conventional method for extraction and isolation of MCs from cyanobacteria blooms was applied. High-performance liquid chromatography (HPLC) analysis showed that the main toxic component in the cyanobacteria materials was MC-LR. The monoclonal antibody (mAb) against MC-LR produced by hybridoma technique was employed for direct competitive ELISA to detect the concentrations of MCs in bloom and water samples collected in 2001. The results not only revealed the presence of MCs but also temporal variations of MCs levels of three sampling stations in Meiliang Bay in 1 year. It is obvious that the MC contents were relatively higher during warm months and related with the status of eutrophication. Our study indicates the threat associated with MCs in water body of Taihu Lake. To prevent the MCs potential hazard on public health in this area, some necessary measures of monitoring and control of growth of cyanobacteria are urgently needed.

  6. Analysis of Samples Collected from the Surface of Interim Storage Canisters at Calvert Cliffs in June 2017: Revision 01.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schindelholz, Eric John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    In June 2017, dust and salt samples were collected from the surface of Spent Nuclear Fuel (SNF) dry storage canisters at the Calvert Cliffs Nuclear Power Plant. The samples were delivered to Sandia National laboratories for analysis. Two types of samples were collected: filter-backed Scotch-Brite TM pads were used to collect dry dust samples for characterization of salt and dust morphologies and distributions; and Saltsmart TM test strips were used to collect soluble salts for determining salt surface loadings per unit area. After collection, the samples were sealed into plastic sleeves for shipping. Condensation within the sleeves containing the Scotch-Brite TM samples remobilized the salts, rendering them ineffective for the intended purpose, and also led to mold growth, further compromising the samples; for these reasons, the samples were not analyzed. The SaltSmart TM samples were unaffected and were analyzed by ion chromatography for major anions and cations. The results of those analyses are presented here.

  7. Mars Science Laboratory Sample Acquisition, Sample Processing and Handling Subsystem: A Description of the Sampling Functionality of the System after being on the Surface for Two Years.

    Science.gov (United States)

    Beegle, L. W.; Anderson, R. C.; Abbey, W. J.

    2014-12-01

    The Sample Acquisition/Sample Processing and Handling (SA/SPaH) subsystem for the Mars Science Library (MSL) is a rover-based sampling system. SA/SPaH consists of a powdering drill and a scooping, sieving, and portioning device mounted on a turret at the end of a robotic arm. Curiosity rover preformed several sample acquisitions and processing of solid samples during its first year of operation. Material were processed and delivered to the two analytical instruments, Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM), both of which required specific particle size for the material delivered to them to perform their analysis to determine its mineralogy and geochemistry content. In this presentation, the functionality of the system will be explained along with the in-situ targets the system has acquire and the samples that were delivered.

  8. Surface-enhanced Raman scattering detection of silver nanoparticles in environmental and biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Huiyuan [Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003 (United States); Xing, Baoshan, E-mail: bx@umass.edu [Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003 (United States); Hamlet, Leigh C.; Chica, Andrea [Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003 (United States); He, Lili, E-mail: lilihe@foodsci.umass.edu [Department of Food Science, University of Massachusetts, Amherst, MA 01003 (United States)

    2016-06-01

    Growing concerns over the potential release and threat of silver nanoparticles (AgNPs) to environmental and biological systems urge researchers to investigate their fate and behavior. However, current analytical techniques cannot meet the requirements for rapidly, sensitively and reliably probing AgNPs in complex matrices. Surface-enhanced Raman spectroscopy (SERS) has shown great capability for rapid detection of AgNPs based on an indicator molecule that can bind on the AgNP surface. The objective of this study was to exploit SERS to detect AgNPs in environmental and biological samples through optimizing the Raman indicator for SERS. Seven indicator molecules were selected and determined to obtain their SERS signals at optimal concentrations. Among them, 1,2-di(4-pyridyl)ethylene (BPE), crystal violet and ferric dimethyl-dithiocarbamate (ferbam) produced the highest SERS intensities. Further experiments on binding competition between each two of the three candidates showed that ferbam had the highest AgNPs-binding ability. The underlying mechanism lies in the strong binding affinity of ferbam with AgNPs via multiple sulfur atoms. We further validated ferbam to be an effective indicator for SERS detection of as low as 0.1 mg/L AgNPs in genuine surface water and 0.57 mg/L in spinach juice. Moreover, limited interference on SERS detection of AgNPs was found from environmentally relevant inorganic ions, organic matter, inorganic particles, as well as biologically relevant components, demonstrating the ferbam-assisted SERS is an effective and sensitive method to detect AgNPs in complex environmental and biological samples. - Graphical abstract: SERS signal intensity of ferbam indicates the concentration of AgNPs. - Highlights: • Ferbam was found to be the best indicator for SERS detection of AgNPs. • SERS was able to detect AgNPs in both environmental and biological samples. • Major components in the two matrices had limited effect on AgNP detection.

  9. Uncertainty analysis of point-by-point sampling complex surfaces using touch probe CMMs DOE for complex surfaces verification with CMM

    DEFF Research Database (Denmark)

    Barini, Emanuele Modesto; Tosello, Guido; De Chiffre, Leonardo

    2010-01-01

    The paper describes a study concerning point-by-point sampling of complex surfaces using tactile CMMs. A four factor, two level completely randomized factorial experiment was carried out, involving measurements on a complex surface configuration item comprising a sphere, a cylinder and a cone, co...

  10. Geochemical signature of land-based activities in Caribbean coral surface samples

    Science.gov (United States)

    Prouty, N. G.; Hughen, K. A.; Carilli, J.

    2008-12-01

    Anthropogenic threats, such as increased sedimentation, agrochemical run-off, coastal development, tourism, and overfishing, are of great concern to the Mesoamerican Caribbean Reef System (MACR). Trace metals in corals can be used to quantify and monitor the impact of these land-based activities. Surface coral samples from the MACR were investigated for trace metal signatures resulting from relative differences in water quality. Samples were analyzed at three spatial scales (colony, reef, and regional) as part of a hierarchical multi-scale survey. A primary goal of the paper is to elucidate the extrapolation of information between fine-scale variation at the colony or reef scale and broad-scale patterns at the regional scale. Of the 18 metals measured, five yielded statistical differences at the colony and/or reef scale, suggesting fine-scale spatial heterogeneity not conducive to regional interpretation. Five metals yielded a statistical difference at the regional scale with an absence of a statistical difference at either the colony or reef scale. These metals are barium (Ba), manganese (Mn), chromium (Cr), copper (Cu), and antimony (Sb). The most robust geochemical indicators of land-based activities are coral Ba and Mn concentrations, which are elevated in samples from the southern region of the Gulf of Honduras relative to those from the Turneffe Islands. These findings are consistent with the occurrence of the most significant watersheds in the MACR from southern Belize to Honduras, which contribute sediment-laden freshwater to the coastal zone primarily as a result of human alteration to the landscape (e.g., deforestation and agricultural practices). Elevated levels of Cu and Sb were found in samples from Honduras and may be linked to industrial shipping activities where copper-antimony additives are commonly used in antifouling paints. Results from this study strongly demonstrate the impact of terrestrial runoff and anthropogenic activities on coastal water

  11. Double modulation pyrometry: A radiometric method to measure surface temperatures of directly irradiated samples

    Science.gov (United States)

    Potamias, Dimitrios; Alxneit, Ivo; Wokaun, Alexander

    2017-09-01

    The design, implementation, calibration, and assessment of double modulation pyrometry to measure surface temperatures of radiatively heated samples in our 1 kW imaging furnace is presented. The method requires that the intensity of the external radiation can be modulated. This was achieved by a rotating blade mounted parallel to the optical axis of the imaging furnace. Double modulation pyrometry independently measures the external radiation reflected by the sample as well as the sum of thermal and reflected radiation and extracts the thermal emission as the difference of these signals. Thus a two-step calibration is required: First, the relative gains of the measured signals are equalized and then a temperature calibration is performed. For the latter, we transfer the calibration from a calibrated solar blind pyrometer that operates at a different wavelength. We demonstrate that the worst case systematic error associated with this procedure is about 300 K but becomes negligible if a reasonable estimate of the sample's emissivity is used. An analysis of the influence of the uncertainties in the calibration coefficients reveals that one (out of the five) coefficient contributes almost 50% to the final temperature error. On a low emission sample like platinum, the lower detection limit is around 1700 K and the accuracy typically about 20 K. Note that these moderate specifications are specific for the use of double modulation pyrometry at the imaging furnace. It is mainly caused by the difficulty to achieve and maintain good overlap of the hot zone with a diameter of about 3 mm Full Width at Half Height and the measurement spot both of which are of similar size.

  12. Geochemical signature of land-based activities in Caribbean coral surface samples

    Science.gov (United States)

    Prouty, N.G.; Hughen, K.A.; Carilli, J.

    2008-01-01

    Anthropogenic threats, such as increased sedimentation, agrochemical run-off, coastal development, tourism, and overfishing, are of great concern to the Mesoamerican Caribbean Reef System (MACR). Trace metals in corals can be used to quantify and monitor the impact of these land-based activities. Surface coral samples from the MACR were investigated for trace metal signatures resulting from relative differences in water quality. Samples were analyzed at three spatial scales (colony, reef, and regional) as part of a hierarchical multi-scale survey. A primary goal of the paper is to elucidate the extrapolation of information between fine-scale variation at the colony or reef scale and broad-scale patterns at the regional scale. Of the 18 metals measured, five yielded statistical differences at the colony and/or reef scale, suggesting fine-scale spatial heterogeneity not conducive to regional interpretation. Five metals yielded a statistical difference at the regional scale with an absence of a statistical difference at either the colony or reef scale. These metals are barium (Ba), manganese (Mn), chromium (Cr), copper (Cu), and antimony (Sb). The most robust geochemical indicators of land-based activities are coral Ba and Mn concentrations, which are elevated in samples from the southern region of the Gulf of Honduras relative to those from the Turneffe Islands. These findings are consistent with the occurrence of the most significant watersheds in the MACR from southern Belize to Honduras, which contribute sediment-laden freshwater to the coastal zone primarily as a result of human alteration to the landscape (e.g., deforestation and agricultural practices). Elevated levels of Cu and Sb were found in samples from Honduras and may be linked to industrial shipping activities where copper-antimony additives are commonly used in antifouling paints. Results from this study strongly demonstrate the impact of terrestrial runoff and anthropogenic activities on coastal water

  13. Pulmonary lobe segmentation based on ridge surface sampling and shape model fitting.

    Science.gov (United States)

    Ross, James C; Kindlmann, Gordon L; Okajima, Yuka; Hatabu, Hiroto; Díaz, Alejandro A; Silverman, Edwin K; Washko, George R; Dy, Jennifer; San José Estépar, Raúl

    2013-12-01

    Performing lobe-based quantitative analysis of the lung in computed tomography (CT) scans can assist in efforts to better characterize complex diseases such as chronic obstructive pulmonary disease (COPD). While airways and vessels can help to indicate the location of lobe boundaries, segmentations of these structures are not always available, so methods to define the lobes in the absence of these structures are desirable. The authors present a fully automatic lung lobe segmentation algorithm that is effective in volumetric inspiratory and expiratory computed tomography (CT) datasets. The authors rely on ridge surface image features indicating fissure locations and a novel approach to modeling shape variation in the surfaces defining the lobe boundaries. The authors employ a particle system that efficiently samples ridge surfaces in the image domain and provides a set of candidate fissure locations based on the Hessian matrix. Following this, lobe boundary shape models generated from principal component analysis (PCA) are fit to the particles data to discriminate between fissure and nonfissure candidates. The resulting set of particle points are used to fit thin plate spline (TPS) interpolating surfaces to form the final boundaries between the lung lobes. The authors tested algorithm performance on 50 inspiratory and 50 expiratory CT scans taken from the COPDGene study. Results indicate that the authors' algorithm performs comparably to pulmonologist-generated lung lobe segmentations and can produce good results in cases with accessory fissures, incomplete fissures, advanced emphysema, and low dose acquisition protocols. Dice scores indicate that only 29 out of 500 (5.85%) lobes showed Dice scores lower than 0.9. Two different approaches for evaluating lobe boundary surface discrepancies were applied and indicate that algorithm boundary identification is most accurate in the vicinity of fissures detectable on CT. The proposed algorithm is effective for lung lobe

  14. Pulmonary lobe segmentation based on ridge surface sampling and shape model fitting

    Energy Technology Data Exchange (ETDEWEB)

    Ross, James C., E-mail: jross@bwh.harvard.edu [Channing Laboratory, Brigham and Women' s Hospital, Boston, Massachusetts 02215 (United States); Surgical Planning Lab, Brigham and Women' s Hospital, Boston, Massachusetts 02215 (United States); Laboratory of Mathematics in Imaging, Brigham and Women' s Hospital, Boston, Massachusetts 02126 (United States); Kindlmann, Gordon L. [Computer Science Department and Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States); Okajima, Yuka; Hatabu, Hiroto [Department of Radiology, Brigham and Women' s Hospital, Boston, Massachusetts 02215 (United States); Díaz, Alejandro A. [Pulmonary and Critical Care Division, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts 02215 and Department of Pulmonary Diseases, Pontificia Universidad Católica de Chile, Santiago (Chile); Silverman, Edwin K. [Channing Laboratory, Brigham and Women' s Hospital, Boston, Massachusetts 02215 and Pulmonary and Critical Care Division, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts 02215 (United States); Washko, George R. [Pulmonary and Critical Care Division, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts 02215 (United States); Dy, Jennifer [ECE Department, Northeastern University, Boston, Massachusetts 02115 (United States); Estépar, Raúl San José [Department of Radiology, Brigham and Women' s Hospital, Boston, Massachusetts 02215 (United States); Surgical Planning Lab, Brigham and Women' s Hospital, Boston, Massachusetts 02215 (United States); Laboratory of Mathematics in Imaging, Brigham and Women' s Hospital, Boston, Massachusetts 02126 (United States)

    2013-12-15

    Purpose: Performing lobe-based quantitative analysis of the lung in computed tomography (CT) scans can assist in efforts to better characterize complex diseases such as chronic obstructive pulmonary disease (COPD). While airways and vessels can help to indicate the location of lobe boundaries, segmentations of these structures are not always available, so methods to define the lobes in the absence of these structures are desirable. Methods: The authors present a fully automatic lung lobe segmentation algorithm that is effective in volumetric inspiratory and expiratory computed tomography (CT) datasets. The authors rely on ridge surface image features indicating fissure locations and a novel approach to modeling shape variation in the surfaces defining the lobe boundaries. The authors employ a particle system that efficiently samples ridge surfaces in the image domain and provides a set of candidate fissure locations based on the Hessian matrix. Following this, lobe boundary shape models generated from principal component analysis (PCA) are fit to the particles data to discriminate between fissure and nonfissure candidates. The resulting set of particle points are used to fit thin plate spline (TPS) interpolating surfaces to form the final boundaries between the lung lobes. Results: The authors tested algorithm performance on 50 inspiratory and 50 expiratory CT scans taken from the COPDGene study. Results indicate that the authors' algorithm performs comparably to pulmonologist-generated lung lobe segmentations and can produce good results in cases with accessory fissures, incomplete fissures, advanced emphysema, and low dose acquisition protocols. Dice scores indicate that only 29 out of 500 (5.85%) lobes showed Dice scores lower than 0.9. Two different approaches for evaluating lobe boundary surface discrepancies were applied and indicate that algorithm boundary identification is most accurate in the vicinity of fissures detectable on CT. Conclusions: The

  15. 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

  16. Comparison of sampling methods to recover germinated Bacillus anthracis and Bacillus thuringiensis endospores from surface coupons.

    Science.gov (United States)

    Mott, T M; Shoe, J L; Hunter, M; Woodson, A M; Fritts, K A; Klimko, C P; Quirk, A V; Welkos, S L; Cote, C K

    2017-05-01

    In an attempt to devise decontamination methods that are both effective and minimally detrimental to the environment, we evaluated germination induction as an enhancement to strategies for Bacillus anthracis spore decontamination. To determine an optimal method for the recovery of germinating spores from different matrices, it was critical to ensure that the sampling procedures did not negatively impact the viability of the germinating spores possibly confounding the results and downstream analyses of field trial data. Therefore, the two main objectives of this study were the following: (i) development of an effective processing protocol capable of recovering the maximum number of viable germinating or germinated spores from different surface materials; and (ii) using a model system of spore contamination, employ this protocol to evaluate the potential applicability of germination induction to wide-area decontamination of B. anthracis spores. We examined parameters affecting the sampling efficiencies of B. anthracis and the surrogate species Bacillus thuringiensis on nonporous and porous materials. The most efficient extraction from all matrices was observed using PBS with 0·01% Tween 80 extraction buffer. The addition of a sonication and/or extended vortex treatment did not yield significant increases in spore or germinated spore recovery. Our data demonstrate that previous germination-induction experiments performed in suspension can be reproduced when Bacillus spores are deposited onto reference surfaces materials. Our proof of concept experiment illustrated that a germination pretreatment step significantly improves conventional secondary decontamination strategies and remediation plans. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  17. Data Validation Package - April and July 2015 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing Site

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Joshua [Dept. of Energy (DOE), Washington, DC (United States). Office of Legacy Management; Campbell, Sam [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-02-01

    This event included annual sampling of groundwater and surface water locations at the Gunnison, Colorado, Processing Site. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites. Samples were collected from 28 monitoring wells, three domestic wells, and six surface locations in April at the processing site as specified in the 2010 Ground Water Compliance Action Plan for the Gunnison, Colorado, Processing Site. Domestic wells 0476 and 0477 were sampled in July because the homes were unoccupied in April, and the wells were not in use. Duplicate samples were collected from locations 0113, 0248, and 0477. One equipment blank was collected during this sampling event. Water levels were measured at all monitoring wells that were sampled. No issues were identified during the data validation process that requires additional action or follow-up.

  18. A New Instrument to Measure the Surface Resistance of Superconducting Samples at 400 MHz

    CERN Document Server

    Mahner, E; Chiaveri, Enrico; Häbel, E; Tessier, J M

    2003-01-01

    A 400-MHz niobium quadrupole resonator has been manufactured to study the rf properties of superconducting bulk and thin film samples at low temperatures. We describe the apparatus, i.e. the construction of the resonator, field calculations with MAFIA, and the experimental procedure. In first validation tests the surface resistance Rs of a reactor-grade bulk niobium sample as a function of temperature and applied rf field has been investigated by using a calorimetric "rf-dc-compensation" method. A critical temperature Tc = 9.15 ± 0.02 K, a thermal conductivity λ (4.2 K) = 6.9 ± 0.7 W/mK, a residual resistance Rres = 19.0 ± 0.3 nΩ and a superconducting energy gap of ∆/kBTc = 1.82 ± 0.01 have been measured. At 4.2 K we achieved a calorimetric detection limit for Rs of 0.16 nΩ at a peak field of 25 mT.

  19. Manual Surface Feature Classification and Error Analysis for NASA's OSIRIS-Rex Asteroid Sample Return Mission Using QGIS

    Science.gov (United States)

    Westermann, M. M.

    2017-06-01

    Error mitigation for manual detection and classification of hazardous surface features for NASA's OSIRIS-REx asteroid sample return mission can be accomplished through the use of open-source GIS and standard land-cover change analysis methods.

  20. Textural description of surface sediment samples collected in August 2015 from Dauphin Island and the surrounding areas

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center collected 303 surface sediment samples from Dauphin Island, Alabama, and...

  1. A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions.

    Science.gov (United States)

    Marquardt, Christian; Paulheim, Alexander; Rohbohm, Nils; Merkel, Rudolf; Sokolowski, Moritz

    2017-08-01

    We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it. The homemade sample mounting was made compatible for the use under the microscope; sample temperatures as low as 6 K can be achieved. The performance of the microscope is demonstrated on two model samples: Brightfield-images of a well-prepared Ag(100) surface show a macroscopic corrugation of the surface, although low energy electron diffraction data indicate a highly ordered crystalline surface. The surface shows macroscopic protrusions with flat regions, about 20-200 μm in diameter, in between. Fluorescence images of diluted 3,4,9,10-perylene tetracarboxylicacid dianhydride (PTCDA) molecules adsorbed on an ultrathin epitaxial KCl film on the Ag(100) surface show a shading effect at surface protrusions due to an inclined angle of incidence of the PTCDA beam during deposition. For some preparations, the distribution of the fluorescence intensity is inhomogeneous and shows a dense network of bright patches about 5 μm in diameter related to the macroscopic corrugation of the surface. We propose that such a light microscope can aid many surface science experiments, especially those dealing with epitaxial growth or fluorescent materials.

  2. Nanoparticles in natural systems I: The effective reactive surface area of the natural oxide fraction in field samples.

    NARCIS (Netherlands)

    Hiemstra, T.; Antelo, J.; Rahnemaie, R.; Riemsdijk, van W.H.

    2010-01-01

    Information on the particle size and reactive surface area of natural samples is essential for the application of surface complexation models (SCM) to predict bioavailability, toxicity, and transport of elements in the natural environment. In addition, this information will be of great help to

  3. Analysis of surface chemistry of boronized TZM samples in NSTX-U between plasma exposures

    Science.gov (United States)

    Schamis, Hanna; Bedoya, Felipe; Allain, Jean Paul; Kaita, Robert; Koel, Bruce

    2016-10-01

    In the National Spherical Torus Experiment Upgrade (NSTX-U) a new plasma facing component diagnostic, the Material Analysis and Particle Probe (MAPP), was installed. MAPP has the capability of conducting XPS studies on materials without exposing them to atmospheric conditions. MAPP was used to conduct XPS studies of TZM (99% Mo, 0.5% Ti, 0.08% Zr) samples. XPS gives information about the chemical composition of up to about 5 nm of the surface, and can be conducted on a day-to-day basis or at higher temporal resolutions e.g. close to in-between plasma shots. MAPP characterization gives insight on boron deposition and fuel retention by following the evolution of atomic concentrations and oxidation states. The data shows that the boron deposited layer was thicker than 5 nm. Additionally, the data shows evidence of sputtering of the boron layers following tens of plasma shots. The data also shows an increase in the oxygen concentration with plasma exposure. The next NSTX-U experimental campaign will feature TZM tiles in the lower divertor region, while the rest of the first wall will continue to be ATJ graphite. Our data provides the basis to analyze how the surface chemistry of the new set of tiles will be influenced by plasma operations, boron conditioning and carbon migration. Work supported by US DOE Contract No. DE-AC02-09CH11466, US DOE Contract No. DE-SC0010717, Award No. DE-SC0012890, and the DOE Science Undergraduate Laboratory Internship (SULI) Program.

  4. Geochemical Signature of Land-based Activities in Caribbean Coral Surface Samples

    Science.gov (United States)

    Prouty, N. G.; Hughen, K.; Carilli, J.

    2007-12-01

    Anthropogenic threats to the Mesoamerican Caribbean Reef Ecoregion, resulting from increased sedimentation, agrochemical run-off, coastal development, tourism and overfishing, are of great concern for future coral reef health and sustainability. Abundances of trace metal in corals can be used to monitor and identify the impact of land-based activities on the reef itself. In this study we demonstrate that surface coral samples from four sites in the Mesoamerican Caribbean Reef Ecoregion, Turneffe Atoll, Sapodilla Cayes and Honduras Bay Islands (Utila and Cayos Cochinos), yield statistically different chemical signatures due to their water quality and relative distance from pollution sources. Specifically, samples from the Sapodilla Cayes and the Bay Islands of Honduras yield elevated Ba/Ca and Mn/Ca levels, indicative of greater exposure to sediment-laden runoff form the south. In a similar manner, elevated coral Pb/Ca and Zn/Ca, and Sb/Ca and Cu/Ca values can be linked to mining activities and the use of antifouling paints, respectively. In addition, site heterogeneity was investigated by analyzing replicate cores at a single site from different colonies. We show that regional variability within the Sapodilla Cayes Marine Reserve can be explained by relative location and orientation within the reef and distance from the continental shelf. Our results indicate good reproducibility for the majority of trace metals investigated (not including Sr/Ca or Mg/Ca), suggesting that local environmental changes such as seawater chemistry, and not climate, is the dominant influence on the metal/Ca ratios.

  5. Applications of Raman and Surface-Enhanced Raman Scattering to the Analysis of Eukaryotic Samples

    Science.gov (United States)

    Schulte, Franziska; Joseph, Virginia; Panne, Ulrich; Kneipp, Janina

    In this chapter, we discuss Raman scattering and surface-enhanced Raman scattering (SERS) for the analysis of cellular samples of plant and animal origin which are several tens to hundreds of microns in size. As was shown in the past several years, the favorable properties of noble metal nanostructures can be used to generate SERS signals in very complex biological samples such as cells, and result in an improved sensitivity and spatial resolution. Pollen grains, the physiological containers that produce the male gametes of seed plants, consist of a few vegetative cells and one generative cell, surrounded by a biopolymer shell. Their chemical composition has been a subject of research of plant physiologists, biochemists [1, 2], and lately even materials scientists [3, 4] for various reasons. In spite of a multitude of applied analytical approaches it could not be elucidated in its entirety yet. Animal cells from cell cultures have been a subject of intense studies due to their application in virtually all fields of biomedical research, ranging from studies of basic biological mechanisms to models for pharmaceutical and diagnostic research. Many aspects of all kinds of cellular processes including signalling, transport, and gene regulation have been elucidated, but many more facts about cell biology will need to be understood in order to efficiently address issues such as cancer, viral infection or genetic disorder. Using the information from spectroscopic methods, in particular combining normal Raman spectroscopy and SERS may open up new perspectives on cellular biochemistry. New sensitive Raman-based tools are being developed for the biochemical analysis of cellular processes [5-8].

  6. STUDY OF DEPENDENCE OF POLYETHYLENE AND CARBON FIBERS COMPOSITES PROPERNIES ON SURFACE CHARACTERISTICS OF FIBER AND TYPE OF SAMPLES

    OpenAIRE

    Petukhova E. S.

    2015-01-01

    PE2NT11 and chopped carbon fibers and PE2NT11 and modified carbon fibers composites were investigated. It was shown that the mechanical properties depend on the surface characteristics of fibers. It was found that laboratory and tube samples have some difference in mechanical properties that connected with specific distribution of fibers in samples

  7. Sampling the conformation of protein surface residues for flexible protein docking

    Directory of Open Access Journals (Sweden)

    Amenta Nina

    2010-11-01

    Full Text Available Abstract Background The problem of determining the physical conformation of a protein dimer, given the structures of the two interacting proteins in their unbound state, is a difficult one. The location of the docking interface is determined largely by geometric complementarity, but finding complementary geometry is complicated by the flexibility of the backbone and side-chains of both proteins. We seek to generate candidates for docking that approximate the bound state well, even in cases where there is backbone and/or side-chain difference from unbound to bound states. Results We divide the surfaces of each protein into local patches and describe the effect of side-chain flexibility on each patch by sampling the space of conformations of its side-chains. Likely positions of individual side-chains are given by a rotamer library; this library is used to derive a sample of possible mutual conformations within the patch. We enforce broad coverage of torsion space. We control the size of the sample by using energy criteria to eliminate unlikely configurations, and by clustering similar configurations, resulting in 50 candidates for a patch, a manageable number for docking. Conclusions Using a database of protein dimers for which the bound and unbound structures of the monomers are known, we show that from the unbound patch we are able to generate candidates for docking that approximate the bound structure. In patches where backbone change is small (within 1 Å RMSD of bound, we are able to account for flexibility and generate candidates that are good approximations of the bound state (82% are within 1 Å and 98% are within 1.4 Å RMSD of the bound conformation. We also find that even in cases of moderate backbone flexibility our candidates are able to capture some of the overall shape change. Overall, in 650 of 700 test patches we produce a candidate that is either within 1 Å RMSD of the bound conformation or is closer to the bound state than the

  8. The apparent effect of sample surface damage on the dielectric parameters of GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, J.A.A. [Physics Department, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)], E-mail: Japie.Engelbrecht@nmmu.ac.za; Hashe, N.G. [Physics Department, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Hillie, K.T. [CSIR-NML Laboratory, P.O. Box 395, Pretoria 0001 (South Africa); Claassens, C.H. [Physics Department, University of the Free State, Bloemfontein 9300 (South Africa)

    2007-12-15

    The dielectric and optical parameters determined by infrared reflectance spectroscopy and computer simulation of a set of GaAs substrates of various surface topologies are reported. The influence of surface damage on the parameters is noted.

  9. Cleaning and materials compatibility test results for elimination of flammable solvents in wipe applications.

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Edwin Paul

    2005-06-01

    In recent years, efforts have been made within the nuclear weapons complex (National Nuclear Security Administration) of the Department of Energy (DOE) to replace Resource Conservation and Recovery Act (RCRA) regulated solvents (i.e., flammable, toxic, corrosive, and reactive) and ozone-depleting chemicals (ODC) with more benign alternatives. Within the National Nuclear Security Administration (NNSA) and the Department of Defense (DoD) sectors, these solvents are used for cleaning hardware during routine maintenance operations. A primary goal of this study is to replace flammable solvents used in wiping applications. Two cleaners, including a hydrofluoroether (HFE) and an azeotrope of the HFE and isopropyl alcohol (IPA), have been studied as potential replacements for flammable solvents. Cleaning efficacy, short-term and long-term materials compatibility, corrosion, drying times, flammability, environment, safety and health (ES&H) and accelerated aging issues were among the experiments used to screen candidate solvents by the interagency team performing this work. This report presents cleaning efficacy results as determined by the contact angle Goniometer as well as materials compatibility results of various metal alloys and polymers. The results indicate that IPA (baseline cleaner) and the HFE/IPA azeotrope are roughly equivalent in their ability to remove fluorinated grease, silicone grease, and a simulated finger print contaminant from various metal alloys. All of the ASTM sandwich and immersion corrosion tests with IPA, HFE or the HFE/IPA azeotrope on metal alloys showed no signs of corrosion. Furthermore, no deleterious effects were noted for polymeric materials immersed in IPA, HFE, or the HFE/IPA azeotrope.

  10. Antibacterial activity of marine culturable bacteria collected from a global sampling of ocean surface waters and surface swabs of marine organisms

    DEFF Research Database (Denmark)

    Gram, Lone; Melchiorsen, Jette; Bruhn, Jesper Bartholin

    2010-01-01

    The purpose of the present study was to isolate marine culturable bacteria with antibacterial activity and hence a potential biotechnological use. Seawater samples (244) and 309 swab samples from biotic or abiotic surfaces were collected on a global Danish marine research expedition (Galathea 3......). Total cell counts at the seawater surface were 5 × 105 to 106 cells/ml, of which 0.1–0.2% were culturable on dilute marine agar (20°C). Three percent of the colonies cultured from seawater inhibited Vibrio anguillarum, whereas a significantly higher proportion (13%) of colonies from inert or biotic...

  11. Time-Efficiency of Sorting Chironomidae Surface-Floating Pupal Exuviae Samples from Urban Trout Streams in Northeast Minnesota, USA

    Directory of Open Access Journals (Sweden)

    Alyssa M Anderson

    2012-10-01

    Full Text Available Collections of Chironomidae surface-floating pupal exuviae (SFPE provide an effective means of assessing water quality in streams. Although not widely used in the United States, the technique is not new and has been shown to be more cost-efficient than traditional dip-net sampling techniques in organically enriched stream in an urban landscape. The intent of this research was to document the efficiency of sorting SFPE samples relative to dip-net samples in trout streams with catchments varying in amount of urbanization and differences in impervious surface. Samples of both SFPE and dip-nets were collected from 17 sample sites located on 12 trout streams in Duluth, MN, USA. We quantified time needed to sort subsamples of 100 macroinvertebrates from dip-net samples, and less than or greater than 100 chironomid exuviae from SFPE samples. For larger samples of SFPE, the time required to subsample up to 300 exuviae was also recorded. The average time to sort subsamples of 100 specimens was 22.5 minutes for SFPE samples, compared to 32.7 minutes for 100 macroinvertebrates in dip-net samples. Average time to sort up to 300 exuviae was 37.7 minutes. These results indicate that sorting SFPE samples is more time-efficient than traditional dip-net techniques in trout streams with varying catchment characteristics.doi: 10.5324/fn.v31i0.1380.Published online: 17 October 2012.

  12. Data Validation Package April 2016 Groundwater and Surface Water Sampling at the Monticello, Utah, Disposal and Processing Sites August 2016

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Jason [USDOE Office of Legacy Management, Washington, DC (United States); Smith, Fred [Navarro Research and Engineering, Oak Ridge, TN (United States)

    2016-08-01

    This semiannual event includes sampling groundwater and surface water at the Monticello Disposal and Processing Sites. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated) and Program Directive MNT-2016-01. Complete sample sets were collected from 42 of 48 planned locations (9 of 9 former mill site wells, 13 of 13 downgradient wells, 7 of 9 downgradient permeable reactive barrier wells, 4 of 7 seeps and wetlands, and 9 of 10 surface water locations). Planned monitoring locations are shown in Attachment 1, Sampling and Analysis Work Order. Locations R6-M3, SW00-01, Seep 1, Seep 2, and Seep 5 were not sampled due to insufficient water availability. A partial sample was collected at location R4-M3 due to insufficient water. All samples from the permeable reactive barrier wells were filtered as specified in the program directive. Duplicate samples were collected from surface water location Sorenson and from monitoring wells 92-07 and RlO-Ml. Water levels were measured at all sampled wells and an additional set of wells. See Attachment2, Trip Report for additional details. The contaminants of concern (COCs) for the Monticello sites are arsenic, manganese, molybdenum, nitrate+ nitrite as nitrogen (nitrate+ nitrite as N), selenium, uranium, and vanadium. Locations with COCs that exceeded remediation goals are listed in Table 1 and Table 2. Time-concentration graphs of the COCs for all groundwater and surface water locations are included in Attachment 3, Data Presentation. An assessment of anomalous data is included in Attachment 4.

  13. Adaptation of G-TAG Software for Validating Touch-and-Go Comet Surface Sampling Design Methodology

    Science.gov (United States)

    Mandic, Milan; Acikmese, Behcet; Blackmore, Lars

    2011-01-01

    The G-TAG software tool was developed under the R&TD on Integrated Autonomous Guidance, Navigation, and Control for Comet Sample Return, and represents a novel, multi-body dynamics simulation software tool for studying TAG sampling. The G-TAG multi-body simulation tool provides a simulation environment in which a Touch-and-Go (TAG) sampling event can be extensively tested. TAG sampling requires the spacecraft to descend to the surface, contact the surface with a sampling collection device, and then to ascend to a safe altitude. The TAG event lasts only a few seconds but is mission-critical with potentially high risk. Consequently, there is a need for the TAG event to be well characterized and studied by simulation and analysis in order for the proposal teams to converge on a reliable spacecraft design. This adaptation of the G-TAG tool was developed to support the Comet Odyssey proposal effort, and is specifically focused to address comet sample return missions. In this application, the spacecraft descends to and samples from the surface of a comet. Performance of the spacecraft during TAG is assessed based on survivability and sample collection performance. For the adaptation of the G-TAG simulation tool to comet scenarios, models are developed that accurately describe the properties of the spacecraft, approach trajectories, and descent velocities, as well as the models of the external forces and torques acting on the spacecraft. The adapted models of the spacecraft, descent profiles, and external sampling forces/torques were more sophisticated and customized for comets than those available in the basic G-TAG simulation tool. Scenarios implemented include the study of variations in requirements, spacecraft design (size, locations, etc. of the spacecraft components), and the environment (surface properties, slope, disturbances, etc.). The simulations, along with their visual representations using G-View, contributed to the Comet Odyssey New Frontiers proposal

  14. Data Validation Package October 2015 Groundwater and Surface Water Sampling at the Monticello, Utah, Processing Site January 2016

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Jason [U.S. Dept. of Energy, Washington, DC (United States). Office of Legacy Management; Smith, Fred [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-01-21

    Sampling Period: October 12–14, 2015. This semiannual event includes sampling groundwater and surface water at the Monticello Mill Tailings Site. Sampling and analyses were conducted as specified in the 2004 Monticello Mill Tailings Site Operable Unit III Post-Record of Decision Monitoring Plan, Draft Final and Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). Samples were collected from 52 of 61 planned locations (15 of 17 former mill site wells, 17 of 18 downgradient wells, 9 of 9 downgradient permeable reactive barrier wells, 2 of 7 seeps and wetlands, and 9 of 10 surface water locations). Locations MW00-07, Seep 1, Seep 2, Seep 3, Seep 5, Seep 6, SW00-01, T01-13, and T01-19 were not sampled because of insufficient water availability. All samples were filtered as specified in the monitoring plan. Duplicate samples were collected from surface water location W3-04 and from monitoring wells 82-08, 92-09, and 92-10. Water levels were measured at all but one sampled well and an additional set of wells. The contaminants of concern (COCs) for the Monticello Mill Tailings Site are arsenic, manganese, molybdenum, nitrate + nitrite as nitrogen (nitrate + nitrite as N), selenium, uranium, and vanadium. Time-concentration graphs of the COCs for all groundwater and surface water locations are included in this report. Locations with COCs that exceeded remediation goals are listed.

  15. Data Validation Package - June 2016 Groundwater and Surface Water Sampling at the Green River, Utah, Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Joshua [USDOE Office of Legacy Management, Washington, DC (United States); Price, Jeffrey [Navarro Research and Engineering, Inc., Las Vegas, NV (United States)

    2016-10-10

    This event included annual sampling of groundwater and surface water locations at the Green River, Utah, Disposal Site. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for US. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated, http://energy.gov/lrnldownloads/sampling-and- analysis-plan-us-department-energy-office-legacy-management-sites). Samples were collected from 15 monitoring wells and two surface locations at the disposal site as specified in the draft 2011 Ground Water Compliance Action Plan for the Green River, Utah, Disposal Site. Planned monitoring locations are shown in Attachment 1, Sampling and Analysis Work Order. A duplicate sample was collected from location 0179. One equipment blank was collected during this sampling event. Water levels were measured at all monitoring wells that were sampled. See Attachment 2, Trip Reports for additional details. The analytical data and associated qualifiers can be viewed in environmental database reports and are also available for viewing with dynamic mapping via the GEMS (Geospatial Environmental Mapping System) website at http://gems.lm.doe.gov/#. No issues were identified during the data validation process that requires additional action or follow-up.

  16. April 2012 Groundwater and Surface Water Sampling at the Salmon, Mississippi, Site (Data Validation Package)

    Energy Technology Data Exchange (ETDEWEB)

    Duray, Jack [S.M. Stoller Corporation, Broomfield, CO (United States)

    2012-10-12

    Sampling and analysis were conducted on April 16-19, 2012, as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office Of Legacy Management Sites (LMS/PLN/S04351, continually updated). Duplicate samples were collected from locations SA1-1-H, HMH-5R, SA3-4-H, SA1-2-H, Pond W of GZ, and SA5-4-4. One trip blank was collected during this sampling event.

  17. Uncertainty analysis of point by point sampling complex surfaces using touch probe CMMs

    DEFF Research Database (Denmark)

    Barini, Emanuele; Tosello, Guido; De Chiffre, Leonardo

    2007-01-01

    The paper describes a study concerning point by point scanning of complex surfaces using tactile CMMs. A four factors-two level full factorial experiment was carried out, involving measurements on a complex surface configuration item comprising a sphere, a cylinder and a cone, combined in a singl...

  18. Data Validation Package, December 2015, Groundwater and Surface Water Sampling at the Monument Valley, Arizona, Processing Site March 2016

    Energy Technology Data Exchange (ETDEWEB)

    Tyrrell, Evan [Navarro Research and Engineering, Inc., Oak Ridge, NV (United States); Denny, Angelita [USDOE Office of Legacy Management, Washington, DC (United States)

    2016-03-23

    Fifty-two groundwater samples and one surface water sample were collected at the Monument Valley, Arizona, Processing Site to monitor groundwater contaminants for evaluating the effectiveness of the proposed compliance strategy as specified in the 1999 Final Site Observational Work Plan for the UMTRA Project Site at Monument Valley, Arizona. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated, http://energy.gov/lm/downloads/sampling-and-analysis-plan-us-department- energy-office-legacy-management-sites). Samples were collected for metals, anions, nitrate + nitrite as N, and ammonia as N analyses at all locations.

  19. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for In-Situ Mars Surface Sample Analysis

    Science.gov (United States)

    Edmunson, J.; Gaskin, J. A.; Jerman, G. A.; Harvey, R. P.; Doloboff, I. J.; Neidholdt, E. L.

    2016-01-01

    The Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Sciences (ROSES), will build upon previous miniaturized SEM designs and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. This project is a collaboration between NASA Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), electron gun and optics manufacturer Applied Physics Technologies, and small vacuum system manufacturer Creare. Dr. Ralph Harvery and environmental SEM (ESEM) inventor Dr. Gerry Danilatos serve as advisors to the team. Variable pressure SEMs allow for fine (nm-scale) resolution imaging and micron-scale chemical study of materials without sample preparation (e.g., carbon or gold coating). Charging of a sample is reduced or eliminated by the gas surrounding the sample. It is this property of ESEMs that make them ideal for locations where sample preparation is not yet feasible, such as the surface of Mars. In addition, the lack of sample preparation needed here will simplify the sample acquisition process and allow caching of the samples for future complementary payload use.

  20. Velvet pad surface sampling of anaerobic and aerobic bacteria: an in vitro laboratory model.

    OpenAIRE

    Raahave, D; Friis-Møller, A

    1982-01-01

    Velvet pads have been evaluated in an experimental, laboratory model, simulating intraoperative sampling of Staphylococcus epidermis, Escherichia coli and Bacteroides fragilis. After sampling, the pad was placed in a transport medium and kept in an anaerobic atmosphere, before being shaken and rinsed, followed by anaerobic and aerobic culture. This technique permitted quantitatively high recoveries of the test bacteria. Velvet pad sampling could be a measure to determine the density of aerobi...

  1. Global structure search for molecules on surfaces: Efficient sampling with curvilinear coordinates

    Science.gov (United States)

    Krautgasser, Konstantin; Panosetti, Chiara; Palagin, Dennis; Reuter, Karsten; Maurer, Reinhard J.

    2016-08-01

    Efficient structure search is a major challenge in computational materials science. We present a modification of the basin hopping global geometry optimization approach that uses a curvilinear coordinate system to describe global trial moves. This approach has recently been shown to be efficient in structure determination of clusters [C. Panosetti et al., Nano Lett. 15, 8044-8048 (2015)] and is here extended for its application to covalent, complex molecules and large adsorbates on surfaces. The employed automatically constructed delocalized internal coordinates are similar to molecular vibrations, which enhances the generation of chemically meaningful trial structures. By introducing flexible constraints and local translation and rotation of independent geometrical subunits, we enable the use of this method for molecules adsorbed on surfaces and interfaces. For two test systems, trans-β-ionylideneacetic acid adsorbed on a Au(111) surface and methane adsorbed on a Ag(111) surface, we obtain superior performance of the method compared to standard optimization moves based on Cartesian coordinates.

  2. Antibiotic resistance patterns of Escherichia coli strains isolated from surface water and groundwater samples in a pig production area

    Directory of Open Access Journals (Sweden)

    Roger Neto Schneider

    2009-09-01

    Full Text Available The use of antibiotics, so excessive and indiscriminate in intensive animal production, has triggered an increase in the number of resistant microorganisms which can be transported to aquatic environments. The aim of this study was to determine the profile of the antimicrobial resistance of samples of Escherichia coli isolated from groundwater and surface water in a region of pig breeding. Through the test of antimicrobial susceptibility, we analyzed 205 strains of E. coli. A high rate of resistance to cefaclor was observed, both in surface water (51.9% and groundwater (62.9%, while all samples were sensitive to amikacin. The percentages of multi-resistant samples were 25.96% and 26.73% in surface water and groundwater, respectively, while 19.23% and 13.86% were sensitive to all antibiotics tested. It was determined that the rate of multiple antibiotic resistance (MAR was 0.164 for surface water and 0.184 for groundwater. No significant differences were found in the profile of the antimicrobial resistance in strains of E. coli isolated in surface water and groundwater, but the index MAR calculated in certain points of groundwater may offer a potential risk of transmission of resistant genes.

  3. An improved thin-layer chromatography/mass spectrometry coupling using a surface sampling probe electrospray ion trap system

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Michael J [ORNL; Van Berkel, Gary J [ORNL

    2004-01-01

    A combined surface sampling probe/electrospray emitter coupled with an ion trap mass spectrometer was used for the direct read out of unmodified reversed-phase C18 thin-layer chromatography (TLC) plates. The operation of the surface sampling electrospray ionization interface in positive and negative ionization modes was demonstrated through the direct analysis of TLC plates on which a commercial test mix comprised of four dye compounds viz., rhodamine B, fluorescein, naphthol blue black, and fast green FCF, and an extract of the caffeine-containing plant Ilex vomitoria, were spotted and developed. Acquisition of full-scan mass spectra and automated collection of MS/MS product ion spectra while scanning a development lane along the surface of a TLC plate demonstrated the advantages of using an ion trap in this combination. Details of the sampling system, benefits of analyzing a developed lane in both positive ion and negative ion modes, levels of detection while surface scanning, surface scan speed effects, and the utility of three-dimensional data display, are also discussed.

  4. Using Paraffin PCM, Cryogel and TEC to Maintain Comet Surface Sample Cold from Earth Approach Through Retrieval

    Science.gov (United States)

    Choi, Michael K.

    2017-01-01

    An innovative thermal design concept to maintain comet surface samples cold (for example, 263 degrees Kelvin, 243 degrees Kelvin or 223 degrees Kelvin) from Earth approach through retrieval is presented. It uses paraffin phase change material (PCM), Cryogel insulation and thermoelectric cooler (TEC), which are commercially available.

  5. Robotic Arm Manipulator Using Active Control for Sample Acquisition and Transfer, and Passive Mode for Surface Compliance

    Science.gov (United States)

    Liu, Jun; Underhill, Michael L.; Trease, Brian P.; Lindemann, Randel A.

    2010-01-01

    A robotic arm that consists of three joints with four degrees of freedom (DOF) has been developed. It can carry an end-effector to acquire and transfer samples by using active control and comply with surface topology in a passive mode during a brief surface contact. The three joints are arranged in such a way that one joint of two DOFs is located at the shoulder, one joint of one DOF is located at the elbow, and one joint of one DOF is located at the wrist. Operationally, three DOFs are moved in the same plane, and the remaining one on the shoulder is moved perpendicular to the other three for better compliance with ground surface and more flexibility of sample handling. Three out of four joints are backdriveable, making the mechanism less complex and more cost effective

  6. Self-Aspirated Atmospheric Pressure Chemical Ionization Source for Direct Sampling of Analytes on Surfaces and in Liquid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Keiji G [ORNL; Ford, Michael J [ORNL; Tomkins, Bruce A [ORNL; Van Berkel, Gary J [ORNL

    2005-01-01

    A self-aspirating heated nebulizer probe is described and demonstrated for use in the direct analysis of analytes on surfaces and in liquid samples by atmospheric pressure chemical ionization (APCI) mass spectrometry. Functionality and performance of the probe as a self-aspirating APCI source is demonstrated using reserpine and progesterone as test compounds. The utility of the probe to sample analytes directly from surfaces was demonstrated first by scanning development lanes of a reversed-phase thin-layer chromatography plate in which a three-component dye mixture, viz., Fat Red 7B, Solvent Green 3, and Solvent Blue 35, was spotted and the components were separated. Development lanes were scanned by the sampling probe operated under computer control (x, y plane) while full-scan mass spectra were recorded using a quadrupole ion trap mass spectrometer. In addition, the ability to sample the surface of pharmaceutical tablets (viz., Extra Strength Tylenol(reg. sign) and Evista(reg. sign) tablets) and to detect the active ingredients (acetaminophen and raloxifene, respectively) selectively was demonstrated using tandem mass spectrometry (MS/MS). Finally, the capability to sample analyte solutions from the wells of a 384-well microtiter plate and to perform quantitative analyses using MS/MS detection was illustrated with cotinine standards spiked with cotinine-d{sub 3} as an internal standard.

  7. Data Validation Package, April and June 2016 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing Site, October 2016

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Joshua [U. S. Department of Energy, Washington, DC (United States). Office of Legacy Management; Campbell, Sam [Navarro Research and Engineering, Oak Ridge, TN (United States)

    2016-10-01

    This event included annual sampling of groundwater and surface water locations at the Gunnison, Colorado, Processing Site. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for US Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated, http://energy.gov/lm/downloads/sampling-and­ analysis-plan-us-department-energy-office-legacy-management-sites). Samples were collected from 28 monitoring wells, three domestic wells, and six surface locations in April at the processing site as specified in the draft 2010 Ground Water Compliance Action Plan for the Gunnison, Colorado, Processing Site. Planned monitoring locations are shown in Attachment 1, Sampling and Analysis Work Order. Domestic wells 0476 and 0477 were sampled in June because the homes were unoccupied in April, and the wells were not in use. Duplicate samples were collected from locations 0126, 0477, and 0780. One equipment blank was collected during this sampling event. Water levels were measured at all monitoring wells that were sampled. See Attachment 2, Trip Reports for additional details. The analytical data and associated qualifiers can be viewed in environmental database reports and are also available for viewing with dynamic mapping via the GEMS (Geospatial Environmental Mapping System) website at http://gems.lm.doe.gov/#. No issues were identified during the data validation process that requires additional action or follow-up. An assessment of anomalous data is included in Attachment 3. Interpretation and presentation of results, including an assessment ofthe natural flushing compliance strategy, will be reported in the upcoming 2016 Verification Monitoring Report. U.S.

  8. Exploration, Sampling, And Reconstruction of Free Energy Surfaces with Gaussian Process Regression.

    Science.gov (United States)

    Mones, Letif; Bernstein, Noam; Csányi, Gábor

    2016-10-11

    Practical free energy reconstruction algorithms involve three separate tasks: biasing, measuring some observable, and finally reconstructing the free energy surface from those measurements. In more than one dimension, adaptive schemes make it possible to explore only relatively low lying regions of the landscape by progressively building up the bias toward the negative of the free energy surface so that free energy barriers are eliminated. Most schemes use the final bias as their best estimate of the free energy surface. We show that large gains in computational efficiency, as measured by the reduction of time to solution, can be obtained by separating the bias used for dynamics from the final free energy reconstruction itself. We find that biasing with metadynamics, measuring a free energy gradient estimator, and reconstructing using Gaussian process regression can give an order of magnitude reduction in computational cost.

  9. Results of Hg speciation testing on tanks 30, 32, and 37 surface samples

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-11-11

    The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team.

  10. Effects of sampling rate on automated fatigue recognition in surface EMG signals

    Directory of Open Access Journals (Sweden)

    Kahl Lorenz

    2015-09-01

    Full Text Available This study investigated the effects different sampling rates may produce on the quality of muscle fatigue detection algorithms. sEMG signals were obtained from isometric contractions of the arm. Subsampled signals resulting in technically relevant sampling rates were computationally deduced from the original recordings. The spectral based fatigue recognition methods mean and median frequency as well as spectral moment ratio were included in this investigation, as well as the sample and the fuzzy approximate entropy. The resulting fatigue indices were evaluated with respect to noise and separability of different load levels. We concluded that the spectral moment ratio provides the best results in fatigue detection over a wide range of sampling rates.

  11. Using public participation to sample trace metals in lake surface sediments: the OPAL Metals Survey.

    Science.gov (United States)

    Turner, S D; Rose, N L; Goldsmith, B; Bearcock, J M; Scheib, C; Yang, H

    2017-05-01

    Members of the public in England were invited in 2010 to take part in a national metals survey, by collecting samples of littoral sediment from a standing water body for geochemical analysis. To our knowledge, this is the first national sediment metals survey using public participation and reveals a snapshot of the extent of metals contamination in ponds and lakes across England. Hg, Ni, Cu, Zn and Pb concentrations exceeding sediment quality guidelines for the health of aquatic biota are ubiquitous in ponds and lakes, not just in areas with a legacy of industrial activity. To validate the public sampling approach, a calibration exercise was conducted at ten water bodies selected to represent a range of lakes found across England. Sediment concentrations of Hg, Ni, Cu, Zn and Pb were measured in samples of soil, stream and littoral and deep water sediment to assess inputs. Significant differences between littoral sediment metal concentrations occur due to local variability, but also organic content, especially in upland, peat soil catchments. Variability of metal concentrations between littoral samples is shown to be low in small (complex inputs and variation in organic content of littoral samples have a greater variability. Collection of littoral sediments in small lakes and ponds, with or without voluntary participation, can provide a reliable sampling technique for the preliminary assessment of metal contamination in standing waters. However, the heterogeneity of geology, soils and history/extent of metal contamination in the English landscape, combined with the random nature of sample collection, shows that systematic sampling for evaluating the full extent of metal contamination in lakes is still required.

  12. Improving satellite-retrieved surface radiative fluxes in polar regions using a smart sampling approach

    NARCIS (Netherlands)

    Van Tricht, Kristof; Lhermitte, S.L.M.; Gorodetskaya, Irina V.; van Lipzig, Nicole P. M.

    2016-01-01

    This study presents a data set of daily, 1 km resolution Greenland ice sheet (GrIS) surface mass balance (SMB) covering the period 1958–2015. Applying corrections for elevation, bare ice albedo and accumulation bias, the high-resolution product is statistically downscaled from the native daily

  13. Critique of Sikkink and Keane's comparison of surface fuel sampling techniques

    Science.gov (United States)

    Clinton S. Wright; Roger D. Ottmar; Robert E. Vihnanek

    2010-01-01

    The 2008 paper of Sikkink and Keane compared several methods to estimate surface fuel loading in western Montana: two widely used inventory techniques (planar intersect and fixed-area plot) and three methods that employ photographs as visual guides (photo load, photoload macroplot and photo series). We feel, however, that their study design was inadequate to evaluate...

  14. Evaluation of the toxicological properties of ground- and surface-water samples from the Aral Sea Basin.

    Science.gov (United States)

    Bosch, K; Erdinger, L; Ingel, F; Khussainova, S; Utegenova, E; Bresgen, N; Eckl, P M

    2007-03-01

    In order to determine whether there is a potential health risk associated with the water supply in the Aral Sea Basin, ground- and surface-water samples were collected in and around Aralsk and from the Aral Sea in 2002. Water samples from Akchi, a small town close to Almaty, served as controls. Bioassays with different toxicological endpoints were employed to assess the general toxicological status. Additionally, the samples were analysed for microbial contamination. The samples were tested in the primary hepatocyte assay for their potential to induce micronuclei and chromosomal aberrations as cumulative indicators for genotoxicity. In parallel, the effects on cell proliferation evidenced by mitotic index and cytotoxicity such as the appearance of necrotic and apoptotic cells, were determined. Furthermore, samples were examined using the Microtox assay for general toxicity. Chemical analysis according to European regulations was performed and soil and water samples were analysed for DDT and DDE. The results obtained indicated no increased cyto- or genotoxic potential of the water samples, nor levels of DDT or DDE exceeding the thresholds levels suggested by WHO. Our data therefore do not support the hypothesis that the contamination of the drinking water in and around Aralsk is responsible for the health effects previously described such as increased rates of liver disease and in particular liver cancer. Microbiological analysis, however, revealed the presence of contamination in most samples analysed.

  15. Guidance Document: Surface Soils Sampling for Munitions Residues in Military Live Fire Training Ranges: Canadian Protocol

    Science.gov (United States)

    2012-12-01

    substances in water , while the Canadian Environmental Protection Act [3] is concerned with pollution prevention and toxic substances releases...dish, metal spatula, interior of fume hood) must be washed thoroughly using soapy hot water (Micro-90 soap is recommended), rinsed with demineralised...aluminum liner (if used) is discarded and all the other materials are washed (sieve, bowl, fume hood surface) using soapy hot water (Micro-90 soap is

  16. Effects of test sample shape and surface production method on the fatigue behaviour of PMMA bone cement.

    Science.gov (United States)

    Sheafi, E M; Tanner, K E

    2014-01-01

    There is no consensus over the optimal criterion to define the fatigue life of bone cement in vitro. Fatigue testing samples have been made into various shapes using different surface preparation techniques with little attention being paid to the importance of these variations on the fatigue results. The present study focuses on the effect of test sample shape and surface production method on the fatigue results. The samples were manufactured with two cross sectional shapes: rectangular according to ISO 527 and circular according to ASTM F2118. Each shape was produced using two methods: direct moulding of the cement dough and machining from oversized rods. Testing was performed using two different bone cements: SmartSet GHV and DePuy CMW1. At least 10 samples of each category were tested, under fully reversed tension-compression fatigue stress at ±20MPa, to allow for Weibull analysis to compare results. The growth of fatigue cracks was observed by means of the changes in the absorbed energy and apparent modulus. It was found that fatigue crack growth can be altered by the sample shape and production method; however it is also dependent on the chemical composition of the cement. The results revealed that moulded samples, particularly those based on the ASTM F2118 standard, can lead to up to 5.5 times greater fatigue lives compared to the machined samples of the same cement. It is thus essential, when comparing the fatigue results of bone cement, to consider the effect of production method along with the shape of the test sample. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Sampling design for compliance monitoring of surface water quality: A case study in a Polder area

    NARCIS (Netherlands)

    Brus, D.J.; Knotters, M.

    2008-01-01

    International agreements such as the EU Water Framework Directive (WFD) ask for efficient sampling methods for monitoring natural resources. In this paper a general methodology for designing efficient, statistically sound monitoring schemes is described. An important decision is the choice between a

  18. Feasibility of surface sampling in automated inspection of concrete aggregates during bulk transport on a conveyor

    NARCIS (Netherlands)

    Bakker, M.C.M.; Di Maio, F.; Lotfi, S.; Bakker, M.; Hu, M.; Vahidi, A.

    2017-01-01

    Automated optic inspection of concrete aggregates for pollutants (e.g. wood, plastics, gypsum and brick) is required to establish the suitability for reuse in new concrete products. Inspection is more efficient when directly sampling the materials on the conveyor belt instead of feeding them in a

  19. Micro-TLC Approach for Fast Screening of Environmental Samples Derived from Surface and Sewage Waters.

    Science.gov (United States)

    Zarzycki, Paweł K; Slączka, Magdalena M; Włodarczyk, Elżbieta; Baran, Michał J

    2013-01-01

    In this work we demonstrated analytical capability of micro-planar (micro-TLC) technique comprising one and two-dimensional (2D) separation modes to generate fingerprints of environmental samples originated from sewage and ecosystems waters. We showed that elaborated separation and detection protocols are complementary to previously invented HPLC method based on temperature-dependent inclusion chromatography and UV-DAD detection. Presented 1D and 2D micro-TLC chromatograms of SPE (solid-phase extraction) extracts were optimized for fast and low-cost screening of water samples collected from lakes and rivers located in the area of Middle Pomerania in northern part of Poland. Moreover, we studied highly organic compounds loaded in the treated and untreated sewage waters obtained from municipal wastewater treatment plant "Jamno" near Koszalin City (Poland). Analyzed environmental samples contained number of substances characterized by polarity range from estetrol to progesterone as well as chlorophyll-related dyes previously isolated and pre-purified by simple SPE protocol involving C18 cartridges. Optimization of micro-TLC separation and quantification protocols of such samples were discussed from the practical point of view using simple separation efficiency criteria including total peaks number, log(product Δ hR F ), signal intensity and peak asymmetry. Outcomes of the presented analytical approach, especially using detection involving direct fluorescence (UV366/Vis) and phosphomolybdic acid (PMA) visualization are compared with UV-DAD HPLC-generated data reported previously. Chemometric investigation based on principal components analysis revealed that SPE extracts separated by micro-TLC and detected under fluorescence and PMA visualization modes can be used for robust sample fingerprinting even after long-term storage of the extracts (up to 4 years) at subambient temperature (-20 °C). Such approach allows characterization of wide range of sample components

  20. Liquid Microjunction Surface Sampling Probe Electrospray Mass Spectrometry for Detection of Drugs and Metabolites in Thin Tissue Sections

    Energy Technology Data Exchange (ETDEWEB)

    Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL; Koeplinger, Kenneth A. [Merck Research Laboratories; Vavek, Marissa [Merck Research Laboratories; Kong, Ah-Ng Tony [Rutgers University

    2008-01-01

    A self-aspirating, liquid micro-junction surface sampling probe/electrospray emitter mass spectrometry system was demonstrated for use in the direct analysis of spotted and dosed drugs and their metabolites in thin tissue sections. Proof-of-principle sampling and analysis directly from tissue without the need for sample preparation was demonstrated first by raster scanning a region on a section of rat liver onto which reserpine was spotted. The mass spectral signal from selected reaction monitoring was used to develop a chemical image of the spotted drug on the tissue. The probe was also used to selectively spot sample areas of sagittal whole mouse body tissue sections that had been dosed orally (90 mg/kg) with R,S-sulforaphane 3 hrs prior to sacrifice. Sulforaphane and its glutathione and N-acetyl cysteine conjugates were monitored with selected reaction monitoring and detected in the stomach and various other tissues from the dosed mouse. No signal for these species was observed in the tissue from a control mouse. The same dosed tissue section was used to illustrate the possibility of obtaining a line scan across the whole body section. In total these results illustrate the potential for rapid screening of the distribution of drugs and metabolites in tissue sections with the micro-liquid junction surface sampling probe/electrospray mass spectrometry approach.

  1. Effects of NaOCl Aqueous Solutions and Ethyl Alcohol Solutions on Removing Protein Surface Contaminants and Re-establishing Antibacterial Activities of Copper-Alloyed Stainless Steel.

    Science.gov (United States)

    Kawakami, Hiroshi; Nishikubo, Hideyuki; Hirayama, Kenta; Suzuki, Satoshi; Sato, Yoshihiro; Kikuchi, Yasushi

    2015-01-01

    Effects of wiping copper-alloyed stainless steel surfaces with disinfectants to remove protein surface contaminants and re-establish their antibacterial activities were quantitatively studied. Disinfectants used were sodium hypochlorite aqueous solutions and ethyl alcohol aqueous solutions. Wiping with NaOCl aqueous solutions effectively removed protein surface contaminants. Ethyl alcohol aqueous solutions were also effective for cleaning, but their efficiency was less than that of NaOCl aqueous solutions. When the amount of residual surface contaminants was reduced to 0.4 ng/mm(2), the surfaces of the copper-alloyed stainless steel regained antibacterial activities to the same level as those in a clean surface condition.

  2. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 1993

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, R.; Childs, M.; Rivera-Dirks, C.; Coriz, F.

    1995-07-01

    Area G, in Technical Area 54, has been the principle facility at Los Alamos National Laboratory for the storage and disposal of low-level and transuranic (TRU) radioactive wastes since 1957. The current environmental investigation consisted of ESH-19 personnel who collected soil and single-stage water samples around the perimeter of Area G to characterize possible contaminant movement through surface-water runoff. These samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241 (soil only), and cesium 137. The metals, mercury, lead, and barium, were analyzed using x-ray fluorescence.

  3. Data Validation Package September 2016 Groundwater and Surface Water Sampling at the Slick Rock, Colorado, Processing Sites January 2017

    Energy Technology Data Exchange (ETDEWEB)

    Traub, David [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States); Nguyen, Jason [US Department of Energy, Washington, DC (United States)

    2017-01-04

    The Slick Rock, Colorado, Processing Sites are referred to as the Slick Rock West Processing Site (SRK05) and the Slick Rock East Processing Site (SRK06). This annual event involved sampling both sites for a total of 16 monitoring wells and 6 surface water locations as required by the 2006 Draft Final Ground Water Compliance Action Plan for the Slick Rock, Colorado, Processing Sites (GCAP). A domestic well was also sampled at a property adjacent to the Slick Rock East site at the request of the landowner.

  4. Hepatitis B Virus DNA in Blood Samples Positive for Antibodies to Core Antigen and Negative for Surface Antigen

    Science.gov (United States)

    Gutiérrez, C.; León, G.; Loureiro, C. L.; Uzcátegui, N.; Liprandi, F.; Pujol, F. H.

    1999-01-01

    Anti-hepatitis B core antigen (HBcAg)-positive hepatitis B surface antigen (HBsAg)-negative plasma samples from blood donors were tested by nested PCR. DNA positivity was more significantly associated with high levels of anti-HBcAg than with low levels of anti-HBsAg antibodies. Analysis of a dilution of anti-HBcAg antibodies might result in a more rational exclusion of anti-HBcAg-positive HBsAg-negative samples, reducing the number of donations discarded and enabling more countries to incorporate anti-HBcAg testing. PMID:10473534

  5. Search for life on Mars in surface samples: Lessons from the 1999 Marsokhod rover field experiment

    Science.gov (United States)

    Newsom, Horton E.; Bishop, J.L.; Cockell, C.; Roush, T.L.; Johnson, J. R.

    2001-01-01

    The Marsokhod 1999 field experiment in the Mojave Desert included a simulation of a rover-based sample selection mission. As part of this mission, a test was made of strategies and analytical techniques for identifying past or present life in environments expected to be present on Mars. A combination of visual clues from high-resolution images and the detection of an important biomolecule (chlorophyll) with visible/near-infrared (NIR) spectroscopy led to the successful identification of a rock with evidence of cryptoendolithic organisms. The sample was identified in high-resolution images (3 times the resolution of the Imager for Mars Pathfinder camera) on the basis of a green tinge and textural information suggesting the presence of a thin, partially missing exfoliating layer revealing the organisms. The presence of chlorophyll bands in similar samples was observed in visible/NIR spectra of samples in the field and later confirmed in the laboratory using the same spectrometer. Raman spectroscopy in the laboratory, simulating a remote measurement technique, also detected evidence of carotenoids in samples from the same area. Laboratory analysis confirmed that the subsurface layer of the rock is inhabited by a community of coccoid Chroococcidioposis cyanobacteria. The identification of minerals in the field, including carbonates and serpentine, that are associated with aqueous processes was also demonstrated using the visible/NIR spectrometer. Other lessons learned that are applicable to future rover missions include the benefits of web-based programs for target selection and for daily mission planning and the need for involvement of the science team in optimizing image compression schemes based on the retention of visual signature characteristics. Copyright 2000 by the American Geophysical Union.

  6. A solution for an inverse problem in liquid AFM: calculation of three-dimensional solvation structure on a sample surface

    CERN Document Server

    Amano, Ken-ich

    2013-01-01

    Recent frequency-modulated atomic force microscopy (FM-AFM) can measure three-dimensional force distribution between a probe and a sample surface in liquid. The force distribution is, in the present circumstances, assumed to be solvation structure on the sample surface, because the force distribution and solvation structure have somewhat similar shape. However, the force distribution is exactly not the solvation structure. If we would like to obtain the solvation structure by using the liquid AFM, a method for transforming the force distribution into the solvation structure is necessary. Therefore, in this letter, we present the transforming method in a brief style. We call this method as a solution for an inverse problem, because the solvation structure is obtained at first and the force distribution is obtained next in general calculation processes. The method is formulated (mainly) by statistical mechanics of liquid.

  7. Rapid detection of polychlorinated biphenyls at trace levels in real environmental samples by surface-enhanced Raman scattering.

    Science.gov (United States)

    Zhou, Qin; Zhang, Xian; Huang, Yu; Li, Zhengcao; Zhang, Zhengjun

    2011-01-01

    Detection of trace levels of persistent pollutants in the environment is difficult but significant. Organic pollutant homologues, due to their similar physical and chemical properties, are even more difficult to distinguish, especially in trace amounts. We report here a simple method to detect polychlorinated biphenyls (PCBs) in soil and distilled spirit samples by the surface-enhanced Raman scattering technique using Ag nanorod arrays as substrates. By this method, polychlorinated biphenyls can be detected to a concentration of 5 μg/g in dry soil samples within 1 minute. Furthermore, based on simulation and understanding of the Raman characteristics of PCBs, we recognized homologues of tetrachlorobiphenyl by using the surface-enhance Raman scattering method even in trace amounts in acetone solutions, and their characteristic Raman peaks still can be distinguished at a concentration of 10(-6) mol/L. This study provides a fast, simple and sensitive method for the detection and recognition of organic pollutants such as polychlorinated biphenyls.

  8. Use and Limitations of Electron Flood Gun Control of Surface Potential During XPS: Two Non-homogeneous Sample Types

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Donald R.; Engelhard, Mark H.; Gaspar, Dan J.; Lea, Alan S.; Windisch, Charles F.

    2002-10-01

    The ability of charge compensation methods to control the surface potentials for two types of non-homogenous samples is examined. Results demonstrate that two newer types of charge compensation systems have improved performance in relation to some previous flood gun methods and reaffirm the concept that a primary objective of charge compensation is to find conditions for which the surface potential of the specimen is as uniform as possible. However, experiments involving both flood gun use and specimen grounding, demonstrate that peak broadening and shifting can occur when two (or more) potentials are present in the region of analysis. Finally, the ability of interface charge to shift specimen potentials and measured binding energies demonstrates fundamental limitations to the absolute accuracy of binding energy measurements, but also remind us that charging phenomena can be used to obtain important information about the sample.

  9. Dependence of the ablative effect of nanosecond laser pulses at the surface of dentine samples on the laser wavelength

    Science.gov (United States)

    Fenic, Constantin G.; Chis, Ioan; Dabu, Razvan V.; Stratan, Aurel; Apostol, Ion G.; Stoian, Razvan; Luculescu, C.; Ghica, Cornel; Nistor, Leona C.

    1998-07-01

    A Q-switched Nd:YAG laser beam and its second and fourth harmonics were focused onto the polished surface of dentine samples in order to compare the ablative effect for the three wavelengths. A photoacoustic technique is applied for the ablation threshold determination. The Scanning Electron Microscope images of the produced craters are investigated and the volume of ablated material is determined. The necessary optical constants for the ablation calculation are experimentally determined.

  10. An optimized SPE-LC-MS/MS method for antibiotics residue analysis in ground, surface and treated water samples by response surface methodology- central composite design.

    Science.gov (United States)

    Mirzaei, Roya; Yunesian, Masoud; Nasseri, Simin; Gholami, Mitra; Jalilzadeh, Esfandiyar; Shoeibi, Shahram; Bidshahi, Hooshang Shafieyan; Mesdaghinia, Alireza

    2017-01-01

    Antibiotic residues are being constantly identified in environmental waters at low concentration. Growing concern has been expressed over the adverse environmental and human health effects even at low concentration. Hence, it is crucial to develop a multi-residues analytical method for antibiotics to generate a considerable dataset which are necessary in the assessment of aquatic toxicity of environmental waters for aquatic organisms and human health. This work aimed to develop a reliable and sensitive multi-residue method based on high performance liquid chromatography coupled with quadrupole-linear ion trap tandem mass spectrometry (HPLC-MS-MS). The method was optimized and validated for simultaneous determination of four classes of antibiotics including, β-lactam, macrolide, fluoroquinolone and nitro-imidazole in treated, ground and surface water matrices. In order to optimize the solid phase extraction process, main parameters influencing the extraction process including, pH, the volume of elution solvent and the amount of Na4EDTA were evaluated. The optimization of extraction process was carried out by response surface methodology using central composite design. Analysis of variance was performed for nine target antibiotics using response surface methodology. The extraction recoveries were found to be sensitive to the independent variables of pH, the volume of elution solvent and the amount of Na4EDTA. The extraction process was pH-dependent and pH was a significant model term in the extraction process of all target antibiotics. Method validation was performed in optimum operation conditions in which the recoveries were obtained in the range of 50-117% for seven antibiotics in spiked treated and ground water samples and for six antibiotics in spiked river water samples. Method validation parameters in terms of method detection limit were obtained in the range of 1-10 ng/L in treated water, 0.8-10 ng/L in the ground water and 0.8-25 ng/L in river water

  11. Recovery of bacillus spore contaminants from rough surfaces: a challenge to space mission cleanliness control.

    Science.gov (United States)

    Probst, Alexander; Facius, Rainer; Wirth, Reinhard; Wolf, Marco; Moissl-Eichinger, Christine

    2011-03-01

    Microbial contaminants on spacecraft can threaten the scientific integrity of space missions due to probable interference with life detection experiments. Therefore, space agencies measure the cultivable spore load ("bioburden") of a spacecraft. A recent study has reported an insufficient recovery of Bacillus atrophaeus spores from Vectran fabric, a typical spacecraft airbag material (A. Probst, R. Facius, R. Wirth, and C. Moissl-Eichinger, Appl. Environ. Microbiol. 76:5148-5158, 2010). Here, 10 different sampling methods were compared for B. atrophaeus spore recovery from this rough textile, revealing significantly different efficiencies (0.5 to 15.4%). The most efficient method, based on the wipe-rinse technique (foam-spatula protocol; 13.2% efficiency), was then compared to the current European Space Agency (ESA) standard wipe assay in sampling four different kinds of spacecraft-related surfaces. Results indicate that the novel protocol out-performed the standard method with an average efficiency of 41.1% compared to 13.9% for the standard method. Additional experiments were performed by sampling Vectran fabric seeded with seven different spore concentrations and five different Bacillus species (B. atrophaeus, B. anthracis Sterne, B. megaterium, B. thuringiensis, and B. safensis). Among these, B. atrophaeus spores were recovered with the highest (13.2%) efficiency and B. anthracis Sterne spores were recovered with the lowest (0.3%) efficiency. Different inoculation methods of seeding spores on test surfaces (spotting and aerosolization) resulted in different spore recovery efficiencies. The results of this study provide a step forward in understanding the spore distribution on and recovery from rough surfaces. The results presented will contribute relevant knowledge to the fields of astrobiology and B. anthracis research.

  12. Analytical Model of the Nonlinear Dynamics of Cantilever Tip-Sample Surface Interactions for Various Acoustic-Atomic Force Microscopies

    Science.gov (United States)

    Cantrell, John H., Jr.; Cantrell, Sean A.

    2008-01-01

    A comprehensive analytical model of the interaction of the cantilever tip of the atomic force microscope (AFM) with the sample surface is developed that accounts for the nonlinearity of the tip-surface interaction force. The interaction is modeled as a nonlinear spring coupled at opposite ends to linear springs representing cantilever and sample surface oscillators. The model leads to a pair of coupled nonlinear differential equations that are solved analytically using a standard iteration procedure. Solutions are obtained for the phase and amplitude signals generated by various acoustic-atomic force microscope (A-AFM) techniques including force modulation microscopy, atomic force acoustic microscopy, ultrasonic force microscopy, heterodyne force microscopy, resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), and the commonly used intermittent contact mode (TappingMode) generally available on AFMs. The solutions are used to obtain a quantitative measure of image contrast resulting from variations in the Young modulus of the sample for the amplitude and phase images generated by the A-AFM techniques. Application of the model to RDF-AFUM and intermittent soft contact phase images of LaRC-cp2 polyimide polymer is discussed. The model predicts variations in the Young modulus of the material of 24 percent from the RDF-AFUM image and 18 percent from the intermittent soft contact image. Both predictions are in good agreement with the literature value of 21 percent obtained from independent, macroscopic measurements of sheet polymer material.

  13. [Establishment of confirmatory test for suspicious hepatitis B surface antigen positive samples].

    Science.gov (United States)

    Chen, Lin; Rong, Yang; Liu, Jia; Xu, Jun; Guo, Jing-Xia; Song, Yong-Ji; Zhao, Jing; Liu, Ai-Xia; Yang, Li-Hua; Li, Bo-An; Mao, Yuan-Li

    2012-08-01

    Establish a confirmatory test based on ELISA, and use to verify the authenticity of HBsAg weak positive samples, pick and get rid of the false result, and avoid the mistake diagnosis. The particles (reagent A) coated by streptavidin and biotinylated HBsAb (reagent B) were mixed in different proportions, then neutralized with serum whose the COI of HBsAg > 20 by ELISA in order to identify the activity of HBsAb in confirmatory reagent. 30 pieces of HBsAg weak positive serum neutralized with the confirmatory reagent, the serum were considered to be positive if rate of decline of HBsAg COI > 50%. The results were compared to Roche confirmatory Kit. Confirmatory reagent was able to neutralized with HBsAg. 24 of 30 pieces of HBsAg weak positive samples were judged to be positive, while 6 poeces were negative. The ELISA comfirm method is fully consistent with Roche confirmatory Kit. The ELISA confirmatory test for suspicious HBsAg positive samples is a simple, accurate and low cost initial validation method, After further clinical trials, should be widely applied.

  14. Examination of pterins using surface-enhanced Raman spectroscopy using low-volume samples

    Science.gov (United States)

    Mehigan, Sam; Smyth, Ciarán.; McCabe, Eithne M.

    2013-02-01

    Raman spectroscopy is a very useful tool for analysing compounds, however its ability to detect low concentrations of a substance are very limited. Surface Enhanced Raman Spectroscopy (SERS) overcomes that issue and is reported to have achieved single molecule detection. Its main shortcoming is the reproducibility of SERS spectra. The variation in signal strength prevents SERS from being usable as a quantitative analytical technique. This variability have been investigated in this work and key factors in improving reproducibility have been considered. Pterins, such as xanthopterin are studied in this paper. Pterins are a group of biological compounds that are found in nature in colour pigmentation and in mammal's metabolic pathways. Moreover, they have been identified in abnormal concentrations in the urine of people suffering from certain kinds of cancer. The potential for pterin's use as a cancer diagnostic points to the importance of SERS detection for pterins.

  15. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    Science.gov (United States)

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. RF Surface Impedance Measurement of Polycrystalline and Large Grain Nb Disk Sample at 7.5 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Binping [BNL; Geng, Rongli [JLAB; Kelley, Michael J. [W& M, JLAB; Marhauser, Frank [JLAB; Phillips, H. Larry [JLAB; Reece, Charles E. [JLAB; Wang, Haipeng [JLAB

    2009-11-01

    A Surface Impedance Characterization (SIC) system has been proposed at the 2005 SRF workshop and recently updated as detailed at the 2009 PAC conference. Currently the SIC system can measure samples in a temperature range from 2K to 20K exposed to an RF magnetic flux density of less than 3mT. We report on new results of a BCP etched large grain Nb sample measured with this system as compared with previous results of a BCP etched polycrystalline Nb sample. The design of an upgraded SIC system for use at higher magnetic flux densities is on the way to more efficiently investigate correlations between local material characteristics and associated SRF properties, both for preparation studies of bulk niobium and also new thin film SRF developments.

  17. Effect of Instrument Lubricants on the Surface Degree of Conversion and Crosslinking Density of Nanocomposites.

    Science.gov (United States)

    de Paula, Felipe Costa; Valentin, Regis de Souza; Borges, Boniek Castillo Dutra; Medeiros, Maria Cristina Dos Santos; de Oliveira, Raiza Freitas; da Silva, Ademir Oliveira

    2016-01-01

    The surface degree of conversion and crosslink density of composites should not be affected by the use of instrument lubricants in order to provide long-lasting tooth restorations. This study aimed to analyze the effect of instrument lubricants on the degree of conversion and crosslink density of nanocomposites. Samples (N = 10) were fabricated according to the composites (Filtek Z350 XT, 3M ESPE, St. Paul, MN, USA; and IPS Empress Direct, Ivoclar Vivadent AG, Schaan, Liechtenstein and lubricants used (Adper Single Bond 2 and Scotchbond Multi-Purpose bonding agent adhesive systems, 3M ESPE; 70% ethanol, absolute ethanol, and no lubricant). Single composite increments were inserted into a Teflon mold using the same dental instrument. The composite surface was then modeled using a brush wiped with each adhesive system and a spatula wiped with each ethanol. The control group was fabricated with no additional modeling. The surface degree of conversion and crosslink density were measured by Fourier transform infrared spectroscopy and the hardness decrease test, respectively. Data were analyzed using two-way analysis of variance and the Tukey's test (p degree of conversion regardless of the lubricant used, whereas the use of adhesive systems and 70% ethanol decreased the degree of conversion for IPS Empress Direct. Only Scotchbond Multi-Purpose bonding agent decreased crosslink density for Filtek Z350 XT, whereas both adhesive systems decreased crosslink density for IPS Empress Direct. Filtek Z350 XT appeared to be less sensitive to the effects of lubricants, and absolute ethanol did not affect the degree of conversion and crosslink density of the nanocomposites tested. Although the use of lubricants may be recommended to minimize the stickiness of dental instruments and composite resin, dentists should choose materials that do not have a negative effect on the surface properties of composites. Only the use of absolute ethanol safely maintains the surface integrity

  18. Molecular Dynamic Simulations of Interaction of an AFM Probe with the Surface of an SCN Sample

    Science.gov (United States)

    Bune, Adris; Kaukler, William; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Molecular dynamic (MD) simulations is conducted in order to estimate forces of probe-substrate interaction in the Atomic Force Microscope (AFM). First a review of available molecular dynamic techniques is given. Implementation of MD simulation is based on an object-oriented code developed at the University of Delft. Modeling of the sample material - succinonitrile (SCN) - is based on the Lennard-Jones potentials. For the polystyrene probe an atomic interaction potential is used. Due to object-oriented structure of the code modification of an atomic interaction potential is straight forward. Calculation of melting temperature is used for validation of the code and of the interaction potentials. Various fitting parameters of the probe-substrate interaction potentials are considered, as potentials fitted to certain properties and temperature ranges may not be reliable for the others. This research provides theoretical foundation for an interpretation of actual measurements of an interaction forces using AFM.

  19. Y-12 Groundwater Protection Program Groundwater and Surface Water Sampling and Analysis Plan For Calendar Year 2009

    Energy Technology Data Exchange (ETDEWEB)

    Elvado Environmental LLC

    2008-12-01

    This plan provides a description of the groundwater and surface water quality monitoring activities planned for calendar year (CY) 2009 at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) that will be managed by the Y-12 Groundwater Protection Program (GWPP). Groundwater and surface water monitoring performed by the GWPP during CY 2009 will be in accordance with DOE Order 540.1 requirements and the following goals: (1) to protect the worker, the public, and the environment; (2) to maintain surveillance of existing and potential groundwater contamination sources; (3) to provide for the early detection of groundwater contamination and determine the quality of groundwater and surface water where contaminants are most likely to migrate beyond the Oak Ridge Reservation property line; (4) to identify and characterize long-term trends in groundwater quality at Y-12; and (5) to provide data to support decisions concerning the management and protection of groundwater resources. Groundwater and surface water monitoring during CY 2009 will be performed primarily in three hydrogeologic regimes at Y-12: the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek and East Fork regimes are located in Bear Creek Valley, and the Chestnut Ridge Regime is located south of Y-12 (Figure A.1). Additional surface water monitoring will be performed north of Pine Ridge, along the boundary of the Oak Ridge Reservation. Modifications to the CY 2009 monitoring program may be necessary during implementation. Changes in programmatic requirements may alter the analytes specified for selected monitoring wells or may add or remove wells from the planned monitoring network. All modifications to the monitoring program will be approved by the Y-12 GWPP manager and documented as addenda to this sampling and analysis plan

  20. Biocompatible channels for field-flow fractionation of biological samples: correlation between surface composition and operating performance.

    Science.gov (United States)

    Roda, Barbara; Cioffi, Nicola; Ditaranto, Nicoletta; Zattoni, Andrea; Casolari, Sonia; Melucci, Dora; Reschiglian, Pierluigi; Sabbatini, Luigia; Valentini, Antonio; Zambonin, Pier Giorgio

    2005-02-01

    Biocompatible methods capable of rapid purification and fractionation of analytes from complex natural matrices are increasingly in demand, particularly at the forefront of biotechnological applications. Field-flow fractionation is a separation technique suitable for nano-sized and micro-sized analytes among which bioanalytes are an important family. The objective of this preliminary study is to start a more general approach to field-flow fractionation for bio-samples by investigation of the correlation between channel surface composition and biosample adhesion. For the first time we report on the use of X-ray photoelectron spectroscopy (XPS) to study the surface properties of channels of known performance. By XPS, a polar hydrophobic environment was found on PVC material commonly used as accumulation wall in gravitational field-flow fractionation (GrFFF), which explains the low recovery obtained when GrFFF was used to fractionate a biological sample such as Staphylococcus aureus. An increase in separation performance was obtained first by conditioning the accumulation wall with bovine serum albumin and then by using the ion-beam sputtering technique to cover the GrFFF channel surface with a controlled inert film. XPS analysis was also employed to determine the composition of membranes used in hollow-fiber flow field-flow fractionation (HF FlFFF). The results obtained revealed homogeneous composition along the HF FlFFF channel both before and after its use for fractionation of an intact protein such as ferritin.

  1. Application of response surface methodology for determination of methyl red in water samples by spectrophotometry method.

    Science.gov (United States)

    Khodadoust, Saeid; Ghaedi, Mehrorang

    2014-12-10

    In this study a rapid and effective method (dispersive liquid-liquid microextraction (DLLME)) was developed for extraction of methyl red (MR) prior to its determination by UV-Vis spectrophotometry. Influence variables on DLLME such as volume of chloroform (as extractant solvent) and methanol (as dispersive solvent), pH and ionic strength and extraction time were investigated. Then significant variables were optimized by using a Box-Behnken design (BBD) and desirability function (DF). The optimized conditions (100μL of chloroform, 1.3mL of ethanol, pH 4 and 4% (w/v) NaCl) resulted in a linear calibration graph in the range of 0.015-10.0mgmL(-1) of MR in initial solution with R(2)=0.995 (n=5). The limits of detection (LOD) and limit of quantification (LOQ) were 0.005 and 0.015mgmL(-1), respectively. Finally, the DLLME method was applied for determination of MR in different water samples with relative standard deviation (RSD) less than 5% (n=5). Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Hötzl, H; Rosner, G; Winkler, R

    1992-06-01

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

  3. Surface Acoustic Wave Nebulisation Mass Spectrometry for the Fast and Highly Sensitive Characterisation of Synthetic Dyes in Textile Samples

    Science.gov (United States)

    Astefanei, Alina; van Bommel, Maarten; Corthals, Garry L.

    2017-10-01

    Surface acoustic wave nebulisation (SAWN) mass spectrometry (MS) is a method to generate gaseous ions compatible with direct MS of minute samples at femtomole sensitivity. To perform SAWN, acoustic waves are propagated through a LiNbO3 sampling chip, and are conducted to the liquid sample, which ultimately leads to the generation of a fine mist containing droplets of nanometre to micrometre diameter. Through fission and evaporation, the droplets undergo a phase change from liquid to gaseous analyte ions in a non-destructive manner. We have developed SAWN technology for the characterisation of organic colourants in textiles. It generates electrospray-ionisation-like ions in a non-destructive manner during ionisation, as can be observed by the unmodified chemical structure. The sample size is decreased by tenfold to 1000-fold when compared with currently used liquid chromatography-MS methods, with equal or better sensitivity. This work underscores SAWN-MS as an ideal tool for molecular analysis of art objects as it is non-destructive, is rapid, involves minimally invasive sampling and is more sensitive than current MS-based methods. [Figure not available: see fulltext.

  4. Indirect competitive immunoassay for the detection of fungicide Thiabendazole in whole orange samples by Surface Plasmon Resonance.

    Science.gov (United States)

    Estevez, M-Carmen; Belenguer, Jose; Gomez-Montes, Silvia; Miralles, Javier; Escuela, Alfonso M; Montoya, Angel; Lechuga, Laura M

    2012-12-07

    A highly sensitive and specific SPR-based competitive immunoassay for the detection of Thiabendazole (TBZ) has been developed. An indirect format where a TBZ-protein conjugate is immobilized onto gold surfaces has been selected. Under the optimal conditions, a LOD of 0.67 nM (0.13 μg L(-1)) and an IC(50) of 3.2 nM (0.64 μg L(-1)) have been achieved which are comparable to the values obtained by conventional ELISA. Analysis of real samples has been attempted by first evaluating the influence of complex matrix samples coming from whole oranges and secondly measuring samples containing TBZ previously evaluated by chromatographic methods. A methanolic extraction procedure followed by a simple dilution in assay buffer has proven to be sufficient to measure orange samples using the developed immunoassay with an excellent recovery percentage. The sensitivity and the feasibility of measuring whole orange samples demonstrate the effectiveness and robustness of the SPR biosensor, which can be useful for the determination of TBZ in food at concentrations below the Maximum Residue Levels (MRLs) established by the European legislation.

  5. Sampling surface particle size distributions and stability analysis of deep channel in the Pearl River Estuary

    Science.gov (United States)

    Feng, Hao-chuan; Zhang, Wei; Zhu, Yu-liang; Lei, Zhi-yi; Ji, Xiao-mei

    2017-06-01

    Particle size distributions (PSDs) of bottom sediments in a coastal zone are generally multimodal due to the complexity of the dynamic environment. In this paper, bottom sediments along the deep channel of the Pearl River Estuary (PRE) are used to understand the multimodal PSDs' characteristics and the corresponding depositional environment. The results of curve-fitting analysis indicate that the near-bottom sediments in the deep channel generally have a bimodal distribution with a fine component and a relatively coarse component. The particle size distribution of bimodal sediment samples can be expressed as the sum of two lognormal functions and the parameters for each component can be determined. At each station of the PRE, the fine component makes up less volume of the sediments and is relatively poorly sorted. The relatively coarse component, which is the major component of the sediments, is even more poorly sorted. The interrelations between the dynamics and particle size of the bottom sediment in the deep channel of the PRE have also been investigated by the field measurement and simulated data. The critical shear velocity and the shear velocity are calculated to study the stability of the deep channel. The results indicate that the critical shear velocity has a similar distribution over large part of the deep channel due to the similar particle size distribution of sediments. Based on a comparison between the critical shear velocities derived from sedimentary parameters and the shear velocities obtained by tidal currents, it is likely that the depositional area is mainly distributed in the northern part of the channel, while the southern part of the deep channel has to face higher erosion risk.

  6. Characterizing the recovery of a solid surface after tungsten nano-tendril formation

    NARCIS (Netherlands)

    Wright, G. M.; van Eden, G. G.; Kesler, L. A.; De Temmerman, G.; Whyte, D. G.; Woller, K.B.

    2015-01-01

    Recovery of a flat tungsten surface from a nano-tendril surface is attempted through three techniques; a mechanical wipe, a 1673 K annealing, and laser-induced thermal transients. Results were determined through SEM imaging and elastic recoil detection to assess the helium content in the

  7. Pollen deposition in tauber traps and surface soil samples in the Mar Chiquita coastal lagoon area, pampa grasslands (Argentina

    Directory of Open Access Journals (Sweden)

    Fabiana Latorre

    2010-12-01

    Full Text Available Estimations of airborne pollen loadings deposited in Tauber traps were studied in a coastal lagoon from south-eastern Pampa grasslands, Argentina, in order to assess their relationship with surface samples and to interpret the representativeness of local, regional and extraregional vegetation. Three different environments were considered: a coastal dune barrier with a psammophytic community, a salt marsh with a halophytic community in Mar Chiquita lagoon, and a freshwater community at Hinojales freshwater lake. Based on a record of surface samples taken from a previous paper, a parametric model was built to classify Tauber samples gathered from the natural vegetation communities of the study area. Results revealed that just like their surface counterparts, Tauber trap records qualitatively reflect the predominant vegetation types, although ecological groups feature different quantitative representations depending on the record type. Pollen loadings showed that airborne pollen transport was predominantly of local range, in accordance with previous results from the same study area. Airborne - surface samples relationships enrich our knowledge of the present environment that could be useful to improve paleoecological interpretations of the area.Se estimó el depósito polínico atmosférico de trampas Tauber en una laguna costera del sudeste de la estepa pampeana argentina, con el objetivo de analizar su relación con muestras de polen superficial e interpretar la representatividad de la vegetación local, regional y extraregional. Se consideraron tres ambientes diferentes: una barrera costera de dunas con vegetación psamofítica, la marisma de la laguna costera Mar Chiquita, con vegetación halofítica, y la laguna continental Hinojales, con vegetación hidrofítica. En base a las muestras de superficie y análisis de un trabajo previo, se construyó un modelo paramétrico para clasificar las muestras Tauber tomadas en la vegetación natural del

  8. An efficient reliability algorithm for locating design point using the combination of importance sampling concepts and response surface method

    Science.gov (United States)

    Shayanfar, Mohsen Ali; Barkhordari, Mohammad Ali; Roudak, Mohammad Amin

    2017-06-01

    Monte Carlo simulation (MCS) is a useful tool for computation of probability of failure in reliability analysis. However, the large number of required random samples makes it time-consuming. Response surface method (RSM) is another common method in reliability analysis. Although RSM is widely used for its simplicity, it cannot be trusted in highly nonlinear problems due to its linear nature. In this paper, a new efficient algorithm, employing the combination of importance sampling, as a class of MCS, and RSM is proposed. In the proposed algorithm, analysis starts with importance sampling concepts and using a represented two-step updating rule of design point. This part finishes after a small number of samples are generated. Then RSM starts to work using Bucher experimental design, with the last design point and a represented effective length as the center point and radius of Bucher's approach, respectively. Through illustrative numerical examples, simplicity and efficiency of the proposed algorithm and the effectiveness of the represented rules are shown.

  9. Characterization of the March 2017 tank 10 surface sample (combination of HTF-10-17-30 AND HTF-10-17-31) and variable depth sample (combination of HTF-10-17-32 and HTF-10-17-33)

    Energy Technology Data Exchange (ETDEWEB)

    Reboul, S. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-19

    Two surface samples (HTF-10-17-30 and HTF-10-17-31) and two variable depth samples (HTF-10-17-32 and HTF-10-17-33) were collected from SRS Tank 10 during March 2017 and submitted to SRNL for characterization. At SRNL, the two surface samples were combined in one container, the two variable depth samples (VDSs) were combined in another container, and then the two composite samples were each characterized by a series of physical, ionic, radiological, and elemental analysis methods. The surface sample composite was characterized primarily for Tank Farm corrosion control purposes, while the VDS composite was characterized primarily for Tank Closure Cesium Removal (TCCR) purposes.

  10. Rapid Detection of Polychlorinated Biphenyls at Trace Levels in Real Environmental Samples by Surface-Enhanced Raman Scattering

    Directory of Open Access Journals (Sweden)

    Zhengjun Zhang

    2011-11-01

    Full Text Available Detection of trace levels of persistent pollutants in the environment is difficult but significant. Organic pollutant homologues, due to their similar physical and chemical properties, are even more difficult to distinguish, especially in trace amounts. We report here a simple method to detect polychlorinated biphenyls (PCBs in soil and distilled spirit samples by the surface-enhanced Raman scattering technique using Ag nanorod arrays as substrates. By this method, polychlorinated biphenyls can be detected to a concentration of 5 μg/g in dry soil samples within 1 minute. Furthermore, based on simulation and understanding of the Raman characteristics of PCBs, we recognized homologues of tetrachlorobiphenyl by using the surface-enhance Raman scattering method even in trace amounts in acetone solutions, and their characteristic Raman peaks still can be distinguished at a concentration of 10-6 mol/L. This study provides a fast, simple and sensitive method for the detection and recognition of organic pollutants such as polychlorinated biphenyls.

  11. Low-fouling surface plasmon resonance biosensor for multi-step detection of foodborne bacterial pathogens in complex food samples.

    Science.gov (United States)

    Vaisocherová-Lísalová, Hana; Víšová, Ivana; Ermini, Maria Laura; Špringer, Tomáš; Song, Xue Chadtová; Mrázek, Jan; Lamačová, Josefína; Scott Lynn, N; Šedivák, Petr; Homola, Jiří

    2016-06-15

    Recent outbreaks of foodborne illnesses have shown that foodborne bacterial pathogens present a significant threat to public health, resulting in an increased need for technologies capable of fast and reliable screening of food commodities. The optimal method of pathogen detection in foods should: (i) be rapid, specific, and sensitive; (ii) require minimum sample preparation; and (iii) be robust and cost-effective, thus enabling use in the field. Here we report the use of a SPR biosensor based on ultra-low fouling and functionalizable poly(carboxybetaine acrylamide) (pCBAA) brushes for the rapid and sensitive detection of bacterial pathogens in crude food samples utilizing a three-step detection assay. We studied both the surface resistance to fouling and the functional capabilities of these brushes with respect to each step of the assay, namely: (I) incubation of the sensor with crude food samples, resulting in the capture of bacteria by antibodies immobilized to the pCBAA coating, (II) binding of secondary biotinylated antibody (Ab2) to previously captured bacteria, and (III) binding of streptavidin-coated gold nanoparticles to the biotinylated Ab2 in order to enhance the sensor response. We also investigated the effects of the brush thickness on the biorecognition capabilities of the gold-grafted functionalized pCBAA coatings. We demonstrate that pCBAA-compared to standard low-fouling OEG-based alkanethiolate self-assemabled monolayers-exhibits superior surface resistance regarding both fouling from complex food samples as well as the non-specific binding of S-AuNPs. We further demonstrate that a SPR biosensor based on a pCBAA brush with a thickness as low as 20 nm was capable of detecting E. coli O157:H7 and Salmonella sp. in complex hamburger and cucumber samples with extraordinary sensitivity and specificity. The limits of detection for the two bacteria in cucumber and hamburger extracts were determined to be 57 CFU/mL and 17 CFU/mL for E. coli and 7.4 × 10

  12. Preparation of Magnetic Sorbent with Surface Modified by C18for Removal of Selected Organic Pollutants from Aqueous Samples

    Science.gov (United States)

    Kuráň, Pavel; Pilnaj, Dominik; Ciencialová, Lucie; Pšenička, Martin

    2017-12-01

    Magnetic sorbents have great potential in environmental applications due to their simple synthesis and separation in magnetic field, usability in heterogeneous systems and low toxicity. Possible syntheses, surface modifications and characteristics were described by Li et al 2013. This type of solid-phase extraction is being successfully used in various fields as health care, microbiology, biotechnologies or sample preconcentration in analytical chemistry. In this preliminary study we report on the preparation and application of magnetically separable sorbent with surface modified by C18 alkyl chain for purification of water contaminated by environmentally hazardous organic compounds. Magnetic cores were co-precipitated from Fe2+ and Fe3+ chlorides in alkalic aqueous solution. Surface of synthetized Fe3O4 was modified with SiO2 by tetraethylorthosilicate to assure physico-chemical stability. Furthermore, Fe3O4/SiO2 complex has been treated by C18 functional group, which provides good affinity towards hydrophobic substances in water. Efficiency of sorption under various conditions has been examined on benzene, toluene, ethylbenzene and xylenes (BTEX), compounds found in petroleum products which contaminate air, soil and groundwater near of store tanks. Sorption kinetics was followed by gas chromatography with mass spectrometry. The preliminary sorption kinetics data and efficiency of BTEX removal point at the possible application of prepared magnetic sorbent for BTEX removal, especially for ethylbenzene and xylenes.

  13. Impact of Spatial Sampling on Continuity of MODIS-VIIRS Land Surface Reflectance Products: A Simulation Approach

    Science.gov (United States)

    Pahlevan, Nima; Sarkar, Sudipta; Devadiga, Sadashiva; Wolfe, Robert E.; Roman, Miguel; Vermote, Eric; Lin, Guoqing; Xiong, Xiaoxiong

    2016-01-01

    With the increasing need to construct long-term climate-quality data records to understand, monitor, and predict climate variability and change, it is vital to continue systematic satellite measurements along with the development of new technology for more quantitative and accurate observations. The Suomi National Polar-orbiting Partnership mission provides continuity in monitoring the Earths surface and its atmosphere in a similar fashion as the heritage MODIS instruments onboard the National Aeronautics and Space Administrations Terra and Aqua satellites. In this paper, we aim at quantifying the consistency of Aqua MODIS and Suomi-NPP Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Reflectance (LSR) and NDVI products as related to their inherent spatial sampling characteristics. To avoid interferences from sources of measurement and/or processing errors other than spatial sampling, including calibration, atmospheric correction, and the effects of the bidirectional reflectance distribution function, the MODIS and VIIRSLSR products were simulated using the Landsat-8s Operational Land Imager (OLI) LSR products. The simulations were performed using the instruments point spread functions on a daily basis for various OLI scenes over a 16-day orbit cycle. It was found that the daily mean differences due to discrepancies in spatial sampling remain below 0.0015 (1) in absolute surface reflectance at subgranule scale (i.e., OLI scene size).We also found that the MODISVIIRS product intercomparisons appear to be minimally impacted when differences in the corresponding view zenith angles (VZAs) are within the range of -15deg to -35deg (VZA(sub v) - VZA(sub m)), where VIIRS and MODIS footprints resemble in size. In general, depending on the spatial heterogeneity of the OLI scene contents, per-grid-cell differences can reach up to 20.Further spatial analysis of the simulated NDVI and LSR products revealed that, depending on the user accuracy requirements for

  14. Modern sedimentation processes in Laguna de Medina, southern Spain, derived from lake surface sediment and catchment soil samples

    Directory of Open Access Journals (Sweden)

    Jasmijn van 't Hoff

    2016-10-01

    Full Text Available Modern processes influencing sediment composition in the endorheic lake Laguna de Medina, southern Spain, are disentangled by analysis of 46 lake surface sediment and 32 catchment soil samples. Based on statistical analysis of the mineralogical, geochemical, elemental, and granulometric compositions of all samples, the lake surface sediments can be divided into six provinces of individual composition and depositional processes. High quartz contents and coarse grain sizes, reflecting input from ancient terraces of the Guadalete River that are exposed in the adjacent hinterland, characterize the lake sedimentation close to the northern shore. At the south-eastern shore, sedimentation is characterized by terrestrial input of the Triassic Keuper facies via the most important inlet, the Arroyo Fuente Bermeja, as reflected by high relative intensities of Ti, K, Al, Fe, Mg, Rb. Sediments close to the northern shore are characterized by high calcite contents, reflecting predominant sediment supply from the adjacent Cretaceous 'capas rojas', a series of Subbetic deep-water marlstones and limestones. Close to the western shore, relatively high gypsum contents presumably are due to precipitation from upwelling ground water. Anthropogenic influence is only indicated in the north-western and central eastern parts of the lake, where the surface sediments are significantly enriched in TOC and TN, reflecting enhanced primary production due to terrestrial organic matter supply from anthropogenic areas in the respective catchment. The central part of the lake is characterized by distal hemipelagic sedimentation, with high concentrations of clay and silt and a chemical and mineralogical composition that reflects a mixture of the sediment sources characterizing individual parts of the lake shores. The results of this study shed new light on the depositional processes and their potential spatial heterogeneity in small endorheic lakes. Furthermore, they will provide

  15. Structure-based sampling and self-correcting machine learning for accurate calculations of potential energy surfaces and vibrational levels

    Science.gov (United States)

    Dral, Pavlo O.; Owens, Alec; Yurchenko, Sergei N.; Thiel, Walter

    2017-06-01

    We present an efficient approach for generating highly accurate molecular potential energy surfaces (PESs) using self-correcting, kernel ridge regression (KRR) based machine learning (ML). We introduce structure-based sampling to automatically assign nuclear configurations from a pre-defined grid to the training and prediction sets, respectively. Accurate high-level ab initio energies are required only for the points in the training set, while the energies for the remaining points are provided by the ML model with negligible computational cost. The proposed sampling procedure is shown to be superior to random sampling and also eliminates the need for training several ML models. Self-correcting machine learning has been implemented such that each additional layer corrects errors from the previous layer. The performance of our approach is demonstrated in a case study on a published high-level ab initio PES of methyl chloride with 44 819 points. The ML model is trained on sets of different sizes and then used to predict the energies for tens of thousands of nuclear configurations within seconds. The resulting datasets are utilized in variational calculations of the vibrational energy levels of CH3Cl. By using both structure-based sampling and self-correction, the size of the training set can be kept small (e.g., 10% of the points) without any significant loss of accuracy. In ab initio rovibrational spectroscopy, it is thus possible to reduce the number of computationally costly electronic structure calculations through structure-based sampling and self-correcting KRR-based machine learning by up to 90%.

  16. Gemini NIFS survey of feeding and feedback processes in nearby active galaxies - II. The sample and surface mass density profiles

    Science.gov (United States)

    Riffel, R. A.; Storchi-Bergmann, T.; Riffel, R.; Davies, R.; Bianchin, M.; Diniz, M. R.; Schönell, A. J.; Burtscher, L.; Crenshaw, M.; Fischer, T. C.; Dahmer-Hahn, L. G.; Dametto, N. Z.; Rosario, D.

    2018-02-01

    We present and characterize a sample of 20 nearby Seyfert galaxies selected for having BAT 14-195 keV luminosities LX ≥ 1041.5 erg s-1, redshift z ≤ 0.015, being accessible for observations with the Gemini Near-Infrared Field Spectrograph (NIFS) and showing extended [O III]λ5007 emission. Our goal is to study Active Galactic Nucleus (AGN) feeding and feedback processes from near-infrared integral-field spectra, which include both ionized (H II) and hot molecular (H2) emission. This sample is complemented by other nine Seyfert galaxies previously observed with NIFS. We show that the host galaxy properties (absolute magnitudes MB, MH, central stellar velocity dispersion and axial ratio) show a similar distribution to those of the 69 BAT AGN. For the 20 galaxies already observed, we present surface mass density (Σ) profiles for H II and H2 in their inner ˜500 pc, showing that H II emission presents a steeper radial gradient than H2. This can be attributed to the different excitation mechanisms: ionization by AGN radiation for H II and heating by X-rays for H2. The mean surface mass densities are in the range (0.2 ≤ ΣH II ≤ 35.9) M⊙ pc-2, and (0.2 ≤ ΣH2 ≤ 13.9)× 10-3 M⊙ pc-2, while the ratios between the H II and H2 masses range between ˜200 and 8000. The sample presented here will be used in future papers to map AGN gas excitation and kinematics, providing a census of the mass inflow and outflow rates and power as well as their relation with the AGN luminosity.

  17. Preventing and Removing Contamination in a Natural Radiocarbon Sample Preparation Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Zermeno, P; Kurdyla, D K; Buchholz, B A; Heller, S J; Frantz, B R; Brown, T A; Kashgarian, M

    2002-10-25

    The introduction of elevated {sup 14}C contamination into a natural radiocarbon sample preparation laboratory can occur through many different pathways. The most difficult to control is the introduction of contaminated samples from outside labs. Laboratories can remain {sup 14}C contaminated as a result of earlier tracer based research, even if ''hot'' work has not occurred in the laboratories in decades. Prior to accepting samples from outside collaborators, it is recommended that the collaborators test their labs for {sup 14}C contamination. Any surface in a lab that has high use by multiple people has the potential to be contaminated. The standard procedure for determining whether a collaborator's lab is contaminated consists of swiping lab surfaces with small glass fiber filters wetted with alcohol and measuring them for {sup 14}C content using AMS. Volatile {sup 14}C can be detected by using aerosol monitors consisting of fine soot that is depleted in {sup 14}C. These monitors can be set out in the laboratory in question to check for volatile {sup 14}C contamination. In the event that a hot sample is introduced in the natural radiocarbon sample prep laboratory, all sample submission should be stopped until the lab is declared clean. Samples already being processed should be completed along with {sup 14}C depleted material and measured by AMS. This will help determine if the contaminated samples have affected other samples in the laboratory. After a contamination event, the laboratory and associated equipment requires cleaning or disposal. All surfaces and equipment should be wiped down with acetone or ethanol. All chemicals in use should be disposed of in the appropriate waste containers and those waste containers removed from the lab. Once the natural radiocarbon laboratory has been thoroughly ''cleaned'', several background samples consisting of {sup 14}C depleted material should be processed through the lab and

  18. Basin and Crater Ejecta Contributions to the South Pole-Aitken Basin (SPA) Regolith; Positive Implications for Robotic Surface Samples

    Science.gov (United States)

    Petro, Noah E.; Jolliff, B. L.

    2011-01-01

    The ability of impacts of all sizes to laterally transport ejected material across the lunar surface is well-documented both in lunar samples [1-4] and in remote sensing data [5-7]. The need to quantify the amount of lateral transport has lead to several models to estimate the scale of this effect. Such models have been used to assess the origin of components at the Apollo sites [8-10] or to predict what might be sampled by robotic landers [11-13]. Here we continue to examine the regolith inside the South Pole-Aitken Basin (SPA) and specifically assess the contribution to the SPA regolith by smaller craters within the basin. Specifically we asses the effects of four larger craters within SPA, Bose, Bhabha, Stoney, and Bellinsgauzen all located within the mafic enhancement in the center of SPA (Figure 1). The region around these craters is of interest as it is a possible landing and sample return site for the proposed Moon-Rise mission [14-17]. Additionally, understanding the provenance of components in the SPA regolith is important for interpreting remotely sensed data of the basin interior [18-20].

  19. Y-12 Groundwater Protection Program Groundwater And Surface Water Sampling And Analysis Plan For Calendar Year 2011

    Energy Technology Data Exchange (ETDEWEB)

    Elvado Environmental LLC

    2010-12-01

    This plan provides a description of the groundwater and surface water quality monitoring activities planned for calendar year (CY) 2011 at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) that will be managed by the Y-12 Groundwater Protection Program (GWPP). Groundwater and surface water monitoring performed by the GWPP during CY 2011 will be in accordance with requirements of DOE Order 540.1A and the following goals: (1) to protect the worker, the public, and the environment; (2) to maintain surveillance of existing and potential groundwater contamination sources; (3) to provide for the early detection of groundwater contamination and determine the quality of groundwater and surface water where contaminants are most likely to migrate beyond the Oak Ridge Reservation property line; (4) to identify and characterize long-term trends in groundwater quality at Y-12; and (5) to provide data to support decisions concerning the management and protection of groundwater resources. Groundwater and surface water monitoring during CY 2011 will be performed primarily in three hydrogeologic regimes at Y-12: the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek and East Fork regimes are located in Bear Creek Valley and the Chestnut Ridge Regime is located south of Y-12 (Figure A.1). Additional surface water monitoring will be performed north of Pine Ridge along the boundary of the Oak Ridge Reservation. Modifications to the CY 2011 monitoring program may be necessary during implementation. Changes in programmatic requirements may alter the analytes specified for selected monitoring wells or may add or remove wells from the planned monitoring network. All modifications to the monitoring program will be approved by the Y-12 GWPP manager and documented as addenda to this sampling and analysis plan

  20. Y-12 Groundwater Protection Program Groundwater And Surface Water Sampling And Analysis Plan For Calendar Year 2010

    Energy Technology Data Exchange (ETDEWEB)

    Elvado Environmental LLC

    2009-09-01

    This plan provides a description of the groundwater and surface water quality monitoring activities planned for calendar year (CY) 2010 at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) that will be managed by the Y-12 Groundwater Protection Program (GWPP). Groundwater and surface water monitoring performed by the GWPP during CY 2010 will be in accordance with requirements of DOE Order 540.1A and the following goals: (1) to protect the worker, the public, and the environment; (2) to maintain surveillance of existing and potential groundwater contamination sources; (3) to provide for the early detection of groundwater contamination and determine the quality of groundwater and surface water where contaminants are most likely to migrate beyond the Oak Ridge Reservation property line; (4) to identify and characterize long-term trends in groundwater quality at Y-12; and (5) to provide data to support decisions concerning the management and protection of groundwater resources. Groundwater and surface water monitoring during CY 2010 will be performed primarily in three hydrogeologic regimes at Y-12: the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek and East Fork regimes are located in Bear Creek Valley, and the Chestnut Ridge Regime is located south of Y-12 (Figure A.1). Additional surface water monitoring will be performed north of Pine Ridge, along the boundary of the Oak Ridge Reservation. Modifications to the CY 2010 monitoring program may be necessary during implementation. Changes in programmatic requirements may alter the analytes specified for selected monitoring wells or may add or remove wells from the planned monitoring network. All modifications to the monitoring program will be approved by the Y-12 GWPP manager and documented as addenda to this sampling and analysis plan

  1. Y-12 Groundwater Protection Program Groundwater And Surface Water Sampling And Analysis Plan For Calendar Year 2012

    Energy Technology Data Exchange (ETDEWEB)

    Elvado Environmental, LLC

    2011-09-01

    This plan provides a description of the groundwater and surface water quality monitoring activities planned for calendar year (CY) 2012 at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) that will be managed by the Y-12 Groundwater Protection Program (GWPP). Groundwater and surface water monitoring performed by the GWPP during CY 2012 is in accordance with the following goals: (1) to protect the worker, the public, and the environment; (2) to maintain surveillance of existing and potential groundwater contamination sources; (3) to provide for the early detection of groundwater contamination and determine the quality of groundwater and surface water where contaminants are most likely to migrate beyond the Oak Ridge Reservation property line; (4) to identify and characterize long-term trends in groundwater quality at Y-12; and (5) to provide data to support decisions concerning the management and protection of groundwater resources. Groundwater and surface water monitoring will be performed in three hydrogeologic regimes at Y-12: the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek and East Fork regimes are located in Bear Creek Valley and the Chestnut Ridge Regime is located south of Y-12 (Figure A.1). Additional surface water monitoring will be performed north of Pine Ridge along the boundary of the Oak Ridge Reservation. Modifications to the CY 2012 monitoring program may be necessary during implementation. Changes in programmatic requirements may alter the analytes specified for selected monitoring wells or may add or remove wells from the planned monitoring network. Each modification to the monitoring program will be approved by the Y-12 GWPP manager and documented as an addendum to this sampling and analysis plan. The following sections of this report provide details regarding

  2. Assessment of the total uranium concentration in surface and underground water samples from the Caetite region, Bahia, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Julia Grasiela Batista; Geraldo, Luiz Paulo [Centro Universitario da Fundacao Educacional de Barretos (UNIFEB), (SP) (Brazil); Yamazaki, Ione Makiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    At the region of Caetite, BA, it is located the largest uranium mine in exploration at present days in Brazil. During the uranium extraction process, it may be having an environmental contamination by this heavy metal due to rain water and other natural transport mechanism, with potential exposition risk to the local population. The aim of this work was to investigate the total uranium concentration in surface and underground water samples collected at the Caetite region, using the nuclear track registration technique (SSNTD) in a polycarbonate plastic. A 100 mL volume of water samples were initially treated in 10 mL of HNO{sub 3} (PA) and concentrated by evaporation at a temperature around 80 deg C. The resulting residue was diluted to a total volume of 25 mL without pass it to a filter. About 10 {mu}L of this solution was deposited on the plastic detector surface (around 1.0 cm{sup 2} area) together with 5 {mu}L of a Cyastat detergent solution (5%) and evaporated under an infrared lamp. All the resulting deposits of non volatile constituents were irradiated, together with a uranium standard sample, at the IPEN-IEA-R1 (3.5 MW) nuclear reactor for approximately 3 min. After irradiations, chemical etching of the plastic detectors was carried out at 60 deg C, for 65 min. in a NaOH (6N) solution. The fission tracks were counted scanning all the deposit area of the polycarbonate plastic detector with a system consisting of an optical microscope together with a video camera and TV monitor. The average values of uranium concentrations obtained in this work ranged from (0.95{+-}0.19) {mu}g.L{sup -1} to (25.60{+-}3.3) {mu}g.L{sup -1}. These results were compared to values reported in the literature for water samples from other regions and discussed in terms of safe limits recommended by WHO -World Health Organization and CONAMA - Conselho Nacional do Meio Ambiente. (author)

  3. Primary health clinic toilet/bathroom surface swab sampling can indicate community profile of sexually transmitted infections

    Science.gov (United States)

    Su, Jiunn-Yih; Andersson, Patiyan; Holt, Deborah C.

    2017-01-01

    relative prevalence of gonorrhoeae in central Australia than in northern Australia. Similarly, the regional clinics yielded p values from 0.0088–0.0022. In contrast, swab and notifications data from the sexual health clinic were not correlated. Discussion Strong correlations between swab and notifications were observed. However, there was evidence for limitations of this approach. Despite the correlation observed with the regional clinics data, one clinic yielded zero positive swabs for C. trachomatis, although this STI constituted 25.1% of the corresponding notifications. This could be ascribed to stochastic effects. The lack of correlation observed for sexual health clinic data was also likely due to stochastic effects. It was concluded that toilet/bathroom surface swab sampling has considerable potential for public health surveillance. The approach may be applicable in situations other than primary health clinics, and for targets other than STIs. PMID:28652937

  4. Primary health clinic toilet/bathroom surface swab sampling can indicate community profile of sexually transmitted infections.

    Science.gov (United States)

    Giffard, Philip M; Su, Jiunn-Yih; Andersson, Patiyan; Holt, Deborah C

    2017-01-01

    in central Australia than in northern Australia. Similarly, the regional clinics yielded p values from 0.0088-0.0022. In contrast, swab and notifications data from the sexual health clinic were not correlated. Strong correlations between swab and notifications were observed. However, there was evidence for limitations of this approach. Despite the correlation observed with the regional clinics data, one clinic yielded zero positive swabs for C. trachomatis, although this STI constituted 25.1% of the corresponding notifications. This could be ascribed to stochastic effects. The lack of correlation observed for sexual health clinic data was also likely due to stochastic effects. It was concluded that toilet/bathroom surface swab sampling has considerable potential for public health surveillance. The approach may be applicable in situations other than primary health clinics, and for targets other than STIs.

  5. Benzodiazepine whole blood concentrations in cases with positive oral fluid on-site screening test results using the DrugWipe(®) single for benzodiazepines.

    Science.gov (United States)

    Blencowe, Tom; Vimpari, Kari; Lillsunde, Pirjo

    2011-07-01

    Reliable on-site oral fluid screening devices are a useful and convenient means of policing traffic. In Finland, benzodiazepines represent a particular challenge to traffic safety. This study presents a retrospective examination of toxicological analysis results from whole blood in cases which gave a positive screening result for benzodiazepines in oral fluid using the DrugWipe Single device (Securetec). Use of oral fluid on-site screening tests and blood confirmation analyses reflects the real situation in many countries. The data were compiled from the databases of Alcohol and Drug Analytics Unit at the National Institute for Health and Welfare. Confirmation analysis results in whole blood were obtained using gas chromatography-mass spectrometry. Data were from 224 real cases in which the Finnish police had conducted a DrugWipe Single benzodiazepines test on drivers suspected of driving under the influence of drugs (DUID). The benzodiazepine concentrations encountered in positive oral fluid screening cases in this study indicate that the device is able to detect these substances even at relatively low levels. However, the DrugWipe device does not enable any distinction between therapeutic use and harmful use of benzodiazepines at higher doses.

  6. TRACKING PYRETHROID TOXICITY IN SURFACE WATER SAMPLES: EXPOSURE DYNAMICS AND TOXICITY IDENTIFICATION TOOLS FOR LABORATORY TESTS WITH HYALELLA AZTECA (AMPHIPODA).

    Science.gov (United States)

    Deanovic, Linda A; Stillway, Marie; Hammock, Bruce G; Fong, Stephanie; Werner, Inge

    2017-09-09

    Pyrethroid insecticides are commonly used in pest control and are present at toxic concentrations in surface waters of agricultural and urban areas worldwide. Monitoring is challenging due to their high hydrophobicity and low toxicity thresholds, which often fall below the detection limits of analytical methods. Standard daphnid bioassays used in surface water monitoring are not sensitive enough to protect more susceptible invertebrate species such as the amphipod, Hyalella azteca, and chemical loss during toxicity testing is of concern. In this study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and present a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in LDPE cubitainers at 4°C of five pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, esfenvalerate) and one organophosphate (chlorpyrifos; used as reference) was 1.4 d, and piperonyl butoxide (PBO) proved an effective tool to potentiate toxicity. We conclude that toxicity tests on ambient water samples containing these hydrophobic insecticides are likely to underestimate toxicity present in the field, and mimic short pulse rather than continuous exposures. Where these chemicals are of concern, the addition of PBO during testing can yield valuable information on their presence or absence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Surface molecularly imprinted silica for selective solid-phase extraction of biochanin A, daidzein and genistein from urine samples.

    Science.gov (United States)

    Chrzanowska, Anna M; Poliwoda, Anna; Wieczorek, Piotr P

    2015-05-01

    Selective molecularly imprinted silica polymer (SiO2MIP) for extraction of biochanin A, daidzein and genistein was synthesized using the surface molecular imprinting technique with the silica gel as a support. Biochanin A (BCA) was used as a template, 3-aminopropyltriethoxysilane (APTES) as a functional monomer, and tetraethoxysilicane (TEOS) as a cross-linker. Non-imprinted polymer with the sol-gel process (SiO2NIP) was also prepared for comparison. The synthesized polymers were characterized by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and a standard Brunauer-Emett-Teller (BET) and Barret-Joyner-Halenda (BJH) analysis. The obtained results indicated the structural differences between imprinted and non-imprinted polymers. Finally, the SiO2MIP and SiO2NIP were adopted as the adsorbents of solid phase extraction for isolation and preconcentration of biochanin A and its structural analogues-daidzein and genistein from aqueous and urine samples. The performance analysis revealed that SiO2MIP displayed better affinity to the three investigated isoflavones compared with SiO2NIP. The recoveries of spiked samples for studied analytes ranged from 65.7% to 102.6% for molecularly imprinted silica polymer and 8.9-16.0% for non-imprinted sorbents. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Assessing total nitrogen in surface-water samples--precision and bias of analytical and computational methods

    Science.gov (United States)

    Rus, David L.; Patton, Charles J.; Mueller, David K.; Crawford, Charles G.

    2013-01-01

    The characterization of total-nitrogen (TN) concentrations is an important component of many surface-water-quality programs. However, three widely used methods for the determination of total nitrogen—(1) derived from the alkaline-persulfate digestion of whole-water samples (TN-A); (2) calculated as the sum of total Kjeldahl nitrogen and dissolved nitrate plus nitrite (TN-K); and (3) calculated as the sum of dissolved nitrogen and particulate nitrogen (TN-C)—all include inherent limitations. A digestion process is intended to convert multiple species of nitrogen that are present in the sample into one measureable species, but this process may introduce bias. TN-A results can be negatively biased in the presence of suspended sediment, and TN-K data can be positively biased in the presence of elevated nitrate because some nitrate is reduced to ammonia and is therefore counted twice in the computation of total nitrogen. Furthermore, TN-C may not be subject to bias but is comparatively imprecise. In this study, the effects of suspended-sediment and nitrate concentrations on the performance of these TN methods were assessed using synthetic samples developed in a laboratory as well as a series of stream samples. A 2007 laboratory experiment measured TN-A and TN-K in nutrient-fortified solutions that had been mixed with varying amounts of sediment-reference materials. This experiment identified a connection between suspended sediment and negative bias in TN-A and detected positive bias in TN-K in the presence of elevated nitrate. A 2009–10 synoptic-field study used samples from 77 stream-sampling sites to confirm that these biases were present in the field samples and evaluated the precision and bias of TN methods. The precision of TN-C and TN-K depended on the precision and relative amounts of the TN-component species used in their respective TN computations. Particulate nitrogen had an average variability (as determined by the relative standard deviation) of 13

  9. Active Sampling Device for Determining Pollutants in Surface and Pore Water - the In Situ Sampler for Biphasic Water Monitoring

    Science.gov (United States)

    Supowit, Samuel D.; Roll, Isaac B.; Dang, Viet D.; Kroll, Kevin J.; Denslow, Nancy D.; Halden, Rolf U.

    2016-02-01

    We designed and evaluated an active sampling device, using as analytical targets a family of pesticides purported to contribute to honeybee colony collapse disorder. Simultaneous sampling of bulk water and pore water was accomplished using a low-flow, multi-channel pump to deliver water to an array of solid-phase extraction cartridges. Analytes were separated using either liquid or gas chromatography, and analysis was performed using tandem mass spectrometry (MS/MS). Achieved recoveries of fipronil and degradates in water spiked to nominal concentrations of 0.1, 1, and 10 ng/L ranged from 77 ± 12 to 110 ± 18%. Method detection limits (MDLs) were as low as 0.040-0.8 ng/L. Extraction and quantitation of total fiproles at a wastewater-receiving wetland yielded concentrations in surface water and pore water ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L, respectively. Detected concentrations were statistically indistinguishable from those determined by conventional, more laborious techniques (p > 0.2 for the three most abundant fiproles). Aside from offering time-averaged sampling capabilities for two phases simultaneously with picogram-per-liter MDLs, the novel methodology eliminates the need for water and sediment transport via in situ solid phase extraction.

  10. U.S. Geological Survey nutrient preservation experiment; nutrient concentration data for surface-, ground-, and municipal-supply water samples and quality-assurance samples

    Science.gov (United States)

    Patton, Charles J.; Truitt, Earl P.

    1995-01-01

    This report is a compilation of analytical results from a study conducted at the U.S. Geological Survey, National Water Quality Laboratory (NWQL) in 1992 to assess the effectiveness of three field treatment protocols to stabilize nutrient concentra- tions in water samples stored for about 1 month at 4C. Field treatments tested were chilling, adjusting sample pH to less than 2 with sulfuric acid and chilling, and adding 52 milligrams of mercury (II) chloride per liter of sample and chilling. Field treatments of samples collected for determination of ammonium, nitrate plus nitrite, nitrite, dissolved Kjeldahl nitrogen, orthophosphate, and dissolved phosphorus included 0.45-micrometer membrane filtration. Only total Kjeldahl nitrogen and total phosphorus were determined in unfiltered samples. Data reported here pertain to water samples collected in April and May 1992 from 15 sites within the continental United States. Also included in this report are analytical results for nutrient concentrations in synthetic reference samples that were analyzed concurrently with real samples.

  11. Nonhazardous solvent composition and method for cleaning metal surfaces

    Science.gov (United States)

    Googin, J.M.; Simandl, R.F.; Thompson, L.M.

    1993-05-04

    A solvent composition for displacing greasy and oily contaminants as well as water and/or aqueous residue from metallic surfaces, especially surfaces of radioactive materials so that such surfaces can be wiped clean of the displaced contaminants, water and/or aqueous residue. The solvent composition consists essentially of a blend of nonpolar aliphatic hydrocarbon solvent having a minimum flash point of about 140 F and 2 to 25 volume percent of a polar solvent having a flash point sufficiently high so as to provide the solvent composition with a minimum flash point of at least 140 F. The solvent composition is nonhazardous so that when it is used to clean the surfaces of radioactive materials the waste in the form of paper or cloth wipes, lab coats and the like used in the cleaning operation is not considered to be mixed waste composed of a hazardous solvent and a radioactive material.

  12. Data Validation Package June 2016 Groundwater and Surface Water Sampling at the Old and New Rifle, Colorado, Processing Sites September 2016

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Richard [USDOE Office of Legacy Management (LM), Washington, DC (United States); Lemke, Peter [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-10-17

    Sampling Period: June 14–17 and July 7, 2016. Water samples were collected from 36 locations at New Rifle and Old Rifle, Colorado, Disposal/Processing Sites. Planned monitoring locations are shown in Attachment 1, Sampling and Analysis Work Order. Duplicate samples were collected from New Rifle locations 0216 and 0855, and Old Rifle location 0655. One equipment blank was collected after decontamination of non-dedicated equipment used to collect one surface water sample. See Attachment 2, Trip Report for additional details. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated, http://energy.gov/lm/downloads/sampling-and- analysis-plan-us-department-energy-office-legacy-management-sites). New Rifle Site Samples were collected at the New Rifle site from 16 monitoring wells and 7 surface locations in compliance with the December 2008 Groundwater Compliance Action Plan [GCAP] for the New Rifle, Colorado, Processing Site (LMS/RFN/S01920). Monitoring well 0216 could not be sampled in June because it was surrounded by standing water due to the high river stage from spring runoff, it was later sampled in July. Monitoring well 0635 and surface location 0322 could not be sampled because access through the elk fence along Interstate 70 has not been completed at this time. Old Rifle Site Samples were collected at the Old Rifle site from eight monitoring wells and five surface locations in compliance with the December 2001 Ground Water Compliance Action Plan for the Old Rifle, Colorado, UMTRA Project Site (GJ0-2000-177-TAR).

  13. Primary health clinic toilet/bathroom surface swab sampling can indicate community profile of sexually transmitted infections

    Directory of Open Access Journals (Sweden)

    Philip M. Giffard

    2017-06-01

    known higher relative prevalence of gonorrhoeae in central Australia than in northern Australia. Similarly, the regional clinics yielded p values from 0.0088–0.0022. In contrast, swab and notifications data from the sexual health clinic were not correlated. Discussion Strong correlations between swab and notifications were observed. However, there was evidence for limitations of this approach. Despite the correlation observed with the regional clinics data, one clinic yielded zero positive swabs for C. trachomatis, although this STI constituted 25.1% of the corresponding notifications. This could be ascribed to stochastic effects. The lack of correlation observed for sexual health clinic data was also likely due to stochastic effects. It was concluded that toilet/bathroom surface swab sampling has considerable potential for public health surveillance. The approach may be applicable in situations other than primary health clinics, and for targets other than STIs.

  14. Investigation of dual-layer membrane cloaking method by surface plasmon resonance for direct chronoamperometric immunoassay of serum sample.

    Science.gov (United States)

    Dai, Zong; Yang, Yan; Wu, Hai; Zou, Xiao-Yong

    2011-10-15

    A "dual-layer membrane cloaking" (DLMC) method was developed to construct disposable electrochemical immunosensor for direct determination of serum sample. Mouse IgG (MIgG) molecules were firstly immobilized on a substrate. After the formation of a didodecyldimethylammonium bromide (DDAB) membrane on the MIgG modified substrate, an additional bovine serum albumin (BSA) thin layer was formed to build a BSA/DDAB dual-layer membrane (DLM). When alkaline phosphatase conjugated anti-mouse IgG antibodies (anti-MIgG-ALP) in human serum were incubated on the substrate, anti-MIgG-ALP was recognized specifically by the immobilized MIgG while all nonspecifically adsorbed proteins were selectively removed together with BSA/DDAB DLM by 5% Triton X-100 (v/v) before final measurements. The BSA/DDAB DLM was characterized and optimized by surface plasmon resonance (SPR) technique, and further employed in a disposable immunoassay based on an ITO chip. Under optimal conditions, MIgG in human serum was directly detected in the range of 2.0-18.0 ng mL(-1) without dilution or separation. A limit of detection as low as 0.922 ng mL(-1) (6.15 pM) was obtained. The proposed DLMC method can efficiently prevent the penetration of matrix proteins through single cloaking membrane and completely eliminate nonspecific adsorption. It has great potential in providing a versatile way for direct determination of serum sample with ultra-sensitivity. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. A pilot study of the efficacy of wipes containing chlorhexidine 0.3%, climbazole 0.5% and Tris-EDTA to reduce Malassezia pachydermatis populations on canine skin

    Science.gov (United States)

    Cavana, Paola; Peano, Andrea; Petit, Jean-Yanique; Tizzani, Paolo; Perrot, Sébastien; Bensignor, Emmanuel; Guillot, Jacques

    2015-01-01

    Background Wipes containing chlorhexidine and azole derivates have been recommended for veterinary use. No study has been published about their activity against Malassezia pachydermatis. Hypothesis/Objectives To evaluate the in vivo and in vitro activity of wipes soaked in a chlorhexidine, climbazole and Tris-EDTA solution against Malassezia pachydermatis. Animals Five research colony shar-pei dogs. Methods Wipes were applied once daily onto the left axilla, left groin and perianal area (protocol A), and twice daily on the right axilla, right groin and umbilical region (protocol B) for 3 days. In vivo activity was evaluated by quantifying Malassezia colonies through contact plates on the selected body areas before and after wipe application. The activity of the solution in which the wipes were soaked was assessed in vitro by contact tests following the European Standard UNI EN 1275 guidelines. Results Samples collected after wipe application showed a significant and rapid reduction of Malassezia yeast CFU. No significant difference in the Malassezia reduction was found between protocols A and B. In vitro assay showed 100% activity against Malassezia yeasts after a 15 min contact time with the wipe solution. Conclusions and clinical importance Wipes containing chlorhexidine, climbazole and Tris-EDTA substantially reduced the M. pachydermatis population on the skin of dogs. The results, although this was an uncontrolled study performed on a small number of dogs, suggest that these wipes may be useful for topical therapy of Malassezia dermatitis involving the lips, paws, perianal area and skin folds. Résumé Contexte Des lingettes contenant de la chlorhexidine et des dérivésazolés ont été recommandés en médicine vétérinaire. Aucune étude n'a été publiée sur leur activité contre Malassezia pachydermatis. Hypothèses/Objectifs Evaluer l'activité in vivo et in vitro de lingettes imprégnées d'une solution de chlorhexidine, climbazole et Tris

  16. Gritty Surface Sample Holder Invented To Obtain Correct X-ray Absorption Fine Structure Spectra for Concentrated Materials by Fluorescence Yield.

    Science.gov (United States)

    Abe, Hitoshi; Niwa, Yasuhiro; Kimura, Masao; Murakami, Youichi; Yokoyama, Toshiharu; Hosono, Hideo

    2016-04-05

    A gritty surface sample holder has been invented to obtain correct XAFS spectra for concentrated samples by fluorescence yield (FY). Materials are usually mixed with boron nitride (BN) to prepare proper concentrations to measure XAFS spectra. Some materials, however, could not be mixed with BN and would be measured in too concentrated conditions to obtain correct XAFS spectra. Consequently, XAFS spectra will be incorrect typically with decreased intensities of the peaks. We have invented the gritty surface sample holders to obtain correct XAFS spectra even for concentrated materials for FY measurements. Pure Cu and CuO powders were measured mounted on the sample holders, and the same spectra were obtained as transmission spectra of properly prepared samples. This sample holder is useful to measure XAFS for any concentrated materials.

  17. Modern sedimentation patterns in Lake El'gygytgyn, NE Russia, derived from surface sediment and inlet streams samples

    Directory of Open Access Journals (Sweden)

    V. Wennrich

    2013-01-01

    Full Text Available Lake El'gygytgyn/NE Russia holds a continuous 3.58 Ma sediment record, which is regarded as the most long-lasting climate archive of the terrestrial Arctic. Based on multi-proxy geochemical, mineralogical, and granulometric analyses of surface sediment, inlet stream and bedrock samples, supplemented by statistical methods, major processes influencing the modern sedimentation in the lake were investigated. Grain-size parameters and chemical elements linked to the input of feldspars from acidic bedrock indicate a wind-induced two-cell current system as major driver of sediment transport and accumulation processes in Lake El'gygytgyn. The distribution of mafic rock related elements in the sediment on the lake floor can be traced back to the input of weathering products of basaltic rocks in the catchment. Obvious similarities in the spatial variability of manganese and heavy metals indicate sorption or co-precipitation of these elements with Fe and Mn hydroxides and oxides. But the similar distribution of organic matter and clay contents might also point to a fixation to organic components and clay minerals. An enrichment of mercury in the inlet streams might be indicative of neotectonic activity around the lake. The results of this study add to the fundamental knowledge of the modern lake processes of Lake El'gygytgyn and its lake-catchment interactions, and thus, yield crucial insights for the interpretation of paleo-data from this unique archive.

  18. Continuous Flow Liquid Microjunction Surface Sampling Probe Connected On-line with HPLC/MS for Spatially Resolved Analysis of Small Molecules and Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL

    2013-01-01

    RATIONALE: A continuous flow liquid microjunction surface sampling probe extracts soluble material from surfaces for direct ionization and detection by MS. Demonstrated here is the on-line coupling of such a probe with HPLC/MS enabling extraction, separation and detection of small molecules and proteins from surfaces in a spatially resolved (~0.5 mm diameter spots) manner. Methods: A continuous flow liquid microjunction surface sampling probe was connected to a 6-port, 2-position valve for extract collection and injection to an HPLC column. A QTRAP 5500 hybrid triple quadrupole linear ion trap equipped with a Turbo V ion source operated in positive ESI mode was used for all experiments. System operation was tested with extraction, separation and detection of propranolol and associated metabolites from drug dosed tissues and proteins from dried sheep blood spots on paper. Results: Confirmed in the tissue were the parent drug and two different hydroxypropranolol glucuronides. The mass spectrometric response for these compounds from different locations in the liver showed an increase with increasing extraction time (5, 20 and 40 s extractions). For on-line separation and detection/identification of extracted proteins from dried sheep blood spots, two major protein peaks dominated the chromatogram and could be correlated with the expected masses for the hemoglobin and chains. Conclusions: Spatially resolved sampling, separation, and detection of small molecules and proteins from surfaces can be accomplished using a continuous flow liquid microjunction surface sampling probe coupled on-line with HPLC/MS detection.

  19. Hard clam walking: Active horizontal locomotion of adult Mercenaria mercenaria at the sediment surface and behavioral suppression after extensive sampling.

    Science.gov (United States)

    Tettelbach, Stephen T; Europe, James R; Tettelbach, Christian R H; Havelin, Jason; Rodgers, Brooke S; Furman, Bradley T; Velasquez, Marissa

    2017-01-01

    Locomotion of infaunal bivalve mollusks primarily consists of vertical movements related to burrowing; horizontal movements have only been reported for a few species. Here, we characterize hard clam walking: active horizontal locomotion of adults (up to 118 mm shell length, SL) of the commercially important species, Mercenaria mercenaria, at the sediment surface-a behavior only briefly noted in the literature. We opportunistically observed walking over a 10-yr period, at 9 different sites in the Peconic Bays, New York, USA, and tested several hypotheses for the underlying cause of this behavior through quantitative field sampling and reproductive analyses. Hard clam walking was exhibited by males and females at equal frequency, predominantly during June/July and October, when clams were in peak spawning condition. Extensive walking behavior appears to be cued by a minimum population density; we suggest it may be mediated by unidentified pheromone(s), infaunal pressure waves and/or other unidentified factors. There was no directionality exhibited by walking clams, but individuals in an area of extensive walking were highly aggregated and walking clams were significantly more likely to move toward a member of the opposite sex. Thus, we conclude that hard clam walking serves to aggregate mature individuals prior to spawning, thereby facilitating greater fertilization success. In the process of investigating this behavior, however, we apparently oversampled one population and reduced clam densities below the estimated minimum threshold density and, in so doing, suppressed extensive walking for a period of >3 years running. This not only reinforces the importance of detailed field investigations of species biology and ecology, even for those that are considered to be well studied, but also highlights the need for greater awareness of the potential for research activities to affect focal species behavior.

  20. Site characterization summary report for dry weather surface water sampling upper East Fork Poplar Creek characterization area Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    This report describes activities associated with conducting dry weather surface water sampling of Upper East Fork Poplar Creek (UEFPC) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. This activity is a portion of the work to be performed at UEFPC Operable Unit (OU) 1 [now known as the UEFPC Characterization Area (CA)], as described in the RCRA Facility Investigation Plan for Group 4 at the Oak- Ridge Y-12 Plant, Oak Ridge, Tennessee and in the Response to Comments and Recommendations on RCRA Facility Investigation Plan for Group 4 at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Volume 1, Operable Unit 1. Because these documents contained sensitive information, they were labeled as unclassified controlled nuclear information and as such are not readily available for public review. To address this issue the U.S. Department of Energy (DOE) published an unclassified, nonsensitive version of the initial plan, text and appendixes, of this Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) Plan in early 1994. These documents describe a program for collecting four rounds of wet weather and dry weather surface water samples and one round of sediment samples from UEFPC. They provide the strategy for the overall sample collection program including dry weather sampling, wet weather sampling, and sediment sampling. Figure 1.1 is a schematic flowchart of the overall sampling strategy and other associated activities. A Quality Assurance Project Plan (QAPJP) was prepared to specifically address four rounds of dry weather surface water sampling and one round of sediment sampling. For a variety of reasons, sediment sampling has not been conducted and has been deferred to the UEFPC CA Remedial Investigation (RI), as has wet weather sampling.

  1. Effect of a gas on the ejection of particles from the free surface of a sample subjected to a shock wave with various intensities

    Energy Technology Data Exchange (ETDEWEB)

    Ogorodnikov, V. A., E-mail: root@gdd.vniief.ru; Mikhailov, A. L.; Sasik, V. S.; Erunov, S. V.; Syrunin, M. A.; Fedorov, A. V.; Nevmerzhitskii, N. V.; Kulakov, E. V.; Kleshchevnikov, O. A.; Antipov, M. V.; Yurtov, I. V.; Rudnev, A. V.; Chapaev, A. V.; Pupkov, A. S.; Sen’kovskii, E. D.; Sotskov, E. A.; Glushikhin, V. V.; Kalashnik, I. A.; Finyushin, S. A.; Chudakov, E. A. [Russian Federal Nuclear Center All-Russia Research Institute of Experimental Physics (VNIIEF) (Russian Federation); and others

    2016-08-15

    In view of the possible effect of contamination of a plasma by metal particles on the operation of a number of facilities or on the detection of the motion of liners by Doppler methods, a particular attention has been recently focused on the problem of the ejection of particles from the shock-loaded free surface of a sample or on the “dusting” problem. Most information concerns the dusting source associated with the roughness of the surface, manufacturing technology, and the defectiveness and aging of a material. Factors affecting this process such as the profile and amplitude of the pressure on the front of the shock wave arriving at the free surface of the sample, the presence of the gas in front of the free surface, and the pressure in this gas are less studied.

  2. Experimental skin deposition of chromium on the hands following handling of samples of leather and metal

    DEFF Research Database (Denmark)

    Bregnbak, David; Thyssen, Jacob P.; Jellesen, Morten Stendahl

    2016-01-01

    Background: Chromium is an important skin sensitizer. Exposure to it has been regulated in cement, and recently in leather. Studies on the deposition of chromium ions on the skin as a result of handling different chromium-containing materials are sparse, but could improve the risk assessment...... of contact sensitization and allergic contact dermatitis caused by chromium. Objectives: To determine whether the handling of chromium-containing samples of leather and metal results in the deposition of chromium onto the skin. Methods: Five healthy volunteers participated. For 30 min, they handled samples...... of leather and metal known to contain and release chromium. Skin deposition of chromium was assessed with the acid wipe sampling technique. Results: Acid wipe sampling of the participants' fingers showed chromium deposition on the skin in all participants who had been exposed to leather (range 0.01–0.20 µg...

  3. Use of XPS to identify the oxidation state of Mn in solid surfaces of filtration media oxide samples from drinking water treatment plants.

    Science.gov (United States)

    Cerrato, José M; Hochella, Michael F; Knocke, William R; Dietrich, Andrea M; Cromer, Thomas F

    2010-08-01

    X-ray photoelectron spectroscopy (XPS) was used to identify Mn(II), Mn(III), and Mn(IV) in the surfaces of pure oxide standards and filtration media samples from drinking water treatment plants through the determination of the magnitude of the Mn 3s multiplet splitting and the position and shape of the Mn 3p photo-line. The Mn 3p region has been widely studied by applied physicists and surface scientists, but its application to identify the oxidation state of Mn in heterogeneous oxide samples has been limited. This study shows that the use of both the Mn 3s multiplet splitting and the position and shape of the Mn 3p photo-line provides a feasible means of determining the oxidation state of manganese in complex heterogeneous, environmentally important samples. Surface analysis of filtration media samples from several drinking water treatment plants was conducted. While Mn(IV) was predominant in most samples, a mixture of Mn(III) and Mn(IV) was also identified in some of the filtration media samples studied. The predominance of Mn(IV) in the media samples was felt to be related to the maintenance of free chlorine (HOCl) at substantial concentrations (2-5 mg*L(-1) as Cl2) across these filters. XPS could be a useful tool to further understand the specific mechanisms affecting soluble Mn removal using MnOx-coated filtration media.

  4. Representation of solid and nutrient concentrations in irrigation water from tailwater recovery systems by surface water grab samples

    Science.gov (United States)

    Tailwater recovery (TWR) systems are being implemented on agricultural landscapes to create an additional source of irrigation water. Existing studies have sampled TWR systems using grab samples; however, the applicability of solids and nutrient concentrations in these samples to water being irrigat...

  5. Draft Genome Sequence of Hymenobacter sp. Strain AT01-02, Isolated from a Surface Soil Sample in the Atacama Desert, Chile

    DEFF Research Database (Denmark)

    Hansen, Anders Cai Holm; Paulino-Lima, Ivan Glaucio; Fujishima, Kosuke

    2016-01-01

    Here, we report the 5.09-Mb draft genome sequence of Hymenobacter sp. strain AT01-02, which was isolated from a surface soil sample in the Atacama Desert, Chile. The isolate is extremely resistant to UV-C radiation and is able to accumulate high intracellular levels of Mn/Fe.......Here, we report the 5.09-Mb draft genome sequence of Hymenobacter sp. strain AT01-02, which was isolated from a surface soil sample in the Atacama Desert, Chile. The isolate is extremely resistant to UV-C radiation and is able to accumulate high intracellular levels of Mn/Fe....

  6. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

    Science.gov (United States)

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-05

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The effects of subsampling and sampling frequency on the use of surface-floating pupal exuviae to measure Chironomidae (Diptera) communities in wadeable temperate streams.

    Science.gov (United States)

    Bouchard, Raymond William; Ferrington, Leonard C

    2011-10-01

    Community, diversity, and biological index metrics for chironomid surface-floating pupal exuviae (SFPE) were assessed at different subsample sizes and sampling frequencies from wadeable streams in Minnesota (USA). Timed collections of SFPE were made using a biweekly sampling interval in groundwater-dominated (GWD) and surface-water-dominated (SWD) streams. These two types of stream were sampled because they support different Chironomidae communities with different phenologies which could necessitate sampling methodologies specific to each stream type. A subsample size of 300 individuals was sufficient to collect on average 85% of total taxa richness and to estimate most metrics with an error of about 1% relative to 1,000 count samples. SWD streams required larger subsample sizes to achieve similar estimates of taxa richness and metric error compared to GWD streams, but these differences were not large enough to recommend different subsampling methods for these stream types. Analysis of sample timing determined that 97% of emergence occurred from April through September. We recommend in studies where estimation of winter emergence is not important that sampling be limited to this period. Sampling frequency also affected the proportion of the community collected. To maximize the portion of the community, collected samples should be taken across seasons although no specific sampling interval is recommended. Subsampling and sampling frequency was also assessed simultaneously. When using a 300-count subsample, a 4-week sampling interval from April through September was required to collect on average 71% of the community. Due to differences in elements of the chironomid community evaluated by different studies (e.g., biological condition, phenology, and taxonomic composition), richness estimates are documented for five sampling intervals (2, 4, 6, 8, 10, and 12 weeks) and five subsample sizes (100, 200, 300, 500, and 1,000 counts). This research will enhance future

  8. Efficacy of a New Post-Mouthwash Intervention (Wiping Plus Oral Nutritional Supplements) for Preventing Aspiration Pneumonia in Elderly People: A Multicenter, Randomized, Comparative Trial.

    Science.gov (United States)

    Higashiguchi, Takashi; Ohara, Hiroshi; Kamakura, Yayoi; Kikutani, Takeshi; Kuzuya, Masafumi; Enoki, Hiromi; Sanada, Hiromi; Matsuzaki, Masami; Maruyama, Michio

    2017-01-01

    Aspiration pneumonia is a common cause of death among the elderly (≥90-year-old) in nursing homes. Studies suggest that its incidence could be reduced by oral care interventions. We aimed to evaluate the efficacy of a new oral care intervention: wiping plus oral nutritional supplements (ONS). This prospective observational study was conducted in 252 patients (age 88.0 ± 6.5 years) in 75 nursing homes, rehabilitation hospitals, and other care facilities. Patients were randomly divided into an intervention group (n = 74) and a control group (n = 107), whose members received conventional oral care. Body mass index, activities of daily living (Barthel index), and complete blood count and biochemistry parameters were measured at 2, 4, 6, and 8 months. The cumulative incidence of pneumonia at 8 months tended to be lower in the intervention than in the control group (7.8 vs. 17.7%, p = 0.056) and was significantly lower for men in the intervention group (p = 0.046). Our new intervention "wiping plus providing ONS" method appears to help prevent aspiration pneumonia, thereby reducing mortality risk. In this study, we disseminate information on how this method is used in Japan. © 2017 S. Karger AG, Basel.

  9. A solid phase extraction based non-disruptive sampling technique to investigate the surface chemistry of macroalgae.

    Science.gov (United States)

    Cirri, Emilio; Grosser, Katharina; Pohnert, Georg

    2016-01-01

    The surface chemistry of aquatic organisms determines their biotic interactions. Metabolites in the spatially limited laminar boundary layer mediate processes, such as antifouling, allelopathy and chemical defense against herbivores. However, very few methods are available for the investigation of such surface metabolites. An approach is described in which surfaces are extracted by means of C18 solid phase material. By powdering wet algal surfaces with this material, organic compounds are adsorbed and can be easily recovered for subsequent liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS) investigations. The method is robust, picks up metabolites of a broad polarity range and is easy to handle. It is more universal compared to established solvent dipping protocols and it does not cause damage to the test organisms. A protocol is introduced for the macroalgae Fucus vesiculosus, Caulerpa taxifolia and Gracilaria vermiculophylla, but it can be easily transferred to other aquatic organisms.

  10. Decontamination of Surfaces Exposed to Carbon-Based Nanotubes and Nanomaterials

    Directory of Open Access Journals (Sweden)

    Paul Su

    2014-01-01

    Full Text Available Contamination of surfaces by nanomaterials can happen due to accidental spillage and release or gradual accumulation during processing or handling. Considering the increasingly wide use of nanomaterials in industry and research labs and also taking into account the diversity of physical and chemical properties of different nanomaterials (such as solubility, aggregation/agglomeration, and surface reactivity, there is a pressing need to define reliable nanomaterial-specific decontamination guidelines. In this paper, we propose and investigate a potential method for surface decontamination of carbon-based nanomaterials using solvent cleaning and wipes. The results show that the removal efficiency for single- and multiwalled carbon nanotubes from silicon wafers sprayed with water-surfactant solutions prior to mechanical wiping is greater than 90% and 95%, respectively. The need for further studies to understand the mechanisms of nanomaterial removal from surfaces and development of standard techniques for surface decontamination of nanomaterials is highlighted.

  11. Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

    Science.gov (United States)

    Kristin Bunte; Steven R. Abt

    2001-01-01

    This document provides guidance for sampling surface and subsurface sediment from wadable gravel-and cobble-bed streams. After a short introduction to streams types and classifications in gravel-bed rivers, the document explains the field and laboratory measurement of particle sizes and the statistical analysis of particle-size distributions. Analysis of particle...

  12. Stevens Pond: A postglacial pollen diagram from a small Typha Swamp in Northwestern Minnesota, interpreted from pollen indicators and surface samples

    NARCIS (Netherlands)

    Janssen, C.R.

    1967-01-01

    The pollen assemblages of a core in the coniferhardwood formation in northwestern Minnesota are compared with the floristics of the recent vegetation in the region. Percentage levels of the main tree components have been compared first with those from recent surface samples taken at the same short

  13. Subsurface seeding of surface harmful algal blooms observed through the integration of autonomous gliders, moored environmental sample processors, and satellite remote sensing in southern California

    KAUST Repository

    Seegers, Bridget N.

    2015-04-01

    An observational study was performed in the central Southern California Bight in Spring 2010 to understand the relationship between seasonal spring phytoplankton blooms and coastal processes that included nutrient input from upwelling, wastewater effluent plumes, and other processes. Multi-month Webb Slocum glider deployments combined with MBARI environmental sample processors (ESPs), weekly pier sampling, and ocean color data provided a multidimensional characterization of the development and evolution of harmful algal blooms (HABs). Results from the glider and ESP observations demonstrated that blooms of toxic Pseudo-nitzschia sp. can develop offshore and subsurface prior to their manifestation in the surface layer and/or near the coast. A significant outbreak and surface manifestation of the blooms coincided with periods of upwelling, or other processes that caused shallowing of the pycnocline and subsurface chlorophyll maximum. Our results indicate that subsurface populations can be an important source for “seeding” surface Pseudo-nitzschia HAB events in southern California.

  14. Sample-first preparation: a method for surface-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of cyclic oligosaccharides.

    Science.gov (United States)

    Wu, Hsin-Pin; Su, Chih-Lin; Chang, Hui-Chiu; Tseng, Wei-Lung

    2007-08-15

    A new sample preparation method for the analysis of cyclic oligosaccharides in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is presented. We call this new technique "sample first method", in which a sample is deposited first and then bare gold nanoparticles (AuNPs), which serve as the SALDI matrixes, are added to the top of the sample layer. The use of the sample first method offers significant advantages for improving shot-to-shot reproducibility, enhancing the ionization efficiency of the analyte, and reducing sample preparation time as compared to the dried-droplet method, wherein samples and bare AuNPs are mixed and dried together. The relative standard deviation (RSD) values of the signal intensity as calculated from 65 sample spots was 25% when the sample first methods were applied to the analysis of beta-cyclodextrin. The results were more homogeneous as compared to the outcome using dried-droplet preparation of AuNPs (RSD=66%) and 2,5-dihydroxybenzoic acid (RSD=209%). We also found out that the optimal concentration of AuNP for ionization efficiency is 7.4 nM (4.52x10(12) particles/mL) while the lowest detectable concentration of cyclic oligosaccharides through this approach is 0.25 microM. Except for the cyclic oligosaccharide, the proposed method was also applied to the analyses of other biological samples, including neutral carbohydrate and steroid, aminothiols, and peptides as well as proteins.

  15. Androgenic activity in surface water samples detected using the AR-LUX assay: Indications for mixture effects

    NARCIS (Netherlands)

    Blankvoort, B.M.G.; Rodenburg, R.J.T.; Murk, A.J.; Koeman, J.H.; Schilt, R.; Aarts, J.M.M.J.G.

    2005-01-01

    This paper describes the screening of 22 extracts from 18 different aquatic environmental samples for androgenic activity, including indirect and interactive effects on androgen receptor (AR)-mediated signal transduction, using the AR-LUX bioassay. Four samples, originating from an industrial

  16. A comparison of tonsillar surface swabbing, fine-needle aspiration core sampling, and dissected tonsillar core biopsy culture in children with recurrent tonsillitis.

    Science.gov (United States)

    Sarkar, Saurav; Sil, Abheek; Sarkar, Soma; Sikder, Biswajit

    2017-06-01

    In recurrent tonsillitis, the pathogenic bacteria are harbored in the tonsil core, and therefore cultures of superficial swab samples are not particularly accurate in identifying specific types of core bacteria. On the other hand, the results of fine-needle aspiration (FNA) cultures of core samples have been closely correlated with the findings of core cultures in excised tonsils, and both methods are far superior to surface swabbing. We conducted a prospective study to compare the accuracy of culture findings from tonsillar tissue obtained by surface swabbing, FNA sampling of the tonsil core in situ, and core sampling of the excised tonsil in children with recurrent tonsillitis. Our patient population was made up of 54 children-22 boys and 32 girls, aged 4 to 14 years (mean: 10.7)-who were undergoing elective tonsillectomy during a 1-year period. On the day of surgery, a surface swab, core FNA sample, and dissected core sample were obtained from each patient and sent for culture. Culture showed that the three methods were in agreement in 34 cases (63.0%). In 9 cases (16.7%) the surface swab culture grew different pathogens from those of the two core cultures, and in 3 other cases (5.6%) the surface swab culture was negative while the two core cultures were positive for the same pathogens. In all, the results of core FNA culture and dissected core culture were in agreement in 46 cases (85.2%); in only 4 cases (7.4%) did the core FNA culture fail to accurately identify the causative pathogens. Overall, the sensitivity and specificity of core FNA sampling were 100 and 50% respectively, compared with 82.9 and 30.8% for the superficial tonsillar swab. We conclude that routine culture of surface swab specimens in patients with chronic or recurrent tonsillitis is neither reliable nor valid. We recommend that core FNA sampling be considered the diagnostic method of choice since it can be done on an outpatient basis, it would reliably allow for culture-directed antibiotic

  17. Fe3O4@Graphene Oxide@Ag Particles for Surface Magnet Solid-Phase Extraction Surface-Enhanced Raman Scattering (SMSPE-SERS): From Sample Pretreatment to Detection All-in-One.

    Science.gov (United States)

    Liu, Zhigang; Wang, Yi; Deng, Rong; Yang, Liyuan; Yu, Shihua; Xu, Shuping; Xu, Weiqing

    2016-06-08

    A multifunctional magnetic graphene surface-enhanced Raman scattering (SERS) substrate was fabricated successfully by the layer-by-layer assembly of silver and graphene oxide (GO) nanoparticles (NPs) on the magnetic ferroferric oxide particles (Fe3O4@GO@Ag). This ternary particle possesses magnetic properties, SERS activity, and adsorption ability simultaneously. Owing to the multifunction of this Fe3O4@GO@Ag ternary complex, we put forward a new method called a surface magnetic solid-phase extraction (SMSPE) technique, for the SERS detections of pesticide residues on the fruit peels. SMSPE integrates many sample pretreatment procedures, such as surface extraction, separation sample, and detection, all-in-one. So this method shows great superiority in simplicity, rapidity, and high efficiency above other standard methods. The whole detection process can be finished within 20 min including the sample pretreatment and SERS detection. Owing to the high density of Ag NPs, the detection sensitivity is high enough that the lowest detectable concentrations are 0.48 and 40 ng/cm(2) for thiram and thiabendazole, which are much lower than the maximal residue limits in fruit prescribed by the U.S. Environmental Protection Agency. This multifunctional ternary particle and its corresponding analytical method have been proven to be applicable for practical samples and also valuable for other surface analysis.

  18. Data Validation Package August 2015 Groundwater and Surface Water Sampling at the Tuba City, Arizona, Disposal Site November 2015

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Richard [USDOE Office of Legacy Management, Washington, DC (United States); Lemke, Peter [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2015-11-01

    The groundwater compliance strategy for the Tuba City, Arizona, Disposal Site is defined in the 1999 Phase I Ground Water Compliance Action Plan for the Tuba City, Arizona, UMTRA Site. Samples are collected and analyzed on a semiannual basis to evaluate the performance of the Phase I remediation system. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). U.S. Environmental Protection Agency (EPA) groundwater standards were exceeded in samples collected from monitoring wells and extraction wells as listed in Table 1. The data from this sampling event are generally consistent with previously obtained values and are acceptable for general use as qualified. Data anomalies are not significant with respect to the known nature and extent of contamination and progress of remedial action at the site. The data from this sampling event will be incorporated into the annual performance evaluation report that will present a comprehensive hydrologic summary and evaluation of groundwater remedial action performance at the Tuba City site through March 2016.

  19. Data Validation Package February 2016 Groundwater and Surface Water Sampling at the Tuba City, Arizona, Disposal Site April 2016

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Richard [USDOE Office of Legacy Management, Washington, DC (United States); Lemke, Peter [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-04-01

    The groundwater compliance strategy for the Tuba City, Arizona, Disposal Site is defined in the 1999 Phase I Ground Water Compliance Action Plan for the Tuba City, Arizona, UMTRA Site. Samples are collected and analyzed on a semiannual basis to evaluate the performance of the Phase I remediation system. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). U.S. Environmental Protection Agency (EPA) groundwater standards were exceeded in samples collected from monitoring wells as listed in Table 1. The data from this sampling event are generally consistent with previously obtained values and are acceptable for general use as qualified. Data anomalies are not significant with respect to the known nature and extent of contamination and progress of remedial action at the site. The data from this sampling event will be incorporated into the annual performance evaluation report that will present a comprehensive hydrologic summary and evaluation of groundwater remedial action performance at the Tuba City site through March 2016.

  20. Test and validation of methods to sample and detect human virus from environmental surfaces using norovirus as a model virus

    DEFF Research Database (Denmark)

    Ibfelt, T.; Frandsen, T.; Permin, Anders

    2016-01-01

    : To validate and test efficient and reliable procedures to detect multiple human pathogenic viruses on surfaces. Methods: The study was divided into two parts. In Part A, six combinations of three different swabs (consisting of cotton, foamed cotton, or polyester head) and two different elution methods (direct...

  1. Improved HF183 quantitative real-time PCR assay for characterization of human fecal pollution in ambient surface water samples

    Science.gov (United States)

    Real-time quantitative PCR assays that target the human-associated HF183 bacterial cluster are considered to be some of the top performing methods for the characterization of human fecal pollution in ambient surface waters. In response, the United States Environmental Protectio...

  2. Gas chromatographic determination of acid herbicides in surface water samples with electron-capture detection and mass spectrometric confirmation

    NARCIS (Netherlands)

    Vink, M.; Poll, J.M. van der

    1996-01-01

    The development of a multi-residue method for the determination of eight polar acidic herbicides (MCPA, MCPB, mecoprop, 2,4-D, dichlorprop, bentazone, dicamba and dikegulac) in surface water is described. The method involves an off-line solid-phase extraction (SPE) procedure prior to instrumental

  3. The Quadrupole Resonator, Design Considerations and Layout of a New Instrument for the RF Characterization of Superconducting Surface Samples

    CERN Document Server

    Brigant, E; Mahner, E

    1998-01-01

    A disk-shaped superconducting sample is welded onto an Nb support cylinder and exposed to the magnetic RF field of a four-wire transmission line resonator. The fields on the cylinder wall decay in a c ut-off like fashion in such a way that they perturb the measurement very little. RF dissipation of the disk is determined by substitution with a d.c. heater on the back of the sample which is made to produce the same temperature rise, controlled by thermometers.

  4. Summary of inorganic compositional data for groundwater, soil-water, and surface-water samples collected at the Headgate Draw subsurface drip irrigation site, Johnson County, Wyoming

    Science.gov (United States)

    Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupancic, John W.

    2011-01-01

    As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

  5. Summary of Inorganic Compositional Data for Groundwater, Soil-Water, and Surface-Water Samples at the Headgate Draw Subsurface Drip Irrigation Site

    Energy Technology Data Exchange (ETDEWEB)

    Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupanic, John W.

    2007-01-01

    As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

  6. Bisphenol A and other bisphenol analogues including BPS and BPF in surface water samples from Japan, China, Korea and India.

    Science.gov (United States)

    Yamazaki, Eriko; Yamashita, Nobuyoshi; Taniyasu, Sachi; Lam, James; Lam, Paul K S; Moon, Hyo-Bang; Jeong, Yunsun; Kannan, Pranav; Achyuthan, Hema; Munuswamy, Natesan; Kannan, Kurunthachalam

    2015-12-01

    Concentrations of eight bisphenol analogues (BPs) including BPA, BPS, and BPF were determined in surface waters collected from select rivers in Japan, Korea, China, and India. BPA was found at a concentration in the range of several tens to several hundreds of nanograms per liter in most of the rivers surveyed and some of the highest concentrations (54-1950 ng/L) were found in rivers in Chennai, India. Concentrations of BPF were one to two orders of magnitude higher than those of BPA in river and sea waters collected from Japan, Korea and China, which suggested that BPF is a major contaminant in surface waters in several Southeast Asian countries. BPF concentrations as high as 2850 ng/L were found in the Tamagawa River in Japan. The flux of BPs through riverine discharges into Tokyo Bay was calculated to be approximately 5.5 t per year. Based on the flux estimates and the mass of BPF found in water column and sediment in Tokyo Bay, it was found that BPF degrades faster than BPA in the environment. Elevated concentrations of BPF found in surface waters suggest the need for further studies to determine the fate and toxicity of this compound. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Estrogen-, androgen- and aryl hydrocarbon receptor mediated activities in passive and composite samples from municipal waste and surface waters.

    Science.gov (United States)

    Jálová, V; Jarošová, B; Bláha, L; Giesy, J P; Ocelka, T; Grabic, R; Jurčíková, J; Vrana, B; Hilscherová, K

    2013-09-01

    Passive and composite sampling in combination with in vitro bioassays and identification and quantification of individual chemicals were applied to characterize pollution by compounds with several specific modes of action in urban area in the basin of two rivers, with 400,000 inhabitants and a variety of industrial activities. Two types of passive samplers, semipermeable membrane devices (SPMD) for hydrophobic contaminants and polar organic chemical integrative samplers (POCIS) for polar compounds such as pesticides and pharmaceuticals, were used to sample wastewater treatment plant (WWTP) influent and effluent as well as rivers upstream and downstream of the urban complex and the WWTP. Compounds with endocrine disruptive potency were detected in river water and WWTP influent and effluent. Year-round, monthly assessment of waste waters by bioassays documented estrogenic, androgenic and dioxin-like potency as well as cytotoxicity in influent waters of the WWTP and allowed characterization of seasonal variability of these biological potentials in waste waters. The WWTP effectively removed cytotoxic compounds, xenoestrogens and xenoandrogens. There was significant variability in treatment efficiency of dioxin-like potency. The study indicates that the WWTP, despite its up-to-date technology, can contribute endocrine disrupting compounds to the river. Riverine samples exhibited dioxin-like, antiestrogenic and antiandrogenic potencies. The study design enabled characterization of effects of the urban complex and the WWTP on the river. Concentrations of PAHs and contaminants and specific biological potencies sampled by POCIS decreased as a function of distance from the city. © 2013.

  8. Multipurpose floating platform for hyperspectral imaging, sampling and sensing of surface water sources used in irrigation and recreation

    Science.gov (United States)

    The objective of this work was to design, construct, and test the self-propelled aquatic platform for imaging, multi-tier water sampling, water quality sensing, and depth profiling to document microbial content and environmental covariates in the interior of irrigation ponds and reservoirs. The plat...

  9. Occurrence of Bacteria and Viruses on Elementary Classroom Surfaces and the Potential Role of Classroom Hygiene in the Spread of Infectious Diseases

    Science.gov (United States)

    Bright, Kelly R.; Boone, Stephanie A.; Gerba, Charles P.

    2010-01-01

    The presence of microorganisms on common classroom contact surfaces (fomites) was determined to identify the areas most likely to become contaminated. Six elementary classrooms were divided into control and intervention groups (cleaned daily with a quaternary ammonium wipe) and tested for heterotrophic bacteria. Three classrooms were also tested…

  10. Surface plasmon resonance sensor based on golden nanoparticles and cold vapour generation technique for the detection of mercury in aqueous samples

    Science.gov (United States)

    Castillo, Jimmy; Chirinos, José; Gutiérrez, Héctor; La Cruz, Marie

    2017-09-01

    In this work, a surface plasmon resonance sensor for determination of Hg based on golden nanoparticles was developed. The sensor follows the change of the signal from solutions in contact with atomic mercury previously generated by the reaction with sodium borohydride. Mie theory predicts that Hg film, as low as 5 nm, induced a significant reduction of the surface plasmon resonance signal of 40 nm golden nanoparticles. This property was used for quantification purposes in the sensor. The device provide limits of detection of 172 ng/L that can compared with the 91 ng/L obtained with atomic fluorescence, a common technique used for Hg quantification in drinking water. This result was relevant, considering that it was not necessary to functionalize the nanoparticles or use nanoparticles deposited in a substrate. Also, thanks that Hg is released from the matrix, the surface plasmon resonance signal was not affected by concomitant elements in the sample.

  11. To tilt or not to tilt: Correction of the distortion caused by inclined sample surfaces in low-energy electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Sojka, Falko, E-mail: falko.sojka@uni-jena.de [Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena (Germany); Meissner, Matthias; Zwick, Christian; Forker, Roman [Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena (Germany); Vyshnepolsky, Michael; Klein, Claudius; Horn-von Hoegen, Michael [University of Duisburg-Essen, Department of Physics, Lotharstr. 1, 47057 Duisburg (Germany); Fritz, Torsten, E-mail: torsten.fritz@uni-jena.de [Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena (Germany)

    2013-10-15

    Low-energy electron diffraction (LEED) is a widely employed technique for the structural characterization of crystalline surfaces and epitaxial adsorbates. For technical reasons the accessible reciprocal space is limited at a given primary electron energy E. This limitation may be overcome by sweeping E to observe higher diffraction orders decisively enhancing the quantitative examination. Yet, in many cases, such as molecular films with rather large unit cells, the adsorbate reflexes become less pronounced at energies high enough to observe substrate reflexes. One possibility to overcome this problem is an intentional inclination of the sample surface during the measurement at the expense of the quantitative interpretability of then severely distorted diffraction patterns. Here, we introduce a correction method for the axially symmetric distortion in LEED images of tilted samples. We provide experimental confirmation for micro-channel plate LEED and spot-profile analysis LEED instruments using the (7×7) reconstructed surface of a Si(111) single crystal as a reference sample. Finally, we demonstrate that the correction of this distortion considerably improves the quantitative analysis of diffraction patterns of adsorbates since substrate and adsorbate reflexes can be evaluated simultaneously. As an illustrative example we have chosen an epitaxial monolayer of 3,4,9,10-perylenetetracarboxylic dianhydride on Ag(111) that is known to form a commensurate superstructure. - Highlights: • We introduce a method to correct distortions in LEED patterns of tilted surfaces. • Higher diffraction orders unobservable at higher beam energies can be evaluated. • Our procedure makes LEED patterns of tilted samples quantitatively analyzable. • Experimental confirmation with SPA-LEED and MCP-LEED is presented. • The method is applied to PTCDA on Ag(111) confirming earlier literature values.

  12. Astrobiological Significance of Definitive Mineralogical Analysis of Martian Surface Samples Using the CheMin XRD/XRF Instrument

    Science.gov (United States)

    Feldman, S. M.; Blake, D. F.; Sarrazin, P.; Bish, D. L.; Chipera, S. J.; Vaniman, D. T.; Collins, S.

    2004-01-01

    The search for evidence of habitability, or of extant or extinct life on Mars, will initially be a search for evidence of past or present conditions supportive of life. The three key requirements for the emergence of life are thought to be liquid water; a suitable energy source; and chemical building blocks. CheMin is a miniaturized XRD/XRF (X-Ray diffraction / X-ray fluorescence) instrument which has been developed for definitive mineralogic analysis of soils and rocks on the Martian surface. The CheMin instrument can provide information that is highly relevant to each of these habitability requirements as summarized below.

  13. Quantification of Saccharides in Honey Samples Through Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Using HgTe Nanostructures

    Science.gov (United States)

    Wang, Chia-Wei; Chen, Wen-Tsen; Chang, Huan-Tsung

    2014-07-01

    Quantification of monosaccharides and disaccharides in five honey samples through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using HgTe nanostructures as the matrix and sucralose as an internal standard has been demonstrated. Under optimal conditions (1× HgTe nanostructure, 0.2 mM ammonium citrate at pH 9.0), the SALDI-MS approach allows detection of fructose and maltose at the concentrations down to 15 and 10 μM, respectively. Without conducting tedious sample pretreatment and separation, the SALDI-MS approach allows determination of the contents of monosaccharides and disaccharides in honey samples within 30 min, with reproducibility (relative standard deviation <15%). Unlike only sodium adducts of standard saccharides detected, sodium adducts and potassium adducts with differential amounts have been found among various samples, showing different amounts of sodium and potassium ions in the honey samples. The SALDI-MS data reveal that the contents of monosaccharides and disaccharides in various honey samples are dependent on their nectar sources. In addition to the abundant amounts of monosaccharides and disaccharides, oligosaccharides in m/z range of 650 - 2700 are only detected in pomelo honey. Having advantages of simplicity, rapidity, and reproducibility, this SALDI-MS holds great potential for the analysis of honey samples.

  14. Recovery Efficiency, False Negative Rate, and Limit of Detection Performance of a Validated Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deatherage Kaiser, Brooke L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sydor, Michael A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barrett, Christopher A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-31

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in. × 2 in.) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2, where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent report.

  15. Recovery Efficiency, False Negative Rate, and Limit of Detection Performance of a Validated Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kaiser, Brooke L. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sydor, Michael A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barrett, Christopher A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-16

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in × 2 in) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2, where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results are discussed in a separate report.

  16. Examination of metals from aerospace-related activity in surface water samples from sites surrounding the Kennedy Space Center (KSC), Florida.

    Science.gov (United States)

    Bowden, John A; Cantu, Theresa M; Scheidt, Douglas M; Lowers, Russell H; Nocito, Brian A; Young, Vaneica Y; Guillette, Louis J

    2014-05-06

    Metal contamination from Space Shuttle launch activity was examined using inductively coupled plasma-atomic emission spectroscopy in a two-tier study sampling surface water collected from several sites at the Kennedy Space Center (KSC) and associated Merritt Island National Wildlife Refuge in east central Florida. The primary study examined both temporal changes in baseline metal concentrations (19 metals) in surface water (1996 to 2009, 11 sites) samples collected at specific long-term monitoring sites and metal deposition directly associated with Space Shuttle launch activity at two Launch Complexes (LC39A and LC39B). A secondary study examined metal concentrations at additional sites and increased the amount of elements measured to 48 elements. Our examination places a heavy focus on those metals commonly associated with launch operations (e.g., Al, Fe, Mn, and Zn), but a brief discussion of other metals (As, Cu, Mo, Ni, and Pb) is also included. While no observable accumulation of metals occurred during the time period of the study, the data obtained postlaunch demonstrated a dramatic increase for Al, Fe, Mn, and Zn. Comparing overall trends between the primary and secondary baseline surface water concentrations, elevated concentrations were generally observed at sampling stations located near the launch complexes and from sites isolated from major water systems. While there could be several natural and anthropogenic sources for metal deposition at KSC, the data in this report indicate that shuttle launch events are a significant source.

  17. Field Geologic Observation and Sample Collection Strategies for Planetary Surface Exploration: Insights from the 2010 Desert RATS Geologist Crewmembers

    Science.gov (United States)

    Hurtado, Jose M., Jr.; Young, Kelsey; Bleacher, Jacob E.; Garry, W. Brent; Rice, James W., Jr.

    2012-01-01

    Observation is the primary role of all field geologists, and geologic observations put into an evolving conceptual context will be the most important data stream that will be relayed to Earth during a planetary exploration mission. Sample collection is also an important planetary field activity, and its success is closely tied to the quality of contextual observations. To test protocols for doing effective planetary geologic field- work, the Desert RATS(Research and Technology Studies) project deployed two prototype rovers for two weeks of simulated exploratory traverses in the San Francisco volcanic field of northern Arizona. The authors of this paper represent the geologist crew members who participated in the 2010 field test.We document the procedures adopted for Desert RATS 2010 and report on our experiences regarding these protocols. Careful consideration must be made of various issues that impact the interplay between field geologic observations and sample collection, including time management; strategies relatedtoduplicationofsamplesandobservations;logisticalconstraintson the volume and mass of samples and the volume/transfer of data collected; and paradigms for evaluation of mission success. We find that the 2010 field protocols brought to light important aspects of each of these issues, and we recommend best practices and modifications to training and operational protocols to address them. Underlying our recommendations is the recognition that the capacity of the crew to flexibly execute their activities is paramount. Careful design of mission parameters, especially field geologic protocols, is critical for enabling the crews to successfully meet their science objectives.

  18. Investigation of Cathode Electrocatalytic Activity using Surface Engineered Thin Film Samples and High Temperature Physical Property Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, Paul [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2014-02-23

    In this Final Technical Report, a summary of the technical output from the award DE-NT0004105 is given. First, the major goals and observations from the project are reviewed and then specific example results are presented as highlights. The surprising importance of microstructure on the surface chemical exchange coefficient in La0.7Sr0.3MnO3 (LSM) was uncovered in this work and is re-emphasized in this report. Significant orientation and thickness dependencies of the surface exchange coefficient are correlated with microstructural effects, especially to the nature of the strain, dislocation content, and grain boundary population. We also illustrate similar microstructural effects are present in other SOFC cathode systems, including LSCF (La1-xSrxCo1-yFeyO3) and La2NiO4 (LNO). Throughout the report, the relation to SOFC cathode performance is discussed.

  19. The antiquity indicator argon-40/argon-36 for lunar surface samples calibrated by uranium-235-xenon-136 dating

    Science.gov (United States)

    Eugster, Otto; Terribilini, Dario; Polnau, Ernst; Kramers, Jan

    2001-08-01

    Several solar gas rich lunar soils and breccias have trapped 40Ar/36Ar ratios >10, although solar Ar is expected to yield a ratio of soils 70001-8, 70181, 74261, and 75081. Uranium and Th concentrations were determined in the 74261 soil for which we obtain the 235U-136Xe time of implantation of Ga ago. On the basis of several cosmogenic noble gas signatures we calculate the duration of this near surface exposure of 393 +/- 45 Ma and an average shielding depth below the lunar surface of 73 +/- 7 g/cm2. A second, recent exposure to solar and cosmic-ray particles occurred after this soil was excavated from Shorty crater 17.2 +/- 1.4 Ma ago. Using a compilation of all lunar data with reliable trapped Ar isotopic ratios and pre-exposure times we infer a calibration curve of implantation times, based on the trapped 40Ar/36Ar ratio. A possible trend for the increase with time of the solar 3He/4He and 20Ne/22Ne ratios of about 12%/Ga and about 2%/Ga, respectively, is also discussed.

  20. Extensive surface protein profiles of extracellular vesicles from cancer cells may provide diagnostic signatures from blood samples

    Directory of Open Access Journals (Sweden)

    Larissa Belov

    2016-04-01

    Full Text Available Extracellular vesicles (EV are membranous particles (30–1,000 nm in diameter secreted by cells. Important biological functions have been attributed to 2 subsets of EV, the exosomes (bud from endosomal membranes and the microvesicles (MV; bud from plasma membranes. Since both types of particles contain surface proteins derived from their cell of origin, their detection in blood may enable diagnosis and prognosis of disease. We have used an antibody microarray (DotScan to compare the surface protein profiles of live cancer cells with those of their EV, based on their binding patterns to immobilized antibodies. Initially, EV derived from the cancer cell lines, LIM1215 (colorectal cancer and MEC1 (B-cell chronic lymphocytic leukaemia; CLL, were used for assay optimization. Biotinylated antibodies specific for EpCAM (CD326 and CD19, respectively, were used to detect captured particles by enhanced chemiluminescence. Subsequently, this approach was used to profile CD19+ EV from the plasma of CLL patients. These EV expressed a subset (~40% of the proteins detected on CLL cells from the same patients: moderate or high levels of CD5, CD19, CD31, CD44, CD55, CD62L, CD82, HLA-A,B,C, HLA-DR; low levels of CD21, CD49c, CD63. None of these proteins was detected on EV from the plasma of age- and gender-matched healthy individuals.

  1. Forsmark site investigation. Hydrochemical monitoring of groundwaters and surface waters. Results from water sampling in the Forsmark area, January-December 2009

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Ann-Chatrin (ed.); Berg, Cecilia; Harrstroem, Johan; Joensson, Stig; Thur, Pernilla (Geosigma AB (Sweden)); Borgiel, Micke; Qvarfordt, Susanne (Sveriges Vattenekologer AB (Sweden))

    2010-09-15

    The fifth year (2009) of hydrochemical monitoring of groundwaters, surface waters and precipitation in Forsmark is documented in the report. The hydrochemical monitoring programme 2009 included water sampling from: - percussion- and core boreholes equipped with installations for long-term pressure monitoring, tracer tests and water sampling in packed off borehole sections, sampling and analysis performed twice (spring and autumn), - near surface groundwaters (sampling four times a year), - private wells (once per year in October), - surface waters (eleven sampling occasions per year). Due to the somewhat different performance of the hydrogeochemical monitoring of the deep groundwaters during the autumn 2009 compared to previous years, some new findings and knowledge were obtained: 1) Removal of water volumes corresponding to three to five times the volume of the borehole section (the routine procedure) is seldom enough to obtain a complete exchange of the water present in the borehole section when the pumping starts. 2) It is likely that the elevated sulphide concentrations observed in the monitoring programme /1/ is due to contamination from initial water present in the borehole sections when the pumping starts. This water may have a very high sulphide concentration. Dirty water in tubes and in stand pipes may also contribute to the enhanced sulphide concentration. 3) Plug flow calculations will be introduced in the future as a new routine procedure to estimate the water volumes to be removed, in order to exchange the section water volume, prior to groundwater sampling in delimited borehole sections. During the autumn sampling, sample series of five samples per sampling location were collected during continuous pumping in thirteen selected borehole sections. Furthermore, special efforts were put on cleaning of stand pipes and exchange of water prior to sampling. The analytical protocol was rather extensive and included sulphide and uranium analyses for each sample

  2. Performance evaluation of different diamond-like carbon samples as charge state conversion surfaces for neutral atom imaging detectors in space applications

    Science.gov (United States)

    Brigitte Neuland, Maike; Allenbach, Marc; Föhn, Martina; Wurz, Peter

    2017-04-01

    The detection of energetic neutral atoms is a substantial requirement on every space mission mapping particle populations of a planetary magnetosphere or plasma of the interstellar medium. For imaging neutrals, these first have to be ionised. Regarding the constraints of weight, volume and power consumption, the technique of surface ionisation complies with all specifications of a space mission. Particularly low energy neutral atoms, which cannot be ionised by passing through a foil, are ionised by scattering on a charge state conversion surface [1]. Since more than 30 years intense research work is done to find and optimise suitable materials for use as charge state conversion surfaces for space application. Crucial parameters are the ionisation efficiency of the surface material and the scattering properties. Regarding these parameters, diamond-like carbon was proven advantageously: While efficiently ionising incoming neutral atoms, diamond stands out by its durability and chemical inertness [2]. In the IBEX-Lo sensor, a diamond-like carbon surface is used for ionisation of neutral atoms. Building on the successes of the IBEX mission [3], the follow up mission IMAP (InterstellarMApping Probe) will take up to further explore the boundaries of the heliosphere. The IMAP mission is planned to map neutral atoms in a larger energy range and with a distinct better angular resolution and sensitivity than IBEX [4]. The aspired performance of the IMAP sensors implies also for charge state conversion surfaces with improved characteristics. We investigated samples of diamond-like carbon, manufactured by the chemical vapour deposition (CVD) method, regarding their ionisation efficiency, scattering and reflexion properties. Experiments were carried out at the ILENA facility at the University of Bern [5] with hydrogen and oxygen atoms, which are the species of main interest in magnetospheric research [1]. We compare the results of earlier investigations of a metallised CVD

  3. Zn(II)-concentration dependent Raman spectra in the dithizone complex on gold nanoparticle surfaces in environmental water samples

    Science.gov (United States)

    Ly, Nguyen Hoang; Joo, Sang-Woo

    2015-11-01

    After the formation of dithizone with metal ion complexes, a selective Raman detection method for the Zn2+ ions in aqueous solutions was developed by observing the intensity change of the ring mode peaks at ∼1585 cm-1 on gold nanoparticles (AuNPs). At high concentrations of Zn2+ ions, the conformation of the dithizone complex may have different orientations on AuNPs to yield the spectral changes at ca. ∼510 and ∼1585 cm-1. The concentration dependent spectra changes indicated that a detection limit would be in the submicromolar region of Zn2+ ions. The other ions of Mg2+, K+, Fe3+, Hg2+, Co2+, Fe2+, Pb2+, Cu2+, Ni2+, Cr3+, NH4+, Cd2+, Na+, Ca2+, and Mn2+ at micromolar concentrations of 1 μM did not produce such spectral changes. The detection limit based on the Raman band intensities was estimated to be as low as 500 nM of Zn2+ ion in aqueous solutions. The three real samples of tap, river, and seawater were tested under the interference of the commonly existing interfering ions. Despite the presence of highly concentrated Na, Ca, Mg, and K, our interfacial spectroscopic methodology of Zn2+ determination could be applied in the environmental water samples.

  4. Comparative exploration of hydrogen sulfide and water transmembrane free energy surfaces via orthogonal space tempering free energy sampling.

    Science.gov (United States)

    Lv, Chao; Aitchison, Erick W; Wu, Dongsheng; Zheng, Lianqing; Cheng, Xiaolin; Yang, Wei

    2016-03-05

    Hydrogen sulfide (H2 S), a commonly known toxic gas compound, possesses unique chemical features that allow this small solute molecule to quickly diffuse through cell membranes. Taking advantage of the recent orthogonal space tempering (OST) method, we comparatively mapped the transmembrane free energy landscapes of H2 S and its structural analogue, water (H2 O), seeking to decipher the molecular determinants that govern their drastically different permeabilities. As revealed by our OST sampling results, in contrast to the highly polar water solute, hydrogen sulfide is evidently amphipathic, and thus inside membrane is favorably localized at the interfacial region, that is, the interface between the polar head-group and nonpolar acyl chain regions. Because the membrane binding affinity of H2 S is mainly governed by its small hydrophobic moiety and the barrier height inbetween the interfacial region and the membrane center is largely determined by its moderate polarity, the transmembrane free energy barriers to encounter by this toxic molecule are very small. Moreover when H2 S diffuses from the bulk solution to the membrane center, the above two effects nearly cancel each other, so as to lead to a negligible free energy difference. This study not only explains why H2 S can quickly pass through cell membranes but also provides a practical illustration on how to use the OST free energy sampling method to conveniently analyze complex molecular processes. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  5. Sample entropy and regularity dimension in complexity analysis of cortical surface structure in early Alzheimer's disease and aging.

    Science.gov (United States)

    Chen, Ying; Pham, Tuan D

    2013-05-15

    We apply for the first time the sample entropy (SampEn) and regularity dimension model for measuring signal complexity to quantify the structural complexity of the brain on MRI. The concept of the regularity dimension is based on the theory of chaos for studying nonlinear dynamical systems, where power laws and entropy measure are adopted to develop the regularity dimension for modeling a mathematical relationship between the frequencies with which information about signal regularity changes in various scales. The sample entropy and regularity dimension of MRI-based brain structural complexity are computed for early Alzheimer's disease (AD) elder adults and age and gender-matched non-demented controls, as well as for a wide range of ages from young people to elder adults. A significantly higher global cortical structure complexity is detected in AD individuals (page-related exacerbation of cortical structural irregularity. The provided model can be potentially used as an imaging bio-marker for early prediction of AD and age-related cognitive decline. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Application of a high surface area solid-phase microextraction air sampling device: collection and analysis of chemical warfare agent surrogate and degradation compounds.

    Science.gov (United States)

    Stevens, Michael E; Tipple, Christopher A; Smith, Philip A; Cho, David S; Mustacich, Robert V; Eckenrode, Brian A

    2013-09-17

    This work examines a recently improved, dynamic air sampling technique, high surface area solid-phase microextraction (HSA-SPME), developed for time-critical, high-volume sampling and analysis scenarios. The previously reported HSA-SPME sampling device, which provides 10-fold greater surface area compared to commercially available SPME fibers, allowed for an increased analyte uptake per unit time relative to exhaustive sampling through a standard sorbent tube. This sampling device has been improved with the addition of a type-K thermocouple and a custom heater control circuit for direct heating, providing precise (relative standard deviation ∼1%) temperature control of the desorption process for trapped analytes. Power requirements for the HSA-SPME desorption process were 30-fold lower than those for conventional sorbent-bed-based desorption devices, an important quality for a device that could be used for field analysis. Comparisons of the HSA-SPME device when using fixed sampling times for the chemical warfare agent (CWA) surrogate compound, diisopropyl methylphosphonate (DIMP), demonstrated that the HSA-SPME device yielded a greater chromatographic response (up to 50%) relative to a sorbent-bed method. Another HSA-SPME air sampling approach, in which two devices are joined in tandem, was also evaluated for very rapid, low-level, and representative analysis when using discrete sampling times for the compounds of interest. The results indicated that subparts per billion by volume concentration levels of DIMP were detectable with short sampling times (∼15 s). Finally, the tandem HSA-SPME device was employed for the headspace sampling of a CWA degradation compound, 2-(diisopropylaminoethyl) ethyl sulfide, present on cloth material, which demonstrated the capability to detect trace amounts of a CWA degradation product that is estimated to be less volatile than sarin. The rapid and highly sensitive detection features of this device may be beneficial in decision

  7. Data Validation Package November 2015 Groundwater and Surface Water Sampling at the Old and New Rifle, Colorado, Processing Sites February 2016

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Richard [USDOE Office of Legacy Management, Washington, DC (United States); Lemke, Peter [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-02-01

    Water samples were collected from 36 locations at New Rifle and Old Rifle, Colorado, Processing Sites. Duplicate samples were collected from New Rifle locations 0659 and 0855, and Old Rifle location 0304. One equipment blank was collected after decontamination of non-dedicated equipment used to collect one surface water sample. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). New Rifle Site Samples were collected at the New Rifle site from 16 monitoring wells and 7 surface locations in compliance with the December 2008 Groundwater Compliance Action Plan [GCAP] for the New Rifle, Colorado, Processing Site (LMS/RFN/S01920), with one exception: New Rifle location 0635 could not be sampled because it was inaccessible; a fence installed by the Colorado Department of Transportation prevents access to this location. DOE is currently negotiating access with the Colorado Department of Transportation. Analytes measured at the New Rifle site included contaminants of concern (COCs) (arsenic, molybdenum, nitrate + nitrite as nitrogen, selenium, uranium, and vanadium) ammonia as nitrogen, major cations, and major anions. Field measurements of total alkalinity, oxidation- reduction potential, pH, specific conductance, turbidity, and temperature were made at each location, and the water level was measured at each sampled well. A proposed alternate concentration limit (ACL) for vanadium of 50 milligrams per liter (mg/L), specific to the compliance (POC) wells (RFN-0217, -0659, -0664, and -0669) is included in the New Rifle GCAP. Vanadium concentrations in the POC wells were below the proposed ACL as shown in the time-concentration graphs in the Data Presentation section (Attachment 2). Time-concentration graphs from all other locations sampled are also included in Attachment 2. Sampling location RFN-0195 was misidentified for the June/August 2014

  8. Full-waveform Airborne and Spaceborne Laser Altimetry for Mapping and Sampling the Earth's Forests, Cryosphere, and Land surfaces

    Science.gov (United States)

    Blair, J. B.; Dubayah, R.; Hofton, M. A.; Luthcke, S. B.; Rabine, D.; Wake, S.; Coyle, B.; Stysley, P.; Salerno, C.

    2014-12-01

    Laser altimetry is an established technique for providing precise and accurate measurements of topography, vegetation, ice sheets, glaciers and sea ice. The Land, Vegetation, and Ice Sensor (LVIS) is a wide swath, full-waveform laser altimeter that has been operational since the late 1990's and has mapped 100,000's of square kilometers around the globe. NASA is developing a Facility version of the LVIS sensor to make it more cost-effective and more easily available to the broader science community. Based heavily on the existing LVIS sensor, the Facility LVIS instrument includes numerous improvements for reliability, resolution, real-time performance monitoring, lower cost for integration and ops, and data consistency. Building upon the foundation provided by LVIS, the Global Ecosystem Dynamics Investigation (GEDI) Lidar was recently selected for funding as a part of NASA's Earth Venture Program and will use multiple laser beams to measure high-resolution forest structure and surface topography from the International Space Station (ISS). Dependent on the funding profile and availability of launch options to ISS, GEDI could launch as early as 2018. Within a single year of operations GEDI will provide billions of vegetation height and structure measurements for the precise estimation of biomass within the orbital coverage provided by ISS (+/- 51.6 degrees latitude). GEDI uses the same high-SNR waveform measurement technique as the airborne LVIS sensor. LVIS will provide calibration and validation of GEDI's on-orbit performance.

  9. MANAGING SOURCES TO REDUCE RISK IN AND AROUND THE INDOOR ENVIRONMENT: IMPACT OF COATINGS ON DISLODGEABLE ARSENIC ON THE SURFACES OF CCA-TREATED WOOD

    Science.gov (United States)

    Due to the potential for ingestion of chromated copper arsenate (CCA) by the hand-to-mouth activities of young children who contact CCA treated wood, EPA has used wipe samples to study the potential benefits of paint-like coatings on CCA treated wood. Citizens who may be concern...

  10. Potential use of copper as a hygienic surface; problems associated with cumulative soiling and cleaning.

    Science.gov (United States)

    Airey, P; Verran, J

    2007-11-01

    It has been suggested that antibacterial copper could be used in place of stainless steel to help reduce the occurrence of hospital-acquired infections. The antibacterial activity of copper has been clearly demonstrated when using cell suspensions held in prolonged contact with copper or copper alloys. The aim of this study was to evaluate the antimicrobial properties of copper in comparison with stainless steel in a generally dry environment. Three stainless steels of varying surface finish and polished copper were soiled with Staphylococcus aureus suspended in a protein-based organic soil (bovine serum album), dried rapidly, and then incubated for 24 h. Surfaces were then wiped clean using a standardised wiping procedure with two cleaning agents recommended by UK National Health Service guidelines. This soiling/cleaning procedure was carried out daily over five days. After each cleaning cycle the amount of residual soil and live cells was assessed using direct epifluorescence microscopy. All materials were easily cleaned after the first soiling episode but a build-up of cells and soil was observed on the copper surfaces after several cleaning/wiping cycles. Stainless steel remained highly cleanable. Accumulation of material on copper is presumably due to the high reactivity of copper, resulting in surface conditioning. This phenomenon will affect subsequent cleaning, aesthetic properties and possibly antibacterial performance. It is important to select the appropriate cleaning/disinfecting protocols for selected surfaces.

  11. Disposable surface plasmon resonance aptasensor with membrane-based sample handling design for quantitative interferon-gamma detection.

    Science.gov (United States)

    Chuang, Tsung-Liang; Chang, Chia-Chen; Chu-Su, Yu; Wei, Shih-Chung; Zhao, Xi-hong; Hsueh, Po-Ren; Lin, Chii-Wann

    2014-08-21

    ELISA and ELISPOT methods are utilized for interferon-gamma (IFN-γ) release assays (IGRAs) to detect the IFN-γ secreted by T lymphocytes. However, the multi-step protocols of the assays are still performed with laboratory instruments and operated by well-trained people. Here, we report a membrane-based microfluidic device integrated with a surface plasmon resonance (SPR) sensor to realize an easy-to-use and cost effective multi-step quantitative analysis. To conduct the SPR measurements, we utilized a membrane-based SPR sensing device in which a rayon membrane was located 300 μm under the absorbent pad. The basic equation covering this type of transport is based on Darcy's law. Furthermore, the concentration of streptavidin delivered from a sucrose-treated glass pad placed alongside the rayon membrane was controlled in a narrow range (0.81 μM ± 6%). Finally, the unbound molecules were removed by a washing buffer that was pre-packed in the reservoir of the chip. Using a bi-functional, hairpin-shaped aptamer as the sensing probe, we specifically detected the IFN-γ and amplified the signal by binding the streptavidin. A high correlation coefficient (R(2) = 0.995) was obtained, in the range from 0.01 to 100 nM. A detection limit of 10 pM was achieved within 30 min. Thus, the SPR assay protocols for IFN-γ detection could be performed using this simple device without an additional pumping system.

  12. Spatial patterns of distribution, abundance, and species diversity of small odontocetes estimated using density surface modeling with line transect sampling

    Science.gov (United States)

    Kanaji, Yu; Okazaki, Makoto; Miyashita, Tomio

    2017-06-01

    Spatial patterns of distribution, abundance, and species diversity of small odontocetes including species in the Delphinidae and Phocoenidae families were investigated using long-term dedicated sighting survey data collected between 1983 and 2006 in the North Pacific. Species diversity indices were calculated from abundance estimated using density surface modeling of line-transect data. The estimated abundance ranged from 19,521 individuals in killer whale to 1,886,022 in pantropical spotted dolphin. The predicted density maps showed that the habitats of small odontocetes corresponded well with distinct oceanic domains. Species richness was estimated to be highest between 30 and 40°N where warm- and cold-water currents converge. Simpson's Diversity Index showed latitudinal diversity gradients of decreasing species numbers toward the poles. Higher diversity was also estimated in the coastal areas and the zonal areas around 35-42°N. Coastal-offshore gradients and latitudinal gradients are known for many taxa. The zonal areas around 35°N and 40°N coincide with the Kuroshio Current and its extension and the subarctic boundary, respectively. These results suggest that the species diversity of small odontocetes primarily follows general patterns of latitudinal and longitudinal gradients, while the confluence of faunas originating in distinct water masses increases species diversify in frontal waters around 30-40°N. Population densities tended to be higher for the species inhabiting higher latitudes, but were highest for intermediate latitudes at approximately 35-40°N. According to latitudinal gradients in water temperature and biological productivity, the costs for thermoregulation will decrease in warmer low latitudes, while feeding efficiency will increase in colder high latitudes. These trade-offs could optimize population density in intermediate latitudes.

  13. Sensitive determination of pesticides residues in wine samples with the aid of single-drop microextraction and response surface methodology.

    Science.gov (United States)

    Garbi, Aimilia; Sakkas, Vasilios; Fiamegos, Yiannis C; Stalikas, Constantine D; Albanis, Triantafyllos

    2010-09-15

    The multi-residue trace-level determination of six pesticides (diazinon, dimethoate, chlorpyrifos, vinclozolin, fenthion and quinalphos) in wine samples, after their single-drop microextraction (SDME) is presented herein. The extraction procedure was optimized using the multivariate optimization approach following a two-stage process. The first screening experimental design brought out the significant parameters and was followed by a central composite design (CCD) experiment, which revealed the simultaneous effect of the significant factors affecting the SDME process. High level of linearity for all target analytes was recorded with r(2) ranging between 0.9978 and 0.9999 while repeatability (intra-day) and reproducibility (inter-day) varied from 5.6% to 7.4% and 4.9% to 12.5%, respectively. Limits of detection (LODs) and limits of quantification (LOQs) were found to range in the low microg L(-1) level. In general, the developed methodology presented simplicity and enhanced sensitivity, rendering it appropriate for routine wine screening purposes. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  14. Gecko-Inspired Nanotentacle Surface-Enhanced Raman Spectroscopy Substrate for Sampling and Reliable Detection of Pesticide Residues in Fruits and Vegetables.

    Science.gov (United States)

    Wang, Pan; Wu, Long; Lu, Zhicheng; Li, Qin; Yin, Wenmin; Ding, Fan; Han, Heyou

    2017-02-21

    Rapid sampling and multicomponent detection are crucial for monitoring of pesticide residues analysis. Here, a gecko-inspired nanotentacle surface-enhanced Raman spectroscopy (G-SERS) platform is proposed for the first time for the simultaneous detection of three kinds of pesticides via a simple and intuitive "press and peeled-off" approach. The G-SERS platform obtained from seeding deposition of silver nanoparticles (Ag NPs) on 3D PDMS nanotentacle array is flexible and free-standing. Compared with other substrates, this G-SERS substrate can simultaneously provide outstanding SERS activity (enhancement factor = 1.2 × 107), superior reproducibility (RSD = 5.8%) and countless flexible nanoscale "tentacles" (∼6.7 × 108/cm2). Moreover, the high density of "tentacles" can freely approach the microarea and enable efficient target collection, which were confirmed by SEM and HPLC. By direct sampling from cucumber, apple, and grape surfaces, thiram (TMTD), methyl parathion (MPT), malachite green (MG), and their multiple components have been rapidly and reliably determined. For example, under the optimal conditions, a sensitivity of 1.6 ng/cm2 (S/N = 3) for TMTD was obtained on apple peels with a correlation coefficient (R) of 0.99. Therefore, the G-SERS substrate could offer a great practical potential for on-spot identification of various pesticide residues on real samples.

  15. Quantitative Thin-Layer Chromatography/Mass Spectrometry Analysis of Caffeine Using a Surface Sampling Probe Electrospray Ionization Tandem Mass Spectrometry System

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Michael J [ORNL; Deibel, Michael A. [Earlham College; Tomkins, Bruce A [ORNL; Van Berkel, Gary J [ORNL

    2005-01-01

    Quantitative determination of caffeine on reversed-phase C8 thin-layer chromatography plates using a surface sampling electrospray ionization system with tandem mass spectrometry detection is reported. The thin-layer chromatography/electrospray tandem mass spectrometry method employed a deuterium-labeled caffeine internal standard and selected reaction monitoring detection. Up to nine parallel caffeine bands on a single plate were sampled in a single surface scanning experiment requiring 35 min at a surface scan rate of 44 {mu}m/s. A reversed-phase HPLC/UV caffeine assay was developed in parallel to assess the mass spectrometry method performance. Limits of detection for the HPLC/UV and thin-layer chromatography/electrospray tandem mass spectrometry methods determined from the calibration curve statistics were 0.20 ng injected (0.50 {mu}L) and 1.0 ng spotted on the plate, respectively. Spike recoveries with standards and real samples ranged between 97 and 106% for both methods. The caffeine content of three diet soft drinks (Diet Coke, Diet Cherry Coke, Diet Pepsi) and three diet sport drinks (Diet Turbo Tea, Speed Stack Grape, Speed Stack Fruit Punch) was measured. The HPLC/UV and mass spectrometry determinations were in general agreement, and these values were consistent with the quoted values for two of the three diet colas. In the case of Diet Cherry Coke and the diet sports drinks, the determined caffeine amounts using both methods were consistently higher (by 8% or more) than the literature values.

  16. False Negative Rates of a Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates via Real-Time PCR

    Energy Technology Data Exchange (ETDEWEB)

    Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sydor, Michael A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kaiser, Brooke L.D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-01

    Surface sampling for Bacillus anthracis spores has traditionally relied on detection via bacterial cultivation methods. Although effective, this approach does not provide the level of organism specificity that can be gained through molecular techniques. False negative rates (FNR) and limits of detection (LOD) were determined for two B. anthracis surrogates with modified rapid viability-polymerase chain reaction (mRV-PCR) following macrofoam-swab sampling. This study was conducted in parallel with a previously reported study that analyzed spores using a plate-culture method. B. anthracis Sterne (BAS) or B. atrophaeus Nakamura (BG) spores were deposited onto four surface materials (glass, stainless steel, vinyl tile, and plastic) at nine target concentrations (2 to 500 spores/coupon; 0.078 to 19.375 colony-forming units [CFU] per cm2). Mean FNR values for mRV-PCR analysis ranged from 0 to 0.917 for BAS and 0 to 0.875 for BG and increased as spore concentration decreased (over the concentrations investigated) for each surface material. FNRs based on mRV-PCR data were not statistically different for BAS and BG, but were significantly lower for glass than for vinyl tile. FNRs also tended to be lower for the mRV-PCR method compared to the culture method. The mRV-PCR LOD95 was lowest for glass (0.429 CFU/cm2 with BAS and 0.341 CFU/cm2 with BG) and highest for vinyl tile (0.919 CFU/cm2 with BAS and 0.917 CFU/cm2 with BG). These mRV-PCR LOD95 values were lower than the culture values (BAS: 0.678 to 1.023 CFU/cm2 and BG: 0.820 to 1.489 CFU/cm2). The FNR and LOD95 values reported in this work provide guidance for environmental sampling of Bacillus spores at low concentrations.

  17. Ab initio molecular dynamics with enhanced sampling for surface reaction kinetics at finite temperatures: CH2⇌ CH + H on Ni(111) as a case study.

    Science.gov (United States)

    Sun, Geng; Jiang, Hong

    2015-12-21

    A comprehensive understanding of surface thermodynamics and kinetics based on first-principles approaches is crucial for rational design of novel heterogeneous catalysts, and requires combining accurate electronic structure theory and statistical mechanics modeling. In this work, ab initio molecular dynamics (AIMD) combined with the integrated tempering sampling (ITS) method has been explored to study thermodynamic and kinetic properties of elementary processes on surfaces, using a simple reaction CH2⇌CH+H on the Ni(111) surface as an example. By a careful comparison between the results from ITS-AIMD simulation and those evaluated in terms of the harmonic oscillator (HO) approximation, it is found that the reaction free energy and entropy from the HO approximation are qualitatively consistent with the results from ITS-AIMD simulation, but there are also quantitatively significant discrepancies. In particular, the HO model misses the entropy effects related to the existence of multiple adsorption configurations arising from the frustrated translation and rotation motion of adsorbed species, which are different in the reactant and product states. The rate constants are evaluated from two ITS-enhanced approaches, one using the transition state theory (TST) formulated in terms of the potential of mean force (PMF) and the other one combining ITS with the transition path sampling (TPS) technique, and are further compared to those based on harmonic TST. It is found that the rate constants from the PMF-based TST are significantly smaller than those from the harmonic TST, and that the results from PMF-TST and ITS-TPS are in a surprisingly good agreement. These findings indicate that the basic assumptions of transition state theory are valid in such elementary surface reactions, but the consideration of statistical averaging of all important adsorption configurations and reaction pathways, which are missing in the harmonic TST, are critical for accurate description of

  18. Ab initio molecular dynamics with enhanced sampling for surface reaction kinetics at finite temperatures: CH2 ⇌ CH + H on Ni(111) as a case study

    Science.gov (United States)

    Sun, Geng; Jiang, Hong

    2015-12-01

    A comprehensive understanding of surface thermodynamics and kinetics based on first-principles approaches is crucial for rational design of novel heterogeneous catalysts, and requires combining accurate electronic structure theory and statistical mechanics modeling. In this work, ab initio molecular dynamics (AIMD) combined with the integrated tempering sampling (ITS) method has been explored to study thermodynamic and kinetic properties of elementary processes on surfaces, using a simple reaction CH 2 ⇌ CH + H on the Ni(111) surface as an example. By a careful comparison between the results from ITS-AIMD simulation and those evaluated in terms of the harmonic oscillator (HO) approximation, it is found that the reaction free energy and entropy from the HO approximation are qualitatively consistent with the results from ITS-AIMD simulation, but there are also quantitatively significant discrepancies. In particular, the HO model misses the entropy effects related to the existence of multiple adsorption configurations arising from the frustrated translation and rotation motion of adsorbed species, which are different in the reactant and product states. The rate constants are evaluated from two ITS-enhanced approaches, one using the transition state theory (TST) formulated in terms of the potential of mean force (PMF) and the other one combining ITS with the transition path sampling (TPS) technique, and are further compared to those based on harmonic TST. It is found that the rate constants from the PMF-based TST are significantly smaller than those from the harmonic TST, and that the results from PMF-TST and ITS-TPS are in a surprisingly good agreement. These findings indicate that the basic assumptions of transition state theory are valid in such elementary surface reactions, but the consideration of statistical averaging of all important adsorption configurations and reaction pathways, which are missing in the harmonic TST, are critical for accurate description of

  19. An on-line SPE-HPLC method for effective sample preconcentration and determination of fenoxycarb and cis, trans-permethrin in surface waters.

    Science.gov (United States)

    Šatínský, Dalibor; Naibrtová, Linda; Fernández-Ramos, Carolina; Solich, Petr

    2015-09-01

    A new on-line SPE-HPLC method using fused-core columns for on-line solid phase extraction and large volume sample injection for increasing the sensitivity of detection was developed for the determination of insecticides fenoxycarb and cis-, trans-permethrin in surface waters. The separation was carried out on fused-core column Phenyl-Hexyl (100×4.6 mm), particle size 2.7 µm with mobile phase acetonitrile:water in gradient mode at flow rate 1.0 mL min(-1), column temperature 45°C. Large volume sample injection (1500 µL) to the extraction dimension using short precolumn Ascentis Express RP C-18 (5×4.6 mm); fused-core particle size 2.7 µm allowed effective sample preconcentration and efficient ballast sample matrix removal. The washing mobile phase consisting of a mixture of acetonitrile:water; 30:70, (v/v) was pumped at flow rate of 0.5 mL min(-1) through the extraction precolumn to the waste. Time of the valve switch for transferring the preconcentrated sample zone from the extraction to the separation column was set at 3rd min. Elution of preconcentrated insecticides from the extraction precolumn and separation on the analytical column was performed in gradient mode. Linear gradient elution started from 40% of acetonitrile at time of valve switch from SPE column (3rd min) to 95% of acetonitrile at 7th min. Synthetic dye sudan I was chosen as an internal standard. UV detection at wavelength 225 nm was used and the method reached the limits of detection (LOD) at ng mL(-1) levels for both insecticides. The method showing on-line sample pretreatment and preconcentration with highly sensitive determination of insecticides was applied for monitoring of fenoxycarb and both permethrin isomers in different surface water samples in Czech Republic. The time of whole analysis including on-line extraction, interferences removal, chromatography separation and system equilibration was less than 8 min. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Preliminary results of high resolution subbottom survey and surface sediment sampling by ROV "NSS" in the Nankai subduction zone off Kumano

    Science.gov (United States)

    Ashi, J.; Kh-10-3 Science Party

    2010-12-01

    The Nankai subduction zone off Kumano has been extensively investigated for site surveys of IODP Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) by bathymetirc survey, 2D and 3D seismic reflection survey, dive observation and sidescan sonar survey. However, subbottom profiling and surface sediment sampling were limited due to steep and complex topography under strong Kuroshio Current. We carried out deep-tow subbottom survey and pinpoint core sampling by ROV "NSS (Navigable Sampling System)" of Atmosphere and Ocean Research Institute, the Univ. Tokyo during Hakuho-maru KH-10-3 cruise. A pilot vehicle of NSS is equipped with four thrusters, observation cameras and a hock for a heavy payload. Depth capability of the pilot vehicle is 4000 m and maximum payload weight is 1.5 tons. We introduced a chirp subbottom profiling system of EdgeTech DW-106 for high resolution mapping of shallow structures and determination of a sampling point on this year's survey. Three survey lines crossed the splay fault area around IODP drilling sites. Subbottom profiles show that seafloor is completely covered by stratified sediments and any fault displacement cannot be identified although maximum penetration of chirp signal is only 15 meters in prism slope regions. In contrast, landward progressive tilting of slope basin sediments and talus deposits on it are well imaged along the steep scarp 30 km southwest of the drilling sites. Dense chemosynthetic biological community revealed by camera observations also suggests existence of active fault in this area. The scarp more gentle slope than the above is located 4 kilometers trenchward of it. Subbottom profiles show well-stratified sediment cover without fault deformation. Seismic reflection profiles and existence of dense traces of bivalves, however, suggest existence of a splay fault beneath it. A long-term heat flow meter of ERI, Univ. Tokyo was installed at each fault scarp for monitoring of cold seep activity. We also present

  1. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Naeemullah; Kazi, Tasneem Gul; Shah, Faheem; Afridi, Hassan Imran; Khan, Sumaira; Arian, Sadaf Sadia; Brahman, Kapil Dev

    2012-01-01

    Cloud point extraction (CPE) has been used for the preconcentration and simultaneous determination of cobalt (Co) and lead (Pb) in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine) as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114), temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS). The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e) was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample. PMID:23227429

  2. Quantitative Detection of Trace Level Cloxacillin in Food Samples Using Magnetic Molecularly Imprinted Polymer Extraction and Surface-Enhanced Raman Spectroscopy Nanopillars.

    Science.gov (United States)

    Ashley, Jon; Wu, Kaiyu; Hansen, Mikkel Fougt; Schmidt, Michael Stenbæk; Boisen, Anja; Sun, Yi

    2017-11-07

    There is an increasing demand for rapid, sensitive, and low cost analytical methods to routinely screen antibiotic residues in food products. Conventional detection of antibiotics involves sample preparation by liquid-liquid or solid-phase extraction, followed by analysis using liquid chromatography-mass spectrometry (LC-MS), capillary electrophoresis (CE), or gas chromatography (GC). The process is labor-intensive, time-consuming, and expensive. In this study, we developed a new analytical method that combines magnetic molecularly imprinted polymer (MMIP)-based sample preparation with surface-enhanced Raman spectroscopy (SERS)-based detection for quantitative analysis of cloxacillin in pig serum. MMIP microspheres were synthesized using a core-shell technique. The large loading capacity and high selectivity of the MMIP microspheres enabled efficient extraction of cloxacillin, while the magnetically susceptible characteristics greatly simplified sample handling procedures. Low cost and robust SERS substrates consisting of vertical gold capped silicon nanopillars were fabricated and employed for the detection of cloxacillin. Quantitative SERS was achieved by normalizing signal intensities using an internal standard. By coherently combining MMIP extraction and silicon nanopillar-based SERS biosensor, good sensitivity toward cloxacillin was achieved. The detection limit was 7.8 pmol. Cloxacillin recoveries from spiked pig plasma samples were found to be more than 80%.

  3. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Naeemullah

    2012-01-01

    Full Text Available Cloud point extraction (CPE has been used for the preconcentration and simultaneous determination of cobalt (Co and lead (Pb in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114, temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS. The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

  4. [Features of adhesion of anaerobic periodontopathogenic bacteria and Candida albicans fungi to experimental samples of basis dental plastic depending on surface roughness and polishing method].

    Science.gov (United States)

    Tsarev, V N; Ippolitov, E V; Trefilov, A G; Arutiunov, S D; Pivovarov, A A

    2014-01-01

    Study the main surface parameters of milled polyacrylic materials using atomic force microscopy and primary microbial adhesion of periodontopathogenic group bacteria and Candida albicans fungi taking into consideration the method of sample polishing. Studied samples: mill-treated without polishing (control); ergobox polished; polished in dental laboratory conditions; polished by a rubber brush in dentists' office. Microbial strains belonging to periodontopathogenic species (clinical isolates) that had been isolated from periodontal pockets of periodontitis patients: Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus sanguis, C. albicans fungi were used for modelling experiments of primary adhesion of microbes to the material samples. S. sanguis had the highest degree of adhesion to polymer after milling, P. gingivalis, C. albicans--medium, F. nucleatum--low. A significant reduction of adhesion is observed during polishing in dental laboratory conditions or ergobox, less significant--during polishing in dental office. The data obtained allow to make a conclusion that the samples from polymer materials for preparation of prosthesis basis have varying degree of intensity of microbial adhesion of members of periodontopathogenic microflora and C. albicans fungi that depends on the polishing method, that accordingly determined the differences in colonization resistance against formation of microbial biofilm during polymer use in clinical conditions. . ,

  5. Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler.

    Science.gov (United States)

    Colt, J S

    1998-11-01

    Epidemiologic studies of the association between residential pesticide use and cancer risk require an assessment of past pesticide exposures. Pesticide levels in carpet dust are believed to reflect long-term pesticide use. Recent epidemiologic studies have found collection of dust samples using the high-volume surface sampler (HVS3) to be expensive and cumbersome. We compared the levels of pesticides and other compounds in dust obtained from subjects' personal used vacuum cleaner bags to that collected by the HVS3 to see if this simpler method could replace the HVS3 in epidemiologic research. We visited the homes of 15 subjects, took the used bags from their vacuums, and collected carpet dust samples with the HVS3. The samples were analyzed for 42 target compounds: 26 pesticides, 10 polycyclic aromatic hydrocarbons (PAHs), and six polychlorinated biphenyl (PCB) congeners using GC/MS in selected ion monitoring mode. The two methods agreed in detecting the presence of the target compounds between 80% and 100% of the time. Neither sampling method was consistently more sensitive. The median target compound concentrations were similar, and a paired t-test showed no significant differences. For many compounds, the concentrations of compounds in the HVS3 samples were higher than those in the used bag samples at the upper end of the concentration ranges. However, the Spearman rank correlation coefficients were 0.85 or higher for most compounds, indicating that homes would be ranked similarly using both methods. Overall, there appears to be no clear difference in the quality of the pesticide, PAH, or PCB concentration data for the two dust collection methods.

  6. Determination of drugs in surface water and wastewater samples by liquid chromatography-mass spectrometry: Methods and preliminary results including toxicity studies with Vibrio fischeri

    Science.gov (United States)

    Farre, M.; Ferrer, I.; Ginebreda, A.; Figueras, M.; Olivella, L.; Tirapu, L.; Vilanova, M.; Barcelo, D.

    2001-01-01

    In the present work a combined analytical method involving toxicity and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) was developed for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics: ibuprofen, ketoprofen, naproxen, and diclofenac, the decomposition product of the acetyl salicylic acid: salicylic acid and one lipid lowering agent, gemfibrozil. The selected compounds are acidic substances, very polar and all of them are analgesic compounds that can be purchased without medical prescription. The developed protocol consisted, first of all, on the use Microtox?? and ToxAlert??100 toxicity tests with Vibrio fischeri for the different pharmaceutical drugs. The 50% effective concentration (EC50) values and the toxicity units (TU) were determined for every compound using both systems. Sample enrichment of water samples was achieved by solid-phase extraction procedure (SPE), using the Merck LiChrolut?? EN cartridges followed by LC-ESI-MS. Average recoveries loading 1 l of samples with pH=2 varied from 69 to 91% and the detection limits in the range of 15-56 ng/l. The developed method was applied to real samples from wastewater and surface-river waters of Catalonia (north-east of Spain). One batch of samples was analyzed in parallel also by High Resolution Gas Chromatography coupled with Mass Spectrometry (HRGC-MS) and the results have been compared with the LC-ESI-MS method developed in this work. ?? 2001 Elsevier Science B.V. All rights reserved.

  7. Development testing of the chemical analysis automation polychlorinated biphenyl standard analysis method during surface soils sampling at the David Witherspoon 1630 site

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, M.A.; Klatt, L.N.; Thompson, D.H. [and others

    1998-02-01

    The Chemical Analysis Automation (CAA) project is developing standardized, software-driven, site-deployable robotic laboratory systems with the objective of lowering the per-sample analysis cost, decreasing sample turnaround time, and minimizing human exposure to hazardous and radioactive materials associated with DOE remediation projects. The first integrated system developed by the CAA project is designed to determine polychlorinated biphenyls (PCB) content in soil matrices. A demonstration and development testing of this system was conducted in conjuction with surface soil characterization activities at the David Witherspoon 1630 Site in Knoxville, Tennessee. The PCB system consists of five hardware standard laboratory modules (SLMs), one software SLM, the task sequence controller (TSC), and the human-computer interface (HCI). Four of the hardware SLMs included a four-channel Soxhlet extractor, a high-volume concentrator, a column cleanup, and a gas chromatograph. These SLMs performed the sample preparation and measurement steps within the total analysis protocol. The fifth hardware module was a robot that transports samples between the SLMs and the required consumable supplies to the SLMs. The software SLM is an automated data interpretation module that receives raw data from the gas chromatograph SLM and analyzes the data to yield the analyte information. The TSC is a software system that provides the scheduling, management of system resources, and the coordination of all SLM activities. The HCI is a graphical user interface that presents the automated laboratory to the analyst in terms of the analytical procedures and methods. Human control of the automated laboratory is accomplished via the HCI. Sample information required for processing by the automated laboratory is entered through the HCI. Information related to the sample and the system status is presented to the analyst via graphical icons.

  8. Polybrominated diphenyl ether (PBDE) concentrations and resulting exposure in homes in California: relationships among passive air, surface wipe and dust concentrations, and temporal variability

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam, electronics, and other home furnishings. A field study was conducted that enrolled 139 households from California, which has had more stringent flame retardant requirements than other countries...

  9. Surface chemistry and reactivity of skin-passed hot dip galvanized coating

    OpenAIRE

    Mataigne, Jean-Michel; Vaché, Véronique; Repoux, Monique

    2009-01-01

    La publication originale est disponible sur le site http://www.revue-metallurgie.org; International audience; GI coatings are covered by a very thin aluminum layer that precipitates after wiping. Anisotropic growing of zinc crystals during solidification induces a strong basal texture in GI coatings. Skin-pass induced changes in GI coating surface chemistry, crystallography and reactivity have been assessed. Local coating analyses have been performed (XPS, TOF-SIMS) in order to describe local...

  10. Recovery data for surface water, groundwater and lab reagent samples analyzed by the USGS National Water Quality Laboratory schedule 2437, water years 2013-15

    Science.gov (United States)

    Shoda, Megan E.; Nowell, Lisa H.; Bexfield, Laura M.; Sandstrom, Mark W.; Stone, Wesley W.

    2017-01-01

    Analytical recovery is the concentration of an analyte measured in a water-quality sample expressed as a percentage of the known concentration added to the sample (Mueller and others, 2015). Analytical recovery (hereafter referred to as “recovery”) can be used to understand method bias and variability and to assess the temporal changes in a method over time (Martin and others, 2009). This data set includes two tables: one table of field spike recovery data and one table of lab reagent spike recovery data. The table of field spike recovery data includes results from paired environmental and spike samples collected by the National Water Quality Program, National Water-Quality Assessment (NAWQA) Project in surface water and groundwater. These samples were collected as part of the NAWQA Project’s National Water Quality Network: Rivers and Streams assessment, Regional Stream Quality Assessment studies and in multiple groundwater networks following standard practices (Mueller and others, 1997).  This table includes environmental and spike water-quality sample data stored in the USGS National Water Information System (NWIS) database (https://dx.doi.org/10.5066/F7P55KJN). Concentrations of pesticides in spike samples, while stored in the NWIS database, are not publically available. The calculation of recovery based on these field sample data is outlined in Mueller and others (2015). Lab reagent spikes are pesticide-free reagent water spiked with a known concentration of pesticide. Lab reagent spikes are prepared in the lab and their recovery can be directly measured. The table of lab reagent spike data contains quality control sample information stored in the USGS National Water Quality Laboratory (NWQL) database. Both tables include fields for data-quality indicators that are described in the data processing steps of this metadata file. These tables were developed in order to support a USGS Scientific Investigations Report with the working title

  11. Correlation between E. coli levels and the presence of foodborne pathogens in surface irrigation water: Establishment of a sampling program.

    Science.gov (United States)

    Truchado, Pilar; Hernandez, Natalia; Gil, Maria I; Ivanek, Renata; Allende, Ana

    2018-01-01

    To establish the association between microbial indicators and the presence of foodborne pathogens in irrigation water, Escherichia coli was enumerated using two quantification methods (plate counts and PMA-qPCR) and presence/absence of pathogenic microorganisms, including five strains from the Shiga toxigenic E. coli (O157:H7, O26, O103, O111 and O145) and Salmonella spp. were evaluated. The results confirmed that surface water can be considered a microbial hazard when used for irrigation. The levels of viable E. coli were very similar to those of cultivable E. coli, except for irrigation water obtained from water reservoirs. Comparison between the E. coli counts in samples positive and negative for the presence of pathogenic bacteria for the evaluated water sources identified E. coli level of 2.35 log cfu/100 mL as a cut-off able to correctly predict positive and negative samples with 93% sensitivity and 66% specificity, respectively. Thus, for the samples with levels of E. coli under 2.35 log cfu/100 mL (e.g., 2.24 log cfu/100 mL) there was a 90% probability that the samples were not contaminated with pathogenic microorganism in locations with similar prevalence. E. coli levels in irrigation water were affected by the ambient temperature confirming that water source and climate conditions should be taken into account by growers when designing a sampling program and the frequency of the monitoring to make a better and more efficient use of their resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Development of a methodology utilizing gas chromatography ion-trap tandem mass spectrometry for the determination of low levels of caffeine in surface marine and freshwater samples.

    Science.gov (United States)

    Verenitch, Sergei S; Mazumder, Asit

    2008-08-01

    A methodology for monitoring low level of caffeine in aqueous samples via gas chromatography coupled with an ion-trap tandem mass spectrometry detection system (IT-MS/MS) was developed. Four IT-MS/MS operating parameters, including the collision-induced dissociation (CID) voltage, the excitation time (ET), the isolation time (IT) and the maximum ionization time (MIT) were optimized in order to maximize the sensitivity of the IT-MS/MS technique towards the analyte and its isotope-labeled standard. After optimization, a limit of detection of 500 fg microl(-1) with S/N = 3 was achieved. Taking into account blank values and the matrix background, a method detection limit of 1.0-2.0 ng l(-1) was derived and applied to all of the samples analyzed in the study. Various mass spectrometric conditions have been applied to caffeine and its trimethyl-(13)C-labeled standard to elucidate fragmentation pathways for new and commonly occurring product ions observed in the collision-induced dissociation (CID) spectra produced by the ion trap. Ion structures and fragmentation pathway mechanisms have been proposed and compared with previously published data. An isotope dilution method using (13)C-labeled caffeine as a surrogate internal standard was employed to determine and correct the recovery of native caffeine in water samples. The developed methodology has been applied for the determination of caffeine in surface marine and freshwater samples collected on the west coast of Vancouver Island in British Columbia, Canada. The results obtained for the marine water samples indicated a wide variation in the level of caffeine, ranging from 4.5 to 149 ng l(-1), depending on the location of the sampling site within the inlet. The concentrations of caffeine in samples from lakes associated with various residential densities ranged from ND to 6.5, 1.8 to 10.4 and 6.1 to 21.7 ng l(-1) for low, moderate and high residential densities, respectively.

  13. False Negative Rates of a Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates via Real-Time PCR

    Energy Technology Data Exchange (ETDEWEB)

    Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sydor, Michael A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deatherage Kaiser, Brooke L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-05-01

    Surface sampling for Bacillus anthracis spores has traditionally relied on detection via bacterial cultivation methods. Although effective, this approach does not provide the level of organism specificity that can be gained through molecular techniques. False negative rates (FNR) and limits of detection (LOD) were determined for two B. anthracis surrogates with modified rapid viability-polymerase chain reaction (mRV-PCR) following macrofoam-swab sampling. This study was conducted in parallel with a previously reported study that analyzed spores using a plate-culture method. B. anthracis Sterne (BAS) or B. atrophaeus Nakamura (BG) spores were deposited onto four surface materials (glass, stainless steel, vinyl tile, and plastic) at nine target concentrations (2 to 500 spores/coupon; 0.078 to 19.375 colony-forming units [CFU] per cm²). Mean FNR values for mRV-PCR analysis ranged from 0 to 0.917 for BAS and 0 to 0.875 for BG and increased as spore concentration decreased (over the concentrations investigated) for each surface material. FNRs based on mRV-PCR data were not statistically different for BAS and BG, but were significantly lower for glass than for vinyl tile. FNRs also tended to be lower for the mRV-PCR method compared to the culture method. The mRV-PCR LOD₉₅ was lowest for glass (0.429 CFU/cm² with BAS and 0.341 CFU/cm² with BG) and highest for vinyl tile (0.919 CFU/cm² with BAS and 0.917 CFU/cm² with BG). These mRV-PCR LOD₉₅ values were lower than the culture values (BAS: 0.678 to 1.023 CFU/cm² and BG: 0.820 to 1.489 CFU/cm²). The FNR and LOD₉₅ values reported in this work provide guidance for environmental sampling of Bacillus spores at low concentrations.

  14. Environmental sampling

    Energy Technology Data Exchange (ETDEWEB)

    Puckett, J.M.

    1998-12-31

    Environmental Sampling (ES) is a technology option that can have application in transparency in nuclear nonproliferation. The basic process is to take a sample from the environment, e.g., soil, water, vegetation, or dust and debris from a surface, and through very careful sample preparation and analysis, determine the types, elemental concentration, and isotopic composition of actinides in the sample. The sample is prepared and the analysis performed in a clean chemistry laboratory (CCL). This ES capability is part of the IAEA Strengthened Safeguards System. Such a Laboratory is planned to be built by JAERI at Tokai and will give Japan an intrinsic ES capability. This paper presents options for the use of ES as a transparency measure for nuclear nonproliferation.

  15. In vivo photoacoustic mouse eye imaging of healing after chemical injury and automated eyeball surface estimation based on a random sample consensus algorithm

    Science.gov (United States)

    Jeon, Seungwan; Song, Hyun Beom; Kim, Jaewoo; Lee, Byung Joo; Kim, Jeong Hun; Kim, Chulhong

    2017-03-01

    Ocular chemical damage may induce limbal vessel ischemia and neovascularization, but the pathophysiology of the disease is not completely known. To observe changes in blood vessels after alkaline burn, we monitored the anterior segment and choroidal vasculature using a photoacoustic microscope (OR-PAM). We were able to observe not only the iris blood vessels but also the choroidal vessels under the sclera, which were difficult to be observed with conventional photographs. After alkali burning, we observed neovascularization and limbal ischemia and successfully tracked changes in vasculature during the 7-day healing process. We also used the RANdom SAmple Consensus (RANSAC) method to segment the abnormally generated blood vessels in the cornea by detecting the eyeball surface and successfully visualize the distance from each PA signal to the center of the eye. We believe that photoacoustic imaging has an important potential to reveal the pathophysiology of limb ischemia and neovascularization.

  16. Performance of laser fluorescence for the detection of enamel caries in non-cavitated occlusal surfaces: clinical study with total validation of the sample.

    Science.gov (United States)

    Abalos, Camilo; Mendoza, Asunción; Jimenez-Planas, Amparo; Guerrero, Elena; Chaparro, Antonio; Garcia-Godoy, Franklin

    2012-02-01

    To evaluate the clinical performance of a laser fluorescence device in detecting enamel caries in non-cavitated occlusal surfaces. The sample included 96 first and second permanent molars, selected according to the criteria of Ekstrand: 44 not suspected of having dentin caries (score: 0-2) and 52 under suspicion (score: 3-4). Once measured by laser fluorescence, all teeth were validated by fissurotomy (gold standard). To avoid ethical questions, the 44 teeth (score: 0-2) used were to serve as abutments for a fixed dental prostheses. Following fissurotomy, the 52 teeth with suspected caries were treated with resin composite restorations. Kruskall-Wallis statistical analysis (PLaser fluorescence showed an area under the Receiver Operating Characteristic (ROC) curve of Az = 0.803 for enamel caries. The cut-off point with the highest sensitivity and specificity was 15, with a sensitivity and specificity of 0.97 and 0.63, respectively. Values under 10 indicated healthy teeth.

  17. Determination of pharmaceutical compounds in surface- and ground-water samples by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry

    Science.gov (United States)

    Cahill, J.D.; Furlong, E.T.; Burkhardt, M.R.; Kolpin, D.; Anderson, L.G.

    2004-01-01

    Commonly used prescription and over-the-counter pharmaceuticals are possibly present in surface- and ground-water samples at ambient concentrations less than 1 μg/L. In this report, the performance characteristics of a combined solid-phase extraction isolation and high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC–ESI-MS) analytical procedure for routine determination of the presence and concentration of human-health pharmaceuticals are described. This method was developed and used in a recent national reconnaissance of pharmaceuticals in USA surface waters. The selection of pharmaceuticals evaluated for this method was based on usage estimates, resulting in a method that contains compounds from diverse chemical classes, which presents challenges and compromises when applied as a single routine analysis. The method performed well for the majority of the 22 pharmaceuticals evaluated, with recoveries greater than 60% for 12 pharmaceuticals. The recoveries of angiotensin-converting enzyme inhibitors, a histamine (H2) receptor antagonist, and antihypoglycemic compound classes were less than 50%, but were retained in the method to provide information describing the potential presence of these compounds in environmental samples and to indicate evidence of possible matrix enhancing effects. Long-term recoveries, evaluated from reagent-water fortifications processed over 2 years, were similar to initial method performance. Method detection limits averaged 0.022 μg/L, sufficient for expected ambient concentrations. Compound-dependent matrix effects on HPLC/ESI-MS analysis, including enhancement and suppression of ionization, were observed as a 20–30% increase in measured concentrations for three compounds and greater than 50% increase for two compounds. Changing internal standard and more frequent ESI source maintenance minimized matrix effects. Application of the method in the national survey demonstrates that several

  18. A Localized Surface Plasmon Resonance Sensing Method for Simultaneous Determination of Atenolol and Amiloride in Pharmaceutical Dosage Forms and Urine Samples

    Directory of Open Access Journals (Sweden)

    Marwa R. El-Zahry

    2018-01-01

    Full Text Available This contribution describes a simple, fast, and sensitive application of localized surface plasmon resonance effect of silver nanoparticles for simultaneous determination of antihypertensive drugs’ mixture atenolol and amiloride in both pharmaceutical dosage forms and in biological samples (urine. Silver nanoparticles were prepared by chemical reduction of silver nitrate using hydroxylamine HCL in an alkaline medium. Application of silver-hydroxylamine nanoparticles (SH NPs provides many advantages including reproducibility, sensitivity, and cost effective way of analyte determination. Amiloride has four amino groups which act as attachment points on the surface of silver nanoparticles resulting in a synergistic effect on the absorption intensity of atenolol, leading to increase the sensitivity of the determination of both compounds. This method shows excellent advantages comparing with the previously reported methods, including accuracy, precision, and selectivity. The linear range of atenolol is 1 × 10−5–1 × 10−4 mol·L−1 and of amiloride is 1 × 10−6–1 × 10−5 mol·L−1. The limit of detection (LOD values of atenolol and amiloride are 0.89 × 10−5 and 0.42 × 10−6 mol·L−1, respectively.

  19. Photogeneration of reactive transient species upon irradiation of natural water samples: Formation quantum yields in different spectral intervals, and implications for the photochemistry of surface waters.

    Science.gov (United States)

    Marchisio, Andrea; Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

    2015-04-15

    Chromophoric dissolved organic matter (CDOM) in surface waters is a photochemical source of several transient species such as CDOM triplet states ((3)CDOM*), singlet oxygen ((1)O2) and the hydroxyl radical (OH). By irradiation of lake water samples, it is shown here that the quantum yields for the formation of these transients by CDOM vary depending on the irradiation wavelength range, in the order UVB > UVA > blue. A possible explanation is that radiation at longer wavelengths is preferentially absorbed by the larger CDOM fractions, which show lesser photoactivity compared to smaller CDOM moieties. The quantum yield variations in different spectral ranges were definitely more marked for (3)CDOM* and OH compared to (1)O2. The decrease of the quantum yields with increasing wavelength has important implications for the photochemistry of surface waters, because long-wavelength radiation penetrates deeper in water columns compared to short-wavelength radiation. The average steady-state concentrations of the transients ((3)CDOM*, (1)O2 and OH) were modelled in water columns of different depths, based on the experimentally determined wavelength trends of the formation quantum yields. Important differences were found between such modelling results and those obtained in a wavelength-independent quantum yield scenario. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Facile preparation of polydopamine-coated imprinted polymers on the surface of SiO2 for estrone capture in milk samples.

    Science.gov (United States)

    Zheng, Penglei; Zhang, Bilin; Luo, Zhimin; Du, Wei; Guo, Pengqi; Zhou, Yulan; Chang, Ruimiao; Chang, Chun; Fu, Qiang

    2016-10-05

    Estrone molecularly imprinted polymers were synthesized through the self-polymerization of dopamine on the surface of silica gels, which had the characteristics of mild polymerization conditions, simple reaction procedure and good specific recognition ability for estrone. The estrone molecularly imprinted polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and nitrogen adsorption-desorption tests. The characterization confirmed that the imprinted polymers were successfully grafted on the surface of silica gels. Through investigating the adsorption performance, the prepared estrone molecularly imprinted polymers exhibited high adsorption capacity, fast mass transfer, as well as excellent selectivity toward estrone. The estrone molecularly imprinted polymers as the solid-phase extraction adsorbent coupled with high-performance liquid chromatography was developed to determine estrone from the milk samples. The developed estrone molecularly imprinted polymer solid-phase extraction with high-performance liquid chromatography method exhibited satisfactory specificity, precision, accuracy and good linearity relationship in the range of 0.2-20 μg/mL. The developed method is simple, fast, effective and high specificity method and it provides a new method to detect the residues of estrone in animal foods. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Stochastic surface walking reaction sampling for resolving heterogeneous catalytic reaction network: A revisit to the mechanism of water-gas shift reaction on Cu

    Science.gov (United States)

    Zhang, Xiao-Jie; Shang, Cheng; Liu, Zhi-Pan

    2017-10-01

    Heterogeneous catalytic reactions on surface and interfaces are renowned for ample intermediate adsorbates and complex reaction networks. The common practice to reveal the reaction mechanism is via theoretical computation, which locates all likely transition states based on the pre-guessed reaction mechanism. Here we develop a new theoretical method, namely, stochastic surface walking (SSW)-Cat method, to resolve the lowest energy reaction pathway of heterogeneous catalytic reactions, which combines our recently developed SSW global structure optimization and SSW reaction sampling. The SSW-Cat is automated and massively parallel, taking a rough reaction pattern as input to guide reaction search. We present the detailed algorithm, discuss the key features, and demonstrate the efficiency in a model catalytic reaction, water-gas shift reaction on Cu(111) (CO + H2O → CO2 + H2). The SSW-Cat simulation shows that water dissociation is the rate-determining step and formic acid (HCOOH) is the kinetically favorable product, instead of the observed final products, CO2 and H2. It implies that CO2 and H2 are secondary products from further decomposition of HCOOH at high temperatures. Being a general purpose tool for reaction prediction, the SSW-Cat may be utilized for rational catalyst design via large-scale computations.

  2. Airborne benzene exposures from cleaning metal surfaces with small volumes of petroleum solvents.

    Science.gov (United States)

    Hollins, Dana M; Kerger, Brent D; Unice, Kenneth M; Knutsen, Jeffrey S; Madl, Amy K; Sahmel, Jennifer E; Paustenbach, Dennis J

    2013-06-01

    Airborne benzene concentrations were measured in a room with controlled air exchange during surface cleaning with two petroleum-based solvents (a paint thinner and an engine degreaser). The solvents were spiked with benzene to obtain target concentrations of 0.001, 0.01, and 0.1% by volume in the liquid. Personal samples on the worker and area samples up to 1.8m away were collected over 12 events (n=84 samples) designed to examine variation in exposure with solvent type, cleaning method (rag wipe or spatula scrape), surface area cleaned, air exchange rate, solvent volume applied, and distance from the cleaned surface. Average task breathing zone concentrations of benzene represented by 18-32 min time-weighted averages were 0.01 ppm, 0.05 ppm, and 0.27 ppm, when the solvents contained approximately 0.003, 0.008, and 0.07% benzene. Solvent benzene concentration, volume applied, and distance from the handling activities had the greatest effect on airborne concentrations. The studied solvent products containing 0.07% benzene (spiked) did not exceed the current OSHA permissible exposure limit of 1 ppm (averaged over 8h) or the ACGIH Threshold Limit Value of 0.5 ppm, in any of the tested short-term exposure scenarios. These data suggest that, under these solvent use scenarios, petroleum-based solvent products produced in the United States after 1978 likely did not produce airborne benzene concentrations above those measured if the concentration was less than 0.1% benzene. Copyright © 2012 Elsevier GmbH. All rights reserved.

  3. Frequency distribution of specific activities and radiological hazard assessment in surface beach sand samples collected in Bangsaen beach in Chonburi province, Thailand

    Science.gov (United States)

    Changkit, N.; Boonkrongcheep, R.; Youngchauy, U.; Polthum, S.; Kessaratikoon, P.

    2017-09-01

    The specific activities of natural radionuclides (40K, 226Ra and 232Th) in 50 surface beach sand samples collected from Bangsaen beach in Chonburi province in the easthern region of Thailand, were measured and evaluated. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system in the special laboratory at Thailand Institute of Nuclear Technology (Public Organization). The IAEA-SOIL-375 reference material was used to analyze the concentration of 40K, 226Ra and 232Th in all samples. It was found that the specific activities of 40K, 226Ra and 232Th were ranged from 510.85 - 771.35, 8.17 - 17.06 and 4.25 - 15.68 Bq/kg. Furthermore, frequency distribution of the specific activities were studied, analyzed and found to be the asymmetrical distribution by using a statistical computer program. Moreover, four radiological hazard indices for the investigated area were also calculated by using the median values of specific activities of 40K, 226Ra and 232Th. The results were also compared with the Office of Atoms for Peace (OAP) annual report data, Thailand and global radioactivity measurement and evaluations.

  4. A competitive immunoassay for ultrasensitive detection of Hg{sup 2+} in water, human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    She, Pei; Chu, Yanxin [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Liu, Chunwei; Guo, Xun [OptoTrace (Suzhou) Technologies, Inc., STE 316, Building 4, No. 218, Xinghu Street, bioBAY, Suzhou Industrial Park, Suzhou 215123 (China); Zhao, Kang [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Li, Jianguo, E-mail: lijgsd@suda.edu.cn [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Du, Haijing; Zhang, Xiang [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Wang, Hong [OptoTrace (Suzhou) Technologies, Inc., STE 316, Building 4, No. 218, Xinghu Street, bioBAY, Suzhou Industrial Park, Suzhou 215123 (China); Deng, Anping, E-mail: denganping@suda.edu.cn [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China)

    2016-02-04

    An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg{sup 2+}. This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg{sup 2+} and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg{sup 2+}. The ICT was able to directly detect Hg{sup 2+} without complexing due to the specific recognition of the mAb with Hg{sup 2+}. The IC{sub 50} and limit of detection (LOD) of the assay for Hg{sup 2+} detection were 0.12 ng mL{sup −1} and 0.45 pg mL{sup −1}, respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg{sup 2+} were in range of 88.3–107.3% with the relative standard deviations (RSD) of 1.5–9.5% (n = 3). The proposed ICT was used for the detection of Hg{sup 2+} in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg{sup 2+} in environmental water samples and biological serum and urine samples. - Highlights: • The proposed ICT was able to directly detect Hg{sup 2+} without formation of Hg{sup 2+}-ligand complex. • The proposed ICT exhibited high sensitivity, specificity, stability, precision and accuracy for Hg{sup 2+} detection. • The proposed ICT was applicable for the detection of trace amount of Hg{sup 2+} in water, human serum and urine samples.

  5. Analysis of Tank 38H (HTF-38-14-150, 151) and Tank 43H (HTF- 43-14-152, 53) Surface and Subsurface Supernatant Samples in Support of Enrichment Control, Corrosion Control and Sodium Aluminosilicate Formation Potential Programs

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-14

    This report provides the results of analyses on Tanks 38H and 43H surface and subsurface supernatant liquid samples in support of the Enrichment Control Program (ECP), the Corrosion Control Program and Sodium Aluminosilicate Formation Potential in the Evaporator.

  6. Evaluation for Loss of Lubrication Performance of Black Oxide, Superfinished, and As-Ground Surfaces for Use in Rotorcraft Transmissions

    Science.gov (United States)

    2016-09-01

    finish, micro machining process (MMP) superfinished by MicroTek, was also compared. The MMP specimens had an average disc Sa roughness of 24 nm. Detailed...and then the motors were shutdown . Residual lubricant was physically wiped out of the oil slinger at the center of the disc and the test was resumed...capacity LoL loss of lubrication LS low speed MJII Mobil Jet II MMP micro machining process Sa average surface roughness Tb ball

  7. Sample dilution and bacterial community composition influence empirical leucine-to-carbon conversion factors in surface waters of the world's oceans.

    Science.gov (United States)

    Teira, Eva; Hernando-Morales, Víctor; Cornejo-Castillo, Francisco M; Alonso-Sáez, Laura; Sarmento, Hugo; Valencia-Vila, Joaquín; Serrano Catalá, Teresa; Hernández-Ruiz, Marta; Varela, Marta M; Ferrera, Isabel; Gutiérrez Morán, Xosé Anxelu; Gasol, Josep M

    2015-12-01

    The transformation of leucine incorporation rates to prokaryotic carbon production rates requires the use of either theoretical or empirically determined conversion factors. Empirical leucine-to-carbon conversion factors (eCFs) vary widely across environments, and little is known about their potential controlling factors. We conducted 10 surface seawater manipulation experiments across the world's oceans, where the growth of the natural prokaryotic assemblages was promoted by filtration (i.e., removal of grazers [F treatment]) or filtration combined with dilution (i.e., also relieving resource competition [FD treatment]). The impact of sunlight exposure was also evaluated in the FD treatments, and we did not find a significant effect on the eCFs. The eCFs varied from 0.09 to 1.47 kg C mol Leu(-1) and were significantly lower in the FD than in the F samples. Also, changes in bacterial community composition during the incubations, as assessed by automated ribosomal intergenic spacer analysis (ARISA), were more pronounced in the FD than in the F treatments, compared to unmanipulated controls. Thus, we discourage the common procedure of diluting samples (in addition to filtration) for eCF determination. The eCFs in the filtered treatment were negatively correlated with the initial chlorophyll a concentration, picocyanobacterial abundance (mostly Prochlorococcus), and the percentage of heterotrophic prokaryotes with high nucleic acid content (%HNA). The latter two variables explained 80% of the eCF variability in the F treatment, supporting the view that both Prochlorococcus and HNA prokaryotes incorporate leucine in substantial amounts, although this results in relatively low carbon production rates in the oligotrophic ocean. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Evaluating and modeling the effects of surface sampling factors on the recovery of organic chemical attribution signatures using the accelerated diffusion sampler and solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Kai-For; Heredia-Langner, Alejandro; Fraga, Carlos G.

    2017-03-01

    In this study, an experimental design matrix was created and executed in order to test the effects of various real-world factors on the ability of the (1) accelerated diffusion sampler with solid phase micro-extraction (ADS-SPME) and (2) solvent extraction to capture organic chemical attribution signatures (CAS) from dimethyl methylphosphonate (DMMP) spiked onto painted wall board (PWB) surfaces. The DMMP CAS organic impurities sampled by ADS-SPME and solvent extraction were analyzed by gas chromatography/mass spectrometry (GC/MS). The number of detected DMMP CAS impurities and their respective GC/MS peak areas were determined as a function of DMMP stock, DMMP spiked volume, exposure time, SPME sampling time, and ADS headspace pressure. Based on the statistical analysis of experimental results, several general conclusions are made: (1) ADS-SPME with vacuum (i.e., reduced pressure) increased the amount of detected CAS impurity, as measured by GC/MS peak area, by a factor of 1.7 to 1.9 for PWB under certain experimental conditions, (2) the amount of detected CAS impurity was most influenced by spiked volume, stock, and ADS headspace pressure, (3) the ADS had no measurable effect on the number of detected DMMP impurities, that is, the ADS (with and without reduced pressure) had no practical effect on the DMMP impurity profile collected from spiked PWB, and (4) solvent extraction out performed ADS-SPME in terms of consistently capturing all or most of the targeted DMMP impurities from spiked PWB.

  9. Evaluating and modeling the effects of surface sampling factors on the recovery of organic chemical attribution signatures using the accelerated diffusion sampler and solvent extraction.

    Science.gov (United States)

    Mo, Kai-For; Heredia-Langner, Alejandro; Fraga, Carlos G

    2017-03-01

    In this study, an experimental design matrix was created and executed to test the effects of various real-world factors on the ability of (1) the accelerated diffusion sampler with solid phase micro-extraction (ADS-SPME) and (2) solvent extraction to capture organic chemical attribution signatures (CAS) from dimethyl methylphosphonate (DMMP) spiked onto painted wall board (PWB) surfaces. The DMMP CAS organic impurities sampled by ADS-SPME and solvent extraction were analyzed by gas chromatography/mass spectrometry (GC/MS). The number of detected DMMP CAS impurities and their respective GC/MS peak areas were determined as a function of DMMP stock, DMMP spiked volume, exposure time, SPME sampling time, and ADS headspace pressure. Based on the statistical analysis of experimental results, several general conclusions are made: (1) the amount of CAS impurity detected using ADS-SPME and GC/MS was most influenced by spiked volume, stock, and ADS headspace pressure, (2) reduced ADS headspace pressure increased the amount of detected CAS impurity, as measured by GC/MS peak area, by up to a factor of 1.7-1.9 compared to ADS at ambient headspace pressure, (3) the ADS had no measurable effect on the number of detected DMMP impurities, that is, ADS (with and without reduced pressure) had no practical effect on the DMMP impurity profile collected from spiked PWB, and (4) solvent extraction out performed ADS-SPME in terms of consistently capturing all or most of the targeted DMMP impurities from spiked PWB. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Sample Dilution and Bacterial Community Composition Influence Empirical Leucine-to-Carbon Conversion Factors in Surface Waters of the World's Oceans

    KAUST Repository

    Teira, Eva

    2015-09-25

    The transformation of leucine incorporation rates to prokaryotic carbon production rates requires the use of either theoretical or empirically determined conversion factors. Empirical leucine-to-carbon conversion factors (eCFs) vary widely across environments, and little is known about their potential controlling factors. We conducted 10 surface seawater manipulation experiments across the world\\'s oceans, where the growth of the natural prokaryotic assemblages was promoted by filtration (i.e., removal of grazers [F treatment]) or filtration combined with dilution (i.e., also relieving resource competition [FD treatment]). The impact of sunlight exposure was also evaluated in the FD treatments, and we did not find a significant effect on the eCFs. The eCFs varied from 0.09 to 1.47 kg C mol Leu−1 and were significantly lower in the FD than in the F samples. Also, changes in bacterial community composition during the incubations, as assessed by automated ribosomal intergenic spacer analysis (ARISA), were more pronounced in the FD than in the F treatments, compared to unmanipulated controls. Thus, we discourage the common procedure of diluting samples (in addition to filtration) for eCF determination. The eCFs in the filtered treatment were negatively correlated with the initial chlorophyll a concentration, picocyanobacterial abundance (mostly Prochlorococcus), and the percentage of heterotrophic prokaryotes with high nucleic acid content (%HNA). The latter two variables explained 80% of the eCF variability in the F treatment, supporting the view that both Prochlorococcus and HNA prokaryotes incorporate leucine in substantial amounts, although this results in relatively low carbon production rates in the oligotrophic ocean.

  11. Long-term trend of CH4 at northern mid-latitudes: Comparison between ground-based infrared solar and surface sampling measurements

    Science.gov (United States)

    Rinsland, Curtis P.; Goldman, Aaron; Elkins, James W.; Chiou, Linda S.; Hannigan, James W.; Wood, Stephen W.; Mahieu, Emmanuel; Zander, Rodolphe

    2006-02-01

    We report average tropospheric CH4 volume mixing ratios retrieved from a 27 year time series of high spectral resolution infrared solar absorption measurements recorded between May 1977 and July 2004 at the US National Solar Observatory station on Kitt Peak (31.9N,111.6W, 2.09 km altitude) and their comparison with surface in situ sampling measurements recorded between 1983 and 2004 at the Climate Monitoring and Diagnostics Laboratory (CMDL) station at Niwot Ridge, Colorado (40.0N,105.5W, 3013 m altitude). The two measurement sets therefore overlap for the 1983 2004 time period. An average tropospheric volume mixing ratios of 1814±48ppbv (1ppbv=10 per unit volume) has been derived from the solar absorption time series with a best-fit increase rate trend equal to 8.26±2.20 ppbv yr in 1983 decreasing to 1.94±3.69 ppbv yr in 2003. The CMDL measurements also show a continuous long-term CH4 volume mixing ratio rise, with subsequent slowing down. A mean ratio of the retrieved average tropospheric volume mixing ratio to the CMDL volume mixing ratio for the overlapping time period of 1.038±0.034 indicates agreement between both data sets within the quantified experimental errors.

  12. Household vacuum cleaners vs. the high-volume surface sampler for collection of carpet dust samples in epidemiologic studies of children.

    Science.gov (United States)

    Colt, Joanne S; Gunier, Robert B; Metayer, Catherine; Nishioka, Marcia G; Bell, Erin M; Reynolds, Peggy; Buffler, Patricia A; Ward, Mary H

    2008-02-21

    Levels of pesticides and other compounds in carpet dust can be useful indicators of exposure in epidemiologic studies, particularly for young children who are in frequent contact with carpets. The high-volume surface sampler (HVS3) is often used to collect dust samples in the room in which the child had spent the most time. This method can be expensive and cumbersome, and it has been suggested that an easier method would be to remove dust that had already been collected with the household vacuum cleaner. However, the household vacuum integrates exposures over multiple rooms, some of which are not relevant to the child's exposure, and differences in vacuuming equipment and practices could affect the chemical concentration data. Here, we compare levels of pesticides and other compounds in dust from household vacuums to that collected using the HVS3. Both methods were used in 45 homes in California. HVS3 samples were collected in one room, while the household vacuum had typically been used throughout the home. The samples were analyzed for 64 organic compounds, including pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls (PCBs), using GC/MS in multiple ion monitoring mode; and for nine metals using conventional microwave-assisted acid digestion combined with ICP/MS. The methods agreed in detecting the presence of the compounds 77% to 100% of the time (median 95%). For compounds with less than 100% agreement, neither method was consistently more sensitive than the other. Median concentrations were similar for most analytes, and Spearman correlation coefficients were 0.60 or higher except for allethrin (0.15) and malathion (0.24), which were detected infrequently, and benzo(k)fluoranthene (0.55), benzo(a)pyrene (0.55), PCB 105 (0.54), PCB 118 (0.54), and PCB 138 (0.58). Assuming that the HVS3 method is the "gold standard," the extent to which the household vacuum cleaner method yields relative risk estimates closer to unity by increasing random

  13. Grafting 3-mercaptopropyl trimethoxysilane on multi-walled carbon nanotubes surface for improving on-line cadmium(II) preconcentration from water samples

    Energy Technology Data Exchange (ETDEWEB)

    Corazza, Marcela Zanetti; Somera, Bruna Fabrin; Segatelli, Mariana Gava [Departamento de Quimica, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, PR 445, Km 380, Campus Universitario, Londrina-PR, CEP 86051-990 (Brazil); Tarley, Cesar Ricardo Teixeira, E-mail: tarley@uel.br [Departamento de Quimica, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, PR 445, Km 380, Campus Universitario, Londrina-PR, CEP 86051-990 (Brazil); Instituto Nacional de Ciencia e Tecnologia (INCT) de Bioanalitica, Universidade Estadual de Campinas (UNICAMP), Instituto de Quimica, Departamento de Quimica Analitica, Cidade Universitaria Zeferino, Vaz, s/n, CEP 13083-970, Campinas-SP (Brazil)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer 3-Mercaptopropyl trimethoxysilane grafted on MWCNT surface was prepared. Black-Right-Pointing-Pointer The material promoted an increase on performance of MWCNT for Cd{sup 2+} adsorption. Black-Right-Pointing-Pointer The life time of adsorbent was very high. Black-Right-Pointing-Pointer An improvement of 84% on the sensitivity was achieved. - Abstract: In the present study, the performance of multi-walled carbon nanotubes (MWCNTs) grafted with 3-mercaptopropyltrimethoxysilane (3-MPTMS), used as a solid phase extractor for Cd{sup 2+} preconcentration in a flow injection system coupled to flame atomic absorption spectrometry (FAAS), was evaluated. The procedure involved the preconcentration of 20.0 mL of Cd{sup 2+} solution at pH 7.5 (0.1 mol L{sup -1} buffer phosphate) through 70 mg of 3-MPTMS-grafted MWCNTs packed into a minicolumn at 6.0 mL min{sup -1}. The elution step was carried out with 1.0 mol L{sup -1} HCl. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to estimate the extent of the MWCNT chemical modification. The 3-MPTMS-grafted MWCNTs provided a 1.68 times improvement in the sensitivity of the Cd{sup 2+} FAAS determination compared to the unsilanized oxidized MWCNTs. The following parameters were obtained: preconcentration factor of 31.5, consumptive index of 0.635 mL, sample throughput of 14 h{sup -1}, and concentration efficiency of 9.46 min{sup -1}. The analytical curve was constructed in the range of 1.0-60.0 {mu}g L{sup -1} (r = 0.9988), and the detection and quantification limits were found to be 0.15 {mu}g L{sup -1} and 0.62 {mu}g L{sup -1}, respectively. Different types of water samples and cigarette sample were successfully analyzed, and the results were compared using electrothermal atomic absorption spectrometry (ETAAS) as reference technique. In addition, the accuracy of proposed method was also checked by analysis of

  14. Household vacuum cleaners vs. the high-volume surface sampler for collection of carpet dust samples in epidemiologic studies of children

    Directory of Open Access Journals (Sweden)

    Buffler Patricia A

    2008-02-01

    Full Text Available Abstract Background Levels of pesticides and other compounds in carpet dust can be useful indicators of exposure in epidemiologic studies, particularly for young children who are in frequent contact with carpets. The high-volume surface sampler (HVS3 is often used to collect dust samples in the room in which the child had spent the most time. This method can be expensive and cumbersome, and it has been suggested that an easier method would be to remove dust that had already been collected with the household vacuum cleaner. However, the household vacuum integrates exposures over multiple rooms, some of which are not relevant to the child's exposure, and differences in vacuuming equipment and practices could affect the chemical concentration data. Here, we compare levels of pesticides and other compounds in dust from household vacuums to that collected using the HVS3. Methods Both methods were used in 45 homes in California. HVS3 samples were collected in one room, while the household vacuum had typically been used throughout the home. The samples were analyzed for 64 organic compounds, including pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls (PCBs, using GC/MS in multiple ion monitoring mode; and for nine metals using conventional microwave-assisted acid digestion combined with ICP/MS. Results The methods agreed in detecting the presence of the compounds 77% to 100% of the time (median 95%. For compounds with less than 100% agreement, neither method was consistently more sensitive than the other. Median concentrations were similar for most analytes, and Spearman correlation coefficients were 0.60 or higher except for allethrin (0.15 and malathion (0.24, which were detected infrequently, and benzo(kfluoranthene (0.55, benzo(apyrene (0.55, PCB 105 (0.54, PCB 118 (0.54, and PCB 138 (0.58. Assuming that the HVS3 method is the "gold standard," the extent to which the household vacuum cleaner method yields relative risk

  15. Coupling non invasive and fast sampling of proteins from work of art surfaces to surface plasmon resonance biosensing: Differential and simultaneous detection of egg components for cultural heritage diagnosis and conservation.

    Science.gov (United States)

    Scarano, S; Carretti, E; Dei, L; Baglioni, P; Minunni, M

    2016-11-15

    Despite the wide application of surface plasmon resonance (SPR) to a broad area of interests, from environment to food analysis, from drug discovery to diagnostics, its exploitation in cultural heritage conservation is still unexplored. Water-based highly viscous polymeric dispersions (HVPD) composed by partially hydrolyzed polyvinyl acetate (PVA), borax, and water, were recently developed and successfully applied for the selective removal of surface degradation patinas (i.e. protein materials, natural resins etc.) from paintings of historical and artistic interest. This approach is here coupled for the first time to a SPR biosensor to simultaneously recognize albumen, yolk, or their mixtures in HVPD extracts. Ovalbumin and immunoglobulin Y are selected as analytes for egg white and yolk recognition, respectively. The biosensor was first characterized on standard analytes within the range 0-400mgL(-1) and then on fresh and dried egg albumen and yolk down to 2·10(^4) and 1·10(^5) dilution factors, respectively. Once optimized, the biosensor was combined to the HVPD application on simulated and real art samples for the evaluation of hen egg presence in the extract, i.e. albumen, yolk, or their co-presence in the matrix. For a contemporary 'sacred icon', realized by the traditional egg tempera procedure described by Cennino Cennini, the biosensor successfully distinguished different uses of egg components for the realization of painted and gilded areas, i.e. yolk and albumen, respectively. Finally, a XVIII century italian painting whose the realization technique is unknown, was tested confirming its egg tempera-based realization technique. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Wip-ing out cancer

    NARCIS (Netherlands)

    Bernards, R.A.

    The Whip1 phosphatase is encoded by an oncogene that is amplified in several forms of human cancer, including breast cancer. Ablation of this gene confers resistance to breast tumors induced by certain oncogenes.

  17. Nerve Agent Sensing Biopolymer Wipe

    Science.gov (United States)

    2003-04-01

    minutes. Polymer synthesis is complete in less than 10 minutes. The CO2 evolved during the reaction of water and isocyanate lifts the foam to a...concrete, stone and asphalt . Excessive dirt or any material that significantly masks clear viewing of the sensor polymer may invalidate sensor

  18. Cleaning Dirty Surfaces: A Three-Body Problem.

    Science.gov (United States)

    Stoehr, Bastian; Hall, Colin; Evans, Drew; Murphy, Peter

    2016-07-20

    Human interaction with touch screens requires physical touch and hence results in contamination of these surfaces, resulting in the necessity of cleaning. In this study we discuss the three bodies of this problem and how each component contributes and can be controlled. Utilizing a standard fingerprint machine and a standard cleanability test, this study examines the influence of parameters such as the wiping speed and pressure, the material and surface area of the cloths, and the surface energy of the contaminated surfaces. It was shown that fingerprint contamination undergoes shear banding and hence is not easily removed. The degree of material removal depends on the position of the shear plane, which is influenced by surface energies and shear rates.

  19. Surface Modification of Nonwoven fabrics by Atmospheric Brush Plasma

    Science.gov (United States)

    Oksuz, Lutfi; Uygun, Emre; Bozduman, Ferhat; Yurdabak Karaca, Gozde; Asan, Orkun Nuri; Uygun Oksuz, Aysegul

    2017-10-01

    Polypropylene nonwoven fabrics (PPNF) are used in disposable absorbent articles, such as diapers, feminine care products, wipes. PPNF need to be wettable by water or aqueous-based liquid. Plasma surface treatment/modification has turned out to be a well-accepted method since it offers superior surface property enhancement than other chemical methods. The cold plasma brush can most efficiently use the discharge power as well as the plasma gas for material and surface treatment. The very low power consumption of such an atmospheric argon plasma brush provides many unique advantages in practical application. The purpose of this study was to reveal the effectiveness of non-thermal atmospheric plasma brush in surface wettability and modification of two different nonwoven surfaces.

  20. Experimental skin deposition of chromium on the hands following handling of samples of leather and metal.

    Science.gov (United States)

    Bregnbak, David; Thyssen, Jacob P; Jellesen, Morten S; Zachariae, Claus; Johansen, Jeanne D

    2016-08-01

    Chromium is an important skin sensitizer. Exposure to it has been regulated in cement, and recently in leather. Studies on the deposition of chromium ions on the skin as a result of handling different chromium-containing materials are sparse, but could improve the risk assessment of contact sensitization and allergic contact dermatitis caused by chromium. To determine whether the handling of chromium-containing samples of leather and metal results in the deposition of chromium onto the skin. Five healthy volunteers participated. For 30 min, they handled samples of leather and metal known to contain and release chromium. Skin deposition of chromium was assessed with the acid wipe sampling technique. Acid wipe sampling of the participants' fingers showed chromium deposition on the skin in all participants who had been exposed to leather (range 0.01-0.20 µg/cm(2) ) and in 3 of 5 participants after they had manually handled metal discs (range 0.02-0.04 µg/cm(2) ). We found that samples of leather and metal had the ability to deposit chromium on the skin at significant levels, in spite of a short duration of exposure. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Uranium favorability of tertiary sedimentary rocks of the western Okanogan highlands and of the upper Columbia River valley, Washington. [Measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples; no known uranium deposits

    Energy Technology Data Exchange (ETDEWEB)

    Marjaniemi, D.K.; Robins, J.W.

    1975-08-01

    Tertiary sedimentary rocks in the northern portions of the western Okanogan highlands and in the upper Columbia River valley were investigated during a regional study to determine the favorability for potential uranium resources of the Tertiary sedimentary rocks of northeastern Washington. This project involved measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples. No portion of the project area of this report is rated of high or of medium favorability for potential uranium resources. Low favorability ratings are given to Oroville, Tonasket, and Pine Creek areas of the Okanogan River valley; to the Republic graben; and to the William Lakes, Colville, and Sheep Creek areas of the upper Columbia River valley. All these areas contain some fluvial, poorly sorted feldspathic or arkosic sandstones and conglomerates. These rocks are characterized by very low permeability and a consistently high siliceous matrix suggesting very low initial permeability. There are no known uranium deposits in any of these areas, and low level uranium anomalies are rare.

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

    OpenAIRE

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

    1999-01-01

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

  3. Rapid on-site detection of explosives on surfaces by ambient pressure laser desorption and direct inlet single photon ionization or chemical ionization mass spectrometry.

    Science.gov (United States)

    Ehlert, S; Hölzer, J; Rittgen, J; Pütz, M; Schulte-Ladbeck, R; Zimmermann, R

    2013-09-01

    Considering current security issues, powerful tools for detection of security-relevant substances such as traces of explosives and drugs/drug precursors related to clandestine laboratories are required. Especially in the field of detection of explosives and improvised explosive devices, several relevant compounds exhibit a very low vapor pressure. Ambient pressure laser desorption is proposed to make these substances available in the gas phase for the detection by adapted mass spectrometers or in the future with ion-mobility spectrometry as well. In contrast to the state-of-the-art thermal desorption approach, by which the sample surface is probed for explosive traces by a wipe pad being transferred to a thermal desorber unit, by the ambient pressure laser desorption approach presented here, the sample is directly shockwave ablated from the surface. The laser-dispersed molecules are sampled by a heated sniffing capillary located in the vicinity of the ablation spot into the mass analyzer. This approach has the advantage that the target molecules are dispersed more gently than in a thermal desorber unit where the analyte molecules may be decomposed by the thermal intake. In the technical realization, the sampling capillary as well as the laser desorption optics are integrated in the tip of an endoscopic probe or a handheld sampling module. Laboratory as well as field test scenarios were performed, partially in cooperation with the Federal Criminal Police Office (Bundeskriminalamt, BKA, Wiesbaden, Germany), in order to demonstrate the applicability for various explosives, drugs, and drug precursors. In this work, we concentrate on the detection of explosives. A wide range of samples and matrices have been investigated successfully.

  4. Data Validation Package May and June 2015 Groundwater and Surface Water Sampling at the Bluewater, New Mexico, Disposal Site, August 2015

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Dick [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States); Tsosie, Bernadette [US Department of Energy, Washington, DC (United States)

    2015-08-01

    Groundwater samples were collected from monitoring wells at the Bluewater, New Mexico, Disposal Site to monitor groundwater contaminants as specified in the 1997 Long-Term Surveillance Plan for the DOE Bluewater (UMTRCA Title II) Disposal Site Near Grants, New Mexico (LTSP). Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). Duplicate samples were collected from locations 14(SG) and 21(M). Sampling originally scheduled for the week of May 11, 2015 was interrupted by heavy rainfall and later completed in June.

  5. Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13

    Science.gov (United States)

    Opsahl, Stephen P.; Crow, Cassi L.

    2014-01-01

    During 2011–13, the U.S. Geological Survey, in cooperation with the San Antonio River Authority and the Guadalupe-Blanco River Authority, analyzed surface-water and streambed-sediment samples collected from 10 sites in the San Antonio River Basin to provide data for a broad range of constituents that might be associated with hydraulic fracturing and the produced waters that are a consequence of hydraulic fracturing. Among surface-water samples, all sulfide concentrations were less than the method detection limit of 0.79 milligrams per liter. Four glycols—diethylene glycol, ethylene glycol, propylene glycol, and triethylene glycol—were analyzed for in surface-water samples collected for this study, and none were detected. Of the 91 semivolatile organic compounds analyzed for this study, there were six detections, all but one of which were in storm-runoff samples. The base-flow sample collected at the San Antonio River at Goliad, Tex. (SAR Goliad), site contained bis(2-ethylhexyl) phthalate, a plasticizer in polyvinyl chloride and a constituent in hydraulic fracturing fluids. The storm-runoff samples collected at the San Antonio River near Elmendorf, Tex. (SAR Elmendorf), and Ecleto Creek at County Road 326 near Runge, Tex. (Ecleto 2), sites also contained bis(2-ethylhexyl) phthalate. The storm-runoff sample collected at the SAR Elmendorf site contained the plasticizer diethyl phthalate. Both storm-runoff samples collected at the Ecleto Creek near Runge, Tex. (Ecleto 1), and Ecleto 2 sites contained benzyl alcohol, a solvent commonly used in paints. Of the 67 volatile organic compounds analyzed in this study, there were a total of six detections, all of which were in base-flow samples. The surface-water sample collected at the SAR Elmendorf site contained bromodichloromethane, dibromochloromethane, and trichloromethane, all of which are disinfection byproducts associated with the chlorination of municipal water supplies and of treated municipal wastewater. The

  6. Genotoxicity testing of samples generated during UV/H2O2 treatment of surface water for the production of drinking water using the Ames test in vitro and the Comet assay and the SCE test in vivo

    NARCIS (Netherlands)

    Penders, E.J.M.; Martijn, A.J.; Spenkelink, A.; Alink, G.M.; Rietjens, I.; Hoogenboezem, W.

    2012-01-01

    UV/H2O2 treatment can be part of the process converting surface water to drinking water, but would pose a potential problem when resulting in genotoxicity. This study investigates the genotoxicity of samples collected from the water treatment plant Andijk, applying UV/H2O2 treatment with an

  7. Evaluation of Beryllium, Total Chromium and Nickel in the Surface Contaminant Layer Available for Dermal Exposure After Abrasive Blasting in a Shipyard

    Science.gov (United States)

    2013-04-24

    production of corrosion resistant products, stainless steel alloys , tanning agents for leather, and electroplating. Since chromium is a frequent cause of... Chromium and Inorganic Compounds. 7. ACGIH. 2009. Beryllium and Compounds. 8. Cumin W. 1827. Remarks on the Medicinal Properties ofMadar, and on the...Vahter M. 2008. Deposition of nickel, chromium , and cobalt on the skin in some occupations - assessment by acid wipe sampling. Contact Dermatitis 58:347

  8. Quantitative Detection of Trace Level Cloxacillin in Food Samples Using Magnetic Molecularly Imprinted Polymer Extraction and Surface-Enhanced Raman Spectroscopy Nanopillars

    DEFF Research Database (Denmark)

    Ashley, Jon; Wu, Kaiyu; Hansen, Mikkel Fougt

    2017-01-01

    the magnetically susceptible characteristics greatly simplified sample handling procedures. Low cost and robust SERS substrates consisting of vertical gold capped silicon nanopillars were fabricated and employed for the detection of cloxacillin. Quantitative SERS was achieved by normalizing signal intensities...... using an internal standard. By coherently combining MMIP extraction and silicon nanopillar-based SERS biosensor, good sensitivity toward cloxacillin was achieved. The detection limit was 7.8 pmol. Cloxacillin recoveries from spiked pig plasma samples were found to be more than 80%....

  9. Tip-enhanced near-field optical microscope with side-on and ATR-mode sample excitation for super-resolution Raman imaging of surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Heilman, A. L.; Gordon, M. J. [Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106-5080 (United States)

    2016-06-14

    A tip-enhanced near-field optical microscope with side-on and attenuated total reflectance (ATR) excitation and collection is described and used to demonstrate sub-diffraction-limited (super-resolution) optical and chemical characterization of surfaces. ATR illumination is combined with an Au optical antenna tip to show that (i) the tip can quantitatively transduce the optical near-field (evanescent waves) above the surface by scattering photons into the far-field, (ii) the ATR geometry enables excitation and characterization of surface plasmon polaritons (SPPs), whose associated optical fields are shown to enhance Raman scattering from a thin layer of copper phthalocyanine (CuPc), and (iii) SPPs can be used to plasmonically excite the tip for super-resolution chemical imaging of patterned CuPc via tip-enhanced Raman spectroscopy (TERS). ATR-illumination TERS is also quantitatively compared with the more conventional side-on illumination scheme. In both cases, spatial resolution was better than 40 nm and tip on/tip off Raman enhancement factors were >6500. Furthermore, ATR illumination was shown to provide similar Raman signal levels at lower “effective” pump powers due to additional optical energy delivered by SPPs to the active region in the tip-surface gap.

  10. Dedicated Tool for Irradiation and Electrical Measurement of Large Surface Samples on the Beamline of a 2.5 Mev Pelletron Electron Accelerator: Application to Solar Cells

    Directory of Open Access Journals (Sweden)

    Lefèvre Jérémie

    2017-01-01

    After a brief description of the SIRIUS irradiation facility hosted at Laboratoire des Solides Irradiés (LSI, this paper gives detailed information about the Large Surface Irradiated-Cell (LSIC device. Preliminary results obtained during the ongoing qualification phase of the setup are also discussed.

  11. Laboratory spectroscopy experiment : Spectral reflectance of beach sand as function of surface moisture content with sample of beach sand collected from the Sand Motor, the Netherlands

    NARCIS (Netherlands)

    Nolet, C.; Roosjen, P.P.J.

    2015-01-01

    Spectral reflectance of beach sand (350-2500 nm) under different moisture conditions at 1 nm interval, obtained by a laboratory spectroscopy experiment. Optical remote sensing has the potential to measure surface moisture at a high spatio-temporal resolution. It is based on the principle that wet

  12. Combined use of direct analysis in real-time/Orbitrap mass spectrometry and micro-Raman spectroscopy for the comprehensive characterization of real explosive samples.

    Science.gov (United States)

    Bridoux, Maxime C; Schwarzenberg, Adrián; Schramm, Sébastien; Cole, Richard B

    2016-08-01

    Direct Analysis in Real Time (DART™) high-resolution Orbitrap™ mass spectrometry (HRMS) in combination with Raman microscopy was used for the detailed molecular level characterization of explosives including not only the charge but also the complex matrix of binders, plasticizers, polymers, and other possible organic additives. A total of 15 defused military weapons including grenades, mines, rockets, submunitions, and mortars were examined. Swabs and wipes were used to collect trace (residual) amounts of explosives and their organic constituents from the defused military weapons and micrometer-size explosive particles were transferred using a vacuum suction-impact collection device (vacuum impactor) from wipe and swap samples to an impaction plate made of carbon. The particles deposited on the carbon plate were then characterized using micro-Raman spectroscopy followed by DART-HRMS providing fingerprint signatures of orthogonal nature. The optical microscope of the micro-Raman spectrometer was first used to localize and characterize the explosive charge on the impaction plate which was then targeted for identification by DART-HRMS analysis in both the negative and positive modes. Raman spectra of the explosives TNT, RDX and PETN were acquired from micrometer size particles and characterized by the presence of their characteristic Raman bands obtained directly at the surface of the impaction plate nondestructively without further sample preparation. Negative mode DART-HRMS confirmed the types of charges contained in the weapons (mainly TNT, RDX, HMX, and PETN; either as individual components or as mixtures). These energetic compounds were mainly detected as deprotonated species [M-H](-), or as adduct [M + (35)Cl](-), [M + (37)Cl](-), or [M + NO3](-) anions. Chloride adducts were promoted in the heated DART reagent gas by adding chloroform vapors to the helium stream using an "in-house" delivery method. When the polarity was switched to positive mode

  13. Guidance values for surface monitoring of antineoplastic drugs in German pharmacies.

    Science.gov (United States)

    Schierl, Rudolf; Böhlandt, Antje; Nowak, Dennis

    2009-10-01

    Antineoplastic drugs are widely used in anticancer therapy due to their cytotoxic activity but many of them are classified as carcinogenic, mutagenic, or teratogenic to humans. In order to evaluate personal exposure, surface monitoring has been successfully applied for several years. In this study, we present a statistical description of our data set from 102 German pharmacies and propose 'threshold guidance values (TGVs)' to facilitate interpretation of monitoring results. Our database included 1008 results for platinum (PT) and 1237 for 5-fluorouracil (FU) collected in 102 pharmacies in Germany. Wipe sampling on site was performed with one validated procedure. PT concentrations were measured by voltammetry and FU by gas chromatography/mass spectrometry. Data were stratified into 10 locations and statistically evaluated. Contamination was detected on all surfaces in the pharmacies with high levels on storage shelves and floors. The median values for the different locations ranged from 0.20 to 1.70 pg cm(-2) (mean: 0.57 pg cm(-2)) for PT and from 2.50 to 10.00 pg cm(-2) (mean: 5.34 pg cm(-2)) for FU. The mean 75th percentiles were 3.92 pg cm(-2) (PT) and 28.90 pg cm(-2) (FU). The TGV 1 value was set at the median value and results below demonstrate good working practices. Contaminations above the TGV 2, which was assigned at the 75th percentile, show a clear need for optimizing the handling procedures. The introduction of TGVs helps to reduce occupational exposure and allows pharmacy personnel to benchmark their own contamination levels. This provides a basis for improvement in occupational safety precautions and for regular contamination controls.

  14. Simplified sample preparation method for protein identification by matrix-assisted laser desorption/ionization mass spectrometry: in-gel digestion on the probe surface

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard

    2001-01-01

    for protein identification similar to that obtained by the traditional protocols for in-gel digestion and MALDI peptide mass mapping of human proteins, i.e. approximately 60%. The overall performance of the novel on-probe digestion method is comparable with that of the standard in-gel sample preparation...... protocol while being less labour intensive and more cost-effective due to minimal consumption of reagents, enzymes and consumables. Preliminary data obtained on a MALDI quadrupole-TOF tandem mass spectrometer demonstrated the utility of the on-probe digestion protocol for peptide mass mapping and peptide....../ionization-time of flight mass spectrometry (MALDI-TOF-MS) is used as the first protein screening method in many laboratories because of its inherent simplicity, mass accuracy, sensitivity and relatively high sample throughput. We present a simplified sample preparation method for MALDI-MS that enables in-gel digestion...

  15. Comparison of microbial communities in Lake Tahoe surface sample with Tonga Trench water column samples using High Pressure Liquid Chromatography - Electrospray Ionization - Mass Spectroscopy (HPLC - ESI - MS) and Global Natural Products Social Molecular Network (GNPS)

    Science.gov (United States)

    Belmonte, M. A.

    2015-12-01

    Intact polar lipids (IPLs) are lipids composed of a head group, a glycerol, and a fatty acid chain that make up the lipid bilayer of cell membranes in living cells; and the varying head groups can be indicative of the type of microbes present in the environment (Van Mooy 2010). So by distinguishing and identifying the IPL distribution in an environment one can make inferences about the microbial communities in the said environment. In this study, we used High Pressure Liquid Chromatography-Electrospray Ionization- Mass Spectroscopy (HPLC-ESI-MS) and Global Natural Products Social Molecular Networking (GNPS) to compare the IPL distributions of two oligotrophic environments: surface waters of Lake Tahoe in the Sierra Nevada Mountains, and the water column of the Tonga Trench in the South Pacific. We hypothesized that the similar nutrient dynamics of the two oligotrophic environments would result in similar eukaryotic and prokaryotic communities, which would be reflected in the IPL composition of suspended particulate organic matter (POM). For simplicity we focused on the classes of IPLs most commonly observed in the marine environment: phosphotidylglycerol (PG), phosphotidylethanolamine (PE), diacylglyceryl-trimethyl-homoserine (DGTS), diacylglyceryl-hydroxymethyl-trimethylalanine (DGTA), sulfoquinovosyldiacylglycerol (SQDG), monoglycosyldiacylglycerol (MGDG) and diglycosyldiacylglycerol (DGDG). Our results showed that all of the marine IPLs of interest were present in Lake Tahoe which confirms that there are many of the same microbial communities in the fresh waters of Lake Tahoe and the salt waters Tonga Trench.

  16. The short-term effects of various oral care methods in dependent elderly: comparison between toothbrushing, tongue cleaning with sponge brush and wiping on oral mucous membrane by chlorhexidine.

    Science.gov (United States)

    Tashiro, Kazuhisa; Katoh, Tamiko; Yoshinari, Nobuo; Hirai, Kaname; Andoh, Nobuyuki; Makii, Kakuma; Matsuo, Kouichiro; Ogasawara, Tadashi

    2012-06-01

    To explore the short-term effects from toothbrushing, tongue cleaning with sponge brush and wiping on oral mucous membrane by chlorhexidine. Numerous reports have been seen in recent years proving the effectiveness of mouth cleaning with a toothbrush for the prevention of respiratory infections among the dependent elderly. However, the short-term effects from each oral care method have not yet been clarified. Hence, an investigation was conducted by having each subject independently perform various oral care methods for five consecutive days. The subjects consisted of 12 assistance-dependent elderly who have difficulties with tooth brushing by themselves, have 10 or more residual teeth and are not yet using plate dentures. After the pre-intervention examination, each of the following oral care methods were performed on the same subject on an approximately three week basis: 1) Tooth brushing 2) Tongue cleaning with sponge brush 3) Wiping on oral mucous with sponge brush by chlorhexidine. Each method was performed independently, once a day for 5 consecutive days and the subjects were reexamined on the sixth day for comparative verification. Consequently, toothbrushing decreased the plaque index and gingival index significantly and an improvement of oral malodour was also acknowledged (p brush decreased the tongue coat score significantly (p brush soaked in chlorhexidine significantly decreased opportunistic infections in the pharynx region (p < 0.05). It was suggested that the use of not only a toothbrush but also chlorhexidine gluconate may be indicated for dependent elderly people in whom pathogens of opportunistic infection are detected. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  17. Appendix to Health and Safety Laboratory environmental quarterly, March 1, 1976--June 1, 1976. [Tabulated data on content of lead in surface air and /sup 7/Be, /sup 95/Zr, /sup 137/Cs, /sup 144/Ce, and /sup 90/Sr in surface air, milk, drinking water, and foods sampled in USA

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, E.P. Jr.

    1976-07-01

    Tabulated data are presented on: the monthly deposition of /sup 89/Sr and /sup 90/Sr at some 100 world land sites; the content of lead and /sup 7/Be, /sup 95/Zr, /sup 137/Cs, and /sup 144/Ce in samples of surface air from various world sites; and the content of /sup 90/Sr in samples of milk, drinking water, and animal and human diets collected at various locations throughout the USA. (CH)

  18. False-negative rate, limit of detection and recovery efficiency performance of a validated macrofoam-swab sampling method for low surface concentrations of Bacillus anthracis Sterne and Bacillus atrophaeus spores

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, G. F. [Applied Statistics and Computational Sciences, Pacific Northwest National Laboratory, Richland WA USA; Deatherage Kaiser, B. L. [Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland WA USA; Amidan, B. G. [Applied Statistics and Computational Sciences, Pacific Northwest National Laboratory, Richland WA USA; Sydor, M. A. [Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland WA USA; Barrett, C. A. [Analytical Chemistry of Nuclear Materials, Pacific Northwest National Laboratory, Richland WA USA; Hutchison, J. R. [Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland WA USA

    2016-05-06

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in × 2 in) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS and 40.2% with BG) and the highest for glass (92.8% with BAS and 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG; values increased as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent article.

  19. Enrichment of rare-earth elements (REE) and Gd-DTPA in surface water samples by means of countercurrent chromatography (CCC)

    Energy Technology Data Exchange (ETDEWEB)

    Hennebrueder, Kristina [UFZ Centre for Environmental Research Leipzig-Halle Ltd., Department of Analytical Chemistry, Permoserstr. 15, 04318 Leipzig (Germany); University of Leipzig, Institute of Analytical Chemistry, Linnestr. 3, 04103 Leipzig (Germany); Engewald, Werner [University of Leipzig, Institute of Analytical Chemistry, Linnestr. 3, 04103 Leipzig (Germany); Staerk, Hans-Joachim [UFZ Centre for Environmental Research Leipzig-Halle Ltd., Department of Analytical Chemistry, Permoserstr. 15, 04318 Leipzig (Germany); Wennrich, Rainer [UFZ Centre for Environmental Research Leipzig-Halle Ltd., Department of Analytical Chemistry, Permoserstr. 15, 04318 Leipzig (Germany)]. E-mail: rainer.wennrich@ufz.de

    2005-06-29

    An analytical scheme was developed for the determination of rare-earth elements and gadolinium diethylenetriaminepentaacetate (Gd-DTPA) in river water by ICP-MS. Since the concentration of Gd-DTPA and the rare-earth elements in river water is often lower than the limits of detection in quadrupole ICP-MS applying pneumatic nebulization, a preconcentration procedure is essential. In this work, the capabilities of countercurrent chromatography (CCC) for preconcentration of REE were investigated. For preconcentration ethylhexylphosphates as stationary phase had been used. Acidified aqueous samples (pH 2) and river water spiked with REE and Gd-DTPA were under study. The procedure was compared with solid phase extraction (SPE) using the same samples and ethylhexylphosphates as stationary phase. The recovery of the light and middle REE was found to be at about 100%, which was found to be more efficient than applying SPE. In contrast, the recovery rates for Yb and Lu were low (and poorly reproducible) using CCC (57% and 73%, respectively) while significant better results were obtained with SPE (89% and 84%, respectively). The recoveries of Gd applying Gd-DTPA were 80 {+-} 4% in the investigation of river water samples.

  20. Two Consecutive Standardized Skin Surface Biopsies: An Improved Sampling Method to Evaluate Demodex Density as a Diagnostic Tool for Rosacea and Demodicosis.

    Science.gov (United States)

    Forton, Fabienne M N; De Maertelaer, Viviane

    2017-02-08

    Diagnosing papulopustular rosacea is not always straightforward; no specific diagnostic test is currently available. A high density of Demodex mites is consistently observed in this condition. This retrospective study assesses an improved method for evaluating Demodex density among 1,044 patients presenting to our dermatology practice. The skin was cleaned with ether and Demodex densities were measured in 2 consecutive standardized skin surface biopsies taken from the same site. Mean densities in patients with rosacea and demodicosis were much higher than those in healthy controls and patients with other facial dermatoses. The optimal cut-off values for the 2 biopsies were combined and the resultant criterion (presence of a first biopsy density rosacea or demodicosis with a sensitivity of 98.7% and specificity of 95.5%, making this a valuable diagnostic tool for dermatologists in routine clinical practice.

  1. Surface boxplots

    KAUST Repository

    Genton, Marc G.

    2014-01-22

    In this paper, we introduce a surface boxplot as a tool for visualization and exploratory analysis of samples of images. First, we use the notion of volume depth to order the images viewed as surfaces. In particular, we define the median image. We use an exact and fast algorithm for the ranking of the images. This allows us to detect potential outlying images that often contain interesting features not present in most of the images. Second, we build a graphical tool to visualize the surface boxplot and its various characteristics. A graph and histogram of the volume depth values allow us to identify images of interest. The code is available in the supporting information of this paper. We apply our surface boxplot to a sample of brain images and to a sample of climate model outputs.

  2. Time-dependent integrity during storage of natural surface water samples for the trace analysis of pharmaceutical products, feminizing hormones and pesticides

    Directory of Open Access Journals (Sweden)

    Prévost Michèle

    2010-04-01

    Full Text Available Abstract Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids, and selected pesticides under refrigerated storage conditions. The analysis was performed using multi-residue methods using an on-line solid-phase extraction combined with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS in the selected reaction monitoring mode. After 21 days of storage, no significant difference in the recoveries was observed compared to day 0 for pharmaceutical products, while for pesticides, significant losses occurred for DIA and simazine after 10 days (14% and 17% reduction respectively and a statistically significant decrease in the recovery was noted for cyanazine (78% disappearance. However, the estrogen and progestogen steroids were unstable during storage. The disappearance rates obtained after 21 days of storage vary from 63 to 72% for the feminizing hormones. Overall, pharmaceuticals and pesticides seem to be stable for refrigerated storage for up to about 10 days (except cyanazine and steroidal hormones can be quite sensitive to degradation and should not be stored for more than a few days.

  3. Risk assessment of manufacturing equipment surfaces contaminated with DDTs and dicofol.

    Science.gov (United States)

    Luo, Fei; Song, Jing; Chen, Meng-Fang; Wei, Jing; Pan, Yun-Yu; Yu, Hai-Bo

    2014-01-15

    Decommissioning of manufacturing plant in the chemical industry includes inspection of the surfaces of production equipment for potential contamination and associated health risks. In the present study wipe-samples were taken from the surfaces of dicofol manufacturing equipment at a chemical factory in north China and analyzed for chemicals of concern (COCs). Occupational hygiene assessment was conducted to assess the risks to demolition workers and health risk assessment was performed to evaluate the risks to demolition and general industrial workers. The concentrations of COCs on the equipment surfaces were found to be 0.54-3.75 × 10(4)mg DDTs m(-2) and 0.15-4.38 × 10(3)mg dicofolm(-2). The average concentration of p,p'-DDT does not represent an unacceptable risk to the demolition workers using occupational hygiene assessment. Under the industrial scenario the carcinogenic risks of COCs ranged from 2.28 × 10(-7) to 1.79 × 10(-2) for p,p'-DDT, 6.18 × 10(-7) to 3.04 × 10(-3) for p,p'-DDD and 1.89 × 10(-6) to 0.16 for p,p'-DDE. The non-carcinogenic hazard indices ranged from 3.86 × 10(-3) to 3.03 × 10(2) for p,p'-DDT and 1.16 × 10(-3) to 33.94 for dicofol. Both carcinogenic risk and hazard index of COCs under the industrial scenario were higher than under the demolition scenario. Oral ingestion and dermal contact were the major pathways and accounted for >88% of the total exposure of COCs. Parameter sensitivity analysis shows that equipment surface concentration (Cs), frequency of contact with surface (EV), fraction of dust transferred from surface to skin (FTss) and exposure frequency (EF) were the most sensitive parameters and these should be acquired on a site-specific basis. The accuracy of the risk assessment was controlled largely by the variation in the sensitive parameters and the uncertainty of the exposure model for the inhalation pathway. © 2013.

  4. WAFER TEST CAVITY -Linking Surface Microstructure to RF Performance: a ‘Short-­Sample Test Facility’ for characterizing superconducting materials for SRF cavities.

    Energy Technology Data Exchange (ETDEWEB)

    Pogue, Nathaniel; Comeaux, Justin; McIntyre, Peter

    2014-05-30

    The Wafer Test cavity was designed to create a short sample test system to determine the properties of the superconducting materials and S-I-S hetero-structures. The project, funded by ARRA, was successful in accomplishing several goals to achieving a high gradient test system for SRF research and development. The project led to the design and construction of the two unique cavities that each severed unique purposes: the Wafer test Cavity and the Sapphire Test cavity. The Sapphire Cavity was constructed first to determine the properties of large single crystal sapphires in an SRF environment. The data obtained from the cavity greatly altered the design of the Wafer Cavity and provided the necessary information to ascertain the Wafer Test cavity’s performance.

  5. Influence of diluent and sample processing methods on the recovery of the biocontrol agent Pantoea agglomerans CPA-2 from different fruit surfaces.

    Science.gov (United States)

    Torres, R; Viñas, I; Usall, J; Remón, D; Teixidó, N

    2012-08-01

    Determining the populations of biocontrol agents applied as a postharvest treatment on fruit surfaces is fundamental to the assessment of the microorganisms' ability to colonise and persist on fruit. To obtain maximum recovery, we must develop a methodology that involves both diluent and processing methods and that does not affect the viability of the microorganisms. The effect of diluent composition was evaluated using three diluents: phosphate buffer, peptone saline and buffered peptone saline. An additional study was performed to compare three processing methods (shaking plus sonication, stomaching and shaking plus centrifugation) on the recovery efficiency of Pantoea agglomerans strain CPA-2 from apples, oranges, nectarines and peaches treated with this biocontrol agent. Overall, slight differences occurred among diluents, although the phosphate buffer maintained the most ideal pH for CPA-2 growth (between 5.2 and 6.2). Stomaching, using the phosphate buffer as diluent, was the best procedure for recovering and enumerating the biocontrol agent; this fact suggested that no lethal effects from naturally occurring antimicrobial compounds present on the fruit skins and/or produced when the tissues were disrupted affected the recovery of the CPA-2 cells, regardless of fruit type. The growth pattern of CPA-2 on fruits maintained at 20°C and under cold conditions was similar to that obtained in previous studies, which confirms the excellent adaptation of this strain to conditions commonly used for fruit storage. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Applicability of the direct injection liquid chromatographic tandem mass spectrometric analytical approach to the sub-ngL-1 determination of perfluoro-alkyl acids in waste, surface, ground and drinking water samples.

    Science.gov (United States)

    Ciofi, Lorenzo; Renai, Lapo; Rossini, Daniele; Ancillotti, Claudia; Falai, Alida; Fibbi, Donatella; Bruzzoniti, Maria Concetta; Santana-Rodriguez, José Juan; Orlandini, Serena; Del Bubba, Massimo

    2018-01-01

    The applicability of a direct injection UHPLC-MS/MS method for the analysis of several perfluoroalkyl acids (PFAAs) in a wide range of water matrices was investigated. The method is based on the direct injection of 100µL of centrifuged water sample, without any other sample treatment. Very good method detection limits (0.014-0.44ngL-1) and excellent intra and inter-day precision (RSD% values in the range 1.8-4.4% and 2.7-5.7%, respectively) were achieved, with a total analysis time of 20min per sample. A high number of samples - i.e. 8 drinking waters (DW), 12 ground waters (GW), 13 surface waters (SW), 8 influents and 11 effluents of wastewater treatment plants (WWTPIN and WWTPOUT) were processed and the extent of matrix effect (ME) was calculated, highlighting the strong prevalence of |ME| 50% was occasionally observed only for perfluorooctanesulphonic and perfluorodecanoic acids. Linear discriminant analysis highlighted the great contribution of the sample origin (i.e. DW, GW, SW, WWTPIN and WWTPOUT) to the ME. Partial least square regression (PLS) and leave-one-out cross-validation were performed in order to interpret and predict the signal suppression or enhancement phenomena as a function of physicochemical parameters of water samples (i.e. conductivity, hardness and chemical oxygen demand) and background chromatographic area. The PLS approach resulted only in an approximate screening, due to the low prediction power of the PLS models. However, for most analytes in most samples, the fitted and cross-validated values were such as to correctly distinguish between | ME | higher than 20% or below this limit. PFAAs in the aforementioned water samples were quantified by means of the standard addition method, highlighting their occurrence mainly in WWTP influents and effluents, at concentrations as high as one hundred of µgL-1. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Determination of Glucocorticoids in UPLC-MS in Environmental Samples from an Occupational Setting

    Directory of Open Access Journals (Sweden)

    Enrico Oddone

    2015-01-01

    Full Text Available Occupational exposures to glucocorticoids are still a neglected issue in some work environments, including pharmaceutical plants. We developed an analytical method to quantify simultaneously 21 glucocorticoids using UPLC coupled with mass spectrometry to provide a basis to carry out environmental monitoring. Samples were taken from air, hand-washing tests, pad-tests and wipe-tests. This paper reports the contents of the analytical methodology, along with the results of this extensive environmental and personal monitoring of glucocorticoids. The method in UPLC-MS turned out to be suitable and effective for the aim of the study. Wipe-test and pad-test desorption was carried out using 50 mL syringes, a simple technique that saves time without adversely affecting analyte recovery. Results showed a widespread environmental pollution due to glucocorticoids. This is of particular concern. Evaluation of the dose absorbed by each worker and identification of a biomarker for occupational exposure will contribute to assessment and prevention of occupational exposure.

  8. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  9. Repellent materials. Robust self-cleaning surfaces that function when exposed to either air or oil.

    Science.gov (United States)

    Lu, Yao; Sathasivam, Sanjayan; Song, Jinlong; Crick, Colin R; Carmalt, Claire J; Parkin, Ivan P

    2015-03-06

    Superhydrophobic self-cleaning surfaces are based on the surface micro/nanomorphologies; however, such surfaces are mechanically weak and stop functioning when exposed to oil. We have created an ethanolic suspension of perfluorosilane-coated titanium dioxide nanoparticles that forms a paint that can be sprayed, dipped, or extruded onto both hard and soft materials to create a self-cleaning surface that functions even upon emersion in oil. Commercial adhesives were used to bond the paint to various substrates and promote robustness. These surfaces maintained their water repellency after finger-wipe, knife-scratch, and even 40 abrasion cycles with sandpaper. The formulations developed can be used on clothes, paper, glass, and steel for a myriad of self-cleaning applications. Copyright © 2015, American Association for the Advancement of Science.

  10. Robust self-cleaning surfaces that function when exposed to either air or oil

    Science.gov (United States)

    Lu, Yao; Sathasivam, Sanjayan; Song, Jinlong; Crick, Colin R.; Carmalt, Claire J.; Parkin, Ivan P.

    2015-03-01

    Superhydrophobic self-cleaning surfaces are based on the surface micro/nanomorphologies; however, such surfaces are mechanically weak and stop functioning when exposed to oil. We have created an ethanolic suspension of perfluorosilane-coated titanium dioxide nanoparticles that forms a paint that can be sprayed, dipped, or extruded onto both hard and soft materials to create a self-cleaning surface that functions even upon emersion in oil. Commercial adhesives were used to bond the paint to various substrates and promote robustness. These surfaces maintained their water repellency after finger-wipe, knife-scratch, and even 40 abrasion cycles with sandpaper. The formulations developed can be used on clothes, paper, glass, and steel for a myriad of self-cleaning applications.

  11. Synthesis of surface molecular imprinted polymers based on carboxyl-modified silica nanoparticles with the selective detection of dibutyl phthalate from tap water samples

    Science.gov (United States)

    Xu, Wanzhen; Zhang, Xiaoming; Huang, Weihong; Luan, Yu; Yang, Yanfei; Zhu, Maiyong; Yang, Wenming

    2017-12-01

    In this work, the molecular imprinted polymers were synthesized with the low monomer concentrations for dibutyl phthalate (DBP). The polymers were prepared over carboxyl-modified silica nanoparticle, which used methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker agent and azoisobutyronitrile as the initiator in the process of preparation. Various measures were used to characterize the structure and morphology in order to get the optimal polymer. The characterization results show that the optimal polymer has suitable features for further adsorption process. And adsorption capacity experiments were evaluated to analyze its adsorption performance, through adsorption isotherms/kinetics, selectivity adsorption and desorption and regeneration experiments. These results showed that the molecular imprinted polymers had a short equilibrium time about 60 min and high stability with 88% after six cycles. Furthermore, the molecular imprinted polymers were successfully applied to remove dibutyl phthalate. The concentration range was 5.0-30.0 μmol L-1, and the limit of detection was 0.06 μmol L-1 in tap water samples.

  12. A facile and selective approach for enrichment of l-cysteine in human plasma sample based on zinc organic polymer: Optimization by response surface methodology.

    Science.gov (United States)

    Bahrani, Sonia; Ghaedi, Mehrorang; Ostovan, Abbas; Javadian, Hamedreza; Mansoorkhani, Mohammad Javad Khoshnood; Taghipour, Tahere

    2018-02-05

    In this research, a facile and selective method was described to extract l-cysteine (l-Cys), an essential α-amino acid for anti-ageing playing an important role in human health, from human blood plasma sample. The importance of this research was the mild and time-consuming synthesis of zinc organic polymer (Zn-MOP) as an adsorbent and evaluation of its ability for efficient enrichment of l-Cys by ultrasound-assisted dispersive micro solid-phase extraction (UA-DMSPE) method. The structure of Zn-MOP was investigated by FT-IR, XRD and SEM. Analysis of variance (ANOVA) was applied for the experimental data to reach the best optimum conditions. The quantification of l-Cys was carried out by high performance liquid chromatography with UV detection set at λ=230nm. The calibration graph showed reasonable linear responses towards l-Cys concentrations in the range of 4.0-1000μg/L (r 2 =0.999) with low limit of detection (0.76μg/L, S/N=3) and RSD≤2.18 (n=3). The results revealed the applicability and high performance of this novel strategy in detecting trace l-Cys by Zn-MOP in complicated matrices. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Development of garlic bioactive compounds analytical methodology based on liquid phase microextraction using response surface design. Implications for dual analysis: Cooked and biological fluids samples.

    Science.gov (United States)

    Ramirez, Daniela Andrea; Locatelli, Daniela Ana; Torres-Palazzolo, Carolina Andrea; Altamirano, Jorgelina Cecilia; Camargo, Alejandra Beatriz

    2017-01-15

    Organosulphur compounds (OSCs) present in garlic (Allium sativum L.) are responsible of several biological properties. Functional foods researches indicate the importance of quantifying these compounds in food matrices and biological fluids. For this purpose, this paper introduces a novel methodology based on dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography with ultraviolet detector (HPLC-UV) for the extraction and determination of organosulphur compounds in different matrices. The target analytes were allicin, (E)- and (Z)-ajoene, 2-vinyl-4H-1,2-dithiin (2-VD), diallyl sulphide (DAS) and diallyl disulphide (DADS). The microextraction technique was optimized using an experimental design, and the analytical performance was evaluated under optimum conditions. The desirability function presented an optimal value for 600μL of chloroform as extraction solvent using acetonitrile as dispersant. The method proved to be reliable, precise and accurate. It was successfully applied to determine OSCs in cooked garlic samples as well as blood plasma and digestive fluids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Profiling of adrenocorticotropic hormone and arginine vasopressin in human pituitary gland and tumor thin tissue sections using droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS.

    Science.gov (United States)

    Kertesz, Vilmos; Calligaris, David; Feldman, Daniel R; Changelian, Armen; Laws, Edward R; Santagata, Sandro; Agar, Nathalie Y R; Van Berkel, Gary J

    2015-08-01

    Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections, using a fully automated droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS system for spatially resolved sampling, HPLC separation, and mass spectrometric detection. Excellent correlation was found between the protein distribution data obtained with this method and data obtained with matrix-assisted laser desorption/ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis), and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH-secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH-secreting adenomas and in normal anterior adenohypophysis compared with non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis, as expected. This work reveals that a fully automated droplet-based liquid-microjunction surface-sampling system coupled to HPLC-ESI-MS-MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, including AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity, and specificity of this method support the potential of this basic technology, with further advancement, for assisting surgical decision-making. Graphical Abstract Mass spectrometry based profiling of hormones in human pituitary gland and tumor thin tissue sections.

  15. Estimation of the proportion of some elements and their distribution on a surface of thallus of lichenized fungus Xanthoria parietina (L. Th. Fr. using sample-nondestructive μ-XRF spectrometer M4 Tornado

    Directory of Open Access Journals (Sweden)

    Biazrov Lev Georgievich

    2013-10-01

    Full Text Available The composition of 19 elements - Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Ba, Pb - were compared in the peripheral (younger and central (older parts of the upper surface of the epiphytic lichen Xanthoria parietina thallus from the bark of Sorbus aucuparia in Moscow city using sample-nondestructive μ-XRF spectrometer. This species is often used in biomonitoring of air quality. The results showed that the elements content was highly variable. Mean values of atomic percent of Fe, Co, Zn, and Pb were statistically higher in the central part of the upper surface, while P, S, Cl, K, Ca, and Mn were higher in the peripheral part. Differences between other elements were not statistically valid, but there is a trend to greater maintenance of the majority of the elements on the surface of the central part of the thallus. Mapping the distribution of some elements on the part of the thallus surface is presented.

  16. Sequential digestion for measuring leachable and total lead in the same sample of dust or paint chips by ICP-MS.

    Science.gov (United States)

    Le Bot, Barbara; Arcelin, Claire; Briand, Emmanuel; Glorennec, Philippe

    2011-01-01

    House lead exposure is generally assessed using total lead, except in France, where acid-leachable lead is used for routine regulatory purposes. In order to allow an international comparison of French lead dust contamination, a sequential digestion protocol is developed to determine both leachable and total lead on the same sample with a two-step digestion stage: firstly, hydrochloric acid is added to the sample at 37°C to solubilize leachable lead; then nitric acid is added to an aliquot at 95°C to solubilize residual (i.e., non-leachable) lead. Both sample fractions are analyzed with inductively coupled plasma mass spectrometry (ICP-MS). The sum of the two fractions allows to determine total lead. This new protocol has been tested with wiped dust (n = 111) and paint chip (n = 46) samples collected in houses (n = 16). The leachability of lead ranged from 63 to 100% in dust and from 4 to 100% in paint. These findings confirm the strong variability of lead leachability in houses samples and thus the importance of considering it for lead poisoning prevention. This double determination of leachable and total lead for each wiped dust or paint sample appears to be a reproducible, simple, low-cost protocol and thus a useful tool for international comparison of house dust lead contamination.

  17. Sample Acquisition for Materials in Planetary Exploration (SAMPLE) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to analyze, design, and develop a device for autonomous lunar surface/subsurface sampling and processing applications. The Sample Acquisition for...

  18. Analysis of Tank 38H (HTF-38-15-119, 127) Surface, Subsurface and Tank 43H (HTF-43-15-116, 117 and 118) Surface, Feed Pump Suction and Jet Suction Subsurface Supernatant Samples in Support of Enrichment, Corrosion Control and Salt Batch Planning Programs

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-17

    Compositional feed limits have been established to ensure that a nuclear criticality event for the 2H and 3H Evaporators is not possible. The Enrichment Control Program (ECP) requires feed sampling to determine the equivalent enriched uranium content prior to transfer of waste other than recycle transfers (requires sampling to determine the equivalent enriched uranium at two locations in Tanks 38H and 43H every 26 weeks) The Corrosion Control Program (CCP) establishes concentration and temperature limits for key constituents and periodic sampling and analysis to confirm that waste supernate is within these limits. This report provides the results of analyses on Tanks 38H and 43H surface and subsurface supernatant liquid samples in support of the ECP, the CCP, and the Salt Batch 10 Planning Program.

  19. Diel Sampling of Groundwater and Surface Water for Trace Elements and Select Water-Quality Constituents at a Former Zinc Smelter Site near Hegeler, Illinois, August 1-3, 2007

    Science.gov (United States)

    Kay, Robert T.; Groschen, George E.; Dupre, David H.; Drexler, Timothy D.; Thingvold, Karen L.; Rosenfeld, Heather J.

    2009-01-01

    Surface water can exhibit substantial diel variations in the concentration of a number of constituents. Sampling regimens that do not characterize diel variations in water quality can result in an inaccurate understanding of site conditions and of the threat posed by the site to human health and the environment. Surface- and groundwater affected by acid drainage were sampled every 60 to 90 minutes over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, in Hegeler, Ill. Groundwater-quality data from a well at the site indicate stable, low pH, weakly oxidizing geochemical conditions in the aquifer. With the exceptions of temperature and pH, no constituents exhibited diel variations in groundwater. Variations in temperature and pH likely were not representative of conditions in the aquifer. Surface water was sampled at a site on Grape Creek. Diel variations were observed in temperature, dissolved oxygen, pH, and specific conductance, and in the concentrations of nitrite, barium, iron, lead, vanadium, and possibly uranium. Concentrations during the diel cycles varied by about an order of magnitude for nitrite and varied by about a factor of two for barium, iron, lead, vanadium, and uranium. Temperature, dissolved oxygen, specific conductance, nitrite, barium, lead, and uranium generally reached maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally reached minimum values during the afternoon and maximum values during the night. These variations would need to be accounted for during sampling of surface-water quality in similar hydrologic settings. The temperature variations in surface water were affected by variations in air temperature. Concentrations of dissolved oxygen were affected by variations in the intensity of photosynthetic activity and respiration. Nitrite likely was formed by the oxidation of ammonium by dissolved oxygen and degraded by its anaerobic oxidation by ammonium or

  20. Dummy-surface molecularly imprinted polymers as a sorbent of micro-solid-phase extraction combined with dispersive liquid-liquid microextraction for determination of five 2-phenylpropionic acid NSAIDs in aquatic environmental samples.

    Science.gov (United States)

    Guo, Ping; Yuan, Xucan; Zhang, Jingjing; Wang, Binjie; Sun, Xiaoyang; Chen, Xiaohui; Zhao, Longshan

    2018-01-01

    A highly binding dummy template surface of molecularly imprinted polymers (MWNTs-MIPs) was synthesized on multi-walled carbon nanotubes surface using 2-phenylpropionic acid as dummy template, 4-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and DMF as porogen by precipitation polymerization method. MIPs were characterized by FT-IR spectroscopy, scanning electron microscope, thermo-gravimetric analysis, and nitrogen adsorption-desorption experiment. Adsorption and selectivity experiments of MIPs and non-imprinted polymers (NIPs) verified that the MIPs had a good selectivity and adsorption properties for five 2-phenylpropionic acid nonsteroidal anti-inflammatory drugs (NSAIDs). Imprinted polymer was used as a sorbent material for μSPE in current work and μSPE-DLLME method was selected for pretreatment of water samples. The μSPE-DLLME method was successfully used for the pre-concentration of five non-steroidal anti-inflammatory drugs in different environmental water samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry. Efficiencies of μSPE and DLLME were thoroughly investigated and optimized in this study. The optimal results were obtained by using 3 mL of 1% formic acid-acetonitrile as elution solvent and dichloroethane and acetonitrile as extractant and disperser solvent, respectively. Limits of detection and quantification of five NSAIDs for different water matrices varied from 0.50 to 1.10 ng L-1 and 0.93 to 2.20 ng L-1, respectively. Each target analyte had a good linearity in its corresponding concentration range. Enrichment factors of target analytes ranged from 91 to 215. Recoveries of the target analytes were between 72.43 and 113.99% at the concentration levels of 0.02, 0.1, and 0.5 μg L-1. The developed method was successfully applied to extraction and analysis of NSAIDs in different water samples with satisfactory results which could help us better understand their

  1. The uncertain universality of the Macbeth effect with a Spanish sample.

    Science.gov (United States)

    Gámez, Elena; Díaz, José M; Marrero, Hipólito

    2011-05-01

    Recently a psychological mechanism has been proposed between bodily purity and moral purity: the "Macbeth effect". The act of washing their hands seems to free individuals of their guilt. However, the universality of this psychological mechanism is an empirical question that should be studied. In four studies we replicated the original Zhong & Liljenquist's experiments with Spanish samples. We were unsuccessful in replicating the Zhong & Liljenquist's results that supported cleansing as a psychological mechanism for compensating guilty: results couldn't confirm an increased mental accessibility of cleansing-related concepts or even a greater desire for cleansing products, neither a greater likelihood of taking antiseptic wipes. In addition we didn't find that physical cleansing alleviates the upsetting consequences of unethical behaviour. Spanish samples showed sensibility to morality and helping behaviour but not with cleansing as a way to reduce their threatened morality.

  2. A Mars Sample Return Sample Handling System

    Science.gov (United States)

    Wilson, David; Stroker, Carol

    2013-01-01

    alloy caps [5] if the heating does not affect the sample, or by crimping caps similar to bottle capping. We prefer cap sealing surfaces be external to the cup rim to prevent sample dust inside the cups interfering with sealing, or, contamination of the sample by Teflon seal elements (if adopted). Finally the sample collection rover, or a Fetch rover, selects cups with best choice samples and loads them into a sample tray, before delivering it to the Earth Return Vehicle (ERV) in the MSR Dragon capsule as described in [1] (Fig 1). This ensures best use of the MSR payload mass allowance. A 3 meter long jointed robot arm is extended from the Dragon capsule's crew hatch, retrieves the sample tray and inserts it into the sample canister payload located on the ERV stage. The robot arm has capacity to obtain grab samples in the event of a rover failure. The sample canister has a robot arm capture casting to enable capture by crewed or robot spacecraft when it returns to Earth orbit

  3. Language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik

    1998-01-01

    This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...... sampling method is used with different genetic classifications (Voegelin & Voegelin 1977, Ruhlen 1987, Grimes ed. 1997) and argue that —on the whole— our sampling technique compares favourably with other methods, especially in the case of exploratory research....

  4. The role of surface disinfection in infection prevention.

    Science.gov (United States)

    Gebel, Jürgen; Exner, Martin; French, Gary; Chartier, Yves; Christiansen, Bärbel; Gemein, Stefanie; Goroncy-Bermes, Peter; Hartemann, Philippe; Heudorf, Ursel; Kramer, Axel; Maillard, Jean-Yves; Oltmanns, Peter; Rotter, Manfred; Sonntag, Hans-Günther

    2013-01-01

    The Rudolf Schuelke Foundation addresses topics related to hygiene, infection prevention and public health. In this context a panel of scientists from various European countries discussed "The Role of Surface Disinfection in Infection Prevention". The most important findings and conclusions of this meeting are summarised in the present consensus paper. Although the relevance of surface disinfection is increasingly being accepted, there are still a number of issues which remain controversial. In particular, the following topics were addressed: Transferral of microbes from surface to patients as a cause of infection, requirements for surface disinfectants, biocidal resistance and toxicity, future challenges. After discussion and review of current scientific literature the authors agreed that contaminated surfaces contribute to the transmission of pathogens and may thus pose an infection hazard. Targeted surface disinfection based on a risk profile is seen as an indispensable constituent in a multibarrier approach of universal infection control precautions. Resistance and cross-resistance depend on the disinfectant agent as well as on the microbial species. Prudent implementation of surface disinfection regimens tested to be effective can prevent or minimize adverse effects. Disinfection must be viewed as a holistic process. There is a need for defining standard principles for cleaning and disinfection, for ensuring compliance with these principles by measures such as written standard operating procedures, adequate training and suitable audit systems. Also, test procedures must be set up in order to demonstrate the efficacy of disinfectants including new application methods such as pre-soaked wipes for surface disinfection.

  5. Venous Sampling

    Science.gov (United States)

    ... neck to help locate abnormally functioning glands or pituitary adenoma . This test is most often used after an unsuccessful neck exploration. Inferior petrosal sinus sampling , in which blood samples are taken from veins that drain the pituitary gland to study disorders related to pituitary hormone ...

  6. Sampling Development

    Science.gov (United States)

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  7. Language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik

    1998-01-01

    This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...

  8. Ice Surfaces

    Science.gov (United States)

    Shultz, Mary Jane

    2017-05-01

    Ice is a fundamental solid with important environmental, biological, geological, and extraterrestrial impact. The stable form of ice at atmospheric pressure is hexagonal ice, Ih. Despite its prevalence, Ih remains an enigmatic solid, in part due to challenges in preparing samples for fundamental studies. Surfaces of ice present even greater challenges. Recently developed methods for preparation of large single-crystal samples make it possible to reproducibly prepare any chosen face to address numerous fundamental questions. This review describes preparation methods along with results that firmly establish the connection between the macroscopic structure (observed in snowflakes, microcrystallites, or etch pits) and the molecular-level configuration (detected with X-ray or electron scattering techniques). Selected results of probing interactions at the ice surface, including growth from the melt, surface vibrations, and characterization of the quasi-liquid layer, are discussed.

  9. Elevating sampling

    Science.gov (United States)

    Labuz, Joseph M.; Takayama, Shuichi

    2014-01-01

    Sampling – the process of collecting, preparing, and introducing an appropriate volume element (voxel) into a system – is often under appreciated and pushed behind the scenes in lab-on-a-chip research. What often stands in the way between proof-of-principle demonstrations of potentially exciting technology and its broader dissemination and actual use, however, is the effectiveness of sample collection and preparation. The power of micro- and nanofluidics to improve reactions, sensing, separation, and cell culture cannot be accessed if sampling is not equally efficient and reliable. This perspective will highlight recent successes as well as assess current challenges and opportunities in this area. PMID:24781100

  10. Biotic, temporal and spatial variability of tritium concentrations in transpirate samples collected in the vicinity of a near-surface low-level nuclear waste disposal site and nearby research reactor.

    Science.gov (United States)

    Twining, J R; Hughes, C E; Harrison, J J; Hankin, S; Crawford, J; Johansen, M; Dyer, L

    2011-06-01

    The results of a 21 month sampling program measuring tritium in tree transpirate with respect to local sources are reported. The aim was to assess the potential of tree transpirate to indicate the presence of sub-surface seepage plumes. Transpirate gathered from trees near low-level nuclear waste disposal trenches contained activity concentrations of (3)H that were significantly higher (up to ∼700 Bq L(-1)) than local background levels (0-10 Bq L(-1)). The effects of the waste source declined rapidly with distance to be at background levels within 10s of metres. A research reactor 1.6 km south of the site contributed significant (p nuclear waste site. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  11. Molecularly imprinted polymer coated solid-phase microextraction fiber prepared by surface reversible addition-fragmentation chain transfer polymerization for monitoring of Sudan dyes in chilli tomato sauce and chilli pepper samples.

    Science.gov (United States)

    Hu, Xiaogang; Fan, Yanan; Zhang, Yi; Dai, Guimei; Cai, Quanling; Cao, Yujuan; Guo, Changjuan

    2012-06-20

    Surface reversible addition-fragmentation chain transfer (RAFT) polymerization method was firstly applied to the preparation of molecularly imprinted polymer (MIP) coated silicon solid-phase microextraction (SPME) fibers. With Sudan I as template, an ultra-thin MIP coating with about 0.55-μm thickness was obtained with homogeneous structure and controlled composition, due to the controllable radical growing and chain propagation in surface RAFT polymerization. The MIP-coated fibers were found with enhanced selectivity coefficients (3.0-6.5) to Sudan I-IV dyes in contrast with those reported in our previous work. Furthermore, the ultra-thin thickness of MIP coating was helpful to the effective elution of template and fast adsorption/desorption kinetics, so only about 18 min was needed for MIP-coated SPME operation. The detection limits of 21-55 ng L(-1) were achieved for four Sudan dyes, when MIP-coated SPME was coupled with liquid chromatography (LC) and mass spectrometry (MS) detection. The MIP-coated SPME-LC-MS/MS method was tested for the monitoring of ultra trace Sudan dyes in spiked chilli tomato sauce and chilli pepper samples, and high enrichment effect, remarkable matrix peaks-removing capability, and consequent high sensitivities were achieved to four Sudan dyes. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Sampling and chemical analysis in environmental samples around Nuclear Power Plants and some environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2002-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, a grain of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that sere sampled at 60 point of district in Korea were analyzed. Tritium were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied from KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin Npps and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  13. Response surface methodology based on central composite design as a chemometric tool for optimization of dispersive-solidification liquid-liquid microextraction for speciation of inorganic arsenic in environmental water samples.

    Science.gov (United States)

    Asadollahzadeh, Mehdi; Tavakoli, Hamed; Torab-Mostaedi, Meisam; Hosseini, Ghaffar; Hemmati, Alireza

    2014-06-01

    Dispersive-solidification liquid-liquid microextraction (DSLLME) coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of inorganic arsenic (III, V) in water samples. At pH=1, As(III) formed complex with ammonium pyrrolidine dithiocarbamate (APDC) and extracted into the fine droplets of 1-dodecanol (extraction solvent) which were dispersed with ethanol (disperser solvent) into the water sample solution. After extraction, the organic phase was separated by centrifugation, and was solidified by transferring into an ice bath. The solidified solvent was transferred to a conical vial and melted quickly at room temperature. As(III) was determined in the melted organic phase while As(V) remained in the aqueous layer. Total inorganic As was determined after the reduction of the pentavalent forms of arsenic with sodium thiosulphate and potassium iodide. As(V) was calculated by difference between the concentration of total inorganic As and As(III). The variable of interest in the DSLLME method, such as the volume of extraction solvent and disperser solvent, pH, concentration of APDC (chelating agent), extraction time and salt effect, was optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). In the optimum conditions, the proposed method has been successfully applied to the determination of inorganic arsenic in different environmental water samples and certified reference material (NIST RSM 1643e). Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Preparation, characterization, and applications of a novel solid-phase microextraction fiber by sol-gel technology on the surface of stainless steel wire for determination of poly cyclic aromatic hydrocarbons in aquatic environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Es-haghi, Ali, E-mail: a.eshaghi@rvsri.ac.ir [Department of Physico Chemistry, Razi Vaccine and Serum Research Institute, PO Box 31975/148, Karaj (Iran, Islamic Republic of); Hosseininasab, Valiallah; Bagheri, Habib [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, PO Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2014-02-01

    Highlights: • A novel solid-phase microextraction (SPME) fiber was prepared using sol–gel technology. • Sol–gel coating was performed on stainless steel substrate. • The new fibers are robust and unbreakable with temperature stability. • The fibers were used for extraction of PAHs from aqueous samples. Abstract: A novel solid-phase microextraction(SPME) fiber was prepared using sol–gel technology with ethoxylated nonylphenol as a fiber coating material. The fiber was employed to develop a headspace SPME–GC–MS method suitable for quantification of 13 polycyclic aromatic hydrocarbons (PAHs) in water samples. Surface characteristics of the fibers were inspected by energy dispersive X-ray (EDX) spectroscopy as well as by scanning electron microscopy (SEM). The SEM measurements showed the presence of highly porous nano-sized particles in the coating. Important parameters affecting the extraction efficiency such as extraction temperature and time, desorption conditions as well as ionic strength have been evaluated and optimized. In the next step, the validation of the new method have been performed, finding it to be specific in the trace analysis of PAHs, with the limit of detection (LOD) ranging from 0.01 to 0.5 μg L⁻¹ and the linear range from the respective LOD to 200 μg L⁻¹with RSD amounting to less than 8%. The thermal stability of the fibers was investigated as well and they were found to be durable at 280 °C for 345 min. Furthermore, the proposed method was successfully applied for quantification of PAHs in real water samples.

  15. Age and isotopic systematics of Cretaceous borehole and surface samples from the greater Los Angeles Basin region: Implications for the types of crust that might underlie Los Angeles and their distribution along late Cenozoic fault systems

    Science.gov (United States)

    Premo, Wayne R.; Morton, Douglas M.; Kistler, Ronald W.

    2014-01-01

    Nine U-Pb zircon ages were determined on plutonic rocks sampled from surface outcrops and rock chips of drill core from boreholes within the greater Los Angeles Basin region. In addition, lead-strontium-neodymium (Pb-Sr-Nd) whole-rock isotopic data were obtained for eight of these samples. These results help to characterize the crystalline basement rocks hidden in the subsurface and provide information that bears on the tectonic history of the myriad of fault systems that have dissected the Los Angeles region over the past 15 m.y. Seven of the nine samples have U-Pb ages ranging from 115 to 103 Ma and whole-rock Pb-Sr-Nd isotopic characteristics that indicate the crystalline basement underneath the greater Los Angeles Basin region is mostly part of the Peninsular Ranges batholith. Furthermore, these data are interpreted as evidence for (1) the juxtaposition of mid-Cretaceous, northern Peninsular Ranges batholith plutonic rocks against Late Cretaceous plutonic rocks of the Transverse Ranges in the San Fernando Valley, probably along the Verdugo fault; (2) the juxtaposition of older northwestern Peninsular Ranges batholith rocks against younger northeastern Peninsular Ranges batholith rocks in the northern Puente Hills, implying transposition of northeastern Peninsular Ranges batholith rocks to the west along unrecognized faults beneath the Chino Basin; and (3) juxtaposition of northern Peninsular Ranges batholith plutonic rocks against Late Cretaceous plutonic rocks of the Transverse Ranges along the San Jose fault in the northern San Jose Hills at Ganesha Park. These mainly left-lateral strike-slip faults of the eastern part of the greater Los Angeles Basin region could be the result of block rotation within the adjacent orthogonal, right-lateral, Elsinore-Whittier fault zone to the west and the subparallel San Jacinto fault zone to the east. The San Andreas fault system is the larger, subparallel, driving force further to the east.

  16. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample, profile and underway - surface observations using CTD, Carbon dioxide (CO2) gas analyzer and other instruments from the METEOR in the South Atlantic Ocean from 1992-12-27 to 1993-01-31 (NODC Accession 0115173)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115173 includes chemical, discrete sample, meteorological, physical, profile and underway - surface data collected from METEOR in the South Atlantic...

  17. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from Surface underway, discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from PELICAN in the Coastal Waters of Louisiana, Coastal Waters of Texas and Gulf of Mexico from 2013-09-09 to 2013-09-22 (NCEI Accession 0157461)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157461 includes Surface underway, chemical, discrete sample, meteorological, physical and profile data collected from PELICAN in the Coastal Waters...

  18. Dissolved inorganic carbon, total alkalinity, pH, nutrients and other variables collected from surface discrete sampling using flow through pump and other instruments from NOAA Ship Gordon Gunter in the U.S. East Coast during the East Coast Ocean Acidification (GU-15-04 ECOA1) from 2015-06-20 to 2015-07-23 (NCEI Accession 0157389)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains dissolved inorganic carbon, total alkalinity, pH, nutrients and other variables collected from surface discrete sampling using flow...

  19. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from Surface underway, discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from MIRAI in the Bering Sea, North Pacific Ocean and South Pacific Ocean from 2007-10-08 to 2007-12-26 (NODC Accession 0108123)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108123 includes Surface underway, discrete sample and profile data collected from MIRAI in the Bering Sea, North Pacific Ocean and South Pacific...

  20. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete