scholarly journals Investigation on stability of acetaldehyde standard gas generated with the permeation tube method

2017 ◽  
Vol 20 (1) ◽  
pp. 3-10
Author(s):  
Reiji AOYAGI ◽  
Shiro IKEDA ◽  
Yuichiro KAIFUKU ◽  
Kunitoshi MATSUNOBU ◽  
Yoshika SEKINE
Keyword(s):  
Permeation Tube ◽  
Standard Gas

The controlling effect of temperature in the application of permeation tube devices in standard gas generation

2012 ◽  
Vol 1225 ◽  
pp. 8-16 ◽  
Author(s):  
Janice Susaya ◽  
Ki-Hyun Kim ◽  
Jinwoo Cho ◽  
David Parker
Keyword(s):  
Effect Of Temperature ◽  
Gas Generation ◽  
Permeation Tube ◽  
Controlling Effect ◽  
Standard Gas

Development of 100 μmol mol−1 HCl primary standard gas mixtures in high-pressure cylinders

Metrologia ◽  
2018 ◽  
Vol 56 (1) ◽  
pp. 015007 ◽  
Author(s):  
Jinsang Jung ◽  
ByungMoon Kim ◽  
Sanghyub Oh
Keyword(s):  
High Pressure ◽  
Primary Standard ◽  
Gas Mixtures ◽  
Primary Standard Gas Mixtures ◽  
Standard Gas Mixtures ◽  
Standard Gas

Evaluation of two alternative ablation treatments for cervical pre-cancer against standard gas-based cryotherapy: a randomized non-inferiority study

2019 ◽  
Vol 29 (5) ◽  
pp. 851-856 ◽  
Author(s):  
Miriam Cremer ◽  
Karla Alfaro ◽  
Jillian Garai ◽  
Manuel Salinas ◽  
Mauricio Maza ◽  
...  
Keyword(s):  
Low Income ◽  
Histological Evaluation ◽  
Cervical Tissue ◽  
Post Surgery ◽  
Pain Scores ◽  
Patient Pain ◽  
The Difference ◽  
Cure Rates ◽  
Treatment Application ◽  
Standard Gas

IntroductionGas-based cryotherapy is the conventional ablative treatment for cervical pre-cancer in low-income settings, but the use of gas poses significant challenges. We compared the depth of necrosis induced by gas-based cryotherapy with two gas-free alternatives: cryotherapy using CryoPen,and thermoablation.MethodsWe conducted a five-arm randomized non-inferiority trial: double-freeze carbon dioxide (CO2) cryotherapy (referent), single-freeze CO2 cryotherapy, double-freeze CryoPen, single-freeze CryoPen, and thermoablation. Subjects were 130 women scheduled for hysterectomy for indications other than cervical pathology, and thus with healthy cervical tissue available for histological evaluation of depth of necrosis post-surgery. The null hypothesis was rejected (ie, conclude non-inferiority) if the upper bound of the 90% confidence interval (90% CI) for the difference in mean depth of necrosis (referent minus each experimental method) was <1.14 mm. Patient pain during treatment was reported on a scale of 0 (no pain) to 10 (worst pain).ResultsA total of 133 patients were enrolled in the study. The slides from three women were deemed unreadable. One patient was excluded because her hysterectomy was postponed for reasons unrelated to the study, and two patients were excluded because treatment application did not follow the established protocol. For the remaining 127 women, mean depth of necrosis for double-freeze CO2 (referent) was 6.0±1.6 mm. Differences between this and other methods were: single-freeze CO2 = 0.4 mm (90% CI −0.4 to 1.2 mm), double-freeze CryoPen= 0.7 mm (90% CI 0.04 to 1.4 mm), single-freeze CryoPen= 0.5 mm (90% CI −0.2 to 1.2 mm), and thermoablation = 2.6 mm (90% CI 2.0 to 3.1 mm). Mean pain levels were 2.2±1.0 (double-freeze CO2 cryotherapy), 1.8±0.8 (single-freeze CO2 cryotherapy), 2.5±1.4 (double-freeze CryoPen), 2.6±1.4 (single-freeze CryoPen), and 4.1±2.3 (thermoablation).DiscussionCompared with the referent, non-inferiority could not be concluded for other methods. Mean pain scores were low for all treatments. Depth of necrosis is a surrogate for treatment efficacy, but a randomized clinical trial is necessary to establish true cure rates.

The preparation of standard gas mixtures. A review

The Analyst ◽  
1981 ◽  
Vol 106 (1265) ◽  
pp. 817 ◽  
Author(s):  
R. S. Barratt
Keyword(s):  
Gas Mixtures ◽  
Standard Gas Mixtures ◽  
Standard Gas

scholarly journals The Determination of Nitric Oxide in Gas Phase Cigarette Smoke by Non-dispersive Infrared Analysis

1980 ◽  
Vol 10 (2) ◽  
Author(s):  
T. B. Williams
Keyword(s):  
Nitric Oxide ◽  
Gas Phase ◽  
Cigarette Smoke ◽  
Relative Error ◽  
Dead Volume ◽  
High Yield ◽  
Infrared Analysis ◽  
Colorimetric Analysis ◽  
Standard Gas

AbstractNitric oxide in cigarette smoke was conveniently determined by non-dispersive infrared analysis (NDIR). Recoveries of 95 % were obtained with standard gas-air mixtures but recoveries from smoke increased from 87% for high-yield to 91 % for low-yield cigarettes. Relative error was about 4 %. A reduction in the dead volume of Cambridge filter cassettes, to reduce the amount of NO reacted between puffs, increased NO deliveries of cigarettes by 4%. Deliveries of NO were estimated to average 4 % lower due to oxidation, but reaction with other smoke components reduced them further depending upon concentrations. The NO deliveries of cigarettes increased as blend nitrate increased and as the flow of air around cigarettes decreased. Nitric oxide in smoke and in standard gas-air mixtures, determined by non-dispersive infrared (NDIR) spectroscopy, was substantiated by an automated colorimetric analysis. Interfering smoke species were determined and circumvented in both methods.

Permeation Tube Equilibration Times and Long-Term Stability

2009 ◽  
pp. 183-183-15 ◽  
Author(s):  
DL Williams
Keyword(s):  
Term Stability ◽  
Long Term Stability ◽  
Permeation Tube

Application of standard gas validation and supporting vector machine in spectral fidelity improvement

2019 ◽  
Vol 27 (10) ◽  
pp. 2144-2153
Author(s):  
季文海 JI Wen-hai ◽  
宋 迪 SONG Di ◽  
吕晓翠 L Xiao-cui ◽  
李国林 LI Guo-lin
Keyword(s):  
Spectral Fidelity ◽  
Standard Gas

Assay of NF Ethylene by Gas Chromatography

1972 ◽  
Vol 55 (5) ◽  
pp. 1067-1069
Author(s):  
N Aubrey Carson
Keyword(s):  
Atmospheric Pressure ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph ◽  
Gas Sampling ◽  
Gas Chromatographic Method ◽  
Standard Gas

Abstract A gas chromatographic method, utilizing a 6′ × 1/4″ Poropak R column and a thermal conductivity detector, was developed for the analysis of NF ethylene. The sample was introduced into the gas chromatograph at atmospheric pressure, using a gas sampling valve with calibrated loop. A high purity standard gas was used for comparison. With the instrument set for optimum operating conditions the precision for multiple injections of standard gas was excellent. The assay value of a sample was found to be 99.7%, when determined on 3 separate days. A collaborative study of the method is recommended.

Sign in / Sign up

Export Citation Format

Share Document