Abstract: A heat exchanger includes a body 4 on the surface of which are provided helical or spiral paths 5 which will provide multiple and turbulent flow paths A for a first fluid such as water which is caused to flow through chamber 3 relative to a spirally wound heat exchange tube 6 and in a heat transfer relationship with a second fluid flowing through the tube 6. The tube 6 has one or more further helical or spiral flow paths 9 on its external surface. The multiple flow paths A will extend the residence time for the first fluid within the heat exchanger 1 and this together with the turbulence will maximise heat transfer. Preferably a portion of the first fluid flow will be through a central aperture in body 4 where turbulence is also created by the helical or spiral paths of the tube 6 as it extends through the aperture.

Abstract: A herbicide mixture comprising alpha terpinol and tall oil is herein described.

Abstract: A refrigerant reverse cycle balancing receiver includes an outer housing with a volume formed therein. A refrigerant pipeline extends through the volume for connection with a refrigerant line of a refrigeration system. The refrigerant pipeline is provided with a refrigerant relief port within the outer housing for allowing excess refrigerant to back up and fill the volume of the receiver when required in use.

Abstract: The presently claimed invention is directed to agricultural compositions which find primary use as a herbicide, through may also be used for pesticidal and fungicidal roles. The presently claimed invention comprises compositions combining monterpene compounds with fatty acid soaps. In particular monterpene alcohols are preferred as a primary phytoactive agent. Preferred embodiments are based on coniferous oils, such as pine oil, in combination with a tall oil reacted with an alkali to form a fatty acid soap. Preferred methods of application include spraying in a manner in which some foaming effect is observed, which appears to confer advantage over the spray application of monoterpene compounds alone.

Abstract: This invention concerns the manufacture of helically corrugated conduit having at least a portion of its length corrugated in the form of at lease one helix. The method includes the driving of a smooth walled tube into a forming head having forming wheels which engage the outside of the tube and the wheels are at an angle relative to the longitudinal axis of the tube. The forming wheels form the helical spiral as part of a cold rolled forming process. More than one helical spiral can be formed simultaneously using a multiplicity of forming wheels.

Abstract: A multiple-frequency feed assembly for an antenna system having two coaxial cavities, with a smaller, high-frequency cavity mounted coaxially within a larger, low-frequency cavity. A separate rotatable probe is mounted within each cavity. The smaller cavity is mounted within the larger cavity by any of several structures, such as a ring-shaped spider, a ring-shaped spacer in the form of a planar washer, or a harp extending rearwardly in the larger cavity. In all of the embodiments, a continuous, uninterrupted signal path is provided within the low-frequency cavity, around the high-frequency cavity, for conveying incident electromagnetic signals to the low-frequency probe mounted at the rear of the low-frequency cavity. In other embodiments, the feed assembly is adapted to detect incident electromagnetic signals in a third band of frequencies, lower than the low-frequency band, using a third probe located within the low-frequency cavity, immediately adjacent to the high-frequency cavity.

Abstract: A dual frequency feed assembly for an antenna system having two coaxial cavities, with a smaller, high-frequency cavity mounted coaxially within a larger, low-frequency cavity. A separately rotatable probe is mounted within each cavity. The smaller cavity is mounted within the larger cavity by any of several structures, such as a ring-shaped spider, a ring-shaped spacer in the form of a planar washer, or a harp extending rearwardly in the larger cavity.

Abstract: A dual frequency feed assembly for antenna systems employing a pair of rotatably mounted probes each in respective coaxial cavities. The smaller cavity is supported by the rotating means for the larger probe and the smaller probe rotates with the larger probe driven by a common motor. The higher frequency signal is taken from the side wall of the lower frequency cavity. In an alternate embodiment, the smaller cavity is supported by a spider which rotates the smaller probe by means of external gearing and a separate motor. Other embodiments show coaxial lines which enter from the front face of the assembly and allow rotation of the smaller probe.