INDEX determination

FIGURE 16.17 Nonbranched/long chain branched glucans of potato starch dissolved in hot water-steam and 0.1 M NaOH 1.2 ml of the 18-mg/ml solution was separated on Sephacryl S-1000 (95 X 1.6 cm) 3-ml fractions were collected for further analysis normalized (area = 1.0) eluogram profiles (ev) constructed from an off-line determined mass of carbohydrates for each of the fractions branching index ( ) determined from iodine-complexing potential of individual 3-ml fractions flow rate 0.40 ml/ min V ,i = 75 ml, Vtot = 162 ml eluent 0.005 tA NaOH. 

To correct a refractive index determined for airjliquid to the absolute index vacutimlliquid, the observed value should be multiplied by I 00029. This correction is, however, too small to be of the slightest value in practice. 

Why are sugar and alcohol content in foods commonly determined by refractive index determinations ... 

Here we will describe an example of data extraction during processing of texture pattern of brucite and show the results of indexing, determination of unit cell parameters and extraction of intensities. 

The amount of polymer adsorbed on each sample was measured by pressure filtration through a 0.1 m filter, followed by analysis of the filtrate for residual polymer by gel permeation chromatography with refractive index determination. Particle zeta potentials were measured by taking a small sample of the solids from the centrifuge and re-suspending them in the supernatant prior to analysis in a Malvern Instruments Zetasizer . The concentration of all other types of ions in the supernatant was analysed by ICP atomic emission spectroscopy. 

LCO quality was determined by two different methods. Before 2-D chromatography was available, liquid product aromatics were measured for all samples using a variation of the ASTMD 5186-96 method. A selected number of samples were cut between 221°C and 343°C using a TBP column to produce an LCO fraction for direct ASTMD 3747 cetane index determination. The cetane values of the LCO cuts were then correlated to the total liquid product aromatics (Figure 2.1) and the correlation was used to estimate the LCO quality of the other samples. 

D. DIESEL FUEL CETANE NUMBER AND CETANE INDEX DETERMINATIONS... 

Reference electrode, 1104, 1108, 1113 potential, 819, 874 Refractive index, determination with ellipsometry, 1148. 1151 Reflection coefficient, 1151 Residence time, definition, 1310 Reversal techniques, determination of intermediate radicals, 1416 Reversible adsorption of organic molecules, 969, 970... 

Refractive Index. Determine RI at 20°C using an accurate refractometer such as Abbe (See SGA Scientific Inc, Bloomfield, NJ Catalog (1972), p 742 or other suppliers... 

No carbon was recorded for the D-treated film. The O/Si composition ratio was found to be 2.08 and is attributed to the extent of condensation as the organic phase has been removed completely. Based on the amount of Si for sample D and assuming a density of 2.3 g cm3 for amorphous SiC>2, the top layer would correspond to a thickness of 154 nm, if a dense layer is assumed. As the actual layer thickness is 458 nm, this would imply a porosity of 66%. Here a considerable discrepancy with the porosity obtained from ellipsometry is evident. In this respect it should be noted that the RBS measurement was done more to the edge of the sample than ellisometry, where the thickness is smaller than in the centre. Further, the refractive index determined with ellipsometry is very accurate. However, the relation of porosity with refractive index depends on the model used. 

In practice, the retention index is simply derived from a plot of the logarithm of the adjusted retention time versus carbon number times 100 (Figure 4.4). To obtain a retention index, the compound of interest and at least three hydrocarbon standards are injected onto the column. At least one of the hydrocarbons must elute before the compound of interest and at least one must elute after it. A plot of the logarithm of the adjusted retention time versus the Kovats index is constructed from the hydrocarbon data. The logarithm of the adjusted retention time of the unknown is calculated and the Kovats index determined from the curve (Figure 4.4). 

Iodobenzene [591-50-4], C6HBI, mol wt 204.02, 62.23% I, mp —30°C, bp 188—189°C, is a colodess liquid that rapidly becomes yellow and has a characteristic odor. It is insoluble in water, but completely miscible with alcohol, chloroform, and ether. It has a density of 1.832 g/mL at 20°C and a refractive index of 1.621 at 4°C. Iodobenzene is prepared by the reaction of iodine and benzene in the presence of an oxidizing agent and from benzeneiazonium sulfate and potassium iodide (122). Iodobenzene is used as a heavy liquid for refractive index determinations, but probably its principal use is in the synthesis of iodoso compounds, RIO iodoxy compounds, RI02 and iodonium salts, R IX. 

Many of the thinner platelets are transparent and a rich ruby-red color in transmission. They give a uniaxial negative interference figure. The crystals are too deeply colored for refractive index determination, but the mean value is greater than 2. 

The flexibility index determines the largest uncertainty range (scaled hyperrectangle) for which the HEN is resilient. The flexibility index is scaled in terms of an expected uncertainty range (0N - F Afl <0<0N + F A0+). 

From Reference 167, using the CI/SINDOl method. Bond lengths in A, bond angles in degrees. Aromaticity index determined by the lowest ring bond order. 

Figure 16.44. Correlation between the humification index determined by LIF spectroscopy (Huf) in whole soil samples and the humification index /t465 (Milori et al., 2002) determined by conventional fluorescence in the corresponding humic acid samples. The indexes are expressed as arbitrary units (a.u.) (Milori et al., 2006).

Peirs, A., Scheerlinck, N., De Baerdemaeker, J. and Nicolai B. M. (2003) Starch index determination of apple fruit by means of a hyperspectral near infrared reflectance imaging system. J. Near Infrared Spectrosc. 11, 379-89. 

The effect of zeolite porosity on the reaction rate was also well demonstrated in liquid-phase oxidation over titanium-containing molecular sieves. Indeed, the remarkable activity in many oxidations with aqueous H2O2 of titanium silicalite (TS-1) discovered by Enichem is claimed to be due to isolation of Ti(IV) active sites in the hydrophobic micropores of silicalite.[42,47,68 69] The hydrophobicity of this molecular sieve allows for the simultaneous adsorption within the micropores of both the hydrophobic substrate and the hydrophilic oxidant. The positive role of hydrophobicity in these oxidations, first demonstrated with titanium microporous glasses,[70] has been confirmed later with a series of titanium silicalites differing by their titanium content or their synthesis procedure.[71] The hydrophobicity index determined by the competitive adsorption of water and n-octane was shown to decrease linearly with the titanium content of the molecular sieve, hence with the content in polar Si-O-Ti bridges in the framework for Si/Al > 40.[71] This index can be correlated with the activity of the TS-1 samples in phenol hydroxylation with aqueous H2C>2.[71] The specific activity of Ti sites of Ti/Al-MOR[72] and BEA[73] molecular sieves in arene hydroxylation and olefin epoxidation, respectively, was also found to increase significantly with the Si/Al ratio and hence with the hydrophobicity of the framework. 

Finally, n was determined by spectroscopic ellipsometry. The main drawback with this technique when applied to anisotropic samples is that the measured ellipsometric functions tanlF and cos A are related both to the incidence angle and the anisotropic reflectance coefficient for polarizations parallel and perpendicular to the incidence plane. The parameters thus have to be deconvolved from a set of measurements performed with different orientations of the sample [see (2.15) and (2.16)]. The complex refractive index determined by ellipsometry is reliable only in the spectral region where the sample can be considered as a bulk material. In fact, below the absorption... 

An example of the use of EIS measurements to make long-term corrosion predictions for polymer coated metals is shown in Fig. 46 (110). In this plot, the ASTM D610 and D714 visual rankings of corrosion damage after 550 days of exposure in simulated seawater are plotted against a protection index, < (/), determined after only 10 days of exposure. The damage protection index is determined from the breakpoint frequency, /, as... 

Refractive Index Determine as directed under Refractive Index, Appendix IIB, using an Abbe or other refractometer of equal or greater accuracy. 

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