A cementitious panel comprising a cementitious core which is fabric-reinforced at the surface thereof and whose longitudinal edges are reinforced by a network of fibers. A panel may be obtained wherein the surface edge reinforcement layers are relatively strong and hard such that a nail or screw may be driven through the edge of panel without pre-drilling and without breaking, even when nailed or screwed almost at the very limit of the edge of the panel. Such a panel may provide a long lasting substrate for humid or wet areas such as shower rooms and bath rooms.

The present invention relates to reinforced cementitious panels or boards comprising a cementitious core, the boards or panels being fabric-reinforced at the surface thereof. More particularly, it relates to panels or boards whose opposed broad faces are reinforced by a network of fibers which may be adhered at a surface thereof e.g. be adhered to or embedded at or just below the cementitious surfaces thereof. Still more particularly, the present invention relates to a cementitious board whose longitudinal edges are reinforced by a network of fibers. Such a cementitious panel or board may, for example, be a light-weight concrete panel, a tile backerboard panel, or the like.
The word xe2x80x9ccementitiousxe2x80x9d as used herein is to be understood as referring to any material, substance or composition containing or derived from a hydraulic cement such as for example, portland cement (see below). The term xe2x80x9cslurryxe2x80x9d is to be understood as referring to a flowable mixture, e.g. a flowable mixture of water and a hydraulic cement. The term xe2x80x9ccorexe2x80x9d is to be understood as referring to a mixture of a hydraulic cement, water and aggregate (such as sand, expanded shale or clay, expanded polystyrene beads, slag and similar materialsxe2x80x94see below), as well as, if desired or necessary, additional additives such as foaming agents, modifiers and the like.
The term xe2x80x9cslurry pervious reinforcing meshxe2x80x9d is to be understood as characterizing a mesh as being suitable for use in the preparation of a concrete panel by having openings sufficiently large to permit penetration of a cementitious slurry or a slurry component of a core mix into and through the openings so as to permit (mechanical) bonding of the mesh to the core either by for example by being cemented to the core or by being embedded in a face or surface of the core of a panel.
The expression xe2x80x9cslurry impervious meshxe2x80x9d is to be understood as characterizing a mesh as being water impervious or as being able to filter out or inhibit the penetration of slurry solids therein so as to inhibit (mechanical) bonding of the mesh to the core by the cementitious material.
It is to be understood herein that the expression xe2x80x9cadhered toxe2x80x9d in relation to a reinforcing mesh component (e.g. mesh, mat, fabric, tissue, etc.) means that the mesh component may be adhered for example to a face or surface by any suitable means such as by an adhesive, by a cement, or by being embedded in, at or immediately beneath the surface of a respective face or surface such that the mesh component is effectively bonded to the core, i.e. a hardened or set cementitious material extends through the interstices of the fibrous layers.
Keeping the above immediate definition in mind, it is to be understood herein that the expression xe2x80x9cadhered to said core atxe2x80x9d in relation to a reinforcing mesh component (e.g. mesh, mat, fabric, tissue, etc.) means that the mesh component does not extend beyond the specified face, area, region, or the like, i.e. it is restricted to the specified face region etc. Thus for example in relation to a broad face reinforcing mesh indicated as being adhered to a core at a broad face means that the mesh is restricted to being adhered to the broad face.
The word xe2x80x9cwovenxe2x80x9d as used herein is to be understood as characterizing a material such as a reinforcing mesh (e.g. mat, fabric, tissue or the like) as comprising fibers or filaments which are oriented; oriented fibers or filaments being disposed in an organized fashion.
The word xe2x80x9cnon-wovenxe2x80x9d as used herein is to be understood as characterizing a material such as a reinforcing mesh (e.g. mat, fabric, tissue or the like) as comprising fibers or filaments which are oriented (as described above) or which are non-oriented; non-oriented fibers or filaments being disposed in random fashion.
In general, a reinforced cementitious panel or board may be fastened to a wall frame for the construction of a wall and particularly for the construction of a wall where high moisture conditions are to be encountered. Such a wall panel may provide a long lasting substrate for humid or wet areas such as shower rooms and bath rooms and provide high impact resistance where there is high number of people circulating. For example, such a reinforced cementitious panel or board may be used as a substrate for ceramic tile in bath rooms, shower rooms, locker rooms, swimming pool rooms and other areas where the wall are subject to frequent splashing of water and high humidity. Once the panel is affixed to a wall frame a wall facing material may, as desired or necessary, in turn be affixed thereto such as, for example, ceramic tile, thin brick, thin marble panels, stucco or the like. Reinforced cementitious panels or boards having cores formed of a cementitious composition with the faces being reinforced with a layer of fabric bonded thereto are known; see for example U.S. Pat. No. 1,439,954, U.S. Pat. No. 3,284,980, U.S. Pat. No. 4,450,022, U.S. Pat. No. 4,916,604, etc.
Various processes for the preparation of such cementitious boards or panels are also known. British Patent application no. 2,053,779 for example discloses a method for the continuous production of a building board which comprises advancing a pervious fabric on a lower support surface, depositing a slurry of cementitious material onto the advancing fabric, contacting the exposed face of the slurry with a second fabric such that the slurry penetrates through the fabric to form a thin, continuous film on the outer faces of the fabric.
Because of its cementitious nature, a cement board may have a tendency to be relatively brittle.
Cementitious wall board or panels are often attached at their marginal edges to the building framework with for example fasteners such as nails, screws and the like. When fasteners for example such as screws or nails are installed near the edge (less than xc2xdxe2x80x3), it is highly desirable that the edge be able to retain sufficient structural integrity such that the panel remains attached to a wall member, i.e. that the panel have a relatively high fastener pull resistance such that the fastener will not laterally pull through or break through the board edge.
It is known to augment the strength of the border edge regions by wrapping the fabric covering one broad face of the board around the edge so as to overlay the fabric on the other opposite broad side thereof.
U.S. Pat. No. 4,916,004, for example, discloses a cement board having a woven mesh of glass fibers immediately below each face thereof, the mesh in one broad face continuing under the surface of both longitudinal edge faces, with the two meshes in an abutting or an overlapping relation along the longitudinal margins of the opposite face. Please also see U.S. Pat. Nos. 5,221,386 and 5,350,554.
U.S. Pat. No. 4,504,533, for example, discloses a gypsum board in which a composite web of a non-woven fiberglass felt and a woven fiberglass mat covers the upper and lower faces of a gypsum core while only the lower non-woven fiberglass felt is wrapped around the longitudinal edges of the gypsum core so that the non-woven fiberglass felt extends partially inward on the upper face of the core such that the border edge regions are covered only by non-woven fiberglass felt.
U.S. Pat. No. 1,787,163 on the other hand discloses a gypsum board in which side edge portions include a separate strip of U-shaped fabric extending from one broad face across the edge to the other broad face; the fabric legs of this separate strip each extend into the plaster core body beneath a respective sheet of fibrous material covering a respective broad face, i.e. the legs are submerged below the broad face and in particular below the broad face reinforcement means.
The problem common to all methods of production of fiber mesh reinforced cementitious panels still remains as to how to effectively reinforce longitudinal edges of cementitious panels. The problem is particularly difficult when the economics of continuous production are desired. Glass fiber mesh, is a common reinforcing fabric and is used in the form of a fibreglass scrim. The open fibreglass scrim may be relatively easily damaged and commonly has openings sized such that the core material can pass through when sufficient force is applied, thus reducing the integrity of the board. Therefore, its edges may be particularly fragile such that special care is needed when manipulating or installing such a cementitious board or panel.
It would be advantageous to be able to have an alternate manner of making an alternative type panel configured such that when a nail, screw or like shaft fastener is inserted close to the edge of a panel the mesh reinforced edge may minimize edge break out by the nail or screw or like shaft fastener of edge and thus provide secure attachment of the panel to a framing support.
It would for example be advantageous to be able to customize the reinforcement characteristics of the longitudinal edge area of a panel by being able to choose a desired reinforcement mesh component which is different from the mesh used for the broad faces of a wall panel core and being able to choose a desired attachment technique to the longitudinal edge. It would be advantageous for example too be able to have a panel or board wherein the edge reinforcing mesh may be different from the broad face reinforcing mesh (e.g. of a different substance, of different mesh openings, of non-oriented fibers or filaments rather than oriented fibers or filaments).
It would be advantageous to be able to have a panel wherein the longitudinal edge face of the panel may be more or less free of cementitious material so as to allow the longitudinal edge face to be used as a support substrate for a visual indicia such as colour, images, symbols, words, etc., i.e. such that an indica would not be covered up during the manufacturing process by cementitious material.
It would be advantageous to be able to have a means of treating the side edges of the board in the course of manufacture in such a manner as to enhance its structural qualities and its use for the purposes intended. It in particular would be advantageous to be able to have a means of manufacturing the edges of the board in such a manner that it will have impact resistant edges and be able to be constructed so as to be able to offer a relatively higher lateral fastener pull resistance in the edge area than in the central core area.
The present invention in an aspect provides a cementitious panel comprising a longitudinal side edge face, a pair of opposed broad faces, a longitudinal marginal edge, a light weight cementitious core, a first broad face reinforcing mesh component, a second broad face reinforcing mesh component, and a first edge reinforcing mesh component,
each broad face comprising a marginal area bordering said longitudinal edge face
said longitudinal marginal edge comprising a marginal area of one of said broad faces, an opposed marginal area of the other of said broad faces and said longitudinal side edge face,
said first and second broad face reinforcing mesh components each being adhered to said core at a respective broad face,
said first edge reinforcing mesh component comprising an edge strip member being adhered to said core at a marginal area of said longitudinal marginal edge,
said first and second broad face reinforcing meshes and said first edge reinforcing mesh being configured and disposed such that said strip member overlaps one of said first and second reinforcing meshes in a respective marginal area of said longitudinal marginal edge.
In accordance with the present invention the reinforcing mesh overlaped by said strip member may be is offset inwardly relative to the longitudinal side edge face of said longitudinal marginal edge.
In accordance with another aspect the present invention provides a cementitious panel comprising a longitudinal side edge face, a pair of opposed broad faces, a longitudinal marginal edge, a light weight cementitious core, a first broad face reinforcing is mesh component, a second broad face reinforcing mesh component, and a first edge reinforcing mesh component,
each broad face comprising a marginal area bordering said longitudinal edge face
said longitudinal marginal edge comprising a marginal area of one of said broad faces, an opposed marginal area of the other of said broad faces and said longitudinal side edge face,
said first and second broad face reinforcing mesh components each being adhered to said core at a respective broad face,
said first edge reinforcing mesh component comprising first and second edge strip members being adhered to said core at respective opposed marginal areas of said longitudinal marginal edge,
said first and second broad face reinforcing meshes and said first edge reinforcing mesh being configured and disposed such that said first and second strip members respectively overlap the first and second reinforcing meshes in the marginal areas of said longitudinal marginal edge.
In accordance with the present invention the first and second broad face reinforcing meshes may be offset inwardly relative to the longitudinal side edge face of said longitudinal marginal edge.
In accordance with the present invention there is provided a cementitious panel comprising a longitudinal side edge face, a pair of opposed broad faces, a longitudinal marginal edge, a light weight cementitious core, a first broad face reinforcing mesh component, a second broad face reinforcing mesh component, and a first U-shaped edge reinforcing mesh component,
each broad face comprising a marginal area bordering said longitudinal edge face
said longitudinal marginal edge comprising a marginal area of one of said broad faces, an opposed marginal area of the other of said broad faces and said longitudinal side edge face,
said first and second broad face reinforcing mesh components each being adhered to said core at a respective broad face,
said first U-shaped edge reinforcing mesh component comprising first and second edge strip members and a bridging member connecting said first and second edge strip members, said first and second edge strip members being adhered to said core at respective opposed marginal areas of said longitudinal marginal edge,
said first and second broad face reinforcing meshes and said first U-shaped edge reinforcing mesh being configured and disposed such that said first and second strip members respectively overlap the first and second reinforcing meshes in the marginal areas of said longitudinal marginal edge.
In accordance with the present invention the first and second broad face reinforcing meshes may as mentioned above be offset inwardly relative to the longitudinal side edge face of said longitudinal marginal edge.
In accordance with the present invention the bridge member may be non-adhered to said core at said longitudinal side edge face.
In accordance with the present invention the first and second broad face reinforcing meshes may be offset inwardly relative to the longitudinal side edge face of said longitudinal marginal edge and a bridge member may be non-adhered to said core at said longitudinal side edge face.
In accordance with the present invention marginal area(s) may comprise an adhesion region and a non-adhesion region, said non-adhesion region(s) bordering said longitudinal side edge face(s) and the first and second edge strip members may be non-adhered to said core at respective non-adhesion regions; may be non-embedded; may be abutting appropriate faces, etc.
In accordance with a further aspect the present invention provides a cementitious panel comprising a pair of opposed longitudinal side edge faces, a pair of opposed broad faces, a pair of opposed longitudinal marginal edges, a light weight cementitious core, a first broad face reinforcing mesh component, a second broad face reinforcing mesh component, a first U-shaped edge reinforcing mesh component and a second U-shaped edge reinforcing mesh component,
each broad face comprising a marginal area bordering each longitudinal edge face
each longitudinal marginal edge comprising a marginal area of one of said broad faces, an opposed marginal area of the other of said broad faces and a respective longitudinal side edge face,
said first and second broad face reinforcing mesh components each being adhered to said core at a respective broad face,
said first and second U-shaped edge reinforcing mesh components each comprising first and second edge strip members and a bridging member connecting said first and second edge strip members, said first and second edge strip members being adhered to said core at respective opposed marginal areas of a respective longitudinal marginal edge,
said first and second broad face reinforcing mesh components and said first and second U-shaped edge reinforcing mesh components being configured and disposed such that said first and second strip members respectively overlap the first and second reinforcing meshes in the marginal areas of a respective longitudinal marginal edge.
In accordance with the present invention, as mentioned above, the first and second broad face reinforcing meshes may be offset inwardly relative to the longitudinal side edge faces of said longitudinal marginal edges.
In accordance with the present invention as mentioned above a bridge member(s) may be non-adhered to said core at respective longitudinal side edge face(s).
In accordance with the present invention as mentioned above the first and second broad face reinforcing meshes may be offset inwardly relative to the longitudinal side edge faces of said longitudinal marginal edges and bridge members may be non-adhered to said core at respective longitudinal side edge faces.
In accordance with the present invention as mentioned above marginal areas may comprise an adhesion region and a non-adhesion region, said non-adhesion regions bordering said longitudinal side edge faces and first and second edge strip members may be non-adhered to said core at respective non-adhesion regions.
In accordance with the present invention the first and second broad face reinforcing mesh components may each be embedded in a respective broad face of said core and first and second edge strip members may be cemented to said core at respective opposed marginal areas of a respective longitudinal marginal edge.
In accordance with the present invention as mentioned first and second broad face reinforcing meshes may be offset inwardly relative to the longitudinal side edge faces of said longitudinal marginal edges and bridge members may be non-adhered to said core at respective longitudinal side edge faces.
In accordance with the present invention a bridge member(s) may be are non-adhered to said core at respective longitudinal side edge face(s).
In accordance with the present invention as mentioned first and second broad face reinforcing meshes may be offset inwardly relative to the longitudinal side edge faces of said longitudinal marginal edges, bridge members may be non-adhered to said core at respective longitudinal side edge faces.
In accordance with the present invention as mentioned marginal areas may comprise an adhesion region and a non-adhesion region, said non-adhesion regions bordering said longitudinal side edge faces and first and second edge strip members may be non-adhered to said core at respective non-adhesion region.
In accordance with the present invention a core may have an average unit weight of not more than about 120 pounds per cubic foot.
In accordance with the present invention first and second broad face mesh components may be of a non-woven oriented mesh and the U-shaped edge reinforcing mesh component may be of a non-woven non-oriented reinforcing mesh.
In accordance with the present invention a panel may be provided with reinforced broad side face as follows: the web of fabric is deposited onto a supporting web member (e.g., a plastic protective film), a cementitious slurry is fed to the upper surface of the web and then is spread uniformly over the web in controlled amount by means of a doctor (blade, bar or roller) adjustably spaced from the supporting member. The web is drawn out of the slot formed by the doctor and supporting member, thereby applying the desired coating of slurry to the first reinforcing mesh; the core mix is then applied. Then the second web is deposited upon the upper face of the core layer; vibrating the layer of slurry in contact with the fabric or web until slurry penetrates the web and the latter is completely embedded.
In accordance with a different aspect the present invention provides a method for manufacturing a reinforced cementitious panel having a reinforced longitudinal edge comprising:
forming a first slurry comprising a cementitious material and water;
forming a core mix comprising a cementitious material, lightweight aggregate and water
providing a panel forming support substrate;
laying over said panel forming support substrate a band of reinforcing mesh;
laying a first sheet of reinforcing mesh over said panel forming support substrate such that said sheet of reinforcing mesh overlaps said band at an outer marginal portion of said first sheet of reinforcing mesh,
depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
laying a second sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh.
In accordance with another aspect the present invention provides a method for manufacturing a reinforced cementitious panel having a reinforced longitudinal edge comprising:
forming a first slurry comprising a cementitious material and water;
forming a core mix comprising a cementitious material, lightweight aggregate and water
providing a panel forming support substrate;
laying a first sheet of reinforcing mesh over said panel forming support substrate,
depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
laying a second long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh
laying over said upper broad surface a band of reinforcing mesh such that said band overlaps said second sheet of reinforcing mesh band at an outer marginal portion of said panel and first sheet of reinforcing mesh and is embedded in said upper broad surface.
In accordance with an additional aspect the present invention provides a method for manufacturing a reinforced cementitious panel having a reinforced longitudinal edge comprising:
forming a first slurry comprising a cementitious material and water;
forming a core mix comprising a cementitious material, lightweight aggregate and water
providing a panel forming support substrate, said panel forming support substrate being wider than the panel to be made;
laying over said panel forming support substrate a band of reinforcing mesh;
laying a first sheet of reinforcing mesh over said panel forming support substrate such that said first sheet of reinforcing mesh overlaps a predetermined portion of said first band so as to leave an outer portion of said band uncovered by said first sheet of reinforcing mesh,
depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
laying a second indefinitely long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh,
bending the outer marginal portions of said band upwardly to an upright position,
folding upright portions of said band inwardly so as to overlap said second sheet of reinforcing mesh and such that said band defines a U-shaped edge reinforcing mesh.
In accordance with the present invention a method for the manufacture of a panel wherein said U-shaped edge reinforcing mesh comprises first and second edge strip members and a bridging member connecting said first and second edge strip members, and said bridge member is non-adhered to said core, may be carried out wherein said band has a non adhesion zone for the formation of said bridge member.
In accordance with a further aspect the present invention provides a method for manufacturing a reinforced cementitious panel having reinforced longitudinal edges comprising:
forming a first slurry comprising a cementitious material and water;
forming a core mix comprising a cementitious material, lightweight aggregate and water
providing a panel forming support substrate, said panel forming support substrate being wider than the panel to be made;
laying over said panel forming support substrate, in spaced apart parallel relation, a first band of reinforcing mesh and second band of reinforcing mesh;
laying a first sheet of reinforcing mesh over said panel forming support substrate such that said first sheet of reinforcing mesh overlaps a predetermined portion of each of said first and second bands so as to leave an outer portion of each band uncovered by said first sheet of reinforcing mesh,
depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
laying a second indefinitely long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh,
bending the outer marginal portions of said first and second bands upwardly to an upright position,
folding upright portions of said first and second bands inwardly so as to overlap said second sheet of reinforcing mesh and such that each of said first and second bands define a U-shaped edge reinforcing mesh.
In accordance with another aspect the present invention provides a method for manufacturing a reinforced cementitious panel having reinforced longitudinal edges comprising:
continuously forming a first slurry comprising a cementitious material and water;
continuously forming a core mix comprising a cementitious material, lightweight aggregate and water
continuously advancing an indefinitely long panel forming support substrate over a support surface, said panel forming support substrate being wider than the panel to be made;
continuously laying over said panel forming support substrate, in spaced apart parallel relation, an indefinitely long first band of reinforcing mesh and an indefinitely long second band of reinforcing mesh;
continuously laying a first indefinitely long sheet of reinforcing mesh over said panel forming support substrate such that said first sheet of reinforcing mesh overlaps a predetermined portion of each of said first and second bands so as to leave an outer portion of each band uncovered by said first sheet of reinforcing mesh,
continuously depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
continuously depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
continuously laying a second indefinitely long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface so as to leave an outer marginal portion of each of said bands uncovered by said second sheet of reinforcing mesh,
continuously bending the outer marginal portions of said first and second bands upwardly to an upright position,
folding upright portions of said first and second bands inwardly so as to overlap said second indefinitely long sheet of reinforcing mesh and such that each of said first and second bands define a U-shaped edge reinforcing mesh.
In accordance with a different aspect the present invention provides an apparatus for manufacturing a reinforced cementitious panel having reinforced longitudinal edges comprising
means for forming a first slurry comprising a cementitious material and water;
means for forming a core mix comprising a cementitious material, lightweight aggregate and water
means for providing a panel forming support substrate;
means for laying over said panel forming support substrate a band of reinforcing mesh;
means for laying a first sheet of reinforcing mesh over said panel forming support substrate such that said sheet of reinforcing mesh overlaps said band at an outer marginal portion of said first sheet of reinforcing mesh,
means for depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
means for depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
means for laying a second sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh.
In accordance with another aspect the present invention provides a method for manufacturing a reinforced cementitious panel having a reinforced longitudinal edge comprising:
means for forming a first slurry comprising a cementitious material and water;
means for forming a core mix comprising a cementitious material, lightweight aggregate and water
means for providing a panel forming support substrate;
means for laying a first sheet of reinforcing mesh over said panel forming support substrate,
means for depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
means for depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
means for laying a second long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh
means for laying over said upper broad surface a band of reinforcing mesh such that said band overlaps said second sheet of reinforcing mesh band at an outer marginal portion of said panel and first sheet of reinforcing mesh and is embedded in said upper broad surface.
In accordance with an additional aspect the present invention provides an apparatus for manufacturing a reinforced cementitious panel having a reinforced longitudinal edge comprising:
means for forming a first slurry comprising a cementitious material and water;
means for forming a core mix comprising a cementitious material, lightweight aggregate and water
means for providing a panel forming support substrate, said panel forming support substrate being wider than the panel to be made;
means for laying over said panel forming support substrate a band of reinforcing mesh;
means for laying a first sheet of reinforcing mesh over said panel forming support substrate such that said first sheet of reinforcing mesh overlaps a predetermined portion of said first band so as to leave an outer portion of said band uncovered by said first sheet of reinforcing mesh,
means for depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
means for depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
means for laying a second indefinitely long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh,
means for bending the outer marginal portions of said band upwardly to an upright position,
means for folding upright portions of said band inwardly so as to overlap said second sheet of reinforcing mesh and such that said band defines a U-shaped edge reinforcing mesh.
In accordance with the present invention an for the manufacture of a panel wherein said U-shaped edge reinforcing mesh comprises first and second edge strip members and a bridging member connecting said first and second edge strip members, and said bridge member is non-adhered to said core, may be used wherein the apparatus includes means for applying a non adhesion zone to said band for the formation of said bridge member.
In accordance with a further aspect the present invention provides an apparatus for manufacturing a reinforced cementitious panel having reinforced longitudinal edges comprising:
means for forming a first slurry comprising a cementitious material and water;
means for forming a core mix comprising a cementitious material, lightweight aggregate and water
means for providing a panel forming support substrate, said panel forming support substrate being wider than the panel to be made;
means for laying over said panel forming support substrate, in spaced apart parallel relation, a first band of reinforcing mesh and second band of reinforcing mesh;
means for laying a first sheet of reinforcing mesh over said panel forming support substrate such that said first sheet of reinforcing mesh overlaps a predetermined portion of each of said first and second bands so as to leave an outer portion of each band uncovered by said first sheet of reinforcing mesh,
means for depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
means for depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
means for laying a second indefinitely long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface and overlies said first sheet of reinforcing mesh,
means for bending the outer marginal portions of said first and second bands upwardly to an upright position,
means for folding upright portions of said first and second bands inwardly so as to overlap said second sheet of reinforcing mesh and such that each of said first and second bands define a U-shaped edge reinforcing mesh.
In accordance with another aspect the present invention provides an apparatus for manufacturing a reinforced cementitious panel having reinforced longitudinal edges comprising:
means for continuously forming a first slurry comprising a cementitious material and water;
means for continuously forming a core mix comprising a cementitious material, lightweight aggregate and water
means for continuously advancing an indefinitely long panel forming support substrate over a support surface, said panel forming support substrate being wider than the panel to be made;
means for continuously laying over said panel forming support substrate, in spaced apart parallel relation, an indefinitely long first band of reinforcing mesh and an indefinitely long second band of reinforcing mesh;
means for continuously laying a first indefinitely long sheet of reinforcing mesh over said panel forming support substrate such that said first sheet of reinforcing mesh overlaps a predetermined portion of each of said first and second bands so as to leave an outer portion of each band uncovered by said first sheet of reinforcing mesh,
means for continuously depositing said first slurry on said first sheet of reinforcing mesh and distributing it across the breadth of said first sheet of reinforcing mesh so as to form a slurried reinforcement layer of predetermined thickness such that the first sheet of reinforcing mesh is embedded in said slurried reinforcement layer;
means for continuously depositing said core mix on said slurried reinforcement layer and distributing the core mix across said first sheet of reinforcing mesh so as to form a core layer of predetermined depth having an upper broad surface
means for continuously laying a second indefinitely long sheet of reinforcing mesh over said core layer such that said second sheet of reinforcing mesh is embedded in said upper broad surface so as to leave an outer marginal portion of each of said bands uncovered by said second sheet of reinforcing mesh,
means for continuously bending the outer marginal portions of said first and second bands upwardly to an upright position,
means for folding upright portions of said first and second bands inwardly so as to overlap said second indefinitely long sheet of reinforcing mesh and such that each of said first and second bands define a U-shaped edge reinforcing mesh.
In accordance with the present invention a bridge member may be non-embedded in a longitudinal side edge face.
In accordance with the present invention a support substrate may comprise a conveyor belt (supported on tab) and a protective film. If desired or necessary the protective film may be dispensed with but in such a case it may be necessary tho coat a particular conveyor belt with agents such as anti-stick agents.
As mentioned above, in accordance with the present invention the first and second edge strip members of a U-shaped edge reinforcing mesh may be adhered to said core at respective marginal areas of a respective longitudinal marginal edge by being cemented thereto or as desired by being embedded in respective broad faces. A bridging member may as desired also be cemented to or as desired be embedded in a respective longitudinal edge face. On the other hand a bridging member need not if desired be adhered to a respective longitudinal edge face but may merely abut such face or as desired be spaced apart therefrom; in this latter case the bridging member may be water impervious such that, for example, cementitious material may not pass into or through the bridging member during the manufacture of a panel such that it is possible to for example provide the exposed side of the bridging member with a desired indica as described above.
A cementitious board or panel of the present invention may be designed to be used as a backerboard for tile, thin brick, thin stones, synthetic or natural stucco, paint, exterior insulation and finish systems or other finishes that can be applied onto concrete. It may be of interior or exterior grade and can be used in such places as kitchens, bath room, shower room, corridors, exterior wall, or any places that require water resistance and impact resistance. It may be used to construct fire resistant partition walls.
As may be understood, in accordance with the present invention a cementitious panel may have a composite or sandwich like construction wherein a cementitious core is bounded on each of its two major or broad faces by a respective reinforcing mesh component of fibrous material; each reinforcing mesh component being adhered to the panel core at a respective major face thereof.
The longitudinal edge faces of a panel may also be covered or closed off by an edge reinforcing mesh component. The edge reinforcing mesh component may be adhered to the longitudinal edge face, merely abut the longitudinal edge face or be spaced apart from the longitudinal face; this type of reinforcing mesh component may, for example take on a U-shaped configuration as discussed herein. Alternatively, if desired, the longitudinal edge face or a part thereof may be open, i.e. not covered by a reinforcing mesh material. In this latter case one or both of the marginal areas adjacent a longitudinal edge on opposite broad faces may be provided with an edge reinforcing member.
A panel in accordance with the present invention may have a longitudinal edge face which may be more or less free of cementitious material so as to allow the longitudinal edge face to be used as a support substrate for a visual indicia such as color, images, symbols, words, etc., i.e. the reinforcing mesh may be configured such that an indica support area would not be covered up during the manufacturing process by cementitious material.
The reinforcing mesh components or members thereof whether for a broad or major face or for a longitudinal edge face may take the form of a woven or non woven fabric or mesh such as a woven mesh or scrim, a non-woven mesh, a non-woven pervious mesh or mat, etc.. Suitable fiber filaments may be formed into a woven material by the employment of a suitable method such as knitting or weaving. Suitable fiber filaments may be formed into non-woven material by the employment of a suitable method such as gluing or fusion.
The reinforcing mesh for a broad face may for example take the form of a woven mesh or a non-woven oriented mesh. On the other hand a mesh for a longitudinal edge face may take the form of a non-woven mesh, in particular a non-woven non-oriented mesh.
A woven mesh for a broad face may for example be composed of glass fibers and be in the form of woven or knitted fabric or scrim. When a glass fiber network is used in conjunction with an alkaline cementitious material, for example, a highly alkaline Portland, cementitious composition, the glass fibers may be made from an alkaline resistant glass or have a protective resin coating so that damage which might result from reaction with the alkaline cementitious material, may be minimized; this may be accomplished by coating the fibers with an alkali resistant coating such as an epoxy resin. The reinforcing mesh may, for example, be a fibre-glass scrim, in particular, a woven mesh of vinyl (e.g. polyvinylchloride) coated glass-fibre yarns.
The reinforcing mesh for a broad face may, if desired, alternatively, be in the form of a non-woven oriented fabric or web, bonded with a suitable synthetic resin or by heat. The mesh may be of non-woven oriented glass fibre tissue. A non-woven glass fibre tissue may be of resin-bonded fibers or filaments, for example fibers bonded with urea-formaldehyde and may have a weight of about 2 to 4 oz. per square yard, the fibers may for example have a diameter of e.g. 10 to 20 um.
However, a woven or non-woven oriented mesh of other materials may be used for reinforcing a broad face of a panel. Such a mesh may for example be of an inorganic material such as for example, of a metal (e.g. a steel fibre) of asbestos, of alumina, of zirconia, of carbon and the like. Alternatively, a mesh may be of synthetic material such as for example of organic polymeric fibers, for example, nylon fibers, polyvinylidene chloride fibers, polyester fibre yarns coated with PVC, aramid resin fibers (e.g as sold under the trade-mark Kevlar), polyolefin fiber, e.g. polyethylene or polypropylene; of fluorinated polyolefin, e.g. polyvinylidene fluoride or polytetrafluoroethylene; or polyamide fibre; or of polyester fibre, e.g. poly(ethylene terephthalate); or of cellulosic fibre and the like.
The mesh size and the fiber diameter for a woven or non-woven oriented mesh used to reinforce the broad or major faces of the core may be selected according to the strength desired in the board and the size of the aggregate in the concrete mix. A mesh for a broad face reinforcement may, for example, have a relatively loose thread or mesh count per inch (warpxc3x97fill) such as for example, of from 4xc3x974 to 18xc3x9718, of 10xc3x978, etc. for most purposes.
In accordance with the present invention the reinforcement of the edges and margins of a cementitious board or panel may be accomplished by using a separate type of woven or non-woven mesh or mat fabric as compared with the reinforcing mesh used for the broad faces; advantageously, the reinforcing mesh for the edge face may be a non-woven non-oriented mesh. For example, a reinforcing mesh for the longitudinal edges may have relatively tight intercises as compared with a reinforcing mesh for a broad facesxe2x80x942 to 4 oz. per sq. yd.xe2x80x94; the relatively tight intercises makes attachment of the board to a wall framework with nails or screws more secure, due to of a greater amount of mesh material per unit area than is present for the central portion of the major or broad faces of the panel.
The fibres in a non-woven mesh for reinforcing a longitudinal marginal edge may be either randomly distributed or orientated. In the first case the longitudinal edges of the board will have substantially the same breaking strength in the longitudinal and the transverse directions. In the latter case, the longitudinal edges of the board can have high strength in the transverse direction but a lower strength in the longitudinal direction or vice versa. Thus, by varying the tissue characteristics, the edges may be made stronger in a particular direction, or additional strength can be provided in desired locations, e.g. along the board edges, by using tissues of appropriate fibre distribution.
The mesh size and the fiber diameter for a non-woven oriented mesh used to reinforce the longitudinal marginal edge face adjacent the longitudinal edge face may also be selected according to the strength desired in the longitudinal edge. However, a mesh for a longitudinal edge margin face may for example have a tighter weave or intercices than is used for the broad faces, i.e. for example a thread or mesh count tighter than 10xc3x978. Thus the reinforcing meshes for the marginal edge faces may have relatively small openings such as for example meshes with a 16xc3x9710 count per inch may be used so as to secure the desired or necessary penetration of the fabric along the edge margins with the cementitious composition.
The nonwoven mesh for reinforcing a longitudinal marginal edge may for example comprise fleece-like mats or felts of fibers arranged in a non-oriented manner. The nonwoven non oriented mesh reinforcing material may be three dimensional in nature with the fibers thereof defining interconnecting voids. In general, the non-oriented mesh which may be employed in the reinforcement of the longitudinal marginal edges are generally those in which the voids are relatively small in size, i.e. the fibers in the mesh, mat or felt are relatively tightly packed, e.g. of 2 to 4 oz. Per square yard.
A mesh for reinforcing a longitudinal marginal edge may be of a material as described above for the mesh for reinforcing the broad face of a panel. Such a mesh may, for example be of a synthetic material (i.e. polymer) such as described above; it may in particular be of polypropylene or of a polyester. The fibers in the non woven mesh, may be held in place by needle punching or, in the case of fibers derived from synthetic material such as an above describe polymer, by melt bonding or glueing (with a suitable adhesive) of the individual fibers to each other at points of intersection.
Illustrative of the non-woven spatial fabrics which can be employed in preparing the structures of the invention is the material synfab which is described herein below;
If desired the mat may be a mixture of two or more different types of fibre, or two or more mats of different fibrous material may be used.
The fibres in the mat may be multi-filament or monofilament.
It is preferred to use meshes that are flexible, and for this reason it is preferred to use relatively thin mats having a maximum thickness of the order of about 0.5 mm to 1 mm (e.g. up to 0.2 mm) and to use meshes made of relatively thin fibres, e.g. having a fibre diameter of no more than 1 mm in particular no more than 0.2 mm (i.e. 200 microns).
A reinforcing mesh whether for the broad faces or for the longitudinal marginal edges may be bonded to the core in any suitable fashion keeping in mind the reinforcing role that these meshes are to play. A reinforcing mesh may for example be bonded to a core by a cementitious slurry, for example, a portland cement slurry, or may be bonded by a cementitious component of a core mix extending through the openings in the mesh.
In accordance with the present invention a longitudinal edge face of a longitudinal marginal edge (i.e. a minor side face of a panel) need not be reinforced with or be covered with a reinforcing fabric. If, for example, a longitudinal edge margin is reinforced with a U-shaped reinforcement mesh component the bridge member thereof need not, if so desired, be adhered to the longitudinal edge face; on the other hand the bridge member may, if desired, be adhered to a longitudinal face as, for example, by an adhesive, by cementing or by being embedded in the core surface cement material. As may be appreciated from the above a bridge member links or connects a pair of arm members (i.e. edge strip members). These arm members are adhered to a marginal area of a respective broad face. However, such adherence need not be over the entire lateral width thereof. For example, a marginal area may comprise a grip region and an adhesion free region. The adhesion free region may border the longitudinal edge face. In this latter case an arm member may be adhered only to the grip region and not to the adhesion free region such that the cross section of the marginal edge may show that a U-shape surface including the surface of the longitudinal edge is not adhered to the U-shaped reinforcement mesh component, distal end portions only of the arm members are adhered to the marginal edge faces. Keeping in mind that the purpose of the U-shaped reinforcement mesh component is to reinforce the longitudinal edge of a panel the lateral width of a grip region is preferably larger (e.g. substantially larger) the lateral width of an adhesion free region bordering the longitudinal edge face.
The reinforcing mesh of the major faces and a mesh disposed about a longitudinal marginal edge faces may, for example, be held in place in the set product by allowing a cementitious composition to infiltrate intercices of such a mesh such that at least some of the fibers of the mesh may be embedded in the hardened cementitious composition. In this case in order to facilitate such penetration of a mesh by the cementitious composition, the fabrics should comprise a sufficient or desired degree of voidage so as to allow the unhardened cement composition to penetrate the mesh. In other words, a reinforcing mesh adhered to a broad face of a core and at least the portion of an edge reinforcing mesh adhered to a core along a marginal area thereof may be pervious meshes (i.e. pervious to cementitious slurry); the openings in a mesh, scrim or other fabric in this case are to be sufficiently large to permit passage of the mesh bonding material such as a portland cement slurry, i.e. such that a mesh or scrim is cemented to or embedded in a face or surface.
In accordance with the present invention a cementitious panel may be produced employing a core mix alone or if desired by also employing a cementitious slurry.
By way of example only, a cementitious panel in accordance with the present invention, may be obtained by following the immediately herein below described steps. A first web of reinforcing mesh may first be provided for a core face which during manufacture forms part of the bottom layer of the panel and which is not as wide as the panel width. A marginal section or area of the first web on each side of the centre may be disposed to overlap a portion of an edge reinforcing web or mesh of fabric leaving outer edge portions thereof uncovered thereby; the uncovered portion may be folded over to wrap each of the two edges of the core layer and also to extend over on to the top face of the core layer and overlap the upper broad face reinforcement mesh. A cementitious slurry may first be applied onto the first web so as to embed it therein and may be applied so as to leave uncovered at least an outer portion of the edge reinforcing webs for covering the longitudinally edge faces. The centre section of the first web receives the core layer after the application of the slurry if used and it also may be laid down so as to leave exposed outer marginal portions of the web or mesh to be wrapped about the longitudinal edges. A second web of reinforcing fabric (which forms the top layer of the panel) which is of the same width as the first web may be laid down on top of the core layer so as to overlay it and as desired or necessary is pushed just under the upper surface of the core so as to be embedded in the top surface. Bonding material such as a portland cement slurry may also as desired or necessary is applied to the second web either before or after it is laid down on the core layer.
A core mix may for example comprise water, a cementitious material (i.e. a hydraulic cement which is able to set on hydration such as for example, portland cement, magnesia cement, alumina cement, gypsum, and the like or a blend thereof) and an aggregate component selected from among mineral and/or non-mineral (e.g. organic) aggregate(s). The ratio of mineral aggregate to hydraulic cement may be in ratio of 1:6 to 6:1. The ratio of non-mineral aggregate to hydraulic cement may be in ratio of 1:100 to 6:1.
The particle size distribution of the aggregate may vary over a wide range e.g. up to about ⅓ (e.g. up xc2xc) of the thickness of the panel or smaller, such as for example from {fraction (1/32)} of an inch to xc2xc of an inch.
The core mix may in particular be composed so as to comprise a lightweight mineral and/or non-mineral (e.g. organic) aggregate(s) (e.g. sand, expanded clay, expanded shale, expanded perlite, expanded vermericulite, expanded closed-cell glass beads, closed-cell polystyrene beads and/or the like). Suitable lightweight aggregates, may for example in particular be cellular in nature; a suitable non-mineral lightweight aggregate is for example expanded closed-cell polystyrene beads.
Aggregate for use in the cementitious core mix composition may be selected in accordance with the desired density of the finished panel. Aggregate may, for example, have a density of up to 120 pounds per cubic foot. For example, lightweight aggregates such as obtained from expanded forms of slag, clay, shale, slate, perlite, vermericulite and the like may produce panels having a density of from about 80 to about 115 pounds per cubic foot. On the other hand a material such as closed-cell glass beds or a plastic such as polystyrene beads may be used to obtain a panel having a density of from about 40 to 70 pounds per cubic foot or lower.
A cementitious slurry may for example comprise water and a cementitious material (i.e. a hydraulic cement as described above). A cementitious slurry, such as a portland cement slurry, is strongly basic or alkaline having a pH of at least 11, due to the presence of calcium hydroxide, e.g. a pH of from 11 to 14, such as a pH of 11 to 13, e.g. a pH of 12.5 to 13. Such a slurry tends to react with, or have an affinity for, base-reactive surfaces and consequently have a decided tendency to cling to these surfaces.
As mentioned above a reinforcing mesh is adhered to the face of a panel. It possible in accordance with the present invention for example to embed a mesh in a broad or narrow face of the core such that the mesh is disposed at or near the surface of the board so as to enhance the strength of the board or panel, i.e. the strength of the panel is enhanced if a mesh is adhered at a core face. The embedment of the reinforcing fibers just beneath the surfaces of the core may for example be carried out at a depth of submersion of mesh from for example about 0.5 mm to about 2.0 mm or less, e.g. 0.5 mm or less.
The core mix may be applied in any desired thickness, for example of values so as to be able to obtain a panel having the standard thicknesses of plasterboard. A panel may be produced in varying thickness depending upon end use: e.g. in thicknesses of xc2xcxe2x80x3, xe2x85x9cxe2x80x3, xc2xdxe2x80x3, ⅝xe2x80x3, xc2xexe2x80x3, 1xe2x80x3 etc.
In accordance with the present invention a cemetitious core mix composition may be used which when cured has cells present due to entrained or entrapped air. Accordingly a core mix may for example include or comprise a suitable air entrainment or foaming agent in such amounts so as to produce the desired or necessary degree of air entrainment.
As mentioned above the initial side edge meshes and first broad face mesh are laid down on a suitable carrier support web; the carrier support web may for example advantageously be of a non-stick material relative to the cementitious material, i.e. the carrier on which the board is formed may be of a material to which the cementitious slurry does not readily adhere, example material are polyethylene or polypropylene film, 1.0 to 5.0 mils think: polyethylene coated Kraft paper, 30 lbs to 100 lbs of strength.
As mentioned above however it may be desired to provide an edge face mesh which is not adhered to the edge face so as to avoid having the cementitious composition covering up a desired indica which is to appear on the side edge of a panel. This may be achieved for example by providing the above mentioned edge reinforcing web with an at least substantially water impervious outer surface opposite the edge face or with a fibre or filament structure which may filter out any solids at the surface thereof so as to inhibit a mechanical bond on setting of the cementitious material.
The edges reinforcements may, for example extend inwardly from a longitudinal edge face approximately 0.5xe2x80x3 to 2.5xe2x80x3.
As mentioned above polystyrene may be used as lightweight aggregate. Polystyrene should be expanded following manufacturers instruction. Bin and equipment must be of the sufficient size to comply with the production rate and the time/recipe requirements. Polystyrene preferably is expanded to the desired density with a tolerance of 0.1 lb. per cubic foot. Anti-static liquid dispensing equipment may be provided for a free flow of material into measuring bins. Rotary valves will permit the incorporation of the necessary quantity in the core mixer, e.g. to the nearest 0.01 Kg.
As mentioned other agents may be added to the cementitious material for example, an air entraining agent. Air entraining agent works like a soap except it is able to create very small air bubbles that are visible only with a microscope. The air entraining agent is not necessarily used to make the board lighter. A given amount of a specific type of air entraining agent may be chosen to create air bubbles which will inhibit damage that can be caused by freezing and thawing cycles. The bubbles may be so small that water does not have a tendency to penetrate them, so the water absorption of the board is not affected.
A panel in accordance with the present invention may thus comprise relatively thin surface reinforcement elements on the faces thereof so as to provide the panel with a relatively high strength. The panel may also have a core which is relatively readily penetrable by nails, screws and other fasteners. A panel may be obtained wherein the surface edge reinforcement layers are relatively strong and hard such that a nail or screw may be driven through the edge of panel without pre-drilling and without breaking, even when nailed or screwed almost at the very limit of the edge of the panel.

Method and apparatus for manufacturing cementitious panel with reinforced longitudinal edge


A method for purification of a gaseous stream having at least one impurity in which a porous material having at least one polyoxometalate-based material is contacted with the gaseous stream and the at least one impurity is passed through the porous material, producing a purified gaseous stream.

1. Field of the Invention
This invention relates to a method and apparatus for removal at high temperatures of undesirable components, or impurities, from a gaseous stream containing said undesirable components. Depending upon the source of the gaseous stream, e.g. fossil fuel combustion or reforming, the undesirable components that may be addressed by various embodiments of the method and apparatus of this invention include, but are not limited to, NOx, SOx, HgO, H2S, CO2, HCl, and NH3. More particularly, this invention relates to the use of polyoxometalate materials for purification of gaseous streams, such as hydrogen-containing gaseous streams produced by fossil fuel reforming, flue gases produced by fossil fuel combustion, and solid fuel gasification products, and for processing gaseous streams such as natural gas processing, comprising these undesirable components at high temperatures. The polyoxometalate materials selectively remove the undesirable components by absorption and/or diffusion through a layer of the polyoxometalate materials by concentration difference and concentrate them for more effective and efficient removal by currently available technologies.
2. Description of Related Art
H2S, CO2, HCl, and NH3 are byproducts from natural gas, coal gasification or fossil oil reforming which can produce a hydrogen-rich fuel. Removing these contaminants from the hydrogen-rich fuel supplied to proton exchange membrane fuel cell systems (PEMFC) is necessary as the H2S, HCl, and NH3 poison the fuel cell membrane and catalysts. The CO2 and extra water then dilute the fuel and reduce the fuel cell performance. However, these can be removed by other means.
Current techniques for removing these contaminants include low-temperature membrane gas separation to remove CO2 and NH3 at temperatures less than about 120° C., CuO/ZnO catalysts to remove H2S at moderately high temperatures, and Pd-based membranes for hydrogen separation. However, these techniques generally suffer from various limitations including short lifetimes and non-continuous removal of impurities, and they require substantial efforts for regeneration.
Polyoxometalate-based organic-inorganic hybrid materials, which are well-defined, discrete transition metal oxide clusters with a variety of organic ligands as charge-compensating cations, have been applied in many fields, such as catalysis, medicine, materials, surface chemistry, and photo- and electro-chromism. These unique materials are thermally stable at temperatures greater than 300° C. and capable of reversible sorption of gases and organic vapors (CO2, CHCl3, etc.). In addition, polyoxometalates are based on very low-cost starting materials, thereby providing the potential for very attractive manufacturing costs.
Pressure swing adsorption (PSA) is an adiabatic process for purification of gases in which the impurities in the gases are removed by adsorption through suitable adsorbents in fixed beds contained in pressure vessels under high pressure. Regeneration of the adsorbents is accomplished by countercurrent depressurization and by purging at low pressure with previously recovered substantially product-quality gas. To obtain a continuous flow of product, a minimum of two adsorbers is required. In this manner, one adsorber receives feed gas and actually produces a product gas of desired purity while the other adsorber performs the steps of depressurization, purging and repressurization back to the adsorption pressure. After such adsorbent regeneration and repressurization, the functions of the adsorbers are switched. Depending upon the type of impurity to be adsorbed and removed, adsorbents to be used comprise zeolitic molecular sieves, activated carbon, silica gel and activated alumina. Typically, layers of different adsorbent beds are used, thereby dividing the adsorber contents into a number of distinct zones. Monitoring and proper control of process parameters ensures a stable operation. Stable operation means a pendulating swing in each particular location, in adsorber bed or piping, of values for all parameters, i.e. pressure, temperature, flow and composition of gaseous and adsorbed phase.

Polyoxometalate material for gaseous stream purification at high temperature


The present invention provides an optical waveguide device wherein a driving voltage to be applied is reduced. The optical waveguide device comprises a substrate cut in a Z-axis direction and having an electro-optical effect, an interference type optical waveguide formed on the substrate for causing lights which propagate along a plurality of parallel optical waveguides to interfere with each other, and a lumped-constant type electrode for applying a voltage for the electro-optical effect to the light propagating along the optical waveguides which form the interference type optical waveguide. The lumped-constant type electrode complements potentials to be supplied to adjacent ones of the plurality of parallel optical waveguides to each other such that voltages having an equal absolute value but having the opposite signs are applied to the adjacent optical waveguides. The apparatus of the present invention is applied to, for example, an optical communication system.

1) Field of the Invention
This invention relates to an optical waveguide device suitable for use with an optical communication system.
2) Description of the Related Art
With the increase of the data transfer rate in recent years, in the field of optical communication systems, development of an optical waveguide device for modulating a data signal from an electric signal into an optical signal is proceeding energetically.
FIG. 3 is schematic view showing an optical modulator 110 to which a conventional optical waveguide device 100 for performing such optical modulation as just described is applied. The optical modulator 110 shown in FIG. 3 is formed by connecting RF signal generators 106a and 106b and biasing power supplies 107a and 107b, which are hereinafter described, to the optical waveguide device 100.
In the optical waveguide device 100 shown in FIG. 3, a Mach-Zehnder type optical waveguide 102 including a light incoming side Y-branch waveguide 102a, linear waveguides 102b and 102c and a light outgoing side Y-branch waveguide 102d is formed on a substrate 101Z wherein LiNbO3 (lithium niobate) is cut in vertical to the Z-axis of crystal orientation or a Z-cut direction.
Further, reference characters 103a and 103b denote signal electrodes mounted on the linear waveguides 102b and 102c, respectively. The signal electrodes 103a and 103b are connected to separate RF (Radio Frequency) signal generators 106a and 106b and apply RF signals, whose phases are opposite each other, from the RF signal generators 106a and 106b as modulation signals, respectively.
Further, reference characters 104a and 104b denote bias electrodes provided separately from the signal electrodes 103a and 103b, respectively. The bias electrode 104a is connected to the power supply 107a which produces a DC voltage (+V0), and provides a voltage as a DC (Direct Current) bias component to a microwave applied to the signal electrode 103a. The bias electrode 104b is connected to the power supply 107b which produces another DC voltage (−V0) and provides a voltage as a DC bias component to a microwave applied to the signal electrode 103b.
Further, reference numeral 105 denotes a ground electrode. The ground electrode 105 provides a ground potential as a reference for the voltages to be supplied from the signal electrodes 103a and 103b and bias electrodes 104a and 104b and is formed in a predetermined spaced relationship from the formation areas of the electrodes 103a, 103b, 104a and 104b.
Consequently, the voltages (−V0 and +V0) whose absolute values are equal to each other but whose signs are opposite to each other with reference to the potential of the ground electrode 105 are applied to the bias electrodes 104a and 104b to control a drive point corresponding to the signal electrodes 103a and 103b, respectively.
In the case of such a dual electrode structure as shown in FIG. 3 wherein the signal electrodes 103a and 103b are formed on the linear waveguides 102b and 102c, respectively, since wavelength chirp in the linear waveguides 102b and 102c can cancel each other in the outgoing side Y-branch waveguide 102d, the dual electrode structure of FIG. 3 is useful to an optical modulator for long distance transmission in that distortion of a pulse waveform as modulation data can be suppressed.
FIG. 4 is a schematic view showing a second optical modulator 210 to which another conventional optical waveguide device 200 for performing light modulation is applied. In the optical waveguide device 200 shown in FIG. 4, a Mach-Zehnder type optical waveguide 202 having a branch width smaller than that in the optical waveguide device 100 described hereinabove with reference to FIG. 3 is formed on a substrate 101X wherein LiNbO3 (lithium niobate) is cut in vertical to the X-axis of crystal orientation or a X-cut direction. It is to be noted that the optical waveguide 202 includes a light incoming side Y-branch waveguide 202a, linear waveguides 202b and 202c, and a light outgoing side Y-branch waveguide 202d.
In the optical waveguide device 200 shown in FIG. 4, since the electric field direction when a voltage is applied is different from that in the optical waveguide device 100 shown in FIG. 3, a single signal electrode 203 and a single bias electrode 204 are formed on a formation face for the linear waveguides 202b and 202c in parallel along and between the linear waveguides 202b and 202c. Consequently, similarly as in the case of FIG. 3, the signal electrode 203 can cancel wavelength chirp in the linear waveguides 202b and 202c.
It is to be noted that reference numeral 205 denotes a ground electrode, 206 an RF signal generator connected to the signal electrode 203, and 207 a power supply connected to the bias electrode 204.
It is to be noted that, where such a substrate 101X which extends in parallel to the X-axis of crystal orientation as shown in FIG. 4 is used, it is difficult to establish velocity matching between the microwave and the light. Therefore, it is usually the case that, when high-rate data is to be modulated, an optical waveguide device having the configuration shown in FIG. 3 is utilized to form an optical modulator.
However, where an optical waveguide device having such a configuration as described hereinabove with reference to FIG. 3 is utilized to form an optical modulator, since it is obliged to secure some lengths for the signal electrodes 103a and 103b on the linear waveguide 102b and 102c, it cannot be avoided to form the bias electrodes 104a and 104b comparatively short.
Since the product of the operating point voltage and the length of the electrode is specified to a fixed value from the characteristic of the device, it cannot be avoided to set the driving voltage for each of the bias electrodes 104a and 104b having a small length, that is, the driving voltages of the power supplies 107a and 107b, to a comparatively high voltage. Further, where the dual electrode structure is used, there is a subject that it cannot be avoided to prepare a plurality of power supplies for supplying such comparatively high driving voltages as described above.

Optical waveguide device with reduced driving voltage


A network monitoring system (10) for monitoring a network along which network traffic flows in a form of packets. The system comprises circuitry (36, 42) for receiving a packet communicated along the network and for determining whether the received packet satisfies a set of conditions. The system further comprises circuitry (36/30, 46), responsive to a determination that the received packet satisfies the set, for determining a measure, wherein the measure is determined over a defined time interval and comprises a ratio of packet arrival variance and a mean of packets arriving during the time interval and for comparing the measure to a threshold. Lastly, the system comprises circuitry (36, 52), responsive to the measure exceeding the threshold, for adjusting network resources.

The present embodiments relate to computer networks and are more particularly directed to a system for monitoring network performance and correcting network congestion by evaluating changes in packet arrival variance relative to mean packet arrival.
As the number of users and traffic volume continue to grow on the global Internet and other networks, an essential need has arisen to have a set of mechanisms to monitor network performance and to take corrective measures in response to falling performance. Such performance may be evaluated in various forms, including but not limited to detecting and troubleshooting network congestion. Network congestion results from mismatches between network capacity and network demand. The mismatch may be a long-term one, or at instantaneous time scales. Further, network capacity may appear to be ample when using tools that look at long-term traffic averages; however these approaches are not always suitable because a more subtle problem may arise with short bursts of packets, or peak demand. With congestion analyses mechanisms, the reliability and availability of the network nodes (e.g., IP routers) and the given internet paths can be evaluated. This is especially true for Internet Service Providers ("ISPs") seeking to comply with the Service Level Agreements ("SLAs") that they are now providing to customers. Additionally, such a need is prevalent for the underlying internet protocol ("IP") networks in the Internet.
The Internet is also evolving towards an advanced architecture that seeks to guarantee the quality of service ("QoS") for real-time applications. QoS permits the controlling of what happens to packets when there is congestion in a network, or more precisely when there is insufficient network capacity to deliver all of the offered load without any noticeable queuing delays. One type of QoS framework seeks to provide hard specific network performance guarantees to applications such as band-width/delay reservations for an imminent or future data flow. Such QoS is usually characterized in terms of ability to guarantee to an application-specified peak and average band-width, delay, jitter and packet loss. Another type is to use Class-of-Service ("CoS") such as Differentiated Services ("Diff-Serv") to represent the less ambitious approach of giving preferential treatment to certain kinds of packets, but without making any performance guarantees.
During the QoS process to provide services better than the traditional best effort, network congestion detection often becomes the starting point for the network performance analysis. In the past, a number of congestion detection and control schemes have been investigated in data networks. One congestion detection scheme uses the transport-layer protocols to infer congestion from the estimated bottleneck service time or from changes in throughput or end-to-end delay, as well as from packet drops. Specifically, the Internet has traditionally relied on mechanisms in the Transport Control Protocol ("TCP"), such as sliding window control and retransmission timer deficiencies to avoid congestion. TCP operates to seek excess bandwidth by increasing transmission rates until the network becomes congested and then reducing transmission rate once congestion occurs. A few limitations arise from this approach. First, TCP congestion detection at a first node requires an acknowledgement from a second node, that is, the increased transmission is continued until no acknowledgement is received from the second node; thus, a feedback communication is required from another node and that feedback also utilizes bandwidth on the network. Second, in its effort to identify bandwidth, TCP necessarily causes the very congestion which it then seeks to minimize, where the congestion is caused as the TCP increases the bandwidth to a point that exceeds the network capacity. Another type of congestion detection scheme is to involve network components such as routers in the entire process. As most network congestion occurs in routers, they may be considered an ideal position to monitor network load and congestion and respond thereto in a control scheme. Such network-based congestion control uses explicit signaling between routers to provide feedback congestion information to a transmitting router, where the transmitting router may then alter its behavior in response to the feedback, or an overall scheme can change the packet processing within one or more routers so as to reduce congestion. In any event, this latter scheme also requires a form of feedback from a recipient router, thereby increasing traffic on the network to accommodate the feedback and also requiring the reliance of the transmitting router on the integrity of a different router.
In view of the above, there arises a need to address the drawbacks of the prior art, as is accomplished by the preferred embodiments described below.

Network monitoring system responsive to changes in packet arrival variance and mean


A hanging fitness device for exercising abdominals includes a flatbed upper arm platform assembly having an arm cushion, vinyl cushion covering, two rubber non-skid floor stands, and a vertical stabilizer bar with an opening to connect to a vertical handle extender and a connector rod. The fitness device includes a safety bar assembly including a small opening that connects the safety bar to the flatbed upper arm platform assembly by a transverse member. The fitness device also includes a handle extender assembly with small vertical round openings on all four sides and horizontal insertion round bar with an inner V spring button. A hand grip unit assembly is configured to slidably receive the horizontal insertion bar of the handle extender, the insertion bar being locked therein by way of an inner V spring button. The device also includes a top hook assembly with a connection assembly to connect a height girder member of the hand grip unit assembly and the connector rod.

The present invention is directed generally to an exercise apparatus. More particularly, the present invention is directed to an apparatus for exercising on an overhead bar and more specifically an arm attachment apparatus for exercising the human abdominal muscles.
Exercising or working out can be accomplished in many ways and for a variety of reasons. People exercise to build and shape the body or to achieve general good health and fitness. Exercise routines can be as simple as walking, running or jogging or can be highly involved and structured to achieve a desired goal.
Gravity training as a form of exercise can be used not only for bodybuilding and toning but also can be used as a aerobic workout. In the past, gravity training was typically performed with the use of weight machines, free weights or on the floor itself. All have their advantages and disadvantages.
While the up and down movement of conventional sit-ups has it's advantages, such as specifically isolating and targeting a few midsection muscles, this movement can cause strain on the lower back muscles and spine. the positive effect of working your abdominal muscles comes at a price of sacrificing increased strength that relates to movements found in daily life.
Non impact gravity training, on the other hand, requires less impact on knees, joints and lower back and it tends to promote increased activity of more muscle groups. Non impact gravity training promotes stretching and relaxing in a way that conventional sit-ups and abdominal machines cannot. With non impact gravity training, less demands are made on the lower back that has to counteract the forward motion of the weight resisted shoulders and chest. With hanging non impact gravity training, safer workouts are accomplished though constant downward lower back stretching and movements.
Abdominal muscles are very important when it come to outward appearance of the human anatomy. This is the reason why there are so many different abdominal machines and gadgets for abs on the market today. When a conventional sit-up or a conventional abdominal machine is being used, not only are the abdominal muscles are in at work, but a host of other muscles are activated to help execute the movement. Most of the time though these movements, the lower back muscles has to take the stress of pressing against the hard surface of the floor or seat.
It is apparent that overhead bars and abdominal workouts can compliment each other. Exercise routines, especially ones that focuses on strength training should include exercises using modalities that helps stretch the muscles as well. such complimentary use of stretching and gravity is achievable when working out off the floor. However, when it came to working out the abdominal and midsection in the past. Conventional sit-ups and conventional abdominal machines were the only practical option.
There are seemingly many more knee and leg lift exercises that can be performed while off of the ground or floor than can be performed while pressing against the floor. The fact that one cannot eliminate the pressing against the floor without some form of hanging support, prevents the exercise person from benefiting from all the advantages that hanging nonimpact gravity workout has to offer.
Conventional abdominal machines are not designed for portability or mobility. Especially the ones that has heavy resistance weights as part of the machine. These machines are very costly and expensive to up keep. These machines are also large and can only be used in large health club facilities. Although conventional sit-ups can be performed almost anywhere, there is still the remaining problem of the neck and lower back constricting and overexerting themselves while lying on the floor. Even while performing leg lifts, lower back stress can easily occur. Also the constant repetitive back and forth movement of the head neck and shoulders causes dizziness and a desire not to continue the exercise. What is needed is a device which would allow the user to contract their midsection while at the same time stretch their lower back. This can most effectively be achieved though hanging nonimpact workout.


In a method for operating an indirect extrusion press, wherein the indirect extrusion press includes an indirect punch having a tool head that can be accommodated on the indirect punch, a closure piece, and a longitudinally movable block holder having a material block accommodation for accommodating a material block, after pressing a material block and forming a shell in a shell chamber, a tool head to be replaced is pushed out of the block holder by a tool head to be inserted, so that very operationally reliable removal of a shell formed during one or more pressing procedures is possible. For this purpose, an indirect extrusion press can have a maximal distance between a closure piece and an indirect punch that corresponds at least to the sum of the expanses of the tool head and of the block holder in the movement direction.

1. Field of the Invention
The invention relates to a method for operation of an indirect extrusion press and an indirect extrusion press.
2. Description of the Related Art
During indirect pressing of crude metal blocks, the forming procedure to produce the pressed product takes place with the formation of a shell, for example. The crude metal blocks may be made, for example, of copper, brass or corresponding alloys, and the shell is formed in order to avoid contaminants on the surface of the block to be formed from getting into the finished pressed product. In this connection, a tool head comprising a die plate is kept smaller in its diameter than the inside diameter of a block, to such an extent that a shell having a wall thickness of about 0.2 mm to 2.0 mm remains on the inner wall of the block holder, in each instance, as is also disclosed, for example, in EP 0 224 115 B1. The formation of a shell can also be correspondingly advantageous in the case of other materials, for example aluminum.
In this connection, a distinction should be made between direct and indirect pressing procedures, whereby in direct pressing, larger pressed products can generally be produced, with guidance of a pressing punch and of the metal to be formed in the same direction. In indirect pressing, in which the pressing punch is called an indirect punch and the material are guided in opposite directions, significantly lower friction forces generally occur, because the material does not need to be displaced relative to the block holder. In general, however, only smaller pressed products can be produced in indirect pressing, because the pressed product must be discharged through the indirect punch.
To reduce material tensions in the indirect punch, DE 101 31 901 A1 proposes screwing a clearing ring onto the indirect punch and relieving stress with a counter-nut. Alternatively, a wear plate and/or a die plate is attached by way of insertion bolts that are shrunk-fit into corresponding bores of the indirect punch.
After one or more pressing procedures, the shell that has formed as a result of pressing of the block material must generally be removed, in order to be able to implement operationally reliable pressing for subsequent pressing procedures. In known methods, in order to remove the shell, the latter is pulled out of the block holder together with the tool head, accompanied by great disassembly effort and assembly effort. Almost complete removal of the shell from the block holder, without remnant, however, is not possible in this way. Moreover, a remaining remnant of the shell has a detrimental effect on subsequent pressing procedures or on the operational reliability of subsequent pressing procedures. This detrimental effect results because the remaining remnant can lead, particularly during pressing, to undesirable block compression of the metal block or material block during the loading procedure that is intended for the subsequent pressing procedure. Furthermore, the remaining remnant of the shell can hinder secure introduction of a new tool head or of a cleaned or repaired tool head into the block holder. In particular, the tool head can become jammed on the remaining remnant.

Method for operation of an indirect extrusion press and an indirect extrusion press


Cement compositions that include improved lost circulation materials are provided. In certain exemplary embodiments, the improved lost circulation materials include inelastic particles of polyethylene, polystyrene, and/or polypropylene. Optionally, the cement compositions also may include additives such as fly ash, a surfactant, a dispersant, a fluid loss control additive, a conventional lost circulation material, an accelerator, a retarder, a salt, a mica, fiber, a formation-conditioning agent, fumed silica, bentonite, expanding additives, microspheres, weighting materials, or a defoamer.

The present invention relates to subterranean cementing operations and, more particularly, to cement compositions comprising improved lost circulation materials, and methods of using such cement compositions in subterranean formations.
Hydraulic cement compositions commonly are utilized in subterranean operations, particularly subterranean well completion and remedial operations. For example, hydraulic cement compositions are used in primary cementing operations whereby pipe strings such as casings and liners are cemented in well bores. In performing primary cementing, hydraulic cement compositions are pumped into the annular space between the walls of a well bore and the exterior surface of the pipe string disposed therein. The cement composition is permitted to set in the annular space, thereby forming an annular sheath of hardened substantially impermeable cement therein that substantially supports and positions the pipe string in the well bore and bonds the exterior surface of the pipe string to the walls of the well bore. Hydraulic cement compositions also are used in remedial cementing operations such as plugging highly permeable zones or fractures in well bores, plugging cracks and holes in pipe strings, and the like.
Subterranean formations traversed by well bores often may be weak, highly permeable, and extensively fractured. In some cases, such formations may be unable to withstand the hydrostatic pressure normally associated with fluids (e.g., cement compositions and the like) being injected into the formation. In such cases, the hydrostatic pressure may be sufficient to force such fluids into the natural or created fractures and/or permeable zones of the formation, which may result in a significant loss of fluid into the formation. This loss of fluid circulation may be problematic for a number of reasons. For example, where the loss of circulation occurs during a cementing operation, excessive fluid loss may cause a cement composition to dehydrate prematurely. Premature dehydration of the cement composition may excessively viscosify the cement composition, and potentially may cause an operator to terminate the cementing operation, wash out the cement composition from the well bore, and restart the cementing operation anew.
Previous attempts to minimize the loss of circulation into the subterranean formation have involved adding a variety of additives, including, but not limited to, asphaltenes, ground coal, cellulosic materials, plastic materials, walnut hulls, sized waste formica, and the like, to the cement composition. Such additives have been included, for example, to attempt to plug or bridge formation fractures and/or the permeable zones in the formation where the treatment fluids typically may be lost. However, conventional materials often are not rigid, and thus a greater concentration of these materials may be required to effectively prevent the loss of circulation during a cementing operation.
Polyethylene is used extensively in manufacturing, for instance, trash cans, buckets, baskets, and other materials of commerce. With time, the plasticizer that often is a component of a typical polyethylene product may begin to degrade, which may cause the polyethylene to become increasingly brittle, which may reduce its usable life. Consumers generally have no use for brittle polyethylene materials and often discard or otherwise dispose of them, commonly in a landfill, where the polyethylene may reside indefinitely, because it generally does not deteriorate until after a very long time.

Cement compositions comprising improved lost circulation materials and methods of use in subterranean formations


Systems, devices and methods are described for determining attributes identifying media items from other media items. A first video sequence of a first media item is received from a media source, the video sequence including one or more images having first banner information embedded therein. The attributes of the first media item are determined based on at least the first banner information extracted from the first video sequence. The determined attributes of the first media item can then be stored or otherwise processed as desired.

A personal media broadcaster (e.g., a SLINGBOX product created by Sling Media of Foster City, Calif.) is any device or other system that allows a user to access media items from various media sources at remote locations. The media sources are typically coupled to the personal media broadcaster to feed audio/video ("AV") signals of the media item from the media source to the personal media broadcaster. The personal media broadcaster converts the A/V signal into a datastream suitable for transmission over a network. The user can receive the datastream at remote locations and access the media item using a client device including software or hardware components that operate in conjunction with the personal media broadcaster.
While accessing the media item on the client device, a user may want to store the media items for later viewing on the client device or for sharing the media item with other people. If the user wants to share the media item, the user may clip and send the media item to a server via a network. After the clipped media item is uploaded to the server, other people may log onto the server via the network and access the media item. Various systems may be developed to take advantage of the clipped media items stored on the server. One example of such a system would involve sending advertisements together with the media file from the server. The advertisements may then become a source of revenue for the service operator.
In some cases it may be advantageous to store attributes or the identity of the media item together with the media item itself on the client device or the server. The attributes of the media item may include, among other information, the name of the network broadcasting the media item, the time the media item was broadcasted, the title of the media item, the genre of the media item, episode number, content advisory and rating information, program synopsis, copy control advisory, the identity of the key players in the program, and/or other information as appropriate. These attributes may be used to uniquely identify the media item. By storing the identity or attributes of the media item, various value-added services (e.g., more convenient and efficient search and retrieval of the media items) may be implemented on the server. Further, by storing the identity or attributes of the media item, unauthorized distribution of a copyrighted or other protected media item may be blocked. In order to prevent unwanted distribution of the media item, however, the identity or attributes of the media item must typically be first determined to check if the media item is protected.
Users, however, may find it inconvenient and time-consuming to manually indicate the identity or attributes of the media item after selecting, editing or clipping the media item for storing or sharing. Even if the server requests entry of the identity or the attributes of the media item for storage or sharing, the users may simply omit the identity or attributes of the media item or enter false identity or attributes of the media item. Such incorrect or false identity or attributes may become an issue in providing the value-added servers or blocking distribution of the copyrighted media items.
It is therefore desirable to create systems and techniques for automatically determining attributes of media items accessed via a personal media broadcaster or the like. Various desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background section.

Systems and methods for determining attributes of media items accessed via a personal media broadcaster