Abstract: A method of manufacture of high-solids hydroxide slurries from caustic calcined carbonate powder is described, whereby the properties of the slurry are its low resistance to shear thinning to facilitate transport, a high stability for transport and storage, ease of reconstitution after long periods of storage, and, as required, a high concentration of chemically reactive species at the particle surface. The method achieves these specifications by mixing caustic calcined carbonate or hydroxide powder with water in an insulated reactor vessel, and agitating the slurry sufficiently such that the hydration reaction causes the water to spontaneously boil, such that the remaining hydration proceeds spontaneously under the fixed conditions of boiling through the water loss. The mixing process is preferably carried out by a shear pump. A viscosity modifier, such as acetic acid, is used to thin the slurry to enable the mixing system to maintain uniform mixing.

Abstract: A method of manufacture of high-solids hydroxide slurries from caustic calcined carbonate powder is described, whereby the properties of the slurry are its low resistance to shear thinning to facilitate transport, a high stability for transport and storage, ease of reconstitution after long periods of storage, and, as required, a high concentration of chemically reactive species at the particle surface. The method achieves these specifications by mixing caustic calcined carbonate or hydroxide powder with water in an insulated reactor vessel, and agitating the slurry sufficiently such that the hydration reaction causes the water to spontaneously boil, such that the remaining hydration proceeds spontaneously under the fixed conditions of boiling through the water loss. The mixing process is preferably carried out by a shear pump. A viscosity modifier, such as acetic acid, is used to thin the slurry to enable the mixing system to maintain uniform mixing.

Abstract: A process and apparatus for manufacture of biocide products are described. The biocide properties arise from the caustic calcined powder, from carbonates such as such as magnesite and dolomite, and from hydroxides such as brucite. The method of manufacture is based on the production of high surface area oxide particles using an indirectly heated counterflow reactors for specifically calcining the carbonates and the hydroxides without significant sintering. The biocide products may be a powder or a hydrated slurry. A hydrated slurry is preferred for agricultural applications as a spray. For aquaculture applications, the products have a preferred particle size distribution to impact the aquatic and benthic ecosystems, and a Ca/Mg ratio that promotes the growth of the cultivates species when applied as a powder or a slurry.

Abstract: A process and apparatus for manufacture of oxide products for use as biocide, chemical detoxifying, and catalytic support products, from caustic calcined carbonate powder, preferably from magnesite, dolomite, or hydromagnesite, is described. These oxide particles are characterized by high surface area, high porosity and a high degree of calcination, and the method of manufacture utilizes an indirectly heated counterflow reactor. The oxides may be used as a powder, granules, or formulated into a slurry and used as a spray, emulsion, foam or fog, or the powder product may be directly applied. Also described is the formation of particles with microstructures defined by at least one nano-crystalline structure positioned on the outer surface of the particles.

Abstract: A formulation of a pathogen inhibitor or probiotic as a slurry concentrate of a hydrated metal oxide for applications in agriculture, aquaculture, and as an anti antibiotic in which the bioactivity, when applied by dilution, is controlled by a precursor of Reactive Oxygen Species, and the release rate is controlled by the particle size. The invention may include a means whereby the precursor concentration may be controlled to meet the requirements of the ecosystem, from the maintenance of an aerobic system, to killing pathogenic, anaerobic microbes, or producing sterile ecosystems. In addition, the metal oxide may be selected to provide essential nutrients for growth of the agricultural or aquacultural products.

Abstract: A process for producing a highly calcined and uniformly calcined product from a feedstock. The process comprising the steps of grinding the feedstock to powder, preheating the powder, and calcining the powder in a reactor plant that comprises a number of reactor segments in which a flash calciner is used in each progressive reactor segment to incrementally react the powder by raising the temperature in each segment. The last segment may be a high-temperature reactor that has a controlled residence time and temperature that may allow controlled finishing of the calcination process to achieve a desired degree of calcination and sintering of the product; and cooling of the product.

Abstract: A method of manufacture of Portland cement clinker is described in a dry process that captures the carbon dioxide emitted from the calcination of carbonate minerals, principally limestone. The process uses an indirectly heated, counter-flow reactor to pre-heat and calcine the cement meal to produce a separate calcined meal and carbon dioxide gas stream, with external heat being provided by the combustion of a secondary fuel stream with pre-heated air. This calcined meal is injected into the conventional rotary kiln, where the hot flue gas from combustion of the primary fuel with pre-heated air is used to fuse, react and sinter the powders to form granules of cement clinker. The clinker and carbon dioxide streams are cooled by the air pre-heaters.

Abstract: A process and apparatus for manufacture of oxide products for use as biocide, chemical detoxifying, and catalytic support products, from caustic calcined carbonate powder, preferably from magnesite, dolomite, or hydromagnesite, is described. These oxide particles are characterized by high surface area, high porosity and a high degree of calcination, and the method of manufacture of utilizes an indirectly heated counterflow reactor. The oxides may be used as a powder, granules, or formulated into a slurry and used as a spray, emulsion, foam or fog, or the powder product may be directly applied. Also described is the formation of particles with microstructures defined by at least one nano-crystalline structure positioned on the outer surface of the particles.

Abstract: A method of manufacture of high-solids hydroxide slurries from caustic calcined carbonate powder is described, whereby the properties of the slurry are its low resistance to shear thinning to facilitate transport, a high stability for transport and storage, ease of reconstitution after long periods of storage, and, as required, a high concentration of chemically reactive species at the particle surface. The method achieves these specifications by mixing caustic calcined carbonate or hydroxide powder with water in an insulated reactor vessel, and agitating the slurry sufficiently such that the hydration reaction causes the water to spontaneously boil, such that the remaining hydration proceeds spontaneously under the fixed conditions of boiling through the water loss. The mixing process is preferably carried out by a shear pump. A viscosity modifier, such as acetic acid, is used to thin the slurry to enable the mixing system to maintain uniform mixing.

Abstract: A method of writing a grating structure with at least one of predetermined amplitude, period and phase properties in a photosensitive waveguide, the method comprising providing at least two light beams which overlap in an overlap region to form an interference pattern; moving the photosensitive waveguide through the overlap region; and modulating the phase of at least one of the light beams relative to the phase of the other light beams using a non-mechanical beam modulator so that the interference pattern appears to move through the overlap region, the apparent movement being variably controlled in response to the movement of the photosensitive waveguide such that a grating structure is written with the at least one of predetermined amplitude, period and phase properties. The apparent movement of the interference pattern may be variably controlled to match the movement of the waveguide, or to be deliberately detuned. The grating structure may be chirped or apodized.

Abstract: An optical waveguide in the form of an optical fibre (10) having at least one longitudinally extending light guiding core region (11) composed at least in part of a polymeric material, a longitudinally extending core-surrounding region (12) composed of a polymeric material, and a plurality of light confining elements (15), such as, for example, channel-like holes, located within the core surrounding region. The light confining elements extend in the longitudinal direction of the core region and are distributed about the core region, and at least a majority of the light confining elements having a refractive index less than that of the polymeric material from which the core-surrounding region is composed. A preform for use in manufacture of the optical waveguide is also disclosed.

Abstract: A method of writing a grating structure with at least one of predetermined amplitude, period and phase properties in a photosensitive waveguide, the method comprising providing at least two light beams which overlap in an overlap region to form an interference pattern; moving the photosensitive waveguide through the overlap region; and modulating the phase of at least one of the light beams relative to the phase of the other light beams using a non-mechanical beam modulator so that the interference pattern appears to move through the overlap region, the apparent movement being variably controlled in response to the movement of the photosensitive waveguide such that a grating structure is written with the at least one of predetermined amplitude, period and phase properties. The apparent movement of the interference pattern may be variably controlled to match the movement of the waveguide, or to be deliberately detuned. The grating structure may be chirped or apodized.

Abstract: A method of writing a photo-induced structure into a photosensitive material substrate, the method comprising the steps of creating an interference pattern utilising at least two light beams, exposing the substrate to the interference pattern for photo-inducing material changes in the substrate, and creating an irregularity in the interference pattern by controlling a wavefront of at least one of the beams, for creating a functional defect in the photo-induced structure.

Abstract: A method of writing an extended grating structure in a photosensitive waveguide comprising the steps of utilizing at least two overlapping beams of light to form an interference pattern, moving the waveguide through said overlapping beams, simultaneously controlling a relative phase delay between the beams utilising a phase modulator, thereby controlling the positions of maxima within said interference pattern to move at approximately the same velocity as the photosensitive waveguide, wherein the phase modulator does not comprise a mechanical means for effecting the phase modulation, and modifying the relative phase delay between the beams during the writing of the grating structure, whereby a deliberate detuning of the velocity of the positions of maxima within said interference pattern and the velocity of the photosensitive waveguide is utilized to vary a period of the written grating structure in the photosensitive waveguide.

Abstract: This invention provides an optical fibre (1) incorporating a body (2), and an array of longitudinally extending holes or inclusions (3) formed in the body (2), the holes or inclusions (3) having a different refractive index from the surrounding body (2) and being arranged to form a full or partial ring structure (5) extending generally around a longitudinal axis of the fibre, the ring structure (5) being disposed so as to approximate the refractive or reflective transmission characteristics of a multi-layer optical fibre. The fibre (1) may have a solid core or a hollow air core. The invention also provides a method of forming the microstructured optical fibre (1).

Abstract: An optical waveguide in the form of an optical fibre (10) having at least one longitudinally extending light guiding core region (11) composed at least in part of a polymeric material, a longitudinally extending core-surrounding region (12) composed of a polymeric material, and a plurality of light confining elements (15), such as, for example, channel-like holes, located within the core surrounding region. The light confining elements extend in the longitudinal direction of the core region and are distributed about the core region, and at least a majority of the light confining elements having a refractive index less than that of the polymeric material from which the core-surrounding region is composed. A preform for use in manufacture of the optical waveguide is also disclosed.

Abstract: An optical communications system comprises, among other things, a laser source; an optical waveguide interconnected to the laser source to carry an optical signal from the source to an optical receiver; an optical receiver interconnected to the optical waveguide for decoding the signal; and a mechanical modulator adapted to substantially continuously mechanically perturb a portion of the optical waveguide so as to reduce Rayleigh backscattering from the optical waveguide.

Abstract: An optical fibre (1) having at least one longitudinally extending light guiding core region (11), a longitudinally extending core-surrounding region (12), and a plurality of light confining elements (15, 16, 17, 18), such as, for example, channel-like holes, located within the core-surrounding region (12). The light confining elements (15, 16, 17, 18) extend in the longitudinal direction of the core region and are located geometrically in zones that surround the core region. The aggregate cross-sectional area defined by the light confining elements within the respective zones increases with increasing radial distance of the zones from the core region. A preform for use in manufacture of the optical fibre is also defined.

Abstract: A method of writing an extended grating structure in a photosensitive waveguide comprising the steps of utilising at least two overlapping beams of light to form an interference pattern, moving the waveguide through said overlapping beams, simultaneously controlling a relative phase delay between the beams utilising a phase modulator, thereby controlling the positions of maxima within said interference pattern to move at approximately the same velocity as the photosensitive waveguide, wherein the phase modulator does not comprise a mechanical means for effecting the phase modulation, and modifying the relative phase delay between the beams during the writing of the grating structure, whereby a deliberate detuning of the velocity of the positions of maxima within said interference pattern and the velocity of the photosensitive waveguide is utilised to vary a period of the written grating structure in the photosensitive waveguide.

Abstract: A device for processing an optical signal, the device comprising a processing element monolithically integrated with a planar silica-based waveguide structure in which the optical signal propagates.