Abstract: An inexpensive high-performance cutting or grinding oil capable of significantly improving the cutting efficiency. Into a liquid component of the cutting or grinding oil are dispersed fine powders of boron nitride of hexagonal system and/or crystal line turbostratic structure, particularly crystalline turbostratic structure, having a mean particle size of primary particles not larger than 1 .mu.m.

Abstract: A device and method for automatically selecting a CPU (central processing unit) driving frequency may include one or more of frequency selecting apparatus that receives a control signal, and outputs a selection signal, clock supply apparatus that receives the selection signal from the frequency selecting apparatus and outputs an external supply frequency, a CPU that receives the external supply frequency from the clock supply apparatus and the selection signal from the frequency selecting apparatus, and operates by determining the internal operation frequency, and frequency selection controlling apparatus that receives an output signal from the CPU and outputs the signal controlling the frequency selecting apparatus. Since the present invention selects and supplies the appropriate frequency to the CPU after identifying an ID (identification) of the CPU, it has no trouble in selecting an appropriate frequency.

Abstract: An object of the present invention is to provide a novel ceramic composite that has not only excellent dynamic characteristics, but also good electromagnetic characteristics, typified by dielectric characteristics, and the present invention relates to a ceramic composite, characterized in that an oxide having a perovskite structure which includes as raw materials lead and/or an alkaline earth metal is dispersed in a ceramic matrix, and in the above-mentioned ceramic composite, preferably the ceramic matrix is MgO, MgAl.sub.2 O.sub.4, or ZrO.sub.2, and also, preferably in the above-mentioned ceramic composite, the perovskite structure oxide particles are covered with MgO, MgAl.sub.2 O.sub.4, or ZrO.sub.2, and the ceramic matrix is Al.sub.2 O.sub.3.

Abstract: A power supply for automatically supplying a proper voltage to a central processing unit, includes: a voltage detecting pin of the central processing unit for outputting an operating voltage indicating signal; a selector for causing corresponding operating voltage to be inputted to the central processing unit by sensing the voltage detecting pin state outputted by the central processing unit; a power supply which supplies a proper voltage to the central processing unit; and a controller which outputs a control signal so as to supply the proper operating voltage to the central processing unit by determining the type of the central processing unit.