Abstract: A device enclosure includes a housing, a shaft, and a front panel. The housing defines a receiving bay configured to slidably receive an electronic device. The shaft is slidably mounted on a sidewall of said housing, includes a rear flange, and is slidable between a retracted position and a deployed position. The front panel is rotatably mounted on the shaft by a hinge and having a fulcrum projection and is rotatable between a closed position that closes a front of the receiving bay and a fully open position which extends away from the housing.

Abstract: A thermal transfer system for reducing temperature cycling of an electronic device. The thermal system includes a thermally conductive device to which the electronic device is mounted, a heat sink and a thermal rail mounted to the heat sink. The thermal system further includes a plurality of shape memory alloy (SMA) elements extending through aligned openings in the rail and the thermally conductive device, where the SMA elements are shaped in a deformed wire-like configuration and attempt to return to an undeformed spring-like configuration when the plurality of SMA elements are heated above a transition temperature so as to increase a heat transfer contact pressure between the thermally conductive device and the rail.

Abstract: A housing module having a circuit board quick-assembling function is applied to an electronic device with a circuit board having a specific height. The housing module includes a housing, an spacer and two pivoting components. The housing includes a substrate and several lateral boards. The spacer includes a main body, two pivoting portions and a locking portion. The pivoting portions are disposed on corresponding sides of the main body, the locking portion stretches from a lower side of the main body and is fixed on the circuit board via an external fixing component. The pivoting portions pass through the lateral boards and are connected to the pivoting portions. While the circuit board slides relative to the substrate to push the spacer, the main body is rotated inside the housing via the pivoting portions to lift the lower side.

Abstract: An electronic module for a modular electronic device may include improved features for retaining the electronic module relative to a frame of the modular electronic device and/or for subsequently removing such module from the frame.

Abstract: An oven rack assembly (2000) can be used with an oven (128?) having sets of liner ribs (1004). The oven rack assembly (2000) includes an oven rack (208), slide system (2018) and subframe (2040). The oven rack assembly (2000) also includes a retention/release assembly (2060) for facilitating retention of a position of the subframe (2040) onto liner ribs (2004) and for facilitating release of the subframe (2040) when a user wishes to remove or move the assembly (2000) from the oven. Attachment plates (2065) can also be included, with the plates (2065) mounted to side stampings (2022). The oven rack assembly (2000) also includes protruding forms (2122) on the subframe (2040) which interact with forms (2124) positioned along the liner ribs (2004) to prevent tipping of the subframe (2040) when the oven rack (2008) is moved to an extended position.

Abstract: An electronic assembly and method of manufacturing includes: an airflow bracket having a circular rail and an airflow tab, the airflow bracket electrically coupling the circular rail and the airflow tab; a top board attached to the circular rail for electrically coupling the top board and the circular rail; and a bottom board attached to the circular rail for electrically coupling the top board and the circular rail, the bottom board positioned to form a thermal channel between the top board and the bottom board for directing air through a vent opening of the circular rail.

Abstract: One embodiment provides an apparatus, including: a processor; a housing including a plurality of slots; and a single piece card retainer, comprising: a back surface; a front surface comprising a plurality of independent projections, wherein each of the plurality of independent projections is flexible and aligns with a slot of the plurality of slots; and at least two connection points that connect the single piece card retainer to the housing, where the single piece card retainer rotates about the at least two connection points to open and close with respect to the plurality of slots. Other embodiments are described and claimed.

Abstract: A modification kit for converting an existing signage mounting structure to an electronic sign generally includes at least one sectional sign assembly including a frame section having a back-facing portion configured to be coupled to the existing signage mounting structure and a front-facing portion including an array of bays, each individual bay having removably mounted therein an LED display module and being prewired with a power routing system; wherein the power routing system includes an input end that branches out to a plurality of output ends, each disposed in one of the bays and each configured to directly couple to one of the LED display modules; a power kit configured to couple the input end of each power routing system to an AC power source; and an installation kit configured to facilitate mounting said back-facing portion to the existing signage mounting structure.

Abstract: An example device in accordance with an aspect of the present disclosure includes a unibody socket to receive a memory module that is to interface with a computing system. A portion of the unibody socket extends into a latch extension. The latch extension is to retain the memory module based on a positive locking latch retention force that is to increase in response to an unseating force of the memory module, to prevent removal of the memory module while the latch extension is in a latched position.

Abstract: Thermally actuated vents for electronic devices. An embodiment of an apparatus includes a vent having a first position and a second position, wherein the first position is an open position and the second position is a closed position; a muscle wire, a first end of the muscle wire being coupled with a connection to the vent and a second end of the muscle wire being coupled with an anchor point; and a tension element, a first end of the tension element being coupled with the vent at a connection point. The muscle wire is to apply a force to the vent to move the vent to the open position upon the muscle wire entering a contracted state, and the tension element pulling the vent to the closed position upon the muscle wire entering a relaxed state.

Abstract: Thermally actuated printed circuit board (PCB) retainer assemblies that utilize at least one thermally actuated element to secure a received PCB to a heat sink in accordance with embodiments of the invention are disclosed. In one embodiment, a thermally actuated PCB retainer assembly includes a heat sink having an elongated groove configured to receive a PCB and a PCB retainer that includes a pair of complementary elongated bodies each having a first elongated face and a second elongated face where the second elongated faces of the elongated bodies are disposed in a cooperative sliding relation and at least one thermally actuated element in contact with at least one of the elongated bodies such that the thermally actuated element applies a force on the at least one elongated body in response to temperature changes such that the elongated bodies move in the cooperative sliding relation.

Abstract: An apparatus with deflectable dividers separating peripheral components is disclosed. The apparatus includes a shroud housing coupleable to a circuit board of a computer. In an installed position, the shroud housing facilitates a proper electrical connection between peripheral components and the circuit board. The apparatus also includes at least one deflectable divider that is deflectably mounted to the shroud housing. In the installed position, the at least one deflectable divider is disposed between adjacent peripheral components. The at least one deflectable divider is operably displaced away from a selected peripheral component in a displacement motion by fingers of a user during a component swap operation to allow space for the fingers of the user to grasp the selected peripheral component.

Abstract: A data storage carrier includes a middle member with at least one handle between ends of the middle member. Side members are coupled to the respective ends of the middle member via living hinges. The side members each include at least two protrusions configured to interface with side mounting holes of a data storage drive. The living hinges are bendable so that the protrusions interface with the side mounting holes of the drive and the middle member interfaces with a back side of the drive.

Abstract: In various embodiments, a high-density solid-state storage unit includes a base section and a cassette section having plurality of flash cards. The cassette section can be removably attached to the base section to provide security of data stored on the plurality of flash cards. The cassette section provides for physical security of the flash cards in part through packaging of the enclosure and energy transfer to the base station. The cassette section further provides for security of the data stored on the flash cards in part through a trusted platform module (TPM) embodied as a removable module connected to a universal serial bus (USB) style connector.

Abstract: An expansion card securing mechanism is configured to secure different kinds of expansion cards. The expansion card securing mechanism includes a base and a plurality of securing members which are secured on the base. The base includes a latch portion. The latch portion defines a plurality of latch holes, the securing member can be secured in the latch hole. Each securing member defines a cavity, the latch hole and the cavity can receive different kinds of expansion cards to secure the expansion cards.

Abstract: One aspect of the invention discloses an apparatus for mating computing device structures. The apparatus comprises one or more rotatable latches, the one or more rotatable latches each including a respective screw mechanism housed within the one or more rotatable latches. The apparatus further comprises one or more spring assemblies, the one or more spring assemblies each including a respective thread assembly housed within the one or more spring assemblies. The respective thread assemblies comprise threading that is capable of receiving a corresponding screw mechanism of the one or more rotatable latches.

Abstract: The loading density of canisters fitted to a supporting substrate of a storage enclosure is reduced. A plurality of rail structure bodies are provided in parallel with the Y-axis direction so as to be spaced apart by a first predetermined distance in the X-axis direction. A pair of the rail structure bodies arranged on left and right sides in the Y-axis direction support the canisters. The rail structure body includes first contact parts extended in parallel with the Y-axis direction, second contact parts formed continuously with the first contact parts so as to protrude by a second predetermined distance to one side in the X-axis direction, and coupling parts formed continuously with the first contact parts and the second contact parts. The canister is supported between one side surface of the second contact part of one rail structure body and the other side surface of the contact part.

Abstract: Various embodiments described herein include systems, methods and/or devices for dissipating heat generated by electronic components in an electronic system (e.g., a memory system that includes closely spaced memory modules). In one aspect, an electronic assembly includes a first circuit board, a second circuit board flexibly coupled to the first circuit board, a connecting module coupled to the second circuit board, and a fastener. The fastener is configured to couple the first circuit board to the connecting module such that the first circuit board and the second circuit board are substantially parallel and are separated by a space, wherein the space forms at least part of a channel that is configured to direct airflow through the space between the first circuit board, second circuit board, and connecting module.

Abstract: A mounting rail for an insert assembly provided to fix in an installation frame of a computer includes one bearing surface to fix in a guide rail of the installation cage, one fastening for the insert assembly, whereby the mounting rail can be fixed laterally on the insert assembly, and a lever at a first end wherein the lever is mounted on a shaft such that an eccentric shape is formed and, by actuating the lever in an installed state, the mounting rail is lifted in a direction of the insert assembly.

Abstract: A cable backplane system includes a plurality of cable connectors interconnected by cables, each cable connector having a header holding signal contacts at a mating end of the header configured for mating with a card connector. A cable tray having side walls surrounds a cavity defining a raceway for the cables. The cable tray has a front edge and holds header frames between the side walls. The header frames hold headers of corresponding cable connectors. An organizer plate is coupled to the cable tray at the front edge. The organizer plate has a plurality of connector channels receiving mating ends of corresponding headers. The connector channels hold the headers in position relative to one another.

Abstract: A cable backplane system includes cable connectors having cables extending therefrom. Each cable connector has a header holding signal contacts at a mating end of the header configured for mating with a card connector. The cable backplane system includes a cable tray having side walls surrounding a cavity defining a raceway for the cables. The cable tray has a front edge. A plurality of connector bricks are received in the cable tray. The connector bricks each having a header frame comprising end spacers and side spacers defining a header opening receiving a plurality of the cable connectors. The end walls hold the headers of corresponding cable connectors. The side spacers have guide paddles extending from a front of the side spacers forward of the cable connectors.

Abstract: Aspects of the disclosure relate generally to relates server rack architecture for housing computing components on a plurality of shelves. More specifically, the shelves of a particular rack may each include a power and data bus (“PDB”) pre-configured to support a particular number of devices of the shelf. A PDB may also include a number of power and data connections for blind mating with the devices of the shelf. The PDB may include two blades which extend away from the PDB and blind mate with the main bus bar. Thus, each PDB may route both power and data signals between a main bus bar for the rack and each of the devices of the shelf. A shelf may be reconfigured for a different number of devices by changing the configuration of the PDB.

Abstract: A method and system for providing a customized storage container includes a generally rectangular housing and at least one printed circuit board contained within the rectangular housing. The customized storage container encloses a first row of interconnector modules that are positioned adjacent to a first, open end of the rectangular housing. The customized storage container also encloses a second row of interconnector modules positioned adjacent to the first, open end of the rectangular housing. At least one air vent is positioned along a side of the rectangular housing and adjacent to a second, closed end of the rectangular housing. According to one exemplary embodiment, the storage container can comprise a single printed circuit board for supporting the first and second row of interconnector modules. In another exemplary embodiment, the storage container can comprise two printed circuit boards for supporting the first and second rows interconnector modules.

Abstract: A module unit includes a receiving element formed from an extrusion profile and configured to receive at least one circuit board. The receiving element includes at least two recesses. Two lateral elements are each configured to be received in a respective one of the at least two recesses so as to fasten the lateral elements to the receiving element by latching.

Abstract: A positioning apparatus includes a support structure, a positioning structure, and a fixture for retaining MEMS devices. A shaft spans between the support structure and the positioning structure, and is configured to rotate about a first axis relative to the support structure in order to rotate the positioning structure and the fixture about the first axis. The positioning structure includes a pair of beams spaced apart by a third beam. Another shaft spans between the pair of beams and is configured to rotate about a second axis relative to the positioning structure in order to rotate the fixture about the second axis. Methodology entails installing the positioning apparatus into a chamber, orienting the fixture into various positions, and obtaining output signals from the MEMS devices to determine functionality of the MEMS devices.

Abstract: A mounting structure in a power supply chassis includes a mounting portion and a securing portion. The mounting portion is located on a first sidewall of the power supply chassis. The mounting portion includes a first protruding plate for supporting a circuit board, a second protruding plate parallel to the first protruding plate, and a positioning portion to receive the circuit board. The positioning portion is located between the first protruding plate and the second protruding plate. The securing portion includes a resilient portion extending into the positioning portion. When the circuit board is installed in the power supply chassis, the circuit board is received in the positioning portion and supported by the first protruding plate, with the resilient portion engaged in a securing hole defined in the circuit board.

Abstract: A system for dissipating thermal energy from electronic components disposed within a rotatable shaft includes an annular carrier shaft having one end formed to couple to an end of a rotor shaft. The system also includes a transmitter assembly. The transmitter includes an outer casing, a daughter board and a circuit board electronically coupled to the daughter board within an inner pocket of the transmitter housing. The circuit board comprises a strip of thermally conductive material. The transmitter assembly further includes a lid that at least partially seals the inner pocket. A contact surface of the lid is in thermal communication with the thermally conductive material of the circuit board and at least a portion of a top surface of the lid is thermally coupled to an inner surface of the carrier shaft during rotation thereof. A method for dissipating thermal energy away from the circuit board is also provided.

Abstract: Bottom mounting rails are used to secure a double wide plug-in module or two full wide plug in-modules into a double wide bay of an electronic device. This allows the size of the electronic device to be minimized. Further, the space adjacent to the sides of plug-in modules is left open facilitating airflow through the electronic device and efficient cooling thereof. The bottom mounting rails allow either a double wide plug-in module or two full wide plug-in modules to be readily installed.

Abstract: Embodiments of the present invention relate to a structure and method for providing better antenna element retention in the any environment. The structure may comprise at least two card guides attached to a base. Each card guide may have at least one antenna slot, and individual antenna elements may be guided into position by an antenna slot of two different card guides. The individual antenna elements may have their freedom of motion restricted in the direction of their insertion by caps attached to the card guides. The individual antenna elements may have their freedom of motion restricted in a direction transverse to their direction of insertion by retention members attached to the card guides. By allowing for the “top-down” assembly of individual antenna elements in a modular fashion, embodiments of the present invention may facilitate easier repair of antenna element arrays, than prior art array assemblies.

Abstract: The present disclosure relates to an electronic apparatus (100) comprising a backplane (120) and methods of assembling and disassembling such an apparatus. The electronic apparatus (100) comprises a chassis (101) having plural walls and a circuit board (140) fastened to a wall of the chassis, a surface of the circuit board having a plurality of conductive pads (146). A backplane (120) is fastened in a received position in the chassis substantially perpendicular to the circuit board. The backplane has a connector (130) at an edge of the backplane, the connector comprising a plurality of sprung conductive elements (132,134) which extend outwards beyond the edge of the backplane to make electrical contact with respective conductive pads (146) on the circuit board.

Abstract: Thermally actuated vents for electronic devices. An embodiment of an apparatus includes a vent having a first position and a second position, wherein the first position is an open position and the second position is a closed position; a muscle wire, a first end of the muscle wire being coupled with a connection to the vent and a second end of the muscle wire being coupled with an anchor point; and a tension element, a first end of the tension element being coupled with the vent at a connection point. The muscle wire is to apply a force to the vent to move the vent to the open position upon the muscle wire entering a contracted state, and the tension element pulling the vent to the closed position upon the muscle wire entering a relaxed state.

Abstract: A pluggable apparatus of a circuit board is provided, which solves the problem that hot plugging of a Peripheral Component Interconnect Express (PCI-E) card is difficult to implement. The pluggable apparatus of the circuit board includes a base plate, a pulling strip, a rotating member, and a carrier plate, where the pulling strip is movably connected to the base plate by using a transverse guide mechanism, sawteeth are formed on a body of the pulling strip, the pulling strip further includes a handle that extends out of the base plate; the rotating member is in a bending line shape; the carrier plate is movably connected to the base plate by using a longitudinal guide mechanism; and a clamping trough is disposed on the carrier plate and is configured to fasten the circuit board.

Abstract: A memory combination includes a first riser board, a second riser board, a pivotal plate, a first engaging member, and a second engaging member. The first riser board has a first edge and a second edge parallel to each other. The second riser board has a third edge and a fourth edge parallel to each other. The pivotal plate are pivotally connected to the first riser board to be adjacent to the first edge and to the second riser board to be adjacent to the third edge. The first and second engaging members are respectively disposed on the first and second riser boards to be respectively adjacent to the second and fourth edges. When the first and second riser boards rotate to be perpendicular to the pivotal plate, the first engaging member is engaged with the second engaging member.

Abstract: Daughter cards couple to an information handling system chassis and are secured in place with insertion of a retainer in a retainer guide that aligns to engage with securing elements of the daughter cards coupled to the chassis. A hinge member couples the retainer to the retainer guide between an inserted position and an idle position to maintain the retainer attached to the chassis but removed out of the way for daughter card manipulation during addition or removal of the daughter card at the chassis.

Abstract: A photovoltaic system includes a pole member which stands on an installation surface, a connecting support member disposed on an upper end section of the pole member, a rail member supported by the connecting support member, and a photovoltaic cell module disposed on the rail member, wherein the pole supporting member includes a lower section that covers at least a portion of an outer peripheral surface of the upper end section of the pole member.

Abstract: The present invention relates to an electronic device including plural circuit board units that can be removed from the electronic device. The electronic device is designed to increase a data transfer rate between the circuit board units by using a circuit board for interconnect for electrically coupling the circuit board units placed in the electronic device, and using a cable for electrically or optically coupling the circuit board units placed in the electric device, or both of the cables.

Abstract: An assembly for positioning photovoltaic panels on a structure includes a main frame connectable to the structure, and a subassembly connectable to the main frame to support a photovoltaic panel, in which the subassembly is rotatable with respect to the main frame to place the subassembly in a deployed position. The assembly may further include a stop-arm connectable to the main frame to support the subassembly when in the deployed position.

Abstract: A mounting apparatus includes a mounting case, a mounting piece, and a securing member. The mounting case includes a bottom plate. A mounting portion is located on the bottom plate. The mounting piece is used to secure a front end of an expansion card to the mounting case. The securing member includes a first securing panel, a second securing panel, and a rotating portion. The first securing panel and the second securing panel are connected to the mounting portion. The second securing panel is rotatable about the rotating portion to engage with the first securing panel, so that the first securing panel and the second securing panel cooperatively bind a rear end portion of the expansion card.

Abstract: A motherboard sliding mechanism adapted for removing a motherboard out from a housing of an electronic device includes a bracket, a connecting member, and a sliding assembly. The bracket includes a supporting board and a sidewall perpendicularly extending from an edge of the supporting board, the supporting board defines a guiding groove. The connecting member slidably passes through the guiding groove, and is capable of detachably fixing the bracket to the housing of the electronic device. The sliding assembly is rotatably assembled on the bracket and detachably connected to the connecting member. The sliding assembly is capable of being rotated to lock or unlock the connecting member to drive the connecting member lock or unlock with the bracket, and the motherboard sliding mechanism with the motherboard can be conveniently slid out of the housing of the electronic device or firmly fixed in the housing of the electronic device.

Abstract: A module is insertable into a cage based on movement along a first axis. The module is to contain an interface card. A mechanism is to move the module along a second axis perpendicular to the first axis, to couple the interface card with the cage.

Abstract: In one aspect, a radar array assembly includes two or more vertical stiffeners each having bores with threads and a first radar module. The first radar module includes radar transmit and receive (T/R) modules and a chassis having channels configured to receive a coolant. The chassis includes shelves having ribs. The ribs have channels configured to receive the coolant and the ribs form slots to receive circuit cards disposed in parallel. The circuit cards include the T/R modules. The chassis also includes set screws attached to opposing sides of the chassis. The set screws have bores to accept fasteners to engage the threads on a corresponding one of the two or more vertical stiffeners. The first radar module is configured to operate as a stand-alone radar array.

Abstract: A support rack for a substantially planar circuit board includes first and second spaced apart sides. The sides define a plurality of spaced apart product receiving support surfaces where corresponding surfaces on each side are parallel to one another and spaced apart by a central region to form a U-shaped rack. Between pairs of support surfaces on a selected side are truncated, trapezoidal-like protrusions which terminate in product retaining clips. Integrally formed braces can be provided to increase rack strength.

Abstract: A fastening device for an expansion card includes a first rack located at a front side, a second rack located at a rear side, a supporting member fastened to the first rack, and a rotating member rotatably connected to the supporting member. A pole extends up from the supporting member. When the rotating member is rotated up, a first end of the expansion card is operable to abut a top of the supporting member and the pole extends through a mounting hole defined in the first end of the expansion card. The rotating member is operable to rotate down to abut a top of the expansion card and engage with the supporting member. A second end of the expansion card opposite to the first end is fastened to the second rack.

Abstract: A tray cleaning apparatus having a top plate, a bottom plate, a first bearing plate assembly and a second bearing plate assembly. The first bearing plate assembly disposed between top plate and bottom plate comprises a first supporting plate, plural first blocks and plural second blocks, the first supporting plate comprises an inner surface having a first disposing area and a second disposing area. The first blocks are disposed at the first disposing area and the second blocks are disposed at the second disposing area. The second bearing plate assembly disposed between top plate and bottom plate comprises a second supporting plate, plural third blocks and plural fourth blocks, the second supporting plate comprises an outer surface having a third disposing area and a fourth disposing area. The third blocks are disposed at the third disposing area and the fourth blocks are disposed at the fourth disposing area.

Abstract: Some embodiments are directed to cooling frames for mezzanine cards, mezzanine card assemblies and circuit card assemblies. A recessed cooling frame may be used to dissipate heat generated by components of a mezzanine card. The cooling frame may be directly coupled to a host card or host card cooling frame, thereby reducing the number of interfaces and reducing the thermal resistance of the heat dissipation pathway. The cooling frames of some embodiments may provide more efficient heat dissipation and thereby allow higher performance mezzanine cards to be used. Some embodiments provide a mezzanine card assembly that conforms to the mechanical envelope dimensions of the VITA 20, VITA 42 or VITA 61 specifications.

Abstract: A base seat structure for supporting a chip card includes a tray which is utilized to configured a chip card and capable of being formed by a reciprocally-moved type, a base frame disposed on the tray, a fastening frame disposed on the tray and having a retarding portion, and a earner which is configured between the base frame and the fastening frame and capable of being motioned between a first position and a second position to follow the reciprocally-moved tray. When the carrier is motioned toward the first position, the retarding portion of the fastening frame presses the carrier to pass through a limitation of the base frame to motion toward the second position, thereby pushing or allowing the tray for movement. Moreover, when the tray and the carrier are motioned toward the first position, the chip card is located or electronically connected.

Abstract: A method and apparatus for loading IC's into a socket lid is disclosed. The IC is first loaded into a lid. Once the IC has been loaded into the lid, the lid is rotated into a closed position on the frame. The lid is then locked in place on the frame by rotating at least one locking lever into a closed lacked position, where the locking lever forces the lid down against the socket contacts against a spring.

Abstract: Mounting frames for holding electronic devices are described. An example mounting frame for holding electronic devices includes an elongated extruded body having two substantially parallel wiring cavities extending along a length of the body and separated by a wall within the body. The wiring cavities have respective openings facing in opposite directions, and opposing faces of the body have respective process control device mounting rails and respective mounting channels. Each of the mounting channels is configured to hold the mounting frame to a structure.

Abstract: A device for clamping in a slot an electronic card including contacts insertable into connectors, guided by the slot between a first position of the electronic card, the extraction position, where the contacts are not inserted into the connectors, and a second position, the insertion position, where said contacts are fully inserted into the connectors; the device includes clamping means, means of controlling the clamping means, tightening means comprising a first eccentric having a pivoting connection with the electronic card able to control the clamping means, and the tightening means in a second eccentric working with means forming a bearing surface to produce an instantaneous center of rotation of the tightening means on the bearing surface when the electronic card is in the insertion position and the tightening means are operated around the pivot axis for inserting the electronic card.

Abstract: A system (22) for removably connecting a circuit card, such as an extension card (54), to an electronic device, comprises a sliding component (28) adapted to support the circuit card (54) and having a guiding edge (32) configured to be slidably inserted in a channel (26) disposed adjacent a connector (20) of the electronic device so as to position the card mating edge (56) in register with the connector (20). A lever (40) is provided for lowering the mating edge 56 of the extension card (54) until suitable connection is made between the card connector and the connector (20). Advantages of the present invention include the fact that the system allows for ergonomic insertion and removal of extension cards without the need for manual dexterity on behalf of the user.