Abstract: A cordierite honeycomb structure having a coefficient of thermal conductivity of not less than 0.035 J/cm.multidot..degree.K..multidot.sec, a porosity of not more than 16%, and a coefficient of thermal expansion of not more than 1.0.times.10.sup.-6 /.degree.C. at 40.degree. to 800.degree. C. A process for producing a cordierite honeycomb structures, involves at least the steps of: mixing powders of kaolin, talc, and other starting materials for cordierite together so as to provide a chemical composition of cordierite; and extruding the mixture; and firing the extrudate, wherein the kaolin has an average particle diameter of not more than 5 .mu.m and such a particle size distribution that the proportion of particles with diameters of less than 1 .mu.m is 10% by weight and the talc has an average particle diameter of not more than 10 .mu.m and such a particle size distribution that the proportion of particles with diameters of less than 1 .mu.m is not more than 5%.

Abstract: A heat generating element having a thermal characteristic such that its resistance varies in response to changes in temperature is provided in the intake pipe of an engine. A heating power, the voltage of which is set by a reference voltage source, is supplied to the heat generating element via a transistor. The supply of this heating power is controlled by a start pulse signal periodically generated by a set flip-flop circuit when the ignition switch is on. When the heat generating element reaches a predetermined temperature, the supply is cut off by the flip-flop circuit. A measurement signal having a pulse width corresponding to the time period of heating power supply is generated from the flip-flop circuit. The opening of the ignition switch is detected and a one-shot multivibrator is driven to produce a burn-off signal having a pulse width to which the burn-off period corresponds.

Abstract: A shock absorber control system comprises a plurality of switches for setting respective desired dampening forces, and controls a dampening force of a vehicle shock absorber linearly in accordance with a manipulation of one of the switches. The control system further comprises a height sensor for detecting a height of the vehicle and detects the dampening force of the shock absorber by the change of the detected height and corrects the dampening force of the shock absorber in accordance with a difference between the desired dampening force corresponding to the manipulated switch and the detected dampening force.