Abstract: A deposition system for depositing a chemical vapor onto a workpiece, including a deposition chamber having a plurality of components for performing chemical vapor deposition on the workpiece. The deposition chamber includes an inner skin made of Hasteloy for sealing the plurality of components and the workpiece from the air surrounding the deposition system, and an outer skin that encloses the inner skin and is separated from the inner skin by an air gap. The outer skin includes vents that create a convection current in the air gap between the inner skin and outer skin of the deposition chamber. The deposition system also has a gas panel for regulating the flow of gases and vapors into the deposition chamber, and a computer for controlling operation of the gas panel and the components in the deposition chamber.

Abstract: Disclosed is a method for fabricating an optical fiber preform using a double torch in MCVD, which includes a first process of heating a quartz tube (10) at a temperature lower than a sintering temperature by using a first torch (21) with putting reaction gas, oxygen gas and dehydration gas into the tube so that soot particles are generated and deposited, and heating the tube to a predetermined temperature by using a second torch (22) spaced apart from the first torch after the first torch (21) passes so that moisture in the soot particles is removed; and a second process of conducting dehydration for removing moisture in the soot particles by use of the first torch (21) again, and heating the tube above a sintering temperature by using the second torch (22) so that the soot particles free from moisture are vitrified.

Abstract: The present invention directs to a method of manufacturing low water peak single mode optical fiber, which comprises performing deposition in a substrate tube using PCVD technology, whereby a deposited layer of a certain construction design is formed on the inner wall of the substrate tube, melt contracting the substrate tube into a solid core rod according to melt contraction technology, producing an optical fiber preform by combining the core rod and a jacket tube of low hydroxyl content by means of RIT technology or by depositing an outer cladding on the outer surface of the core rod using OVD technology, sending the optical fiber preform into a fiber drawing furnace to draw it into an optical fiber, wherein: in the PCVD technology, the content of impurities in a gas mixture of raw materials, which is characterized by the infrared spectrum transmissivity thereof, is required to a transmissivity of 90% or greater, the water content in O2 is 100 ppb or less, the water content in C2F6 is 1000 ppb or less, the

Abstract: Drawer for detergents for washing machine or the like, with the body of the valve for distribution of water to the various compartments built into the same drawer in any one of its components: lid of the drawer, spray compartment or back of drawer; the solution is characterised in that the valve body is formed by a mould together with one of the above mentioned components, thus entailing elimination of the fittings, seals and same valve body as an independent component.

Abstract: A locking device includes a shackle member that includes an elongated shank portion, a stop portion on a first end and a latch portion on a second end. A locking head includes a locking mechanism that has an entryway to receive the latch portion and is movable between a locked state to retain the latch portion and a unlock state to release the latch portion. A head cover includes a cover portion that engages the locking head and a flange portion that extends inwardly to define an opening to receive the latch portion therethrough. A seal structure is associated with the inner edge of the flange and sealably engages the outer surface margin of the latch portion. The seal structure may be a margin of the flange portion or a separate O-ring. The lock may be constructed as a lockable hitch pin.

Abstract: A theft deterrent device that can be securely connected to an item of merchandise includes a U-shaped clasp that selectively locks within a housing having a base and a hinged lock member. The lock member is movable between unlocked and locked positions with the locked position of the locked member securely locking the end of the clasp within the housing so that it cannot be removed until a specially designed key is used to unlock the lock member from the housing. The lock member engages the end of the clasp in at least two directions on two different sides to form a secure locking arrangement.

Abstract: A method and apparatus for securing an object to a vehicle comprises a mounting bracket for being fixedly secured to a vehicle. A mating unit is removably secured to the mounting unit, the mating unit comprising an adjustable shackle and a locking mechanism, the adjustable shackle operative to secure an object, such as a surfboard, snowboard, wakeboard, or skis, to the mating unit and mounting bracket.

Abstract: A lock for furniture drawers that provides simultaneous constraint of all the drawers and the opening liberation of only one drawer at a time thereby avoiding the tipping of furniture. The lock includes an espagnolette cam lock with a cylinder set in motion by a key. The lock is centrally placed on the superior drawer of the furniture, which mechanism is inlaid on the escutcheons of the drawer and internally protected by a second escutcheons. Internally, the espagnolette cam lock has a system of suitable gears, which rotate a connecting rod to raise an extreme pin. The movement of the pin in the interior of the piece with a slot attached to a side bar, makes the side bar rise, forcing the closing of the other drawers. The side bar is mounted, preferentially in the interior of a narrow channel, excavated in the side wall of the furniture. The side bar ha a pin for each drawer.

Abstract: The present invention concerns a method and a device for reshaping a tube which is mounted between two axially movable pressure rams and which has an initial outside diameter, an initial wall thickness, and an initial length by means of hydraulic pressure produced inside the tube to obtain a finished tube with a different outside diameter or different length, and/or a different wall thickness compared to the initial tube.

Abstract: A thin walled body such as a container is gripped at a holding station and tooling is engaged to deform the wall of the body at a predetermined zone. The predetermined wall zone is co-aligned with the tooling by means of co-ordinated movement of the tooling (typically by means of rotation about a tooling axis) prior to engagement with the wall zone.

Abstract: A tube is bent having a curved portion with a variable radius extending between first and second ends. The curved portion includes a circular arc portion with a constant radius and a clothoid transition portion with a variable radius. The circular arc portion extends from the first end toward a point of integration. At the point of integration, the circular arc portion merges with the transition portion. The transition portion extends from the point of integration to the second end. As the transition portion extends from the point of integration, its radius of curvature increases over its arc length, thereby, improving the quality of the bent tube by gradually bending the tube over a longer distance, thereby reducing local stresses on the bent portion of the tube.

Abstract: The aim of the invention is to provide a method for producing a metal sheet, especially a steel sheet, at least one surface of which is provided with a surface structure that provides as structural elements depressions and/or elevations, and which metal sheet is substantially resistant to scratches and finger prints. According to the inventive method, the surface structure is configured as a random microstructure.

Abstract: The invention relates to a method and a device for changing the work rolls and the back-up rolls (8, 9) of a strip mill, by means of a roll-changing carriage (2) which can be transversally displaced in relation to the roll stand (1). Said roll-changing carriage receives the old sets of rolls removed, enabling them to be exchanged for new sets of rolls.

Abstract: A method and device for checking clearance between a stamping die includes a template representative of relative movement between the stamping die and end tool. A template including a surface representing movement of the end tool relative to the stamping die is positioned relative to the stamping die. The position is indicative of a location of the end tool during operation of the stamping die. Contact between the template and the stamping die along the surface representing movement indicates potential contact between the end tool and the stamping die during operation.

Abstract: Described is an arrangement for a double acting press, whereby a press is constructed with vertically opposed moving faces, both faces are capable of converging in a substantially parallel motion towards a predetermined point between them and then exert a compressive load. The press has a frame arrangement that contains the load. When a time period has elapsed the vertically opposed faces both diverge in a substantially parallel motion away from the predetermined point to a position from which they may begin the sequence again.

Abstract: A pliers-type handtool is provided for crimping an electrical connector upon one end of an insulated conductor, including a crimping drum that is mounted on a fixed member for rotation between first and second positions, and an actuating lever that is reciprocated by pivotal movement of the handle portions of the handtool to rotate the drum between its first and second positions. The actuating lever is connected with the drum by a lateral slot of divergent width that receives a drum pin that extends axially from one end of the drum, the slot having a width adjacent its bottom that corresponds generally with the diameter of the drum pin.

Abstract: A press brake tool that is adapted to be mounted in a tool holder. The tool has a lockable safety key that is moveable between an extended position and a retracted position. The press brake tool has a lock that is operatively coupled to the safety key and is movable between a locked position wherein the safety key is locked in the extended position and an unlocked position wherein the safety key is permitted to move between the extended position and the retracted position. Also provided is a press brake tool having a particularly advantageous, longitudinally-elongated safety key.

Abstract: A failure detection device for detecting a failure of a rotation angle detection sensor, which sensor detects a rotational angle through which a rotary member has rotated, the failure detection device including a first detection element which has an output which increases as the rotational angle of the rotary member increases, a second detection element which has an output that decreases as the rotational angle of the rotary member increases, and a detecting unit that detects the failure of either the first detection element or the second detection element by comparing a calculated value, based on the outputs of both of the first and second detection elements, with at least one predetermined value.

Abstract: An accelerator pedal is positioned at a kickdown position. Then, an output value of a measurement device of an accelerator pedal position sensor is measured. Thereafter, the measured output value of the measurement device is stored in a correction output value storage of the accelerator pedal position sensor along with a corresponding correction value, which is used to correct the measured output value of the measurement device. A couple of fully opened position stop members is provided and is engaged with the accelerator pedal when the accelerator pedal is rotated to a fully opened position. Furthermore, a couple of fully closed position stop members is provided and is engaged with the accelerator pedal when the accelerator pedal is rotated to a fully closed position.

Abstract: A system is provided for monitoring the levels of combustible gas in a gas stream. The system includes means for controlling the relative humidity of the gas stream and maintain a humidity level in the performance range of combustible gas sensors. A number of methods are illustrated for achieving the humidity control including secondary phase separations and the adjusting of the gas stream temperature.

Abstract: A modular gas measuring system with a basic unit (1) with electric supply and data lines connected to it, a measuring unit (2), which is equipped with a gas sensor and with a microprocessor and is connected to the basic unit (1) by means of snap closures to form a functional unit. At least one expansion module, is accommodated by the functional unit. The modular design, of optionally accommodating different expansion modules, so that the properties and the possible applications of the gas measuring system can be expanded in a simple manner.

Abstract: A waveform knock signal detected by a knock sensor is filtered through a band-pass filter. The detected wave form signal is compared with an ideal reference knock waveform to determine an engine knock. The ideal reference knock waveform is derived on the basis of a factor depending on a crank angle, a factor depending on a real time and a factor depending on an engine construction. The factor depending on the real time is calculated based on an energy loss in a combustion chamber and a time constant of the band-pass filter. The factor depending on the engine construction is calculated based on a knock vibration which is generated in a cylinder, transferred to a cylinder block and detected by the knock sensor.

Abstract: In a fuel vapor purge system, a blocked diagnosis zone is pressurized by an air pump, a pressure in the diagnosis zone at the time when the diagnosis zone is pressurized, and an occurrence of leakage in the diagnosis zone is judged based on the comparison between a curvature of a change curve of the pressure and a threshold.

Abstract: The invention relates to a process for the combinatorial investigation of the hardening of hardenable liquid or viscous formulations (a) in which n hardenable formulations are prepared in parallel in n containers, and (b) the degree of hardening is determined at least once on each of the n formulations by inserting a measurement tip into the formulation with a certain force and measuring the maximum penetration depth achieved as a measure of the degree of hardening of this formulation, and (c) for in each case one composition of the formulations, one or more parameters that are characteristic of the kinetics of hardening are determined from the measurement values for the penetration depth at various times after preparation of the formulations.

Abstract: A method of calibrating an AFM scanner head of an AFM machine to determine the arc functions of the scanner head are provided. A method of measuring the actual orientation of an AFM tip in conjunction with the arc functions provides a way to know and control the actual AFM tip orientation for performing better AFM scans, obtaining more accurate depth measurements into a deep feature, and obtaining better portrayals of specific portions of a deep feature in AFM images. AFM images focusing on portraying specific portions of a deep feature structure may be combined to form a composite image of a representative deep feature for a sample.

Abstract: A method and an arrangement for monitoring a torque of a drive unit (1) of a vehicle (5) are suggested. The method and arrangement make possible a reliable detection of a fault condition for an essentially constant actuation of an operator-controlled element. The torque, which is to be monitored, is compared to a permissible torque. The permissible torque is readjusted to the torque, which is to be monitored. A fault is detected when the torque, which is to be monitored, deviates from the permissible torque by more than a first pregiven value. The fault is only detected for the case wherein a position of an operator-controlled element, especially an accelerator pedal position, lies within a pregiven tolerance range at least since a first pregiven time.

Abstract: An apparatus and process for monitoring fluid flow through a nozzle is disclosed. A vibration sensor, such as an accelerometer, is mounted to a nozzle. The vibration output received from the sensor is then analyzed to determine whether or not the nozzle is operating properly. Through the present invention, information can be obtained regarding variations in flow rate, and/or variations in spray pattern and droplet size spectra. If the nozzle flow pulsates, the vibration sensor may also provide information regarding whether the nozzle is pulsating according to a desired frequency duty cycle or waveform.

Abstract: An apparatus for monitoring tire pressurization state in a tire has a magneto-mechanical pressure sensor in or on the tire and an electromagnetic excitation system. The electromagnetic excitation system is for interrogating the magneto-mechanical pressure sensor. The apparatus also has a receiver. The receiver is for receiving information from the electromagnetic excitation system. The apparatus also has a data interpretation system for translating the received information into the tire pressurization state. The data interpretation system is connected to a display. The display communicates the tire pressurization state to an operator.

Abstract: An acoustic sensor for use in a downhole measurement tool is provided. The acoustic sensor includes a piezo-composite transducer element. In various exemplary embodiments, the acoustic sensor further includes a composite backing layer, at least one matching layer, and a barrier layer deployed at an outermost surface of the sensor. Exemplary embodiments of this invention may advantageously withstand the extreme temperatures, pressures, and mechanical shocks frequent in downhole environments and thus may exhibit improved reliability. Exemplary embodiment of this invention may further provide improved signal to noise characteristics. Methods for fabricating acoustic sensors and downhole measurement tools are also provided.

Abstract: A static pressure sensing probe has an aerodynamically shaped cross section, and extends laterally from an aircraft surface sufficiently so that an outer end of the probe is a short distance outside the boundary layer on the aircraft surface on which the probe is mounted. The probe has surface corrugations or ridges along the probe, and the ridges include an upstream ridge adjacent the leading edge, and a downstream ridge spaced rearwardly from the upstream ridge. The ridges cause pressure disturbances along the probe surfaces. Static pressure sensing ports are positioned on the surfaces of the probe relative to the ridges in regions of pressure disturbances caused by the ridges. The probes can be mounted on opposite sides of the aircraft and pneumatically or electrically connected to average the pressures from selected sets of ports.

Abstract: A flow sensor in which all bridge resistor elements of a bridge circuit are arranged on a chip together with a heating resistor element, so that the drift of the bridge resistor elements will then have only a very slight effect on the output signal of the bridge circuit, which may be picked off at the electrical connections.

Abstract: A flow sensor for internal combustion engines in which the temperature control of a heating resistor element is implemented by pulse-width modulation.

Abstract: Cavities are formed so as to extend from a rear surface side of a base material to a protective film, an electrically-insulating film is formed on a rear surface of the base material, wall surfaces of the cavities, and exposed surfaces of the protective film, and a heating resistor portion and a fluid temperature resistance thermometer portion are formed on portions of the electrically-insulating film on the exposed surfaces of the protective film inside the cavities. In addition, leader patterns are formed on the electrically-insulating film so as to extend from end portions of the heating resistor portion and the fluid temperature resistance thermometer portion along the wall surfaces of the cavities onto the rear surface of the base material.

Abstract: An accelerometer includes an inertial platform maintaining an attitude in response to a platform stabilizing controller signal and defining a spin axis and a reference plane. An accelerometer, coupled to the inertial platform a distance from the spin axis, defines a flex axis, which is perpendicular to the stability axis. The accelerometer generates an accelerometer signal in response to acceleration of the accelerometer. A second accelerometer defines a second flex axis also perpendicular to the stability axis, and is also coupled to the inertial platform a distance from the spin axis. The second accelerometer generates a second accelerometer signal in response to acceleration of the second accelerometer. A controller, including an angular acceleration signal generator, receives the first accelerometer signal and the second accelerometer signal and generates an angular acceleration signal from a difference in amplitudes between the first accelerometer signal and the second accelerometer signal.

Abstract: A conductive element for a movable electrical circuit (a conductive element most suitable for an electric circuit that is placed on a movable element in which the shape of the circuit itself changes during circuit operation) which is Al-based and has an average cross sectional area for the crystal grain of 1 micron2 or less. Preferably, this conductive element contains N+O at 550 to 20000 ppm in atomic concentration and also one or more selected from the group consisting of Si at 0.5-5.0% in atomic concentration, Ta at 0.5-5.0%, and Cu at 0.5-5.0%. More preferably, it contains Nd at 0.5-5.0%. This conductive element for a movable circuit is especially suitable for the wiring pattern in a vibrating gyroscope.

Abstract: An accelerometer includes an inertial platform maintaining an attitude in response to a platform stabilizing controller signal and defining a spin axis and a reference plane. An accelerometer, coupled to the inertial platform a distance from the spin axis, defines a flex axis. The accelerometer generates an accelerometer signal in response to acceleration of the accelerometer. A second accelerometer defines a second flex axis, and is also coupled to the inertial platform a distance from the spin axis. The second accelerometer generates a second accelerometer signal in response to acceleration of the second accelerometer. A controller receives the first accelerometer signal and the second accelerometer signal and generates a linear acceleration signal in response to a sum of the first accelerometer signal and the second accelerometer signal and generates an angular acceleration signal from the difference.

Abstract: A collision impact detector detects deceleration of a vehicle caused by its collision with another vehicle or an obstacle. A rotor is rotatably supported on a shaft and biased by a coil spring in a direction opposite to a rotational direction in which the rotor is rotated by the deceleration. One axial end of the coil spring is supported by a first support integrally formed with the rotor, and the other axial end of the coil spring is supported by a second support formed separately from the rotor. In this manner, a friction torque generated between the coil spring and the second support is eliminated, thereby considerably reducing a total friction torque associated with rotation of the rotor. The second support may be formed either integrally with or separately from a housing supporting the shaft.

Abstract: An accleration sensor comprises a fixed case member and a cover assembly collectively defining a closed space in which the oscillation plate and the piezoelectric element received therein. The oscillation plate and the piezoelectric element are oscillatably supported by a supporting portion formed on the central bottom portion of the fixed case member.

Abstract: In industrial sensing applications at least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1, x2, x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array-processing techniques may be employed to determine the speed of sound amix. The speed of sound amix is provided to logic 48, which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture, or fluid, which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid.

Abstract: The invention concerns a method for correction with temperature in the pressure determination of a pressure gauge, comprising: measuring simultaneously with said gauge said pressure Pm(t) and said temperature Tm(t) during time, generating a signal Tf(t) of said measured temperature Tm(t), said measured temperature being filtered of the noise, (19) correcting said measured pressure Pm(t) with a correction function F(t) containing exclusively a dynamic part, said dynamic part containing a term a1 proportional to first derivative of said Tf(t) signal relative to time. In another aspect of the invention the dynamic part further comprises a second additional term a2 proportional to second derivative of said Tf(t) signal relative to time.

Abstract: To improve the characteristics of a portion which can be represented by an approximate first-order line (so-called linearity) in the relation between pressure and diaphragm displacement. To equalize the pressure-applying area/volume of a diaphragm when plural ring-shaped reinforcement ribs are in contact with said cover (no load condition when no pressure is applied to the diaphragm) and the pressure-applying area/volume of a diaphragm when said diaphragm is apart from said cover (the diaphragm is displaced due to pressure load).

Abstract: A micromechanical pressure sensor which is made up of at least one first component element and a second component element bordering on the first component element. In this context, the first component element includes at least one diaphragm and one cavity. The cavity is arranged or structured so that the medium to be measured gains access to the diaphragm through the cavity. In addition, in the second component element an opening is provided which guides the medium to be measured to the cavity. At least a part of the cavity represents an extension, without a transition, of the opening in the second component.

Abstract: A pressure sensor for detecting an effective pressure comprises a first pressure detection means for providing a first pressure measurement signal and a second pressure detection means for providing a second pressure measurement signal, wherein the first pressure measurement signal differs from the second pressure measurement signal, as well as an evaluation means for determining the effective pressure based on the first and the second pressure measurement signal. Thereby it is achieved that in a pressure measurement the measurement errors are reduced.

Abstract: The invention relates to a sensor and guide wire assembly (21; 31; 41) for intravascular measurements of physiological variables in a living body, comprising a core wire (22; 32; 42) and sensor element (23; 33; 43). The sensor element (23; 33; 43) according to the invention comprises basically a mounting base (24; 34; 44) and a pressure sensitive end portion (25; 35; 45) whose upper side is provided with a pressure sensitive device, such as a membrane (26; 36; 46). The mounting base (24; 34; 44) extends downwards from the end opposite to the pressure sensitive end (25; 35; 45), such that, when the sensor element (23; 33; 43) is mounted on the core wire (22; 32; 42), a clearance (27; 37; 47) is formed below the pressure sensitive end (25; 35; 45).

Abstract: The invention relates to a pressure sensor comprising a sensor element (2) having a flat membrane (4) which is transformed at its edge into a hollow-cylindrical ring (6) so that a central recess (20) is provided at the lower side (10) of the membrane (4). On the upper side (8) of the membrane (4) a resistance arrangement consisting of electric resistors is disposed. A sleeve (54) projects into the recess (20) and supports a first elastomeric sealing ring (66) which is tightly arranged at the circumferential area of the recess (20). Furthermore the sleeve (54) supports a second elastomeric sealing ring (68) which serves for sealing at a feeding tube for pressure fluid formed in a component part to which the pressure sensor is mountable. The sleeve (54) is rigidly connected to a disk (56) which is attached with its outer edge (58) to a casing (26) enclosing the sensor element (2).

Abstract: The invention relates to a fastening arrangement for a sensor (2) on a receptacle (1), with a receptacle through-hole (13, 13a) leading to the interior (12) of the receptacle (1), a receptacle stop (16), and a sensor housing (20-23) exhibiting a sensor device (28) and a circumferential housing stop (27). To advantageously fasten the sensor to the receptacle a pressure screw (4) is provided, which exhibits a pressure screw through-hole (41), which receives the housing (20, 23); and exhibits a pressure area (43) used in pressing the housing stop (27) against the receptacle stop (16) to fasten together the sensor housing (20, 23) and the receptacle (1).

Abstract: A strain detector includes an insulating substrate, a power electrode, output electrodes and a ground electrode which are disposed over the insulating substrate, a strain-resistance element provided over the insulating substrate and coupled to the power electrode, the output electrodes and the ground electrode, a protective layer over the strain-resistance element, a frame ground electrode. The insulating substrate includes a stainless steel board, a protective coat on the stainless steel board, and an insulating layer on the protective coat. The frame ground electrode is provided over the stainless steel board and electrically coupled to the stainless board.

Abstract: A sensor array is configured based upon capacitive sensor techniques to measure stresses at various positions in a sheet simultaneously and allow a stress map to be obtained in near real-time. The device consists of single capacitive elements applied in a one or two dimensional array to measure the distribution of stresses across a mat surface in real-time as a function of position for manufacturing and test applications. In-plane and normal stresses in rolling bodies such as tires may thus be monitored.

Abstract: The device for consignments transported one after the other in a path of conveyance has bearing points (3, 8, 11) and a deflection device (5) that can be moved practically vertical to said bearing points in the path of conveyance for bending the consignments (4), measuring means (6) for detecting the extent of deflection of the consignments (4) and/or measuring means for detecting the size of the deflection force and a measuring device for measuring the thickness of the consignment. The extent of the deflection of the consignments (4) at a set constant deflection force or the size of the deflection force for constant and equal deflection of the deflection device (5) is used as indication of the bending strength. The deflection device (5) or the bearing points (3, 8, 11) are positioned before every measurement in such a way that their spacing vertical to the direction of transport corresponds to the thickness of the consignment.

Abstract: The flow sensor serves to measure an electrically conductive fluid flowing in a pipe. It comprises a flow tube designed to be inserted into the pipe for conducting the fluid, the flow tube being electrically nonconductive at least on a fluid-contacting inner side, an electrode arrangement consisting of at least two measuring electrodes disposed on the flow tube for picking up a voltage induced in the fluid, and a magnetic field system likewise disposed on the flow tube. The magnetic field system comprises at least two saddle-shaped field coils for producing a magnetic field cutting the fluid during operation of the flow sensor, a respective ferromagnetic pole piece for each of the two field coils, as well as at least one ferromagnetic return path extending around the flow tube upstream of the two field coils and at least one ferromagnetic return path extending around the flow tube downstream of the two field coils for directing the magnetic field around the flow tube.