Crystal and molecular structure of [N N′-(3,3′-dipropylamine)-bis(salicylideneaminato)monoacetate]cobalt(III) complex

The crystal and molecular structure of [N,N′-(3,3′-dipropylamine)bis(salicyclideneaminato)-monoacetate]cobalt(III) complex has been determined by a three-dimensional X-ray diffraction study. In the complex, the cobalt ion has an octahedral coordination environment with cis-geometry for the two salicyclideneaminato moieties. An oxygen atom of the acetate ion is coordinated to cobalt ion and another oxygen atom is hydrogen-bonded to the secondary amine nitrogen atom.     

A method for determining the relaxation spectrum from the decay curve of electric birefringence of macromolecular solutions

Summary A numerical method for determining the distribution function of relaxation times from the decay curve of electric birefringence in macromolecular solutions has been described. The distribution function is expanded in a series of appropriate functions, and the best values of the coefficients are determined by the method of least squares. An application of this method to poly-Lglutamic acid in methanol is presented. It is shown that the distribution of molecular lengths can be obtained from the relaxation spectrum in the case of helical polypeptides in solution.

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Zusammenfassung Es wird eine numerische Methode beschrieben, die die Relaxationszeit-Verteilungsfunktion aus der Abklingkurve der elektrischen Doppelbrechung bei makromolekularen Lösungen zu bestimmen erlaubt. Die Verteilungsfunktion wird in eine Reihe geeigneter Funktionen entwickelt und die besten Werte der Koeffizienten werden nach der Methode der kleinsten Quadrate bestimmt. Eine Anwendung dieser Methode zur Poly-L-glutaminsäure in Methanol-Lösung wird exemplifiziert. Es zeigt sich, daß die Verteilung von Moleküllängen im Falle helicaler Polypeptide aus dem Relaxationsspektrum gewonnen wird.

     

Decoding performance of linear block codes using a trellis indigital mobile radio

Trellis decoding of linear block codes in a Rayleigh fading channel is discussed. Two methods for calculating metric values for each bit in a received block are considered: the values are calculated from the received signal envelope sample and from the demodulator output. Bit error rate (BER) performances of hard decision and trellis decoding are compared using Hamming (7, 4) and Golay (24, 12) codes in computer simulations and laboratory experiments. A simplified trellis decoding algorithm, in which the hard decision output of a bit with an envelope sample greater than the threshold value is accepted as correct, is presented. Laboratory experimental results for trellis decoding in combination with Gaussian minimum-shift-keying (GMSK) modulation and frequency detection are shown. The effect of n-bit A/D-conversion in signal envelope sampling is investigated experimentally. The results show that the trellis decoding algorithm improves BER performance     

The development of grain-oriented silicon steel with high permeability

We explain the theoretical background, uses and new development of grain-oriented silicon steel with high permeability using A1N as a grain growth inhibitor.New production techniques have made it possible to get superior core loss values; for example, 0.99 W/kg at 1.7 Tesla and 50 Hz (0.30 mm thickness). The presence of A1N precipitated being controlled in the size of about 300 Å or under and in adequate distribution and quantity in the steel is very important for developing secondary grains with high permeability.Core loss improvements on actual transformers using high permeability materials are approximately 10–25% in wound type pole transformers and 5–20% in laminated type large transformers.