Residue analysis amorphous

A second application of DI-MS was in the analysis of archaeological adhesive of a blackish amorphous residue present on the chape of a bronze sword, discovered in a tomb from the Iron Age (ca. 800 700 BC) at the archaeological site of Argancy (Moselle, France). In the mass spectrum (Figure 3.13) the ion fragment at mlz 189, which is characteristic of triterpenoid compounds, is evident and represents the base peak. 

Brinker and Scherer1,64 have carried out a detailed analysis of the impact that the physical factors noted above can have on the free energy of the amorphous material. This analysis leads to the ability to predict the driving force associated with the phase transformation into the crystalline state. A typical approach to this analysis is shown below for estimating the contribution of residual hydroxyl species. 

A typical suite of X-ray diffractograms is shown in Fig. 8 for bottom ash samples. Diffraction peaks differ between sample treatments. With bottom ash, a large amorphous background signal is present. Thirty to 40 peaks are selected for analysis in the search match software. As shown in Tables 6 to 8, a number of metal phosphates were found in the treated samples and the treated and leached samples for the bottom ash, scrubber residue, and vitrification dust samples. Apatite family and tertiary metal phosphates are common to both the treated and unleached samples and the treated and leached samples for all three ashes. 

Analysis of the time and temperature dependent decay of the surface voltage on an amorphous film after charging, but prior to exposure (xerographic dark decay), and of residual decay after exposure can (in combination) be used to map the density of states. 

Further hydrolysis proceeds much slower with very small heat evolution (for R = Et and Bun its value is zero within the accuracy of the experiment, while for R = Pr1 it does not exceed 20% of the overall reaction heat). Composition of the hydrolysis products for all h values approximately corresponds to Ti01s(0R) yR0H, where y = 0.15-1 depending on the nature of alcohol and concentration of alkoxide. Solvating alcohol in the hydrolysis products was confirmed by chemical analysis and IR spectroscopy of the products of their thermal decomposition. Residual carbon on thermal treatment in air is eliminated in two steps — at 300°C with formation of amorphous black powder and then in the process of crystallization at 400 to 500. A mixture of anatase and rutile is usually thus formed, calcination at higher temperature gives pure rutile. 

Most biomolecules, such as polysaccharides, simple sugars, lipids, and proteins, are crystalline (International Centre for Diffraction Data, 2006). If HS consist merely of associations of biological residues, they should have characteristic crystal structures that can be rigorously studied and identified by X-ray diffraction analysis. However, the research evidence clearly shows that environmental organic matter has to be considered as highly amorphous material, which additionally contains microcrystalline regions like polymethylene crystallite (Hu et al., 2000 Schaumann, 2006b). 

Chemical analysis of the residual material yields the results given in Table I. The notable data are the halogen content and the limited availability of the calcium for base exchange. Infrared absorption peaks found for the clean and reacted material are shown in Table II. The important features are the appearance of a band ascribable to Si-F bonds and a shift in an Si-OH band. X-ray diffraction photographs indicate only a small increase in amorphous background and retention of the greater part of original pattern. 

Hydrous sodium titanate was prepared by the method of Dosch and Stephens (1). Titanium isopropoxide was slowly added to a 15 wt% solution of sodium hydroxide in methanol. The resulting solution was hydrolyzed by addition to 10 vol% water in acetone. The hydrolysis product is an amorphous hydrous oxide with a Na Ti ratio of 0.5 which contains, after vacuum drying at room temperature, approximately 13.5 wt% water and 2.5 wt% residual alcohol. The ion-exchange characteristics of the sodium titanate and the hydrolysis behavior of the nickel nitrate solutions were characterized using a combination of potentiometric titrations, inductively coupled plasma atomic emission (ICP) analysis of filtrates, and surface charge measurements obtained using a Matec electrosonic amplitude device. 

The decomposition of Mg(BH4)2 has been extensively studied using in situ XRD techniques coupled with residual gas analysis (RGA) measurements of the gas release. They report that the borohydride decomposed starting at 300°C, releasing 9 wt% H2 by 350°C. No ordered phase was detected by the XRD between these two temperatures, indicative of an amorphous phase or phases. Above 350°C, MgH2 apparently recrystallized and was detected by the XRD. This phase subsequently released the additional hydrogen as the temperature was increased further. Initial attempts to recharge the spent material indicated that only the Mg rehydrided to form MgH2. 

In recent years, the relaxation and yield behavior of amorphous semi-aromatic polyamides has been the subject of a detailed analysis at the molecular level [1-6], Two series of materials were investigated, so-called SAPA-R and SAPA-A (Table 1). In the SAPA-R series, the chemical structure is based on isophthalic or terephthalic acid and 2-methyl 1,5-pentanediamine. In the SAPA-A series, the chemical formulae include isophthalic or terephthalic acid residues, diamino dimethylcyclohexylmethane residues, and lactam-12 sequences. 

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