Abstract: An example of a kit for three-dimensional printing includes a build material composition and a crosslinking agent to be applied to at least a portion of the build material composition during 3D printing. The build material composition of the kit includes an amorphous polymeric material. The crosslinking composition of the kit includes a crosslinking agent to crosslink with the amorphous polymeric material in the at least the portion, to yield a crosslinked polymer network.

Abstract: Examples of an apparatus for dispensing a powdered material are described. The dispensing apparatus comprises a dispenser with an inlet and a dispensing opening, and a vibrating system that is in communication to the dispenser and which provides a continuing periodic oscillation of the dispenser. The apparatus further comprises a controller in communication with a driver of the vibrating system to control a frequency, amplitude and duration of the vibrations such that the powdered material continuously flows out through the dispensing opening during vibration of the dispenser.

Abstract: A method for providing control data to an additive manufacturing device includes a first step of accessing computer-based model data of a partial area of a cross-section of the object, and a second step of generating a data model of the sub-region, by specifying a solidification of the building material by at least one energy beam bundle along at least one solidification path. A plurality of solidification path sections are scanned at least twice with an energy beam bundle and the amount of energy to be introduced during the scanning is specified so that either the amount of energy introduced during the first scanning or a subsequent scanning is is too small to cause a solidification of the building material. In a third step, control data corresponding to the data model generated in the second step are provided for generating a control data set for the additive manufacturing device.

Abstract: Lost wax casting bonding methods and systems. A method for bonding a wax component in a feeder system for a lost wax casting process comprises embedding conductive nano-particles in wax to form a sacrificial susceptor. The method includes coupling the wax component to another component such that the sacrificial susceptor is at an interface of the wax component and the other component. The method comprises inductively heating the sacrificial susceptor to cause the wax of the sacrificial susceptor and at least a portion of wax of the wax component to melt to thereby form a bond between the wax component and the other component.

Abstract: A method for post-processing part obtained by additive manufacturing through sintering of a plastic powder, in order to remove particles detached from the part or partially sintered, the method including, consecutively, stripping (S1) and ionizing blowing (S2). Such a method makes it possible to remove particles having a largest dimension greater than a given dimension. The invention also relates to a corresponding manufacturing method of a plastic material part, and to a corresponding production method.

Abstract: This disclosure describes three-dimensional printing kits, methods, and systems for three-dimensional printing with triethylene glycol fusing agents. In one example, a three-dimensional printing kit can include a powder bed material including polymer particles and a fusing agent to selectively apply to the powder bed material. The fusing agent can include water, a radiation absorber, and triethylene glycol in an amount from about 20 wt % to about 35 wt %. The radiation absorber can absorb radiation energy and convert the radiation energy to heat to fuse the powder bed material.

Abstract: A method, apparatus, and program for additive manufacturing. The additive manufacturing device includes a positioning mechanism configured to provide independent movement of at least one build unit in at least two dimensions. The build unit may further include a gasflow device for providing a flow zone along a first direction with relation to the build unit. The build unit may further include a powder delivery mechanism and an irradiation beam directing unit. The irradiation bean unit may follow a first irradiation path, wherein the first irradiation path forms at least a first solidification line and at least a second solidification line formed at an angle other than 0° and 180° with respect to the first solidification line. During the formation of the first solidification line, the build unit may be positioned in a first orientation such that the first direction of the flow zone is substantially perpendicular to the first solidification line.

Abstract: A powder recirculation system for an apparatus for manufacturing a three-dimensional object (500) from powder is provided. The powder recirculation system comprises: a delivery path coupled to an outlet of a powder tank (410), the powder tank configured to store the powder; a powder repository (115) coupled to an outlet of the delivery path, the delivery path comprising a delivery mechanism for delivering the powder from the powder tank to the powder repository; a powder recirculation path coupled to an outlet (102) of the powder repository, wherein the powder recirculation path is configured to return first excess powder from the powder repository to the delivery path at a location (103, 104) upstream of the outlet of the powder tank.

Abstract: An article of manufacture making system for making an article of manufacture containing a plurality of dry solid additives, such as fibers, that utilizes a dry solid additive delivery system with a relatively low Stokes Number for the dry solid additives.

Abstract: The present invention is a sintering method of a ceramic for sintering characterized by forming a layer containing a carbon powder on a surface of an article consisting of a ceramic for sintering, and then irradiating with laser a surface of the carbon powder-containing layer of a lamination obtained.

Abstract: The disclosed subject matter relates to method for increasing the molecular weight of a polymer material during an additive manufacturing process. The method can comprise disposing a first layer of the polymer material at a target surface; exposing the first layer of the polymer material to an energy source for a sufficient period of time to sinter or melt and undergo a condensation reaction at least at a portion of the polymer material; controlling the condensation reaction to allow a desired increased number average molecular weight of the polymer material; and repeating the method steps to form an object in a layerwise fashion. Controlling the condensation reaction can comprise controlling and/or adjusting an energy 10 source-related parameter, a polymer-related parameter, a temperature related parameter, a vacuum related parameter, a process duration, a processing gas, an air flow volume and/or speed, or a combination thereof.

Abstract: Examples relate to methods of printing a 3D printed tamper evident security structure for protecting a feature; the method comprising repeatedly: depositing a layer of build material; doping one or more than one region of the layer of build material using a dopant to influence a respective electrical attribute of one or more than one region associated with a graph of the structure; and agglomerating one or more than one selected portion of the layer of the build material, including the one or more than one doped region of the layer of build material, to form progressively the graph with a predetermined measurable electrical characteristic.

Abstract: A three-dimensional shaping device includes a laser irradiation unit (10), a shroud (20), and a protection member (14). The laser irradiation unit includes an optical system (12). The shroud (20) includes an inside space (S0) that extends from one end opening portion (202) to another end opening portion (206). The protection member (14) is formed of a transparent material and is arranged at the one end opening portion (202) of the shroud (20) and causes a laser light emitted from the laser irradiation unit (10) to be transmitted therethrough so that a three-dimensional shaped object is fabricated in a shaping area by sintering or melting and solidifying a powder. The shroud (20) further includes a side wall portion (22) that demarcates a first inside space (S1) and a second inside space (S2), an air supply port (210), an exhaust port (220), and ventilation members (212, 214).

Abstract: A control and feedback technique to determine the proper location of powder control temperature regions includes detecting solid parts having specified shape and thermal characteristics. The solid parts are generated by a 3D printer. The solid parts include powder material fused on a layer by layer basis. A powder control temperature region is selected in each layer of powder material, wherein the region is located in unfused powder material adjacent to the solid parts, and wherein the region is selected based on characteristics of the shape of a build area and thermal imaging associated with any of a structural formation of the solid parts adjacent to the region, and an amount of thermal energy radiated by the solid parts adjacent to the region. The amount of thermal energy to cause fusing of the powder material on each subsequent layer is modified based on location of the powder control temperature region.

Abstract: An additive-manufacturing apparatus (100) comprises a support (102) and a powder-material source (106). The additive-manufacturing apparatus (100) further comprises a powder-supply arm (108), which comprises a hollow body (122), having an interior volume (124) that is in communication with the powder-material source (106), a powder-deposition opening (126) in the hollow body (122), and a powder-distribution blade (128), coupled to the hollow body (122) and extending along the powder-deposition opening (126). The additive-manufacturing apparatus (100) also comprises an energy source (110), an energy-supply arm (112), and energy emitters (114), coupled to the energy-supply arm (112). The additive-manufacturing apparatus (100) further comprises a rotary drive (116), configured to rotate the powder-supply arm (108) and the energy-supply arm (112) about a vertical axis A1, passing through the support (102), and intersecting a powder-supply-arm central axis A2 and an energy-supply-arm central axis A3.

Abstract: A process and an apparatus for producing 3D moldings, wherein a spectrum converter is used. Said converter is defined as a means which absorbs a radiation, for example electromagnetic thermal radiation, and radiates or emits one or more defined wavelength ranges; the spectrum converter is here irradiated by an emitter of an electromagnetic thermal radiation (shortwave or longwave radiation), i.e. by a lamp or an emitter, for example an overhead emitter or a sintering unit, and then emits a defined electromagnetic thermal radiation.

Abstract: The invention relates to a device (1) for producing three-dimensional workpieces (15), comprising a carrier (7) for receiving raw material powder (9), a build chamber wall (11, 11a, 11b) which extend substantially vertically and which is adapted to laterally delimit and support the raw material powder (9) applied to the carrier (7); an irradiation unit (17) for selectively irradiating the raw material powder (9) applied to the carrier (7) with electromagnetic radiation or particle radiation in order to produce on the carrier (7) a workpiece (15) manufactured from the raw material powder (9) by an additive layer building method, wherein the irradiation unit (17) comprises at least one optical element; and a vertical movement device (31) which is adapted to move the irradiation unit (17) vertically relative to the carrier (7).

Abstract: A method (300) of fabricating an object by additive manufacturing comprises providing (310) a layer of polymeric material (100), said polymeric material (100) being in particulate form, and comprising linear polymer chains, selectively depositing (320) a reactive liquid (200) onto the layer of particulate polymeric material (100), said reactive liquid (200) comprising reactive units (210a) which are monomeric units, linear oligomeric units, linear polymeric units, or combinations thereof, wherein said reactive units (210a) have two or fewer reactive groups, and allowing (330) linear polymeric chains in said layer of polymeric material (100) to react with reactive units in said reactive liquid (200) so as to form extended polymeric chains that are linear, so as to provide a shaped layer of linear polymer. These steps (310, 320, 330) are repeated as required to form the object from successive shaped layers of linear polymer.

Abstract: According to one example, there is provided a method of distributing build material in a 3D printing system. The method comprises moving a build material support positioned below a hopper, the movement to cause build material stored in the hopper to be deposited on the build material support, and moving a recoater to spread build material from the build material support over a build platform to form a layer of build material thereon, and to return any excess build material back to the build material support.

Abstract: A splatter shield system for an additive manufacturing machine includes one or more splatter shields configured to cover at least a portion of a build area during energy application such that the at least one splatter shield is positioned between an energy source of an additive manufacturing machine and the build area during energy application. The one or more splatter shields are transparent to an energy source (e.g., a laser) of the additive manufacturing system such that energy application occurs through the splatter shield.

Abstract: In an example of a three-dimensional (3D) printing method, a ceramic build material is applied. A liquid functional material, including an anionically stabilized susceptor material, is applied to at least a portion of the ceramic build material. A sintering aid/fixer fluid, including a cationically stabilized amphoteric alumina particulate material, is applied to the at least the portion of the ceramic build material. The applied anionically stabilized susceptor material and the applied cationically stabilized amphoteric alumina particulate material react to immobilize the anionically stabilized susceptor material, thereby patterning the at least the portion of the ceramic build material.

Abstract: An additive manufacturing apparatus includes a dispensing system positionable over a platen to deliver a powder, an actuator to move the dispensing system along a scan axis, and an energy source to fuse a portion of the powder. The dispensing system has a hopper to hold the powder and a dispenser. The dispenser includes a channel extending along a longitudinal axis from a proximal end to a distal end. The proximal end of the channel of the dispenser is configured to receive the powder from the powder source. A powder conveyor is positioned within the channel to move the powder from the proximal end along a length of the channel, and a plurality of apertures are arranged along the longitudinal axis of the channel. The dispenser is configured such that flow of powder through each aperture is independently controllable.

Abstract: The present disclosure generally relates to methods for additive manufacturing (AM) that utilize breakable structures in the process of building objects, as well as novel breakable support structures to be used within these AM processes. A support structure includes a weakened portion and the object includes an outlet. The method includes breaking the removable support structure at the weakened portion into at least two parts.

Abstract: An acoustic honeycomb panel is plugged with an acoustic honeycomb plug. The acoustic honeycomb plug is adhesively bonded in the panel using a honeycomb seam. The honeycomb seam is composed of a honeycomb support that is located within the seam channel and an adhesive. Using honeycomb seams to adhesively bond acoustic honeycomb plugs into acoustic honeycomb panels is useful in repairing damaged areas of acoustic honeycomb panels that are located in the acoustic treatments for jet engines.

Abstract: An additive manufacturing apparatus includes a dispensing system positionable over a platen to deliver a powder, an actuator to move the dispensing system along a scan axis, and an energy source to fuse a portion of the powder. The dispensing system has a hopper to hold the powder and a dispenser. The dispenser includes a channel extending along a longitudinal axis from a proximal end to a distal end. The proximal end of the channel of the dispenser is configured to receive the powder from the powder source. A powder conveyor is positioned within the channel to move the powder from the proximal end along a length of the channel, and a plurality of apertures are arranged along the longitudinal axis of the channel. The dispenser is configured such that flow of powder through each aperture is independently controllable.

Abstract: In one example, a method of fabricating a three-dimensional object includes depositing a layer of build material, depositing a coalescing agent onto the layer of build material according to a slice of three-dimensional model data, irradiating the coalescing agent with microwave radiation such that the coalescing agent converts the microwave radiation into heat to coalesce the build material in which the coalescing agent was deposited.

Abstract: A leveling slider exchange arrangement for use in an apparatus for manufacturing three-dimensional work pieces by irradiating powder layers with electromagnetic radiation or particle radiation, the leveling slider exchange arrangement comprises a powder application device adapted to apply a raw material powder onto a carrier and a leveling slider adapted to level the raw material powder applied onto the carrier by means of the powder application device. An attachment mechanism is adapted to releasably attach the leveling slider in a leveling slider attachment position in the powder application device. A storage chamber is adapted to store at least one exchange leveling slider, the storage chamber being connected to a connecting channel adapted to connect the storage chamber to the leveling slider attachment position in the powder application device.

Abstract: The present disclosure generally relates to methods for additive manufacturing (AM) that utilize support structure in the process of building objects that may be removed by rotating the support structure to a second orientation before removal, as well as novel support structures to be used within these AM processes. The support structures are fabricated in a first orientation and then rotated to the second orientation. The support structures are removed by passing through an outlet of the object.

Abstract: A three-dimensional forming apparatus includes: a stage; a material supply mechanism that supplies a sintered material in which metal powder and a binder are kneaded to a stage; a drying mechanism that dries the sintered material supplied from the material supply mechanism to the stage to form a dry sintered material; an energy radiation mechanism that supplies energy capable of sintering the dry sintered material; and a driving mechanism that is able to three-dimensionally move the material supply mechanism, the drying mechanism, and the energy radiation mechanism relative to the stage. The material supply mechanism includes a material ejection unit supplying a predetermined amount of the sintered material in a gravity direction. The energy radiation mechanism includes an energy radiation unit outputting the energy. The material ejection unit and the energy radiation unit are held in one holding mechanism.

Abstract: An apparatus includes a platen and a dispensing system overlying the platen. The dispensing system includes a powder source. The dispensing system further includes a powder conveyor extending over the top surface of the platen, rings arranged coaxially along a longitudinal axis of the powder conveyor, and a cap plate extending along a length of the tube. The powder conveyor is configured to receive powder from the powder source. The powder conveyor is configured to move the powder. The rings form a tube surrounding the powder conveyor to contain the powder. Each concentric ring includes a ring opening. Each ring is configured to be independently rotatable. The cap plate includes a cap plate opening. The powder is dispensed from the tube through the ring opening and the cap plate opening when the ring opening and the cap plate opening are aligned.

Abstract: Disclosed are methods and apparatus for selectively sintering particulate material, the method comprising: providing a layer (6) of particulate material; providing an amount of a radiation absorbent material over a selected surface portion of the layer (6) of particulate material; providing an amount of a material that comprises a plurality of electrically conductive elements (20) over at least part of the selected surface portion of the layer (6) of particulate material; and providing radiation (8) across the selected surface portion of the layer of particulate material so as to sinter a portion of the material of the layer (6) including causing the plurality of electrically conductive elements (20) to become embedded in the sintered portion of material.

Abstract: A method for forming a three-dimensional article, said method comprising the steps of: providing a predetermined amount of powder for forming a first powder layer on a start plate, distributing said predetermined amount of powder with a powder distributor for forming said first powder layer, directing an energy beam over said start plate causing said first powder layer to fuse in selected locations according to a model to form a first cross section of said three-dimensional article. At least one image of the powder to be distributed is captured with a camera at least one time during said distribution of said powder on said start plate for forming said first powder layer and at least one value of at least one parameter in said image detected with said camera is compared with a reference parameter value.

Abstract: A powder bed deposition apparatus comprises a movable build plate, a powder delivery system, an energy beam apparatus capable of selectively steering at least one focused energy beam over successive quantities of metal powder, a non-metallic barrier layer, and an anchor removably secured to the build plate. The non-metallic barrier layer is disposed over a metal upper surface of the build plate. The anchor has a metal bonding surface flush with the non-metallic barrier layer, the non-metallic barrier layer and the anchor defining a removable build assembly with a powder bed working surface.

Abstract: A method for making a smokeless tobacco article can include combining thermoplastic polymer particles with tobacco particles to form a mixture of particles, compressing the mixture of particles within a pressing apparatus to form the mixture into a predetermined shape, separating the mixture from the pressing apparatus such that it retains the predetermined shape, and heating the mixture outside of the pressing apparatus to at least partially melt at least some of the thermoplastic polymer particles and form a matrix of polymer and tobacco particles.

Abstract: Inter-layer bonding in objects manufactured by 3D printing techniques is improved by one or more targeted heat sources (THSs) that preheat a targeted portion of existing object material before additional material is added to the object. 3D Printing is also improved, optimized or calibrated by pre- or post-heating a targeted area. THS elements may be fixed, mobile, or a combination thereof to apply heat to targeted areas. A THS may be integrated in or as an add-on to an existing 3D printer. A THS controller may use 3D printer information, such as a current direction or a future direction of printing, to select one or more THSs and to perform other targeted heat operations, such as setting energy levels, aiming, moving, etc. Properties, e.g., strength, of 3D printed objects with improved interlayer bonding may, for example, be several multiples better than the same object printed without improved interlayer bonding.

Abstract: The present invention relates to a sustained-release composition containing 2,3,4,5-tetrahydro-2,8-dimethyl-5-[2-(6-methyl-3-pyridyl)ethyl]-1H-pyrido[4,3-b]indole or a pharmaceutically acceptable salt thereof as an active ingredient, preparation thereof and the compound. The composition is suitable for oral administration by one time per day, and achieves the peak plasma concentration at 1.0 to 3 hours after oral administration. The composition is suitable for manufacturing a medicament for treatment of cognitive dysfunction syndrome, Alzheimer's disease, Parkinson's disease, Huntington's disease, or senile dementia.

Abstract: An analytical model simulates the propagation of radiation through a coated continuous web where layer thickness and refractive index, as variables, determine the speed and direction of transmitted radiation. The model predicts characteristics of transmitted radiation based on characteristics of incident radiation and initially assigned values for layer thicknesses. Coating thickness(s) are ascertained in a process whereby incident radiation of known characteristics is directed onto a coated web and thereafter, actual measurements of transmitted radiation are compared to predicted characteristics. Using a fitting algorithm, the assigned thickness(es) of the layer(s) of the model are adjusted and the process repeated until the actual and predicted values are within desired limits at which time, the assigned thickness(es) represent the measured calipers.

Abstract: Disclosed in certain embodiments is a controlled release oral dosage form comprising a therapeutically effective amount of a drug susceptible to abuse together with one or more pharmaceutically acceptable excipients; the dosage form further including a gelling agent in an effective amount to impart a viscosity unsuitable for administration selected from the group consisting of parenteral and nasal administration to a solubilized mixture formed when the dosage form is crushed and mixed with from about 0.5 to about 10 ml of an aqueous liquid; the dosage form providing a therapeutic effect for at least about 12 hours when orally administered to a human patient.

Abstract: The instant invention relates to a device and method for manufacturing patterns in layers. The device includes an auxiliary frame, a vertically displaceable build platform, a dispensing device for applying a binder material onto the build platform, a mounting platform, a mounting platform, and a spreader device for applying particulate material. The mounting platform preferably is connected to the auxiliary frame and includes a cut-out for the build platform. The dispensing device, the spreader device, and the build platform are connected to the mounting platform, so that the dispensing device, the spreader device and the build platform are cable of being mounted, adjusted, and wired to the mounting platform while located outside the auxiliary frame.

Abstract: This disclosure provides methods of flash sintering and composition created by these methods.

Abstract: A method for printing a three-dimensional part and a support structure with an electrophotography-based additive manufacturing system. The method includes developing a support layer of the support structure from a soluble support material with a first electrophotography engine, and transferring the developed support layer from the first electrophotography engine to a transfer medium. The method also includes developing a part layer of the three-dimensional part from an ABS part material with a second electrophotography engine, and transferring the developed part layer from the second electrophotography engine to the transfer medium. The method further includes moving the attracted part and support layers to a layer transfusion assembly with the transfer medium, and transfusing the moved part and support layers together to previously-printed layers with the layer transfusion assembly.

Abstract: The invention relates to a method for recycling furniture containing wooden parts, in particular bed bases, the method comprising the following steps: a step (20) of grinding the wooden parts to form ground wood; a mixing step (22) in which a mixture is prepared, the mixture comprising a predetermined quantity of bi-component fibers; a step (24) of forming a non-consolidated web of material from the mixture; a step (26) of thermally consolidating the non-consolidated web of material; a step (27) of calendering the consolidated web of material.

Abstract: In one aspect of the present invention, a method of fabricating a composite membrane includes: forming a first polymer solution from a first polymer and a second polymer solution from a second polymer, respectively, where the first polymer includes a charged polymer and the second polymer includes an uncharged polymer; electrospinning, separately and simultaneously, the first and second polymer solutions to form a dual fiber mat with first polymer fibers and second polymer fibers; and processing the dual fiber mat by softening and flowing one of the first or second polymer fibers to fill in the void space between the other of the first and second polymer fibers so as to form the composite membrane. In some embodiments, the composite membrane may be a proton exchange membrane (PEM) or an anion exchange membrane (AEM).

Abstract: A spiral fastener is provided. In another aspect, a spiral fastener, is made of layers of material and/or a light curable material. Another aspect uses a three-dimensional printing machine to emit material from an ink jet printing head to build up a fastener having a spiral formation.

Abstract: A powder mixture is described, which is suitable for a layer-wise manufacturing of a three-dimensional object by solidifying a building material in powder form. The powder mixture consists of a mixture of a first polyamide 12 powder and a second polyamide 12 powder, wherein the first polyamide 12 powder is characterized by an increase of its viscosity number determined in accordance with ISO 307 that is less than 10%, when the powder is exposed for 20 hours to a temperature that lies 10° C. below its melting temperature under nitrogen atmosphere, and the second polyamide 12 powder is characterized by an increase of its viscosity number, determined in accordance with ISO 307, by 15% or more, when the powder is exposed for 20 hours to a temperature that lies 10° C. below its melting temperature under nitrogen atmosphere.

Abstract: A method of selectively combining particulate material, comprising: (i) providing a layer of particulate material to a part bed; (ii) providing radiation to sinter a portion of the material of the layer; (iii) providing a further layer of particulate material overlying the prior layer of particulate material including the previously sintered portion of material; (iv) providing radiation to sinter a further portion of the material within the overlying further layer and to sinter said further portion with the previously sintered portion of material in the prior layer; (v) successively repeating blocks (iii) and (iv) to form a three-dimensional object; and wherein at least some of the layers of particulate material are pre-heated with a heater prior to sintering a portion of the material of the respective layer, the heater being configured to move relative to, and proximate, the particulate material.

Abstract: The present invention relates to a polymer powder which comprises polyamide, and to the use of this powder for shaping processes, and also to moldings produced from this polymer powder. The shaping processes are layer-by-layer processes which use powders, where regions of the respective layer are selectively melted via introduction of electromagnetic energy. The selectivity may be achieved, with no intention of restricting the invention thereto, be achieved via masks, application of inhibitors, of absorbers, or of susceptors, or via focusing of the energy introduced. After cooling, the regions then solidified can be removed in the form of moldings from the powder bed.

Abstract: The invention relates to a method and device for generatively producing components, said device comprising a radiation device for selectively radiating a powder bed, and an induction device for inductively heating the component produced by radiating the powder bed, Said induction device comprising at least one voltage source which can simultaneously produce alternating voltages with at least two different frequencies.

Abstract: A method of manufacturing a moulded article from expanded resin particles, the method comprising: placing the particles and a dielectric heat transfer fluid in a mould located between a pair of electrodes; generating a radio-frequency electromagnetic field between the electrodes; applying the electromagnetic field to the mould to dielectrically heat the heat transfer fluid and hence the particles; and heating the particles to a temperature sufficient to cause their surfaces to soften, so that the particles fuse, thereby to form the moulded article as shaped by the mould; preferably, wherein the radio-frequency electromagnetic field has a wavelength greater than an average dimension (or dimensions) of the moulded article.

Abstract: A component, in particular an engine component, which has at least one mark with a predetermined three-dimensional shape for determining a stress in the component and where the component is constructed by a generative manufacturing method, is disclosed.