Abstract: A cuprous oxide powder is produced by the steps of discharging a molten copper, which is kept at a temperature at or higher than the melting point and at or lower than 1450.degree. C. and contained in a container having a nozzle at a bottom, from the nozzle into a reactor vessel disposed below the container to form a downward flow of the molten copper, atomizing the downward flow by a jet stream of an oxygen-contained gas and, thereby simultaneously, oxidizing the molten copper to form cuprous oxide, cooling liquid droplets or solid particles of the thus formed cuprous oxide and then collecting the droplets or particles from the reactor vessel. A cuprous oxide powder can be produced, without requiring a large-scale production facility, in simple steps, and efficiently and continuously.

Abstract: A densitometer for measuring a concentration of matter in a fluid system comprised of liquids and suspended and/or floating matter such as, for example, a densitometer for measuring the concentration of oil in bilge water that includes suspended and/or floating solid material. Two emulsifying conditions of the system are produced by first emulsification with a relatively high power emulsifying action and then a relatively low power emulsification. The amount of light which penetrates the system is a function of the turbidity which varies with the intensity of the emulsification. The concentration of oil in water, for example, in bilge water, is a function of the ratio of the amount of light which passes through the system in the two turbid states.

Abstract: An improved control system for energizing a stepping motor varies the width of the stepping pulse to the stepping motor as the motor transfers from one balanced state to another in order to provide additional starting torque and disconnects the energizing source from the motor when the motor is in its balanced state in order to conserve energy.

Abstract: A servo-motor control system varies a set point input signal to a comparator between predetermined limits in order to establish three detectable output conditions. When the difference between the feedback signal and the set point signal exceeds the average deviation of the set point input to the comparator, the comparator produces a characteristic output signaling rotation in one direction. When this difference signal is less than a negative quantity equal to the average deviation, the comparator produces a characteristic output which signals rotation in the other direction. If the difference signal is less than the absolute average value, then a third characteristic output is produced which causes a cutoff in the energization of the motor.