Abstract: An electronic circuit comprising a circuit substrate with electronic circuit elements bonded onto the circuit substrate with gaps between the circuit substrate and the respective electronic circuit elements has thermal conductive layers comprising an oxidatively curable resin filled into the gaps. The thermal conductive layers are produced by filling a varnish comprising an oxidatively curable resin into the gaps and exhibit excellent moist heat resistance and thermal conductive properties. The electronic circuit elements once mounted on the circuit substrate can easily be removed as required by releasing the bonding between the elements and the substrate.

Abstract: An earth and sand conveyor system comprising a hopper adapted to receive dumped earth and sand, a trough connected to the hopper, a screw conveyor rotatably mounted within the hopper and the trough, a consolidating pipe connected to the trough, a molding pipe connected to the consolidating pipe, a conveyor pipe connected to the molding pipe, a first nozzle formed in the wall of the molding pipe, a second nozzle formed in the wall of the conveyor pipe, an air compressor connected to the first and second nozzles, and a directional control valve disposed between the air compressor and the first and second nozzles for alternately supplying the compressed air to the first and second nozzles.

Abstract: Isovaleric acid ester derivatives and the optical isomers thereof expressed by the general formula I: ##STR1## wherein, R.sub.1 represents hydrogen, methyl group or chlorine atom, andR.sub.2 represents hydrogen or cyano group.