Abstract: An outer wellhead member has a bore with a first profile portion and an annular recess. A tubular inner wellhead member with a centralizer/overpull ring is lowered into the outer wellhead member. The centralizer/overpull ring is biased to expand outward to engage the bore of the outer wellhead member to center the inner wellhead member within the bore as the inner wellhead member is lowered through the bore. The recess of the outer wellhead member is adapted to receive the centralizer/overpull ring and oppose axial movement of the centralizer/overpull ring to enable an upward test pull of the inner wellhead member.

Abstract: A downhole magnet tool comprises a top sub having an inner bore terminating in a downhole facing open end, the inner bore defining a centralizer receptacle of smaller width than a width of the downhole facing open end, a mandrel terminating upwardly in a centralizer stem, the centralizer stem being fitted in the centralizer receptacle of the top sub, and a magnet mounted on a downhole facing surface of the mandrel. A method of assembly of a downhole magnet tool comprises mounting a magnet on the mandrel and inserting the centralizer stem into the centralizer receptacle.

Abstract: A running tool has a stem for connecting to a string of conduit, a body, and a plurality of functional positions selected in response to rotation of the stem relative to the body. A feedback mechanism assembly is connected to the running tool and is operational with rotation of the stem relative to the body. The feedback mechanism assembly increases the torque required to rotate the stem relative to the body when the running tool has reached one of the plurality of its functional positions. The increased torque thereby provides a positive indication that the running tool has reached and is in the desired and proper functional position.

Abstract: A universal dart launcher launches a dart by moving a dart from a first position to a second position. The universal dart launcher has a launcher body defining a central bore having an axis and lower and upper ends configured to attach to a string of pipe. A cartridge housed within the launcher body may move perpendicular to the axis from a first position to a second position. A drop member is positioned within the cartridge so that it will not be in axial alignment with the central bore while in the first position, and will be in axial alignment with the central bore while in the second position. An actuator assembly couples to the launcher body to move the cartridge from the first position to the second position when actuated.

Abstract: An apparatus for controlling fluid pressure, useful in the production of hydrocarbons from underground reservoirs comprises at least one conical segment. A conical segment comprises: an inner conical cylinder with a central axis; an outer conical cylinder, outside of, and coaxial with, the inner conical cylinder; and a swirl chamber disposed between a conical outer surface of the inner conical cylinder and a conical inner surface of the outer conical cylinder. There is a fluid entrance through a wall of the outer conical cylinder of at least one conical segment at an upstream end of the apparatus for directing fluids into such conical segment's swirl chamber. There is also a fluid exit through a wall of the inner conical cylinder of at least one conical segment at a downstream end of the apparatus for directing fluids out of such conical segment's swirl chamber.

Abstract: The present invention provides a check valve comprising a valve housing (1,2), a substantially circular flapper (3), a valve seat (16) for the flapper (3), an expandable chamber (11) in fluid contact with a connecting port (8) for hydraulics fluid, and a piston (4) having a first and a second end, the flapper comprises a first (19) and a second (18) connection point and is pivotably connected at the first connection point (19), said flapper is capable of pivoting between a closed position in close contact with the valve seat (16) and an open position which allows fluid to flow through the valve, the piston (4) is in contact with the expandable chamber (11) and a pre-stressed compressible device (15), said piston (4) pivotably connected at the first end to the flapper (3) via the second connection point and that the second connection point (18) is situated closer to the center of the circular part of the flapper than the first connection point (19).

Abstract: The invention provides a system comprising: a tubular containing a first surface comprising a coating made of a first swellable material coating said first surface, wherein said coating has a second surface and said first swellable material is able to swell in contact with a first fluid on said second surface; and a composition made of a settable material and a second swellable material able to swell in contact with a second fluid. The invention also discloses the method associated with the use of such a system.

Abstract: A pilot valve assembly for regulating the output of a first pressure source relative to a second pressure source, a fluid system equipped with the valve assembly, and a method of operating the valve assembly. The valve assembly includes a valve body with inlet and outlet ports and first and second sensing ports. The first and second sensing ports are adapted to sense, respectively, the fluid pressures of the first and second pressure sources. The inlet port is adapted for fluidically connecting to the first pressure source. The valve assembly defines a flow path between the inlet and outlet ports, and has components for allowing fluid flow from the inlet port, through the flow path, and to the outlet port only if the fluid pressure of the first pressure source exceeds the fluid pressure of the second pressure source by a differential by the flow-allowing components.

Abstract: A method for extinguishing a full surface liquid tank fire including addressing plunge zone issues, the attack including throwing at least one primary stream over a tank wall, the stream landing with a force of impact in, and defining, a plunge zone; the method including extinguishing a full surface heavy liquid tank fire by teasing the fire prior to employing a non-feathered stream to create a foam blanket.

Abstract: A tractor blade assembly is disclosed having a first blade member and one or more replaceable, supplemental blade members. The first blade member has a supplemental blade mounting section extending laterally beyond the side edge of the first blade member and a supplemental blade member that removably attaches to the supplemental blade mounting section such that a side edge of the supplemental blade member abuts the side edge of the first blade member. The tractor blade assembly may include alignment structure to restrict vertical movement of the supplemental blade member relative to the first blade member and align the side edges.

Abstract: A multi-use attachment device that is easily attached to and removed from an all-terrain vehicle (ATV) or a utility-terrain vehicle (UTV) comprises a lift frame including an inner lift frame, an outer lift frame, a first pivotal axis and a second pivotal axis, and is configured to pivot about the first pivotal axis with a first electrical device, and has a second electrical device mounted on the lift frame to pivot the outer lift frame with respect to the inner lift frame. One end of the multi-use attachment is attached to the ATV/UTV, and the other end is attached to an implement such as a loader bucket, a pallet fork, or a plow blade. Some embodiments of the multi-use attachment use tension devices both for pivoting the lift frame about the first pivotal axis and for pivoting the outer lift frame with respect to the inner lift frame about the second pivotal axis.

Abstract: A micro assembly having a substrate and an operating plane coupled to the substrate. The operating plane is movable from an in-plane position to an out-of-plane position. One or more electric connections provide electric power from the substrate to the operating plane in the out-of-plane position. A tool is coupled to the operating plane. The tool is operable to receive electric power from the operating plane to perform work.

Abstract: A rotary tool includes an externally operable operation switch; a motor serving as a power source; a power transfer block for transferring the rotation of the motor; a load detection unit for detecting an amount of load of the motor; and a control unit for controlling the motor. The control unit is configured to perform an operation control by which the motor is controlled so that a rotation speed of the motor is increased in proportion to the operation amount of the operation switch and a feedback control by which the rotation speed of the motor is controlled depending on the detection result of the load detection unit. The control unit inhibits the feedback control during the time when the operation amount of the operation switch is equal to or less than a threshold and performing the feedback control only when the operation amount of the operation switch is greater than the threshold.

Abstract: An electric power tool receives an input power from an electric power source and converts the input power to a driving power to drive an electric motor. The electric power tool further includes a manual control mechanism, a magnetic control element and a power modulation circuit. The manual control mechanism includes a trigger portion movable by depressing of a user and a magnetic element movable with the trigger portion. The magnetic control element outputs an output control signal in proportion to alterations of a magnetic field caused by movements of the magnetic element. The power modulation circuit gets the input power and modulates to the driving power controlled by the output control signal to drive the electric motor. Thus by depressing the trigger portion, output power of the electric motor can be controlled to provide precise control of rotational speed and torque alterations.

Abstract: A method and equipment for displaying holes to be drilled when drilling holes into rock with a rock-drilling rig having control equipment and a display belonging thereto and measuring means for defining the direction and position of a drill rod, by using a pre-designed drilling plan defined in a three-dimensional coordinate system, in which a starting point (19a to 21a) and end point (19b to 21b) is defined for each hole to be drilled. A base plane running through the end point (19b to 21b) of the hole and parallel to the projection plane is defined for each hole (19 to 21), and a projection of the intersection of a hole or its extension created when drilling in accordance with the current location of the drill rod and the defined base plane is displayed with a graphical location symbol on the projection plane.

Abstract: A coring apparatus is provided, which apparatus, in one exemplary embodiment, includes a rotatable member coupled to a drill bit configured to drill a core from a formation, a substantially non-rotatable member in the rotatable member configured to receive the core from the formation, and a sensor configured to provide signals relating to rotation between the rotatable member and the substantially non-rotatable member during drilling of the core from the formation, and a circuit configured to process the signals from the sensor to estimate rotation between the rotatable member and the non-rotatable member.

Abstract: An influx of gas into a borehole can be detected by deploying a string of acoustic sensors along a drill string or other conduit to monitor an acoustic characteristic, such as velocity or attenuation, of the drilling fluid present in the borehole. In response to detection of acoustic pulses propagating in the drilling fluid, the acoustic sensors generate signals that are representative of acoustic characteristics if the drilling fluid. Based on the generated signals, a data acquisition system can determine whether a change in the monitored acoustic characteristic is indicative of a gas influx.

Abstract: An apparatus for use in a wellbore is provided, which in one embodiment includes a drilling motor and a steering unit placed about a shaft between a lower section of a stator in the motor and a drill bit. The steering unit includes a substantially non-rotating member and a force application member on the non-rotating member configured to radially extend the force application member from the non-rotating member. In another embodiment, the steering unit may include, rotating member configured to rotate a drill bit, a steering member configured to orient the drill bit along a selected direction, a first steering device configured to orient the steering member in the wellbore, and a second steering device configured to maintain orientation of the steering member when drilling the wellbore.

Abstract: A method and apparatus for estimating the instantaneous rotational speed of a bottom hole assembly at the lower end of a drill string. In one embodiment, a method includes driving the drill string by a drilling mechanism at the upper end of the drill string. A fundamental frequency of stick-slip oscillations suffered by the drill string is estimated. Variations in a drive torque of the drilling mechanism are determined. Known torsional compliance of the drill string is combined with the variations in the drive torque. An output signal representing the instantaneous rotational speed is provided.

Abstract: Surface texturing is employed to modify the topography of one or more surfaces (radial or cylindrical) of the sealing system for a roller cone rock bit. The surface texturing produces a regular or repeated patterned dimpled surface which retains additional lubricant helpful in reducing friction in the boundary and mixed lubrication regimes.

Abstract: A drill bit for drilling a borehole in earthen formations comprising a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face, the primary blade including a cutter-supporting surface that defines a blade profile in rotated profile view extending from the bit axis to an outer radius of the bit body. The blade profile is continuously contoured and includes a plurality of concave regions. Further, the drill bit comprises a plurality of cutter elements mounted to the cutter-supporting surface of the primary blade. Each cutter element on the primary blade has a forward-facing cutting face with a cutting edge adapted to penetrate and shear the earthen formation.

Abstract: An insert for an earth-boring tool includes a body and a coating disposed over at least a portion of the body. The coating comprises a ceramic comprising boron, aluminum, and magnesium. Polycrystalline diamond compact cutting elements may include a hard polycrystalline material, a supporting substrate, and a coating disposed over at least a portion of the hard polycrystalline material. An earth-boring drill bit may include a bit body and at least one polycrystalline diamond compact cutting element secured to the bit body. The polycrystalline diamond compact cutting element may have a coating comprising a ceramic of boron, aluminum, and magnesium, and may be disposed over at least a portion of a hard polycrystalline material. A method of forming an insert for an earth-boring tool may include forming a protective coating including a ceramic of boron, aluminum, and magnesium over a cutting element.

Abstract: A rotary drag bit for drilling subterranean formations includes a bit body having a face extending from a centerline to a gage. A plurality of blades may be disposed on the face, and may generally extend radially outwardly toward the gage. The bit may further include a plurality of discrete impregnated cutting posts, each of which may extend outwardly from an associated blade. Each discrete impregnated cutting post angles generally toward a front edge of the associated blade and generally toward the intended direction of rotation of the bit. The rotary drag bit may further include a plurality of matrix pockets disposed on the blades. The discrete impregnated cutting posts may be housed within corresponding matrix pockets.

Abstract: A cutter for a downhole cutting tool is disclosed. The cutter includes a cutter body having a cutting face, a peripheral sidewall flank, and a base. The base has a recessed channel that extends inwardly from the peripheral sidewall flank and provides an inlet opening therein. A downhole cutting tool employing the cutter is also disclosed. The cutting tool includes a tool body having a cutter face. The tool also includes a cutter body having a cutting face, a peripheral sidewall flank, and a base, the base having a recessed channel that extends inwardly from the peripheral sidewall flank and provides an inlet opening therein. The tool also includes a braze joint between the base and the bonding surface.

Abstract: Diamond bonded constructions include a diamond body comprising intercrystalline bonded diamond and interstitial regions. The body has a working surface and an interface surface, and may be joined to a metallic substrate. The body has a gradient diamond volume content greater about 1.5 percent, wherein the diamond content at the interface surface is less than 94 percent, and increases moving toward the working surface. The body may include a region that is substantially free of a catalyst material otherwise disposed within the body and present in a gradient amount. An additional material may be included within the body and be present in a changing amount. The body may be formed by high-pressure HPHT processing, e.g., from 6,200 MPa to 10,000 MPa, to produce a sintered body having a characteristic diamond volume fraction v. average grain size relationship distinguishable from that of diamond bonded constructions form by conventional-pressure HPHT processing.

Abstract: In various embodiments, a polycrystalline diamond compact (“PDC”) comprises a substrate including an interfacial surface having a raised region. The PDC comprises a polycrystalline diamond (“PCD”) table bonded to the interfacial surface of the substrate. The PCD table defines an upper surface and exhibits a thickness over the raised region. The PCD table includes a plurality of bonded diamond grains defining a plurality of interstitial regions. A first region of the PCD table adjacent to the substrate includes metal-solvent catalyst disposed interstitially between the bonded diamond grains thereof, and a leached second region of the PCD table extends inwardly from the upper surface. The interstitial regions of the leached second region are depleted of metal-solvent catalyst. The geometry of the PCD table and raised region may be selected so that residual compressive stresses therein are retained to a sufficient level after leaching to provide a damage tolerant/thermally-stable PCD table.

Abstract: An omni-directional wheel assembly for a vehicle that includes a wheel, at least one lower suspension link and an upper attachment joint. Both the at least one lower suspension link and the upper attachment joint are attachable to the vehicle. The wheel is able to rotate at 360°, to steer the vehicle, around a pivot line positioned by the at least one lower suspension link and the upper attachment joint once attached to the vehicle. A projection of the pivot line onto a vertical projection plane comprises a vertical axis passing through a contact point between the wheel and ground defining a caster angle with the vertical axis, where whatever the orientation of the projection plane, the omni-directional wheel assembly includes an adjustment means able to adjust the caster angle within a predetermined range.

Abstract: The present invention provides a heat dissipating system for an electric vehicle drive controller. The heat dissipating system for electric vehicle drive controller includes: high power MOS transistors for controlling magnitude of power supplied to an electric vehicle drive motor and for switching current direction, and a radiator connected to bodies of the MOS transistors, the radiator being made of aluminum alloy material, and a surface of the radiator being plated with a metallic nickel layer. Compared with existing electric vehicle drive controller, the electric vehicle drive controller of the present invention has advantages of low operating temperature, high reliability and long service life.

Abstract: An apparatus is provided for driving wheels for an in-wheel system, including: a driving shaft which is the center of rotatable driving; a fixation supporter rotatably supporting the driving shaft and coupled to the driving shaft; an in-wheel motor generating rotational power, which is coupled to the inside of a wheel in which a tire is mounted on one driving shaft in a shaft direction of the fixation supporter; and a balancing member formed on the other driving shaft in the shaft direction of the fixation supporter and formed at a position corresponding to the wheel coupled with the in-wheel motor. According to the present invention, an eccentricity phenomenon which is caused due to inclination of a wheel and a motor in one direction of a fixation supporter can he prevented in an apparatus of driving wheels for an in-wheel system.

Abstract: A method of monitoring operation of an adjustable shutter adapted for cooling a powertrain in a vehicle includes commanding the shutter to adopt a position and assessing whether the shutter has adopted the commanded position. The method also includes generating a first signal if the shutter has adopted the commanded position, and commanding the shutter to perform a first retry to adopt the commanded position if the shutter has not adopted the commanded position. The method additionally includes generating a second signal if the shutter has adopted the commanded position on the first retry. A vehicle using a controller to perform such a method is also provided.

Abstract: Disclosed is an electric vehicle battery attaching/detaching device including a battery mounting unit formed on an electric vehicle to detachably mount a battery and provided with a connector pin module adapted to be lifted/lowered by a lifting/lowering means; a loader having a plurality of battery stands, each battery stand being adapted to detachably mount a fully-charged battery to be exchanged with the battery mounted on the battery mounting unit; and a battery attaching/detaching unit adapted to move along X-axis, Y-axis, and Z-axis between the battery mounting unit and the battery stand by means of a movement device, detach a battery mounted on the battery mounting unit or the battery stand, and exchange/mount the battery on the battery stand or the battery mounting unit.

Abstract: A structure for a vehicle body lower portion according to the present invention includes: a side sill (3) located on each side in a vehicle width direction and extending in a vehicle front-rear direction; a side member (13) joined to a lower face (1b) of a floor panel (1) and extending in the vehicle front-rear direction at a position above the side sill (3) and inside the side sill (3) in the vehicle width direction; a brace member (39) connecting a lower part of the side member (13) to an upper side of the side sill (3); and an outer cross member (37) connecting the lower part of the side member (13) to a lower side of the side sill (3).

Abstract: A traction control system comprises a detector configured to detect a monitored spin value corresponding to a spin amount of a drive wheel in a vehicle; a condition determiner configured to determine whether or not the monitored spin value detected by the detector meets a driving power suppressing condition; and a controller configured to execute a traction control for reducing a driving power of the drive wheel based on the determination; the condition determiner being configured to set the driving power suppressing condition variably based on at least one of a variable parameter relating to a rotation number difference which is variable according to a change rate of a rotation number difference between the drive wheel and a driven wheel, and a variable parameter relating to rotation of a drive system which is variable according to a rotation change rate of the drive system for driving the drive wheel.

Abstract: A control apparatus for a motor-assisted bicycle detects a pedaling torque applied to a crankshaft with a pedaling force sensor, controls a motor unit of the motor-assisted bicycle in a regenerative control process to charge a battery if the torque value of the detected pedaling torque is equal to or smaller than a predetermined level, and controls the motor unit in an assistive control process if the torque value is greater than the predetermined level. The control apparatus switches between the assistive control process and the regenerative control process depending on the torque value which is detected, increases the predetermined level if the state of charge of the battery becomes lower than a first level, and restores the predetermined level if the state of charge of the battery becomes higher than a second level which is greater than the first level.

Abstract: A vehicle body frame includes a left frame member, a right frame member, a cross member, and a first patch member. The cross member is fitted in both of a left connecting hole and a right connecting hole and welded to the left frame member and the right frame member. The cross member includes a pipe member having a hollow portion which has a first end, and a second end opposite to the first end along the hollow portion. The first patch member is fitted in the first end of the hollow portion and welded to an inner peripheral face of the hollow portion such that a weld bead is provided within a range of a first welding margin provided in the first end of the hollow portion. The first welding margin is provided on the inner peripheral face of the hollow portion.

Abstract: A saddle riding vehicle includes a vehicle body frame, a front wheel, a rear wheel, a power unit, a shift actuator, and an actuator guard. The power unit has a transmission and a shift mechanism for the transmission. The shift actuator is to actuate the shift mechanism and is attached to a lower portion of a side face of the power unit. The actuator guard is to protect the shift actuator from an obstacle and includes a guard frame and a guard member. The guard frame extends in a forward and backward direction of the saddle riding vehicle below the shift actuator. The guard frame is connected to the vehicle body frame. The guard member is connected to the guard frame and covers a lower face and an outer side face of the shift actuator.

Abstract: An air-bag device in which a deployed air-bag has a complete deployment portion positioned on the longitudinally central side and having a substantially constant diameter and incomplete deployment portions positioned on longitudinally opposite end sides and having a diameter that gradually decreases in going toward a blocking member, the incomplete deployment portion has high rigidity compared with the complete deployment portion and is difficult to deform when there is a collision with a pedestrian, thus degrading the impact absorption performance, but disposing the plurality of vent holes in the incomplete deployment portion at a fixed pitch in the longitudinal direction and the circumferential direction of the air-bag enables the rigidity of the incomplete deployment portion to be lowered and the impact absorption performance to be enhanced, thereby giving uniform impact absorption performance over the entire longitudinal length of the air-bag.

Abstract: A cooling unit that is cooled by heat exchange with air is disposed at a rear side in a vehicle longitudinal direction of a power unit. Further, a cooling fan is disposed at a rear in the vehicle longitudinal direction of the cooling unit. Further, catalytic converters are disposed at a rear side in the vehicle longitudinal direction of the power unit. A periphery of these catalytic converters is surrounded by a heat insulator. A duct portion, that communicates an interior of the heat insulator and a space between the cooling unit and the cooling fan, is provided at this heat insulator.

Abstract: An electric power steering apparatus (1) comprises a control device (12), which controls driving of an electric motor (18) based on the detection signals from a rotational position-detecting sensor (72; 72A), which detects the rotational position of the rotor (64) of the electric motor (18), and a steering status detecting sensor (11; 11A). The control device (12) is housed in a housing (100) that is partitioned by a first housing (23), which is at least a portion of the motor housing (25) for the electric motor (18), and a second housing (24; 24A; 24B) that touches the first housing (23). At least one of the rotational position-detecting sensor (72; 72A) and steering state detecting sensor (11; 11A) is connected to the control device (12) by means of only a signal wire (81; 134) inside the first housing (23) or the second housing (24; 24A; 24B).

Abstract: An electric power steering device includes a metallic housing, a steered shaft, an electric motor, a ball screw device, a rolling bearing, elastic members, and a plain bearing. The plain bearing is provided between the housing and an outer ring of the rolling bearing, and formed from a resin material.

Abstract: Method and land-based system for generating seismic signals. The system includes a vehicle configured to move to a desired location above ground, the vehicle having a first end and a second end, opposite to the first end; a vibratory source configured to generate seismic waves into the ground; a lifting system connecting the first end of the vehicle to the vibratory source and configured to lift or lower the vibratory source relative to the ground; and a balancing device connected to the second end of the vehicle and configured to lift the second end of the vehicle from the ground.

Abstract: An excitation device for downhole seismic testing, includes an excitation hammer, a holding arm connected at one end thereof to the excitation hammer to allow the excitation hammer to rotate about the other end thereof, a support post having the other end of the holding arm rotatably coupled to an upper end thereof to support the excitation hammer and the holding arm at a certain height, and an excitation source configured to allow the support post to stand upright on the upper side thereof and which generates a seismic wave when struck by the rotated excitation hammer. The support post is formed at a lower end thereof with a securing section detachably inserted into a groove for the support post formed on the upper side of the excitation source such that the support post, the holding arm, the excitation hammer and the excitation source can be separated from each other.

Abstract: A seismic vibrator includes a baseplate having a surface configured to couple to a ground surface. A driver is coupled to the baseplate and is configured to move the baseplate in a vibratory manner. A decoupling system is coupled to a part of the baseplate other than the ground-contacting surface. The decoupling system includes a first layer having a Young's modulus greater than that of a second layer coupled to the first layer. The second layer is coupled to the baseplate. The Young's moduli, thicknesses and masses of the first and second layer are selected to provide the decoupling system with a resonant frequency of at most, a spatial aliasing frequency of seismic sensors deployed on the ground surface or a lowest seismic frequency of interest.

Abstract: An ear protector (1) with a sound damping filter (3), comprises a membrane (5). The membrane is composed of a material that permits the transmission of air and water vapor with respect to the ear from the into the outside of the ear protector, the membrane is pre stressed mounted in the filter, enabling a bigger surface and hence bigger air and water transport at same sound attenuation.

Abstract: An on-base enclosure for equipment is disclosed. The on-base enclosure has walls attached to a base for equipment such that the walls are attached to the base at a distance away from the base. By providing the walls away from the base, more room is provided around the equipment within the enclosure.

Abstract: A resonator is provided, having an adaptable resonator frequency for absorbing sound generated by a gas stream of a gas turbine. The resonator includes a neck section, a chamber and a deformable element being deformable under influence of a change of a gas turbine temperature of the gas stream. The shape of the deformable element is predetermined with respect to a respective gas turbine temperature. The neck section and the chamber form a volume of the resonator. The neck section forms a passage coupling the volume with the gas turbine. The deformable element is thermally coupled to the gas turbine in such a way that the shape of the deformable element depends on the respective gas turbine temperature. The deformable element forms a spiral and is installed to the neck section in such a way that an effective diameter of the neck section depends on the gas turbine temperature.

Abstract: A sound absorbing structure includes multiple sound absorbers. The sound absorbers are assembled together into a sound absorbing member. The sound absorbing member absorbs sound emitted from a sound source. Each of the sound absorbers is shaped like a hollow tube. Each of the sound absorbers has a hole extending in its axis direction.

Abstract: Air bubbles may be used to reduce radiated underwater noise. Two modalities of sound attenuation by air bubbles were shown to provide a reduction in radiated sound: bubble acoustic resonance damping and acoustic impedance mismatching. The bubbles used for acoustic resonance damping were manifested using gas-filled containers coupled to a support, and the acoustic impedance mismatching bubbles were created using a cloud of freely-rising bubbles, which were both used to surround an underwater sound source.

Abstract: An acoustic absorber includes a wall provided with a plurality of apertures as well as a substantially non-perforated second wall, with the first wall and the second wall being spacedly arranged to one another, and at least one honeycomb structure being provided between the walls, with the honeycomb structure having a substantially cylindrical recess in at least one area, with a funnel element opening to the first and second walls being provided in the recess, and having a height greater than the distance of the walls, with the second wall being designed pot-like in the area of the funnel element.

Abstract: A cargo lifting apparatus for use with a ladder includes a lift track coupled to each ladder side rail. Each lift track includes first and second adjacent channels, the first channel defining a longitudinal slot. The apparatus includes a carrier assembly having a back portion, a pair of support members extending perpendicularly and forwardly from the back portion, opposed mounting members configured to be received in a respective first channel slot, and rollers attached to the back portion configured to bear against respective ladder side rails. A motor/brake combination is coupled to a lower rung of the ladder. A pulley assembly includes a lower sprocket operatively coupled to the motor, an upper sprocket, and a cord extending between the sprockets and coupled to the carrier assembly for selectively raising and lowering the carrier assembly when the motor is activated or deactivated.