Spectroscopic properties of Ni and rare-earth codoped Ge-Ga-Sb-S glass

The infrared emission properties of rare-earth (i.e., Dy³⁺, Pr³⁺ or Sm³⁺) and nickel-codoped Ge-Ga-Sb-S glasses were investigated by photoluminescence measurements. It was found that the emission intensities of the rare-earth doped glasses were significantly weakened even with very few amount of nickel (i.e., 500 at. ppm). On the other hand, the nickel-doped glasses show larger indices of refraction, which property will be desirable in nonlinear optics. Our results, however, suggest that to obtain rare-earth doped chalcogenide glasses of better infrared emission property it is necessary to keep the nickel dopant as low as possible.     

The role of the Czech Metrology Institute in the field of metrology in chemistry

 The main role of a national metrological institute is to assure metrological traceability in the country. Metrology in chemistry is a developing field with specific features quite different from physical metrology and it is very difficult to establish a metrological system in chemistry based on the work of a single national institute, especially in small countries. For this reason the Czech Metrology Institute (CMI) has helped to establish the Association of National Reference Laboratories (METROCHEM) which is responsible for ensuring the traceability of chemical measurements in the Czech Republic. CMI is expected to carry out reference material certification (according to the Law on metrology) and develop special fields (electrochemistry, moisture and protein in grains).     

Spiked and screened oscillatorsV(r) =Ar 2 +B/r 2 +C/r 4 +D/r 6 +F/(1 +Gr)2 and their elementary bound states

We show that the complicated superpositionsV(r) of several important phenomenological forces may still lead to an elementary form of doublets of bound states under transparent algebraic constraints. Constructively, we show how (and when) the constrained couplings preserve compatibility with the physical regularity of wavefunctions.     

Jacobi polynomials and bound states

In their recent note [J. Math. Chem. 16 (1994) 211-215], Simsek and Yalçin claim the elementary exact solvability of an s-wave radial Schrödinger equation with a shifted Pöschl-Teller potential. We re-derive and correct their formulae and weaken their conclusions: Their Jacobi polynomial wavefunctions do not comply with a boundary condition in the origin. After its inclusion, at most a triplet of their quasi-exact bound states may survive, and we have to return to non-polynomial hypergeometric wavefunctions0(r) in general.     

Development of a disposable immunosensor for the detection of human heart fatty-acid binding protein in human whole blood using screen-printed carbon electrodes

An amperometric immunosensor for the rapid detection of human heart fatty-acid binding protein (H-FABP) in whole blood was developed. Due to its rapid kinetics in plasma, H-FABP is a useful biochemical marker for the early assessment of acute myocardial infarction (AMI). A one-step direct sandwich assay in which analyte and alkaline phosphatase (AP) labelled antibody were simultaneously added to the immobilised primary antibody, was employed using two distinct monoclonal mouse anti-human H-FABP antibodies. p-Aminophenyl phosphate was converted to p-aminophenol by AP and the current generated by its subsequent oxidation at +300 mV vs. Ag/AgCl was measured. Total assay time was 50 min and the standard curve was linear between 4 and 250 ngml(-1). The intra- and inter-assay coefficients of variation were below 9%. No cross-reactivity of the antibodies was found with other early cardiac markers and endogenous substances in whole blood did not have an interfering effect. The overall performance of the sensor, wide working range, good precision and specificity demonstrate its potential usefulness for early assessment of AMI.     

Finite element solution of nonlinear elliptic problems

Summary The study of the finite element approximation to nonlinear second order elliptic boundary value problems with mixed Dirichlet-Neumann boundary conditions is presented. In the discretization variational crimes are commited (approximation of the given domain by a polygonal one, numerical integration). With the assumption that the corresponding operator is strongly monotone and Lipschitz-continuous and that the exact solutionuH ¹(), the convergence of the method is proved; under the additional assumptionuH ²(), the rate of convergenceO(h) is derived without the use of Green's theorem.     

Zur Struktur der Dextrane

Zusammenfassung Es wurden die Eigenschaften der in der Tschechoslowakei hergestellten Dextrane mit Hilfe der Perjodatoxydation und Methylierung studiert. Die Resultate, die durch Bestimmung der freiend-Fructose und des Molekulargewichtes ergänzt worden waren, wurden zur Charakterisierung der Verzweigung der Dextrane benützt.Mit 4 Abbildungen     

Modification of flow properties of concentrated lignite dispersions

Concentrated water-based lignite suspensions (pastes) possess unpleasant flow behaviour. Under extrusion-like conditions suspension is rapidly compacted, viscosity rises considerably and flow effectively ceases. Using diluted aqueous solution of carboxymethylcellulose sodium salt as a dispersion medium eliminates this adverse phenomenon and keeps liquid-like flowing of suspension. Moreover, effective dilatant suspension behaviour is transformed to pseudoplastic.