Abstract: A bicycle power source holder is provided that basically has a holder main body part and a frame attaching part. The holder main body part is configured to retain a power source. The frame attaching part is configured to movably mount the holder main body part to a bicycle frame so that the holder main body part is movably mounted in a lateral direction of a bicycle.

Abstract: A bicycle sprocket comprises a sprocket member and an attachment member. The sprocket member comprises a first annular portion, sprocket teeth and a first engaging portion. The first engaging portion is provided on an inner peripheral part of the first annular portion. The attachment member is configured to be bonded to the sprocket member and comprises a second annular portion and a second engaging portion. The second annular portion is provided radially inwardly of the first annular portion. The second engaging portion is configured to engage with the first engaging portion. One of the first engaging portion and the second engaging portion includes a protrusion. The other of the first engaging portion and the second engaging portion includes a groove extending in the circumferential direction. The protrusion is configured to be fitted in the groove.

Abstract: A bicycle gear changing apparatus is basically provided with a controller including memory with a first prescribed shift route for upshifting and a second prescribed shift route for downshifting. The first prescribed shift route defines an order of actuation of at least one of a first gear changing device and a second gear changing device that is different from an order of actuation of at least one of the first and second gear changing devices that is defined by the second prescribed shift route. The controller controls a shifting operation of at least one of the first and second gear changing devices in response to a shift signal and in accordance with one of the first and second prescribed shift routes. The first prescribed shift route includes a least one user settable synchro-upshift point. The second prescribed shift route includes at least one user settable synchro-downshift point.

Abstract: A transmission unit for a vehicle driven by muscle power. The transmission unit has one through shaft and one output shaft, as well as at least two sub-transmissions and at least one intermediate shaft. In the transmission unit at least one of the intermediate shafts and the output shaft is formed as a hollow shaft which is arranged coaxially to another shaft of the transmission unit.

Abstract: A bicycle power control apparatus comprises a power supply sensor and a controller. The power supply sensor detects a power level of a first power supply. The controller is operatively coupled to the power supply sensor to receive a power level signal from the power supply sensor. Thus, the controller selectively operates a bicycle component actuator using power from the first power supply while the power level of the first power supply is detected at or above a first power level, and automatically sets the bicycle component actuator using power from a second power supply to a prescribed operating condition in response to detection of the power level of the first power supply being below the first power level.

Abstract: A motorized or manual extendable and retractable floating device is supported longitudinally by one or more floatation devices. The flotation deck is stored and supported by tracks or rails from beneath and between an upper deck of a houseboat, pontoon boat, tritoon boat, catamaran, floating dock, pier-supported dock or other watercraft or dock. When fully extended, the floating deck will remain attached to the watercraft, and additional width may be achieved with extendable or fold out sides or wings.

Abstract: A retractable keel apparatus for a ship, in particular for a sailboat, including a lift device for a lowerable and retractable fin device having a fin (4) and a fin head plate (20) disposed thereon, the fin head plate making contact with a keel receptacle (5) provided for permanently attaching to a hull when the fin is lowered, the receptacle further having a locking device by which releasable locking can be produced between the fin head plate (20) and the keel receptacle (5). The invention should be designed such that, despite greater stability, including in the event of a crash, the device can be produced and integrated in ships as simply and cost-effectively as possible. For this purpose, the locking device has at least one, preferably a plurality of, preferably driven, longitudinally displaceable locking bolts (15) that can be displaced along a diagonally running displacement path.

Abstract: An arch shaped structural member suitable for use as a wakeboard tower including a pair of legs and a crosspiece supported by the legs, both of the legs and the crosspiece being a coreless cast structural member characterized as a cast structural member and devoid of a hollow interior enclosed by solid portions.

Abstract: A multi-directional signal assembly includes a signal display assembly having one or more display surfaces, and at least one signal indicia affixed to each display surface. The multi-directional display assembly comprises a buoyant construction such that the signal indicia affixed to the display surface(s) are readily visible above the surface of a body of water in which the assembly is deployed. A counterweight assembly is mounted to the signal display assembly to maintain the signal display assembly in a substantially upright, operative orientation when deployed. An illumination assembly comprising one or more illumination members is mounted to the signal display assembly, and is actuated to increase visibility of the signal display assembly while it is deployed on the surface of a body of water.

Abstract: A transfer system is described including a subsea installation fixed relative to a seabed, and a transfer element for transfer of fluid, electrical signals, or electric current between the subsea installation and a floating arrangement. The transfer element is configured to connect to the subsea installation and includes a connector for connecting to the floating arrangement. The transfer system includes a buoyancy element anchored to the seabed, and has a through-going hole in the vertical direction. The transfer element extends through the hole and is movable in both directions through the hole. The transfer element includes a fender system that extends at least partially around the circumference of the transfer element. The fender system abuts the buoyancy element when the transfer element is suspended. When the transfer element is suspended, the transfer element forms an S-shape or J-shape between the subsea installation and the buoyancy element.

Abstract: An aircraft carrier replenishment system conveying goods using containers and oil tanks is disclosed. Two sides of the main body of each of an aircraft carrier and a replenishment ship are each provided with a loading window. The window at one side is a container loading window, and a container crane is provided in the window. The window at the other side is an oil loading window, and an operation room for connecting an oil delivery pipe is provided in the window. A marine crane for hoisting transport and oil travel between the aircraft and the replenishment ship. A network communication system is providing for connecting the aircraft carrier, the replenishment ship and the transport ships.

Abstract: During an offloading operation between a first and a second body, an operating envelope of an offloading system can be displaced to compensate for a drifting movement of one of the bodies. By appropriately displacing the operating envelope, offloading operation can continue under safe conditions even though the working limit of the original operating envelope is breached due to the drifting movement of one of the bodies.

Abstract: A floating offshore platform is disclosed with one or more extension plates fixedly coupled to one or more pontoons on the offshore platform and extending from the pontoons. As the floating platform moves, the pontoon-coupled extension plates separate the water and cause drag on the platform. The water moving with the extension plates also increases the dynamic mass. The added drag and dynamic mass increases the natural period of the motion away from the wave excitation period to minimize the wave driven motion compared to a platform without the extension plates. The extension plates can be coupled to the pontoons during fabrication at the yard directly or through frame members. The extension plates generally are generally located inclusively between the top and bottom elevations of the pontoons, and therefore do not significantly reduce the clearance between the seabed and the hull at the quayside.

Abstract: A deck arrangement for a vessel or platform (1) configured for performing subsea operations, the vessel or platform having a main deck (2) and a working station (4a) and facilities (9b, 6; 28) for supporting activities in the working station, the working station further comprising a working area (4b). One or more deck elements (14a,b, 15) are arranged at an elevation different from than of the main deck (2) and at an elevation where upper surfaces of the deck elements (14a,b, 15) and the upper surface of the working area (4b) are on the same, or substantially same, level. Preferably, the deck elements are arranged above the main deck (2) and above one or more of the facilities (9b, 6, 28). The facilities may be a riser storage compartment, a BOP area and/or a pipe deck.

Abstract: A non-self-propelled, floatable structure for supporting people, animals, machinery or other loads is disclosed, having a floatable body designed to float on water, and a retention skirt that protrudes downwardly from a peripheral edge of the floatable body. The retention skirt is designed to extend underwater, delimiting an internal space between the retention skirt, the floatable body, and the water. The retention skirt is airtight, preventing air passing through the skirt and towards said internal space. Thus, when a downward force is applied on an edge of the floatable body causing the opposite edge to start rising from the water, skirt airtightness beneath the rising edge creates a vacuum effect that stops the edge from rising and prevents the floating structure from swaying excessively and eventually turning over or capsizing. The retention skirt also limits or prevents lateral and transverse motion across the water surface.

Abstract: A self-leveling boat bumper system attached to a nautical structure can include a floating bumper arrangement having a float element, a float extension, and a boat bumper; and a receiver, fixed to the nautical structure and moveably engaged with the arrangement, or fixed to the arrangement and moveably engaged with a guide fixed to the nautical structure. When floating within a body of water, the float element can provide a buoyancy force that maintains the boat bumper in a static position between, and including, first and second positions, and as the level of the water changes.

Abstract: Some embodiments of the present disclosure include a multipurpose swim vest for keeping a user safe around a body of water while also providing the user with entertainment. The swim vest may include a swim vest configured to accommodate a user's torso, a water pistol removably attached to vest fabric of the swim vest, the water pistol having a toy tube extending therefrom, a vest tube positioned within a channel in the swim vest, the vest tube extending from a position proximate to a user's side through the channel and out of a bottom surface of the swim vest, and a siphon tube attached to the vest tube. Water may be siphoned through the siphon tube, the vest tube, and the toy tube into the water pistol when the user pulls a trigger on the water pistol, which may also cause water to squirt out of the water pistol.

Abstract: This invention relates to a breathing sensing device for detecting a pressure drop due to breathing. The device includes a diaphragm (100) having a first pressure chamber (120) on one side and a second pressure chamber (121) on a second side within an actuator housing. The first and second pressure chambers (120,121) are connected to a system pressure (L1) by flow passages (143, 153) having different cross sectional passage area (Ar, Af) arranged to facilitate detection of a pressure drop due to breathing.

Abstract: An underwater personal mobility device is provided. The underwater personal mobility device can include a lower section rotatably connected to a main body comprised of an observation chamber. The device may have at least two configurations, including a folded configuration, to enable ease of transport and storage of the device.

Abstract: Provided is a vehicle control device for an amphibious vehicle that can travel with a stable orientation even when the edge of the water consists of uneven terrain or terrain having an inclined surface along a different direction than the direction of travel. A vehicle control device for an amphibious vehicle capable of traveling on land, navigating on the water, and traveling on the edge of the water comprises a jet direction adjuster (15) for adjusting the direction of a jet created by a propeller (11), an orientation detector (31) for detecting the orientation of an amphibious vehicle (1), and a control device (30) for controlling the jet direction adjuster (15) and/or the propeller (11) on the basis of the orientation of the amphibious vehicle (1) detected by the orientation detector (31) when an edge-of-water travel mode is selected.

Abstract: A pedal propulsion device for use on a small watercraft, having a lightweight portable frame with integral foot-engagement cranks. A propeller and rudder assembly driven by the foot cranks automatically will adjust for obstacles within and below the water, while maintaining direct drive by utilizing a depth stabilizer assembly extending from the support frame.

Abstract: A flywheel housing is for a stern drive of a marine vessel. The flywheel housing comprises an inner mounting face for connection to an engine block of an internal combustion engine of the stern drive and an outer mounting face for connection to a gimbal housing. The inner mounting face and outer mounting face are on opposite axial sides of the flywheel housing. A conduit is formed in the flywheel housing and is configured to receive and discharge exhaust gases from the internal combustion engine. The conduit comprises an inlet port through which the exhaust gases are received from the internal combustion engine and an outlet port through which the exhaust gases are discharged from the flywheel housing.

Abstract: A hydroplaning vessel that exceed speeds of 25 miles per hour with several stability and handling design improvements. It has an enhanced reactive suspension and inner hull lift system positioned in the vessel between an inner hull and a set of outer hulls. There are at least three outer hulls; a front outer hull and a mirror image pair of rear outer hulls, none of which can float on its own and all which have open transoms. Steering and braking are accomplished by a set of rear elevon flaps. The drive unit resides in the inner hull and is connected by an annular drive transmission, which is connected to the jet or prop drive, which resides on the outer hull.

Abstract: A super-rigid hybrid airship having a modular structure with a central tube having a diameter of between 5 to 10% of the diameter of the airship, structural rings surrounding and preferably concentric with the central tube and connected to the tube by bolts; an external cover made from thin metal sheets, interspersed with composite resins and fibbers which is pressurized and pre-stressed by light gases and which is rigid, conductive, non-combustible and impermeable to gases; balloons filed with hydrogen and disposed in structural sections defined by neighboring structural rings; at least two interconnected cuffs inflated by atmospheric air serving as operational ballast and ensuring weight, pressure and volume balance of the airship. Preferably the airship has a blower system for dispersing air, arranged on the centerline of the top layer, wings arranged at each side of the fixed sections, and thrust means.

Abstract: A composite frame includes a plurality of truss elements covered by a cap. The truss elements are flexibly coupled with each other and with the cap. The frame flexes to conform to a contoured surface to which it is attached. Once attached, the installed frame provides the required rigidity to the structure.

Abstract: A device for attachment of a door of an aircraft including a base bracket and a door-engaging fitting that bears the door. The base bracket has two flanges spaced longitudinally along the bracket, and a first flange is attachable to a frame surrounding the door, and the door-engaging fitting is attachable to an opposite, second, flange, the second flange being adapted to adjust a position of the door-engaging fitting, relative to, and in a plane parallel with, that second flange.

Abstract: A high-lift device of a flight vehicle includes: a flap main body provided at a trailing edge portion of a main wing of the flight vehicle so as to be extracted from and be retracted in the trailing edge portion and extending in a wing span direction of the main wing; and a vortex suppressing portion provided at a tip end portion of the flap main body in a wing span direction of the flap main body and configured to suppress a vortex rolling up from a lower surface of a tip end portion of the flap main body to an upper surface of the tip end portion.

Abstract: A pitching stabilization means has at least one stationary stabilization surface extending in a thickness direction from a bottom face to a top face and in a transverse direction from a leading edge towards a trailing edge. The stabilization surface has at least one slot passing through the thickness of the stabilization surface from the top face to the bottom face. The slot is arranged within the stabilization surface between the leading edge and the trailing edge so as to allow a flow of air coming from a rotor to pass from the top face towards the bottom face.

Abstract: A method of diagnosing a trailing edge flap fault in an aircraft having a trailing edge flap system including multiple trailing edge flaps, a flap handle for setting the position of the trailing edge flaps, and a flap position sensor, the method includes receiving a position signal, determining a variation in the position signal relative to a reference position, diagnosing a fault, and providing an indication of the diagnosed fault.

Abstract: A blade (1) provided with a fitting (2) for fastening to a hub and with an airfoil element (10) having a spar (20) extending spanwise from an attachment zone (21) towards a distal zone (22), said attachment zone (21) surrounding a centrifugal force transmission bushing (31) that is connected to said fitting (2) by a through pin (3). The blade comprises a twisting force transmission member (40) provided with a first half-shell (41) and with a second half-shell (42) that together surround said attachment zone (21), each half-shell (41, 42) having a perforated first portion (43?, 43?) giving visual access to said bushing (31) when said airfoil element is removed from the fitting, and a second portion (44?, 44?) co-operating with a torsion box (50) surrounding said distal zone (22), said transmission member (40) being secured to said fitting in rotation about a torsion axis (AX) of the blade (1).

Abstract: A bladed rotor comprises a rotor body 2 carrying blades 6, whose pitch can be varied by means of a pitch input shaft 10. The pitch input shaft 10 drives the respective blade 6 about a spanwise axis X of the blade through a harmonic drive reduction gear 14. The harmonic drive reduction gear 14 comprises a wave generator 16 which is fixed for rotation on the pitch input shaft 10 and a flex spline which meshes with a circular spline 20 and is secured to the blade 6.

Abstract: A split winglet configured for attachment to a wing of an airplane. The split winglet may include an upper winglet smoothly extending from the wing tip above a chord plane of the wing and a ventral fin projecting below the chord plane from a lower surface of the upper winglet. The upper winglet may include a transition section which curves upward from the wing tip into a substantially planar section. Upper and lower surfaces of the upper winglet may be bounded by leading and trailing edges which are swept toward an airstream direction, parallel with the chord plane, and curve toward the airstream direction before terminating at a point distal of the wing tip. Similarly, upper and lower surfaces of the ventral fin may be bounded by leading and trailing edges which curve toward the airstream direction and terminate at a point distal of the wing tip.

Abstract: A nose landing gear arrangement for an aircraft and a method of assembling the nose landing gear arrangement are disclosed herein. The nose landing gear arrangement includes, but is not limited to, a wheel assembly, a shock strut extending upwards from the wheel assembly towards a fuselage of the aircraft, and a torque arm assembly coupled to the wheel assembly and to the shock strut. The torque arm assembly is configured to transmit torque to the wheel assembly. The torque arm assembly is disposed forward of the shock strut with respect to a direction of travel of the aircraft.

Abstract: The aircraft capable of takeoff/landing via the fuselage thereof and the takeoff/landing system of the aircraft according to the present invention are configured such that multiple takeoff/landing rollers are arranged in a sliding direction such that the aircraft fuselage having a landing surface formed at the bottom thereof can safely land and slide in a sliding direction, thus enabling the aircraft fuselage to contact a running surface and takeoff/land without separate landing gear. Thus, not only can the weight of the aircraft be reduced, but the fuel consumption of the aircraft can be reduced as well, the useful space in the aircraft can be broadened, the length of the runway can be shortened due to the frictional force generated by the takeoff/landing device, and the safety during the takeoff/landing of the aircraft can be improved.

Abstract: A rotorcraft ducted rotor comprising a rotary assembly arranged in a passage to rotate about an axis of symmetry (AX1). The rotary assembly (15) has a plurality of blades (20), each fastened to a hub (16), each blade (20) complies with a twisting relationship defining an angle of twist lying in the range zero degrees inclusive to 5 degrees inclusive. Spanwise, each blade (20) comprises a first zone (21) followed by a second zone (22), which second zone presents rearward sweep, being provided with a second trailing edge (30?) situated downstream from a first trailing edge (30?) of the first zone (21). Each first zone (21) includes a root (24) connected to the hub (16) by a fastener device (40) having a rolling bearing (45) without clearance and a conical laminated abutment (50).

Abstract: An unmanned aerial vehicle (UAV) is disclosed that includes a retractable payload delivery system. The payload delivery system can lower a payload to the ground using a delivery device that secures the payload during descent and releases the payload upon reaching the ground. The delivery device can include a channel in which a payload mount attachment for a payload can be inserted. The payload mount attachment can include an aperture for receiving a retaining rod to secure the attachment, and thus the payload, to the delivery device. The retaining rod can assume either an engaged position, in which a portion of the retaining rod engages the payload mount attachment while the payload mount attachment is inserted in the channel, or a disengaged position, in which the retaining rod does not engage the payload mount attachment.

Abstract: Emergency lighting for an aircraft has a primary power source for light units provided by the normal aircraft power supply and a secondary power source provided by power supply units operable to back-up the primary power source. Each light unit may have its own power supply unit operable to power the light unit in an emergency if the normal aircraft power supply fails or is otherwise unable to power the emergency lighting. Each power supply unit includes one or more electric double layer capacitors that are charged whenever the normal aircraft power supply is operational to provide the primary power source. The useful life of the electric double layer capacitors may be prolonged by reducing the capacitor voltage when the emergency lighting is switched off.

Abstract: An internal wall in an aircraft cabin separates a lavatory and a galley of the aircraft. The internal wall has an intermediate notch that increases a lateral width dimension of the lavatory above the notch and thereby improves the spatial environment of the lavatory.

Abstract: Seating arrangements for seats configurable between an upright and lie-flat position are presented. A three-seat grouping can include a lower aft-facing seating assembly, an upper seating assembly, and a lower fore-facing seating assembly in which the lower seating assemblies underlap the upper seating assembly when in a lie-flat position. Lower seats can be aligned or angled with respect to an upper seat in a manner that conserves space. A six-seat grouping can include 3-seat groupings in which lower seats are aligned with upper seats, or are angled with respect to them. Support structures can be shared by adjacent seats. A six-seat grouping can be embodied as a hybrid arrangement in which footspace is narrower for a lower opposing seat than for a lower seat facing the same direction as an upper seat. In an example embodiment, footspace can be divided between an upper seat and a lower opposing seat.

Abstract: A method and architecture for recovery of energy in an aircraft, both at altitude and on the ground, and recovering thermal energy from an exhaust. An architecture for recovery of energy includes an auxiliary power unit APU including an exhaust nozzle and a gas generator including a shaft transmitting power to a load compressor. The compressor supplies compressed air via a supply duct to an ECS air conditioning system of a passenger cabin. A recovery turbocharger is connected, directly or via a transmission case, to the shaft of the APU. The turbocharger includes a recovery turbine powered by a downstream branch of a conduit mounted on a heat exchanger fitted to the nozzle. The conduit includes an upstream branch connected to channels connecting air outlets of the cabin and the compressor. A second exchanger can be mounted between the supply duct and the cabin outlet channel.

Abstract: A ram outlet header includes a ram outlet header body. A ram air fan mounting neck and a ram air fan mounting flange are configured to couple the ram outlet header to a ram air fan housing. A heat exchanger mounting flange is configured to couple the ram outlet header to a heat exchanger assembly. A lower face includes a first stiffener. A mid-section includes a second stiffener, a third stiffener, and a fourth stiffener. The ram air fan mounting flange is positioned between the lower face and the mid-section. A ratio of thickness of the second stiffener to the third stiffener is between 1.04 and 1.16, and a ratio of thickness of the fourth stiffener to the third stiffener is between 1.04 and 1.16.

Abstract: A system capable of detecting the hazardous accumulation of ice on the surfaces, engines, instruments and air intakes of aircrafts or other objects of interest. The system consists of an electromagnetic microwave resonator capable of detecting the formation of ice directly where it could cause problems. The sensor could be mounted around the air intake of pitot tubes, static ports, engines intake, engines core, and can be embedded in the aircraft skin. The system uses algorithms based on the variations of the complex dielectric permittivity of water substance with frequency to distinguish the various types of ice from each other and from water.

Abstract: A fuel tank inerting system includes a bleed air inlet, a bleed air conditioning system, an air separation module, a nitrogen-enriched air conditioning system, a nitrogen-enriched air outlet, and a controller. The bleed air conditioning system is connected to the bleed air inlet and is configured to cool bleed air. The air separation module is connected to the bleed air conditioning system and is configured to produce nitrogen-enriched air. The nitrogen-enriched air conditioning system is connected to the air separation module and is configured to cool nitrogen-enriched air. The controller controls nitrogen-enriched air temperature and nitrogen-enriched air flow rate at the nitrogen-enriched air outlet.

Abstract: The invention concerns an aircraft cockpit comprising at least one instrument panel (4) and a seat (2) for a pilot characterized in that the instrument panel forms a single unit and is carried by a hinged support (6) enabling the pilot to adjust the position of the instrument panel (4) relative to the pilot seat (2). Preferably, the instrument panel forms a single unit and is curved, for example along the arc of a circle, around the pilot seat.

Abstract: The invention concerns an aircraft including a cockpit comprising a viewing surface for piloting giving at least one pilot a view of an outside scene comprising the environment of the aircraft extending forward of the aircraft. At least part of said viewing surface for piloting is free of any glazed surface and is formed by display means for a digital image representing at least part of an outside scene comprising the environment of the aircraft extending forward of the aircraft.

Abstract: Disclosed is a system and method for monitoring the occupancy of seating. Sensors provide measurements to a control circuit that determines an occupancy state for each seat. Information regarding the occupancy of the seats can be presented on a display. In some instances, additional inputs can be used to adjust the occupancy determinations to account for environmental factors. Also, the occupancy states of the seats can be cross-checked with a passenger manifest to facilitate the boarding of a vehicle containing the seating.

Abstract: Embodiments of methods and apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a communication fleet includes: an airborne communication payload subdivided into multiple payload sections; and a plurality of airborne platforms each including a payload section, wherein each airborne platform comprises an airframe, a propulsion system, a power system, and flight control electronics, wherein the propulsion system is configured to provide propulsion power and thrust to maintain level flight, ascend, descend and maneuver the airborne platform, wherein the power system provides electrical power to the propulsion system, the flight control electronics, and the payload section, and wherein the flight control electronics provide capability to control a position, speed, and flight pattern of the airborne platform.

Abstract: Systems and methods are provided for docking an unmanned aerial vehicle (UAV) with a vehicle. The UAV may be able to distinguish a companion vehicle from other vehicles in the area and vice versa. The UAV may take off and/or land on the vehicle. The UAV may be used to capture images and stream the images live to a display within the vehicle. The vehicle may control the UAV. The UAV may be in communication with the companion vehicle while in flight.

Abstract: The invention relates to the safety of airport runways. The invention provides a side bather preventing foreign object debris (FOD) from entering a runway and taxiway and endangering aircraft. The barrier having ground attachment means and being constructed to collapse if the landing wheels of an aircraft impact the barrier and thus allow the aircraft to safely continue landing/takeoff/taxiing.

Abstract: Installation of an engine to a support structure includes temporarily attaching first and second alignment structures to the support structure and the engine. One of the alignment structures has a target pattern on its surface. The installation further includes using a machine vision system from the other of the mounting structures to indicate the relative position of the target pattern with respect to a reference. The relative position of the target pattern with respect to the reference provides information about relative position of an engine mounting element (e.g., bolt hole) with respect to a corresponding mounting element (e.g., bolt hole) in the support structure. The relative position of the target pattern with respect to the reference can be used to maneuver the engine in order to align the mounting elements.