Physico-chemical method

Polyuzhyn I.P., Smirnova O.Ya., Jatchyshyn J.J., Musyanovich R.Ya., Novikov V.P., Tkachenko V.I. - RP-HPLC Separation of Amino Derivatives of 3-Chloro-l,4-Naphtoquinone. // XVII-th International Symposium on Physico-Chemical Methods of the Mixtures Separation Ars Separatoria 2002 .- June 17-20, 2002.- Borowno n.Bydgoszcz, Poland. - Poster P-37. 

Bogdanov, S., Ruoff, K., and Persano Oddo, L. (2004). Physico-chemical methods for the characterisation of unifloral honeys A review. Apidologie 35, S4—S17. 

The specific features of the cluster compounds of technetium are such, that practically each new compound must be studied using single crystal X-ray structural analysis, because their complex structures do not allow the interpretation of the results from other physico-chemical methods of investigation. Therefore, the synthesis of single crystals suitable for X-ray structural analysis is the main and most laborious chemical task. 

On the basis of a number of physico-chemical methods (Mossbauer spectroscopy, electron diffraction, EXAFS) the iron cores of naturally occurring haemosiderins isolated from various iron-loaded animals and man (horse, reindeer, birds and human old age) were consistently shown to have ferrihydrite-like iron cores similar to those of ferritin (Ward et ah, 1992, 2000). In marked contrast, in the tissues of patients with two pathogenic iron-loading syndromes, genetic haemochromatosis and thalassaemia, the haemosiderins isolated had predominantly amorphous ferric oxide and goethite cores, respectively (Dickson etah, 1988 Mann etah, 1988 ... 

By measuring the distribution coefficient, K, of cationic radon on Nafion resin (H+ form) in BrF -trichlorotrifluoroethane solutions as a function of the concentration of BrF, we have been able to show that the charge on the radon cation is +2 and that the parent molecule is RnF2 This physico-chemical method makes use of the fact that BrF produces the univalent cation BrF2, which competes with Rnz for sites on the resin. The following equilibria occur in this system (R represents the anion of the resin) ... 

It becomes clear that research and development in the household and detergency area depend on a profound knowledge of physico-chemical parameters. Thus, an overview will be given of selected physico-chemical methods used in detergency research, most of them based on sensor technologies. 

The currently available quantum chemical computational methods and computer programs have not been utilized to their potential in elucidating the electronic origin of zeolite properties. As more and more physico-chemical methods are used successfully for the description and characterization of zeolites, (e.g. (42-45)), more questions will also arise where computational quantum chemistry may have a useful contribution towards the answer, e.g. in connection with combined approaches where zeolites and metal-metal bonded systems (e.g. (46,47)) are used in combination. The spectacular recent and projected future improvements in computer technology are bound to enlarge the scope of quantum chemical studies on zeolites. Detailed studies on optimum intercavity locations for a variety of molecules, and calculations on conformation analysis and reaction mechanism in zeolite cavities are among the promises what an extrapolation of current developments in computational quantum chemistry and computer technology holds out for zeolite chemistry. 

Quite apart from the problems of chemical synthesis, it is clear that the application of physico-chemical methods to pigment manufacture, first needed in the development of the... 

The character of ORD curves depends on the structure, configuration and conformation of optically active substances and also on the nature of choromophores present and their position relative to asymmetric centre. In many cases the curves depend on solvent and temperature. This is why spectropolarimetry becomes an important physico-chemical method (for investigating organic compounds). By introducing an optically active radial into organic compounds that do not possess optical activity, it is possible to extend the range of investigation by spectropolarimetric methods. 

Physico-chemical methods, the ultimate aim of which is to determine the exact qualitative and quantitative composition of an odorous emission. 

If one considers the structure suggested by Gold and Tye (1952a, b, c) it is obvious which physico-chemical methods can be used to prove the existence of this complex. 

This is particularly true in the case of bioprocesses where the state of the living part of the system must be closely monitored. Extensive surveys have been published and several international conferences have been held on this topic. Furthermore, the last two decades have seen an increasing interest to improve the operation of bioprocesses by applying advanced control schemes. In particular, biological Wastewater Treatment Processes (WWTP s), more efficient than the traditional physico-chemical methods but at the same time... 

Several physico-chemical methods are available for the treatment of pulping and pulp bleaching effluents. The most prominent methods are membrane separation, chemical coagulation, and precipitation using metal salts and advanced oxidation processes. 

If different physico-chemical methods are used and the same results are obtained, it is more probable that the value is near to the. .true" value... 

Davankov, V. A. 1993. Chemical and physico-chemical methods of analysis. Advances in the development of chromatographic methods of analysis. Industrial Laboratory, 58(11) 999-1006. 

Much work has been devoted to [2 + 3] cycloadditions both in the synthesis of and in reactions of this kind of heterocycle. Dimroth rearrangement is another feature which has been explored widely. X-ray structural analysis was extensively used alongside physico-chemical methods to elucidate the structure of novel compounds. 

Living anionic systems are among the most suitable to study the mechanism of polymerizations. Indeed, the high efficiency of anionic Initiators, combined with the good stability of active centers, allows one to study directly the active species by common physico-chemical methods. 

In principle the deviation <5 can be determined by the use of usual analytical chemistry or a highly sensitive thermo-balance. These methods, however, are not suitable for very small deviations. In these cases the following methods are often applied to detect the deviation physico-chemical methods (ionic conductivity, diffusion constant, etc.), electro-chemical methods (coulometric titration, etc.), and physical methods (electric conductivity, nuclear magnetic resonance, electron spin resonance, Mossbauer effect, etc.), some of which will be described in detail. 

Refs l)G.W.Vinal,"Srorage Batteries, Wiley, NY(1940) 2)G.W.Jones et al, USBurMines Tech Paper 6l2,pp 1—10(1940) CA 34, 8284(1940)(Danger of explosion in storage battery rooms due to evolution of hydrogen and formation of explosive mixtures with air) 3 )J. Re illy W.N.Rae "Physico-Chemical Methods Van No strand, NY( 1943), pp 228—36 4)Kirk Othmer 2(1948),pp 340—60 under Batteries (17 refs) 5)Perry(l950),pp 1792—3... 

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