Insight into the chemical reaction of CH2OH with NO: Formation of N-hydroxy formamide as an isocyanic acid precursor

This study has explored the potential energy surface on the chemical reaction of CH₂OH with NO by using ab initio calculation. We have found the new reaction pathway producing N-hydroxy formamide, which can further decompose to generate isocyanic acid as a reducing agent of hydrocarbons selective catalytic reduction.     

Improvement of the technology for obtaining pigment-free brightly colored glazes

A new method of coloring glazes is proposed on the basis of improvements in the technology for obtaining brightly colored glass coatings. The method consists of a complex of physical-chemical processes (adsorption, ion-exchange, and precipitation) which already occur at the stage of preparation of the glaze slips, containing water-soluble salts of variable-valence metals, which imparts intense and uniform color and high-quality to calcined glass coatings. __________ Translated from Steklo i Keramika, No. 3, pp. 21–22, March, 2007.     

Soft decision decoding of block codes using received signalenvelope in digital mobile radio

The codeword error rate (WER) performance of noncoherent frequency-shift keying with soft decision decoding of block codes using Chase's second algorithm (1972) is investigated in a Rayleigh fading channel. The received signal envelope is sampled and used as channel measurement information. The theoretical upper and lower bounds of the WER are derived, assuming independent Rayleigh envelope samples in a received block. When the Golay (23, 12, 7) code is used, soft decision decoding with 6-bit error correction capability (3-bit error and 3-bit erasure) requires an average signal-to-noise power ratio about 5 dB lower than that for minimum distance decoding with 3-bit error correction to obtain a WER=10^-3. The effects of bit interleaving on the WER performance when fading envelope variation is slow compared to the bit rate are investigated through computer simulations     

Solid-solid reactions in the Ca3(AsO4)2-Ca2SiO4-CaSO4 ternary system at elevated temperatures

Exploratory laboratory-scale tests were performed in order to identify the solid phases present in the Ca₂SiO₄-Ca₃(AsO₄)₂ binary system and in the Ca₂SiO₄-Ca₃(AsO₄)₂-CaSO₄-CaO system. A microanalysis study from slow-cooled samples suggests the presence of at least two intermediate phases. These compositions correspond to Ca₅(AsO₄)₂(SiO₄) (1:1) and Ca₈(AsO₄)₄(SiO₄) (1:2). The formation of stable intermediate salts with high melting points is of significant industrial interest in copper converting operations. If excessive amounts of solids form, skimming problems or poor slag-metal separation may become problematic.     

Development of sealing compositions with nanostructure iron-based fillers

The possibility of utilizing nanopowders of iron and Fe-Co-Ni produced bu a thermochemical method in the fabrication of sealing composition materials is investigated. It is established that such hermetic sealing composition materials function reliably under extremal conditions and guarantee elevated strength of adhesion to the surface of the metal and high corrosion and temperature stability. __________ Translated from Poroshkaya Metallurgiya, Nos. 3–4(448), pp. 112–117, March–April, 2006.     

SED88: a Pascal program for the analysis of sedimentation equilibrium data

Analytical ultracentrifugation is commonly used for the determination of molecular weights (sedimentation equilibrium) and sedimentation coefficients (sedimentation rate) of biological macromolecules in solution. A Turbo Pascal program for the analysis of sedimentation equilibrium centrifugation data produced by absorbance optical systems is described. The user may enter data from a scan of absorbance versus distance from the centre of rotation, via a graphics tablet (or ASCII file). This is subsequently manipulated to yield an apparent weight average molecular weight for the given sample. Plots of ln (absorbance) versus (radius2) may also be produced. The method described uses readily available computational equipment requiring only a graphics tablet in addition to an IBM PC compatible computer. This technique and the software developed have been used to investigate the molecular weight range of two International Humic Substances Society (IHSS) reference samples from the Suwannee River.