A specific gas chromatographic method for the determination of microsomal styrene monooxygenase and styrene epoxide hydratase activities.

A gas chromatographic (GC) method for the determination of the metabolite resulting from the activities of microsomal styrene monooxygenase (epoxide synthetase) and epoxide hydratase using styrene or styrene epoxide as substrates has been developed. The determination of the activities of both enzymes is based on the GC determination of phenylethylene glycol after its esterification with n-butylboronic acid. Kinetic parameters for both enzymes are given.     

Construction of representations of the Poincaré Lie algebra by extension of direct integrals of representations ofSL(2,C)

Summary Continuing the program initiated in the first paper of this series, representations of the Lie algebra of the Poincaré group are constructed by forming suitable direct integrals of representations of SL(2, C) and extending them to by means of four additional momentum operators whose matrix elements are derived in a basis adapted to the direct integral structure. The representations obtained here include Wigner’s representations with positive mass and spin and Wigner’s representations with zero mass, spin and helicity ± . Lavoro eseguito con contributo del C.N.R. nell’ambito dell’attività di ricerca del Gruppo Nazionale per la Fisica Matematica e per le applicazioni della Matematica alla Fisica ed all’Ingegneria. Entrata in Redazione il 12 marzo 1972.     

A nonsmooth optimization problem in envelope constrained filtering

In envelope-constrained filtering, the filter is optimized subject to the constraint that the filter response to a given signal lies within a specified envelop or mask. In this note, we develop an efficient method for solving a class of nonsmooth optimization problems which covers the envelope- constrained filtering problem as a special case.     

Pressure effects in the kinetics of cw laser induced reactions

Rate constantsk and translational temperaturesT have been determined for the decompositions of ethyl acetate and perfluorocyclobutane at various pressures induced by a continuous (cw) CO₂ laser. Arrhenius plots give activation energies in good agreement with those reported for thermal rate constantsk ₁. The ratiosk/k ₁ become progressively larger than unity with decreasing reactant pressure, indicative of laser induced non-thermalization, but the values ofk/k _t appear to reach limiting values at low pressures, similar to effects reported elsewhere for CH₃CF₂Cl. Analysis of the data suggests important general features of vibrational-translational energy transfer in polyatomic compounds.     

Kneelike structure in the spectrum of the heavy component of cosmic rays observed with KASCADE-Grande

We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×10(16) eV. This structure is also seen in the all-particle energy spectrum, but is less significant. Whereas the "knee" of the cosmic ray spectrum at 3-5×10(15) eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 10(16) to 10(18) eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.