Some General Problems

The reader is referred to Branscomb s remarks, discussed in Section 

and the message cannot be emphasized too strongly. A literature report of a quantitative value for a rate parameter with an indicated error is no contribution without the necessary relevant information, even if performed by the most effective worker with the utmost care. Its reliability has to be evaluated by the scientific community on a continuing basis in the light of subsequent developments, unavailable to that worker at the time of the measurement. There are three aspects of this relevant information (1) details of the apparatus and technique, (2) details of the control experiments performed, and (3) details of the data treatment. Adequate discussion of all three aspects must be reported in the literature. This means longer articles, but the alternative, which is all too familiar, results in literature, and expensive science, which are at worst valueless. The responsibility of enforcing the policy rests upon referees. 

The evolution of a new experimental technique often follows a rather similar pattern. A particular device, sometimes commercially available, is used, for example, to characterize reaction pathways, and at some time, a worker deduces a rate parameter from such measurements. In order to generate this number, some unknown but essential parameters which 

The careful establishment of the merging-beams technique is an excellent example of what is needed. McDaniel s recent formulation of necessary criteria to be met for a reliable drift-tube measurement is another example. In contrast, one notes the lack of the necessary control experiments during the past development of the mass-spectrometer ion-source technique (Section 3.4.1) and during the recent development of the ion cyclotron resonance technique (Section 3.4.7). The necessary techniques may not always be available, but the effort must be directed to that end and not to the premature acquisition of data of unproven reliability. 

Mass analyzers separate not masses, but mass-to-charge ratios.J The identification of the actual ion responsible is generally a trivial matter, but is not always so, even in the simplest systems. It is clear, for example, from Vance s work that at normal electron energies, the mje = 14 peak in nitrogen contains contributions from both and clearly, such possibilities must be constantly borne in mind. 

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It is first worth mentioning some general problems of fullerene characterization. Not only can a mixture of various multiple adducts result from a given reaction, but also each of them may exist as a mixture of regioisomers that can often only be separated by HPLC. In addition, there is often a poor signal-to-noise ratio for many spectroscopic techniques owing to the use of only small amounts of relatively high molecular mass and low solubility. 

This is nearly the end of the first part of the program, so here are some general problems. 

Some general problems associated with the determination of sulfur in coal are nonuniform distribution of pyrite particles, failure to convert all the sulfur to sulfate, and loss of sulfur as sulfur dioxide during the analysis. The nonuniform distribution of pyrite necessitates the collection of many sample increments to ensure that the gross sample is representative of the lot of coal in question. Pyrite particles are both hard and heavy and have a tendency to segregate during the preparation and handling of samples. Because the particles are harder, they are more difficult to crush and pulverize and tend to concentrate in the last portion of material that remains from these processes. 

TUkey, H. B., Wittwer, S. H., TUkey, H. B., Jr (1958). in Radioisotopes in Scientific Research, Volume IV - Research with Radioisotopes in Plant Biology and Some General Problems Oxford Pergamon Press pp. 304-322. 

Heymann, E. 1989. A proposal to overcome some general problems of the nomenclature esterases. In Enzymes Hydrolyzing Organophosphorus Compounds, E. Reiner, N. Aldridge, and F.C.G. Hoskin, Eds. Ellis Horwood, Chichester, U.K., pp. 226-235. 

The Editor would like to thank the authors for their contributions which give an interesting picture of the current status of selected parts of quantum chemistry. The topics in this volume range from studies of some general problems in theoretical chemistry and diatomic interaction theory, to gap equations and instabilities for extended systems and conductivity properties of certain conjugated systems, to a discussion of the connection between the Hamiltonian and Liouvillian formalisms in the modern quantum theory of matter. 

This chapter is devoted to some general problems which should be discussed before consideration of the reactions of alkanes and other hydrocarbons with non-metal and metal-containing substances. First of all we will consider general chemical properties of hydrocarbons and principle mechanisms of reactions with participation of these compounds. 

Furthermore, some general problems of chemical kinetics are also discussed. In particular, the dynamic characteristic number of the components and intermediate substances, elementary and final reactions that are needed for describing the dynamics of a system composition have been determined for every state of the evolution of a nonequilibrium chemical system. 

Direct analysis using little or no sample preparation has the advantage of time saving and minimum risk of analytic loss. This technique has been applied for highly viscous liquids and has been examined for the determination of Ni (Brandao et al., 2006), Ni and V (Sdva et al., 2007) and Cu, Fe and V (Brandao et al., 2007) in oil samples. However there are some general problems such as volatility, flammability and immisdbility with water. In addition to the problems related to the complexity of the matrix, organic standards, which are indispensable in case of direct sample introduction, are unstable and there are no certified reference materials available for these samples. It is therefore necessary to compare the accuracy of the developed method with results obtained with independent technique, particularly with respect to the sample preparation... 

Kostrov, B.V., Nikitin, L.V. (1970) Some general problems of mechanics of brittle fracture, Arch. Mech. Stosow. 6, 749-776... 

We will discuss in this article first some general problems which arise in the NMR spectroscopy of peptides. Then, NMR techniques for signal assignment and extraction of conformational parameters will be described, followed by a short excursion into structure determination using NMR parameters. The final part will include the analysis of peptide dynamics based on NMR data. 

Mechanical properties of polymeric composititms were studied by many scientists (e.g., see 110-ii.. That is why this section will deal only with some general problems mainly related to relaxation properties. 

An important property of the barrierless discharge of hydrogen ions is that its rate is independent of the HaO concentration and the i( i-potential. By virtue of this property, this effect can be used for solving some general problems whose solution by other means is quite hard to obtain. 

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