MULTIPLE INTERNAL

The above discussion was based on the premise of a single internal reflection. An increase in sensitivity can be realized through the use of multiple internal reflections. In the case of multiple reflections, the absorbance A becomes... 

Latexes of synthetic resins are identified by ir spectrometry. Selective extraction with organic solvents is used to obtain purified fractions of the polymers for spectrometric identification. Polymeric films can be identified by the multiple internal reflectance ir technique, if the film is smooth enough to permit intimate contact with the reflectance plate. TAPPI and ASTM procedures have not been written for these instmmental methods, because the interpretation of spectra is not amenable to standardization. 

Polymer Particle Balances (PEEK In the case of multiconponent emulsion polymerization, a multivariate distribution of pjarticle propierties in terms of multiple internal coordinates is required in this work, the polymer volume in the piarticle, v (continuous coordinate), and the number of active chains of any type, ni,n2,. .,r n (discrete coordinates), are considered. Therefore... 

Multiple internal reflection IR spectra (ATR- IR) to measure e.g. the relative absorption of C00H, NH2 and CH2 bands at 1730,... 

Figure 3.1. Showing geometries for (a) RAIRS (IRAS), where 80° < 0 < 89° and (b) Multiple Internal Reflection spectroscopy (MIR), where 0 > 0criticai-...

Multiple Internal Reflection Spectroscopy (MIR) is an alternative approach in which the IR beam is passed through a thin, IR transmitting sample such that it undergoes total internal reflection alternately from the front and rear faces of the sample (Figure 3.1(b)). At each reflection, some of the IT radiation may be absorbed by species adsorbed on the solid surface. 

Multiple internal reflectance No test Same as USP std.LDPE or HDPE Same as USP std. of PET or PETG... 

Single-Cell Eukaryote Multiple internal vesicles Filaments, shells... 

The methods of choice for the determination of acrylonitrile in environmental samples are GC/NPD (Page 1985), GC/FID (EPA 1982a), and GC/MS (EPA 1982b). Multiple internal reflectance infrared spectrometry (Jacobs and Syrjala 1978) is useful for monitoring low levels of acrylonitrile in air. 

We wondered why NSCs proliferated exclusively on surfaces with EGF-His ligands anchored by coordination. We focused on two aspects in particular the conformational integrity of coordinated EGF-His and the stability of coordinate bonds at the interface. Conformational information was acquired with multiple internal reflection-infrared absorption spectroscopy (MIR-IRAS) [97]. The stability of coordinate bonds was assessed by culturing NSCs on a surface with a small region of EGF-His ligands anchored by coordination. This spatially restricted EGF-His anchoring enabled an intuitive exploration of EGF-His release under cell culture conditions. 

Fig. 12. Transmittance of a Si multiple internal reflection plate before and after H-implantation at room temperature. [From Stein (1975). Reprinted with permission from Journal of Electronic Materials, Vol. 4, p. 159 (1975), a publication of The Metallurgical Society, Warrendale, Pennsylvania.]...

In order to understand the large amplitude motion, the allowed conformations brought about the multiple internal rotations were calculated for a single... 

Internal conversion Involves radiationless transitions between vibronic states of the same total energy (isoenergetic states) and the same multiplicity. Internal conversion between excited states, e.g. S2-Wr> Si is much faster than internal conversion between Si and S0... 

N. J. Harrick and G. I. Loeb, Multiple internal reflection spectrometry, Anal, Chem, 45, 687-691 (1973). 

Schulten, H.-R., and Soldati, F. (1981). Identification of ginsenosides from Panax ginseng in fractions obtained by high-performance liquid chromatography by field desorption mass spectrometry, multiple internal reflection infrared spectroscopy and thin layer chromatography. J. Chromatogr. 212, 37-i9. 

D. AxeIson We published a paper (g. C. Levy, D. E. Axelson, R. Schwartz and J. Hochmann, J. Am. Chem. Soc., 100, ilO (19T8)) late last year on methacrylates in which we tried to interpret the side chains in terms of the effect of the backbone distribution. The side chain was governed by a combination of the distribution and the multiple internal rotations. The problem we had is that when you get to the end of the chain you still can t account for the frequency dependence. We have not proceeded to the stage of doing dilute solution studies because as you mentioned, there may be an Intermolecular effect with other chains. 

A. Jones I don t feel the multiple internal rotations model is applicable for side chains any longer than or k carbons. As soon as it is longer than carbons, a crankshaft type of motion dominates Instead of multiple internal rotations. The viewpoint probably reflects some bias on my part. 

Solid state spectra can be measured by the Attenuated Total Reflectance or Multiple Internal Reflection methods as well as by simple transmission techniques (222). Brooker (223) has reported the discovery of the translational vibrations of NaN02, NaNOs, and CaCOs (calcite). The orientation of the bonds in (U02)(N0s)2. 6 H2O has been ascertained from the spectra obtained in this manner (223). 

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