Science.gov

Sample records for quick-connect self-alining latch

  1. Quick-Connect, Self-Alining Latch

    NASA Technical Reports Server (NTRS)

    Burns, G. C.; Williams, E. J.

    1983-01-01

    Sturdy latch tolerates 10 degrees of angular mismatch in joining structural elements. Hexagonal passive plate nests in active plate, guided by capture plates and alinement keys and grooves. Center hole in both active and passive plates is 1 meter in diameter. Latch has possible uses a pipe joint, connector for parts of portable structures, and fitting for marine risers on offshore drilling rigs.

  2. Quick connect fastener

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (Inventor)

    1994-01-01

    A quick connect fastener and method of use is presented wherein the quick connect fastener is suitable for replacing available bolts and screws, the quick connect fastener being capable of installation by simply pushing a threaded portion of the connector into a member receptacle hole, the inventive apparatus being comprised of an externally threaded fastener having a threaded portion slidably mounted upon a stud or bolt shaft, wherein the externally threaded fastener portion is expandable by a preloaded spring member. The fastener, upon contact with the member receptacle hole, has the capacity of presenting cylindrical threads of a reduced diameter for insertion purposes and once inserted into the receiving threads of the receptacle member hole, are expandable for engagement of the receptacle hole threads forming a quick connect of the fastener and the member to be fastened, the quick connect fastener can be further secured by rotation after insertion, even to the point of locking engagement, the quick connect fastener being disengagable only by reverse rotation of the mated thread engagement.

  3. Design study of Self-Alining Bearingless Planetary (SABP) gear

    NASA Technical Reports Server (NTRS)

    Folenta, D. J.

    1983-01-01

    The feasibility of using the self alining, bearingless planetary (SABP) transmission in an uprated version of the OH-58 helicopter was evaluated, specific performance comparisons of this new transmission with contemporary helicopter transmission systems and with the uprated version of the OH-58 power transmission were made.

  4. Quick-connect fasteners for assembling devices in space

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J. (Inventor); Evenson, Erik E. (Inventor); Ruiz, Steve L. (Inventor)

    1992-01-01

    A quick-connect fastener of a relatively-simple straightforward design is arranged with a tubular body adapted to be engaged against an attachment fitting in coincidental alignment with an opening in that fitting. A tubular collet having flexible finger projecting from its forward end is arranged in the fastener body to be shifted forwardly by an elongated expander member coaxially arranged within the tubular collet for advancing the collet fingers into the opening in the attachment fitting. Biasing means are arranged between the elongated expander member and a rotatable actuator which is threadedly mounted within the tubular collet so as to be rotated for urging the expander member into engagement with the collet fingers. A first coupling member is arranged on the rotatable actuator to be accessible from outside of the fastener so that a second coupling member on the distal end of a flexible shaft can be introduced into the fastener body and coupled to the first coupling member to enable a typical actuating tool coupled to the shaft outside of the fastener body to be operated for advancing the outwardly-enlarged ends of the collet fingers into the opening in the attachment fitting and thereafter rotating the actuator member to expand the fingers to that attachment fitting. Upon expansion of the collet fingers, the biasing means impose a biasing force on the expander to releasably retain the fingers in their latching positions.

  5. Tendon latch

    SciTech Connect

    Watkins, B. J.

    1985-01-01

    A latch connects tendons run from a floating platform to a socket in a foundation on the sea floor. The latch includes a latch body having a plurality of dogs disposed within and urgible outward from the latch body. A piston is releasably disposed within the latch body above the dogs and moves downwardly when released to urge the dogs outwardly from the body into latching engagement with the socket. A trigger mechanism in the latch releases the piston when the latch body lands in the socket and contacts a trigger pin projecting upwardly from the bottom of the socket. A series of wedges are disposed exteriorally on the body and inhibit lateral movement of the body relative to the socket when the tendon is subjected to a cycle bending loads.

  6. Rotary latch

    NASA Technical Reports Server (NTRS)

    Kramer, Joel M. (Inventor)

    1995-01-01

    A rotary latch is disclosed, including a hollow, cylindrical outer member and a concentrically arranged inner rotor. The rotor is rotatable within the outer cylindrical member. The outer cylindrical member includes a pair of aligned openings as a cylinder first end facing a latch pin. The rotor includes a pair of aligned slots at a rotor first end facing the latch pin. Slot extensions are provided in the rotor, the slot extensions extending generally perpendicularly to the slots and generally parallel to the rotor first end. In a first position, the outer cylindrical member openings and the rotor slots are aligned to allow receipt of the latch pin. In a second position, the openings and the slot extensions are aligned thereby engaging the latch pin within a closed area defined by the rotor slot extensions and the outer cylinder openings.

  7. Latch assembly

    DOEpatents

    Frederickson, James R.; Harper, William H.; Perez, Raymond

    1986-01-01

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing.

  8. Latch assembly

    DOEpatents

    Frederickson, J.R.; Harper, W.H.; Perez, R.

    1984-08-17

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing. 2 figs.

  9. A Better Quick-Connect Passive Capture Joint

    NASA Technical Reports Server (NTRS)

    Nabors, Sammy A.

    2015-01-01

    NASA's Marshall Space Flight Center has developed a joint that employs a unique spring-loaded mechanism that automatically secures a ball hitch upon insertion into a coupler. This eliminates the need for the locking lever found in most conventional ball joints. Connections made using MSFC's quick-connect joint are easier, safer, and more reliable than those made using conventional ball joints.

  10. Rotary mechanical latch

    DOEpatents

    Spletzer, Barry L.; Martinez, Michael A.; Marron, Lisa C.

    2012-11-13

    A rotary mechanical latch for positive latching and unlatching of a rotary device with a latchable rotating assembly having a latching gear that can be driven to latched and unlatched states by a drive mechanism such as an electric motor. A cam arm affixed to the latching gear interfaces with leading and trailing latch cams affixed to a flange within the drive mechanism. The interaction of the cam arm with leading and trailing latch cams prevents rotation of the rotating assembly by external forces such as those due to vibration or tampering.

  11. Load regulating latch

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T. (Inventor)

    1977-01-01

    A load regulating mechanical latch is described that has a pivotally mounted latch element having a hook-shaped end with a strike roller-engaging laterally open hook for engaging a stationary strike roller. The latch element or hook is pivotally mounted in a clevis end of an elongated latch stem that is adapted for axial movement through an opening in a support plate or bracket mounted to a structural member. A coil spring is disposed over and around the extending latch stem and the lower end of the coil spring engages the support bracket. A thrust washer is removably attached to the other end of the latch stem and engages the other end of the coil spring and compresses the coil spring thereby preloading the spring and the latch element carried by the latch stem. The hook-shaped latch element has a limited degree of axial travel for loading caused by structural distortion which may change the relative positions of the latch element hook and the strike roller. Means are also provided to permit limited tilt of the latch element due to loading of the hook.

  12. Steam separator latch assembly

    DOEpatents

    Challberg, R.C.; Kobsa, I.R.

    1994-02-01

    A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof. 12 figures.

  13. Steam separator latch assembly

    DOEpatents

    Challberg, Roy C.; Kobsa, Irvin R.

    1994-01-01

    A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof.

  14. 15. MACHINERY DETAILS: LATCH WHEEL BRACKET, LATCH POCKET, LOCK BAR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. MACHINERY DETAILS: LATCH WHEEL BRACKET, LATCH POCKET, LOCK BAR, LATCH CRADLE, SPLIT COLLAR, ETC. - Niantic River Swing Bridge, Spanning Niantic River between East Lyme & Waterford, Old Lyme, New London County, CT

  15. Latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A.

    1991-01-01

    A latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes at least one permanent magnet and at least one electromagnet. The respective sections are, generally, arranged in separate locations or cavities in the assembly. The switch is latched by a permanent magnet assembly and selectively switched by an overriding electromagnetic assembly.

  16. Self indexing latch system

    NASA Technical Reports Server (NTRS)

    Gibson, John C. (Inventor); Calvert, John A. (Inventor); Nesmith, Malcolm F. (Inventor); Cloyd, Richard A. (Inventor)

    1986-01-01

    A self-latching jaw assembly is described which includes a pair of jaws for latching a fitting of an associated structure such as the keel fitting of a space telescope. The jaw assembly automatically locates the fitting received on a positioning pedestal and latches it in its original location on the pedestal without need of precision alignment. The first jaw is actuated and moved to the right whereupon a reciprocating plunger, extended from the nose of the jaw senses the hub of the spool. A jaw position responsive switch is then actuated to terminate the drive motor of the jaw. The astronaut will then actuate the drive motor of the jaw and the jaw will move to the left, whereupon the standoff will engage the face of the jaw in a latching position. In the latching position, the noses of the jaws will be under the flanges of the spool.

  17. Safety rod latch inspection

    SciTech Connect

    Leader, D.R.

    1992-02-01

    During an attempt to raise control rods from the 100 K reactor in December, one rod could not be withdrawn. Subsequent investigation revealed that a small button'' in the latch mechanism had broken off of the lock plunger'' and was wedged in a position that prevented rod withdrawal. Concern that this failure may have resulted from corrosion or some other metallurgical problem resulted in a request that SRL examine six typical latch mechanisms from the 100 L reactor by use of radiography and metallography. During the examination of the L-Area latches, a failed latch mechanism from the 100 K reactor was added to the investigation. Fourteen latches that had a history of problems were removed from K-Area and sent to SRL for inclusion in this study the week after the original seven assemblies were examined, bringing the total of latch assemblies discussed in this report to twenty one. Results of the examination of the K-Area latch that initiated this study is not included in this report.

  18. Safety rod latch inspection

    SciTech Connect

    Leader, D.R.

    1992-02-01

    During an attempt to raise control rods from the 100 K reactor in December, one rod could not be withdrawn. Subsequent investigation revealed that a small ``button`` in the latch mechanism had broken off of the ``lock plunger`` and was wedged in a position that prevented rod withdrawal. Concern that this failure may have resulted from corrosion or some other metallurgical problem resulted in a request that SRL examine six typical latch mechanisms from the 100 L reactor by use of radiography and metallography. During the examination of the L-Area latches, a failed latch mechanism from the 100 K reactor was added to the investigation. Fourteen latches that had a history of problems were removed from K-Area and sent to SRL for inclusion in this study the week after the original seven assemblies were examined, bringing the total of latch assemblies discussed in this report to twenty one. Results of the examination of the K-Area latch that initiated this study is not included in this report.

  19. Optical data latch

    DOEpatents

    Vawter, G. Allen

    2010-08-31

    An optical data latch is formed on a substrate from a pair of optical logic gates in a cross-coupled arrangement in which optical waveguides are used to couple an output of each gate to an photodetector input of the other gate. This provides an optical bi-stability which can be used to store a bit of optical information in the latch. Each optical logic gate, which can be an optical NOT gate (i.e. an optical inverter) or an optical NOR gate, includes a waveguide photodetector electrically connected in series with a waveguide electroabsorption modulator. The optical data latch can be formed on a III-V compound semiconductor substrate (e.g. an InP or GaAs substrate) from III-V compound semiconductor layers. A number of optical data latches can be cascaded to form a clocked optical data shift register.

  20. Preloaded latching device

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J. (Inventor); Nagy, Kornel (Inventor)

    1992-01-01

    A latching device is disclosed which is lever operated sequentially to actuate a set of collet fingers to provide a radial expansion and to actuate a force mechanism to provide a compressive gripping force for attaching first and second devices to one another. The latching device includes a body member having elongated collet fingers which, in a deactuated condition, is insertable through bores on the first and second devices so that gripping terminal portions on the collet fingers are proximate to the end of the bore of the first device while a spring assembly on the body member is located proximate to the outer surface of a second device. A lever is rotatable through 90 deg to move a latching rod to sequentially actuate and expand collet fingers and to actuate the spring assembly by compressing it. During the first 30 deg of movement of the lever, the collet fingers are actuated by the latching rod to provide a radial expansion and during the last 60 deg of movement of the lever, the spring assembly acts as a force mechanism and is actuated to develop a compressive latching force on the devices. The latching rod and lever are connected by a camming mechanism. The amount of spring force in the spring assembly can be adjusted; the body member can be permanently attached by a telescoping assembly to one of the devices; and the structure can be used as a pulling device for removing annular bearings or the like from blind bores.

  1. Static latching arrangement and method

    DOEpatents

    Morrison, Larry

    1988-01-01

    A latching assembly for use in latching a cable to and unlatching it from a given object in order to move an object from one location to another is disclosed herein. This assembly includes a weighted sphere mounted to one end of a cable so as to rotate about a specific diameter of the sphere. The assembly also includes a static latch adapted for connection with the object to be moved. This latch includes an internal latching cavity for containing the sphere in a latching condition and a series of surfaces and openings which cooperate with the sphere in order to move the sphere into and out of the latching cavity and thereby connect the cable to and disconnect it from the latch without using any moving parts on the latch itself.

  2. Perpendicular-Force Latch

    NASA Technical Reports Server (NTRS)

    Mattei, John P.; Buck, Peter A.; Williams, Michael D.

    1990-01-01

    Latching mechanism simultaneously applies force in two perpendicular directions to install or remove electronic-equipment modules. Used to simplify installation and removal of modular equipment where movement restricted by protective clothing as in hazardous environments or where installation and removal to be performed by robots or remote manipulators. Concept adaptable to hydraulic, pneumatic, and mechanical systems.

  3. Low temperature latching solenoid

    NASA Technical Reports Server (NTRS)

    Wang, W. S. (Inventor)

    1981-01-01

    A magnetically latching solenoid includes a pull-in coil and a delatching coil. Each of the coils is constructed with a combination of wire materials, including material of low temperature coefficient of resistivity to enable the solenoid to be operated at cryogenic temperatures while maintaining sufficient coil resistance. An armature is spring-based toward a first position, that may extend beyond the field of force of a permanent magnet. When voltage is temporarily applied across the pull-in magnet, the induced electromagnetic forces overcome the spring force and pulls the armature to a second position within the field of the permanent magnet, which latches the armature in the pulled-in position. Application of voltage across the delatching coil induces electromagnetic force which at least partially temporarily nullifies the field of the permanent magnet at the armature, thereby delatching the armature and allowing the spring to move the armature to the first position.

  4. Magnetic latching solenoid

    DOEpatents

    Marts, D.J.; Richardson, J.G.; Albano, R.K.; Morrison, J.L. Jr.

    1995-11-28

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized. 2 figs.

  5. Magnetic latching solenoid

    DOEpatents

    Marts, Donna J.; Richardson, John G.; Albano, Richard K.; Morrison, Jr., John L.

    1995-01-01

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized.

  6. User experience network. Medical gas quick-connects may spontaneously detach.

    PubMed

    2010-09-01

    "Quick-connect" medical gas connectors may occasionally fail and spontaneously detach from medical gas outlets. Minor injuries are possible, though unlikely. ECRI Institute believes this problem may occur with devices from any supplier and that the best solution is to ensure that they are assessed frequently and removed at the first sign of problems.

  7. Bistable Head Positioning Arm Latch

    NASA Astrophysics Data System (ADS)

    Wasson, Ken; Endo, Juro; Mita, Masahiro; Abelein, Nathan

    A simple, low cost, yet effective device has been developed for immobilizing the head-arm assembly in a disk drive or similar mechanism during power-off conditions. The latching scheme also provides a consistent means of releasing the head-arm assembly from the immobilized position upon power up of the disk drive. The latch uses no electrical power in either immobilized or released state. This design is immune to extreme torque and linear shock forces applied to the disk drive case. The latch system can use the energy stored in the spinning disks to drive the head-arm assembly toward a safe position while simultaneously arming the latch mechanism to secure the head-arm assembly in the safe position upon arrival. A low energy five msec pulse of current drives the latch from one state to the other. Solenoids as presently used in latch mechanisms are bulky, expensive, have variable force characteristics, and often generate contaminants. The latch described in this paper is expected to replace such solenoids. It may also replace small magnet latches, which have limited latch force and apply unwanted torque to a proximate head positioning arm.

  8. Latching micro optical switch

    DOEpatents

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

  9. Strong-back safety latch

    SciTech Connect

    DeSantis, G.N.

    1995-03-06

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  10. 49 CFR 236.801 - Shoe, latch.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Shoe, latch. 236.801 Section 236.801 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Shoe, latch. The casting by means of which the latch rod and the latch block are held to a lever of...

  11. 49 CFR 236.801 - Shoe, latch.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shoe, latch. 236.801 Section 236.801 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Shoe, latch. The casting by means of which the latch rod and the latch block are held to a lever of...

  12. Optical latches using optical amplifiers

    NASA Astrophysics Data System (ADS)

    Li, Wenbo; Hu, Hongyu; Dutta, Niloy K.

    2013-05-01

    Optical latches are important for a wide range of applications including communication systems, optical logic systems, optical random access memory (RAM) and encryption. All optical logic operations using quantum dot (QD) based semiconductor optical amplifier (SOA) and Mach-Zehnder interferometer (MZI) have been studied. The building block of an optical latch such as NAND gate has been fabricated and their operation experimentally demonstrated at ~ 80 GHz. A rate equation model has been developed for the QD-SOA-MZI and it has been used to analyze the Boolean logic operation. The model has been used to analyze the Set-Reset (S-R) latch and the D-Flip-Flop (DFF) devices. The DFF is the basic device for building larger logic circuits. The results show that the latches would work to speeds of ~ 250 Gb/s.

  13. Retaining latch for a water pit gate

    DOEpatents

    Beale, Arden R.

    1997-01-01

    A retaining latch for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame.

  14. Retaining latch for a water pit gate

    DOEpatents

    Beale, A.R.

    1997-11-18

    A retaining latch is described for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame. 4 figs.

  15. Optical set-reset latch

    DOEpatents

    Skogen, Erik J.

    2013-01-29

    An optical set-reset (SR) latch is formed from a first electroabsorption modulator (EAM), a second EAM and a waveguide photodetector (PD) which are arranged in an optical and electrical feedback loop which controls the transmission of light through the first EAM to latch the first EAM in a light-transmissive state in response to a Set light input. A second waveguide PD controls the transmission of light through the second EAM and is used to switch the first EAM to a light-absorptive state in response to a Reset light input provided to the second waveguide PD. The optical SR latch, which may be formed on a III-V compound semiconductor substrate (e.g. an InP or a GaAs substrate) as a photonic integrated circuit (PIC), stores a bit of optical information and has an optical output for the logic state of that bit of information.

  16. Electrical latching of microelectromechanical devices

    DOEpatents

    Garcia, Ernest J.; Sleefe, Gerard E.

    2004-11-02

    Methods are disclosed for row and column addressing of an array of microelectromechanical (MEM) devices. The methods of the present invention are applicable to MEM micromirrors or memory elements and allow the MEM array to be programmed and maintained latched in a programmed state with a voltage that is generally lower than the voltage required for electrostatically switching the MEM devices.

  17. Quick-Connect Windowed Non-Stick Penetrator Tips for Rapid Sampling

    NASA Technical Reports Server (NTRS)

    Sherritt, Stewart; Jones, Jack A.; Badescu, Mircea

    2009-01-01

    Standard penetrator sampling systems were designed in order to allow for sampling via penetrators to produce a full set of sample acquisitions including volatile liquids, fine powders, and solid fragments. A gravity harpoon sampler has been designed with a removable tip and a quick coupling. The separation allows for sample handling and eliminates sample cross-contamination. Also, this design allows for multiple use of the penetrator body, which is the largest and heaviest part of the penetrator, while allowing for multiple changes of the light-mass, penetrator tip to avoid sample cross-contamination. The penetrator tip design has been improved by adding a spring trap to retain the sample, as well as a means for connecting to a quick coupling. Quick connect tips have been demonstrated in a sample handling carousel. The penetrator was released and rewound and the tips were released into a circular platter for rotation into instrument stations. The pyro-harpoon sampler was fabricated and tested with a NASA Standard Initiator (NSI) pyrotechnic charge. Initial tests collected cryogenic ice, but removal of the small pyro-harpoon from the ice was difficult. A brass metal sheath was then fitted over the harpoon tip, and removal from the ice was greatly alleviated by leaving the sheath in the ice. Quartz windows in the tips allow direct optical and spectral imaging and gas chromatography-mass spectrometer (GCMS) pyrolysis, and were found to survive impact. All systems were successfully tested by dropping into sand and into cryogenic ice.

  18. Manned maneuvering unit latching mechanism

    NASA Technical Reports Server (NTRS)

    Allton, C. S.

    1980-01-01

    The astronaut/Manned Maneuvering Unit interface, which presented a challenging set of requirements for a latching mechanism, is described. A spring loaded cam segment with variable ratio pulley release actuator was developed to meet the requirements. To preclude jamming of the mechanism, special precautions were taken such as spring loaded bearing points and careful selection of materials to resist cold welding. The mechanism successfully passed a number of tests which partially simulated orbital conditions.

  19. Quick release latch for reactor scram

    DOEpatents

    Johnson, M.L.; Shawver, B.M.

    1975-09-16

    A simple, reliable, and fast-acting means for releasing a control element and allowing it to be inserted rapidly into the core region of a nuclear reactor for scram purposes is described. A latch mechanism grips a coupling head on a nuclear control element to connect the control element to the control drive assembly. The latch mechanism is closed by tensioning a cable or rod with an actuator. The control element is released by de-energizing the actuator, providing fail-safe, rapid release of the control element to effect reactor shutdown. A sensing rod provides indication that the control element is properly positioned in the latch. Two embodiments are illustrated, one involving a collet- type latch mechanism, the other a pliers-type latch mechanism with the actuator located inside the reactor vessel. (auth)

  20. Quick release latch for reactor scram

    DOEpatents

    Johnson, Melvin L.; Shawver, Bruce M.

    1976-01-01

    A simple, reliable, and fast-acting means for releasing a control element and allowing it to be inserted rapidly into the core region of a nuclear reactor for scram purposes. A latch mechanism grips a coupling head on a nuclear control element to connect the control element to the control drive assembly. The latch mechanism is closed by tensioning a cable or rod with an actuator. The control element is released by de-energizing the actuator, providing fail-safe, rapid release of the control element to effect reactor shutdown. A sensing rod provides indication that the control element is properly positioned in the latch. Two embodiments are illustrated, one involving a collet-type latch mechanism, the other a pliers-type latch mechanism with the actuator located inside the reactor vessel.

  1. Development of a high force thermal latch

    NASA Technical Reports Server (NTRS)

    Nygren, William D.

    1995-01-01

    This paper describes the preliminary development of a high force thermal latch (HFTL). The HFTL has one moving part which is restrained in the latched position by a low melting temperature or fusible metal alloy. When heated the fusible alloy flows to a receiving chamber and in so doing at first releases the tension load in the latch bolt and later releases the bolt itself. The HFTL can be used in place of pyrotechnically activated spacecraft release devices in those instances where the elimination of both pyrotechnic shock-loading and rapid strain-energy release take precedence over the near instantaneous release offered by ordnance initiated devices.

  2. K-Band Latching Switches

    NASA Technical Reports Server (NTRS)

    Piotrowski, W. S.; Raue, J. E.

    1984-01-01

    Design, development, and tests are described for two single-pole-double-throw latching waveguide ferrite switches: a K-band switch in WR-42 waveguide and a Ka-band switch in WR-28 waveguide. Both switches have structurally simple junctions, mechanically interlocked without the use of bonding materials; they are impervious to the effects of thermal, shock, and vibration stresses. Ferrite material for the Ka-band switch with a proper combination of magnetic and dielectric properties was available and resulted in excellent low loss, wideband performance. The high power handling requirement of the K-band switch limited the choice of ferrite to nickel-zinc compositions with adequate magnetic properties, but with too low relative dielectric constant. The relative dielectric constant determines the junction dimensions for given frequency responses. In this case the too low value unavoidably leads to a larger than optimum junction volume, increasing the insertion loss and restricting the operating bandwidth. Efforts to overcome the materials-related difficulties through the design of a composite junction with increased effective dielectric properties efforts to modify the relative dielectric constant of nickel-zinc ferrite are examined.

  3. Minimal Power Latch for Single-Slope ADCs

    NASA Technical Reports Server (NTRS)

    Hancock, Bruce R. (Inventor)

    2015-01-01

    A latch circuit that uses two interoperating latches. The latch circuit has the beneficial feature that it switches only a single time during a measurement that uses a stair step or ramp function as an input signal in an analog to digital converter. This feature minimizes the amount of power that is consumed in the latch and also minimizes the amount of high frequency noise that is generated by the latch. An application using a plurality of such latch circuits in a parallel decoding ADC for use in an image sensor is given as an example.

  4. Resettable binary latch mechanism for use with paraffin linear motors

    NASA Technical Reports Server (NTRS)

    Maus, Daryl; Tibbitts, Scott

    1991-01-01

    A new resettable Binary Latch Mechanism was developed utilizing a paraffin actuator as the motor. This linear actuator alternately latches between extended and retracted positions, maintaining either position with zero power consumption. The design evolution and kinematics of the latch mechanism are presented, as well as the development problems and lessons that were learned.

  5. The actuated latch pin and its development

    NASA Technical Reports Server (NTRS)

    Lawlor, P. J.

    1980-01-01

    An actuated latch pin developed to meet the need for a reusable locking device is described. The unit can function as a pin puller or as a pin pusher latch. Initial prototype testing demonstrated the feasibility of the device with the unit being driven from a 28 V dc supply and using 15 W to drive a 12 mm diameter pin through a stroke of 10 mm with a side load of 100 N in 120 ms. High wear rates with a MOS2 lubrication on the ballscrew and angular contact bearings have necessitated the reduction in the duty cycle from 1000 cycles in air and vacuum to 100 in air and 1000 in vacuum.

  6. Magnetic latch trigger for inherent shutdown assembly

    DOEpatents

    Sowa, Edmund S.

    1976-01-01

    An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core.

  7. Bistable (latching) solenoid actuated propellant isolation valve

    NASA Technical Reports Server (NTRS)

    Wichmann, H.; Deboi, H. H.

    1979-01-01

    The design, fabrication, assembly and test of a development configuration bistable (latching) solenoid actuated propellant isolation valve suitable for the control hydrazine and liquid fluorine to an 800 pound thrust rocket engine is described. The valve features a balanced poppet, utilizing metal bellows, a hard poppet/seat interface and a flexure support system for the internal moving components. This support system eliminates sliding surfaces, thereby rendering the valve free of self generated particles.

  8. Non-latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A.

    1991-01-01

    A non-latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes a permanent magnet and an electromagnet. The respective sections are arranged in separate locations or cavities in the assembly. The switch has a "normal" position and is selectively switched by an overriding electromagnetic assembly. The switch returns to the "normal" position when the overriding electromagnetic assembly is inactive.

  9. Door latching recognition apparatus and process

    DOEpatents

    Eakle, Jr., Robert F.

    2012-05-15

    An acoustic door latch detector is provided in which a sound recognition sensor is integrated into a door or door lock mechanism. The programmable sound recognition sensor can be trained to recognize the acoustic signature of the door and door lock mechanism being properly engaged and secured. The acoustic sensor will signal a first indicator indicating that proper closure was detected or sound an alarm condition if the proper acoustic signature is not detected within a predetermined time interval.

  10. Design, testing and evaluation of latching end effector

    NASA Technical Reports Server (NTRS)

    Walker, B.; Vandersluis, R.

    1995-01-01

    The Latching End Effector (LEE) forms part of the Space Station Remote Manipulator System (SSRMS) for which Spar Aerospace Ltd, Space Systems Division is the prime contractor. The design, testing and performance evaluation of the Latching End Effector mechanisms is the subject of this paper focusing on: (1) ambient, thermal and vibration testing; (2) snare/rigidize performance testing and interaction during payload acquisition; and (3) latch/umbilical test results and performance.

  11. Latch Key: Developing Child Care Programs Through Community Education.

    ERIC Educational Resources Information Center

    Cramer, James P.; And Others

    This guide to the Latch Key program for after-school day care explores rationale and methods for developing Latch Key programs in the public schools to provide low cost after-school care for children (grades 1-6) of working or student parents. (Some programs have been provided for kindergarten children and some have been expanded to full time…

  12. Gate drive latching circuit for an auxiliary resonant commutation circuit

    NASA Technical Reports Server (NTRS)

    Delgado, Eladio Clemente (Inventor); Kheraluwala, Mustansir Hussainy (Inventor)

    1999-01-01

    A gate drive latching circuit for an auxiliary resonant commutation circuit for a power switching inverter includes a current monitor circuit providing a current signal to a pair of analog comparators to implement latching of one of a pair of auxiliary switching devices which are used to provide commutation current for commutating switching inverters in the circuit. Each of the pair of comparators feeds a latching circuit which responds to an active one of the comparators for latching the associated gate drive circuit for one of the pair of auxiliary commutating switches. An initial firing signal is applied to each of the commutating switches to gate each into conduction and the resulting current is monitored to determine current direction and therefore the one of the switches which is carrying current. The comparator provides a latching signal to the one of the auxiliary power switches which is actually conducting current and latches that particular power switch into an on state for the duration of current through the device. The latching circuit is so designed that the only time one of the auxiliary switching devices can be latched on is during the duration of an initial firing command signal.

  13. Characterization of an Autonomous Non-Volatile Ferroelectric Memory Latch

    NASA Technical Reports Server (NTRS)

    John, Caroline S.; MacLeod, Todd C.; Evans, Joe; Ho, Fat D.

    2011-01-01

    We present the electrical characterization of an autonomous non-volatile ferroelectric memory latch using the principle that when an electric field is applied to a ferroelectriccapacitor,the positive and negative remnant polarization charge states of the capacitor are denoted as either data 0 or data 1. The properties of the ferroelectric material to store an electric polarization in the absence of an electric field make the device non-volatile. Further the memory latch is autonomous as it operates with the ground, power and output node connections, without any externally clocked control line. The unique quality of this latch circuit is that it can be written when powered off. The advantages of this latch over flash memories are: a) It offers unlimited reads/writes b) works on symmetrical read/write cycles. c) The latch is asynchronous. The circuit was initially developed by Radiant Technologies Inc., Albuquerque, New Mexico.

  14. Valve latch device for drilling fluid telemetry systems

    SciTech Connect

    Larronde, M. L.; Hoos, R. G.

    1985-07-30

    A latch device for controlling a valve in a mud pulse telemetry system for imparting data pulses to drilling fluids circulating in a drill string is disclosed. A latch device and valve arrangement including an improved shear type, solenoid operated valve for modulating the pressure of the circulating drilling fluid is disclosed. A latching solenoid armature is connected to the valve gate through separate open and close solenoids having their armatures operatively connected to act as a single unit. The single unit armature is normally restrained from movement by the solenoid deactivated latch device. The latch device is arranged so that the vibrational and impact loads on the drill string serve to further maintain the modulating valve in a closed position.

  15. Minimal Power Latch for Single-Slope ADCs

    NASA Technical Reports Server (NTRS)

    Hancock, Bruce R.

    2013-01-01

    Column-parallel analog-to-digital converters (ADCs) for imagers involve simultaneous operation of many ADCs. Single-slope ADCs are well adapted to this use because of their simplicity. Each ADC contains a comparator, comparing its input signal level to an increasing reference signal (ramp). When the ramp is equal to the input, the comparator triggers a latch that captures an encoded counter value (code). Knowing the captured code, the ramp value and hence the input signal are determined. In a column-parallel ADC, each column contains only the comparator and the latches; the ramp and code generation are shared. In conventional latch or flip-flop circuits, there is an input stage that tracks the input signal, and this stage consumes switching current every time the input changes. With many columns, many bits, and high code rates, this switching current can be substantial. It will also generate noise that may corrupt the analog signals. A latch was designed that does not track the input, and consumes power only at the instant of latching the data value. The circuit consists of two S-R (set-reset) latches, gated by the comparator. One is set by high data values and the other by low data values. The latches are cross-coupled so that the first one to set blocks the other. In order that the input data not need an inversion, which would consume power, the two latches are made in complementary polarity. This requires complementary gates from the comparator, instead of complementary data values, but the comparator only triggers once per conversion, and usually has complementary outputs to begin with. An efficient CMOS (complementary metal oxide semiconductor) implementation of this circuit is shown in the figure, where C is the comparator output, D is the data (code), and Q0 and Q1 are the outputs indicating the capture of a zero or one value. The latch for Q0 has a negative-true set signal and output, and is implemented using OR-AND-INVERT logic, while the latch for Q1 uses

  16. 49 CFR 571.113 - Standard No. 113; Hood latch system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Standard No. 113; Hood latch system. 571.113... Motor Vehicle Safety Standards § 571.113 Standard No. 113; Hood latch system. S1. Purpose and scope. This standard establishes the requirement for providing a hood latch system or hood latch systems....

  17. 49 CFR 571.113 - Standard No. 113; Hood latch system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 113; Hood latch system. 571.113... Motor Vehicle Safety Standards § 571.113 Standard No. 113; Hood latch system. S1. Purpose and scope. This standard establishes the requirement for providing a hood latch system or hood latch systems....

  18. 49 CFR 571.113 - Standard No. 113; Hood latch system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Standard No. 113; Hood latch system. 571.113... Motor Vehicle Safety Standards § 571.113 Standard No. 113; Hood latch system. S1. Purpose and scope. This standard establishes the requirement for providing a hood latch system or hood latch systems....

  19. High performance static latches with complete single event upset immunity

    DOEpatents

    Corbett, W.T.; Weaver, H.T.

    1994-04-26

    An asymmetric response latch providing immunity to single event upset without loss of speed is described. The latch has cross-coupled inverters having a hardened logic state and a soft state, wherein the logic state of the first inverter can only be changed when the voltage on the coupling node of that inverter is low and the logic state of the second inverter can only be changed when the coupling of that inverter is high. One of more of the asymmetric response latches may be configured into a memory cell having complete immunity, which protects information rather than logic states. 5 figures.

  20. High performance static latches with complete single event upset immunity

    DOEpatents

    Corbett, Wayne T.; Weaver, Harry T.

    1994-01-01

    An asymmetric response latch providing immunity to single event upset without loss of speed. The latch has cross-coupled inverters having a hardened logic state and a soft state, wherein the logic state of the first inverter can only be changed when the voltage on the coupling node of that inverter is low and the logic state of the second inverter can only be changed when the coupling of that inverter is high. One of more of the asymmetric response latches may be configured into a memory cell having complete immunity, which protects information rather than logic states.

  1. Centerline latch tool for contingency orbiter door closure

    NASA Technical Reports Server (NTRS)

    Trevino, R. C.

    1982-01-01

    The centerline latch tool was designed and developed as an EVA manual backup device for latching the Space Shuttle Orbiter's payload bay doors for reentry in case of a failure of the existing centerline latches to operate properly. The tool was designed to satisfy a wide variety of structural, mechanical, and EVA requirements. It provides a load path for forces on the payload bay doors during reentry. Since the tool would be used by an EVA crewmember, control, handgrips, operating forces, and procedures must be within the capabilities of a partially restrained, suited crewmember in a zero-gravity environment. The centerline latch tool described was designed, developed, and tested to meet these requirements.

  2. Heritage Adoption Lessons Learned: Cover Deployment and Latch Mechanism

    NASA Technical Reports Server (NTRS)

    Wincentsen, James

    2006-01-01

    This viewgraph presentation reviews the lessons learned from heritage adoption designs. A general overview of cover deployment hardware that includes the three mechanisms of latch, hinge, and energy absorbers are also discussed.

  3. Plastic latching accelerometer based on bistable compliant mechanisms

    NASA Astrophysics Data System (ADS)

    Hansen, B. J.; Carron, C. J.; Jensen, B. D.; Hawkins, A. R.; Schultz, S. M.

    2007-10-01

    This paper presents the design, fabrication, and testing of a miniature latching accelerometer that does not require electrical power. Latching is attained by using a bistable compliant mechanism that switches from one mechanical position to another when the force on the accelerometer exceeds a threshold value. Accelerometers were fabricated by laser cutting the compliant mechanism switch out of both ABS and Delrin plastic sheets. Packaging consisted of gluing the single compliant layer to a supporting substrate. The switching thresholds of the accelerometers were varied from 10g to 800g by varying the surface area of the free moving section between 100 and 500 mm2.

  4. Latch fittings for the scientific instruments on the space telescope

    NASA Technical Reports Server (NTRS)

    Dozier, J. D.; Kaelber, E.

    1983-01-01

    Latch fittings which kinematically mount the replaceable scientific instruments onto the Space Telescope must maintain precise alignment and thermal stability for on-orbit observations. Design features which are needed to meet stringent criteria include the use of ceramic isolators for thermal and electrical insulation, materials with different coefficients of thermal expansion for athermalization, precision manufacturing procedures, and extremely tight tolerances. A specific latch fitting to be discussed is a ball-and-socket design. In addition, testing, crew aids, and problems will be covered.

  5. 49 CFR 236.341 - Latch shoes, rocker links, and quadrants.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Latch shoes, rocker links, and quadrants. 236.341 Section 236.341 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.341 Latch shoes, rocker links, and quadrants. Latch shoes, rocker...

  6. 49 CFR 236.341 - Latch shoes, rocker links, and quadrants.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Latch shoes, rocker links, and quadrants. 236.341 Section 236.341 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.341 Latch shoes, rocker links, and quadrants. Latch shoes, rocker...

  7. 49 CFR 236.763 - Locking, latch operated.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, latch operated. 236.763 Section 236.763 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL...

  8. Superconducting A/D converter using latching comparators

    SciTech Connect

    Hamilton, C.A.; Kautz, R.L.; Loyld, F.L.

    1985-03-01

    This paper describes the design and performance of a six-bit A/D converter using fast edge latching comparators. Simulations predicting conversion times of 100 ps and 100 MHz signal bandwidth are verified experimentally. The addition of a superconducting track/hold circuit in front of the A/D converter is expected to substantially improve the signal bandwidth.

  9. Novel latch for adiabatic quantum-flux-parametron logic

    SciTech Connect

    Takeuchi, Naoki Yamanashi, Yuki; Yoshikawa, Nobuyuki; Ortlepp, Thomas

    2014-03-14

    We herein propose the quantum-flux-latch (QFL) as a novel latch for adiabatic quantum-flux-parametron (AQFP) logic. A QFL is very compact and compatible with AQFP logic gates and can be read out in one clock cycle. Simulation results revealed that the QFL operates at 5 GHz with wide parameter margins of more than ±22%. The calculated energy dissipation was only ∼0.1 aJ/bit, which yields a small energy delay product of 20 aJ·ps. We also designed shift registers using QFLs to demonstrate more complex circuits with QFLs. Finally, we experimentally demonstrated correct operations of the QFL and a 1-bit shift register (a D flip-flop)

  10. Dual-Latching, Solenoid-Actuated Tube Valve

    NASA Technical Reports Server (NTRS)

    Brudnicki, Myron J.

    1993-01-01

    Tube-type shutoff valve electrically positioned to open or closed state by concentric solenoid. Solenoid dual latching: it holds position until changed electrically or manually. In tube valve, central tube slides axially, closing off flow when held against seat and allowing flow when backed away from seat. Simple to balance pressure on seal between seat and sharp edge of tube. With pressure-balanced seal, only small force needed to hold valve in position, regardless of pressure acting on valve.

  11. Dual-latching solenoid-actuated valve assembly

    NASA Technical Reports Server (NTRS)

    Brudnicki, Myron J. (Inventor); Yang, Jeff (Inventor)

    1994-01-01

    A tube-type shutoff valve is electrically positioned to its open or closed position by a concentric electromagnetic solenoid. The valve is dual latching in that the armature of the solenoid maintains the sliding tube of the valve in an open or closed position by means of permanent magnets which are effective when current is not supplied to the solenoid. The valve may also be actuated manually.

  12. Heritage Adoption Lessons Learned: Cover Deployment and Latch Mechanism

    NASA Technical Reports Server (NTRS)

    Wincentsen, James

    2006-01-01

    Within JPL, there is a technology thrust need to develop a larger Cover Deployment and Latch Mechanism (CDLM) for future missions. The approach taken was to adopt and scale the CDLM design as used on the Galaxy Evolution Explorer (GALEX) project. The three separate mechanisms that comprise the CDLM will be discussed in this paper in addition to a focus on heritage adoption lessons learned and specific examples. These lessons learned will be valuable to any project considering the use of heritage designs.

  13. Rotational MEMS mirror with latching arm for silicon photonics

    NASA Astrophysics Data System (ADS)

    Brière, Jonathan; Beaulieu, Philippe-Olivier; Saidani, Menouer; Nabki, Frederic; Menard, Michaël.

    2015-02-01

    We present an innovative rotational MEMS mirror that can control the direction of propagation of light beams inside of planar waveguides implemented in silicon photonics. Potential applications include but are not limited to optical telecommunications, medical imaging, scan and spectrometry. The mirror has a half-cylinder shape with a radius of 300 μm that provides low and constant optical losses over the full angular displacement range. A circular comb drive structure is anchored such that it allows free or latched rotation experimentally demonstrated over 8.5° (X-Y planar rotational movement) using 290V electrostatic actuation. The entire MEMS structure was implemented using the MEMSCAP SOIMUMPs process. The center of the anchor beam is designed to be the approximate rotation point of the circular comb drive to counter the rotation offset of the mirror displacement. A mechanical characterization of the MEMS mirror is presented. The latching mechanism provides up to 20 different angular locking positions allowing the mirror to counter any resonance or vibration effects and it is actuated with an electrostatic linear comb drive. An innovative gap closing structure was designed to reduce optical propagation losses due to beam divergence in the interstitial space between the mirror and the planar waveguide. The gap closing structure is also electrostatically actuated and includes two side stoppers to prevent stiction.

  14. Soil sampling device with latch assembly having a variable circumferential shape

    DOEpatents

    Meyer, Robert D.

    1996-01-01

    The invention relates to an improved sampler which can be operated in any orientation. The design features a positive gripping of the operating rod in a manner to reduce point loads so as to reduce any possibility of jamming of the rod on a retraction stroke until such time as it is positively retained in the fully withdrawn position. In the preferred embodiment, a pair of mating cylindrical latch pieces, held together by a circumferential spring, are used for positive actuation. The inner rod has an angular cut-out which provides the base for the latch when aligned with the latch. A release fixture can be used to free the latch from the cone rod after actuation. The latches are formed in such a manner as they may support themselves within the housing of the sampler until they engage the operating rod.

  15. Soil sampling device with latch assembly having a variable circumferential shape

    DOEpatents

    Meyer, R.D.

    1996-12-24

    The invention relates to an improved sampler which can be operated in any orientation. The design features a positive gripping of the operating rod in a manner to reduce point loads so as to reduce any possibility of jamming of the rod on a retraction stroke until such time as it is positively retained in the fully withdrawn position. In the preferred embodiment, a pair of mating cylindrical latch pieces, held together by a circumferential spring, are used for positive actuation. The inner rod has an angular cut-out which provides the base for the latch when aligned with the latch. A release fixture can be used to free the latch from the cone rod after actuation. The latches are formed in such a manner as they may support themselves within the housing of the sampler until they engage the operating rod. 11 figs.

  16. Evolution of the IBDM Structural Latch Development into a Generic Simplified Design

    NASA Technical Reports Server (NTRS)

    DeVriendt, K.; Dittmer, H.; Vrancken, D.; Urmston, P.; Gracia, O.

    2010-01-01

    This paper presents the evolution in the development of the structural latch for the International Berthing Docking Mechanism (IBDM, see Figure 1). It reports on the lessons learned since completion of the test program on the engineering development unit of the first generation latching system in 2007. The initial latch design has been through a second generation concept in 2008, and now evolved into a third generation of this mechanism. Functional and structural testing on the latest latch hardware has recently been completed with good results. The IBDM latching system will provide the structural connection between two mated space vehicles after berthing or docking. The mechanism guarantees that the interface seals become compressed to form a leak-tight pressure system that creates a passageway for the astronauts.

  17. Engineering Evaluation of International Low Impact Docking System Latch Hooks

    NASA Technical Reports Server (NTRS)

    Martinez, J.; Patin, R.; Figert, J.

    2013-01-01

    The international Low Impact Docking System (iLIDS) provides a structural arrangement that allows for visiting vehicles to dock with the International Space Station (ISS) (Fig 1). The iLIDS docking units are mechanically joined together by a series of active and passive latch hooks. In order to preserve docking capability at the existing Russian docking interfaces, the iLIDS latch hooks are required to conform to the existing Russian design. The latch hooks are classified as being fail-safe. Since the latch hooks are fail-safe, the hooks are not fracture critical and a fatigue based service life assessment will satisfy the structural integrity requirements. Constant amplitude fatigue testing to failure on four sets of active/passive iLIDS latch hooks was performed at load magnitudes of 10, 11, and 12 kips. Failure analysis of the hook fatigue failures identified multi-site fatigue initiation that was effectively centered about the hook mid-plane (consistent with the 3D model results). The fatigue crack initiation distribution implies that the fatigue damage accumulation effectively results in a very low aspect ratio surface crack (which can be simulated as thru-thickness crack). Fatigue damage progression resulted in numerous close proximity fatigue crack initiation sites. It was not possible to determine if fatigue crack coalescence occurs during cyclic loading or as result of the fast fracture response. The presence of multiple fatigue crack initiation sites on different planes will result in the formation of ratchet marks as the cracks coalesce. Once the stable fatigue crack becomes unstable and the fast fracture advances across the remaining ligament and the plane stress condition at a free-surface will result in failure along a 45 deg. shear plane (slant fracture) and the resulting inclined edge is called a shear lip. The hook thickness on the plane of fatigue crack initiation is 0.787". The distance between the shear lips on this plane was on the order of 0

  18. Miga Aero Actuator and 2D Machined Mechanical Binary Latch

    NASA Technical Reports Server (NTRS)

    Gummin, Mark A.

    2013-01-01

    Shape memory alloy (SMA) actuators provide the highest force-to-weight ratio of any known actuator. They can be designed for a wide variety of form factors from flat, thin packages, to form-matching packages for existing actuators. SMA actuators can be operated many thousands of times, so that ground testing is possible. Actuation speed can be accurately controlled from milliseconds to position and hold, and even electronic velocity-profile control is possible. SMA actuators provide a high degree of operational flexibility, and are truly smart actuators capable of being accurately controlled by onboard microprocessors across a wide range of voltages. The Miga Aero actuator is a SMA actuator designed specifically for spaceflight applications. Providing 13 mm of stroke with either 20- or 40-N output force in two different models, the Aero actuator is made from low-outgassing PEEK (polyether ether ketone) plastic, stainless steel, and nickel-titanium SMA wires. The modular actuator weighs less than 28 grams. The dorsal output attachment allows the Aero to be used in either PUSH or PULL modes by inverting the mounting orientation. The SPA1 actuator utilizes commercially available SMA actuator wire to provide 3/8-in. (approx. =.1 cm) of stroke at a force of over 28 lb (approx. = .125 N). The force is provided by a unique packaging of the single SMA wire that provides the output force of four SMA wires mechanically in parallel. The output load is shared by allowing the SMA wire to slip around the output attachment end to adjust or balance the load, preventing any individual wire segment from experiencing high loads during actuation. A built-in end limit switch prevents overheating of the SMA element following actuation when used in conjunction with the Miga Analog Driver [a simple MOSFET (metal oxide semiconductor field-effect transistor) switching circuit]. A simple 2D machined mechanical binary latch has been developed to complement the capabilities of SMA wire

  19. Latching chains in K-nearest-neighbor and modular small-world networks.

    PubMed

    Song, Sanming; Yao, Hongxun; Simonov, Alexander Yurievich

    2015-01-01

    Latching dynamics retrieve pattern sequences successively by neural adaption and pattern correlation. We have previously proposed a modular latching chain model in Song et al. (2014) to better accommodate the structured transitions in the brain. Different cortical areas have different network structures. To explore how structural parameters like rewiring probability, threshold, noise and feedback connections affect the latching dynamics, two different connection schemes, K-nearest-neighbor network and modular network both having modular structure are considered. Latching chains are measured using two proposed measures characterizing length of intra-modular latching chains and sequential inter-modular association transitions. Our main findings include: (1) With decreasing threshold coefficient and rewiring probability, both the K-nearest-neighbor network and the modular network experience quantitatively similar phase change processes. (2) The modular network exhibits selectively enhanced latching in the small-world range of connectivity. (3) The K-nearest-neighbor network is more robust to changes in rewiring probability, while the modular network is more robust to the presence of noise pattern pairs and to changes in the strength of feedback connections. According to our findings, the relationships between latching chains in K-nearest-neighbor and modular networks and different forms of cognition and information processing emerging in the brain are discussed.

  20. Driving and latching of the Starlab pointing mirror doors

    NASA Technical Reports Server (NTRS)

    Beaven, Herbert R., Jr.; Avina, Raymond R.

    1990-01-01

    The Starlab Experiment, a major SDIO technology initiative, is an attached payload which will be delivered into Earth orbit aboard NASA's Space Shuttle in 1991. Starlab will generate and aim an 80 cm diameter laser beam into space through a large opening in the structure which houses the pointing mirror. Two doors, each somewhat larger than a desktop, cover the opening when the laser optics system is nonoperational. Latch Mechanism Assemblies hold the doors shut during liftoff and ascent and, again, during Orbiter reentry. Each door is powered by a Door Drive System during the many open/close cycles between various experiments. The design, testing, and resultant failure modes of these mechanisms are examined.

  1. A High-Speed and Low-Offset Dynamic Latch Comparator

    PubMed Central

    Rahman, Labonnah Farzana; Reaz, Mamun Bin Ibne; Yin, Chia Chieu; Rahman, Mohammad Anisur

    2014-01-01

    Circuit intricacy, speed, low-offset voltage, and resolution are essential factors for high-speed applications like analog-to-digital converters (ADCs). The comparator circuit with preamplifier increases the power dissipation, as it requires higher amount of currents than the latch circuitry. In this research, a novel topology of dynamic latch comparator is illustrated, which is able to provide high speed, low offset, and high resolution. Moreover, the circuit is able to reduce the power dissipation as the topology is based on latch circuitry. The cross-coupled circuit mechanism with the regenerative latch is employed for enhancing the dynamic latch comparator performance. In addition, input-tracking phase is used to reduce the offset voltage. The Monte-Carlo simulation results for the designed comparator in 0.18 μm CMOS process show that the equivalent input-referred offset voltage is 720 μV with 3.44 mV standard deviation. The simulated result shows that the designed comparator has 8-bit resolution and dissipates 158.5 μW of power under 1.8 V supply while operating with a clock frequency of 50 MHz. In addition, the proposed dynamic latch comparator has a layout size of 148.80 μm × 59.70 μm. PMID:25114959

  2. A high-speed and low-offset dynamic latch comparator.

    PubMed

    Rahman, Labonnah Farzana; Bin Ibne Reaz, Mamun; Yin, Chia Chieu; Marufuzzaman, Mohammad; Rahman, Mohammad Anisur

    2014-01-01

    Circuit intricacy, speed, low-offset voltage, and resolution are essential factors for high-speed applications like analog-to-digital converters (ADCs). The comparator circuit with preamplifier increases the power dissipation, as it requires higher amount of currents than the latch circuitry. In this research, a novel topology of dynamic latch comparator is illustrated, which is able to provide high speed, low offset, and high resolution. Moreover, the circuit is able to reduce the power dissipation as the topology is based on latch circuitry. The cross-coupled circuit mechanism with the regenerative latch is employed for enhancing the dynamic latch comparator performance. In addition, input-tracking phase is used to reduce the offset voltage. The Monte-Carlo simulation results for the designed comparator in 0.18 μm CMOS process show that the equivalent input-referred offset voltage is 720 μV with 3.44 mV standard deviation. The simulated result shows that the designed comparator has 8-bit resolution and dissipates 158.5 μW of power under 1.8 V supply while operating with a clock frequency of 50 MHz. In addition, the proposed dynamic latch comparator has a layout size of 148.80 μm × 59.70 μm. PMID:25114959

  3. A high-speed and low-offset dynamic latch comparator.

    PubMed

    Rahman, Labonnah Farzana; Bin Ibne Reaz, Mamun; Yin, Chia Chieu; Marufuzzaman, Mohammad; Rahman, Mohammad Anisur

    2014-01-01

    Circuit intricacy, speed, low-offset voltage, and resolution are essential factors for high-speed applications like analog-to-digital converters (ADCs). The comparator circuit with preamplifier increases the power dissipation, as it requires higher amount of currents than the latch circuitry. In this research, a novel topology of dynamic latch comparator is illustrated, which is able to provide high speed, low offset, and high resolution. Moreover, the circuit is able to reduce the power dissipation as the topology is based on latch circuitry. The cross-coupled circuit mechanism with the regenerative latch is employed for enhancing the dynamic latch comparator performance. In addition, input-tracking phase is used to reduce the offset voltage. The Monte-Carlo simulation results for the designed comparator in 0.18 μm CMOS process show that the equivalent input-referred offset voltage is 720 μV with 3.44 mV standard deviation. The simulated result shows that the designed comparator has 8-bit resolution and dissipates 158.5 μW of power under 1.8 V supply while operating with a clock frequency of 50 MHz. In addition, the proposed dynamic latch comparator has a layout size of 148.80 μm × 59.70 μm.

  4. K-band high power latching switch. [communication satellite system

    NASA Technical Reports Server (NTRS)

    Mlinar, M. J.; Piotrowski, W. S.; Raue, J. E.

    1980-01-01

    A 19 GHz waveguide latching switch with a bandwidth of 1400 MHz and an exceptionally low insertion loss of 0.25 dB was demonstrated. The RF and driver ferrites are separate structures and can be optimized individually. This analysis for each structure is separately detailed. Basically, the RF section features a dual turnstile junction. The circulator consists of a dielectric tube which contains two ferrite rods, and a dielectric spacer separating the ferrite parts along the center of symmetry of the waveguide to form two turnstiles. This subassembly is indexed and locked in the center of symmetry of a uniform junction of three waveguides by the metallic transformers installed in the top and bottom walls of the housing. The switching junction and its actuating circuitry met all RF performance objectives and all shock and vibration requirements with no physical damage or performance degradation. It exceeds thermal requirements by operating over a 100 C temperature range (-44 C to +56 C) and has a high power handling capability allowing up to 100 W of CW input power.

  5. Quick-Connect Heavy-Duty Fastener

    NASA Technical Reports Server (NTRS)

    Moore, D. M.

    1986-01-01

    Attaching device combines fast connection and disconnection with high strength. T-shaped stud engages groove in receptacle after one-quarter turn. Further turning tightens nut on receptacle. Like quarter-turn attaching devices, connected and disconnected quickly. Like threaded devices, adjusted to desired preload, withstand high loads, and accommodate wide range of grip lengths.

  6. Short period of oxygenation releases latch on peat decomposition.

    PubMed

    Brouns, Karlijn; Verhoeven, Jos T A; Hefting, Mariet M

    2014-05-15

    Extreme summer droughts are expected to occur more often in the future in NW Europe due to climate change. These droughts might accelerate the rate of peat oxidation in drained peat areas, with impacts on soil subsidence, GHG emission and water quality. This study aimed at providing more insight in the oxidation of deep peat layers that had not previously been exposed to air, the so-called secondary decomposition. We incubated two types of peat (eutrophic and oligotrophic), sampled from permanently anoxic peat layers from nature reserves and agricultural peat meadows. Peat samples were incubated for thirteen weeks under anoxic conditions, but were exposed to air for one to eight weeks. The production of CO2 and CH4 was quantified as a proxy for decomposition; concentrations of soluble nutrients and phenolic compounds were also measured. The results showed that oxygenation led to a steep increase in the rate of decomposition, indicated by higher carbon loss rates during and after oxygenation compared to non-oxygenated samples. Carbon loss rates increased more for eutrophic peat (agricultural area: 352%, nature reserve: 182%) than for oligotrophic peat (83% and 159% respectively). Most peat samples investigated showed higher post-oxygenation CO2 and/or CH4 production compared to the anoxic pre-oxygenation period. This indicates that oxygenation stimulates decomposition, even after anoxic conditions have returned. Contrary to the enzymic latch theory, no effects of oxygenation on the concentrations of soluble or condensed phenolic compounds were detected. Soluble nutrient concentrations did not change due to oxygenation either. Noteworthy is the occurrence of pyrite mineralization and associated acidification in eutrophic peat. Thus, low summer water levels, for example due to climate change, should be avoided in order to limit exceptionally high decomposition rates and associated problems such as increasing subsidence rates, greenhouse gas emission, sulfate release

  7. Misuse study of latch attachment: a series of frontal sled tests.

    PubMed

    Menon, Rajiv; Ghati, Yoganand

    2007-01-01

    This study was initiated to quantify the effects of the misuse in LATCH lower webbing. In the short period since the implementation of the LATCH system several cases of potential misuses have been reported. A series of sled tests in frontal impact mode were conducted with various misuse conditions (loose attachment of LATCH lower webbing, misrouting of LATCH lower webbing and child seat back inclination) for both forward and rearward facing child safety seats (FFCSS and RFCSS). Results from these tests are compared and discussed with that of the standard test with no misuse and showed that as the slack in the lower LATCH webbing increased, ATD injury measures exceeded the limits. The FFCSS tests in the reclined condition yielded lower injury values for all except the chest G's when compared to the standard upright test. In the misrouting tests the ATD kinematics depended on the routing pivot point, the lower the pivot point the better the ATD kinematics. Similar findings were also observed in the RFCSS tests. The use of top tether with the FFCSS substantially improved the performance of the Hybrid III 3 year old ATD in spite of misuse conditions and the injury values were lower than the corresponding tests with no top tether. The effective reduction was 37% in the HIC values, 6% in the chest G's, 30% in the head excursion, 22 % in the knee excursion and finally 37 % reduction in the Nij values. PMID:18184489

  8. Misuse study of latch attachment: a series of frontal sled tests.

    PubMed

    Menon, Rajiv; Ghati, Yoganand

    2007-01-01

    This study was initiated to quantify the effects of the misuse in LATCH lower webbing. In the short period since the implementation of the LATCH system several cases of potential misuses have been reported. A series of sled tests in frontal impact mode were conducted with various misuse conditions (loose attachment of LATCH lower webbing, misrouting of LATCH lower webbing and child seat back inclination) for both forward and rearward facing child safety seats (FFCSS and RFCSS). Results from these tests are compared and discussed with that of the standard test with no misuse and showed that as the slack in the lower LATCH webbing increased, ATD injury measures exceeded the limits. The FFCSS tests in the reclined condition yielded lower injury values for all except the chest G's when compared to the standard upright test. In the misrouting tests the ATD kinematics depended on the routing pivot point, the lower the pivot point the better the ATD kinematics. Similar findings were also observed in the RFCSS tests. The use of top tether with the FFCSS substantially improved the performance of the Hybrid III 3 year old ATD in spite of misuse conditions and the injury values were lower than the corresponding tests with no top tether. The effective reduction was 37% in the HIC values, 6% in the chest G's, 30% in the head excursion, 22 % in the knee excursion and finally 37 % reduction in the Nij values.

  9. Latch-up based bidirectional npn selector for bipolar resistance-change memory

    NASA Astrophysics Data System (ADS)

    Kim, Sungho; Moon, Dong-Il; Lu, Wei; Hwan Kim, Dae; Myong Kim, Dong; Choi, Yang-Kyu; Choi, Sung-Jin

    2013-07-01

    A vertically integrated latch-up based n-p-n bidirectional diode, which is analogous to an open-base bipolar junction transistor, is demonstrated for bipolar resistance-change memory selector application. A maximum current density of >50 MA/cm2 and a selectivity of >104 are observed at a fast switching speed of within 10 ns. The high selectivity as a consequence of the sudden latch-up process is feasible owing to the positive-feedback process initiated by impact ionization. The optimization of the turn-on voltage is comprehensively investigated by numerical device simulation, which ensures the promising potential of the latch-up based selector device.

  10. Design and Development of a Miniaturized Double Latching Solenoid Valve for the Sample Analysis at Mars Instrument Suite

    NASA Technical Reports Server (NTRS)

    Smith, James T.

    2008-01-01

    The development of the in-house Miniaturized Double Latching Solenoid Valve, or Microvalve, for the Gas Processing System (GPS) of the Sample Analysis at Mars (SAM) instrument suite is described. The Microvalve is a double latching solenoid valve that actuates a pintle shaft axially to hermetically seal an orifice. The key requirements and the design innovations implemented to meet them are described.

  11. A Modular, Reusable Latch and Decking System for Securing Payloads During Launch and Planetary Surface Transport

    NASA Technical Reports Server (NTRS)

    Doggett, William R.; Dorsey, John T.; Jones, Thomas C.; King, Bruce D.; Mikulas, Martin M.

    2010-01-01

    Efficient handling of payloads destined for a planetary surface, such as the moon or Mars, requires robust systems to secure the payloads during transport on the ground, in-space and on the planetary surface. In addition, mechanisms to release the payloads need to be reliable to ensure successful transfer from one vehicle to another. An efficient payload handling strategy must also consider the devices available to support payload handling. Cranes used for overhead lifting are common to all phases of payload handling on Earth. Similarly, both recent and past studies have demonstrated that devices with comparable functionality will be needed to support lunar outpost operations. A first generation test-bed of a new high performance device that provides the capabilities of both a crane and a robotic manipulator, the Lunar Surface Manipulation System (LSMS), has been designed, built and field tested and is available for use in evaluating a system to secure payloads to transportation vehicles. National Institute of Aerospace, Hampton Va 23662 A payload handling approach must address all phases of payload management including: ground transportation, launch, planetary transfer and installation in the final system. In addition, storage may be required during any phase of operations. Each of these phases requires the payload to be lifted and secured to a vehicle, transported, released and lifted in preparation for the next transportation or storage phase. A critical component of a successful payload handling approach is a latch and associated carrier system. The latch and carrier system should minimize requirements on the: payload, carrier support structure and payload handling devices as well as be able to accommodate a wide range of payload sizes. In addition, the latch should; be small and lightweight, support a method to apply preload, be reusable, integrate into a minimal set of hard-points and have manual interfaces to actuate the latch should a problem occur. A

  12. A Modular, Reusable Latch and Decking System for Securing Payloads During Launch and Planetary Surface Transport

    NASA Technical Reports Server (NTRS)

    Doggett, William R.; Dorsey, John T.; Jones, Thomas C.; King, Bruce D.; Mikulas, Martin M.

    2011-01-01

    Efficient handling of payloads destined for a planetary surface, such as the moon or mars, requires robust systems to secure the payloads during transport on the ground, in space and on the planetary surface. In addition, mechanisms to release the payloads need to be reliable to ensure successful transfer from one vehicle to another. An efficient payload handling strategy must also consider the devices available to support payload handling. Cranes used for overhead lifting are common to all phases of payload handling on Earth. Similarly, both recent and past studies have demonstrated that devices with comparable functionality will be needed to support lunar outpost operations. A first generation test-bed of a new high performance device that provides the capabilities of both a crane and a robotic manipulator, the Lunar Surface Manipulation System (LSMS), has been designed, built and field tested and is available for use in evaluating a system to secure payloads to transportation vehicles. A payload handling approach must address all phases of payload management including: ground transportation, launch, planetary transfer and installation in the final system. In addition, storage may be required during any phase of operations. Each of these phases requires the payload to be lifted and secured to a vehicle, transported, released and lifted in preparation for the next transportation or storage phase. A critical component of a successful payload handling approach is a latch and associated carrier system. The latch and carrier system should minimize requirements on the: payload, carrier support structure and payload handling devices as well as be able to accommodate a wide range of payload sizes. In addition, the latch should; be small and lightweight, support a method to apply preload, be reusable, integrate into a minimal set of hard-points and have manual interfaces to actuate the latch should a problem occur. A latching system which meets these requirements has been

  13. Apollo 14 mission: Failure to achieve docking probe capture latch engagement

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Six docking attempts were required in order to successfully achieve capture latch engagement during the transposition and docking phase following translunar injection. After docking, the probe and drogue were examined by the crew. Probe operation appeared normal and radial marks were noted on the drogue. During all subsequent operations, the probe operated properly.

  14. OFF-ON-OFF Fluorescence Switch with T-Latch Function

    PubMed Central

    2011-01-01

    A novel molecular system with characteristics of an OFF-ON-OFF fluorescence switch was designed to integrate the function of a T-latch. In detail, a receptor1-fluorophore-receptor2 architecture was adopted to achieve fluorescence switching upon addition of protons. PMID:21932803

  15. 49 CFR 571.113 - Standard No. 113; Hood latch system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Motor Vehicle Safety Standards § 571.113 Standard No. 113; Hood latch system. S1. Purpose and scope.... Application. This standard applies to passenger cars, multipurpose passenger vehicles, trucks, and buses. S3... engine, luggage, storage, or battery compartment. S4. Requirements. S4.1Each hood must be provided with...

  16. Latching operation in a tunable wavelength filter using Si sampled grating waveguide with ferroelectric liquid crystal cladding.

    PubMed

    Nakatsuhara, Katsumi; Kato, Akifumi; Hayama, Yoshiki

    2014-04-21

    A tunable wavelength filter fabricated with a latching function is proposed. The proposed tunable wavelength filter consists of a silicon sampled grating waveguide and ferro-electric liquid crystal (FLC) cladding. The sampled grating waveguide in a silicon-on-insulator (SOI) wafer achieved narrower stop bands than that with the conventional uniform grating structure. Enhanced wavelength shift was also obtained due to the increased effect in FLC by using a thinner silicon core. Bistable switching operation with the fabricated device, which was latching without state-sustaining power, was successfully demonstrated. Its switching and latching characteristics are also reported. PMID:24787847

  17. Field use patterns and performance of child restraints secured by lower anchors and tethers for children (LATCH).

    PubMed

    Arbogast, Kristy B; Jermakian, Jessica Steps

    2007-05-01

    A revised attachment system for child restraint systems (CRS), Lower Anchors and Tethers for Children (LATCH), was introduced to address issues of misuse of attachment of the CRS to the vehicle. This study provides the first real-world experience of this new restraint system. Relevant cases were selected from the partners for child passenger safety (PCPS) child-specific crash surveillance system based in the United States. Vehicles qualifying for the PCPS study were those model year 1990 or newer involved in a crash with at least one passenger LATCH lower anchors were used was chosen for in-depth crash investigation and interview. Review of these data found misuse remained a frequent occurrence (5/7 cases). The presence of a loose harness in several cases demonstrated that the focus of LATCH on the attachment of the CRS to the vehicle did not remove one of the most common CRS misuses. Further, significant injuries still do occur although LATCH lower anchor performance was not necessarily a contributing factor to any of these injuries. This subset of cases demonstrates that consumers are using the LATCH technology, at times with significant misuse and that significant injury still may occur, despite use of LATCH. PMID:17270136

  18. Heritage Adoption Lessons Learned, Active Mirror Telescope Cover Deployment and Latch Mechanism

    NASA Technical Reports Server (NTRS)

    Wincentsen, James E.

    2006-01-01

    The Active Mirror Telescope (AMT) task adopted the Cover Deployment and Latch Mechanism (CDLM) design as used on the Galaxy Evolution Explorer (GALEX) project. The three separate mechanisms that comprise the CDLM will be discussed in this paper in addition to a focus on heritage adoption lessons learned and specific examples. These lessons learned will be valuable to any project considering the use of heritage designs.

  19. Comparative research on “high currents” induced by single event latch-up and transient-induced latch-up

    NASA Astrophysics Data System (ADS)

    Chen, Rui; Han, Jian-Wei; Zheng, Han-Sheng; Yu, Yong-Tao; Shangguang, Shi-Peng; Feng, Guo-Qiang; Ma, Ying-Qi

    2015-04-01

    By using the pulsed laser single event effect facility and electro-static discharge (ESD) test system, the characteristics of the “high current”, relation with external stimulus and relevance to impacted modes of single event latch-up (SEL) and transient-induced latch-up (TLU) are studied, respectively, for a 12-bit complementary metal-oxide semiconductor (CMOS) analog-to-digital converter. Furthermore, the sameness and difference in physical mechanism between “high current” induced by SEL and that by TLU are disclosed in this paper. The results show that the minority carrier diffusion in the PNPN structure of the CMOS device which initiates the active parasitic NPN and PNP transistors is the common reason for the “high current” induced by SEL and for that by TLU. However, for SEL, the minority carrier diffusion is induced by the ionizing radiation, and an underdamped sinusoidal voltage on the supply node (the ground node) is the cause of the minority carrier diffusion for TLU. Project supported by the National Natural Science Foundation of China (Grant No. 41304148).

  20. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    PubMed

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  1. A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

    SciTech Connect

    Melcher, Karsten; Ng, Ley-Moy; Zhou, X Edward; Soon, Fen-Fen; Xu, Yong; Suino-Powell, Kelly M; Park, Sang-Youl; Weiner, Joshua J; Fujii, Hiroaki; Chinnusamy, Viswanathan; Kovach, Amanda; Li, Jun; Wang, Yonghong; Li, Jiayang; Peterson, Francis C; Jensen, Davin R; Yong, Eu-Leong; Volkman, Brian F; Cutler, Sean R; Zhu, Jian-Kang; Xu, H Eric

    2010-01-12

    Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved β-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling.

  2. Dissociation of Bak α1 helix from the core and latch domains is required for apoptosis.

    PubMed

    Alsop, Amber E; Fennell, Stephanie C; Bartolo, Ray C; Tan, Iris K L; Dewson, Grant; Kluck, Ruth M

    2015-01-01

    During apoptosis, Bak permeabilizes mitochondria after undergoing major conformational changes, including poorly defined N-terminal changes. Here, we characterize those changes using 11 antibodies that were epitope mapped using peptide arrays and mutagenesis. After Bak activation by Bid, epitopes throughout the α1 helix are exposed indicating complete dissociation of α1 from α2 in the core and from α6-α8 in the latch. Moreover, disulfide tethering of α1 to α2 or α6 blocks cytochrome c release, suggesting that α1 dissociation is required for further conformational changes during apoptosis. Assaying epitope exposure when α1 is tethered shows that Bid triggers α2 movement, followed by α1 dissociation. However, α2 reaches its final position only after α1 dissociates from the latch. Thus, α1 dissociation is a key step in unfolding Bak into three major components, the N terminus, the core (α2-α5) and the latch (α6-α8). PMID:25880232

  3. Enhancing the force capability of permanent magnet latching actuators for electromechanical valve actuation systems

    NASA Astrophysics Data System (ADS)

    Rens, J.; Clark, R. E.; Jewell, G. W.; Howe, D.

    2005-05-01

    This article introduces a topology of parallel-polarized permanent magnet latching actuator for use in electromagnetic valve actuation systems for internal combustion engines. The actuator has a number of advantages over reluctance actuators, commonly employed in such systems, in terms of reduced starting currents and fail-safe capability. The influence of a number of design features on actuator performance, such as tooth tapering, additional magnets to improve the main magnet flux path and prevent the onset of saturation, and mechanical clearances required to protect the permanent magnet from shock loads are investigated. The design study findings are verified by measurements on a prototype actuator.

  4. Bench-level characterization of a CMOS standard-cell D-latch using alpha-particle sensitive test circuits

    NASA Technical Reports Server (NTRS)

    Blaes, B. R.; Soli, G. A.; Buehler, M. G.

    1991-01-01

    A methodology is described for predicting the SEU susceptibility of a standard-cell D-latch using an alpha-particle sensitive SRAM, SPICE critical charge simulation results, and alpha-particle interaction physics. Measurements were made on a 1.6-micron n-well CMOS 4-kb test SRAM irradiated with an Am-241 alpha-particle source. A collection depth of 6.09 micron was determined using these results and TRIM computer code. Using this collection depth and SPICE derived critical charge results on the latch design, an LET threshold of 34 MeV sq cm/mg was predicted. Heavy ion tests were then performed on the latch and an LET threshold of 41 MeV sq cm/mg was determined.

  5. Design of High Speed and Low Offset Dynamic Latch Comparator in 0.18 µm CMOS Process

    PubMed Central

    Rahman, Labonnah Farzana; Reaz, Mamun Bin Ibne; Yin, Chia Chieu; Ali, Mohammad Alauddin Mohammad; Marufuzzaman, Mohammad

    2014-01-01

    The cross-coupled circuit mechanism based dynamic latch comparator is presented in this research. The comparator is designed using differential input stages with regenerative S-R latch to achieve lower offset, lower power, higher speed and higher resolution. In order to decrease circuit complexity, a comparator should maintain power, speed, resolution and offset-voltage properly. Simulations show that this novel dynamic latch comparator designed in 0.18 µm CMOS technology achieves 3.44 mV resolution with 8 bit precision at a frequency of 50 MHz while dissipating 158.5 µW from 1.8 V supply and 88.05 µA average current. Moreover, the proposed design propagates as fast as 4.2 nS with energy efficiency of 0.7 fJ/conversion-step. Additionally, the core circuit layout only occupies 0.008 mm2. PMID:25299266

  6. A novel latch-up free SCR-LDMOS with high holding voltage for a power-rail ESD clamp

    NASA Astrophysics Data System (ADS)

    Hongwei, Pan; Siyang, Liu; Weifeng, Sun

    2013-01-01

    The low snapback holding voltage of the SCR-LDMOS device makes it susceptible to latch-up failure, when used in power-rail ESD (electro-static discharge) clamp circuits. In order to eliminate latch-up risk, this work presents a novel SCR-LDMOS structure with an N-type implantation layer to achieve a 17 V holding voltage and a 5.2 A second breakdown current. The device has been validated using TLP measurement analysis and is applied to a power-rail ESD clamp in half-bridge driver ICs.

  7. Assessing the SEU resistance of CMOS latches using alpha-particle sensitive test circuits

    NASA Technical Reports Server (NTRS)

    Buehler, M.; Blaes, B.; Nixon, R.

    1990-01-01

    The importance of Cosmic Rays on the performance of integrated circuits (IC's) in a space environment is evident in the upset rate of the Tracking and Data Relay Satellite (TDRS) launched in Apr. 1983. This satellite experiences a single-event-upset (SEU) per day which must be corrected from the ground. Such experience caused a redesign of the Galileo spacecraft with SEU resistant IC's. The solution to the SEU problem continues to be important as the complexity of spacecraft grows, the feature size of IC's decreases, and as space systems are designed with circuits fabricated at non-radiation hardened foundries. This paper describes an approach for verifying the susceptibility of CMOS latches to heavy-ion induced state changes. The approach utilizes alpha particles to induce the upsets in test circuits. These test circuits are standard cells that have offset voltages which sensitize the circuits to upsets. These results are then used to calculate the upsetability at operating voltages. In this study results are presented for the alpha particle upset of a six-transistor static random access memory (SRAM) cell. Then a methodology is described for the analysis of a standard-cell inverter latch.

  8. Different Electrostatic Potentials Define ETGE and DLG Motifs as Hinge and Latch in Oxidative Stress Response▿

    PubMed Central

    Tong, Kit I.; Padmanabhan, Balasundaram; Kobayashi, Akira; Shang, Chengwei; Hirotsu, Yosuke; Yokoyama, Shigeyuki; Yamamoto, Masayuki

    2007-01-01

    Nrf2 is the regulator of the oxidative/electrophilic stress response. Its turnover is maintained by Keap1-mediated proteasomal degradation via a two-site substrate recognition mechanism in which two Nrf2-Keap1 binding sites form a hinge and latch. The E3 ligase adaptor Keap1 recognizes Nrf2 through its conserved ETGE and DLG motifs. In this study, we examined how the ETGE and DLG motifs bind to Keap1 in a very similar fashion but with different binding affinities by comparing the crystal complex of a Keap1-DC domain-DLG peptide with that of a Keap1-DC domain-ETGE peptide. We found that these two motifs interact with the same basic surface of either Keap1-DC domain of the Keap1 homodimer. The DLG motif works to correctly position the lysines within the Nrf2 Neh2 domain for efficient ubiquitination. Together with the results from calorimetric and functional studies, we conclude that different electrostatic potentials primarily define the ETGE and DLG motifs as a hinge and latch that senses the oxidative/electrophilic stress. PMID:17785452

  9. The design and development of a miniature bi-stable latching solenoid valve for low thrust resistojets

    NASA Technical Reports Server (NTRS)

    Lynch, R. A.

    1972-01-01

    The design approach and development demonstration are presented for a flightweight, miniature, magnetic latching shutoff valve, suitable for use with the ruggedized H2 and NH3 resistojet and the biowaste resistojet. The design criteria established provided for compatibility with specified ruggedized resistojet propellants as well as the biowaste and other propulsion system propellants.

  10. Screening of nanosatellite microprocessors using californium single-event latch-up test results

    NASA Astrophysics Data System (ADS)

    Tomioka, Takahiro; Okumura, Yuta; Masui, Hirokazu; Takamiya, Koichi; Cho, Mengu

    2016-09-01

    A single-event latch-up (SEL) test using a 252Cf radioisotope was carried out. The results were compared with those of a proton test and from observation in orbit. A radioisotope can reproduce phenomena observed in orbit that are caused by protons. Considering the inexpensive nature of the 252Cf test, it is more suitable for nanosatellites that require low cost and fast delivery. A SEL occurrence rate of a commercial-off-the-shelf microprocessor was derived from the ground test results. The 252Cf test provided a SEL rate approximately 1×106 times greater than that in orbit. This data can be used to derive the minimum SEL occurrence rate in orbit and help satellite designers to evaluate the risk of SEL and take measures if necessary.

  11. Design and analysis of a novel latch system implementing fiber-reinforced composite materials

    NASA Astrophysics Data System (ADS)

    Guevara Arreola, Francisco Javier

    The use of fiber-reinforced composite materials have increased in the last four decades in high technology applications due to their exceptional mechanical properties and low weight. In the automotive industry carbon fiber have become popular exclusively in luxury cars because of its high cost. However, Carbon-glass hybrid composites offer an effective alternative to designers to implement fiber-reinforced composites into several conventional applications without a considerable price increase maintaining most of their mechanical properties. A door latch system is a complex mechanism that is under high loading conditions during car accidents such as side impacts and rollovers. Therefore, the Department of Transportation in The United States developed a series of tests that every door latch system comply in order to be installed in a vehicle. The implementation of fiber-reinforced composite materials in a door latch system was studied by analyzing the material behavior during the FMVSS No. 206 transverse test using computational efforts and experimental testing. Firstly, a computational model of the current forkbolt and detent structure was developed. Several efforts were conducted in order to create an effective and time efficient model. Two simplified models were implemented with two different contact interaction approaches. 9 composite materials were studied in forkbolt and 5 in detent including woven carbon fiber, unidirectional carbon fiber, woven carbon-glass fiber hybrid composites and unidirectional carbon-glass fiber hybrid composites. The computational model results showed that woven fiber-reinforced composite materials were stiffer than the unidirectional fiber-reinforced composite materials. For instance, a forkbolt made of woven carbon fibers was 20% stiffer than a forkbolt made of unidirectional fibers symmetrically stacked in 0° and 90° alternating directions. Furthermore, Hybrid composite materials behaved as expected in forkbolt noticing a decline

  12. Polarization encoded all-optical quaternary R-S flip-flop using binary latch

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay; Roy, Jitendra Nath; Chakraborty, Ajoy Kumar

    2009-04-01

    The developments of different multi-valued logic (MVL) systems have received considerable interests in recent years all over the world. In electronics, efforts have already been made to incorporate multi-valued system in logic and arithmetic data processing. But, very little efforts have been given in realization of MVL with optics. In this paper we present novel designs of certain all-optical circuits that can be used for realizing multi-valued logic functions. Polarization encoded all-optical quaternary (4-valued) R-S flip-flop is proposed and described. Two key circuits (all-optical encoder/decoder and a binary latch) are designed first. They are used to realize quaternary flip-flop in all-optical domain. Here the different quaternary logical states are represented by different polarized state of light. Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch can take an important role. Computer simulation result confirming described methods and conclusion are given in this paper.

  13. Water/Ice Heat Sink With Quick-Connect Couplings

    NASA Technical Reports Server (NTRS)

    Lomax, Curtis; Webbon, Bruce

    1996-01-01

    Report presents additional detailed information on apparatus described in "Direct-Interface, Fusible Heat Sink" (ARC-11920). Describes entire apparatus, with special emphasis on features of quick-disconnect couplings governing flow of water under various operating conditions and plumbing configuration.

  14. Quick-Connect/Disconnect Joint For Truss Structures

    NASA Technical Reports Server (NTRS)

    Sprague, Benny B.

    1991-01-01

    Simple connector used for temporary structures and pipes. Truss connector joins and aligns structural members. Consists of two sections, one flanged and other with mating internal groove. When flanged half inserted in groove, moves lever of trigger mechanism upward. Cone then shoots into grooved half. Attached without tools in less than 2 seconds and taken apart just as quickly and easily. Developed for assembling structures in outer space, also useful for temporary terrestrial structures like scaffolds and portable bleachers. With modifications, used to join sections of pipelines carrying liquids or gases.

  15. Psychometric Evaluation of 5- and 4-Item Versions of the LATCH Breastfeeding Assessment Tool during the Initial Postpartum Period among a Multiethnic Population

    PubMed Central

    Htun, Tha Pyai; Lim, Peng Im; Ho-Lim, Sarah

    2016-01-01

    Objectives The aim of this study was to evaluate the internal consistency, structural validity, sensitivity and specificity of the 5- and 4-item versions of the LATCH assessment tool among a multiethnic population in Singapore. Methods The study was a secondary analysis of a subset of data (n = 907) from our previous breastfeeding survey from 2013 to 2014. The internal consistency of the LATCH was examined using Cronbach’s alpha. The structural validity was assessed using an exploratory factor analysis (EFA), and the proposed factors were confirmed by confirmatory factor analysis (CFA) using separate samples. Receiver operating characteristic analysis was used to evaluate the sensitivity and specificity of the LATCH score thresholds for predicting non-exclusive breastfeeding. Results The Cronbach’s alpha values of the 5- and 4-item LATCH assessments were 0.70 and 0.74, respectively. The EFA demonstrated a one-factor structure for the 5- and 4-item LATCH assessments among a randomized split of 334 vaginally delivered women. Two CFA of the 4-item LATCH demonstrated better fit indices of the models compared to the two CFA of the 5-item LATCH among another randomized split of 335 vaginally delivered women and 238 cesarean delivered women. Using cutoffs of 5.5 and 3.5 were recommended when predicting non-exclusive breastfeeding for 5- and 4-item versions of the LATCH assessment among vaginally delivered women (n = 669), with satisfactory sensitivities (94% and 95%), low specificities (0% and 2%), low positive predictive values (25%) and negative predictive values (20% and 47%). A cutoff of 5.5 was recommended to predict non-exclusive breastfeeding for 5- and 4-item versions among cesarean delivered women (n = 238) with satisfactory sensitivities (93% and 98%), low specificities (4% and 9%), low positive predictive values (41%) and negative predictive values (65% and 75%). Therefore, the tool has good sensitivity but poor specificity, positive and negative predictive

  16. Breaking The Enzymatic Latch: Do Anaerobic Conditions Constrain Decomposition In Humid Tropical Forest Soil?

    NASA Astrophysics Data System (ADS)

    Hall, S. J.; Silver, W. L.

    2011-12-01

    Anaerobic conditions have been proposed to impose a "latch" on soil organic matter decomposition by inhibiting the activity of extracellular enzymes that catalyze the transformation of organic polymers into monomers for microbial assimilation. Here, we tested the hypothesis that anaerobiosis inhibits soil hydrolytic enzyme activity in a humid tropical forest ecosystem in Puerto Rico. We sampled surface and sub-surface soil from each of 59 plots (n = 118) stratified across distinct topographical zones (ridges, slopes, and valleys) known to vary in soil oxygen (O2) concentrations, and measured the potential activity of five hydrolytic enzymes that decompose carbon (C), nitrogen (N), and phosphorus (P) substrates. We measured reduced iron (Fe (II)) concentrations in soil extractions to provide a spatially and temporally integrated index of anaerobic microbial activity, since iron oxides constitute the dominant anaerobic terminal electron acceptor in this ecosystem. Surprisingly, we observed positive relationships between Fe (II) concentrations and the activity of all enzymes that we assayed. Linear mixed effects models that included Fe (II) concentration, topographic position, and their interaction explained between 30 to 70 % of the variance of enzyme activity of β-1,4-glucosidase, β-cellobiohydrolase, β-xylosidase, N-acetylglucosaminidase, and acid phosphatase. Soils from ridges and slopes contained between 10 and 800 μg Fe (II) g-1 soil, and exhibited consistently positive relationships (p < 0.0001) between Fe (II) and enzyme activity. Valley soils did not display significant relationships between enzyme activity and Fe (II), although they displayed variation in soil Fe (II) concentrations similar to ridges and slopes. Overall, valleys exhibited lower enzyme activity and lower Fe (II) concentrations than ridges or slopes, possibly related to decreased root biomass and soil C. Our data provide no indication that anaerobiosis suppresses soil enzyme activity, but

  17. Incorporating Peatland Plant Communities into the Enzymic 'Latch' Hypothesis: Can Vegetation Influence Carbon Storage Mechanisms?

    NASA Astrophysics Data System (ADS)

    Romanowicz, K. J.; Daniels, A. L.; Potvin, L. R.; Kane, E. S.; Kolka, R. K.; Chimner, R. A.; Lilleskov, E. A.

    2012-12-01

    High water table conditions in peatland ecosystems are known to favor plant production over decomposition and carbon is stored. Dominant plant communities change in response to water table but little is know of how these changes affect belowground carbon storage. One hypothesis known as the enzymic 'latch' proposed by Freeman et al. suggests that oxygen limitations due to high water table conditions inhibit microorganisms from synthesizing specific extracellular enzymes essential for carbon and nutrient mineralization, allowing carbon to be stored as decomposition is reduced. Yet, this hypothesis excludes plant community interactions on carbon storage. We hypothesize that the dominant vascular plant communities, sedges and ericaceous shrubs, will have inherently different effects on peatland carbon storage, especially in response to declines in water table. Sedges greatly increase in abundance following water table decline and create extensive carbon oxidation and mineralization hotspots through the production of deep roots with aerenchyma (air channels in roots). Increased oxidation may enhance aerobic microbial activity including increased enzyme activity, leading to peat subsidence and carbon loss. In contrast, ericaceous shrubs utilize enzymatically active ericoid mycorrhizal fungi that suppress free-living heterotrophs, promoting decreased carbon mineralization by mediating changes in rhizosphere microbial communities and enzyme activity regardless of water table declines. Beginning May 2010, bog monoliths were harvested, housed in mesocosm chambers, and manipulated into three vegetation treatments: unmanipulated (+sedge, +Ericaceae), sedge (+sedge, -Ericaceae), and Ericaceae (-sedge, +Ericaceae). Following vegetation manipulations, two distinct water table manipulations targeting water table seasonal profiles were implemented: (low intra-seasonal variability, higher mean water table; high intra-seasonal variability, lower mean water table). In 2012, peat

  18. Teaching home safety and survival skills to latch-key children: a comparison of two manuals and methods.

    PubMed Central

    Peterson, L

    1984-01-01

    I evaluated the influence of two training manuals on latch-key children's acquisition of home safety and survival skills. The widely used, discussion-oriented "Prepared for Today" manual was compared with a behaviorally oriented "Safe at Home" manual. Data were scored by response criteria developed by experts and by parents' and experts' ratings of children's spontaneous answers. With both methods of scoring, three behaviorally trained children demonstrated clear and abrupt increases in skill following training in each of seven trained modules, and these increases largely persisted in real world generalization probes and at 5-month follow-up. Smaller and less stable increases in skill were found in the three discussion-trained children across the seven modules; lower skill levels were also seen in real world generalization probes and at follow-up. Neither group of children demonstrated skill increases in home safety areas that were not explicitly trained. Both training methods produced small decreases in children's self-report of general anxiety and anxiety concerning home safety. Results are discussed in terms of their implications for cost-effective training of latch-key children. PMID:6511698

  19. Latch-up signature analysis technique for plastic dual-in-line package (PDIP) devices using scanning acoustic microscopy

    SciTech Connect

    Mahanpour, M.; Morgan, I.; Li, S.; Kaufmann, M.

    1995-12-31

    Cracks in the top surface of plastic package product (PDIP), as shown in a figure, resulting from Latch-Up (LU), DC Vcc Over-Voltage, or Reverse Insertion in the socket are usually similar in appearance. A scanning acoustic microscope can not determine the root cause of this Electrical Over-Stress (EOS) damage since all of the above show similar delamination. Even after device decapsulation, carbonized epoxy around Vcc and Vss bond wires doesn`t always indicate the exact root cause of failure. However, a nondestructive technique has been developed to distinguish (LU) from other EOS failures using a Scanning Acoustic Microscope (SAM). Finally, to verify the validity of the results, a computer analysis using a 3-Dimensional Finite Element Model (FEM) was used. The calculated stress distribution in the plastic IC package in the sustained LU condition agreed with the observations of delamination using SAM on product subjected to Transient Latch-Up (TLU) simulation on the power supply pin.

  20. Integrating the automatic and the controlled: strategies in semantic priming in an attractor network with latching dynamics.

    PubMed

    Lerner, Itamar; Bentin, Shlomo; Shriki, Oren

    2014-01-01

    Semantic priming has long been recognized to reflect, along with automatic semantic mechanisms, the contribution of controlled strategies. However, previous theories of controlled priming were mostly qualitative, lacking common grounds with modern mathematical models of automatic priming based on neural networks. Recently, we introduced a novel attractor network model of automatic semantic priming with latching dynamics. Here, we extend this work to show how the same model can also account for important findings regarding controlled processes. Assuming the rate of semantic transitions in the network can be adapted using simple reinforcement learning, we show how basic findings attributed to controlled processes in priming can be achieved, including their dependency on stimulus onset asynchrony and relatedness proportion and their unique effect on associative, category-exemplar, mediated and backward prime-target relations. We discuss how our mechanism relates to the classic expectancy theory and how it can be further extended in future developments of the model.

  1. Trend of tunnel magnetoresistance and variation in threshold voltage for keeping data load robustness of metal–oxide–semiconductor/magnetic tunnel junction hybrid latches

    SciTech Connect

    Ohsawa, T.; Ikeda, S.; Hanyu, T.; Ohno, H.; Endoh, T.

    2014-05-07

    The robustness of data load of metal–oxide–semiconductor/magnetic tunnel junction (MOS/MTJ) hybrid latches at power-on is examined by using Monte Carlo simulation with the variations in magnetoresistances for MTJs and in threshold voltages for MOSFETs involved in 90 nm technology node. Three differential pair type spin-transfer-torque-magnetic random access memory cells (4T2MTJ, 6T2MTJ, and 8T2MTJ) are compared for their successful data load at power-on. It is found that the 4T2MTJ cell has the largest pass area in the shmoo plot in TMR ratio (tunnel magnetoresistance ratio) and V{sub dd} in which a whole 256 kb cell array can be powered-on successfully. The minimum TMR ratio for the 4T2MTJ in 0.9 V < V{sub dd} < 1.9 V is 140%, while the 6T2MTJ and the 8T2MTJ cells require TMR ratio larger than 170%.

  2. Low field driven latching-type Bi3Fe5O12/Gd3Ga5O12 magneto-optical display

    NASA Astrophysics Data System (ADS)

    Grishin, A. M.; Khartsev, S. I.; Bonetti, S.

    2006-06-01

    Series of heteroepitaxial all-garnet magneto-optical (MO) Bi3Fe5O12n/Gd3Ga5O12m (BIGn/GGGm, n =1, 2, 3, 4, 5 and m =1 and 2 are the numbers of unit cells) nanostructured multilayers have been sintered by pulsed laser deposition technique. Processing parameters and structure of grown films have been optimized to obtain perpendicular magnetic anisotropy and square hysteresis loop with low coercive and saturation magnetic fields. Regular alternating of lattice mismatched BIG and GGG atomic layers inhibited nucleation of misfit dislocations; thus a long range coherent compressive strain was preserved through the whole thickness of BIGn/GGGm multilayer stack. 2.5μm thick BIG3/GGG2 sample (1200 BIG and 800 GGG unit cells) at λ =678nm shows MO Faraday rotation ΘF=±1.4°, transmittance of 82%, attenuation α =3400dB/cm, squareness of magnetization loop (remnant-to-saturation magnetizations ratio) as high as 92%, and saturation and coercive fields as low as 56 and 25Oe, respectively. MO remanence (latching capability) enables application of nanostructured garnet as a magnetic relief replicator/visualizer and as a material for low power consuming displays.

  3. Wide-Grasp Latching Mechanism

    NASA Technical Reports Server (NTRS)

    Nesmith, M. F.

    1985-01-01

    Fingers capture and clamp without accurate positioning. Fully open position, fingers encompass large envelope. When activated by rack and pinion, fingertips move together, thereby grasping object within envelope.

  4. Helmet latching and attaching ring

    NASA Technical Reports Server (NTRS)

    Chase, E. W.; Viikinsalo, S. J. (Inventor)

    1970-01-01

    A neck ring releasably secured to a pressurized garment carries an open-ended ring normally in the engagement position fitted into an annular groove and adapted to fit into a complementary annular groove formed in a helmet. Camming means formed on the inner surface at the end of the helmet engages the open-ended ring to retract the same and allow for one motion donning even when the garment is pressurized. A projection on the end of the split ring is engageable to physically retract the split ring.

  5. Latch ring for connecting tubular member

    SciTech Connect

    Milberger, L.J.

    1991-06-04

    This patent describes a device for releasably locking an inner member well bore of a tubular outer member, comprising a combination of a grooved inner member profile formed on the exterior of the inner member; a grooved outer member profile formed in the bore of the outer member; a split ring carried by the inner member the ring having a grooved outer profile on its exterior mates with the outer member profile; and the inner member being axially movable.

  6. How can two soft bodied animals be precisely connected? a miniature quick-connect system in the slugs, Arion lusitanicus and Arion rufus.

    PubMed

    Allgaier, Christoph

    2015-06-01

    Among stylommatophoran gastropods, many species have simplified or reduced their copulatory organs, for example, within the Arionidae, many species lack penes. In this study, I ask two questions 1) How are soft bodied slugs which do not possess a penis connected during copulation? and 2) Is there a mechanical isolating barrier between related sympatric slug species? Observations on the mating behavior and the functional morphology of the distal genital apparatus were made in a mixed population of Arion lusitanicus and Arion rufus. The investigated Arion species exhibit an elaborate copulation process with a quick genital coupling. Prior to full eversion of the distal genitalia, the genital coupling proceeds inside the atrium cavity of one of the partners. This is in contrast to the symmetrical mutual eversion in penis-bearing species. The donor-recipient channels are tightly connected to one after another and fit precisely. During copulation, the jelly-coated spermatophore of the donor is pressed out into the connected channel of the partner, where it is implanted only with its frontal part. In the field, successful interspecific matings in terms of spermatophore transfer were rarely observed. The observations presented indicate a mechanical barrier which may profoundly influence the intraspecific and interspecific mating success. PMID:25532726

  7. Galileo and the Pendulum: Latching on to Time

    ERIC Educational Resources Information Center

    Machamer, Peter; Hepburn, Brian

    2004-01-01

    Galileo changed the very concepts or categories by which natural philosophy could deal with matter and motion. Central to these changes was his introduction of time as a fundamental concept. He worked with the pendulum and with the inclined plane to discover his new concept of motion. Both of these showed him that acceleration and time were…

  8. Oriented valve and latch for side pocket mandrel

    SciTech Connect

    Crawford, D.W.; Crawford, W.B.; Crawford, M.S.

    1991-10-22

    This patent describes a gas lift valve apparatus for use with a side pocket mandrel having a main bore, a seating bore laterally offset from said main bore, and a longitudinal slot formed in a wall of said mandrel between said man and seating bores. It comprises: a body section having guide means thereon adapted to enter said slot and maintain rotational orientation of said body section in a predetermined position, said body section having gas flow passage; and outlet prot means in said body section communicating with said passage and opening through an outer wall of said guide means, whereby lift gas emanating from said port means is directed only toward main bore of the mandrel.

  9. Flight Avionics Sequencing Telemetry (FAST) DIV Latching Display

    NASA Technical Reports Server (NTRS)

    Moore, Charlotte

    2010-01-01

    The NASA Engineering (NE) Directorate at Kennedy Space Center provides engineering services to major programs such as: Space Shuttle, Inter national Space Station, and the Launch Services Program (LSP). The Av ionics Division within NE, provides avionics and flight control syste ms engineering support to LSP. The Launch Services Program is respons ible for procuring safe and reliable services for transporting critical, one of a kind, NASA payloads into orbit. As a result, engineers mu st monitor critical flight events during countdown and launch to asse ss anomalous behavior or any unexpected occurrence. The goal of this project is to take a tailored Systems Engineering approach to design, develop, and test Iris telemetry displays. The Flight Avionics Sequen cing Telemetry Delta-IV (FAST-D4) displays will provide NASA with an improved flight event monitoring tool to evaluate launch vehicle heal th and performance during system-level ground testing and flight. Flight events monitored will include data from the Redundant Inertial Fli ght Control Assembly (RIFCA) flight computer and launch vehicle comma nd feedback data. When a flight event occurs, the flight event is ill uminated on the display. This will enable NASA Engineers to monitor c ritical flight events on the day of launch. Completion of this project requires rudimentary knowledge of launch vehicle Guidance, Navigatio n, and Control (GN&C) systems, telemetry, and console operation. Work locations for the project include the engineering office, NASA telem etry laboratory, and Delta launch sites.

  10. Femtojoule-Scale All-Optical Latching and Modulation via Cavity Nonlinear Optics

    NASA Astrophysics Data System (ADS)

    Kwon, Yeong-Dae; Armen, Michael A.; Mabuchi, Hideo

    2013-11-01

    We experimentally characterize Hopf bifurcation phenomena at femtojoule energy scales in a multiatom cavity quantum electrodynamical (cavity QED) system and demonstrate how such behaviors can be exploited in the design of all-optical memory and modulation devices. The data are analyzed by using a semiclassical model that explicitly treats heterogeneous coupling of atoms to the cavity mode. Our results highlight the interest of cavity QED systems for ultralow power photonic signal processing as well as for fundamental studies of mesoscopic nonlinear dynamics.

  11. Self-latching eccentric cam for dual stroke compressor or pump

    DOEpatents

    Sisk, Francis J.

    1985-01-01

    For a dual capacity refrigerant compressor of the type which has an eccentric cam rotatable on a crankpin between two opposite positions which changes the total eccentricity of the crankpin and cam so as to obtain two different stroke lengths, the rotation of the cam on the crankpin being effected by a reversal of motor operation, the cam moves through an angle of about 270.degree. around the crankpin so that a centrifugal force torque tending to hold the cam in place is available at least in the reduced stroke length position of the cam, and by providing lightening cavities and eccentric weightings, the center of mass 74 of the cam can be shifted to obtain the centrifugal torque in the proper direction at both the maximum and reduced stroke positions.

  12. Self-latching eccentric cam for dual stroke compressor or pump

    DOEpatents

    Sisk, F.J.

    1985-01-22

    For a dual capacity refrigerant compressor of the type which has an eccentric cam rotatable on a crankpin between two opposite positions which changes the total eccentricity of the crankpin and cam so as to obtain two different stroke lengths, the rotation of the cam on the crankpin being effected by a reversal of motor operation, the cam moves through an angle of about 270[degree] around the crankpin so that a centrifugal force torque tending to hold the cam in place is available at least in the reduced stroke length position of the cam, and by providing lightening cavities and eccentric weightings, the center of mass of the cam can be shifted to obtain the centrifugal torque in the proper direction at both the maximum and reduced stroke positions. 7 figs.

  13. Accentuate the Negative to Latch onto the Affirmative (How to Save Mockingbirds).

    ERIC Educational Resources Information Center

    Shallcross, Tony

    1995-01-01

    Outlines a simple values clarification technique which can be used to assess students' attitudes towards a controversial issue in order to facilitate group selection. Presents a case study that illustrates the use of the technique for group differentiation, summative evaluation, and research. Examines theoretical questions about how role play…

  14. Spreading Activation in an Attractor Network with Latching Dynamics: Automatic Semantic Priming Revisited

    ERIC Educational Resources Information Center

    Lerner, Itamar; Bentin, Shlomo; Shriki, Oren

    2012-01-01

    Localist models of spreading activation (SA) and models assuming distributed representations offer very different takes on semantic priming, a widely investigated paradigm in word recognition and semantic memory research. In this study, we implemented SA in an attractor neural network model with distributed representations and created a unified…

  15. The carboxyl terminus of the Galpha-subunit is the latch for triggered activation of heterotrimeric G proteins.

    PubMed

    Nanoff, Christian; Koppensteiner, Romana; Yang, Qiong; Fuerst, Elisabeth; Ahorn, Horst; Freissmuth, Michael

    2006-01-01

    The receptor-mimetic peptide D2N, derived from the cytoplasmic domain of the D(2) dopamine receptor, activates G protein alpha-subunits (G(i) and G(o)) directly. Using D2N, we tested the current hypotheses on the mechanism of receptor-mediated G protein activation, which differ by the role assigned to the Gbetagamma-subunit: 1) a receptor-prompted movement of Gbetagamma is needed to open up the nucleotide exit pathway ("gear-shift" and "lever-arm" model) or 2) the receptor first engages Gbetagamma and then triggers GDP release by interacting with the carboxyl (C) terminus of Galpha (the "sequential-fit" model). Our results with D2N were compatible with the latter hypothesis. D2N bound to the extreme C terminus of the alpha-subunit and caused a conformational change that was transmitted to the switch regions. Hence, D2N led to a decline in the intrinsic tryptophan fluorescence, increased the guanine nucleotide exchange rate, and modulated the Mg(2+) control of nucleotide binding. A structural alteration in the outer portion of helix alpha5 (substitution of an isoleucine by proline) blunted the stimulatory action of D2N. This confirms that helix alpha5 links the guanine nucleotide binding pocket to the receptor contact site on the G protein. However, neither the alpha-subunit amino terminus (as a lever-arm) nor Gbetagamma was required for D2N-mediated activation; conversely, assembly of the Galphabetagamma heterotrimer stabilized the GDP-bound species and required an increased D2N concentration for activation. We propose that the receptor can engage the C terminus of the alpha-subunit to destabilize nucleotide binding from the "back side" of the nucleotide binding pocket.

  16. Experimental investigation of the cornering of a C40 x 14-21 cantilever aircraft tire

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Tanner, J. A.

    1973-01-01

    An experimental investigation was conducted at the Langley aircraft landing loads and traction facility to define the cornering characteristics of a size C40 x14-21 aircraft tire of cantilever design. These characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained for the tire operating on dry, damp, and flooded runway surfaces over a range of yaw angles from 0 deg to 20 deg and at ground speeds of 5 to 100 knots, both with and without braking. The results of this investigation show that the cornering-force and drag-force friction coefficients and self-alining torque were influenced by the yaw angle, ground speed, brake torque, surface wetness, and the locked-wheel condition.

  17. Low-Speed Yawed-Rolling Characteristics of a Pair of 56-Inch-Diameter, 32-Ply-Rating, Type 7 Aircraft Tires

    NASA Technical Reports Server (NTRS)

    Thompson, Wilbur E.; Horne, Walter B.

    1959-01-01

    The low-speed (up to 4 miles per hour) yawed-rolling characteristics of two 56 x 16 32-ply-rating, type 7 aircraft tires under straight-yawed rolling were determined over a range of inflation pressures and yaw angles for a vertical load approximately equal to 75 percent of the rated vertical load. The quantities measured or determined included cornering force, drag force self-alining torque, pneumatic caster vertical tire deflection, yaw angle, and relaxation length. During straight-yawed rolling the normal force generally increased with increasing yaw angle within the test range. The self-alining torque increased to a maximum value and then decreased with increasing angle of yaw. The pneumatic caster tended to decrease with increasing yaw angle.

  18. Voltage-sensor transitions of the inward-rectifying K+ channel KAT1 indicate a latching mechanism biased by hydration within the voltage sensor.

    PubMed

    Lefoulon, Cécile; Karnik, Rucha; Honsbein, Annegret; Gutla, Paul Vijay; Grefen, Christopher; Riedelsberger, Janin; Poblete, Tomás; Dreyer, Ingo; Gonzalez, Wendy; Blatt, Michael R

    2014-10-01

    The Kv-like (potassium voltage-dependent) K(+) channels at the plasma membrane, including the inward-rectifying KAT1 K(+) channel of Arabidopsis (Arabidopsis thaliana), are important targets for manipulating K(+) homeostasis in plants. Gating modification, especially, has been identified as a promising means by which to engineer plants with improved characteristics in mineral and water use. Understanding plant K(+) channel gating poses several challenges, despite many similarities to that of mammalian Kv and Shaker channel models. We have used site-directed mutagenesis to explore residues that are thought to form two electrostatic countercharge centers on either side of a conserved phenylalanine (Phe) residue within the S2 and S3 α-helices of the voltage sensor domain (VSD) of Kv channels. Consistent with molecular dynamic simulations of KAT1, we show that the voltage dependence of the channel gate is highly sensitive to manipulations affecting these residues. Mutations of the central Phe residue favored the closed KAT1 channel, whereas mutations affecting the countercharge centers favored the open channel. Modeling of the macroscopic current kinetics also highlighted a substantial difference between the two sets of mutations. We interpret these findings in the context of the effects on hydration of amino acid residues within the VSD and with an inherent bias of the VSD, when hydrated around a central Phe residue, to the closed state of the channel. PMID:25185120

  19. Voltage-sensor transitions of the inward-rectifying K+ channel KAT1 indicate a latching mechanism biased by hydration within the voltage sensor.

    PubMed

    Lefoulon, Cécile; Karnik, Rucha; Honsbein, Annegret; Gutla, Paul Vijay; Grefen, Christopher; Riedelsberger, Janin; Poblete, Tomás; Dreyer, Ingo; Gonzalez, Wendy; Blatt, Michael R

    2014-10-01

    The Kv-like (potassium voltage-dependent) K(+) channels at the plasma membrane, including the inward-rectifying KAT1 K(+) channel of Arabidopsis (Arabidopsis thaliana), are important targets for manipulating K(+) homeostasis in plants. Gating modification, especially, has been identified as a promising means by which to engineer plants with improved characteristics in mineral and water use. Understanding plant K(+) channel gating poses several challenges, despite many similarities to that of mammalian Kv and Shaker channel models. We have used site-directed mutagenesis to explore residues that are thought to form two electrostatic countercharge centers on either side of a conserved phenylalanine (Phe) residue within the S2 and S3 α-helices of the voltage sensor domain (VSD) of Kv channels. Consistent with molecular dynamic simulations of KAT1, we show that the voltage dependence of the channel gate is highly sensitive to manipulations affecting these residues. Mutations of the central Phe residue favored the closed KAT1 channel, whereas mutations affecting the countercharge centers favored the open channel. Modeling of the macroscopic current kinetics also highlighted a substantial difference between the two sets of mutations. We interpret these findings in the context of the effects on hydration of amino acid residues within the VSD and with an inherent bias of the VSD, when hydrated around a central Phe residue, to the closed state of the channel.

  20. Voltage-Sensor Transitions of the Inward-Rectifying K+ Channel KAT1 Indicate a Latching Mechanism Biased by Hydration within the Voltage Sensor1[W][OPEN

    PubMed Central

    Lefoulon, Cécile; Karnik, Rucha; Honsbein, Annegret; Gutla, Paul Vijay; Grefen, Christopher; Riedelsberger, Janin; Poblete, Tomás; Dreyer, Ingo; Gonzalez, Wendy; Blatt, Michael R.

    2014-01-01

    The Kv-like (potassium voltage-dependent) K+ channels at the plasma membrane, including the inward-rectifying KAT1 K+ channel of Arabidopsis (Arabidopsis thaliana), are important targets for manipulating K+ homeostasis in plants. Gating modification, especially, has been identified as a promising means by which to engineer plants with improved characteristics in mineral and water use. Understanding plant K+ channel gating poses several challenges, despite many similarities to that of mammalian Kv and Shaker channel models. We have used site-directed mutagenesis to explore residues that are thought to form two electrostatic countercharge centers on either side of a conserved phenylalanine (Phe) residue within the S2 and S3 α-helices of the voltage sensor domain (VSD) of Kv channels. Consistent with molecular dynamic simulations of KAT1, we show that the voltage dependence of the channel gate is highly sensitive to manipulations affecting these residues. Mutations of the central Phe residue favored the closed KAT1 channel, whereas mutations affecting the countercharge centers favored the open channel. Modeling of the macroscopic current kinetics also highlighted a substantial difference between the two sets of mutations. We interpret these findings in the context of the effects on hydration of amino acid residues within the VSD and with an inherent bias of the VSD, when hydrated around a central Phe residue, to the closed state of the channel. PMID:25185120

  1. 77 FR 18137 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will...), latch pin migration, and broken latch pin fittings. This proposed AD would require various repetitive... cargo door latch mechanism and/or the lower sill structure. The migration of two or more latch pins...

  2. High Speed Edge Detection

    NASA Technical Reports Server (NTRS)

    Prokop, Norman F (Inventor)

    2015-01-01

    Analog circuits for detecting edges in pixel arrays are disclosed. A comparator may be configured to receive an all pass signal and a low pass signal for a pixel intensity in an array of pixels. A latch may be configured to receive a counter signal and a latching signal from the comparator. The comparator may be configured to send the latching signal to the latch when the all pass signal is below the low pass signal minus an offset. The latch may be configured to hold a last negative edge location when the latching signal is received from the comparator.

  3. High Speed Edge Detection

    NASA Technical Reports Server (NTRS)

    Prokop, Norman F (Inventor)

    2016-01-01

    Analog circuits for detecting edges in pixel arrays are disclosed. A comparator may be configured to receive an all pass signal and a low pass signal for a pixel intensity in an array of pixels. A latch may be configured to receive a counter signal and a latching signal from the comparator. The comparator may be configured to send the latching signal to the latch when the all pass signal is below the low pass signal minus an offset. The latch may be configured to hold a last negative edge location when the latching signal is received from the comparator.

  4. 78 FR 21576 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ...-200, 757-200CB, and 757-200PF airplanes. This proposed AD was prompted by a report that a forward- most cam latch of the forward center cam latch pair on a main cargo door (MCD) broke during flight... proposed AD. Discussion We received a report that the forward-most cam latch on the forward center...

  5. 49 CFR 571.206 - Standard No. 206; Door locks and door retention components.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Warning System is a system that will activate a visual signal when a door latch system is not in its fully... door must be linked to an alarm system consisting of either a flashing visible signal located in the... latched position, with or without a secondary latched position, and fitted to a door or door...

  6. 78 FR 9346 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will... slides installed on airplane doors were not fully closed. The current latch design uses friction to keep the latch hook closed. Corrosion and worn parts reduce friction between the parts of the latch...

  7. 75 FR 34956 - Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... AD would require a one-time inspection of the flap operating system for an unauthorized latch plate design installation. This proposed AD results from a report of a latch plate failing in service that was.... Discussion We have received a report of a latch plate supplied under part number (P/N) C1-CF-1489 failing...

  8. 49 CFR 571.206 - Standard No. 206; Door locks and door retention components.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... doors. Double Door is a system of two doors where the front door or wing door opens first and connects... hinge panels that swing, slide, or rotate; does not have a striker and latch assembly. Fork-bolt is the part of the latch that engages and retains the striker when in a latched position. Fork-bolt...

  9. 49 CFR 571.206 - Standard No. 206; Door locks and door retention components.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... doors. Double Door is a system of two doors where the front door or wing door opens first and connects... hinge panels that swing, slide, or rotate; does not have a striker and latch assembly. Fork-bolt is the part of the latch that engages and retains the striker when in a latched position. Fork-bolt...

  10. 49 CFR 571.206 - Standard No. 206; Door locks and door retention components.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... doors. Double Door is a system of two doors where the front door or wing door opens first and connects... hinge panels that swing, slide, or rotate; does not have a striker and latch assembly. Fork-bolt is the part of the latch that engages and retains the striker when in a latched position. Fork-bolt...

  11. 49 CFR 571.206 - Standard No. 206; Door locks and door retention components.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... doors. Double Door is a system of two doors where the front door or wing door opens first and connects... hinge panels that swing, slide, or rotate; does not have a striker and latch assembly. Fork-bolt is the part of the latch that engages and retains the striker when in a latched position. Fork-bolt...

  12. Synchronous semiconductor memory device

    SciTech Connect

    Onno, C.; Hirata, M.

    1989-11-21

    This patent describes a synchronous semiconductor memory device. It comprises: first latch means for latching a write command in synchronism with clock signal; second latch means for latching a write data in synchronism with the clock signal and for outputting two write process signals based on the write data latched thereby; pulse generating means for generating an internal write pulse signal based on the write command latched by the first latch means. The internal write pulse signal having a semiconductor memory device; write control means supplied with the internal write pulse signal and the write process signals for controlling write and read operations of the synchronous semiconductor memory device; memory means for storing the write data latched by the second latch means; and noise preventing means coupled to the second latch means and the write control means for supplying the write process signals to the write control means only in the write mode responsive to the internal write pulse signal and for setting the write process signals to fixed potentials during a time other than the write mode.

  13. Two fault tolerant toggle-hook release

    NASA Technical Reports Server (NTRS)

    Graves, Thomas Joseph (Inventor); Brown, Christopher William (Inventor)

    1991-01-01

    A coupling device is disclosed which is mechanically two fault tolerant for release. The device comprises a fastener plate and fastener body, each of which is attachable to a different one of a pair of structures to be joined. The fastener plate and body are coupled by an elongate toggle mounted at one end in a socket on the fastener plate for universal pivotal movement thereon. The other end of the toggle is received in an opening in the fastener body and adapted for limited pivotal movement therein. The toggle is adapted to be restrained by three latch hooks arranged in symmetrical equiangular spacing about the axis of the toggle, each hook being mounted on the fastener body for pivotal movement between an unlatching non-contact position with respect to the toggle and a latching position in engagement with a latching surface of the toggle. The device includes releasable lock means for locking each latch hook in its latching position whereby the toggle couples the fastener plate to the fastener body and means for releasing the lock means to unlock each said latch hook from the latch position whereby the unlocking of at least one of the latch hooks from its latching position results in the decoupling of the fastener plate from the fastener body.

  14. The 23rd Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Technological areas covered include space lubrication, bearings, aerodynamic devices, spacecraft latches, deployment, positioning, and pointing. Devices for Space Station docking and manipulator and teleoperator mechanisms are also described.

  15. Tendon bottom connector for a tension leg platform

    SciTech Connect

    Kipp, R.M.

    1991-04-02

    This patent describes a floating tension-leg platform having anchoring tendons extending from the platform with the lower ends of the tendons being connected in tension to anchor means fixedly secured to the ocean floor in deep water, the connection being made by underwater-actuatable and remotely-connectable and releasable tendon connector means. It includes first and second connector portions a first inwardly-directed camming surface; a circumferential latching groove; a latching shoulder; a second camming surface; a latching sleeve; collet spring fingers; and outwardly-extending latches.

  16. Orbiter door closure tools

    NASA Technical Reports Server (NTRS)

    Acres, W. R.

    1980-01-01

    Safe reentry of the shuttle orbiter requires that the payload bay doors be closed and securely latched. Since a malfunction in the door drive or bulkhead latch systems could make safe reentry impossible, the requirement to provide tools to manually close and secure the doors was implemented. The tools would disconnect a disabled door or latch closure system and close and secure the doors if the normal system failed. The tools required to perform these tasks have evolved into a set that consists of a tubing cutter, a winch, a latching tool, and a bolt extractor. The design, fabrication, and performance tests of each tool are described.

  17. Cornering characteristics of a 40 by 14-16 type 7 aircraft tire and a comparison with characteristics of a C40 by 14-21 cantilever aircraft tire

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.; Dreher, R. C.

    1973-01-01

    An investigation was conducted at the Langley aircraft landing loads and traction facility to determine the cornering characteristics of a 40 x 14-16 type VII aircraft tire. These characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained for the tire operating on dry, damp and flooded runway surfaces over a range of yaw angles from 0 deg to 20 deg and at ground speeds from 5 to 100 knots, both with and without braking. The results of this investigation indicated that the cornering capability of the 40 x 14-16 type VII aircraft tire is degraded by high ground speeds, thin-film lubrication and tire hydroplaning effects on the wet surfaces, and brake torque. The cornering capability is greatly diminished when locked-wheel skids are encountered.

  18. A Faster Fastener

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A licensing agreement between Marshall Space Flight Center and M&A Screw and Machineworks has brought the quick connect nut to the commerical market. Originally designed as part of a project seeking in-space assembly techniques, the quick connect nut is secured around a bolt merely by pushing it onto the bolt and giving it a single twist. Applications for the nuts include oil drilling platforms, mining industry, and other practices that rely on speedy assembly for success.

  19. Photocopy of drawing. ALTITUDE CHAMBERS “L” & “R” STRUCTURES. NASA, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing. ALTITUDE CHAMBERS “L” & “R” STRUCTURES. NASA, John F. Kennedy Space Center, Florida. Drawing 68-K-L-11213, NASA KSC, March, 1971. DOOR LATCH MECHANISM & DOOR LATCHING RATCHET. Sheet 14 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  20. Extra-safe tractor-trailer coupling

    NASA Technical Reports Server (NTRS)

    Albrecht, W. P.; Sparks, R. H.

    1979-01-01

    Built-in safety mechanism for tractor-trailer "fifth-wheel" coupling keeps rig together in case kingpin failure. Modified coupling utilizes all standard components, such as two wear plates, kingpin, and kingpin latch. It is modified by adding semicircular lip to top wear plate, matching semicircular slot to bottom wear plate, and two latching stop mechanisms.

  1. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  2. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  3. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  4. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  5. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  6. Contact dynamics testing of automated three-point docking mechanism

    NASA Astrophysics Data System (ADS)

    Rourke, Kenneth H.

    An evaluation of an OMV docking mechanism, based on an adaptation of the Shuttle Flight Support System Pallet Berthing Mechanism was completed. The mechanism uses automatically actuated motorized latches to engage towel bars on the target satellite. LED sensors establish the towel bar position within the capture envelope and the latch capture commands are issued. Then, locking pawls engage the bar, locking and pre-loading the mechanism. Two series of tests were conducted to test nominal and failure mode captures and to evaluate design parameters such as LED sensor locations, automatic closure algorithms, latch closure velocity, position/velocity entry envelopes, and closure method. The first test series involved single latch testing on the Flat Floor Facility, the 6 DOF Facility, and an analytic simulation model. The intent was to compare results in order to validate the various facilities. Reasonably good agreement was achieved. The second test series repeated the single latch testing on the refurbished 6 DOF Facility to validate the facility modifications. The individual latches were tested under free-drift conditions for functionality and performance. Next, the three-latch configuration underwent parametric testing. Test results validated the improved fidelity of the 6 DOF Facility and verified successful docking at the required entry velocity. The tests determined the 'best' design parameter definitions and concluded that the locking pawls should not lock until all three latches completely close.

  7. 77 FR 6522 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... 12866, (2) Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... inspections for fractured or missing latch pin retention bolts, replacement of existing titanium bolts with... titanium with new Inconel bolts; replacing the latch pin fitting assembly; repairing the lower sill of...

  8. 40 CFR 86.117-96 - Evaporative emission enclosure calibrations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: (1) Prepare the enclosure. (i) Variable-volume enclosures may be operated in either latched or... hours before the 4-hour background sampling period begins. (3) Zero and span (calibrate if required) the.... For variable-volume enclosures, latch the enclosure to a fixed volume when the enclosure is held at...

  9. 75 FR 53861 - Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ... inspection of the flap operating system for an unapproved latch plate design installation, with replacement as necessary. This AD results from a report of a latch plate failing in service that was not made in... June 21, 2010 (75 FR 34956). The NPRM proposed to require a one-time inspection of the flap...

  10. 14 CFR 25.783 - Fuselage doors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... pressurized flight, no single failure in the locking system would prevent the locks from restraining the... with a single failure of the latching mechanism. (5) It must not be possible to position the lock in... must not be possible to unlatch the latches with the locks in the locked position. Locks must...

  11. 14 CFR 25.783 - Fuselage doors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pressurized flight, no single failure in the locking system would prevent the locks from restraining the... with a single failure of the latching mechanism. (5) It must not be possible to position the lock in... must not be possible to unlatch the latches with the locks in the locked position. Locks must...

  12. Push-To-Lock, Push-To-Release Mechanism

    NASA Technical Reports Server (NTRS)

    Lozano, Anselmo, Jr.

    1991-01-01

    Latch locked or unlocked with single motion of hand. No tools needed to operate it, and user easily opens or closes it with heavily gloved hand. When unlocked, stem free of main body. In locked state, dowel pins in main body hold stem. Latch equipped with lock and key so only authorized users operate it.

  13. 77 FR 56701 - Morgan Olson, LLC, Denial of Petition for Decision of Inconsequential Noncompliance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ... drivers, and that a trained commercial driver, such as one driving ] a walk-in van manufactured by Morgan... public comment period, on March 29, 2012, in the Federal Register (77 FR 19055). No comments were... equipped with either: (a) At least one primary door latch system, or (b) a door latch system with a...

  14. R AND D 100 EARLYBIRD AWARD ENTRY

    SciTech Connect

    Dugan, J; Debbie Chapman, D

    2007-01-30

    The Smart Latch{trademark} is an electronically enhanced door lockset device for industrial and consumer applications, which uses existing neural network technology to analyze the sequence, timing, and acoustic signatures associated with lockset functions and provides immediate indication of failure to correctly lock and latch. It essentially ''listens'' to and learns the sequences and acoustic signatures associated with lockset function and latching. When triggered by specific door activity the Smart Latch{trademark} begins analyzing sequences, frequencies and other parameters. With a satisfactory outcome the device provides positive feedback (e.g. visual and/or audible) and returns to a ''sleep'' state awaiting the next activity. If any part of the normal door operation, including latching and length of time, are incorrect various alarm signals can be generated. With electronics and 5+ year battery integrated, the device is simple to install and transparent to the user. Because the device uses proven voice recognition algorithms, it could meet or exceed the performance of the human ear in detecting the unique and complex acoustic signature associated with a properly operating and secured door. Unlike existing technologies, such as limit switches, it is not easily spoofed or defeated and has a high level of immunity to interference. The Smart Latch{trademark} technology can be integrated into existing lockset and door hardware designs, including both low price consumer products and high end electronic/cipher locks. The concept and design are based on a simple security industry adage: ''It isn't locked if it isn't latched''. Even the most elaborate and robust security barriers are of little use if the locking and latching mechanisms are not properly functioning and engaged. Smart Latch{trademark} provides automatic verification of the first and most important step in facility security: Close and properly latch doors and barriers. It is a compelling product for

  15. Low standby leakage 12T SRAM cell characterisation

    NASA Astrophysics Data System (ADS)

    Yadav, Arjun; Nakhate, Sangeeta

    2016-09-01

    In this work, a low power and variability-aware static random access memory (SRAM) architecture based on a twelve-transistor (12T) cell is proposed. This cell obtains low static power dissipation due to a parallel global latch (G-latch) and storage latch (S-latch), along with a global wordline (GWL), which offer a high cell ratio and pull-up ratio for reliable read and write operations and a low cell ratio and pull-up ratio during idle mode to reduce the standby power dissipation. In the idle state, only the S-latch stores bits, while the G-latch is isolated from the S-latch and the GWL is deactivated. The leakage power consumption of the proposed SRAM cell is thereby reduced by 38.7% compared to that of the conventional six-transistor (6T) SRAM cell. This paper evaluates the impact of the chip supply voltage and surrounding temperature variations on the standby leakage power and observes considerable improvement in the power dissipation. The read/write access delay, read static noise margin (SNM) and write SNM were evaluated, and the results were compared with those of the standard 6T SRAM cell. The proposed cell, when compared with the existing cell using the Monte Carlo method, shows an appreciable improvement in the standby power dissipation and layout area.

  16. D-1A nose fairing separation fitting load test

    NASA Technical Reports Server (NTRS)

    Vanvleet, J. O.

    1976-01-01

    Structural testing of the D-1A Centaur nose fairing was completed to determine the loads imposed during flight on the latch bolts of the fairing separation system. This testing was conducted to supplement and/or verify the analytic techniques used in calculating bolt loads for the D-1A, and to gain insight into the general structural behavior of separation latch systems. It was shown that the assumed bolt load magnification due to prying action of the latch fittings on the bolt does occur, but is strongly dependent on fairing shell stiffness.

  17. Nuclear reactor control apparatus

    DOEpatents

    Sridhar, Bettadapur N.

    1983-11-01

    Nuclear reactor core safety rod release apparatus comprises a control rod having a detent notch in the form of an annular peripheral recess at its upper end, a control rod support tube for raising and lowering the control rod under normal conditions, latches pivotally mounted on the control support tube with free ends thereof normally disposed in the recess in the control rod, and cam means for pivoting the latches out of the recess in the control rod when a scram condition occurs. One embodiment of the invention comprises an additional magnetically-operated latch for releasing the control rod under two different conditions, one involving seismic shock.

  18. Electronic door locking mechanism

    DOEpatents

    Williams, G.L.; Kirby, P.G.

    1997-10-21

    The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch. 6 figs.

  19. Electronic door locking mechanism

    DOEpatents

    Williams, Gary Lin; Kirby, Patrick Gerald

    1997-01-01

    The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch.

  20. BAYONET TYPE COUPLING WITH PIVOTED SEGMENT RELEASE MEANS

    DOEpatents

    Work, R.O.

    1963-08-13

    A remotely actuated quick-disconnect electrical connector that comprises a pair of mating connector halves releasably retained together by an interlocking pin and groove arrangement is described. Pivotal latch means disposed in one of the connector halves adjacent the ends of the coupling grooves are normally held in an abutting relationship with the coupling pins by a slidable, lanyard actuated sleeve. The latch retains the pins in the grooves until the lanyard moves the sleeve and enables the latch to pivot out of the path of the pins for effecting disengagement of the coupling. (AEC)

  1. 87. April 1967 CHILD'S BED OF SILVERED WOOD CARVED IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    87. April 1967 CHILD'S BED OF SILVERED WOOD CARVED IN ANIMAL MOTIFS. NOTE DOORS WITH SQUIRREL LATCHES AND DECORATIVE SIMULATED HINGES - Mar-a-Lago, 1100 South Ocean Boulevard, Palm Beach, Palm Beach County, FL

  2. Method of fabricating a cooled electronic system

    DOEpatents

    Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

    2014-02-11

    A method of fabricating a liquid-cooled electronic system is provided which includes an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket. The method includes providing a liquid-cooled cold rail at the one end of the socket, and a thermal spreader to couple the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

  3. Cooled electronic system with thermal spreaders coupling electronics cards to cold rails

    DOEpatents

    Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

    2013-07-23

    Liquid-cooled electronic systems are provided which include an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket or removal of the card from the socket. A liquid-cooled cold rail is disposed at the one end of the socket, and a thermal spreader couples the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The thermally conductive extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

  4. 7. Historic American Buildings Survey, E.J. Stein, Photographer, November 1927, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey, E.J. Stein, Photographer, November 1927, DETAIL OF IRON DOOR LATCH, Gift of New York State Department of Education. - Shaker Meetinghouse (second), Watervliet Shaker Road, Colonie Township, Watervliet, Albany County, NY

  5. Pulling tool for use with reeled tubing and method for operating tools from wellbores

    SciTech Connect

    Pleasants, C.W.

    1991-08-20

    This patent describes a tool for latching to and/or pulling a well operating tool having a fishing neck from a downhole location in pipe in a well bore. It comprises an elongated tubular housing assembly defining a longitudinal bore; means connecting the housing assembly to an end of a string of reeled tubing for passing the housing assembly through the wellbore and into contact with the fishing neck and for introducing fluid into the longitudinal bore; means disposed on the housing assembly for automatically latching to the fishing neck upon the housing assembly engaging the fishing neck; means responsive to a predetermined fluid condition in the bore for releasing the latching means from the fishing neck to permit the tool to be removed from the wellbore; and means responsive to a predetermined mechanical force exerted, via the reeled tubing, on the housing assembly and on the fishing neck for releasing the latching means from the fishing neck.

  6. The 24th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The proceedings of the symposium are reported. Technological areas covered include actuators, aerospace mechanism applications for ground support equipment, lubricants, latches, connectors, and other mechanisms for large space structures.

  7. Ninteenth Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The proceedings of the 19th Aerospace Mechanisms Symposium are reported. Technological areas covered include space lubrication, bearings, aerodynamic devices, spacecraft/Shuttle latches, deployment, positioning, and pointing. Devices for spacecraft docking and manipulator and teleoperator mechanisms are also described.

  8. Drug Trio Shows Major Promise Against Myeloma

    MedlinePlus

    ... 19 percent. The drug, which is given by infusion, latches onto a specific protein on myeloma cells ... and Drug Administration, the most common ones include infusion-related reactions, fatigue, nausea, back pain and fever. ...

  9. 49 CFR 579.4 - Terminology.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... bus, Gross Vehicle Weight Rating (GVWR), motorcycle, multipurpose passenger vehicle, passenger car... motor vehicles or motor vehicle equipment. Electrical system means any electrical or electronic... operation of a latching device such as remote release cables (and associated components), electric...

  10. Gardening from a Wheelchair

    MedlinePlus

    ... Paralysis > Health > Staying active > Gardening from a wheelchair Gardening from a wheelchair ☷ ▾ Page contents Tips from community ... round handles) on gate latches, doors, and faucets. Gardening as therapy For Gene Rothert gardening is a ...

  11. Automatic compression adjusting mechanism for internal combustion engines

    NASA Technical Reports Server (NTRS)

    Akkerman, J. W. (Inventor)

    1983-01-01

    Means for controlling the compression pressure in an internal combustion engine having one or more cylinders and subject to widely varying power output requirements are provided. Received between each crank pin and connecting rod is an eccentric sleeve selectively capable of rotation about the crank pin and/or inside the rod and for latching with the rod to vary the effective length of the connecting rod and thereby the clearance volume of the engine. The eccentric normally rotates inside the connecting rod during the exhaust and intake strokes but a latching pawl carried by the eccentric is movable radially outwardly to latch the rod and eccentric together during the compression and power strokes. A control valve responds to intake manifold pressure to time the supply of hydraulic fluid to move the latch-pawl outwardly, varying the effective rod length to maintain a substantially optimum firing chamber pressure at all intake manifold pressures.

  12. Slide release mechanism. [for space shuttle orbiter/external tank connection device

    NASA Technical Reports Server (NTRS)

    Bunker, J. W.; Ritchie, R. S. (Inventor)

    1985-01-01

    A releasable support device is described which is comprised of a hollow body with a sleeve extending transversely there-through for receiving the end of a support shank. A slider-latch, optionally lubricated, extends through side recesses in the sleeve to straddle the shank, respectively, in latched and released positions. The slider-latch is slid from its latched to its unlatched position by a pressure squib whereupon a spring or other pressure means pushes the shank out of the sleeve. At the same time, a follower element is lodged in and closed the hole in the body wall from which the shank was discharged. The mechanism was designed for the shuttle orbiter/external tank connection device.

  13. The 25th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Twenty-two papers are documented regarding aeronautical and spacecraft hardware. Technological areas include actuators, latches, cryogenic mechanisms, vacuum tribology, bearings, robotics, ground support equipment for aerospace applications, and other mechanisms.

  14. An overview of the neuron ring model

    NASA Technical Reports Server (NTRS)

    Taber, Rod

    1991-01-01

    The Neuron Ring model employs an avalanche structure with two important distinctions at the neuron level. Each neuron has two memory latches; one traps maximum neuronal activation during pattern presentation, and the other records the time of latch content change. The latches filter short term memory. In the process, they preserve length 1 snapshots of activation theory history. The model finds utility in pattern classification. Its synaptic weights are first conditioned with sample spectra. The model then receives a test or unknown signal. The objective is to identify the sample closest to the test signal. Class decision follows complete presentation of the test data. The decision maker relies exclusively on the latch contents. Presented here is an overview of the Neuron Ring at the seminar level.

  15. SEU Performance of TAG Based Flip Flops

    NASA Technical Reports Server (NTRS)

    Shuler, Robert L.; Kouba, Coy; O'Neill, Patrick M.

    2005-01-01

    We describe heavy ion test results for two new SEU tolerant latches based on transition nand gates, one for single rail asynchronous and the other for dual rail synchronous designs, implemented in AMI 0.5microprocess.

  16. 78 FR 79391 - Foreign-Trade Zone (FTZ) 22-Chicago, Illinois, Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... turn retainers; catch springs; flap springs; springs; torque springs; wire racks; bake pans; pizza pans...; latch, pedal, coil and torque springs; wire racks; bake pans; retaining rings; bushing axles; pizza...

  17. What Are Some Ways to Promote Infant Safety in a Car?

    MedlinePlus

    ... including your child's size and the type of vehicle you have. With so many different car seats ... LATCH system, you will have to use the vehicle's safety belts to secure an appropriate car seat. ...

  18. Proton radiation testing of an 18 bit A/D converter

    NASA Technical Reports Server (NTRS)

    Thelen, Donald C.; Wiseman, Don R.

    1993-01-01

    An 18-bit first order incremental analog to digital converter (ADC) has been constructed in a 2 mu commercial CMOS process. The ADC was exposed to energetic protons at the Harvard Cyclotron Laboratory to simulate latch-up and noise behavior in low earth orbits. Results of the test indicate no latch-up problems and only a small loss in accuracy while operating in proton radiation with energies similar to the South Atlantic Anomaly.

  19. Apparatus for retaining and releasing a payload

    NASA Technical Reports Server (NTRS)

    Carrier, Alain (Inventor); Cobb, Bruce (Inventor)

    2000-01-01

    An apparatus for latching an object, such as a payload for a space vehicle, includes an expandible latch which is shifted between a relaxed open condition and a flexed closed condition by actuation of a pair of temperature-responsive members, such as shaped memory alloy (SMA) coil springs. One of the two temperature-responsive members biases an actuator into a first position that allows the expandible latch to open. The other SMA member biases the actuator in the opposite position to close the expandible latch. Heating the appropriate SMA member causes the actuator to move from one position to the other position. In the preferred embodiment, no power is required to maintain the actuator in either position once the position has been established. For example, the actuator may have a rest position that allows the expandible latch to remain open when the two SMA members are cooled and allowed to reach an equilibrium condition with respect to applied force to the actuator. A detent-and-ball arrangement may be used to maintain the position of the actuator after the expandible latch has been closed.

  20. Experimental investigation of the cornering characteristics of 18 by 5.5, type 7, aircraft tires with different tread patterns

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Tanner, J. A.

    1974-01-01

    The characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained on dry, damp, and flooded runway surfaces over a range of yaw angles from 0 deg to 12 deg and at ground speeds from approximately 5 to 90 knots. The results indicate that a tread pattern with pinholes in the ribs reduces the tire cornering capability at high yaw angles on a damp surface but improves cornering on a dry surface. A tread pattern which has transverse grooves across the entire width of the tread improves the tire cornering performance slightly at high speeds on the flooded runway surface. The cornering capability of all the tires is degraded at high ground speeds by thin film lubrication and/or tire hydroplaning effects. Alterations to the conventional tread pattern provide only marginal improvements in the tire cornering capability which suggests that runway surface treatments may be a more effective way of improving aircraft ground performance during wet operations.

  1. Graphite fiber polyimide composites for spherical bearings to 340 C (650 F)

    NASA Technical Reports Server (NTRS)

    Sliney, H. E.; Johnson, R. L.

    1972-01-01

    Journal bearings with self-alining spherical elements of graphite-fiber-reinforced-polyimide composites were tested from 24 to 340 C (75 to 650 F) at unit loads up to 3.5 times 10 to the 7th power N/sq m (5000 psi). The journal oscillated in the cylindrical bore of the composite element + or - 15 deg at 1 hertz. Outer races and journals were metal hardened of Rockwell C-32 and finished to 10 to the minus 7th power m. A 45 wt. percent graphite-fiber composite gave low friction (0.08 to 0.13), low wear, and almost no plastic deformation under any of the test conditions. Composites with 15 and 25 wt. percent graphite fiber failed by plastic deformation at 315 C (600 F) and 3.5 times 10 to the 7th power N/sq m (5000 psi). A composite with 60 wt. percent graphite fiber failed by brittle fracture under the same conditions, but had very low friction coefficients (0.05 to 0.10) and may be a good bearing material at lighter loads.

  2. General Chemistry II: Setting the Stage on the First Day with "Jeopardy"

    ERIC Educational Resources Information Center

    Eves, Daniel J.; Redd, J. Ty

    2014-01-01

    Sequential science courses that cover multiple semesters, with each course serving as a prerequisite for subsequent courses, create a unique challenge for student engagement and success, as students are expected not only to engage with the new material, but also to quickly connect it with previously learned material. Games, simulations, and other…

  3. Terminal System for Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    Maloney, T. J.

    1984-01-01

    Quick-connect terminal system provides electrical contact and physical alinement between adjacent photovoltaic modules. Dual-ended plugs connect adjacent modules; single-ended plugs connect bus cables. No tools required to insert plugs and no live terminals exposed before, during, or after connection.

  4. Trigger mechanism for engines

    SciTech Connect

    Clark, L.R.

    1989-02-28

    A trigger mechanism is described for a blower-vacuum apparatus having a trigger mounted within a handle and a small engine comprising: a throttle; a ''L'' shaped lever having first and second legs mounted for rotation about an intermediate pivot within the handle when the trigger is depressed, interconnecting the trigger and the throttle, the second leg having first teeth defined therein, the lever further having idle, full throttle and stop positions; a normally raised latch means adapted to be rotated and axially depressed, the latch means having second teeth situated on a cam to engage the first teeth for holding the lever in an intermediate position between the idle and full throttle positions when the latch means is rotated. The latch means further are cam teeth into potential engagement with the lever teeth when the trigger is depressed, lever is biased to the stop position; and idle adjusting means means for intercepting the second leg for preventing the second leg from reaching the stop position when the latch means is raised.

  5. Apparatus for controlling transmission gear shift selection

    SciTech Connect

    Bailey, T.M.

    1986-07-29

    In an automotive engine having an electrical power source and an automatic or semi-automatic transmission including a manually operated transmission gear shift lever having at least two forward drive positions, an apparatus is described which consists of: (a) a speed sensing means for sensing the rotation speed of the engine and generating an output signal when the engine reaches a preselected rotational speed; and (b) a gear shifting means for changing the shift positions of the gear shift lever from a first drive position to a second drive position automatically in response to the output signal from the speed sensing means, the gear shifting means including (i) a latch actuable between open and closed positions, (ii) a normally de-energized solenoid having a plunger connected to the latch and operable to move the latch to the open position when the solenoid is energized by the electrical power source, (iii) a relay means for allowing the energizing of the solenoid by the power source in response to the output signal from the speed sensing means, and (iv) an actuating means, including a spring biased linkage mechanism operably connected to the gear shift lever and the latch, for actuating the movement of the gear shift lever from the first drive position to the second drive position in response to movement of the latch from the closed to the open position, thereby causing gear shifting to occur when the engine reaches the preselected rotational speed.

  6. Remote controlled vacuum joint closure mechanism

    DOEpatents

    Doll, David W.; Hager, E. Randolph

    1986-01-01

    A remotely operable and maintainable vacuum joint closure mechanism for a noncircular aperture is disclosed. The closure mechanism includes an extendible bellows coupled at one end to a noncircular duct and at its other end to a flange assembly having sealed grooves for establishing a high vacuum seal with the abutting surface of a facing flange which includes an aperture forming part of the system to be evacuated. A plurality of generally linear arrangements of pivotally coupled linkages and piston combinations are mounted around the outer surface of the duct and aligned along the length thereof. Each of the piston/linkage assemblies is adapted to engage the flange assembly by means of a respective piston and is further coupled to a remote controlled piston drive shaft to permit each of the linkages positioned on a respective flat outer surface of the duct to simultaneously and uniformly displace a corresponding piston and the flange assembly with which it is in contact along the length of the duct in extending the bellows to provide a high vacuum seal between the movable flange and the facing flange. A plurality of latch mechanisms are also pivotally mounted on the outside of the duct. A first end of each of the latch mechanisms is coupled to a remotely controlled latch control shaft for displacing the latch mechanism about its pivot point. In response to the pivoting displacement of the latch mechanism, a second end thereof is displaced so as to securely engage the facing flange.

  7. Microconical interface fitting and interface grasping tool

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael L. (Inventor); Wightman, William D. (Inventor); Johnston, Alistair P. (Inventor)

    1994-01-01

    A small and light weight microconical interface fitting may be attached to the surface of a space vehicle or equipment to provide an attachment device for an astronaut or robot to capture the space vehicle or equipment. The microconical interface fitting of the present invention has an axisymmetrical conical body having a base portion with a torque reaction surface for preventing rotation of the interface grasping tool; a cavitated, sunken or hollowed out intermediate locking portion which has a cavity shaped for receiving the latches of the grasping tool and an upper guiding portion for guiding the grasping tool into axial alignment with the microconical interface fitting. The capture is accomplished with an interface grasping tool. The grasping tool comprises an outer sleeve with a handle attached, an inner sleeve which may be raised and lowered within the outer sleeve with a plurality of latches supported at the lower end and a cam to raise and lower the inner sleeve. When the inner sleeve is at its lowest position, the latches form the largest diameter opening for surrounding the microconical fitting and the latches form the smallest diameter or a locking, grasping position when raised to the highest position within the outer sleeve. The inner sleeve may be at an intermediate, capture position which permits the latches to be biased outwardly when contacting the microconical fitting under very low forces to grasp the fitting and permits capture (soft docking) without exact alignment of the fitting and the tool.

  8. Chi hotspots trigger a conformational change in the helicase-like domain of AddAB to activate homologous recombination

    PubMed Central

    Gilhooly, Neville S.; Carrasco, Carolina; Gollnick, Benjamin; Wilkinson, Martin; Wigley, Dale B.; Moreno-Herrero, Fernando; Dillingham, Mark S.

    2016-01-01

    In bacteria, the repair of double-stranded DNA breaks is modulated by Chi sequences. These are recognised by helicase-nuclease complexes that process DNA ends for homologous recombination. Chi activates recombination by changing the biochemical properties of the helicase-nuclease, transforming it from a destructive exonuclease into a recombination-promoting repair enzyme. This transition is thought to be controlled by the Chi-dependent opening of a molecular latch, which enables part of the DNA substrate to evade degradation beyond Chi. Here, we show that disruption of the latch improves Chi recognition efficiency and stabilizes the interaction of AddAB with Chi, even in mutants that are impaired for Chi binding. Chi recognition elicits a structural change in AddAB that maps to a region of AddB which resembles a helicase domain, and which harbours both the Chi recognition locus and the latch. Mutation of the latch potentiates the change and moderately reduces the duration of a translocation pause at Chi. However, this mutant displays properties of Chi-modified AddAB even in the complete absence of bona fide hotspot sequences. The results are used to develop a model for AddAB regulation in which allosteric communication between Chi binding and latch opening ensures quality control during recombination hotspot recognition. PMID:26762979

  9. Connection system. [insuring against loss of a tool component without using multiple tethers

    NASA Technical Reports Server (NTRS)

    Mccandless, B., II (Inventor)

    1984-01-01

    A mechanical connection system comprises a first body defining a receptable and a second body defining a pin matingly receivable in the receptacle by relative movement in a first directional mode. A primary latch is engagable between the two bodies to retain the pin in the receptacle. The primary latch is reciprocable in a second directional mode transverse to the first directional mode. A lock member carried by one of the bodies is operatively associated with the primary latch and movable, transverse to the second directional mode, between a locking position maintaining engagement of the primary latch and a releasing position permitting release of the primary latch. The lock includes an operator portion engagable to move the lock member from its locking position to its releasing position. The operator is located internally of the first body. An actuator is selectivity insertable into and disengagable from the first body. The actuator is movable relative to the first body when it is inserted for engagement with and operation of the operator.

  10. Multi-function magnetic jack control drive mechanism

    DOEpatents

    Bollinger, L.R.; Crawford, D.C.

    1983-10-06

    A multi-function magnetic jack control drive mechanism for controlling a nuclear reactor is provided. The mechanism includes an elongate pressure housing in which a plurality of closely spaced drive rods are located. Each drive rod is connected to a rod which is insertable in the reactor core. An electromechanical stationary latch device is provided which is actuatable to hold each drive rod stationary with respect to the pressure housing. An electromechanical movable latch device is also provided for each one of the drive rods. Each movable latch device is provided with a base and is actuatable to hold a respective drive rod stationary with respect to the base. An electromechanical lift device is further provided for each base which is actuatable for moving a respective base longitudinally along the pressure housing. In this manner, one or more drive rods can be moved in the pressure housing by sequentially and repetitively operating the electromechanical devices. Preferably, each latch device includes a pair of opposed latches which grip teeth located on the respective drive rod. Two, three, or four drive rods can be located symmetrically about the longitudinal axis of the pressure housing.

  11. Multi-function magnetic jack control drive mechanism

    DOEpatents

    Bollinger, Lawrence R.; Crawford, Donald C.

    1986-01-01

    A multi-function magnetic jack control drive mechanism for controlling a nuclear reactor is provided. The mechanism includes an elongate pressure housing in which a plurality of closely spaced drive rods are located. Each drive rod is connected to a rod which is insertable in the reactor core. An electromechanical stationary latch device is provided which is actuatable to hold each drive rod stationary with respect to the pressure housing. An electromechanical movable latch device is also provided for each one of the drive rods. Each movable latch device is provided with a base and is actuatable to hold a respective drive rod stationary with respect to the base. An electromechanical lift device is further provided for each base which is actuatable for moving a respective base longitudinally along the pressure housing. In this manner, one or more drive rods can be moved in the pressure housing by sequentially and repetitively operating the electromechanical devices. Preferably, each latch device includes a pair of opposed latches which grip teeth located on the respective drive rod. Two, three, or four drive rods can be located symmetrically about the longitudinal axis of the pressure housing.

  12. Development of a resettable, flexible aperture cover

    NASA Technical Reports Server (NTRS)

    Christiansen, Scott

    1992-01-01

    A flexible aperture cover and latch were developed for the Thermal Ion Detection Experiment (TIDE). The latch utilized a high-output paraffin (HOP) linear motor to supply the force to operate the latch. The initial approach for the cover was to use a heat-treated, coiled strip of 0.05 mm (.002-inch)-thick beryllium-copper as the cover. Development test results showed that one end of the cover developed a trajectory during release that threatened to impact against adjacent instruments. An alternative design utilizing constant force springs and a flexible, metallized Kapton cover was then tested. Results from development tests, microgravity tests, and lessons learned during the development of the aperture cover are discussed.

  13. Well valve control system

    SciTech Connect

    Schwendemann, K.L.; McCracken, O.W.; Mondon, C.G.; Wortham, L.C.

    1987-01-13

    A system is described for controlling well testing through an upper and lower test string with a subsea test tree connected therebetween and latch means to release the upper test string from the subsea test tree comprising: a. first and second selectively programmable microprocessor means; b. means for storing system operating limits in each microprocessor means; c. means for changing the operating limits in response to changes in well conditions; d. means for communicating operating fluid pressure to the subsurface test tree and the latch means; e. solenoid pilot valves controlling the flow of the operating fluid pressure to the subsea test tree and the latch means; f. the first microprocessor means located at a central control console; g. the second microprocessor means located near the solenoid valves; h. means for transmitting signals between the first and second microprocessor means and validating the accuracy of the signals; and i. electronic circuits to control operation of the solenoid valves in response to validated signals.

  14. SKITTER/implement mechanical interface

    NASA Technical Reports Server (NTRS)

    Cash, John Wilson, III; Cone, Alan E.; Garolera, Frank J.; German, David; Lindabury, David Peter; Luckado, Marshall Cleveland; Murphey, Craig; Rowell, John Bryan; Wilkinson, Brad

    1988-01-01

    SKITTER (Spacial Kinematic Inertial Translatory Tripod Extremity Robot) is a three-legged transport vehicle designed to perform under the unique environment of the moon. The objective of this project was to design a mechanical interface for SKITTER. This mechanical latching interface will allow SKITTER to use a series of implements such as drills, cranes, etc., and perform different tasks on the moon. The design emphasized versatility and detachability; that is, the interface design is the same for all implements, and connection and detachment is simple. After consideration of many alternatives, a system of three identical latches at each of the three interface points was chosen. The latching mechanism satisfies the design constraints because it facilitates connection and detachment. Also, the moving parts are protected from the dusty environment by housing plates.

  15. Method and apparatus for releasably connecting first and second objects

    NASA Technical Reports Server (NTRS)

    Monford, Leo G., Jr. (Inventor)

    1991-01-01

    The apparatus and method are disclosed for releasably connecting first and second objects, where a magnetic end effector may include at least one elongated pin number, a proximal end of which is connected to the first object and the distal end of which may be inserted into a receiving portion in the second object. Latch members are carried by the pin member for radial movement between retracted and expanded positions for releasing and locking, respectively, first and second objects. A plunger member carried by the pin member is axially moveable between first and second positions. In the first plunger position, the latch members are located in the expanded (locked) position and in the second plunger position the latch members are released for movement to retracted or unlocked position. The magnetic end effector is provided for releasable attachment to the first object and for moving the plunger member to the second position, releasing the first object.

  16. Device for automatically charging a woodburning stove

    SciTech Connect

    Michael, J.A.

    1981-12-29

    A device for automatically dropping logs at a predetermined time for charging a fire laid on the bottom of a woodburning stove. The device includes a pair of elongated arcuate shaped log supporting members each of which is journaled within the stove adjacent a respective top side corner thereof. A latching system is connected to the log supporting member for releasably maintaining the log supporting members in a substantially horizontal supporting position. An electrically operated movable member is connected to the latching system for releasing the latching system upon being energized under control of a timing device at a predetermined time. As a result, the stove can be automatically charged during the middle of the night ensuring a fire in the morning.

  17. Application of the ADAMS program to deployable space truss structures

    NASA Technical Reports Server (NTRS)

    Calleson, R. E.

    1985-01-01

    The need for a computer program to perform kinematic and dynamic analyses of large truss structures while deploying from a packaged configuration in space led to the evaluation of several existing programs. ADAMS (automatic dynamic analysis of mechanical systems), a generalized program from performing the dynamic simulation of mechanical systems undergoing large displacements, is applied to two concepts of deployable space antenna units. One concept is a one cube folding unit of Martin Marietta's Box Truss Antenna and the other is a tetrahedral truss unit of a Tetrahedral Truss Antenna. Adequate evaluation of dynamic forces during member latch-up into the deployed configuration is not yet available from the present version of ADAMS since it is limited to the assembly of rigid bodies. Included is a method for estimating the maximum bending stress in a surface member at latch-up. Results include member displacement and velocity responses during extension and an example of member bending stresses at latch-up.

  18. Microelectromechanical safe arm device

    DOEpatents

    Roesler, Alexander W.

    2012-06-05

    Microelectromechanical (MEM) apparatus and methods for operating, for preventing unintentional detonation of energetic components comprising pyrotechnic and explosive materials, such as air bag deployment systems, munitions and pyrotechnics. The MEM apparatus comprises an interrupting member that can be moved to block (interrupt) or complete (uninterrupt) an explosive train that is part of an energetic component. One or more latching members are provided that engage and prevent the movement of the interrupting member, until the one or more latching members are disengaged from the interrupting member. The MEM apparatus can be utilized as a safe and arm device (SAD) and electronic safe and arm device (ESAD) in preventing unintentional detonations. Methods for operating the MEM apparatus include independently applying drive signals to the actuators coupled to the latching members, and an actuator coupled to the interrupting member.

  19. A modular docking mechanism for in-orbit assembly and spacecraft servicing

    NASA Technical Reports Server (NTRS)

    Gampe, F.; Priesett, K.; Bentall, R. H.

    1985-01-01

    A Docking Mechanism concept is described which is suitable for use with autonomous docking systems. The central feature of using simple cylindrical handles on one side and a type of prism seating on the other is offered as a practical method of achieving a standardized structural interface without freezing continued development of the latches, either technically or commercially. The main emphasis in docking mechanism concepts is in two directions: (1) a very simple docking mechanism, involving mainly the latch mechanism to achieve a structural link; and (2) a sophisticated Docking Mechanism, where the latch mechanism is designed for nonrigid spacecraft and the achievement of very low dynamic interactions between spacecraft during the docking process.

  20. Development of a prototype self-configuring building block

    NASA Astrophysics Data System (ADS)

    Lin, Hung-Yu; Tsui, Chi-Leung; Wu, Wen-Jong; Wang, Wei-Chih

    2011-04-01

    The paper presents the concept and construction of a prototype self-configuring building block for potential application in smart dynamic structure. The design contains several modular self-configuring blocks with integrated controllers, gear trains, extending arms and magnetic latches. The structure could be reconfigured via the connection and disconnection of magnetic latch between the modules. Through the coordination of the individual cubes themselves, the entire structure can reassemble via pushing and pulling the individual components into almost any desired shape. Information as to the current location or the next necessary movement could be passed from cube to cube by a physical connection between the cubes or remotely through broadcast signals. To provide the hardware strategy, we present the mechanical design of the self-configure modules and their latch mechanism of Halbach array. In the end, we will discuss our proposed application in dynamic building structure and storage management.

  1. Waves in space plasma dipole antenna subsystem

    NASA Technical Reports Server (NTRS)

    Thomson, Mark

    1993-01-01

    The Waves In Space Plasma (WISP) flight experiment requires a 50-meter-long deployable dipole antenna subsystem (DASS) to radiate radio frequencies from the STS Orbiter cargo bay. The transmissions are to excite outer ionospheric plasma between the dipole and a free-flying receiver (Spartan) for scientific purposes. This report describes the singular DASS design requirements and how the resulting design satisfies them. A jettison latch is described in some detail. The latch releases the antenna in case of any problems which might prevent the bay doors from closing for re-entry and landing of the Orbiter.

  2. Safe Lock

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Model 1150 electronic spring latch, which provides controlled and timed access to a safe, was developed by Burnett Electronics Lab, Inc., San Diego, CA, and is marketed by KeyOne, Inc. also of San Diego. The Model 1150 is a spinoff from a spinoff. The original spinoff, the acoustic pinger, is an underwater transmitting device developed by Langley Research Center and the Navy for location and recovery of sounding rocket research payloads from the ocean. Long functioning life is a vital requirement for both the acoustic pinger and the Model 1150. The electronic spring latch employs the pinger power management technology to get long life out of the battery power source.

  3. Safety Lock

    NASA Astrophysics Data System (ADS)

    1991-01-01

    The Model 1150 electronic spring latch, which provides controlled and timed access to a safe, was developed by Burnett Electronics Lab, Inc., San Diego, CA, and is marketed by KeyOne, Inc. also of San Diego. The Model 1150 is a spinoff from a spinoff. The original spinoff, the acoustic pinger, is an underwater transmitting device developed by Langley Research Center and the Navy for location and recovery of sounding rocket research payloads from the ocean. Long functioning life is a vital requirement for both the acoustic pinger and the Model 1150. The electronic spring latch employs the pinger power management technology to get long life out of the battery power source.

  4. The Performance of Various Rear Facing Child Restraint Systems in a Frontal Crash

    PubMed Central

    Sherwood, C. P.; Abdelilah, Y.; Crandall, J. R.; Stevens, S. L.; Saggese, J. M.; Eichelberger, M. R.

    2004-01-01

    Current forward facing (FF) child restraint designs use LATCH and ISOFIX systems to couple the restraint to the vehicle. Rear facing (RF) child restraints, however, have multiple coupling methods that vary by manufacturer and country of origin. Sled tests were performed with the CRABI 12 month dummy in six different RF attachment conditions. The performance of the rear facing child restraints (restraint kinematics, head accelerations, and neck loads) was highly dependent on the coupling method used. The results were also compared to a FF LATCH restraint. PMID:15319132

  5. Method for characterizing the upset response of CMOS circuits using alpha-particle sensitive test circuits

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor); Nixon, Robert H. (Inventor); Soli, George A. (Inventor)

    1995-01-01

    A method for predicting the SEU susceptibility of a standard-cell D-latch using an alpha-particle sensitive SRAM, SPICE critical charge simulation results, and alpha-particle interaction physics. A technique utilizing test structures to quickly and inexpensively characterize the SEU sensitivity of standard cell latches intended for use in a space environment. This bench-level approach utilizes alpha particles to induce upsets in a low LET sensitive 4-k bit test SRAM. This SRAM consists of cells that employ an offset voltage to adjust their upset sensitivity and an enlarged sensitive drain junction to enhance the cell's upset rate.

  6. Self-actuated nuclear reactor shutdown system using induction pump to facilitate sensing of core coolant temperature

    DOEpatents

    Sievers, Robert K.; Cooper, Martin H.; Tupper, Robert B.

    1987-01-01

    A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes. The latching mechanism has an inner flow passage extending between and in flow communication with the absorber bundles and the inner flow channel of the top nozzle for accommodating primary coolant flow upwardly through the control assembly. Also, an outer flow passage separate from the inner flow passage extends through the latching mechanism between and in flow communication with the inner duct and the outer flow channel of the top nozzle for accommodating inflow of a portion of the heated coolant from the adjacent fuel assemblies. The latching mechanism contains a magnetic material sensitive to temperature and operable to cause mating or latching together of the components of the latching mechanism when the temperature sensed is below a known temperature and unmating or unlatching thereof when the temperature sensed is above a given temperature. The temperature sensitive magnetic material is positioned in communication with the heated coolant flow through the outer flow passage for directly sensing the temperature thereof. Finally, the pumping means includes a jet induction pump nozzle and diffuser disposed adjacent the bottom nozzle of the control assembly

  7. Locking mechanism for orthopedic braces

    NASA Technical Reports Server (NTRS)

    I-Lechao, J.; Epps, C. H., Jr. (Inventor)

    1976-01-01

    A locking mechanism for orthopedic braces is described which automatically prevents or permits the relative pivotable movement between a lower brace member and an upper brace member. The upper and lower brace members are provided with drilled bores within which a slidable pin is disposed, and depending upon the inclination of the brace members with respect to a vertical plane, the slidable pin will be interposed between both brace members. The secondary or auxiliary latching device includes a spring biased, manually operable lever bar arrangement which is manually unlatched and automatically latched under the influence of the spring.

  8. An Innovative Aperture Cover Mechanism Used on SDO/EVE and MMS/SDP

    NASA Technical Reports Server (NTRS)

    Steg, Stephen; Vermeer, William; Tucker, Scott; Passe, Heather

    2014-01-01

    This paper describes an aperture cover mechanism that was successfully flown in four locations on SDO/EVE, and is awaiting launch in sixteen locations on MMS. This design uses a paraffin actuator and a latch that secures the cover closed and removes the actuator from the load path. This latch allows the assembly to operate both as a light weight contamination cover (SDO/EVE), and also as a high-strength sensor restraint mechanism (MMS/SDP). The paper provides design/analysis/test information about the mechanism.

  9. Connector systems for structures

    NASA Technical Reports Server (NTRS)

    Evenson, Erik E. (Inventor); Lupo, Christian P. (Inventor); Wesselski, Clarence J. (Inventor)

    1995-01-01

    A releasable coupling device for connecting two members to one another where a collet type fastener has normally retracted latching fingers insertable into a latching recess and a longitudinally movable expander for activating the fastener is described. The longitudinal movement is retained with a paraffin actuated system which can reset. The longitudinal movement of the expander in one direction is through a one way threaded ratchet system which provides an automatic locking action and the expander is movable in either direction by an independently operated threaded action.

  10. Micro environmental sensing device

    DOEpatents

    Polosky, Marc A.; Lukens, Laurance L.

    2006-05-02

    A microelectromechanical (MEM) acceleration switch is disclosed which includes a proof mass flexibly connected to a substrate, with the proof mass being moveable in a direction substantially perpendicular to the substrate in response to a sensed acceleration. An electrode on the proof mass contacts one or more electrodes located below the proof mass to provide a switch closure in response to the sensed acceleration. Electrical latching of the switch in the closed position is possible with an optional latching electrode. The MEM acceleration switch, which has applications for use as an environmental sensing device, can be fabricated using micromachining.

  11. Connector systems for structures

    NASA Technical Reports Server (NTRS)

    Lupo, Christian (Inventor); Evenson, Erik (Inventor); Wesselski, Clarence (Inventor)

    1993-01-01

    A releasable coupling device for connecting two members to one another where a collet type fastener has normally retracted latching fingers insertable into a latching recess and a longitudinally movable expander for activating the fastener is described. The longitudinal movement is retained with a paraffin actuated system which can reset. The longitudinal movement of the expander in one direction is through a one way threaded ratchet system which provides an automatic locking action and the expander is movable in either direction by an independently operated threaded action.

  12. PEPC LRU: Ball Support Assembly

    SciTech Connect

    Alger, T

    1999-05-14

    The PEPC LRU upper ball support assembly consists of a ball and a pneumatic air cylinder/conical seat latching mechanism to be attached to the optics support frame,and a ball attached to the PEPC LRU. Both components are designed to allow manual positioning in three axes. Upon insertion of the PEPC LRU into the structure, the upper pneumatic cylinder is actuated to latch the two assemblies together through the conical seat device to grab the lower ball to support the LRU weight. To be conservative, the design load for the assembly is 1500 pounds (the prototype PEPC LRU weight was measured to be near 1380 pounds).

  13. Non-linear control of the ''clam'' wave energy device. Final report

    SciTech Connect

    Not Available

    1983-09-01

    A promising wave energy device being currently investigated is the ''clam'' device. The clam extracts energy by pumping air through a specially designed (Wells) turbine. Although operation of the Wells turbine does not require a rectified air flow, some additional control will be necessary to optimize the phase of the clam motion for good efficiencies. An examination of the equation of motion in the time domain suggests the possibility of non-linear phase control by mechanical, power take-off, or pneumatic latching. Latching can be shown to increase the efficiency of the device in the longer wavelengths of the wave spectrum, i.e. those of high incident wave power.

  14. Prosthetic Tool For Holding Small Ferromagnetic Parts

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Carden, James R.; Belcher, Jewell G., Jr.; Vest, Thomas W.

    1995-01-01

    Tool attached to prosthetic hand or arm enables user to hold nails, screws, nuts, rivets, and other small ferromagnetic objects on small magnetic tip. Device adjusted to hold nail or screw at proper angle for hammering or for use of screwdriver, respectively. Includes base connector with threaded outer surface and lower male member inserted in standard spring-action, quick-connect/quick-disconnect wrist adapter on prosthetic hand or arm.

  15. Disposable remote zero headspace extractor

    DOEpatents

    Hand, Julie J.; Roberts, Mark P.

    2006-03-21

    The remote zero headspace extractor uses a sampling container inside a stainless steel vessel to perform toxicity characteristics leaching procedure to analyze volatile organic compounds. The system uses an in line filter for ease of replacement. This eliminates cleaning and disassembly of the extractor. All connections are made with quick connect fittings which can be easily replaced. After use, the bag can be removed and disposed of, and a new sampling container is inserted for the next extraction.

  16. Magnetic coupling device

    DOEpatents

    Nance, Thomas A.

    2009-08-18

    A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.

  17. IET. Coupling station and track foundations under construction. Camera facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    IET. Coupling station and track foundations under construction. Camera facing northerly. Four-rail track foundations lead to coupling station. Service leads from there will go through opening for "quick connects" below. Retaining wall under construction will separate earthen shielding of control building (out of view to right) from coupling station and track. Date: October 20, 1954. INEEL negative no. 12550 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  18. Tenth Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Design studies and analyses were performed to describe the loads and dynamics of the space shuttle tail service masts. Of particular interest is the motion and interaction of the umbilical carrier plate, lanyard system, vacuum jacketed hoses, latches, links, and masthead.

  19. 76 FR 33173 - Airworthiness Directives; Bombardier Inc. Model DHC-8-102, -103, -106, -201, -202, -301, -311...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... issued AD 2006-12-16, Amendment 39-14642 (71 FR 34006, June 13, 2006). That AD required actions intended... latch block for the affected aircraft serial numbers. * * * You may obtain further information by... production. FAA's Determination and Requirements of This Proposed AD This product has been approved by...

  20. The 17th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The proceedings of the Aerospace Mechanisms Symposium are reported. Technological areas covered include space lubrication, aerodynamic devices, spacecraft/Shuttle latches, deployment, positioning, and pointing. Devices for spacecraft tether, magnetic bearing suspension, explosive welding, and a deployable/retractable mast are also described.

  1. Weird Science: Further Thoughts on the STEM Educational Challenge

    ERIC Educational Resources Information Center

    Halfond, Jay A.

    2010-01-01

    The author notes that the sciences are now something one must latch onto early and successfully as a teenager, and endure against all odds. This pivotal point requires maturity and even myopia--delayed gratification and voluntary dorkiness--traits not common in the young. As a nation, Americans are losing their hegemony in the sciences. In just…

  2. My Favorite Exam Question

    NASA Astrophysics Data System (ADS)

    Styer, Dan

    2015-12-01

    My favorite exam question comes from the final exam in an introductory mechanics course: A rolling 31 ton railroad boxcar collides with a stationary flatcar. The coupling mechanism activates so the cars latch together and roll down the track attached. Of the initial kinetic energy, 38% dissipates as heat, sound, vibrations, mechanical deformation, and so forth. How much does the flatcar weigh?

  3. Educators Assess "Open Content" Movement

    ERIC Educational Resources Information Center

    Trotter, Andrew

    2009-01-01

    This article discusses the open-content movement in education. A small but growing movement of K-12 educators is latching on to educational resources that are "open," or free for others to use, change, and republish on web sites that promote sharing. The open-content movement is fueled partly by digital creation tools that make it easy to create…

  4. The sail wing windmill and its adaptation for use in rural India

    NASA Technical Reports Server (NTRS)

    Sherman, M. M.

    1973-01-01

    An 8 meter-diameter prototype sail wing windmill is reported that uses a one meter-diameter bullock cartwheel to which three bamboo poles are latched in a triangular pattern with overlapping ends, to form the airframe for cloth sails. This device lifts 300 pounds to a height of 20 feet in one minute in a 10 mph wind.

  5. 47. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms. Latching mechanism, E end of turn span, viewed from W. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  6. 48. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. MISSISSIPPI, LOWNDES CO. COLUMBUS RAILROAD BRIDGE End of 1st St. S., Columbus, Ms Latching mechanism, E end of turn span, view from N. Sarcone Photography, Columbus, MS. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  7. Data eye monitor method and apparatus

    DOEpatents

    Gara, Alan G.; Marcella, James A.; Ohmacht, Martin

    2012-01-31

    An apparatus and method for providing a data eye monitor. The data eye monitor apparatus utilizes an inverter/latch string circuit and a set of latches to save the data eye for providing an infinite persistent data eye. In operation, incoming read data signals are adjusted in the first stage individually and latched to provide the read data to the requesting unit. The data is also simultaneously fed into a balanced XOR tree to combine the transitions of all incoming read data signals into a single signal. This signal is passed along a delay chain and tapped at constant intervals. The tap points are fed into latches, capturing the transitions at a delay element interval resolution. Using XORs, differences between adjacent taps and therefore transitions are detected. The eye is defined by segments that show no transitions over a series of samples. The eye size and position can be used to readjust the delay of incoming signals and/or to control environment parameters like voltage, clock speed and temperature.

  8. Counseling Young Students at Risk: Resources for Elementary Guidance Counselors. First Edition.

    ERIC Educational Resources Information Center

    Bleuer, Jeanne C., Ed.; Schreiber, Penny A., Ed.

    This collection of papers addresses seven critical problem areas that can place today's young students at risk. "Children in Self-Care" (Merlyn Pitney) discusses the key problems of the rapidly increasing number of "latch key" students who must fend for themselves before and/or after school. "Stress Management for Children" (Kristine Kunkle) shows…

  9. 76 FR 53648 - Federal Motor Vehicle Safety Standards: Occupant Crash Protection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-29

    ... vehicle seats. The NPRM preceding this final rule was published September 12, 2008 (73 FR 52939, Docket No...'' requirement. \\1\\ 58 FR 52922, (Oct. 13, 1993). \\2\\ A locking clip is a flat H-shaped metal clip intended to... components on most CRSs to allow the CRS to connect to a LATCH system on a vehicle. \\4\\ 64 FR 10786, (Mar....

  10. 75 FR 57846 - Airworthiness Directives; Robert E. Rust, Jr. Model DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ....gov . SUPPLEMENTARY INFORMATION: Airworthiness Directive 2010-18-12, amendment 39-16426 (75 FR 53861...-025-AD; Amendment 39-16426; AD 2010-18-12] RIN 2120-AA64 Airworthiness Directives; Robert E. Rust, Jr... unapproved latch plate design installation, with replacement as necessary for Robert E. Rust, Jr. Model...

  11. 49 CFR 229.119 - Cabs, floors, and passageways.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Cabs, floors, and passageways. 229.119 Section 229... braced. Cab doors shall be equipped with a secure and operable latching device. (b) Cab windows of the... position in the cab. (See also, Safety Glazing Standards, 49 CFR part 223, 44 FR 77348, Dec. 31, 1979.)...

  12. Toggle release

    NASA Technical Reports Server (NTRS)

    Graves, Thomas J. (Inventor); Yang, Robert A. (Inventor); Brown, Christopher W. (Inventor)

    1989-01-01

    A pyrotechnic actuated structural release device 10 which is mechanically two fault tolerant for release. The device 10 comprises a fastener plate 11 and fastener body 12, each attachable to a different one of a pair of structures to be joined. The fastener plate 11 and body 12 are fastenable by a toggle 13 supported at one end on the fastener plate and mounted for universal pivotal movement thereon. At its other end which is received in a central opening in the fastener body 12 and adapted for limited pivotal movement therein the toggle 13 is restrained by three retractable latching pins 61 symmetrically disposed in equiangular spacing about the axis of the toggle 13 and positionable in latching engagement with an end fitting on the toggle. Each pin 61 is individually retractable by combustion of a pyrotechnic charge 77, the expanding gases of which are applied to a pressure receiving face 67 on the latch pin 61 to effect its retraction from the toggle. While retraction of all three pins 62 releases the toggle, the fastener is mechanically two fault tolerant since the failure of any single one or pair of the latch pins to retract results in an asymmetrical loading on the toggle and its pivotal movement to effect a release. An annular bolt 18 is mounted on the fastener plate 11 as a support for the socket mounting 30, 37 of the toggle whereby its selective axial movement provides a means for preloading the toggle.

  13. A Symbol of Kinship

    ERIC Educational Resources Information Center

    Chiariello, Michael S.

    2007-01-01

    Carved from cedar trees by the Native people of the Northwest Coast, totems are outgrowths of the region's aboriginal art forms. Originally an important part of the pot-latch ceremony--a feast with deep meaning to coastal First Nations--totem poles were once raised to represent a family clan, its kinship system, dignity, accomplishments, prestige,…

  14. My Favorite Exam Question

    ERIC Educational Resources Information Center

    Styer, Dan

    2015-01-01

    My favorite exam question comes from the final exam in an introductory mechanics course: "A rolling 31 ton railroad boxcar collides with a stationary flatcar. The coupling mechanism activates so the cars latch together and roll down the track attached. Of the initial kinetic energy, 38% dissipates as heat, sound, vibrations, mechanical…

  15. 21 CFR 1030.10 - Microwave ovens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., including doors, door handles, latches, and control knobs. (8) Equivalent plane-wave power density means the... ohms). (c) Requirements—(1) Power density limit. The equivalent plane-wave power density existing in... to be prevented, only if a test magnet held in place on the oven by gravity or its own...

  16. 21 CFR 1030.10 - Microwave ovens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., including doors, door handles, latches, and control knobs. (8) Equivalent plane-wave power density means the... ohms). (c) Requirements—(1) Power density limit. The equivalent plane-wave power density existing in... to be prevented, only if a test magnet held in place on the oven by gravity or its own...

  17. 21 CFR 1030.10 - Microwave ovens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., including doors, door handles, latches, and control knobs. (8) Equivalent plane-wave power density means the... ohms). (c) Requirements—(1) Power density limit. The equivalent plane-wave power density existing in... to be prevented, only if a test magnet held in place on the oven by gravity or its own...

  18. 21 CFR 1030.10 - Microwave ovens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., including doors, door handles, latches, and control knobs. (8) Equivalent plane-wave power density means the... ohms). (c) Requirements—(1) Power density limit. The equivalent plane-wave power density existing in... to be prevented, only if a test magnet held in place on the oven by gravity or its own...

  19. FPGA Implementation of Metastability-Based True Random Number Generator

    NASA Astrophysics Data System (ADS)

    Hata, Hisashi; Ichikawa, Shuichi

    True random number generators (TRNGs) are important as a basis for computer security. Though there are some TRNGs composed of analog circuit, the use of digital circuits is desired for the application of TRNGs to logic LSIs. Some of the digital TRNGs utilize jitter in free-running ring oscillators as a source of entropy, which consume large power. Another type of TRNG exploits the metastability of a latch to generate entropy. Although this kind of TRNG has been mostly implemented with full-custom LSI technology, this study presents an implementation based on common FPGA technology. Our TRNG is comprised of logic gates only, and can be integrated in any kind of logic LSI. The RS latch in our TRNG is implemented as a hard-macro to guarantee the quality of randomness by minimizing the signal skew and load imbalance of internal nodes. To improve the quality and throughput, the output of 64-256 latches are XOR'ed. The derived design was verified on a Xilinx Virtex-4 FPGA (XC4VFX20), and passed NIST statistical test suite without post-processing. Our TRNG with 256 latches occupies 580 slices, while achieving 12.5Mbps throughput.

  20. Internally damped, self-arresting vertical drop-weight impact test apparatus

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R. (Inventor); Prasad, Chunchu B. (Inventor); Waters, Jr., William A. (Inventor); Stockum, Robert W. (Inventor); Water, Manfred A. (Inventor)

    1995-01-01

    A vertical dropped-weight impact test machine has a dropped-weight barrel vertically supported on upper and lower support brackets. The dropped-weight barrel is chambered to receive a dropped-weight assembly having a latch pin at its upper end, a damping unit in the middle, and a tup at its lower end. The tup is adapted for gathering data during impact testing. The latch pin releasably engages a latch pin coupling assembly. The latch pin coupling assembly is attached to a winch via a halyard for raising and lowering the dropped-weight assembly. The lower end of the dropped-weight barrel is provided with a bounce-back arresting mechanism which is activated by the descending passage of the dropped-weight assembly. After striking the specimen, the dropped-weight assembly rebounds vertically and is caught by the bounce-back arresting mechanism. The damping unit of the dropped-weight assembly serves to dissipate energy from the rebounding dropped-weight assembly and prevents the dropped-weight assembly from rebounding from the self-arresting mechanism.

  1. Internally damped, self-arresting vertical drop-weight impact test apparatus

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R. (Inventor); Prasad, Chunchu B. (Inventor); Waters, Jr., William A. (Inventor); Stockum, Robert W. (Inventor); Walter, Manfred A. (Inventor)

    1996-01-01

    A vertical dropped-weight impact test machine has a dropped-weight barrel vertically supported on upper and lower support brackets. The dropped-weight barrel is chambered to receive a dropped-weight assembly having a latch pin at its upper end, a damping unit in the middle, and a tup at its lower end. The tup is adapted for gathering data during impact testing. The latch pin releasably engages a latch pin coupling assembly. The latch pin coupling assembly is attached to a winch via a halyard for raising and lowering the dropped-weight assembly. The lower end of the dropped-weight barrel is provided with a bounce-back arresting mechanism which is activated by the descending passage of the dropped-weight assembly. After striking the specimen, the dropped-weight assembly rebounds vertically and is caught by the bounce-back arresting mechanism. The damping unit of the dropped-weight assembly serves to dissipate energy from the rebounding dropped-weight assembly and prevents the dropped-weight assembly from rebounding from the self-arresting mechanism.

  2. 78 FR 4047 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-18

    ... FR 18137). That NPRM proposed to require various repetitive inspections of the MDSCD latch pin... presents the comments received on the proposal (77 FR 18137, March 27, 2012) and the FAA's response to each... limit the applicability of the NPRM (77 FR 18137, March 27, 2012) to airplanes with a...

  3. 78 FR 10686 - Notice of Receipt of Petition for Decision That Nonconforming Long-Wheel Base 2005 Mercedes-Benz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-14

    ... in the Federal Register published on April 11, 2000 (65 FR 19477-78). How to Read Comments submitted...; 105 Hydraulic and Electric Brake Systems; 106 Brake Hoses; 113 Hood Latch System; 116 Motor Vehicle... Selection and Rims for Motor Vehicles Other than Passenger Cars: Installation of a tire information...

  4. The 21st Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1987-01-01

    During the symposium technical topics addressed included deployable structures, electromagnetic devices, tribology, actuators, latching devices, positioning mechanisms, robotic manipulators, and automated mechanisms synthesis. A summary of the 20th Aerospace Mechanisms Symposium panel discussions is included as an appendix. However, panel discussions on robotics for space and large space structures which were held are not presented herein.

  5. 16 CFR 1509.7 - Hardware.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... NON-FULL-SIZE BABY CRIBS § 1509.7 Hardware. (a) The hardware in a non-full-size baby crib shall be... abuse. (b) Non-full-size baby cribs shall incorporate locking or latching devices for dropsides or... non-full-size baby crib....

  6. The 27th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    Mancini, Ron (Compiler)

    1993-01-01

    The proceedings of the 27th Aerospace Mechanisms Symposium, which was held at ARC, Moffett Field, California, on 12-14 May 1993, are reported. Technological areas covered include the following: actuators, aerospace mechanism applications for ground support equipment, lubricants, latches, connectors, robotic mechanisms, and other mechanisms for large space structures.

  7. 29 CFR 1926.753 - Hoisting and rigging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; (ii) Hooks with self-closing safety latches or their equivalent shall be used to prevent components...: (i) A multiple lift rigging assembly is used; (ii) A maximum of five members are hoisted per lift... limitations. (2) Components of the multiple lift rigging assembly shall be specifically designed and...

  8. Colorado's Singular "No"

    ERIC Educational Resources Information Center

    Wiedeman, Reeves

    2008-01-01

    Supporters of affirmative action may have finally found a way to defeat state ballot measures that would ban such programs: Latch onto an inspirational presidential candidate with piles of cash and an unprecedented voter-turnout machine. Those activists won a narrow victory in Colorado this month, when 50.7 percent of voters made the state the…

  9. The 22nd Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The proceedings of the symposium, which was held at the NASA Langley Research Center, on May 4 to 6, 1988, are reported. Technological areas covered include space lubrication, bearings, aerodynamic devices, spacecraft latches, deployment, positioning, and pointing. Devices for space station docking and manipulator and teleoperator mechanisms are also described.

  10. The Demonology of Pollution.

    ERIC Educational Resources Information Center

    Landsberg, Hans H.

    This paper offers a fresh perspective on causes of and solutions to environmental problems, and would be useful as an initiator of classroom discussions. The author argues that in our pursuit of a society based on environmentally sound principles, we have perhaps misidentified the villains, and have latched into solutions that may be either naive,…

  11. 76 FR 13541 - Airworthiness Directives; The Boeing Company Model 757-200, -200CB, and -300 Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ...-11266 (64 FR 45436, August 20, 1999), which was based on Boeing Service Bulletin 757-25-0182, Revision 1... Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska, and (4) Will... the bearings and lockbase retainer in the door latch assembly, relocating and adjusting of the...

  12. Skin-implant multiwire connector

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1977-01-01

    Construction of device utilizing high-purity carbon is biocompatible as well as hygienic, Design allows for easy connections and disconnections in dark, cleaning and maintenance and less snagging of clothing and other articles by device. Guides and magnetic coupling preclude need for locks, screwing, or latching.

  13. 75 FR 50869 - Airworthiness Directives; Pilatus Aircraft Ltd. Model PC-12/47E Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... Register on June 10, 2010 (75 FR 32863). That NPRM proposed to correct an unsafe condition for the... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) Will not have a significant... power control friction wheel is tightened, the reverse thrust latch may stick and subsequently allow...

  14. 49 CFR 192.163 - Compressor stations: Design and construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... minimize the possibility of fire being communicated to the compressor building from structures on adjacent... fire-fighting equipment. (b) Building construction. Each building on a compressor station site must be... escape and an unobstructed passage to a place of safety. Each door latch on an exit must be of a...

  15. 49 CFR 229.119 - Cabs, floors, and passageways.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... braced. Cab doors shall be equipped with a secure and operable latching device. (b) Cab windows of the... position in the cab. (See also, Safety Glazing Standards, 49 CFR part 223, 44 FR 77348, Dec. 31, 1979.) (c... obstruction that creates a slipping, tripping or fire hazard. Floors shall be properly treated to...

  16. 49 CFR 192.163 - Compressor stations: Design and construction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... minimize the possibility of fire being communicated to the compressor building from structures on adjacent... fire-fighting equipment. (b) Building construction. Each building on a compressor station site must be... escape and an unobstructed passage to a place of safety. Each door latch on an exit must be of a...

  17. Magnetic bearings for a high-performance optical disk buffer, volume 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The operating instructions for the magnetic bearings of a high-performance optical disk buffer are provided. Among the topics that are discussed are the following: front panel layout, turn-on procedure, shut-down procedure, and latch-up protection. Additionally, comprehensive engineering drawings are presented for the design.

  18. A novel tape spring hinge mechanism for quasi-static deployment of a satellite deployable using shape memory alloy.

    PubMed

    Jeong, Ju Won; Yoo, Young Ik; Shin, Dong Kil; Lim, Jae Hyuk; Kim, Kyung Won; Lee, Jung Ju

    2014-02-01

    A tape spring hinge (TSH) is a typical flexible deployment device for a satellite and becomes frequently used due to its simplicity, lightweight, low cost, and high deployment reliability. However, the performance of a TSH is quite limited due to trade-offs among deployed stiffness, deployment torque, and latch-up shock despite its many advantages. In this study, a novel conceptual design that circumvents the trade-offs among functional requirements (FRs) is proposed. The trade-offs are obviated by a newly proposed shape memory alloy damper that converts the deployment behavior of a conventional TSH from unstable dynamic to stable quasi-static. This makes it possible to maximize the deployment stiffness and deployment torque of a conventional TSH, which are larger-the-better FR, without any increase in the latch-up shock. Therefore, in view of conceptual design, it is possible to design a highly improved TSH that has much higher deployed stiffness and deployment torque compared to a conventional TSH while minimizing latch-up shock and deployment unstableness. Detailed design was performed through response surface method and finite element analysis. Finally, a prototype was manufactured and tested in order to verify its performance (four point, deployment torque, and latch-up shock tests). The test results confirm the feasibility of the proposed TSH mechanism. PMID:24593388

  19. Reusable Release Mechanism

    NASA Technical Reports Server (NTRS)

    Bunker, J. W.; Ritchie, R. S.

    1984-01-01

    Slider release mechanism reusable. Bears heavy loads while latched, yet gives smooth release motion. Release effected by explosively driving perpendicular slider out of engagement with load-bearing shank. Device has potential industrial applications such as emergency release of lifting cables from helicopters, cranes and hoists.

  20. Magnetically Operated Holding Plate And Ball-Lock Pin

    NASA Technical Reports Server (NTRS)

    Monford, Leo G., Jr.

    1992-01-01

    Magnetically operated holding plate and ball-locking-pin mechanism part of object attached to, or detached from second object. Mechanism includes tubular housing inserted in hole in second object. Plunger moves inside tube forcing balls to protrude from sides. Balls prevent tube from sliding out of second object. Simpler, less expensive than motorized latches; suitable for robotics applications.

  1. Miniature diaphragm valve for medical equipment

    NASA Technical Reports Server (NTRS)

    Stadler, T. J.; Taylor, J. R.

    1978-01-01

    Valve assembly keeps nutrient out of moving parts of valve by physically isolating plunger from fluid. Poppet and diaphragm are molded together, and latter is shaped to act as static seal, which remains seated during the operation. As plunger moves, diaphragm also moves to form separate cavity for nutrient and thus isolates it from plunger cavity and latching mechanism.

  2. STS-54 MS Runco and MS Harbaugh participate in briefing at JSC's WETF

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-54 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist 1 (MS1) Mario Runco, Jr (right) and MS2 Gregory J. Harbaugh, holding an ESSEX wrench, examine mockup and tools prior to an underwater simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Runco and Harbaugh discuss the trunnion / payload retention latch assembly (PRLA) configuration.

  3. 21 CFR 1030.10 - Microwave ovens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., including doors, door handles, latches, and control knobs. (8) Equivalent plane-wave power density means the... ohms). (c) Requirements—(1) Power density limit. The equivalent plane-wave power density existing in... by measurement of the equivalent plane-wave power density made with an instrument which reaches...

  4. 14 CFR 25.783 - Fuselage doors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... means must be independent of the locking system. (3) Each door subject to pressurization, and for which... operating system must be designed or, where impracticable, distinctively and permanently marked, to minimize... from the latching and locking systems prior to flight and it must not be possible to restore power...

  5. Protective circuit for thyristor controlled systems and thyristor converter embodying such protective circuit

    DOEpatents

    Downhower, Jr., Francis H.; Finlayson, Paul T.

    1984-04-10

    A snubber circuit coupled across each thyristor to be gated in a chain of thyristors determines the critical output of a NOR LATCH whenever one snubber circuit could not be charged and discharged under normal gating conditions because of a short failure.

  6. Viscous rotary vane actuator/damper. [for Mariner and Viking programs

    NASA Technical Reports Server (NTRS)

    Harper, J. D.

    1976-01-01

    A compact viscous rotary actuator/damper for use on the Mariner '71 and Viking Programs was developed. Several functions were combined into this single mechanism to control the deployment, latching, and damping of the solar panel arrays used on these space vehicles. The design, development, and testing of the actuator/damper are described, and major problems encountered are discussed.

  7. 75 FR 78594 - Airworthiness Directives; The Boeing Company Model 777-200 Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... starter in the engine core compartment; the fire progressed into the latch beam cavity and was fueled by... on May 7, 2009 (74 FR 21284). That NPRM proposed to require installing a new insulation blanket on... which a T/R is installed with a design change known as ``Commonality T/R,'' which is common to Model...

  8. Versatile solid-state relay

    NASA Technical Reports Server (NTRS)

    Fox, D. A.

    1977-01-01

    Solid-state relay (SSR), containing multinode control logic, is operated as normally open, normally closed, or latched. Moreover several can be paralleled to form two-pole or double-throw relays. Versatile unit ends need to design custom control circuit for every relay application. Technique can be extended to incorporate selectable time delay, on operation or release, or pulsed output.

  9. 40 CFR 86.1217-96 - Evaporative emission enclosure calibrations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... determination of hydrocarbons. Proceed as follows: (1) Prepare the enclosure. (i) Variable-volume enclosures may... fan operated for a period of up to 12 hours before the 4-hour background sampling period begins. (3... irregularities (such as braces) and calculate the internal volume. For variable-volume enclosures, latch...

  10. 78 FR 60676 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... (78 FR 9346). The NPRM proposed to require determining if the latches on main deck escape slides... presents the comments received on the proposal (78 FR 9346, February 8, 2013) and the FAA's response to... time in the NPRM (78 FR 9346, February 8, 2013) be extended to 60 months. DAL stated that this...

  11. Structural Patterns in Conversations with a Woman Who Has Autism.

    ERIC Educational Resources Information Center

    Dobbinson, Sushie; Perkins, Michael R.; Boucher, Jill

    1998-01-01

    Conversational analysis was used to evaluate conversation between an adult with autism and a researcher. Analysis identified differences in conversational style based on such features as topic movement, topic maintenance, repairs, interference from earlier structures, common collocations, overlaps, latching, and pauses. Findings suggest the…

  12. 77 FR 19055 - Morgan Olson, LLC, Receipt of Petition for Decision of Inconsequential Noncompliance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... drivers. A trained commercial driver, such as one driving a walk-in van manufactured by Morgan Olson....1 Latch System. Each sliding door system shall be equipped with either: (a) At least one primary... in passenger vans, which often contain children in the back seat(s).\\3\\ \\3\\ 72 FR 5385. Morgan...

  13. Bus-Programmable Slave Card

    NASA Technical Reports Server (NTRS)

    Hall, William A.

    1990-01-01

    Slave microprocessors in multimicroprocessor computing system contains modified circuit cards programmed via bus connecting master processor with slave microprocessors. Enables interactive, microprocessor-based, single-loop control. Confers ability to load and run program from master/slave bus, without need for microprocessor development station. Tristate buffers latch all data and information on status. Slave central processing unit never connected directly to bus.

  14. The 26th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The proceedings of the 26th Aerospace Mechanisms Symposium, which was held at the Goddard Space Flight Center on May 13, 14, and 15, 1992 are reported. Technological areas covered include actuators, aerospace mechanism applications for ground support equipment, lubricants, latches, connectors and other mechanisms for large space structures.

  15. INTERIOR VIEW OF THE CORRIDOR DOOR TO THE SOUTH ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF THE CORRIDOR DOOR TO THE SOUTH ROOM SHOWING THE STRAP HINGES AND LATCHES. VIEW FACING SOUTHWEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  16. 78 FR 14080 - Kolcraft Enterprises, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-04

    ... engaged failure analysis experts to examine and test the latching system on the Play Yards. By August 2005.... 2069, Kolcraft is subject to civil penalties for its knowing failure to report, as required under... failure of Kolcraft to make the foregoing payment when due, interest on the unpaid amount shall accrue...

  17. Remote controlled vacuum joint closure mechanism

    DOEpatents

    Doll, D.W.; Hager, E.R.

    1984-02-22

    A remotely operable and maintainable vacuum joint closure mechanism for a noncircular aperture is disclosed. The closure mechanism includes an extendible bellows coupled at one end to a noncircular duct and at its other end to a flange assembly having sealed grooves for establishing a high vacuum seal with the abutting surface of a facing flange which includes an aperture forming part of the system to be evacuated. A plurality of generally linear arrangements of pivotally coupled linkages and piston combinations are mounted around the outer surface of the duct and aligned along the length thereof. Each of the piston/linkage assemblies is adapted to engage the flange assembly by means of a respective piston and is further coupled to a remote controlled piston drive shaft to permit each of the linkages positioned on a respective flat outer surface of the duct to simultaneously and uniformly displace a corresponding piston and the flange assembly with which it is in contact along the length of the duct in extending the bellows to provide a high vacuum seal between the movable flange and the facing flange. A plurality of latch mechanisms are also pivotally mounted on the outside of the duct. A first end of each of the latch mechanisms is coupled to a remotely controlled latch control shaft for displacing the latch mechanism about its pivot point. In response to the pivoting displacement of the latch mechanism, a second end thereof is displaced so as to securely engage the facing flange and maintain the high vacuum seal established by the displacement of the flange assembly and extension of the bellows without displacing the entire duct.

  18. USGS Coal Desorption Equipment and a Spreadsheet for Analysis of Lost and Total Gas from Canister Desorption Measurements

    USGS Publications Warehouse

    Barker, Charles E.; Dallegge, Todd A.; Clark, Arthur C.

    2002-01-01

    We have updated a simple polyvinyl chloride plastic canister design by adding internal headspace temperature measurement, and redesigned it so it is made with mostly off-the-shelf components for ease of construction. Using self-closing quick connects, this basic canister is mated to a zero-head manometer to make a simple coalbed methane desorption system that is easily transported in small aircraft to remote localities. This equipment is used to gather timed measurements of pressure, volume and temperature data that are corrected to standard pressure and temperature (STP) and graphically analyzed using an Excel(tm)-based spreadsheet. Used together these elements form an effective, practical canister desorption method.

  19. Design of a mercury Propellant Storage and Distribution assembly

    NASA Technical Reports Server (NTRS)

    Holcomb, L. B.; Womack, J. R.

    1973-01-01

    A study has been conducted of a Propellant Storage and Distribution (PSD) assembly for a solar electric propulsion (SEP) thrust subsystem. As a result of the trade-off study an elastomeric diaphragm propellant tank with nitrogen blowdown pressurization was the method selected for propellant expulsion. This study included the following propellant management devices: surface tension, metallic bellows, and metallic and elastomeric diaphragms. Pressurant supply concepts investigated were blowdown, externally pressure regulated, vaporizing Freon 113, and heated CO2/Zeolite. The configuration selected consists of a single propellant tank, a single main propellant latching-solenoid valve, and individual thruster latching-solenoid valves. Stainless steel was the selected tankage material and AF-E-332 was the selected diaphragm material. The PSD design characteristics and interfaces are summarized.

  20. A compact PE memory for vision chips

    NASA Astrophysics Data System (ADS)

    Cong, Shi; Zhe, Chen; Jie, Yang; Nanjian, Wu; Zhihua, Wang

    2014-09-01

    This paper presents a novel compact memory in the processing element (PE) for single-instruction multiple-data (SIMD) vision chips. The PE memory is constructed with 8 × 8 register cells, where one latch in the slave stage is shared by eight latches in the master stage. The memory supports simultaneous read and write on the same address in one clock cycle. Its compact area of 14.33 μm2/bit promises a higher integration level of the processor. A prototype chip with a 64 × 64 PE array is fabricated in a UMC 0.18 μm CMOS technology. Five types of the PE memory cell structure are designed and compared. The testing results demonstrate that the proposed PE memory architecture well satisfies the requirement of the vision chip in high-speed real-time vision applications, such as 1000 fps edge extraction.

  1. Transient fault behavior in a microprocessor: A case study

    NASA Technical Reports Server (NTRS)

    Duba, Patrick

    1989-01-01

    An experimental analysis is described which studies the susceptibility of a microprocessor based jet engine controller to upsets caused by current and voltage transients. A design automation environment which allows the run time injection of transients and the tracing from their impact device to the pin level is described. The resulting error data are categorized by the charge levels of the injected transients by location and by their potential to cause logic upsets, latched errors, and pin errors. The results show a 3 picoCouloumb threshold, below which the transients have little impact. An Arithmetic and Logic Unit transient is most likely to result in logic upsets and pin errors (i.e., impact the external environment). The transients in the countdown unit are potentially serious since they can result in latched errors, thus causing latent faults. Suggestions to protect the processor against these errors, by incorporating internal error detection and transient suppression techniques, are also made.

  2. Clock Controller For Ac Self-Timing Analysis Of Logic System

    DOEpatents

    Lo, Tinchee; Flanagan, John D.

    2004-05-18

    A clock controller and clock generating method are provided for AC self-test timing analysis of a logic system. The controller includes latch circuitry which receives a DC input signal at a data input, and a pair of continuous out-of-phase clock signals at capture and launch clock inputs thereof. The latch circuitry outputs two overlapping pulses responsive to the DC input signal going high. The two overlapping pulses are provided to waveform shaper circuitry which produces therefrom two non-overlapping pulses at clock speed of the logic system to be tested. The two non-overlapping pulses are a single pair of clock pulses which facilitate AC self-test timing analysis of the logic system.

  3. Optimization of the Switch Mechanism in a Circuit Breaker Using MBD Based Simulation

    PubMed Central

    Jang, Jin-Seok; Yoon, Chang-Gyu; Ryu, Chi-Young; Kim, Hyun-Woo; Bae, Byung-Tae; Yoo, Wan-Suk

    2015-01-01

    A circuit breaker is widely used to protect electric power system from fault currents or system errors; in particular, the opening mechanism in a circuit breaker is important to protect current overflow in the electric system. In this paper, multibody dynamic model of a circuit breaker including switch mechanism was developed including the electromagnetic actuator system. Since the opening mechanism operates sequentially, optimization of the switch mechanism was carried out to improve the current breaking time. In the optimization process, design parameters were selected from length and shape of each latch, which changes pivot points of bearings to shorten the breaking time. To validate optimization results, computational results were compared to physical tests with a high speed camera. Opening time of the optimized mechanism was decreased by 2.3 ms, which was proved by experiments. Switch mechanism design process can be improved including contact-latch system by using this process. PMID:25918740

  4. Self-locking mechanical center joint

    NASA Technical Reports Server (NTRS)

    Bush, H. G.; Wallsom, R. E. (Inventor)

    1985-01-01

    A device for connecting, rotating and locking together a pair of structural half columns is described. The device is composed of an identical pair of cylindrical hub assemblies connected at their inner faces by a spring loaded hinge; each hub assembly having a structural half column attached to its outer end. Each hub assembly has a spring loading locking ring member movably attached adjacent to its inner face and includes a latch member for holding the locking ring in a rotated position subject to the force of its spring. Each hub assembly also has a hammer member for releasing the latch on the opposing hub assembly when the hub assemblies are rotated together. The spring loaded hinge connecting the hub assemblies rotates the hub assemblies and attached structural half columns together bringing the inner faces of the opposing hub assemblies into contact with one another.

  5. Method and apparatus for eliminating unsuccessful tries in a search tree

    NASA Technical Reports Server (NTRS)

    Peterson, John C. (Inventor); Chow, Edward (Inventor); Madan, Herb S. (Inventor)

    1991-01-01

    A circuit switching system in an M-ary, n-cube connected network completes a best-first path from an originating node to a destination node by latching valid legs of the path as the path is being sought out. Each network node is provided with a routing hyperswitch sub-network, (HSN) connected between that node and bidirectional high capacity communication channels of the n-cube network. The sub-networks are all controlled by routing algorithms which respond to message identification headings (headers) on messages to be routed along one or more routing legs. The header includes information embedded therein which is interpreted by each sub-network to route and historically update the header. A logic circuit, available at every node, implements the algorithm and automatically forwards or back-tracks the header in the network legs of various paths until a completed path is latched.

  6. Patient handling arrangements for NMR imaging systems

    SciTech Connect

    Carper, R.L.; Keller, J.T.

    1988-02-23

    In a nuclear magnetic resonance imaging system, including a magnet having a bore in which a subject to be imaged is to be located, a patient handling system is described comprising: a patient table which may be located so as to oppose the magnet bore, the patient table including a bottom portion and a top portion; a patient pallet, movably located on the top portion and adapted to be moved between the top portion and the magnet bore; mechanically driven transport means for transporting the patient pallet into and out of the magnet bore, including latch means for connecting the transport means to the patient pallet; and release means, located on the pallet, for manually releasing the latch means from the pallet, whereby the pallet may be manually removed from the magnet bore.

  7. FOCUS - An experimental environment for fault sensitivity analysis

    NASA Technical Reports Server (NTRS)

    Choi, Gwan S.; Iyer, Ravishankar K.

    1992-01-01

    FOCUS, a simulation environment for conducting fault-sensitivity analysis of chip-level designs, is described. The environment can be used to evaluate alternative design tactics at an early design stage. A range of user specified faults is automatically injected at runtime, and their propagation to the chip I/O pins is measured through the gate and higher levels. A number of techniques for fault-sensitivity analysis are proposed and implemented in the FOCUS environment. These include transient impact assessment on latch, pin and functional errors, external pin error distribution due to in-chip transients, charge-level sensitivity analysis, and error propagation models to depict the dynamic behavior of latch errors. A case study of the impact of transient faults on a microprocessor-based jet-engine controller is used to identify the critical fault propagation paths, the module most sensitive to fault propagation, and the module with the highest potential for causing external errors.

  8. CAMAC-based interlock system for power-supply-hardware protection on MFTF

    SciTech Connect

    Strauch, M.S.

    1981-09-30

    This interlock module accepts 16 inputs and generates, in conjunction with an internal PROM map, 8 outputs. This decision process is autonomous of the CAMAC dataway and host computer. The map is generated, burned and verified by a user interactive program written to accept input/output equations in Boolean algebra. The interlock module requires the host computer to periodically interrogate it to verify proper operation of the module, host computer and date link; otherwise, permissives are dropped. An internal mask register may be used to override interlock inputs. This mask is perishable and must be constantly refreshed. Output drivers may be operated in a latch/no latch mode. This prevents outputs, once dropped, from being reasserted even if the proper input sequence is reestablished. A first-out register may be utilized to determine which input has dropped first in the event that chain reactions are developed among the interlock inputs.

  9. Designing berthing mechanisms for international compatibility

    NASA Technical Reports Server (NTRS)

    Winch, John; Gonzalez-Vallejo, Juan J.

    1991-01-01

    The paper examines the technological issues regarding common berthing interfaces for the Space Station Freedom and pressurized modules from U.S., European, and Japanese space programs. The development of the common berthing mechanism (CBM) is based on common requirements concerning specifications, launch environments, and the unique requirements of ESA's Man-Tended Free Flyer. The berthing mechanism is composed of an active and a passive half, a remote manipulator system, 4 capture-latch assemblies, 16 structural bolts, and a pressure gage to verify equalization. Extensive graphic and verbal descriptions of each element are presented emphasizing the capture-latch motion and powered-bolt operation. The support systems to complete the interface are listed, and the manufacturing requirements for consistent fabrication are discussed to ensure effective international development.

  10. Feasibility study of using elastic memory composites for the deployment of precision optical space instruments

    NASA Astrophysics Data System (ADS)

    Francis, Will; Lake, Mark S.; Hinkle, Jason D.; Peterson, Lee D.

    2004-09-01

    The use of an elastic memory composite member (EMC) as the active element in deployable optical instruments has tremendous potential. Elastic memory composite mechanisms can remove the need for mechanical latches and remove the post deployed microdynamic instabilities associated with them while providing a low shock, controlled deployment. Additionally, elastic memory composite mechanisms are lightweight, simple, and have a very low coefficient of thermal expansion, which are also desirable properties for deployable optical systems. This paper describes an effort that has been done to explore this possibility. A mechanical latching actuator in an existing precision deployable optical testbed was replaced by an EMC self-locking actuator. Feasibility was assessed through a detailed design and fabrication exercise followed by experimental evaluation of a prototype actuator system in the ground-based deployable optics testbed.

  11. Programmable Differential Delay Circuit With Fine Delay Adjustment

    DOEpatents

    DeRyckere, John F.; Jenkins, Philip Nord; Cornett, Frank Nolan

    2002-07-09

    Circuitry that provides additional delay to early arriving signals such that all data signals arrive at a receiving latch with same path delay. The delay of a forwarded clock reference is also controlled such that the capturing clock edge will be optimally positioned near quadrature (depending on latch setup/hold requirements). The circuitry continuously adapts to data and clock path delay changes and digital filtering of phase measurements reduce errors brought on by jittering data edges. The circuitry utilizes only the minimum amount of delay necessary to achieve objective thereby limiting any unintended jitter. Particularly, this programmable differential delay circuit with fine delay adjustment is designed to allow the skew between ASICS to be minimized. This includes skew between data bits, between data bits and clocks as well as minimizing the overall skew in a channel between ASICS.

  12. Microelectromechanical acceleration-sensing apparatus

    DOEpatents

    Lee, Robb M.; Shul, Randy J.; Polosky, Marc A.; Hoke, Darren A.; Vernon, George E.

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  13. Orifice well safety valve with release mechanism

    SciTech Connect

    Blizzard, W.A. Jr.

    1991-07-09

    This patent describes an orifice well safety valve. It comprises a housing having a bore therethrough, a valve element connected to the housing and movable between open and closed positions in the bore, a flow tube telescopically movable in the housing for controlling the movement of the valve element, coiled spring means positioned between the housing and the flow tube for yieldably moving the tube in a direction for opening the valve, a choke bean connected to the flow tube, releasable latch means in the housing releasably engaging the flow tube, belleville spring means biasing the latch means in a direction yieldably opposing the movement of the tube in a direction for closing the valve, the belleville spring remaining out of engagement with the flow tube.

  14. Dynamic performance of the mechanism of an automatically deployable ROPS.

    PubMed

    Etherton, J R; Cutlip, R G; Harris, J R; Ronaghi, M; Means, K H; Howard, S

    2002-02-01

    The mechanism for an automatically deployable ROPS (AutoROPS) has been designed and tested. This mechanism is part of an innovative project to provide passive protection against rollover fatality to operators of new tractors used in both low-clearance and unrestricted-clearance tasks. The device is a spring-action, telescoping structure that releases on signal to pyrotechnic squibs that actuate release pins. Upper post motion begins when the release pins clear an internal piston. The structure extends until the piston impacts an elastomeric ring and latches at the top position. In lab tests the two-post structure consistently deployed in less than 0.3 s and latched securely. Static load tests of the telescoping structure and field upset tests of the fully functional AutoROPS have been successfully completed. PMID:12002370

  15. End effectors and grapple fixtures

    NASA Astrophysics Data System (ADS)

    Vandersluis, Ron; Quittner, Erik

    1992-01-01

    An end effector has been developed for use with a space station remote manipulator system where capture and release capabilities are required, and which will provide for the transfer of substantial loads together with electrical power and signals across the end effector grapple fixture interface. The end effector has a latching mechanism for the transfer of substantial loads across the end effector grapple fixture interface. The functions associated with known nonlatching end effectors, namely their snaring and rigidizing capabilities, are maintained and can be operated independently of the new latching mechanisms and umbilical connectors of the end effector. The end effector is capable of functioning equally as a wrist (manipulator) and shoulder (arm base) unit. Applications of the new end effector include space station assembly, payload handling, capture of free-flyers, payload servicing, and providing stable bases for extravehicular activity work stations or robotic devices.

  16. Rack Protection Monitor - A Simple System

    SciTech Connect

    Orr, S.

    1997-12-01

    The Rack Protection Monitor is a simple, fail-safe device to monitor smoke, temperature and ventilation sensors. It accepts inputs from redundant sensors and has a hardwired algorithm to prevent nuisance power trips due to random sensor failures. When a sensor is triggered the Rack Protection Monitor latches and annunicates the alarm. If another sensor is triggered, the Rack Protection Monitor locally shuts down the power to the relay rack and sends alarm to central control.

  17. STS-47 MS Davis and MS/PLC Lee inspect SLJ Rack 5 during KSC training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist N. Jan Davis and MS and Payload Commander (PLC) Mark C. Lee, wearing clean suits, check latches on the Spacelab Japan (SLJ) Rack 5 Adult Frog Compartment during an inspection of the SLJ module which is currently undergoing preflight processing in a high bay of the Kennedy Space Center's (KSC's) Orbiter Processing Facility (OPF). View provided by KSC with alternate KSC number KSC-92PC-1643.

  18. Relaxation of a qubit measured by a driven Duffing oscillator

    SciTech Connect

    Serban, I.; Dykman, M. I.; Wilhelm, F. K.

    2010-02-15

    We investigate the relaxation of a superconducting qubit for the case when its detector, the Josephson bifurcation amplifier, remains latched in one of its two (meta)stable states of forced vibrations. The qubit relaxation rates are different in different states. They can display strong dependence on the qubit frequency and resonant enhancement, which is due to quasienergy resonances. Coupling to the driven oscillator changes the effective temperature of the qubit.

  19. "The Most Famous Brain in the World" Performance and Pedagogy on an Amnesiac's Brain

    ERIC Educational Resources Information Center

    Sweaney, Katherine W.

    2012-01-01

    Project H.M. was just the sort of thing one might expect the Internet to latch onto: it was a live streaming video of a frozen human brain being slowly sliced apart. Users who clicked the link on Twitter or Facebook between the 2nd and 4th of December 2009 were immediately confronted with a close-up shot of the brain's interior, which was…

  20. Sequencing device utilizing planetary gear set

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T. (Inventor)

    1979-01-01

    A planetary (epicyclic) gear set is provided with a reversible rotating input shaft and individual outputs shafts actuated, respectively, by the ring gear and planet gear carrier. Latch means is positioned to selectively and automatically stop the ring gear or carrier member while releasing the other to provide the desired sequential output operation. The output shafts are reversed in sequence and direction of rotation by reversing rotational direction of the input shaft.

  1. Mechanical end joint system for structural column elements

    NASA Technical Reports Server (NTRS)

    Bush, H. G.; Wallsom, R. E. (Inventor)

    1982-01-01

    A mechanical end joint system, useful for the transverse connection of strut elements to a common node, comprises a node joint half with a semicircular tongue and groove, and a strut joint half with a semicircular tongue and groove. The two joint halves are engaged transversely and the connection is made secure by the inherent physical property characteristics of locking latches and/or by a spring-actioned shaft. A quick release mechanism provides rapid disengagement of the joint halves.

  2. Linear dynamic range enhancement in a CMOS imager

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor)

    2008-01-01

    A CMOS imager with increased linear dynamic range but without degradation in noise, responsivity, linearity, fixed-pattern noise, or photometric calibration comprises a linear calibrated dual gain pixel in which the gain is reduced after a pre-defined threshold level by switching in an additional capacitance. The pixel may include a novel on-pixel latch circuit that is used to switch in the additional capacitance.

  3. Laser scan microscope and infrared laser scan microcope: two important tools for device testing

    NASA Astrophysics Data System (ADS)

    Ziegler, Eberhard

    1991-03-01

    The optical beam induced current (OBIC) produced in devices by a laser scan microscope (LSM) is used to localize hot spots, leakage currents, electrostatic discharge defects and weak points. The LSM also allows photoluminescence measurements with high spatial and energy resolution. Using the infrared laser scan microscope (IR LSM), defects in the metallization and latch-up sensitive region could be detected from the back of the device.

  4. Radiation Status of Sub-65 nm Electronics

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.

    2011-01-01

    Ultra-scaled complementary metal oxide semiconductor (CMOS) includes commercial foundry capabilities at and below the 65 nm technology node Radiation evaluations take place using standard products and test characterization vehicles (memories, logic/latch chains, etc.) NEPP focus is two-fold: (1) Conduct early radiation evaluations to ascertain viability for future NASA missions (i.e. leverage commercial technology development). (2) Uncover gaps in current testing methodologies and mechanism comprehension -- early risk mitigation.

  5. Effects of child restraint system features on installation errors.

    PubMed

    Klinich, Kathleen D; Manary, Miriam A; Flannagan, Carol A C; Ebert, Sheila M; Malik, Laura A; Green, Paul A; Reed, Matthew P

    2014-03-01

    This study examined how child restraint system (CRS) features contribute to CRS installation errors. Sixteen convertible CRS, selected to include a wide range of features, were used in volunteer testing with 32 subjects. Subjects were recruited based on their education level (high or low) and experience with installing CRS (none or experienced). Each subject was asked to perform four child restraint installations in the right-rear passenger seat of a 2006 Pontiac G6 sedan using a crash dummy as a child surrogate. Each subject installed two CRS forward-facing (FF), one with LATCH and one with the vehicle seatbelt, and two CRS rear-facing (RF), one with LATCH and one with the seatbelt. After each installation, the experimenter evaluated 42 factors for each installation, such as choice of belt routing path, tightness of installation, and harness snugness. Analyses used linear mixed models to identify CRS installation outcomes associated with CRS features. LATCH connector type, LATCH strap adjustor type, and the presence of belt lockoffs were associated with the tightness of the CRS installation. The type of harness shoulder height adjuster was associated with the rate of achieving a snug harness. Correct tether use was associated with the tether storage method. In general, subject assessments of the ease-of-use of CRS features were not highly correlated with the quality of their installation, suggesting a need for feedback with incorrect installations. The data from this study provide quantitative assessments of some CRS features that were associated with reductions in CRS installation errors. These results provide child restraint designers with design guidelines for developing easier-to-use products. Research on providing effective feedback during the child restraint installation process is recommended. PMID:23731627

  6. Relatchable launch restraint mechanism for deployable booms

    NASA Technical Reports Server (NTRS)

    Warden, Robert M.

    1990-01-01

    A new Relatchable Launch Mechanism was developed which enables a deployable system to be restrained and released repeatedly rather than the normal one shot release systems of the past. The deployable systems are of the self extending type which rely on a lanyard attached to a drive motor to control the deployment and retraction. The Relatch Mechanism uses the existing drive motor to also actuate the latch. The design and kinematics of the Relatch Mechanism as used on two flight programs are described.

  7. Analog-digital simulation of transient-induced logic errors and upset susceptibility of an advanced control system

    NASA Technical Reports Server (NTRS)

    Carreno, Victor A.; Choi, G.; Iyer, R. K.

    1990-01-01

    A simulation study is described which predicts the susceptibility of an advanced control system to electrical transients resulting in logic errors, latched errors, error propagation, and digital upset. The system is based on a custom-designed microprocessor and it incorporates fault-tolerant techniques. The system under test and the method to perform the transient injection experiment are described. Results for 2100 transient injections are analyzed and classified according to charge level, type of error, and location of injection.

  8. The Voyager magnetometer boom

    NASA Technical Reports Server (NTRS)

    Miller, D. C.

    1979-01-01

    The Voyager spacecraft magnetometer experiment utilizes two sensors on a deployable boom. The boom is an Astromast. The implementation of the Astromast into the Voyager design is described along with the hardware used to hold, latch, and deploy the mast and the tests to demonstrate damping, deployment, and alignments. Several problems encountered are discussed and their solutions are given. Flight deployment and preliminary alignment results are presented. Finally, the design is evaluated in retrospect.

  9. Locking mechanism

    DOEpatents

    Williams, Gary L.; Goin, Jr., Jesse L.; Kirby, Patrick G.; McKenna, John P.

    1997-01-01

    The invention is a motorized linkage for operating a door strike. A six volt power source, controlled by a security code, rotates a small electric motor when a proper security code is given. The motor rotates a shaft which engages a coil spring. This moves a locking cam. When a catch on the locking cam separates from the locking lever catch, the latch bolt keeper may be manipulated by a user.

  10. Complementary heterojunction FET technology for space application

    NASA Technical Reports Server (NTRS)

    Larue, George

    1993-01-01

    A 32-bit serial integer multiplier was designed to investigate the yield and performance of complementary heterojunction FET (CHFET) technology. This is the largest reported CHFET logic circuit. The maximum operating frequency was 500 MHz. Very low power dissipation of 3 mW was obtained at 5 MHz operation. Single-event upset (SEU) characteristics of CHFET devices and latches were also measured and indicates the potential for SEU hard circuits for space and military applications.

  11. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a gas-safe space. (b) Each air lock must: (1) Consist of two steel doors, at least 1.5 m (4.9 ft.) but not more than 2.5 m (8.2 ft.) apart, each gasketed and tight when tested with a fire hose at not less 207 kPa gauge (30 psig); (2) Have self-closing doors with no latches or other devices for...

  12. Fireplace door

    SciTech Connect

    Wilkening, D. W.

    1985-05-07

    A fireplace door assembly having doors pivotally mounted on a frame to be mounted on the opening of a fireplace. The doors are mounted on hinges that provide adjustment along a vertical axis of rotation and the front of the frame. An adjustable fire resistant gasket is used for an air seal. A gravity operated latch is provided to maintain the door in a closed position.

  13. The design and testing of a memory metal actuated boom release mechanism

    NASA Technical Reports Server (NTRS)

    Powley, D. G.; Brook, G. B.

    1979-01-01

    A boom latch and release mechanism was designed, manufactured and tested, based on a specification for the ISEE-B satellite mechanism. From experimental results obtained, it is possible to calculate the energy available and the operating torques which can be achieved from a torsional shape memory element in terms of the reversible strain induced by prior working. Some guidelines to be followed when designing mechanisms actuated by shape memory elements are included.

  14. Radiation effects on scientific CMOS image sensor

    NASA Astrophysics Data System (ADS)

    Yuanfu, Zhao; Liyan, Liu; Xiaohui, Liu; Xiaofeng, Jin; Xiang, Li

    2015-11-01

    A systemic solution for radiation hardened design is presented. Besides, a series of experiments have been carried out on the samples, and then the photoelectric response characteristic and spectral characteristic before and after the experiments have been comprehensively analyzed. The performance of the CMOS image sensor with the radiation hardened design technique realized total-dose resilience up to 300 krad(Si) and resilience to single-event latch up for LET up to 110 MeV·cm2/mg.

  15. 77 FR 9726 - Utilimaster Corporation, Receipt of Petition for Decision of Inconsequential Noncompliance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ..., do not fully comply with paragraph S4.2.1 of Federal Motor Vehicle Safety Standard (FMVSS) No. 206... system, as required by paragraph S4.2.1 of FMVSS No. 206, is installed. Paragraph S4.2.1 of FMVSS No. 206 requires in pertinent part: S4.2 Sliding Side Doors. S4.2.1 Latch System. Each sliding door system shall...

  16. Combustion powered linear actuator

    DOEpatents

    Fischer, Gary J.

    2007-09-04

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  17. Wheeled hopping robot

    DOEpatents

    Fischer, Gary J.

    2010-08-17

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  18. Effects of child restraint system features on installation errors.

    PubMed

    Klinich, Kathleen D; Manary, Miriam A; Flannagan, Carol A C; Ebert, Sheila M; Malik, Laura A; Green, Paul A; Reed, Matthew P

    2014-03-01

    This study examined how child restraint system (CRS) features contribute to CRS installation errors. Sixteen convertible CRS, selected to include a wide range of features, were used in volunteer testing with 32 subjects. Subjects were recruited based on their education level (high or low) and experience with installing CRS (none or experienced). Each subject was asked to perform four child restraint installations in the right-rear passenger seat of a 2006 Pontiac G6 sedan using a crash dummy as a child surrogate. Each subject installed two CRS forward-facing (FF), one with LATCH and one with the vehicle seatbelt, and two CRS rear-facing (RF), one with LATCH and one with the seatbelt. After each installation, the experimenter evaluated 42 factors for each installation, such as choice of belt routing path, tightness of installation, and harness snugness. Analyses used linear mixed models to identify CRS installation outcomes associated with CRS features. LATCH connector type, LATCH strap adjustor type, and the presence of belt lockoffs were associated with the tightness of the CRS installation. The type of harness shoulder height adjuster was associated with the rate of achieving a snug harness. Correct tether use was associated with the tether storage method. In general, subject assessments of the ease-of-use of CRS features were not highly correlated with the quality of their installation, suggesting a need for feedback with incorrect installations. The data from this study provide quantitative assessments of some CRS features that were associated with reductions in CRS installation errors. These results provide child restraint designers with design guidelines for developing easier-to-use products. Research on providing effective feedback during the child restraint installation process is recommended.

  19. International Docking Standardization NASA

    NASA Technical Reports Server (NTRS)

    Donahoe, Stanley; Lewis, J.; Carroll, M.; Le, T.

    2009-01-01

    This slide presentation reviews the different types of docking types. The objective is the pressurized vehicle connection and crew transfer. Androgynous Docking is defined as the joining or coming together of two free flying space vehicles with alike interfaces. Androgynous mating allows for collaboration between any two vehicles. The subsytems of an androgynous mating system are reviewed, including: Hard docking subsystems: latch system, tunnel housing, alignment system and seal.

  20. Data port security lock

    DOEpatents

    Quinby, Joseph D.; Hall, Clarence S.

    2008-06-24

    In a security apparatus for securing an electrical connector, a plug may be fitted for insertion into a connector receptacle compliant with a connector standard. The plug has at least one aperture adapted to engage at least one latch in the connector receptacle. An engagement member is adapted to partially extend through at least one aperture and lock to at least one structure within the connector receptacle.

  1. Development of a large deployable space reflector structure

    NASA Astrophysics Data System (ADS)

    Russell, A. G.

    An account is given of the configuration design selection and development of a 5-m diameter reflector structure encompassing an RF-reflective surface of Au-plated Mo knitted wire mesh, supported from the nodes of a tatrahedral truss. The structure's six deployable tetrahedrons are symmetrically disposed around a central node. The critical structural components are a light and simple self-latching hinge and long, stiff, inexpensive carbon fiber tubes produced by pultrusion.

  2. Piezo-phototronic Boolean logic and computation using photon and strain dual-gated nanowire transistors.

    PubMed

    Yu, Ruomeng; Wu, Wenzhuo; Pan, Caofeng; Wang, Zhaona; Ding, Yong; Wang, Zhong Lin

    2015-02-01

    Using polarization charges created at the metal-cadmium sulfide interface under strain to gate/modulate electrical transport and optoelectronic processes of charge carriers, the piezo-phototronic effect is applied to process mechanical and optical stimuli into electronic controlling signals. The cascade nanowire networks are demonstrated for achieving logic gates, binary computations, and gated D latches to store information carried by these stimuli.

  3. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    SciTech Connect

    Clark, Lawrence T.; McIver, III, John K.

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  4. Hatch Cover Slides Through Hatch

    NASA Technical Reports Server (NTRS)

    Alton, Charles; Okane, James H.

    1989-01-01

    Hatch cover for pressurized vessel provides tight seal but opened quickly from either side. In opening or closing, cover sweeps out relatively little volume within vessel, so it does not hinder movement of people or objects from vessel to outside or placement of people or objects near hatch. Cover uses internal pressure to create seal when closed. Design of cover eliminates leakage paths, and cover immune to hazards of sudden decompression or jamming when bolts and latches fail.

  5. Non explosive low shock reusable 20 kN hold-down release actuator

    NASA Astrophysics Data System (ADS)

    Vázquez, J.; Bueno, Ignacio

    2001-09-01

    SENER has developed a Non Explosive Hold-Down Release Actuator: NEHRA (Patented). The mechanism is based on a segmented nut kept in position by a preloaded mechanism. The preloaded mechanism is clamped with a latch than can be triggered by a wire of Shape Memory Alloy (SMA). A demonstrator model has been manufactured, assembled and functionally tested. The size developed is for a high strength M8 bolt (with an ultimate load about 40000 N, and a nominal preload of 20000 N).

  6. International Space Station alpha remote manipulator system workstation controls test report

    NASA Technical Reports Server (NTRS)

    Ehrenstrom, William A.; Swaney, Colin; Forrester, Patrick

    1994-01-01

    Previous development testing for the space station remote manipulator system workstation controls determined the need for hardware controls for the emergency stop, brakes on/off, and some camera functions. This report documents the results of an evaluation to further determine control implementation requirements, requested by the Canadian Space Agency (CSA), to close outstanding review item discrepancies. This test was conducted at the Johnson Space Center's Space Station Mockup and Trainer Facility in Houston, Texas, with nine NASA astronauts and one CSA astronaut as operators. This test evaluated camera iris and focus, back-up drive, latching end effector release, and autosequence controls using several types of hardware and software implementations. Recommendations resulting from the testing included providing guarded hardware buttons to prevent accidental actuation, providing autosequence controls and back-up drive controls on a dedicated hardware control panel, and that 'latch on/latch off', or on-screen software, controls not be considered. Generally, the operators preferred hardware controls although other control implementations were acceptable. The results of this evaluation will be used along with further testing to define specific requirements for the workstation design.

  7. Selectable towline spin chute system

    NASA Technical Reports Server (NTRS)

    Vairo, Daniel M. (Inventor); Whipple, Raymond D. (Inventor)

    1991-01-01

    An emergency spin recovery parachute is presented that is housed within a centrally mounted housing on the aft end of an aircraft and connected to a ring fitting within the housing. Two selectively latching shackles connected to separate towlines are openly disposed adjacent the ring fitting. The towlines extend in opposite directions from the housing along the aircraft wing to attachment points adjacent the wing-tips where the other end of each towline is secured. Upon pilot command, one of the open shackles latches to the ring fitting to attach the towline connected thereto, and a second command signal deploys the parachute. Suitable break-away straps secure the towlines to the aircraft surface until the parachute is deployed and the resulting force on the towline attached to the parachute overcomes the straps and permits the towline to extend to the point of attachment to exert sufficient drag on the spinning aircraft to permit the pilot to regain control of the aircraft. To employ the parachute as a drag chute to reduce landing speeds, both shackles and their respective towlines are latched to the ring fitting.

  8. Well tool lock mandrel and handling tools therefor

    SciTech Connect

    Higgins, B.D.

    1988-05-24

    A lock mandrel and running tool assembly for setting and locking a well tool in a landing nipple along a well bore is described comprising: a lock mandrel having a body provided with at least one side window; a support shoulder on the body for supporting the mandrel in a no-go landing nipple; a radially movable locking dog in the side window; a longitudinally movable expander sleeve in the body movable within the dog for expanding and locking the dog outwardly and releasing the dog for inward movement, the expander sleeve having an internal annular recess for engagement by a handling tool to move the sleeve upwardly and downwardly and an external annular latch boss along an upper end portion thereof; and a latch ring in the body around the expander sleeve above the locking dog for engagement with the latch boss on the sleeve when the sleeve is at an upper locking position to releasably hold the sleeve in the upper position. The running tool includes a head assembly for connection with an operating tool string; an upper retainer dog assembly supported from the head assembly for releasably coupling the running tool with the body of the lock mandrel; a lower locking lug assembly supported from the head assembly for releasably coupling the running tool with the expander sleeve of the lock mandrel to move the expander sleeve between locking and release positions.

  9. DEVICE FOR CONTROLLING INSERTION OF ROD

    DOEpatents

    Beaty, B.J.

    1958-10-14

    A device for rapidly inserting a safety rod into a nuclear reactor upon a given signal or in the event of a power failure in order to prevent the possibility of extensive damage caused by a power excursion is described. A piston is slidably mounted within a vertical cylinder with provision for an electromagnetic latch at the top of the cylinder. This assembly, with a safety rod attached to the piston, is mounted over an access port to the core region of the reactor. The piston is normally latched at the top of the cylinder with the safety rod clear of the core area, however, when the latch is released, the piston and rod drop by their own weight to insert the rod. Vents along the side of the cylinder permit the escape of the air entrapped under the piston over the greater part of the distance, however, at the end of the fall the entrapped air is compressed thereby bringing the safety rod gently to rest, thus providing for a rapid automatic insertion of the rod with a minimum of structural shock.

  10. Solar oven

    SciTech Connect

    Burns, T.J.; Burns, C.L.

    1989-07-18

    This patent describes a solar oven. It comprises: an oven chamber having an open end and defining an interior cooking chamber; means providing a flat-back interior surface on the cooking chamber for absorbing sunlight and converting the absorbed sunlight into heat; an oven door hingedly mounted over the open end and movable between open and closed positions relative to the open end; means for pivotably supporting the oven chamber about a first substantially horizontal pivot axis; user-actuable latch means for selectively retaining the oven chamber in selected positions around the first horizontal axis, the user-actuable latch means including a user releasable ratchet mechanism including a plurality of ratchet teeth formed on the oven chamber and ratchet pawl pivoted to the support means in a position to engage selective ones of the ratchet teeth to retain the over chamber in selected orientations around the horizontal axis, the latch means further including means for pivoting the pawl into and out of the path of movement of the ratchet teeth to thereby achieve the selective positioning; a tray disposed within the interior cooking chamber for supporting foodstuffs during coking; pivot means for pivotally mounting the tray within the interior cooking chamber for movement around a second substantially horizontal pivot axis such that the tray can be positioned so as to maintain the foodstuffs in a substantially level position independently of the position of the oven chamber around the first pivot axis.

  11. Latchup Tests on pALPIDEfs

    NASA Astrophysics Data System (ADS)

    Michael, Elad; Alice Collaboration

    2015-10-01

    In 2018, the ALICE ITS will be upgraded to keep up with new beam requirements. ALPIDE is one of the proposed silicon pixel detector designs; However, the pixel design suffers from a side effect called latch-up. Latchup is inevitable with transistors on such small scale, but it can be minimized if the silicon is designed well. The goal of this experiment is to quantify the probability of latch-up in ALPIDE for different particle cocktails and pixel geometries, to determine the viability of the design. The chip records two currents, from different silicon blocks; when either current rises above a user-set threshold the latchup power cycle process begins. The waveforms began in one of two general shapes, determined by the areas of the sensor that were latching up, but after a potentially damaging event there were several other waveforms that developed, which may have some indication to the damage done to the chip. To attempt to differentiate data that was effected by the damage, a machine learning algorithm using logistic regression was implemented to sort the current waveforms recorded during testing. The algorithm successfully categorizes latchups in 4 different categories, 2 categories of good data, and two particularly frequent categories of damaged waveform.

  12. Mechanical end joint system for connecting structural column elements

    NASA Technical Reports Server (NTRS)

    Bush, Harold G. (Inventor); Mikulas, Martin M., Jr. (Inventor); Wallsom, Richard E. (Inventor)

    1990-01-01

    A mechanical end joint system is presented that eliminates the possibility of free movements between the joint halves during loading or vibration. Both node joint body (NJB) and column end joint body (CEJB) have cylindrical engaging ends. Each of these ends has an integral semicircular tongue and groove. The two joint halves are engaged transversely - the tongue of the NJB mating with the groove of the CEJB and vice versa. The joint system employs a spring loaded internal latch mechanism housed in the CEJB. During mating, this mechanism is pushed away from the NJB and enters the NJB when mating is completed. In order to lock the joint and add a preload across the tongue and groove faces, an operating ring collar is rotated through 45 deg causing an internal mechanism to compress a Belleville washer preload mechanism. This causes an equal and opposite force to be exerted on the latch bolt and the latch plunger. This force presses the two joint halves tightly together. In order to prevent inadvertent disassembly, a secondary lock is also engaged when the joint is closed. Plungers are carried in the operating ring collar. When the joint is closed, the plungers fall into tracks on the CEJB, which allows the joint to be opened only when the operating ring collar and plungers are pushed directly away from the joining end. One application of this invention is the rapid assembly and disassembly of diverse skeletal framework structures which is extremely important in many projects involving the exploration of space.

  13. Input/output system for multiprocessors

    SciTech Connect

    Bernick, D.L.; Chan, K.K.; Chan, W.M.; Dan, Y.F.; Hoang, D.M.; Hussain, Z.; Iswandhi, G.I.; Korpi, J.E.; Sanner, M.W.; Zwangerman, J.A.

    1989-04-11

    A device controller is described, comprising: a first port-input/output controller coupled to a first input/output channel bus; and a second port-input/output controlled coupled to a second input/output channel bus; each of the first and second port-input/output controllers having: a first ownership latch means for granting shared ownership of the device controller to a first host processor to provide a first data path on a first I/O channel through the first port I/O controller between the first host processor and any peripheral, and at least a second ownership latch means operative independently of the first ownership latch means for granting shared ownership of the device controller to a second host processor independently of the first port input/output controller to provide a second data path on a second I/O channel through the second port I/O controller between the second host processor and any peripheral devices coupled to the device controller.

  14. The X-43 Fin Actuation System Problem - Reliability in Shades of Gray

    NASA Technical Reports Server (NTRS)

    Peebles, Curtis

    2006-01-01

    Following the loss of the first X-43 during launch, the mishap investigation board indicated the Fin Actuator System (FAS) needed to have a larger torque margin. To supply this added torque, a second actuator was added. The consequences of what seemed to be a simple modification would trouble the X-43 program. Because of the second actuator, a new computer board was required. This proved to be subject to electronic noise. This resulted in the actuator latch up in ground tests of the FAS for the second launch. Such a latch up would cause the Pegasus booster to fail, as the FAS was a single string system. The problem was corrected and the second flight was successful. The same modifications were added to the FAS for flight three. When the FAS underwent ground tests, it also latched up. The failure indicated that each computer board had a different tolerance to electronic noise. The problem with the FAS was corrected. Subsequently, another failure occurred, raising questions about the design, and the probability of failure for the X-43 Mach 10 flight. This was not simply a technical issue, but illuminated the difficulties facing both managers and engineers in assessing risk, design requirements, and probabilities in cutting edge aerospace projects.

  15. Well christmas tree guard apparatus

    SciTech Connect

    Camos, W.M.; Doize, W.L.

    1981-11-17

    An oil or gas well christmas tree guard apparatus provides an annular guard body which is protectively secured about a bolted flanged connection of the well christmas tree, the guard so placed forming an envelope about the flanged connection and preventing access by a thief to the bolts and thus discouraging removal of the bolts from the bolted connection. The protective guard body thus prevents removal of the christmas tree from its location at the well head by theft denying access to the bolted connection which flanges the christmas tree to the remainder of the well. In the preferred embodiment the guard body provides a pair of annular shroud halves which are hingedly connected allowing them to be pivotally moved from an outer position allowing removal from the flanged connection to an inner closed operative position providing an overall annular guard body which is latched into position about the desired bolted connection. The guard body hinge as well as the latch structure can be protectively covered by a connected shroud or housing about the latch structure, or the hinge respectively.

  16. Technology development for cryogenic deployable telescope structures and mechanisms

    NASA Astrophysics Data System (ADS)

    Atkinson, Charles B.; Gilman, Larry; Reynolds, Paul

    2003-12-01

    At 6-7 meters in diameter, the James Webb Space Telescope (JWST) will require structures that remain stable to levels that are on the order of 10 nanometers under dynamic and thermal loading while operating at cryogenic temperatures. Moreover, the JWST will be the first telescope in space that is deployed, resulting in an aperture that is not only segmented, but has hinge-lines and the associated joining systems or latches in it. In order to understand the behavior and reduce the risk associated with very large, deployed structures and the stability of the associated structure and latches, we developed and tested the largest cryogenic structure ever built and then characterized its stability. This paper presents a description of the design of the Development Optical Telescope Assembly (DOTA), the testing performed, and the results of the testing performed on it. We discuss the material selection and characterization processes, give a description of the test configurations, describe the metrology equipment and the validation process for it, provide the test results, and summarize the conclusions drawn from the results. The testing and associated results include characterization of the thermal stability of the large-scale structure, characterization of the micro-dynamic stability of the latching system, and measurements of the deployment capability of the mechanisms. We also describe how the DOTA design relates to the JWST design and how the test results relate to the JWST requirements.

  17. Eight-Channel Continuous Timer

    NASA Technical Reports Server (NTRS)

    Cole, Steven

    2004-01-01

    A custom laboratory electronic timer circuit measures the durations of successive cycles of nominally highly stable input clock signals in as many as eight channels, for the purpose of statistically quantifying the small instabilities of these signals. The measurement data generated by this timer are sent to a personal computer running software that integrates the measurements to form a phase residual for each channel and uses the phase residuals to compute Allan variances for each channel. (The Allan variance is a standard statistical measure of instability of a clock signal.) Like other laboratory clock-cycle-measuring circuits, this timer utilizes an externally generated reference clock signal having a known frequency (100 MHz) much higher than the frequencies of the input clock signals (between 100 and 120 Hz). It counts the number of reference-clock cycles that occur between successive rising edges of each input clock signal of interest, thereby affording a measurement of the input clock-signal period to within the duration (10 ns) of one reference clock cycle. Unlike typical prior laboratory clock-cycle-measuring circuits, this timer does not skip some cycles of the input clock signals. The non-cycle-skipping feature is an important advantage because in applications that involve integration of measurements over long times for characterizing nominally highly stable clock signals, skipping cycles can degrade accuracy. The timer includes a field-programmable gate array that functions as a 20-bit counter running at the reference clock rate of 100 MHz. The timer also includes eight 20-bit latching circuits - one for each channel - at the output terminals of the counter. Each transition of an input signal from low to high causes the corresponding latching circuit to latch the count at that instant. Each such transition also sets a status flip-flop circuit to indicate the presence of the latched count. A microcontroller reads the values of all eight status flipflops

  18. Depressurization valve

    DOEpatents

    Skoda, George I.

    1989-01-01

    A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring--preferably of the Belleville variety--acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion. The latch plate in surrounding the stem is limited in its outward movement by a boss attached to the stem at the end of

  19. Affinity for MgADP and force of unbinding from actin of myosin purified from tonic and phasic smooth muscle

    PubMed Central

    Léguillette, Renaud; Zitouni, Nedjma B.; Govindaraju, Karuthapillai; Fong, Laura M.; Lauzon, Anne-Marie

    2008-01-01

    Smooth muscle is unique in its ability to maintain force at low MgATP consumption. This property, called the latch state, is more prominent in tonic than phasic smooth muscle. Studies performed at the muscle strip level have suggested that myosin from tonic muscle has a greater affinity for MgADP and therefore remains attached to actin longer than myosin from phasic muscle, allowing for cross-bridge dephosphorylation and latch-bridge formation. An alternative hypothesis is that after dephosphorylation, myosin reattaches to actin and maintains force. We investigated these fundamental properties of smooth muscle at the molecular level. We used an in vitro motility assay to measure actin filament velocity (νmax) when propelled by myosin purified from phasic or tonic muscle at increasing [MgADP]. Myosin was 25% thiophosphorylated and 75% unphosphorylated to approximate in vivo conditions. The slope of νmax versus [MgADP] was significantly greater for tonic (−0.51 ± 0.04) than phasic muscle myosin (−0.15 ± 0.04), demonstrating the greater MgADP affinity of myosin from tonic muscle. We then used a laser trap assay to measure the unbinding force from actin of populations of unphosphorylated tonic and phasic muscle myosin. Both myosin types attached to actin, and their unbinding force (0.092 ± 0.022 pN for phasic muscle and 0.084 ± 0.017 pN for tonic muscle) was not statistically different. We conclude that the greater affinity for MgADP of tonic muscle myosin and the reattachment of dephosphorylated myosin to actin may both contribute to the latch state. PMID:18614813

  20. Reconfigurable Fault Tolerance for FPGAs

    NASA Technical Reports Server (NTRS)

    Shuler, Robert, Jr.

    2010-01-01

    The invention allows a field-programmable gate array (FPGA) or similar device to be efficiently reconfigured in whole or in part to provide higher capacity, non-redundant operation. The redundant device consists of functional units such as adders or multipliers, configuration memory for the functional units, a programmable routing method, configuration memory for the routing method, and various other features such as block RAM, I/O (random access memory, input/output) capability, dedicated carry logic, etc. The redundant device has three identical sets of functional units and routing resources and majority voters that correct errors. The configuration memory may or may not be redundant, depending on need. For example, SRAM-based FPGAs will need some type of radiation-tolerant configuration memory, or they will need triple-redundant configuration memory. Flash or anti-fuse devices will generally not need redundant configuration memory. Some means of loading and verifying the configuration memory is also required. These are all components of the pre-existing redundant FPGA. This innovation modifies the voter to accept a MODE input, which specifies whether ordinary voting is to occur, or if redundancy is to be split. Generally, additional routing resources will also be required to pass data between sections of the device created by splitting the redundancy. In redundancy mode, the voters produce an output corresponding to the two inputs that agree, in the usual fashion. In the split mode, the voters select just one input and convey this to the output, ignoring the other inputs. In a dual-redundant system (as opposed to triple-redundant), instead of a voter, there is some means to latch or gate a state update only when both inputs agree. In this case, the invention would require modification of the latch or gate so that it would operate normally in redundant mode, and would separately latch or gate the inputs in non-redundant mode.

  1. Space storable propulsion components development

    NASA Technical Reports Server (NTRS)

    Hagler, R., Jr.

    1982-01-01

    The current development status of components to control the flow of propellants (liquid fluorine and hydrazine) in a demonstration space storable propulsion system is discussed. The criteria which determined the designs for the pressure regulator, explosive-actuated valves, propellant shutoff valve, latching solenoid-actuated valve and propellant filter are presented. The test philosophy that was followed during component development is outlined. The results from compatibility demonstrations for reusable connectors, flange seals, and CRES/Ti-6Al4V transition tubes and the evaluations of processes for welding (hand-held TIG, automated TIG, and EB), cleaning for fluorine service, and decontamination after fluorine exposure are described.

  2. During STS-32 retrieval, RMS lowers LDEF into OV-102's payload bay (PLB)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    During STS-32 retrieval activities, the Long Duration Exposure Facility (LDEF) grappled by the remote manipulator system (RMS) end effector is lowered into Columbia's, Orbiter Vehicle (OV) 102's, lit payload bay (PLB). The scene is framed in an aft flight deck viewing window. Visible on the 14 ft (4.3 meter) end of LDEF is the support structure with payload retention latch assembly (PRLA) trunnions that will secure the reusable 12-sided structure in the PLB during reentry and landing. In the background, highlighted against the Earth's surface are OV-102's wings, the orbital maneuvering system (OMS) pods, and the vertical tail.

  3. Gaseous-fuel engine technology

    SciTech Connect

    1995-12-31

    This publication contains three distinct groups of papers covering gaseous-fuel injection and control, gaseous-fuel engine projects, and gaseous-fuel engine/vehicle applications. Contents include: ultra rapid natural gas port injection; a CNG specific fuel injector using latching solenoid technology; development of an electronically-controlled natural gas-fueled John Deere PowerTech 8.1L engine; adapting a Geo Metro to run on natural gas using fuel-injection technology; behavior of a closed loop controlled air valve type mixer on a natural gas fueled engine under transient operation; and a turbocharged lean-burn 4.3 liter natural gas engine.

  4. Applications of optical computing to problems with symbolic computations. Quarterly report No. 7, 1 August 1986-1 November 1987

    SciTech Connect

    Kushner, B.G.

    1987-10-31

    This report experimentally demonstrates digital all-optical Compare and Energy circuits based on original designs. The circuits uses ZnS bistable optical devices in novel operational modes such as bidirectional and latching logic. These modes are central to the low complexity of the implementation. In addition, the experimental demonstration utilizes polarization multiplexing and filtering to reduce crosstalk, losses, and feedback in the optical system. The capabilities of optical-interconnection networks are generally useful in parallel processing and specifically useful in sorting.

  5. Charge state hysteresis in semiconductor quantum dots

    SciTech Connect

    Yang, C. H.; Rossi, A. Lai, N. S.; Leon, R.; Lim, W. H.; Dzurak, A. S.

    2014-11-03

    Semiconductor quantum dots provide a two-dimensional analogy for real atoms and show promise for the implementation of scalable quantum computers. Here, we investigate the charge configurations in a silicon metal-oxide-semiconductor double quantum dot tunnel coupled to a single reservoir of electrons. By operating the system in the few-electron regime, the stability diagram shows hysteretic tunnelling events that depend on the history of the dots charge occupancy. We present a model which accounts for the observed hysteretic behaviour by extending the established description for transport in double dots coupled to two reservoirs. We demonstrate that this type of device operates like a single-electron memory latch.

  6. Optimised quantum hacking of superconducting nanowire single-photon detectors.

    PubMed

    Tanner, Michael G; Makarov, Vadim; Hadfield, Robert H

    2014-03-24

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack. PMID:24664022

  7. Processes to Open the Container and the Sample Catcher of the Hayabusa Returned Capsule in the Planetary Material Sample Curation Facility of JAXA

    NASA Technical Reports Server (NTRS)

    Fujimura, A.; Abe, M.; Yada, T.; Nakamura, T.; Noguchi, T.; Okazaki, R.; Ishibashi, Y.; Shirai, K.; Okada, T.; Yano, H.; Zolensky, M. E.; Sandford, S.; Ueno, M.; Mukai, T.; Yoshikawa, M.; Kawaguchi, J.

    2011-01-01

    Japanese spacecraft Hayabusa, which returned from near-Earth-asteroid Itokawa, successfully returned its reentry capsule to the Earth, the Woomera Prohibited Area in Australia in Jun 13th, 2010, as detailed in another paper [1]. The capsule introduced into the Planetary Material Sample Curation Facility in the Sagamihara campus of JAXA in the early morning of June 18th. Hereafter, we describe a series of processes for the returned capsule and the container to recover gas and materials in there. A transportation box of the recovered capsule was cleaned up on its outer surface beforehand and introduced into the class 10,000 clean room of the facility. Then, the capsule was extracted from the box and its plastic bag was opened and checked and photographed the outer surface of the capsule. The capsule was composed of the container, a backside ablator, a side ablator, an electronic box and a supporting frame. The container consists of an outer lid, an inner lid, a frame for latches, a container and a sample catcher, which is composed of room A and B and a rotational cylinder. After the first check, the capsule was packed in a plastic bag with N2 again, and transferred to the Chofu campus in JAXA, where the X-ray CT instrument is situated. The first X-ray CT analysis was performed on the whole returned capsule for confirming the conditions of latches and O-ring seal of the container. The analysis showed that the latches of the container should have worked normally, and that the double Orings of the container seemed to be sealed its sample catcher with no problem. After the first X-ray CT, the capsule was sent back to Sagamihara and introduced in the clean room to exclude the electronic box and the side ablator from the container by hand tools. Then the container with the backside ablator was set firmly to special jigs to fix the lid of container tightly to the container and set to a milling machine. The backside ablator was drilled by the machine to expose heads of bolts

  8. Fabrication of Electrostatically Actuated Microshutters Arrays

    NASA Technical Reports Server (NTRS)

    Oh, L.; Li, M.; Kelly, D.; Kutyrev, A.; Moseley, S.

    2016-01-01

    A new fabrication process has been developed to actuate microshutter arrays (MSA) electrostatically at NASA Goddard Space Flight Center. The microshutters, made with silicon nitride membranes with a pixel size of 100 x 200 sq microns, rotate on torsion bars. The microshutters are actuated, latched, and addressed electrostatically by applying voltages on the electrodes the front and back sides of the microshutters. The atomic layer deposition (ALD) of aluminum oxide was used to insulate electrodes on the back side of walls; the insulation can withstand over 100 V. The ALD aluminum oxide is dry etched, and then the microshutters are released in vapor HF.

  9. Scaling and Single Event Effects (SEE) Sensitivity

    NASA Technical Reports Server (NTRS)

    Oldham, Timothy R.

    2003-01-01

    This paper begins by discussing the potential for scaling down transistors and other components to fit more of them on chips in order to increasing computer processing speed. It also addresses technical challenges to further scaling. Components have been scaled down enough to allow single particles to have an effect, known as a Single Event Effect (SEE). This paper explores the relationship between scaling and the following SEEs: Single Event Upsets (SEU) on DRAMs and SRAMs, Latch-up, Snap-back, Single Event Burnout (SEB), Single Event Gate Rupture (SEGR), and Ion-induced soft breakdown (SBD).

  10. Astronaut Story Musgrave during STS-6 EVA

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Astronaut F. Story Musgrave, STS-6 mission specialist, translates down the Challenger's payload bay door hinge line with a bag of latch tools. In the lower left foreground are three canisters containing three getaway special (GAS) experiments. Part of the starboard wing and orbital maneuvering system (OMS) pod are seen backdropped against the blackness of space. The gold-foil protected object on the right is the airborne support equipment for the now vacated inertial upper stage (IUS) which aided the deployment of the tracking and data relay satellite (TDRS).

  11. Optimised quantum hacking of superconducting nanowire single-photon detectors.

    PubMed

    Tanner, Michael G; Makarov, Vadim; Hadfield, Robert H

    2014-03-24

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.

  12. Optimised quantum hacking of superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    Tanner, Michael G.; Makarov, Vadim; Hadfield, Robert H.

    2014-03-01

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.

  13. Space platform advanced technology study

    NASA Technical Reports Server (NTRS)

    Burns, G.

    1981-01-01

    Current and past space platform and power module studies were utilized to point the way to areas of development for mechanical devices that will be required for the ultimate implementation of a platform erected and serviced by the Shuttle/Orbiter. The study was performed in accordance with a study plan which included: a review of space platform technology; orbiter berthing system requirements; berthing latch interface requirements, design, and model fabrication; berthing umbilical interface requirements and design; adaptive end effector design and model fabrication; and adaptive end effector requirements.

  14. Remotely replaceable tokamak plasma limiter tiles

    DOEpatents

    Gallix, R.

    1987-12-09

    U-shaped tiles placed end-to-end over a pair of parallel runners have two rods which engage L-shaped slots. A sliding bar between the runners has grooves with clips to retain the rods pressed into receiving legs of the L-shaped slots in the runners. Sliding the bar in the direction of retaining legs of the L-shaped slots latches the tiles in place over the wall. Resilient contact strips under the parallel sides of the U-shaped tile assure thermal and electrical contact with the wall. 6 figs.

  15. Motion synchronization of a mechanism to deploy and restow a truss beam

    NASA Technical Reports Server (NTRS)

    Lucy, M.

    1988-01-01

    The functions of the Control of Flexible Structures I (COFS I) deployer and retractor assembly (DRA) are primarily to deploy and retract the Mast I beam, and secondarily to latch, unlatch, and restow the DRA mechanism. The problems associated with the diagonal folding mechanism that retracts the beam is presented, the synchronization requirements critical to the process of restowing the beam is discussed, and a proposed solution to the problem of synchronization between the mechanical systems is presented. In addition, a detailed description is presented of the design and functioning of the DRA.

  16. Breastfeeding infants with congenital torticollis.

    PubMed

    Genna, Catherine Watson

    2015-05-01

    Infants with unilateral sternocleidomastoid tension and associated craniofacial, spinal, and hip asymmetries may feed poorly. Anatomic and muscular asymmetry stress both biomechanics and state control, increasing the potential for difficulty latching and sucking. A combination of positioning modifications to allow the infant to maintain his or her comfortable head tilt and turn, supportive techniques to restore alignment of oral structures, and handling techniques to help activate the weak contralateral muscles have been effective in the author's practice. Lactation consultants can promote positioning and muscle activation strategies and encourage physical therapy referrals for infants who do not respond promptly to reduce the risk of craniofacial deformity and developmental problems.

  17. LAM actuated propellant flow control device

    NASA Astrophysics Data System (ADS)

    Reinicke, Robert H.; Cust, Kevin M.

    1992-02-01

    An advanced design LAM (limited angle motor) positions an integral flow control element for bi-level flow control of storable propellants. The LAM incorporates permanent magnet latching to maintain the flow control element in either the low or high flow position without continuous electrical energization. The LAM stator and rotor are fully sheathed within stainless steel. This construction method permits the LAM to control storable propellants without using dynamic seals to isolate the LAM from the propellants. All welded construction prevents external leakage. The design concept selection rationale and the computer FEA (finite element analysis) methods employed to optimize design characteristics are presented. Correlations of analyses to test results are described.

  18. Soft-error generation due to heavy-ion tracks in bipolar integrated circuits

    NASA Technical Reports Server (NTRS)

    Zoutendyk, J. A.

    1984-01-01

    Both bipolar and MOS integrated circuits have been empirically demonstrated to be susceptible to single-particle soft-error generation, commonly referred to as single-event upset (SEU), which is manifested in a bit-flip in a latch-circuit construction. Here, the intrinsic characteristics of SEU in bipolar (static) RAM's are demonstrated through results obtained from the modeling of this effect using computer circuit-simulation techniques. It is shown that as the dimensions of the devices decrease, the critical charge required to cause SEU decreases in proportion to the device cross-section. The overall results of the simulations are applicable to most integrated circuit designs.

  19. ICPP radioactive liquid and calcine waste technologies evaluation final report and recommendation

    SciTech Connect

    1995-04-01

    Using a formalized Systems Engineering approach, the Latched Idaho Technologies Company developed and evaluated numerous alternatives for treating, immobilizing, and disposing of radioactive liquid and calcine wastes at the Idaho Chemical Processing Plant. Based on technical analysis data as of March, 1995, it is recommended that the Department of Energy consider a phased processing approach -- utilizing Radionuclide Partitioning for radioactive liquid and calcine waste treatment, FUETAP Grout for low-activity waste immobilization, and Glass (Vitrification) for high-activity waste immobilization -- as the preferred treatment and immobilization alternative.

  20. Wireline system for multiple direct push tool usage

    SciTech Connect

    Bratton, Wesley L.; Farrington, Stephen P.; Shinn, II, James D.; Nolet, Darren C.

    2003-11-11

    A tool latching and retrieval system allows the deployment and retrieval of a variety of direct push subsurface characterization tools through an embedded rod string during a single penetration without requiring withdrawal of the string from the ground. This enables the in situ interchange of different tools, as well as the rapid retrieval of soil core samples from multiple depths during a single direct push penetration. The system includes specialized rods that make up the rod string, a tool housing which is integral to the rod string, a lock assembly, and several tools which mate to the lock assembly.

  1. Collapsible high gain antenna

    NASA Technical Reports Server (NTRS)

    Cribb, H. E. (Inventor)

    1973-01-01

    A lightweight small high gain antenna which is capable of being packaged in a collapsed form and automatically expanded when in use is described. The antenna includes a cylindrical housing having a rod with a piston adjacent to one end extending through it. Attached to the outer end of the rod in a normally collapsed state is a helical wire coil. When the gas producing means is activated the piston and rod are shifted outwardly to expand the wire coil. A latch is provided for holding the helical coil in the expanded position.

  2. Design, development and testing of the x-ray timing explorer High Gain Antenna System

    NASA Technical Reports Server (NTRS)

    Lecha, Javier; Woods, Claudia; Phan, Minh

    1995-01-01

    The High Gain Antenna System (HGAS), consisting of two High Gain Antenna Deployment Systems (HGADS) and two Antenna Pointing Systems (APS), is used to position two High Gain Antennas (HGA) on the X-Ray Timing Explorer (XTE). A similar APS will be used on the upcoming Tropical Rainfall Measuring Mission (TRMM). Both XTE and TRMM are NASA in-house satellites. The salient features of the system include the two-axis gimbal and control electronics of the APS and the spring deployment and latch/release mechanisms of the HGADS. This paper describes some of the challenges faced in the design and testing of this system and their resolutions.

  3. Rectifier cabinet static breaker

    SciTech Connect

    Costantino, R.A.; Gliebe, R.J.

    1990-01-01

    A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload.

  4. A novel double trench reverse conducting IGBT with robust freewheeling switch

    NASA Astrophysics Data System (ADS)

    Liheng, Zhu; Xingbi, Chen

    2014-08-01

    The phenomenon that the wide P-emitter region in the conventional reverse conducting insulated gate bipolar transistor (RC-IGBT) results in the non-uniform current distribution in the integrated freewheeling diode (FWD), and then causes a parasitic thyristor to latch-up during its reverse-recovery process, which induces a hot spot in the local region of the device is revealed for the first time. Furthermore, a novel RC-IGBT based on double trench IGBT is proposed. It not only solves the snapback problem but also has uniform current distribution and high ruggedness during the reverse-recovery process.

  5. Optical AND/OR gates based on monolithically integrated vertical cavity laser with depleted optical thyristor structure.

    PubMed

    Choi, Woon-Kyung; Kim, Doo-Gun; Kim, Do-Gyun; Choi, Young-Wan; Choquette, Kent D; Lee, Seok; Woo, Deok-Ha

    2006-11-27

    Latching optical switches and optical logic gates with AND and OR functionality are demonstrated for the first time by the monolithic integration of a vertical cavity lasers with depleted optical thyristor structure. The thyristors have a low threshold current of 0.65 mA and a high on/off contrast ratio of more than 50 dB. By simply changing a reference switching voltage, this single device operates as two logic functions, optical logic AND and OR. The thyristor laser fabricated by using the oxidation process and has achieved high optical output power efficiency and a high sensitivity to the optical input light.

  6. Evaluation of vacuum relays for multi-hundred volt switching applications

    NASA Astrophysics Data System (ADS)

    Larose, A. R.; Dowlet, B. A.

    Twenty-one ITT Jennings RF 4B-26S latching vacuum relays were repetitively operated both with and without arc suppression circuitry in tests simulating high voltage power distribution applications and regulator applications in spacecraft. The simulations covered the 110-170V, 11-15A range for power distribution and the 180-400V, 5-12A range for regulator applications. One relay failed during unsnubbered operation after 45,000 regulator application switching events. The remaining twenty vacuum relays completed the testing schedule successfully.

  7. New Multiple-Times Programmable CMOS ROM Cell

    NASA Astrophysics Data System (ADS)

    Chung, In-Young; Jeong, Seong Yeol; Seo, Sung Min; Lee, Myungjin; Jang, Taesu; Cha, Seon-Yong; Park, Young June

    New concept of CMOS nonvolatile memory is presented with demonstration of cell implementations. The memory cell, which is a comparator basically, makes use of comparator offset for storage quantity and the FN stress phenomena for cell programming. We also propose the stress-packet operation which is the relevant programming method to finely control the offset of the memory cell. The memory cell is multiple-time programmable while it is implemented in a standard CMOS process. We fabricated the memory cell arrays of the latch comparator and demonstrated that it is rewritten several times. We also investigated the reliability of cell data retention by monitoring programmed offsets for several months.

  8. Rectifier cabinet static breaker

    DOEpatents

    Costantino, Jr, Roger A.; Gliebe, Ronald J.

    1992-09-01

    A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload.

  9. 20th Aerospace Mechanisms Symposium. Revised

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The proceedings of the 20th Aerospace Mechanisms Symposium, hosted by the NASA Lewis Research Center, Cleveland, Ohio, on May 7-9, 1986, is documented herein. During the 3 days, 23 technical papers were presented by experts from the United States and Western Europe. A panel discussion by an International group of experts on future directions In mechanisms was also presented; this discussion, however, is not documented herein. The technical topics addressed included deployable structures, electromagnetic devices, tribology, thermal/mechanical/hydraulic actuators, latching devices, positioning mechanisms, robotic manipulators, and computerized mechanisms synthesis.

  10. The Submillimeter Wave Astronomy Satellite (SWAS) solar array system

    NASA Technical Reports Server (NTRS)

    Sneiderman, Gary

    1993-01-01

    The SWAS (Submillimeter Wave Astronomy Satellite) solar array system is described. It is an innovative approach to meet the missions requirements. The SWAS satellite provides a three axis stabilized platform to survey a variety of galactic cloud structures. This system includes highly reliable, lightweight launch latch, deployment, and lock mechanisms, and solar array panels that provide the maximum solar cell area. The design of the solar arrays are the result of system trades that included instrument and spacecraft thermal constraints, attitude control system maneuvering rates and pointing accuracies, the power system, and the spacecraft structure.

  11. Task Panel Sensing with a Movable Camera

    NASA Astrophysics Data System (ADS)

    Wolfe, William J.; Mathis, Donald W.; Magee, Michael; Hoff, William A.

    1990-03-01

    This paper discusses the integration of model based computer vision with a robot planning system. The vision system deals with structured objects with several movable parts (the "Task Panel"). The robot planning system controls a T3-746 manipulator that has a gripper and a wrist mounted camera. There are two control functions: move the gripper into position for manipulating the panel fixtures (doors, latches, etc.), and move the camera into positions preferred by the vision system. This paper emphasizes the issues related to repositioning the camera for improved viewpoints.

  12. Personnel emergency carrier vehicle

    NASA Technical Reports Server (NTRS)

    Owens, Lester J. (Inventor); Fedor, Otto H. (Inventor)

    1987-01-01

    A personnel emergency carrier vehicle is disclosed which includes a vehicle frame supported on steerable front wheels and driven rear wheels. A supply of breathing air is connected to quick connect face mask coupling and umbilical cord couplings for supplying breathing air to an injured worker or attendant either with or without a self-contained atmospheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motion is utilized to drive the vehicle and suitable direction and throttling controls are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator. A steering axis is steerable through a handle to steer the front wheels through a linkage assembly.

  13. Ice Pack Heat Sink Subsystem - Phase I. [astronaut liquid cooling garment design and testing

    NASA Technical Reports Server (NTRS)

    Roebelen, G. J., Jr.

    1973-01-01

    This paper describes the design and test at one-g of a functional laboratory model (non-flight) Ice Pack Heat Sink Subsystem to be used eventually for astronaut cooling during manned space missions. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick connect/disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

  14. The emergence of spontaneous activity in neuronal cultures

    NASA Astrophysics Data System (ADS)

    Orlandi, J. G.; Alvarez-Lacalle, E.; Teller, S.; Soriano, J.; Casademunt, J.

    2013-01-01

    In vitro neuronal networks of dissociated hippocampal or cortical tissues are one of the most attractive model systems for the physics and neuroscience communities. Cultured neurons grow and mature, develop axons and dendrites, and quickly connect to their neighbors to establish a spontaneously active network within a week. The resulting neuronal network is characterized by a combination of excitatory and inhibitory neurons coupled through synaptic connections that interact in a highly nonlinear manner. The nonlinear behavior emerges from the dynamics of both the neurons' spiking activity and synaptic transmission, together with biological noise. These ingredients give rise to a rich repertoire of phenomena that are still poorly understood, including the emergence and maintenance of periodic spontaneous activity, avalanches, propagation of fronts and synchronization. In this work we present an overview on the rich activity of cultured neuronal networks, and detail the minimal theoretical considerations needed to describe experimental observations.

  15. Photoactive Self-Shaping Hydrogels as Noncontact 3D Macro/Microscopic Photoprinting Platforms.

    PubMed

    Liao, Yue; An, Ning; Wang, Ning; Zhang, Yinyu; Song, Junfei; Zhou, Jinxiong; Liu, Wenguang

    2015-12-01

    A photocleavable terpolymer hydrogel cross-linked with o-nitrobenzyl derivative cross-linker is shown to be capable of self-shaping without losing its physical integrity and robustness due to spontaneous asymmetric swelling of network caused by UV-light-induced gradient cleavage of chemical cross-linkages. The continuum model and finite element method are used to elucidate the curling mechanism underlying. Remarkably, based on the self-changing principle, the photosensitive hydrogels can be developed as photoprinting soft and wet platforms onto which specific 3D characters and images are faithfully duplicated in macro/microscale without contact by UV light irradiation under the cover of customized photomasks. Importantly, a quick response (QR) code is accurately printed on the photoactive hydrogel for the first time. Scanning QR code with a smartphone can quickly connect to a web page. This photoactive hydrogel is promising to be a new printing or recording material. PMID:26439808

  16. Ice pack heat sink subsystem - Phase 1, Volume 1

    NASA Technical Reports Server (NTRS)

    Roebelen, G. J., Jr.

    1973-01-01

    The design, development, fabrication, and test at one-g of a functional laboratory model (non-flight) ice pack heat sink subsystem to be used eventually for astronaut cooling during manned space missions are discussed. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick connect/disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

  17. 2010 ESMD Faculty Fellowship Project

    NASA Technical Reports Server (NTRS)

    Carmen, Christina L.; Morris, Tommy; Schmidt, Peter; van Susante, Paul; Zalewski, Janusz; Murphy, Gloria

    2010-01-01

    This slide presentation reviews is composed of 6 individual sections. The first is a introductory section that explains the Exploration Systems Mission Directorate (ESMD) Faculty Fellowship Project, the purpose of which is to prepare selected university faculty to work with senior design students to complete projects that have potential to contribute to NASA objectives. The following university presentations represent the chosen projects: (1) the use of Exploration Toolset for the Optimization of Launch and Space Systems (X-TOOLSS) to optimize the Lunar Wormbot design; (2) development of Hardware Definition Language (HDL) realization of ITU G.729 for FGPA; (3) cryogenic fluid and electrical quick connect system and a lunar regolith design; (4) Lunar Landing Pad development; and (5) Prognostics for complex systems.

  18. Photoactive Self-Shaping Hydrogels as Noncontact 3D Macro/Microscopic Photoprinting Platforms.

    PubMed

    Liao, Yue; An, Ning; Wang, Ning; Zhang, Yinyu; Song, Junfei; Zhou, Jinxiong; Liu, Wenguang

    2015-12-01

    A photocleavable terpolymer hydrogel cross-linked with o-nitrobenzyl derivative cross-linker is shown to be capable of self-shaping without losing its physical integrity and robustness due to spontaneous asymmetric swelling of network caused by UV-light-induced gradient cleavage of chemical cross-linkages. The continuum model and finite element method are used to elucidate the curling mechanism underlying. Remarkably, based on the self-changing principle, the photosensitive hydrogels can be developed as photoprinting soft and wet platforms onto which specific 3D characters and images are faithfully duplicated in macro/microscale without contact by UV light irradiation under the cover of customized photomasks. Importantly, a quick response (QR) code is accurately printed on the photoactive hydrogel for the first time. Scanning QR code with a smartphone can quickly connect to a web page. This photoactive hydrogel is promising to be a new printing or recording material.

  19. Computational design of digital and memory biological devices

    PubMed Central

    Rodrigo, Guillermo

    2008-01-01

    The use of combinatorial optimization techniques with computational design allows the development of automated methods to design biological systems. Automatic design integrates design principles in an unsupervised algorithm to sample a larger region of the biological network space, at the topology and parameter levels. The design of novel synthetic transcriptional networks with targeted behaviors will be key to understand the design principles underlying biological networks. In this work, we evolve transcriptional networks towards a targeted dynamics, by using a library of promoters and coding sequences, to design a complex biological memory device. The designed sequential transcription network implements a JK-Latch, which is fully predictable and richer than other memory devices. Furthermore, we present designs of transcriptional devices behaving as logic gates, and we show how to create digital behavior from analog promoters. Our procedure allows us to propose a scenario for the evolution of multi-functional genetic networks. In addition, we discuss the decomposability of regulatory networks in terms of genetic modules to develop a given cellular function. Summary. We show how to use an automated procedure to design logic and sequential transcription circuits. This methodology will allow advancing the rational design of biological devices to more complex systems, and we propose the first design of a biological JK-latch memory device. Electronic supplementary material The online version of this article (doi:10.1007/s11693-008-9017-0) contains supplementary material, which is available to authorized users. PMID:19003443

  20. A study of rendez-vous docking system

    NASA Astrophysics Data System (ADS)

    Sawai, Shujiro; Kawaguchi, Jun'ichiro; Ishii, Nobuaki; Nakatani, Ichiro; Matsuo, Hiroki

    Ground simulation facilities for docking missions, a docking mechanism, and a relative position/attitude sensor for proximity phase are treated. In the development of a docking mechanism, a ground simulation facility that demonstrates relative motion of two spacecraft (s/c) is a mighty and important tool. Such a simulator shall (1) reproduce relative motion rigorously and, (2) be able to cope with various simulation conditions easily. For docking mechanisms, existing simulator ideas were surveyed. As a result, it was revealed that conventional simulators are not sufficient when it comes to soft-docking with flexible structures. To overcome this difficulty, a new type hardware simulator designated as 'servo-free type' was proposed. As for the docking mechanism itself, a new soft-docking mechanism was proposed. Its target module has four perches placed in a circle, while the chaser module has four corresponding mating mechanisms; diagonally, two of them are ordinary latches that grasp the perches of the target s/c, and the others are just grooves in which the perches fit. In spite of its reduced redundancy, this mechanism works well and is found simpler and lighter than conventional ones. Hardware tests proved the feasibility of a latch controller based on a neural network scheme. A visual sensor was selected as a proximity relative position/attitude sensor. In hardware tests of the sensor, marks were identified easily by using color data, although images were sometimes contaminated.

  1. Simulation of SEU transients in CMOS ICs

    SciTech Connect

    Kaul, N.; Bhuva, B.L.; Kerns, S.E. )

    1991-12-01

    This paper reports that available analytical models of the number of single-event-induced errors (SEU) in combinational logic systems are not easily applicable to real integrated circuits (ICs). An efficient computer simulation algorithm set, SITA, predicts the vulnerability of data stored in and processed by complex combinational logic circuits to SEU. SITA is described in detail to allow researchers to incorporate it into their error analysis packages. Required simulation algorithms are based on approximate closed-form equations modeling individual device behavior in CMOS logic units. Device-level simulation is used to estimate the probability that ion-device interactions produce erroneous signals capable of propagating to a latch (or n output node), and logic-level simulation to predict the spread of such erroneous, latched information through the IC. Simulation results are compared to those from SPICE for several circuit and logic configurations. SITA results are comparable to this established circuit-level code, and SITA can analyze circuits with state-of-the-art device densities (which SPICE cannot). At all IC complexity levels, SITAS offers several factors of 10 savings in simulation time over SPICE.

  2. High resolution digital delay timer

    DOEpatents

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  3. Design and implementation of low power clock gated 64-bit ALU on ultra scale FPGA

    NASA Astrophysics Data System (ADS)

    Gupta, Ashutosh; Murgai, Shruti; Gulati, Anmol; Kumar, Pradeep

    2016-03-01

    64-bit energy efficient Arithmetic and Logic Unit using negative latch based clock gating technique is designed in this paper. The 64-bit ALU is designed using multiplexer based full adder cell. We have designed a 64-bit ALU with a gated clock. We have used negative latch based circuit for generating gated clock. This gated clock is used to control the multiplexer based 64-bit ALU. The circuit has been synthesized on kintex FPGA through Xilinx ISE Design Suite 14.7 using 28 nm technology in Verilog HDL. The circuit has been simulated on Modelsim 10.3c. The design is verified using System Verilog on QuestaSim in UVM environment. We have achieved 74.07%, 92. 93% and 95.53% reduction in total clock power, 89.73%, 91.35% and 92.85% reduction in I/Os power, 67.14%, 62.84% and 74.34% reduction in dynamic power and 25.47%, 29.05% and 46.13% reduction in total supply power at 20 MHz, 200 MHz and 2 GHz frequency respectively. The power has been calculated using XPower Analyzer tool of Xilinx ISE Design Suite 14.3.

  4. Electrothermal Microactuators With Peg Drive Improve Performance for Brain Implant Applications

    PubMed Central

    Anand, Sindhu; Sutanto, Jemmy; Baker, Michael S.; Okandan, Murat; Muthuswamy, Jit

    2013-01-01

    This paper presents a new actuation scheme for in-plane bidirectional translation of polysilicon microelectrodes. The new Chevron-peg actuation scheme uses microelectromechanical systems (MEMS) based electrothermal microactuators to move microelectrodes for brain implant applications. The design changes were motivated by specific needs identified by the in vivo testing of an earlier generation of MEMS microelectrodes that were actuated by the Chevron-latch type of mechanism. The microelectrodes actuated by the Chevron-peg mechanism discussed here show improved performance in the following key areas: higher force generation capability (111 μN per heat strip compared to 50 μN), reduced power consumption (91 mW compared to 360 mW), and reliable performance with consistent forward and backward movements of microelectrodes. Failure analysis of the Chevron-latch and the Chevron-peg type of actuation schemes showed that the latter is more robust to wear over four million cycles of operation. The parameters for the activation waveforms for Chevron-peg actuators were optimized using statistical analysis. Waveforms with a 1-ms time period and a 1-Hz frequency of operation showed minimal error between the expected and the actual movement of the microelectrodes. The new generation of Chevron-peg actuators and microelectrodes are therefore expected to enhance the longevity and performance of implanted microelectrodes in the brain.  [2011-0341] PMID:24431926

  5. Comparative Performance of Rear Facing Child Restraint Systems on the CMVSS 213 Bench and Vehicle Seats

    PubMed Central

    Tylko, Suzanne; Locey, Caitlin M.; Garcia-Espana, J. Felipe; Arbogast, Kristy B.; Maltese, Matthew R.

    2013-01-01

    The purpose of this study was to compare the dynamic response of rear-facing child restraint systems (RFCRS) installed on the CMVSS 213 sled bench and a selection of vehicle seats. Thirty-six sled tests were conducted: three models of rear facing CRS with an anthropomorphic test device (ATD) representing a 12 month old child (CRABI) were affixed via lower anchors (LATCH), 3 point belt without CRS base, and 3 point belt with CRS base to one of three vehicle seats or the CMVSS 213 bench seat. All CRS were subjected to an identical sled acceleration pulse. Two types of matched pair analysis: “bench-to-vehicle” and “method of attachment” were conducted. Statistically significant differences were observed in the kinematic responses of the ATD and the CRS. This is the first study to quantify differences between the regulatory bench and vehicle seats on a system level and evaluate the influence of attachment method. Our results show that the difference in RFCRS forward excursion between 3-point belt with base and LATCH installations was between 1 and 7 percent on the bench and 22 to 76 percent on the vehicle seats. When evaluating the dynamic performance of RFCRS, the use of real vehicle seats from vehicles that commonly carry children may provide valuable insight. The findings would require further confirmation using a broader selection of RFCRS and vehicle seats, before generalizable conclusions can be drawn. PMID:24406967

  6. Capacitor charging FET switcher with controller to adjust pulse width

    NASA Astrophysics Data System (ADS)

    Mihalka, A. M.

    1986-04-01

    A switching power supply includes an FET full bridge, a controller to drive the FETs, a programmable controller to dynamically control final output current by adjusting pulse width, and a variety of protective systems, including an overcurrent latch for current control. Power MOSFETS are switched at a variable frequency from 20 to 50 kHz to charge a capacitor load from 0 to 6 kV. A ferrite transformer steps up the dc input. The transformer primary is a full bridge configuration with the FET switches and the secondary is fed into a high voltage full wave rectifier whose output is connected directly to the energy storage capacitor. The peak current is held constant by varying the pulse width using predetermined timing resistors and counting pulses. The pulse width is increased as the capacitor charges to maintain peak current. A digital ripple counter counts pulses, and after the desired number is reached, an up-counter is clocked. The up-counter output is decoded to choose among different resistors used to discharge a timing capacitor, thereby determining the pulse width. A current latch shuts down the supply on overcurrent due to either excessive pulse width causing transformer saturation or a major bridge fault, i.e., FET or transformer failure, or failure of the drive circuitry.

  7. Digital time delay

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

  8. Deep well pump

    SciTech Connect

    Downen, J.L.; Sutliff, W.N.

    1981-06-16

    A pump barrel open at its lower end is coupled at its upper end by a tubular adapter assembly to the lower end of a pump tubing string. This assembly presents an internal bevelled sealing latching annulus, an axially bored pump head being radially expansively spring latched in a fixed axial sealed relation with the annulus to seal the upper end of the pump barrel from the adapter assembly to form a pump compression chamber surrounding a hollow polish rod extending upwardly from a plunger mounted on the lower end of the polish rod for reciprocation in the pump barrel. The plunger carries tandem travelling valves close beneath its connection with the polish rod. The lower valve opening to receive oil through the barrel and plunger on the down stroke and concurrently delivering such oil into the compression chamber. The upper valve closes on the down stroke and opening on the up stroke during which the lower valve closes to expel oil trapped in the compression chamber upward through the upper valve into the lower end of the hollow polish rod which oil is discharged at the upper end thereof into the pump tubing string through the fitting adapting the polish rod to the lower end of the sucker rod.

  9. Toggle release

    NASA Technical Reports Server (NTRS)

    Graves, Thomas Joseph (Inventor); Yang, Robert Alexander (Inventor); Brown, Christopher William (Inventor)

    1988-01-01

    The invention relates to a pyrotechnic actuated release mechanism which is mechanically two fault tolerant for effecting release. It is particularly well suited for releasably connecting structures to be used in the space environment or in other aerospace applications. The device comprises a fastener plate and fastener body, each attachable to either one of a pair of structures to be joined. The fastener plate and the body are fastenable by a toggle supported at one end on the fastener plate and mounted for universal pivotal movement thereon. At its other end, which is received in a central opening in the fastener body and adapted for limited pivotal movement therein, the toggle is restrained by three retractable latching pins. Each pin is individually retractable by combustion of a pyrotechnic charge. While retraction of all three pins releases the toggle, the fastener is mechanically two fault tolerant since the failure of any single or pair of the latch pins to retract results in an asymmetrical loading on the toggle and its pivotal movement to effect a release. An annular bolt is mounted on the fastener plate as a support for the socket mounting of the toggle whereby its selective axial movement provides a means for pre-loading the toggle.

  10. Reliability Design for Neutron Induced Single-Event Burnout of IGBT

    NASA Astrophysics Data System (ADS)

    Shoji, Tomoyuki; Nishida, Shuichi; Ohnishi, Toyokazu; Fujikawa, Touma; Nose, Noboru; Hamada, Kimimori; Ishiko, Masayasu

    Single-event burnout (SEB) caused by cosmic ray neutrons leads to catastrophic failures in insulated gate bipolar transistors (IGBTs). It was found experimentally that the incident neutron induced SEB failure rate increases as a function of the applied collector voltage. Moreover, the failure rate increased sharply with an increase in the applied collector voltage when the voltage exceeded a certain threshold value (SEB cutoff voltage). In this paper, transient device simulation results indicate that impact ionization at the n-drift/n+ buffer boundary is a crucially important factor in the turning-on of the parasitic pnp transistor, and eventually latch-up of the parasitic thyristor causes SEB. In addition, the device parameter dependency of the SEB cutoff voltage was analytically derived from the latch-up condition of the parasitic thyristor. As a result, it was confirmed that reducing the current gain of the parasitic transistor, such as by increasing the n-drift region thickness d was effective in increasing the SEB cutoff voltage. Furthermore, `white' neutron-irradiation experiments demonstrated that suppressing the inherent parasitic thyristor action leads to an improvement of the SEB cutoff voltage. It was confirmed that current gain optimization of the parasitic transistor is a crucial factor for establishing highly reliable design against chance failures.

  11. Novel substrate trigger SCR-LDMOS stacking structure for high-voltage ESD protection application

    NASA Astrophysics Data System (ADS)

    Ma, Jin-Rong; Ming, Qiao; Zhang, Bo

    2015-04-01

    A novel substrate trigger semiconductor control rectifier-laterally diffused metal-oxide semiconductor (STSCR-LDMOS) stacked structure is proposed and simulated using the transimission line pulser (TLP) multiple-pulse simulation method in a 0.35-μm, 60-V biploar-CMOS-DMOS (BCD) process without additional masks. On account of a very low holding voltage, it is susceptible to latch-up-like danger for the semiconductor control rectifier-laterally diffused metal-oxide semiconductor (SCR-LDMOS) in high-voltage electro-static discharge (ESD) protection applications. Although the conventional stacking structure has achieved strong latch-up immunity by increasing holding voltage, excessive high trigger voltage does not meet requirements for an ESD protection device. The holding voltage of the proposed stacked structure is proportional to the stacking number, whereas the trigger voltage remains nearly the same. A high holding voltage of 30.6 V and trigger voltage of 75.4 V are achieved.

  12. The integration of novel EAP-based Braille cells for use in a refreshable tactile display

    NASA Astrophysics Data System (ADS)

    Di Spigna, N.; Chakraborti, P.; Winick, D.; Yang, P.; Ghosh, T.; Franzon, P.

    2010-04-01

    Structures demonstrating the viability of both the hydraulic and latching Braille dot, and the dielectric elastomer fiber Braille dot have been fabricated and characterized. A hydraulic proof-of-concept structure has achieved the necessary volumetric change required to lift a Braille dot over 0.5mm at voltages under 1000V and at speeds under 100ms. Long bimorphs have been fabricated that demonstrate large tip displacements over 2mm that could be used to mechanically latch the Braille rod in the 'up' position to achieve the force requirement. The addition of radial prestrain in dielectric elastomer tubes has reduced the wall thickness and directed the strain in the axial direction which has had a dramatic impact on their resulting characteristics. The required bias voltage for the dielectric elastomer fiber Braille dot has been reduced from 15.5kV to 8.75kV while the Braille head tip displacement of a fabricated prototype has almost tripled on average and now also exceeds the required displacement for a refreshable Braille display. Finally, potential solutions to the current shortcomings of both designs in meeting all of the requirements for such a display are discussed.

  13. Magnetic docking aid for orbiter to ISS docking

    NASA Technical Reports Server (NTRS)

    Schneider, William C.; Nagy, Kornel; Schliesing, John A.

    1996-01-01

    The present docking system for the Orbiter uses mechanical capture latches that are actuated by contact forces. The forces are generated when the two approaching masses collide at the docking mechanism. There is always a trade-off between having high enough momentum to effect capture and low enough momentum to avoid structural overload or unacceptable angular displacements. The use of the present docking system includes a contact thrusting maneuver that causes high docking loads to be included into Space Station. A magnetic docking aid has been developed to reduce the load s during docking. The magnetic docking aid is comprised of two extendible booms that are attached adjacent to the docking structure with electromagnets attached on the end of the boom. On the mating vehicle, two steel plates are attached. As the Orbiter approaches Space Station, the booms are extended, and the magnets attach to the actuated (without thrusting), by slowly driving the extendible booms to the stowed position, thus reacting the load into the booms. This results in a docking event that has lower loads induced into Space Station structure. This method also greatly simplifies the Station berthing tasks, since the Shuttle Remote Manipulation System (SRMS) arm need only place the element to be berthed on the magnets (no load required), rather than firing the Reaction Control System (RCS) jets to provide the required force for capture latch actuation. The Magnetic Docking Aid was development testing on a six degree-of-freedom (6 DOF) system at JSC.

  14. Subsea production test valve assembly

    SciTech Connect

    Yates, P.D.

    1988-03-22

    In the subsea test assembly securable within a blowout preventer stack above a subterranean well and positionable between upper and lower portions of a tubular conduit in fluid communication with a production zone within the well, the test assembly is described including an upper subassembly carriable with the upper conduit portion, a lower subassembly carriable with the lower conduit portion, and valve means in the lower subassembly manipulatable between opened and closed positions to control fluid flow within the conduit. The improvement comprises: the upper subassembly including an upper housing and first rigid dog means fixedly secured to the upper housing; the lower subassembly including a lower housing and second rigid dog means fixedly secured to the lower housing; the first rigid dog means positionable between a latch position for latching the upper and lower subassemblies and an unlatch position for unlatching the upper and lower subassemblies upon rotational movement of the first dog means with respect to the second dog means; and lock means axially movable relative to the first and second dog means from a lock position for limiting rotational movement of the first dog means with respect to the second dog means to an unlock position for allowing the first dog means to rotate relative to the second dog means and unlatch the upper subassembly from the lower subassembly.

  15. Release mechanism for releasing and reattaching experiments on the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Clark, A. V.

    1980-01-01

    The release mechanism (REM) unlatches an experiment so that it can be moved about inside and outside the shuttle bay by the remote manipulator system (RMS), and then reattaches it to the REM base. Operated from the crew compartment after the RMS has been attached to the experiment, the REM releases the experiment by an electric motor driving a gear train and linkage which extracts four pins from holes in four plates. Electrical connectors on the REM are disengaged by the mechanical action of the structural pins retracting from the plates. When the REM releases the experiment, an unlatched indicator is actuated in the crew compartment, and then the experiment can be moved by using the RMS. To reattach the experiment to the REM, the RMS places the experiment with REM attachment angles against the flat, smooth surface of the REM; then the RMS moves the experiment into position for latchup. Actuation of an electric motor drives the four pins into the four holes in the plates. When fully latched, a switch actuated by the motion of the linkage, shuts the electric motor off and gives an indication to the crew compartment that the REM is latched.

  16. Electrothermal Microactuators With Peg Drive Improve Performance for Brain Implant Applications.

    PubMed

    Anand, Sindhu; Sutanto, Jemmy; Baker, Michael S; Okandan, Murat; Muthuswamy, Jit

    2012-07-13

    This paper presents a new actuation scheme for in-plane bidirectional translation of polysilicon microelectrodes. The new Chevron-peg actuation scheme uses microelectromechanical systems (MEMS) based electrothermal microactuators to move microelectrodes for brain implant applications. The design changes were motivated by specific needs identified by the in vivo testing of an earlier generation of MEMS microelectrodes that were actuated by the Chevron-latch type of mechanism. The microelectrodes actuated by the Chevron-peg mechanism discussed here show improved performance in the following key areas: higher force generation capability (111 μN per heat strip compared to 50 μN), reduced power consumption (91 mW compared to 360 mW), and reliable performance with consistent forward and backward movements of microelectrodes. Failure analysis of the Chevron-latch and the Chevron-peg type of actuation schemes showed that the latter is more robust to wear over four million cycles of operation. The parameters for the activation waveforms for Chevron-peg actuators were optimized using statistical analysis. Waveforms with a 1-ms time period and a 1-Hz frequency of operation showed minimal error between the expected and the actual movement of the microelectrodes. The new generation of Chevron-peg actuators and microelectrodes are therefore expected to enhance the longevity and performance of implanted microelectrodes in the brain.  [2011-0341].

  17. Head excursion of restrained human volunteers and hybrid III dummies in steady state rollover tests.

    PubMed

    Moffatt, Edward; Hare, Barry; Hughes, Raymond; Lewis, Lance; Iiyama, Hiroshi; Curzon, Anne; Cooper, Eddie

    2003-01-01

    Seatbelts provide substantial benefits in rollover crashes, yet occupants still receive head and neck injuries from contacting the vehicle roof interior when the roof exterior strikes the ground. Prior research has evaluated rollover restraint performance utilizing anthropomorphic test devices (dummies), but little dynamic testing has been done with human volunteers to learn how they move during rollovers. In this study, the vertical excursion of the head of restrained dummies and human subjects was measured in a vehicle being rotated about its longitudinal roll axis at roll rates from 180-to-360 deg/sec and under static inversion conditions. The vehicle's restraint design was the commonly used 3-point seatbelt with continuous loop webbing and a sliding latch plate. This paper presents an analysis of the observed occupant motion and provides a comparison of dummy and human motion under similar test conditions. Thirty-five tests (eighteen static and seventeen dynamic) were completed using two different sizes of dummies and human subjects in both near and far-side roll directions. The research indicates that far-side rollovers cause the restrained test subjects to have greater head excursion than near-side rollovers, and that static inversion testing underestimates head excursion for far-side occupants. Human vertical head excursion of up to 200 mm was found at a roll rate of 220 deg/sec. Humans exhibit greater variability in head excursion in comparison to dummies. Transfer of seatbelt webbing through the latch plate did not correlate directly with differences in head excursion.

  18. Biological signal processing with a genetic toggle switch.

    PubMed

    Hillenbrand, Patrick; Fritz, Georg; Gerland, Ulrich

    2013-01-01

    Complex gene regulation requires responses that depend not only on the current levels of input signals but also on signals received in the past. In digital electronics, logic circuits with this property are referred to as sequential logic, in contrast to the simpler combinatorial logic without such internal memory. In molecular biology, memory is implemented in various forms such as biochemical modification of proteins or multistable gene circuits, but the design of the regulatory interface, which processes the input signals and the memory content, is often not well understood. Here, we explore design constraints for such regulatory interfaces using coarse-grained nonlinear models and stochastic simulations of detailed biochemical reaction networks. We test different designs for biological analogs of the most versatile memory element in digital electronics, the JK-latch. Our analysis shows that simple protein-protein interactions and protein-DNA binding are sufficient, in principle, to implement genetic circuits with the capabilities of a JK-latch. However, it also exposes fundamental limitations to its reliability, due to the fact that biological signal processing is asynchronous, in contrast to most digital electronics systems that feature a central clock to orchestrate the timing of all operations. We describe a seemingly natural way to improve the reliability by invoking the master-slave concept from digital electronics design. This concept could be useful to interpret the design of natural regulatory circuits, and for the design of synthetic biological systems.

  19. Design and optimization of an ultra-wide frequency range CMOS divide-by-two circuit

    NASA Astrophysics Data System (ADS)

    Bo, Lu; Niansong, Mei; Hu, Chen; Zhiliang, Hong

    2010-11-01

    A novel toggled flip-flop (TFF) divide-by-two circuit (DTC) and its optimization method based on a large-signal analysis approach are proposed. By reducing the output RC constant in tracking mode and making it large in latching mode, compressing the internal signal swing as well as compensating the current leaked in the latching mode, the operating frequency range is greatly expanded. Implemented in a SMIC 0.13 μm RF CMOS process with a 1.2 V power supply, it can work under an ultra-wide frequency band ranging from 320 MHz to 29.6 GHz. Experimental results show that two phase-locked loops (PLLs) with the proposed DTC can achieve in-band phase noise of -94 dBc/Hz @ 10 kHz under 4224 MHz operating frequency and -84 dBc/Hz @ 10 kHz under 10 GHz operating frequency, respectively. The power consumption of the proposed DTC is reduced by almost 50% compared with the conventional counterparts.

  20. Depressurization as an accident management strategy to minimize the consequences of direct containment heating

    SciTech Connect

    Hanson, D.J.; Golden, D.W.; Chambers, R.; Miller, J.D.; Hallbert, B.P.; Dobbe, C.A. )

    1990-10-01

    Probabilistic Risk Assessments (PRAs) have identified severe accidents for nuclear power plants that have the potential to cause failure of the containment through direct containment heating (DCH). Prevention of DCH or mitigation of its effects may be possible using accident management strategies that intentionally depressurize the reactor coolant system (RCS). The effectiveness of intentional depressurization during a station blackout TMLB' sequence was evaluated considering the phenomenological behavior, hardware performance, and operational performance. Phenomenological behavior was calculated using the SCDAP/RELAP5 severe accident analysis code. Two strategies to mitigate DCH by depressurization of the RCS were considered. One strategy, called early depressurization, assumed that the reactor head vent and pressurizer power-operated relief valves (PORVs) were latched open at steam generator dryout. The second strategy, called late depression, assumed that the head vent and PORVs were latched open at a core exit temperature of {approximately}922 K (1200{degree}F). Depressurization of the RCS to a low value that may mitigate DCH was predicted prior to reactor pressure vessel breach for both early and late depressurization. The strategy of late depressurization is preferred over early depressurization because there are greater opportunities to recover plant functions prior to core damage and because failure uncertainties are lessened. 22 refs., 38 figs., 6 tabs.

  1. A new on-chip all-digital three-phase full-bridge dc/ac power inverter with feedforward and frequency control techniques.

    PubMed

    Chen, Jiann-Jong; Kung, Che-Min

    2010-09-01

    The communication speed between components is far from satisfactory. To achieve high speed, simple control system configuration, and low cost, a new on-chip all-digital three-phase dc/ac power inverter using feedforward and frequency control techniques is proposed. The controller of the proposed power inverter, called the shift register, consists of six-stage D-latch flip-flops with a goal of achieving low-power consumption and area efficiency. Variable frequency is achieved by controlling the clocks of the shift register. One advantage regarding the data signal (D) and the common clock (CK) is that, regardless of the phase difference between the two, all of the D-latch flip-flops are capable of delaying data by one CK period. To ensure stability, the frequency of CK must be six times higher than that of D. The operation frequency of the proposed power inverter ranges from 10 Hz to 2 MHz, and the maximum output loading current is 0.8 A. The prototype of the proposed circuit has been fabricated with TSMC 0.35 μm 2P4M CMOS processes. The total chip area is 2.333 x 1.698 mm2. The three-phase dc/ac power inverter is applicable in uninterrupted power supplies, cold cathode fluorescent lamps, and motors, because of its ability to convert the dc supply voltage into the three-phase ac power sources.

  2. Miniature electrically operated diaphragm valve

    DOEpatents

    Adkins, Douglas R.; Spletzer, Barry L.; Wong, Chungnin C.; Frye-Mason, Gregory C.; Fischer, Gary J.; Hesketh, Peter J.

    2001-01-01

    The present invention provides a miniature electrically operated valve that can stand off significant pressures, that can be inexpensively produced, and that can be made to operate without continuous electrical power. A valve according to the present invention comprises a housing and a beam mounted with the housing. A diaphragm mounted with the housing forms a sealed fluid volume. An electromagnetic energy source, such as an electromagnetic coil, mounts with the housing and when energized urges the beam in one direction. The beam can be urged in the opposing direction by passive means or by reversing the polarity of the electromagnetic energy source or by a second electromagnetic energy source. Two fluid ports mount with the housing. A first fluid port mounts so that, as the beam is urged in one direction or the opposite, the beam urges the diaphragm to move between engaging and substantially sealing the fluid port and disengaging and not substantially sealing the fluid port. A seat can be mounted with the diaphragm to aid in sealing the fluid port. Latching mechanisms such as permanent magnets can be mounted so that the valve remains in the open or closed positions without continuous electrical power input. Fluid can flow through the housing between the two fluid ports when the diaphragm does not seal the first fluid port, but can be prevented from flowing by urging the beam so that the diaphragm seals the first fluid port. Various embodiments accommodate various latching mechanisms, electromagnetic energy sources, number of fluid ports, and diaphragm design considerations.

  3. Surge Pressure Mitigation in the Global Precipitation Measurement Mission Core Propulsion System

    NASA Technical Reports Server (NTRS)

    Scroggins, Ashley R.; Fiebig, Mark D.

    2014-01-01

    The Global Precipitation Measurement (GPM) mission is an international partnership between NASA and JAXA whose Core spacecraft performs cutting-edge measurements of rainfall and snowfall worldwide and unifies data gathered by a network of precipitation measurement satellites. The Core spacecraft's propulsion system is a blowdown monopropellant system with an initial hydrazine load of 545 kg in a single composite overwrapped propellant tank. At launch, the propulsion system contained propellant in the tank and manifold tubes upstream of the latch valves, with low-pressure helium gas in the manifold tubes downstream of the latch valves. The system had a relatively high beginning-of- life pressure and long downstream manifold lines; these factors created conditions that were conducive to high surge pressures. This paper discusses the GPM project's approach to surge mitigation in the propulsion system design. The paper describes the surge testing program and results, with discussions of specific difficulties encountered. Based on the results of surge testing and pressure drop analyses, a unique configuration of cavitating venturis was chosen to mitigate surge while minimizing pressure losses during thruster maneuvers. This paper concludes with a discussion of overall lessons learned with surge pressure testing for NASA Goddard spacecraft programs.

  4. Research on Streamlines and Aerodynamic Heating for Unstructured Grids on High-Speed Vehicles

    NASA Technical Reports Server (NTRS)

    DeJarnette, Fred R.; Hamilton, H. Harris (Technical Monitor)

    2001-01-01

    Engineering codes are needed which can calculate convective heating rates accurately and expeditiously on the surfaces of high-speed vehicles. One code which has proven to meet these needs is the Langley Approximate Three-Dimensional Convective Heating (LATCH) code. It uses the axisymmetric analogue in an integral boundary-layer method to calculate laminar and turbulent heating rates along inviscid surface streamlines. It requires the solution of the inviscid flow field to provide the surface properties needed to calculate the streamlines and streamline metrics. The LATCH code has been used with inviscid codes which calculated the flow field on structured grids, Several more recent inviscid codes calculate flow field properties on unstructured grids. The present research develops a method to calculate inviscid surface streamlines, the streamline metrics, and heating rates using the properties calculated from inviscid flow fields on unstructured grids. Mr. Chris Riley, prior to his departure from NASA LaRC, developed a preliminary code in the C language, called "UNLATCH", to accomplish these goals. No publication was made on his research. The present research extends and improves on the code developed by Riley. Particular attention is devoted to the stagnation region, and the method is intended for programming in the FORTRAN 90 language.

  5. Biological Signal Processing with a Genetic Toggle Switch

    PubMed Central

    Hillenbrand, Patrick; Fritz, Georg; Gerland, Ulrich

    2013-01-01

    Complex gene regulation requires responses that depend not only on the current levels of input signals but also on signals received in the past. In digital electronics, logic circuits with this property are referred to as sequential logic, in contrast to the simpler combinatorial logic without such internal memory. In molecular biology, memory is implemented in various forms such as biochemical modification of proteins or multistable gene circuits, but the design of the regulatory interface, which processes the input signals and the memory content, is often not well understood. Here, we explore design constraints for such regulatory interfaces using coarse-grained nonlinear models and stochastic simulations of detailed biochemical reaction networks. We test different designs for biological analogs of the most versatile memory element in digital electronics, the JK-latch. Our analysis shows that simple protein-protein interactions and protein-DNA binding are sufficient, in principle, to implement genetic circuits with the capabilities of a JK-latch. However, it also exposes fundamental limitations to its reliability, due to the fact that biological signal processing is asynchronous, in contrast to most digital electronics systems that feature a central clock to orchestrate the timing of all operations. We describe a seemingly natural way to improve the reliability by invoking the master-slave concept from digital electronics design. This concept could be useful to interpret the design of natural regulatory circuits, and for the design of synthetic biological systems. PMID:23874595

  6. Torsion/cantilever-based MEMS bistable mechanisms with different support configurations: structure design and comparison

    NASA Astrophysics Data System (ADS)

    Wu, Yibo; Zhang, Congchun; Wang, Hong; Ding, Guifu

    2011-04-01

    Three types of torsion/cantilever-based MEMS bistable mechanisms (BMs) with different support configurations have been constructed, modeled and experimented. For the support configuration, there is a crisscross-shaped, a ring-shaped and a diamond-shaped support beam, respectively. The proposed MEMS BMs consist of a free-free torsion-based cantilever which forms a symmetrical rocker lever. The free-free cantilever is suspended by a support skeleton which in turn is attached to a torsion cantilever. A permanent magnet is attached beside for holding the closed state with a permalloy soft magnetic circuit. The different special support configurations account for a low torsional compliance with the overhanging beams. In order to deduce the equivalent stiffness coefficient of BM systems, mechanical modeling of three types of torsion/cantilever-based MEMS BMs was performed by the classical beam theorem. Meanwhile, the magnetostatic latching force was also deduced by the Maxwell electromagnetism theory. The performances of these MEMS BMs have been compared by the evaluation of static deformation variations, equivalent stiffness coefficients and dynamical switching characterizations. Finally, mechanical performance was characterized by atomic force microscopy, combined with a Nanoindentation Tester. In addition, bistabilities of the MEMS BMs were proved by theoretical analysis as well as experimental results. Among these BMs, the ring-shaped MEMS BM is extremely prone to deflect due to relatively low stiffness compared with other types. The torsion/cantilever-based MEMS BMs have potential application in the field of latching relays with low power consumption.

  7. Capacitor charging FET switcher with controller to adjust pulse width

    DOEpatents

    Mihalka, Alex M.

    1986-01-01

    A switching power supply includes an FET full bridge, a controller to drive the FETs, a programmable controller to dynamically control final output current by adjusting pulse width, and a variety of protective systems, including an overcurrent latch for current control. Power MOSFETS are switched at a variable frequency from 20-50 kHz to charge a capacitor load from 0 to 6 kV. A ferrite transformer steps up the DC input. The transformer primary is a full bridge configuration with the FET switches and the secondary is fed into a high voltage full wave rectifier whose output is connected directly to the energy storage capacitor. The peak current is held constant by varying the pulse width using predetermined timing resistors and counting pulses. The pulse width is increased as the capacitor charges to maintain peak current. A digital ripple counter counts pulses, and after the desired number is reached, an up-counter is clocked. The up-counter output is decoded to choose among different resistors used to discharge a timing capacitor, thereby determining the pulse width. A current latch shuts down the supply on overcurrent due to either excessive pulse width causing transformer saturation or a major bridge fault, i.e., FET or transformer failure, or failure of the drive circuitry.

  8. Separable fastening device

    DOEpatents

    Harvey, Andrew C.; Ribich, William A.; Marinaccio, Paul J.; Sawaf, Bernard E.

    1987-12-01

    A separable fastener system has a first separable member that includes a series of metal hook sheets disposed in stacked relation that defines an array of hook elements on its broad surface. Each hook sheet is a planar metal member of uniform thickness and has a body portion with a series of hook elements formed along one edge of the body. Each hook element includes a stem portion, a deflecting surface portion, and a latch portion. Metal spacer sheets are disposed between the hook sheets and may be varied in thickness and in number to control the density of the hook elements on the broad surface of the first fastener member. The hook and spacer sheets are secured together in stacked relation. A second fastener member has a surface of complementary engaging elements extending along its broad surface which are releasably interengageable with the hook elements of the first fastener member, the deflecting surfaces of the hook elements of the first fastener member tending to deflect hook engaging portions of the second fastener member and the latch portions of the hook elements of the first fastener member engaging portions of the second fastener member in fastening relation.

  9. Optimizing POF/PCF based optical switch for indoor LAN

    NASA Astrophysics Data System (ADS)

    Bhuiyan, M. M. I.; Rashid, M. M.; Ahmed, Sayem; Bhuiyan, M.; Kajihara, M.

    2013-12-01

    For indoor local area network (LAN) the Polymer optical fiber (POF) is mostly appropriate, because of its large core diameter and flexible material. A 1×2 optical switch for indoor LAN using POF and a shape memory alloy (SMA) coil actuator with magnetic latches was successfully fabricated and tested. To achieve switching by the movement of a POF, large displacement is necessary because the core diameter is large (e.g., 0.486mm). A SMA coil actuator is used for large displacement and a magnetic latching system is used for fixing the position of the shifted POF. The insertion loss is 0.40 to 0.50dB and crosstalk is more than 50dB without index-matching oil. Switching speed is less than 1s at a driving current of 80mA. A cycling test was performed 1.4 million times. Polymer clad fiber optical (PCF) switch also fabricated and tasted.

  10. The RGO Generation II: muscle stimulation powered orthosis as a practical walking system for thoracic paraplegics.

    PubMed

    Solomonow, M; Baratta, R; Hirokawa, S; Rightor, N; Walker, W; Beaudette, P; Shoji, H; D'Ambrosia, R

    1989-10-01

    The RGO Generation II reciprocating gait orthosis was jointly developed by Louisiana State University Medical Center and Durr-Fillauer Medical, Inc, to overcome four problems encountered with the existing model: 1) The high energy cost of locomotion; 2) the great arm strength required for patients to stand up from the seated position without assistance; 3) difficulty (especially for patients with hamstring contracture) in remaining standing owing to failure of the knee latch to lock except in full extension; and 4) problems in balancing when ambulating on an incline. The RGO Generation II employs concurrent electrostimulation of the rectus femoris and hamstrings to assist in rising and balancing and a ratchet-type latching device to improve safety and stability in standing. Alternating stimulation of the rectus femoris and contralateral hamstrings are used for locomotion. Testing in six patients with thoracic paraplegia demonstrated an average 30+% reduction in energy expenditure at a walking speed of .05 m/s and a 15+% reduction at .37 m/s; improved mobility and better balance on inclines; and unassisted rising in all patients. Walking range was increased from an average of 100 m to an average of 800 m. More research is needed to provide stair-climbing ability and to further reduce energy expenditure.

  11. Dexterous end effector flight demonstration

    NASA Technical Reports Server (NTRS)

    Carter, Edward L.; Monford, Leo G.

    1994-01-01

    The Dexterous End Effector Flight Experiment is a flight demonstration of newly developed equipment and methods which make for more dexterous manipulation of robotic arms. The following concepts are to be demonstrated: The Force Torque Sensor is a six axis load cell located at the end of the RMS which displays load data to the operator on the orbiter CCTV monitor. TRAC is a target system which provides six axis positional information to the operator. It has the characteristic of having high sensitivity to attitude misalignment while being flat. AUTO-TRAC is a variation of TRAC in which a computer analyzes a target, displays translational and attitude misalignment information, and provides cues to the operator for corrective inputs. The Magnetic End Effector is a fault tolerant end effector which grapples payloads using magnetic attraction. The Carrier Latch Assembly is a fault tolerant payload carrier, which uses mechanical latches and/or magnetic attraction to hold small payloads during launch/landing and to release payloads as desired. The flight experiment goals and objectives are explained. The experiment equipment is described, and the tasks to be performed during the demonstration are discussed.

  12. Fabrication of MEMS-Based Microshutter Arrays for Optical Transmission Selection

    NASA Technical Reports Server (NTRS)

    Lynch, Bernard A.; Franz, David E.; Hu, R. G.; Jhabvala, M. D.; Kotecki, C. A.; Li, M. J.; Oh, H.; Zheng, Y.

    2004-01-01

    A MEMS-based programmable aperture mask is under development at the NASA Goddard Space Flight Center. Termed the Microshutter (u-shutter) Array, the device will be used to control the transmission of light, with both high efficiency and contrast, to a multi-object spectrometer on the James Webb Space Telescope. Fabrication of the p-shutter array employs several novel designs and processing techniques. The current generation of micro-shutters consists of 128x64 pixel arrays with unit cell dimensions of 100x200 microns. Shutters are patterned in silicon nitride and sit on a 100 micron silicon frame that is DRIE etched below each shutter. The front and back sides of the device are shown. A magnetic cobalt-iron alloy patterned on top of the shutter allows it to be actuated 90 degrees out-of-plane, into the frame, by an external magnetic field. An electrode on the shutter and a vertical electrode on the sidewall of the frame, approximately 90pm deep, allow them to be electrostatically latched in their rotated position. The vertical electrode is deposited and patterned on the backside of the frame in a single step using a directionally controlled evaporation. Individual addressing of shutters for electrostatic latching is accomplished via a crosspoint addressing scheme, with no on-chip active components. A portion of an array with shutters in the open, latched, and closed positions is shown. Light loss at shutter edges is minimized by an overhanging aluminum light-shield that is anchored to the frame. A photoresist sacrificial layer is used to raise the light-shield up and over the 2 micron gap that surrounds each pixel. After completion, arrays are subjected to life cycle, environmental and optical testing. Fabricated devices have survived 10(exp 6) actuation cycles at both room and cryogenic temperatures and a 14g rms launch-simulation test. Optical testing has shown contrast measurements between open and closed shutters up to 10000:1.

  13. Programmable Aperture with MEMS Microshutter Arrays

    NASA Technical Reports Server (NTRS)

    Moseley, Samuel; Li, Mary; Kutyrev, Alexander; Kletetschka, Gunther; Fettig, Rainer

    2011-01-01

    A microshutter array (MSA) has been developed for use as an aperture array for multi-object selections in James Webb Space Telescope (JWST) technology. Light shields, molybdenum nitride (MoN) coating on shutters, and aluminum/aluminum oxide coatings on interior walls are put on each shutter for light leak prevention, and to enhance optical contrast. Individual shutters are patterned with a torsion flexure that permits shutters to open 90 deg. with a minimized mechanical stress concentration. The shutters are actuated magnetically, latched, and addressed electrostatically. Also, micromechanical features are tailored onto individual shutters to prevent stiction. An individual shutter consists of a torsion hinge, a shutter blade, a front electrode that is coated on the shutter blade, a backside electrode that is coated on the interior walls, and a magnetic cobalt-iron coating. The magnetic coating is patterned into stripes on microshutters so that shutters can respond to an external magnetic field for the magnetic actuation. A set of column electrodes is placed on top of shutters, and a set of row electrodes on sidewalls is underneath the shutters so that they can be electrostatically latched open. A linear permanent magnet is aligned with the shutter rows and is positioned above a flipped upside-down array, and sweeps across the array in a direction parallel to shutter columns. As the magnet sweeps across the array, sequential rows of shutters are rotated from their natural horizontal orientation to a vertical open position, where they approach vertical electrodes on the sidewalls. When the electrodes are biased with a sufficient electrostatic force to overcome the mechanical restoring force of torsion bars, shutters remain latched to vertical electrodes in their open state. When the bias is removed, or is insufficient, the shutters return to their horizontal, closed positions. To release a shutter, both the electrode on the shutter and the one on the back wall where

  14. The scanning mechanism for ROSETTA/MIDAS: from an engineering model to the flight model

    NASA Astrophysics Data System (ADS)

    Le Letty, R.; Barillot, F.; Lhermet, N.; Claeyssen, F.; Yorck, M.; Gavira Izquierdo, J.; Arends, H.

    2001-09-01

    The MIDAS (Micro Imaging Dust Analysis System) instrument jointly developed by IWF Graz (AT) and the Solar Space Division of ESA/ESTEC (NL) will flow on ROSETTA and will analyse the dust of the 46P/Wirtanen comet using an Atomic Force Microscope (AFM). A piezoelectric XYZ stage, used to scan the sample in 3 axis, is part of the instrument and has been fully designed and qualified under the ESA/ESTEC contract no13090/98/NL/MV. Two qualification models (EQM/QM) and two flight models (FM/FSM) have been integrated and fully tested within 18 months. The basic principle of the stage has been described in a previous paper. The XY stage includes a latch mechanism based on two Shape Memory actuators. This paper focuses on the lessons learned during the qualification campaign, especially on the testing activities and on the latch mechanism. The XYZ stage has followed a full qualification campaign including Thermal Vacuum cycles, Random Vibrations tests and lifetime tests. The latch mechanism has been designed and tested with the following features: easiness of locking and refurbishment operations, compatibility with the parallel two degrees of freedom mechanism, low shock device. It has been tested more than 20 times, including 4 tests in the worst case conditions (eg the most demanding power case at -20°C) and 2 times after a vibration test. The results and the parameters influencing the reproducibility are discussed. The functional performances have been assessed using a dedicated test bench. Comments are made on the measurements techniques used to get results independent from the drift effect displayed by the piezo components. The calibration work (static and gain of the position sensors) have played an important role during the testing activities. Several parameters (temperature, piezo drift effect and external forces acting on the stage and coming from the coarse approach mechanism) affects the static position. Because of the limited stroke range of reading of the

  15. Microshutter Array Development for the Multi-Object Spectrograph for the New Generation Space Telescope, and Its Ground-based Demonstrator

    NASA Technical Reports Server (NTRS)

    Woodgate, Bruce E.; Moseley, Harvey; Fettig, Rainer; Kutyrev, Alexander; Ge, Jian; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The 6.5-m NASA/ESA/Canada New Generation Space Telescope to be operated at the L2 Lagrangian point will require a multi-object spectrograph (MOS) operating from 1 to 5 microns. Up to 3000 targets will be selected for simultaneous spectroscopy using a programmable cryogenic (approx. 35K) aperture array, consisting of a mosaic of arrays of micromirrors or microshutters. We describe the current status of the GSFC microshutter array development. The 100 micron square shutters are opened magnetically and latched open or closed electrostatically. Selection will be by two crossed one-dimensional addressing circuits. We will demonstrate the use of a 512 x 512 unit array on a ground-based IR MOS which will cover 0.6 to 5 microns, and operate rapidly to include spectroscopy of gamma ray burst afterglows.

  16. A wide range tunable fiber Bragg grating using fast changeable electromagnetic force

    NASA Astrophysics Data System (ADS)

    Fayed, Heba A.; Mahmoud, Mohamed; Aboul Seoud, A. K.; Aly, Moustafa H.

    2010-06-01

    We demonstrate a silica-based tunable fiber Bragg grating (TFBG) filter with a wavelength tuning range over 60 nm. A magnetically TFBG package is employed to obtain a wide wavelength tuning range from 1540 to 1602 nm which covers the entire C band and most of the L-band. TFBG is achieved by varying an input current to a solenoid, resulting in an electromagnetic force, used as a strain (tension and compression) on the FBG. This approach is fast, has a broad band of tuning wavelengths and achieves a power reduction as no continuous supply of power is needed to maintain the set shift, due to the latch system used. This novel TFBG device can have a variety of applications in optical fiber communication systems such as programmable optical add/drop multiplexers (OADMs), dispersion compensators and tunable lasers.

  17. Logging-while-coring method and apparatus

    DOEpatents

    Goldberg, David S.; Myers, Gregory J.

    2007-01-30

    A method and apparatus for downhole coring while receiving logging-while-drilling tool data. The apparatus includes core collar and a retrievable core barrel. The retrievable core barrel receives core from a borehole which is sent to the surface for analysis via wireline and latching tool The core collar includes logging-while-drilling tools for the simultaneous measurement of formation properties during the core excavation process. Examples of logging-while-drilling tools include nuclear sensors, resistivity sensors, gamma ray sensors, and bit resistivity sensors. The disclosed method allows for precise core-log depth calibration and core orientation within a single borehole, and without at pipe trip, providing both time saving and unique scientific advantages.

  18. Logging-while-coring method and apparatus

    DOEpatents

    Goldberg, David S.; Myers, Gregory J.

    2007-11-13

    A method and apparatus for downhole coring while receiving logging-while-drilling tool data. The apparatus includes core collar and a retrievable core barrel. The retrievable core barrel receives core from a borehole which is sent to the surface for analysis via wireline and latching tool The core collar includes logging-while-drilling tools for the simultaneous measurement of formation properties during the core excavation process. Examples of logging-while-drilling tools include nuclear sensors, resistivity sensors, gamma ray sensors, and bit resistivity sensors. The disclosed method allows for precise core-log depth calibration and core orientation within a single borehole, and without at pipe trip, providing both time saving and unique scientific advantages.

  19. A Study of the Economic Benefit Potential of Intermodal Transports

    NASA Technical Reports Server (NTRS)

    Nelson, J. M.; Kawai, R. T.; Gregg, R. D.; McKinley, Robert E., Jr. (Technical Monitor)

    2001-01-01

    A conceptual study was conducted to determine the benefit potential of an Intermodal Transport in which quick change payload modules are used to reduce the cost of air travel by increasing daily utilization. Three basic concepts varying the degree of modularity were investigated for a 122,000 pounds payload 3,000 NM range regional wide body transport. The profit potential for operating as a passenger transport during the day and as a freighter at night was assessed. Assuming current levels of profitability, Intermodal operations could offer an operating cost reduction potential up to 20%. Enabling technology needs are identified as very quiet aircraft for expanded night operations, distributed load carrying quick disconnect latching, and configuration dependent safety issues. Recommendations are made to explore if additional benefits are possible from alternative mission and usage modules.

  20. Charging machine

    DOEpatents

    Medlin, John B.

    1976-05-25

    A charging machine for loading fuel slugs into the process tubes of a nuclear reactor includes a tubular housing connected to the process tube, a charging trough connected to the other end of the tubular housing, a device for loading the charging trough with a group of fuel slugs, means for equalizing the coolant pressure in the charging trough with the pressure in the process tubes, means for pushing the group of fuel slugs into the process tube and a latch and a seal engaging the last object in the group of fuel slugs to prevent the fuel slugs from being ejected from the process tube when the pusher is removed and to prevent pressure liquid from entering the charging machine.

  1. Special features of the CLUSTER antenna and radial booms design, development and verification

    NASA Technical Reports Server (NTRS)

    Gianfiglio, G.; Yorck, M.; Luhmann, H. J.

    1995-01-01

    CLUSTER is a scientific space mission to in-situ investigate the Earth's plasma environment by means of four identical spin-stabilized spacecraft. Each spacecraft is provided with a set of four rigid booms: two Antenna Booms and two Radial Booms. This paper presents a summary of the boom development and verification phases addressing the key aspects of the Radial Boom design. In particular, it concentrates on the difficulties encountered in fulfilling simultaneously the requirements of minimum torque ratio and maximum allowed shock loads at boom latching for this two degree of freedom boom. The paper also provides an overview of the analysis campaign and testing program performed to achieve sufficient confidence in the boom performance and operation.

  2. Optics and symbolic computing. Semiannual report, 14 August 1987-31 March 1988

    SciTech Connect

    Athale, R.

    1988-03-31

    Sorting is central to the solution of many knowledge-based and switching problems in advance computation and communication systems. Parallel-pipelined sorting algorithms are appropriate for applications that demand high throughput, low delay, and many data channels. One such algorithm, the bitonic sor, can be implemented with passive perfect shuffle interconnects between active stages of compare-and-exchange elements. This paper focuses on optical hardware to implement the CandE operation and show that by taking advantage of a distinctive feature of optical logic, namely bistability, comparison circuits of remarkable simplicity are attainable. Described are implementations of CandE in a Variety of optical device technologies capable of performing latching and nonlatching logic. Based on the device characteristics potential application areas for each technology are outlined.

  3. Evaluation of Pactruss design characteristics critical to space station primary structure

    NASA Technical Reports Server (NTRS)

    Hedgepeth, John M.

    1987-01-01

    Several aspects of the possible application of the Pactruss concept to the primary truss structure of the space station are investigated. Estimates are made of the loads and hinge moments in deploying diagonal members as full deployment is approached. Included are the effects of beam columning and compliance of the surrounding structure. Requirements for joint design are suggested and a two-stage mid-diagonal latching hinge concept is described or analyzed. The problems with providing the experimental and theoretical tools needed for assuring reliable synchronous deployment are discussed and a first attempt at high-fidelity analytical simulation with NASTRAN is described. An alternative construction scenario in which the entire dual-keel truss structure is deployed as a single Shuttle payload is suggested.

  4. The On-Orbit Calibrations for the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Ampe, J.; Anderson, B.; Atwood, W.B.; Axelsson, M.; Bagagli, R.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bartelt, J.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bederede, D.; Bellardi, F.; Bellazzini, R.; Belli, F.; Berenji, B.; Bisello, D.; /more authors..

    2011-11-17

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope began its on-orbit operations on June 23, 2008. Calibrations, defined in a generic sense, correspond to synchronization of trigger signals, optimization of delays for latching data, determination of detector thresholds, gains and responses, evaluation of the perimeter of the South Atlantic Anomaly (SAA), measurements of live time, of absolute time, and internal and spacecraft boresight alignments. Here we describe on-orbit calibration results obtained using known astrophysical sources, galactic cosmic rays, and charge injection into the front-end electronics of each detector. Instrument response functions will be described in a separate publication. This paper demonstrates the stability of calibrations and describes minor changes observed since launch. These results have been used to calibrate the LAT datasets to be publicly released in August 2009.

  5. An integrated driving circuit implemented with p-type LTPS TFTs for AMOLED

    NASA Astrophysics Data System (ADS)

    Zhao, Li-Qing; Wu, Chun-Ya; Hao, Da-Shou; Yao, Ying; Meng, Zhi-Guo; Xiong, Shao-Zhen

    2009-03-01

    Based on the technology of low temperature poly silicon thin film transistors (poly-Si-TFTs), a novel p-type TFT AMOLED panel with self-scanned driving circuit is introduced in this paper. A shift register formed with novel p-type TFTs is proposed to realize the gate driver. A flip-latch cooperated with the shift register is designed to conduct the data writing. In order to verify the validity of the proposed design, the circuits are simulated with SILVACO TCAD tools, using the MODEL in which the parameters of LTPS TFTs were extracted from the LTPS TFTs made in our lab. The simulation results indicate that the circuit can fulfill the driving function.

  6. Single event upset hardening techniques

    SciTech Connect

    Weaver, H.T.; Corbett, W.T.

    1990-01-01

    Integrated circuit logic states are maintained by virtue of specific transistor combinations being either on'' (conducting) or off'' (nonconducting). High energy ion strikes on the microcircuit generate photocurrents whose primary detrimental effect is to make off'' transistors appear on,'' confusing the logic state and leading to single event upset (SEU). Protection against these soft errors is accomplished using either technology or circuit techniques, actions that generally impact yield and performance relative to unhardened circuits. We describe, and using circuit simulations analyze, a technique for hardening latches which requires combinations of technology and circuit modifications, but which provides SEU immunity without loss of speed. Specifically, a single logic state is hardened against SEU using technology methods and the information concerning valid states is then used to simplify hardened circuit design. The technique emphasizes some basic hardening concepts, ideas for which will be reviewed. 3 refs., 2 figs.

  7. Definition of a design methodology and study of the driving and protection functions of a smart power switch

    NASA Astrophysics Data System (ADS)

    Elmoznine, Abdellatif

    The design of a smart power switch in MOS technology, in particular the high side switch mode, is studied. Special emphasis is given to the study of unwanted electrical coupling through the substrate between the power and the logic sections of the device. A new concept that leads to a completely latch-up free circuit and based on a floating well is proposed. The driving and protection functions of the power switch are presented. A charge pump circuit is proposed, allowing minimum power dissipation and high speed to be achieved. A circuit for sensing the device's temperature is presented. The short circuit and open circuit protection functions are proposed. The circuit generating, on chip, the voltage supply and a detector of its stability are presented.

  8. Human factors in equipment development for the Space Shuttle - A study of the general purpose work station

    NASA Technical Reports Server (NTRS)

    Junge, M. K.; Giacomi, M. J.

    1981-01-01

    The results of a human factors test to assay the suitability of a prototype general purpose work station (GPWS) for biosciences experiments on the fourth Spacelab mission are reported. The evaluation was performed to verify that users of the GPWS would optimally interact with the GPWS configuration and instrumentation. Six male subjects sat on stools positioned to allow assimilation of the zero-g body posture. Trials were run concerning the operator viewing angles facing the console, the console color, procedures for injecting rates with dye, a rat blood cell count, mouse dissection, squirrel monkey transfer, and plant fixation. The trials were run for several days in order to gage improvement or poor performance conditions. Better access to the work surface was found necessary, together with more distinct and better located LEDs, better access window latches, clearer sequences on control buttons, color-coded sequential buttons, and provisions made for an intercom system when operators of the GPWS work in tandem.

  9. Structural analyses of the JPL Mars Pathfinder impact

    SciTech Connect

    Gwinn, K.W.

    1994-12-31

    The purpose of this paper is to demonstrate that finite element analysis can be used in the design process for high performance fabric structures. These structures exhibit extreme geometric nonlinearity; specifically, the contact and interaction of fabric surfaces with the large deformation which necessarily results from membrane structures introduces great complexity to analyses of this type. All of these features are demonstrated here in the analysis of the Jet Propulsion Laboratory (JPL) Mars Pathfinder impact onto Mars. This lander system uses airbags to envelope the lander experiment package, protecting it with large deformation upon contact. Results from the analysis show the stress in the fabric airbags, forces in the internal tendon support system, forces in the latches and hinges which allow the lander to deploy after impact, and deceleration of the lander components. All of these results provide the JPL engineers with design guidance for the success of this novel lander system.

  10. Development of Test Article Building Block (TABB) for deployable platform systems

    NASA Technical Reports Server (NTRS)

    Greenberg, H. S.; Barbour, R. T.

    1984-01-01

    The concept of a Test Article Building Block (TABB) is described. The TABB is a ground test article that is representative of a future building block that can be used to construct LEO and GEO deployable space platforms for communications and scientific payloads. This building block contains a main housing within which the entire structure, utilities, and deployment/retraction mechanism are stowed during launch. The end adapter secures the foregoing components to the housing during launch. The main housing and adapter provide the necessary building-block-to-building-block attachments for automatically deployable platforms. Removal from the shuttle cargo bay can be accomplished with the remote manipulator system (RMS) and/or the handling and positioning aid (HAPA). In this concept, all the electrical connections are in place prior to launch with automatic latches for payload attachment provided on either the end adapters or housings. The housings also can contain orbiter docking ports for payload installation and maintenance.

  11. Mescaline action on "memory decay" and "problem solving" behavior in the rat.

    PubMed

    Molinengo, L; Cassone, M C; Baroli, A; Orsetti, M

    1986-01-01

    The modifications of behavior caused in the rat by a chronic oral administration of mescaline have been studied in three experimental situations. In the staircase maze mescaline accelerated the spontaneous decay on the conditioned reflex (memory decay) during the period without daily training. Only the results observed at 30 mg/kg/day of mescaline were statistically significant. In a T maze two lateral alleys closed by two swinging doors, 30 mg/kg/day of mescaline increased the time spent in opening the first door. When the two doors of the lateral alleys were closed with a latch, mescaline 30 mg/kg/day, caused an increase in the time spent by the rat in opening the doors. Mescaline caused an increase in food consumption. The increase at 30 mg/kg/day is statistically significant.

  12. Heavy Ion Transient Characterization of a Photobit Hardened-by-Design Active Pixel Sensor Array

    NASA Technical Reports Server (NTRS)

    Marshall, Paul W.; Byers, Wheaton B.; Conger, Christopher; Eid, El-Sayed; Gee, George; Jones, Michael R.; Marshall, Cheryl J.; Reed, Robert; Pickel, Jim; Kniffin, Scott

    2002-01-01

    This paper presents heavy ion data on the single event transient (SET) response of a Photobit active pixel sensor (APS) four quadrant test chip with different radiation tolerant designs in a standard 0.35 micron CMOS process. The physical design techniques of enclosed geometry and P-channel guard rings are used to design the four N-type active photodiode pixels as described in a previous paper. Argon transient measurements on the 256 x 256 chip array as a function of incident angle show a significant variation in the amount of charge collected as well as the charge spreading dependent on the pixel type. The results are correlated with processing and design information provided by Photobit. In addition, there is a large degree of statistical variability between individual ion strikes. No latch-up is observed up to an LET of 106 MeV/mg/sq cm.

  13. Method for refreshing a non-volatile memory

    DOEpatents

    Riekels, James E.; Schlesinger, Samuel

    2008-11-04

    A non-volatile memory and a method of refreshing a memory are described. The method includes allowing an external system to control refreshing operations within the memory. The memory may generate a refresh request signal and transmit the refresh request signal to the external system. When the external system finds an available time to process the refresh request, the external system acknowledges the refresh request and transmits a refresh acknowledge signal to the memory. The memory may also comprise a page register for reading and rewriting a data state back to the memory. The page register may comprise latches in lieu of supplemental non-volatile storage elements, thereby conserving real estate within the memory.

  14. Near-field NanoThermoMechanical memory

    SciTech Connect

    Elzouka, Mahmoud; Ndao, Sidy

    2014-12-15

    In this letter, we introduce the concept of NanoThermoMechanical Memory. Unlike electronic memory, a NanoThermoMechanical memory device uses heat instead of electricity to record, store, and recover data. Memory function is achieved through the coupling of near-field thermal radiation and thermal expansion resulting in negative differential thermal resistance and thermal latching. Here, we demonstrate theoretically via numerical modeling the concept of near-field thermal radiation enabled negative differential thermal resistance that achieves bistable states. Design and implementation of a practical silicon based NanoThermoMechanical memory device are proposed along with a study of its dynamic response under write/read cycles. With more than 50% of the world's energy losses being in the form of heat along with the ever increasing need to develop computer technologies which can operate in harsh environments (e.g., very high temperatures), NanoThermoMechanical memory and logic devices may hold the answer.

  15. Frontal Sled Tests Comparing Rear and Forward Facing Child Restraints with 1–3 Year Old Dummies

    PubMed Central

    Sherwood, C. P.; Crandall, J. R.

    2007-01-01

    Although most countries recommend transitioning children from rear facing (RF) to forward facing (FF) child restraints at one year of age, Swedish data suggests that RF restraints are more effective. The objective of this study was to compare RF and FF orientations in frontal sled tests. Four dummies (CRABI 12mo, Q1.5, Hybrid III 3yr, and Q3) were used to represent children from 1 to 3 years of age. Restraint systems tested included both 1) LATCH and 2) rigid ISOFIX with support leg designs. Rear facing restraints with support legs provided the best results for all injury measures, while RF restraints in general provided the lowest chest displacements and neck loads. PMID:18184491

  16. Structural basis for leucine sensing by the Sestrin2-mTORC1 pathway

    PubMed Central

    Saxton, Robert A.; Knockenhauer, Kevin E.; Wolfson, Rachel L.; Chantranupong, Lynne; Pacold, Michael E.; Wang, Tim; Schwartz, Thomas U.; Sabatini, David M.

    2015-01-01

    Eukaryotic cells coordinate growth with the availability of nutrients through mTOR complex 1 (mTORC1), a master growth regulator. Leucine is of particular importance and activates mTORC1 via the Rag GTPases and their regulators GATOR1 and GATOR2. Sestrin2 interacts with GATOR2 and is a leucine sensor. We present the 2.7-Å crystal structure of Sestrin2 in complex with leucine. Leucine binds through a single pocket that coordinates its charged functional groups and confers specificity for the hydrophobic side chain. A loop encloses leucine and forms a lid-latch mechanism required for binding. A structure-guided mutation in Sestrin2 that decreases its affinity for leucine leads to a concomitant increase in the leucine concentration required for mTORC1 activation in cells. These results provide a structural mechanism of amino acid sensing by the mTORC1 pathway. PMID:26586190

  17. Towards Accelerated Aging Methodologies and Health Management of Power MOSFETs (Technical Brief)

    NASA Technical Reports Server (NTRS)

    Celaya, Jose R.; Patil, Nishad; Saha, Sankalita; Wysocki, Phil; Goebel, Kai

    2009-01-01

    Understanding aging mechanisms of electronic components is of extreme importance in the aerospace domain where they are part of numerous critical subsystems including avionics. In particular, power MOSFETs are of special interest as they are involved in high voltage switching circuits such as drivers for electrical motors. With increased use of electronics in aircraft control, it becomes more important to understand the degradation of these components in aircraft specific environments. In this paper, we present an accelerated aging methodology for power MOSFETs that subject the devices to indirect thermal overstress during high voltage switching. During this accelerated aging process, two major modes of failure were observed - latch-up and die attach degradation. In this paper we present the details of our aging methodology along with details of experiments and analysis of the results.

  18. Wind turbine rotor assembly

    SciTech Connect

    Kaiser, H. W.

    1984-11-20

    A vertical axis wind turbine having a horizontal arm member which supports an upright blade assembly. Bearing structure coupling the blade assembly to the turbine arm permits blade movement about its longitudinal axis as well as flexing motion of the blade assembly about axes perpendicular to the longitudinal axis. A latching mechanism automatically locks the blade assembly to its supporting arm during normal turbine operation and automatically unlocks same when the turbine is at rest. For overspeed prevention, a centrifugally actuated arm functions to unlatch the blade assembly permitting same to slipstream or feather into the wind. Manually actuated means are also provided for unlatching the moving blade assembly. The turbine arm additionally carries a switching mechanism in circuit with a turbine generator with said mechanism functioning to open and hence protect the generator circuit in the event of an overspeed condition of the turbine.

  19. Seal device for ferromagnetic containers

    DOEpatents

    Meyer, Ross E.; Jason, Andrew J.

    1994-01-01

    A temporary seal or patch assembly prevents the escape of contents, e.g., fluids and the like, from within a container having a breach therethrough until the contents can be removed and/or a repair effected. A frame that supports a sealing bladder can be positioned over the breach and the frame is then attached to the container surface, which must be of a ferromagnet material, by using switchable permanent magnets. The permanent magnets are designed to have a first condition that is not attracted to the ferromagnetic surface and a second conditions whereby the magnets are attracted to the surface with sufficient force to support the seal assembly on the surface. Latching devices may be attached to the frame and engage the container surface with hardened pins to prevent the lateral movement of the seal assembly along the container surface from external forces such as fluid drag or gravity.

  20. Variable Delay Element For Jitter Control In High Speed Data Links

    DOEpatents

    Livolsi, Robert R.

    2002-06-11

    A circuit and method for decreasing the amount of jitter present at the receiver input of high speed data links which uses a driver circuit for input from a high speed data link which comprises a logic circuit having a first section (1) which provides data latches, a second section (2) which provides a circuit generates a pre-destorted output and for compensating for level dependent jitter having an OR function element and a NOR function element each of which is coupled to two inputs and to a variable delay element as an input which provides a bi-modal delay for pulse width pre-distortion, a third section (3) which provides a muxing circuit, and a forth section (4) for clock distribution in the driver circuit. A fifth section is used for logic testing the driver circuit.

  1. Structural Basis for Nick Recognition by a Minimal Pluripotent DNA Ligase

    SciTech Connect

    Nair,P.; Nandakumar, J.; Smith, P.; Odell, M.; Lima, C.; Shuman, S.

    2007-01-01

    Chlorella virus DNA ligase, the smallest eukaryotic ligase known, has pluripotent biological activity and an intrinsic nick-sensing function, despite having none of the accessory domains found in cellular ligases. A 2.3-{angstrom} crystal structure of the Chlorella virus ligase-AMP intermediate bound to duplex DNA containing a 3'-OH-5'-PO{sub 4} nick reveals a new mode of DNA envelopment, in which a short surface loop emanating from the OB domain forms a {beta}-hairpin 'latch' that inserts into the DNA major groove flanking the nick. A network of interactions with the 3'-OH and 5'-PO{sub 4} termini in the active site illuminates the DNA adenylylation mechanism and the crucial roles of AMP in nick sensing and catalysis. Addition of a divalent cation triggered nick sealing in crystallo, establishing that the nick complex is a bona fide intermediate in the DNA repair pathway.

  2. What's new in artificial lift; Part 1: Industry developments in electrical submersible pumps and accessories; gas lift innovations; and new tools for control and measurement

    SciTech Connect

    Lea, J.F. ); Winkler, H.W. , Lubbock, TX )

    1994-03-01

    In this first article of a two-part series, several new developments by manufacturers of downhole electrical submersible pumps (ESPs) are discussed, including a progressive cavity pump and motor system, advances in cables and penetrators, and new lines of sensors and drives. Several gas-lift innovations are covered, such as: an electric surface controlled gas-lift valve, a retrievable valve latch, spoolable retrievable gas-lift valves and sidepocket mandrels, and an improved plunger-lift seal. Also described in the category of miscellaneous new equipment are: a high-rate waterflood mandrel and valve, net oil meter, less expensive downhole memory gauge, downhole oil/water separation system and a new laser coating process. Part 2, to follow next month, will introduce advances in beam and progressive cavity pumping.

  3. LED instrument approach instruction display

    NASA Technical Reports Server (NTRS)

    Meredith, B. D.; Kelly, W. L., IV; Crouch, R. K.

    1979-01-01

    A display employing light emitting diodes (LED's) was developed to demonstrate the feasibility of such displays for presenting landing and navigation information to reduce the workload of general aviation pilots during IFR flight. The display consists of a paper tape reader, digital memory, control electronics, digital latches, and LED alphanumeric displays. A presentable digital countdown clock-timer is included as part of the system to provide a convenient means of monitoring time intervals for precise flight navigation. The system is a limited capability prototype assembled to test pilot reaction to such a device under simulated IFR operation. Pilot opinion indicates that the display is helpful in reducing the IFR pilots workload when used with a runway approach plate. However, the development of a compact, low power second generation display was recommended which could present several instructions simultaneously and provide information update capability. A microprocessor-based display could fulfill these requirements.

  4. Interplanetary Particle Environment. Proceedings of a Conference

    NASA Technical Reports Server (NTRS)

    Feynman, Joan (Editor); Gabriel, Stephen (Editor)

    1988-01-01

    A workshop entitled the Interplanetary Charged Particle Environment was held at the Jet Propulsion Laboratory (JPL) on March 16 and 17, 1987. The purpose of the Workshop was to define the environment that will be seen by spacecraft operating in the 1990s. It focused on those particles that are involved in single event upset, latch-up, total dose and displacement damage in spacecraft microelectronic parts. Several problems specific to Magellan were also discussed because of the sensitivity of some electronic parts to single-event phenomena. Scientists and engineers representing over a dozen institutions took part in the meeting. The workshop consisted of two major activities, reviews of the current state of knowledge and the formation of working groups and the drafting of their reports.

  5. Junction box wiring and connector durability issues in photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Kalejs, Juris

    2014-10-01

    We report here on Photovoltaic (PV) module durability issues associated with junction boxes which are under study in Task 10 of the International PV Quality Assurance Task Force (PVQAT). A number of failure modes are being identified in junction boxes in PV arrays in the field which have less than 5 years outdoor operation. Observed failure modes include melted contacts and plastic walls in the junction boxes, separated external connectors and broken latches. Standard IEC and UL tests for modules are designed to expose early mortality failures due to materials selection and design in the assembled module and their impact on performance and safety. Test standards for individual junction box components, when not part of a PV module, are still in development. We will give an overview of the reported field failures associated with junction boxes, and examine standard development as it may impact on testing for durability of junction box connectors over a 25 year life.

  6. An investigation of the phototropic effect on seedling orientation in a microgravity environment: A student involvement project. [radish germination

    NASA Technical Reports Server (NTRS)

    Barainca, J. W.

    1984-01-01

    A microgravity growth chamber was designed to investigate the phototropic response of radish seedlings. Enclosed in a one fourth inch thick, hexagonal, fiberglass-foam spacepak nineteen inches across corners, the experiment consists of a growth chamber and germination tray, a water reservoir and solenoid valve, a fluorescent light for photo simulation, a Minolta X700 camera with programmable back, a 50 mm macro lens and flash, a battery pack, and a computer controller. Two temperature sensors and one light sensor located in the walls of the growth chamber provide temperature and illumination data. A computer provides 8 K command and 34 K data storage capability. The experiment was not activated during the STS flight because a malfunctioning latching relay stuck and reduced the battery power level.

  7. Radiation Mitigation and Power Optimization Design Tools for Reconfigurable Hardware in Orbit

    NASA Technical Reports Server (NTRS)

    French, Matthew; Graham, Paul; Wirthlin, Michael; Wang, Li; Larchev, Gregory

    2005-01-01

    The Reconfigurable Hardware in Orbit (RHinO)project is focused on creating a set of design tools that facilitate and automate design techniques for reconfigurable computing in space, using SRAM-based field-programmable-gate-array (FPGA) technology. In the second year of the project, design tools that leverage an established FPGA design environment have been created to visualize and analyze an FPGA circuit for radiation weaknesses and power inefficiencies. For radiation, a single event Upset (SEU) emulator, persistence analysis tool, and a half-latch removal tool for Xilinx/Virtex-II devices have been created. Research is underway on a persistence mitigation tool and multiple bit upsets (MBU) studies. For power, synthesis level dynamic power visualization and analysis tools have been completed. Power optimization tools are under development and preliminary test results are positive.

  8. Landing Gear Components Noise Study - PIV and Hot-Wire Measurements

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Burley, Casey L.; Stead, Daniel J.; Becker, Lawrence E.; Price, Jennifer L.

    2010-01-01

    PIV and hot-wire measurements of the wake flow from rods and bars are presented. The test models include rods of different diameters and cross sections and a rod juxtaposed to a plate. The latter is representative of the latch door that is attached to an aircraft landing gear when the gear is deployed, while the single and multiple rod configurations tested are representative of some of the various struts and cables configuration present on an aircraft landing gear. The test set up is described and the flow measurements are presented. The effect of model surface treatment and freestream turbulence on the spanwise coherence of the vortex shedding is studied for several rod and bar configurations.

  9. Evaluation of an Ultra-Low Power Reed Solomon Encoder for NASA's Space Technology 5 Mission

    NASA Technical Reports Server (NTRS)

    Lei, K. E.; Xapsos, M. A.; Poivey, C.; LaBel, K. A.; Stone, R. F.; Yeh, P-S.; Gambles, J.; Hass, J.; Maki, G.; Murguia, J.

    2003-01-01

    Radiation test results and analyses are presented for ultra-low power Reed Solomon encoder circuits that are being considered for use on the Space Technology 5 (ST5) mission. The total ionizing dose tolerance is in excess of 100 krad(Si) and is due to the low supply voltage and the use of back-bias, which suppresses radiation-induced leakage currents in the n-channel devices. The circuits do not latch-up for ion LET values of at least 90 MeV-sq cm/mg. A hardened-by-design approach to SEU has achieved an upset threshold of about 20 MeV-sq cm/mg. The SEU rate expected for these circuits in the geosynchronous transfer orbit of ST5 is low.

  10. Remotely replaceable tokamak plasma limiter tiles

    DOEpatents

    Tsuo, Simon , Langford, Alison A.

    1989-01-01

    U-shaped limiter tiles placed end-to-end over a pair of parallel runners secured to a wall have two rods which engage L-shaped slots in the runners. The short receiving legs of the L-shaped slots are perpendicular to the wall and open away from the wall, while long retaining legs are parallel to and adjacent the wall. A sliding bar between the runners has grooves with clips to retain the rods pressed into receiving legs of the L-shaped slots in the runners. Sliding the bar in the direction of retaining legs of the L-shaped slots latches the tiles in place over the runners. Resilient contact strips between the parallel arms of the U-shaped tiles and the wall assure thermal and electrical contact with the wall.

  11. First experiences with a fastbus system at Brookhaven

    SciTech Connect

    Leipuner, L B; Larsen, R C; Makowiecki, D S

    1980-07-14

    A new concept in high energy data acquisition systems called Fastbus has been developed and implemented at Brookhaven. The system which is capable of sub-gigabit/sec speeds has been operating for some time now. A number of modules including an on-bus processor, a PDP11 interface, 32 channel coincidence latches, a 16 channel scaler, a 32 channel ..mu..-clock device, a 60 nsec memory and a predetermined time module have been developed and built. Features of the system include extensive use of ECL logic and a water cooled crate with conduction heat transfer within a module. The system is used in an on-line experiment at the AGS. Operating experience will be discussed.

  12. MEMS Microshutter Arrays for James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Li, Mary J.; Beamesderfer, Michael; Babu, Sachi; Bajikar, Sateesh; Ewin, Audrey; Franz, Dave; Hess, Larry; Hu, Ron; Jhabvala, Murzy; Kelly, Dan; King, Todd; Kletetschkar, Gunther; Kutyrev, Alexander; Lynch, Barney; Moseley, Harvey; Mott, Brent; Oh, Lance; Rapchum, Dave; Ray, Chris; Sappington, Carol; Silverberg, Robert; Smith, Wayne; Snodgrass, Steve; Steptoe-Jackson, Rosalind; Valeriano

    2006-01-01

    MEMS microshutter arrays are being developed at NASA Goddard Space Flight Center for use as an aperture array for a Near-Infrared Spectrometer (NirSpec). The instruments will be carried on the James Webb Space Telescope (JWST), the next generation of space telescope after Hubble Space Telescope retires. The microshutter arrays are designed for the selective transmission of light with high efficiency and high contrast, Arrays are close-packed silicon nitride membranes with a pixel size of 100x200 microns. Individual shutters are patterned with a torsion flexure permitting shutters to open 90 degrees with a minimized mechanical stress concentration. Light shields are made on to each shutter for light leak prevention so to enhance optical contrast, Shutters are actuated magnetically, latched and addressed electrostatically. The shutter arrays are fabricated using MEMS technologies.

  13. New insights into the Hendra virus attachment and entry process from structures of the virus G glycoprotein and its complex with Ephrin-B2.

    PubMed

    Xu, Kai; Chan, Yee-Peng; Rajashankar, Kanagalaghatta R; Khetawat, Dimple; Yan, Lianying; Kolev, Momchil V; Broder, Christopher C; Nikolov, Dimitar B

    2012-01-01

    Hendra virus and Nipah virus, comprising the genus Henipavirus, are recently emerged, highly pathogenic and often lethal zoonotic agents against which there are no approved therapeutics. Two surface glycoproteins, the attachment (G) and fusion (F), mediate host cell entry. The crystal structures of the Hendra G glycoprotein alone and in complex with the ephrin-B2 receptor reveal that henipavirus uses Tryptophan 122 on ephrin-B2/B3 as a "latch" to facilitate the G-receptor association. Structural-based mutagenesis of residues in the Hendra G glycoprotein at the receptor binding interface document their importance for viral attachments and entry, and suggest that the stability of the Hendra-G-ephrin attachment complex does not strongly correlate with the efficiency of viral entry. In addition, our data indicates that conformational rearrangements of the G glycoprotein head domain upon receptor binding may be the trigger leading to the activation of the viral F fusion glycoprotein during virus infection.

  14. Design Development of a Combined Deployment and Pointing System for the International Space Station Neutron Star Interior Composition Explorer Telescope

    NASA Technical Reports Server (NTRS)

    Budinoff, Jason; Gendreau, Keith; Arzoumanian, Zaven; Baker, Charles; Berning, Robert; Colangelo, TOdd; Holzinger, John; Lewis, Jesse; Liu, Alice; Mitchell, Alissa; Monroe, Chuck; Pugh, Richard; Wiley, Roger

    2016-01-01

    This paper describes the design of a unique suite of mechanisms that make up the Deployment and Pointing System (DAPS) for the Neutron Star Interior Composition Explorer (NICER/SEXTANT) instrument, an X-Ray telescope, which will be mounted on the International Space Station (ISS). The DAPS system uses four stepper motor actuators to deploy the telescope box, latch it in the deployed position, and allow it to track sky targets. The DAPS gimbal architecture provides full-hemisphere coverage, and is fully re-stowable. The compact design of the mechanism allowed the majority of total instrument volume to be used for science. Override features allow DAPS to be stowed by ISS robotics.

  15. Design Development of a Combined Deployment and Pointing System for the International Space Station Neutron Star Interior Composition Explorer Telescope

    NASA Technical Reports Server (NTRS)

    Budinoff, Jason; Gendreau, Keith; Arzoumanian, Zaven; Baker, Charles; Berning, Robert; Colangelo, Todd; Holzinger, John; Lewis, Jesse; Liu, Alice; Mitchell, Alissa; Monroe, Chuck; Pugh, Richard; Willey, Roger

    2015-01-01

    This paper describes the design of a unique suite of mechanisms which make up the Deployment and Pointing System (DAPS) for the Neutron Star Interior Composition Explorer (NICER/SEXTANT) instrument, an X-Ray telescope, which will be mounted on the International Space Station (ISS). The DAPS system uses 4 stepper motor actuators to deploy the telescope box, latch it in the deployed position, and allow it to track sky targets. The DAPS gimbal architecture provides full-hemisphere coverage, and is fully re-stowable. The compact design of the mechanism allowed the majority of total instrument volume to be used for science. Override features allow DAPS to be stowed by ISS robotics.

  16. Space Station Freedom solar array containment box mechanisms

    NASA Astrophysics Data System (ADS)

    Johnson, Mark E.; Haugen, Bert; Anderson, Grant

    1994-05-01

    Space Station Freedom will feature six large solar arrays, called solar array wings, built by Lockheed Missiles & Space Company under contract to Rockwell International, Rocketdyne Division. Solar cells are mounted on flexible substrate panels which are hinged together to form a 'blanket.' Each wing is comprised of two blankets supported by a central mast, producing approximately 32 kW of power at beginning-of-life. During launch, the blankets are fan-folded and compressed to 1.5 percent of their deployed length into containment boxes. This paper describes the main containment box mechanisms designed to protect, deploy, and retract the solar array blankets: the latch, blanket restraint, tension, and guidewire mechanisms.

  17. Seal device for ferromagnetic containers

    DOEpatents

    Meyer, R.E.; Jason, A.J.

    1994-10-18

    A temporary seal or patch assembly prevents the escape of contents, e.g., fluids and the like, from within a container having a breach there through until the contents can be removed and/or a repair effected. A frame that supports a sealing bladder can be positioned over the breach and the frame is then attached to the container surface, which must be of a ferromagnet material, by using switchable permanent magnets. The permanent magnets are designed to have a first condition that is not attracted to the ferromagnetic surface and a second conditions whereby the magnets are attracted to the surface with sufficient force to support the seal assembly on the surface. Latching devices may be attached to the frame and engage the container surface with hardened pins to prevent the lateral movement of the seal assembly along the container surface from external forces such as fluid drag or gravity. 10 figs.

  18. HAZBOT - A hazardous materials emergency response mobile robot

    NASA Technical Reports Server (NTRS)

    Stone, H. W.; Edmonds, G.

    1992-01-01

    The authors describe the progress that has been made towards the development of a mobile robot that can be used by hazardous materials emergency response teams to perform a variety of tasks including incident localization and characterization, hazardous material identification/classification, site surveillance and monitoring, and ultimately incident mitigation. In September of 1991, the HAZBOT II vehicle performed its first end-to-end demonstration involving a scenario in which the vehicle: navigated to the incident location from a distant (150-200 ft.) deployment site; entered a building through a door with thumb latch style handle and door closer; located and navigated to the suspected incident location (a chemical storeroom); unlocked and opened the storeroom's door; climbed over the storeroom's 12 in. high threshold to enter the storeroom; and located and identified a broken container of benzene.

  19. Single-event effects in avionics

    SciTech Connect

    Normand, E.

    1996-04-01

    The occurrence of single-event upset (SEU) in aircraft electronics has evolved from a series of interesting anecdotal incidents to accepted fact. A study completed in 1992 demonstrated that SEU`s are real, that the measured in-flight rates correlate with the atmospheric neutron flux, and that the rates can be calculated using laboratory SEU data. Once avionics DEU was shown to be an actual effect, it had to be dealt with in avionics designs. The major concern is in random access memories (RAM`s), both static (SRAM`s) and dynamic (DRAM`s), because these microelectronic devices contain the largest number of bits, but other parts, such as microprocessors, are also potentially susceptible to upset. In addition, other single-event effects (SEE`s), specifically latch-up and burnout, can also be induced by atmospheric neutrons.

  20. Design and testing of the U.S. Space Station Freedom primary propulsion system

    NASA Astrophysics Data System (ADS)

    Morano, Joseph S.; Delventhal, Rex A.; Chilcot, Kimberly J.

    1992-07-01

    The primary propulsion system (PPS) for the Space Station Freedom is discussed in terms of salient design characteristics and key testing procedures. The rocket engine modules contain reboost and attitude control thrusters, and their designs are illustrated showing the mounting structures, thruster solenoid valves, and thrust chambers. The propellant tank assembly for storing gaseous N pressurant and hydrazine propellant is described as are the system avionics, thruster solenoid valves, and latching isolation valves. PPS testing conducted on the development systems includes the use of a propulsion-module development unit, a development test article, and system qualification testing. Specific test articles include functional heaters, mass/thermal simulated components, flight-quality structures, and software control operations.

  1. Passive all-optical polarization switch, binary logic gates, and digital processor.

    PubMed

    Zaghloul, Y A; Zaghloul, A R M; Adibi, A

    2011-10-10

    We introduce the passive all-optical polarization switch, which modulates light with light. That switch is used to construct all the binary logic gates of two or more inputs. We discuss the design concepts and the operation of the AND, OR, NAND, and NOR gates as examples. The rest of the 16 logic gates are similarly designed. Cascading of such gates is straightforward as we show and discuss. Cascading in itself does not require a power source, but feedback at this stage of development does. The design and operation of an SR Latch is presented as one of the popular basic sequential devices used for memory cells. That completes the essential components of an all-optical polarization digital processor. The speed of such devices is well above 10 GHz for bulk implementations and is much higher for chip-size implementations. In addition, the presented devices do have the four essential characteristics previously thought unique to the microelectronic ones.

  2. A preliminary evaluation of child restraints and anchorage systems for an Australian car.

    PubMed

    Charlton, Judith L; Fildes, Brian; Laemmle, Ronald; Smith, Stuart; Douglas, Fiona

    2004-01-01

    This study examined the performance of three rear-facing and two forward-facing child restraints (CRS) with three anchorage systems: standard seatbelt, LATCH (flexible) and ISOFIX (rigid). Frontal (64 km/h) and side impact (15 km/h) HyGe sled tests were conducted using a sedan buck. Overall, the preliminary findings suggested superior performance of rigid over seatbelt and flexible anchorages, particularly in side impacts. The results also suggest a need for design improvement for CRS with flexible anchorages to increase stability in side impacts. The findings have important implications for the proposed introduction of changes to Australian Standards for CRS to permit both flexible and rigid systems to coexist with conventional seatbelt anchorage systems. PMID:15319118

  3. Current distribution in a three-dimensional IC analyzed by a perturbation method. Part 1: A simple steady state theory

    NASA Technical Reports Server (NTRS)

    Edmonds, Larry D.

    1987-01-01

    The steady state current distribution in a three dimensional integrated circuit is presented. A device physics approach, based on a perturbation method rather than an equivalent lumped circuit approach, is used. The perturbation method allows the various currents to be expressed in terms of elementary solutions which are solutions to very simple boundary value problems. A Simple Steady State Theory is the subtitle because the most obvious limitation of the present version of the analysis is that all depletion region boundary surfaces are treated as equipotential surfaces. This may be an adequate approximation in some applications but it is an obvious weakness in the theory when applied to latched states. Examples that illustrate the use of these analytical methods are not given because they will be presented in detail in the future.

  4. TAMPERPROOF FILM BADGE

    DOEpatents

    Kocher, L.F.

    1958-10-01

    A persornel dosimeter film badge made of plastic, with provision for a picture of the wearer and an internal slide containing photographic film that is sensitive to various radiations, is described. Four windows made of differing material selectively attenuate alpha, beta, gamma rays, and neutrons so as to distinguish the particular type of radiation the wearer was subjected to. In addition, a lead shield has the identification number of the wearer perforated thereon so as to identify the film after processing. An internal magnetically actuated latch securely locks the slide within the body, and may be withdrawn only upon the external application of two strong magnetic forces in order to insure that the wearer or other curious persons will not accidentally expose the film to visual light.

  5. Synchronous OEIC Integrating Receiver for Optically Reconfigurable Gate Arrays.

    PubMed

    Sánchez-Azqueta, Carlos; Goll, Bernhard; Celma, Santiago; Zimmermann, Horst

    2016-05-25

    A monolithically integrated optoelectronic receiver with a low-capacitance on-chip pin photodiode is presented. The receiver is fabricated in a 0.35 μm opto-CMOS process fed at 3.3 V and due to the highly effective integrated pin photodiode it operates at μW. A regenerative latch acting as a sense amplifier leads in addition to a low electrical power consumption. At 400 Mbit/s, sensitivities of -26.0 dBm and -25.5 dBm are achieved, respectively, for λ = 635 nm and λ = 675 nm (BER = 10(-9) ) with an energy efficiency of 2 pJ/bit.

  6. Advanced mechanisms for robotics

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1992-01-01

    An overview of applied research and development at NASA-Goddard (GSFC) on mechanisms and the collision avoidance skin for robots is presented. First the work on robot end effectors is outlined, followed by a brief discussion on robot-friendly payload latching mechanisms and compliant joints. This, in turn, is followed by the collision avoidance/management skin and the GSFC research on magnetostrictive direct drive motors. Finally, a new project, the artificial muscle, is introduced. Each of the devices is described in sufficient detail to permit a basic understanding of its purpose, fundamental principles of operation, and capabilities. In addition, the development status of each is reported along with descriptions of breadboards and prototypes and their test results. In each case, the implications of the research for commercialization is discussed. The chronology of the presentation will give a clear idea of both the evolution of the R&D in recent years and its likely direction in the future.

  7. Optical fiber sensors for spacecraft: applications and challenges

    NASA Astrophysics Data System (ADS)

    Friebele, Edward J.; Askins, Charles G.; Miller, Gary A.; Peele, John R.; Wasserman, Lucienne R.

    2004-10-01

    Optical fiber sensors offer a number of advantages for spacecraft applications, including freedom from electromagnetic interference, light weight, and low power consumption. One application is strain sensing, where high sensitivity and bandwidth and the ability to individually interrogate tens of multiplexed sensors via a single fiber lead has been demonstrated. This paper will describe 2 recent NRL uses of distributed strain sensing using arrays of fiber Bragg gratings (FBGs) on spacecraft parts, structures, and ground test hardware: distributed dynamic strain monitoring of a lightweight reflector during acoustic qualification tests and high-frequency, high-sensitivity strain measurements of a latch fixture. A second fiber sensor being seriously considered for spacecraft is the interferometric fiber optic gyroscope (IFOG). Although its performance in a benign environment is quite attractive, deployment of this and other optical fiber sensors requires addressing issues such as the deleterious effects of the space radiation environment. These challenges, unique to this application, will be discussed.

  8. High power ferrite microwave switch

    NASA Technical Reports Server (NTRS)

    Bardash, I.; Roschak, N. K.

    1975-01-01

    A high power ferrite microwave switch was developed along with associated electronic driver circuits for operation in a spaceborne high power microwave transmitter in geostationary orbit. Three units were built and tested in a space environment to demonstrate conformance to the required performance characteristics. Each unit consisted of an input magic-tee hybrid, two non-reciprocal latching ferrite phase shifters, an out short-slot 3 db quadrature coupler, a dual driver electronic circuit, and input logic interface circuitry. The basic mode of operation of the high power ferrite microwave switch is identical to that of a four-port, differential phase shift, switchable circulator. By appropriately designing the phase shifters and electronic driver circuits to operate in the flux-transfer magnetization mode, power and temperature insensitive operation was achieved. A list of the realized characteristics of the developed units is given.

  9. Analysis Of Lapan-Tubsat Anomaly During Periode Of 2010-2011 Using SIA

    NASA Astrophysics Data System (ADS)

    Neflia, Neflia; Ahmad, Nizam

    2016-07-01

    LAPAN-TUBSAT is the first Indonesia micro-satellite that was launched on January 10, 2007. During periode of 2010 -2011, LAPAN-TUBSAT was reported experienced anomaly called single event latch up (SEL). The anomaly events is believed correlated with the particle distribution in the space during the anomaly. Using SIAS (Satellite Anomaly Information System), we tried to locate the satellite position during the anomaly time and analyze the possible source of the anomaly. During these periode of times, there were 84 cases of anomaly. 20 cases occured in south pole, 21 cases in north pole, 4 cases in SAA, 16 case in Atlantic ocean, 4 cases in hindia ocean and 20 cases in other locations. About 43 cases of these anomaly occured during quite high particle flux distribution. This result showed that particle fluxes is not the only cause of anomaly. Further analyze needed to find the other causes of anomaly.

  10. Wind turbine spoiler

    DOEpatents

    Sullivan, W.N.

    An aerodynamic spoiler system for a vertical axis wind turbine includes spoilers on the blades initially stored near the rotor axis to minimize drag. A solenoid latch adjacent the central support tower releases the spoilers and centrifugal force causes the spoilers to move up the turbine blades away from the rotor axis, thereby producing a braking effect and actual slowing of the associated wind turbine, if desired. The spoiler system can also be used as an infinitely variable power control by regulated movement of the spoilers on the blades over the range between the undeployed and fully deployed positions. This is done by the use of a suitable powered reel and cable located at the rotor tower to move the spoilers.

  11. The design and development of a release mechanism for space shuttle life-science experiments

    NASA Technical Reports Server (NTRS)

    Jones, H. M.; Daniell, R. G.

    1984-01-01

    The design, development, and testing of a release mechanism for use in two life science experiments on the Spacelab 1, 4, and D1 missions is described. The mechanism is a self latching ball lock device actuated by a linear solenoid. An unusual feature is the tapering of the ball lock plunger to give it a near constant breakout force for release under a wide range of loads. The selection of the design, based on the design requirements, is discussed. A number of problems occurred during development and test, including problems caused by human factors that became apparent after initial delivery for crewtraining sessions. These problems and their solutions are described to assist in the design and testing of similar mechanisms.

  12. Frontal sled tests comparing rear and forward facing child restraints with 1-3 year old dummies.

    PubMed

    Sherwood, C P; Crandall, J R

    2007-01-01

    Although most countries recommend transitioning children from rear facing (RF) to forward facing (FF) child restraints at one year of age, Swedish data suggests that RF restraints are more effective. The objective of this study was to compare RF and FF orientations in frontal sled tests. Four dummies (CRABI 12 mo, Q1.5, Hybrid III 3 yr, and Q3) were used to represent children from 1 to 3 years of age. Restraint systems tested included both 1) LATCH and 2) rigid ISOFIX with support leg designs. Rear facing restraints with support legs provided the best results for all injury measures, while RF restraints in general provided the lowest chest displacements and neck loads.

  13. NASA Lessons Learned from Space Lubricated Mechanisms

    NASA Technical Reports Server (NTRS)

    Predmore, Roamer E.

    2000-01-01

    This document reviews the lessons learned from short-life and long life lubricated space mechanisms. A short-life lubricated mechanisms complete their life test qualification requirements after a few cycles. The mechanisms include the hinges, motors and bearings for deployment, release mechanisms, latches, release springs and support shops. Performance testing can be difficult and expensive but must be accomplished. A long-life lubricated mechanisms requires up to 5 years of life testing, or 10 to 100 years of successful flight. The long-life mechanisms include reaction wheels, momentum wheels, antenna gimbals, solar array drives, gyros and despin mechanisms. Several instances of how a mechanisms failed either in test, or in space use, and the lessons learned from these failures are reviewed. The effect of the movement away from CFC-113 cleaning solvent to ODC (Ozone-Depleting Chemical) -free is reviewed, and some of the alternatives are discussed.

  14. Development of the maypole (hoop/column) deployable reflector concept for large space systems application

    NASA Technical Reports Server (NTRS)

    Montgomery, D. C.

    1981-01-01

    A review of the NASA supplied mission scenarios for the communications, radiometry and radio astronomy missions. Led to specific hoop/column antenna configurations for each mission. The mission configurations were then evaluated to identify specific technology items requiring further development. The compilation of these technology drivers resulted in a specification of an artificial or point design, the design element around which all design and performance estimates for the rest of the program were made. Mechanisms for deployment and stowing are examined including the cable driven mast and the latch pulley roller. Methods for determining the thermal expansion of candidate materials, the development of the cables, cords, and hinged joints, and surface adjustment are considered.

  15. Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.; Marshall, Paul W.; Rodbell, Kenneth P.; Gordon, Michael S.; LaBel, Kenneth A.; Schwank, James R.; Dodds, Nathaniel A.; Castaneda, Carlos M.; Berg, Melanie D.; Kim, Hak S.; Phan, Anthony M.; Seidleck, Christina M.

    2014-01-01

    We report low-energy proton and low-energy alpha particle single-event effects (SEE) data on a 32 nm silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) latches and static random access memory (SRAM) that demonstrates the criticality of using low-energy protons for SEE testing of highly-scaled technologies. Low-energy protons produced a significantly higher fraction of multi-bit upsets relative to single-bit upsets when compared to similar alpha particle data. This difference highlights the importance of performing hardness assurance testing with protons that include energy distribution components below 2 megaelectron-volt. The importance of low-energy protons to system-level single-event performance is based on the technology under investigation as well as the target radiation environment.

  16. Demultiplexer circuit for neural stimulation

    DOEpatents

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  17. Aeroheating Predictions for X-34 Using an Inviscid-Boundary Layer Method

    NASA Technical Reports Server (NTRS)

    Riley, Christropher J.; Kleb, William L.

    1998-01-01

    Radiative equilibrium surface temperatures and surface heating rates from a combined inviscid-boundary layer method are presented for the X-34 Reusable Launch Vehicle for several points along the hypersonic descent portion of its trajectory. Inviscid, perfect-gas solutions are generated with the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and the Data-Parallel Lower-Upper Relaxation (DPLUR) code. Surface temperatures and heating rates are then computed using the Langley Approximate Three-Dimensional Convective Heating (LATCH) engineering code employing both laminar and turbulent flow models. The combined inviscid-boundary layer method provides accurate predictions of surface temperatures over most of the vehicle and requires much less computational effort than a Navier-Stokes code. This enables the generation of a more thorough aerothermal database which is necessary to design the thermal protection system and specify the vehicle's flight limits.

  18. Tensile-stressed microelectromechanical apparatus and microelectromechanical relay formed therefrom

    DOEpatents

    Fleming, James G.

    2008-03-04

    A microelectromechanical (MEM) apparatus is disclosed which includes a shuttle suspended above a substrate by two or more sets of tensile-stressed beams which are operatively connected to the shuttle and which can comprise tungsten or a silicon nitride/polysilicon composite structure. Initially, the tensile stress in each set of beams is balanced. However, the tensile stress can be unbalanced by heating one or more of the sets of beams; and this can be used to move the shuttle over a distance of up to several tens of microns. The MEM apparatus can be used to form a MEM relay having relatively high contact and opening forces, and with or without a latching capability.

  19. On hybrid circuits exploiting thermistive properties of slime mould.

    PubMed

    Walter, Xavier Alexis; Horsfield, Ian; Mayne, Richard; Ieropoulos, Ioannis A; Adamatzky, Andrew

    2016-04-06

    Slime mould Physarum polycephalum is a single cell visible by the unaided eye. Let the slime mould span two electrodes with a single protoplasmic tube: if the tube is heated to approximately ≈40 °C, the electrical resistance of the protoplasmic tube increases from ≈3 MΩ to ≈10,000 MΩ. The organism's resistance is not proportional nor correlated to the temperature of its environment. Slime mould can therefore not be considered as a thermistor but rather as a thermic switch. We employ the P. polycephalum thermic switch to prototype hybrid electrical analog summator, NAND gates, and cascade the gates into Flip-Flop latch. Computing operations performed on this bio-hybrid computing circuitry feature high repeatability, reproducibility and comparably low propagation delays.

  20. On hybrid circuits exploiting thermistive properties of slime mould

    NASA Astrophysics Data System (ADS)

    Walter, Xavier Alexis; Horsfield, Ian; Mayne, Richard; Ieropoulos, Ioannis A.; Adamatzky, Andrew

    2016-04-01

    Slime mould Physarum polycephalum is a single cell visible by the unaided eye. Let the slime mould span two electrodes with a single protoplasmic tube: if the tube is heated to approximately ≈40 °C, the electrical resistance of the protoplasmic tube increases from ≈3 MΩ to ≈10,000 MΩ. The organism’s resistance is not proportional nor correlated to the temperature of its environment. Slime mould can therefore not be considered as a thermistor but rather as a thermic switch. We employ the P. polycephalum thermic switch to prototype hybrid electrical analog summator, NAND gates, and cascade the gates into Flip-Flop latch. Computing operations performed on this bio-hybrid computing circuitry feature high repeatability, reproducibility and comparably low propagation delays.