Abstract: A process for reacting a zirconia-based material comprises reacting, in a reaction step, plasma dissociated zircon with aqueous hydrogen fluoride to produce a soluble fluoro zirconic acid compound.

Abstract: The invention provides a process for producing a component of a plastics material which is strengthened and reinforced by a resin-impregnated fibrous material which adheres to a surface thereof The surface of the component is contacted with a fibrous material impregnated with a resin in a settable state, and setting of the resin is effected, while the fibrous material is caused to adhere to the surface of the component. The plastics component is a polyolefin material, and the surface is subjected to activation by oxyfluorination thereof prior to the contacting.

Abstract: A process for producing a composite material, structure or artifact comprising a cementitious substrate or matrix which is strengthened or reinforced by reinforcing material which adheres thereto, includes bringing a reinforcing component into contact with a cementitious substrate component which is in a settable state. The substrate component is allowed to set in contact with the reinforcing component, thereby to adhere thereto. Adhesion of the substrate component to the reinforcing component is enhanced by, prior to bringing the components into contact with each other, subjecting the reinforcing component to surface fluorination thereof.

Abstract: A process for treating dissociated zircon comprises reacting dissociated zircon with gaseous hydrogen fluoride at an elevated reaction temperature. The reaction temperature is controlled to obtain at least one desired zirconium-based compound and at least one desired silicon-based compound.

Abstract: A transmission 10 includes a drive member 12 which is rotatable about a first axis of rotation 20 and a driven member 14 which is rotatable about a second axis of rotation 26 and which is spaced axially from the drive member 12. The transmission 10 further includes an intermediate member 34 which is positioned between the drive and driven members 12, 14 and which is rotatable about a third axis of rotation 36. A plurality of axially displaceable drive elements 38 is provided for transmitting drive between at least one of the drive member and the intermediate member and the intermediate member and the driven member. The eccentricity of the intermediate member 34 relative to the drive and driven members 12, 14 is adjustable thereby to permit adjustment of the transmission ratio.

Abstract: A process for producing uranium hexafluoride comprises bringing fluorine gas into contact with reactive particles comprising uranium metal, as well as with non-reactive particles which are substantially inert and which are in contact with the reactive particles. The reactive particles are kept distinct from the non-reactive particles. The fluorine gas is allowed to react with the uranium metal at elevated temperature, thereby to produce gaseous uranium hexafluoride. The uranium hexafluoride is separated from any residual fluorine.

Abstract: A filter system 10 includes a pre-filter in a pre-filter zone 18 and a final filter in a final filter zone 22. The pre-filter is in the form of at least one inertial filter, e.g. an array 28 of axial flow cyclones 30. The final filter is in the form of a media filter 36 formed of a lofted bat of fibrous material which is of non-homogeneous structure through its depth. An upstream side is lofty, and a downstream side is of set structure. A contaminated fluid flow stream enters via an inlet 12. Contaminants are filtered out by the axial flow cyclones to be removed via a dust cover 32. Pre-filtered fluid flows via a chamber 20 through the media filter 36. After final filtration in the media filter it exits via a chamber 24 and an outlet 14.

Abstract: A filter system 10 includes a pre-filter in a pre-filter zone 18 and a final filter in a final filter zone 22. The pre-filter is in the form of at least one inertial filter, e.g. an array 28 of axial flow cyclones 30. The final filter is in the form of a media filter 36 formed of a lofted bat of fibrous material which is of non-homogeneous structure through its depth. An upstream side is lofty, and a downstream side is of set structure. A contaminated fluid flow stream enters via an inlet 12. Contaminants are filtered out by the axial flow cyclones to be removed via a dust cover 32. Pre-filtered fluid flows via a chamber 20 through the media filter 36. After final filtration in the media filter it exits via a chamber 24 and an outlet 14.

Abstract: The invention provides a radon daughter dosemeter made up of a cyclone, a filter in a filter holder and a radiation detector spaced from the filter. The filter is arranged to filter dust and aerosol particles from air issuing from the air outlet of the cyclone, and the detector is arranged to detect radiation from dust and aerosol particles on the filter. The invention also provides a method of monitoring radiation exposure of persons; and an electrochemical etching cell for the etching of detectors used in the dosemeter.