Macromolecules in the Bayer Process

This is the publisher's version, also available electronically from http://www.degruyter.com/view/j/revce.2003.19.5/revce.2003.19.5.431/revce.2003.19.5.431.xml.See article for abstract

32: Funeral Arrangements for Plants: An Essay in Organic Geochemistry

This paper is based on the Liversidge Research Lecture presented before the Royal Society of New South Wales by Professor Michael A. Wilson on 5th July, 2000. Reproduced by permission of the Royal Society of New South Wales from J. Proc. Roy. Soc. N.S.W., 2000, 133, 71-85."Organic geochemistry literally is the dead end of science since it is concerned with the transformation of decaying plant material into humic substances, coal, petroleum and natural gas. The transformation process is primarily controlled by the possible degree of oxidation. Under reducing conditions coal and gas are formed and under oxidising conditions humic material is formed. Not surprisingly, the nature of the input vegetation also has an effect on the type of decomposed organic matter produced. One new finding for oxidising environments reported here, is the concept of a host-guest structures where smaller molecules reside within a framework of a macromolecular host primarily derived from lignin. The guests within the host cannot be removed by physical separation. The structure of the host can be determined by pyrolysis gas chromatography mass spectrometry and nuclear magnetic resonance techniques. Differential thermal analysis, calorimetry, methylation and gas chromatography mass spectrometry and nuclear magnetic resonance data can be used to identify the guests. Some of the guests are probably held by hydrogen bonding but others are true prisoners in that they are alkanes and hence have no binding sites.

International Comparison CCQM-K51 - Carbon Monoxide (CO) in Nitrogen (5 µmol mol-1)

The first key comparison on carbon monoxide (CO) in nitrogen dates back to 1992 (CCQM-K1a). It was one of the first types of gas mixtures that were used in an international key comparison. Since then, numerous national metrology institutes (NMIs) have been setting up facilities for gas analysis, and have developed claims for their Calibration and Measurement Capabilities (CMCs) for these mixtures. Furthermore, in the April 2005 meeting of the CCQM (Consultative Committee for Amount of Substance) Gas Analysis Working Group, a policy was proposed to repeat key comparisons for stable mixtures every 10 years. This comparison was performed in line with the policy proposal and provided an opportunity for NMIs that could not participate in the previous comparison. NMISA from South Africa acted as the pilot laboratory. Of the 25 participating laboratories, 19 (76%) showed satisfactory degrees of equivalence to the gravimetric reference value. The results show that the CO concentration is not influenced by the measurement method used, and from this it may be concluded that the pure CO, used to prepare the gas mixtures, was not 13C-isotope depleted. This was confirmed by the isotope ratio analysis carried out by KRISS on a 1% mixture of CO in nitrogen, obtained from the NMISA. There is no indication of positive or negative bias in the gravimetric reference value, as the results from the different laboratories are evenly distributed on both sides of the key comparison reference value.JRC.H.2-Air and Climat

International Comparison CCQM K23b: natural gas type II

71 p. : il.The measurement of composition of natural gas mixtures is commonly used for the calculation of its calorific value. Natural gas is a fossil fuel and its economic value per unit of volume or mass is mainly determined by its calorific value. Other aspects that might impact the economic value of natu-ral gas, such as its sulphur content, have not been addressed in this key comparison. In most cases, the calorific value and other thermodynamical properties are calculated from composition data. At the highest metrological level, natural gas standards are commonly prepared gravimetrically as PSMs (Primary Standard Mixtures). This international key comparison is a repeat of CCQM-K1e-g. The mixtures concerned contain nitrogen, carbon dioxide and the alkanes up to butane. The only dif-ference with CCQM-K1e-g is the addition of iso-butane to the list. This part of the comparison con-cerns the type II natural gas. The results on the types I and III natural gas are reported elsewhere [1]

International Comparison CCQM K23b – Natural gas types I and III

87 p. : il.The measurement of composition of natural gas mixtures is commonly used for the calculation of its calorific value. Natural gas is a fossil fuel and its economic value per unit of volume or mass is mainly determined by its calorific value. Other aspects that might impact the economic value of natural gas, such as its sulphur content, have not been addressed in this key comparison. In most cases, the calorific value and other thermodynamical properties are calculated from composition data. At the highest metrological level, natural gas standards are commonly prepared gravimetrically as PSMs (Primary Standard Mixtures). This international key comparison is a repeat of CCQM-K1e-g. The mixtures concerned contain nitrogen, carbon dioxide and the alkanes up to butane. The only difference with CCQM-K1e-g is the addition of iso-butane to the list. This part of the comparison concerns the types I and III natural gas

International comparison CCQM K52: carbon dioxide in synthetic air

61 p. : il.The first key comparison on carbon dioxide in nitrogen dates from 1993-1994 (CCQM-K1b) [1]. It is in fact one of the first types of gas mixtures that was used in an international (key) comparison. Since then, numerous National Metrology Institutes (NMIs) have been setting up facilities for gas analysis, and have developed claims for their Calibration and Measurement Capabilities (CMCs) for these mixtures. Also, in 2003 a comparison (CCQM-P41 [2, 3]) was carried out between NMIs and WMO laboratories for the determination of greenhouse gases showing a good overall agreement between the participants. In the April 2005 meeting of the CCQM Gas Analysis Working Group, a policy was proposed to repeat key comparisons for stable mixtures every 10 years. Consequently, this comparison is consistent with the proposed policy and enables NMIs that could not participate in the previous comparison to take part. This report describes the results of a key comparison for carbon dioxide in synthetic air (oxygen + nitrogen). The amount–of–substance fraction level of carbon dioxide chosen for this key comparison (360 μmol/mol) represents the ambient level of this component in air. This key comparison aims to support CMC-claims for carbon dioxide in both nitrogen or air (synthetic and purified) from 100 μmol/mol to 20 cmol/mol