Catalysis of chemical reactions by methods assumed to be similar to enzymatic methods

Russian Chemical Bulletin -     

How to validate analytical methods

The requirement for laboratories to use a `fully validated' method of analysis is now accepted or required in many sectors of analysis. Fully validated means that a method must have been assessed in a collaborative trial. The significance of these requirements is described because analysts will increasingly be required to justify their choice of method in the light of them. In addition, the requirements and procedures that may be used to obtain methods that have been validated `in-house', without full validation through collaborative trial, are also outlined in the article, these pointing the way to international acceptance of such methods in future as the cost of carrying out full validation of methods through collaborative trials becomes prohibitory.     

Diagram approach to group algebraic methods

Class sum theory, the duality with IRREP methods and tensor operators in the group algebra are discussed by generalizing the diagrammatic approach of conventional IRREP theory to include group label manipulation. Concepts such as invariant nodes and Jucys–Levinson–Vanagas reduction theorems generalize straightforwardly. The results are capable of unique simplification for certain nodes, when the group rearrangement theorem is useable or when a class sum is performed. A duality transformation (between IRREP –partner and class–element labels) emerges as an important concept.     

Moving from official to traceable methods

The primary purpose in performing analysis is to obtain information on which information decisions can be made. This article will discuss the principles of the concept `moving from official to traceable methods', where traceable methods are validated methods which are not published as official/standard methods.     

A perturbation approach to finite difference methods

A perturbation theoretic approach to finite difference methods for the calculation of eigenvalues is shown to permit an increase in the accuracy of the calculations and also to make possible the calculation of expectation values along with the eigenvalues. An application of the virial theorem can then boost the order of accuracy of any given finite difference method. Integrated probabilities and point values of the normalized wavefunction can be found without any use of quadratures. Illustrative examples are given involving the Schrodinger equation for simple polynomial potentials.     

Accelerated approach to self-consistency in molecular-orbital methods

Interpolation between two successive approximations for the bond-order matrix is used in a method of deducing corrections to the matrix; a matrix equation for the corrections is derived and solved. It is shown by reference to pyridine that the correction greatly accelerates the approach to self-consistency.Read at the Symposium on Quantum Chemistry, Palanga, June 1965.     

Application of electrochemical methods to iodatometric titrations

Summary The application of biamperometry and bipotentiometry to the titration of Hg^I, SCN^–, Sb^III and Tl^I with iodate has been investigated, Probable errors range from 0.16% for Sb^III to 0.96% for SCN^–, for quantities between 10^–5 and 2×10^–4moles.

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Zusammenfassung Es wird über die Verwendung von biamperometrischen und bipotentiometrischen Methoden bei jodatometrischen Titrationen von Hg^I, SCN^–, Sb^III und Tl^I berichtet.Die wahrscheinliche Abweichung des Verfahrens beträgt 0,16% (Sb^III) bis 0,96% (SCN^–) für Mengen von 10^–5 bis 2 · 10^–4 Mol.

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This work was supported by the Italian Council of Research (Consiglio Nazionale delle Ricerche).     

Layer-by-layer assembly: from conventional to unconventional methods

Layer-by-layer (LbL) assembly is a powerful means for fabricating multilayer thin films with controlled architecture and composition. This feature article discusses different types of methods for LbL assembly. On the one hand, some of the conventional LbL methods are introduced, which are driven by electrostatic interactions, hydrogen bonds, step-by-step reactions, sol-gel processes, molecular recognition, charge-transfer, stepwise stereocomplex assembly, and electrochemistry. On the other hand, some of the unconventional methods for fabricating of the building blocks which can not be assembled by conventional methods are also summarized. These unconventional methods usually involve the formation of supramolecular structures via one type of self-assembly. These structures can subsequently be used as building blocks in another type of self-assembly. To take advantage of these conventional and unconventional methods, a great number of building blocks can be fabricated into multilayer thin films with a defined sequence structure in a designed way. It has been demonstrated that LbL methods provide new horizons for surface molecular engineering.     

Modern optical microscopy methods to study biomolecular condensates

Cells achieve highly intricate internal organization via membrane-bound and membraneless organelles. Research over the past decade has implicated liquid–liquid phase separation, a phenomenon by which charged and often disordered biological macromolecules assemble into reversible liquid-like condensates, as the mechanism of formation of membraneless organelles in cells. During the same period, optical microscopy saw exciting advancements, including the super-resolution revolution, that were quickly adopted by researchers in the biological community. Today, there exists a vast library of techniques capable of providing unprecedented information regarding the formation, function, and dynamics of biomolecular condensates. In this review, we discuss a select number of modern optical microscopy methods that are particularly suited for studying biomolecular condensates both in vitro and in cells, as well as the associated technical challenges.     

Link to the SI via primary direct methods

The possible approaches to realising a link to the SI system and the status of primary direct methods in the traceability chain of chemical measurements are discussed. Some results obtained with the new coulometric standard system are presented.     

Sonochemical synthetic methods to produce functionalized conducting copolymers

Polyaniline (PANI) is one of the most investigated intrinsically conducting polymers. Copolymerization of aniline with aniline derivatives was considered one of the most effective and promising ways of improving the properties of PANI. In this work, firstly ethyl 3‐aminobenzoate and butyl 3‐aminobenzoate were synthesized from 3‐aminobenzoic acid by direct esterification. Then the copolymerization of 3‐amino benzoic acid, ethyl 3‐aminobenzoate, and butyl 3‐aminobenzoate with aniline was carried out by sonochemical polymerization in aqueous hydrochloric acid using ammonium persulfate (APS) as an initiator. The effects of variation in the molar ratio of the two monomers on chain structure, conductivity, and the redox properties of the copolymer are discussed. The prepared polymers are characterized by ¹H NMR spectroscopy, X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT‐IR). Thermal behavior of the prepared copolymers was studied by differential scanning calorimetry. The copolymers were doped with HCl and their conductivity was measured. Copyright © 2009 John Wiley & Sons, Ltd.     

Thermal analysis methods to study the reservoir bitumens

Journal of Thermal Analysis and Calorimetry - The bitumen-containing reservoir rocks taken from Devonian terrigenous formation of Romashkino and Bavly oil fields (Russia) were sampled and...     

Link to the SI via primary direct methods

 The possible approaches to realising a link to the SI system and the status of primary direct methods in the traceability chain of chemical measurements are discussed. Some results obtained with the new coulometric standard system are presented.