Minimization of interference effects from iodine-consuming samples in the determination of water with the karl fischer reagent in a flow-injection system

A principal feature of the flow-injection approach for determination of water with the Karl Fischer reagent is the small influence of side reactions. This is confirmed by the determination of water in an iodine-consuming sample, penicillin (fugacillin).     

On a 1-D Model of Stress Relaxation in an Annealed Glass

A 1-D model of a slab of glass of a small thickness is considered. The governing equations are those of the classical 1-D linear viscoelasticity. A load due to the temperature gradients is assumed. The aim is to model the process called annealing. It is shown that an additional load due to structural strain is crucial for the success of the model. Algorithms of a numerical solution of the governing equations are proposed. Numerical results are presented and commented.     

Determination of stability constants of chelate complexes: Part I. Theory

A method for the calculation of the stability constants of chelate complexes from pH and pM values is presented. The method, which is based on a consistent use of side-reaction coefficients, is applicable also to systems containing a large number of complexes. The values of the constants are obtained graphically in a simple way, but in many cases corrections are necessary. Methods of correction are described.     

The Radon-Nikodym theorem for von neumann algebras

Let ϕ be a faithful normal semi-finite weight on a von Neumann algebraM. For each normal semi-finite weight ϕ onM, invariant under the modular automorphism group Σ of ϕ, there is a unique self-adjoint positive operatorh, affiliated with the sub-algebra of fixed-points for Σ, such that ϕ=ϕ(h·). Conversely, each suchh determines a Σ-invariant normal semi-finite weight. An easy application of this non-commutative Radon-Nikodym theorem yields the result thatM is semi-finite if and only if Σ consists of inner automorphisms. Partially supported by NSF Grant # 28976 X. Partially supported by NSF Grant # GP-28737 This revised version was published online in November 2006 with corrections to the Cover Date.     

Numerical modeling of an integrated erbium-doped glass laser

An effective method for determining the laser wavelength, pump-power threshold, and slope efficiency of an integrated erbium-doped glass laser with step index profile is presented. Calculations based on this method show good agreement with experimental results published in the literature. Optimization of the laser wave-guide was also performed.     

Investigations of reactions involved in flameless atomic absorption procedures : Part I. Application of high-temperature equilibrium calculations to a multicomponent system with special reference to the interference from chlorine in the flameless atomic absorption method for lead in steel

In order to study the interference from chlorine in the flameless a.a.s. method for lead in steel, high-temperature equilibrium calculations were applied to a system containing Fe, Pb, C, Cl, S, H, O, N and Ar. The temperatures as well as the input amounts of elements considered could be varied over a wide range, and a survey of the most important parameters governing the system was thereby obtained. The results indicate that a sample must be ashed in the presence of a sufficiently large amount of hydrogen and at a temperature of about 900 K in order to remove the chlorine from the graphite tube. Otherwise, the volatile lead chlorides PbCl₂, and PbCl are formed, which results in a decreased signal from lead.     

Spin relaxation rates in CuFe measured by neutron scattering

The absolute value and the temperature dependence of the spin relaxation rate of the Kondo system $\text{Cu}$Fe has been deduced from the magnetic scattering of unpolarized neutrons with energy analysis.