Quantitative investigations

Several modes of measurement are used in the tomographic system. The most rapid one is applied as an estimation mode, the estimation error being a factor of 1.5 to 2 higher than that one of the conventional mode. With the estimation mode defective section can be detected rapidly and then they can be quantitatively investigated in detail using other modes... 

Orrell K G, Sik V and Stephenson D 1990 Quantitative investigations of moieouiar stereodynamios by ID and 2D NMR methods Prog. Nucl. Magn. Reson. Specfrosc. 22 141-208... 

Near critical points, special care must be taken, because the inequality L will almost certainly not be satisfied also, cridcal slowing down will be observed. In these circumstances a quantitative investigation of finite size effects and correlation times, with some consideration of the appropriate scaling laws, must be undertaken. Examples of this will be seen later one of the most encouraging developments of recent years has been the establishment of reliable and systematic methods of studying critical phenomena by simulation. 

Hydrogen exchange, in thiazole, especially deuteration, has been quantitatively investigated (379,380), but the mechanism of the reaction carried out at acidic or neutral pH corresponds to a protonation-deprotonation process (380), different from electrophilic substitution and is discussed in section I.3.E. 

This, on the one hand, reduces the detection limit so that less sample has to be applied and, thus, the amounts of interfering substanees are reduced. On the other hand, the linearity of the calibration curves can also be increased and, hence, fewer standards need to be applied and scanned in routine quantitative investigations so that more tracks are made available for sample separations. However, the introduction of a large molecular group can lead to the equalization of the chromatographic properties. 

When undertaking quantitative investigations it should be checked that the reaction on the TLC plate is complete — or at least stoichiometric and reproducible. In all cases it is also useful to apply reagent and sample solutions separately on neighboring tracks in order to be able to determine where the starting products appear in the chromatogram under the reaction conditions. In this way it is possible to decide whether additional by-products are produced. 

Methods of the first type have been used for both qualitative and quantitative investigation. An important limitation is that the rates of interconversion of the tautomeric forms must be small as compared with those of the test reaction (s). The method is further complicated since the test reactions are sometimes complex and it is difficult to be certain that only one tautomer is reacting. An even more fundamental objection is that much chemical evidence is based on incorrect reaction mechanisms. Thus, the formation of condensation products (30) with aldehydes has repeatedly been quoted as evidence for structures of type 31 and against type 32,. whereas if 31 does react with an aldehyde it must either first tautomerize to 32 or ionize to 33. 

It is well known that the rates of all azo coupling reactions in aqueous or partly aqueous solutions are highly dependent on acidity. Conant and Peterson (1930) made the first quantitative investigation of this problem. They demonstrated that the rate of coupling of a series of naphtholsulfonic acids is proportional to [OH-] in the range pH 4.50-9.15. They concluded that the substitution proper is preceded by an acid-base equilibrium in one of the two reactants, which was assumed to be the equilibrium between the diazohydroxide and the diazonium ion, in other words, that the reacting equilibrium forms are the undissociated naphthol and the diazohydroxide. 

A quantitative investigation of the influence exerted by a substrate on the properties of disperse catalysts is hampered by the distorting effects of many other factors, particularly the macrokinetic limitations and the size effects mentioned in Section 28.5.4. 

In this chapter, we will give a general description of electrochemical interfaces representing thermodynamically closed systems constrained by the presence of a hnite voltage between electrode and electrolyte, which will then be taken as the basis for extending the ab initio atomistic thermodynamics approach [Kaxiras et ah, 1987 Scheffler and Dabrowski, 1988 Qian et al., 1988 Reuter and Scheffler, 2002] to electrochemical systems. This will enable us to qualitatively and quantitatively investigate and predict the structures and stabilities of full electrochemical systems or single electrode/electrolyte interfaces as a function of temperature, activi-ties/pressures, and external electrode potential. 

Polymer crystallization is usually divided into two separate processes primary nucleation and crystal growth [1]. The primary nucleation typically occurs in three-dimensional (3D) homogeneous disordered phases such as the melt or solution. The elementary process involved is a molecular transformation from a random-coil to a compact chain-folded crystallite induced by the changes in ambient temperature, pH, etc. Many uncertainties (the presence of various contaminations) and experimental difficulties have long hindered quantitative investigation of the primary nucleation. However, there are many works in the literature on the early events of crystallization by var-... 

The contribution by Rouzaud et al. teaches to apply a modified version of high resolution Transmission Electron Microscopy (TEM) as an efficient technique of quantitative investigation of the mechanism of irreversible capacity loss in various carbon candidates for application in lithium-ion batteries. The authors introduce the Corridor model , which is interesting and is likely to stimulate active discussion within the lithium-ion battery community. Besides carbon fibers coated with polycarbon (a candidate anode material for lithium-ion technology), authors study carbon aerogels, a known material for supercapacitor application. Besides the capability to form an efficient double electric layer in these aerogels, authors... 

Aryl phosphites inhibit the initiated oxidation of hydrocarbons and polymers by breaking chains on the reaction with peroxyl radicals (see Table 17.3). The low values of the inhibition coefficient / for aryl phosphites are explained by their capacity for chain autoxidation [14]. Quantitative investigations of the inhibited oxidation of tetralin and cumene at 338 K showed that with increasing concentration of phosphite /rises tending to 1 [27]. 

Kopriwa BM. Quantitative investigation of cellular intensification for light and electron microscope radiautography. J Histochem Cytochem 1980 68 265-279. 

Qualitative and Quantitative Investigation of Electrode Reaction Mechanisms... 

Quantitative investigations of the kinetics of these a-coupling steps suffered because rate constants were beyond the timescale of normal voltammetric experiments until ultramicroelectrodes and improved electrochemical equipment made possible a new transient method calledjhst scan voltammetry [27]. With this technique, cyclic voltammetric experiments up to scan rates of 1 MV s are possible, and species with lifetimes in the nanosecond scale can be observed. Using this technique, P. Hapiot et al. [28] were the first to obtain data on the lifetimes of the electrogenerated pyrrole radical cation and substituted derivatives. The resulting rate constants for the dimerization of such monomers lie in the order of 10 s . The same... 

Accurate numerical techniques are available, which allow quantitative investigation of the atom-surface scattering process to be made, and which provide a standard for assessing the validity of the various approximations Despite the different approaches adopted by the numerical methods reviewed here, they are, nonetheless, interrelated and do lead to substantially the same results. 

It is remarkable that the initial description of the mechanism, although based on qualitative evidence, has so successfully passed the test of time and of quantitative investigations. The latter have allowed a more precise description of the kinetics and the assignment of the termination steps, but the core of the mechanism, i.e. the propagation loop (103), has essentially remained untouched (see, however, the discussion at the end of this section). 

Quantitative investigations of the electrostatic potential and electron density by EDSA. 

Fliszar, S., and J. Renard. Quantitative investigation of the ozonolysis reaction. XIV. A simple carbonium ion stabilization approach to the ozone cleavage of un-symmetrical olefins. Can. J. Chem. 48 3002-3018, 1970. 

Kruska, D. and Rohrs, M. (1974). Comparative-quantitative investigations on brains of feral pigs from the Galapagos Islands and of European domestic pigs. Zeitschriftfur AnatomieundEntwicklungsgeschichte 144,61-73. 

In solution, dipole-dipole interactions constitute a relaxation mechanism, and the dipolar relaxation which is the basis for the well-known nuclear Overhauser effect (NOE), mostly used in the homonuclear H, H case. The 2D HOESY method between H and Li has been used to obtain structural information of many organolithium systems in solution and this field was reviewed in 1995. Li is commonly used as the relaxation is dominated by the dipole-dipole mechanism and the relaxation time is relatively long. Knowledge of the proximity of the lithium cation relative to protons in the substrate is used to derive information about the structure and aggregation of organolithium systems in solution. In a few cases quantitative investigations have been made °. An average error of the lithium position of ca 0.2 A was reported. 

Move 1] Plant leaf tissue has been documented to contain significant amounts of mercury (Hg) [Move 2[ however, the role of leaf tissue Hg relative to atmospheric deposition and soil pools of Hg is not well established. [Move 3] A quantitative investigation was conducted to assess the role of plants in the deposition and fate of mercury within an upland forest watershed and the potential implications for soft-water lake ecosystems of the northeastern USA. Plant tissue samples were collected over a two-year period. 

Wegener K, Wesch H. 1979. Pathological changes of lymph nodes in Thorotrast patients patho anatomical auto radiographical and quantitative investigations. Env Res 18 245-255. 

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