A multi-element analyser with a small mass spectrometer as detector

Summary An instrument for the simultaneous determination of up to eight elements in organic material is described. A few milligrams of the sample are rapidly burnt in a stream of oxygen with platinum gauze serving as a catalyst. A small fraction of the combustion gases is directly fed into a simple quadrupole mass spectrometer which, by rapid scanning, monitors twelvem/e values of interest. With the aid of a multiplexer the signals are individually integrated and the results are directly printed in percentages. The whole procedure takes about 2 min. The method has been successfully applied to samples containing the elements carbon, hydrogen, nitrogen, sulphur, fluorine, chlorine, bromine and iodine. The relative precision is in the order of a few percent.

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Multielement-Analysator mit kleinem Massenspektrometer als Detektor

Zusammenfassung Ein Gerät zur gleichzeitigen Bestimmung von bis 8 Elementen in organischen Substanzen wird beschrieben. Einige Milligramm werden schnell in einem Sauerstoffstrom mit Pt-Gaze als Katalysator verbrannt. Ein kleiner Teil der Verbrennungsgase wird direkt in ein einfaches Quadrupol-Massenspektrometer eingegeben, das 12 interessierendem/e-Werte erfaßt. Mit einem Multiplexer werden die Signale einzeln integriert und die Ergebnisse direkt in Prozent ausgedruckt. Die gesamte Operation erfordert 2 min. Das Verfahren wurde erfolgreich für Proben mit Gehalten an C, H, N, S, F, Cl, Br und J angewandt. Die relative Genauigkeit liegt in der Größenordnung einiger Prozente.

Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9. 1972 in Heidelberg, Germany.     

Initial Segments in Rogers Semilattices of \Sigma _n^0 -Computable Numberings

S. Goncharov and S. Badaev showed that for , there exist infinite families whose Rogers semilattices contain ideals without minimal elements. In this connection, the question was posed as to whether there are examples of families that lack this property. We answer this question in the negative. It is proved that independently of a family chosen, the class of semilattices that are principal ideals of the Rogers semilattice of that family is rather wide: it includes both a factor lattice of the lattice of recursively enumerable sets modulo finite sets and a family of initial segments in the semilattice of -degrees generated by immune sets.     

Pseudo-Anosov Flows and Incompressible Tori

We study incompressible tori in 3-manifolds supporting pseudo-Anosov flows and more generally ZZ subgroups of the fundamental group of such a manifold. If no element in this subgroup can be represented by a closed orbit of the pseudo-Anosov flow, we prove that the flow is topologically conjugate to a suspension of an Anosov diffeomorphism of the torus. In particular it is non singular and is an Anosov flow. It follows that either a pseudo-Anosov flow is topologically conjugate to a suspension Anosov flow, or any immersed incompressible torus can be realized as a free homotopy from a closed orbit of the flow to itself. The key tool is an analysis of group actions on non-Hausdorff trees, also known as R-order trees – we produce an invariant axis in the free action case. An application of these results is the following: suppose the manifold has an R-covered foliation transverse to a pseudo-Anosov flow. If the flow is not an R-covered Anosov flow, then it follows that the manifold is atoroidal.     

On a Theorem of Holický and Zelený Concerning Borel Maps Without σ-Compact Fibers

The paper is concerned with a recent very interesting theorem obtained by Holický and Zelený. We provide an alternative proof avoiding games used by Holický and Zelený and give some generalizations to the case of set-valued mappings.     

Induced product representations of extended Cuntz algebras

Let _H be the extended Cuntz algebra over the Hilbert space H. Since its zero grade part _H⁰ is the C^*-inductive limit of B(H^r), we look for some family of representations on an inductive limit of H^r as r. When such construction is shaped according to the structure of _H⁰, von Neumanns notion of a reference sequence of unit vectors for Hilbert infinite tensor products emerges; after a further Rieffel induction step, a class IPR[H] of representations of _H arises. For any two such representations, we describe explicitly their associated intertwiners. Any two representations in IPR[H] are either disjoint or unitarily equivalent. Actions of the group by translation on sequences of unit vectors are involved, as well as the ideals of .     

On ＂Problems on von Neumann Algebras by R. Kadison, 1967＂

A brief summary of the development on Kadison‘s famous problems (1967) is given. A new set of problems in von Neumann algebras is listed.     

The Generalized Chern Character and Lefschetz Numbers in W*-Modules

We define N-theory as being an analogue of K-theory on the category of von Neumann algebras such that K ₀(A)N ₀(A) for any von Neumann algebra A. Moreover, it turns out to be possible to construct the extension of the Chern character to some homomorphism from N ₀(A) to an even Banach cyclic homology of A. Also, we define generalized Lefschetz numbers for an arbitrary unitary endomorphism U of an A-elliptic complex. We study them in the situation when U is an element of a representation of some compact Lie group.     

Molecular structure of N-(2-phenylethyl)amide of α-(1,1-ethylenedioxy)-ethyl γ-hydroxybutyric acid (I) and1H NMR spectra of (I) and N-(p-methoxybenzyl)derivative (III)

The spectroscopic and X-ray investigation of the N-(2-phenylethyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are reported. The¹H NMR spectra for the title structure and for the N-(p-methoxybenzyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are given. The N-(2-phenylethyl)amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid, C₁₆H₂₃O₄N, crustallizes in the monoclinic space groupP2 ₁/c witha=21.547(5),b=6.333(2),c=11.822(3) Å and =101.01(2)°. The dioxolane ring has a half-chair conformation with C₂(O3)=2.4° and ||_av=18.2°. The inconsiderable deviations from planarity of the six atoms of the amide group are caused mainly by twist around the C4–N1 bond and out-of-plane bending at the N1 atom ((C4–N1)=4°, X_N =7°, X_c =0.4° ). The amide group plane is nearly coplanar with the phenyl ring. The molecules are connected by two intermolecular hydrogen bonds.