Summary: Solution casting technique served to prepare solid solutions of lithium perchlorate and poly(ethylene oxide) (PEO) having different molecular masses. Salt concentrations of solutions were varied between around 2 and 13 wt%. Crystallinity and melting point depression served to determine composition and content of amorphous phase as well as thermodynamic behavior of the solutions. Conductivity as a function of salt concentration in the amorphous phase follows a power law at constant temperature (30 °C). It results that both exponent and mobility of charge carriers increase with ascending molecular mass of PEO. The mobility follows an increase with molecular mass proportional to M2.8 indicating dependence of mobility on interstitial volume between chain molecules. Deviation of solution from perfect behavior can be evaluated by melting point depression. Accordingly, increase in conductivity is preferably related to approach to perfect solution behavior. Determination of dielectric function allows some conclusion about ion pair formation in the systems under discussion. It turns out that probability of ion pair formation decreases with increasing molecular mass of PEO in agreement with thermodynamic behavior of the solutions.
PEO 1 351.7 DT/K ¼ 68.3X S (0.988) 1 þ 0.45X S 0.45 (1 À X S ) PEO 2 351.2 DT/K ¼ 68.5 X S (0.988) 1 þ 0.45X S 0.45 (1 À X S ) PEO 3 350.6 DT/K ¼ 69.7 X S (0.997) 1 þ 0.43X S 0.43 (1 À X S )
Methane is one of the major greenhouse gases that affect climate change. To mitigate anthropogenic CH4 emissions effectively, it is necessary to measure and monitor CH4 emissions from the production and transport of fossil fuels. Therefore, it is important for NMIs to demonstrate measurement equivalence for the standard gases of CH4.
This is the third comparison on methane in nitrogen or air. The first comparison is the key comparison of CCQM-K82 (ambient level methane in air) and the second comparison is the supplementary comparison of APMP.QM-S7 (2000 μmol/mol methane in nitrogen). As a supplementary comparison, the purpose of this comparison is to study the comparability of CH4 standard gas mixtures at emission level (0.05 cmol/mol - 0.5 mol/mol in nitrogen or air). Furthermore, this comparison can provide a link to APMP.QM-S7 through KRISS who participated in both previous comparisons. In this comparison, KRISS prepared gas standards and sent to participants. Each participant measured the standard on their laboratory and reported their measurement results to KRISS according to the measurement protocol.
This report describes the results of a supplementary comparison for methane in nitrogen at 2000 μmol/mol.
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The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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