Characteristics of samples

Establish a register of all reference materials used to judge characteristics of samples. 

ANIMAL SAMPLES, CHARACTERISTICS OF SAMPLING LOCALITY, AND ANALYTICAL METHODS... 

Pyrolysis gas chromatography is an indirect method of analysis in which heat is used to transform a sample into a series of volatile products characteristic of sample and the... 

In principle, measurement of the phosphorescence characteristics of samples obtained after extraction of polymers with organic solvents may also yield useful information regarding the nature and concentration of the additives present. Parker and Hatchard [157] have examined the possibilities of phosphorescence measurements for V-phenyl-2-naphthylamine. Although it should be possible to determine various analytes simultaneously by correct choice of ex and em wavelengths and phosphorescence decay, no pertinent reports are available. Phosphorescence finds limited application for the direct determination of additives in polymers (without prior extraction). 

The NIR spectrum contains information about the physical characteristics of samples, as well as chemical information, which are the basis of the previously discussed applications. NIR is thus suitable for determining physical parameters. 

In addition to chemical information, NIR spectra also contain information about the physical characteristics of samples and systems that can manifest itself, for example, as a baseline shift caused by scattering differences. On the one hand, this information is extremely useful in characterising particle size [102],... 

The nucleation characteristics of samples were examined by the relation between superheating temperature JTu ( = Tu —Tm) and supercooling temperature JTsc ( = Tm—Tsc). Where, Tm is the melting point of CaCl2 6H20 sample, that is, 302K. 

As explained in Sections 16.4 and 16.5, the comprehensive characterization of complex polymer systems is hardly possible by the SEC alone. SEC employs only one retention mechanism which simnltaneonsly responds to all molecular characteristics of sample. Similarly, also the coupling of the different retention mechanisms within one single column only exceptionally allows fulfilling this task. Evidently several retention mechanisms should be applied in a tandem approach that is within at least two different on-line chromatographic systems. This is the basic idea of the two- and multidimensional polymer HPLC. In the present section, the principles of two-dimensional polymer HPLC, 2D polymer HPLC or (2D-LC) will be briefly elucidated. There are several reviews available [23-31,249,250] dealing with the 2D polymers. It is anticipated that also the three- and multidimensional polymer HPLC will be developed in future. 

Catalytic tests were carried out following a protocol that allowed establish relationships between the characteristics of fresh and spent catalysts and the catalytic performance. Specifically, within the first 5-10 hours reaction time, the catalytic performance was not stable, due to variations in samples characteristics. Therefore, two different sets of results were taken, the first after less than 1 hour (representative of fresh samples), and the second one after 3-4 hours (representative of spent samples). Only in the case of the equilibrated sample, no difference was found between the characteristics of samples eq and eqsp (Tables 1 and 2) for this catalyst, also the catalytic performance did not vary at all during catalytic tests. 

PCA is a statistical method that compress many correlated variables to one or a small number of non-correlated variables [2]. This method compresses the information observed in the NIR spectrum. A limitation of PCA is that it is often difficult to establish the correspondence between principal components obtained and concrete characteristics of samples. Figure 3 shows the application of the PCA to spectra of flours with different processing qualities. On a plane consisting of the first and the second principal components, the difference between each flour can be distinguished. The first principal component shows information related to sample particle size in this study. 

Figure IV 2 4. The quasipartical differential conductivity v2 = V2 / IV2 at T = 4.2 K as extracted from the I-V characteristics of sample 2 and 7 (Fig. 4c in Ref. [8]). Lines are fits for v < 10 mV. Insert Corresponding J-v curves...

Prediction-set samples were then passed to the network and assigned to the nearest neuron. They are represented as superscripts in Figure 9.18. All 19 prediction-set samples were assigned to neurons that had spectra with the same class label. The validation of the self-organizing maps using these 19 prediction-set samples implies that information is contained in the Raman spectra of the plastics characteristic of sample type. Classification of the plastics by the self-organizing map was as reliable as that obtained by other methods, and more importantly, the classification was obtained without any preassumptions about the data. 

Hydrogen-storage characteristics of samples of four types were studied as synthesized MgH2(l), MgH2 after mechanical activation, m/a (2) MgH2-graphite (3) and MgH2-carbon nanofibers (CNF) both after mechanical activation. 

Special features of Raman spectroscopy in the NIR range 155 Influence of the characteristics of sample and spectrometer 155 Conclusions concerning optimization of NIR Raman spectroscopy 161... 

Maintenance of the physical characteristics of samples under test was to be maximized. The methods should be chosen to prevent this and should "...provide the minimal interference with the irradiation of samples under test." The particle size of powders was to be "...with a particle size distribution representative of material as released for use..." and "...a thickness of not more than (NMT) 5mm."... 

Some characteristics of samples obtained by treatment of decationized US-41 ultrasile by trichloride phosphorus and triethylborate (BP- US-41 (1)) and mixture of acids (BP-US-41 (2)) are represented in table 3. 

Characteristics of samples prepared by addition of separate poisonous elements to the fresh de-NOx catalyst. ... 

Measurements of the dielectric characteristics of samples of ice and ice particle aggregates were conducted with a LCR-meter (HIOKI, 3531). Most measurements were performed at frequencies between 50 Hz and 5 MHz and at temperatures between -15 °C and -0 °C. The basic accuracy of LCR meter is as being less than 2% in a frequency range of 100 Hz to 1 MHz, 3.5% below 100 Hz, and 7% above 1 MHz. 

The temperature and percent oxygen saturation were associated with the thermal characteristics of sampling sites and were responsible for 14 percent of variance In the SRP water systems. The thermal regime significantly increased the concentration of Mg, Na and ortho-phosphate... 

Adsorption-structural characteristics of samples obtained by building-up of gel particles... 

Figure 8.7 (a) Drain-current (/p)-drain-voltage (Fd) characteristics of sample A measured at room temperature, (b) /n-Fn curves from (a) corrected for leakage currents across the gate insulator, (c) as (b), but corrected for ohmic currents in addition. The lines in (c) represent simulated... 

A number of methods have been used in the synthesis of perovskites the choice of a particular one depends mostly on the expected use for these oxides. Obviously, no attention has been paid to textural characteristics of samples whose uses are based on their electric or magnetic properties. However, application of perovskites in the field of catalysis requires solids with a well-developed porous network. As the present review is concerned particularly with the surface and catalytic properties of perovskites, we will place special emphasis on preparation methods leading to a high surface volume ratio. Also, methods yielding homogeneous solids will be discussed because of the important effect that inhomogeneities may play in heterogeneous catalysis. 

Sampling is an essential function of spectrometric analytical control. The sample, which is as small as possible, must be representative of the medium to be analyzed. The analysis must be rapid in order to be able to take any required action on the process. The general characteristics of sampling require a knowledge of the fluid flow rates, mass transfer, and temperature variations, especially in compiling a material balance. 

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