68results about How to "Powerful cleaning" patented technology

The invention provides a two cycle engine which effectively suppresses an intrusion of a combustion gas into a crank chamber. Further, the invention provides a two cycle engine tool provided with the two cycle engine mentioned above. An engine is provided with a cylinder having two scavenge air ports at different positions in a cylinder circumference direction, and scavenge air inflow ports communicating individually with these two scavenge air ports via a scavenge air passage, and a piston in which two scavenge air communication ports are formed at positions corresponding to the scavenge air inflow ports, and is structured to swirl the gas flowing into the piston from the cylinder through the scavenge air passage, in an upper portion of the internal space of the piston, and retains the gas in the upper portion of the internal space of the piston.

The invention discloses a silicon core cleaning technique, and relates to a processing technique of polysilicon, in particular to a method for cleaning silicone core. According to the technical schemeprovided by the invention, the silicon core cleaning technique comprises the following steps: a, silicon core pretreatment: firstly using anhydrous ethyl alcohol to wipe off the impurities on the surface of the silicon core, and then using acetone to wipe off oil stains on the surface of the silicon core; then putting the silicon core in an ultrasonic cleaning instrument for ultrasonic cleaning;and carrying out vacuum drying; b, cleaning: putting the cleaned silicon core in a closed reaction vessel, carrying out the following reaction under the temperature of 300 DEG C to 320 DEG C: Si+3HC-SiHCl3+H2; in the reaction process, introducing the mixed gas of hydrogen and hydrogen chloride into the reaction vessel; and c, repeated utilization of tail gas: adopting the reaction product of hydrogen trichloride and hydrogen as raw materials for preparing polysilicon, carrying out gas returning of the reaction product by a gas inlet pipe and a gas outlet pipe, and entering working section of reduction by a pipeline. The reaction product can be completely recovered, thus realizing zero emission of nitride and improving environment.

The present invention provides a cleaning apparatus of an ion source extraction electrode system, which can eliminate deposit in high speed along a wide area that form a leading-out electrode system of an ion source. The cleaning apparatus comprises the following components: a cleaning gas source (42) which supplies cleaning gas (48) between two opposite electrodes (11,12) of a leading-out electrode system (10), thereby keeping the gas pressure between the two electrodes to a gas pressure for generating glow discharge; and a glow discharge power supply (60) which applies DC voltage between the electrodes (11,12) for generating glow discharge (80). The cleaning apparatus further comprises the following components: an abnormal discharge measurer (84) which measures times (N) of abnormal discharge between the the electrodes (11,12) in preset time; and a power supply controller (86) which controls through the measured time (N) of abnormal discharge for increasing or reducing the output current of the glow discharge power supply (60) for a preset amplitude.

The invention relates to a brush bar which comprises a fixing part and a bristle part. The bristle part comprises multiple bristle wires which are distributed in the width direction of a brush, one ends of the multiple bristle wires are fixed by the fixing part, the bristle part further comprises soft sheets, and one ends of the soft sheets are fixed by the fixing part. According to the brush bar, the soft sheets are additionally arranged in the bristle wires, on one hand, the support force of the brush can be increased; on the other hand, gaps between the bristle wires are blocked, the brush bar is more beneficial for cleaning, and the vacuum degree can be increased when the brush bar is used for dust collection.

The invention relates to a method for cleaning an insulating oil sample bottle and a utilized cleaning device. The insulating oil sample bottle cleaning method comprises the steps of (1) ultrasonic decontamination: before work, preheating water to a suitable temperature firstly, adding laundry powder, placing an oil sample bottle in a cleaning basket which is then placed in a cleaning tank, rotating the cleaning basket to enable the oil sample bottle to be filled with a cleaning solution, and starting a decontamination ultrasonic generator for the decontamination; and (2) ultrasonic rinse: opening a blowdown valve after the decontamination cleaning is finished, cleaning the cleaning tank appropriately after the cleaning solution is discharged completely, closing the valve, opening a water inlet valve, opening the ultrasonic generator, heating the water to a suitable temperature, placing the oil sample bottle into the water for rinse, and after the oil sample bottle is rinsed cleanly, taking the bottle out of a vessel and performing draining separation. The method for cleaning the insulating oil sample bottle and the utilized cleaning device have the advantages as follows: (1) the cleaning speed is high, the cleaning effect is good, the cleanliness is high, and the damage to the surface of a workpiece is prevented; (2) hands of a worker are not contacted with the cleaning solution, and deep holes, thin seams and hidden positions of the workpiece can also be cleaned up safely and reliably; and (3), the cleaning precision is high, and tiny stain particles can be cleaned powerfully.

The invention discloses a novel home cleaning tool, capable of effectively solving the problem that a broom can be stained by hair, fluff, dust and mud. The cleaning tool comprises a dustpan, a dustpan rod, telescopic rods and hollow rolling wheels, wherein the dustpan rod is fixedly arranged at the upper side of the dustpan and a piston is inserted in the dustpan rod; hollow shafts are fixed to the lower ends of the left and right sides of the dustpan rod; a baffle plate is arranged at the left side of the dustpan rod in a mode of sliding up and down; the telescopic rods include a thick telescopic rod and a thin telescopic rod; the thick telescopic rod is arranged at the front side of the dustpan rod in a sliding mode in a vertical direction, and the thin telescopic rod is inserted into the thick telescopic rod; each hollow rolling wheel is rotatably arranged on the corresponding hollow shaft; and a plurality of hollow brush rods, which communicate with the interior of each hollow rolling wheel, are uniformly distributed on the hollow rolling wheel. The cleaning tool provided by the invention is mainly used for cleaning some hair tangled on the broom; the dustpan rod enables the brush rods on the rolling wheels spray gas and water by virtue of the piston device, so that dirt on the broom can be cleaned more efficiently and more strongly; and by arranging a linkage control structure on the dustpan rod, gears can be selected optionally, so that relatively high autonomy and flexibility are guaranteed.

The invention relates to a scraper structure, which is generally comprised of a long handle for handgrip and a scraping section in its front. Basically, the scraping section of the scraper is comprised of a jaw plate, a blade, a fastener and a fastening button. The front end of the scraping section extends downward or forward to form a blade slot and has a jaw base at the bottom to connect to the blade slot. The jaw plate has identical shape to the clamp jaw in the front of the jaw base. The fastener and the fastening button are combined to provide tightening and enable the clamp jaw in the front of the jaw plate to exert great pressure onto the blade and achieve quick blade replacement and assembly. Further, the fastening button can exert more force by the front hand in grasping the handle and achieve powerful scraping.

The invention discloses a multifunctional dust collector. The dust collector comprises a first shell, an inner cavity of the first shell is hollow, two groups of symmetrical rollers are connected withthe bottom of the first shell, an air compressor, a first motor, a second motor and a third motor are connected with the top wall of the first shell in the horizontal direction in sequence, one sideof the first motor, one side of the second motor and one side of the third motor are fixedly connected with a first rotary shaft, a second rotary shaft and a third rotary shaft respectively, the firstrotary shaft and the third rotary shaft are connected to the rollers, and a first transmission belt and a second transmission belt are arranged at the connection positions of the first and second rotary shafts and the rollers respectively. The second rotary shaft penetrates through the bottom wall of the first shell, a dust collection plate is fixedly connected with the end, away from the secondmotor, of the second rotary shaft, and a first through hole is formed in the dust collection plate. The multifunctional dust collector is simple in structure and convenient to operate, the functions of purifying air and wetting air are achieved, and the situation that the dust collector is damaged because of sucking wet air is avoided.

The invention discloses a cleaning device for a floor drain. The cleaning device comprises a grabbing mechanism, a turnover mechanism and a flushing mechanism, wherein the grabbing mechanism is used for grabbing a filter screen of the floor drain, moving the filter screen to a preset position and then loosening the filter screen, and is further used for taking out the cleaned filter screen from the preset position and moving the filter screen to the floor drain; the turnover mechanism is used for clamping the filter screen placed at the preset position and turning over the filter screen by 180degrees along the horizontal line; the turnover mechanism is located above the flushing mechanism, a water outlet pipe is connected to the flushing mechanism, and the water outlet pipe is located above the turnover mechanism; and the water outlet pipe is used for spraying water to the filter screen from top to bottom. The cleaning device can be used for conveniently cleaning the floor drain, especially the filter screen of the floor drain.

The invention discloses an intelligent cleaning robot suitable for underwater environment cleaning and brushing. The intelligent cleaning robot comprises an underwater robot and a ground station console; the underwater robot comprises a robot body and cleaning equipment; the cleaning equipment is flexibly mounted on the robot body; and the ground station console is electrically connected with the robot body. The ground station console is used for controlling the underwater robot and providing electric energy needed by operation of the underwater robot, semi-automatic control operation is achieved, and the robot body has high-maneuverability space movement capacity; the cleaning equipment is driven by the robot body, marine organisms attached to the underwater structure for a long time can be powerfully cleaned, and the underwater structure can be cleaned in all directions.

The invention belongs to the field of microbiological equipment, and particularly relates to a fermentation tank cleaning machine for the microbiological field. According to the technical scheme, thefermentation tank cleaning machine for the microbiological field has the effects that workers can operate the cleaning machine conveniently, and the labor intensity of the workers can be reduced; thecleaning machine can facilitate cleaning of a fermentation tank, and benefit cleaning of the inner wall of the fermentation tank; and the cleaning machine can be used for cleaning different fermentation tanks. The fermentation tank cleaning machine for the microbiological field comprises a working table, wheels, a control mechanism, a water storage tank, an inlet, a sealing cover, a water pumpingmechanism, a lifting mechanism, a shower pipe, an angle regulating mechanism, a cleaning mechanism, a bracket and mounting bases; the mounting bases are installed on the front and rear sides of the working table. The fermentation tank cleaning machine has the effects that the workers can operate the cleaning machine conveniently, and the labor intensity of the workers can be reduced; the cleaningmachine can facilitate cleaning of a fermentation tank, and benefit cleaning of the inner wall of the fermentation tank; and the cleaning machine can be used for cleaning different fermentation tanks.

The invention discloses a soap body cleaning device of an extruder, and relates to an auxiliary device of an extruder. The soap body cleaning device consists of a transmission table of a packing machine and limiting baffles, wherein more than two sets of the limiting baffles are respectively arranged on both sides of the transmission table of the packing machine; brushes I of which the brushing directions are opposite are arranged at gap positions between the limiting baffles on the both sides, a brush II of which the direction faces downwards is arranged directly above the transmission table of the packing machine, and the upper part of the brush II is connected with a machine frame through a regulating screw rod; more than one lateral hollow groove is formed in the transmission table of the packing machine, and brushes III of which the brushing directions face upwards are arranged in the lateral hollow grooves. The soap body cleaning device disclosed by the invention is simple in structure and low in manufacturing cost and can be mounted and used on existing equipment, the equipment cost is low, the soap body cleaning device has a good cleaning function and a good cleaning effect for a soap body, the situation that the soap body with a residual fertilizer enters into the packing machine is avoided, so that the frequency that the packing machine is faulted is further reduced, and the successful production is facilitated.

An alternative fuel combustion engine enhancer for the vast improvement of combustion engines through a greener environment with lowered emissions, decreased fuel consumption, increased engine life and increased power. The alternative fuel combustion engine enhancer generally includes Copper Pipes, Stainless Steel Rods, Stainless Steel Wire, Silver Solder, Machined Acrylic End Caps, Copper Wire, a Water Supply, a Wiring Harness, and a Control Panel.

The invention discloses an intelligent power grid voltage reactive power adjustment device, which belongs to the technical field of intelligent power grid reactive power adjustment. The intelligent power grid voltage reactive power adjustment device comprises a compensation device, a reactor, a thyristor, a fuse and a controller, wherein the cathode of the thyristor is grounded, and the anode is connected with the compensation device via the reactor; the compensation device is connected with the power grid via a circuit breaker and the fuse; the grid of the thyristor is connected with the controller; the controller comprises a current sampling module, a voltage sampling module and a microprocessor module; the compensation device comprises a chopper switch, a fly-wheel switch, a transformer, a plurality of groups of capacitors and an energy-saving device; the chopper switch is in parallel connection with the transformer, the plurality of groups of capacitors and the energy-saving device; and the fly-wheel switch is in serial connection with the chopper switch, the transformer, the plurality of groups of capacitors and the energy-saving device. The voltage phase and the reactive power parameters of a transmission line can be adjusted, features of voltage reactive power dynamic compensation and unbalance reduction are realized, and actual use demands are met.

The invention provides a flywheel stored energy power generation plant, which is composed of a flywheel, a clutch, a belt and a motor, wherein, the axis part of the motor is provided with a transmission and the clutch, the motor is dual-purpose motor for power generation and electromotion, the axial part of the flywheel is provided with the clutch, a power generator is connected with the transmission via the clutch, belt pulleys of the transmission are connected with those of the clutch at the axial part of the flywheel via the belts; when power consumption is at low level at night, power is converted by the motor into inertial power of the flywheel which is then stored, when power consumption is at high level during the daytime, the inertial power stored in the flywheel is released by means of the power generation of a driving power generator, the power generated by the power generator is then transmitted to electric network to reduce the power consumption peak value. The device of the invention has simple structure and good easiness for implementation, can solve the problem of unbalance power consumption of electric network between night and daytime, saves energy and reduces the likelihood that electric loads impact some key nodes of electric network intensively so that the load of the power transmission trunk road can dramatically be lessened and protected.

The invention discloses an integrated swimming pool dirt suction device and belongs to the field of dirt suction devices. The integrated swimming pool dirt suction device comprises a water pump, a blowdown pipe connector, a base plate, wheels and a blowdown pipe, wherein the base plate is horizontally arranged, the middle portion of the base plate is provided with a through hole penetrating through the upper surface and the lower surface of the base plate, the water pump is installed on the upper surface of the base plate, a water inlet of the water pump is connected with the upper end of the through hole, a water outlet of the water pump is detachably connected with the blowdown pipe through the blowdown pipe connector, and at least three wheels are installed on the lower surface of the base plate and are uniformly distributed at the edge of the base plate. The water pump, the base plate, the blowdown pipe and the like are integrated, operation is convenient, and the dirt suction efficiency is high.

The invention relates to a method for producing a washing machine tank cleaning agent, and the method is as foillows: mixing sodium percarbonate, lauryl sodium sulfate and fatty alcohol-polyoxyethylene ether for stirring to obtain a mixture; heating the mixture to 80-95 DEG c, wherein the heating time is 1-3 hours, then adding sodium carbonate, bicarbonate and methylisothiazolinone, continuously heating to 95-120 DEG c, wherein the heating time is 40-50 minutes, cooling to room temperature, then adding EDTA (ethylene diamine tetraacetic acid)-tetrasodium, sodium metasilicate pentahydrate and pancreatic bio-enzyme, continuously stirring and heating to 50-75 DEG c, wherein the heating time is 30-40 minutes, and then preparing the granular or powdery finished product according to a conventional technical method. The washing machine tank cleaning agnet integrates cleaning, descaling, antibacterial, anti-dirting, re-deposition and other functions, and is good in washing performance, easy tobiologically degrade, environment-friendly and capable of effectively cleaning, stripping and decomposing dirt, fiber, impurities, bacteria and other pollutants accumulated in a washing machine, so that secondary pollution of the washing machine is avoided.

The invention relates to a method for cleaning an insulating oil sample bottle and a utilized cleaning device. The insulating oil sample bottle cleaning method comprises the steps of (1) ultrasonic decontamination: before work, preheating water to a suitable temperature firstly, adding laundry powder, placing an oil sample bottle in a cleaning basket which is then placed in a cleaning tank, rotating the cleaning basket to enable the oil sample bottle to be filled with a cleaning solution, and starting a decontamination ultrasonic generator for the decontamination; and (2) ultrasonic rinse: opening a blowdown valve after the decontamination cleaning is finished, cleaning the cleaning tank appropriately after the cleaning solution is discharged completely, closing the valve, opening a water inlet valve, opening the ultrasonic generator, heating the water to a suitable temperature, placing the oil sample bottle into the water for rinse, and after the oil sample bottle is rinsed cleanly, taking the bottle out of a vessel and performing draining separation. The method for cleaning the insulating oil sample bottle and the utilized cleaning device have the advantages as follows: (1) the cleaning speed is high, the cleaning effect is good, the cleanliness is high, and the damage to the surface of a workpiece is prevented; (2) hands of a worker are not contacted with the cleaning solution, and deep holes, thin seams and hidden positions of the workpiece can also be cleaned up safely and reliably; and (3), the cleaning precision is high, and tiny stain particles can be cleaned powerfully.

The invention relates to a rail antiskid device for cars of a coke oven. The rail antiskid device is characterized by comprising driving wheels, driven wheels, driving wheel speed measuring coders, driven wheel speed measuring coders, an automatic cleaning control system, a control line, a water tank water level detecting device, high-pressure pump branch pipes, cleaning solenoid valves and cleaning nozzles, wherein the driving wheel speed measuring coders are arranged on the driving wheels, and the driven driving wheel speed measuring coders are arranged on the driven wheels. The rail antiskid device is compact and simple in structure, and can automatically judge whether rails are polluted or not according to the skid condition of the cars of the coke oven and automatically clean the rails and perform interlock protection to guarantee high-speed and safe operation of four cars of the coke oven.

The invention features a switch circuit, a rectification and voltage-stabilizing circuit, an IC execution time controlling circuit, a main control circuit, and a second winding circuit of a high-accuracy multi-tapping stabilizer and a first voltage circuit. A step-down current-limited circuit, a break contact delaying circuit and a third step-down current-limited circuit is connected between said second winding circuit of high-accuracy multi-tapping and the first voltage circuit.

The invention discloses a buzzer vibration plate perforating device, and relates to the field of electronic products. The buzzer vibration plate perforating device comprises a base box, wherein a table top is fixedly installed on the left side of the base box; supporting legs are fixedly installed on the front side and the rear side of the left end of the bottom of the table top; a control equipment box is fixedly installed on the top of the base box; and control equipment is arranged in a hollow area in the control equipment box. According to the buzzer vibration plate perforating device provided by the invention, a sealed rubber plate can be expanded in a slotted hole through inertia generated by rotation of a drill bit, and an adjusting rod in the sealed rubber plate is forced to enable an auxiliary motion block and a main motion block to rub in the sealed rubber plate through the deformation force of the sealed rubber plate and the rotation inertia of the drill bit; and static electricity is attached to a metal cone through conduction of a metal plate and a metal cone, and the metal cone discontinuously makes contact with the inner wall of a groove hole in the vibration plate in cooperation with deformation expansion of the sealed rubber plate, so that the metal powder on the inner walls of the holes in the vibration plate can be effectively adsorbed.

Natural plant fibers which are harmless to the human body are smashed and mixed with a small amount of coagulum, and the casting of a die is carried out according to the design needs; wherein, the structure is as follows: a projecting part with the length of 20mm, the height of 8mm and the thickness of the bottom part of 2mm is arranged in the middle of an oval toothbrush base along the longitudinal direction, the top part of the projecting part is jagged and vertical to the toothbrush oval base, the projecting parts with the length of 18mm, the height of 6mm, the thickness of 1.5mm and the jagged top parts are respectively arranged on the both sides thereof, the arrangement direction is parallel to the middle projecting part, an included angle of 55 degrees is formed with the oval toothbrush base, a plurality of rows of single thin brush wires are regularly arranged in the middle of the three rows of the projecting parts, and the height thereof is slightly higher than the three rows of the projecting parts.

The invention discloses an energy-saving vector synchronous-control frequency converter. Since the drive control of a synchronous motor is required in various different electrical environments, the over-voltage and the surge current generated caused by the operation on an AC incoming switch have an impact on a vector synchronous-control frequency converter. Meanwhile, a harmonic wave generated by the vector synchronous-control frequency converter will contaminate the power grid in turn so as to influence the stability and the reliability of the vector synchronous-control frequency converter. The energy-saving vector synchronous-control frequency converter comprises a rectifier bridge connected with a grid side, and an inverter bridge connected with a load side. The rectifier bridge and the inverter bridge are connected in parallel with a capacitor. The energy-saving vector synchronous-control frequency converter is characterized in that a DC reactor is arranged between the rectifier bridge and the inverter bridge. The DC reactor is connected in series between a rectifier and the capacitor so as to form a reactive power energy storage element of a load together with the capacitor. According to the invention, ripple waves in the DC are effectively suppressed or filtered out. Therefore, the waveform distortion of the input current, caused by the filtering of the capacitor, can be improved. The conversion efficiency and the energy-saving effect of the energy-saving vector synchronous-control frequency converter are improved.

The invention relates to the technical field of assisted living devices, in particular to a practical integration tool for housekeeping. The practical integration tool for housekeeping is diverse in working modes, higher in cleaning effect and higher in practicability; can be used for effectively cleaning walls, windows and other positions, and is lower in use limitation, so that the use reliability is improved. The practical integration tool for housekeeping comprises a machine body, a drive motor, a plurality of groups of sensors, a receiver, a universal wheel and two groups of drive pulleys, wherein a working chamber is arranged in the machine body; the drive motor is arranged in the working chamber; the universal wheel is arranged on the right side of the bottom end of the machine body. The practical integration tool for housekeeping also comprises a water tank, a communicating hose, a high pressure water pump, a sprayer, two groups of fixing frames, a rotary roller, a plurality ofgroups of bristles, a dust collecting chamber, a servo motor and an installation plate, wherein the water tank is arranged in the working chamber; a water storage cavity is arranged in the water tank; the high pressure water pump is arranged on the communicating hose; the two groups of fixing frames are respectively fixed to the front side and the rear side of the bottom end of the machine body.The practical integration tool for housekeeping also comprises two groups of driven pulleys, two groups of belts and a plurality of groups of suckers, wherein the plurality of groups of suckers are respectively arranged on side walls of the two groups of belts.

A sticky-layer-cleaner for removing residues adhered to a sticky flat layer includes a receptacle for a cleaning-liquid and a cleaning-roll in contact with the sticky flat layer, wherein the cleaning-roll includes an elongated carpet fabric which is helically folded around the cleaning-roll and a pile of which includes yarn tufts in loop and / or cut configuration, and the cleaning-roll further includes a helical channel along the length of the folded carpet fabric for draining the cleaning-liquid from the cleaning-roll and / or for wetting the cleaning-roll with the cleaning-liquid.

The invention discloses a circulating cleaning machine for electromechanical equipment parts. The circulating cleaning machine structurally comprises a supporting frame, a water tank, a water inlet pipe, a water pump, a cleaning box, a control panel and a top cover, wherein the rear end of the supporting frame is welded to the lower end of the water tank, water pressure conduction is conducted through a conduction pipe, then pressure division is conducted through a pressure division pipe, water is sprayed into a connecting pipe, the inclined gaps of a bevel wheel sawteeth are sprayed, a bevelgear rotates stably and horizontally through rotation of a rotating plate, so that the bevel gear is prevented from being blocked by the saw teeth easily in the process of high-pressure jet cleaning of the narrow gap, the cleaning effect of dirt in the gaps of the bevel gear is improved, oil stains adhered to the surface of the bevel gear float upwards, oil stains flow to the upper surface of theplate body from flowing openings, flow towards the two sides and then flow to the upper surface of an adhesion plate to be placed in an adhesion mode, the upper layer of the bevel gear is prevented from making contact with the oil stains again, and the cleaning effect of the upper surface layer of the bevel gear is improved.

The present invention relates to a brush strip, which comprises a fixing part and a bristle part, the bristle part includes a plurality of bristle filaments, the plurality of bristle filaments are distributed along the width direction of the brush, and the plurality of bristle filaments are distributed along the width direction of the brush. One end of the bristle filament is fixed by the fixing part, and the bristle part further includes a soft sheet, and one end of the soft sheet is fixed by the fixing part. The present invention adds soft flakes to the bristles, on the one hand, it can increase the support force of the brush, and on the other hand, it also blocks the gaps between the bristles, making it more powerful and clean, and can also improve the vacuum degree during vacuuming.

The invention discloses efficient deburring equipment for automobile hub production based on precision machining, and relates to the technical field of automobile hub production. Comprising a machining table, a motor box is arranged over the machining table, a first motor is fixedly arranged in the motor box, an output shaft of the first motor is fixedly connected with a first rotating shaft, a grinding disc is fixedly arranged at one end of the first rotating shaft, and a cooling fan is arranged at the top of the motor box; and heat dissipation openings are formed in the two sides of the motor box correspondingly, the heat dissipation openings are in a round opening shape, cleaning plates are movably arranged on the tops and the bottoms of the inner walls of the heat dissipation openings correspondingly, and mounting bases are movably arranged on the inner sides of the cleaning plates. By arranging the heat dissipation fan and the heat dissipation opening, wind power of the heat dissipation fan can accelerate flowing of air in the motor box, heat is discharged out of the box body through the heat dissipation opening, a certain heat dissipation effect is achieved, damage of the heat to the first motor is reduced, and the service life of the first motor is prolonged.