Analysis of Elastomers by Gas Chromatography

1964 ◽  
Vol 37 (1) ◽  
pp. 297-309 ◽  
Author(s):  
H. Hulot ◽  
P. Lebel
Keyword(s):  
Gas Chromatography ◽  
Small Samples ◽  
Feeding System ◽  
Analysis Method ◽  
Accurate Analysis ◽  
Volatile Products ◽  
Chromatographic Unit ◽  
Last Stage ◽  
Set Up ◽  
Basic Constituent

Abstract This study is the last stage in the design of a new analysis method for either pure or mixed elastomers. Such elastomers are polymers which, when brought to high temperatures, are dissociated into their basic constituent monomers (isoprene for natural rubber, isobutylene for butyl rubber, and so on) and other more or less volatile products. The principle of the study consists in analyzing such different fractions with a chromatographic unit which exhibit peaks used to differentiate various polymers according to their relative positions. The main novelty of the method is the elimination of less volatile fractions which are trapped in ice at 0° C, so that only lighter fractions are fed to the chromatograph. In order that the latter may be fully available or ready for analysis, pyrolysis is carried out directly in the carrier gas circuit, in a furnace set-up, instead of in the gas sample feeding system of the chromatographic unit. Pyrolysis made directly in the unit offers several advantages: Very accurate analysis, since all the pyrolyzate is fed to the unit; Very small samples (1–4 mg); Reduced handling.

Production of 2-Methyliso-Borneol by Two Benthic Cyanophyta

1983 ◽  
Vol 15 (6-7) ◽  
pp. 211-220 ◽  
Author(s):  
G Izaguirre ◽  
C J Hwang ◽  
S W Krasner ◽  
M J McGuire
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Drinking Water ◽  
Closed Loop ◽  
Water Supply Systems ◽  
Source Water ◽  
Analysis Method ◽  
Sediment Samples ◽  
Taste And Odor ◽  
Supply Systems

Two Oscillatoria strains have been isolated from three different water supply systems in California that have experienced taste and odor problems in their drinking water. The algae were obtained from sediment samples and rock scrapings from source-water reservoirs. Unialgal cultures, free of actinomycetes, were purged using the closed-loop stripping analysis method, and the resulting extracts were analyzed by gas chromatography and mass spectrometry. The organisms, Oscillatoriacurviceps and O.tenuis variant levis Gardner, yielded 2-methylisoborneol (MIB) at 60–150 µg/l. In both instances, MIB had previously been identified in the sediment samples from which the organisms were isolated. O.curviceps was implicated in a taste and odor episode involving MIB in a major reservoir during two consecutive summers.

GIS Based Multi-Criteria decision support system and machine learning for Hospital Site Selection case study Oran - Algeria

2022 ◽  
Vol 14 (1) ◽  
pp. 0-0
Keyword(s):  
Site Selection ◽  
Decision Makers ◽  
Analysis Method ◽  
Automatic Learning ◽  
Hospital Site ◽  
Set Up ◽  
High Level ◽  
Selection Of ◽  
The Ideal

The selection of hospital sites is one of the most important choice a decision maker has to take so as to resist the pandemic. The decision may considerably affect the outbreak transmission in terms of efficiency , budget, etc. The main targeted objective of this study is to find the ideal location where to set up a hospital in the willaya of Oran Alg. For this reason, we have used a geographic information system coupled to the multi-criteria analysis method AHP in order to evaluate diverse criteria of physiological positioning , environmental and economical. Another objective of this study is to evaluate the advanced techniques of the automatic learning . the method of the random forest (RF) for the patterning of the hospital site selection in the willaya of Oran. The result of our study may be useful to decision makers to know the suitability of the sites as it provides a high level of confidence and consequently accelerate the power to control the COVID19 pandemic.

scholarly journals IDENTIFIKASI DAN PENENTUAN KADAR RESIDU INSEKTISIDA PADA KUBIS DAN TOMAT DI MODOINDING DAN RURUKAN

EUGENIA ◽  
2019 ◽  
Vol 25 (1) ◽  
Author(s):  
Yoakhim Y. E Oessoe
Keyword(s):  
Gas Chromatography ◽  
Yield Components ◽  
Laboratory Data ◽  
Daily Intake ◽  
Plant Diseases ◽  
Acceptable Daily Intake ◽  
Analysis Method ◽  
Negative Effects ◽  
Tomato Plants ◽  
Vegetable Farmers

This research aims to study 1) Maternal effect on the inheritance of yield components of Manado Yellow Use of Insecticides is one way that is very often made vegetable farmersto cope with pest and plant diseases. However, the use of insecticides may give negative effects for consumers of food containing residues of these poisons.Methodology of research is survey and laboratory. Collecting data in the survey was an interview of 20 vegetable farmers, each 10 from Modoinding and 10 from Rurukan that determined purposively. Laboratory data obtainedwith the ways to identify residues in the cabbage and tomatoes from Modoinding and Rurukan , using Gas Chromatography (GC) according to the analysis method of Pusat Pengujian Obat dan Makanan.Vegetable farmers in Modoinding and Rurukan often apply the insecticide organophospate and pyretroid on cabbage and tomato plants. The residues level in ccabbage and tomato from Modoinding and Rurukan far exceed the value of Acceptable Daily Intake of profonefos allowed.

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