Proximate analysis paper

The particle size distribution of the bagasse and the proximate analysis of the fractions obtained are shown in Table 1. The fine particles contained in the two last fractions which represented 7 wt.% of the total bagasse, were removed due to their high ash content. All the data reported in this paper refer to the fraction > 0.4S0 ram. 

Much effort has been exerted during the past 50—75 years in attempts to determine the chemical nature of humus and its mode of formation. Waksman (1938) has summarized the earlier studies adequately, but it does seem advisable to make specific reference to the paper by Schreiner and Dawson (1927) and to Waksman s proximate analysis method. 

Several methods have been used for the characterization of refuse. Some of these have been derived from the techniques employed for the characterization of solid fuels such as the proximate and ultimate analyses. The reader will recall from the previous section that by proximate analysis we mean the moisture, volatile, fixed carbon, and ash content of the refuse. The ultimate analysis gives the actual chemical composition of the refuse. Still another classification which is frequently employed provides a breakdown of the refuse components according to their origin, viz., glass, leather, paper, etc. 

The lower path is somewhat more complicated. The first step in the path involves either PCA (83) or principal-coordinate analysis (PCO) (83). This step can be followed by optimization of a function that minimizes the error between the proximity measure computed in the reduced-dimension and full coordinate systems if desired. Xie et al. (84) recently published an interesting paper along these lines. Kruscal stress (79) is a widely used function in this regard... 

Some aspects of the sources, occurrence, and dispersion of airborne pesticide residues (6, 27) and methods for their sampling and analysis (28, 29, 30, 31) have been reviewed elsewhere. In this paper, the focus will be on sampling methodology, experimental design, and some results from recent field tests aimed at determining the entry and proximate fate of airborne residues in relation to specific agricultural treatments. 

The carbon compounds individuated and identified in carbon chemistry—the remaining stoichiometric plant and animal substances and the pure carbon compounds isolated from coal tar, as well as the artificial carbon compounds created in the laboratory—were nested in extended networks of experiments and work on paper. In the late 1840s, when the culture of carbon chemistry was firmly established, the individuation and identification of carbon compounds required quantitative elemental analysis, control of stoichiometric purity by studies of the chemical properties and reactions of a substance, experimental examination of their proximate components or constitution (later structure ), and work on paper with chemical formulae to demarcate the substances and to model their constitution and chemical reactions. Analysis of composition (qualitative and quantitative), control of purity, studies of reactions, and modeling on paper allowed chemists to draw ever more sophisticated... 

The modification of electrodes with enzymes and other biological macromolecules was well underway before 1978, and a detailed history of this field is beyond the scope of the present paper. A brief discussion of biological systems is given, however, to place them in context with other modification layers. A recent review by Frew and Hill (121) discusses past and future strategies for design of electrochemical biosensors. Topics discussed were enzyme electrodes, electron transfer mediators, conducting salts, electrochemical immunoassay, enzyme labels, and cell-based biosensors. In general, the bioactive molecule or cell is immobilized in proximity to an electrochemical transducer and exposed to the analyte solution for real-time analysis. 

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