Walter A. Frank

Learn More
In this paper we describe a noise reduction preprocessing algorithm for the adaptive multirate (AMR) speech codec of the GSM system. The algorithm is based on spectral weighting and explicitly takes into account the properties of the human auditory system. The weighting rule results in the smallest possible speech distortion under the constraint that the(More)
The asymmetric unit of the title mol-ecular salt, [C5H7N2+][(HO)2OP(CH2)9PO2(OH)-], consists of one 4-amino-pyridinium cation and one hydrogen (9-phos-phono-non-yl)phospho-nate anion, both in general positions. As expected, the 4-amino-pyridinium moieties are protonated exclusively at their endocyclic nitro-gen atom due to a mesomeric stabilization by the(More)
The title compound, [Al(H(2)O)(6)](CH(3)SO(3))(3) (common name: aluminium methane-sulfonate hexa-hydrate), was crystallized from an aqueous solution prepared by the precipitation reaction of aluminium sulfate and barium methane-sulfonate. Its crystal structure is the first of the boron group methane-sulfonates to be determined. The characteristic building(More)
Single crystals of the title compound, (imidazolium-2-yl)phenyl-phosphinate monohydrate, C(9)H(9)N(2)O(2)·H(2)O, were ob-tained from methanol/water after deprotection and oxidation of bis-(1-diethoxy-methyl-imidazol-2-yl)phenyl-phosphane. In the structure, several N-H⋯O and P-O⋯H-O hydrogen bonds are found. π-π inter-actions between the protonated(More)
  • George Bekefi, Abraham Bers, Flora Y F Chu, Bruno Coppi, Thomas H Dupree, Elias P Gyftopoulos +94 others
  • 2009
Introduction In order to produce negative hydrogen or deuterium ion beams, the output of a positive ion source must undergo charge exchange with neutral atoms such as cesium. The maximum efficiency of this process is 217 for 800-eV H + interacting with cesium.1 It has been suggested that by optically exciting the cesium, the efficiency can be improved. 2(More)
SINGLE CRYSTALS OF THE NEW TITLE COMPOUND [SYSTEMATIC NAME: 1,4,7,10-tetra-zoniadecane hexa-chloridorhodate(III) chloride], [H(3)N(CH(2))(2)NH(2)(CH(2))(2)NH(2)(CH(2))(2)NH(3)][RhCl(6)]Cl, were obtained from the corresponding amine and rhodium trichloride in hydro-chloric acid solution by slow crystallization under diffusion-controlled conditions at room(More)