Beta decay and nuclear structure: Rb86

It was aimed to gain information on the nuclear structure of Rb⁸⁶ by investigation of the 2^?→2⁺ β transition. For this purpose the energy dependence of theβγ angular correlation and the angle dependence of theβγ circular polarization correlation have been measured. A novel experimental set-up has been used for the angular correlation measurement allowing a simultaneous determination of the anisotropy coefficientsA ₂ andA ₄ under considerable reduction of systematical and statistical errors. For the polarization correlation measurement an unusual experimental arrangement has been applied providing the possibility of simultaneous observation under four different angles. Employing additional data on shape factor measurements and energy dependent circular polarization correlations from other authors the nuclear structure of the 2^? state in Rb⁸⁶ and the 2⁺ first excited state in Sr⁸⁶ have been evaluated. For the latter purpose the unified model with weak coupling has been chosen.     

Freundlich's adsorption isotherm

We present a brief derivation of Freundlich's adsorption isotherm using straightforeward methods of statistical mechanics. The assumption that the adsorbed atoms move in Morse potential wells of different depths leads to the observed compensation effect in the energy dependence of the occupation probability of surface sites, essential for the understanding of Halsey's form of the Freundlich isotherm.     

Converging flow of a viscoelastic liquid

Two-dimensional creeping sink flow of a Maxwell fluid is an accurate approximation to a bounded converging flow of contraction ratio at least 5 : 1 and covergence half-angles of up to 45°. In this range, a perturbation expansion in Weissenberg number can be used over most of the flow field in the range where stable processing can be carried out.     

Neues Verfahren zur Darstellung von Phosphorsäureesteramiden,Phosphinsäureamiden,Phosphinsäureestern und gemischt substituierten Phosphorsäuretriestern

A New Synthesis of Phosphoric Acid Ester Amides, Phosphinic Acid Amides, Phosphinic Acid Esters and Mixed Substituted Phosphoric Acid Triesters The system triphenylphosphine/carbon tetrachloride may be used as a dehydrating agent for the intermolecular amide and ester condensation of phosphoric acid mono- or diesters and phosphinic acids. Conveniently the process is carried out as a simultaneous reaction at room temperature with the four components phosphoric acid/phosphine/carbon tetrachloride/amine (alcohol).     

On the discretisation error of the weighted Simpson rule

A method of estimating the discretisation error for the weighted Simpson rule is given. The results are used to obtain the convergence rates of a numerical method for solving integral equations with various singular kernel functions.     

Exploring antibody polyspecificity using synthetic combinatorial libraries

Summary Extensive mapping studies for seven antigen-antibody interactions have been carried out using both individual analogs and peptide libraries. With competitive ELISA, these studies have revealed that monoclonal antibodies exhibit a broad range of specificities, from antibodies that recognize only conservative substitutions for 1–2 positions of the antigenic determinant, to antibodies that recognize sequences that are completely unrelated to the parent antigen with comparable affinities. Synthetic combinatorial libraries, containing millions of peptide sequences, permit a more systematic and rapid evaluation of the extent of multiple-binding specificities of monoclonal antibodies than individual analogs. The peptide libraries used here comprise mixtures of compounds having specifically defined positions and mixture positions. The same diversity of sequences in different formats, which differ by the numbers of positions singularly defined and different locations defined within the sequence, can be examined. Comparison of the screening results, selection criteria of the most active mixtures, and different approaches used for the deconvolution of active individual compounds are discussed. Synthetic combinatorial libraries greatly facilitate the understanding of antigen-antibody interactions at the amino acid level and will assist in the development of improved immunodiagnostics.