Improvement of the Froissart-Martin bound for complex scattering angles

Extension of the Froissart-Martin bound for complex scattering angles is improved using the solution of the Dirichlet boundary value problem for doubly connected domain. The Froissart-Martin bound for physical scattering angles is used as input value on one of the two boundaries. The obtained bound is valid in an ellipse smaller than the Lehmann-Martin one. Possiblities of further improvements and applications are discussed. Details will be published elsewhere (Chaichian M., Fischer J., Nelipa N. F.,Vrko I. Preprint of the University of Helsinki, HU-TFT-81-22, to be published).Abstract of the paper presented at the International Symposium Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 14–19, 1981.     

Selectrode—the universal ion-selective electrode : Part VII. A valinomycin-based potassium electrode with nonporous polymer membrane and solid-state inner reference system

A potassium electrode utilizing a solution of valinomycin in diphenylether and a porous membrane is compared with selectrodes in which the diphenylether has been replaced by a suitable plasticizer and the porous membrane support by a polymer net-work. The development of the polymer membrane allows the use of simplified selectrode construction with a “solid-state” calomel reference system; Rules for a successful choice of a suitable solvent-polymer combination are suggested and used for development of new Polyvinylchloride- and polyurethane-based membranes.     

Study of radioactive labelled chromium (III) ion adsorption on stearic acid monomolecular layer

A study of chromium(III) ion adsorption on a stearic acid monomolecular layer (MML), spread on the surface of a⁵¹CrCl₃ aqueous solution, is presented. From the analysis of the experimental results it can be concluded that MML saturation is achieved at CrCl₃ concentrations above 10^?6M. When the maximum adsorption pH value of Cr(III) ions on MML is 6.7, MML is completely ionized and chromium ion is bonded as Cr(OH) ₂ ⁺ . The kinetics of Cr(III) ion adsorption on MML could be expressed as A^S=A _∞ ^S (1?e^{?k t}).     

Palladium extraction from nitrate solutions by tertiary amines and quaternary ammonium salts

The mechanism of palladium extraction by trilaurylamine and trilaurylmethylammonium nitrate from nitric acid solutions was studied. The composition of the extracted compounds was determined by the Job method as well as by organic phase saturation. Both reagents were found to extract palladium as Am₂Pd/NO₃/₄ /Am=ammonium cation/.     

pH-dependent electrochemical behaviour of hydrophilic ampholytic membranes

Ampholytic membranes were synthesized by copolymerizing (2-hydroxyethyl)methacrylate as the hydrophilic component, methacrylic acid and (N,N-diethylaminoethyl)methacrylate as ionogenic components (both ionogenic monomers in amounts 2.5 mol% or 10 mol%), and ethylenedimethacrylate as the crosslinking agent (3,5 or 10 mol%). The effects of pH on the swelling and membrane potentials of the membranes were investigated. The dependence of the membrane potentials on pH is characterized by the position of the isoelectric point and by the slope of the straight part of the dependence. This slope reflects the attained degree of ideality of the membrane. By varying the degree of cross linking and the content of ionogenic components, it is possible to vary the pH-dependent response of the membranes.     

Analytische Bestimmung von Niob,Tantal, Phosphor,Chlorid und 2,2-Dipyridyl in einigen Komplexverbindungen

Zusammenfassung Die analytische Bestimmung der Metalle, des Dipyridyls und der Chloride in Oxo-chloro-alkoxo-dipyridyl-Komplexverbindungen des Niobs und Tantals wurde beschrieben. Eine modifizierte Methode der Dipyridylanalyse, wie auch der Chloridbestimmung in Gegenwart von Dipyridyl wurde angegeben. Die radiometrische Metallbestimmung in Extraktionsverbindungen von Niob und Tantal mit Di-oktyl-methylenbis-phosphonsäure wurde dargelegt.

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Summary The analytical determination of metals, dipyridyl and chlorides in oxochloro-alkoxo-dipyridyl complex compounds of niobium and tantalum is described. A modified procedure of the dipyridyl analysis and also of the determination of chloride in the presence of dipyridyl is given. The radiometric determination of the metals in extraction compounds of niobium and tantalum with di-octyl-methylene-bis-phosphonic acid is discussed.

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Résumé On décrit le dosage des métaux, du dipyridyle et des chlorures dans les composés complexes oxo, chloro, alcoxo, dipyridyle, du niobium et du tantale. On indique une méthode modifiée pour le dosage de dipyridyle ainsi que pour la détermination des chlorures, en présence de dipyridyle. On décrit le dosage radiométrique des métaux dans les produits d'extraction du niobium et du tantale par l'acide di-octyl-méthylène-bis-phosphonique.

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Vorgetragen beim Symposium für analytische Chemie in Graz, 29. September bis 1. Oktober 1965.     

Kinetic determination of ultramicro amounts of copper

A new catalytic reaction is proposed and a kinetic method developed for the determination of ultramicro amounts of Cu(II) on the basis of its catalytic activity in oxidation of the 2-thiosemicarbazone of sodium 1,2-naphthoquinone-4-sulphonate by hydrogen peroxide in the presence of ascorbic acid. Under optimal conditions the sensitivity of the method is 0.25 ng/ml. The relative error is 4.8-18.2% for the concentration range 5-0.8 ng/ml. Most foreign ions do not change the rate of the catalysed reaction. Co(2+) and I(-) catalyse the reaction, Ni(2+) extensively inhibits it, and in the presence of EDTA only the uncatalysed reaction takes place.     

Laser properties of YAG : Nd grown from the melt contained in molybdenum crucibles

YAG:Nd grown from the melt using resitance furnace and molybdenum crucibles were compared with those grown by conventional method using r.f. heating and iridium crucibles. The former were succesfully grown in 98% Ar + 2% H₂ protective a mosphere using an excess of Y₂O₃ in the melt and after it annealed in an oxidizing atmosphere followed by treatment in hydrogen to reach the material with minimum losses. Laser rods machined from such crystals, showed nearly the same properties as those prepared by conventional method.     

Eine kennzeichnende Eigenschaft der Zykel der Galileischen Ebene

Ohne Zusammenfassung     

Non-destructive measurement of the mobility in semiconductors by means of the microwave Faraday effect

The paper describes the measurement of the electron mobility in semiconducting plates placed between two cylindrical antennas with diameterd–0·75 ₀ by means of the microwave Faraday effect. This system enables (i) to measure the Faraday rotation in semiconducting plates of arbitrary transverse dimensions, greater or at least equal to the diameter of dielectric antennas, (ii) to evaluate the unknown value of the charge carrier mobility from the measured rotation in an unbounded solid state plasma slab approximation. The measurement of the Faraday rotation in n-type Ge plates are reported. The comparison of the experimental data with the theory shows good agreement.