Abstract: The invention provides a light oil composition that does not cause deterioration in a Nylon-based material. Specifically, the invention provides a light oil composition containing paraffin(s) at a concentration of 97% by mass or more, wherein the content of isoparaffin(s) having 14 or fewer carbon atoms in the paraffin(s) is 10% by mass or less.

Abstract: Light oil for reduced particulate emission which minimizes both the SOF and ISF of particulate matter emitted from a diesel engine is provided. The light oil for reduced particulate, (especially reduced SOF) emission comprises hydrocarbons, with the content of the distillation residue at 320° C. being 3% by volume or less in a distillation test according to ASTMD86-90. The light oil for reduced particulate (especially reduced soot) emission comprises straight chain paraffin, wherein when hydrocarbons except straight chain paraffin are mainly composed of branched chain paraffin and/or naphthene, their contents are 2% by volume or less, and when hydrocarbons except straight chain paraffin in the fuel are mainly composed of aromatics, their contents are 1% by volume or less.

Abstract: A solute and a solvent with close boiling points or close polarities are separated and concentrated by vaporizing at least one of the solvent and solute, and selectively adsorbing the vaporized component in an apparatus having a vessel, and an absorbent with an opening into the vessel.

Abstract: A low noise amplifier, comprising a grounded emitter transistor amplifier having a parallel impedance element connected between base and collector and a series impedance element connected between emitter and ground. The parallel impedance element is selected to have a pole near a zero of the series impedance element, and the parallel impedance element also has a zero near a pole of the series impedance element. The impedances of the series impedance element and of the parallel impedance element vary oppositely with respect to frequency, so that the input impedance of the amplifier is constant with respect to frequency. However, by selection of two impedances which are thus matched, the gain is increased at high frequencies and slightly reduced at low frequencies. Thus, the total noise figure is improved, due to the higher gain at the higher frequency range.

Abstract: An optical fiber communication system using group transmission which transmits PCM information by utilizing an optical fiber group composed of a plurality of optical fibers. The PCM information in a plurality of optical fibers is stored in a memory of the system's sending terminal, the stored information of each memory is read out by simultaneous clock pulses so as to send out the information to a transmission line which is composed of a plurality of said optical fibers. A repeater is provided in the transmission line having at least one of the following circuits, an AGC circuit, a light element control circuit, a power supply circuit and a supervisory circuit. The supervisory circuit is commonly provided for checking a plurality of signals which is transmitted by the above-mentioned optical fibers.