A composition useful in oral immunisation of animals such as poultry comprises dry free-flowing particles each consisting of a solid beadlet of lipid-continuous emulsion containing from about 25% to about 50% by weight water in a lipid, such as hardened palm kernel oil, having a slip point in the range 35.degree. to 45.degree. C., each beadlet having an average diameter of about 2 to 3 millimeters and containing at least 1 viable encysted protozoan, such as a sporulated oocyst of a species of co...

A protection circuit is disclosed for protecting a P-channel enhancement-type metal oxide semiconductor transistor from rupturing due to static voltage building up between its gate and source electrodes. The protection circuit includes at least one N-channel depletion-type transistor having its drain and source electrodes connected between the gate and source electrodes of the enhancement-type transistor and its gate electrode coupled to a negative power supply terminal. A resistor is also inclu...

A process for the protection of converter mouths and, more particularly, to an improved process for protecting the metal and refractory lining at the mouth of a converter by applying about the converter mouth prior to operating the converter a coating which comprises a mixture of a ceramic material and sodium silicate.

A protection circuit limits the collector current of a transistor employed as a clamp-to-ground stage in the event the collector terminal of the transistor is accidentally short circuited during conduction to a low-impedance voltage source. The protection circuit includes a transistor which has its base-emitter junction coupled across the base-emitter junction of the clamping transistor and has a collector resistor chosen to provide a saturation current for the protection transistor which holds ...

An envelope made wholly or partly of flexible impermeable material, and adapted to enclose an aircraft, there being an access opening in the envelope, the envelope including a re-usable airtight fastener, operable to close and seal the opening against ingress of air into the envelope, the envelope also having apertures through which wheels of an aircraft can protrude, together with sealing means for sealing said apertures to parts of the aircraft's undercarriage, and valve means controlling an o...

The circuit of the invention operates in conjunction with an imaging transducer to sense the loss of applied horizontal or vertical deflection signals, and to respond to such loss by changing the bias voltage on the transducer in a direction to turn "off" its electron beam.

Covers an arrangement for protecting people and property carried by a vehicle, such as an automobile or aircraft. The arrangement may include an impact switch, a control valve mechanism, a tank filled with fluid, one component of which may be a fire extinguishing agent, and an inflatable bag, the arrangement being so organized that, upon impact with another vehicle or a stationary body, the switch will complete a circuit to operate the control valve mechanism to release the fluid contents of the...

A system for the protection of electrical power transformers in the event of a fault occurring in which measurements of both the differential current and the voltage at the terminals of one of the windings of the transformer are utilised to provide a tripping signal to disconnect the transformer in the event of a fault occurring. The system distinguishes between a fault and a magnetising inrush situation by detecting saturation of the transformer core and operates faster than protective devices ...

An electrode for use in electric prevention for corrosion, the electrode comprising a sintered body of a mixture of iron oxide of 90 to 55 mol % in terms of Fe.sub.2 O.sub.3 and a metal oxide of 10 to 45 mol % in terms of MO (M is at least one metal selected from the group consisting of Mn, Ni, Co, Cu and Zn), and a process of electric prevention for corrosion by using said electrode as an anode.

A protection circuit suitable for use with electronic test equipment contains a switch which is open circuited if an overload condition is detected. The opening of the switch isolates the overload detector from the applied overload thereby allowing the detector to have a relatively low power handling capability. If the switch is manually closed whilst the overload condition persists the switch is automatically re-opened within a short predetermined time.