Soil air sample storage and handling using polypropylene syringes and glass vials

2003 ◽  
Vol 83 (5) ◽  
pp. 631-637 ◽  
Author(s):  
Philippe Rochette ◽  
Normand Bertrand
Keyword(s):  
Gas Adsorption ◽  
Accurate Determination ◽  
Contamination Rate ◽  
Soil Air ◽  
Air Samples ◽  
Adequate Sampling ◽  
Air Sample ◽  
Key Words Nitrous Oxide ◽  
High Level ◽  
And Storage

Accurate determination of gas concentration in soil air samples implies adequate sampling and storage procedures to preserve sample integrity. In this study, we tested polypropylene syringes and glass vials for handling and storage of N2O air samples. Losses of N2O were large and rapid when a gas standard was stored in polypropylene syringes (16% after 24 h). Moreover, gas adsorption on the inner walls (and rubber gasket) of the syringes reached a maximum of 5.8% of the initial N2O after 7 h of storage. These results indicated that polypropylene syringes are not reliable for storing air samples. Commercially available glass vials maintained a moderately high level of vacuum over time (89% after 136 d). However, their overall performance was decreased by contamination (approx. 3%) occurring at the end of the evacuation procedure when the hole left by the needle of the evacuation line took a few seconds to close up. The addition of a silicone septum was proposed to reduce this contamination. The modified vials maintained an average vacuum level of 98% after 136 d. The average contamination rate of N2O samples during the first 129 d of storage was 0.20 and 0.13% d-1 with one and two septa, respectively. Key words: Nitrous oxide, air sample

scholarly journals Monthly endoscopy surveillance culture facilitates detection of breaches in the scope reprocessing procedure: 5 year-experience in an endoscopy center

2019 ◽  
Author(s):  
Hsu-Heng Yen ◽  
Shu-Hui Chen ◽  
Huei-Wen Lai ◽  
Hui-Lan Chang ◽  
Yu-Chun Hsu ◽  
...  
Keyword(s):  
Odds Ratio ◽  
Human Factor ◽  
Positive Culture ◽  
Clinical Impact ◽  
Contamination Rate ◽  
Surveillance Culture ◽  
Common Cause ◽  
High Level ◽  
And Storage ◽  
Aerobic And Anaerobic

Abstract AIM To review the clinical impact of monthly microbiology surveillance culture for monitoring endoscope contamination after high-level disinfection.METHODS Monthly surveillance culture of the endoscopes was conducted from January 2014 to December 2018 at our endoscopy center. A total of 1931 cultures were collected, including 765 cultures from 16 gastroscopes, 730 cultures from 18 colonoscopes, 379 cultures from 8 duodenalscopes, 46 cultures from 1 echoscopes, and 11 cultures from 1 enterscope. Cultures were obtained from ready-to-use endoscopes after a full reprocessing cycle and storage. Samples were cultured to test for aerobic and anaerobic bacteria.RESULTS The positive culture rates for the endoscope were 2% (15/765) for gastroscopes, 1.9% (14/730) for colonoscopes, 0.8% (3/379) for duodenscopes, 4.3% (2/46) for echoscopes, and 9.1% (1/11) for enterscopes. These findings were predominantly attributed to human factors (71.4%, 25/35) followed by storage cabinet failure (14.3%, 5/35), automatic endoscope reprocessing failure (11.4%, 4/35), and endoscope channel damage (2.8%, 1/35). Multivariate analysis showed that the years 2015 [odds ratio (OR) 0.19, 0.04 to 0.91], 2016 (OR 0.21, 0.05 to 0.80), and 2017 (OR 0.22, 0.06 to 0.83) were associated with decreased risk of endoscope contamination. The age, type, and number of times the scope was used were not related to contamination.CONCLUSIONS A low risk of endoscope contamination was found over a 5-year period in our endoscopy center. The most common cause of contamination was human factor. Duodenalscopes showed the lowest scope contamination rate. We suggested the implantation of a systematic endoscope culture regardless of the type of scope to facilitate early detection of breaches in the scope reprocessing procedure in clinical practice.

scholarly journals The Influence Mechanism of Temperature and Storage Period on Polarization Properties of Poly (Vinylidene Fluoride–Trifluoroethylene) Ultrathin Films

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 301
Author(s):  
Xingjia Li ◽  
Zhi Shi ◽  
Xiuli Zhang ◽  
Xiangjian Meng ◽  
Zhiqiang Huang ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Remanent Polarization ◽  
Vinylidene Fluoride ◽  
Storage Period ◽  
Testing Temperature ◽  
Fatigue Properties ◽  
Inhibition Mechanism ◽  
Poly Vinylidene Fluoride ◽  
High Level ◽  
And Storage

The effect of testing temperature and storage period on the polarization fatigue properties of poly (vinylidene fluoride-trifluoroethylene) (P(VDF–TrFE)) ultrathin film devices were investigated. The experimental results show that, even after stored in air for 150 days, the relative remanent polarization (Pr/Pr(0)) of P(VDF–TrFE) of ultrathin films can keep at a relatively high level of 0.80 at 25 °C and 0.70 at 60 °C. To account for this result, a hydrogen fluoride (HF) formation inhibition mechanism was proposed, which correlated the testing temperature and the storage period with the microstructure of P(VDF–TrFE) molecular chain. Moreover, a theoretical model was constructed to describe the polarization fatigue evolution of P(VDF–TrFE) samples.

scholarly journals Barriometry – an enhanced database of accurate barrier heights for gas-phase reactions

2018 ◽  
Vol 20 (16) ◽  
pp. 10732-10740 ◽  
Author(s):  
Bun Chan ◽  
John M. Simmie
Keyword(s):  
Gas Phase ◽  
Accurate Determination ◽  
Gas Phase Reactions ◽  
Barrier Heights ◽  
High Level ◽  
Kinetics Of

The kinetics of many reactions are critically dependent upon the barrier heights for which accurate determination can be difficult. More than 100 accurate barriers are obtained with the high-level W3X-L composite procedure.

Canister Sealing for High Level Waste Encapsulation

2001 ◽  
Author(s):  
Richard E. Andrews
Keyword(s):  
Electron Beam Welding ◽  
Deep Level ◽  
High Level Waste ◽  
Spent Fuel ◽  
Reduced Pressure ◽  
Friction Stir ◽  
The Uk ◽  
High Level ◽  
Welding Processes ◽  
And Storage

Abstract Sweden has chosen to manage spent fuel rods by direct encapsulation and storage in a deep level repository. Two welding processes are being investigated for the sealing of copper vessels that form the outer barrier of the disposal canisters. TWI Ltd in the UK has developed Reduced Pressure Electron Beam Welding and Friction Stir Welding for 50mm thick copper. This paper describes some of the investigations and compares the techniques. Over the past 3 years a full-size canister welding machine has been designed and built. Specialised tools have been developed for the welding of thick sections in copper with very encouraging results.

Application of Leakage Rates Measured on Scaled Cask or Component Models to the Package Containment Safety Assessment

2018 ◽  
Author(s):  
Annette Rolle ◽  
Viktor Ballheimer ◽  
Tino Neumeyer ◽  
Frank Wille
Keyword(s):  
Test Results ◽  
Spent Fuel ◽  
Thermal Tests ◽  
Containment System ◽  
Leak Tightness ◽  
Accident Conditions ◽  
High Level ◽  
Elastomeric Seals ◽  
Component Models ◽  
And Storage

The containment systems of transport and storage casks for spent fuel and high level radioactive waste usually include bolted lids with metallic or elastomeric seals. The mechanical and thermal loadings associated with the routine, normal and accident conditions of transport can have a significant effect on the leak tightness of such containment system. Scaled cask models are often used for providing the required mechanical and thermal tests series. Leak tests have been conducted on those models. It is also common practice to use scaled component tests to investigate the influence of deformations or displacements of the lids and the seals on the standard leakage rate as well as to study the temperature and time depending alteration of the seals. In this paper questions of the transferability of scaled test results to the full size design of the containment system will be discussed.

scholarly journals Tailored Gas Adsorption Properties of Electrospun Carbon Nanofibers for Gas Separation and Storage

ChemSusChem ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3180-3191 ◽  
Author(s):  
Ansgar Kretzschmar ◽  
Victor Selmert ◽  
Henning Weinrich ◽  
Hans Kungl ◽  
Hermann Tempel ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Gas Separation ◽  
Gas Adsorption ◽  
Adsorption Properties ◽  
And Storage

scholarly journals RNA Identification and Detection of Nucleic Acids as Aerosols in Air Samples by Means of Photon and Electron Interactions

Instruments ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 23
Author(s):  
John I. Adlish ◽  
Piero Neuhold ◽  
Riccardo Surrente ◽  
Luca J. Tagliapietra
Keyword(s):  
Molecular Structure ◽  
Monte Carlo ◽  
Atomic Hydrogen ◽  
Air Samples ◽  
Viral Particles ◽  
Dna Strands ◽  
Cluster Configuration ◽  
Air Sample ◽  
Energy Channels ◽  
Electron Interactions

This study presents a methodology to reveal traces of viral particles, as aerosol with known chemical and molecular structure, in a sample by means of photon and electron interactions. The method is based on Monte Carlo simulations and on the analysis of photon-electron fluxes-spectra through energy channels counts as a function of different aerosol viral concentrations in the air sample and looking at the peculiar photon/electron interactions with the potential abnormal atomic hydrogen (H), oxygen (O), carbon (C), and phosphorus (P) compositions present in the air sample as a function of living and nonliving matter with PO4 group RNA/DNA strands in a cluster configuration.

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