Comments on "Determination of matrix transfer function in the form of matrix fraction from input-output observations"

-Furuta and Paquet have proposed an algorithm for determining coefficients of an input-output relation from input-output observations. The purpose of this note is to point out that these coefficients can be obtaiined by a simpler algorithm which requires less computation and that there are other algorithms for minimal realization from these coefficients.     

Solid Solubility of Aluminum and Boron in Silicon Carbide

Solid solubility of aluminum in silicon carbide was studied by the powder X-ray diffraction technique (Debye-Scherrer method). At 2200° C the solubility limit was 1.0 wt%. Measurements of the lattice parameter of Al-saturated samples as a function of temperature gave a heat of solution of 147 kJ/mol. The change in the lattice parameter indicates that Al substitutes for Si. Literature data are interpreted as indicating that B replaces both Si and C.     

Design and Performance of a DSI Terminal for Domestic Applications

The development of a microprocessor-controlled 96/48 DSI terminal is described. The terminal is intended for domestic use, and is designed so as to maximize compatibility with existing digital carrier systems, it merges four T1 signals into two T1 compatible bit streams for transmission. The terminal is given sufficient excess capacity to accommodate voiceband data, while retaining toll-grade transmission quality for speech. Implementation approaches and considerations in both calculated and measured system characteristics are described.     

Electrodeposition of high purity manganese from low temperature (∼ −16° C) chloride electrolyte

Electrolytic manganese (99-98% purity and sulphur) is commercially produced by using sulphate electrolyte at 35° C with the addition of sulphur compounds at current efficiencies of about 60–65%. In the present investigations, adherent, compact and higher purity manganese was obtained by electrolysis in manganese chloride solutions at lower temperature (–16° C) without any additives such as sulphur or selenium compounds. A basic study was made to determine the current efficiency of deposition from low temperature chloride electrolytes. Factors affecting the process were: bath temperature, current density, ammonium salt concentration, pH and time of deposition. It was concluded that the electrodeposition of high purity manganese from low temperature chloride electrolyte was feasible. From a comparison between the MnCl₂-NH₄SO₃NH₂ and MnCl₂-NH₄Cl systems adopted, it was shown that the former had the advantage over the latter in its higher current efficiency (87% against 84%) below –8° C, while the latter was superior to the former with regard to its wider range of optimum current density (1–4 A dm^–2). The process may be used with advantage when high purity and ductile manganese free of impurities such as sulphur is required and when cooling of the bath is not an important and economic consideration.     

Localized nature of the luminescence during galvanostatic anodizing of high purity aluminium in inorganic electrolytes

Luminescence during galvanostatic anodizing of high purity aluminium containing Fe, Si and Cu as major impurities in inorganic electrolytes, typically an aqueous solution of ammonium borate, was found to be a local phenomenon which takes place at “flaws” in the growing oxide film. The intensity of the luminescence was found to be closely correlated to the concentration of “flaws” in the film: the intensity of the luminescence being roughly proportional to the concentration of “flaws” in the film. Rough estimate of the concentration of ”flaws“ in the film formed on “as received”, “chemically cleaned” and “electropolished” aluminium plate was 2 × 10⁸.3 × 10⁷ and 10⁵/cm², respectively. Any mechanism deeming the luminescence to be an electroluminescence in a homogeneous oxide with the collision excitation of the impurities or with the recombination at impurity centres has been rejected.     

Analysis of air pollution and prevalence rate of allergic diseases among elementary school children in Kawaguchi and Hatogaya city

Kawaguchi and Hatogaya City are located on the northern edge of Tokyo. We analysed between air pollution and prevalence rate of allergic diseases among elementary school children in this area. A prevalence rate of allergic diseases in 1996 May and June was as follows; bronchial asthma 13.5%, atopic dermatitis 24.5%, allergic rhinitis and/or conjunctivitis 22.8%, urticaria 12.4%, food allergy 7.8% and drug allergy 2.2%, respectively. Air pollution of this area was analysed to check the levels of nitrogen dioxide (NO2), sulfur dioxide (SO2) and suspended particulate matters (SPM). NO2 pollution was relatively high in urban area, and SPM pollution was especially high around the highways. SO2 pollution was lower than the environmental standard. No relationship was found between the prevalence rate of bronchial asthma, atopic dermatitis, allergic rhinitis and/or conjunctivitis and air pollution, but it was found that these diseases are slightly related to population density (p < 0.1, p < 0.01, p < 0.1, respectively).