Abstract: There is provided an enzymatic method of rapid quantitative assay for 1,5-anhydroglucitol which is also applicable to an automated analysis device. The enzymatic method of quantitative assay for 1,5-anhydroglucitol is characterized by using a pyranose oxidase derived from Basidiomycetous fungi No. 52 as a pyranose oxidase. According to the assaying method of the present invention, assay for 1,5-anhydroglucitol in a specimen can be performed using an automated analysis device, results in rapid assay and improved accuracy.

Abstract: Optical surge preventing systems and methods for rare earth-doped optical fiber amplifiers are disclosed. The systems are so arranged as to cause any signal existing in a doped fiber section so as not to over excite the rare earth elements in the doped fiber section. In one embodiment, a background signal light with such a wavelength as to cause induced emission in the doped fiber section is always coupled into the doped fiber section regardless of whether a message signal light exists or not. The background signal light may be generated by any suitable light source or a light spontaneously emitted from either end of the doped fiber section. In another embodiment, a dummy signal light is coupled into the doped fiber section if the level of the message signal light becomes less than a predetermined value. Coupling of the background signal light or the dummy signal light into the doped fiber section may be done from either of the message signal input and output sides.

Abstract: A method of measuring the total ketone body in a sample comprising converting acetoacetic acid in the sample to 3-hydroxybutyric acid in advance and subsequently converting the whole 3-hydroxybutyric acid including 3-hydroxybutyric acid existing in the sample originally to acetoacetic acid to lead the reduction of nicotinamide adenine dinucleotide according to the action of 3-hydroxybutyrate dehydrogenase and a sample reagent thereof is disclosed. According to this invention an assay of the total ketone body in samples can be carried out conveniently, highly precisely and quickly.

Abstract: An electric field sensor comprises an electric field sensor head (3) for varying an intensity of a propagating light beam in response to an electric field intensity of an input signal received by a reception antenna (1). The electric field sensor head (3) comprises an incident optical waveguide (9), two phase-shift optical waveguides (10) having a variable refractive index which varies in response to the electric field intensity, an outgoing optical waveguide (11) and, at least one modulation electrode (12) formed in the vicinity of at least one of the two phase-shift optical waveguides (19). The electric field sensor further comprises a circuit element (2) connected between the modulation electrode (12) and the reception antenna (1). The modulation electrode (12) has a thickness not smaller than 1 .mu.m. The modulation electrode (12) may comprise a plurality of split electrodes which are split in a light propagating direction and which are capacitively coupled.

Abstract: There is provided a method of quantitative assay for 1,5-anhydroglucitol in a specimen characterized by effectively removing maltose present in the specimen using .alpha.-glucosidase. Maltose present in a specimen is previously converted into glucose by the action of .alpha.-glucosidase derived from a microorganism belonging to the genus Bacillus to remove the affect by maltose. Then 1,5-anhydroglucitol in the specimen is quantitatively determined.

Abstract: A quantitative assay for 1,5-anhydroglucitol in a specimen is described. This assay comprises treating a specimen with a phosphorylating enzyme in the presence of 5 to 500 mM adenosine-5'-triphosphate in a pH range of 7.2 to 8.5, to selectively eliminate sugars other than 1,5-anhydroglucitol, and reacting the product of this reaction, without removing the residual ATP, with pyranose oxidase in the above pH range. This assay is quite rapid and suitable for performance using an automated device.

Abstract: A single transmission line bidirectional optical communication system comprising a directional coupler employing a polarizing beam splitter, an optical transmitting circuit for coding the data and converting the coded data into optical signals and outputting said signals, an optical receiving circuit employing a comparator having a function of automatically establishing a threshold for converting optical input signals into electrical signals and then decoding the data, a circuit for detecting the frequency differences between the sending signals and receiving signals, and a line diagnosing circuit.The polarizing beam splitter eliminates a near-end reflected beam, and the optical receiving circuit having a function of automatically establishing a threshold eliminates a remote-end reflected beam. The line diagnosing circuit diagnoses the line condition by comparing the sending frequency and receiving frequency.

Abstract: A noise simulator including a reflection absorbing circuit connected between a high-frequency noise pulse generator based on the principle of a charged delay line and a DC capacitor connected to the power line of the equipment under test. The reflection absorbing circuit is composed of a parallel resistor and a series resistor. The resistances of these resistors are determined so that the impedance at the input side of the reflection absorbing circuit in a condition that a predetermined standard impedance connected thereto is equal to the output impedance of the generator and that the impedance at the output side of the reflection absorbing circuit in the condition that the generator is connected thereto is equal to the predetermined standard impedance. A grounded electric conductor plate is movably disposed commonly adjacent to the series resistor and the DC-cut capacitor to adjust the stray capacitance prior to use for noise simulation.

Abstract: A simulated-noise signal is injected in the power line of equipment under test without loss of AC power by the use of a series resonance circuit having a resonance frequency equal to the frequency of the AC power supply. The series resonance circuit is connected in the power line in parallel with the equipment, and a capacitor is connected to the power line in parallel with the series resonance circuit and the equipment. A switching element is used to short-circuit the resonance circuit when noise simulation is not carried out. For the simulation of lightening strikes the circuit further comprises a simulated-noise signal generator including a capacitor charged by a DC power supply, a first switching element to discharge the charge of the capacitor to the equipment, and a second switching element for establishing a by-pass of the discharging current. By closing the second switching element after the first switching element is closed, a square-wave signal is fed to the equipment.