Abstract: A piston for an internal combustion engine which includes a crown having spiral features designed to increase swirl of combustion gases in a cylinder of the engine is provided. The spiral features can be located in a combustion surface or in a combustion bowl of the crown. The increased swirl of the combustion gases is expected to improve mixing of the air and fuel injected into the cylinder, and thus cause the fuel to burn more completely, achieve better efficiency out of the injected fuel, and reduce unburned hydrocarbons in the exhaust gas.

Abstract: A piston may have an annular body including a crown portion defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a plane containing the longitudinal axis and the radial direction, and a contoured combustion bowl. In the plane containing the longitudinal axis and the radial direction, the crown portion includes a radially outer squish surface, and a swirl pocket having a reentrant surface that extends axially downwardly and radially outwardly from the squish surface defining a tangent that forms a reentrant angle with the squish surface that ranges from 53.0 degrees to 57.0 degrees.

Abstract: Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A bypass valve, positioned on a bypass pipeline connecting the supply pipeline to the return pipeline, may be adjusted to a position sufficient to maintain temperature of the flow of gas above a threshold based on the inlet and outlet temperature.

Abstract: A thrust reverser with movable grids, includes structure for connecting, by recessing, a front frame of an outer cowl and a rear frame of the grids. The reverser includes loading structure configured to exert a stress pressing against the connecting structure, under the action of a circumferential pull of the front frame of the outer cowl or of a tightening band supported by the front frame.

Abstract: A rocket engine system including a thrust chamber including walls that define an interior surface and a combustion section which is fluidically coupled to an output section. A coolant source containing a coolant. A means of heating the coolant. At least one port configured to apply the coolant to the interior surface to achieve a film cooling of the interior surface and wherein the coolant source is fluidically coupled to the means of heating and the at least one port.

Abstract: A DC power plant generating DC power from a variety of engines including a Stirling cycle engine. The DC power plant includes a relatively small start-up power source that is discontinued after the engine is running. A method for producing DC power for a load including starting up an engine using power supplied by a relatively small power supply supplemented by a capacitor bank, providing output from the engine to a generator, producing alternating current (AC) power by the generator, converting the AC power to direct current (DC) power, disabling output of the DC power during a first set of pre-selected conditions, limiting a rate of change of current of the DC power during a second set of pre-selected conditions, reducing conducted and radiated emissions of the DC power, disconnecting the DC power from the load under a third set of pre-selected conditions, and providing the DC power to the load.

Abstract: The invention relates to an ignition device (1) for an internal combustion engine, more particularly for a hydrogen-fueled internal combustion engine, comprising a primary circuit (2.1) and a secondary circuit (2.2), wherein—the primary circuit (2.1) has a primary coil (3), wherein—the secondary circuit (2.2) has a secondary coil (4) inductively coupled to the primary coil (3), a diode (5) for suppressing a start-up spark, and a high-voltage connector (6) for connection to a spark plug (7), characterized in that a parallel path (10) is formed electrically in parallel to the diode (5) of the secondary circuit (2.2), in which parallel path there is arranged an ohmic load resistor (11) or an electric switch (20) and by means of which parallel path residual energy, in particular residual voltage, which remains in the secondary circuit (2.2) following discharge of the ignition device (1), can be extinguished, in particular by feeding the residual energy in the secondary circuit (2.

Abstract: The inventive technology, in particular embodiments thereof, may be described as an apparatus (e.g., a pump) that imparts work to and redirects a fluid, and that features an impeller configured to contact and redirect an impeller inflow along a toroidal flowpath to generate an impeller discharge that has both axial and tangential velocity components, where the axial velocity component is substantially 180 degrees relative to a direction of an impeller inflow, in a meridional plane, the apparatus also featuring a diffuser having a diffuser axis that is aligned with an impeller axis of rotation, the diffuser featuring a diffuser outlet annular radial size that is greater than a diffuser inlet annular radial size; and/or curved diffuser vanes established as part of the diffuser, that redirect the impeller discharge so as to reduce the tangential velocity components.

Abstract: Hydrostatic radial piston unit comprising a front case part accommodating a drive shaft via shaft bearing means so that the drive shaft can rotate around a central axis relative to the front case part. A rear case part is attached on one side to the front case part and closed on another side in order to define an internal volume. A cylinder block is disposed in the internal volume and attached to the drive shaft in a torque proof manner. Axially disposed timing holes in the cylinder block connect radially oriented working volumes in the cylinder block with a cylinder block front face that is arranged perpendicularly to the central axis and faces away from the front case part. Integrally within the rear case part internal annular flow passages are formed and are connected to an inlet and an outlet of the radial piston unit and running basically in circumferential direction around the central axis.

Abstract: Disclosed is an integrated blade having coupled blades for wind turbine (IBWT) device. The disclosed solution provides a significant increase of generated power realized mainly by using coupled blades. The coupled blades are situated close to each other and oriented near-parallel to each other. They are mounted in the same body/frame and only one fixation mechanism is needed to fix the device/construction on the rotation rod connected to a turbine.

Abstract: A turbine of a power generating system includes a rotary shaft, blades, stoppers and elastic members. Each of the blades includes a connecting side and an active side opposite to the connecting side, and the blades are disposed on the rotary shaft at intervals by a predetermined distance, in which the blades are pivotally connected to the rotary shaft through the connecting sides. The stoppers respectively correspond to the blades and are disposed over the rotary shaft for limiting expansion angles of the blades. Each of the elastic members includes a fixed end and a moving end opposite to the fixed end, and the fixed ends attach to the rotary shaft, and the moving ends respectively attach to the blades. Each of the blades pivots between an expanded position and a closed position.

Abstract: A system includes a wind turbine a wind and a first control device for controlling the wind turbine. The first control device is configured to acquire a yaw misalignment of the wind turbine, which yaw misalignment is a difference between the actual yaw angle and a wind direction at the wind turbine; and to determine at least one of a target pitch angle of the blade and a target torque of the generator based on the yaw misalignment to optimize a power output from the wind turbine. Further, a wind farm includes the system and a method of controlling a wind turbine.

Abstract: A method of operating a wind turbine during disconnection from a utility grid includes a generator, a wind turbine converter, in particular including a grid side converter portion connectable to the utility grid, a DC link, a generator side converter portion, and a UPS, the method including: allowing the UPS to draw, according to an UPS active power reference, active power from the wind turbine converter (104); controlling the wind turbine converter by a converter power reference to meet the UPS active power reference. Controlling the wind turbine converter by the converter power reference includes modulating a frequency of the converter terminal voltage in dependence of the converter power operating point, in particular the converter power reference.

Abstract: A method of joining first and second blade components of a rotor blade of a wind turbine includes providing corresponding first and second positioning elements at an interface of the first and second blade components. The method also includes aligning and securing the first positioning element of the first blade component with the second positioning element of the second blade component so as to temporarily secure the first and second blade components together. Further, the corresponding first and second positioning elements maintain a desired spacing between the first and second blade components. Moreover, the method includes permanently securing the first and second blade components together such that the desired spacing is maintained between the first and second blade components.

Abstract: An apparatus 100 for determining orientation of a segment 32 and 30 of a wind turbine blade 28 is disclosed. The apparatus includes an elongated member 1 and a support plate 2 provided at one end of the elongated member 1. The support plate 2 is defined with one or more provisions 4 to facilitate connection with the segment 32 and 30 of the wind turbine blade 28. Further, a measuring plate 3 is provided at another end opposite to the one end of the elongated member 1, where the measuring plate 3 is defined with a substantially airfoil profile 35. The measuring plate 3 includes a plurality of markers 18 disposed along an airfoil region 34 where, each of the plurality of markers 18 is indicative of one or more of multiple parameters to determine the orientation of the segment 32 and 30. FIG. 6 is the representative figure.

Abstract: A fluid film bearing for a rotor hub of a wind turbine is provided including a first part and a second part rotatably coupled to each other about a longitudinal axis. The first part includes an annular first sliding surface extending in the circumferential direction of the fluid film bearing along the first part. In addition, the second part includes a support structure and a first group of bearing pads coupled to the support structure and having a bearing pad sliding surface configured to slide on the first sliding surface. In addition, the support structure includes a plurality of openings for replacing the bearing pads.

Abstract: An engine system includes three communicating fluid vessels that each contain a fluid. A first interconnecting fluid conduit containing the fluid rotatably couples the second fluid vessel to the first fluid vessel and acts as a lever. A second interconnecting fluid conduit containing the fluid rotatably couples the third fluid vessel to the first fluid vessel and acts as another lever. By increasing the fluid column heights in the communicating fluid vessels, torque is applied to the levers to cause the second and third fluid vessels to revolve around the first fluid vessel.

Abstract: A power generating device using free falling of object due to gravity is provided, which includes a lifting channel, a falling channel, and mass blocks capable of circularly moving in the lifting channel and the falling channel. Gear structures configured for driving an electric generator to generate power are arranged at a bottom of the falling channel. Racks configured for meshing with the gear structures are arranged on sides of each of the mass blocks, and the mass blocks are capable of driving the gear structures to rotate so as to drive the electric generator to generate power. Mass blocks are lifted up to a top of a falling channel, so as to accumulate gravitational potential energy. A high speed is obtained as the mass blocks fall, and then racks are configured for driving gear structures to rotate so as to drive an electric generator to generate power.

Abstract: A power transmission assembly includes a base, a rotating frame rotatably coupled to the base and configured to rotate about an axis, an output shaft coupled to the rotating frame, a weight selectively repositionable relative to the rotating frame, and a weight actuator configured to reposition the weight relative to the rotating frame to move the weight from a subtraction position located at a first height to an addition position located at a second height. The second height is greater than the first height such that a gravitational force on the weight drives the rotating frame to rotate about the axis and drive the output shaft.

Abstract: An energy generating device may include a first body portion with at least one first force input structure coupled to the first body portion and configured to receive an external force. The energy generating device also may include a second body portion, the second body portion rotatable relative to the first body portion. Further, the energy generating device may include an electrical generator configured to use the relative motion between the first body portion and the second body portion to generate electricity. The first body portion and the second body portion are configured to descend through a medium at least partially under the force of gravity or ascend through the medium at least partially by buoyant forces in such a way that the medium causes a force on the at least one first force input structure by impinging on the at least one force input structure causing relative rotation between the first body portion and the second body portion.

Abstract: An apparatus includes a thermal actuator switch configured to control a transfer of thermal energy through the thermal actuator switch. The thermal actuator switch includes first and second plates and a piston movable laterally between the first and second plates. The thermal actuator switch also includes a phase change material configured to (i) expand to move a surface of the piston into a first position and (ii) contract to allow the surface of the piston to move into a second position. The surface of the piston thermally contacts the first plate and increases thermal energy transfer between the first and second plates when in one of the first and second positions. The surface of the piston is spaced apart from the first plate and decreases thermal energy transfer between the first and second plates when in another of the first and second positions.

Abstract: A power engine for amplifying one or more sets of attributes such as torque and force is disclosed. The power engine unit includes a first system, a second system, and a compressor system. The first system includes a crankshaft wheel and the first set of cylinders, wherein the crankshaft flywheel is configured on one side of the first set of cylinders to provide a heavy circular output from the linear motion. The second system includes a second set of cylinders and a set of pistons corresponding to the second set of cylinders. The second set of cylinders are coupled to the first set of cylinders. The compressor system is coupled with the first set of cylinders and the second set of cylinders, where the compressor system includes a first cylinder hole to allow the flow of compressor oil from the first set of cylinders of the first system.

Abstract: The present invention discloses a semi-trailer-loaded turbine fracturing equipment, which adopts a linear connection of the whole equipment and a special chassis design, so that the center of gravity is double lowered to guarantee its stability and safety, the structure is simpler, the investment and operation costs are decreased, the risk of total breakdown of the fracturing site is reduced, and the equipment has a good transmission performance and is suitable for continuous operation conditions with long time and heavy load.

Abstract: A valve assembly for a piston compressor, in particular an oil-free piston compressor for generating compressed air in a rail vehicle, includes a valve plate having a compressed-air opening, a valve retainer and a valve lamina which is flexible and/or movable in relation to the valve retainer and is provided for opening and closing the compressed-air opening; wherein a damping and/or braking device is provided which is associated with the valve lamina.

Abstract: Provided is a diaphragm pump. The diaphragm pump operates such that a viscous liquid is discharged by transferring a pressing force via a diaphragm that is elastically deformed. The diaphragm pump has a structure capable of rapidly and accurately discharging the viscous liquid of high viscosity by using a diaphragm. Also, the diaphragm pump is capable of effectively pressing the viscous liquid while preventing the damage to the particles contained in the viscous liquid, by preventing the mechanical structure pressing the viscous liquid from coming into direct contact with the viscous liquid.

Abstract: This fluid handling system has: a fluid handling device that includes a flow path and a rotary membrane pump that is connected to the flow path and has a diaphragm for causing fluid to flow along the flow path; and a rotary member that has a protrusion for pressing the diaphragm of the rotary membrane pump. The width of the rotary member protrusion is less than the width of the diaphragm of the rotary membrane pump.

Abstract: Disclosed are an outer ring for an oil pump having an increased number and size of open pores in a surface of a molded article and a method for manufacturing the outer ring.

Abstract: Provided is a progressive cavity pump. The progressive cavity pump operates such that a viscous liquid is discharged by rotating an eccentric rotor with respect to a stator. The progressive cavity pump may be easily disassembled for repair and maintenance, and may be easily attached to an accurate position during re-assembly. Also, in the progressive cavity pump, main components such as a nozzle, a rotor, a stator, etc. may be easily replaced so as to easily adjust dispensing characteristic, while the driving units such as a motor and a rotary shaft are installed in a dispenser, and thus, an idle time of the dispenser may be reduced.

Abstract: Rotary positive displacement machines based on trochoidal geometry and including a helical rotor that undergoes planetary motion relative to a helical stator can be designed and configured so that the axial load or rotor pressure force is positive, negative, or neutral. In some embodiments, a change in axial load, caused by a change in differential pressure across the machine, can be used to trigger a change in a mechanical configuration of the machine.

Abstract: A compressor includes: a housing; a compressor body to compress gas; a motor to drive the compressor body; a control board to control the motor; and a tank to store the gas outputted from the compressor body, wherein the housing has: a machine chamber storing the compressor body and the motor; a B-chamber having piping to connect the compressor body with the tank; an A-chamber storing the tank; an A-partition separating the machine chamber from the A-chamber and B-chamber; and a B-partition between the A-chamber and the B-chamber, the A-chamber has an air intake port to introduce ambient air, the A-partition has an A-vent as a hole to communicate between the machine chamber and the A-chamber, and a suction port of the compressor body is located in vicinity to the A-vent.

Abstract: A vacuum pump which can reduce a stress generated in a connected part between a rotating body and a rotating shaft is provided. A rotating body is provided having rotor blades provided on an outer periphery of a rotor-blade forming portion, and fastened to the rotor shaft by a bolt, and rotatable with the rotor shaft. At least either one of a fitting hole portion fitted with the rotating shaft and a through hole portion, through which a bolt penetrates, in the rotating body is a stress-reduction target portion, and a groove portion that reduces stress generated in the stress-reduction target portion during rotation of the rotating body is provided.

Abstract: A fan motor is disclosed. The fan motor includes a heat dissipation fin. The heat dissipation fin includes an outer ring part, an inner ring part disposed inside the outer ring part, and a connection part connecting the outer ring part and the inner ring part. The inner ring part is elastically deformed to be inclined in parallel to a rotational shaft which is inclined when axial alignment between bearings is not made. Accordingly, the heat dissipation fin can reduce a temperature of the bearing while enclosing the bearing, and improve concentricity (axial alignment) of the bearing.

Abstract: A ceiling fan or ceiling fan includes a body defining an interior passage having an inlet and an outlet provided on the body. The inlet, outlet, and interior passage can be annular. An impeller is mounted within the interior passage and driven by a motor mounted within the body to draw a volume of air through the interior passage from the inlet to the outlet. A movable deflector including an inner angled surface and a lower angled surface is provided at the outlet to direct the airflow in a generally outward or generally downward direction, respectively.

Abstract: Pump system with at least one pump, in particular a vacuum pump or a compressor, a controller connected to the at least one pump, wherein the controller comprises: a first processing unit directly connected to the at least one pump for providing low level services to the at least one pump, and a second processing unit connected to the first processing unit to provide high level services to the pump system, wherein the second processing unit is connectable to an external network.

Abstract: A monitoring apparatus includes: input reception circuitry configured to receive a signal indicative of a characteristic of rotating assembly rotation; and bearing wear monitoring circuitry configured to analyze the signal characteristic of rotating assembly rotation. The bearing wear monitoring circuitry is also configured to identify one or more signal features indicative of bearing wear. Bearing wear produces variation in rolling friction of the bearing and therefore is one cause of variation in shaft torque. Aspects recognise that variations in shaft torque can be indirectly monitored, measured and/or determined by appropriate measurement or monitoring of operational characteristics of a pump motor and that it may be possible to distinguish variations in shaft torque which can be attributed to bearing wear from those variations in shaft torque caused by one or more other factors.

Abstract: The present disclosure provides a fan. The fan includes a fan main body, a circuit board, and an operating element. The circuit board is provided with a stepless adjusting member. The operating element is connected to the stepless adjusting member. The fan main body includes a first motor electrically connected to the circuit board and a fan blade connected to the first motor. The circuit board adjusts power output to the first motor when the operating element rotates and operates the stepless adjusting member. So as to adjust a rotating speed of the first motor. In this way, the user can adjust a desired wind speed of the fan blade according to a need, which solves the problem that the wind speed of the existing fan cannot be freely adjusted and improves the operating performance and the user experience.

Abstract: A well pumping apparatus including a discharge head (110), a drive string rod (130) in fluid communication with an inner cavity (142) of a production tubing (140), a pre-lubrication port (160) at the discharge head, and lubrication cups (134) installed along the drive string rod adjacent to sets of bearings (150) distributed along the drive string rod.

Abstract: The invention relates to a turbomachine (1) for supplying air to a fuel cell system, comprising at least one compressor wheel (3) conjointly connected to a shaft (2), and an electric motor (4) for driving the shaft (2), the compressor wheel (3) being connected via a hub portion (5) to a preferably hollow-cylinder-shaped shaft portion (6) of the shaft (2). According to the invention, at least one air channel (7, 8) is formed in the hub portion (5), by means of which air channel a compressor inlet (9) is connected to an annular space (10) on the side of the compressor wheel (3) facing away from the compressor inlet (9) such that substantially the same air pressure is present on both sides of the compressor wheel (3). The invention further relates to a method for operating a turbomachine (1).

Abstract: A mixed flow inline fan assembly includes an outer housing, a motor assembly disposed within the outer housing, a fan wheel disposed within the outer housing, where a shaft of the motor assembly is coupled to the fan wheel, and the fan wheel includes a hub, a plurality of blades coupled to the hub via first mechanical fasteners, and a shroud coupled to the plurality of blades via second mechanical fasteners

Abstract: A centrifugal fan (1) has a fan unit (10) with an impeller (11), a motor (12) for driving the impeller (11), and a support structure (13) for securing the fan unit (10) in the intended detachable manner to a flange plate with an intake opening (21, 22). The support structure (13) is designed to hold the fan unit (10) on the flange plate (21, 22) by itself. A plurality of air guide segments (23), that together form a downstream guide device (20), are secured to the support structure (13) and/or to the flange plate (21, 22).

Abstract: A centrifugal pump having at least one impeller is provided with a guide device arranged downstream of the impeller configured to convert a portion of the velocity of a flowing medium to an increased pressure in the medium. The guide device includes at least two generatively manufactured segments.

Abstract: A motor includes a rotor rotatable in a circumferential direction around a center axis extending vertically, a stator to rotate the rotor, a lead wire connected to the stator, and a housing covering the rotor and the stator from a radially outer side. The housing includes a first housing located on a first side in an axial direction, and a second housing located on a second side in the axial direction. The first housing includes a wiring convex portion protruding toward the second side in the axial direction. The second housing includes a wiring recess that is recessed toward the second side in the axial direction and penetrates in a radial direction. The wiring convex portion is located in the wiring recess. The wiring convex portion includes a tip surface opposing the second side. The wiring recess includes a bottom surface opposing the first side.

Abstract: A fan cage assembly includes a cage and a handle mechanism, the handle mechanism includes a mount member including a mount portion and an extension portion respectively located at different sides of the cage and an operative member movably disposed on the extension portion of the mount member.

Abstract: The present disclosure relates to a rotor assembly 102 for a turbomolecular pump 100. The rotor assembly 102 comprises a rotor shaft 116, a plurality of rotor blades 126 extending from the rotor shaft 116, and a balancing member 130 fitted within the rotor shaft 116 with an interference fit. The rotor shaft 116 extends along a longitudinal axis 122 about which the rotor assembly 102 is configured to rotate. The interference fit is such that the balancing member 130 is retained in compression by the rotor assembly 102. The present disclosure also relates to a turbomolecular pump 100 including the rotor assembly 102 and a method of assembling a rotor assembly 102 for the same.

Abstract: One feature pertains to an acoustic attenuation device. The acoustic attenuation device comprises a fan assembly, the fan assembly including at least one fan module that directs airflow in at least one direction, wherein the at least one fan module includes a top surface and a bottom surface, a plurality of air deflectors mounted to the top surface and the bottom surface of the at least one fan module, wherein the plurality of air deflectors include a plurality of surfaces, and wherein at least one of the plurality of surfaces is an angled surface that redirects the airflow 90-degrees, and acoustic attenuating foam, wherein the acoustic attenuating foam has a two-dimensional (2-D) surface and is applied to interior surfaces of the plurality of surfaces.

Abstract: A hydraulic supply device includes: a first oil pump configured to supply oil to a supply passage; a second oil pump driven together with the first oil pump or driven when the first oil pump is stopped; a first check valve provided in a first oil passage that allows a suction side of the second oil pump to communicate with an oil source, and configured to close the first oil passage when the second oil pump is stopped; a second check valve provided in a second oil passage that allows a discharge side of the second oil pump to communicate with the supply passage, and configured to close the second oil passage when the second oil pump is stopped; and a third oil passage into which the oil supplied to the supply passage flows, wherein the oil flowing into the third oil passage is used as an auxiliary pressure for operation of the second check valve when the second oil passage is closed.

Abstract: There is provided a control module for a hydraulic system. The module comprises a tank and a plurality of valves. The tank is configured to store hydraulic fluid and is substantially cylindrical. The plurality of valves fluidly connect with the tank and are configured to control distribution of hydraulic fluid from the tank to one or more components of the system. The plurality of valves are spaced around a circumference of the tank. One or more passages fluidly connect the tank with at least one of the plurality of valves and/or a first of the plurality of valves with a second of the plurality of valves.

Abstract: A phononic material includes an interface surface and a subsurface feature mechanically connected to the interface surface. When a hypersonic flow having at least one instability flows past the interface surface, the interface surface vibrates in response to one or more frequency components of the pressure. The interface surface couples each frequency component into the subsurface feature, which at least partially reflects and phase-shifts each frequency component to generate a corresponding phase-shifted frequency component. The interface surface vibrates in response to the phase-shifted frequency component, thereby coupling the phase-shifted frequency component back into the hypersonic flow. The phase-shifted frequency component interferes with said each frequency component within the hypersonic flow. The subsurface feature may perform phase-shifting such that the phase-shifted frequency component destructively interferes with said each frequency component, thereby reducing the at least one instability.

Abstract: A linkage mechanism includes a first fixing member and a movable member. The first fixing member defines a first slot. The movable member includes a handle, a steering plate, and a latching plate. The handle is rotatably connected to the first fixing member. The steering plate has first and second portions. The first portion is rotatably connected to the handle. The second portion has a sliding slot. The latching plate includes a main body portion, latching portion, and sliding post. The main body portion is rotatably attached to the first fixing member about a first axis. Part of the main body portion extends to form the latching portion. The latching portion corresponds to the first slot. One end of the sliding post is fixed to the main body portion. Another end movably fits into the sliding slot.

Abstract: A fastening body and an application method thereof include a locking part, an elastic element and a blocking section. The blocking section is movably disposed at the locking part. The elastic element is disposed between the locking part and the blocking section, and the blocking section cooperates with the elastic element to apply an elastic pressure to an engaged object. Accordingly, the fastening body and the application method thereof can provide the required object and the engaged object to achieve a stable combination and have the effect of being shockproof.