Abstract: A magnetostrictive torque sensor comprising a first magnetostrictive film, a second magnetostrictive film, and a third magnetostrictive film formed over the entire circumferential periphery of a surface of a rotating shaft. A first sensor coil, a second sensor coil, and a third sensor coil for sensing changes in impedance are provided for the first, second, and third magnetostrictive films, respectively. Signals according to the changes in impedance outputted from the first through third sensor coils are inputted to a torque calculating unit. The torque calculating unit calculates the torque applied to the rotating shaft on the basis of the output signal from the first sensor coil and the output signal from the second sensor coil. Furthermore, the output signals from the first through third sensor coils are compared, and failures in the first magnetostrictive film or the second magnetostrictive film are detected by a failure detector.

Abstract: A process for producing an aliphatic polyester by subjecting a cyclic ester to ring-opening polymerization, which comprises adding water to a cyclic ester purified to the extent that a water content is at most 60 ppm to control an overall proton concentration in the cyclic ester, thereby controlling at least one physical property among melt viscosity, molecular weight and yellowness index of the resulting aliphatic polyester.

Abstract: The invention provides a polyester production process by bulk polymerization in a reactor, wherein the volume of the resulting polyester is shrunk for a release from the inner surface of the reactor, so that the polyester can be recovered in the form of a bulky mass. The invention also provides a reactor for bulk polymerization for polyester, which comprises an inner surface that enabling the resulting polyester to be released therefrom upon its volume shrinkage.

Abstract: For forming an annular magnetostrictive coat on an outer peripheral surface of a rotational shaft associated with a magnetostrictive torque sensor, a magnetostrictive-coat forming method comprises a step of fitting a cylindrical masking jig over the outer peripheral surface of the rotational shaft and securing the masking jig to the outer peripheral surface, a step of placing the rotational shaft in a plating tank to thereby form the magnetostrictive coat by plating on the outer peripheral surface, and a step of detaching the masking jig from the rotational shaft.

Abstract: The invention provides a polyester production process by bulk polymerization in a reactor, wherein the volume of the resulting polyester is shrunk for a release from the inner surface of the reactor, so that the polyester can be recovered in the form of a bulky mass. The invention also provides a reactor for bulk polymerization for polyester, which comprises an inner surface that enabling the resulting polyester to be released therefrom upon its volume shrinkage.