Abstract: A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and are coated with electrode structures, e.g.

Abstract: A bistable nematic liquid crystal device cell (1) is provided with a surface alignment grating on at least one cell wall (3) and a surface treatment on the other wall (4). Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its grove height to width selected to give approximately equal energy within nematic material (2) in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell (1) is switched by dc pulses coupling to a flexoelectric coefficient in the material (2), or by use of a two frequency addressing scheme and a suitable two frequency material. Polarizers (13,13′) either side of the cell (1) distinguish between the two switched states. The cell walls (3,4) may be rigid or flexible, and are coated with electrode structures (6,7), e.g.

Abstract: In order to reduce the effects of impact on liquid crystal devices a polymer network is introduced into ferroelectric liquid crystal cells. A liquid crystal device comprises two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, characterised in that the liquid crystal material contains a small amount of monomer. The liquid crystal material may also contain a photoinitiator. The monomer material may be cured to produce the polymer networks the curing many be carried out in the presence of an electric or magnetic field. Further, the monomer may be cured in an isotropic or liquid crystal phase.

Abstract: In order to the effects of impact on liquid crystal devices a polymer network is introduced into ferroelectric liquid crystal cells. A liquid crystal device comprises two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, characterised in that the liquid crystal material contains a small amount of monomer. The liquid crystal material may also contain a photoinitiator. The monomer material may be cured to produce the polymer network; the curing may be carried out in the presence of an electric or magnetic field. Further, the monomer may be cured in an isotropic or liquid crystal phase.

Abstract: A method of aligning liquid crystal material by bringing into contact with a thin layer of polymer which contains the anthracenyl group, the polymer having previously been treated with plane polarised ultraviolet light. A liquid crystal cell is described wherein each of the substrates defining two opposing cell walls are coated on their inner surface with a suitable polymer for carrying out the invention. A typical embodiment of the invention would have repeat unit (II).

Abstract: A liquid crystal display cell comprises two cell walls spaced apart to enclose a layer of liquid crystal material. The cell walls carry electrode structures, e.g. arranged in rows and columns to give an x, y matrix of addressable elements or pixels. The liquid crystal material is aligned by a grating (grooved) structure on one or both cell walls. This grating structure is a bigrating with one symmetrical grating and an asymmetric grating which may be orthogonal to the symmetric grating. The grooves of the asymmetric grating varying their depth or asymmetry along the lengths to give a locally varying pretilt whose longer range average provides a pretilt in a preferred range, e.g. about 2-24 degrees.

Abstract: A nematic liquid crystal device with two bistable switched states, having two cell walls treated which provide a bigrating on one or both cell walls. The bigrating enables the liquid crystal molecules at a surface to lie in two different angular directions, 45 or 90 degrees apart. The bigrating may be symmetric or asymmetric, with the surface energy of each of the gratings of the bigratings being nearly equal.

Abstract: A twisted nematic type of liquid crystal device comprises two cell walls enclosing a layer of a nematic or long pitch cholesteric liquid crystal material. The device has both an alignment direction and a surface tilt provided by an asymmetric grooves structure alignment on one or both walls. The alignment treatment may be provided by a shaped layer of a photolithographic material. Embossing, ruling, or transferred from a carrier layer material may alternatively provide the alignment. The amount of twist may be multiples of about 90.degree. and the device arranged between two polarisers.

Abstract: A ferroelectric liquid crystal device comprises a layer of a ferroelectric liquid crystal material contained between two cell walls carrying electrode structures and a surface alignment treatment. The surface alignment is provided by a profiled surface, e.g., a grating, on at least one cell wall. The grating may be a monograting or a bigrating, with a symmetric or asymmetric profile. Such a profiling enables surface tilt and alignment anchoring energy to be independently arranged to suit liquid crystal material and device type to give a required molecular arrangement and low device defect. The grating may be provided by interferography, photolithography, embossing, ruling, or carrier layer transfer. Alignment directions on the cell walls may be parallel or non-parallel. The surface tilt on both cell walls may be the same or different values. The cell walls may be relatively rigid, e.g., glass slides, or flexible, e.g.

Abstract: The present invention discloses a bioreactor for aerobically composting organic waste. The bioreactor includes a container for supporting the organic waste, a rotatably positioned lid cover for enclosing the container, a mixing assembly slidably mounted to the lid cover, and an aeration system for promoting the aerobic composting process. The mixing assembly is mounted to the lid cover using a slide system which permits the mixing auger to move radially within the container. The mixing assembly includes a mixing auger and a motor for rotating the mixing auger. Preferably, the mixing auger is configured with sharp cutting edges to facilitate grinding of the composting organic waste.

Abstract: The invention provides a liquid crystal device having an aligned and surface tilted liquid crystal layer contained between two cell walls. The cell walls carry electrodes for applying voltages across the layer thickness to provide a display. The alignment is provided by a layer of a material that undergoes optically induced ordering during cross linking. That is, a material capable of aligning liquid crystal molecules after cross linking with polarized light. One such material is polyvinylcinnamate. The aligning layer is profiled with an asymmetric grating, eg approximately sawtooth in cross section by interferometer, oblique incidence photolithography, or embossing. The shape of the grating provides the surface tilt. The liquid crystal material may be nematic, cholesteric, or smectic.

Abstract: An optical sensing device that incorporates either a surface plasmon-polariton or guided mode apparatus for converting radiation between s and p modes together with a sensor for detecting a maximum in conversion between the s and p modes.

Abstract: There is provided an apparatus for composting organic waste in a container with an uneven aeration floor positioned above the bottom of the container. Preferably, the aeration floor slopes down and in from its outer edges to encourage liquid formed during composting to collect under the perforated center portion of the aeration floor. Preferably, the perforated center portion of the aeration floor is arched or peaked. This particular aeration floor configuration directs more air toward the center of the composting mass while minimizing the amount of air following the path of least resistance up the side wall. A chamber is defined by the aeration floor and the bottom of the container. Air enters (or exits) the chamber through an orifice and exits (or enters) the chamber through the perforations in the aeration floor. The container may also have a top wall or cover and a means for exhausting or introducing air through the top of the container.

Abstract: The present invention is a compost apparatus that is simple, economical, reliable and may be transportable, yet contains all odorous emissions. Odorous materials are handled in a fully enclosed manner using containers which may be capable of providing in-vessel agitation using pressurized air. The container consists of side walls and a bottom wall. A cover may also be included. A perforated second floor is positioned above the bottom wall for supporting organic waste. The container is capable of allowing pressurized air to be introduced between the perforated second floor and the bottom floor for aerating the organic waste. The container is further capable of allowing odorous gases collected within the container to be exhausted. A bladder may be positioned within the container to agitate the organic waste load.