Melting data collection

Snow, especially its water-soluble fraction, is one of the most sensitive and informative indicators of mass-transfer in the chain air - soil - drinking water. Therefore analytical data on snow-melt samples were selected for inter-laboratory quality control. Inter-laboratory verification of analytical results estimated in all the groups have shown that relative standard errors for the concentrations of all the determined elements do not exceed (5-15)% in the concentration range 0.01 - 10000 microg/1, which is consistent with the metrological characteristics of the methods employed. All analytical data collected by different groups of analysts were tested for reliability and... 

Of particular importance are in situ SFM measurements, which allow real-time data collection during structure evolution [111, 112, 117, 133-135], Both concentrated block copolymer solutions [117, 136, 137] and block copolymer melts [111, 112] have been imaged in situ to access the microdomain dynamics. Figure 3... 

The DSC thermogram of spironolactone was obtained using a Du Pont TA-9900 thermal analyzer system, interfaced to the Du Pont data collection system. The thermogram shown in Figure 3 was collected over a range of 50 to 250°C, using a heating rate of 10°C/minute. It was found that the compound melted at 210.5°C, with an enthalpy of fusion equal to 43.40 J/g. 

As alluded to in the introduction, thermal analysis instruments must be calibrated using well-characterized materials. The melting of pure metals is the most common calibrant for DTA s and DSC s. Table 3.1 provides the melting temperature and latent heats of transformation of standard materials. The software in more contemporary instruments permit input of peak area values and onset temperatures determined by a test run, as well as values from the literature, into a program. It then automatically applies abscissa and ordinate corrections to all future data collected by the instrument. 

Figure 9 shows a typical temporal series XRD patterns, for a polystyrene Mw= 30,000 (PS30)/octadecyl-ammonium modified fluorohectorite (C18FH) mixture annealed in-situ at 160 °C in vacuum. Details regarding the data collection and analysis are presented in reference [ 12]. The width of the original unintercalated peak and the final intercalated peak appear to be similar, suggesting that the polystyrene melt intercalation does not drastically alter the coherence length or disrupt the layer structure of the silicate crystallites. 

Figure 2.16 Photograph of a 1mm diameter thin walled (10 pm thick) borosilicate glass capillary, glued with melted wax into a brass holder for clamping to a spinner. The sample is a white organic compound, but exposure to an intense X ray beam turns it yellow. This sample was translated between successive data collection scans to avoid radiation damage, resulting in the striped appearance.

One study examined the same furnace after it was rebuilt [45] and compared it to data collected before the rebuild [42]. The natural gas fuel composition and CO2 and H2O generated from the melt were essentially the same before and after the rebuild. Table 32.1 shows a comparison of some other key parameters before and after the rebuild. The same instrumentation (see above) was used for the measurements before and after the rebuild. Post-rebuild profiles of velocity, species concentrations (O2, CO, and CO2), and gas temperature data were reported and compared with the pre-rebuild data measured previously in the same furnace. Additionally, measurements were also taken below one of the regenerators in the tunnel leading to the furnace stack. Fewer... 

Figure 5.13 Comparison of vibrational spectroscopic data with SAXS data collected for (a) LLDPE (2) and (b) DHDPE samples in the isothermal crystallization process from the melt. Q. invariant, d) lamellar thickness, Li and I(Li) the long period and the corresponding SAXS peak intensity of lamellar stacking structure LI for 800 A period and L2 for 400 A period.

In the same manner, the crystallization behavior of SiO -PET nanocomposites is evaluated by means of DSC studies [33]. Basically polyethylene terephthalate is a crystalline polymer. The endothermic peak of the pure PET appears at 225°C and corresponds to melting temperature. The endothermic peak appears at high temperature for SiO -PET nanocomposite system. The data collected through DSC thermal analysis are given in Table 9.3. 

Table 9.5 Size distributions of organoclay in in-situ polymerized and melt-blended nanocomposites in spedlied area. Data collected from [61].

Fig. 24a. Melting point df folded-chain polyethylene single crystals of apjffoxi-matdy 130 A fold length as a function of luting rate. The bars represent tl limits of a large number of data collected at a particular heating rate. [Re 104)2...

Recent trends in x-ray diffraction are the increased use of electronic data collection and computer analysis, and in situ or dynamic experiments. These include experiments where the x-ray patterns are obtained while the sample is stretched, heated to its melting point, or aligned with an electric field. Synchrotron radiation is several orders of magnitude more intense than regular laboratory x-ray sources, and its use allows real-time study of deformation or fiber spinning, for example. More synchrotron sources usable for polymer science are currently being built, and although they are limited to national facilities, access should improve in the future. The increased power of computer data analysis permits whole pattern analysis where the crystal structure, orientation and crystallinity are simultaneously determined [10]. More detailed numerical analysis has led to interpretation of x-ray patterns in terms of three phases in semicrystalline polymers instead of the usual two. 

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