Independence of samples

Reduced assumptions. By using an appropriate factor space, we may be able to eliminate some assumptions about our data that aren t always completely true. Examples of assumptions that can hurt us are linearity of the data, independence of samples, number of components. 

Hot split Column independent 50 ppm (FID) Ease of operation Independent of sample Rugged Qualitative analysis Flash vaporisation Thermal degradation Discrimination of higher boiling compounds possible Not suitable for trace analysis Poor, indirect quantification... 

Cliff and Lorimer (1975) used this equation to form the basis for X-ray microanalysis of thin foils, where the constant kAB contains all the factors needed to correct for atomic number differences. kAB varies with operating voltage, but is independent of sample thickness and composition if the two intensities are measured simultaneously. Its value can be determined experimentally with accuracy, using specimens of known composition. The value of kAB can be determined by calculation more rapidly, but with less accuracy. 

Simply calculating specific surface areas from the values in Tables 3-5 leads to apparent specific surface areas of approximately 400-500 m2/g [49,51], Specific surface areas obtained from similar analyses of nonpolar gas (nitrogen or krypton) adsorption studies, however, are typically in the range of 1 m2/g, independent of sample pretreatment. 

It is important to recognize that all of the terrestrial isotopic data lie along the best-fit line (nearly always within 2o) independent of sample mineralogy and Mg content. We observed no systematic deviations from this line due to molecular... 

The yield of strand breaks appears to be relatively independent of sample irradiation temperature, as discussed above. This implies that competing processes do not have much impact on reactions 1,2, 5, and 8. That is, the competitions between holes tunneling from the solvent to DNA and deprotonation of HsO " and between hole tunneling form the sugar phosphate to the bases and deprotonation of the sugar are fairly temperature-insensitive (from 4 to 300 K). In contrast, the mobility of the holes and excess electrons centered on the bases is very temperature-sensitive, zero at 4 K, onset at —40 K, and highly mobile at 180 K. By our model, the mobility is controlled by the proton transfer... 

The other components were independent of sampling design, and they collect the random errors with a multivariate normal distribution, where some significant correlations among variables are still present. 

Many polymers are too tough to be ground even at liquid nitrogen temperatures. Consequently, surface techniques are often used. Internal reflectance or attenuated total reflectance (ATR) is the second most commonly used infrared technique [38-40]. For soft or pliable polymers or solutions, ATR is an extremely versatile technique and the spectrum is similar to a transmission spectrum. Unlike transmission, the spectrum obtained is independent of sample thickness. 

Internal Standard. The results are calculated relative to a standard added to the sample in a known amount. Results are independent of sample size. The internal standard must he a compound not normally present in the sample and well separated from other components in the sample. 

These are simple in basic structure, consisting typically of two metal plates or eleclrodes spaced within an insulating chamber. Examples are show n in Figs. 6 and 7. This arrangement permits isolation and measurement of a portion of lhe solution and serves lo make the measured resistance independent of sample volume and proximity to conductive and nonconductive surfaces. In laboratory cells, platinum eleclrodes mounted in a glass are commonly employed for their excellent chemical resistance. 

The distribution of material is statistically stationary—meaning that the results of sampling along arbitrary lines of sight over sufficiently long characteristic times are independent of sampling epoch. 

Quantitative process approach High throughput analysis Sample volume Provide increased support when a go decision is made for development. Increased resources and/or improved methods of analysis. Independent of sample generation. Intralaboratory integration (i.e., automation). 

The effect of concentration on recovery by single or repeated extractions can be examined. Instead of assuming a concentration of 4.0 x 10 10 M for the aqueous sample to be extracted as stated in the original problem, the values in Table 2.4 can be recalculated after substitution with a concentration of 0.01 M. If the same four steps outlined previously are followed, it can be demonstrated that the recovery values in Table 2.4 are identical regardless of concentration. The most desirable analytical protocols are independent of sample concentration in the range of samples to be analyzed. 

If the amount of extracted analyte is independent of sample volume, the concentration extracted will correspond directly to the matrix concentration [51,128], Therefore, SPME is directly applicable for field applications in air and water sampling. 

Before discussing the THz spectra of explosives, some discussion should be made regarding explosive sample preparation method. Ideally, for security applications, the THz spectra should be independent of sample preparation. However, structural changes of the material and impurities or fillers introduced during sample preparation can affect... 

Interference between X-rays scattered at different atomic centres occurs in exactly the same way as for an atom. The scattered amplitude becomes a function of an atomic distribution function. In an amorphous fluid, a gas or non-crystalline solid the function is spherically symmetrical and the scattering independent of sample orientation. It only depends on the radial distribution of scattering centres (atoms). 

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