Abstract: A dental prosthetic appliance excellent in adhesion to the oral mucosa is provided. A saponified ethylene-vinyl ester copolymer is used as a material for the dental prosthetic appliance.

Abstract: The refractive, transmissive or diffractive optical elements are made from a ceramic containing one or more oxides of the type X2O3, which is transmissive for visible light and/or for infrared radiation and which has a cubic crystal structure analogous to that of Y2O3. In preferred embodiments X is Y, Sc, In, or a lanthanide element, namely La to Lu, and in particular is Lu, Yb, Gd, or La. Also mixtures of oxides of the type X2O3 with oxides having different stoichiometries, such as HfO2 and/or ZrO2, may be present, as long as the cubic structure of the ceramic is maintained.

Abstract: The optical elements are made from an opto-ceramic material that is characterized by high density, transparency for visible light and IR, high refractive index, high Abbe number and outstanding relative partial dispersion. Mixed oxides are sintered to obtain the opto-ceramic material. The mixed oxides contain zirconium oxide and hafnium oxide mixed with one or more oxides of yttrium, scandium, lanthanide elements, and optionally mixed with one or more of SiO2, Na2O, and TiO2. Alternatively the mixed oxides contain zirconium oxide and hafnium oxide mixed with CaO and/or MgO and optionally mixed with one or more of SiO2, Na2O, and TiO2. In addition, the mixed oxides can also include one or more oxides of Al, Ga, In, and Sc; optionally one or more oxides of yttrium, some lanthanide elements; and optionally one or more of SiO2, Na2O, MgO, CaO, and TiO2.

Abstract: The opto-ceramics and optical elements of the present invention are transmissive to visible light and/or to infrared radiation. They consist of a crystal combination in which individual crystallites have a cubic structure of the type Y2O3 and are made from In2O3 or a mixture of oxides of the type X2O3 in which X=Y, Lu, Sc, Yb, In, Gd, or La. Also mixtures of X2O3 with oxides having different stoichiometries, such as zirconium and hafnium oxide, are possible, as long as the cubic structure of the opto-ceramic is maintained. The optical elements prepared from the opto-ceramics are particularly suitable for mapping optics, such as objectives having reduced chromatic aberrations, in particular with approximately apochromatic mapping behavior. The optical elements of the present invention may be used in lens systems in combination with lenses of glass, but also with other ceramic lenses.

Abstract: The optical elements are made from an opto-ceramic material that is characterized by high density, transparency for visible light and IR, high refractive index, high Abbe number and outstanding relative partial dispersion. Mixed oxides are sintered to obtain the opto-ceramic material. The mixed oxides contain zirconium oxide and hafnium oxide mixed with one or more oxides of yttrium, scandium, lanthanide elements, and optionally mixed with one or more of SiO2, Na2O, and TiO2. Alternatively the mixed oxides contain zirconium oxide and hafnium oxide mixed with CaO and/or MgO and optionally mixed with one or more of SiO2, Na2O, and TiO2. In addition, the mixed oxides can also include one or more oxides of Al, Ga, In, and Sc; optionally one or more oxides of yttrium, some lanthanide elements; and optionally one or more of SiO2, Na2O, MgO, CaO, and TiO2.

Abstract: A boron nitride fiber comprising hexagonal and/or turbostratic boron nitride having C planes oriented substantially parallel to the fiber axis and a degree of orientation of 0.74 or above can be obtained by heating an adduct between a boron trihalide such as boron trichloride or the like and a nitrile compound such as acetonitrile, benzonitrile or the like, and an ammonium halide or a primary amine hydrohalide in the presence of a boron trihalide at around 125.degree. C. to form a boron nitride precursor, dissolving the boron nitride precursor in a solvent such as N,N'-dimethyl formamide or the like, capable of dissolving the precursor, spinning the solution to obtain a boron nitride precursor fiber, heat-treating the precursor fiber in an inert gas atmosphere and then in an ammonia gas atmosphere to obtain a boron nitride fiber, and heat-treating the boron nitride fiber with a tensile stress being applied to the fiber. The boron nitride fiber of the present invention has a degree of orientation of 0.

Abstract: In a system for the transaction operation with terminal units connected to a central unit through the communication line, the transaction operation by use of an ineligible terminal unit is prevented. An illegality preventive information is provided for each terminal unit and stored in each terminal unit and the central unit. When the terminal unit transmits transaction data to the central unit, it also transmits the illegality preventive information registered in it. The central unit carries out the transaction process when the received illegality preventive information coincides with or has a certain relationship to the registered information.

Abstract: A portable terminal device is adapted to effect transaction operation by transmitting and receiving data to and from a central unit. When transaction data is entered, the transactions including the current transaction are accumulated, and when the accumulated transaction exceeds a predetermined limit determined by a preset transaction limiting data, the transaction based on the input data is inhibited.

Abstract: In a system having a central unit, a terminal control equipment and terminal devices connected through communication lines, a transaction operation by an unauthorized terminal device is prevented.Unauthorized use prevention information is registered to each of the terminal devices and the unauthorized use prevention information of the respective terminal devices is registered to the terminal control equipment. The terminal device, when it transmits transaction data to the terminal control equipment, transmits the unauthorized use prevention information of its own. The terminal control equipment compares the received unauthorized use prevention information with the registered unauthorized use prevention information of the corresponding terminal device and, if they are in a predetermined relation, permits the transaction operation.