scholarly journals Methodical aspects of quantitative elemental analysis of organic compounds using automated CHNS-analyzers

2019 ◽  
Vol 58 (5) ◽  
pp. 154-158
Author(s):  
Igor M. Fitsev ◽  
◽  
Maria Yu. Vakhitova ◽  
Vasily M. Babaev ◽  
Ksenia S. Bulygina ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Organic Compounds ◽  
Elemental Analysis ◽  
Standard Sample ◽  
Thermal Conductivity Detector ◽  
Standard Samples ◽  
Unknown Compound ◽  
Quantitative Elemental Analysis ◽  
Before And After ◽  
Operative Control

In this article the methodical aspects of quantitative elemental analysis of organic compounds on the automatic CHNS-analyzers, combining the method of Dumas-Pregl and gas chromatographic separation of analytic forms elements (N2, CO2, H2O, SO2) recorded by the thermal conductivity detector are explored. Also there are shown methods of calibration of the thermal conductivity detector, including the traditional way that uses one standard sample and the way that uses three standard samples with different quantitative content determined elements. Besides, attached the methodical approach, which is used in quantitative elemental analysis of organic compounds and their mixtures on the automatic CHNS-analyzers made on local and abroad plants, is based on operative control of calibration characteristics that we get from the thermal conductivity detector (characteristics and results of a standard sample of known composition before and after elemental analysis of unknown compound).

scholarly journals A standard sample determination method for the testing of smoke detectors and its application research

2020 ◽  
Vol 185 ◽  
pp. 02035
Author(s):  
Tingting Wang ◽  
Guoping Wu ◽  
Pei Zhang ◽  
Dake Zhang
Keyword(s):  
Ionization Chamber ◽  
Standard Sample ◽  
Sample Selection ◽  
Difficult Problem ◽  
Application Research ◽  
Standard Samples ◽  
Selection Scheme ◽  
Before And After ◽  
Smoke Detectors ◽  
The Stability

The stability of the standard sample plays a key role in the testing of the smoke detectors. A scientific and effective standard sample selection scheme is proposed in this paper. The repeatability and uniformity of the tested samples are evaluated before and after the environmental acceleration testing, and the most stable standard sample is obtained. At the same time, this paper explores the new application of the standard sample, which can be used in the calibration of the measuring ionization chamber (MIC). This work can greatly reduce the selection time and provide the standard samples for the laboratory of the smoke detectors testing which is scientific and reliable. At the same time, the difficult problem of the calibration of the measuring ionization chamber (MIC) is solved here.

scholarly journals Apparatus for routine measurements of the thermal conductivity of ice cores

1999 ◽  
Vol 29 ◽  
pp. 151-154 ◽  
Author(s):  
Crescenzo Festa ◽  
Aristide Rossi
Keyword(s):  
Thermal Conductivity ◽  
Ice Cores ◽  
Maximum Temperature ◽  
Transient Hot Wire ◽  
Hot Wire ◽  
Standard Samples ◽  
Experimental Conditions ◽  
Heating Source ◽  
Central Segment ◽  
Wire Method

AbstractAn apparatus is described for measuring the thermal conductivity of ice by the transient hot-wire method. Thermal conductivity A, is determined by tracking the thermal pulse induced in the sample by a heating source consisting of a platinum resistor. A central segment of the same platinum heating resistor acts also as a thermal sensor. A heat pulse transferred to the ice for a period of 40s gives a maximum temperature increment of about 7-14°C. In good experimental conditions, the expected reproducibility of the measurements is within ±3%. The accuracy of the method depends on whether the instrument has been calibrated by reliable standard samples, certified by absolute methods.

scholarly journals Species and characteristics of volatile organic compounds emitted from an auto-repair painting workshop

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Y. Song ◽  
H. Chun
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Large Scale ◽  
Butyl Acetate ◽  
Small Scale ◽  
Indoor Environments ◽  
Voc Emissions ◽  
Volatile Organic ◽  
Before And After ◽  
Adsorption Systems

AbstractVolatile organic compounds (VOCs) are secondary pollutant precursors having adverse impacts on the environment and human health. Although VOC emissions, their sources, and impacts have been investigated, the focus has been on large-scale industrial sources or indoor environments; studies on relatively small-scale enterprises (e.g., auto-repair workshops) are lacking. Here, we performed field VOC measurements for an auto-repair painting facility in Korea and analyzed the characteristics of VOCs emitted from the main painting workshop (top coat). The total VOC concentration was 5069–8058 ppb, and 24–35 species were detected. The VOCs were mainly identified as butyl acetate, toluene, ethylbenzene, and xylene compounds. VOC characteristics differed depending on the paint type. Butyl acetate had the highest concentration in both water- and oil-based paints; however, its concentration and proportion were higher in the former (3256 ppb, 65.5%) than in the latter (2449 ppb, 31.1%). Comparing VOC concentration before and after passing through adsorption systems, concentrations of most VOCs were lower at the outlets than the inlets of the adsorption systems, but were found to be high at the outlets in some workshops. These results provide a theoretical basis for developing effective VOC control systems and managing VOC emissions from auto-repair painting workshops.

A Graphene-Based Thermal Conductivity Detector for Low Power Gas Detection

2021 ◽  
Author(s):  
Yunhao Peng ◽  
Ashrafuzzaman Bulbul ◽  
Seungbeom Noh ◽  
Shakir-ul Haque Khan ◽  
Kyeong Heon Kim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Low Power ◽  
Gas Detection ◽  
Thermal Conductivity Detector
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