Abstract: A molten refractory product having the following average chemical composition, in wt % on the basis of oxides and for a total of 100%: Al2O3: balance to 100%; Fe2O3: 0.6%-5.0% and/or TiO2: 1.5%-10.0%; Fe2O3+TiO2?10.0%; Na2O+K2O: 1.0%-8.0%; SiO2: 0.2%-2.0%; CaO+BaO+SrO: ?0.5%; Other oxide species: ?1.5%. Also, a glass-melting furnace and the use of the refractory product in the glass-melting furnace.

Abstract: Refractory tile systems for covering an internal wall of a high temperature furnace or boiler are described. The systems may comprise a base tile having a front face and a back face, and a shielding tile having a front face and a back face. The back face of the base tile may comprise one or more attachment points for mounting the base tile to the internal wall using an anchoring system, wherein the shielding tile is equipped with a protrusion along a first side, extending from the back face of the shielding tile and adapted to stably arrange the shielding tile in a suspended position from the base tile when mounted to the internal wall, and an overhang along a second side opposite the first side and extending from the front side of the shielding tile, such that in a mounted position, the overhang partially covers an adjacent shielding tile.

Abstract: A fluidized bed system having a containment vessel, a precast and predried monolithic refractory floor module positioned in the vessel, and a plurality of precast and predried monolithic refractory wall modules stacked within the vessel. The plurality of wall modules includes a first wall module is positioned on the floor module, wherein the floor module and the first wall module have interlocking surfaces, and wall modules adjacent to one another have interlocking surfaces. A method for assembling a fluidized bed reactor is also provided.

Abstract: A combustion device in the form of an elevated fixed-grate that includes arcuately shaped solid refractory brick with ribs placed thereunder so as to allow horizontal air flow for fuel combustion. The brick are arranged atop one another in a stacked concentric configuration that forms a central fuel passageway and allows cascading of a fuel pile throughout the combustion stages. The device provides the benefit of proper de-ashing online while distributing the underfire air radially around the fuel pile. The elevated design of the bricks allows the air to be evenly distributed throughout the fuel pile and further allows the isolation of overfire and underfire air. Segregating overfire and underfire air in an evenly distributed manner allows the burner to combust a wide range of fuel moisture contents without modifying the mechanical components of the burner.

Abstract: A wall lining of industrial ovens for protecting from corrosion, in particular, a heat-resistant wall made of concrete, steel, sheet metal, or the like. The lining of the wall is made of at least two layers, wherein a layer is pressurized as a blocking layer.

Abstract: The invention relates to designs for the linings and roofs of heat-engineering units for mechanical engineering and can be used in the construction of industrial furnaces in the metallurgical, heat-engineering, petroleum-processing and petrochemical industries, in the production of construction materials and in other branches of industry. The aim of the invention is to produce a strong refractory lining for resistance furnaces with a low consumption of electrical energy and a reduction in the weight and overall dimensions of the furnace. All parts of the furnace lining are formed using monolithic blocks made of high-strength refractory, electrically nonconductive phosphate concretes and are used as load-bearing construction elements. Said elements are used in resistance furnaces with an operating temperature of up to 1000° C.

Abstract: SO3 is formed from a replenished circulating inventory of fresh and recycled SO2. Also, a feed stream of replenished SO2 is heated by indirect heat exchange with a hot stream of SO2 and SO3 whereby the hot stream is cooled for separating the two gases. The heated feed stream of replenished SO2 serves as a hot gaseous feed to a sulfur burner. This SO2 feed is divided into two feed streams, one being oxygenated with pure oxygen and the other remains as an SO2 feed. These feeds plus a feed of molten sulfur are concurrently and separately introduced into the sulfur burner where additional SO2 is formed via continuous exothermic reaction. Although heated, the oxygenated feed(s) of SO2 bring in the needed oxygen for the reaction and the feeds of the oxygenated and non-oxygenated SO2 serve as a heat sink in the sulfur burner to reduce the temperature therein.

Abstract: An improved corbel includes a first tier having first blocks and a second tier having second blocks. Each of the first blocks includes a first aperture extending through the block from a first surface to a back surface and a second aperture formed through a top surface of the block, extending into the first aperture. The first blocks are arranged on a substantially planar surface to align the respective first apertures to define a first passageway. Each of the second blocks includes a third aperture extending through the second block from a top surface to a bottom surface. The second blocks are disposed above the first tier to align the third aperture of each of the second blocks with the second aperture of the first blocks to form a second passageway.

Abstract: A reversible jamb block for a furnace, oven or kiln, having an attachment side adapted to removably attach to the first side of a doorway for the furnace, oven or kiln, and adapted to removably attach to the second side of the doorway, such that one face of the jamb block is directed away from the furnace when the attachment side of the jamb block is attached to the first side of the doorway, and a second face opposite the first face, is directed away from the furnace when the attachment side of the jamb block is attached to the second side of the doorway.

Abstract: There is described a heat shield element comprising a hot side which is turned towards the hot medium, a cold side which is turned away from the hot medium, peripheral sides which connect the hot side to the cold side and a material volume which is defined by the hot side, the cold side and the peripheral sides, wherein the material volume comprises at least two material areas which are made of different materials. The materials are different from each other at least in respect of their resistance and/or thermal expansion coefficient.

Abstract: A heat chamber having multiple segments formed from castable material.

Abstract: A brick hearth system includes a rigid containment shell in which a concave bottom is lined with a hearth refractory sub-layer and hearth brick working layer. The outer perimeter of the hearth refractory is ringed with thrust blocks to compress the whole toward the center and to thereby deny gaps from forming between the separate bricks. Many individual thrust rods penetrate the outer bottom of the containment shell, and such are used to transmit compression forces generated outside the shell to be applied against the thrust blocks in unison. Each thrust rod receives an adjustable amount of inward force from a spring, acting either directly or through a beam or rocker arm. These are anchored to and use the hoop strength of the containment shell as leverage. As the hearth brick working layer grows during its service life, the ring of thrust blocks grows in diameter as well inside the margins provided within the containment shell.

Abstract: A refractory structural element is provided that is useful for lining the inner surface of a construct typically used as a kiln or other high temperature system. An element includes a stem portion associated with a flared end block portion whereby the flared end block portion is compatible with other structural elements to form a substantially continuous tiled surface when a plurality of refractory structural elements are laid adjacent to each other. The stem portion optionally has a plurality of protrusions decorated on its outer surface that may serve to adjust heat dissipation from the element.

Abstract: A brick hearth system comprises a rigid containment shell in which a concave bottom is lined with a hearth refractory sub-layer and hearth brick working layer. The outer perimeter of the hearth refractory is ringed with thrust blocks to compress the whole toward the center and to thereby deny gaps from forming between the separate bricks. Many individual thrust rods penetrate the outer bottom of the containment shell, and such are used to transmit compression forces generated outside the shell to be applied against the thrust blocks in unison. Each thrust rod receives an adjustable amount of inward force from a spring, acting either directly or through a beam or rocker arm. These are anchored to and use the hoop strength of the containment shell as leverage. As the hearth brick working layer grows during its service life, the ring of thrust blocks grows in diameter as well inside the margins provided within the containment shell.

Abstract: A refractory tile has a body formed from a refractory material. The body has a front side that defines a front plane, and a rear side that defines a rear plane that is opposite the front plane. A concave portion is formed in the rear side and is contoured to a wall of boiler tubes. The body also has an inclined portion extending from the front plane to the rear plane. The inclined portion is formed at an acute angle with respect to the rear plane. The inclined portion defines an edge at an intersection with the rear plane. The edge directly contacts the wall without a backfill material. The tiles form an array of upper refractory tiles located only on an uppermost row of the array above lower refractory, against the bare wall of boiler tubes.

Abstract: An improved corbel includes a first tier having first blocks and a second tier having second blocks. Each of the first blocks includes a first aperture extending through the block from a first surface to a back surface and a second aperture formed through a top surface of the block, extending into the first aperture. The first blocks are arranged on a substantially planar surface to align the respective first apertures to define a first passageway. Each of the second blocks includes a third aperture extending through the second block from a top surface to a bottom surface. The second blocks are disposed above the first tier to align the third aperture of each of the second blocks with the second aperture of the first blocks to form a second passageway.

Abstract: A refractory brick and mortar joint comprise a cold face of the refractory brick; a hot face of the refractory brick opposite the cold face, wherein the hot face is shorter in length than the cold face; and at least one tapered mortar joint extending from the hot face to the cold face, wherein the at least one tapered mortar joint is thicker at the hot face of the refractory brick than at the cold face of the refractory brick. A refractory brick comprises a cold face; a hot face opposite the cold face, wherein the hot face is shorter in length than the cold face; and at least one surface extending from the cold face to the hot face, wherein the at least one surface is angled to accommodate the difference in length between the cold face and the hot face.

Abstract: The furnace of the present invention includes a body of a furnace having a cylindrical shape; a steel shell which is arranged at an inside surface of the furnace; and a lining refractory which is arranged at an inside of the steel shell and includes a plurality of refractory blocks, wherein: each of the refractory blocks includes a hot-face end surface which has a hexagonal shape exposed to a middle of the furnace, and a cold-face end surface which has a hexagonal shape larger than the hot-face end surface, the cold-face end surface being arranged at an outer periphery side of the furnace; the refractory blocks are arranged such that each position of the hot-face end surface is positioned along the radial direction of the furnace at a predetermined reference position; and the refractory blocks are arrayed along the circumferential direction of an inside surface of the steel shell, thereby being stacked in a honeycomb manner.

Abstract: A combustion device in the form of an elevated fixed-grate that includes arcuately shaped solid refractory brick with ribs placed thereunder so as to allow horizontal air flow for fuel combustion. The brick are arranged atop one another in a stacked concentric configuration that forms a central fuel passageway and allows cascading of a fuel pile throughout the combustion stages. The device provides the benefit of proper de-ashing online while distributing the underfire air radially around the fuel pile. The elevated design of the bricks allows the air to be evenly distributed throughout the fuel pile and further allows the isolation of overfire and underfire air. Segregating overfire and underfire air in an evenly distributed manner allows the burner to combust a wide range of fuel moisture contents without modifying the mechanical components of the burner.

Abstract: Presented are an insulation brick and the method of using an insulation brick to create a thermal lining. A set of corrugations are formed into a sidewall of the brick to increase the thermal insulation. A first end of the insulation brick has a convex portion while the second end of the insulation brick has a convex portion. This allows a first insulation brick to mate with another brick in an end to end configuration.

Abstract: An insulating block for lining an interior surface of a furnace wall. The block is comprised of at least two insulating module sections. Each module section is formed from two or more layers of a ceramic (material) blanket. The layers of the ceramic blanket are held together by one or more plastic fasteners, each plastic fastener comprised of an elongated fiber portion that is dimensioned to extend at least partially through at least two of the layers and enlarged end sections dimensioned to engage the layers. The layers of the blanket are held together side-by-side by the plastic fasteners. A support member has at least one anchor rod (tube) affixed thereto. The insulating module sections are mounted on the anchor rod.

Abstract: A refractory brick and mortar joint comprise a cold face of the refractory brick; a hot face of the refractory brick opposite the cold face, wherein the hot face is shorter in length than the cold face; and at least one tapered mortar joint extending from the hot face to the cold face, wherein the at least one tapered mortar joint is thicker at the hot face of the refractory brick than at the cold face of the refractory brick. A refractory brick comprises a cold face; a hot face opposite the cold face, wherein the hot face is shorter in length than the cold face; and at least one surface extending from the cold face to the hot face, wherein the at least one surface is angled to accommodate the difference in length between the cold face and the hot face.

Abstract: A brick hearth system comprises a rigid containment shell in which a concave bottom is lined with a hearth refractory sub-layer and hearth brick working layer. The outer perimeter of the hearth refractory is ringed with thrust blocks to compress the whole toward the center and to thereby deny gaps from forming between the separate bricks. Many individual thrust rods penetrate the outer bottom of the containment shell, and such are used to transmit compression forces generated outside the shell to be applied against the thrust blocks in unison. Each thrust rod receives an adjustable amount of inward force from a spring, acting either directly or through a beam or rocker arm. These are anchored to and use the hoop strength of the containment shell as leverage. As the hearth brick working layer grows during its service life, the ring of thrust blocks grows in diameter as well inside the margins provided within the containment shell.

Abstract: A tile for lining an internal surface in a heavy wear area. The tile includes at least one locating rod embedded within said tile and an internal mechanism for laterally extending said at least one locating rod out of said tile and into a gap in an adjoining structure which may be another tile. The tiles forming the lining surface are securely held in place as a result of the selective deployment of the locating rods into a gap in the adjoining structure.

Abstract: A method includes containing a high-temperature alkali salt containing environment using a refractory containment liner containing MgAl2O4 spinel. A method, includes forming a refractory brick containing MgAl2O4 spinel having an exterior chill zone defined by substantially columnar crystallization and an interior zone defined by substantially equiaxed crystallization; and removing at least a portion of the exterior chill zone from the refractory brick containing MgAl2O4 spinel by scalping the refractory brick containing MgAl2O4 spinel to define at least one outer surface having an area of substantially equiaxed crystallization. A product of manufacture includes a refractory brick containing MgAl2O4 spinel including an interior zone defined by substantially equiaxed crystallization; and at least one outer surface having an area of substantially equiaxed crystallization.

Abstract: A brick hearth system comprises a rigid containment shell in which a concave bottom is lined with a hearth refractory sub-layer and hearth brick working layer. The outer perimeter of the hearth refractory is ringed with thrust blocks to compress the whole toward the center and to thereby deny gaps from forming between the separate bricks. Many individual thrust rods penetrate the outer bottom of the containment shell, and such are used to transmit compression forces generated outside the shell to be applied against the thrust blocks in unison. Each thrust rod receives an adjustable amount of inward force from a spring, acting either directly or through a beam or rocker arm. These are anchored to and use the hoop strength of the containment shell as leverage. As the hearth brick working layer grows during its service life, the ring of thrust blocks grows in diameter as well inside the margins provided within the containment shell.

Abstract: The invention concerns a refractory tile having two aligned fixing points, any two adjacent fixing points of the alignment being spaced apart by a constant distance A, first (44) and last (46) fixing points of the alignment being remote, in the direction of the alignment, by distances ?1 and ?2 from the first (40) and second (42) edges of the tile extending proximate the first (44) and last (46) fixing points, respectively. The tile is characterized in that 0<A?(a1+a2). The invention is applicable to gasifiers.

Abstract: A refractory brick having a plurality of segments positioned along a longitudinal axis of the refractory brick. Each segment has at least two arcuate recesses and at least two arcuate ridges. The recesses of a first segment of the segments are positioned at a radial offset with respect to the recesses of a second segment which is adjacent the first segment. A plurality of refractory bricks are interlocked with respect to each other to form a refractory construction.

Abstract: A thermal shielding brick is useable for lining a combustion chamber wall. The thermal shielding brick has a hot side, which can be exposed to a hot medium a wall side located opposite the hot side, and a peripheral side that is joined to the hot side and to the wall side. A damping element is placed on the peripheral side and effectively prevents fragments from detaching from the thermal shielding brick if broken. A combustion chamber having an inner combustion chamber lining, includes the thermal shielding bricks. Further, a gas turbine, includes the combustion chamber.

Abstract: A tile anchoring system for use in reactors and other furnace like equipment which involves the use of a tile that contains various internal parts. According to the various embodiments of the present invention, the tile is formed as more than one part. In the present invention, various techniques and parts are used to anchor tiles to surfaces wherein the various parts and the tiles themselves “snap” into place with one another and/or with an existing hexmetal mesh structure.

Abstract: Methods for improving the strength of alumina refractory materials are disclosed. The method involves exposing the alumina material to a halogen gas. The treated materials can be used in furnaces for producing fused silica optical members.

Abstract: A lining (10) for a furnace the lining (10) having insulating material (12) attached to an inside wall (11) of the furnace, the insulating material (12) in use having a hot face (20) which faces inwardly of the furnace, and a cold face at or adjacent the furnace wall (11) characterized in that a protective element (26) is provided at least partially to cover the hot face (20), and/or the cold (C) face, the protective element (26) being secured relative to the face by a securing means (27, 27b), which co-operates with a member (25, 25a; 25b; 25c) which is embedded in the insulating material (12).

Abstract: A coke oven buckstay moving device and method which can be used to quickly, reliably, and smoothly repair buckstays compared to conventional methods and devices. The coke oven buckstay moving means includes a main car, a subcar, a frame, and securing means. The main car is used when repairing pillered buckstays that support oven walls of the coke oven, and moves on a coke side platform or a machine side platform. The subcar is placed on the main car, and can freely move forward and backward in a direction of a lengthwise direction of the coke oven. The frame is provided in a standing manner on the subcar. The securing members are mounted to the frame and are used to grasp and secure the buckstays. According to the method, a damaged portion of the buckstay is secured to the subcar, cut, and then removed. Reversing the steps, a replacement buckstay is secured to the subcar, moved into position, and welded into place. The subcar is detached, and the oven repaired.

Abstract: The invention relates to a heat shield block, in particular for lining a combustion chamber wall, having a hot side which can be subjected to a hot medium, a wall side opposite the hot side, and a peripheral side adjoining the hot side and the wall side. A tension element which can be prestressed to a prestress (Fz) is attached to the peripheral side, release of a fragment, formed during a fracture, of the heat shield block being reliably prevented by the prestress (Fz) of the tension element. The invention also relates to the use of a heat shield block, in particular for lining a combustion chamber wall of a gas turbine.

Abstract: A refractory brick having a plurality of segments positioned along a longitudinal axis of the refractory brick. Each segment has at least two arcuate recesses and at least two arcuate ridges. The recesses of a first segment of the segments are positioned at a radial offset with respect to the recesses of a second segment which is adjacent the first segment. A plurality of refractory bricks are interlocked with respect to each other to form a refractory construction.

Abstract: Methods for improving the strength of alumina refractory materials are disclosed. The method involves exposing the alumina material to a halogen gas. The treated materials can be used in furnaces for producing fused silica optical members.

Abstract: The invention relates to a thermal shielding brick (1, 1A, 1B), especially for lining a combustion chamber wall. Said thermal shielding brick has a hot side (5), which can be exposed to a hot medium, a wall side (7) located opposite said hot side (5), and a peripheral side (69) that is joined to the hot side and to the wall side. A damping element (3, 3A, 3B) is placed on the peripheral side and effectively prevents fragments (81,81A) from detaching from the thermal shielding brick (1, 1A, 1B) if broken. The invention also relates to a combustion chamber having an inner combustion chamber lining, which comprises said thermal shielding bricks (1, 1A, 1B), and to a gas turbine with a combustion chamber.

Abstract: A brick is made of refractory material, preferably for use in a furnace for calcining carbon bodies, wherein at least one surface of the brick that is facing towards an adjacent brick is provided with mating elements such as recesses and projections. The mating elements are rotationally symmetric about an axis that is perpendicular to the surface.

Abstract: Methods for improving the strength of alumina refractory materials are disclosed. The method involves exposing the alumina material to a halogen gas. The treated materials can be used in furnaces for producing fused silica optical members.

Abstract: An article of relatively pure silica, and a furnace and method of producing the article. The article is produced by collecting molten silica particles in a refractory furnace in which at least a portion of the refractory has been exposed to a halogen-containing gas to react with contaminating metal ions in the refractory.

Abstract: A wall segment is for a combustion area to which a hot fluid can be applied. The wall segment includes a metallic supporting structure, with a heat protection element mounted on it. The metallic supporting structure is provided at least in places with a thin and/or metallic, heat-resistant separating layer. The separating layer is fitted between the metallic supporting structure and the heat protection element.

Abstract: A refractory anchor and method of use. The anchor is made by combining two similar sections that are clinched together to form an elongated X-shape. The bilateral symmetrical shape affords maximum anchorage of the refractory, and through-flow of the refractory is afforded by voids through the anchor. The anchor has feet that attach to the surface to be protected, thus allowing refractory to migrate under the anchor. The similar sections can also be used alone as anchors where placement area is limited or irregular. In an alternative embodiment, the anchors have only center feet, to allow them to be stud welded. The anchors are useful in both repair work as well as new refractory applications.

Abstract: Chimney-like cooling passages that have opposite outlet and inlet end regions open to ambient air also have central regions that extend through heated components of industrial furnaces. The passages preferably are defined by conduits that are oriented and configured in a manner that enables thermally induced flows of ambient air to self establish through the conduits to cool the furnace components once the furnace components become heated. The passages function like chimneys, with each having its outlet located higher than its inlet so that ambient air will effectively rise as it flows from the inlet to the outlet. The passages may provide increases in cross-sectional area somewhere along their lengths so that heated ambient air expanding in the passages is encouraged to discharge from the less restrictive, larger area outlets rather than from the smaller area inlets.

Abstract: A sintered material includes a polycrystalline substance of MgAl2O4 and/or Al2O3; and 3 to 90 weight percent of Cr2O3 and/or CeO2. Furnace material, furnace wall block, high temperature protection tube, and high temperature protecting member are made of such sintered material, and have higher heat resistance and corrosion resistance.

Abstract: An arrangement for insulating a wall of a metallic combustion chamber is disclosed. A layer of insulating material is applied to the metallic wall and a plurality of ceramic wall panels are applied over the ceramic insulation material. The wall panels are retained by fastening elements that pass through an opening in the wall panels. The opening in the wall panels has a frusto-conical surface and the engagement surface of the fastening element is at least partially spherical to avoid mechanical and thermal stresses.

Abstract: A burner apparatus comprises a conduit adapted to convey preheated oxidant and having outlet and inlet ends, and a conduit adapted to convey preheated fuel and having outlet and inlet ends. The conduit adapted to convey preheated fuel is substantially parallel to the conduit adapted to convey preheated oxidant. The conduit adapted to convey preheated oxidant is positioned substantially vertically above the conduit adapted to convey preheated fuel. The conduit adapted to convey preheated oxidant and the conduit adapted to convey preheated fuel each are positioned within its own respective elongate cavity in a refractory burner block. Each of the conduits are positioned in their respective cavity such that a substantially annular region is present between an outer surface of each conduit and its respective cavity. Each conduit inlet end extends through a respective plenum for receiving an ambient temperature fluid, the plenums adapted to pass the ambient temperature fluid into the respective annular regions.

Abstract: A coke oven wall (4) comprising a plurality of bricks (38, 42, 46, 120) laid so as to define first and second wall faces (40, 44), and plurality of flue cavities (14) extending therein characterized in that at least part of the wall is made first, second and third bricks (38, 42, 120) which are laid together and define in part the first and second faces and the flue cavities wherein the first brick comprises a first body portion (48) and an inwardly projecting first leg (50), the second brick comprises a second body portion (64) and an inwardly projecting second leg (66) the third brick comprises a flue wall brick (46, 120) which is located between and aligned with the first and second legs.

Abstract: The present invention encompasses a modular fireplace having a first side wall, a second side wall, and a back wall that is contiguous with the first side wall and the second side wall and defines an interior open-faced firebox region having a substantially "U" shape in top plan view. The first side wall is constructed from a plurality of sequentially stacked modular first side blocks and the second side wall is formed from a plurality of sequentially stacked modular second side blocks. The back wall has a first modular corner block, a second modular corner block, and at least one substantially vertical spacer block that are joined so that the first corner block and the second corner block are contiguous with the spacer block. To aid in the efficient drafting of the fireplace, each of the spacer blocks may have a spacer block air chamber extending therein from an open upper end on the spacer block top end to a closed lower end proximate the spacer block bottom end.

Abstract: In the case of a ceramic liner for combustion spaces, comprising at least one wall element (3), made of refractory structural ceramic and having at least one through-opening (6), and a fastening element (4), consisting of refractory structural ceramic, per opening (6), the fastening element (4) is resiliently fastened by its foot in a metallic holding device (5) fastened on the metallic supporting wall (1). The head (20) of the fastening element (4) rests in the opening (6) in the wall element (3).The wall element (3) is designed in the form of a box, having a base (25) which runs parallel to the metallic wall (1), having an inside wall (23) which surrounds the opening (6) in an annular manner and is supported directly or indirectly on the metallic supporting wall (1), and having outside walls (24) which extend up to the metallic supporting wall (1) without touching the latter.

Abstract: A high temperature industrial roof assembly having two refractory bricks with adjacent faces, opposing hanger recesses, a hanger rod extending from the recesses to the top of the assembly, the refractory bricks being held in an adjacent position by a securing device, a hanger rod with a locking mechanism at one end and a hook at the other end, a hanger having opposed refractory engaging projections adapted to engage the hanger recesses, a hanger rod hole allowing free rotation about the hanger rod end above the locking mechanism, and a locking mechanism engagement recess which when engaged with the locking mechanism prevents rotation of the hanger rod in relation to the hanger at 90 degree increments and provides that depression of the one end of the hanger rod into the locking mechanism engagement recess permits rotation of the hanger rod with respect to the hanger. The locking mechanism comprises opposing tabs.