Sample records for safety control rod

  1. HWCTR CONTROL ROD AND SAFETY ROD DRIVE SYSTEMS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kale, S.H.

    1963-07-01

    The Heavy Water Components Test Reactor (HWCTR) is a pressurized, D/sub 2/O reactor designed for operation up to 70 Mw at 1500 psig and 3l5 deg C. It has 18 control rods and six safety rods, each driven by an electric motor through a rack and pinion gear train. Racks, pinions, and bearings are located inside individual pressure housings that are penetrated by means of floating ring labyrinth seals. The drives are mounted on the reactor vessel top head. Safety rods have electromagnetic clutches and fall into the reactor when scrammed. The reliability and performance of the rod drives aremore » very good. Seal leakage is well within design limits. Recent inspections of seals and control rod plants showed no evidence of crud buildup or stress corrosion cracking of type 17- 4PH'' stainless steel components. (auth)« less

  2. SAFETY SYSTEM FOR CONTROL ROD

    DOEpatents

    Paget, J.A.

    1963-05-14

    A structure for monitoring the structural continuity of a control rod foi a neutron reactor is presented. A electric conductor readily breakable under mechanical stress is fastened along the length of the control rod at a plurality of positions and forms a closed circuit with remote electrical components responsive to an open circuit. A portion of the conductor between the control rod and said components is helically wound to allow free and normally unrestricted movement of the segment of conductor secured to the control rod relative to the remote components. Any break in the circuit is indicative of control rod breakage. (AEC)

  3. Automatic safety rod for reactors

    DOEpatents

    Germer, John H.

    1988-01-01

    An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-core flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

  4. Automatic safety rod for reactors. [LMFBR

    DOEpatents

    Germer, J.H.

    1982-03-23

    An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

  5. Reactor control rod timing system

    DOEpatents

    Wu, Peter T. K.

    1982-01-01

    A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

  6. Reactor control rod timing system. [LMFBR

    DOEpatents

    Wu, P.T.K.

    1980-03-18

    A fluid driven jet-edge whistle timing system is described for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

  7. Temperature actuated automatic safety rod release

    DOEpatents

    Hutter, E.; Pardini, J.A.; Walker, D.E.

    1984-03-13

    A temperature-actuated apparatus is disclosed for releasably supporting a safety rod in a nuclear reactor, comprising a safety rod upper adapter having a retention means, a drive shaft which houses the upper adapter, and a bimetallic means supported within the drive shaft and having at least one ledge which engages a retention means of the safety rod upper adapter. A pre-determined increase in temperature causes the bimetallic means to deform so that the ledge disengages from the retention means, whereby the bimetallic means releases the safety rod into the core of the reactor.

  8. Temperature actuated automatic safety rod release

    DOEpatents

    Hutter, Ernest; Pardini, John A.; Walker, David E.

    1987-01-01

    A temperature-actuated apparatus is disclosed for releasably supporting a safety rod in a nuclear reactor, comprising a safety rod upper adapter having a retention means, a drive shaft which houses the upper adapter, and a bimetallic means supported within the drive shaft and having at least one ledge which engages a retention means of the safety rod upper adapter. A pre-determined increase in temperature causes the bimetallic means to deform so that the ledge disengages from the retention means, whereby the bimetallic means releases the safety rod into the core of the reactor.

  9. Control rod drive

    DOEpatents

    Hawke, Basil C.

    1986-01-01

    A control rod drive uses gravitational forces to insert one or more control rods upwardly into a reactor core from beneath the reactor core under emergency conditions. The preferred control rod drive includes a vertically movable weight and a mechanism operatively associating the weight with the control rod so that downward movement of the weight is translated into upward movement of the control rod. The preferred control rod drive further includes an electric motor for driving the control rods under normal conditions, an electrically actuated clutch which automatically disengages the motor during a power failure and a decelerator for bringing the control rod to a controlled stop when it is inserted under emergency conditions into a reactor core.

  10. 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.

  11. CONTROL ROD DRIVE

    DOEpatents

    Chapellier, R.A.; Rogers, I.

    1961-06-27

    Accurate and controlled drive for the control rod is from an electric motor. A hydraulic arrangement is provided to balance a piston against which a control rod is urged by the application of fluid pressure. The electric motor drive of the control rod for normal operation is made through the aforementioned piston. In the event scramming is required, the fluid pressure urging the control rod against the piston is relieved and an opposite fluid pressure is applied. The lack of mechanical connection between the electric motor and control rod facilitates the scramming operation.

  12. VIEW OF WEST BANK OF “SAFETY ROD PACKAGE,” INCLUDING SAFETY ...

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

    VIEW OF WEST BANK OF “SAFETY ROD PACKAGE,” INCLUDING SAFETY ROD MOTOR DRIVES (B AND C), DRUMS, AND CLUTCHES, IN A THREE-TIERED RACK IN THE PDP ROOM AT LEVEL +27’, LOOKING SOUTHWEST - Physics Assembly Laboratory, Area A/M, Savannah River Site, Aiken, Aiken County, SC

  13. VIEW OF EAST BANK OF “SAFETY ROD PACKAGE,” INCLUDING SAFETY ...

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

    VIEW OF EAST BANK OF “SAFETY ROD PACKAGE,” INCLUDING SAFETY ROD MOTOR DRIVES (B AND C), DRUMS, AND CLUTCHES, IN A THREE-TIERED RACK IN THE PDP ROOM AT LEVEL +27’, LOOKING SOUTHEAST - Physics Assembly Laboratory, Area A/M, Savannah River Site, Aiken, Aiken County, SC

  14. CRUCIFORM CONTROL ROD JOINT

    DOEpatents

    Thorp, A.G. II

    1962-08-01

    An invention is described which relates to nuclear reactor control rod components and more particularly to a joint between cruciform control rod members and cruciform control rod follower members. In one embodiment this invention provides interfitting crossed arms at adjacent ends of a control rod and its follower in abutting relation. This holds the members against relative opposite longitudinal movement while a compression member keys the arms against relative opposite rotation around a common axis. Means are also provided for centering the control rod and its follower on a common axis and for selectively releasing the control rod from its follower for the insertion of a replacement of the control rod and reuse of the follower. (AEC)

  15. Double-clad nuclear fuel safety rod

    DOEpatents

    McCarthy, William H.; Atcheson, Donald B.; Vaidyanathan, Swaminathan

    1984-01-01

    A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.

  16. Double-clad nuclear-fuel safety rod

    DOEpatents

    McCarthy, W.H.; Atcheson, D.B.

    1981-12-30

    A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.

  17. Control rod driveline and grapple

    DOEpatents

    Germer, John H.

    1987-01-01

    A control rod driveline and grapple is disclosed for placement between a control rod drive and a nuclear reactor control rod containing poison for parasitic neutron absorption required for reactor shutdown. The control rod is provided with an enlarged cylindrical handle which terminates in an upwardly extending rod to provide a grapple point for the driveline. The grapple mechanism includes a tension rod which receives the upwardly extending handle and is provided with a lower annular flange. A plurality of preferably six grapple segments surround and grip the control rod handle. Each grapple rod segment grips the flange on the tension rod at an interior upper annular indentation, bears against the enlarged cylindrical handle at an intermediate annulus and captures the upwardly flaring frustum shaped handle at a lower and complementary female segment. The tension rods and grapple segments are surrounded by and encased within a cylinder. The cylinder terminates immediately and outward extending annulus at the lower portion of the grapple segments. Excursion of the tension rod relative to the encasing cylinder causes rod release at the handle by permitting the grapple segments to pivot outwardly and about the annulus on the tension rod so as to open the lower defined frustum shaped annulus and drop the rod. Relative movement between the tension rod and cylinder can occur either due to electromagnetic release of the tension rod within defined limits of travel or differential thermal expansion as between the tension rod and cylinder as where the reactor exceeds design thermal limits.

  18. CONTROL RODS FOR NUCLEAR REACTORS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, F.R.

    1963-01-16

    A means for controlling the control rod in emergency, when it is desired to shutdown the reactor with the shortest possible delay, is described. When the emergency occurs the control rod is allowed to drop freely under gravity from the control rod support tube into the bore in the reactor core. A normal shutdown is reached almost at the lowest rod position. In the shut-down position and also below it, the control rod had its full effect of reducing the level of activity in the core. When the shut-down position was reached, a brake came into action to decelerate themore » rod and reduce shock and the likelihood of damage. (C.E.S.)« less

  19. REACTOR CONTROL ROD OPERATING SYSTEM

    DOEpatents

    Miller, G.

    1961-12-12

    A nuclear reactor control rod mechanism is designed which mechanically moves the control rods into and out of the core under normal conditions but rapidly forces the control rods into the core by catapultic action in the event of an emergency. (AEC)

  20. Variable flow control for a nuclear reactor control rod

    DOEpatents

    Carleton, Richard D.; Bhattacharyya, Ajay

    1978-01-01

    A variable flow control for a control rod assembly of a nuclear reactor that depends on turbulent friction though an annulus. The annulus is formed by a piston attached to the control rod drive shaft and a housing or sleeve fitted to the enclosure housing the control rod. As the nuclear fuel is burned up and the need exists for increased reactivity, the control rods are withdrawn, which increases the length of the annulus and decreases the rate of coolant flow through the control rod assembly.

  1. NEUTRONIC REACTOR CONTROL ROD DRIVE APPARATUS

    DOEpatents

    Oakes, L.C.; Walker, C.S.

    1959-12-15

    ABS>A suspension mechanism between a vertically movable nuclear reactor control rod and a rod extension, which also provides information for the operator or an automatic control signal, is described. A spring connects the rod extension to a drive shift. The extension of the spring indicates whether (1) the rod is at rest on the reactor, (2) the rod and extension are suspended, or (3) the extension alone is suspended, the spring controlling a 3-position electrical switch.

  2. CONTROL ROD DRIVE

    DOEpatents

    Chapellier, R.A.

    1960-05-24

    BS>A drive mechanism was invented for the control rod of a nuclear reactor. Power is provided by an electric motor and an outside source of fluid pressure is utilized in conjunction with the fluid pressure within the reactor to balance the loadings on the motor. The force exerted on the drive mechanism in the direction of scramming the rod is derived from the reactor fluid pressure so that failure of the outside pressure source will cause prompt scramming of the rod.

  3. COMPOSITE CONTROL ROD

    DOEpatents

    Rock, H.R.

    1963-12-24

    A composite control rod for use in controlling a nuclear reactor is described. The control rod is of sandwich construction in which finned dowel pins are utilized to hold together sheets of the neutron absorbing material and nonabsorbing structural material thereby eliminating the need for being dependent on the absorbing material for structural support. The dowel pins perform the function of absorbing the forces due to differential thermal expansion, seating further with the fins into the sheets of material and crushing before damage is done either to the absorbing or non-absorbing material. (AEC)

  4. CONTROL ROD

    DOEpatents

    Zinn, W.H.; Ross, H.V.

    1958-11-18

    A control rod is described for a nuclear reactor. In certaln reactor designs it becomes desirable to use a control rod having great width but relatively llttle thickness. This patent is addressed to such a need. The neutron absorbing material is inserted in a triangular tube, leaving volds between the circular insert and the corners of the triangular tube. The material is positioned within the tube by the use of dummy spacers to achleve the desired absorption pattern, then the ends of the tubes are sealed with suitable plugs. The tubes may be welded or soldered together to form two flat surfaces of any desired width, and covered with sheetmetal to protect the tubes from damage. This design provides a control member that will not distort under the action of outside forces or be ruptured by gases generated within the jacketed control member.

  5. Safety control circuit for a neutronic reactor

    DOEpatents

    Ellsworth, Howard C.

    2004-04-27

    A neutronic reactor comprising an active portion containing material fissionable by neutrons of thermal energy, means to control a neutronic chain reaction within the reactor comprising a safety device and a regulating device, a safety device including means defining a vertical channel extending into the reactor from an aperture in the upper surface of the reactor, a rod containing neutron-absorbing materials slidably disposed within the channel, means for maintaining the safety rod in a withdrawn position relative to the active portion of the reactor including means for releasing said rod on actuation thereof, a hopper mounted above the active portion of the reactor having a door disposed at the bottom of the hopper opening into the vertical channel, a plurality of bodies of neutron-absorbing materials disposed within the hopper, and means responsive to the failure of the safety rod on actuation thereof to enter the active portion of the reactor for opening the door in the hopper.

  6. Nuclear reactor remote disconnect control rod coupling indicator

    DOEpatents

    Vuckovich, Michael

    1977-01-01

    A coupling indicator for use with nuclear reactor control rod assemblies which have remotely disengageable couplings between the control rod and the control rod drive shaft. The coupling indicator indicates whether the control rod and the control rod drive shaft are engaged or disengaged. A resistive network, utilizing magnetic reed switches, senses the position of the control rod drive mechanism lead screw and the control rod position indicating tube, and the relative position of these two elements with respect to each other is compared to determine whether the coupling is engaged or disengaged.

  7. Control rod for a nuclear reactor

    DOEpatents

    Roman, Walter G.; Sutton, Jr., Harry G.

    1979-01-01

    A control rod assembly for a nuclear reactor is disclosed having a remotely disengageable coupling between the control rod and the control rod drive shaft. The coupling is actuated by first lowering then raising the drive shaft. The described motion causes axial repositioning of a pin in a grooved rotatable cylinder, each being attached to different parts of the drive shaft which are axially movable relative to each other. In one embodiment, the relative axial motion of the parts of the drive shaft is used either to couple or to uncouple the connection by forcing resilient members attached to the drive shaft into or out of shouldered engagement, respectively, with an indentation formed in the control rod.

  8. Hydraulic Actuator for Ganged Control Rods

    NASA Technical Reports Server (NTRS)

    Thompson, D. C.; Robey, R. M.

    1986-01-01

    Hydraulic actuator moves several nuclear-reactor control rods in unison. Electromagnetic pump pushes liquid lithium against ends of control rods, forcing them out of or into nuclear reactor. Color arrows show lithium flow for reactor startup and operation. Flow reversed for shutdown. Conceived for use aboard spacecraft, actuator principle applied to terrestrial hydraulic machinery involving motion of ganged rods.

  9. Inverted Control Rod Lock-In Device

    DOEpatents

    Brussalis, W. G.; Bost, G. E.

    1962-12-01

    A mechanism which prevents control rods from dropping out of the reactor core in the event the vessel in which the reactor is mounted should capsize is described. The mechanism includes a pivoted toothed armature which engages the threaded control rod lead screw and prevents removal of the rod whenever the armature is not attracted by the provided electromagnetic means. (AEC)

  10. Advanced gray rod control assembly

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Drudy, Keith J; Carlson, William R; Conner, Michael E

    An advanced gray rod control assembly (GRCA) for a nuclear reactor. The GRCA provides controlled insertion of gray rod assemblies into the reactor, thereby controlling the rate of power produced by the reactor and providing reactivity control at full power. Each gray rod assembly includes an elongated tubular member, a primary neutron-absorber disposed within the tubular member said neutron-absorber comprising an absorber material, preferably tungsten, having a 2200 m/s neutron absorption microscopic capture cross-section of from 10 to 30 barns. An internal support tube can be positioned between the primary absorber and the tubular member as a secondary absorber tomore » enhance neutron absorption, absorber depletion, assembly weight, and assembly heat transfer characteristics.« less

  11. CONTROL ROD

    DOEpatents

    Walker, D.E.; Matras, S.

    1963-04-30

    This patent shows a method of making a fuel or control rod for a nuclear reactor. Fuel or control material is placed within a tube and plugs of porous metal wool are inserted at both ends. The metal wool is then compacted and the tube compressed around it as by swaging, thereby making the plugs liquid- impervious but gas-pervious. (AEC)

  12. Magnetic switch for reactor control rod

    DOEpatents

    Germer, John H.

    1986-01-01

    A magnetic reed switch assembly for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electromagnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.

  13. CONTROL RODS FOR NUCLEAR REACTOR CORES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, F.R.

    1961-11-15

    A reactor control rod is designed which has increased effectiveness as compared with the width of the aperture in the pressure vessel through which it passes. The control rod carries six fins, three on each side, and two of the fins are fixed while the other, being adjustable, is capable of movement from between the fixed fins to an extended position. Thus, the control rod assembly can be arranged so that the parts within the core form a substantially complete shell around the reactor central axis, while the apertures on the pressure vessel wall are well spaced for strength. (D.L.C.)

  14. Magnetic switch for reactor control rod. [LMFBR

    DOEpatents

    Germer, J.H.

    1982-09-30

    A magnetic reed switch assembly is described for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electro-magnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.

  15. CONTROL ROD DRIVE MECHANISM FOR A NUCLEAR REACTOR

    DOEpatents

    Hawke, B.C.; Liederbach, F.J.; Lones, W.

    1963-05-14

    A lead-screw-type control rod drive featuring an electric motor and a fluid motor arranged to provide a selectably alternative driving means is described. The electric motor serves to drive the control rod slowly during normal operation, while the fluid motor, assisted by an automatic declutching of the electric motor, affords high-speed rod insertion during a scram. (AEC)

  16. COAXIAL CONTROL ROD DRIVE MECHANISM FOR NEUTRONIC REACTORS

    DOEpatents

    Fox, R.J.; Oakes, L.C.

    1959-04-14

    A drive mechanism is presented for the control rod or a nuclear reactor. In this device the control rod is coupled to a drive shaft which extends coaxially through the rotor of an electric motor for relative rotation with respect thereto. A gear reduction mehanism is coupled between the rotor and the drive shaft to convert the rotary motion of the motor into linear motion of the shaft with a comparatively great reduction in speed, thereby providing relatively glow linear movement of the shaft and control rod for control purposes.

  17. VARIABLE AREA CONTROL ROD FOR NUCLEAR REACTOR

    DOEpatents

    Huston, N.E.

    1960-05-01

    A control rod is described which permits continual variation of its absorbing strength uniformly along the length of the rod. The rod is fail safe and is fully inserted into the core but changes in its absorbing strength do not produce axial flux distortion. The control device comprises a sheet containing a material having a high thermal-neutron absorption cross section. A pair of shafts engage the sheet along the longitudinal axis of the shafts and gears associated with the shafts permit winding and unwinding of the sheet around the shafts.

  18. Control rod drive for reactor shutdown

    DOEpatents

    McKeehan, Ernest R.; Shawver, Bruce M.; Schiro, Donald J.; Taft, William E.

    1976-01-20

    A means for rapidly shutting down or scramming a nuclear reactor, such as a liquid metal-cooled fast breeder reactor, and serves as a backup to the primary shutdown system. The control rod drive consists basically of an in-core assembly, a drive shaft and seal assembly, and a control drive mechanism. The control rod is driven into the core region of the reactor by gravity and hydraulic pressure forces supplied by the reactor coolant, thus assuring that common mode failures will not interfere with or prohibit scramming the reactor when necessary.

  19. Linear motion device and method for inserting and withdrawing control rods

    DOEpatents

    Smith, Jay E.

    1984-01-01

    A linear motion device, more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core, is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism.

  20. Linear motion device and method for inserting and withdrawing control rods

    DOEpatents

    Smith, J.E.

    Disclosed is a linear motion device and more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core. The CRDM and method disclosed is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism.

  1. HIGH STRENGTH CONTROL RODS FOR NEUTRONIC REACTORS

    DOEpatents

    Lustman, B.; Losco, E.F.; Cohen, I.

    1961-07-11

    Nuclear reactor control rods comprised of highly compressed and sintered finely divided metal alloy panticles and fine metal oxide panticles substantially uniformly distributed theretbrough are described. The metal alloy consists essentially of silver, indium, cadmium, tin, and aluminum, the amount of each being present in centain percentages by weight. The oxide particles are metal oxides of the metal alloy composition, the amount of oxygen being present in certain percentages by weight and all the oxygen present being substantially in the form of metal oxide. This control rod is characterized by its high strength and resistance to creep at elevated temperatures.

  2. Fast-acting nuclear reactor control device

    DOEpatents

    Kotlyar, Oleg M.; West, Phillip B.

    1993-01-01

    A fast-acting nuclear reactor control device for moving and positioning a fety control rod to desired positions within the core of the reactor between a run position in which the safety control rod is outside the reactor core, and a shutdown position in which the rod is fully inserted in the reactor core. The device employs a hydraulic pump/motor, an electric gear motor, and solenoid valve to drive the safety control rod into the reactor core through the entire stroke of the safety control rod. An overrunning clutch allows the safety control rod to freely travel toward a safe position in the event of a partial drive system failure.

  3. High temperature control rod assembly

    DOEpatents

    Vollman, Russell E.

    1991-01-01

    A high temperature nuclear control rod assembly comprises a plurality of substantially cylindrical segments flexibly joined together in succession by ball joints. The segments are made of a high temperature graphite or carbon-carbon composite. The segment includes a hollow cylindrical sleeve which has an opening for receiving neutron-absorbing material in the form of pellets or compacted rings. The sleeve has a threaded sleeve bore and outer threaded surface. A cylindrical support post has a threaded shaft at one end which is threadably engaged with the sleeve bore to rigidly couple the support post to the sleeve. The other end of the post is formed with a ball portion. A hollow cylindrical collar has an inner threaded surface engageable with the outer threaded surface of the sleeve to rigidly couple the collar to the sleeve. the collar also has a socket portion which cooperates with the ball portion to flexibly connect segments together to form a ball and socket-type joint. In another embodiment, the segment comprises a support member which has a threaded shaft portion and a ball surface portion. The threaded shaft portion is engageable with an inner threaded surface of a ring for rigidly coupling the support member to the ring. The ring in turn has an outer surface at one end which is threadably engageably with a hollow cylindrical sleeve. The other end of the sleeve is formed with a socket portion for engagement with a ball portion of the support member. In yet another embodiment, a secondary rod is slidably inserted in a hollow channel through the center of the segment to provide additional strength. A method for controlling a nuclear reactor utilizing the control rod assembly is also included.

  4. Ultrasound control of magnet growing rod distraction in early onset scoliosis.

    PubMed

    Pérez Cervera, T; Lirola Criado, J F; Farrington Rueda, D M

    2016-01-01

    The growing rod technique is currently one of the most common procedures used in the management of early onset scoliosis. However, in order to preserve spine growth and control the deformity it requires frequent surgeries to distract the rods. Magnetically driven growing rods have recently been introduced with same treatment goal, but without the inconvenience of repeated surgical distractions. One of the limitations of this technical advance is an increase in radiation exposure due to the increase in distraction frequency compared to conventional growing rods. An improvement of the original technique is presented, proposing a solution to the inconvenience of multiple radiation exposure using ultrasound technology to control the distraction process of magnetically driven growing rods. Copyright © 2014 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. CONTROL ROD FOR A NUCLEAR REACTOR AND METHOD OF PREPARATION

    DOEpatents

    Hausner, H.H.

    1958-12-30

    BS>An improved control rod is presented for a nuclear reactor. This control rod is comprised of a rare earth metal oxide or rare earth metal carbide such as gadolinium oxide or gadolinium carbide, uniformly distributed in a metal matrix having a low cross sectional area of absorption for thermal neutrons, such as aluminum, beryllium, and zirconium.

  6. Control rod system useable for fuel handling in a gas-cooled nuclear reactor

    DOEpatents

    Spurrier, Francis R.

    1976-11-30

    A control rod and its associated drive are used to elevate a complete stack of fuel blocks to a position above the core of a gas-cooled nuclear reactor. A fuel-handling machine grasps the control rod and the drive is unlatched from the rod. The stack and rod are transferred out of the reactor, or to a new location in the reactor, by the fuel-handling machine.

  7. POSITIONING MEANS FOR THE CONTROL ROD IN A NUCLEAR REACTOR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, F.R.

    1963-09-26

    An electric motor and transmission means for adjusting the position of the control rod in relation to the reactor core to control the level of activity in either sense and a lock that is retained in a locking condition by a longitudinal force derived electrically from the motor but arranged to be released when the electrical force is removed to allow the control rod in an emergency to drop into its shut-down position are described. (Gmelin Inst.)

  8. Control rod calibration and reactivity effects at the IPEN/MB-01 reactor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pinto, Letícia Negrão; Gonnelli, Eduardo; Santos, Adimir dos

    2014-11-11

    Researches that aim to improve the performance of neutron transport codes and quality of nuclear cross section databases are very important to increase the accuracy of simulations and the quality of the analysis and prediction of phenomena in the nuclear field. In this context, relevant experimental data such as reactivity worth measurements are needed. Control rods may be made of several neutron absorbing materials that are used to adjust the reactivity of the core. For the reactor operation, these experimental data are also extremely important: with them it is possible to estimate the reactivity worth by the movement of themore » control rod, understand the reactor response at each rod position and to operate the reactor safely. This work presents a temperature correction approach for the control rod calibration problem. It is shown the control rod calibration data of the IPEN/MB-01 reactor, the integral and differential reactivity curves and a theoretical analysis, performed by the MCNP-5 reactor physics code, developed and maintained by Los Alamos National Laboratory, using the ENDF/B-VII.0 nuclear data library.« less

  9. Controllability of semi-infinite rod heating by a point source

    NASA Astrophysics Data System (ADS)

    Khurshudyan, A.

    2018-04-01

    The possibility of control over heating of a semi-infinite thin rod by a point source concentrated at an inner point of the rod, is studied. Quadratic and piecewise constant solutions of the problem are derived, and the possibilities of solving appropriate problems of optimal control are indicated. Determining of the parameters of the piecewise constant solution is reduced to a problem of nonlinear programming. Numerical examples are considered.

  10. Urea controlled hydrothermal synthesis of ammonium aluminum carbonate hydroxide rods

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Zhu, Jianfeng; Liu, Hui

    2018-03-01

    In this study, ammonium aluminum carbonate hydroxide (AACH) rods were controllably prepared using the hydrothermal method by manipulating the amount of urea in the reaction system. The experimental results showed that AACH in rod shape was able to be gradually transformed from γ-AlOOH in cluster shape during the molar ratios of urea to Al in the reactants were ranged from 8 to 10, and the yield of AACH has increased accordingly. When the molar ratio of urea to Al reaches 11, pure AACH rods with a diameter of 500 nm and a length of 10 μm approximately was able to be produced. Due to the slow decomposition of urea during the hydrothermal reaction, the nucleation and growth of AACH crystal proceed step by step. Therefore, the crystal can fully grow on each crystal plane and eventually produce a highly crystalline rod-shaped product. The role of urea in controlling the morphology and yield of AACH was also discussed in this paper systematically.

  11. NEUTRONIC REACTOR CONTROL ROD AND METHOD OF FABRICATION

    DOEpatents

    Porembka, S.W. Jr.

    1961-06-27

    A reactor control rod formed from a compacted powder dispersion is patented. The rod consists of titanium sheathed with a cladding alloy. The cladding alloy contains 1.3% to 1.6% by weight of tin, 0.07% to 0.12% by weight of chromium, 0.04% to 0.08% by weight of nickel, 0.09% to 0.16% by weight of iron, carbon not exceeding 0.05%, less than 0.5% by weight of incidental impurities, and the balance zirconium.

  12. Underwater characterization of control rods for waste disposal using SMOPY

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gallozzi-Ulmann, A.; Couturier, P.; Amgarou, K.

    Storage of spent fuel assemblies in cooling ponds requires careful control of the geometry and proximity of adjacent assemblies. Measurement of the fuel burnup makes it possible to optimise the storage arrangement of assemblies taking into account the effect of the burnup on the criticality safety margins ('burnup credit'). Canberra has developed a measurement system for underwater measurement of spent fuel assemblies. This system, known as 'SMOPY', performs burnup measurements based on gamma spectroscopy (collimated CZT detector) and neutron counting (fission chamber). The SMOPY system offers a robust and waterproof detection system as well as the needed capability of performingmore » radiometric measurements in the harsh high dose - rate environments of the cooling ponds. The gamma spectroscopy functionality allows powerful characterization measurements to be performed, in addition to burnup measurement. Canberra has recently performed waste characterisation measurements at a Nuclear Power Plant. Waste activity assessment is important to control costs and risks of shipment and storage, to ensure that the activity level remains in the range allowed by the facility, and to declare activity data to authorities. This paper describes the methodology used for the SMOPY measurements and some preliminary results of a radiological characterisation of AIC control rods. After describing the features and normal operation of the SMOPY system, we describe the approach used for establishing an optimum control rod geometric scanning approach (optimum count time and speed) and the method of the gamma spectrometry measurements as well as neutron check measurements used to verify the absence of neutron sources in the waste. We discuss the results obtained including {sup 60}Co, {sup 110m}Ag and {sup 108m}Ag activity profiles (along the length of the control rods) and neutron results including Total Measurement Uncertainty evaluations. Full self-consistency checks were performed

  13. Boiling water reactor radiation shielded Control Rod Drive Housing Supports

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baversten, B.; Linden, M.J.

    1995-03-01

    The Control Rod Drive (CRD) mechanisms are located in the area below the reactor vessel in a Boiling Water Reactor (BWR). Specifically, these CRDs are located between the bottom of the reactor vessel and above an interlocking structure of steel bars and rods, herein identified as CRD Housing Supports. The CRD Housing Supports are designed to limit the travel of a Control Rod and Control Rod Drive in the event that the CRD vessel attachement went to fail, allowing the CRD to be ejected from the vessel. By limiting the travel of the ejected CRD, the supports prevent a nuclearmore » overpower excursion that could occur as a result of the ejected CRD. The Housing Support structure must be disassembled in order to remove CRDs for replacement or maintenance. The disassembly task can require a significant amount of outage time and personnel radiation exposure dependent on the number and location of the CRDs to be changed out. This paper presents a way to minimize personal radiation exposure through the re-design of the Housing Support structure. The following paragraphs also delineate a method of avoiding the awkward, manual, handling of the structure under the reactor vessel during a CRD change out.« less

  14. ADVANCED DESIGNS OF MAGNETIC JACK-TYPE CONTROL ROD DRIVE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Young, J.N.

    1959-11-01

    The magnetic jack is a device for positioning the control rods In a nuclear reactor, especially in a reactor containing water under pressure. Magnetic actuation precludes the need for shaft seals and eliminates the problems associated with mechanisms operating in water. It consists of a pressure shell, four sets of external stationary magnet coils (hold, grip, lift, pull down), and one Internal moving part (ammature) that impants linear motion to a cluster of rods. (W.L.H.)

  15. CONTROL ROD ALLOY CONTAINING NOBLE METAL ADDITIONS

    DOEpatents

    Anderson, W.K.; Ray, W.E.

    1960-05-01

    Silver-base alloys suitable for use in the fabrication of control rods for neutronic reactors are given. The alloy consists of from 0.5 wt.% to about 1.5 wt.% of a noble metal of platinum, ruthenium, rhodium, osmium, or palladium, up to 10 wt.% of cadmium, from 2 to 20 wt.% indium, the balance being silver.

  16. 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.

  17. VIEW OF CABLES AND TAPES ASSOCIATED WITH ADRIVE CONTROL ROD ...

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

    VIEW OF CABLES AND TAPES ASSOCIATED WITH A-DRIVE CONTROL ROD SYSTEM, AT LEVEL +15’, DIRECTLY ABOVE PDP CONTROL ROOM, LOOKING NORTH - Physics Assembly Laboratory, Area A/M, Savannah River Site, Aiken, Aiken County, SC

  18. Final Report: Contractor Readiness Assessment (CRA) for TREAT Fuel Movement and Control Rod Drives Isolation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rowsell, David Leon

    This report documents the Contractor Readiness Assessment (CRA) for TREAT Fuel Movement and Control Rod Drives Isolation. The review followed the approved Plan of Action (POA) and Implementation Plan (IP) using the identified core requirements. The activity was limited scope focusing on the control rod drives functional isolation and fuel element movement. The purpose of this review is to ensure the facility's readiness to move fuel elements thus supporting inspection and functionally isolate the control rod drives to maintain the required shutdown margin.

  19. Nuclear reactor safety device

    DOEpatents

    Hutter, Ernest

    1986-01-01

    A safety device is disclosed for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of an upward thermal excursion. Such safety device comprises a laminated helical ribbon configured as a tube-like helical coil having contiguous helical turns with slidably abutting edges. The helical coil is disclosed as a portion of a drive member connected axially to the control rod. The laminated ribbon is formed of outer and inner laminae. The material of the outer lamina has a greater thermal coefficient of expansion than the material of the inner lamina. In the event of an upward thermal excursion, the laminated helical coil curls inwardly to a smaller diameter. Such inward curling causes the total length of the helical coil to increase by a substantial increment, so that the control rod is axially repositioned by a corresponding amount to reduce the power output of the reactor.

  20. Nuclear reactor safety device

    DOEpatents

    Hutter, E.

    1983-08-15

    A safety device is described for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of a thermal excursion. It comprises a laminated strip helically configured to form a tube, said tube being in operative relation to said control rod. The laminated strip is formed of at least two materials having different thermal coefficients of expansion, and is helically configured such that the material forming the outer lamina of the tube has a greater thermal coefficient of expansion than the material forming the inner lamina of said tube. In the event of a thermal excursion the laminated strip will tend to curl inwardly so that said tube will increase in length, whereby as said tube increases in length it exerts a force on said control rod to axially reposition said control rod with respect to said core.

  1. Maintaining a Critical Spectra within Monteburns for a Gas-Cooled Reactor Array by Way of Control Rod Manipulation

    DOE PAGES

    Adigun, Babatunde John; Fensin, Michael Lorne; Galloway, Jack D.; ...

    2016-10-01

    Our burnup study examined the effect of a predicted critical control rod position on the nuclide predictability of several axial and radial locations within a 4×4 graphite moderated gas cooled reactor fuel cluster geometry. To achieve this, a control rod position estimator (CRPE) tool was developed within the framework of the linkage code Monteburns between the transport code MCNP and depletion code CINDER90, and four methodologies were proposed within the tool for maintaining criticality. Two of the proposed methods used an inverse multiplication approach - where the amount of fissile material in a set configuration is slowly altered until criticalitymore » is attained - in estimating the critical control rod position. Another method carried out several MCNP criticality calculations at different control rod positions, then used a linear fit to estimate the critical rod position. The final method used a second-order polynomial fit of several MCNP criticality calculations at different control rod positions to guess the critical rod position. The results showed that consistency in prediction of power densities as well as uranium and plutonium isotopics was mutual among methods within the CRPE tool that predicted critical position consistently well. Finall, while the CRPE tool is currently limited to manipulating a single control rod, future work could be geared toward implementing additional criticality search methodologies along with additional features.« less

  2. VIEW OF CABLES AND TAPES ASSOCIATED WITH ADRIVE CONTROL ROD ...

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

    VIEW OF CABLES AND TAPES ASSOCIATED WITH A-DRIVE CONTROL ROD SYSTEM, AT LEVEL +15’, DIRECTLY ABOVE PDP CONTROL ROOM, LOOKING NORTHWEST. THE CABLES FROM THE PDP ROOM GO THROUGH THE CONCRETE WALL, MAKE A RIGHT ANGLE TURN DOWNWARD, AND DESCEND INTO THE PDP CONTROL ROOM AS VERTICAL TAPES - Physics Assembly Laboratory, Area A/M, Savannah River Site, Aiken, Aiken County, SC

  3. Control rod drive hydraulic system

    DOEpatents

    Ose, Richard A.

    1992-01-01

    A hydraulic system for a control rod drive (CRD) includes a variable output-pressure CR pump operable in a charging mode for providing pressurized fluid at a charging pressure, and in a normal mode for providing the pressurized fluid at a purge pressure, less than the charging pressure. Charging and purge lines are disposed in parallel flow between the CRD pump and the CRD. A hydraulic control unit is disposed in flow communication in the charging line and includes a scram accumulator. An isolation valve is provided in the charging line between the CRD pump and the scram accumulator. A controller is operatively connected to the CRD pump and the isolation valve and is effective for opening the isolation valve and operating the CRD pump in a charging mode for charging the scram accumulator, and closing the isolation valve and operating the CRD pump in a normal mode for providing to the CRD through the purge line the pressurized fluid at a purge pressure lower than the charging pressure.

  4. Controlled self-assembly of conjugated rod-coil block copolymers for applications in organic optoelectronics

    NASA Astrophysics Data System (ADS)

    Tao, Yuefei

    Organic electronics are of great interest in manufacturing light weight, mechanical flexible, and inexpensive large area devices. While significant improvements have been made over the last several years and it is now clear that morphology on the lengthscale of exciton diffusion (10nm) is of crucial importance, a clear relationship between structure and device properties has not emerged. This lack of understanding largely emerges from an inability to control morphology on this lengthscale. This thesis will center around an approach, based on block copolymer self-assembly, to generate equilibrium nanostructures on the 10 nm lengthscale of exciton diffusion and study their effects on device performance. Self-assembly of semiconducting block copolymers is complicated by the non-classical chain shape of conjugated polymers. Unlike classical polymers, the chains do not assume a Gaussian coil shape which is stretched near block copolymer interfaces, instead the chains are elongated and liquid crystalline. Previous work has demonstrated how these new molecular interactions and shapes control the phase diagram of so-called rod-coil block copolymers. Here, we will focus on controlling domain size, orientation, and chemical structure. While domain size can be controlled directly through molecular weight, this requires significant additional synthesis of domain size is to be varied. Here, the domain size is controlled by blending homopolymers into a self-assembling rod-coil block copolymer. When coil-like blocks are incorporated, the domains swell, as expected. When rod-like blocks are incorporated, they interdigitate with the rods of the block copolymers. This results in an increase in interfacial area which forces the coils to rearrange and an overall decrease in domain size with increasing rod content. Control over lamellar orientation is crucial in order to design and control charge transport pathways and exciton recombination or separation interfaces. While numerous

  5. Autofusion in the immature spine treated with growing rods.

    PubMed

    Cahill, Patrick J; Marvil, Sean; Cuddihy, Laury; Schutt, Corey; Idema, Jocelyn; Clements, David H; Antonacci, M Darryl; Asghar, Jahangir; Samdani, Amer F; Betz, Randal R

    2010-10-15

    Retrospective case review of skeletally immature patients treated with growing rods. Patients received an average of 9.6 years follow-up care. (1) to identify the rate of autofusion in the growing spine with the use of growing rods; (2) to quantify how much correction can be attained with definitive instrumented fusion after long-term treatment with growing rods; and (3) to describe the extent of Smith-Petersen osteotomies required to gain correction of an autofused spine following growing rod treatment. The safety and use of growing rods for curve correction and maintenance in the growing spine population has been established in published reports. While autofusion has been reported, the prevalence and sequelae are not known. Nine skeletally immature children with scoliosis were identified who had been treated using growing rods. A retrospective review of the medical records and radiographs was conducted and the following data collected: complications, pre- and postoperative Cobb angles at time of initial surgery (growing rod placement), pre- and postoperative Cobb angles at time of final surgery (growing rod removal and definitive fusion), total spine length as measured from T1-S1, % correction since initiation of treatment and at definitive fusion, total number of surgeries, and number of patients found to have autofusion at the time of device removal. The rate of autofusion in children treated with growing rods was 89%. The average percent of the Cobb angle correction obtained at definitive fusion was 44%. On average, 7 osteotomies per patient were required at the time of definitive fusion due to autofusion. Although growing rods have efficacy in the control of deformity within the growing spine, they also have adverse effects on the spine. Immature spines treated with a growing rod have high rates of unintended autofusion which can possibly lead to difficult and only moderate correction at the time of definitive fusion.

  6. Development of control system of coating of rod hydraulic cylinders

    NASA Astrophysics Data System (ADS)

    Aizhambaeva, S. Zh; Maximova, A. V.

    2018-01-01

    In this article, requirements to materials of hydraulic cylinders and methods of eliminating the main factors affecting the quality of the applied coatings rod hydraulic cylinders. The chromium plating process - one of ways of increase of anti-friction properties of coatings rods, stability to the wear and corrosion. The article gives description of differences of the stand-speed chromium plating process from other types of chromium plating that determines a conclusion about cutting time of chromium plating process. Conducting the analysis of technological equipment suggested addressing the modernization of high-speed chromium plating processes by automation and mechanization. Control system developed by design of schematic block diagram of a modernized and stand-speed chromium plating process.

  7. DESIGN AND DEVELOPMENT REPORT ON TREAT CONTROL ROD DRIVE II

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Batch, R.V.

    1961-05-01

    A discussion is given of the development of TREAT control rod drive II, which describes the basic design, the problems involved with the design, the various design methods pursued, the testing procedures, and the evaluation of the performance characteristics of the final drive. (B.O.G.)

  8. Dynamic Rod Worth Measurement

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chao, Y.A.; Chapman, D.M.; Hill, D.J.

    2000-12-15

    The dynamic rod worth measurement (DRWM) technique is a method of quickly validating the predicted bank worth of control rods and shutdown rods. The DRWM analytic method is based on three-dimensional, space-time kinetic simulations of the rapid rod movements. Its measurement data is processed with an advanced digital reactivity computer. DRWM has been used as the method of bank worth validation at numerous plant startups with excellent results. The process and methodology of DRWM are described, and the measurement results of using DRWM are presented.

  9. Nuclear reactor shutdown control rod assembly

    DOEpatents

    Bilibin, Konstantin

    1988-01-01

    A temperature responsive, self-actuated nuclear reactor shutdown control rod assembly 10. The upper end 18 of a lower drive line 17 fits within the lower end of an upper drive line 12. The lower end (not shown) of the lower drive line 17 is connected to a neutron absorber. During normal temperature conditions the lower drive line 17 is supported by detent means 22,26. When an overtemperature condition occurs thermal actuation means 34 urges ring 26 upwardly sufficiently to allow balls 22 to move radially outwardly thereby allowing lower drive line 17 to move downwardly toward the core of the nuclear reactor resulting in automatic reduction of the reactor powder.

  10. Rod electrical coupling is controlled by a circadian clock and dopamine in mouse retina

    PubMed Central

    Jin, Nan Ge; Chuang, Alice Z; Masson, Philippe J; Ribelayga, Christophe P

    2015-01-01

    Key points Rod photoreceptors play a key role in vision in dim light; in the mammalian retina, although rods are anatomically connected or coupled by gap junctions, a type of electrical synapse, the functional importance and regulation of rod coupling has remained elusive. We have developed a new technique in the mouse: perforated patch-clamp recording of rod inner segments in isolated intact retinae maintained by superfusion. We find that rod electrical coupling is controlled by a circadian clock and dopamine, and is weak during the day and stronger at night. The results also indicate that the signal-to-noise ratio for a dim light response is increased at night because of coupling. Our observations will provide a framework for understanding the daily variations in human vision as well as the basis of specific retinal malfunctions. Abstract Rod single-photon responses are critical for vision in dim light. Electrical coupling via gap junction channels shapes the light response properties of vertebrate photoreceptors, but the regulation of rod coupling and its impact on the single-photon response have remained unclear. To directly address these questions, we developed a perforated patch-clamp recording technique and recorded from single rod inner segments in isolated intact neural mouse retinae, maintained by superfusion. Experiments were conducted at different times of the day or under constant environmental conditions, at different times across the circadian cycle. We show that rod electrical coupling is regulated by a circadian clock and dopamine, so that coupling is weak during the day and strong at night. Altogether, patch-clamp recordings of single-photon responses in mouse rods, tracer coupling, receptive field measurements and pharmacological manipulations of gap junction and dopamine receptor activity provide compelling evidence that rod coupling is modulated in a circadian manner. These data are consistent with computer modelling. At night, single

  11. Flexible growing rods: a pilot study to determine if polymer rod constructs may provide stability to skeletally immature spines

    PubMed Central

    2015-01-01

    Background Surgical treatments for early onset scoliosis (EOS), including growing rod constructs, involve many complications. Some are due to biomechanical factors. A construct that is more flexible than current instrumentation systems may reduce complications. The purpose of this preliminary study was to determine spine range of motion (ROM) after implantation of simulated growing rod constructs with a range of clinically relevant structural properties. The hypothesis was that ROM of spines instrumented with polyetheretherketone (PEEK) rods would be greater than metal rods and lower than noninstrumented controls. Further, adjacent segment motion was expected to be lower with polymer rods compared to conventional systems. Methods Biomechanical tests were conducted on 6 skeletally immature porcine thoracic spines (domestic swine, 35-40 kg). Spines were harvested after death from swine that had been utilized for other studies (IACUC approved) which had not involved the spine. Paired pedicle screws were used as anchors at proximal and distal levels. Specimens were tested under the following conditions: control, then dual rods of PEEK (6.25 mm), titanium (4 mm), and CoCr (5 mm) alloy. Lateral bending (LB) and flexion-extension (FE) moments of ±5 Nm were applied. Vertebral rotations were measured using video. Differences were determined by two-tailed t-tests and Bonferroni correction with four primary comparisons: PEEK vs control and PEEK vs CoCr, in LB and FE (α=0.05/4). Results In LB, ROM of specimens with PEEK rods was lower than control at each instrumented level. ROM was greater for PEEK rods than both Ti and CoCr at every instrumented level. Mean ROM at proximal and distal noninstrumented levels was lower for PEEK than for Ti and CoCr. In FE, mean ROM at proximal and distal noninstrumented levels was lower for PEEK than for metal. Combining treated levels, in LB, ROM for PEEK rods was 35% of control (p<0.0001) and 270% of CoCr rods (p<0.01). In FE, ROM with PEEK

  12. Stability and failure analysis of steering tie-rod

    NASA Astrophysics Data System (ADS)

    Jiang, GongFeng; Zhang, YiLiang; Xu, XueDong; Ding, DaWei

    2008-11-01

    A new car in operation of only 8,000 km, because of malfunction, resulting in lost control and rammed into the edge of the road, and then the basic vehicle scrapped. According to the investigation of the site, it was found that the tie-rod of the car had been broken. For the subjective analysis of the accident and identifying the true causes of rupture of the tierod, a series of studies, from the angle of theory to experiment on the bended broken tie-rod, were conducted. The mechanical model was established; the stability of the defective tie-rod was simulated based on ANSYS software. Meanwhile, the process of the accident was simulated considering the effect of destabilization of different vehicle speed and direction of the impact. Simultaneously, macro graphic test, chemical composition analysis, microstructure analysis and SEM analysis of the fracture were implemented. The results showed that: 1) the toughness of the tie-rod is at a normal level, but there is some previous flaws. One quarter of the fracture surface has been cracked before the accident. However, there is no relationship between the flaw and this incident. The direct cause is the dynamic instability leading to the large deformation of impact loading. 2) The declining safety factor of the tie-rod greatly due to the previous flaws; the result of numerical simulation shows that previous flaw is the vital factor of structure instability, on the basis of the comparison of critical loads of the accident tie-rod and normal. The critical load can decrease by 51.3% when the initial defect increases 19.54% on the cross-sectional area, which meets the Theory of Koiter.

  13. A two-step method for developing a control rod program for boiling water reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Taner, M.S.; Levine, S.H.; Hsiao, M.Y.

    1992-01-01

    This paper reports on a two-step method that is established for the generation of a long-term control rod program for boiling water reactors (BWRs). The new method assumes a time-variant target power distribution in core depletion. In the new method, the BWR control rod programming is divided into two steps. In step 1, a sequence of optimal, exposure-dependent Haling power distribution profiles is generated, utilizing the spectral shift concept. In step 2, a set of exposure-dependent control rod patterns is developed by using the Haling profiles generated at step 1 as a target. The new method is implemented in amore » computer program named OCTOPUS. The optimization procedure of OCTOPUS is based on the method of approximation programming, in which the SIMULATE-E code is used to determine the nucleonics characteristics of the reactor core state. In a test in cycle length over a time-invariant, target Haling power distribution case because of a moderate application of spectral shift. No thermal limits of the core were violated. The gain in cycle length could be increased further by broadening the extent of the spetral shift.« less

  14. ELECTROMAGNETIC APPARATUS FOR MOVING A ROD

    DOEpatents

    Young, J.N.

    1958-04-22

    An electromagnetic apparatus for moving a rod-like member in small steps in either direction is described. The invention has particular application in the reactor field where the reactor control rods must be moved only a small distance and where the use of mechanical couplings is impractical due to the high- pressure seals required. A neutron-absorbing rod is mounted in a housing with gripping uaits that engage the rod, and coils for magnetizing the gripping units to make them grip, shift, and release the rod are located outside the housing.

  15. Analysis of dose rates received around the storage pool for irradiated control rods in a BWR nuclear power plant.

    PubMed

    Ródenas, J; Abarca, A; Gallardo, S

    2011-08-01

    BWR control rods are activated by neutron reactions in the reactor. The dose produced by this activity can affect workers in the area surrounding the storage pool, where activated rods are stored. Monte Carlo (MC) models for neutron activation and dose assessment around the storage pool have been developed and validated. In this work, the MC models are applied to verify the expected reduction of dose when the irradiated control rod is hanged in an inverted position into the pool. 2010 Elsevier Ltd. All rights reserved.

  16. Subplane-based Control Rod Decusping Techniques for the 2D/1D Method in MPACT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Graham, Aaron M; Collins, Benjamin S; Downar, Thomas

    2017-01-01

    The MPACT transport code is being jointly developed by Oak Ridge National Laboratory and the University of Michigan to serve as the primary neutron transport code for the Virtual Environment for Reactor Applications Core Simulator. MPACT uses the 2D/1D method to solve the transport equation by decomposing the reactor model into a stack of 2D planes. A fine mesh flux distribution is calculated in each 2D plane using the Method of Characteristics (MOC), then the planes are coupled axially through a 1D NEM-Pmore » $$_3$$ calculation. This iterative calculation is then accelerated using the Coarse Mesh Finite Difference method. One problem that arises frequently when using the 2D/1D method is that of control rod cusping. This occurs when the tip of a control rod falls between the boundaries of an MOC plane, requiring that the rodded and unrodded regions be axially homogenized for the 2D MOC calculations. Performing a volume homogenization does not properly preserve the reaction rates, causing an error known as cusping. The most straightforward way of resolving this problem is by refining the axial mesh, but this can significantly increase the computational expense of the calculation. The other way of resolving the partially inserted rod is through the use of a decusping method. This paper presents new decusping methods implemented in MPACT that can dynamically correct the rod cusping behavior for a variety of problems.« less

  17. Sample Federal Facility Land Use Control ROD Checklist and Suggested Language (LUC Checklist)

    EPA Pesticide Factsheets

    The LUC Checklist provides direction on describing and documenting land use controls (LUCs) in federal facility actrions under CERCLA in Records of Decision (RODs), remedial designs (RDs), and remedial action work plans (RAWPs).

  18. Patient-specific Distraction Regimen to Avoid Growth-rod Failure.

    PubMed

    Agarwal, Aakash; Jayaswal, Arvind; Goel, Vijay K; Agarwal, Anand K

    2018-02-15

    A finite element study to establish the relationship between patient's curve flexibility (determined using curve correction under gravity) in juvenile idiopathic scoliosis and the required distraction frequency to avoid growth rod fracture, as a function of time. To perform a parametric analysis using a juvenile scoliotic spine model (single mid-thoracic curve with the apex at the eighth thoracic vertebra) and establish the relationship between curve flexibility (determined using curve correction under gravity) and the distraction interval that allows a higher factor of safety for the growth rods. Previous studies have shown that frequent distraction with smaller magnitude of distractions are less likely to result in rod failure. However there has not been any methodology or a chart provided to apply this knowledge on to the individual patients that undergo the treatment. This study aims to fill in that gap. The parametric study was performed by varying the material properties of the disc, hence altering the axial stiffness of the scoliotic spine model. The stresses on the rod were found to increase with increased axial stiffness of the spine, and this resulted in the increase of required optimal frequency to achieve a factor of safety of two for growth rods. A relationship between the percentage correction in Cobb's angle due to gravity alone, and the required distraction interval for limiting the maximum von Mises stress to 255 MPa on the growth rods was established. The distraction interval required to limit the stresses to the selected nominal value reduces with increase in stiffness of the spine. Furthermore, the appropriate distraction interval reduces for each model as the spine becomes stiffer with time (autofusion). This points to the fact the optimal distraction frequency is a time-dependent variable that must be achieved to keep the maximum von Mises stress under the specified factor of safety. The current study demonstrates the possibility of

  19. Experimental critical loadings and control rod worths in LWR-PROTEUS configurations compared with MCNPX results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Plaschy, M.; Murphy, M.; Jatuff, F.

    2006-07-01

    The PROTEUS research reactor at the Paul Scherrer Inst. (PSI) has been operating since the sixties and has already permitted, due to its high flexibility, investigation of a large range of very different nuclear systems. Currently, the ongoing experimental programme is called LWR-PROTEUS. This programme was started in 1997 and concerns large-scale investigations of advanced light water reactors (LWR) fuels. Until now, the different LWR-PROTEUS phases have permitted to study more than fifteen different configurations, each of them having to be demonstrated to be operationally safe, in particular, for the Swiss safety authorities. In this context, recent developments of themore » PSI computer capabilities have made possible the use of full-scale SD-heterogeneous MCNPX models to calculate accurately different safety related parameters (e.g. the critical driver loading and the shutdown rod worth). The current paper presents the MCNPX predictions of these operational characteristics for seven different LWR-PROTEUS configurations using a large number of nuclear data libraries. More specifically, this significant benchmarking exercise is based on the ENDF/B6v2, ENDF/B6v8, JEF2.2, JEFF3.0, JENDL3.2, and JENDL3.3 libraries. The results highlight certain library specific trends in the prediction of the multiplication factor k{sub eff} (e.g. the systematically larger reactivity calculated with JEF2.2 and the smaller reactivity associated with JEFF3.0). They also confirm the satisfactory determination of reactivity variations by all calculational schemes, for instance, due to the introduction of a safety rod pair, these calculations having been compared with experiments. (authors)« less

  20. Genetic algorithm based active vibration control for a moving flexible smart beam driven by a pneumatic rod cylinder

    NASA Astrophysics Data System (ADS)

    Qiu, Zhi-cheng; Shi, Ming-li; Wang, Bin; Xie, Zhuo-wei

    2012-05-01

    A rod cylinder based pneumatic driving scheme is proposed to suppress the vibration of a flexible smart beam. Pulse code modulation (PCM) method is employed to control the motion of the cylinder's piston rod for simultaneous positioning and vibration suppression. Firstly, the system dynamics model is derived using Hamilton principle. Its standard state-space representation is obtained for characteristic analysis, controller design, and simulation. Secondly, a genetic algorithm (GA) is applied to optimize and tune the control gain parameters adaptively based on the specific performance index. Numerical simulations are performed on the pneumatic driving elastic beam system, using the established model and controller with tuned gains by GA optimization process. Finally, an experimental setup for the flexible beam driven by a pneumatic rod cylinder is constructed. Experiments for suppressing vibrations of the flexible beam are conducted. Theoretical analysis, numerical simulation and experimental results demonstrate that the proposed pneumatic drive scheme and the adopted control algorithms are feasible. The large amplitude vibration of the first bending mode can be suppressed effectively.

  1. Measurement of Diffusion in Entangled Rod-Coil Triblock Copolymers

    NASA Astrophysics Data System (ADS)

    Olsen, B. D.; Wang, M.

    2012-02-01

    Although rod-coil block copolymers have attracted increasing attention for functional nanomaterials, their dynamics relevant to self-assembly and processing have not been widely investigated. Because the rod and coil blocks have different reptation behavior and persistence lengths, the mechanism by which block copolymers will diffuse is unclear. In order to understand the effect of the rigid block on reptation, tracer diffusion of a coil-rod-coil block copolymer through an entangled coil polymer matrix was experimentally measured. A monodisperse, high molecular weight coil-rod-coil triblock was synthesized using artificial protein engineering to prepare the helical rod and bioconjugaiton of poly(ethylene glycol) coils to produce the final triblock. Diffusion measurements were performed using Forced Rayleigh scattering (FRS), at varying ratios of the rod length to entanglement length, where genetic engineering is used to control the protein rod length and the polymer matrix concentration controls the entanglement length. As compared to PEO homopolymer tracers, the coil-rod-coil triblocks show markedly slower diffusion, suggesting that the mismatch between rod and coil reptation mechanisms results in hindered diffusion of these molecules in the entangled state.

  2. Method for depleting BWRs using optimal control rod patterns

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Taner, M.S.; Levine, S.H.; Hsiao, M.Y.

    1991-01-01

    Control rod (CR) programming is an essential core management activity for boiling water reactors (BWRs). After establishing a core reload design for a BWR, CR programming is performed to develop a sequence of exposure-dependent CR patterns that assure the safe and effective depletion of the core through a reactor cycle. A time-variant target power distribution approach has been assumed in this study. The authors have developed OCTOPUS to implement a new two-step method for designing semioptimal CR programs for BWRs. The optimization procedure of OCTOPUS is based on the method of approximation programming and uses the SIMULATE-E code for nucleonicsmore » calculations.« less

  3. CRITICALITY SAFETY CONTROLS AND THE SAFETY BASIS AT PFP

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kessler, S

    2009-04-21

    With the implementation of DOE Order 420.1B, Facility Safety, and DOE-STD-3007-2007, 'Guidelines for Preparing Criticality Safety Evaluations at Department of Energy Non-Reactor Nuclear Facilities', a new requirement was imposed that all criticality safety controls be evaluated for inclusion in the facility Documented Safety Analysis (DSA) and that the evaluation process be documented in the site Criticality Safety Program Description Document (CSPDD). At the Hanford site in Washington State the CSPDD, HNF-31695, 'General Description of the FH Criticality Safety Program', requires each facility develop a linking document called a Criticality Control Review (CCR) to document performance of these evaluations. Chapter 5,more » Appendix 5B of HNF-7098, Criticality Safety Program, provided an example of a format for a CCR that could be used in lieu of each facility developing its own CCR. Since the Plutonium Finishing Plant (PFP) is presently undergoing Deactivation and Decommissioning (D&D), new procedures are being developed for cleanout of equipment and systems that have not been operated in years. Existing Criticality Safety Evaluations (CSE) are revised, or new ones written, to develop the controls required to support D&D activities. Other Hanford facilities, including PFP, had difficulty using the basic CCR out of HNF-7098 when first implemented. Interpretation of the new guidelines indicated that many of the controls needed to be elevated to TSR level controls. Criterion 2 of the standard, requiring that the consequence of a criticality be examined for establishing the classification of a control, was not addressed. Upon in-depth review by PFP Criticality Safety staff, it was not clear that the programmatic interpretation of criterion 8C could be applied at PFP. Therefore, the PFP Criticality Safety staff decided to write their own CCR. The PFP CCR provides additional guidance for the evaluation team to use by clarifying the evaluation criteria in DOE-STD-3007

  4. Pleiotropic function of DLX3 in amelogenesis: from regulating pH and keratin expression to controlling enamel rod decussation.

    PubMed

    Duverger, Olivier; Morasso, Maria I

    2018-12-01

    DLX3 is essential for tooth enamel development and is so far the only transcription factor known to be mutated in a syndromic form of amelogenesis imperfecta. Through conditional deletion of Dlx3 in the dental epithelium in mouse, we have previously established the involvement of DLX3 in enamel pH regulation, as well as in controlling the expression of sets of keratins that contribute to enamel rod sheath formation. Here, we show that the decussation pattern of enamel rods was lost in conditional knockout animals, suggesting that DLX3 controls the coordinated migration of ameloblasts during enamel secretion. We further demonstrate that DLX3 regulates the expression of some components of myosin II complexes potentially involved in driving the movement of ameloblasts that leads to enamel rod decussation.

  5. Incidence of proximal junctional kyphosis with magnetic expansion control rods in early onset scoliosis.

    PubMed

    Inaparthy, P; Queruz, J C; Bhagawati, D; Thakar, C; Subramanian, T; Nnadi, C

    2016-10-01

    The introduction of magnetic expansion control growth rods for the surgical management of EOS has gained popularity. However, there are no published studies on the incidence of proximal junctional kyphosis (PJK) using this technique. The aim of this study is to report the incidence of PJK following treatment with magnetic growth rods in EOS. Retrospective review of data from 21 cases (12 males, 9 females) over 3 years. PJK was obtained from whole spine X-rays pre-op, immediate post-op and last follow-up. Cobb angle was measured between the superior end plate of vertebra two levels above the upper instrumented vertebra (UIV) and the inferior end plate of the UIV. A difference of >10° between the pre-operative x-rays and the last follow-up X-rays was recorded as PJK. 6/21 (28.6 %) had proximal junctional kyphosis of more than 10° at last follow-up. Average age was 5.3. Average follow-up was 32.5 months. All the patients with PJK were syndromic. Four out of these six patients were males (66 %). Average PJK angle was 25.55°. Average pre-operative kyphosis was 52.5°. Average number of distractions was 7.4. All six patients had syndromic association. 3/6 patients (50 %) were conversion cases treated with traditional growth rods previously (TGR). None of the patients required unplanned surgery for PJK. The incidence of PJK in EOS patients treated with magnetic rods is favourably comparable to that reported with traditional growth rods. Also, children who are male, syndromic, hyperkyphotic, and younger must be monitored closely.

  6. A prospective randomized controlled trial comparing early postoperative complications in patients undergoing loop colostomy with and without a stoma rod.

    PubMed

    Franklyn, J; Varghese, G; Mittal, R; Rebekah, G; Jesudason, M R; Perakath, B

    2017-07-01

    A stoma rod or bridge has been traditionally placed under the bowel loop while constructing a loop colostomy. This is believed to prevent stomal retraction and provide better faecal diversion. However, the rod can cause complications such as mucosal congestion, oedema and necrosis. This single-centre prospective randomized controlled trial compared outcomes after creation of loop colostomy with and without a supporting stoma rod. The primary outcome studied was stoma retraction rate; other stoma-related complications were studied as secondary outcomes. One hundred and fifty-one patients were randomly allotted to one of two arms, colostomy with or without a supporting rod. Postoperative complications such as retraction, mucocutaneous separation, congestion and re-exploration for stoma-related complications were recorded. There was no difference in the stoma retraction rate between the two arms (8.1% in the rod arm and 6.6% in the no-rod arm; P = 0.719). Stomal necrosis (10.7% vs 1.3%; P = 0.018), oedema (23% vs 3.9%; P = 0.001), congestion (20.3% vs 2.6%; P = 0.001) and re-admission rates (8.5% vs 0%; P = 0.027) were significantly increased in the arm randomized to the rod. The stoma rod does not prevent stomal retraction. However, complication rates are significantly higher when a stoma rod is used. Routine use of a stoma rod for construction of loop colostomy can be avoided. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

  7. Fretting wear behaviors of a dual-cooled nuclear fuel rod under a simulated rod vibration

    NASA Astrophysics Data System (ADS)

    Lee, Young-Ho; Kim, Hyung-Kyu; Kang, Heung-Seok; Yoon, Kyung-Ho; Kim, Jae-Yong; Lee, Kang-Hee

    2012-06-01

    Recently, a dual-cooled fuel (i.e., annular fuel) that is compatible with current operating PWR plants has been proposed in order to realize both a considerable amount of power uprating and an increase of safety margins. As the design concept should be compatible with current operating PWR plants, however, it shows a narrow gap between the fuel rods when compared with current solid nuclear fuel arrays and needs to modify the spacer grid shapes and their positions. In this study, fretting wear tests have been performed to evaluate the wear resistance of a dual-cooled fuel by using a proposed spring and dimple of spacer grids that have a cantilever type and hemispherical shape, respectively. As a result, the wear volume of the spring specimen gradually increases as the contact condition is changed from a certain gap, just contact to positive force. However, in the dimple specimen, just contact condition shows a large wear volume. In addition, a circular rod motion at upper region of contact surface is gradually increased and its diametric size depends on the wear depth increase. Based on the test results, the fretting wear resistance of the proposed spring and dimple is analyzed by comparing the wear measurement results and rod motion in detail.

  8. FUEL ROD ASSEMBLY

    DOEpatents

    Hutter, E.

    1959-09-01

    A cluster of nuclear fuel rods aod a tubular casing through which a coolant flows in heat-change contact with the ruel rods are described. The casting is of trefoil section and carries the fuel rods, each of which has two fin engaging the serrated fins of the other two fuel rods, whereby the fuel rods are held in the casing and are interlocked against relative longitudinal movement.

  9. Calculation of the Phenix end-of-life test 'Control Rod Withdrawal' with the ERANOS code

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tiberi, V.

    2012-07-01

    The Inst. of Radiological Protection and Nuclear Safety (IRSN) acts as technical support to French public authorities. As such, IRSN is in charge of safety assessment of operating and under construction reactors, as well as future projects. In this framework, one current objective of IRSN is to evaluate the ability and accuracy of numerical tools to foresee consequences of accidents. Neutronic studies step in the safety assessment from different points of view among which the core design and its protection system. They are necessary to evaluate the core behavior in case of accident in order to assess the integrity ofmore » the first barrier and the absence of a prompt criticality risk. To reach this objective one main physical quantity has to be evaluated accurately: the neutronic power distribution in core during whole reactor lifetime. Phenix end of life tests, carried out in 2009, aim at increasing the experience feedback on sodium cooled fast reactors. These experiments have been done in the framework of the development of the 4. generation of nuclear reactors. Ten tests have been carried out: 6 on neutronic and fuel aspects, 2 on thermal hydraulics and 2 for the emergency shutdown. Two of them have been chosen for an international exercise on thermal hydraulics and neutronics in the frame of an IAEA Coordinated Research Project. Concerning neutronics, the Control Rod Withdrawal test is relevant for safety because it allows evaluating the capability of calculation tools to compute the radial power distribution on fast reactors core configurations in which the flux field is very deformed. IRSN participated to this benchmark with the ERANOS code developed by CEA for fast reactors studies. This paper presents the results obtained in the framework of the benchmark activity. A relatively good agreement was found with available measures considering the approximations done in the modeling. The work underlines the importance of burn-up calculations in order to have a

  10. Nuclear reactor control apparatus

    DOEpatents

    Sridhar, Bettadapur N.

    1983-10-25

    Nuclear reactor safety rod release apparatus comprises a ring which carries detents normally positioned in an annular recess in outer side of the rod, the ring being held against the lower end of a drive shaft by magnetic force exerted by a solenoid carried by the drive shaft. When the solenoid is de-energized, the detent-carrying ring drops until the detents contact a cam surface associated with the lower end of the drive shaft, at which point the detents are cammed out of the recess in the safety rod to release the rod from the drive shaft. In preferred embodiments of the invention, an additional latch is provided to release a lower portion of a safety rod under conditions that may interfere with movement of the entire rod.

  11. Safety and efficacy of Implanon, a single-rod implantable contraceptive containing etonogestrel.

    PubMed

    Funk, Sidney; Miller, Michael M; Mishell, Daniel R; Archer, David F; Poindexter, Alfred; Schmidt, Juergen; Zampaglione, Edio

    2005-05-01

    The safety and efficacy of a single-rod implantable contraceptive containing etonogestrel (Implanontrade mark) were investigated in a multicenter clinical trial. Sexually active American women (N=330) with apparently normal menstrual cycles used the implant for up to 2 years. All subjects recorded bleeding and/or spotting daily in a diary. Safety was assessed through adverse experiences (AEs), laboratory tests and physical and gynecologic examinations. Total exposure was 474 woman-years (6186 cycles), and 68% of subjects had at least 1 year of exposure. No pregnancies occurred. The most common bleeding pattern observed throughout the study was infrequent bleeding, defined as less than three episodes of bleeding in a reference period (excluding amenorrhea). The least common pattern was frequent bleeding, defined as more than five episodes of bleeding in a reference period. Infrequent, prolonged and frequent bleeding patterns were most common early in the study and declined thereafter. During the 3-month Reference Periods 2-8 (Months 4-24), the incidence of amenorrhea ranged from 14% to 20%. Forty-three subjects (13%) withdrew from the study because of bleeding pattern changes and 76 subjects (23%) discontinued because of other AEs. Other common AEs leading to discontinuation, besides bleeding irregularities, were emotional lability (6.1%), weight increase (3.3%), depression (2.4%) and acne (1.5%). Use of Implanon (etonogestrel subdermal implant, referred to herein as ENG implant) for up to 2 years had no clinically significant effects on laboratory parameters, physical and pelvic examinations, vital signs or body mass index. The average length of time required for ENG implant insertion and that for removal were 0.5 and 3.5 min, respectively, and all the procedures were uncomplicated. The return to normal menstrual cycles and fertility was rapid after removal. Implanon is a safe, highly effective and rapidly reversible new method of contraception.

  12. Is An Ostomy Rod Useful for Bridging the Retraction During the Creation of a Loop Ileostomy? A Randomized Control Trial.

    PubMed

    Uchino, Motoi; Ikeuchi, Hiroki; Bando, Toshihiro; Chohno, Teruhiro; Sasaki, Hirofumi; Horio, Yuki

    2017-08-01

    A loop ileostomy is generally created during restorative proctocolectomy (RPC) for treating ulcerative colitis (UC), and an ostomy rod is often used to prevent stoma retraction. However, its usefulness or harmfulness has not been proven. We performed a prospective randomized control study to investigate the non-inferiority of ostomy creation without a rod to prevent stoma retraction. Patients with UC who underwent RPC were enrolled and randomly divided into groups either with or without ostomy rod use. Incidences of stoma retraction and dermatitis were compared. Of the 320 patients in the study groups, 308 qualified for the intention-to-treat (ITT) analysis, and 257 were included in the per-protocol (PP) analysis. Ostomy retraction was recognized in 6 patients, 3 with a rod and 3 without. The difference with rod use (95% confidence interval) was 0.1 (-2.9 to 3.1)% in the PP analysis and 0.0 (-2.2 to 2.2)% in the ITT analysis. There were no significant differences in stoma retraction regardless of whether an ostomy rod was used in either analysis. Dermatitis was more common in patients with rod use (84/154) than in those without (40/154) (p < 0.01). Although median body mass indices were extremely low (20 kg/m 2 ), an ostomy rod is not routinely needed as it may increase the risk of dermatitis. However, results in obese patients may differ from those shown here, which should be clarified via further studies.

  13. System for fuel rod removal from a reactor module

    DOEpatents

    Matchett, R.L.; Fodor, G.; Kikta, T.J.; Bacvinsicas, W.S.; Roof, D.R.; Nilsen, R.J.; Wilczynski, R.

    1988-07-28

    A robotic system for remote underwater withdrawal of the fuel rods from fuel modules of a light water breeder reactor includes a collet/grapple assembly for gripping and removing fuel rods in each module, which is positioned by use of a winch and a radial support means attached to a vertical support tube which is mounted over the fuel module. A programmable logic controller in conjunction with a microcomputer, provides control for the accurate positioning and pulling force of the rod grapple assembly. Closed circuit television cameras are provided which aid in operator interface with the robotic system. 7 figs.

  14. System for fuel rod removal from a reactor module

    DOEpatents

    Matchett, Richard L.; Roof, David R.; Kikta, Thomas J.; Wilczynski, Rosemarie; Nilsen, Roy J.; Bacvinskas, William S.; Fodor, George

    1990-01-01

    A robotic system for remote underwater withdrawal of the fuel rods from fuel modules of a light water breeder reactor includes a collet/grapple assembly for gripping and removing fuel rods in each module, which is positioned by use of a winch and a radial support means attached to a vertical support tube which is mounted over the fuel module. A programmable logic controller in conjunction with a microcomputer, provides control for the accurate positioning and pulling force of the rod grapple assembly. Closed circuit television cameras are provided which aid in operator interface with the robotic system.

  15. Probabilistic analysis on the failure of reactivity control for the PWR

    NASA Astrophysics Data System (ADS)

    Sony Tjahyani, D. T.; Deswandri; Sunaryo, G. R.

    2018-02-01

    The fundamental safety function of the power reactor is to control reactivity, to remove heat from the reactor, and to confine radioactive material. The safety analysis is used to ensure that each parameter is fulfilled during the design and is done by deterministic and probabilistic method. The analysis of reactivity control is important to be done because it will affect the other of fundamental safety functions. The purpose of this research is to determine the failure probability of the reactivity control and its failure contribution on a PWR design. The analysis is carried out by determining intermediate events, which cause the failure of reactivity control. Furthermore, the basic event is determined by deductive method using the fault tree analysis. The AP1000 is used as the object of research. The probability data of component failure or human error, which is used in the analysis, is collected from IAEA, Westinghouse, NRC and other published documents. The results show that there are six intermediate events, which can cause the failure of the reactivity control. These intermediate events are uncontrolled rod bank withdrawal at low power or full power, malfunction of boron dilution, misalignment of control rod withdrawal, malfunction of improper position of fuel assembly and ejection of control rod. The failure probability of reactivity control is 1.49E-03 per year. The causes of failures which are affected by human factor are boron dilution, misalignment of control rod withdrawal and malfunction of improper position for fuel assembly. Based on the assessment, it is concluded that the failure probability of reactivity control on the PWR is still within the IAEA criteria.

  16. RECOVERY OF ROD PHOTORESPONSES IN ABCR-DEFICIENT MICE

    PubMed Central

    Pawar, Ambarish S.; Qtaishat, Nasser M.; Little, Deborah M.; Pepperberg, David R.

    2010-01-01

    Purpose ABCR protein in the rod outer segment is thought to facilitate movement of the all-trans retinal photoproduct of rhodopsin bleaching out of the disk lumen. We investigated the extent to which ABCR deficiency affects post-bleach recovery of the rod photoresponse in ABCR-deficient (abcr−/−) mice. Methods Electroretinographic (ERG) a-wave responses were recorded from abcr−/− mice and two control strains. Using a bright probe flash, we examined the course of rod recovery following fractional rhodopsin bleaches of ~10−6, ~3×10−5, ~0.03 and ~0.30–0.40. Results Dark-adapted abcr−/− mice and controls exhibited similar normalized near-peak amplitudes of the paired-flash-ERG-derived, weak-flash response. Response recovery following ~10−6 bleaching exhibited an average exponential time constant of 319, 171 and 213 ms, respectively, in the abcr−/− and the two control strains. Recovery time constants determined for ~3×10−5 bleaching did not differ significantly among strains. However, those determined for the ~0.03 bleach indicated significantly faster recovery in abcr−/− (2.34 ± 0.74 min) than in the controls (5.36 ± 2.20 min, and 5.92 ± 2.44 min). Following ~0.30–0.40 bleaching, the initial recovery in the abcr−/− was on average faster than in controls. Conclusions By comparison with controls, abcr−/− mice exhibit faster rod recovery following a bleach of ~0.03. The data suggest that ABCR in normal rods may directly or indirectly prolong all-trans retinal clearance from the disk lumen over a significant bleaching range, and that the essential function of ABCR may be to promote the clearance of residual amounts of all-trans retinal that remain in the disks long after bleaching. PMID:18263807

  17. Strike action electromagnetic machine for immersion of rod elements into ground

    NASA Astrophysics Data System (ADS)

    Usanov, K. M.; Volgin, A. V.; Chetverikov, E. A.; Kargin, V. A.; Moiseev, A. P.; Ivanova, Z. I.

    2017-10-01

    During construction, survey work, and drilling shallow wells by striking, operations associated with dipping and removing the rod elements are the most common. At the same time relatively long, with small diameter, elements, in which the ratio of length to diameter l/d is 100 or more, constitute a significant proportion. At present, the application of power pulse linear electromagnetic motors to drive drum machines is recognized to be highly effective. However, the mechanical method of transmission of shocks does not allow dipping long longitudinally unstable core elements. In this case, mechanical energy must be transferred from the motor to the rod through its side surface. The design of the strike action electromagnetic machine with a through axial channel for non-mechanical end striking of the pile of long, longitudinally unstable metal rods is proposed. Electromagnetic striking machine for non-mechanical end striking rod elements provides operations characterized by ecological compatibility, safety and high quality.

  18. Parallel Operation of Multiple Closely Spaced Small Aspect Ratio Rod Pinches

    DOE PAGES

    Harper-Slaboszewicz, Victor J.; Leckbee, Joshua; Bennett, Nichelle; ...

    2014-12-10

    A series of simulations and experiments to resolve questions about the operation of arrays of closely spaced small aspect ratio rod pinches has been performed. Design and post-shot analysis of the experimental results are supported by 3D particle-in-cell simulations. Both simulations and experiments support these conclusions. Penetration of current to the interior of the array appears to be efficient, as the current on the center rods is essentially equal to the current on the outer rods. Current loss in the feed due to the formation of magnetic nulls was avoided in these experiments by design of the feed surface ofmore » the cathode and control of the gap to keep the electric fields on the cathode below the emission threshold. Some asymmetry in the electron flow to the rod was observed, but the flow appeared to symmetrize as it reached the end of the rod. Interaction between the rod pinches can be controlled to allow the stable and consistent operation of arrays of rod pinches.« less

  19. Neutronic safety parameters and transient analyses for Poland's MARIA research reactor.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bretscher, M. M.; Hanan, N. A.; Matos, J. E.

    1999-09-27

    Reactor kinetic parameters, reactivity feedback coefficients, and control rod reactivity worths have been calculated for the MARIA Research Reactor (Swierk, Poland) for M6-type fuel assemblies with {sup 235}U enrichments of 80% and 19.7%. Kinetic parameters were evaluated for family-dependent effective delayed neutron fractions, decay constants, and prompt neutron lifetimes and neutron generation times. Reactivity feedback coefficients were determined for fuel Doppler coefficients, coolant (H{sub 2}O) void and temperature coefficients, and for in-core and ex-core beryllium temperature coefficients. Total and differential control rod worths and safety rod worths were calculated for each fuel type. These parameters were used to calculate genericmore » transients for fast and slow reactivity insertions with both HEU and LEU fuels. The analyses show that the HEU and LEU cores have very similar responses to these transients.« less

  20. ELECTROMAGNETIC APPARATUS FOR MOVING A ROD

    DOEpatents

    Young, J.N.

    1957-08-20

    An electromagnetic device for moving an object in a linear path by increments is described. The device is specifically adapted for moving a neutron absorbing control rod into and out of the core of a reactor and consists essentially of an extension member made of magnetic material connected to one end of the control rod and mechanically flexible to grip the walls of a sleeve member when flexed, a magnetic sleeve member coaxial with and slidable between limit stops along the flexible extension, electromagnetic coils substantially centrally located with respect to the flexible extension to flex the extension member into gripping engagement with the sleeve member when ener gized, moving electromagnets at each end of the sleeve to attract the sleeve when energized, and a second gripping electromagnet positioned along the flexible extension at a distance from the previously mentioned electromagnets for gripping the extension member when energized. In use, the second gripping electromagnet is deenergized, the first gripping electromagnet is energized to fix the extension member in the sleeve, and one of the moving electromagnets is energized to attract the sleeve member toward it, thereby moving the control rod.

  1. 26. A typical outer rod room, or rack room, showing ...

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

    26. A typical outer rod room, or rack room, showing the racks for the nine horizontal control rods (HCRs) that would be inserted or withdrawn from the pile to control the rate of reaction. In this case, it is the 105-F Reactor in February 1945. The view is looking away from the pile, which is out of the picture on the left. Several of the cooling water hose reels for the rods can be seen at the end of the racks near the wall. D-8323 - B Reactor, Richland, Benton County, WA

  2. Safety Control and Safety Education at Technical Institutes

    NASA Astrophysics Data System (ADS)

    Iino, Hiroshi

    The importance of safety education for students at technical institutes is emphasized on three grounds including safety of all working members and students in their education, research and other activities. The Kanazawa Institute of Technology re-organized the safety organization into a line structure and improved safety minds of all their members and now has a chemical materials control system and a set of compulsory safety education programs for their students, although many problems still remain.

  3. Overview of Fuel Rod Simulator Usage at ORNL

    NASA Astrophysics Data System (ADS)

    Ott, Larry J.; McCulloch, Reg

    2004-02-01

    During the 1970s and early 1980s, the Oak Ridge National Laboratory (ORNL) operated large out-of-reactor experimental facilities to resolve thermal-hydraulic safety issues in nuclear reactors. The fundamental research ranged from material mechanical behavior of fuel cladding during the depressurization phase of a loss-of-coolant accident (LOCA) to basic heat transfer research in gas- or sodium-cooled cores. The largest facility simulated the initial phase (less than 1 min. of transient time) of a LOCA in a commercial pressurized-water reactor. The nonnuclear reactor cores of these facilities were mimicked via advanced, highly instrumented electric fuel rod simulators locally manufactured at ORNL. This paper provides an overview of these experimental facilities with an emphasis on the fuel rod simulators.

  4. Relief of Residual Stress in Streamline Tie Rods by Heat Treatment

    NASA Technical Reports Server (NTRS)

    Pollard, R E; Reinhart, Fred M

    1941-01-01

    About two-thirds of the residual stress in cold-worked SAE 1050 steel tie rods was relieved by heating 30 minutes at 600 degrees Fahrenheit. Cold-worked austenitic stainless-steel tie rods could be heated at temperatures up to 1000 degrees Fahrenheit without lowering the important physical properties. The corrosion resistance, in laboratory corrosion test, of straight 18:8 and titanium-treated 18:8 materials appeared to be impaired after heating at temperatures above 800 degrees or 900 degrees fahrenheit. Columbium-treated and molybdenum-treated 18:8 steel exhibited improved stability over a wide range of temperatures. Tie rods of either material could be heated 30 minutes with safety at any temperature up to 1000 degrees Fahrenheit. At this temperature most of the residual stress would be relieved.

  5. NUCLEAR REACTOR CONTROL SYSTEM

    DOEpatents

    Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

    1959-11-01

    A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

  6. 28. A typical main control panel in a 105 reactor ...

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

    28. A typical main control panel in a 105 reactor building, in this case 105-F in February 1945. A single operator sat at the controls to regulate the pile's rate of reaction and monitor it for safety. The galvanometer screens (the two horizontal bars just below the nine round gauges that showed the positions of the control rods) showed the pile's current power setting. With that information, the operator could set the control rod positions to increase, decrease, or maintain the power. D-8310 - B Reactor, Richland, Benton County, WA

  7. Lightning discharge protection rod

    NASA Technical Reports Server (NTRS)

    Bryan, Charles F., Jr. (Inventor)

    1987-01-01

    A system for protecting an in-air vehicle from damage due to a lighning strike is disclosed. It is an extremely simple device consisting of a sacrificial graphite composite rod, approximately the diameter of a pencil with a length of about five inches. The sacrificial rod is constructed with the graphite fibers running axially within the rod in a manner that best provides a path of conduction axially from the trailing edge of an aircraft to the trailing end of the rod. The sacrificial rod is inserted into an attachment hole machined into trailing edges of aircraft flight surfaces, such as a vertical fin cap and attached with adhesive in a manner not prohibiting the conduction path between the rod and the aircraft. The trailing end of the rod may be tapered for aerodynamic and esthetic requirements. This rod is sacrificial but has the capability to sustain several lightning strikes and still provide protection.

  8. Surface properties of sprayed and electrodeposited ZnO rod layers

    NASA Astrophysics Data System (ADS)

    Gromyko, I.; Krunks, M.; Dedova, T.; Katerski, A.; Klauson, D.; Oja Acik, I.

    2017-05-01

    Herein we present a comparative study on as-deposited, two-month-stored, and heat-treated ZnO rods obtained by spray pyrolysis (SP) at 550 °C, and electrodeposition (ED) at 80 °C. The aim of the study is to establish the reason for different behaviour of wettability and photocatalytic activity (PA) of SP and ED rods. Samples were studied using XPS, SEM, XRD, Raman, contact angle (CA) measurements and photocatalytic oxidation of doxycycline. Wettability and PA are mainly controlled by surface composition rather than by morphology. The relative amount of hydroxyl groups on the surface of as-deposited ED rods is four times higher compared to as-deposited SP rods. Opposite to SP rods, ED rods contain oxygen vacancy defects (Vo). Therefore, as-deposited ED rods are superhydrophilic (CA ∼ 3°) and show highest PA among studied samples, being three times higher compared to SP rods (removing of 75% of doxycycline after 30 min). It was revealed that as-deposited ED rods are inclined to faster contamination. The amount of Cdbnd C groups on the surface of aged ED rods is six times higher compared to aged SP rods. Stored ED samples become hydrophobic (CA ∼ 120°) and PA decreases sharply while SP rods remain hydrophilic (CA ∼ 50°), being more resistive to the contamination.

  9. Piston rod seal

    DOEpatents

    Lindskoug, Stefan

    1984-01-01

    In a piston rod seal of the type comprising a gland through which the piston rod is passed the piston is provided with a sleeve surrounding the piston rod and extending axially so as to axially partly overlap the gland when the piston is in its bottom dead center position.

  10. Crossflow between subchannels in a 5 x 5 rod-bundle geometry

    NASA Astrophysics Data System (ADS)

    Lee, Jungjin; Park, Hyungmin

    2017-11-01

    In the present study, we experimentally investigate the single-phase (water as a working fluid) flow in a vertical 5 x 5 rod-bundle geometry using a particle image velociemtry, especially focusing on the crossflow phenomena between subchannels. This crossflow phenomena is very important in determining the performance and safety of nuclear power plant. To measure the flow behind the rod, it is made of FEP (Fluorinated Ethylene Propylene) to achieve the index matching. The ratio of pitch between rods and rod diameter is 1.4, and the considered Reynolds number based on a hydraulic diameter of a channel and an axial bulk velocity is 10000. Also, the typical grid spacer is installed periodically along the streamwise direction. Depending on the location of subchannel (e.g., distance to the side wall or grid spacer), the flow (turbulence) statistics show large variations that will be discussed in detail. Furthermore, we will suggest a modified crossflow model that can explain the varying crossflow phenomena more clearly. Supported by NRF Grant (NRF-2016M2B2A9A02945068) of the Korean government.

  11. Light responses in rods of vitamin A-deprived Xenopus.

    PubMed

    Solessio, Eduardo; Umino, Yumiko; Cameron, David A; Loew, Ellis; Engbretson, Gustav A; Knox, Barry E; Barlow, Robert B

    2009-09-01

    Accumulation of free opsin by mutations in rhodopsin or insufficiencies in the visual cycle can lead to retinal degeneration. Free opsin activates phototransduction; however, the link between constitutive activation and retinal degeneration is unclear. In this study, the photoresponses of Xenopus rods rendered constitutively active by vitamin A deprivation were examined. Unlike their mammalian counterparts, Xenopus rods do not degenerate. Contrasting phototransduction in vitamin A-deprived Xenopus rods with phototransduction in constitutively active mammalian rods may provide new understanding of the mechanisms that lead to retinal degeneration. The photocurrents of Xenopus tadpole rods were measured with suction electrode recordings, and guanylate cyclase activity was measured with the IBMX (3-isobutyl-1-methylxanthine) jump technique. The amount of rhodopsin in rods was determined by microspectrophotometry. The vitamin A-deprived rod outer segments were 60% to 70% the length and diameter of the rods in age-matched animals. Approximately 90% of its opsin content was in the free or unbound form. Analogous to bleaching adaptation, the photoresponses were desensitized (10- to 20-fold) and faster. Unlike bleaching adaptation, the vitamin A-deprived rods maintained near normal saturating (dark) current densities by developing abnormally high rates of cGMP synthesis. Their rate of cGMP synthesis in the dark (15 seconds(-1)) was twofold greater than the maximum levels attainable by control rods ( approximately 7 seconds(-1)). Preserving circulating current density and response range appears to be an important goal for rod homeostasis. However, the compensatory changes associated with vitamin A deprivation in Xenopus rods come at the high metabolic cost of a 15-fold increase in basal ATP consumption.

  12. Methodology of the Westinghouse dynamic rod worth measurement technique

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chao, Y.A.; Chapman, D.M.; Easter, M.E.

    1992-01-01

    During zero-power physics testing, plant operations personnel use one of various techniques to measure the reactivity worth of the control rods to confirm shutdown margin. A simple and fast procedure for measuring rod worths called dynamic rod worth measurement (DRWM) has been developed at Westinghouse. This procedure was tested at the recent startups of Point Beach Nuclear Power Plant Unit 1 cycle 20 and Unit 2 cycle 18. The results of these tests show that DRWM measures rod worths with accuracy comparable to that of both boron dilution and rod bank exchange measurements. The DRWM procedure is a fast processmore » of measuring the reactivity worth of individual banks by inserting and withdrawing the bank continuously at the maximum stepping speed without changing the boron concentration and recording the signals of the ex-core detectors.« less

  13. Fission gas release restrictor for breached fuel rod

    DOEpatents

    Kadambi, N. Prasad; Tilbrook, Roger W.; Spencer, Daniel R.; Schwallie, Ambrose L.

    1986-01-01

    In the event of a breach in the cladding of a rod in an operating liquid metal fast breeder reactor, the rapid release of high-pressure gas from the fission gas plenum may result in a gas blanketing of the breached rod and rods adjacent thereto which impairs the heat transfer to the liquid metal coolant. In order to control the release rate of fission gas in the event of a breached rod, the substantial portion of the conventional fission gas plenum is formed as a gas bottle means which includes a gas pervious means in a small portion thereof. During normal reactor operation, as the fission gas pressure gradually increases, the gas pressure interiorly of and exteriorly of the gas bottle means equalizes. In the event of a breach in the cladding, the gas pervious means in the gas bottle means constitutes a sufficient restriction to the rapid flow of gas therethrough that under maximum design pressure differential conditions, the fission gas flow through the breach will not significantly reduce the heat transfer from the affected rod and adjacent rods to the liquid metal heat transfer fluid flowing therebetween.

  14. Locked-wrap fuel rod

    DOEpatents

    Kaplan, Samuel; Chertock, Alan J.; Punches, James R.

    1977-01-01

    A method for spacing fast reactor fuel rods using a wire wrapper improved by orienting the wire-wrapped fuel rods in a unique manner which introduces desirable performance characteristics not attainable by previous wire-wrapped designs. Use of this method in a liquid metal fast breeder reactor results in: (a) improved mechanical performance, (b) improved rod-to-rod contact, (c) reduced steel volume, and (d) improved thermal-hydraulic performance. The method produces a "locked wrap" design which tends to lock the rods together at each of the wire cluster locations.

  15. Measuring the efficiency of control rods in the RBMK critical assembly using a model of RKI-1 reactimeter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhitarev, V. E., E-mail: vejitarev@yandex.ru; Lebedev, G. V.; Sergevnin, A. Yu.

    2016-12-15

    The efficiency of control rods of the RBMK critical assembly is measured in a series of experiments. The aim of measurements is to determine the characteristics of the model of an RKI-1 reactimeter. The RKI-1 reactimeter is intended for measuring the efficiency of control rods when, according to conditions of operation, the metrological certification of results of an experiment is required. Complications with the metrological certification of reactimeters arise owing to the fact that usually calculated corrections to the results of measurements are required. When the RKI-1 reactimeter is used, there is no need to introduce calculated corrections; the resultmore » of measurements is given with the indication of substantiated errors. In connection with this, the metrological certification of the results of measurements using the RKI-1 reactimeter is simplified.« less

  16. Cost analysis of magnetically controlled growing rods compared with traditional growing rods for early-onset scoliosis in the US: an integrated health care delivery system perspective

    PubMed Central

    Polly, David W; Ackerman, Stacey J; Schneider, Karen; Pawelek, Jeff B; Akbarnia, Behrooz A

    2016-01-01

    Purpose Traditional growing rod (TGR) for early-onset scoliosis (EOS) is effective but requires repeated invasive surgical lengthenings under general anesthesia. Magnetically controlled growing rod (MCGR) is lengthened noninvasively using a hand-held magnetic external remote controller in a physician office; however, the MCGR implant is expensive, and the cumulative cost savings have not been well studied. We compared direct medical costs of MCGR and TGR for EOS from the US integrated health care delivery system perspective. We hypothesized that over time, the MCGR implant cost will be offset by eliminating repeated TGR surgical lengthenings. Methods For both TGR and MCGR, the economic model estimated the cumulative costs for initial implantation, lengthenings, revisions due to device failure, surgical-site infections, device exchanges (at 3.8 years), and final fusion, over a 6-year episode of care. Model parameters were estimated from published literature, a multicenter EOS database of US institutions, and interviews. Costs were discounted at 3.0% annually and represent 2015 US dollars. Results Of 1,000 simulated patients over 6 years, MCGR was associated with an estimated 270 fewer deep surgical-site infections and 197 fewer revisions due to device failure compared with TGR. MCGR was projected to cost an additional $61 per patient over the 6-year episode of care compared with TGR. Sensitivity analyses indicated that the results were sensitive to changes in the percentage of MCGR dual rod use, months between TGR lengthenings, percentage of hospital inpatient (vs outpatient) TGR lengthenings, and MCGR implant cost. Conclusion Cost neutrality of MCGR to TGR was achieved over the 6-year episode of care by eliminating repeated TGR surgical lengthenings. To our knowledge, this is the first cost analysis comparing MCGR to TGR – from the US provider perspective – which demonstrates the efficient provision of care with MCGR. PMID:27695352

  17. Role of recoverin in rod photoreceptor light adaptation.

    PubMed

    Morshedian, Ala; Woodruff, Michael L; Fain, Gordon L

    2018-04-15

    Recoverin is a small molecular-weight, calcium-binding protein in rod outer segments that can modulate the rate of rhodopsin phosphorylation. We describe two additional and perhaps more important functions during photoreceptor light adaptation. Recoverin influences the rate of change of adaptation. In wild-type rods, sensitivity and response integration time adapt with similar time constants of 150-200 ms. In Rv-/- rods lacking recoverin, sensitivity declines faster and integration time is already shorter and not significantly altered. During steady light exposure, rod circulating current slowly increases during a time course of tens of seconds, gradually extending the operating range of the rod. In Rv-/- rods, this mechanism is deleted, steady-state currents are already larger and rods saturate at brighter intensities. We propose that recoverin modulates spontaneous and light-activated phophodiesterase-6, the phototransduction effector enzyme, to increase sensitivity in dim light but improve responsiveness to change in brighter illumination. Recoverin is a small molecular-weight, calcium-binding protein in rod outer segments that binds to G-protein receptor kinase 1 and can alter the rate of rhodopsin phosphorylation. A change in phosphorylation should change the lifetime of light-activated rhodopsin and the gain of phototransduction, but deletion of recoverin has little effect on the sensitivity of rods either in the dark or in dim-to-moderate background light. We describe two additional functions perhaps of greater physiological significance. (i) When the ambient intensity increases, sensitivity and integration time decrease in wild-type (WT) rods with similar time constants of 150-200 ms. Recoverin is part of the mechanism controlling this process because, in Rv-/- rods lacking recoverin, sensitivity declines more rapidly and integration time is already shorter and not further altered. (ii) During steady light exposure, WT rod circulating current slowly

  18. Railing for safety: job demands, job control, and safety citizenship role definition.

    PubMed

    Turner, Nick; Chmiel, Nik; Walls, Melanie

    2005-10-01

    This study investigated job demands and job control as predictors of safety citizenship role definition, that is, employees' role orientation toward improving workplace safety. Data from a survey of 334 trackside workers were framed in the context of R. A. Karasek's (1979) job demands-control model. High job demands were negatively related to safety citizenship role definition, whereas high job control was positively related to this construct. Safety citizenship role definition of employees with high job control was buffered from the influence of high job demands, unlike that of employees with low job control, for whom high job demands were related to lower levels of the construct. Employees facing both high job demands and low job control were less likely than other employees to view improving safety as part of their role orientation. Copyright (c) 2005 APA, all rights reserved.

  19. Maximum striking velocities in strikes with steel rods-the influence of rod length, rod mass and volunteer parameters.

    PubMed

    Trinh, T X; Heinke, S; Rode, C; Schenkl, S; Hubig, M; Mall, G; Muggenthaler, Holger

    2018-03-01

    In blunt force trauma to the head caused by attacks with blunt instruments, contact forces can be estimated based on the conservation of momentum if impact velocities are known. The aims of this work were to measure maximum striking velocities and to examine the influence of rod parameters such as rod mass and length as well as volunteer parameters such as sex, age, body height, body mass, body mass index and the average amount of physical exercise. Steel rods with masses of 500, 1000 and 1500 g as well as lengths of 40, 65 and 90 cm were exemplarily tested as blunt instruments. Twenty-nine men and 22 women participated in this study. Each volunteer performed several vertical strikes with the steel rods onto a passive immobile target. Maximum striking velocities were measured by means of a Qualisys motion capture system using high-speed cameras and infrared light. Male volunteers achieved maximum striking velocities between 14.0 and 35.5 m/s whereas female volunteers achieved values between 10.4 and 28.3 m/s. Results show that maximum striking velocities increased with smaller rod masses and less consistently with higher rod lengths. Statistically significant influences were found in the volunteers' sex and average amount of physical exercise.

  20. 46 CFR 62.25-15 - Safety control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....35-50. Note: Safety control systems include automatic and manual safety trip controls and automatic... engines. (e) Automatic safety trip control systems must— (1) Be provided where there is an immediate... 46 Shipping 2 2011-10-01 2011-10-01 false Safety control systems. 62.25-15 Section 62.25-15...

  1. Thermoreversible Gels Composed of Colloidal Silica Rods with Short-Range Attractions

    DOE PAGES

    Murphy, Ryan P.; Hong, Kunlun; Wagner, Norman J.

    2016-07-28

    Dynamic arrest transitions of colloidal suspensions containing non-spherical particles are of interest for the design and processing of various particle technologies. To better understand the effects of particle shape anisotropy and attraction strength on gel and glass formation, we present a colloidal model system of octadecyl-coated silica rods, termed as adhesive hard rods (AHR), which enables control of rod aspect ratio and temperature-dependent interactions. The aspect ratios of silica rods were controlled by varying the initial TEOS concentration following the work of Kuijk et al. (J. Am. Chem. Soc., 2011, 133, 2346–2349) and temperature-dependent attractions were introduced by coating themore » calcined silica rods with an octadecyl-brush and suspending in tetradecane. The rod length and aspect ratio were found to increase with TEOS concentration as expected, while other properties such as the rod diameter, coating coverage, density, and surface roughness were nearly independent of the aspect ratio. Ultra-small angle X-ray scattering measurements revealed temperature-dependent attractions between octadecyl-coated silica rods in tetradecane, as characterized by a low-q upturn in the scattered intensity upon thermal quenching. Lastly, the rheology of a concentrated AHR suspension in tetradecane demonstrated thermoreversible gelation behavior, displaying a nearly 5 orders of magnitude change in the dynamic moduli as the temperature was cycled between 15 and 40 °C. We find the adhesive hard rod model system serves as a tunable platform to explore the combined influence of particle shape anisotropy and attraction strength on the dynamic arrest transitions in colloidal suspensions with thermoreversible, short-range attractions.« less

  2. Development of burnup dependent fuel rod model in COBRA-TF

    NASA Astrophysics Data System (ADS)

    Yilmaz, Mine Ozdemir

    predictions. After confirming that the new fuel thermal conductivity model in CTF worked and provided consistent results with FRAPTRAN predictions for a single fuel rod configuration, the same type of analysis was carried out for a bigger system which is the 4x4 PWR bundle consisting of 15 fuel pins and one control guide tube. Steady- state calculations at Hot Full Power (HFP) conditions for control guide tube out (unrodded) were performed using the 4x4 PWR array with CTF/TORT-TD coupled code system. Fuel centerline, surface and average temperatures predicted by CTF/TORT-TD with and without the new fuel thermal conductivity model were compared against CTF/TORT-TD/FRAPTRAN predictions to demonstrate the improvement in fuel centerline predictions when new model was used. In addition to that constant and CTF dynamic gap conductance model were used with the new thermal conductivity model to show the performance of the CTF dynamic gap conductance model and its impact on fuel centerline and surface temperatures. Finally, a Rod Ejection Accident (REA) scenario using the same 4x4 PWR array was run both at Hot Zero Power (HZP) and Hot Full Power (HFP) condition, starting at a position where half of the control rod is inserted. This scenario was run using CTF/TORT-TD coupled code system with and without the new fuel thermal conductivity model. The purpose of this transient analysis was to show the impact of thermal conductivity degradation (TCD) on feedback effects, specifically Doppler Reactivity Coefficient (DRC) and, eventually, total core reactivity.

  3. Coiling of elastic rods on rigid substrates

    PubMed Central

    Jawed, Mohammad K.; Da, Fang; Joo, Jungseock; Grinspun, Eitan; Reis, Pedro M.

    2014-01-01

    We investigate the deployment of a thin elastic rod onto a rigid substrate and study the resulting coiling patterns. In our approach, we combine precision model experiments, scaling analyses, and computer simulations toward developing predictive understanding of the coiling process. Both cases of deposition onto static and moving substrates are considered. We construct phase diagrams for the possible coiling patterns and characterize them as a function of the geometric and material properties of the rod, as well as the height and relative speeds of deployment. The modes selected and their characteristic length scales are found to arise from a complex interplay between gravitational, bending, and twisting energies of the rod, coupled to the geometric nonlinearities intrinsic to the large deformations. We give particular emphasis to the first sinusoidal mode of instability, which we find to be consistent with a Hopf bifurcation, and analyze the meandering wavelength and amplitude. Throughout, we systematically vary natural curvature of the rod as a control parameter, which has a qualitative and quantitative effect on the pattern formation, above a critical value that we determine. The universality conferred by the prominent role of geometry in the deformation modes of the rod suggests using the gained understanding as design guidelines, in the original applications that motivated the study. PMID:25267649

  4. Pull rod assembly

    DOEpatents

    Cioletti, O.C.

    1988-04-21

    A pull rod assembly comprising a pull rod having three peripheral grooves, a piston device including an adaptor ring and a seal ring, said piston device being mounted on the pull rod by a split ring retainer situated in one groove and extending into an interior groove in the adaptor and a resilient split ring retained in another groove and positioned to engage the piston device and to retain the seal on its adaptor.

  5. ALLOY COMPOSITION FOR NEUTRONIC REACTOR CONTROL RODS

    DOEpatents

    Lustman, B.; Losco, E.F.; Snyder, H.J.; Eggleston, R.R.

    1963-01-22

    This invention relates to alloy compositons suitable as cortrol rod material consisting of, by weight, from 85% to 85% Ag, from 2% to 20% In, from up to 10% of Cd, from up to 5% Sn, and from up to 1.5% Al, the amount of each element employed being determined by the equation X + 2Y + 3Z + 3W + 4V = 1.4 and less, where X, Y, Z, W, and V represent the atom fractions of the elements Ag, Cd, In, Al and Sn. (AEC)

  6. Correlated cone noise decreases rod signal contributions to the post-receptoral pathways.

    PubMed

    Hathibelagal, Amithavikram R; Feigl, Beatrix; Zele, Andrew J

    2018-04-01

    This study investigated how invisible extrinsic temporal white noise that correlates with the activity of one of the three [magnocellular (MC), parvocellular (PC), or koniocellular (KC)] post-receptoral pathways alters mesopic rod signaling. A four-primary photostimulator provided independent control of the rod and three cone photoreceptor excitations. The rod contributions to the three post-receptoral pathways were estimated by perceptually matching a 20% contrast rod pulse by independently varying the LMS (MC pathway), +L-M (PC pathway), and S-cone (KC pathway) excitations. We show that extrinsic cone noise caused a predominant decrease in the overall magnitude and ratio of the rod contributions to each pathway. Thus, the relative cone activity in the post-receptoral pathways determines the relative mesopic rod inputs to each pathway.

  7. In-pile tests at Karlsruhe of LWR fuel-rod behavior during the heatup phase of a LOCA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Karb, E.H.

    1980-01-01

    In order to investigate the influence of a nuclar environment on the mechanisms of fuel-rod failure, in-pile tests simulating the heatup phase of a loss-of-coolant accident in a pressurized-water reactor are being conducted with irradiated and unirradiated short-length single rods in the FR2 reactor at Kernforschungszentrum karlsruhe (Karlsruhe Nuclear Reasearch Center), Federal Republic of Germany, within the Project Nuclear Safety. With nearly 70% of the scheduled tests completed, no such influences have been found. The in-pile burst and deformation data are in good agreement with results from nonnuclear tests with electrically heated fuel-rod simulators. The phenomenon of pellet disintegration, whichmore » has been observed in all tests with previously irradiated rods, needs further investigation.« less

  8. Heat transfer in laminar flow along circular rods in infinite square arrays

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, J.H.; Li, W.H.

    1988-02-01

    The need to understand heat transfer characteristics over rods or tube bundles often arises in the design of compact heat exchangers and safety analysis of nuclear reactors. In particular, the fuel bundles of typical light water nuclear reactors are composed of a large number of circular rods arranged in square array pattern. The purpose of the present study is to analyze heat transfer characteristics of flow in such a multirod geometric configuration. The analysis given here will follow as closely as possible the method of Sparrow et al. who analyzed a similar problem for circular cylinders arranged in an equilateralmore » triangular array. The following major assumptions are made in the present analysis: (1) Flow is fully developed laminar flow paralleled to the axis of rods. (2) The axial profile of the surface heat flux to the fluid is uniform.(3) Thermodynamic properties are assumed constant.« less

  9. Quantitative safety assessment of air traffic control systems through system control capacity

    NASA Astrophysics Data System (ADS)

    Guo, Jingjing

    Quantitative Safety Assessments (QSA) are essential to safety benefit verification and regulations of developmental changes in safety critical systems like the Air Traffic Control (ATC) systems. Effectiveness of the assessments is particularly desirable today in the safe implementations of revolutionary ATC overhauls like NextGen and SESAR. QSA of ATC systems are however challenged by system complexity and lack of accident data. Extending from the idea "safety is a control problem" in the literature, this research proposes to assess system safety from the control perspective, through quantifying a system's "control capacity". A system's safety performance correlates to this "control capacity" in the control of "safety critical processes". To examine this idea in QSA of the ATC systems, a Control-capacity Based Safety Assessment Framework (CBSAF) is developed which includes two control capacity metrics and a procedural method. The two metrics are Probabilistic System Control-capacity (PSC) and Temporal System Control-capacity (TSC); each addresses an aspect of a system's control capacity. And the procedural method consists three general stages: I) identification of safety critical processes, II) development of system control models and III) evaluation of system control capacity. The CBSAF was tested in two case studies. The first one assesses an en-route collision avoidance scenario and compares three hypothetical configurations. The CBSAF was able to capture the uncoordinated behavior between two means of control, as was observed in a historic midair collision accident. The second case study compares CBSAF with an existing risk based QSA method in assessing the safety benefits of introducing a runway incursion alert system. Similar conclusions are reached between the two methods, while the CBSAF has the advantage of simplicity and provides a new control-based perspective and interpretation to the assessments. The case studies are intended to investigate the

  10. Process-based tolerance assessment of connecting rod machining process

    NASA Astrophysics Data System (ADS)

    Sharma, G. V. S. S.; Rao, P. Srinivasa; Surendra Babu, B.

    2016-06-01

    Process tolerancing based on the process capability studies is the optimistic and pragmatic approach of determining the manufacturing process tolerances. On adopting the define-measure-analyze-improve-control approach, the process potential capability index ( C p) and the process performance capability index ( C pk) values of identified process characteristics of connecting rod machining process are achieved to be greater than the industry benchmark of 1.33, i.e., four sigma level. The tolerance chain diagram methodology is applied to the connecting rod in order to verify the manufacturing process tolerances at various operations of the connecting rod manufacturing process. This paper bridges the gap between the existing dimensional tolerances obtained via tolerance charting and process capability studies of the connecting rod component. Finally, the process tolerancing comparison has been done by adopting a tolerance capability expert software.

  11. Long-term effects of retinopathy of prematurity (ROP) on rod and rod-driven function.

    PubMed

    Harris, Maureen E; Moskowitz, Anne; Fulton, Anne B; Hansen, Ronald M

    2011-02-01

    The purpose of this study was to determine whether recovery of scotopic sensitivity occurs in human ROP, as it does in the rat models of ROP. Following a cross-sectional design, scotopic electroretinographic (ERG) responses to full-field stimuli were recorded from 85 subjects with a history of preterm birth. In 39 of these subjects, dark adapted visual threshold was also measured. Subjects were tested post-term as infants (median age 2.5 months) or at older ages (median age 10.5 years) and stratified by severity of ROP: severe, mild, or none. Rod photoreceptor sensitivity, S (ROD), was derived from the a-wave, and post-receptor sensitivity, log σ, was calculated from the b-wave stimulus-response function. Dark adapted visual threshold was measured using a forced-choice preferential procedure. For S (ROD), the deficit from normal for age varied significantly with ROP severity but not with age group. For log σ, in mild ROP, the deficit was smaller in older subjects than in infants, while in severe ROP, the deficit was quite large in both age groups. In subjects who never had ROP, S (ROD) and log σ in both age groups were similar to those in term born controls. Deficits in dark adapted threshold and log σ were correlated in mild but not in severe ROP. The data are evidence that sensitivity of the post-receptor retina improves in those with a history of mild ROP. We speculate that beneficial reorganization of the post-receptor neural circuitry occurs in mild but not in severe ROP.

  12. Automated power control system for reactor TRIGA PUSPATI

    NASA Astrophysics Data System (ADS)

    Ghazali, Anith Khairunnisa; Minhat, Mohd Sabri; Hassan, Mohd Khair

    2017-01-01

    Reactor TRIGA PUSPATI (RTP) Mark II type undergoes safe operation for more than 30 years and the only research reactor exists in Malaysia. The main safety feature of Instrumentation and Control (I&C) system design is such that any failure in the electronic, or its associated components, does not lead to an uncontrolled rate of reactivity. The existed controller using feedback approach to control the reactor power. This paper introduces proposed controllers such as Model Reference Adaptive Control (MRAC) and Proportional Integral Derivatives (PID) controller for the RTP simulation. In RTP, the most important considered parameter is the reactor power and act as nervous system. To design a controller for complex plant like RTP is quite difficult due to high cost and safety factors cause by the failure of the controller. Furthermore, to overcome these problems, a simulator can be used to replace functions the hardware and test could then be simulated using this simulator. In order to find the best controller, several controllers were proposed and the result will be analysed for study the performances of the controller. The output result will be used to find out the best RTP power controller using MATLAB/Simulink and gives result as close as the real RTP performances. Currently, the structures of RTP was design using MATLAB/Simulink tool that consist of fission chamber, controller, control rod position, height-to-worth of control rods and a RTP model. The controller will control the control rod position to make sure that the reactivity still under the limitation parameter. The results given from each controller will be analysed and validated through experiment data collected from RTP.

  13. Rod stiffness as a risk factor of proximal junctional kyphosis after adult spinal deformity surgery: comparative study between cobalt chrome multiple-rod constructs and titanium alloy two-rod constructs.

    PubMed

    Han, Sanghyun; Hyun, Seung-Jae; Kim, Ki-Jeong; Jahng, Tae-Ahn; Lee, Subum; Rhim, Seung-Chul

    2017-07-01

    Little is known about the effect of rod stiffness as a risk factor of proximal junctional kyphosis (PJK) after adult spinal deformity (ASD) surgery. The aim of this study was to compare radiographic outcomes after the use of cobalt chrome multiple-rod constructs (CoCr MRCs) and titanium alloy two-rod constructs (Ti TRCs) for ASD surgery with a minimum 1-year follow-up. Retrospective case-control study in two institutes. We included 54 patients who underwent ASD surgery with fusion to the sacrum in two academic institutes between 2002 and 2015. Radiographic outcomes were measured on the standing lateral radiographs before surgery, 1 month postoperatively, and at ultimate follow-up. The outcome measures were composed of pre- and postoperative sagittal vertical axis (SVA), pre- and postoperative lumbar lordosis (LL), pre- and postoperative thoracic kyphosis (TK)+LL+pelvic incidence (PI), pre- and postoperative PI minus LL, level of uppermost instrumented vertebra (UIV), evaluation of fusion after surgery, the presence of PJK, and the occurrence of rod fracture. We reviewed the medical records of 54 patients who underwent ASD surgery. Of these, 20 patients had CoCr MRC and 34 patients had Ti TRC. Baseline data and radiographic measurements were compared between the two groups. The Mann-Whitney U test, the chi-square test, and the Fisher exact test were used to compare outcomes between the groups. The patients of the groups were similar in terms of age, gender, diagnosis, number of three-column osteotomy, levels fused, bone mineral density, preoperative TK, pre- and postoperative TK+LL+PI, SVA difference, LL change, pre- and postoperative PI minus LL, and location of UIV (upper or lower thoracic level). However, there were significant differences in the occurrence of PJK and rod breakage (PJK: CoCr MRC: 12 [60%] vs. Ti TRC: 9 [26.5%], p=.015; occurrence of rod breakage: CoCr MRC: 0 [0%] vs. Ti TRC: 11 [32.4%], p=.004). The time of PJK was less than 12 months after

  14. Vibrational Power Flow Analysis of Rods and Beams

    NASA Technical Reports Server (NTRS)

    Wohlever, James Christopher; Bernhard, R. J.

    1988-01-01

    A new method to model vibrational power flow and predict the resulting energy density levels in uniform rods and beams is investigated. This method models the flow of vibrational power in a manner analogous to the flow of thermal power in a heat conduction problem. The classical displacement solutions for harmonically excited, hysteretically damped rods and beams are used to derive expressions for the vibrational power flow and energy density in the rod and beam. Under certain conditions, the power flow in these two structural elements will be shown to be proportional to the energy density gradient. Using the relationship between power flow and energy density, an energy balance on differential control volumes in the rod and beam leads to a Poisson's equation which models the energy density distribution in the rod and beam. Coupling the energy density and power flow solutions for rods and beams is also discussed. It is shown that the resonant behavior of finite structures complicates the coupling of solutions, especially when the excitations are single frequency inputs. Two coupling formulations are discussed, the first based on the receptance method, and the second on the travelling wave approach used in Statistical Energy Analysis. The receptance method is the more computationally intensive but is capable of analyzing single frequency excitation cases. The traveling wave approach gives a good approximation of the frequency average of energy density and power flow in coupled systems, and thus, is an efficient technique for use with broadband frequency excitation.

  15. Solid-state-laser-rod holder

    DOEpatents

    Gettemy, D.J.; Barnes, N.P.; Griggs, J.E.

    1981-08-11

    The disclosure relates to a solid state laser rod holder comprising Invar, copper tubing, and epoxy joints. Materials and coefficients of expansion of the components of the holder combine with the rod to produce a joint which will give before the rod itself will. The rod may be lased at about 70 to 80/sup 0/K and returned from such a temperature to room temperature repeatedly without its or the holder's destruction.

  16. Fuel rod assembly to manifold attachment

    DOEpatents

    Donck, Harry A.; Veca, Anthony R.; Snyder, Jr., Harold J.

    1980-01-01

    A fuel element is formed with a plurality of fuel rod assemblies detachably connected to an overhead support with each of the fuel rod assemblies having a gas tight seal with the support to allow internal fission gaseous products to flow without leakage from the fuel rod assemblies into a vent manifold passageway system on the support. The upper ends of the fuel rod assemblies are located at vertically extending openings in the support and upper threaded members are threaded to the fuel rod assemblies to connect the latter to the support. The preferred threaded members are cap nuts having a dome wall encircling an upper threaded end on the fuel rod assembly and having an upper sealing surface for sealing contact with the support. Another and lower seal is achieved by abutting a sealing surface on each fuel rod assembly with the support. A deformable portion on the cap nut locks the latter against inadvertent turning off the fuel rod assembly. Orienting means on the fuel rod and support primarily locates the fuel rods azimuthally for reception of a deforming tool for the cap nut. A cross port in the fuel rod end plug discharges into a sealed annulus within the support, which serves as a circumferential chamber, connecting the manifold gas passageways in the support.

  17. 46 CFR 62.25-15 - Safety control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... manual safety trip controls must be provided for all main boilers, turbines, and internal combustion... 46 Shipping 2 2012-10-01 2012-10-01 false Safety control systems. 62.25-15 Section 62.25-15... AUTOMATION General Requirements for All Automated Vital Systems § 62.25-15 Safety control systems. (a...

  18. 46 CFR 62.25-15 - Safety control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... manual safety trip controls must be provided for all main boilers, turbines, and internal combustion... 46 Shipping 2 2013-10-01 2013-10-01 false Safety control systems. 62.25-15 Section 62.25-15... AUTOMATION General Requirements for All Automated Vital Systems § 62.25-15 Safety control systems. (a...

  19. 46 CFR 62.25-15 - Safety control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... manual safety trip controls must be provided for all main boilers, turbines, and internal combustion... 46 Shipping 2 2014-10-01 2014-10-01 false Safety control systems. 62.25-15 Section 62.25-15... AUTOMATION General Requirements for All Automated Vital Systems § 62.25-15 Safety control systems. (a...

  20. Use of Ionic Liquids in Rod-Coil Block Copolyimides for Improved Lithium Ion Conduction

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Tigelaar, Dean M.; Chapin, Kara; Bennett, William R.

    2007-01-01

    Solvent-free, solid polymer electrolytes (SPE) have the potential to improve safety, increase design flexibility and enhance performance of rechargeable lithium batteries. Solution based electrolytes are flammable and typically incompatible with lithium metal anodes, limiting energy density. We have previously demonstrated use of polyimide rod coil block copolymers doped with lithium salts as electrolytes for lithium polymer batteries. The polyimide rod blocks provide dimensional stability while the polyethylene oxide (PEO) coil portions conduct ions. Phase separation of the rods and coils in these highly branched polymers provide channels with an order of magnitude improvement in lithium conduction over polyethylene oxide itself at room temperature. In addition, the polymers have been demonstrated in coin cells to be compatible with lithium metal. For practical use at room temperature and below, however, at least an order of magnitude improvement in ion conduction is still required. The addition of nonvolatile, room temperature ionic liquids has been shown to improve the ionic conductivity of high molecular weight PEO. Herein we describe use of these molten salts to improve ionic conductivity in the rod-coil block copolymers.

  1. Experimental Study on Surrogate Nuclear Fuel Rods under Reversed Cyclic Bending

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Hong; Wang, Jy-An John

    The mechanical behavior of spent nuclear fuel (SNF) rods under reversed cyclic bending or bending fatigue must be understood to evaluate their vibration integrity in a transportation environment. This is especially important for high-burnup fuels (>45 GWd/MTU), which have the potential for increased structural damage. It has been demonstrated that the bending fatigue of SNF rods can be effectively studied using surrogate rods. In this investigation, surrogate rods made of stainless steel (SS) 304 cladding and aluminum oxide pellets were tested under load or moment control at a variety of amplitude levels at 5 Hz using the Cyclic Integrated Reversible-Bendingmore » Fatigue Tester developed at Oak Ridge National Laboratory. The behavior of the rods was further characterized using flexural rigidity and hysteresis data, and fractography was performed on the failed rods. The proposed surrogate rods captured many of the characteristics of deformation and failure mode observed in SNF, including the linear-to-nonlinear deformation transition and large residual curvature in static tests, PPI and PCMI failure mechanisms, and large variation in the initial structural condition. Rod degradation was measured and characterized by measuring the flexural rigidity; the degradation of the rigidity depended on both the moment amplitude applied and the initial structural condition of the rods. It was also shown that a cracking initiation site can be located on the internal surface or the external surface of cladding. Finally, fatigue damage to the bending rods can be described in terms of flexural rigidity, and the fatigue life of rods can be predicted once damage model parameters are properly evaluated. The developed experimental approach, test protocol, and analysis method can be used to study the vibration integrity of SNF rods in the future.« less

  2. Chemical State Mapping of Degraded B4C Control Rod Investigated with Soft X-ray Emission Spectrometer in Electron Probe Micro-analysis.

    PubMed

    Kasada, R; Ha, Y; Higuchi, T; Sakamoto, K

    2016-05-10

    B4C is widely used as control rods in light water reactors, such as the Fukushima Daiichi nuclear power plant, because it shows excellent neutron absorption and has a high melting point. However, B4C can melt at lower temperatures owing to eutectic interactions with stainless steel and can even evaporate by reacting with high-temperature steam under severe accident conditions. To reduce the risk of recriticality, a precise understanding of the location and chemical state of B in the melt core is necessary. Here we show that a novel soft X-ray emission spectrometer in electron probe microanalysis can help to obtain a chemical state map of B in a modeled control rod after a high-temperature steam oxidation test.

  3. STABILIZED RARE EARTH OXIDES FOR A CONTROL ROD AND METHOD OF PREPARATION

    DOEpatents

    McNees, R.A.; Potter, R.A.

    1964-01-14

    A method is given for preparing mixed oxides of the formula MR/sub x/O/ sub 12/ wherein M is tungsten or molybdenum and R is a rare earth in the group consisting of samarium, europium, dysprosium, and gadolinium and x is 4 to 5. Oxides of this formula, and particularly the europiumcontaining species, are useful as control rod material for water-cooled nuclear reactors owing to their stability, favorable nuclear properties, and resistance to hydration. These oxides may be utilized as a dispersion in a stainlesssteel matrix. Preparation of these oxides is effected by blending tungsten oxide or molybdenum oxide with a rare earth oxide, compressing the mixture, and firing at an elevated temperature in an oxygen-containing atmosphere. (AEC)

  4. Vertical rod temperatures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roy, G.M.

    1951-08-14

    An important factor affecting the decision on the use of a seal around the VSR on ``C`` is the temperature at which the rod can be expected to reach. Also the temperature of the rod-tip affects the choice of tip moderating material. These temperatures are calculated for a given set of conditions for ``C`` pile. The results of the calculations are best seen by referring to the attached figures. The affects of emissivity and weight of rod can be estimated by comparing the proper curves. The assumed conditions for calculating each curve are important and therefore, the basis for eachmore » curve is given separately.« less

  5. The biomechanical consequences of rod reduction on pedicle screws: should it be avoided?

    PubMed

    Paik, Haines; Kang, Daniel G; Lehman, Ronald A; Gaume, Rachel E; Ambati, Divya V; Dmitriev, Anton E

    2013-11-01

    Rod contouring is frequently required to allow for appropriate alignment of pedicle screw-rod constructs. When residual mismatch is still present, a rod persuasion device is often used to achieve further rod reduction. Despite its popularity and widespread use, the biomechanical consequences of this technique have not been evaluated. To evaluate the biomechanical fixation strength of pedicle screws after attempted reduction of a rod-pedicle screw mismatch using a rod persuasion device. Fifteen 3-level, human cadaveric thoracic specimens were prepared and scanned for bone mineral density. Osteoporotic (n=6) and normal (n=9) specimens were instrumented with 5.0-mm-diameter pedicle screws; for each pair of comparison level tested, the bilateral screws were equal in length, and the screw length was determined by the thoracic level and size of the vertebra (35 to 45 mm). Titanium 5.5-mm rods were contoured and secured to the pedicle screws at the proximal and distal levels. For the middle segment, the rod on the right side was intentionally contoured to create a 5-mm residual gap between the inner bushing of the pedicle screw and the rod. A rod persuasion device was then used to engage the setscrew. The left side served as a control with perfect screw/rod alignment. After 30 minutes, constructs were disassembled and vertebrae individually potted. The implants were pulled in-line with the screw axis with peak pullout strength (POS) measured in Newton (N). For the proximal and distal segments, pedicle screws on the right side were taken out and reinserted through the same trajectory to simulate screw depth adjustment as an alternative to rod reduction. Pedicle screws reduced to the rod generated a 48% lower mean POS (495±379 N) relative to the controls (954±237 N) (p<.05) and significantly decreased work energy to failure (p<.05). Nearly half (n=7) of the pedicle screws had failed during the reduction attempt with visible pullout of the screw. After reduction, decreased

  6. MEANS FOR CONTROLLING A NUCLEAR REACTOR

    DOEpatents

    Wilson, V.C.; Overbeck, W.P.; Slotin, L.; Froman, D.K.

    1957-12-17

    This patent relates to nuclear reactors of the type using a solid neutron absorbing material as a means for controlling the reproduction ratio of the system and thereby the power output. Elongated rods of neutron absorbing material, such as boron steel for example, are adapted to be inserted and removed from the core of tae reactor by electronic motors and suitable drive means. The motors and drive means are controlled by means responsive to the neutron density, such as ionization chambers. The control system is designed to be responsive also to the rate of change in neutron density to automatically maintain the total power output at a substantially constant predetermined value. A safety rod means responsive to neutron density is also provided for keeping the power output below a predetermined maximum value at all times.

  7. Job Demands-Control-Support model and employee safety performance.

    PubMed

    Turner, Nick; Stride, Chris B; Carter, Angela J; McCaughey, Deirdre; Carroll, Anthony E

    2012-03-01

    The aim of this study was to explore whether work characteristics (job demands, job control, social support) comprising Karasek and Theorell's (1990) Job Demands-Control-Support framework predict employee safety performance (safety compliance and safety participation; Neal and Griffin, 2006). We used cross-sectional data of self-reported work characteristics and employee safety performance from 280 healthcare staff (doctors, nurses, and administrative staff) from Emergency Departments of seven hospitals in the United Kingdom. We analyzed these data using a structural equation model that simultaneously regressed safety compliance and safety participation on the main effects of each of the aforementioned work characteristics, their two-way interactions, and the three-way interaction among them, while controlling for demographic, occupational, and organizational characteristics. Social support was positively related to safety compliance, and both job control and the two-way interaction between job control and social support were positively related to safety participation. How work design is related to employee safety performance remains an important area for research and provides insight into how organizations can improve workplace safety. The current findings emphasize the importance of the co-worker in promoting both safety compliance and safety participation. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  8. Lightning protection using energized Franklin rods

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abdel-Salam, M.; Al-Abdul-Latif, U.

    1995-12-31

    In this paper, the onset criterion of the upward streamers from an energized Franklin rod is formulated as a function of the geometry of the rod and the height and current of the downward leader. The electric field in the vicinity of the lightning rod is calculated using the charge simulation technique. The dependency of the radius of protection on the amplitude of the pulse voltage applied to Franklin rod, the downward leader current and the tip radius and height of the rod is investigated.

  9. Piston and connecting rod assembly

    NASA Technical Reports Server (NTRS)

    Brogdon, James William (Inventor); Gill, David Keith (Inventor); Chatten, John K. (Inventor)

    2001-01-01

    A piston and connecting rod assembly includes a piston crown, a piston skirt, a connecting rod, and a bearing insert. The piston skirt is a component separate from the piston crown and is connected to the piston crown to provide a piston body. The bearing insert is a component separate from the piston crown and the piston skirt and is fixedly disposed within the piston body. A bearing surface of a connecting rod contacts the bearing insert to thereby movably associate the connecting rod and the piston body.

  10. FUEL ROD CLUSTERS

    DOEpatents

    Schultz, A.B.

    1959-08-01

    A cluster of nuclear fuel rods and a tubular casing therefor through which a coolant flows in heat-exchange contact with the fuel rods is described. The fuel rcds are held in the casing by virtue of the compressive force exerted between longitudinal ribs of the fuel rcds and internal ribs of the casing or the internal surfaces thereof.

  11. Rod-Coil Block Polyimide Copolymers

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B. (Inventor); Kinder, James D. (Inventor)

    2005-01-01

    This invention is a series of rod-coil block polyimide copolymers that are easy to fabricate into mechanically resilient films with acceptable ionic or protonic conductivity at a variety of temperatures. The copolymers consist of short-rigid polyimide rod segments alternating with polyether coil segments. The rods and coil segments can be linear, branched or mixtures of linear and branched segments. The highly incompatible rods and coil segments phase separate, providing nanoscale channels for ion conduction. The polyimide segments provide dimensional and mechanical stability and can be functionalized in a number of ways to provide specialized functions for a given application. These rod-coil black polyimide copolymers are particularly useful in the preparation of ion conductive membranes for use in the manufacture of fuel cells and lithium based polymer batteries.

  12. Homeostatic Plasticity Mediated by Rod-Cone Gap Junction Coupling in Retinal Degenerative Dystrophic RCS Rats

    PubMed Central

    Hou, Baoke; Fu, Yan; Weng, Chuanhuang; Liu, Weiping; Zhao, Congjian; Yin, Zheng Qin

    2017-01-01

    Rod-cone gap junctions open at night to allow rod signals to pass to cones and activate the cone-bipolar pathway. This enhances the ability to detect large, dim objects at night. This electrical synaptic switch is governed by the circadian clock and represents a novel form of homeostatic plasticity that regulates retinal excitability according to network activity. We used tracer labeling and ERG recording in the retinae of control and retinal degenerative dystrophic RCS rats. We found that in the control animals, rod-cone gap junction coupling was regulated by the circadian clock via the modulation of the phosphorylation of the melatonin synthetic enzyme arylalkylamine N-acetyltransferase (AANAT). However, in dystrophic RCS rats, AANAT was constitutively phosphorylated, causing rod-cone gap junctions to remain open. A further b/a-wave ratio analysis revealed that dystrophic RCS rats had stronger synaptic strength between photoreceptors and bipolar cells, possibly because rod-cone gap junctions remained open. This was despite the fact that a decrease was observed in the amplitude of both a- and b-waves as a result of the progressive loss of rods during early degenerative stages. These results suggest that electric synaptic strength is increased during the day to allow cone signals to pass to the remaining rods and to be propagated to rod bipolar cells, thereby partially compensating for the weak visual input caused by the loss of rods. PMID:28473754

  13. Controlled versus automatic processes: which is dominant to safety? The moderating effect of inhibitory control.

    PubMed

    Xu, Yaoshan; Li, Yongjuan; Ding, Weidong; Lu, Fan

    2014-01-01

    This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT) reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end.

  14. Controlled versus Automatic Processes: Which Is Dominant to Safety? The Moderating Effect of Inhibitory Control

    PubMed Central

    Xu, Yaoshan; Li, Yongjuan; Ding, Weidong; Lu, Fan

    2014-01-01

    This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT) reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end. PMID:24520338

  15. Domain and network aggregation of CdTe quantum rods within Langmuir Blodgett monolayers

    NASA Astrophysics Data System (ADS)

    Zimnitsky, Dmitry; Xu, Jun; Lin, Zhiqun; Tsukruk, Vladimir V.

    2008-05-01

    Control over the organization of quantum rods was demonstrated by changing the surface area at the air-liquid interface by means of the Langmuir-Blodgett (LB) technique. The LB isotherm of CdTe quantum rods capped with a mixture of alkylphosphines shows a transition point in the liquid-solid state, which is caused by the inter-rod reorganization. As we observed, at low surface pressure the quantum rods are assembled into round-shaped aggregates composed of a monolayer of nanorods packed in limited-size clusters with random orientation. The increase of the surface pressure leads to the rearrangement of these aggregates into elongated bundles composed of uniformly oriented nanorod clusters. Further compression results in denser packing of nanorods aggregates and in the transformation of monolayered domains into a continuous network of locally ordered quantum rods.

  16. Light Water Breeder Reactor fuel rod design and performance characteristics (LWBR Development Program)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Campbell, W.R.; Giovengo, J.F.

    1987-10-01

    Light Water Breeder Reactor (LWBR) fuel rods were designed to provide a reliable fuel system utilizing thorium/uranium-233 mixed-oxide fuel while simultaneously minimizing structural material to enhance fuel breeding. The fuel system was designed to be capable of operating successfully under both load follow and base load conditions. The breeding objective required thin-walled, low hafnium content Zircaloy cladding, tightly spaced fuel rods with a minimum number of support grid levels, and movable fuel rod bundles to supplant control rods. Specific fuel rod design considerations and their effects on performance capability are described. Successful completion of power operations to over 160 percentmore » of design lifetime including over 200 daily load follow cycles has proven the performance capability of the fuel system. 68 refs., 19 figs., 44 tabs.« less

  17. Method of targeted delivery of laser beam to isolated retinal rods by fiber optics.

    PubMed

    Sim, Nigel; Bessarab, Dmitri; Jones, C Michael; Krivitsky, Leonid

    2011-11-01

    A method of controllable light delivery to retinal rod cells using an optical fiber is described. Photo-induced current of the living rod cells was measured with the suction electrode technique. The approach was tested with measurements relating the spatial distribution of the light intensity to photo-induced current. In addition, the ion current responses of rod cells to polarized light at two different orientation geometries of the cells were studied.

  18. Aerobic Glycolysis Is Essential for Normal Rod Function and Controls Secondary Cone Death in Retinitis Pigmentosa.

    PubMed

    Petit, Lolita; Ma, Shan; Cipi, Joris; Cheng, Shun-Yun; Zieger, Marina; Hay, Nissim; Punzo, Claudio

    2018-05-29

    Aerobic glycolysis accounts for ∼80%-90% of glucose used by adult photoreceptors (PRs); yet, the importance of aerobic glycolysis for PR function or survival remains unclear. Here, we further established the role of aerobic glycolysis in murine rod and cone PRs. We show that loss of hexokinase-2 (HK2), a key aerobic glycolysis enzyme, does not affect PR survival or structure but is required for normal rod function. Rods with HK2 loss increase their mitochondrial number, suggesting an adaptation to the inhibition of aerobic glycolysis. In contrast, cones adapt without increased mitochondrial number but require HK2 to adapt to metabolic stress conditions such as those encountered in retinitis pigmentosa, where the loss of rods causes a nutrient shortage in cones. The data support a model where aerobic glycolysis in PRs is not a necessity but rather a metabolic choice that maximizes PR function and adaptability to nutrient stress conditions. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. Nuclear thermionic converter. [tungsten-thorium oxide rods

    NASA Technical Reports Server (NTRS)

    Phillips, W. M.; Mondt, J. F. (Inventor)

    1977-01-01

    Efficient nuclear reactor thermionic converter units are described which can be constructed at low cost and assembled in a reactor which requires a minimum of fuel. Each converter unit utilizes an emitter rod with a fluted exterior, several fuel passages located in the bulges that are formed in the rod between the flutes, and a collector receiving passage formed through the center of the rod. An array of rods is closely packed in an interfitting arrangement, with the bulges of the rods received in the recesses formed between the bulges of other rods, thereby closely packing the nuclear fuel. The rods are constructed of a mixture of tungsten and thorium oxide to provide high power output, high efficiency, high strength, and good machinability.

  20. System for controlling child safety seat environment

    NASA Technical Reports Server (NTRS)

    Elrod, Susan V. (Inventor); Dabney, Richard W. (Inventor)

    2008-01-01

    A system is provided to control the environment experienced by a child in a child safety seat. Each of a plurality of thermoelectric elements is individually controllable to be one of heated and cooled relative to an ambient temperature. A first portion of the thermoelectric elements are positioned on the child safety seat such that a child sitting therein is positioned thereover. A ventilator coupled to the child safety seat moves air past a second portion of the thermoelectric elements and filters the air moved therepast. One or more jets coupled to the ventilator receive the filtered air. Each jet is coupled to the child safety seat and can be positioned to direct the heated/cooled filtered air to the vicinity of the head of the child sitting in the child safety seat.

  1. Ordering of Glass Rods in Nematic and Cholesteric Liquid Crystals

    DTIC Science & Technology

    2011-12-01

    3), 483–508 (2007). 2. M. D. Lynch and D. L. Patrick, “Controlling the orientation of micron-sized rod-shaped SiC particles with nematic liquid...Elastic torque and the levitation of metal wires by a nematic liquid crystal,” Science 303(5658), 652–655 (2004). 17. R. Eelkema, M. M. Pollard, J...Building Blocks for Iterative Methods, 2nd ed. (SIAM, 1994). 1. Introduction Incorporating rod-like particles into liquid crystal (LC) media can lead

  2. Sino-implant (II) - a levonorgestrel-releasing two-rod implant: systematic review of the randomized controlled trials

    PubMed Central

    Steiner, Markus J.; Lopez, Laureen M.; Grimes, David A.; Cheng, Linan; Shelton, Jim; Trussell, James; Farley, Timothy M.M.; Dorflinger, Laneta

    2013-01-01

    Background Sino-implant (II) is a subdermal contraceptive implant manufactured in China. This two-rod levonorgestrel-releasing implant has the same amount of active ingredient (150 mg levonorgestrel) and mechanism of action as the widely available contraceptive implant Jadelle. We examined randomized controlled trials of Sino-implant (II) for effectiveness and side effects. Study design We searched electronic databases for studies of Sino-implant (II), and then restricted our review to randomized controlled trials. The primary outcome of this review was pregnancy. Results Four randomized trials with a total of 15,943 women assigned to Sino-implant (II) had first-year probabilities of pregnancy ranging from 0.0% to 0.1%. Cumulative probabilities of pregnancy during the four years of the product's approved duration of use were 0.9% and 1.06% in the two trials that presented date for four-year use. Five-year cumulative probabilities of pregnancy ranged from 0.7% to 2.1%. In one trial, the cumulative probability of pregnancy more than doubled during the fifth year (from 0.9% to 2.1%), which may be why the implant is approved for four years of use in China. Five-year cumulative probabilities of discontinuation due to menstrual problems ranged from 12.5% to 15.5% for Sino-implant (II). Conclusions Sino-implant (II) is one of the most effective contraceptives available today. These available clinical data, combined with independent laboratory testing, and the knowledge that 7 million women have used this method since 1994, support the safety and effectiveness of Sino-implant (II). The lower cost of Sino-implant (II) compared with other subdermal implants could improve access to implants in resource-constrained settings. PMID:20159174

  3. Traditional growing rod versus magnetically controlled growing rod for treatment of early onset scoliosis: Cost analysis from implantation till skeletal maturity.

    PubMed

    Wong, Carlos King Ho; Cheung, Jason Pui Yin; Cheung, Prudence Wing Hang; Lam, Cindy Lo Kuen; Cheung, Kenneth Man Chee

    2017-01-01

    To compare the yearly cost involved per patient in the use of magnetically controlled growing rod (MCGR) and traditional growing rods (TGRs) in the treatment of early onset scoliosis (EOS) and to assess the overall cost burden of MCGR with reference to patient and health-care infrastructure. For a hypothetical case of a 5-year-old girl with a diagnosis of EOS, a decision-tree model using TreeAge Software was developed to simulate annual health state transitions and compare the 8-year accumulative direct, indirect, and total cost among the four groups: (1) dual MCGRs with exchange every 2 years, (2) dual MCGRs with exchange every 3 years, (3) TGR with surgical distraction every year, and (4) TGR with surgical distraction every 6 months. Base-case values and ranges of clinical parameters reflecting complication rate after each type of surgical distraction were determined from a review of literature and expert opinion. Government gazette and expert opinion provided cost estimation of growing rods, surgeries, surgical complications, and routine follow-up. Microsimulation of 1000 individuals was conducted to test the variation in total direct costs (in 2016 Hong Kong dollars (HKD)) between individuals, and estimated the standard deviations of total direct costs for each group. Over the projected treatment period, indirect costs incurred by patients and family were higher for the MCGR as compared to the TGR. However, the total costs incurred by MCGR groups (group 1: HKD164k; group 2: HKD138k) were lower than those incurred by TGR groups (group 3: HKD191k; group 4: HKD290k). Although the accumulative costs of three groups (TGR with distraction every year and MCGR replacing every 2 and 3 years) were approaching each other in the first 2 years after initial implantation, at year 3 the accumulative cost of MCGR exchange every 2 years was HKD36k more than the yearly TGR surgery due to the cost of implant exchange. The cost incurred by both the MCGR groups was less than that

  4. Vortex Noise from Rotating Cylindrical Rods

    NASA Technical Reports Server (NTRS)

    Stowell, E Z; Deming, A F

    1935-01-01

    A series of round rods of the some diameter were rotated individually about the mid-point of each rod. Vortices are shed from the rods when in motion, giving rise to the emission of sound. With the rotating system placed in the open air, the distribution of sound in space, the acoustical power output, and the spectral distribution have been studied. The frequency of emission of vortices from any point on the rod is given by the formula von Karman. From the spectrum estimates are made of the distribution of acoustical power along the rod, the amount of air concerned in sound production, the "equivalent size" of the vortices, and the acoustical energy content for each vortex.

  5. Intraoperative pulmonary embolism of Harrington rod during spinal surgery: the potential dangers of rod cutting.

    PubMed

    Aylott, Caspar E W; Hassan, Kamran; McNally, Donal; Webb, John K

    2006-12-01

    This is a case report and laboratory-based biomechanics study. The objective is to report the first case of Titanium rod embolisation during scoliosis surgery into the Pulmonary artery. To investigate the potential of an unconstrained cut Titanium rod fragment to cause wounding with reference to recognised weapons. Embolisation of a foreign body to the heart is rare. Bullet embolisation to the heart and lungs is infrequently reported in the last 80 years. Iatrogenic cases of foreign body embolisation are very rare. Fifty 1-2 cm segments of Titanium rod were cut in an unconstrained manner and a novel method was used to calculate velocity. A high-speed camera (6,000 frames/s) was used to further measure velocity and study projectile motion. The wounding potential was investigated using lambs liver, high-speed photography and local dissection. Rod velocities were measured in excess of 23 m s(-1). Rods were seen to tumble end-over-end with a maximum speed of 560 revolutions/s. The maximum kinetic energy was 0.61 J which is approximately 2% that of a crossbow. This is sufficient to cause significant liver damage. The degree of surface damage and internal disruption was influenced by the orientation of the rod fragment at impact. An unconstrained cut segment of a Titanium rod has a significant potential to wound. Precautions should be taken to avoid this potentially disastrous but preventable complication.

  6. Large-eddy simulation, fuel rod vibration and grid-to-rod fretting in pressurized water reactors

    DOE PAGES

    Christon, Mark A.; Lu, Roger; Bakosi, Jozsef; ...

    2016-10-01

    Grid-to-rod fretting (GTRF) in pressurized water reactors is a flow-induced vibration phenomenon that results in wear and fretting of the cladding material on fuel rods. GTRF is responsible for over 70% of the fuel failures in pressurized water reactors in the United States. Predicting the GTRF wear and concomitant interval between failures is important because of the large costs associated with reactor shutdown and replacement of fuel rod assemblies. The GTRF-induced wear process involves turbulent flow, mechanical vibration, tribology, and time-varying irradiated material properties in complex fuel assembly geometries. This paper presents a new approach for predicting GTRF induced fuelmore » rod wear that uses high-resolution implicit large-eddy simulation to drive nonlinear transient dynamics computations. The GTRF fluid–structure problem is separated into the simulation of the turbulent flow field in the complex-geometry fuel-rod bundles using implicit large-eddy simulation, the calculation of statistics of the resulting fluctuating structural forces, and the nonlinear transient dynamics analysis of the fuel rod. Ultimately, the methods developed here, can be used, in conjunction with operational management, to improve reactor core designs in which fuel rod failures are minimized or potentially eliminated. Furthermore, robustness of the behavior of both the structural forces computed from the turbulent flow simulations and the results from the transient dynamics analyses highlight the progress made towards achieving a predictive simulation capability for the GTRF problem.« less

  7. Large-eddy simulation, fuel rod vibration and grid-to-rod fretting in pressurized water reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Christon, Mark A.; Lu, Roger; Bakosi, Jozsef

    Grid-to-rod fretting (GTRF) in pressurized water reactors is a flow-induced vibration phenomenon that results in wear and fretting of the cladding material on fuel rods. GTRF is responsible for over 70% of the fuel failures in pressurized water reactors in the United States. Predicting the GTRF wear and concomitant interval between failures is important because of the large costs associated with reactor shutdown and replacement of fuel rod assemblies. The GTRF-induced wear process involves turbulent flow, mechanical vibration, tribology, and time-varying irradiated material properties in complex fuel assembly geometries. This paper presents a new approach for predicting GTRF induced fuelmore » rod wear that uses high-resolution implicit large-eddy simulation to drive nonlinear transient dynamics computations. The GTRF fluid–structure problem is separated into the simulation of the turbulent flow field in the complex-geometry fuel-rod bundles using implicit large-eddy simulation, the calculation of statistics of the resulting fluctuating structural forces, and the nonlinear transient dynamics analysis of the fuel rod. Ultimately, the methods developed here, can be used, in conjunction with operational management, to improve reactor core designs in which fuel rod failures are minimized or potentially eliminated. Furthermore, robustness of the behavior of both the structural forces computed from the turbulent flow simulations and the results from the transient dynamics analyses highlight the progress made towards achieving a predictive simulation capability for the GTRF problem.« less

  8. The COPERNIC3 project: how AREVA is successfully developing an advanced global fuel rod performance code

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Garnier, Ch.; Mailhe, P.; Sontheimer, F.

    2007-07-01

    Fuel performance is a key factor for minimizing operating costs in nuclear plants. One of the important aspects of fuel performance is fuel rod design, based upon reliable tools able to verify the safety of current fuel solutions, prevent potential issues in new core managements and guide the invention of tomorrow's fuels. AREVA is developing its future global fuel rod code COPERNIC3, which is able to calculate the thermal-mechanical behavior of advanced fuel rods in nuclear plants. Some of the best practices to achieve this goal are described, by reviewing the three pillars of a fuel rod code: the database,more » the modelling and the computer and numerical aspects. At first, the COPERNIC3 database content is described, accompanied by the tools developed to effectively exploit the data. Then is given an overview of the main modelling aspects, by emphasizing the thermal, fission gas release and mechanical sub-models. In the last part, numerical solutions are detailed in order to increase the computational performance of the code, with a presentation of software configuration management solutions. (authors)« less

  9. Eulerian Formulation of Spatially Constrained Elastic Rods

    NASA Astrophysics Data System (ADS)

    Huynen, Alexandre

    Slender elastic rods are ubiquitous in nature and technology. For a vast majority of applications, the rod deflection is restricted by an external constraint and a significant part of the elastic body is in contact with a stiff constraining surface. The research work presented in this doctoral dissertation formulates a computational model for the solution of elastic rods constrained inside or around frictionless tube-like surfaces. The segmentation strategy adopted to cope with this complex class of problems consists in sequencing the global problem into, comparatively simpler, elementary problems either in continuous contact with the constraint or contact-free between their extremities. Within the conventional Lagrangian formulation of elastic rods, this approach is however associated with two major drawbacks. First, the boundary conditions specifying the locations of the rod centerline at both extremities of each elementary problem lead to the establishment of isoperimetric constraints, i.e., integral constraints on the unknown length of the rod. Second, the assessment of the unilateral contact condition requires, in principle, the comparison of two curves parametrized by distinct curvilinear coordinates, viz. the rod centerline and the constraint axis. Both conspire to burden the computations associated with the method. To streamline the solution along the elementary problems and rationalize the assessment of the unilateral contact condition, the rod governing equations are reformulated within the Eulerian framework of the constraint. The methodical exploration of both types of elementary problems leads to specific formulations of the rod governing equations that stress the profound connection between the mechanics of the rod and the geometry of the constraint surface. The proposed Eulerian reformulation, which restates the rod local equilibrium in terms of the curvilinear coordinate associated with the constraint axis, describes the rod deformed configuration

  10. LOGIC CIRCUIT

    DOEpatents

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  11. The development of a thermal hydraulic feedback mechanism with a quasi-fixed point iteration scheme for control rod position modeling for the TRIGSIMS-TH application

    NASA Astrophysics Data System (ADS)

    Karriem, Veronica V.

    Nuclear reactor design incorporates the study and application of nuclear physics, nuclear thermal hydraulic and nuclear safety. Theoretical models and numerical methods implemented in computer programs are utilized to analyze and design nuclear reactors. The focus of this PhD study's is the development of an advanced high-fidelity multi-physics code system to perform reactor core analysis for design and safety evaluations of research TRIGA-type reactors. The fuel management and design code system TRIGSIMS was further developed to fulfill the function of a reactor design and analysis code system for the Pennsylvania State Breazeale Reactor (PSBR). TRIGSIMS, which is currently in use at the PSBR, is a fuel management tool, which incorporates the depletion code ORIGEN-S (part of SCALE system) and the Monte Carlo neutronics solver MCNP. The diffusion theory code ADMARC-H is used within TRIGSIMS to accelerate the MCNP calculations. It manages the data and fuel isotopic content and stores it for future burnup calculations. The contribution of this work is the development of an improved version of TRIGSIMS, named TRIGSIMS-TH. TRIGSIMS-TH incorporates a thermal hydraulic module based on the advanced sub-channel code COBRA-TF (CTF). CTF provides the temperature feedback needed in the multi-physics calculations as well as the thermal hydraulics modeling capability of the reactor core. The temperature feedback model is using the CTF-provided local moderator and fuel temperatures for the cross-section modeling for ADMARC-H and MCNP calculations. To perform efficient critical control rod calculations, a methodology for applying a control rod position was implemented in TRIGSIMS-TH, making this code system a modeling and design tool for future core loadings. The new TRIGSIMS-TH is a computer program that interlinks various other functional reactor analysis tools. It consists of the MCNP5, ADMARC-H, ORIGEN-S, and CTF. CTF was coupled with both MCNP and ADMARC-H to provide the

  12. 46 CFR 61.30-20 - Automatic control and safety tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Automatic control and safety tests. 61.30-20 Section 61... TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-20 Automatic control and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

  13. Intelligent vehicle safety control strategy in various driving situations

    NASA Astrophysics Data System (ADS)

    Moon, Seungwuk; Cho, Wanki; Yi, Kyongsu

    2010-12-01

    This paper describes a safety control strategy for intelligent vehicles with the objective of optimally coordinating the throttle, brake, and active front steering actuator inputs to obtain both lateral stability and longitudinal safety. The control system consists of a supervisor, control algorithms, and a coordinator. From the measurement and estimation signals, the supervisor determines the active control modes among normal driving, longitudinal safety, lateral stability, and integrated safety control mode. The control algorithms consist of longitudinal and lateral stability controllers. The longitudinal controller is designed to improve the driver's comfort during normal, safe-driving situations, and to avoid rear-end collision in vehicle-following situations. The lateral stability controller is designed to obtain the required manoeuvrability and to limit the vehicle body's side-slip angle. To obtain both longitudinal safety and lateral stability control in various driving situations, the coordinator optimally determines the throttle, brake, and active front steering inputs based on the current status of the subject vehicle. Closed-loop simulations with the driver-vehicle-controller system are conducted to investigate the performance of the proposed control strategy. From these simulation results, it is shown that the proposed control algorithm assists the driver in combined severe braking/large steering manoeuvring so that the driver can maintain good manoeuvrability and prevent the vehicle from crashing in vehicle-following situations.

  14. Convergent synthesis of multiporphyrin light-harvesting rods

    DOEpatents

    Lindsey, Jonathan S.; Loewe, Robert S.

    2003-08-05

    The present invention provides a convergent method for the synthesis of light harvesting rods. The rods are oligomers of the formula A.sup.1 (A.sup.b+1).sub.b, wherein b is at least 1, A.sup.1 through A.sup.b+1 are covalently coupled rod segments, and each rod segment A.sup.1 through A.sup.1+b comprises a compound of the formula X.sup.1 (X.sup.m+1).sub.m wherein m is at least 1 and X.sup.1 through X.sup.m+1 are covalently coupled porphyrinic macrocycles. Light harvesting arrays and solar cells containing such light harvesting rods are also described, along with intermediates useful in such methods and rods produced by such methods.

  15. Final report, PT IP-535-C: Test of smaller VSR`s in DR reactor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vaughn, A.D.

    1963-04-17

    Because of rod-sticking problems at DR Reactor, a knuckle rod of B Reactor design was installed in vertical safety channel number 28. The substitute VSR, which has a smaller diameter than the original DR rod, has been tested for its operational feasibility including both drop time and reactivity effect. The reactivity effect of the rod was estimated by comparison of the reactivity transient caused by insertion of the specific B-type rod after scramming into the pile, with similar transients caused by normal vertical safety rod in an adjacent channel. This document lists the indicated relative control strength of the rodmore » as an empirical basis for future safety calculations. Results indicate that the B-type knuckel rod in DR reactor is about 80% as strong as a normal DR vertical safety rod if used in equivalent flux distribution and location; this makes it reasonable to assume that the local control strength of the B-type knuckel rod is 98 {mu}b.« less

  16. 21 CFR 876.4270 - Colostomy rod.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Colostomy rod. 876.4270 Section 876.4270 Food and... GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4270 Colostomy rod. (a) Identification. A colostomy rod is a device used during the loop colostomy procedure. A loop of colon is surgically brought out through...

  17. Learned arbitrary responses to light in mice without rods or cones

    NASA Astrophysics Data System (ADS)

    Mrosovsky, N.; Salmon, Peggy

    2002-10-01

    The aim of this investigation was to discover whether mice lacking classical photoreceptors (rods and cones) can nevertheless be trained to respond to light. Mice with the coneless (cl) transgene have an attenuated diphtheria toxin fused to a cone opsin promotor. Mutant mice homozygous for the retinal degeneration (rd) gene undergo loss of their rods. By mating these two strains, mice lacking both cones and rods can be generated (Lucas et al. 1999). Such coneless-rodless mice were able to use light as a signal to make a behavioural response to avoid impending shock. Nevertheless, especially initially, they used the light as a cue less often than wildtype controls, indicating that normally the rods and cones are used for such responses. However, other photoreceptors are able to take over this role to some extent. When the lights were covered with opaque material, the performance of rodless-coneless mice dropped to chance level, indicating that they had been using the light as a cue for avoidance.

  18. Stimulus-evoked outer segment changes in rod photoreceptors

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaohui; Thapa, Damber; Wang, Benquan; Lu, Yiming; Gai, Shaoyan; Yao, Xincheng

    2016-06-01

    Rod-dominated transient retinal phototropism (TRP) has been recently observed in freshly isolated mouse and frog retinas. Comparative confocal microscopy and optical coherence tomography revealed that the TRP was predominantly elicited from the rod outer segment (OS). However, the biophysical mechanism of rod OS dynamics is still unknown. Mouse and frog retinal slices, which displayed a cross-section of retinal photoreceptors and other functional layers, were used to test the effect of light stimulation on rod OSs. Time-lapse microscopy revealed stimulus-evoked conformational changes of rod OSs. In the center of the stimulated region, the length of the rod OS shrunk, while in the peripheral region, the rod OS swung toward the center region. Our experimental observation and theoretical analysis suggest that the TRP may reflect unbalanced rod disc-shape changes due to localized visible light stimulation.

  19. Stimulus-evoked outer segment changes in rod photoreceptors

    PubMed Central

    Zhao, Xiaohui; Thapa, Damber; Wang, Benquan; Lu, Yiming; Gai, Shaoyan; Yao, Xincheng

    2016-01-01

    Abstract. Rod-dominated transient retinal phototropism (TRP) has been recently observed in freshly isolated mouse and frog retinas. Comparative confocal microscopy and optical coherence tomography revealed that the TRP was predominantly elicited from the rod outer segment (OS). However, the biophysical mechanism of rod OS dynamics is still unknown. Mouse and frog retinal slices, which displayed a cross-section of retinal photoreceptors and other functional layers, were used to test the effect of light stimulation on rod OSs. Time-lapse microscopy revealed stimulus-evoked conformational changes of rod OSs. In the center of the stimulated region, the length of the rod OS shrunk, while in the peripheral region, the rod OS swung toward the center region. Our experimental observation and theoretical analysis suggest that the TRP may reflect unbalanced rod disc-shape changes due to localized visible light stimulation. PMID:27334933

  20. 46 CFR 61.30-20 - Automatic control and safety tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC... and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

  1. 46 CFR 61.30-20 - Automatic control and safety tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC... and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

  2. 46 CFR 61.30-20 - Automatic control and safety tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC... and safety tests. Operational tests and checks of all safety and limit controls, combustion controls...

  3. 46 CFR 62.25-15 - Safety control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Safety control systems. 62.25-15 Section 62.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION General Requirements for All Automated Vital Systems § 62.25-15 Safety control systems. (a...

  4. Impact of nonabsorbing control rod tips on kinetics feedback for BWR turbine trip without bypass RETRAN-03 analyses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feltus, M.A.; Knerr, R.; Shoop, U.

    1993-01-01

    RETRAN-03 studies were performed for the boiling water reactor (BWR) turbine trip without bypass (TTWOB) event to investigate how the non-neutron-absorbing material on control rod tips affect scram delay timing and reactivity feedback. Scram delay, Doppler temperature, and moderator void (density) feedback were varied to assess their relative impact on kinetics behavior. Although a generic point-kinetics RETRAN-03 TTWOB model 2 was employed, actual plant information was used to develop the basic and parametric cases.

  5. The Moment of Inertia of a Rectangular Rod

    NASA Astrophysics Data System (ADS)

    Takeuchi, Takao

    2007-11-01

    Recently an inexpensive setup to obtain the moment of inertia of a rotating system was proposed by Peter E. Banks. An equally simple and inexpensive experiment to obtain the moment of inertia of a uniform rod is proposed in this paper. A rectangular rod with a hole somewhere in the rod was used for this purpose. The moment of inertia of a rectangular rod around the hole location was attempted. The experimental setup is shown in Fig. 1. Various supporting rods, clamps, and rubber stoppers to hold the rectangular rod in place at point p are not shown.

  6. Modeling and simulation performance of sucker rod beam pump

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aditsania, Annisa, E-mail: annisaaditsania@gmail.com; Rahmawati, Silvy Dewi, E-mail: silvyarahmawati@gmail.com; Sukarno, Pudjo, E-mail: psukarno@gmail.com

    2015-09-30

    Artificial lift is a mechanism to lift hydrocarbon, generally petroleum, from a well to surface. This is used in the case that the natural pressure from the reservoir has significantly decreased. Sucker rod beam pumping is a method of artificial lift. Sucker rod beam pump is modeled in this research as a function of geometry of the surface part, the size of sucker rod string, and fluid properties. Besides its length, sucker rod string also classified into tapered and un-tapered. At the beginning of this research, for easy modeling, the sucker rod string was assumed as un-tapered. The assumption provedmore » non-realistic to use. Therefore, the tapered sucker rod string modeling needs building. The numerical solution of this sucker rod beam pump model is computed using finite difference method. The numerical result shows that the peak of polished rod load for sucker rod beam pump unit C-456-D-256-120, for non-tapered sucker rod string is 38504.2 lb, while for tapered rod string is 25723.3 lb. For that reason, to avoid the sucker rod string breaks due to the overload, the use of tapered sucker rod beam string is suggested in this research.« less

  7. In vitro degradation, flexural, compressive and shear properties of fully bioresorbable composite rods.

    PubMed

    Felfel, R M; Ahmed, I; Parsons, A J; Walker, G S; Rudd, C D

    2011-10-01

    Several studies have investigated self-reinforced polylactic acid (SR-PLA) and polyglycolic acid (SR-PGA) rods which could be used as intramedullary (IM) fixation devices to align and stabilise bone fractures. This study investigated totally bioresorbable composite rods manufactured via compression moulding at ~100 °C using phosphate glass fibres (of composition 50P(2)O(5)-40CaO-5Na(2)O-5Fe(2)O(3) in mol%) to reinforce PLA with an approximate fibre volume fraction (v(f)) of 30%. Different fibre architectures (random and unidirectional) were investigated and pure PLA rods were used as control samples. The degradation profiles and retention of mechanical properties were investigated and PBS was selected as the degradation medium. Unidirectional (P50 UD) composite rods had 50% higher initial flexural strength as compared to PLA and 60% higher in comparison to the random mat (P50 RM) composite rods. Similar initial profiles for flexural modulus were also seen comparing the P50 UD and P50 RM rods. Higher shear strength properties were seen for P50 UD in comparison to P50 RM and PLA rods. However, shear stiffness values decreased rapidly (after a week) whereas the PLA remained approximately constant. For the compressive strength studies, P50 RM and PLA rods remained approximately constant, whilst for the P50 UD rods a significantly higher initial value was obtained, which decreased rapidly after 3 days immersion in PBS. However, the mechanical properties decreased after immersion in PBS as a result of the plasticisation effect of water within the composite and degradation of the fibres. The fibres within the random and unidirectional composite rods (P50 RM and P50 UD) degraded leaving behind microtubes as seen from the SEM micrographs (after 28 days degradation) which in turn created a porous structure within the rods. This was the main reason attributed for the increase seen in mass loss and water uptake for the composite rods (~17% and ~16%, respectively). Copyright

  8. Crystal truncation rods from miscut surfaces

    DOE PAGES

    Petach, Trevor A.; Mehta, Apurva; Toney, Michael F.; ...

    2017-05-08

    Crystal truncation rods are used to study surface and interface structure. Since real surfaces are always somewhat miscut from a low index plane, it is important to study the effect of miscuts on crystal truncation rods. We develop a model that describes the truncation rod scattering from miscut surfaces that have steps and terraces. We show that nonuniform terrace widths and jagged step edges are both forms of roughness that decrease the intensity of the rods. Nonuniform terrace widths also result in a broad peak that overlaps the rods. We use our model to characterize the terrace width distribution andmore » step edge jaggedness on three SrTiO 3 (001) samples, showing excellent agreement between the model and the data, confirmed by atomic force micrographs of the surface morphology. As a result, we expect our description of terrace roughness will apply to many surfaces, even those without obvious terracing.« less

  9. Granular materials interacting with thin flexible rods

    NASA Astrophysics Data System (ADS)

    Neto, Alfredo Gay; Campello, Eduardo M. B.

    2017-04-01

    In this work, we develop a computational model for the simulation of problems wherein granular materials interact with thin flexible rods. We treat granular materials as a collection of spherical particles following a discrete element method (DEM) approach, while flexible rods are described by a large deformation finite element (FEM) rod formulation. Grain-to-grain, grain-to-rod, and rod-to-rod contacts are fully permitted and resolved. A simple and efficient strategy is proposed for coupling the motion of the two types (discrete and continuum) of materials within an iterative time-stepping solution scheme. Implementation details are shown and discussed. Validity and applicability of the model are assessed by means of a few numerical examples. We believe that robust, efficiently coupled DEM-FEM schemes can be a useful tool to the simulation of problems wherein granular materials interact with thin flexible rods, such as (but not limited to) bombardment of grains on beam structures, flow of granular materials over surfaces covered by threads of hair in many biological processes, flow of grains through filters and strainers in various industrial segregation processes, and many others.

  10. Control centers design for ergonomics and safety.

    PubMed

    Quintana, Leonardo; Lizarazo, Cesar; Bernal, Oscar; Cordoba, Jorge; Arias, Claudia; Monroy, Magda; Cotrino, Carlos; Montoya, Olga

    2012-01-01

    This paper shows the general design conditions about ergonomics and safety for control centers in the petrochemical process industry. Some of the topics include guidelines for the optimized workstation design, control room layout, building layout, and lighting, acoustical and environmental design. Also takes into account the safety parameters in the control rooms and centers design. The conditions and parameters shown in this paper come from the standards and global advances on this topic on the most recent publications. And also the work was supplemented by field visits of our team to the control center operations in a petrochemical company, and technical literature search efforts. This guideline will be useful to increase the productivity and improve the working conditions at the control rooms.

  11. Safety in the Chemical Laboratory: Fire Safety and Fire Control in the Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Wilbraham, A. C.

    1979-01-01

    Discusses fire safety and fire control in the chemistry laboratory. The combustion process, extinguishing equipment, extinguisher maintenance and location, and fire safety and practices are included. (HM)

  12. Compact Hybrid Laser Rod and Laser System

    NASA Technical Reports Server (NTRS)

    Pierrottet, Diego F. (Inventor); Busch, George E. (Inventor); Amzajerdian, Farzin (Inventor)

    2017-01-01

    A hybrid fiber rod includes a fiber core and inner and outer cladding layers. The core is doped with an active element. The inner cladding layer surrounds the core, and has a refractive index substantially equal to that of the core. The outer cladding layer surrounds the inner cladding layer, and has a refractive index less than that of the core and inner cladding layer. The core length is about 30 to 2000 times the core diameter. A hybrid fiber rod laser system includes an oscillator laser, modulating device, the rod, and pump laser diode(s) energizing the rod from opposite ends. The rod acts as a waveguide for pump radiation but allows for free-space propagation of laser radiation. The rod may be used in a laser resonator. The core length is less than about twice the Rayleigh range. Degradation from single-mode to multi-mode beam propagation is thus avoided.

  13. Evaluation of ceramic packed-rod regenerator matrices

    NASA Technical Reports Server (NTRS)

    Lawless, W. N.; Arenz, R. W.

    1981-01-01

    An extensive evaluation of a modified cryocooler with various regenerator matrices is reported. The matrices examined are 0.015 in. diam. Pb spheres and 0.008, 0.015, and 0.030 in. diam. rods of a 0.2% SnCl2 doped ceramic labelled LS-8A. Specific heat and thermal conductivity data on these rod materials are also reported. The chronic pulverization/dusting problem common to Pb spheres was investigated. During a 1000 hr life test with 0.0008 in. diam. rods there was no degradation of the refrigerator performance, and a subsequent examination of the rods themselves revealed no evidence of breakage or pulverization. The load temperature characteristics for the rod packed regenerators were inferior to that for the Pb spheres, the effect being to shift the Pb spheres load curve up in temperature. This temperature shift was 5.0, 7.4, and 11.6K for the 0.0008, 0.015, and 0.030 in. diam. rods, respectively.

  14. Statistical properties of a folded elastic rod

    NASA Astrophysics Data System (ADS)

    Bayart, Elsa; Deboeuf, Stéphanie; Boué, Laurent; Corson, Francis; Boudaoud, Arezki; Adda-Bedia, Mokhtar

    2010-03-01

    A large variety of elastic structures naturally seem to be confined into environments too small to accommodate them; the geometry of folded structures span a wide range of length-scales. The elastic properties of these confined systems are further constrained by self-avoidance as well as by the dimensionality of both structures and container. To mimic crumpled paper, we devised an experimental setup to study the packing of a dimensional elastic object in 2D geometries: an elastic rod is folded at the center of a circular Hele-Shaw cell by a centripetal force. The initial configuration of the rod and the acceleration of the rotating disk allow to span different final folded configurations while the final rotation speed controls the packing intensity. Using image analysis we measure geometrical and mechanical properties of the folded configurations, focusing on length, curvature and energy distributions.

  15. Cuisenaire Rods Go to College.

    ERIC Educational Resources Information Center

    Chinn, Phyllis; And Others

    1992-01-01

    Presents examples of questions and answers arising from a hands-on and exploratory approach to discrete mathematics using cuisenaire rods. Combinatorial questions about trains formed of cuisenaire rods provide the setting for discovering numerical patterns by experimentation and organizing the results using induction and successive differences.…

  16. CONTROL FOR NEUTRONIC REACTOR

    DOEpatents

    Lichtenberger, H.V.; Cameron, R.A.

    1959-03-31

    S>A control rod operating device in a nuclear reactor of the type in which the control rod is gradually withdrawn from the reactor to a position desired during stable operation is described. The apparatus is comprised essentially of a stop member movable in the direction of withdrawal of the control rod, a follower on the control rod engageable with the stop and means urging the follower against the stop in the direction of withdrawal. A means responsive to disengagement of the follower from the stop is provided for actuating the control rod to return to the reactor shut-down position.

  17. Combustion of solid carbon rods in zero and normal gravity. Ph.D. Thesis - Toledo Univ., Ohio

    NASA Technical Reports Server (NTRS)

    Spuckler, C. M.

    1981-01-01

    In order to investigate the mechanism of carbon combustion and to assess the importance of gravitational induced convection on the process, zero and normal gravity experiments were conducted in which spectroscopic carbon rods were resistance ignitied and burned in dry oxygen environments. In the zero-gravity drop tower tests, a blue flame surrounded the rod, showing that a gas phase reaction in which carbon monoxide was oxidized to carbon dioxide was taking place. The ratio of flame diameter to rod diameter was obtained as a function of time. It was found that this ratio was inversely proportional to both the oxygen pressure and the rod diameter. In the normal gravity tests, direct mass spectrometric sampling was used to measure gas phase concentrations. The gas sampling probe was positioned near the circumference of a horizontally mounted 0.615 cm diameter carbon rod, either at the top or at angles of 45 deg to 90 deg from the top, and yielded concentration profiles of CO2, CO, and O2 as a function of distance from the surface. The mechanism controlling the combustion process was found to change from chemical process control at the 90 deg and 45 deg probe positions to mass transfer control at the 0 deg probe position at the top of the rod. Under the experimental conditions used, carbon combustion was characterized by two surface reactions, 2C + O2 yields 2CO and CO2 + C yields 2CO, and a gas phase reaction, 2CO + O2 yields 2CO2.

  18. Air traffic controller lightning strike.

    PubMed Central

    Spieth, M. E.; Kimura, R. L.; Schryer, T. D.

    1994-01-01

    Andersen Air Force Base in Guam boasts the tallest control tower in the Air Force. In 1986, an air traffic controller was struck by lightning as the bolt proceeded through the tower. Although he received only a backache, the lightning left a hole with surrounding scorch marks on his fatigue shirt and his undershirt. The lightning strike also ignited a portion of the field lighting panel, which caused the runway lights to go out immediately. Lack of a lightning rod is the most likely reason the controller was struck. Proper precautions against lightning strikes can prevent such occupational safety hazards. PMID:7966436

  19. Measurements of lightning rod responses to nearby strikes

    NASA Astrophysics Data System (ADS)

    Moore, C. B.; Aulich, G. D.; Rison, W.

    2000-05-01

    Following Benjamin Franklin's invention of the lightning rod, based on his discovery that electrified objects could be discharged by approaching them with a metal needle in hand, conventional lightning rods in the U.S. have had sharp tips. In recent years, the role of the sharp tip in causing a lightning rod to act as a strike receptor has been questioned leading to experiments in which pairs of various sharp-tipped and blunt rods have been exposed beneath thunderclouds to determine the better strike receptor. After seven years of tests, none of the sharp Franklin rods or of the so-called “early streamer emitters” has been struck, but 12 blunt rods with tip diameters ranging from 12.7 mm to 25.4 mm have taken strikes. Our field experiments and our analyses indicate that the strike-reception probabilities of Franklin's rods are greatly increased when their tips are made moderately blunt.

  20. The evolution of rod photoreceptors

    PubMed Central

    Morshedian, Ala

    2017-01-01

    Photoreceptors in animals are generally of two kinds: the ciliary or c-type and the rhabdomeric or r-type. Although ciliary photoreceptors are found in many phyla, vertebrates seem to be unique in having two distinct kinds which together span the entire range of vision, from single photons to bright light. We ask why the principal photoreceptors of vertebrates are ciliary and not rhabdomeric, and how rods evolved from less sensitive cone-like photoreceptors to produce our duplex retina. We suggest that the principal advantage of vertebrate ciliary receptors is that they use less ATP than rhabdomeric photoreceptors. This difference may have provided sufficient selection pressure for the development of a completely ciliary eye. Although many of the details of rod evolution are still uncertain, present evidence indicates that (i) rods evolved very early before the split between the jawed and jawless vertebrates, (ii) outer-segment discs make no contribution to rod sensitivity but may have evolved to increase the efficiency of protein renewal, and (iii) evolution of the rod was incremental and multifaceted, produced by the formation of several novel protein isoforms and by changes in protein expression, with no one alteration having more than a few-fold effect on transduction activation or inactivation. This article is part of the themed issue ‘Vision in dim light’. PMID:28193819

  1. The evolution of rod photoreceptors.

    PubMed

    Morshedian, Ala; Fain, Gordon L

    2017-04-05

    Photoreceptors in animals are generally of two kinds: the ciliary or c-type and the rhabdomeric or r-type. Although ciliary photoreceptors are found in many phyla, vertebrates seem to be unique in having two distinct kinds which together span the entire range of vision, from single photons to bright light. We ask why the principal photoreceptors of vertebrates are ciliary and not rhabdomeric, and how rods evolved from less sensitive cone-like photoreceptors to produce our duplex retina. We suggest that the principal advantage of vertebrate ciliary receptors is that they use less ATP than rhabdomeric photoreceptors. This difference may have provided sufficient selection pressure for the development of a completely ciliary eye. Although many of the details of rod evolution are still uncertain, present evidence indicates that (i) rods evolved very early before the split between the jawed and jawless vertebrates, (ii) outer-segment discs make no contribution to rod sensitivity but may have evolved to increase the efficiency of protein renewal, and (iii) evolution of the rod was incremental and multifaceted, produced by the formation of several novel protein isoforms and by changes in protein expression, with no one alteration having more than a few-fold effect on transduction activation or inactivation.This article is part of the themed issue 'Vision in dim light'. © 2017 The Author(s).

  2. Competing mechanisms in the wear resistance behavior of biomineralized rod-like microstructures

    NASA Astrophysics Data System (ADS)

    Escobar de Obaldia, Enrique; Herrera, Steven; Grunenfelder, Lessa Kay; Kisailus, David; Zavattieri, Pablo

    2016-11-01

    The remarkable mechanical properties observed in biological composite materials relative to those of their individual constituents distinguish them from common engineering materials. Some naturally occurring high-performance ceramics, like the external veneer of the Chiton (Cryptochiton stelleri) tooth, have been shown to have superior hardness and impressive abrasion resistance properties. The mechanical performance of the chiton tooth has been attributed to a hierarchical arrangement of nanostructured magnetite rods surrounded with organic material. While nanoindentation tests provide useful information about the overall performance of this biological composite, understanding the key microstructural features and energy dissipation mechanisms at small scales remains a challenging task. We present a combined experimental/numerical approach to elucidate the role of material deformation in the rods, debonding at the rod interfaces and the influence of energy dissipation mechanisms on the ability of the microstructure to distribute damage under extreme loading conditions. We employ a 3D finite element-based micromechanical model to simulate the nanoindentation tests performed in geological magnetite and cross-sections of the chiton tooth. This proposed model is capable of capturing the inelastic deformation of the rods and the failure of their interfaces, while damage, fracture and fragmentation of the mineralized rods is assessed using a probabilistic function. Our results show that these natural materials achieve their abrasion resistant properties by controlling the interface strength between rods, alleviating the tensile stress on the rods near the indentation tip and therefore decreasing the probability of catastrophic failure without significantly sacrificing resistance to penetration. The understanding of these competing energy dissipating mechanisms provides a path to the prediction of new combination of materials. In turns, these results suggest certain

  3. CONTROL SYSTEM FOR NEUTRONIC REACTORS

    DOEpatents

    Crever, F.E.

    1962-05-01

    BS>A slow-acting shim rod for control of major variations in reactor neutron flux and a fast-acting control rod to correct minor flux variations are employed to provide a sensitive, accurate control system. The fast-acting rod is responsive to an error signal which is produced by changes in the neutron flux from a predetermined optimum level. When the fast rod is thus actuated in a given direction, means is provided to actuate the slow-moving rod in that direction to return the fast rod to a position near the midpoint of its control range. (AEC)

  4. Crippling Strength of Axially Loaded Rods

    NASA Technical Reports Server (NTRS)

    Natalis, FR

    1921-01-01

    A new empirical formula was developed that holds good for any length and any material of a rod, and agrees well with the results of extensive strength tests. To facilitate calculations, three tables are included, giving the crippling load for solid and hollow sectioned wooden rods of different thickness and length, as well as for steel tubes manufactured according to the standards of Army Air Services Inspection. Further, a graphical method of calculation of the breaking load is derived in which a single curve is employed for determination of the allowable fiber stress. Finally, the theory is discussed of the elastic curve for a rod subject to compression, according to which no deflection occurs, and the apparent contradiction of this conclusion by test results is attributed to the fact that the rods under test are not perfectly straight, or that the wall thickness and the material are not uniform. Under the assumption of an eccentric rod having a slight initial bend according to a sine curve, a simple formula for the deflection is derived, which shows a surprising agreement with test results. From this a further formula is derived for the determination of the allowable load on an eccentric rod. The resulting relations are made clearer by means of a graphical representation of the relation of the moments of the outer and inner forces to the deflection.

  5. Casting technology for manufacturing metal rods from simulated metallic spent fuels

    NASA Astrophysics Data System (ADS)

    Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

    2000-09-01

    A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

  6. The effect of different screw-rod design on the anti-rotational torque: a biomechanical comparison of three conventional screw-rod constructs.

    PubMed

    Huang, Zifang; Wang, Chongwen; Fan, Hengwei; Sui, Wenyuan; Li, Xueshi; Wang, Qifei; Yang, Junlin

    2017-07-28

    Screw-rod constructs have been widely used to correct spinal deformities, but the effects of different screw-rod systems on anti-rotational torque have not been determined. This study aimed to analyze the biomechanical effect of different rod-screw constructs on anti-rotational torque. Three conventional spinal screw-rod systems (Legacy, RF-F-10 and USSII) were used to test the anti-rotational torque in the material test machine. ANOVA was performed to evaluate the anti-rotational capacity of different pedicle screws-rod constructs. The anti-rotational torque of Legacy group, RF-F-10 group and USSII group were 12.3 ± 1.9 Nm, 6.8 ± 0.4 Nm, and 3.9 ± 0.8 Nm, with a P value lower than 0.05. This results indicated that the Legacy screws-rod construct could provide a highest anti-rotation capacity, which is 68% and 210% greater than RF-F-10 screw-rod construct and USSII screw-rod respectively. The anti-rotational torque may be mainly affected by screw cap and groove design. Our result showed the anti-rotational torque are: Legacy system > RF-F-10 system > USSII system, suggesting that appropriate rod-screw constructs selection in surgery may be vital for anti-rotational torque improvement and preventing derotation correction loss.

  7. Brownian dynamics simulations with stiff finitely extensible nonlinear elastic-Fraenkel springs as approximations to rods in bead-rod models.

    PubMed

    Hsieh, Chih-Chen; Jain, Semant; Larson, Ronald G

    2006-01-28

    A very stiff finitely extensible nonlinear elastic (FENE)-Fraenkel spring is proposed to replace the rigid rod in the bead-rod model. This allows the adoption of a fast predictor-corrector method so that large time steps can be taken in Brownian dynamics (BD) simulations without over- or understretching the stiff springs. In contrast to the simple bead-rod model, BD simulations with beads and FENE-Fraenkel (FF) springs yield a random-walk configuration at equilibrium. We compare the simulation results of the free-draining bead-FF-spring model with those for the bead-rod model in relaxation, start-up of uniaxial extensional, and simple shear flows, and find that both methods generate nearly identical results. The computational cost per time step for a free-draining BD simulation with the proposed bead-FF-spring model is about twice as high as the traditional bead-rod model with the midpoint algorithm of Liu [J. Chem. Phys. 90, 5826 (1989)]. Nevertheless, computations with the bead-FF-spring model are as efficient as those with the bead-rod model in extensional flow because the former allows larger time steps. Moreover, the Brownian contribution to the stress for the bead-FF-spring model is isotropic and therefore simplifies the calculation of the polymer stresses. In addition, hydrodynamic interaction can more easily be incorporated into the bead-FF-spring model than into the bead-rod model since the metric force arising from the non-Cartesian coordinates used in bead-rod simulations is absent from bead-spring simulations. Finally, with our newly developed bead-FF-spring model, existing computer codes for the bead-spring models can trivially be converted to ones for effective bead-rod simulations merely by replacing the usual FENE or Cohen spring law with a FENE-Fraenkel law, and this convertibility provides a very convenient way to perform multiscale BD simulations.

  8. Brownian dynamics simulations with stiff finitely extensible nonlinear elastic-Fraenkel springs as approximations to rods in bead-rod models

    NASA Astrophysics Data System (ADS)

    Hsieh, Chih-Chen; Jain, Semant; Larson, Ronald G.

    2006-01-01

    A very stiff finitely extensible nonlinear elastic (FENE)-Fraenkel spring is proposed to replace the rigid rod in the bead-rod model. This allows the adoption of a fast predictor-corrector method so that large time steps can be taken in Brownian dynamics (BD) simulations without over- or understretching the stiff springs. In contrast to the simple bead-rod model, BD simulations with beads and FENE-Fraenkel (FF) springs yield a random-walk configuration at equilibrium. We compare the simulation results of the free-draining bead-FF-spring model with those for the bead-rod model in relaxation, start-up of uniaxial extensional, and simple shear flows, and find that both methods generate nearly identical results. The computational cost per time step for a free-draining BD simulation with the proposed bead-FF-spring model is about twice as high as the traditional bead-rod model with the midpoint algorithm of Liu [J. Chem. Phys. 90, 5826 (1989)]. Nevertheless, computations with the bead-FF-spring model are as efficient as those with the bead-rod model in extensional flow because the former allows larger time steps. Moreover, the Brownian contribution to the stress for the bead-FF-spring model is isotropic and therefore simplifies the calculation of the polymer stresses. In addition, hydrodynamic interaction can more easily be incorporated into the bead-FF-spring model than into the bead-rod model since the metric force arising from the non-Cartesian coordinates used in bead-rod simulations is absent from bead-spring simulations. Finally, with our newly developed bead-FF-spring model, existing computer codes for the bead-spring models can trivially be converted to ones for effective bead-rod simulations merely by replacing the usual FENE or Cohen spring law with a FENE-Fraenkel law, and this convertibility provides a very convenient way to perform multiscale BD simulations.

  9. Scoliosis corrective force estimation from the implanted rod deformation using 3D-FEM analysis.

    PubMed

    Abe, Yuichiro; Ito, Manabu; Abumi, Kuniyoshi; Sudo, Hideki; Salmingo, Remel; Tadano, Shigeru

    2015-01-01

    Improvement of material property in spinal instrumentation has brought better deformity correction in scoliosis surgery in recent years. The increase of mechanical strength in instruments directly means the increase of force, which acts on bone-implant interface during scoliosis surgery. However, the actual correction force during the correction maneuver and safety margin of pull out force on each screw were not well known. In the present study, estimated corrective forces and pull out forces were analyzed using a novel method based on Finite Element Analysis (FEA). Twenty adolescent idiopathic scoliosis patients (1 boy and 19 girls) who underwent reconstructive scoliosis surgery between June 2009 and Jun 2011 were included in this study. Scoliosis correction was performed with 6mm diameter titanium rod (Ti6Al7Nb) using the simultaneous double rod rotation technique (SDRRT) in all cases. The pre-maneuver and post-maneuver rod geometry was collected from intraoperative tracing and postoperative 3D-CT images, and 3D-FEA was performed with ANSYS. Cobb angle of major curve, correction rate and thoracic kyphosis were measured on X-ray images. Average age at surgery was 14.8, and average fusion length was 8.9 segments. Major curve was corrected from 63.1 to 18.1 degrees in average and correction rate was 71.4%. Rod geometry showed significant change on the concave side. Curvature of the rod on concave and convex sides decreased from 33.6 to 17.8 degrees, and from 25.9 to 23.8 degrees, respectively. Estimated pull out forces at apical vertebrae were 160.0N in the concave side screw and 35.6N in the convex side screw. Estimated push in force at LIV and UIV were 305.1N in the concave side screw and 86.4N in the convex side screw. Corrective force during scoliosis surgery was demonstrated to be about four times greater in the concave side than in convex side. Averaged pull out and push in force fell below previously reported safety margin. Therefore, the SDRRT maneuver was

  10. The actin-activated ATPase of co-polymer filaments of myosin and myosin-rod.

    PubMed Central

    Stepkowski, D; Orlova, A A; Moos, C

    1994-01-01

    The actin activated ATPase of myosin at low ionic strength shows a complex dependence on actin concentration, in contrast with the simple hyperbolic actin activation kinetics of heavy meromyosin and subfragment-1. To investigate how the aggregation of myosin influences the actomyosin ATPase kinetics, we have studied the actin-activated ATPase of mixed filaments in which the myosin molecules are separated from each other by copolymerization with myosin rod. Electron microscopy of copolymer filaments, alone and bound to actin, indicates that the myosin heads are distributed randomly along the co-polymer filaments. The actin-activated ATPase of myosin decreases with increasing rod, approaching a plateau of about 30% of the control at a rod/myosin molar ratio of 4:1. The decrease in ATPase persists even at Vmax, the extrapolated limit at infinite actin, indicating that it is not due merely to the loss of cooperative actin binding. Furthermore, the actin dependence of the ATPase still shows a biphasic character like that of control myosin, even at rod/myosin ratio of 12:1, so this complexity is not probably due solely to the structural proximity of myosin molecules, but may involve a non-equivalence of myosin heads or myosin molecules in the filament environment. Images Figure 1 Figure 2 PMID:8198528

  11. Stuck fuel rod capping sleeve

    DOEpatents

    Gorscak, Donald A.; Maringo, John J.; Nilsen, Roy J.

    1988-01-01

    A stuck fuel rod capping sleeve to be used during derodding of spent fuel assemblies if a fuel rod becomes stuck in a partially withdrawn position and, thus, has to be severed. The capping sleeve has an inner sleeve made of a lower work hardening highly ductile material (e.g., Inconel 600) and an outer sleeve made of a moderately ductile material (e.g., 304 stainless steel). The inner sleeve may be made of an epoxy filler. The capping sleeve is placed on a fuel rod which is then severed by using a bolt cutter device. Upon cutting, the capping sleeve deforms in such a manner as to prevent the gross release of radioactive fuel material

  12. Adaptive control method for core power control in TRIGA Mark II reactor

    NASA Astrophysics Data System (ADS)

    Sabri Minhat, Mohd; Selamat, Hazlina; Subha, Nurul Adilla Mohd

    2018-01-01

    The 1MWth Reactor TRIGA PUSPATI (RTP) Mark II type has undergone more than 35 years of operation. The existing core power control uses feedback control algorithm (FCA). It is challenging to keep the core power stable at the desired value within acceptable error bands to meet the safety demand of RTP due to the sensitivity of nuclear research reactor operation. Currently, the system is not satisfied with power tracking performance and can be improved. Therefore, a new design core power control is very important to improve the current performance in tracking and regulate reactor power by control the movement of control rods. In this paper, the adaptive controller and focus on Model Reference Adaptive Control (MRAC) and Self-Tuning Control (STC) were applied to the control of the core power. The model for core power control was based on mathematical models of the reactor core, adaptive controller model, and control rods selection programming. The mathematical models of the reactor core were based on point kinetics model, thermal hydraulic models, and reactivity models. The adaptive control model was presented using Lyapunov method to ensure stable close loop system and STC Generalised Minimum Variance (GMV) Controller was not necessary to know the exact plant transfer function in designing the core power control. The performance between proposed adaptive control and FCA will be compared via computer simulation and analysed the simulation results manifest the effectiveness and the good performance of the proposed control method for core power control.

  13. Hypoxic preconditioning protects photoreceptors against light damage independently of hypoxia inducible transcription factors in rods.

    PubMed

    Kast, Brigitte; Schori, Christian; Grimm, Christian

    2016-05-01

    Hypoxic preconditioning protects photoreceptors against light-induced degeneration preserving retinal morphology and function. Although hypoxia inducible transcription factors 1 and 2 (HIF1, HIF2) are the main regulators of the hypoxic response, photoreceptor protection does not depend on HIF1 in rods. Here we used rod-specific Hif2a single and Hif1a;Hif2a double knockout mice to investigate the potential involvement of HIF2 in rods for protection after hypoxic preconditioning. To identify potential HIF2 target genes in rods we determined the retinal transcriptome of hypoxic control and rod-specific Hif2a knockouts by RNA sequencing. We show that rods do not need HIF2 for hypoxia-induced increased survival after light exposure. The transcriptomic analysis revealed a number of genes that are potentially regulated by HIF2 in rods; among those were Htra1, Timp3 and Hmox1, candidates that are interesting due to their connection to human degenerative diseases of the retina. We conclude that neither HIF1 nor HIF2 are required in photoreceptors for protection by hypoxic preconditioning. We hypothesize that HIF transcription factors may be needed in other cells to produce protective factors acting in a paracrine fashion on photoreceptor cells. Alternatively, hypoxic preconditioning induces a rod-intrinsic response that is independent of HIF transcription factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Outcomes of support rod usage in loop stoma formation.

    PubMed

    Whiteley, Ian; Russell, Michael; Nassar, Natasha; Gladman, Marc A

    2016-06-01

    Traditionally, support rods have been used when creating loop stomas in the hope of preventing retraction. However, their effectiveness has not been clearly established. This study aimed to investigate the rate of stoma rod usage and its impact on stoma retraction and complication rates. A prospective cohort of 515 consecutive patients who underwent loop ileostomy/colostomy formation at a tertiary referral colorectal unit in Sydney, Australia were studied. Mortality and unplanned return to theatre rates were calculated. The primary outcome measure of interest was stoma retraction, occurring within 30 days of surgery. Secondary outcome measures included early stoma complications. The 10-year temporal trends for rod usage, stoma retraction, and complications were examined. Mortality occurred in 23 patients (4.1 %) and unplanned return to theatre in 4 patients (0.8 %). Stoma retraction occurred in four patients (0.78 %), all without rods. However, the rate of retraction was similar, irrespective of whether rods were used (P = 0.12). There was a significant decline in the use of rods during the study period (P < 0.001) but this was not associated with an increase in stoma retraction rates. Early complications occurred in 94/432 patients (21.8 %) and were more likely to occur in patients with rods (64/223 versus 30/209 without rods, P < 0.001). Stoma retraction is a rare complication and its incidence is not significantly affected by the use of support rods. Further, complications are common post-operatively, and the rate appears higher when rods are used. The routine use of rods warrants judicious application. WHAT DOES THIS PAPER ADD TO THE LITERATURE?: It remains unclear whether support rods prevent stoma retraction. This study, the largest to date, confirms that stoma retraction is a rare complication and is not significantly affected by the use of rods. Consequently, routine rod usage cannot be recommended, particularly as it is associated with

  15. Nonlinear Waves in Rods

    DTIC Science & Technology

    1981-05-01

    0 and P > 0 everywhere. This also implies from (17) that Www 1Wuu - Wu w1 > 0 so that necking instabilities have been ruled out (see Antman [12], pp... Antman , "Qualitative Theory of the Ordinary Differential Equa- tions of Nonlinear Elasticity," in Mechanics Today, V. 1, ed. S. Nemat- Nasser...the Propagation of Plastic Strain in a Cylindrical Rod," J. Mech. Phys. Sol., 13, 1965, pp. 55-68. 7. S. S. Antman , The Theory of Rods, Handbuch der

  16. Close packing of rods on spherical surfaces

    NASA Astrophysics Data System (ADS)

    Smallenburg, Frank; Löwen, Hartmut

    2016-04-01

    We study the optimal packing of short, hard spherocylinders confined to lie tangential to a spherical surface, using simulated annealing and molecular dynamics simulations. For clusters of up to twelve particles, we map out the changes in the geometry of the closest-packed configuration as a function of the aspect ratio L/D, where L is the cylinder length and D the diameter of the rods. We find a rich variety of cluster structures. For larger clusters, we find that the best-packed configurations up to around 100 particles are highly dependent on the exact number of particles and aspect ratio. For even larger clusters, we find largely disordered clusters for very short rods (L/D = 0.25), while slightly longer rods (L/D = 0.5 or 1) prefer a global baseball-like geometry of smectic-like domains, similar to the behavior of large-scale nematic shells. Intriguingly, we observe that when compared to their optimal flat-plane packing, short rods adapt to the spherical geometry more efficiently than both spheres and longer rods. Our results provide predictions for experimentally realizable systems of colloidal rods trapped at the interface of emulsion droplets.

  17. Fluid intensifier having a double acting power chamber with interconnected signal rods

    DOEpatents

    Whitehead, John C.

    2001-01-01

    A fluid driven reciprocating apparatus having a double acting power chamber with signal rods serving as high pressure pistons, or to transmit mechanical power. The signal rods are connected to a double acting piston in the power chamber thereby eliminating the need for pilot valves, with the piston being controlled by a pair of intake-exhaust valves. The signal rod includes two spaced seals along its length with a vented space therebetween so that the driving fluid and driven fluid can't mix, and performs a switching function to eliminate separate pilot valves. The intake-exhaust valves can be integrated into a single housing with the power chamber, or these valves can be built into the cylinder head only of the power chamber, or they can be separate from the power chamber.

  18. 76 FR 35130 - Pipeline Safety: Control Room Management/Human Factors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-16

    ... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts...: Control Room Management/Human Factors AGENCY: Pipeline and Hazardous Materials Safety Administration... safety standards, risk assessments, and safety policies for natural gas pipelines and for hazardous...

  19. Immunomodulation-accelerated neuronal regeneration following selective rod photoreceptor cell ablation in the zebrafish retina.

    PubMed

    White, David T; Sengupta, Sumitra; Saxena, Meera T; Xu, Qingguo; Hanes, Justin; Ding, Ding; Ji, Hongkai; Mumm, Jeff S

    2017-05-02

    Müller glia (MG) function as inducible retinal stem cells in zebrafish, completely repairing the eye after damage. The innate immune system has recently been shown to promote tissue regeneration in which classic wound-healing responses predominate. However, regulatory roles for leukocytes during cellular regeneration-i.e., selective cell-loss paradigms akin to degenerative disease-are less well defined. To investigate possible roles innate immune cells play during retinal cell regeneration, we used intravital microscopy to visualize neutrophil, macrophage, and retinal microglia responses to induced rod photoreceptor apoptosis. Neutrophils displayed no reactivity to rod cell loss. Peripheral macrophage cells responded to rod cell loss, as evidenced by morphological transitions and increased migration, but did not enter the retina. Retinal microglia displayed multiple hallmarks of immune cell activation: increased migration, translocation to the photoreceptor cell layer, proliferation, and phagocytosis of dying cells. To test function during rod cell regeneration, we coablated microglia and rod cells or applied immune suppression and quantified the kinetics of ( i ) rod cell clearance, ( ii ) MG/progenitor cell proliferation, and ( iii ) rod cell replacement. Coablation and immune suppressants applied before cell loss caused delays in MG/progenitor proliferation rates and slowed the rate of rod cell replacement. Conversely, immune suppressants applied after cell loss had been initiated led to accelerated photoreceptor regeneration kinetics, possibly by promoting rapid resolution of an acute immune response. Our findings suggest that microglia control MG responsiveness to photoreceptor loss and support the development of immune-targeted therapeutic strategies for reversing cell loss associated with degenerative retinal conditions.

  20. Immunomodulation-accelerated neuronal regeneration following selective rod photoreceptor cell ablation in the zebrafish retina

    PubMed Central

    White, David T.; Sengupta, Sumitra; Saxena, Meera T.; Xu, Qingguo; Hanes, Justin; Ding, Ding; Ji, Hongkai

    2017-01-01

    Müller glia (MG) function as inducible retinal stem cells in zebrafish, completely repairing the eye after damage. The innate immune system has recently been shown to promote tissue regeneration in which classic wound-healing responses predominate. However, regulatory roles for leukocytes during cellular regeneration—i.e., selective cell-loss paradigms akin to degenerative disease—are less well defined. To investigate possible roles innate immune cells play during retinal cell regeneration, we used intravital microscopy to visualize neutrophil, macrophage, and retinal microglia responses to induced rod photoreceptor apoptosis. Neutrophils displayed no reactivity to rod cell loss. Peripheral macrophage cells responded to rod cell loss, as evidenced by morphological transitions and increased migration, but did not enter the retina. Retinal microglia displayed multiple hallmarks of immune cell activation: increased migration, translocation to the photoreceptor cell layer, proliferation, and phagocytosis of dying cells. To test function during rod cell regeneration, we coablated microglia and rod cells or applied immune suppression and quantified the kinetics of (i) rod cell clearance, (ii) MG/progenitor cell proliferation, and (iii) rod cell replacement. Coablation and immune suppressants applied before cell loss caused delays in MG/progenitor proliferation rates and slowed the rate of rod cell replacement. Conversely, immune suppressants applied after cell loss had been initiated led to accelerated photoreceptor regeneration kinetics, possibly by promoting rapid resolution of an acute immune response. Our findings suggest that microglia control MG responsiveness to photoreceptor loss and support the development of immune-targeted therapeutic strategies for reversing cell loss associated with degenerative retinal conditions. PMID:28416692

  1. Slip-spring model of entangled rod-coil block copolymers

    NASA Astrophysics Data System (ADS)

    Wang, Muzhou; Likhtman, Alexei E.; Olsen, Bradley D.

    2015-03-01

    Understanding the dynamics of rod-coil block copolymers is important for optimal design of functional nanostructured materials for organic electronics and biomaterials. Recently, we proposed a reptation theory of entangled rod-coil block copolymers, predicting the relaxation mechanisms of activated reptation and arm retraction that slow rod-coil dynamics relative to coil and rod homopolymers, respectively. In this work, we introduce a coarse-grained slip-spring model of rod-coil block copolymers to further explore these mechanisms. First, parameters of the coarse-grained model are tuned to match previous molecular dynamics simulation results for coils, rods, and block copolymers. For activated reptation, rod-coil copolymers are shown to disfavor configurations where the rod occupies curved portions of the entanglement tube of randomly varying curvature created by the coil ends. The effect of these barriers on diffusion is quantitatively captured by considering one-dimensional motion along an entanglement tube with a rough free energy potential. Finally, we analyze the crossover between the two mechanisms. The resulting dynamics from both mechanisms acting in combination is faster than from each one individually.

  2. Mouse rods signal through gap junctions with cones.

    PubMed

    Asteriti, Sabrina; Gargini, Claudia; Cangiano, Lorenzo

    2014-01-01

    Rod and cone photoreceptors are coupled by gap junctions (GJs), relatively large channels able to mediate both electrical and molecular communication. Despite their critical location in our visual system and evidence that they are dynamically gated for dark/light adaptation, the full impact that rod-cone GJs can have on cone function is not known. We recorded the photovoltage of mouse cones and found that the initial level of rod input increased spontaneously after obtaining intracellular access. This process allowed us to explore the underlying coupling capacity to rods, revealing that fully coupled cones acquire a striking rod-like phenotype. Calcium, a candidate mediator of the coupling process, does not appear to be involved on the cone side of the junctional channels. Our findings show that the anatomical substrate is adequate for rod-cone coupling to play an important role in vision and, possibly, in biochemical signaling among photoreceptors. DOI: http://dx.doi.org/10.7554/eLife.01386.001.

  3. Development of a HTSMA-Actuated Surge Control Rod for High-Temperature Turbomachinery Applications

    NASA Technical Reports Server (NTRS)

    Padula, Santo, II; Noebe, Ronald; Bigelow, Glen; Culley, Dennis; Stevens, Mark; Penney, Nicholas; Gaydosh, Darrell; Quackenbush, Todd; Carpenter, Bernie

    2007-01-01

    In recent years, a demand for compact, lightweight, solid-state actuation systems has emerged, driven in part by the needs of the aeronautics industry. However, most actuation systems used in turbomachinery require not only elevated temperature but high-force capability. As a result, shape memory alloy (SMA) based systems have worked their way to the forefront of a short list of viable options to meet such a technological challenge. Most of the effort centered on shape memory systems to date has involved binary NiTi alloys but the working temperatures required in many aeronautics applications dictate significantly higher transformation temperatures than the binary systems can provide. Hence, a high temperature shape memory alloy (HTSMA) based on NiTiPdPt, having a transformation temperature near 300 C, was developed. Various thermo-mechanical processing schemes were utilized to further improve the dimensional stability of the alloy and it was later extruded/drawn into wire form to be more compatible with envisioned applications. Mechanical testing on the finished wire form showed reasonable work output capability with excellent dimensional stability. Subsequently, the wire form of the alloy was incorporated into a benchtop system, which was shown to provide the necessary stroke requirements of approx.0.125 inches for the targeted surge-control application. Cycle times for the actuator were limited to 4 seconds due to control and cooling constraints but this cycle time was determined to be adequate for the surge control application targeted as the primary requirement was initial actuation of a surge control rod, which could be completed in approximately one second.

  4. Rotating Rod Renewable Microcolumns for Automated, Solid-Phase DNA Hybridization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bruckner-Lea, Cynthia J.; Stottlemyre, Mark R.; Holman, David A.

    1999-12-01

    The development of a new temperature-controlled renewable microcolumn flow cell for solid-phase nucleic acid analysis in a sequential injection system is described. The flow cell includes a stepper motor-driven rotating rod with the working end cut to a 45 degree angle. In one position, the end of the rod prevents passage of microbeads while allowing fluid flow; rotation of the rod by 180 degrees release the beads. This system was used to rapidly test many hybridization and elution protocols to examine the temperature and solution conditions required for sequence specific nucleic acid hybridization. Target nucleic acids labeled with a near-infraredmore » fluorescent dye were detected immediately post-column using a flow-through fluorescence detector, with a detection limit of 40 pM dye concentration at a flow rate of 5 mu l/s. Temperature control of the column and the presence of Triton X-100 surfactant were critical for specific hybridization. Perfusion of the column with complementary oligonucleotide (200 mu l, 10nM) resulted in hybridization with 8% of the DNA binding sites on the microbeads with a solution residence time of less than a second and a total sample perfusion time of 40 seconds. The use of the renewable column system for detection of an unlabeled PCR product in a sandwich assay was also demonstrated.« less

  5. Experience using individually supplied heater rods in critical power testing of advanced BWR fuel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Majed, M.; Morback, G.; Wiman, P.

    1995-09-01

    The ABB Atom FRIGG loop located in Vasteras Sweden has during the last six years given a large experience of critical power measurements for BWR fuel designs using indirectly heated rods with individual power supply. The loop was built in the sixties and designed for maximum 100 bar pressure. Testing up to the mid eighties was performed with directly heated rods using a 9 MW, 80 kA power supply. Providing test data to develop critical power correlations for BWR fuel assemblies requires testing with many radial power distributions over the full range of hydraulic conditions. Indirectly heated rods give largemore » advantages for the testing procedure, particularly convenient for variation of individual rod power. A test method being used at Stern Laboratories (formerly Westinghouse Canada) since the early sixties, allows one fuel assembly to simulate all required radial power distributions. This technique requires reliable indirectly heated rods with independently controlled power supplies and uses insulated electric fuel rod simulators with built-in instrumentation. The FRIGG loop was adapted to this system in 1987. A 4MW power supply with 10 individual units was then installed, and has since been used for testing 24 and 25 rod bundles simulating one subbundle of SVEA-96/100 type fuel assemblies. The experience with the system is very good, as being presented, and it is selected also for a planned upgrading of the facility to 15 MW.« less

  6. Rasch-built Overall Disability Scale (R-ODS) for immune-mediated peripheral neuropathies.

    PubMed

    van Nes, S I; Vanhoutte, E K; van Doorn, P A; Hermans, M; Bakkers, M; Kuitwaard, K; Faber, C G; Merkies, I S J

    2011-01-25

    To develop a patient-based, linearly weighted scale that captures activity and social participation limitations in patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and gammopathy-related polyneuropathy (MGUSP). A preliminary Rasch-built Overall Disability Scale (R-ODS) containing 146 activity and participation items was constructed, based on the WHO International Classification of Functioning, Disability and Health, literature search, and patient interviews. The preliminary R-ODS was assessed twice (interval: 2-4 weeks; test-retest reliability studies) in 294 patients who experienced GBS in the past (n = 174) or currently have stable CIDP (n = 80) or MGUSP (n = 40). Data were analyzed using the Rasch unidimensional measurement model (RUMM2020). The preliminary R-ODS did not meet the Rasch model expectations. Based on disordered thresholds, misfit statistics, item bias, and local dependency, items were systematically removed to improve the model fit, regularly controlling the class intervals and model statistics. Finally, we succeeded in constructing a 24-item scale that fulfilled all Rasch requirements. "Reading a newspaper/book" and "eating" were the 2 easiest items; "standing for hours" and "running" were the most difficult ones. Good validity and reliability were obtained. The R-ODS is a linearly weighted scale that specifically captures activity and social participation limitations in patients with GBS, CIDP, and MGUSP. Compared to the Overall Disability Sum Score, the R-ODS represents a wider range of item difficulties, thereby better targeting patients with different ability levels. If responsive, the R-ODS will be valuable for future clinical trials and follow-up studies in these conditions.

  7. Directionally Interacting Spheres and Rods Form Ordered Phases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Wenyan; Mahynski, Nathan A.; Gang, Oleg

    The structures formed by mixtures of dissimilarly shaped nanoscale objects can significantly enhance our ability to produce nanoscale architectures. However, understanding their formation is a complex problem due to the interplay of geometric effects (entropy) and energetic interactions at the nanoscale. Spheres and rods are perhaps the most basic geometrical shapes and serve as convenient models of such dissimilar objects. The ordered phases formed by each of these individual shapes have already been explored, but, when mixed, spheres and rods have demonstrated only limited structural organization to date. We show using experiments and theory that the introduction of directional attractionsmore » between rod ends and isotropically interacting spherical nanoparticles (NPs) through DNA base pairing leads to the formation of ordered three-dimensional lattices. The spheres and rods arrange themselves in a complex alternating manner, where the spheres can form either a face-centered cubic (FCC) or hexagonal close-packed (HCP) lattice, or a disordered phase, as observed by in situ X-ray scattering. Increasing NP diameter at fixed rod length yields an initial transition from a disordered phase to the HCP crystal, energetically stabilized by rod-rod attraction across alternating crystal layers, as revealed by theory. In the limit of large NPs, the FCC structure is instead stabilized over the HCP by rod entropy. Thus, we propose that directionally specific attractions in mixtures of anisotropic and isotropic objects offer insight into unexplored self-assembly behavior of noncomplementary shaped particles.« less

  8. Directionally Interacting Spheres and Rods Form Ordered Phases

    DOE PAGES

    Liu, Wenyan; Mahynski, Nathan A.; Gang, Oleg; ...

    2017-05-10

    The structures formed by mixtures of dissimilarly shaped nanoscale objects can significantly enhance our ability to produce nanoscale architectures. However, understanding their formation is a complex problem due to the interplay of geometric effects (entropy) and energetic interactions at the nanoscale. Spheres and rods are perhaps the most basic geometrical shapes and serve as convenient models of such dissimilar objects. The ordered phases formed by each of these individual shapes have already been explored, but, when mixed, spheres and rods have demonstrated only limited structural organization to date. We show using experiments and theory that the introduction of directional attractionsmore » between rod ends and isotropically interacting spherical nanoparticles (NPs) through DNA base pairing leads to the formation of ordered three-dimensional lattices. The spheres and rods arrange themselves in a complex alternating manner, where the spheres can form either a face-centered cubic (FCC) or hexagonal close-packed (HCP) lattice, or a disordered phase, as observed by in situ X-ray scattering. Increasing NP diameter at fixed rod length yields an initial transition from a disordered phase to the HCP crystal, energetically stabilized by rod-rod attraction across alternating crystal layers, as revealed by theory. In the limit of large NPs, the FCC structure is instead stabilized over the HCP by rod entropy. Thus, we propose that directionally specific attractions in mixtures of anisotropic and isotropic objects offer insight into unexplored self-assembly behavior of noncomplementary shaped particles.« less

  9. Connectedness percolation of hard deformed rods

    NASA Astrophysics Data System (ADS)

    Drwenski, Tara; Dussi, Simone; Dijkstra, Marjolein; van Roij, René; van der Schoot, Paul

    2017-12-01

    Nanofiller particles, such as carbon nanotubes or metal wires, are used in functional polymer composites to make them conduct electricity. They are often not perfectly straight cylinders but may be tortuous or exhibit kinks. Therefore we investigate the effect of shape deformations of the rod-like nanofillers on the geometric percolation threshold of the dispersion. We do this by using connectedness percolation theory within a Parsons-Lee type of approximation, in combination with Monte Carlo integration for the average overlap volume in the isotropic fluid phase. We find that a deviation from a perfect rod-like shape has very little effect on the percolation threshold, unless the particles are strongly deformed. This demonstrates that idealized rod models are useful even for nanofillers that superficially seem imperfect. In addition, we show that for small or moderate rod deformations, the universal scaling of the percolation threshold is only weakly affected by the precise particle shape.

  10. Robust technology and system for management of sucker rod pumping units in oil wells

    NASA Astrophysics Data System (ADS)

    Aliev, T. A.; Rzayev, A. H.; Guluyev, G. A.; Alizada, T. A.; Rzayeva, N. E.

    2018-01-01

    We propose a technology for calculating the robust, normalized correlation functions of the signal from the force sensor on the rod string attached to the hanger of the sucker rod pumping unit. The robust normalized correlation functions are used to form sets of informative attribute combinations, each of which corresponds to a technical condition of the sucker rod pumping unit. We demonstrate how these sets can be used to solve identification and management problems in the oil production process in real time using inexpensive controllers. The results obtained from using the system on real objects are also presented in this paper. It was determined that the energy saved and prolonged overhaul period substantially increased the cost-effectiveness.

  11. Study on Sumbawa gold ore liberation using rod mill: effect of rod-number and rotational speed on particle size distribution

    NASA Astrophysics Data System (ADS)

    Prasetya, A.; Mawadati, A.; Putri, A. M. R.; Petrus, H. T. B. M.

    2018-01-01

    Comminution is one of crucial steps in gold ore processing used to liberate the valuable minerals from gaunge mineral. This research is done to find the particle size distribution of gold ore after it has been treated through the comminution process in a rod mill with various number of rod and rotational speed that will results in one optimum milling condition. For the initial step, Sumbawa gold ore was crushed and then sieved to pass the 2.5 mesh and retained on the 5 mesh (this condition was taken to mimic real application in artisanal gold mining). Inserting the prepared sample into the rod mill, the observation on effect of rod-number and rotational speed was then conducted by variating the rod number of 7 and 10 while the rotational speed was varied from 60, 85, and 110 rpm. In order to be able to provide estimation on particle distribution of every condition, the comminution kinetic was applied by taking sample at 15, 30, 60, and 120 minutes for size distribution analysis. The change of particle distribution of top and bottom product as time series was then treated using Rosin-Rammler distribution equation. The result shows that the homogenity of particle size and particle size distribution is affected by rod-number and rotational speed. The particle size distribution is more homogeneous by increasing of milling time, regardless of rod-number and rotational speed. Mean size of particles do not change significantly after 60 minutes milling time. Experimental results showed that the optimum condition was achieved at rotational speed of 85 rpm, using rod-number of 7.

  12. Wetting of a partially immersed compliant rod

    NASA Astrophysics Data System (ADS)

    Hui, Chung-Yuen; Jagota, Anand

    2016-11-01

    The force on a solid rod partially immersed in a liquid is commonly used to determine the liquid-vapor surface tension by equating the measured force required to remove the rod from the liquid to the vertical component of the liquid-vapor surface tension. Here, we study how this process is affected when the rod is compliant. For equilibrium, we enforce force and configurational energy balance, including contributions from elastic energy. We show that, in general, the contact angle does not equal that given by Young's equation. If surface stresses are tensile, the strain in the immersed part of the rod is found to be compressive and to depend only on the solid-liquid surface stress. The strain in the dry part of the rod can be either tensile or compressive, depending on a combination of parameters that we identify. We also provide results for compliant plates partially immersed in a liquid under plane strain and plane stress. Our results can be used to extract solid surface stresses from such experiments.

  13. 30 CFR 7.103 - Safety system control test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the temperature sensor in the exhaust gas stream which will automatically activate the safety shutdown... control that might interfere with the evaluation of the operation of the exhaust gas temperature sensor... allowable low water level. Run the engine until the exhaust gas temperature sensor activates the safety...

  14. 30 CFR 7.103 - Safety system control test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the temperature sensor in the exhaust gas stream which will automatically activate the safety shutdown... control that might interfere with the evaluation of the operation of the exhaust gas temperature sensor... allowable low water level. Run the engine until the exhaust gas temperature sensor activates the safety...

  15. Translocation of "rod-coil" polymers: probing the structure of single molecules within nanopores.

    PubMed

    de Haan, Hendrick W; Slater, Gary W

    2013-01-25

    Using simulation and analytical techniques, we demonstrate that it is possible to extract structural information about biological molecules by monitoring the dynamics as they translocate through nanopores. From Langevin dynamics simulations of polymers exhibiting discrete changes in flexibility (rod-coil polymers), distinct plateaus are observed in the progression towards complete translocation. Characterizing these dynamics via an incremental mean first passage approach, the large steps are shown to correspond to local barriers preventing the passage of the coils while the rods translocate relatively easily. Analytical replication of the results provides insight into the corrugated nature of the free energy landscape as well as the dependence of the effective barrier heights on the length of the coil sections. Narrowing the width of the pore or decreasing the charge on either the rod or the coil segments are both shown to enhance the resolution of structural details. The special case of a single rod confined within a nanopore is also studied. Here, sufficiently long flexible sections attached to either end are demonstrated to act as entropic anchors which can effectively trap the rod within the pore for an extended period of time. Both sets of results suggest new experimental approaches for the control and study of biological molecules within nanopores.

  16. Influence of implant rod curvature on sagittal correction of scoliosis deformity.

    PubMed

    Salmingo, Remel Alingalan; Tadano, Shigeru; Abe, Yuichiro; Ito, Manabu

    2014-08-01

    Deformation of in vivo-implanted rods could alter the scoliosis sagittal correction. To our knowledge, no previous authors have investigated the influence of implanted-rod deformation on the sagittal deformity correction during scoliosis surgery. To analyze the changes of the implant rod's angle of curvature during surgery and establish its influence on sagittal correction of scoliosis deformity. A retrospective analysis of the preoperative and postoperative implant rod geometry and angle of curvature was conducted. Twenty adolescent idiopathic scoliosis patients underwent surgery. Average age at the time of operation was 14 years. The preoperative and postoperative implant rod angle of curvature expressed in degrees was obtained for each patient. Two implant rods were attached to the concave and convex side of the spinal deformity. The preoperative implant rod geometry was measured before surgical implantation. The postoperative implant rod geometry after surgery was measured by computed tomography. The implant rod angle of curvature at the sagittal plane was obtained from the implant rod geometry. The angle of curvature between the implant rod extreme ends was measured before implantation and after surgery. The sagittal curvature between the corresponding spinal levels of healthy adolescents obtained by previous studies was compared with the implant rod angle of curvature to evaluate the sagittal curve correction. The difference between the postoperative implant rod angle of curvature and normal spine sagittal curvature of the corresponding instrumented level was used to evaluate over or under correction of the sagittal deformity. The implant rods at the concave side of deformity of all patients were significantly deformed after surgery. The average degree of rod deformation Δθ at the concave and convex sides was 15.8° and 1.6°, respectively. The average preoperative and postoperative implant rod angle of curvature at the concave side was 33.6° and 17.8

  17. Validation of updated neutronic calculation models proposed for Atucha-II PHWR. Part I: Benchmark comparisons of WIMS-D5 and DRAGON cell and control rod parameters with MCNP5

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mollerach, R.; Leszczynski, F.; Fink, J.

    2006-07-01

    In 2005 the Argentine Government took the decision to complete the construction of the Atucha-II nuclear power plant, which has been progressing slowly during the last ten years. Atucha-II is a 745 MWe nuclear station moderated and cooled with heavy water, of German (Siemens) design located in Argentina. It has a pressure-vessel design with 451 vertical coolant channels, and the fuel assemblies (FA) are clusters of 37 natural UO{sub 2} rods with an active length of 530 cm. For the reactor physics area, a revision and update calculation methods and models (cell, supercell and reactor) was recently carried out coveringmore » cell, supercell (control rod) and core calculations. As a validation of the new models some benchmark comparisons were done with Monte Carlo calculations with MCNP5. This paper presents comparisons of cell and supercell benchmark problems based on a slightly idealized model of the Atucha-I core obtained with the WIMS-D5 and DRAGON codes with MCNP5 results. The Atucha-I core was selected because it is smaller, similar from a neutronic point of view, and more symmetric than Atucha-II Cell parameters compared include cell k-infinity, relative power levels of the different rings of fuel rods, and some two-group macroscopic cross sections. Supercell comparisons include supercell k-infinity changes due to the control rods (tubes) of steel and hafnium. (authors)« less

  18. Patient safety and infection control: bases for curricular integration.

    PubMed

    Silva, Andréa Mara Bernardes da; Bim, Lucas Lazarini; Bim, Felipe Lazarini; Sousa, Alvaro Francisco Lopes; Domingues, Pedro Castania Amadio; Nicolussi, Adriana Cristina; Andrade, Denise de

    2018-05-01

    To analyze curricular integration between teaching of patient safety and good infection prevention and control practices. Integrative review, designed to answer the question: "How does curricular integration of content about 'patient safety teaching' and content about 'infection prevention and control practices' occur in undergraduate courses in the health field?". The following databases were searched for primary studies: CINAHL, LILACS, ScienceDirect, Web of Science, Scopus, Europe PMC and MEDLINE. The final sample consisted of 13 studies. After content analysis, primary studies were grouped into two subject categories: "Innovative teaching practices" and "Curricular evaluation. Patient safety related to infection prevention and control practices is present in the curriculum of health undergraduate courses, but is not coordinated with other themes, is taught sporadically, and focuses mainly on hand hygiene.

  19. Structural Integrity Testing Method for PRSEUS Rod-Wrap Stringer Design

    NASA Technical Reports Server (NTRS)

    Wang, John T.; Grenoble, Ray W.; Pickell, Robert D.

    2012-01-01

    NASA Langley Research Center and The Boeing Company are developing an innovative composite structural concept, called PRSEUS, for the flat center section of a future environmentally friendly hybrid wing body (HWB) aircraft. The PRSEUS (Pultruded Rod Stitched Efficient Unitized Structure) concept uses dry textile preforms for the skins, frames, and stiffener webs. The highly loaded stiffeners are made from precured unidirectional carbon/epoxy rods and dry fiber preforms. The rods are wrapped with the dry fiber preforms and a resin infusion process is used to form the rod-wrap stiffeners. The structural integrity of the rod-wrap interface is critical for maintaining the panel s high strength and bending rigidity. No standard testing method exists for testing the strength of the rod-wrap bondline. Recently, Boeing proposed a rod push-out testing method and conducted some preliminary tests using this method. This paper details an analytical study of the rod-wrap bondline. The rod-wrap interface is modeled as a cohesive zone for studying the initiation and growth of interfacial debonding during push-out testing. Based on the correlations of analysis results and Boeing s test data, the adequacy of the rod-wrap testing method is evaluated, and potential approaches for improvement of the test method are proposed.

  20. Spatially confined synthesis of SiOx nano-rod with size-controlled Si quantum dots in nano-porous anodic aluminum oxide membrane.

    PubMed

    Pai, Yi-Hao; Lin, Gong-Ru

    2011-01-17

    By depositing Si-rich SiOx nano-rod in nano-porous anodic aluminum oxide (AAO) membrane using PECVD, the spatially confined synthesis of Si quantum-dots (Si-QDs) with ultra-bright photoluminescence spectra are demonstrated after low-temperature annealing. Spatially confined SiOx nano-rod in nano-porous AAO membrane greatly increases the density of nucleated positions for Si-QD precursors, which essentially impedes the route of thermally diffused Si atoms and confines the degree of atomic self-aggregation. The diffusion controlled growth mechanism is employed to determine the activation energy of 6.284 kJ mole(-1) and diffusion length of 2.84 nm for SiO1.5 nano-rod in nano-porous AAO membrane. HRTEM results verify that the reduced geometric dimension of the SiOx host matrix effectively constrain the buried Si-QD size at even lower annealing temperature. The spatially confined synthesis of Si-QD essentially contributes the intense PL with its spectral linewidth shrinking from 210 to 140 nm and its peak intensity enhancing by two orders of magnitude, corresponding to the reduction on both the average Si-QD size and its standard deviation from 2.6 to 2.0 nm and from 25% to 12.5%, respectively. The red-shifted PL wavelength of the Si-QD reveals an inverse exponential trend with increasing temperature of annealing, which is in good agree with the Si-QD size simulation via the atomic diffusion theory.

  1. Nanopipes in gallium nitride nanowires and rods.

    PubMed

    Jacobs, Benjamin W; Crimp, Martin A; McElroy, Kaylee; Ayres, Virginia M

    2008-12-01

    Gallium nitride nanowires and rods synthesized by a catalyst-free vapor-solid growth method were analyzed with cross section high-resolution transmission electron microscopy. The cross section studies revealed hollow core screw dislocations, or nanopipes, in the nanowires and rods. The hollow cores were located at or near the center of the nanowires and rods, along the axis of a screw dislocation. The formation of the hollow cores is consistent with effect of screw dislocations with giant Burgers vector predicted by Frank.

  2. Biophysical mechanism of transient retinal phototropism in rod photoreceptors.

    PubMed

    Zhao, Xiaohui; Thapa, Damber; Wang, Benquan; Gai, Shaoyan; Yao, Xincheng

    2016-02-13

    Oblique light stimulation evoked transient retinal phototropism (TRP) has been recently detected in frog and mouse retinas. High resolution microscopy of freshly isolated retinas indicated that the TRP is predominated by rod photoreceptors. Comparative confocal microscopy and optical coherence tomography (OCT) revealed that the TRP predominantly occurred from the photoreceptor outer segment (OS). However, biophysical mechanism of rod OS change is still unknown. In this study, frog retinal slices, which open a cross section of retinal photoreceptor and other functional layers, were used to test the effect of light stimulation on rod OS. Near infrared light microscopy was employed to monitor photoreceptor changes in retinal slices stimulated by a rectangular-shaped visible light flash. Rapid rod OS length change was observed after the stimulation delivery. The magnitude and direction of the rod OS change varied with the position of the rods within the stimulated area. In the center of stimulated region the length of the rod OS shrunk, while in the peripheral region the rod OS tip swung towards center region in the plane perpendicular to the incident stimulus light. Our experimental result and theoretical analysis suggest that the observed TRP may reflect unbalanced disc-shape change due to localized pigment bleaching. Further investigation is required to understand biochemical mechanism of the observed rod OS kinetics. Better study of the TRP may provide a noninvasive biomarker to enable early detection of age-related macular degeneration (AMD) and other diseases that are known to produce retinal photoreceptor dysfunctions.

  3. Biophysical mechanism of transient retinal phototropism in rod photoreceptors

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaohui; Thapa, Damber; Wang, Benquan; Gai, Shaoyan; Yao, Xincheng

    2016-03-01

    Oblique light stimulation evoked transient retinal phototropism (TRP) has been recently detected in frog and mouse retinas. High resolution microscopy of freshly isolated retinas indicated that the TRP is predominated by rod photoreceptors. Comparative confocal microscopy and optical coherence tomography (OCT) revealed that the TRP predominantly occurred from the photoreceptor outer segment (OS). However, biophysical mechanism of rod OS change is still unknown. In this study, frog retinal slices, which open a cross section of retinal photoreceptor and other functional layers, were used to test the effect of light stimulation on rod OS. Near infrared light microscopy was employed to monitor photoreceptor changes in retinal slices stimulated by a rectangular-shaped visible light flash. Rapid rod OS length change was observed after the stimulation delivery. The magnitude and direction of the rod OS change varied with the position of the rods within the stimulated area. In the center of stimulated region the length of the rod OS shrunk, while in the peripheral region the rod OS tip swung towards center region in the plane perpendicular to the incident stimulus light. Our experimental result and theoretical analysis suggest that the observed TRP may reflect unbalanced disc-shape change due to localized pigment bleaching. Further investigation is required to understand biochemical mechanism of the observed rod OS kinetics. Better study of the TRP may provide a noninvasive biomarker to enable early detection of age-related macular degeneration (AMD) and other diseases that are known to produce retinal photoreceptor dysfunctions.

  4. Rod Has High Tensile Strength And Low Thermal Expansion

    NASA Technical Reports Server (NTRS)

    Smith, D. E.; Everton, R. L.; Howe, E.; O'Malley, M.

    1996-01-01

    Thoriated tungsten extension rod fabricated to replace stainless-steel extension rod attached to linear variable-differential transformer in gap-measuring gauge. Threads formed on end of rod by machining with special fixtures and carefully chosen combination of speeds and feeds.

  5. Method and means of packaging nuclear fuel rods for handling

    DOEpatents

    Adam, Milton F.

    1979-01-01

    Nuclear fuel rods, especially spent nuclear fuel rods that may show physical distortion, are encased within a metallic enclosing structure by forming a tube about the fuel rod. The tube has previously been rolled to form an overlapping tubular structure and then unrolled and coiled about an axis perpendicular to the tube. The fuel rod is inserted into the tube as the rolled tube is removed from a coiled strip and allowed to reassume its tubular shape about the fuel rod. Rollers support the coiled strip in an open position as the coiled strip is uncoiled and allowed to roll about the fuel rod.

  6. [Infection control and safety culture in German hospitals].

    PubMed

    Hansen, Sonja; Schwab, Frank; Gropmann, Alexander; Behnke, Michael; Gastmeier, Petra

    2016-07-01

    Healthcare-associated infections (HAI) are the most frequent adverse events in the healthcare setting and their prevention is an important contribution to patient safety in hospitals. To analyse to what extent safety cultural aspects with relevance to infection control are implemented in German hospitals. Safety cultural aspects of infection control were surveyed with an online questionnaire; data were analysed descriptively. Data from 543 hospitals with a median of [IQR] 275 [157; 453] beds were analysed. Almost all hospitals (96.6 %) had internal guidelines for infection control (IC) in place; 82 % defined IC objectives, most often regarding hand hygiene (HH) (93 %) and multidrug resistant organisms (72 %) and less frequently for antibiotic stewardship (48 %) or prevention of specific HAI. In 94 % of hospitals, a reporting system for adverse events was in place, which was also used to report low compliance with HH, outbreaks and Clostridium difficile-associated infections. Members of the IC team were most often seen to hold daily responsibility for IC in the hospital, but rarely other hospital staff (94 versus 19 %). Safety cultural aspects are not fully implemented in German hospitals. IC should be more strongly implemented in healthcare workers' daily routine and more visibly supported by hospital management.

  7. Verification and Implementation of Operations Safety Controls for Flight Missions

    NASA Technical Reports Server (NTRS)

    Smalls, James R.; Jones, Cheryl L.; Carrier, Alicia S.

    2010-01-01

    There are several engineering disciplines, such as reliability, supportability, quality assurance, human factors, risk management, safety, etc. Safety is an extremely important engineering specialty within NASA, and the consequence involving a loss of crew is considered a catastrophic event. Safety is not difficult to achieve when properly integrated at the beginning of each space systems project/start of mission planning. The key is to ensure proper handling of safety verification throughout each flight/mission phase. Today, Safety and Mission Assurance (S&MA) operations engineers continue to conduct these flight product reviews across all open flight products. As such, these reviews help ensure that each mission is accomplished with safety requirements along with controls heavily embedded in applicable flight products. Most importantly, the S&MA operations engineers are required to look for important design and operations controls so that safety is strictly adhered to as well as reflected in the final flight product.

  8. Market-based control mechanisms for patient safety

    PubMed Central

    Coiera, E; Braithwaite, J

    2009-01-01

    A new model is proposed for enhancing patient safety using market-based control (MBC), inspired by successful approaches to environmental governance. Emissions trading, enshrined in the Kyoto protocol, set a carbon price and created a carbon market—is it possible to set a patient safety price and let the marketplace find ways of reducing clinically adverse events? To “cap and trade,” a regulator would need to establish system-wide and organisation-specific targets, based on the cost of adverse events, create a safety market for trading safety credits and then police the market. Organisations are given a clear policy signal to reduce adverse event rates, are told by how much, but are free to find mechanisms best suited to their local needs. The market would inevitably generate novel ways of creating safety credits, and accountability becomes hard to evade when adverse events are explicitly measured and accounted for in an organisation’s bottom line. PMID:19342522

  9. Distributed temperature sensing inside a 19-rod bundle

    DOE PAGES

    Lomperski, S.; Bremer, N.; Gerardi, C.

    2017-05-23

    The temperature field within a model of a sodium-cooled fast reactor fuel rod bundle was measured using Ø155 μm fiber optic distributed temperature sensors (DTS). The bundle consists of 19 electrically-heated rods Ø6.3 mm and 865 mm long. Working fluids were argon and air at atmospheric pressure and Reynolds numbers up to 300. A 20 m-long DTS was threaded through Ø1 mm capillaries wound around rods as wire-wraps. The sensor generated 173 measurements along each rod at 5 mm resolution for a total of 3300 data locations. A second DTS, 58 m long, was suspended between rods to provide 9300more » fluid temperature measurements at 20 mm resolution. Such data density makes it possible to construct 3D maps of the temperature field that are beyond the reach of traditional sensors such as thermocouples. This is illustrated through a series of steady-state and transient tests. As a result, the work demonstrates the feasibility of mapping temperature within the close confines of a rod bundle at resolutions suitable for validation of computational fluid dynamics codes.« less

  10. Assessment of Safety Standards for Automotive Electronic Control Systems

    DOT National Transportation Integrated Search

    2016-06-01

    This report summarizes the results of a study that assessed and compared six industry and government safety standards relevant to the safety and reliability of automotive electronic control systems. These standards include ISO 26262 (Road Vehicles - ...

  11. Biomineralization of uniform gallium oxide rods with cellular compatibility.

    PubMed

    Yan, Danhong; Yin, Guangfu; Huang, Zhongbing; Liao, Xiaoming; Kang, Yunqing; Yao, Yadong; Hao, Baoqing; Gu, Jianwen; Han, Dong

    2009-07-20

    Monodispersed single crystalline alpha-GaOOH rods coated by silk fibroin (SF) have been prepared via a facile biomineralization process in the template of SF peptide. The carbon-coated alpha-Ga(2)O(3) and beta-Ga(2)O(3) rods are obtained by thermal treatment of the alpha-GaOOH rods at 600 and 800 degrees C, respectively. In vitro cytotoxicity studies of these gallium oxide rods showed no significant effect leading to restraint of cell proliferation of L929, Hela, and HaCat cells in less than 0.1 mg/mL prepared rods. On the basis of their excellent luminescence emission properties and cellular compatibilities, possible applications for bio-optoelectronic devices can be envisioned.

  12. Browns Ferry Nuclear Plant Unit 2: Control rod drive scram discharge headers decontamination effort

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Traynor, J.C.

    1983-08-01

    The control rod drive (CRD) scram discharge headers were decontaminated during the Browns Ferry unit 2, cycle 4 refueling outage (August 2-5, 1982). Hydrolasing (high-pressure water blasting) was used as the method of decontamination to remove fixed and loose radioactive contaminants from the headers. It was found that hydrolasing of the west scram discharge headers resulted in approximate maximum and average decontamination factors (DFs) on contact of 13 and 5, respectively. For the east scram discharge headers, hydrolasing resulted in a maximum and average DF on contact of approximately 3. The maximum and average DFs on contact for the individualmore » headers ranged from 1 to 33 and 1 to 10, respectively, while the walkway (head-level) DFs were in the range of 3 to 4. Higher DFs were impeded by inadequate drainage and backwashing of fluid. This led to increased radiation levels in some areas and recontamination of adjacent headers.« less

  13. Samd7 is a cell type-specific PRC1 component essential for establishing retinal rod photoreceptor identity

    PubMed Central

    Omori, Yoshihiro; Kubo, Shun; Kon, Tetsuo; Furuhashi, Mayu; Narita, Hirotaka; Kominami, Taro; Ueno, Akiko; Tsutsumi, Ryotaro; Chaya, Taro; Yamamoto, Haruka; Suetake, Isao; Ueno, Shinji; Koseki, Haruhiko; Furukawa, Takahisa

    2017-01-01

    Precise transcriptional regulation controlled by a transcription factor network is known to be crucial for establishing correct neuronal cell identities and functions in the CNS. In the retina, the expression of various cone and rod photoreceptor cell genes is regulated by multiple transcription factors; however, the role of epigenetic regulation in photoreceptor cell gene expression has been poorly understood. Here, we found that Samd7, a rod-enriched sterile alpha domain (SAM) domain protein, is essential for silencing nonrod gene expression through H3K27me3 regulation in rod photoreceptor cells. Samd7-null mutant mice showed ectopic expression of nonrod genes including S-opsin in rod photoreceptor cells and rod photoreceptor cell dysfunction. Samd7 physically interacts with Polyhomeotic homologs (Phc proteins), components of the Polycomb repressive complex 1 (PRC1), and colocalizes with Phc2 and Ring1B in Polycomb bodies. ChIP assays showed a significant decrease of H3K27me3 in the genes up-regulated in the Samd7-deficient retina, showing that Samd7 deficiency causes the derepression of nonrod gene expression in rod photoreceptor cells. The current study suggests that Samd7 is a cell type-specific PRC1 component epigenetically defining rod photoreceptor cell identity. PMID:28900001

  14. Samd7 is a cell type-specific PRC1 component essential for establishing retinal rod photoreceptor identity.

    PubMed

    Omori, Yoshihiro; Kubo, Shun; Kon, Tetsuo; Furuhashi, Mayu; Narita, Hirotaka; Kominami, Taro; Ueno, Akiko; Tsutsumi, Ryotaro; Chaya, Taro; Yamamoto, Haruka; Suetake, Isao; Ueno, Shinji; Koseki, Haruhiko; Nakagawa, Atsushi; Furukawa, Takahisa

    2017-09-26

    Precise transcriptional regulation controlled by a transcription factor network is known to be crucial for establishing correct neuronal cell identities and functions in the CNS. In the retina, the expression of various cone and rod photoreceptor cell genes is regulated by multiple transcription factors; however, the role of epigenetic regulation in photoreceptor cell gene expression has been poorly understood. Here, we found that Samd7, a rod-enriched sterile alpha domain (SAM) domain protein, is essential for silencing nonrod gene expression through H3K27me3 regulation in rod photoreceptor cells. Samd7- null mutant mice showed ectopic expression of nonrod genes including S-opsin in rod photoreceptor cells and rod photoreceptor cell dysfunction. Samd7 physically interacts with Polyhomeotic homologs (Phc proteins), components of the Polycomb repressive complex 1 (PRC1), and colocalizes with Phc2 and Ring1B in Polycomb bodies. ChIP assays showed a significant decrease of H3K27me3 in the genes up-regulated in the Samd7 -deficient retina, showing that Samd7 deficiency causes the derepression of nonrod gene expression in rod photoreceptor cells. The current study suggests that Samd7 is a cell type-specific PRC1 component epigenetically defining rod photoreceptor cell identity.

  15. Structure and Growth of Rod-Shaped Mn Ultrafine Particle

    NASA Astrophysics Data System (ADS)

    Kido, Osamu; Suzuki, Hitoshi; Saito, Yoshio; Kaito, Chihiro

    2003-09-01

    The structure of rod-shaped Mn ultrafine particles was elucidated by electron microscopy. Mn ultrafine particles have characteristic tristetrahedron (α-Mn), rhombic dodecahedron (β-Mn) and rod-shape crystal habits. It was found that the rod-shaped particle resulted from the parallel coalescence of β-Mn particles with the size of 50 nm. Detailed analysis of the defects seen in large rod-shaped particles with the width of 100 nm indicated a mixture of α- and β-phases. A size effect on the phase transition from β to α was observed throughout the rod-shaped crystal structure. The structure and growth of Mn particles were discussed based on the outline of the smoke and the temperature distribution in the smoke.

  16. Mixed Convection Blowoff Limits as a Function of Oxygen Concentration and Upward Forced Stretch Rate for Burning Pmma Rods of Various Sizes

    NASA Technical Reports Server (NTRS)

    Marcum, Jeremy W.; Ferkul, Paul V.; Olson, Sandra L.

    2017-01-01

    Normal gravity flame blowoff limits in an axisymmetric pmma rod geometry in upward axial stagnation flow are compared with microgravity Burning and Suppression of Solids II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (pmma) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18 by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity upward flame spread test method which extrapolates the linear blowoff boundary to the zero stretch limit to resolve microgravity flammability limits, something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.

  17. Thermal modeling of W rod armor.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nygren, Richard Einar

    2004-09-01

    Sandia has developed and tested mockups armored with W rods over the last decade and pioneered the initial development of W rod armor for International Thermonuclear Experimental Reactor (ITER) in the 1990's. We have also developed 2D and 3D thermal and stress models of W rod-armored plasma facing components (PFCs) and test mockups and are applying the models to both short pulses, i.e. edge localized modes (ELMs), and thermal performance in steady state for applications in C-MOD, DiMES testing and ITER. This paper briefly describes the 2D and 3D models and their applications with emphasis on modeling for an ongoingmore » test program that simulates repeated heat loads from ITER ELMs.« less

  18. CONTROL IN NUCLEAR REACTORS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, F.R.

    1963-01-16

    An arrangement was described for scramming a reactor in an emergency. Control rods were position adjusted by an electric motor and transmission. A locking system kept the control rods in position but was arranged to be released in an emergency to allow the rods to drop into their shutdown position. (C.E.S.)

  19. The R&D PERFROI Project on Thermal Mechanical and Thermal Hydraulics Behaviors of a Fuel Rod Assembly during a Loss of Coolant Accident

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Repetto, G.; Dominguez, C.; Durville, B.

    The safety principle in case of a LOCA is to preserve the short and long term coolability of the core. The associated safety requirements are to ensure the resistance of the fuel rods upon quench and post-quench loads and to maintain a coolable geometry in the core. An R&D program has been launched by IRSN with the support of EDF, to perform both experimental and modeling activities in the frame of the LOCA transient, on technical issues such as: - flow blockage within a fuel rods bundle and its potential impact on coolability, - fuel fragment relocation in the balloonedmore » areas: its potential impact on cladding PCT (Peak Cladding Temperature) and on the maximum oxidation rate, - potential loss of cladding integrity upon quench and post-quench loads. The PERFROI project (2014-2019) focusing on the first above issue, is structured in two axes: 1. axis 1: thermal mechanical behavior of deformation and rupture of cladding taking into account the contact between fuel rods; specific research at LaMCoS laboratory focus on the hydrogen behavior in cladding alloys and its impact on the mechanical behavior of the rod; and, 2. axis 2: thermal hydraulics study of a partially blocked region of the core (ballooned area taking into account the fuel relocation with local over power), during cooling phase by water injection; More detailed activities foreseen in collaboration with LEMTA laboratory will focus on the characterization of two phase flows with heat transfer in deformed structures.« less

  20. Pultruded Rod/Overwrap Testing for Various Stitched Stringer Configurations

    NASA Technical Reports Server (NTRS)

    Leone, Frank A., Jr.

    2016-01-01

    The unidirectional carbon pultruded rod running through the tops of the stringers is a key design feature of the Pultruded Rod Efficient Unitized Structure (PRSEUS) concept as applied to aircraft fuselage structure. Reported herein are the test methods and results from a test campaign in which the strength of the rod/overwrap interface of various PRSEUS stringer configurations were characterized. The different stringer configurations included different materials and stacking sequences for the stringer overwrap and whether or not an additional layer of adhesive was included between the rod and the overwrap.

  1. Safety Metrics for Human-Computer Controlled Systems

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy G; Hatanaka, Iwao

    2000-01-01

    The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems.This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

  2. Rods and cones contain antigenically distinctive S-antigens.

    PubMed

    Nork, T M; Mangini, N J; Millecchia, L L

    1993-09-01

    S-antigen (48 kDa protein or arrestin) is known to be present in rod photoreceptors. Its localization in cones is less clear with several conflicting reports among various species examined. This study employed three different anti-S-antigen antibodies (a48K, a polyclonal antiserum and two monoclonal antibodies, MAb A9-C6 and MAb 5c6.47) and examined their localization in rods and cones of human and cat retinas. To identify the respective cone types, an enzyme histochemical technique for carbonic anhydrase (CA) was employed to distinguish blue cones (CA-negative) from red or green cones (CA-positive). S-antigen localization was then examined by immunocytochemical staining of adjacent sections. In human retinas, a similar labeling pattern was seen with both a48K and MAb A9-C6, i.e., the rods and blue-sensitive cones were strongly positive, whereas the red- or green-sensitive cones showed little immunoreactivity. All human photoreceptors showed reactivity to MAb 5c6.47. In the cat retina, only CA-positive cones could be found. As in the human retina, both rods and cones of the cat were positive for MAb 5c6.47. A difference from the labeling pattern in human retina was noted for the other S-antigen antibodies; a48K labeled rods and all of the cones, whereas MAb A9-C6 reacted strongly with the rods but showed no cone staining. These results suggest that both rods and cones contain S-antigen but that they are antigenically distinctive.

  3. 46 CFR 61.30-20 - Automatic control and safety tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Automatic control and safety tests. 61.30-20 Section 61.30-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-20 Automatic control and safety tests. Operational tests and check...

  4. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intramedullary fixation rod. 888.3020 Section 888.3020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. (a...

  5. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intramedullary fixation rod. 888.3020 Section 888.3020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. (a...

  6. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intramedullary fixation rod. 888.3020 Section 888.3020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. (a...

  7. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intramedullary fixation rod. 888.3020 Section 888.3020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. (a...

  8. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intramedullary fixation rod. 888.3020 Section 888.3020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. (a...

  9. Cone rod dystrophies

    PubMed Central

    Hamel, Christian P

    2007-01-01

    Cone rod dystrophies (CRDs) (prevalence 1/40,000) are inherited retinal dystrophies that belong to the group of pigmentary retinopathies. CRDs are characterized by retinal pigment deposits visible on fundus examination, predominantly localized to the macular region. In contrast to typical retinitis pigmentosa (RP), also called the rod cone dystrophies (RCDs) resulting from the primary loss in rod photoreceptors and later followed by the secondary loss in cone photoreceptors, CRDs reflect the opposite sequence of events. CRD is characterized by primary cone involvement, or, sometimes, by concomitant loss of both cones and rods that explains the predominant symptoms of CRDs: decreased visual acuity, color vision defects, photoaversion and decreased sensitivity in the central visual field, later followed by progressive loss in peripheral vision and night blindness. The clinical course of CRDs is generally more severe and rapid than that of RCDs, leading to earlier legal blindness and disability. At end stage, however, CRDs do not differ from RCDs. CRDs are most frequently non syndromic, but they may also be part of several syndromes, such as Bardet Biedl syndrome and Spinocerebellar Ataxia Type 7 (SCA7). Non syndromic CRDs are genetically heterogeneous (ten cloned genes and three loci have been identified so far). The four major causative genes involved in the pathogenesis of CRDs are ABCA4 (which causes Stargardt disease and also 30 to 60% of autosomal recessive CRDs), CRX and GUCY2D (which are responsible for many reported cases of autosomal dominant CRDs), and RPGR (which causes about 2/3 of X-linked RP and also an undetermined percentage of X-linked CRDs). It is likely that highly deleterious mutations in genes that otherwise cause RP or macular dystrophy may also lead to CRDs. The diagnosis of CRDs is based on clinical history, fundus examination and electroretinogram. Molecular diagnosis can be made for some genes, genetic counseling is always advised. Currently

  10. cAMP controls rod photoreceptor sensitivity via multiple targets in the phototransduction cascade

    PubMed Central

    Astakhova, Luba A.; Samoiliuk, Evgeniia V.; Govardovskii, Victor I.

    2012-01-01

    In early studies, both cyclic AMP (cAMP) and cGMP were considered as potential secondary messengers regulating the conductivity of the vertebrate photoreceptor plasma membrane. Later discovery of the cGMP specificity of cyclic nucleotide–gated channels has shifted attention to cGMP as the only secondary messenger in the phototransduction cascade, and cAMP is not considered in modern schemes of phototransduction. Here, we report evidence that cAMP may also be involved in regulation of the phototransduction cascade. Using a suction pipette technique, we recorded light responses of isolated solitary rods from the frog retina in normal solution and in the medium containing 2 µM of adenylate cyclase activator forskolin. Under forskolin action, flash sensitivity rose more than twofold because of a retarded photoresponse turn-off. The same concentration of forskolin lead to a 2.5-fold increase in the rod outer segment cAMP, which is close to earlier reported natural day/night cAMP variations. Detailed analysis of cAMP action on the phototransduction cascade suggests that several targets are affected by cAMP increase: (a) basal dark phosphodiesterase (PDE) activity decreases; (b) at the same intensity of light background, steady background-induced PDE activity increases; (c) at light backgrounds, guanylate cyclase activity at a given fraction of open channels is reduced; and (d) the magnitude of the Ca2+ exchanger current rises 1.6-fold, which would correspond to a 1.6-fold elevation of [Ca2+]in. Analysis by a complete model of rod phototransduction suggests that an increase of [Ca2+]in might also explain effects (b) and (c). The mechanism(s) by which cAMP could regulate [Ca2+]in and PDE basal activity is unclear. We suggest that these regulations may have adaptive significance and improve the performance of the visual system when it switches between day and night light conditions. PMID:23008435

  11. Failure kinetics in borosilicate glass during rod impact

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Orphal, Dennis L.; Anderson, Charles E. Jr.; Behner, Thilo

    2007-12-12

    Failure front (FF) and penetration velocity have been measured for long gold rods impacting and penetrating borosilicate (BS) glass. Data are obtained by visualizing simultaneously FF propagation with a high speed camera and rod penetration with flash X-rays. Results for BS glass are qualitatively similar to those of DEDF (PbO) glass. FF velocity rapidly decreases from an initial value to a lower, approximately constant value. FF velocity increases with impact velocity, v{sub p}. The FF velocity remains significantly lower than the shear velocity, even at the highest impact velocity tested, about 2.5 km/s. The ratio of the FF velocity tomore » the rod penetration velocity, v{sub F}/u, decreases with increasing v{sub p} and appears to be approaching v{sub F}/u = 1 asymptotically, as observed previously for DEDF glass. The separation of the FF and the tip of the rod decreases with increasing impact velocity. Importantly, since v{sub F}/u{>=}1, the gold rod is always penetrating glass behind the FF.« less

  12. Self-cleaning threaded rod spinneret for high-efficiency needleless electrospinning

    NASA Astrophysics Data System (ADS)

    Zheng, Gaofeng; Jiang, Jiaxin; Wang, Xiang; Li, Wenwang; Zhong, Weizheng; Guo, Shumin

    2018-07-01

    High-efficiency production of nanofibers is the key to the application of electrospinning technology. This work focuses on multi-jet electrospinning, in which a threaded rod electrode is utilized as the needless spinneret to achieve high-efficiency production of nanofibers. A slipper block, which fits into and moves through the threaded rod, is designed to transfer polymer solution evenly to the surface of the rod spinneret. The relative motion between the slipper block and the threaded rod electrode promotes the instable fluctuation of the solution surface, thus the rotation of threaded rod electrode decreases the critical voltage for the initial multi-jet ejection and the diameter of nanofibers. The residual solution on the surface of threaded rod is cleaned up by the moving slipper block, showing a great self-cleaning ability, which ensures the stable multi-jet ejection and increases the productivity of nanofibers. Each thread of the threaded rod electrode serves as an independent spinneret, which enhances the electric field strength and constrains the position of the Taylor cone, resulting in high productivity of uniform nanofibers. The diameter of nanofibers decreases with the increase of threaded rod rotation speed, and the productivity increases with the solution flow rate. The rotation of electrode provides an excess force for the ejection of charged jets, which also contributes to the high-efficiency production of nanofibers. The maximum productivity of nanofibers from the threaded rod spinneret is 5-6 g/h, about 250-300 times as high as that from the single-needle spinneret. The self-cleaning threaded rod spinneret is an effective way to realize continuous multi-jet electrospinning, which promotes industrial applications of uniform nanofibrous membrane.

  13. Kinetics of Exocytosis Is Faster in Cones Than in Rods

    PubMed Central

    Rabl, Katalin; Cadetti, Lucia; Thoreson, Wallace B.

    2006-01-01

    Cone-driven responses of second-order retinal neurons are considerably faster than rod-driven responses. We examined whether differences in the kinetics of synaptic transmitter release from rods and cones may contribute to differences in postsynaptic response kinetics. Exocytosis from rods and cones was triggered by membrane depolarization and monitored in two ways: (1) by measuring EPSCs evoked in second-order neurons by depolarizing steps applied to presynaptic rods or cones during simultaneous paired whole-cell recordings or (2) by direct measurements of exocytotic increases in membrane capacitance. The kinetics of release was assessed by varying the length of the depolarizing test step. Both measures of release revealed two kinetic components to the increase in exocytosis as a function of the duration of a step depolarization. In addition to slow sustained components in both cell types, the initial fast component of exocytosis had a time constant of <5 ms in cones, >10-fold faster than that of rods. Rod/cone differences in the kinetics of release were substantiated by a linear correlation between depolarization-evoked capacitance increases and EPSC charge transfer. Experiments on isolated rods indicate that the slower kinetics of exocytosis from rods was not a result of rod–rod coupling. The initial rapid release of vesicles from cones can shape the postsynaptic response and may contribute to the faster responses of cone-driven cells observed at light offset. PMID:15872111

  14. Dynamics of Longitudinal Impact in the Variable Cross-Section Rods

    NASA Astrophysics Data System (ADS)

    Stepanov, R.; Romenskyi, D.; Tsarenko, S.

    2018-03-01

    Dynamics of longitudinal impact in rods of variable cross-section is considered. Rods of various configurations are used as elements of power pulse systems. There is no single method to the construction of a mathematical model of longitudinal impact on rods. The creation of a general method for constructing a mathematical model of longitudinal impact for rods of variable cross-section is the goal of the article. An elastic rod is considered with a cross-sectional area varying in powers of law from the longitudinal coordinate. The solution of the wave equation is obtained using the Fourier method. Special functions are introduced on the basis of recurrence relations for Bessel functions for solving boundary value problems. The expression for the square of the norm is obtained taking into account the orthogonality property of the eigen functions with weight. For example, the impact of an inelastic mass along the wide end of a conical rod is considered. The expressions for the displacements, forces and stresses of the rod sections are obtained for the cases of sudden velocity communication and the application of force. The proposed mathematical model makes it possible to carry out investigations of the stress-strain state in rods of variable and constant cross-section for various conditions of dynamic effects.

  15. Mutations in cell elongation genes mreB, mrdA and mrdB suppress the shape defect of RodZ-deficient cells.

    PubMed

    Shiomi, Daisuke; Toyoda, Atsushi; Aizu, Tomoyuki; Ejima, Fumio; Fujiyama, Asao; Shini, Tadasu; Kohara, Yuji; Niki, Hironori

    2013-03-01

    RodZ interacts with MreB and both factors are required to maintain the rod shape of Escherichia coli. The assembly of MreB into filaments regulates the subcellular arrangement of a group of enzymes that synthesizes the peptidoglycan (PG) layer. However, it is still unknown how polymerization of MreB determines the rod shape of bacterial cells. Regulatory factor(s) are likely to be involved in controlling the function and dynamics of MreB. We isolated suppressor mutations to partially recover the rod shape in rodZ deletion mutants and found that some of the suppressor mutations occurred in mreB. All of the mreB mutations were in or in the vicinity of domain IA of MreB. Those mreB mutations changed the property of MreB filaments in vivo. In addition, suppressor mutations were found in the periplasmic regions in PBP2 and RodA, encoded by mrdA and mrdB genes. Similar to MreB and RodZ, PBP2 and RodA are pivotal to the cell wall elongation process. Thus, we found that mutations in domain IA of MreB and in the periplasmic domain of PBP2 and RodA can restore growth and rod shape to ΔrodZ cells, possibly by changing the requirements of MreB in the process. © 2013 Blackwell Publishing Ltd.

  16. Mutations in cell elongation genes mreB, mrdA and mrdB suppress the shape defect of RodZ-deficient cells

    PubMed Central

    Shiomi, Daisuke; Toyoda, Atsushi; Aizu, Tomoyuki; Ejima, Fumio; Fujiyama, Asao; Shini, Tadasu; Kohara, Yuji; Niki, Hironori

    2013-01-01

    RodZ interacts with MreB and both factors are required to maintain the rod shape of Escherichia coli. The assembly of MreB into filaments regulates the subcellular arrangement of a group of enzymes that synthesizes the peptidoglycan (PG) layer. However, it is still unknown how polymerization of MreB determines the rod shape of bacterial cells. Regulatory factor(s) are likely to be involved in controlling the function and dynamics of MreB. We isolated suppressor mutations to partially recover the rod shape in rodZ deletion mutants and found that some of the suppressor mutations occurred in mreB. All of the mreB mutations were in or in the vicinity of domain IA of MreB. Those mreB mutations changed the property of MreB filaments in vivo. In addition, suppressor mutations were found in the periplasmic regions in PBP2 and RodA, encoded by mrdA and mrdB genes. Similar to MreB and RodZ, PBP2 and RodA are pivotal to the cell wall elongation process. Thus, we found that mutations in domain IA of MreB and in the periplasmic domain of PBP2 and RodA can restore growth and rod shape to ΔrodZ cells, possibly by changing the requirements of MreB in the process. PMID:23301723

  17. Rod-shaped cavitation bubble structure in ultrasonic field.

    PubMed

    Bai, Lixin; Wu, Pengfei; Liu, Huiyu; Yan, Jiuchun; Su, Chang; Li, Chao

    2018-06-01

    Rod-shaped cavitation bubble structure in thin liquid layers in ultrasonic field is investigated experimentally. It is found that cavitation structure successively experiences several stages with the change of the thickness of the thin liquid layer. Rod-shaped structure is a stable structure of the boundary between the cavitation cloud region and the non-cavitation liquid region, which can be formed in two different ways. Cavitation bubbles in a thin liquid layer have a distribution in the thickness direction. The rod-shaped structures tend to crosslink with each other to form stable Y-branch structures. The angle of the Y-branch structure is Gauss distribution with mathematical expectation μ = 119.93. A special rod-shaped cavitation structure with source is also investigated in detail. Due to the pressure gradient in the normal direction, the primary Bjerknes force causes the bubbles in the rod-shaped structure on both sides to converge to the axis. The secondary Bjerknes forces between the bubbles also make the cluster converge, so the large bubbles which are attached to the radiating surface tend to align themselves along the central line. According to the formula deduced in this paper, the variation of curvature of curved rod-shaped structure is qualitatively analyzed. The Y-branch structure of cavitation cloud and Plateau boundary of soap bubbles are compared. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. 35. INTERIOR VIEW, SAME AS ABOVE WITH THE FEEDER ROD ...

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

    35. INTERIOR VIEW, SAME AS ABOVE WITH THE FEEDER ROD INSERTED INTO THE MACHINE; NOTE THE WOOD FEEDER ROD AND FEEDER ROD REST ON THE BACK OF THE STOOL - LaBelle Iron Works, Thirtieth & Wood Streets, Wheeling, Ohio County, WV

  19. Gelation And Mechanical Response of Patchy Rods

    NASA Astrophysics Data System (ADS)

    Kazem, Navid; Majidi, Carmel; Maloney, Craig

    We perform Brownian Dynamics simulations to study the gelation of suspensions of attractive, rod-like particles. We show that details of the particle-particle interactions can dramatically affect the dynamics of gelation and the structure and mechanics of the networks that form. If the attraction between the rods is perfectly smooth along their length, they will collapse into compact bundles. If the attraction is sufficiently corrugated or patchy, over time, a rigid space spanning network forms. We study the structure and mechanical properties of the networks that form as a function of the fraction of the surface that is allowed to bind. Surprisingly, the structural and mechanical properties are non-monotonic in the surface coverage. At low coverage, there are not a sufficient number of cross-linking sites to form networks. At high coverage, rods bundle and form disconnected clusters. At intermediate coverage, robust networks form. The elastic modulus and yield stress are both non-monotonic in the surface coverage. The stiffest and strongest networks show an essentially homogeneous deformation under strain with rods re-orienting along the extensional axis. Weaker, clumpy networks at high surface coverage exhibit relatively little re-orienting with strong non-affine deformation. These results suggest design strategies for tailoring surface interactions between rods to yield rigid networks with optimal properties. National Science Foundation and the Air Force Office of Scientific Research.

  20. Drop Ejection From an Oscillating Rod

    NASA Technical Reports Server (NTRS)

    Wilkes, E. D.; Basaran, O. A.

    1999-01-01

    The dynamics of a drop of a Newtonian liquid that is pendant from or sessile on a solid rod that is forced to undergo time-periodic oscillations along its axis is studied theoretically. The free boundary problem governing the time evolution of the shape of the drop and the flow field inside it is solved by a method of lines using a finite element algorithm incorporating an adaptive mesh. When the forcing amplitude is small, the drop approaches a limit cycle at large times and undergoes steady oscillations thereafter. However, drop breakup is the consequence if the forcing amplitude exceeds a critical value. Over a wide range of amplitudes above this critical value, drop ejection from the rod occurs during the second oscillation period from the commencement of rod motion. Remarkably, the shape of the interface at breakup and the volume of the primary drop formed are insensitive to changes in forcing amplitude. The interface shape at times close to and at breakup is a multi-valued function of distance measured along the rod axis and hence cannot be described by recently popularized one-dimensional approximations. The computations show that drop ejection occurs without the formation of a long neck. Therefore, this method of drop formation holds promise of preventing formation of undesirable satellite droplets.

  1. Thermomechanical effects of spine surgery rods composed of different metals and alloys.

    PubMed

    Noshchenko, Andriy; Patel, Vikas V; Baldini, Todd; Yun, Lu; Lindley, Emily M; Burger, Evalina L

    2011-05-15

    A basic science study monitoring changes in the curvature of hand contoured commercially pure titanium (CPTi), titanium-aluminum-vanadium alloy (Ti-6Al-4V), and stainless steel (SS) rods maintained at different temperature conditions. To quantify changes in rod-shape at temperatures representative of those used in clinical practice. The shape of implanted rods can be displaced due to thermo-mechanical properties of the materials. Warmer temperatures likely initiate this effect. A study of shape loss characteristics of various rod implants may help eliminate undesirable outcomes caused by shape displacement. Three different types of rods (CPTi, SS, and Ti-6Al-4V) were hand contoured and then maintained in one of following temperature conditions for 35 days: (1) room temperature (20 °C-25 °C) without autoclaving before contouring; (2) preliminary autoclaving (1, 5, 10, 20 cycles) at 135.0 °C ± 2 °C before contouring followed by body temperature (37.2 °C ± 2 °C). Each rod was 5 mm in diameter and 200 mm long. The rods were mounted over graph paper in fixed positions and photographed to measure displacement of the tip as a function of the curvature. RESULTS.: Statistically significant shape loss of the rods manufactured from all the tested materials was found. The hand contoured CPTi rods displayed considerably higher loss of curvature over time than Ti-6Al-4V and SS rods at all tested temperature conditions. Preliminary autoclaving at 135 °C before contouring tended to amplify this effect, in particular 1 cycle of autoclaving. If the number of preliminary autoclaving cycles was higher (5-10), a tendency of decrease of shape loss effect was observed in Ti-6Al-4V and CPTi rods. The shape of the hand contoured CPTi rods was the least stable of the rods across all applied temperature conditions. The SS and Ti-6Al-4V rods were more stable than CPTi rods. Autoclaving before handcontouring tended to increase rods' shape loss.

  2. Suppressing turbulence of self-propelling rods by strongly coupled passive particles.

    PubMed

    Su, Yen-Shuo; Wang, Hao-Chen; I, Lin

    2015-03-01

    The strong turbulence suppression, mainly for large-scale modes, of two-dimensional self-propelling rods, by increasing the long-range coupling strength Γ of low-concentration passive particles, is numerically demonstrated. It is found that large-scale collective rod motion in forms of swirls or jets is mainly contributed from well-aligned dense patches, which can push small poorly aligned rod patches and uncoupled passive particles. The more efficient momentum transfer and dissipation through increasing passive particle coupling leads to the formation of a more ordered and slowed down network of passive particles, which competes with coherent dense active rod clusters. The frustration of active rod alignment ordering and coherent motion by the passive particle network, which interrupt the inverse cascading of forming large-scale swirls, is the key for suppressing collective rod motion with scales beyond the interpassive distance, even in the liquid phase of passive particles. The loosely packed active rods are weakly affected by increasing passive particle coupling due to the weak rod-particle interaction. They mainly contribute to the small-scale modes and high-speed motion.

  3. CNGA3 deficiency affects cone synaptic terminal structure and function and leads to secondary rod dysfunction and degeneration.

    PubMed

    Xu, Jianhua; Morris, Lynsie M; Michalakis, Stylianos; Biel, Martin; Fliesler, Steven J; Sherry, David M; Ding, Xi-Qin

    2012-03-01

    To investigate rod function and survival after cone dysfunction and degeneration in a mouse model of cone cyclic nucleotide-gated (CNG) channel deficiency. Rod function and survival in mice with cone CNG channel subunit CNGA3 deficiency (CNGA3-/- mice) were evaluated by electroretinographic (ERG), morphometric, and Western blot analyses. The arrangement, integrity, and ultrastructure of photoreceptor terminals were investigated by immunohistochemistry and electron microscopy. The authors found loss of cone function and cone death accompanied by impairment of rods and rod-driven signaling in CNGA3-/- mice. Scotopic ERG b-wave amplitudes were reduced by 15% at 1 month, 30% at 6 months, and 40% at 9 months and older, while scotopic a-wave amplitudes were decreased by 20% at 9 months, compared with ERGs of age-matched wild-type mice. Outer nuclear layer thickness in CNGA3-/- retina was reduced by 15% at 12 months compared with age-matched wild-type controls. This was accompanied by a 30%-40% reduction in expression of rod-specific proteins, including rhodopsin, rod transducin α-subunit, and glutamic acid-rich protein (GARP). Cone terminals in the CNGA3-/- retina showed a progressive loss of neurochemical and ultrastructural integrity. Abnormalities were observed as early as 1 month. Disorganized rod terminal ultrastructure was noted by 12 months. These findings demonstrate secondary rod impairment and degeneration after cone degeneration in mice with cone CNG channel deficiency. Loss of cone phototransduction accompanies the compromised integrity of cone terminals. With time, rod synaptic structure, function, and viability also become compromised.

  4. ZnO Nano-Rod Devices for Intradermal Delivery and Immunization.

    PubMed

    Nayak, Tapas R; Wang, Hao; Pant, Aakansha; Zheng, Minrui; Junginger, Hans; Goh, Wei Jiang; Lee, Choon Keong; Zou, Shui; Alonso, Sylvie; Czarny, Bertrand; Storm, Gert; Sow, Chorng Haur; Lee, Chengkuo; Pastorin, Giorgia

    2017-06-15

    Intradermal delivery of antigens for vaccination is a very attractive approach since the skin provides a rich network of antigen presenting cells, which aid in stimulating an immune response. Numerous intradermal techniques have been developed to enhance penetration across the skin. However, these methods are invasive and/or affect the skin integrity. Hence, our group has devised zinc oxide (ZnO) nano-rods for non-destructive drug delivery. Chemical vapour deposition was used to fabricate aligned nano-rods on ZnO pre-coated silicon chips. The nano-rods' length and diameter were found to depend on the temperature, time, quality of sputtered silicon chips, etc. Vertically aligned ZnO nano-rods with lengths of 30-35 µm and diameters of 200-300 nm were selected for in vitro human skin permeation studies using Franz cells with Albumin-fluorescein isothiocyanate (FITC) absorbed on the nano-rods. Fluorescence and confocal studies on the skin samples showed FITC penetration through the skin along the channels formed by the nano-rods. Bradford protein assay on the collected fluid samples indicated a significant quantity of Albumin-FITC in the first 12 h. Low antibody titres were observed with immunisation on Balb/c mice with ovalbumin (OVA) antigen coated on the nano-rod chips. Nonetheless, due to the reduced dimensions of the nano-rods, our device offers the additional advantage of excluding the simultaneous entrance of microbial pathogens. Taken together, these results showed that ZnO nano-rods hold the potential for a safe, non-invasive, and painless intradermal drug delivery.

  5. In-reactor performance of LWR-type tritium target rods

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lanning, D.D.; Paxton, M.M.; Crumbaugh, L.

    Pacific Northwest Laboratory has conducted several 1-yr irradiation tests of light water reactor-type tritium target rods. These tests have been sponsored by the U.S. Department of Energy's Office of New Production Reactors. The first test, designated water capsule-1 (WC-1), was conducted in the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory from November 1989 to December 1990. The test vehicle contained a single 4-ft target rod within a pressurized water capsule. The capsule maintained the rod at pressurized water reactor (PWR)-type water temperature and pressure conditions. Posttest nondestructive examinations of the WC-1 rod involved visual examinations, dimensional checks,more » gamma scanning, and neutron radiography. The results indicate that the rod maintained the integrity of its pressure seal and was otherwise unaltered both mechanically and dimensionally by its irradiation and posttest handling.« less

  6. How Past Loss of Control Accidents May Inform Safety Cases for Advanced Control Systems on Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Holloway, C. M.; Johnson, C. W.

    2008-01-01

    This paper describes five loss of control accidents involving commercial aircraft, and derives from those accidents three principles to consider when developing a potential safety case for an advanced flight control system for commercial aircraft. One, among the foundational evidence needed to support a safety case is the availability to the control system of accurate and timely information about the status and health of relevant systems and components. Two, an essential argument to be sustained in the safety case is that pilots are provided with adequate information about the control system to enable them to understand the capabilities that it provides. Three, another essential argument is that the advanced control system will not perform less safely than a good pilot.

  7. 77 FR 58567 - Information Collection Activities: Well Control and Production Safety Training, Submitted for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ...-0006; OMB Number 1014-0008] Information Collection Activities: Well Control and Production Safety... requirements in the regulations under Subpart O, ``Well Control and Production Safety Training.'' This notice... and Production Safety Training. OMB Control Number: 1014-0008. Abstract: The Outer Continental Shelf...

  8. Who is in control of road safety? A STAMP control structure analysis of the road transport system in Queensland, Australia.

    PubMed

    Salmon, Paul M; Read, Gemma J M; Stevens, Nicholas J

    2016-11-01

    Despite significant progress, road trauma continues to represent a global safety issue. In Queensland (Qld), Australia, there is currently a focus on preventing the 'fatal five' behaviours underpinning road trauma (drug and drink driving, distraction, seat belt wearing, speeding, and fatigue), along with an emphasis on a shared responsibility for road safety that spans road users, vehicle manufacturers, designers, policy makers etc. The aim of this article is to clarify who shares the responsibility for road safety in Qld and to determine what control measures are enacted to prevent the fatal five behaviours. This is achieved through the presentation of a control structure model that depicts the actors and organisations within the Qld road transport system along with the control and feedback relationships that exist between them. Validated through a Delphi study, the model shows a diverse set of actors and organisations who share the responsibility for road safety that goes beyond those discussed in road safety policies and strategies. The analysis also shows that, compared to other safety critical domains, there are less formal control structures in road transport and that opportunities exist to add new controls and strengthen existing ones. Relationships that influence rather than control are also prominent. Finally, when compared to other safety critical domains, the strength of road safety controls is brought into question. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Disposal Of Irradiated Cadmium Control Rods From The Plumbrook Reactor Facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Posivak, E.J.; Berger, S.R.; Freitag, A.A.

    2008-07-01

    Innovative mixed waste disposition from NASA's Plum Brook Reactor Facility was accomplished without costly repackaging. Irradiated characteristic hardware with contact dose rates as high as 8 Sv/hr was packaged in a HDPE overpack and stored in a Secure Environmental Container during earlier decommissioning efforts, awaiting identification of a suitable pathway. WMG obtained regulatory concurrence that the existing overpack would serve as the macro-encapsulant per 40CFR268.45 Table 1.C. The overpack vent was disabled and the overpack was placed in a stainless steel liner to satisfy overburden slumping requirements. The liner was sealed and placed in shielded shoring for transport to themore » disposal site in a US DOT Type A cask. Disposition via this innovative method avoided cost, risk, and dose associated with repackaging the high dose irradiated characteristic hardware. In conclusion: WMG accomplished what others said could not be done. Large D and D contractors advised NASA that the cadmium control rods could only be shipped to the proposed Yucca mountain repository. NASA management challenged MOTA to find a more realistic alternative. NASA and MOTA turned to WMG to develop a methodology to disposition the 'hot and nasty' waste that presumably had no path forward. Although WMG lead a team that accomplished the 'impossible', the project could not have been completed with out the patient, supportive management by DOE-EM, NASA, and MOTA. (authors)« less

  10. Safety margins in older adults increase with improved control of a dynamic object

    PubMed Central

    Hasson, Christopher J.; Sternad, Dagmar

    2014-01-01

    Older adults face decreasing motor capabilities due to pervasive neuromuscular degradations. As a consequence, errors in movement control increase. Thus, older individuals should maintain larger safety margins than younger adults. While this has been shown for object manipulation tasks, several reports on whole-body activities, such as posture and locomotion, demonstrate age-related reductions in safety margins. This is despite increased costs for control errors, such as a fall. We posit that this paradox could be explained by the dynamic challenge presented by the body or also an external object, and that age-related reductions in safety margins are in part due to a decreased ability to control dynamics. To test this conjecture we used a virtual ball-in-cup task that had challenging dynamics, yet afforded an explicit rendering of the physics and safety margin. The hypotheses were: (1) When manipulating an object with challenging dynamics, older adults have smaller safety margins than younger adults. (2) Older adults increase their safety margins with practice. Nine young and 10 healthy older adults practiced moving the virtual ball-in-cup to a target location in exactly 2 s. The accuracy and precision of the timing error quantified skill, and the ball energy relative to an escape threshold quantified the safety margin. Compared to the young adults, older adults had increased timing errors, greater variability, and decreased safety margins. With practice, both young and older adults improved their ability to control the object with decreased timing errors and variability, and increased their safety margins. These results suggest that safety margins are related to the ability to control dynamics, and may explain why in tasks with simple dynamics older adults use adequate safety margins, but in more complex tasks, safety margins may be inadequate. Further, the results indicate that task-specific training may improve safety margins in older adults. PMID:25071566

  11. Active Brownian rods

    NASA Astrophysics Data System (ADS)

    Peruani, Fernando

    2016-11-01

    Bacteria, chemically-driven rods, and motility assays are examples of active (i.e. self-propelled) Brownian rods (ABR). The physics of ABR, despite their ubiquity in experimental systems, remains still poorly understood. Here, we review the large-scale properties of collections of ABR moving in a dissipative medium. We address the problem by presenting three different models, of decreasing complexity, which we refer to as model I, II, and III, respectively. Comparing model I, II, and III, we disentangle the role of activity and interactions. In particular, we learn that in two dimensions by ignoring steric or volume exclusion effects, large-scale nematic order seems to be possible, while steric interactions prevent the formation of orientational order at large scales. The macroscopic behavior of ABR results from the interplay between active stresses and local alignment. ABR exhibit, depending on where we locate ourselves in parameter space, a zoology of macroscopic patterns that ranges from polar and nematic bands to dynamic aggregates.

  12. Biomechanical Evaluation of a Growth-Friendly Rod Construct

    PubMed Central

    Galvis, Sarah; Arnold, Josh; Mannen, Erin; Wong, Benjamin; Sis, Hadley; Cadel, Eileen; Anderson, John; Anderson, Dennis; Arnold, Paul; Friis, Elizabeth

    2017-01-01

    Background Distraction type rods mechanically stabilize the thorax and improve lung growth and function by applying distraction forces at the rib, spine, pelvis, or a combination of locations. However, the amount of stability the rods provide and the amount the thorax needs is unknown. Methods Five freshly frozen and thawed cadaveric thoracic spine specimens were tested lateral bending, flexion/extension, and axial rotation in displacement control (1°/sec) to a load limit of ± 5 Nm for five cycles after which a growth-friendly unilateral rod was placed in a simulated rib-to-lumbar attachment along the right side. The specimens were tested again the same modes of bending. From the seven Optotrak Orthopedic Research Pin markers (Northern Digital Inc., Waterloo, ON, Canada) inserted into the top potting to denote T1, and the right pedicles at T2, T4, T5, T8, T9, and T11 and the Standard Needle Tip Pressure Transducers (Gaeltech, Isle of Skye, Scotland) inserted into the T4/T5 and T8/T9 discs, motion, stiffness, and pressure data were calculated. Parameters from the third cycle of the intact case and the construct case were compared using two-tailed paired t-tests with 0.05 as the level of significance. Results With the construct attached, the T1–T4 segment showed a 30% increase in NZS during extension (p = 0.001); the T8–T12 segment experienced a 63% reduction in the in-plane ROM during flexion (p = 0.04); and the T8/T9 spinal motion unit had a significant decrease of 24% in EZS during left axial rotation (p = 0.04). Conclusions It’s clear the device as tested here does not produce large biomechanical changes, but the balance between providing desired changes while preventing complications remains difficult. Clinical Relevance Investigating the biomechanical effect growth-friendly rods have on the thoracic spine could lead to better understanding of treatment outcomes, both positive and negative. PMID:28038688

  13. Risk Factors for Proximal Junctional Kyphosis Associated With Dual-rod Growing-rod Surgery for Early-onset Scoliosis.

    PubMed

    Watanabe, Kota; Uno, Koki; Suzuki, Teppei; Kawakami, Noriaki; Tsuji, Taichi; Yanagida, Haruhisa; Ito, Manabu; Hirano, Toru; Yamazaki, Ken; Minami, Shohei; Taneichi, Hiroshi; Imagama, Shiro; Takeshita, Katsushi; Yamamoto, Takuya; Matsumoto, Morio

    2016-10-01

    A retrospective, multicenter study. To identify risk factors for proximal junctional kyphosis (PJK) when treating early-onset scoliosis (EOS) with dual-rod growing-rod (GR) procedure. The risk factors for PJK associated with GR treatment for EOS have not been adequately studied. We evaluated clinical and radiographic results from 88 patients with EOS who underwent dual-rod GR surgery in 12 spine centers in Japan. The mean age at the time of the initial surgery was 6.5±2.2 years (range, 1.5-9.8 y), and the mean follow-up period was 3.9±2.6 years (range, 2.0-12.0 y). Risk factors for PJK were analyzed by binomial multiple logistic regression analysis. The potential factors analyzed were sex, etiology, age, the number of rod-lengthening procedures, coronal and sagittal parameters on radiographs, the type of foundation (pedicle screws or hooks), the uppermost level of the proximal foundation, and the lowermost level of the distal foundation. PJK developed in 23 patients (26%); in 19 of these, the proximal foundation became dislodged following PJK. Binomial multiple logistic regression analysis identified the following significant independent risk factors for PJK: a lower instrumented vertebra at or cranial to L3 [odds ratio (OR), 3.32], a proximal thoracic scoliosis of ≥40 degrees (OR, 2.95), and a main thoracic kyphosis of ≥60 degrees (OR, 5.08). The significant independent risk factors for PJK during dual-rod GR treatment for EOS were a lower instrumented vertebra at or cranial to L3, a proximal thoracic scoliosis of ≥40 degrees, and a main thoracic kyphosis of ≥60 degrees.

  14. Rod- versus cone-driven ERGs at different stimulus sizes in normal subjects and retinitis pigmentosa patients.

    PubMed

    Aher, Avinash J; McKeefry, Declan J; Parry, Neil R A; Maguire, John; Murray, I J; Tsai, Tina I; Huchzermeyer, Cord; Kremers, Jan

    2018-02-01

    To study how rod- and cone-driven responses depend on stimulus size in normal subjects and patients with retinitis pigmentosa (RP), and to show that comparisons between responses to full-field (FF) and smaller stimuli can be useful in diagnosing and monitoring disorders of the peripheral retina without the need for lengthy dark adaptation periods. The triple silent substitution technique was used to isolate L-cone-, M-cone- and rod-driven ERGs with 19, 18 and 33% photoreceptor contrasts, respectively, under identical mean luminance conditions. Experiments were conducted on five normal subjects and three RP patients. ERGs on control subjects were recorded at nine different temporal frequencies (between 2 and 60 Hz) for five different stimulus sizes: FF, 70°, 60°, 50° and 40° diameter circular stimuli. Experiments on RP patients involved rod- and L-cone-driven ERG measurements with FF and 40° stimuli at 8 and 48 Hz. Response amplitudes were defined as those of the first harmonic component after Fourier analysis. In normal subjects, rod-driven responses displayed a fundamentally different behavior than cone-driven responses, particularly at low temporal frequencies. At low and intermediate temporal frequencies (≤ 12 Hz), rod-driven signals increased by a factor of about four when measured with smaller stimuli. In contrast, L- and M-cone-driven responses in this frequency region did not change substantially with stimulus size. At high temporal frequencies (≥ 24 Hz), both rod- and cone-driven response amplitudes decreased with decreasing stimulus size. Signals obtained from rod-isolating stimuli under these conditions are likely artefactual. Interestingly, in RP patients, both rod-driven and L-cone-driven ERGs were similar using 40° and FF stimuli. The increased responses with smaller stimuli in normal subjects to rod-isolating stimuli indicate that a fundamentally different mechanism drives the ERGs in comparison with the cone-driven responses. We

  15. 13. SOUTHEAST TO SUCKER ROD WORK BENCH AND WOODEN SUCKER ...

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

    13. SOUTHEAST TO SUCKER ROD WORK BENCH AND WOODEN SUCKER ROD STORAGE RACKS ALONG EAST WALL OF FACTORY INTERIOR. AT THIS BENCH WORKERS RIVETED THREADED WROUGHT IRON CONNECTORS TO THE ENDS OF 20' LONG WOODEN SUCKER RODS (THE RODS WHICH EXTEND DOWNWARD IN THE WELL FROM THE GROUND SURFACE TO PISTON DISPLACEMENT PUMPS WHICH ACTUALLY ELEVATE WATER TO THE SURFACE). ROZNOR HEATER AT THE FAR RIGHT WAS ADDED CIRCA 1960. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  16. Strategy Access Rods: A Hands-On Approach.

    ERIC Educational Resources Information Center

    Worthing, Bernadette; Laster, Barbara

    2002-01-01

    Describes Strategy Access Rods (SARs), balsa-wood, prism-like or rectangular rods on which a one-sentence reading strategy phrase in the first person is printed. Notes SARs serve as a visual, auditory, kinesthetic, and tactile reminder of the strategies available to developing readers. Discusses use of SARs for word recognition and comprehension.…

  17. Residual Stress Measurement and the Effect of Heat Treatment in Cladded Control Rod Drive Specimens

    NASA Astrophysics Data System (ADS)

    Bowman, Ashley; Kingston, Ed; Katsuyama, Jinya; Udagawa, Makoto; Onizawa, Kunio

    This paper presents results of residual stress measurements and modelling within the cladding and J-groove weld of Control Rod Drive (CRD) specimens in the as-welded and Post Weld Heat Treated (PWHT) states. Knowledge of the residual stresses present in CRD nozzles is critical when modelling the fracture mechanics of failures of nuclear power plant components to dictate inspections intervals and optimise plant downtime. The specimens comprised of ferritic steel blocks with 309L stainless steel cladding and a single J-groove weld attaching the 304 stainless steel nozzles. Multiple measurements were made through the thickness of the specimens in order to give biaxial residual stress profiles through all the different fusion boundaries. The results show the effect of PWHT in reducing residual stresses both in the weld and ferritic material. The beneficial use of measurements is highlighted to provide confidence in the modelled results and prevent over conservatism in integrity calculations, costing unnecessary time and money.

  18. Power requirement of rotating rods in airflow

    NASA Technical Reports Server (NTRS)

    Barna, P. S.; Crossman, G. R.

    1974-01-01

    Experiments were performed to determine the power required for rotating a rotor disc fitted with a number of radially arranged rods placed into a ducted airflow. An array of stationary rods, also radially arranged, were placed upstream close to the rotor with a small gap between the rods to cause wake interference. The results show that power increased with increasing airflow and the rate of increase varied considerably. At lower values of airflow the rate of increase was larger than at higher airflow and definite power peaks occurred at certain airflow rates, where the power attained a maximum within the test airflow range. During the test a maximum blade passage frequency of 2037 Hz was attained.

  19. Watershed safety and quality control by safety threshold method

    NASA Astrophysics Data System (ADS)

    Da-Wei Tsai, David; Mengjung Chou, Caroline; Ramaraj, Rameshprabu; Liu, Wen-Cheng; Honglay Chen, Paris

    2014-05-01

    Taiwan was warned as one of the most dangerous countries by IPCC and the World Bank. In such an exceptional and perilous island, we would like to launch the strategic research of land-use management on the catastrophe prevention and environmental protection. This study used the watershed management by "Safety Threshold Method" to restore and to prevent the disasters and pollution on island. For the deluge prevention, this study applied the restoration strategy to reduce total runoff which was equilibrium to 59.4% of the infiltration each year. For the sediment management, safety threshold management could reduce the sediment below the equilibrium of the natural sediment cycle. In the water quality issues, the best strategies exhibited the significant total load reductions of 10% in carbon (BOD5), 15% in nitrogen (nitrate) and 9% in phosphorus (TP). We found out the water quality could meet the BOD target by the 50% peak reduction with management. All the simulations demonstrated the safety threshold method was helpful to control the loadings within the safe range of disasters and environmental quality. Moreover, from the historical data of whole island, the past deforestation policy and the mistake economic projects were the prime culprits. Consequently, this study showed a practical method to manage both the disasters and pollution in a watershed scale by the land-use management.

  20. Designing Crane Controls with Applied Mechanical and Electrical Safety Features

    NASA Technical Reports Server (NTRS)

    Lytle, Bradford P.; Walczak, Thomas A.

    2002-01-01

    The use of overhead traveling bridge cranes in many varied applications is common practice. In particular, the use of cranes in the nuclear, military, commercial, aerospace, and other industries can involve safety critical situations. Considerations for Human Injury or Casualty, Loss of Assets, Endangering the Environment, or Economic Reduction must be addressed. Traditionally, in order to achieve additional safety in these applications, mechanical systems have been augmented with a variety of devices. These devices assure that a mechanical component failure shall reduce the risk of a catastrophic loss of the correct and/or safe load carrying capability. ASME NOG-1-1998, (Rules for Construction of Overhead and Gantry Cranes, Top Running Bridge, and Multiple Girder), provides design standards for cranes in safety critical areas. Over and above the minimum safety requirements of todays design standards, users struggle with obtaining a higher degree of reliability through more precise functional specifications while attempting to provide "smart" safety systems. Electrical control systems also may be equipped with protective devices similar to the mechanical design features. Demands for improvement of the cranes "control system" is often recognized, but difficult to quantify for this traditionally "mechanically" oriented market. Finite details for each operation must be examined and understood. As an example, load drift (or small motions) at close tolerances can be unacceptable (and considered critical). To meet these high functional demands encoders and other devices are independently added to control systems to provide motion and velocity feedback to the control drive. This paper will examine the implementation of Programmable Electronic Systems (PES). PES is a term this paper will use to describe any control system utilizing any programmable electronic device such as Programmable Logic Controllers (PLC), or an Adjustable Frequency Drive (AID) 'smart' programmable

  1. Nonlinear finite element modeling of vibration control of plane rod-type structural members with integrated piezoelectric patches

    NASA Astrophysics Data System (ADS)

    Chróścielewski, Jacek; Schmidt, Rüdiger; Eremeyev, Victor A.

    2018-05-01

    This paper addresses modeling and finite element analysis of the transient large-amplitude vibration response of thin rod-type structures (e.g., plane curved beams, arches, ring shells) and its control by integrated piezoelectric layers. A geometrically nonlinear finite beam element for the analysis of piezolaminated structures is developed that is based on the Bernoulli hypothesis and the assumptions of small strains and finite rotations of the normal. The finite element model can be applied to static, stability, and transient analysis of smart structures consisting of a master structure and integrated piezoelectric actuator layers or patches attached to the upper and lower surfaces. Two problems are studied extensively: (i) FE analyses of a clamped semicircular ring shell that has been used as a benchmark problem for linear vibration control in several recent papers are critically reviewed and extended to account for the effects of structural nonlinearity and (ii) a smart circular arch subjected to a hydrostatic pressure load is investigated statically and dynamically in order to study the shift of bifurcation and limit points, eigenfrequencies, and eigenvectors, as well as vibration control for loading conditions which may lead to dynamic loss of stability.

  2. PLUTONIUM FUEL RODS FOR PREPARATION OF TRANSPLUTONIC ELEMENTS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bailey, W.J.

    1962-02-01

    Production by coextrusion of metallurgically bonded, Alclad, Al-7.35 wt% Pu alloy fuel rods with integral ends is discussed. The rods had a diameter of 0.94 in., length of, 60 in., and a nominal cladding thickness of 0.070 in. The Pu concentration was maintained at 83.3 g/rod. The coextrusion billets can be assembled with fuel cores in the as-cast condition. The casting hot-tops can be returned to the process stream. The process is useful for preparing transplutonic elements and production of high-exposure Pu. (J.R.D.)

  3. Curvilinear pigmentary lesions in a rod-cone dystrophy.

    PubMed

    Tamaki, Y; Sawa, M; Yannuzzi, L A

    2005-01-01

    To report a peculiar curvilinear pigmentary lesion in the peripheral fundus in a rod-cone dystrophy. Observational case report. Fundus examination of a 57-year-old woman who was known to have a generalized rod-cone dystrophy since she was 8 years old. The peripheral fundus examination revealed a curvilinear lesion which resembles a well-known finding associated with a presumed ocular histoplasmosis syndrome or multifocal choroiditis. The differential diagnosis of a peculiar curvilinear pigmentary lesion in the peripheral fundus may be expanded to include a generalized rod-cone dystrophy.

  4. Biomechanical stability according to different configurations of screws and rods.

    PubMed

    Ha, Kee-Yong; Hwang, Sung-Chul; Whang, Tae-Hyuk

    2013-05-01

    Comparison of biomechanical strength according to 2 different configurations of screws and rods. To compare the biomechanical strength of different configurations of screws and rods composed of the same material and of the same size. Many complications related to instrumentation have been reported. The incidence of metallic failure would differ according to the materials and configurations of the assembly of the screws and rods used. However, to our knowledge, the biomechanical effects of implant assembly rods and screws with different configurations and different contours have not been reported. Biomechanical testing was conducted to compare top tightening (TT) screw-rod configuration with side tightening (ST) screw-rod configuration. All tests were conducted using a hydraulic all-purpose testing machine. All data were acquired at a rate of 10 Hz. Both screw systems used spinal rods of 6 mm diameter and were made of TiAl4V ELI material. Among 5 types of tests, 3 were conducted on the basis of American Society for Testing and Materials (ASTM) F 1798 to 97 and F1717-10. The other 2 tests were conducted for comparing the characteristics between TT and ST pedicle screws according to modified methods from ASTM F 1717-10 and ASTM F 1798-97. All results including axial gripping capacity and yield forces were obtained using the same methods on the basis of the mentioned ASTM standards. In the axial gripping capacity test, the mean axial gripping capacity of the TT screw-rod configuration was 3332 ± 118 N and that of ST was 2222 ± 147 N in straight rods (P = 0.019). In 15-degree contoured rods, TT was 2988 ± 199 N and ST was 2116 ± 423 N (P = 0.014). In 30-degree contoured rods, TT was 2227 ± 408 N and ST was 1814 ± 285 N (P = 0.009). In the pulling-out test, the pulling-out force of ST was 8695 ± 1616 N and that of TT was 6106 ± 195 N (P = 0.014). In the rod-pushing test, the failure force of ST was 4131 ± 205 N and that of TT was 5639 ± 105 N. In the

  5. Rod-cone interaction in light adaptation

    PubMed Central

    Latch, M.; Lennie, P.

    1977-01-01

    1. The increment-threshold for a small test spot in the peripheral visual field was measured against backgrounds that were red or blue. 2. When the background was a large uniform field, threshold over most of the scotopic range depended exactly upon the background's effect upon rods. This confirms Flamant & Stiles (1948). But when the background was small, threshold was elevated more by a long wave-length than a short wave-length background equated for its effect on rods. 3. The influence of cones was explored in a further experiment. The scotopic increment-threshold was established for a short wave-length test spot on a large, short wave-length background. Then a steady red circular patch, conspicuous to cones, but below the increment-threshold for rod vision, was added to the background. When it was small, but not when it was large, this patch substantially raised the threshold for the test. 4. When a similar experiment was made using, instead of a red patch, a short wave-length one that was conspicuous in rod vision, threshold varied similarly with patch size. These results support the notion that the influence of small backgrounds arises in some size-selective mechanism that is indifferent to the receptor system in which visual signals originate. Two corollaries of this hypothesis were tested in further experiments. 5. A small patch was chosen so as to lift scotopic threshold substantially above its level on a uniform field. This threshold elevation persisted for minutes after extinction of the patch, but only when the patch was small. A large patch made bright enough to elevate threshold by as much as the small one gave rise to no corresponding after-effect. 6. Increment-thresholds for a small red test spot, detected through cones, followed the same course whether a large uniform background was long- or short wave-length. When the background was small, threshold upon the short wave-length one began to rise for much lower levels of background illumination

  6. Research on Occupational Safety, Health Management and Risk Control Technology in Coal Mines.

    PubMed

    Zhou, Lu-Jie; Cao, Qing-Gui; Yu, Kai; Wang, Lin-Lin; Wang, Hai-Bin

    2018-04-26

    This paper studies the occupational safety and health management methods as well as risk control technology associated with the coal mining industry, including daily management of occupational safety and health, identification and assessment of risks, early warning and dynamic monitoring of risks, etc.; also, a B/S mode software (Geting Coal Mine, Jining, Shandong, China), i.e., Coal Mine Occupational Safety and Health Management and Risk Control System, is developed to attain the aforementioned objectives, namely promoting the coal mine occupational safety and health management based on early warning and dynamic monitoring of risks. Furthermore, the practical effectiveness and the associated pattern for applying this software package to coal mining is analyzed. The study indicates that the presently developed coal mine occupational safety and health management and risk control technology and the associated software can support the occupational safety and health management efforts in coal mines in a standardized and effective manner. It can also control the accident risks scientifically and effectively; its effective implementation can further improve the coal mine occupational safety and health management mechanism, and further enhance the risk management approaches. Besides, its implementation indicates that the occupational safety and health management and risk control technology has been established based on a benign cycle involving dynamic feedback and scientific development, which can provide a reliable assurance to the safe operation of coal mines.

  7. Research on Occupational Safety, Health Management and Risk Control Technology in Coal Mines

    PubMed Central

    Zhou, Lu-jie; Cao, Qing-gui; Yu, Kai; Wang, Lin-lin; Wang, Hai-bin

    2018-01-01

    This paper studies the occupational safety and health management methods as well as risk control technology associated with the coal mining industry, including daily management of occupational safety and health, identification and assessment of risks, early warning and dynamic monitoring of risks, etc.; also, a B/S mode software (Geting Coal Mine, Jining, Shandong, China), i.e., Coal Mine Occupational Safety and Health Management and Risk Control System, is developed to attain the aforementioned objectives, namely promoting the coal mine occupational safety and health management based on early warning and dynamic monitoring of risks. Furthermore, the practical effectiveness and the associated pattern for applying this software package to coal mining is analyzed. The study indicates that the presently developed coal mine occupational safety and health management and risk control technology and the associated software can support the occupational safety and health management efforts in coal mines in a standardized and effective manner. It can also control the accident risks scientifically and effectively; its effective implementation can further improve the coal mine occupational safety and health management mechanism, and further enhance the risk management approaches. Besides, its implementation indicates that the occupational safety and health management and risk control technology has been established based on a benign cycle involving dynamic feedback and scientific development, which can provide a reliable assurance to the safe operation of coal mines. PMID:29701715

  8. Efficiency of Hysteresis Rods in Small Spacecraft Attitude Stabilization

    PubMed Central

    Farrahi, Assal; Sanz-Andrés, Ángel

    2013-01-01

    A semiempirical method for predicting the damping efficiency of hysteresis rods on-board small satellites is presented. It is based on the evaluation of dissipating energy variation of different ferromagnetic materials for two different rod shapes: thin film and circular cross-section rods, as a function of their elongation. Based on this formulation, an optimum design considering the size of hysteresis rods, their cross section shape, and layout has been proposed. Finally, the formulation developed was applied to the case of four existing small satellites, whose corresponding in-flight data are published. A good agreement between the estimated rotational speed decay time and the in-flight data has been observed. PMID:24501579

  9. Attentionally splitting the mass distribution of hand-held rods.

    PubMed

    Burton, G; Turvey, M T

    1991-08-01

    Two experiments on the length-perception capabilities of effortful or dynamic touch differed only in terms of what the subject intended to perceive, while experimental conditions and apparatus were held constant. In each trial, a visually occluded rod was held as still as possible by the subject at an intermediate position. For two thirds of the trials, a weight was attached to the rod above or below the hand. In Experiment 1, in which the subject's task was to perceive the distance reachable with the portion of the rod forward of the hand, perceived extent was a function of the first moment of the mass distribution associated with the forward portion of the rod, and indifferent to the first moment of the entire rod. In Experiment 2, in which the task was to perceive the distance reachable with the entire rod if it was held at an end, the pattern of results was reversed. These results indicate the capability of selective sensitivity to different aspects of a hand-held object's mass distribution, without the possibility of differential exploration specific to these two tasks. Results are discussed in relation to possible roles of differential information, intention, and self-organization in the explanations of selective perceptual abilities.

  10. Morphological Diversity of the Rod Spherule: A Study of Serially Reconstructed Electron Micrographs

    PubMed Central

    Li, Shuai; Mitchell, Joe; Briggs, Deidrie J.; Young, Jaime K.; Long, Samuel S.; Fuerst, Peter G.

    2016-01-01

    Purpose Rod spherules are the site of the first synaptic contact in the retina’s rod pathway, linking rods to horizontal and bipolar cells. Rod spherules have been described and characterized through electron micrograph (EM) and other studies, but their morphological diversity related to retinal circuitry and their intracellular structures have not been quantified. Most rod spherules are connected to their soma by an axon, but spherules of rods on the surface of the Mus musculus outer plexiform layer often lack an axon and have a spherule structure that is morphologically distinct from rod spherules connected to their soma by an axon. Retraction of the rod axon and spherule is often observed in disease processes and aging, and the retracted rod spherule superficially resembles rod spherules lacking an axon. We hypothesized that retracted spherules take on an axonless spherule morphology, which may be easier to maintain in a diseased state. To test our hypothesis, we quantified the spatial organization and subcellular structures of rod spherules with and without axons. We then compared them to the retracted spherules in a disease model, mice that overexpress Dscam (Down syndrome cell adhesion molecule), to gain a better understanding of the rod synapse in health and disease. Methods We reconstructed serial EM images of wild type and DscamGoF (gain of function) rod spherules at a resolution of 7 nm in the X-Y axis and 60 nm in the Z axis. Rod spherules with and without axons, and retracted spherules in the DscamGoF retina, were reconstructed. The rod spherule intracellular organelles, the invaginating dendrites of rod bipolar cells and horizontal cell axon tips were also reconstructed for statistical analysis. Results Stereotypical rod (R1) spherules occupy the outer two-thirds of the outer plexiform layer (OPL), where they present as spherical terminals with large mitochondria. This spherule group is highly uniform and composed more than 90% of the rod spherule

  11. Morphological Diversity of the Rod Spherule: A Study of Serially Reconstructed Electron Micrographs.

    PubMed

    Li, Shuai; Mitchell, Joe; Briggs, Deidrie J; Young, Jaime K; Long, Samuel S; Fuerst, Peter G

    2016-01-01

    Rod spherules are the site of the first synaptic contact in the retina's rod pathway, linking rods to horizontal and bipolar cells. Rod spherules have been described and characterized through electron micrograph (EM) and other studies, but their morphological diversity related to retinal circuitry and their intracellular structures have not been quantified. Most rod spherules are connected to their soma by an axon, but spherules of rods on the surface of the Mus musculus outer plexiform layer often lack an axon and have a spherule structure that is morphologically distinct from rod spherules connected to their soma by an axon. Retraction of the rod axon and spherule is often observed in disease processes and aging, and the retracted rod spherule superficially resembles rod spherules lacking an axon. We hypothesized that retracted spherules take on an axonless spherule morphology, which may be easier to maintain in a diseased state. To test our hypothesis, we quantified the spatial organization and subcellular structures of rod spherules with and without axons. We then compared them to the retracted spherules in a disease model, mice that overexpress Dscam (Down syndrome cell adhesion molecule), to gain a better understanding of the rod synapse in health and disease. We reconstructed serial EM images of wild type and DscamGoF (gain of function) rod spherules at a resolution of 7 nm in the X-Y axis and 60 nm in the Z axis. Rod spherules with and without axons, and retracted spherules in the DscamGoF retina, were reconstructed. The rod spherule intracellular organelles, the invaginating dendrites of rod bipolar cells and horizontal cell axon tips were also reconstructed for statistical analysis. Stereotypical rod (R1) spherules occupy the outer two-thirds of the outer plexiform layer (OPL), where they present as spherical terminals with large mitochondria. This spherule group is highly uniform and composed more than 90% of the rod spherule population. Rod spherules

  12. Optimization of a rod pinch diode radiography source at 2.3 MV

    NASA Astrophysics Data System (ADS)

    Menge, P. R.; Johnson, D. L.; Maenchen, J. E.; Rovang, D. C.; Oliver, B. V.; Rose, D. V.; Welch, D. R.

    2003-08-01

    Rod pinch diodes have shown considerable capability as high-brightness flash x-ray sources for penetrating dynamic radiography. The rod pinch diode uses a small diameter (0.4-2 mm) anode rod extended through a cathode aperture. When properly configured, the electron beam born off of the aperture edge can self-insulate and pinch onto the tip of the rod creating an intense, small x-ray source. Sandia's SABRE accelerator (2.3 MV, 40 Ω, 70 ns) has been utilized to optimize the source experimentally by maximizing the figure of merit (dose/spot diameter2) and minimizing the diode impedance droop. Many diode parameters have been examined including rod diameter, rod length, rod material, cathode aperture diameter, cathode thickness, power flow gap, vacuum quality, and severity of rod-cathode misalignment. The configuration producing the greatest figure of merit uses a 0.5 mm diameter gold rod, a 6 mm rod extension beyond the cathode aperture (diameter=8 mm), and a 10 cm power flow gap to produce up to 3.5 rad (filtered dose) at 1 m from a 0.85 mm x-ray on-axis spot (1.02 mm at 3° off axis). The resultant survey of parameter space has elucidated several physics issues that are discussed.

  13. REACTOR CONTROL

    DOEpatents

    Fortescue, P.; Nicoll, D.

    1962-04-24

    A control system employed with a high pressure gas cooled reactor in which a control rod is positioned for upward and downward movement into the neutron field from a position beneath the reactor is described. The control rod is positioned by a coupled piston cylinder releasably coupled to a power drive means and the pressurized coolant is directed against the lower side of the piston. The coolant pressure is offset by a higher fiuid pressure applied to the upper surface of the piston and means are provided for releasing the higher pressure on the upper side of the piston so that the pressure of the coolant drives the piston upwardly, forcing the coupled control rod into the ncutron field of the reactor. (AEC)

  14. CNGA3 Deficiency Affects Cone Synaptic Terminal Structure and Function and Leads to Secondary Rod Dysfunction and Degeneration

    PubMed Central

    Xu, Jianhua; Morris, Lynsie M.; Michalakis, Stylianos; Biel, Martin; Fliesler, Steven J.; Sherry, David M.

    2012-01-01

    Purpose. To investigate rod function and survival after cone dysfunction and degeneration in a mouse model of cone cyclic nucleotide-gated (CNG) channel deficiency. Methods. Rod function and survival in mice with cone CNG channel subunit CNGA3 deficiency (CNGA3−/− mice) were evaluated by electroretinographic (ERG), morphometric, and Western blot analyses. The arrangement, integrity, and ultrastructure of photoreceptor terminals were investigated by immunohistochemistry and electron microscopy. Results. The authors found loss of cone function and cone death accompanied by impairment of rods and rod-driven signaling in CNGA3−/− mice. Scotopic ERG b-wave amplitudes were reduced by 15% at 1 month, 30% at 6 months, and 40% at 9 months and older, while scotopic a-wave amplitudes were decreased by 20% at 9 months, compared with ERGs of age-matched wild-type mice. Outer nuclear layer thickness in CNGA3−/− retina was reduced by 15% at 12 months compared with age-matched wild-type controls. This was accompanied by a 30%–40% reduction in expression of rod-specific proteins, including rhodopsin, rod transducin α-subunit, and glutamic acid-rich protein (GARP). Cone terminals in the CNGA3−/− retina showed a progressive loss of neurochemical and ultrastructural integrity. Abnormalities were observed as early as 1 month. Disorganized rod terminal ultrastructure was noted by 12 months. Conclusions. These findings demonstrate secondary rod impairment and degeneration after cone degeneration in mice with cone CNG channel deficiency. Loss of cone phototransduction accompanies the compromised integrity of cone terminals. With time, rod synaptic structure, function, and viability also become compromised. PMID:22247469

  15. Control of Industrial Safety Based on Dynamic Characteristics of a Safety Budget-Industrial Accident Rate Model in Republic of Korea.

    PubMed

    Choi, Gi Heung; Loh, Byoung Gook

    2017-06-01

    Despite the recent efforts to prevent industrial accidents in the Republic of Korea, the industrial accident rate has not improved much. Industrial safety policies and safety management are also known to be inefficient. This study focused on dynamic characteristics of industrial safety systems and their effects on safety performance in the Republic of Korea. Such dynamic characteristics are particularly important for restructuring of the industrial safety system. The effects of damping and elastic characteristics of the industrial safety system model on safety performance were examined and feedback control performance was explained in view of cost and benefit. The implications on safety policies of restructuring the industrial safety system were also explored. A strong correlation between the safety budget and the industrial accident rate enabled modeling of an industrial safety system with these variables as the input and the output, respectively. A more effective and efficient industrial safety system could be realized by having weaker elastic characteristics and stronger damping characteristics in it. A substantial decrease in total social cost is expected as the industrial safety system is restructured accordingly. A simple feedback control with proportional-integral action is effective in prevention of industrial accidents. Securing a lower level of elastic industrial accident-driving energy appears to have dominant effects on the control performance compared with the damping effort to dissipate such energy. More attention needs to be directed towards physical and social feedbacks that have prolonged cumulative effects. Suggestions for further improvement of the safety system including physical and social feedbacks are also made.

  16. Systematic control of nonmetallic materials for improved fire safety

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The elements of a systematic fire safety program are summarized and consist of fire safety criteria, design considerations, testing of materials, development of nonmetallic materials, nonmetallic materials information systems, design reviews, and change control. The system described in this report was developed for the Apollo spacecraft. The system can, however, be tailored to many industrial, commercial, and military activities.

  17. Method of increasing magnetostrictive response of rare earth-iron alloy rods

    DOEpatents

    Verhoeven, John D.; McMasters, O. Dale; Gibson, Edwin D.; Ostenson, Jerome E.; Finnemore, Douglas K.

    1989-04-04

    This invention comprises a method of increasing the magnetostrictive response of rare earth-iron (RFe) magnetostrictive alloy rods by a thermal-magnetic treatment. The rod is heated to a temperature above its Curie temperature, viz. from 400.degree. to 600.degree. C.; and, while the rod is at that temperature, a magnetic field is directionally applied and maintained while the rod is cooled, at least below its Curie temperature.

  18. Method of increasing magnetostrictive response of rare earth-iron alloy rods

    DOEpatents

    Verhoeven, J.D.; McMasters, O.D.; Gibson, E.D.; Ostenson, J.E.; Finnemore, D.K.

    1989-04-04

    This invention comprises a method of increasing the magnetostrictive response of rare earth-iron (RFe) magnetostrictive alloy rods by a thermal-magnetic treatment. The rod is heated to a temperature above its Curie temperature, viz. from 400 to 600 C; and, while the rod is at that temperature, a magnetic field is directionally applied and maintained while the rod is cooled, at least below its Curie temperature. 2 figs.

  19. Finite-sized one-dimensional silica microstructures (rods): Synthesis, assembly, and applications

    DOE PAGES

    Sharma, Jaswinder

    2017-01-28

    Colloidal silica structures are highly important for applications ranging from surface modifications such as superhydrophobic, oleophobic, icephobic, and anti-biofouling coatings, as reinforcements in polymer-ceramic or metal-matrix composites, and phonon management. In addition to various types of silica structures, a unique structure silica rods has been synthesized by employing the emulsion droplets made by dissolving polyvinlypyrrolidone in pentanol. While a significant progress has been made in further modifying their shape and chemistry, in their assembly, and in their applications, however, no review article compiled the progress in this field. Furthermore, this minireview intends to highlight the development in the synthesis, assembly,more » and application of these rods, and discuss the remaining challenges for precise control of size and shape, possible solutions, and potential applications.« less

  20. Flexible Control of Safety Margins for Action Based on Environmental Variability.

    PubMed

    Hadjiosif, Alkis M; Smith, Maurice A

    2015-06-17

    To reduce the risk of slip, grip force (GF) control includes a safety margin above the force level ordinarily sufficient for the expected load force (LF) dynamics. The current view is that this safety margin is based on the expected LF dynamics, amounting to a static safety factor like that often used in engineering design. More efficient control could be achieved, however, if the motor system reduces the safety margin when LF variability is low and increases it when this variability is high. Here we show that this is indeed the case by demonstrating that the human motor system sizes the GF safety margin in proportion to an internal estimate of LF variability to maintain a fixed statistical confidence against slip. In contrast to current models of GF control that neglect the variability of LF dynamics, we demonstrate that GF is threefold more sensitive to the SD than the expected value of LF dynamics, in line with the maintenance of a 3-sigma confidence level. We then show that a computational model of GF control that includes a variability-driven safety margin predicts highly asymmetric GF adaptation between increases versus decreases in load. We find clear experimental evidence for this asymmetry and show that it explains previously reported differences in how rapidly GFs and manipulatory forces adapt. This model further predicts bizarre nonmonotonic shapes for GF learning curves, which are faithfully borne out in our experimental data. Our findings establish a new role for environmental variability in the control of action. Copyright © 2015 the authors 0270-6474/15/359106-16$15.00/0.

  1. 49 CFR 230.96 - Main, side, and valve motion rods.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Main, side, and valve motion rods. 230.96 Section... Locomotives and Tenders Driving Gear § 230.96 Main, side, and valve motion rods. (a) General. Main, side or... immediately and repaired or renewed. (b) Repairs. Repairs, and welding of main, side or valve motion rods...

  2. 49 CFR 230.96 - Main, side, and valve motion rods.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Main, side, and valve motion rods. 230.96 Section... Locomotives and Tenders Driving Gear § 230.96 Main, side, and valve motion rods. (a) General. Main, side or... immediately and repaired or renewed. (b) Repairs. Repairs, and welding of main, side or valve motion rods...

  3. 49 CFR 230.96 - Main, side, and valve motion rods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Main, side, and valve motion rods. 230.96 Section... Locomotives and Tenders Driving Gear § 230.96 Main, side, and valve motion rods. (a) General. Main, side or... immediately and repaired or renewed. (b) Repairs. Repairs, and welding of main, side or valve motion rods...

  4. 49 CFR 230.96 - Main, side, and valve motion rods.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Main, side, and valve motion rods. 230.96 Section... Locomotives and Tenders Driving Gear § 230.96 Main, side, and valve motion rods. (a) General. Main, side or... immediately and repaired or renewed. (b) Repairs. Repairs, and welding of main, side or valve motion rods...

  5. 49 CFR 230.96 - Main, side, and valve motion rods.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Main, side, and valve motion rods. 230.96 Section... Locomotives and Tenders Driving Gear § 230.96 Main, side, and valve motion rods. (a) General. Main, side or... immediately and repaired or renewed. (b) Repairs. Repairs, and welding of main, side or valve motion rods...

  6. Measurements of Induced-Charge Electroosmotic Flow Around a Metallic Rod

    NASA Astrophysics Data System (ADS)

    Beskok, Ali; Canpolat, Cetin

    2012-11-01

    A cylindrical gold-coated stainless steel rod was positioned at the center of a straight microchannel connecting two fluid reservoirs on either end. The microchannel was filled with 1 mM KCl containing 0.5 micron diameter carboxylate-modified spherical particles. Induced-charge electro-osmotic (ICEO) flow occurred around the metallic rod under a sinusoidal AC electric field applied using two platinum electrodes. The ICEO flows around the metallic rod were measured using micro particle image velocimetry (micro-PIV) technique as functions of the AC electric field strength and frequency. The present study provides experimental data about ICEO flow in the weakly nonlinear limit of thin double layers, in which, the charging dynamics of the double layer cannot be presented analytically. Flow around the rod is quadrupolar, driving liquid towards the rod along the electric field and forcing it away from the rod in the direction perpendicular to the imposed electric field. The measured ICEO flow velocity is proportional to the square of the electric field strength, and depends on the applied AC frequency.

  7. Bilateral Symmetry of Visual Function Loss in Cone-Rod Dystrophies.

    PubMed

    Galli-Resta, Lucia; Falsini, Benedetto; Rossi, Giuseppe; Piccardi, Marco; Ziccardi, Lucia; Fadda, Antonello; Minnella, Angelo; Marangoni, Dario; Placidi, Giorgio; Campagna, Francesca; Abed, Edoardo; Bertelli, Matteo; Zuntini, Monia; Resta, Giovanni

    2016-07-01

    To investigate bilateral symmetry of visual impairment in cone-rod dystrophy (CRD) patients and understand the feasibility of clinical trial designs treating one eye and using the untreated eye as an internal control. This was a retrospective study of visual function loss measures in 436 CRD patients followed at the Ophthalmology Department of the Catholic University in Rome. Clinical measures considered were best-corrected visual acuity, focal macular cone electroretinogram (fERG), and Ganzfeld cone-mediated and rod-mediated electroretinograms. Interocular agreement in each of these clinical indexes was assessed by t- and Wilcoxon tests for paired samples, structural (Deming) regression analysis, and intraclass correlation. Baseline and follow-up measures were analyzed. A separate analysis was performed on the subset of 61 CRD patients carrying likely disease-causing mutations in the ABCA4 gene. Statistical tests show a very high degree of bilateral symmetry in the extent and progression of visual impairment in the fellow eyes of CRD patients. These data contribute to a better understanding of CRDs and support the feasibility of clinical trial designs involving unilateral eye treatment with the use of fellow eye as internal control.

  8. Effect of Controlled Rolling and Cooling On Microstructure and Mechanical Properties of 30crmnti Wire Rod

    NASA Astrophysics Data System (ADS)

    Ruan, Shipeng; Dong, Qing; Zhang, Lei; Wang, Lijun

    2017-09-01

    The effect of controlled rolling and cooling on microstructure and mechanical properties of alloy structure steel 30CrMnTi wire rod with diameter 6.5mm was studied. The results show that the lower finish rolling temperature resulted in a decrease in tensile strength but an increase in elongation and reduction of area. When the finish rolling temperature decreases from 950°C to 850°C, the tensile strength value decreases from 750MPa to 660MPa, and the elongation increases from 21% to 30%, the reduction of area increases from 64% to 71%. The grain size also refines from 20μm to 9.9μm when the finish rolling temperature decreases from 950°C to 850°C. The decrease of tensile strength is due to the change of microstructure which evolved from more bainite to ferrite and pearlite.

  9. Pedicle screw-rod fixation: a feasible treatment for dogs with severe degenerative lumbosacral stenosis.

    PubMed

    Tellegen, Anna R; Willems, Nicole; Tryfonidou, Marianna A; Meij, Björn P

    2015-12-07

    Degenerative lumbosacral stenosis is a common problem in large breed dogs. For severe degenerative lumbosacral stenosis, conservative treatment is often not effective and surgical intervention remains as the last treatment option. The objective of this retrospective study was to assess the middle to long term outcome of treatment of severe degenerative lumbosacral stenosis with pedicle screw-rod fixation with or without evidence of radiological discospondylitis. Twelve client-owned dogs with severe degenerative lumbosacral stenosis underwent pedicle screw-rod fixation of the lumbosacral junction. During long term follow-up, dogs were monitored by clinical evaluation, diagnostic imaging, force plate analysis, and by using questionnaires to owners. Clinical evaluation, force plate data, and responses to questionnaires completed by the owners showed resolution (n = 8) or improvement (n = 4) of clinical signs after pedicle screw-rod fixation in 12 dogs. There were no implant failures, however, no interbody vertebral bone fusion of the lumbosacral junction was observed in the follow-up period. Four dogs developed mild recurrent low back pain that could easily be controlled by pain medication and an altered exercise regime. Pedicle screw-rod fixation offers a surgical treatment option for large breed dogs with severe degenerative lumbosacral stenosis with or without evidence of radiological discospondylitis in which no other treatment is available. Pedicle screw-rod fixation alone does not result in interbody vertebral bone fusion between L7 and S1.

  10. Development of Rod Function in Term Born and Former Preterm Subjects

    PubMed Central

    Fulton, Anne B.; Hansen, Ronald M.; Moskowitz, Anne

    2009-01-01

    Purpose Provide an overview of some of our electroretinographic and psychophysical studies of normal development of rod function and their application to retinopathy of prematurity (ROP). Methods Electroretinographic (ERG) responses to full-field stimuli were recorded from dark adapted subjects. Rod photoreceptor sensitivity, SROD, was calculated by fit of a biochemical model of the activation of phototransduction to the ERG a-wave. Dark adapted psychophysical thresholds for detecting 2° spots in parafoveal (10° eccentric) and peripheral (30° eccentric) retina were measured and the difference between the thresholds, Δ10-30, was examined as a function of age. SROD and Δ10-30 in term born and former preterm subjects were compared. Results In term born infants, (1) the normal developmental increase in SROD changes proportionately with the amount of rod visual pigment, rhodopsin, and (2) rod mediated function in central retina is immature compared to that in peripheral retina. In subjects born prematurely, deficits in rod photoreceptor sensitivity persist long after active ROP has resolved. Maturation of rod mediated thresholds in the central retina is prolonged by mild ROP. Conclusions Characterization of the development of normal rod and rod mediated function provides a foundation for understanding ROP. PMID:19483509

  11. Evaluation of spinal instrumentation rod bending characteristics for in-situ contouring.

    PubMed

    Noshchenko, Andriy; Xianfeng, Yao; Armour, Grant Alan; Baldini, Todd; Patel, Vikas V; Ayers, Reed; Burger, Evalina

    2011-07-01

    Bending characteristics were studied in rods used for spinal instrumentation at in-situ contouring conditions. Five groups of five 6 mm diameter rods made from: cobalt alloy (VITALLIUM), titanium-aluminum-vanadium alloy (SDI™), β-titanium alloy (TNTZ), cold worked stainless steel (STIFF), and annealed stainless steel (MALLEABLE) were studied. The bending procedure was similar to that typically applied for in-situ contouring in the operating room and included two bending cycles: first--bending to 21-24° under load with further release of loading for 10 min, and second--bending to 34-37° at the previously bent site and release of load for 10 min. Applied load, bending stiffness, and springback effect were studied. Statistical evaluation included ANOVA, correlation and regression analysis. TNTZ and SDI™ rods showed the highest (p < 0.05) springback at both bending cycles. VITALLIUM and STIFF rods showed mild springback (p < 0.05). The least (p < 0.05) springback was observed in the MALLEABLE rods. Springback significantly correlated with the bend angle under load (p < 0.001). To reach the necessary bend angle after unloading, over bending should be 37-40% of the required angle in TNTZ and SDI™ rods, 27-30% in VITALLIUM and STIFF rods, and around 20% in MALLEABLE rods. Copyright © 2011 Wiley Periodicals, Inc.

  12. Cost analysis of a growth guidance system compared with traditional and magnetically controlled growing rods for early-onset scoliosis: a US-based integrated health care delivery system perspective.

    PubMed

    Luhmann, Scott J; McAughey, Eoin M; Ackerman, Stacey J; Bumpass, David B; McCarthy, Richard E

    2018-01-01

    Treating early-onset scoliosis (EOS) with traditional growing rods (TGR) is effective but requires periodic surgical lengthening, risking complications. Alternatives include magnetically controlled growing rods (MCGR) that lengthen noninvasively and the growth guidance system (GGS), which obviate the need for active, distractive lengthenings. Previous studies have reported promising clinical effectiveness for GGS; however the direct medical costs of GGS compared to TGR and MCGR have not yet been explored. To estimate the cost of GGS compared with MCGR and TGR for EOS an economic model was developed from the perspective of a US integrated health care delivery system. Using dual-rod constructs, the model estimated the cumulative costs associated with initial implantation, rod lengthenings (TGR, MCGR), revisions due to device failure, surgical-site infections, device exchange, and final spinal fusion over a 6-year episode of care. Model parameters were from peer-reviewed, published literature. Medicare payments were used as a proxy for provider costs. Costs (2016 US$) were discounted 3% annually. Over a 6-year episode of care, GGS was associated with fewer invasive surgeries per patient than TGR (GGS: 3.4; TGR: 14.4) and lower cumulative costs than MCGR and TGR, saving $25,226 vs TGR. Sensitivity analyses showed that results were sensitive to changes in construct costs, rod breakage rates, months between lengthenings, and TGR lengthening setting of care. Within the model, GGS resulted in fewer invasive surgeries and deep surgical site infections than TGR, and lower cumulative costs per patient than both MCGR and TGR, over a 6-year episode of care. The analysis did not account for family disruption, pain, psychological distress, or compromised health-related quality of life associated with invasive TGR lengthenings, nor for potential patient anxiety surrounding the frequent MCGR lengthenings. Further analyses focusing strictly on current generation technologies should

  13. Cost analysis of a growth guidance system compared with traditional and magnetically controlled growing rods for early-onset scoliosis: a US-based integrated health care delivery system perspective

    PubMed Central

    Luhmann, Scott J; McAughey, Eoin M; Ackerman, Stacey J; Bumpass, David B; McCarthy, Richard E

    2018-01-01

    Purpose Treating early-onset scoliosis (EOS) with traditional growing rods (TGR) is effective but requires periodic surgical lengthening, risking complications. Alternatives include magnetically controlled growing rods (MCGR) that lengthen noninvasively and the growth guidance system (GGS), which obviate the need for active, distractive lengthenings. Previous studies have reported promising clinical effectiveness for GGS; however the direct medical costs of GGS compared to TGR and MCGR have not yet been explored. Methods To estimate the cost of GGS compared with MCGR and TGR for EOS an economic model was developed from the perspective of a US integrated health care delivery system. Using dual-rod constructs, the model estimated the cumulative costs associated with initial implantation, rod lengthenings (TGR, MCGR), revisions due to device failure, surgical-site infections, device exchange, and final spinal fusion over a 6-year episode of care. Model parameters were from peer-reviewed, published literature. Medicare payments were used as a proxy for provider costs. Costs (2016 US$) were discounted 3% annually. Results Over a 6-year episode of care, GGS was associated with fewer invasive surgeries per patient than TGR (GGS: 3.4; TGR: 14.4) and lower cumulative costs than MCGR and TGR, saving $25,226 vs TGR. Sensitivity analyses showed that results were sensitive to changes in construct costs, rod breakage rates, months between lengthenings, and TGR lengthening setting of care. Conclusion Within the model, GGS resulted in fewer invasive surgeries and deep surgical site infections than TGR, and lower cumulative costs per patient than both MCGR and TGR, over a 6-year episode of care. The analysis did not account for family disruption, pain, psychological distress, or compromised health-related quality of life associated with invasive TGR lengthenings, nor for potential patient anxiety surrounding the frequent MCGR lengthenings. Further analyses focusing strictly on

  14. Skin bridge versus rod colostomy in children - comparison between complications.

    PubMed

    Askarpour, Shahnam; Peyvasteh, Mehran; Changai, Bahram; Javaherizadeh, Hazhir

    2012-10-01

    Due to economic problems, sigmoid loop colostomy using glass rod may cause problems for our patients for finding glass rod and several visits. The aim of the study was to compare rod versus skin bridge colostomy. In this study, 42 cases who are candidate for colostomy were included. Cases were randomly placed in skin bridge and rod colostomy group. Independent sample t-test and Chi-square were used for comparison. SPSS version 16.0 (SPSS Inc, Chicago, IL, USA) was used for analysis. Of 42 cases, 20 were male and 22 were female. Hirschsprung's disease was the indication of colostomy in 33 cases. In nine cases, imperforate anus was the indication of colostomy. Mean time of surgery was 79.4 and 82.5 minute for the rod and skin bridge group respectively (P>0.05). Retraction was seen in 2 case of rod group, and no case of skin bridge group. Prolapse was seen in 2 (9.5%) case of rod group and 1(4.7%) case in skin bridge. There were no reports of necrosis, stenosis, and hernia in both groups. In the skin bridge group the rates of complications were lower but the groups are too small for statistical analysis. Colostomy with a skin bridge method may decrease number of revision and expenses and may be appropriate option. Sigmoid loop colostomy using skin bridge flap may be appropriate choice in developing country. Another study with more samples is recommended to better comparison of Skin Bridge versus rod colostomy.

  15. ZnO Nano-Rod Devices for Intradermal Delivery and Immunization

    PubMed Central

    Nayak, Tapas R.; Wang, Hao; Pant, Aakansha; Zheng, Minrui; Junginger, Hans; Goh, Wei Jiang; Lee, Choon Keong; Zou, Shui; Alonso, Sylvie; Czarny, Bertrand; Storm, Gert; Sow, Chorng Haur; Lee, Chengkuo; Pastorin, Giorgia

    2017-01-01

    Intradermal delivery of antigens for vaccination is a very attractive approach since the skin provides a rich network of antigen presenting cells, which aid in stimulating an immune response. Numerous intradermal techniques have been developed to enhance penetration across the skin. However, these methods are invasive and/or affect the skin integrity. Hence, our group has devised zinc oxide (ZnO) nano-rods for non-destructive drug delivery. Chemical vapour deposition was used to fabricate aligned nano-rods on ZnO pre-coated silicon chips. The nano-rods’ length and diameter were found to depend on the temperature, time, quality of sputtered silicon chips, etc. Vertically aligned ZnO nano-rods with lengths of 30–35 µm and diameters of 200–300 nm were selected for in vitro human skin permeation studies using Franz cells with Albumin-fluorescein isothiocyanate (FITC) absorbed on the nano-rods. Fluorescence and confocal studies on the skin samples showed FITC penetration through the skin along the channels formed by the nano-rods. Bradford protein assay on the collected fluid samples indicated a significant quantity of Albumin-FITC in the first 12 h. Low antibody titres were observed with immunisation on Balb/c mice with ovalbumin (OVA) antigen coated on the nano-rod chips. Nonetheless, due to the reduced dimensions of the nano-rods, our device offers the additional advantage of excluding the simultaneous entrance of microbial pathogens. Taken together, these results showed that ZnO nano-rods hold the potential for a safe, non-invasive, and painless intradermal drug delivery. PMID:28617335

  16. A Characterization of the Radiation from a Rod-Pinch Diode

    NASA Astrophysics Data System (ADS)

    Swanekamp, Stephen B.; Allen, Raymond J.; Hinshelwood, David D.; Mosher, David; Schumer, Joseph W.

    2002-12-01

    Coupled PIC-Monte-Carlo simulations of the electron-flow and radiation production in a rod-pinch diode show that multiple scatterings in the rod produce incident electron energies that ranging from zero to slightly higher than the applied voltage. It is speculated that those electrons that gain energy do so by remaining in phase with a rapidly varying electric field near the tip of the rod. The simulations also show that multiple passes in the rod produce a wide spread in incident electron angles. For diode voltages of V=2 MV, the angular distribution of electrons incident on the rod is broad and peaked near 90° to the axis of the rod with a larger fraction of electrons striking the rod at angles less than 90°. The electron angular distribution for V=4 MV is narrower and peaked at 105° with a larger fraction of electrons incident on the rod with angles greater than 90°. The photon distributions are peaked along the direction of the high-energy electrons. For V=2 MV the dose filtered through 21/4-cm thick Plexiglas is peaked at 90° and is 1.8 times higher than the forward-directed [0°] dose. For V=4 MV the dose filtered through 21/4-cm thick Plexiglas is peaked at 120° and is 2.3 times higher than the forward-directed dose. Similar angular variation of the dose has been observed on the 4-MV Asterix accelerator [2] and on 1-2 MV accelerators at the Atomic Weapons Establishment [8].

  17. Comparative Study Between Cobalt Chrome and Titanium Alloy Rods for Multilevel Spinal Fusion: Proximal Junctional Kyphosis More Frequently Occurred in Patients Having Cobalt Chrome Rods.

    PubMed

    Han, Sanghyun; Hyun, Seung-Jae; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2017-07-01

    The use of titanium alloy (Ti) rods is frequently associated with rod fracture after spinal fixation. To address this issue, cobalt chrome (CoCr) rods, which are advantageous because of their greater strength and resistance to fatigue relative to Ti rods, have been introduced. The purpose of the present study was to compare radiographic outcomes after the use of Ti versus CoCr rods in a matched cohort of patients undergoing posterior spinal fusion for treatment of spinal instability. We retrospectively reviewed data from patients who had undergone spinal fusion involving more than 3 levels at a single institution between 2004 and 2015. Patients were matched for age, diagnosis, 3-column osteotomy, levels fused, and T score. Fifty patients with Ti rods were identified and appropriately matched to 50 consecutive patients with CoCr rods. The distributions of age at surgery, sex, diagnosis, 3-column osteotomy, levels fused, number of patients with previous surgical procedures, and T score did not significantly differ between the 2 groups. However, there were significant differences in length of follow-up (CoCr, 25.0 vs. Ti, 28.5 months; P < 0.001), fusion rate (CoCr, 45 [90%] vs. Ti, 33 [66%]; P = 0.004), occurrence of rod breakage (CoCr, 0 vs. T, 8 [16%]; P = 0.006), and junctional kyphosis (CoCr, 24 [46%] vs. Ti, 9 [18%]; P = 0.003). Our findings indicate that the use of CoCr rods is effective in ensuring stability of the posterior spinal construct and accomplishment of spinal fusion. Furthermore, our results indicate that junctional kyphosis may occur more frequently in CoCr systems than in Ti systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Mouse rods signal through gap junctions with cones

    PubMed Central

    Asteriti, Sabrina; Gargini, Claudia; Cangiano, Lorenzo

    2014-01-01

    Rod and cone photoreceptors are coupled by gap junctions (GJs), relatively large channels able to mediate both electrical and molecular communication. Despite their critical location in our visual system and evidence that they are dynamically gated for dark/light adaptation, the full impact that rod–cone GJs can have on cone function is not known. We recorded the photovoltage of mouse cones and found that the initial level of rod input increased spontaneously after obtaining intracellular access. This process allowed us to explore the underlying coupling capacity to rods, revealing that fully coupled cones acquire a striking rod-like phenotype. Calcium, a candidate mediator of the coupling process, does not appear to be involved on the cone side of the junctional channels. Our findings show that the anatomical substrate is adequate for rod–cone coupling to play an important role in vision and, possibly, in biochemical signaling among photoreceptors. DOI: http://dx.doi.org/10.7554/eLife.01386.001 PMID:24399457

  19. Choice of mathematical models for technological process of glass rod drawing

    NASA Astrophysics Data System (ADS)

    Alekseeva, L. B.

    2017-10-01

    The technological process of drawing glass rods (light guides) is considered. Automated control of the drawing process is reduced to the process of making decisions to ensure a given quality. The drawing process is considered as a control object, including the drawing device (control device) and the optical fiber forming zone (control object). To study the processes occurring in the formation zone, mathematical models are proposed, based on the continuum mechanics basics. To assess the influence of disturbances, a transfer function is obtained from the basis of the wave equation. Obtaining the regression equation also adequately describes the drawing process.

  20. The Application of Software Safety to the Constellation Program Launch Control System

    NASA Technical Reports Server (NTRS)

    Kania, James; Hill, Janice

    2011-01-01

    The application of software safety practices on the LCS project resulted in the successful implementation of the NASA Software Safety Standard NASA-STD-8719.138 and CxP software safety requirements. The GOP-GEN-GSW-011 Hazard Report was the first report developed at KSC to identify software hazard causes and their controls. This approach can be applied to similar large software - intensive systems where loss of control can lead to a hazard.

  1. Rod/Coil Block Copolyimides for Ion-Conducting Membranes

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Kinder, James D.

    2003-01-01

    Rod/coil block copolyimides that exhibit high levels of ionic conduction can be made into diverse products, including dimensionally stable solid electrolyte membranes that function well over wide temperature ranges in fuel cells and in lithium-ion electrochemical cells. These rod/coil block copolyimides were invented to overcome the limitations of polymers now used to make such membranes. They could also be useful in other electrochemical and perhaps some optical applications, as described below. The membranes of amorphous polyethylene oxide (PEO) now used in lithium-ion cells have acceptably large ionic conductivities only at temperatures above 60 C, precluding use in what would otherwise be many potential applications at lower temperatures. PEO is difficult to process, and, except at the highest molecular weights it is not very dimensionally stable. It would be desirable to operate fuel cells at temperatures above 80 C to take advantage of better kinetics of redox reactions and to reduce contamination of catalysts. Unfortunately, proton-conduction performance of a typical perfluorosulfonic polymer membrane now used as a solid electrolyte in a fuel cell decreases with increasing temperature above 80 C because of loss of water from within the membrane. The loss of water has been attributed to the hydrophobic nature of the polymer backbone. In addition, perfluorosulfonic polymers are expensive and are not sufficiently stable for long-term use. Rod/coil block copolyimides are so named because each molecule of such a polymer comprises short polyimide rod segments alternating with flexible polyether coil segments (see figure). The rods and coils can be linear, branched, or mixtures of linear and branched. A unique feature of these polymers is that the rods and coils are highly incompatible, giving rise to a phase separation with a high degree of ordering that creates nanoscale channels in which ions can travel freely. The conduction of ions can occur in the coil phase

  2. Microgravity Flammability of PMMA Rods in Concurrent Flow

    NASA Technical Reports Server (NTRS)

    Olson, Sandra L.; Ferkul, Paul V.

    2015-01-01

    Microgravity experiments burning cast PMMA cylindrical rods in axial flow have been conducted aboard the International Space Station in the Microgravity Science Glovebox (MSG) facility using the Burning and Suppression of Solids (BASS) flow duct, as part of the BASS-II experiment. Twenty-four concurrent-flow tests were performed, focusing on finding flammability limits as a function of oxygen and flow speed. The oxygen was varied by using gaseous nitrogen to vitiate the working volume of the MSG. The speed of the flow parallel to the rod was varied using a fan at the entrance to the duct. Both blowoff and quenching limits were obtained at several oxygen concentrations. Each experiment ignited the rod at the initially hemispherical stagnation tip of the rod, and allowed the flame to develop and heat the rod at a sufficient flow to sustain burning. For blowoff limit tests, the astronaut quickly turned up the flow to obtain extinction. Complementary 5.18-second Zero Gravity Facility drop tests were conducted to compare blowoff limits in short and long duration microgravity. For quenching tests, the flow was incrementally turned down and the flame allowed to stabilize at the new flow condition for at least the solid-phase response time before changing it again. Quenching was observed when the flow became sufficiently weak that the flame could no longer provide adequate heat flux to compensate for the heat losses (conduction into the rod and radiation). A surface energy balance is presented that shows the surface radiative loss exceeds the conductive loss into the rod near the limit. The flammability boundary is shown to represent a critical Damkohler number, expressed in terms of the reaction rate divided by the stretch rate. For the blowoff branch, the boundary exhibits a linear dependence on oxygen concentration and stretch rate, indicating that the temperature at blowoff must be fairly constant. For the quenching branch, the dominance of the exponential nature of

  3. A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads.

    PubMed

    Lin, Hao-Ting

    2017-06-04

    This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

  4. A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads

    PubMed Central

    Lin, Hao-Ting

    2017-01-01

    This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally. PMID:28587220

  5. Evaluation of the finite element fuel rod analysis code (FRANCO)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, K.; Feltus, M.A.

    1994-12-31

    Knowledge of temperature distribution in a nuclear fuel rod is required to predict the behavior of fuel elements during operating conditions. The thermal and mechanical properties and performance characteristics are strongly dependent on the temperature, which can vary greatly inside the fuel rod. A detailed model of fuel rod behavior can be described by various numerical methods, including the finite element approach. The finite element method has been successfully used in many engineering applications, including nuclear piping and reactor component analysis. However, fuel pin analysis has traditionally been carried out with finite difference codes, with the exception of Electric Powermore » Research Institute`s FREY code, which was developed for mainframe execution. This report describes FRANCO, a finite element fuel rod analysis code capable of computing temperature disrtibution and mechanical deformation of a single light water reactor fuel rod.« less

  6. Occupancy of the Chromophore Binding Site of Opsin Activates Visual Transduction in Rod Photoreceptors

    PubMed Central

    Kefalov, Vladimir J.; Carter Cornwall, M.; Crouch, Rosalie K.

    1999-01-01

    The retinal analogue β-ionone was used to investigate possible physiological effects of the noncovalent interaction between rod opsin and its chromophore 11-cis retinal. Isolated salamander rod photoreceptors were exposed to bright light that bleached a significant fraction of their pigment, were allowed to recover to a steady state, and then were exposed to β-ionone. Our experiments show that in bleach-adapted rods β-ionone causes a decrease in light sensitivity and dark current and an acceleration of the dim flash photoresponse and the rate constants of guanylyl cyclase and cGMP phosphodiesterase. Together, these observations indicate that in bleach-adapted rods β-ionone activates phototransduction in the dark. Control experiments showed no effect of β-ionone in either fully dark-adapted or background light-adapted cells, indicating direct interaction of β-ionone with the free opsin produced by bleaching. We speculate that β-ionone binds specifically in the chromophore pocket of opsin to produce a complex that is more catalytically potent than free opsin alone. We hypothesize that a similar reaction may occur in the intact retina during pigment regeneration. We propose a model of rod pigment regeneration in which binding of 11-cis retinal to opsin leads to activation of the complex accompanied by a decrease in light sensitivity. The subsequent covalent attachment of retinal to opsin completely inactivates opsin and leads to the recovery of sensitivity. Our findings resolve the conflict between biochemical and physiological data concerning the effect of the occupancy of the chromophore binding site on the catalytic potency of opsin. We show that binding of β-ionone to rod opsin produces effects opposite to its previously described effects on cone opsin. We propose that this distinction is due to a fundamental difference in the interaction of rod and cone opsins with retinal, which may have implications for the different physiology of the two types of

  7. Variation in sensitivity, absorption and density of the central rod distribution with eccentricity.

    PubMed

    Tornow, R P; Stilling, R

    1998-01-01

    To assess the human rod photopigment distribution and sensitivity with high spatial resolution within the central +/-15 degrees and to compare the results of pigment absorption, sensitivity and rod density distribution (number of rods per square degree). Rod photopigment density distribution was measured with imaging densitometry using a modified Rodenstock scanning laser ophthalmoscope. Dark-adapted sensitivity profiles were measured with green stimuli (17' arc diameter, 1 degrees spacing) using a T ubingen manual perimeter. Sensitivity profiles were plotted on a linear scale and rod photopigment optical density distribution profiles were converted to absorption profiles of the rod photopigment layer. Both the absorption profile of the rod photopigment and the linear sensitivity profile for green stimuli show a minimum at the foveal center and increase steeply with eccentricity. The variation with eccentricity corresponds to the rod density distribution. Rod photopigment absorption profiles, retinal sensitivity profiles, and the rod density distribution are linearly related within the central +/-15 degrees. This is in agreement with theoretical considerations. Both methods, imaging retinal densitometry using a scanning laser ophthalmoscope and dark-adapted perimetry with small green stimuli, are useful for assessing the central rod distribution and sensitivity. However, at present, both methods have limitations. Suggestions for improving the reliability of both methods are given.

  8. Flame spread along thermally thick horizontal rods

    NASA Astrophysics Data System (ADS)

    Higuera, F. J.

    2002-06-01

    An analysis is carried out of the spread of a flame along a horizontal solid fuel rod, for which a weak aiding natural convection flow is established in the underside of the rod by the action of the axial gradient of the pressure variation that gravity generates in the warm gas surrounding the flame. The spread rate is determined in the limit of infinitely fast kinetics, taking into account the effect of radiative losses from the solid surface. The effect of a small inclination of the rod is discussed, pointing out a continuous transition between upward and downward flame spread. Flame spread along flat-bottomed solid cylinders, for which the gradient of the hydrostatically generated pressure drives the flow both along and across the direction of flame propagation, is also analysed.

  9. Highway Safety Program Manual: Volume 16: Debris Hazard Control and Cleanup.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 16 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) concentrates on debris hazard control and cleanup. The purpose and objectives of such a program are outlined. Federal authority in the area of highway safety and policies regarding a debris control…

  10. Fasudil, a Clinically Used ROCK Inhibitor, Stabilizes Rod Photoreceptor Synapses after Retinal Detachment.

    PubMed

    Townes-Anderson, Ellen; Wang, Jianfeng; Halász, Éva; Sugino, Ilene; Pitler, Amy; Whitehead, Ian; Zarbin, Marco

    2017-06-01

    Retinal detachment disrupts the rod-bipolar synapse in the outer plexiform layer by retraction of rod axons. We showed that breakage is due to RhoA activation whereas inhibition of Rho kinase (ROCK), using Y27632, reduces synaptic damage. We test whether the ROCK inhibitor fasudil, used for other clinical applications, can prevent synaptic injury after detachment. Detachments were made in pigs by subretinal injection of balanced salt solution (BSS) or fasudil (1, 10 mM). In some animals, fasudil was injected intravitreally after BSS-induced detachment. After 2 to 4 hours, retinae were fixed for immunocytochemistry and confocal microscopy. Axon retraction was quantified by imaging synaptic vesicle label in the outer nuclear layer. Apoptosis was analyzed using propidium iodide staining. For biochemical analysis by Western blotting, retinal explants, detached from retinal pigmented epithelium, were cultured for 2 hours. Subretinal injection of fasudil (10 mM) reduced retraction of rod spherules by 51.3% compared to control detachments ( n = 3 pigs, P = 0.002). Intravitreal injection of 10 mM fasudil, a more clinically feasible route of administration, also reduced retraction (28.7%, n = 5, P < 0.05). Controls had no photoreceptor degeneration at 2 hours, but by 4 hours apoptosis was evident. Fasudil 10 mM reduced pyknotic nuclei by 55.7% ( n = 4, P < 0.001). Phosphorylation of cofilin and myosin light chain, downstream effectors of ROCK, was decreased with 30 μM fasudil ( n = 8-10 explants, P < 0.05). Inhibition of ROCK signaling with fasudil reduced photoreceptor degeneration and preserved the rod-bipolar synapse after retinal detachment. These results support the possibility, previously tested with Y27632, that ROCK inhibition may attenuate synaptic damage in iatrogenic detachments.

  11. 32 CFR 989.21 - Record of decision (ROD).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Record of decision (ROD). 989.21 Section 989.21 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ENVIRONMENTAL PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.21 Record of decision (ROD). (a) The proponent and the EPF...

  12. Percolation, phase separation, and gelation in fluids and mixtures of spheres and rods

    NASA Astrophysics Data System (ADS)

    Jadrich, Ryan; Schweizer, Kenneth S.

    2011-12-01

    The relationship between kinetic arrest, connectivity percolation, structure and phase separation in protein, nanoparticle, and colloidal suspensions is a rich and complex problem. Using a combination of integral equation theory, connectivity percolation methods, naïve mode coupling theory, and the activated dynamics nonlinear Langevin equation approach, we study this problem for isotropic one-component fluids of spheres and variable aspect ratio rigid rods, and also percolation in rod-sphere mixtures. The key control parameters are interparticle attraction strength and its (short) spatial range, total packing fraction, and mixture composition. For spherical particles, formation of a homogeneous one-phase kinetically stable and percolated physical gel is predicted to be possible, but depends on non-universal factors. On the other hand, the dynamic crossover to activated dynamics and physical bond formation, which signals discrete cluster formation below the percolation threshold, almost always occurs in the one phase region. Rods more easily gel in the homogeneous isotropic regime, but whether a percolation or kinetic arrest boundary is reached first upon increasing interparticle attraction depends sensitively on packing fraction, rod aspect ratio and attraction range. Overall, the connectivity percolation threshold is much more sensitive to attraction range than either the kinetic arrest or phase separation boundaries. Our results appear to be qualitatively consistent with recent experiments on polymer-colloid depletion systems and brush mediated attractive nanoparticle suspensions.

  13. Wavelength-selective thermal emitters using Si-rods on MgO

    NASA Astrophysics Data System (ADS)

    Suemitsu, Masahiro; Asano, Takashi; De Zoysa, Menaka; Noda, Susumu

    2018-01-01

    Supporting substrates for Si rod-type photonic crystals (PCs) are investigated for realizing highly wavelength-selective near-infrared thermal emitters. Three materials—SiO2, Al2O3, and MgO—are considered for their low infrared emission (transparency) and remarkable heat resistance. Theoretical calculations of the emissivity spectra of Si-rod PCs (rod height = 500 nm, rod diameter = 300 nm, and lattice constant = 600 nm) on 50 μm-thick supporting substrates at 1400 K indicate that the long-wavelength (>3 μm) emission power from the emitter using MgO is less than 1/10 of that of the other two materials. Fabrication of the Si-rod PCs on the 50 μm-thick MgO substrate requires the insertion of a thin (30 nm) HfO2 film between MgO and Si to improve the stability at high temperatures (>1400 K). Experimental results of the fabricated structure show that at 1400 K, the ratio of emissive power at wavelengths <1.8 μm to the total emissive power is 34% and that this can be increased to over 53% in an optimized rod-array structure with a 10 μm-thick MgO substrate.

  14. Impact of Passive Safety on FHR Instrumentation Systems Design and Classification

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Holcomb, David Eugene

    2015-01-01

    Fluoride salt-cooled high-temperature reactors (FHRs) will rely more extensively on passive safety than earlier reactor classes. 10CFR50 Appendix A, General Design Criteria for Nuclear Power Plants, establishes minimum design requirements to provide reasonable assurance of adequate safety. 10CFR50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors, provides guidance on how the safety significance of systems, structures, and components (SSCs) should be reflected in their regulatory treatment. The Nuclear Energy Institute (NEI) has provided 10 CFR 50.69 SSC Categorization Guideline (NEI-00-04) that factors in probabilistic risk assessment (PRA) model insights, as well as deterministic insights, throughmore » an integrated decision-making panel. Employing the PRA to inform deterministic requirements enables an appropriately balanced, technically sound categorization to be established. No FHR currently has an adequate PRA or set of design basis accidents to enable establishing the safety classification of its SSCs. While all SSCs used to comply with the general design criteria (GDCs) will be safety related, the intent is to limit the instrumentation risk significance through effective design and reliance on inherent passive safety characteristics. For example, FHRs have no safety-significant temperature threshold phenomena, thus enabling the primary and reserve reactivity control systems required by GDC 26 to be passively, thermally triggered at temperatures well below those for which core or primary coolant boundary damage would occur. Moreover, the passive thermal triggering of the primary and reserve shutdown systems may relegate the control rod drive motors to the control system, substantially decreasing the amount of safety-significant wiring needed. Similarly, FHR decay heat removal systems are intended to be running continuously to minimize the amount of safety-significant instrumentation needed to

  15. Scalable diode array pumped Nd rod laser

    NASA Technical Reports Server (NTRS)

    Zenzie, H. H.; Knights, M. G.; Mosto, J. R.; Chicklis, E. P.; Perkins, P. E.

    1991-01-01

    Experiments were carried out on a five-array pump head which utilizes gold-coated reflective cones to couple the pump energy to Nd:YAG and Nd:YLF rod lasers, demonstrating high efficiency and uniform energy deposition. Because the cones function as optical diodes to light outside their acceptance angle (typically 10-15 deg), much of the diode energy not absorbed on the first pass can be returned to the rod.

  16. Development of rod function in term born and former preterm subjects.

    PubMed

    Fulton, Anne B; Hansen, Ronald M; Moskowitz, Anne

    2009-06-01

    To provide an overview of some of our electroretinographic (ERG) and psychophysical studies of normal development of rod function and their application to retinopathy of prematurity (ROP). ERG responses to full-field stimuli were recorded from dark adapted subjects. Rod photoreceptor sensitivity (SROD) was calculated by fit of a biochemical model of the activation of phototransduction to the ERG a-wave. Dark adapted psychophysical thresholds for detecting 2 degrees spots in parafoveal (10 degrees eccentric) and peripheral (30 degrees eccentric) retina were measured and the difference between the thresholds, Delta10-30, was examined as a function of age. SROD and Delta10-30 in term born and former preterm subjects were compared. In term born infants, (1) the normal developmental increase in SROD changes proportionately with the amount of rod visual pigment, rhodopsin, and (2) rod-mediated function in central retina is immature compared with that in peripheral retina. In subjects born prematurely, deficits in SROD persist long after active ROP has resolved. Maturation of rod-mediated thresholds in the central retina is prolonged by mild ROP. Characterization of the development of normal rod and rod-mediated function provides a foundation for understanding ROP.

  17. 30. Engine controls and valve gear, looking aft on main ...

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

    30. Engine controls and valve gear, looking aft on main (promenade) deck level. Threaded admission valve lift rods (two at immediate left of chronometer) permit adjustment of valve timing in lower and upper admission valves of cylinder (left rod controls lower valve, right rod upper valve). Valve rods are lifted by jaw-like "wipers" during operation. Exhaust valve lift rods and wipers are located to right of chronometer. Crank at extreme right drives valve wiper shaft when engaged to end of eccentric rod, shown under "Crank Indicator" dial. Pair of handles to immediate left of admission valve rods control condenser water valves; handles to right of exhaust valve rods control feedwater flow to boilers from pumps. Gauges indicate boiler pressure (left) and condenser vacuum (right); "Crank Indicator" on wall aids engineer in keeping engine crank off "dead-center" at stop so that engine may be easily restarted. - Steamboat TICONDEROGA, Shelburne Museum Route 7, Shelburne, Chittenden County, VT

  18. Correlation of Mechanical Properties with Diameter and Cooling Rate of 1080 Wire-Rod

    NASA Astrophysics Data System (ADS)

    Kohli, A.; Poirier, D. R.

    2017-12-01

    More than 540 heats of 1080 wire-rod were statistically analyzed by regression analyses to see whether tensile strength and percent reduction in area (%RA) relate to wire-rod diameter and composition. As diameter increases from 5.6 to 12.7 mm, the trend in %RA shows a decrease with negligible effect on the trend of the tensile strength. It was found that the estimated cooling rate at 700 °C during controlled cooling is responsible for the "diameter effect." The effect of composition on %RA is minor when contrasted to the "diameter effect." In particular, the effect of the concentrations of the residual elements on %RA within the compositional range studied is negligible.

  19. Effect of rod gap spacing on a suction panel for laminar flow and noise control in supersonic wind tunnels. M.S. Thesis - Old Dominion Univ.

    NASA Technical Reports Server (NTRS)

    Harvey, W. D.

    1975-01-01

    Results are presented of a coordinated experimental and theoretical study of a sound shield concept which aims to provide a means of noise reduction in the test section of supersonic wind tunnels at high Reynolds numbers. The model used consists of a planar array of circular rods aligned with the flow, with adjustable gaps between them for boundary layer removal by suction, i.e., laminar flow control. One of the basic requirements of the present sound shield concept is to achieve sonic cross flow through the gaps in order to prevent lee-side flow disturbances from penetrating back into the shielded region. Tests were conducted at Mach 6 over a local unit Reynolds number range from about 1.2 x 10 to the 6th power to 13.5 x 10 to the 6th power per foot. Measurements of heat transfer, static pressure, and sound levels were made to establish the transition characteristics of the boundary layer on the rod array and the sound shielding effectiveness.

  20. SPRING DRIVEN ACTUATING MECHANISM FOR NUCLEAR REACTOR CONTROL

    DOEpatents

    Bevilacqua, F.; Uecker, D.F.; Groh, E.F.

    1962-01-23

    l962. rod in a nuclear reactor to shut it down. The control rod or an extension thereof is wound on a drum as it is withdrawn from the reactor. When an emergency occurs requiring the reactor to be shut down, the drum is released so as to be free to rotate, and the tendency of the control rod or its extension coiled on the drum to straighten itself is used for quickly returning the control rod to the reactor. (AEC)

  1. Potential safety benefits of intelligent cruise control systems.

    PubMed

    Chira-Chavala, T; Yoo, S M

    1994-04-01

    Potential safety impact of a hypothetical intelligent cruise control system (ICCS) is evaluated in terms of changes in traffic accidents and some traffic operation characteristics affecting safety. The analysis of changes in traffic accidents is accomplished by in-depth examinations of police accident reports for four major counties in California. The evaluation of changes in traffic operation characteristics affecting safety is accomplished by vehicle simulation. The accident analysis reveals that the use of the hypothetical ICCS could potentially reduce traffic accidents by up to 7.5%. Preliminary vehicle simulation results based on a 10-vehicle convoy indicate that the use of the hypothetical ICCS could reduce frequencies of hard acceleration and deceleration, enhance speed harmonization among vehicles, and reduce incidence of "less-safe" headway.

  2. 78 FR 76815 - Steel Threaded Rod From India: Preliminary Affirmative Countervailing Duty Determination and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-533-856] Steel Threaded Rod From... exporters of steel threaded rod from India. The period of investigation (``POI'') is January 1, 2012... this investigation is steel threaded rod. Steel threaded rod is certain threaded rod, bar, or studs, of...

  3. Unilateral retinitis pigmentosa and cone-rod dystrophy

    PubMed Central

    Farrell, Donald F

    2009-01-01

    Purpose: The purpose of this paper is to report 14 new cases of unilateral retinitis pigmentosa and three new cases of cone-rod dystrophy and to compare the similarities and dissimilarities to those found in the bilateral forms of these disorders. Methods: A total of 272 cases of retinitis pigmentosa and 167 cases of cone-rod dystrophy were studied by corneal full field electroretinograms and electrooculograms. The student t-test was used to compare categories. Results: The percentage of familial and nonfamilial cases was the same for the bilateral and unilateral forms of the disease. In our series, unilateral retinitis pigmentosa makes up approximately 5% of the total population of retinitis pigmentosa, while unilateral cone-rod dystrophy makes up only about 2% of the total. In the familial forms of unilateral retinitis pigmentosa the most common inheritance pattern was autosomal dominant and all affected relatives had bilateral disease. Conclusion: Unilateral retinitis pigmentosa and cone-rod dystrophy appear to be directly related to the more common bilateral forms of these disorders. The genetic mechanisms which account for asymmetric disorders are not currently understood. It may be a different unidentified mutation at a single loci or it is possible that nonlinked mutations in multiple loci account for this unusual disorder. PMID:19668577

  4. Intraoperative implant rod three-dimensional geometry measured by dual camera system during scoliosis surgery.

    PubMed

    Salmingo, Remel Alingalan; Tadano, Shigeru; Abe, Yuichiro; Ito, Manabu

    2016-05-12

    Treatment for severe scoliosis is usually attained when the scoliotic spine is deformed and fixed by implant rods. Investigation of the intraoperative changes of implant rod shape in three-dimensions is necessary to understand the biomechanics of scoliosis correction, establish consensus of the treatment, and achieve the optimal outcome. The objective of this study was to measure the intraoperative three-dimensional geometry and deformation of implant rod during scoliosis corrective surgery.A pair of images was obtained intraoperatively by the dual camera system before rotation and after rotation of rods during scoliosis surgery. The three-dimensional implant rod geometry before implantation was measured directly by the surgeon and after surgery using a CT scanner. The images of rods were reconstructed in three-dimensions using quintic polynomial functions. The implant rod deformation was evaluated using the angle between the two three-dimensional tangent vectors measured at the ends of the implant rod.The implant rods at the concave side were significantly deformed during surgery. The highest rod deformation was found after the rotation of rods. The implant curvature regained after the surgical treatment.Careful intraoperative rod maneuver is important to achieve a safe clinical outcome because the intraoperative forces could be higher than the postoperative forces. Continuous scoliosis correction was observed as indicated by the regain of the implant rod curvature after surgery.

  5. Store-operated channels regulate intracellular calcium in mammalian rods

    PubMed Central

    Molnar, Tünde; Barabas, Peter; Birnbaumer, Lutz; Punzo, Claudio; Kefalov, Vladimir; Križaj, David

    2012-01-01

    Exposure to daylight closes cyclic nucleotide-gated (CNG) and voltage-operated Ca2+-permeable channels in mammalian rods. The consequent lowering of the cytosolic calcium concentration ([Ca2+]i), if protracted, can contribute to light-induced damage and apoptosis in these cells. We here report that mouse rods are protected against prolonged lowering of [Ca2+]i by store-operated Ca2+ entry (SOCE). Ca2+ stores were depleted in Ca2+-free saline supplemented with the endoplasmic reticulum (ER) sequestration blocker cyclopiazonic acid. Store depletion elicited [Ca2+]i signals that exceeded baseline [Ca2+]i by 5.9 ± 0.7-fold and were antagonized by an inhibitory cocktail containing 2-APB, SKF 96365 and Gd3+. Cation influx through SOCE channels was sufficient to elicit a secondary activation of L-type voltage-operated Ca2+ entry. We also found that TRPC1, the type 1 canonical mammalian homologue of the Drosophila photoreceptor TRP channel, is predominantly expressed within the outer nuclear layer of the retina. Rod loss in Pde6brd1 (rd1), Chx10/Kip1−/−rd1 and Elovl4TG2 dystrophic models was associated with ∼70% reduction in Trpc1 mRNA content whereas Trpc1 mRNA levels in rodless cone-full Nrl−/− retinas were decreased by ∼50%. Genetic ablation of TRPC1 channels, however, had no effect on SOCE, the sensitivity of the rod phototransduction cascade or synaptic transmission at rod and cone synapses. Thus, we localized two new mechanisms, SOCE and TRPC1, to mammalian rods and characterized the contribution of SOCE to Ca2+ homeostasis. By preventing the cytosolic [Ca2+]i from dropping too low under sustained saturating light conditions, these signalling pathways may protect Ca2+-dependent mechanisms within the ER and the cytosol without affecting normal rod function. PMID:22674725

  6. The Case for Using Blunt-Tipped Lightning Rods as Strike Receptors.

    NASA Astrophysics Data System (ADS)

    Moore, C. B.; Aulich, G. D.; Rison, William

    2003-07-01

    Conventional lightning rods used in the United States have sharp tips, a practice derived from Benjamin Franklin's discovery of a means to obtain protection from lightning. However, the virtue of sharp tips for strike reception has never been established. An examination of the relevant physics shows that very strong electric fields are required above the tips of rods in order that they function as strike receptors but that the gradients of the field strength over sharp-tipped rods are so great that, at distances of a few millimeters, the local fields are often too weak for the development of upward-going streamers. In field tests, rods with rounded tips have been found to be better strike receptors than were nearby sharp-tipped rods.

  7. Three-Phase Coexistence in Colloidal Rod-Plate Mixtures.

    PubMed

    Woolston, Phillip; van Duijneveldt, Jeroen S

    2015-09-01

    Aqueous suspensions of clay particles, such as montmorillonite (MMT) platelets and sepiolite (Sep) rods, tend to form gels at concentrations around 1 vol %. For Sep rods, adsorbing sodium polyacrylate to the surface allows for an isotropic-nematic phase separation to be seen instead. Here, MMT is added to such Sep suspensions, resulting in a complex phase behavior. Across a range of clay concentrations, separation into three phases is observed: a lower, nematic phase dominated by Sep rods, a MMT-rich middle layer, which is weakly birefringent and probably a gel, and a dilute top phase. Analysis of phase volumes suggests that the middle layer may contain as much as 6 vol % MMT.

  8. Noise Radiation from Single and Multiple Rod Configurations

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, Thomas F.

    2006-01-01

    Acoustic measurements were performed on single and multiple rod configurations to study the effect of Reynolds number, surface roughness, freestream turbulence, proximity and wake interference on the radiated noise. The Reynolds number ranged from 3.8 x 10(exp 3) to 10(exp 5). Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the different model configurations tested. The dependence of the peak Sound Pressure Level on velocity was also examined. Several concepts for the reduction of the noise radiating from cylindrical rods were tested. It was shown that wire wraps and collar distributions could be used to significantly reduce the noise radiating from rods in tandem configurations.

  9. ZIRCONIA RODS FOR COATING ARTICLES BY FLAME SPRAYING

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    1960-04-21

    An improved ZrO/sub 2/ rod for flame spraying guns is described which consists of a sintered ZrO/sub 2/ rod of mostly cubic and tetragonal crystals and has a porosity of 8% to 40% by volume. These rods are prepared by mixing 100 parts of ZrO/sub 2/ 75 parts fused, stabilized, 216 mu size, containing 5% CaO, 15 parts fused, stabilized, 25 to 50 mu size, with 5% CaO, 10 parts fused, unstabilized lime-free with 17 parts water, 1 part dextrine, 2 parts corn starch, and extruding. They are then dried and fired in a kiln heated to cone 35 Orton.more » (T.R.H.)« less

  10. Grid-to-rod flow-induced impact study for PWR fuel in reactor

    DOE PAGES

    Jiang, Hao; Qu, Jun; Lu, Roger Y.; ...

    2016-06-10

    The source for grid-to-rod fretting in a pressurized water nuclear reactor (PWR) is the dynamic contact impact from hydraulic flow-induced fuel assembly vibration. In order to support grid-to-rod fretting wear mitigation research, finite element analysis (FEA) was used to evaluate the hydraulic flow-induced impact intensity between the fuel rods and the spacer grids. Three-dimensional FEA models, with detailed geometries of the dimple and spring of the actual spacer grids along with fuel rods, were developed for flow impact simulation. The grid-to-rod dynamic impact simulation provided insights of the contact phenomena at grid-rod interface. Finally, it is an essential and effectivemore » way to evaluate contact forces and provide guidance for simulative bench fretting-impact tests.« less

  11. Truss beam having convex-curved rods, shear web panels, and self-aligning adapters

    NASA Technical Reports Server (NTRS)

    Fernandez, Ian M. (Inventor)

    2013-01-01

    A truss beam comprised of a plurality of joined convex-curved rods with self-aligning adapters (SAA) adhesively attached at each end of the truss beam is disclosed. Shear web panels are attached to adjacent pairs of rods, providing buckling resistance for the truss beam. The rods are disposed adjacent to each other, centered around a common longitudinal axis, and oriented so that adjacent rod ends converge to at least one virtual convergence point on the common longitudinal axis, with the rods' curvature designed to increase prevent buckling for the truss beam. Each SAA has longitudinal bores that provide self-aligning of the rods in the SAA, the self-aligning feature enabling creation of strong adhesive bonds between each SAA and the rods. In certain embodiments of the present invention, pultruded unidirectional carbon fiber rods are coupled with carbon fiber shear web panels and metal SAA(s), resulting in a lightweight, low-cost but strong truss beam that is highly resistant to buckling.

  12. Stress analysis in a pedicle screw fixation system with flexible rods in the lumbar spine.

    PubMed

    Kim, Kyungsoo; Park, Won Man; Kim, Yoon Hyuk; Lee, SuKyoung

    2010-01-01

    Breakage of screws has been one of the most common complications in spinal fixation systems. However, no studies have examined the breakage risk of pedicle screw fixation systems that use flexible rods, even though flexible rods are currently being used for dynamic stabilization. In this study, the risk of breakage of screws for the rods with various flexibilities in pedicle screw fixation systems is investigated by calculating the von Mises stress as a breakage risk factor using finite element analysis. Three-dimensional finite element models of the lumbar spine with posterior one-level spinal fixations at L4-L5 using four types of rod (a straight rod, a 4 mm spring rod, a 3 mm spring rod, and a 2 mm spring rod) were developed. The von Mises stresses in both the pedicle screws and the rods were analysed under flexion, extension, lateral bending, and torsion moments of 10 Nm with a follower load of 400 N. The maximum von Mises stress, which was concentrated on the neck region of the pedicle screw, decreased as the flexibility of the rod increased. However, the ratio of the maximum stress in the rod to the yield stress increased substantially when a highly flexible rod was used. Thus, the level of rod flexibility should be considered carefully when using flexible rods for dynamic stabilization because the intersegmental motion facilitated by the flexible rod results in rod breakage.

  13. Techniques and equipment for assessing the structural integrity of subterranean tower anchor rods

    DOEpatents

    Hinz, William R.; Parker, Matthew J.

    2001-01-01

    Techniques and equipment for evaluating structural integrity of buried anchor rods in situ are disclosed. The techniques avoid excavation of soil and avoid, or at least reduce, the possibility of damage to the rods or the concrete in which they may be embedded when evaluations are conducted. Instead, ultrasonic energy is transmitted through the rod from a portable transducer, and returned energy (in either or both of direct and mode-converted states) may be analyzed to assist in detecting flaws, corrosion, wastage, or other degradation of the rod. Data from a field evaluation may be compared with baseline data maintained either for a specific rod or for rods of similar composition and length (or both), and periodic field evaluations of a rod may be used to analyze trends in its structure over time.

  14. 75 FR 5536 - Pipeline Safety: Control Room Management/Human Factors, Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts...: Control Room Management/Human Factors, Correction AGENCY: Pipeline and Hazardous Materials Safety... following correcting amendments: PART 192--TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM...

  15. [Experimental study of recovery force of surface-modified TiNi memory alloy rod].

    PubMed

    Wang, Aiyuan; Peng, Jiang; Zhang, Xian; Xu, Wenjin; Wang, Xing; Sun, Minxue; Lu, Shibi

    2006-08-01

    The recovery force of Ti-Nb coated and uncoated TiNi shape memory alloy rods was investigated. The rods were 6.0 mm, 6.5 mm and 7.0 mm in diameter respectively. The mean transition temperature was 33.0 degrees C. The rods were stored at -18 degrees C and pre-bent with a three-point bending fixture, the span was 20. 0 centimeters and the deflections were 5.0 mm, 10.0 mm, 15.0 mm and 20.0 mm, respectively. The rods were then heated in a constant temperature saline solution chamber. The experimental temperature was 37.0 C and 50.0 C respectively. The recovery force was measured in a constant displacement mode on biomaterial test machine. The results showed that the recovery force of the memory alloy rod increased with increasing recovery temperature, rod diameter and deformation of both Ti-Nb coated and uncoated surface. The recovery force of Ti-Nb coated rods of 6.0 and 6.5 millimeter in diameter was lower than the uncoated rods in the same diameter. However, the recovery force of 7.0-mm-diameter rods showed no significant difference between coated and uncoated surface.

  16. Energy distributions in rods and beams

    NASA Technical Reports Server (NTRS)

    Wohlever, J. C.; Bernhard, R. J.

    1989-01-01

    A hypothesis proposed by Nefske and Sung (1987) that the mechanical energy flow in acoustic/structural systems can be modeled using a thermal energy flow analogy was tested for both longitudinal vibration in rods and transverse flexural vibrations in beams. It was found that the rod behaves according to the energy flow analogy. However, the beam solutions behaved significantly differently than predicted by the thermal analogy, unless spatially averaged energy and power flow were considered. Otherwise, the beam analysis is restricted to frequencies where the near-field terms in the displacement solution are negligible over most of the beam.

  17. Microbiological Safety of Kitchen Sponges Used in Food Establishments

    PubMed Central

    Bacha, Ketema

    2016-01-01

    Kitchen sponges are among the possible sources of contaminants in food establishments. The main purpose of the current study was, therefore, to assess the microbiological safety of sponges as it has been used in selected food establishments of Jimma town. Accordingly, the microbiological safety of a total of 201 kitchen sponges randomly collected from food establishments was evaluated against the total counts of aerobic mesophilic bacteria (AMB), Enterobacteriaceae, coliforms, and yeast and molds. The mean counts of aerobic mesophilic bacteria ranged from 7.43 to 12.44 log CFU/mm3. The isolated genera were dominated by Pseudomonas (16.9%), Bacillus (11.1%), Micrococcus (10.6%), Streptococcus (7.8%), and Lactobacillus (6%) excluding the unidentified Gram positive rods (4.9%) and Gram negative rods (9.9%). The high microbial counts (aerobic mesophilic bacteria, coliforms, Enterobacteriaceae, and yeast and molds) reveal the existence of poor kitchen sponge sanitization practice. Awareness creation training on basic hygienic practices to food handlers and periodic change of kitchen sponges are recommended. PMID:27840819

  18. Job characteristics and safety climate: the role of effort-reward and demand-control-support models.

    PubMed

    Phipps, Denham L; Malley, Christine; Ashcroft, Darren M

    2012-07-01

    While safety climate is widely recognized as a key influence on organizational safety, there remain questions about the nature of its antecedents. One potential influence on safety climate is job characteristics (that is, psychosocial features of the work environment). This study investigated the relationship between two job characteristics models--demand-control-support (Karasek & Theorell, 1990) and effort-reward imbalance (Siegrist, 1996)--and safety climate. A survey was conducted with a random sample of 860 British retail pharmacists, using the job contents questionnaire (JCQ), effort-reward imbalance indicator (ERI) and a measure of safety climate in pharmacies. Multivariate data analyses found that: (a) both models contributed to the prediction of safety climate ratings, with the demand-control-support model making the largest contribution; (b) there were some interactions between demand, control and support from the JCQ in the prediction of safety climate scores. The latter finding suggests the presence of "active learning" with respect to safety improvement in high demand, high control settings. The findings provide further insight into the ways in which job characteristics relate to safety, both individually and at an aggregated level.

  19. 77 FR 1504 - Stainless Steel Wire Rod From India

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-10

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-638 (Third Review)] Stainless Steel Wire... stainless steel wire rod From India would be likely to lead to continuation or recurrence of material injury... USITC Publication 4300 (January 2012), entitled Stainless Steel Wire Rod From India: Investigation No...

  20. Packed rod neutron shield for fast nuclear reactors

    DOEpatents

    Eck, John E.; Kasberg, Alvin H.

    1978-01-01

    A fast neutron nuclear reactor including a core and a plurality of vertically oriented neutron shield assemblies surrounding the core. Each assembly includes closely packed cylindrical rods within a polygonal metallic duct. The shield assemblies are less susceptible to thermal stresses and are less massive than solid shield assemblies, and are cooled by liquid coolant flow through interstices among the rods and duct.

  1. Numerical Simulations of a 96-rod Polysilicon CVD Reactor

    NASA Astrophysics Data System (ADS)

    Guoqiang, Tang; Cong, Chen; Yifang, Cai; Bing, Zong; Yanguo, Cai; Tihu, Wang

    2018-05-01

    With the rapid development of the photovoltaic industry, pressurized Siemens belljar-type polysilicon CVD reactors have been enlarged from 24 rods to 96 rods in less than 10 years aimed at much greater single-reactor productivity. A CFD model of an industry-scale 96-rod CVD reactor was established to study the internal temperature distribution and the flow field of the reactor. Numerical simulations were carried out and compared with actual growth results from a real CVD reactor. Factors affecting polysilicon depositions such as inlet gas injections, flow field, and temperature distribution in the CVD reactor are studied.

  2. Large Deformation of an Elastic Rod with Structural Anisotropy Subjected to Fluid Flow

    NASA Astrophysics Data System (ADS)

    Hassani, Masoud; Mureithi, Njuki; Gosselin, Frederick

    2015-11-01

    In the present work, we seek to understand the fundamental mechanisms of three-dimensional reconfiguration of plants by studying the large deformation of a flexible rod in fluid flow. Flexible rods made of Polyurethane foam and reinforced with Nylon fibers are tested in a wind tunnel. The rods have bending-torsion coupling which induces a torsional deformation during asymmetric bending. A mathematical model is also developed by coupling the Kirchhoff rod theory with a semi-empirical drag formulation. Different alignments of the material frame with respect to the flow direction and a range of structural properties are considered to study their effect on the deformation of the flexible rod and its drag scaling. Results show that twisting causes the flexible rods to reorient and bend with the minimum bending rigidity. It is also found that the drag scaling of the rod in the large deformation regime is not affected by torsion. Finally, using a proper set of dimensionless numbers, the state of a bending and twisting rod is characterized as a beam undergoing a pure bending deformation.

  3. Statistical analysis of QC data and estimation of fuel rod behaviour

    NASA Astrophysics Data System (ADS)

    Heins, L.; Groβ, H.; Nissen, K.; Wunderlich, F.

    1991-02-01

    The behaviour of fuel rods while in reactor is influenced by many parameters. As far as fabrication is concerned, fuel pellet diameter and density, and inner cladding diameter are important examples. Statistical analyses of quality control data show a scatter of these parameters within the specified tolerances. At present it is common practice to use a combination of superimposed unfavorable tolerance limits (worst case dataset) in fuel rod design calculations. Distributions are not considered. The results obtained in this way are very conservative but the degree of conservatism is difficult to quantify. Probabilistic calculations based on distributions allow the replacement of the worst case dataset by a dataset leading to results with known, defined conservatism. This is achieved by response surface methods and Monte Carlo calculations on the basis of statistical distributions of the important input parameters. The procedure is illustrated by means of two examples.

  4. 75 FR 67450 - Pipeline Safety: Control Room Management Implementation Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-02

    ... PHMSA-2010-0294] Pipeline Safety: Control Room Management Implementation Workshop AGENCY: Pipeline and...) on the implementation of pipeline control room management. The workshop is intended to foster an understanding of the Control Room Management Rule issued by PHMSA on December 3, 2009, and is open to the public...

  5. Braided reinforced composite rods for the internal reinforcement of concrete

    NASA Astrophysics Data System (ADS)

    Gonilho Pereira, C.; Fangueiro, R.; Jalali, S.; Araujo, M.; Marques, P.

    2008-05-01

    This paper reports on the development of braided reinforced composite rods as a substitute for the steel reinforcement in concrete. The research work aims at understanding the mechanical behaviour of core-reinforced braided fabrics and braided reinforced composite rods, namely concerning the influence of the braiding angle, the type of core reinforcement fibre, and preloading and postloading conditions. The core-reinforced braided fabrics were made from polyester fibres for producing braided structures, and E-glass, carbon, HT polyethylene, and sisal fibres were used for the core reinforcement. The braided reinforced composite rods were obtained by impregnating the core-reinforced braided fabric with a vinyl ester resin. The preloading of the core-reinforced braided fabrics and the postloading of the braided reinforced composite rods were performed in three and two stages, respectively. The results of tensile tests carried out on different samples of core-reinforced braided fabrics are presented and discussed. The tensile and bending properties of the braided reinforced composite rods have been evaluated, and the results obtained are presented, discussed, and compared with those of conventional materials, such as steel.

  6. Adaptive control of 5 DOF upper-limb exoskeleton robot with improved safety.

    PubMed

    Kang, Hao-Bo; Wang, Jian-Hui

    2013-11-01

    This paper studies an adaptive control strategy for a class of 5 DOF upper-limb exoskeleton robot with a special safety consideration. The safety requirement plays a critical role in the clinical treatment when assisting patients with shoulder, elbow and wrist joint movements. With the objective of assuring the tracking performance of the pre-specified operations, the proposed adaptive controller is firstly designed to be robust to the model uncertainties. To further improve the safety and fault-tolerance in the presence of unknown large parameter variances or even actuator faults, the adaptive controller is on-line updated according to the information provided by an adaptive observer without additional sensors. An output tracking performance is well achieved with a tunable error bound. The experimental example also verifies the effectiveness of the proposed control scheme. © 2013 ISA. Published by ISA. All rights reserved.

  7. Fretting corrosion behavior of nitinol spinal rods in conjunction with titanium pedicle screws.

    PubMed

    Lukina, Elena; Kollerov, Mikhail; Meswania, Jay; Khon, Alla; Panin, Pavel; Blunn, Gordon W

    2017-03-01

    Untypical corrosion damage including erosions combined with the build-up of titanium oxide as a corrosion product on the surface of explanted Nitinol spinal rods in the areas where it was in contact with titanium pedicle screw head is reported. It was suggested that Nitinol rods might have inferior fretting corrosion resistance compared with that made of titanium or CoCr. Fretting corrosion of Nitinol spinal rods with titanium (Ti6Al4V) pedicle screws were tested in-vitro by conducting a series of potentiostatic measurements of the peak-to-peak values of fretting corrosion current under bending in a 10% solution of calf serum in PBS. The test included Nitinol rods locked in titanium pedicle screws of different designs. Performance of commercially available titanium (Ti6Al4V) and CoCr spinal rods was also investigated for a comparison. Corrosion damage observed after the in-vitro tests was studied using SEM and EDAX analysis and was compared with patterns on Nitinol rods retrieved 12months after initial surgery. Metal ions level was measured in the test media after in-vitro experiments and in the blood and tissues of the patients who had the rods explanted. The results of this study revealed that Nitinol spinal rods locked in Ti pedicle screws are susceptible to fretting corrosion demonstrating higher fretting corrosion current compared with commercially used Ti6Al4V and CoCr rods. On the surface of Nitinol rods after in-vitro tests and on those retrieved from the patients similar corrosion patterns were observed. Improved resistance to fretting corrosion was observed with Nitinol rods in the in-vitro tests where pedicle screws were used with a stiffer locking mechanism. Since the development of the localized corrosion damage might increase the risk of premature fatigue failure of the rods and result in leaching of Ni ions, it is concluded that Nitinol rods should not be used in conjunction with Ti pedicle screws without special protection especially where the

  8. National Transportation Safety Board : weak internal control impaired financial accountability

    DOT National Transportation Integrated Search

    2001-09-28

    The U. S. General Accounting Office (GAO) was asked to review the National Transportation Safety Board's (NTSB) internal controls over selected types of fiscal year expenditures. They were asked to determine whether internal control weaknesses were a...

  9. Fabrication of vertically aligned ferroelectric polyvinylidene fluoride mesoscale rod arrays

    DOE PAGES

    Kim, Dongjin; Hong, Seungbum; Hong, Jongin; ...

    2013-05-14

    Here, we have fabricated vertically aligned ferroelectric PVDF mesoscale rod arrays comprising and phases using a 200 nm diameter anodized aluminum oxide (AAO) as the porous template. We could synthesize the ferroelectric phase in mesoscale rod forms by combining the well-established recipe for crystallizing the phase using dimethyl sulfoxide (DMSO) at low temperature and template-guided infiltration processing for the rods using AAO. We also measured the dimensions of the PVDF rods by scanning electron microscopy and identified the polymorph phases by X-ray diffraction and Fourier transform infrared spectroscopy. The length of the rods varied from 3.82 m to 1.09 mmore » and the diameter from 232 nm to 287 nm when the volume ratio between DMSO and acetone changed from 5 : 5 to 10 : 0. We obtained well-defined piezoresponse hysteresis loops for all rods with remnant piezoresponse ranging from 2.12 pm/V to 5.04 pm/V and coercive voltage ranging from 2.29 V to 2.71 V using piezoresponse force microscopy. These results serve as a processing platform for flexible electronic devices that need high capacitance and piezoelectric functionalities such as flexible memory devices or body energy harvesting devices for intelligent systems. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3842-3848, 2013« less

  10. 78 FR 979 - Petition for Positive Train Control Safety Plan Approval and System Certification of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ...] Petition for Positive Train Control Safety Plan Approval and System Certification of the Electronic Train... the Federal Railroad Administration (FRA) for Positive Train Control (PTC) Safety Plan (PTCSP...-based train control system safety overlay designed to protect against the consequences of train-to-train...

  11. Case-control analysis in highway safety: Accounting for sites with multiple crashes.

    PubMed

    Gross, Frank

    2013-12-01

    There is an increased interest in the use of epidemiological methods in highway safety analysis. The case-control and cohort methods are commonly used in the epidemiological field to identify risk factors and quantify the risk or odds of disease given certain characteristics and factors related to an individual. This same concept can be applied to highway safety where the entity of interest is a roadway segment or intersection (rather than a person) and the risk factors of interest are the operational and geometric characteristics of a given roadway. One criticism of the use of these methods in highway safety is that they have not accounted for the difference between sites with single and multiple crashes. In the medical field, a disease either occurs or it does not; multiple occurrences are generally not an issue. In the highway safety field, it is necessary to evaluate the safety of a given site while accounting for multiple crashes. Otherwise, the analysis may underestimate the safety effects of a given factor. This paper explores the use of the case-control method in highway safety and two variations to account for sites with multiple crashes. Specifically, the paper presents two alternative methods for defining cases in a case-control study and compares the results in a case study. The first alternative defines a separate case for each crash in a given study period, thereby increasing the weight of the associated roadway characteristics in the analysis. The second alternative defines entire crash categories as cases (sites with one crash, sites with two crashes, etc.) and analyzes each group separately in comparison to sites with no crashes. The results are also compared to a "typical" case-control application, where the cases are simply defined as any entity that experiences at least one crash and controls are those entities without a crash in a given period. In a "typical" case-control design, the attributes associated with single-crash segments are weighted

  12. Integrated control of transporter endocytosis and recycling by the arrestin-related protein Rod1 and the ubiquitin ligase Rsp5.

    PubMed

    Becuwe, Michel; Léon, Sébastien

    2014-11-07

    After endocytosis, membrane proteins can recycle to the cell membrane or be degraded in lysosomes. Cargo ubiquitylation favors their lysosomal targeting and can be regulated by external signals, but the mechanism is ill-defined. Here, we studied the post-endocytic trafficking of Jen1, a yeast monocarboxylate transporter, using microfluidics-assisted live-cell imaging. We show that the ubiquitin ligase Rsp5 and the glucose-regulated arrestin-related trafficking adaptors (ART) protein Rod1, involved in the glucose-induced internalization of Jen1, are also required for the post-endocytic sorting of Jen1 to the yeast lysosome. This new step takes place at the trans-Golgi network (TGN), where Rod1 localizes dynamically upon triggering endocytosis. Indeed, transporter trafficking to the TGN after internalization is required for their degradation. Glucose removal promotes Rod1 relocalization to the cytosol and Jen1 deubiquitylation, allowing transporter recycling when the signal is only transient. Therefore, nutrient availability regulates transporter fate through the localization of the ART/Rsp5 ubiquitylation complex at the TGN.

  13. Repurposing historical control clinical trial data to provide safety context.

    PubMed

    Bhuyan, Prakash; Desai, Jigar; Louis, Matthew St; Carlsson, Martin; Bowen, Edward; Danielson, Mark; Cantor, Michael N

    2016-02-01

    Billions of dollars spent, millions of subject-hours of clinical trial experience and an abundance of archived study-level data, yet why are historical data underutilized? We propose that historical data can be aggregated to provide safety, background incidence rate and context to improve the evaluation of new medicinal products. Here, we describe the development and application of the eControls database, which is derived from the control arms of studies of licensed products, and discuss the challenges and potential solutions to the proper application of historical data to help interpret product safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Nuclear reactor fuel rod attachment system

    DOEpatents

    Not Available

    1980-09-17

    A reusable system is described for removably attaching a nuclear reactor fuel rod to a support member. A locking cap is secured to the fuel rod and a locking strip is fastened to the support member. The locking cap has two opposing fingers shaped to form a socket having a body portion. The locking strip has an extension shaped to rigidly attach to the socket's body portion. The locking cap's fingers are resiliently deflectable. For attachment, the locking cap is longitudinally pushed onto the locking strip causing the extension to temporarily deflect open the fingers to engage the socket's body portion. For removal, the process is reversed.

  15. Technical description of RODS: a real-time public health surveillance system.

    PubMed

    Tsui, Fu-Chiang; Espino, Jeremy U; Dato, Virginia M; Gesteland, Per H; Hutman, Judith; Wagner, Michael M

    2003-01-01

    This report describes the design and implementation of the Real-time Outbreak and Disease Surveillance (RODS) system, a computer-based public health surveillance system for early detection of disease outbreaks. Hospitals send RODS data from clinical encounters over virtual private networks and leased lines using the Health Level 7 (HL7) message protocol. The data are sent in real time. RODS automatically classifies the registration chief complaint from the visit into one of seven syndrome categories using Bayesian classifiers. It stores the data in a relational database, aggregates the data for analysis using data warehousing techniques, applies univariate and multivariate statistical detection algorithms to the data, and alerts users of when the algorithms identify anomalous patterns in the syndrome counts. RODS also has a Web-based user interface that supports temporal and spatial analyses. RODS processes sales of over-the-counter health care products in a similar manner but receives such data in batch mode on a daily basis. RODS was used during the 2002 Winter Olympics and currently operates in two states-Pennsylvania and Utah. It has been and continues to be a resource for implementing, evaluating, and applying new methods of public health surveillance.

  16. Preliminary Marine Safety Risk Assessment, Brandon Road Lock and Dam Invasive Species Control Measures

    DTIC Science & Technology

    2016-12-01

    i Classification | CG-926 RDC | author | audience | month year Preliminary Marine Safety Risk Assessment, Brandon Road Lock & Dam...No. 4. Title and Subtitle Preliminary Marine Safety Risk Assessment, Brandon Road Lock & Dam Invasive Species Control Measures 5. Report Date...safety due to proposed invasive species control measures located in the vicinity of the Brandon Road Lock and Dam (BRLD) Navigation Project on the

  17. Multiple rod-cone and cone-rod photoreceptor transmutations in snakes: evidence from visual opsin gene expression.

    PubMed

    Simões, Bruno F; Sampaio, Filipa L; Loew, Ellis R; Sanders, Kate L; Fisher, Robert N; Hart, Nathan S; Hunt, David M; Partridge, Julian C; Gower, David J

    2016-01-27

    In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor 'transmutation'. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and nocturnal geckos and snakes that appeared to have pure-cone or pure-rod retinas (in forms that Walls believed evolved from ancestors with the reverse complement) or which possessed intermediate photoreceptor cells. Walls was limited in testing his theory because the precise identity of visual pigments present in photoreceptors was then unknown. Subsequent molecular research has hitherto neglected this topic but presents new opportunities. We identify three visual opsin genes, rh1, sws1 and lws, in retinal mRNA of an ecologically and taxonomically diverse sample of snakes central to Walls' theory. We conclude that photoreceptors with superficially rod- or cone-like morphology are not limited to containing scotopic or photopic opsins, respectively. Walls' theory is essentially correct, and more research is needed to identify the patterns, processes and functional implications of transmutation. Future research will help to clarify the fundamental properties and physiology of photoreceptors adapted to function in different light levels. © 2016 The Author(s).

  18. Effects of organizational safety practices and perceived safety climate on PPE usage, engineering controls, and adverse events involving liquid antineoplastic drugs among nurses.

    PubMed

    DeJoy, David M; Smith, Todd D; Woldu, Henok; Dyal, Mari-Amanda; Steege, Andrea L; Boiano, James M

    2017-07-01

    Antineoplastic drugs pose risks to the healthcare workers who handle them. This fact notwithstanding, adherence to safe handling guidelines remains inconsistent and often poor. This study examined the effects of pertinent organizational safety practices and perceived safety climate on the use of personal protective equipment, engineering controls, and adverse events (spill/leak or skin contact) involving liquid antineoplastic drugs. Data for this study came from the 2011 National Institute for Occupational Safety and Health (NIOSH) Health and Safety Practices Survey of Healthcare Workers which included a sample of approximately 1,800 nurses who had administered liquid antineoplastic drugs during the past seven days. Regression modeling was used to examine predictors of personal protective equipment use, engineering controls, and adverse events involving antineoplastic drugs. Approximately 14% of nurses reported experiencing an adverse event while administering antineoplastic drugs during the previous week. Usage of recommended engineering controls and personal protective equipment was quite variable. Usage of both was better in non-profit and government settings, when workers were more familiar with safe handling guidelines, and when perceived management commitment to safety was higher. Usage was poorer in the absence of specific safety handling procedures. The odds of adverse events increased with number of antineoplastic drugs treatments and when antineoplastic drugs were administered more days of the week. The odds of such events were significantly lower when the use of engineering controls and personal protective equipment was greater and when more precautionary measures were in place. Greater levels of management commitment to safety and perceived risk were also related to lower odds of adverse events. These results point to the value of implementing a comprehensive health and safety program that utilizes available hazard controls and effectively communicates

  19. Electrical servo actuator bracket. [fuel control valves on jet engines

    NASA Technical Reports Server (NTRS)

    Sawyer, R. V. (Inventor)

    1981-01-01

    An electrical servo actuator is mounted on a support arm which is allowed to pivot on a bolt through a fixed mounting bracket. The actuator is pivotally connected to the end of the support arm by a bolt which has an extension allowed to pass through a slot in the fixed mounting bracket. An actuator rod extends from the servo actuator to a crank arm which turns a control shaft. A short linear thrust of the rod pivots the crank arm through about 90 for full-on control with the rod contracted into the servo actuator, and full-off control when the rod is extended from the actuator. A spring moves the servo actuator and actuator rod toward the control crank arm once the actuator rod is fully extended in the full-off position. This assures the turning of the control shaft to a full-off position. A stop bolt and slot are provided to limit pivot motion. Once fully extended, the spring pivots the motion.

  20. 75 FR 69912 - Pipeline Safety: Control Room Management/Human Factors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... 192 and 195 [Docket ID PHMSA-2007-27954] RIN 2137-AE64 Pipeline Safety: Control Room Management/Human... rulemaking; Extension of comment period. SUMMARY: On September 17, 2010, PHMSA published a Control Room... Control Room Management/Human Factors rule at 49 CFR 192.631 and 195.446. The NPRM proposes to expedite...

  1. Evaluating a Website to Teach Children Safety with Dogs: A Randomized Controlled Trial

    PubMed Central

    Schwebel, David C.; Li, Peng; McClure, Leslie A.; Severson, Joan

    2016-01-01

    Dog bites represent a significant threat to child health. Theory-driven interventions scalable for broad dissemination are sparse. A website was developed to teach children dog safety via increased knowledge, improved cognitive skills in relevant domains, and increased perception of vulnerability to bites. A randomized controlled trial was conducted with 69 children aged 4–5 randomly assigned to use the dog safety website or a control transportation safety website for ~3 weeks. Assessment of dog safety knowledge and behavior plus skill in three relevant cognitive constructs (impulse control, noticing details, and perspective-taking) was conducted both at baseline and following website use. The dog safety website incorporated interactive games, instructional videos including testimonials, a motivational rewards system, and messaging to parents concerning child lessons. Our results showed that about two-thirds of the intervention sample was not adherent to website use at home, so both intent-to-treat and per-protocol analyses were conducted. Intent-to-treat analyses yielded mostly null results. Per-protocol analyses suggested children compliant to the intervention protocol scored higher on knowledge and recognition of safe behavior with dogs following the intervention compared to the control group. Adherent children also had improved scores post-intervention on the cognitive skill of noticing details compared to the control group. We concluded that young children’s immature cognition can lead to dog bites. Interactive eHealth training on websites shows potential to teach children relevant cognitive and safety skills to reduce risk. Compliance to website use is a challenge, and some relevant cognitive skills (e.g., noticing details) may be more amenable to computer-based training than others (e.g., impulse control). PMID:27918466

  2. Evaluating a Website to Teach Children Safety with Dogs: A Randomized Controlled Trial.

    PubMed

    Schwebel, David C; Li, Peng; McClure, Leslie A; Severson, Joan

    2016-12-02

    Dog bites represent a significant threat to child health. Theory-driven interventions scalable for broad dissemination are sparse. A website was developed to teach children dog safety via increased knowledge, improved cognitive skills in relevant domains, and increased perception of vulnerability to bites. A randomized controlled trial was conducted with 69 children aged 4-5 randomly assigned to use the dog safety website or a control transportation safety website for ~3 weeks. Assessment of dog safety knowledge and behavior plus skill in three relevant cognitive constructs (impulse control, noticing details, and perspective-taking) was conducted both at baseline and following website use. The dog safety website incorporated interactive games, instructional videos including testimonials, a motivational rewards system, and messaging to parents concerning child lessons. Our results showed that about two-thirds of the intervention sample was not adherent to website use at home, so both intent-to-treat and per-protocol analyses were conducted. Intent-to-treat analyses yielded mostly null results. Per-protocol analyses suggested children compliant to the intervention protocol scored higher on knowledge and recognition of safe behavior with dogs following the intervention compared to the control group. Adherent children also had improved scores post-intervention on the cognitive skill of noticing details compared to the control group. We concluded that young children's immature cognition can lead to dog bites. Interactive eHealth training on websites shows potential to teach children relevant cognitive and safety skills to reduce risk. Compliance to website use is a challenge, and some relevant cognitive skills (e.g., noticing details) may be more amenable to computer-based training than others (e.g., impulse control).

  3. Ileostomy rod--is it a bridge too far?

    PubMed

    Speirs, M; Leung, E; Hughes, D; Robertson, I; Donnelly, L; Mackenzie, I; Macdonald, A

    2006-07-01

    Defunctioning loop ileostomies are used commonly to protect low colorectal anastomoses and thereby reducing the serious complications of leakage. However, they are associated with specific complications such as retraction. Traditionally, a supporting rod is placed as a bridge to support both limbs of the stoma in the hope of reducing the incidence of stomal retraction. There is little evidence in the published literature to support this practice. The aim of this study was to determine whether using an ileostomy rod would reduce the incidence of stomal retraction. A prospective, randomised controlled trial was performed in 60 consecutive patients who required a defunctioning loop ileostomy. Patients were allocated to either a 'bridge' or 'bridge-less' protocol. All the patients were assessed by dedicated stoma nurses for at least 3 months and until their stomas were closed. Their postoperative symptoms, including stoma activity and retraction rate, were recorded. Between May 2001 and June 2004, 57 patients completed the study (28 bridge; 29 bridge-less). There were no significant differences in the retraction rate between the groups. No clinical anastomotic leakage was recorded and none of the patients required early closure. If a loop ileostomy is constructed properly, stomal retraction is uncommon and routine use of a bridge is unnecessary.

  4. 5. DETAIL OF ROD MILL BASE AND CONVEYOR BELT SUPPORT, ...

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

    5. DETAIL OF ROD MILL BASE AND CONVEYOR BELT SUPPORT, EAST VIEW. - Vanadium Corporation of America (VCA) Naturita Mill, Grinding Rod Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  5. Changes in wall teichoic acid during the rod-sphere transition of Bacillus subtilis 168.

    PubMed Central

    Pollack, J H; Neuhaus, F C

    1994-01-01

    Wall teichoic acid (WTA) is essential for the growth of Bacillus subtilis 168. To clarify the function of this polymer, the WTAs of strains 168, 104 rodB1, and 113 tagF1 (rodC1) grown at 32 and 42 degrees C were characterized. At the restrictive temperature, the rodB1 and tagF1 (rodC1) mutants undergo a rod-to-sphere transition that is correlated with changes in the WTA content of the cell wall. The amount of WTA decreased 33% in strain 104 rodB1 and 84% in strain 113 tagF1 (rodC1) when they were grown at the restrictive temperature. The extent of alpha-D-glucosylation (0.84) was not affected by growth at the higher temperature in these strains. The degree of D-alanylation decreased from 0.22 to 0.10 in the rodB1 mutant but remained constant (0.12) in the tagF1 (rodC1) mutant at both temperatures. Under these conditions, the degree of D-alanylation in the parent strain decreased from 0.27 to 0.21. The chain lengths of WTA in strains 168 and 104 rodB1 grown at both temperatures were approximately 53 residues, with a range of 45 to 60. In contrast, although the chain length of WTA from the tagF1 (rodC1) mutant at 32 degrees C was similar to that of strains 168 and 104 rodB1, it was approximately eight residues at the restrictive temperature. The results suggested that the rodB1 mutant is partially deficient in completed poly(glycerophosphate) chains. The precise biochemical defect in this mutant remains to be determined. The results for strain 113 tagF1(rodC1) are consistent with the temperature-sensitive defect in the CDP-glycerol:poly(glycerophosphate) glycerophosphotransferase (H. M. Pooley, F.-X. Abellan, and D. Karamata, J. Bacteriol. 174:646-649, 1992). Images PMID:7961496

  6. Trunnion Rod Microcrack Detection

    DTIC Science & Technology

    2013-08-01

    Richard W. Haskins, Joseph A. Padula , and John E. Hite BACKGROUND: Post-tensioned rods are used to anchor spillway gates and transfer the forces...email: James.A.Evans@usace.army.mil). This technical note should be cited as follows: Evans, J. A., Haskins, R. W., Padula , J. A., and Hite, J. E. 2013

  7. MEANS FOR CONTROLLING REACTIONS

    DOEpatents

    Nordheim, L.W.; Wigner, E.P.

    1961-06-27

    The patented means is described for controlling a nuclear reactor which comprises a tank containing a dispersion of a thermally fissionable material in a liquid moderator and a material convertible to a thermally fissionable material in a container disposed about the tank. The control means comprises a control rod chamber, containing only a liquid moderator, disposed within the container and adjacent to the tank and a control rod designed to be inserted into the chamber.

  8. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Wang, Jy-An John

    2016-10-01

    Behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending was studied. Tests were performed under load or moment control at 5 Hz. The surrogate rods fractured under moment amplitudes greater than 10.16 Nm with fatigue lives between 2.4 × 103 and 2.2 × 106 cycles. Fatigue response of Zry-4 cladding was characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition affect surrogate rod failure. Both debonding of PPI/PCI and pellet fracturing contribute to surrogate rod bending fatigue. The effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective gauge length is effective in sensor spacing correction. The database developed and the understanding gained in this study can serve as input to analysis of SNF (spent nuclear fuel) vibration integrity.

  9. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    DOE PAGES

    Wang, Hong; Wang, Jy-An John

    2016-07-20

    We studied behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending. Tests were performed under load or moment control at 5 Hz, and an empirical correlation was established between rod fatigue life and amplitude of the applied moment. Fatigue response of Zry-4 cladding was further characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment applied and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition all affect surrogate rod failure. Bonding/debonding of PPI/PCI and pellet fracturing contribute to surrogatemore » rod bending fatigue. Also, the effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective specimen gauge length is effective in sensor spacing correction. Finally, we developed the database and gained understanding in this study such that it will serve as input to analysis of SNF vibration integrity.« less

  10. [Healthcare-Associated Infection Control with Awareness of Patient Safety].

    PubMed

    Murakami, Nobuo

    2016-03-01

    In order to provide safe and secure medical care for patients, health care-associated infections (HAI) must not occur. HAI should be considered as incidents, and countermeasures should be viewed as a patient safety management itself. Healthcare-associated infection control (HAIC) is practiced by the infection control team (ICT), which is based on multidisciplinary cooperation. Team members have to recognize that it is the most important to make use of the expertise of each discipline. In addition, all members must try to respond quickly, to help the clinic staff. Visualized rapid information provision and sharing, environmental improvement, outbreak factor analysis, hand hygiene compliance rate improvement, proper antibiotic use (Antimicrobial Stewardship Program: ASP), and regional cooperation & leadership comprise the role of the ICT in the flagship hospital. Regarding this role, we present our hospital's efforts and the outcomes. In conclusion, for medical practice quality improvement, healthcare-associated infection control should be conducted thoroughly along with an awareness of patient safety.

  11. Benchmark of Atucha-2 PHWR RELAP5-3D control rod model by Monte Carlo MCNP5 core calculation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pecchia, M.; D'Auria, F.; Mazzantini, O.

    2012-07-01

    Atucha-2 is a Siemens-designed PHWR reactor under construction in the Republic of Argentina. Its geometrical complexity and peculiarities require the adoption of advanced Monte Carlo codes for performing realistic neutronic simulations. Therefore core models of Atucha-2 PHWR were developed using MCNP5. In this work a methodology was set up to collect the flux in the hexagonal mesh by which the Atucha-2 core is represented. The scope of this activity is to evaluate the effect of obliquely inserted control rod on neutron flux in order to validate the RELAP5-3D{sup C}/NESTLE three dimensional neutron kinetic coupled thermal-hydraulic model, applied by GRNSPG/UNIPI formore » performing selected transients of Chapter 15 FSAR of Atucha-2. (authors)« less

  12. Combustion of solid carbon rods in zero and normal gravity

    NASA Technical Reports Server (NTRS)

    Spuckler, C. M.; Kohl, F. J.; Miller, R. A.; Stearns, C. A.; Dewitt, K. J.

    1979-01-01

    In order to investigate the mechanism of carbon combustion, spectroscopic carbon rods were resistance ignited and burned in an oxygen environment in normal and zero gravity. Direct mass spectrometric sampling was used in the normal gravity tests to obtain concentration profiles of CO2, CO, and O2 as a function of distance from the carbon surface. The experimental concentrations were compared to those predicted by a stagnant film model. Zero gravity droptower tests were conducted in order to assess the effect of convection on the normal gravity combustion process. The ratio of flame diameter to rod diameter as a function of time for oxygen pressures of 5, 10, 15, and 20 psia was obtained for three different diameter rods. It was found that this ratio was inversely proportional to both the oxygen pressure and the rod diameter.

  13. 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.

  14. 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.

  15. Chemical Dosimeter Tube With Coaxial Sensing Rod

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E.

    1993-01-01

    Improved length-of-stain (LOS) chemical dosimeter indicates total dose of chemical vapor in air. Made with rods and tubes of various diameters to obtain various sensitivities and dynamic ranges. Sensitivity larger and dose range smaller when more room for diffusion in gap between tube and rod. Offers greater resistance to changing of color of exposed dye back to color of unexposed condition, greater sensitivity, and higher degree of repeatability. Developed to measure doses of gaseous HCI, dosimeter modified by use of other dyes to indicate doses of other chemical vapors.

  16. HFE safety reviews of advanced nuclear power plant control rooms

    NASA Technical Reports Server (NTRS)

    Ohara, John

    1994-01-01

    Advanced control rooms (ACR's) will utilize human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator's overall role and means of interacting with the system. The Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) aspects of HSI's to ensure that they are designed to good HFE principles and support performance and reliability in order to protect public health and safety. However, the only available NRC guidance was developed more than ten years ago, and does not adequately address the human performance issues and technology changes associated with ACR's. Accordingly, a new approach to ACR safety reviews was developed based upon the concept of 'convergent validity'. This approach to ACR safety reviews is described.

  17. Design and testing of the reactor-internal hydraulic control rod drive for the nuclear heating plant

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Batheja, P.; Meier, W.J.; Rau, P.J.

    A hydraulically driven control rod is being developed at Kraftwerk Union for integration in the primary system of a small nuclear district heating reactor. An elaborate test program, under way for --3 yr, was initiated with a plexiglass rig to understand the basic principles. A design specification list was prepared, taking reactor boundary conditions and relevant German rules and regulations into account. Subsequently, an atmospheric loop for testing of components at 20 to 90/sup 0/C was erected. The objectives involved optimization of individual components such as a piston/cylinder drive unit, electromagnetic valves, and an ultrasonic position indication system as wellmore » as verification of computer codes. Based on the results obtained, full-scale components were designed and fabricated for a prototype test rig, which is currently in operation. Thus far, all atmospheric tests in this rig have been completed. Investigations under reactor temperature and pressure, followed by endurance tests, are under way. All tests to date have shown a reliable functioning of the hydraulic drive, including a novel ultrasonic position indication system.« less

  18. Calcium-induced calcium release in rod photoreceptor terminals boosts synaptic transmission during maintained depolarization

    PubMed Central

    Cadetti, Lucia; Bryson, Eric J.; Ciccone, Cory A.; Rabl, Katalin; Thoreson, Wallace B.

    2008-01-01

    We examined the contribution of calcium-induced calcium release (CICR) to synaptic transmission from rod photoreceptor terminals. Whole-cell recording and confocal calcium imaging experiments were conducted on rods with intact synaptic terminals in a retinal slice preparation from salamander. Low concentrations of ryanodine stimulated calcium increases in rod terminals, consistent with the presence of ryanodine receptors. Application of strong depolarizing steps (−70 to −10 mV) exceeding 200 ms or longer in duration evoked a wave of calcium that spread across the synaptic terminals of voltage-clamped rods. This secondary calcium increase was blocked by high concentrations of ryanodine, indicating it was due to CICR. Ryanodine (50 μM) had no significant effect on rod calcium current (Ica) although it slightly diminished rod light-evoked voltage responses. Bath application of 50 μM ryanodine strongly inhibited light-evoked currents in horizontal cells. Whether applied extracellularly or delivered into the rod cell through the patch pipette, ryanodine (50 μM) also inhibited excitatory post-synaptic currents (EPSCs) evoked in horizontal cells by depolarizing steps applied to rods. Ryanodine caused a preferential reduction in the later portions of EPSCs evoked by depolarizing steps of 200 ms or longer. These results indicate that CICR enhances calcium increases in rod terminals evoked by sustained depolarization, which in turn acts to boost synaptic exocytosis from rods. PMID:16819987

  19. Depletion of calcium stores regulates calcium influx and signal transmission in rod photoreceptors

    PubMed Central

    Szikra, Tamas; Cusato, Karen; Thoreson, Wallace B; Barabas, Peter; Bartoletti, Theodore M; Krizaj, David

    2008-01-01

    Tonic synapses are specialized for sustained calcium entry and transmitter release, allowing them to operate in a graded fashion over a wide dynamic range. We identified a novel plasma membrane calcium entry mechanism that extends the range of rod photoreceptor signalling into light-adapted conditions. The mechanism, which shares molecular and physiological characteristics with store-operated calcium entry (SOCE), is required to maintain baseline [Ca2+]i in rod inner segments and synaptic terminals. Sustained Ca2+ entry into rod cytosol is augmented by store depletion, blocked by La3+ and Gd3+ and suppressed by organic antagonists MRS-1845 and SKF-96365. Store depletion and the subsequent Ca2+ influx directly stimulated exocytosis in terminals of light-adapted rods loaded with the activity-dependent dye FM1–43. Moreover, SOCE blockers suppressed rod-mediated synaptic inputs to horizontal cells without affecting presynaptic voltage-operated Ca2+ entry. Silencing of TRPC1 expression with small interference RNA disrupted SOCE in rods, but had no effect on cone Ca2+ signalling. Rods were immunopositive for TRPC1 whereas cone inner segments immunostained with TRPC6 channel antibodies. Thus, SOCE modulates Ca2+ homeostasis and light-evoked neurotransmission at the rod photoreceptor synapse mediated by TRPC1. PMID:18755743

  20. 75 FR 21658 - Carbon and Certain Alloy Steel Wire Rod From Trinidad and Tobago

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... Certain Alloy Steel Wire Rod From Trinidad and Tobago AGENCY: United States International Trade Commission... Investigation No. 731-TA-961 concerning carbon and certain alloy steel wire rod (``wire rod'') from Trinidad and... of imports of wire rod from Trinidad and Tobago that were sold in the United States at less than fair...

  1. Bacterial Flagella as a Model Rigid Rod of Tunable Shape

    NASA Astrophysics Data System (ADS)

    Schwenger, Walter; Yardimci, Sevim; Gibaud, Thomas; Snow, Henry; Urbach, Jeff; Dogic, Zvonimir

    In this research, we study the physical properties of suspensions of bacterial flagella from Salmonella typhimurium prepared in a variety of rigid polymorphic shapes. Flagella act as a rigid colloidal particle that can exhibit non-trivial geometry including helices of varying dimensions, straight rods, or a combination of the two in the same filament. By controlling the conditions in which flagella are prepared, the polymorphic shape assumed by the filament can be controlled. Utilizing different polymorphic shapes, we combine results from optical microscopy observations of single filaments with bulk rheological measurements to help understand the role that constituent colloidal geometry plays in complex bulk behavior.

  2. Administrative goals and safety standards for hazard control on forested recreation sites

    Treesearch

    Lee A. Paine

    1973-01-01

    For efficient control of tree hazard on recreation sites, a specific administrative goal must be selected. A safety standard designed to achieve the selected goal and a uniform hazard-rating procedure will then promote a consistent level of safety at an acceptable cost. Safety standards can be established with the aid of data for past years, and dollar evaluations are...

  3. Analysis of enamel rod end patterns on tooth surface for personal identification--ameloglyphics.

    PubMed

    Manjunath, Krishnappa; Sivapathasundharam, Balasundharam; Saraswathi, Thillai R

    2012-05-01

    Ameloglyphics is the study of enamel rod end patterns on a tooth surface. Our aim was to study the in vivo analysis of enamel rod end patterns on tooth surfaces for personal identification. In this study, the maxillary left canine and 1st premolar of 30 men and 30 women were included. The cellulose acetate peel technique was used to record enamel rod endings on tooth surfaces. Photomicrographs of the acetate peel imprint were subjected to VeriFinger Standard SDK v5.0 software for obtaining enamel rod end patterns. All 120 enamel rod end patterns were subjected to visual analysis and biometric analysis. Biometric analysis revealed that the enamel rod end pattern is unique for each tooth in an individual. It shows both intra- and interindividual variation. Enamel rod end patterns were unique between the male and female subjects. Visual analysis showed that wavy branched subpattern was the predominant subpattern observed among examined teeth. Hence, ameloglyphics is a reliable technique for personal identification. © 2012 American Academy of Forensic Sciences.

  4. A biomechanical investigation of dual growing rods used for fusionless scoliosis correction.

    PubMed

    Quick, M E; Grant, C A; Adam, C J; Askin, G N; Labrom, R D; Pearcy, M J

    2015-01-01

    The use of dual growing rods is a fusionless surgical approach to the treatment of early onset scoliosis which aims to harness potential growth and correct spinal deformity. The purpose of this study was to compare the in-vitro biomechanical response of two different dual rod designs under axial rotation loading. Six porcine spines were dissected into seven level thoracolumbar multi-segment units. Each specimen was mounted and tested in a biaxial Instron machine, undergoing nondestructive left and right axial rotation to peak moments of 4 Nm at a constant rotation rate of 8 deg. s(-1). A motion tracking system (Optotrak) measured 3D displacements of individual vertebrae. Each spine was tested in an un-instrumented state first and then with appropriately sized semi-constrained and 'rigid' growing rods in alternating sequence. The range of motion, neutral zone size and stiffness were calculated from the moment-rotation curves and intervertebral range of motion was calculated from Optotrak data. Irrespective of test sequence, rigid rods showed a significant reduction of total rotation across all instrumented levels (with increased stiffness) whilst semi-constrained rods exhibited similar rotational behavior to the un-instrumented spines (P<0.05). An 11.1% and 8.0% increase in stiffness for left and right axial rotation respectively and 14.9% reduction in total range of motion were recorded with dual rigid rods compared with semi-constrained rods. Based on these findings, the Semi-constrained growing rods were shown to not increase axial rotation stiffness compared with un-instrumented spines. This is thought to provide a more physiological environment for the growing spine compared to dual rigid rod constructs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A nonlinear theory for fibre-reinforced magneto-elastic rods

    NASA Astrophysics Data System (ADS)

    Ciambella, Jacopo; Favata, Antonino; Tomassetti, Giuseppe

    2018-01-01

    We derive a model for the finite motion of a fibre-reinforced magneto-elastic rod. The reinforcing particles are assumed weakly and uniformly magnetized, rigid and firmly embedded into the elastomeric matrix. We deduce closed-form expressions of the quasi-static motion of the rod in terms of the external magnetic field and of the body forces. The dependences of the motion on the shape of the inclusions, their orientation, their anisotropic magnetic properties and the Young modulus of the matrix are analysed and discussed. Two case studies are presented, in which the rod is used as an actuator suspended in a cantilever configuration. This work can foster new applications in the field of soft-actuators.

  6. Impact Initiation of Rods of Pressed Polytetrafluoroethylene (PTFE) and Aluminum Powders

    NASA Astrophysics Data System (ADS)

    Mock, Willis, Jr.

    2005-07-01

    A gas gun has been used to investigate the shock initiation of rods consisting of a mixture of 74 wt % PTFE (28 μm particle size) and 26 wt % aluminum (5 μm particle size) powders. The 7.6 mm diameter by 51 mm long rods were fabricated from material that had been pressed and sintered to a full density of 2.27 gm/cm^ 3. The rods were sabot-launched into 4340 steel anvils at impact velocities ranging from 104 to 777 m/s. This corresponds to calculated impact stresses of 3.3 to 48 kbar. The experiments were carried out in a 50-100 mtorr vacuum. A framing camera was used to observe the time sequence of events. These include changes in rod shape, fracture, and the initiation and evolution of the reaction phenomena. Observation of first visible light after impact was taken as the initiation time. Initiation of the reaction occurred at discrete locations in the rod material. At low velocity, no initiation occurred. Above an initiation threshold, the initiation time dropped abruptly from 56 μs just above threshold to 4 μs at the highest impact velocity. Two experiments were performed for pure PTFE material for comparison with the PTFE/Al rods. The pure PTFE showed more extensive radial flow without obvious brittle fracture. For the 784 m/s impact experiment, small points of light were observed on the edge of the mushroomed portion of the rod about 20 μs after impact, suggesting the onset of chemical reaction.

  7. Experimental measurement of coil-rod-coil block copolymer tracer diffusion through entangled coil homopolymers

    PubMed Central

    Wang, Muzhou; Timachova, Ksenia; Olsen, Bradley D.

    2014-01-01

    The diffusion of coil-rod-coil triblock copolymers in entangled coil homopolymers is experimentally measured and demonstrated to be significantly slower than rod or coil homopolymers of the same molecular weight. A model coil-rod-coil triblock was prepared by expressing rodlike alanine-rich α-helical polypeptides in E. coli and conjugating coillike poly(ethylene oxide) (PEO) to both ends to form coil-rod-coil triblock copolymers. Tracer diffusion through entangled PEO homopolymer melts was measured using forced Rayleigh scattering at various rod lengths, coil molecular weights, and coil homopolymer concentrations. For rod lengths, L, that are close to the entanglementh length, a, the ratio between triblock diffusivity and coil homopolymer diffusivity decreases monotonically and is only a function of L/a, in quantitative agreement with previous simulation results. For large rod lengths, diffusion follows an arm retraction scaling, which is also consistent with previous theoretical predictions. These experimental results support the key predictions of theory and simulation, suggesting that the mismatch in curvature between rod and coil entanglement tubes leads to the observed diffusional slowing. PMID:25484454

  8. One-dimensional nanoferroic rods; synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Ahmed, M. A.; Seddik, U.; Okasha, N.; Imam, N. G.

    2015-11-01

    One-dimensional nanoferroic rods of BaTiO3 were synthesized by improved citrate auto-combustion technology using tetrabutyl titanate. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) have been used to characterize the prepared sample. The results indicated that the crystal structure of BaTiO3 is tetragonal phase with an average crystallite size of 47 nm. SEM image gives a cauliflower-like morphology of the agglomerated nanorods. The stoichiometry of the chemical composition of the BaTiO3 ceramic was confirmed by EDX. TEM micrograph exhibited that BaTiO3 nanoparticles have rod-like shape with an average length of 120 nm and width of 43 nm. AFM was used to investigate the surface topography and its roughness. The topography image in 3D showed that the BaTiO3 particles have a rod shape with an average particle size of 116 nm which in agreement with 3D TEM result.

  9. Analysis of the causes of recurrence after frontalis suspension using silicone rods for congenital ptosis

    PubMed Central

    Kim, Chang Yeom; Son, Byeong Jae; Son, Jangyup; Hong, Jongill; Lee, Sang Yeul

    2017-01-01

    Background Silicone rod is a commonly used synthetic suspension material in frontalis suspension surgery to correct blepharoptosis. The most challenging problem and a decisive drawback of the use of silicone rod is a considerable rate of ptosis recurrence after surgery. We examined patients with recurred ptosis and assessed the physical and micromorphological properties of implanted silicone rods to determine the causative mechanisms of recurred ptosis after frontalis suspension using silicone rod. Methods This is a prospective observational case series of 22 pediatric patients with recurred ptosis after frontalis suspension using silicone rods for congenital ptosis. Implanted silicone rods were observed and removed during the operation for correction of recurred ptosis. The removed silicone rods were physically and micromorphologically evaluated to determine the cause of recurrence. Results Pretarsal fixation positions migrated upward, whereas suprabrow fixation positions migrated downward during ptosis recurrence. The breaking strength of implanted silicone rods was reduced by approximately 50% during 3 years. Cracks, debris, and loss of homogenous structure with disintegration were observed on scanning electron micrographs of implanted silicone rods in patients with recurred ptosis. Preoperative severe degree of ptosis also contributed to recurred ptosis. Conclusions Recurrence of ptosis after frontalis suspension using silicone rod was associated with physical changes of implanted silicone rods, including positional migration, weakened tensile strength, and micromorphological changes in combination with patients’ characteristics. PMID:28207846

  10. Rod Electroretinograms Elicited by Silent Substitution Stimuli from the Light-Adapted Human Eye

    PubMed Central

    Maguire, John; Parry, Neil R. A.; Kremers, Jan; Kommanapalli, Deepika; Murray, Ian J.; McKeefry, Declan J.

    2016-01-01

    Purpose To demonstrate that silent substitution stimuli can be used to generate electroretinograms (ERGs) that effectively isolate rod photoreceptor function in humans without the need for dark adaptation, and that this approach constitutes a viable alternative to current clinical standard testing protocols. Methods Rod-isolating and non-isolating sinusoidal flicker stimuli were generated on a 4 primary light-emitting diode (LED) Ganzfeld stimulator to elicit ERGs from participants with normal and compromised rod function who had not undergone dark-adaptation. Responses were subjected to Fourier analysis, and the amplitude and phase of the fundamental were used to examine temporal frequency and retinal illuminance response characteristics. Results Electroretinograms elicited by rod-isolating silent substitution stimuli exhibit low-pass temporal frequency response characteristics with an upper response limit of 30 Hz. Responses are optimal between 5 and 8 Hz and between 10 and 100 photopic trolands (Td). There is a significant correlation between the response amplitudes obtained with the silent substitution method and current standard clinical protocols. Analysis of signal-to-noise ratios reveals significant differences between subjects with normal and compromised rod function. Conclusions Silent substitution provides an effective method for the isolation of human rod photoreceptor function in subjects with normal as well as compromised rod function when stimuli are used within appropriate parameter ranges. Translational Relevance This method of generating rod-mediated ERGs can be achieved without time-consuming periods of dark adaptation, provides improved isolation of rod- from cone-based activity, and will lead to the development of faster clinical electrophysiologic testing protocols with improved selectivity. PMID:27617180

  11. Experience reveals ways to minimize failures in rod-pumped wells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patterson, J.C.; Bucaram, S.M.; Curfew, J.V.

    From the experience gained over the past 25 years, ARCO Oil and Gas Co. has developed recommendations to reduce equipment failure in sucker-rod pumping installations. These recommendations include equipment selection and design, operating procedures, and chemical treatment. Equipment failure and its attendant costs are extremely important in today's petroleum industry. Because rod pumping is the predominant means of artificial lift, minimizing equipment failure in rod pumped wells can have a significant impact on profitability. This compilation of recommendations comes from field locations throughout the US and other countries. The goal is to address and solve problems on a well-by-well basis.

  12. Impact of the World Health Organization's Surgical Safety Checklist on safety culture in the operating theatre: a controlled intervention study

    PubMed Central

    Haugen, A. S.; Søfteland, E.; Eide, G. E.; Sevdalis, N.; Vincent, C. A.; Nortvedt, M. W.; Harthug, S.

    2013-01-01

    Background Positive changes in safety culture have been hypothesized to be one of the mechanisms behind the reduction in mortality and morbidity after the introduction of the World Health Organization's Surgical Safety Checklist (SSC). We aimed to study the checklist effects on safety culture perceptions in operating theatre personnel using a prospective controlled intervention design at a single Norwegian university hospital. Methods We conducted a study with pre- and post-intervention surveys using the intervention and control groups. The primary outcome was the effects of the Norwegian version of the SSC on safety culture perceptions. Safety culture was measured using the validated Norwegian version of the Hospital Survey on Patient Safety Culture. Descriptive characteristics of operating theatre personnel and checklist compliance data were also recorded. A mixed linear regression model was used to assess changes in safety culture. Results The response rate was 61% (349/575) at baseline and 51% (292/569) post-intervention. Checklist compliance ranged from 77% to 85%. We found significant positive changes in the checklist intervention group for the culture factors ‘frequency of events reported’ and ‘adequate staffing’ with regression coefficients at −0.25 [95% confidence interval (CI), −0.47 to −0.07] and 0.21 (95% CI, 0.07–0.35), respectively. Overall, the intervention group reported significantly more positive culture scores—including at baseline. Conclusions Implementation of the SSC had rather limited impact on the safety culture within this hospital. PMID:23404986

  13. 76 FR 78882 - Carbon and Certain Alloy Steel Wire Rod From Mexico: Affirmative Preliminary Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-20

    ... Steel Wire Rod From Mexico: Affirmative Preliminary Determination of Circumvention of the Antidumping.... SUMMARY: We preliminarily determine that carbon and certain alloy steel wire rod (wire rod) with an actual.... de C.V. (Deacero) is circumventing the antidumping duty order on wire rod from Mexico (Wire Rod Order...

  14. Complete band gaps of phononic crystal plates with square rods.

    PubMed

    El-Naggar, Sahar A; Mostafa, Samia I; Rafat, Nadia H

    2012-04-01

    Much of previous work has been devoted in studying complete band gaps for bulk phononic crystal (PC). In this paper, we theoretically investigate the existence and widths of these gaps for PC plates. We focus our attention on steel rods of square cross sectional area embedded in epoxy matrix. The equations for calculating the dispersion relation for square rods in a square or a triangular lattice have been derived. Our analysis is based on super cell plane wave expansion (SC-PWE) method. The influence of inclusions filling factor and plate thickness on the existence and width of the phononic band gaps has been discussed. Our calculations show that there is a certain filling factor (f=0.55) below which arrangement of square rods in a triangular lattice is superior to the arrangement in a square lattice. A comparison between square and circular cross sectional rods reveals that the former has superior normalized gap width than the latter in case of a square lattice. This situation is switched in case of a triangular lattice. Moreover, a maximum normalized gap width of 0.7 can be achieved for PC plate of square rods embedded in a square lattice and having height 90% of the lattice constant. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Does the size of the rod affect the surgical results in adolescent idiopathic scoliosis? 5.5-mm versus 6.35-mm rod.

    PubMed

    Huang, Tsung-Hsi; Ma, Hsiao-Li; Wang, Shih-Tien; Chou, Po-Hsin; Ying, Szu-Han; Liu, Chien-Lin; Yu, Wing-Kwong; Chang, Ming-Chau

    2014-08-01

    Favorable clinical outcomes of surgical treatment with Cotrel-Dubousset instrumentation (CDI) or instrumentations that follow the principles of CDI, for adolescent idiopathic scoliosis (AIS) have been reported. However, there are few studies concerning the results with rods of different sizes. To find out whether the rod size affects the surgical results for AIS. A retrospective cohort study based on the same spinal system with different sizes of rod. A consecutive series of 93 patients, who underwent posterior correction with posterior instrumentation and fusion for AIS, were included and retrospectively analyzed. Postoperative radiologic outcomes were evaluated using coronal curves, percentage of curve correction, and coronal global balance. Ninety-three patients treated during the period January 2000 to December 2008 were included in this study; 48 patients were treated with the Cotrel-Dubousset Horizon (CDH) M10 system with a 6.35-mm rod from January 2000 through December 2004, and a CDH M8 was used with a 5.5-mm rod in another 45 patients from January 2005 through December 2008. The Cobb angle, Risser grade, coronal curves, flexibility of curve, percentage of curve correction, coronal global balance, operative time, and estimated blood loss were measured and analyzed. The same parameters were used when the patient was followed at the OPD. All of the patients underwent regular follow-up for at least 2 years. No statistical significance was observed in the demographic data, including age, sex, BMI, and Risser grade, between these 2 groups. The overall average percentage of correction was 60.0%±12.7%: 60.7%±12.5% for the CDH M10 group, and 59%±13.1% for the CDH M8 group. At the final follow-up, the overall average loss of correction was 4.8±3.9° for the CDH M10 group, and 4.3±4.0° for the CDH M8 group. The average percentage of correction at the final follow-up was 50.9%±15.1% for the CDH M10 group, and 51.1%±16.1% for the M8 group. No statistical

  16. Partial preservation of rod and cone ERG function following subretinal injection of ARPE-19 cells in RCS rats.

    PubMed

    Sauvé, Y; Pinilla, I; Lund, R D

    2006-04-01

    We quantified rod- and cone-related electroretinogram (ERG) responses following subretinal injections of the human-derived retinal pigment epithelial (hRPE) cell line ARPE-19 at age P23 to prevent progressive photoreceptor loss in the Royal College of Surgeons (RCS) rat. Culture medium-injected eyes served as sham controls. At P60, in comparison with sham-injected eyes, all recordings from hRPE-injected eyes showed preserved scotopic a- and b-waves, oscillatory potentials, double-flash-derived rod b-waves and photopic cone b-waves, and flicker critical fusion frequencies and amplitudes. Although the actual preservation did not exceed 10% of a-wave and 20% of b-wave amplitude values in non-dystrophic RCS and deteriorated rapidly by P90, rod- and cone-related ERG parameters were still recordable up to P120 unlike the virtually unresponsive sham-injected eyes.

  17. Theory of thin-walled rods

    NASA Technical Reports Server (NTRS)

    Goldenveizer, A L

    1951-01-01

    Starting with the Love equations for bending of extensible shells, "principal stress states" are sought for a thin-walled rod of arbitrary but open cross section. Principal stress states exclude those local states arising from end conditions which damp out with distance from the ends. It is found that for rods of intermediate length, long enough to avoid local bending at a support, and short enough that elementary torsion and bending are not the most significant stress states, four principal states exist. Three of these states are associated with the planar distribution of axial stress and are equivalent to the engineering theory of extension and bending of solid sections. The fourth state resembles that which has been called in the literature "bending stress due to torsional", except that cross sections are permitted to bend and the shear along the center line of the cross section is permitted to differ from zero.

  18. Influence of ethylene oxide exposure on the extraction of indomethacin from dimethicone polymeric rods.

    PubMed

    Hurst, P R; Peplow, P V; von Dadelszen, P

    1982-05-01

    Dimethicone polymeric rods were made to contain 0.3, 2.0, or 3.3% by weight of indomethacin. For each different loading of indomethacin, some of the rods were treated with ethylene oxide at 55 degrees for 1 hr, while others were not exposed to the gas. Treated and untreated rods were sliced, placed in ethanol to extract the indomethacin, and the concentrations of indomethacin in the extracts determined by fluorometry and high-performance liquid chromatography (HPLC). After ethylene oxide treatment, the quantity of indomethacin in the extracts was significantly reduced in rods containing 0.3 and 2.0% indomethacin. For the rods containing 3.3% indomethacin, the recovery of the drug from treated rods was not significantly different from those not exposed.

  19. Bound states in the continuum and polarization singularities in periodic arrays of dielectric rods

    NASA Astrophysics Data System (ADS)

    Bulgakov, Evgeny N.; Maksimov, Dmitrii N.

    2017-12-01

    We consider optical bound states in the continuum (BICs) in periodic arrays of dielectric rods. The full classification of BICs in the above system is provided, including the modes propagating along the axes of the rods and bidirectional BICs propagating both along the axes of the rods and the axis of periodicity. It is shown that the leaky zones supporting the BICs generally have elliptically polarized far-field radiation patterns, with the polarization ellipses collapsing on approach to the BICs in momentum space. That allowed us to apply the concept of polarization singularities and demonstrate that the BICs possess a topological charge defined as the winding number of the polarization direction [Phys. Rev. Lett. 113, 257401 (2014), 10.1103/PhysRevLett.113.257401]. It is found that the evolution of the BICs, including their creation and annihilation, under variation of geometric parameters is controlled by the topological charge. Three scenarios of such evolution for different leaky zones are described. Finally, it is shown that the topological properties of the BICs can be extracted from transmission spectra when the system is illuminated by a plane wave of circular polarization.

  20. Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Passerini, Stefano; Ponciroli, Roberto; Vilim, Richard B.

    Here, the interaction of the active control system with passive safety behavior is investigated for sodium-cooled fast reactors. A claim often made of advanced reactors is that they are passively safe against unprotected upset events. In practice, such upset events are not analyzed in the context of the plant control system, but rather the analyses are performed without considering the normally programmed response of the control system (open-loop approach). This represents an oversimplification of the safety case. The issue of passive safety override arises since the control system commands actuators whose motions have safety consequences. Depending on the upset involvingmore » the control system ( operator error, active control system failure, or inadvertent control system override), an actuator does not necessarily go in the same direction as needed for safety. So neglecting to account for control system action during an unprotected upset is nonconservative from a safety standpoint. It is important then, during the design of the plant, to consider the potential for the control system to work against the inherent and safe regulating effects of purposefully engineered temperature feedbacks.« less

  1. Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background

    DOE PAGES

    Passerini, Stefano; Ponciroli, Roberto; Vilim, Richard B.

    2017-06-21

    Here, the interaction of the active control system with passive safety behavior is investigated for sodium-cooled fast reactors. A claim often made of advanced reactors is that they are passively safe against unprotected upset events. In practice, such upset events are not analyzed in the context of the plant control system, but rather the analyses are performed without considering the normally programmed response of the control system (open-loop approach). This represents an oversimplification of the safety case. The issue of passive safety override arises since the control system commands actuators whose motions have safety consequences. Depending on the upset involvingmore » the control system ( operator error, active control system failure, or inadvertent control system override), an actuator does not necessarily go in the same direction as needed for safety. So neglecting to account for control system action during an unprotected upset is nonconservative from a safety standpoint. It is important then, during the design of the plant, to consider the potential for the control system to work against the inherent and safe regulating effects of purposefully engineered temperature feedbacks.« less

  2. Torsion of DNA modeled as a heterogeneous fluctuating rod

    NASA Astrophysics Data System (ADS)

    Argudo, David; Purohit, Prashant K.

    2014-01-01

    We discuss the statistical mechanics of a heterogeneous elastic rod with bending, twisting and stretching. Our model goes beyond earlier works where only homogeneous rods were considered in the limit of high forces and long lengths. Our methods allow us to consider shorter fluctuating rods for which boundary conditions can play an important role. We use our theory to study structural transitions in torsionally constrained DNA where there is coexistence of states with different effective properties. In particular, we examine whether a newly discovered left-handed DNA conformation called L-DNA is a mixture of two known states. We also use our model to investigate the mechanical effects of the binding of small molecules to DNA. For both these applications we make experimentally falsifiable predictions.

  3. Nucleation and growth of electrodeposited Mn oxide rods for supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Clark, Michael; Ivey, Douglas G.

    2015-09-01

    The nucleation and growth of electrodeposited Mn oxide rods has been investigated by preparing deposits on Au coated Si at varying deposition times between 0.5 s and 10 min. The deposits were investigated using high resolution scanning and transmission electron microscopy. A model for the nucleation and growth of Mn oxide rods has been proposed. Nucleation begins as thin sheets along Au grain boundaries and triple points. As these nucleation sites are consumed, nucleation spreads across the grains. Nucleation of sheets in close proximity causes agglomeration and the formation of rounded particles. Some of these rounded particles then accelerate in growth, initially in all directions and then primarily in the direction normal to the sample surface. Accelerated growth normal to the sample surface leads to the formation of rods. As rods grow, the growth of other particles accelerates and they become rods themselves. Eventually the entire sample surface is covered with rods 15-20 μm long and about 2 μm wide. The sheet-like morphology of the deposits is retained at all stages of deposition. Electron diffraction analysis of 3 s and 6 s deposits shows that the sheets are initially amorphous and then begin to crystallize into a cubic spinel Mn3O4 crystal structure. High resolution imaging of the 6 s sample shows small crystalline regions (˜5 nm in size) within an amorphous matrix.

  4. Hierarchically porous and heteroatom doped carbon derived from tobacco rods for supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhao, Yong-Qing; Lu, Min; Tao, Peng-Yu; Zhang, Yun-Jie; Gong, Xiao-Ting; Yang, Zhi; Zhang, Guo-Qing; Li, Hu-Lin

    2016-03-01

    A novel tobacco rods-derived carbon (TC) has been prepared by hydrothermal carbonization and potassium hydroxide activation strategy for supercapacitors application. The physicochemical properties of TC are investigated by X-ray diffraction, Raman spectra, Scanning electron microscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and four-probe tests. Results show TC derived from different tobacco rods possesses similar properties, such as amorphous state, high specific surface area, hierarchical porous structure, numerous heteroatom groups, and good electrical conductivity. The electrochemical characteristics of TC are examined via cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements. In a three-electrode system, TC exhibits high capacitance with 286.6 F g-1 at 0.5 A g-1, excellent rate performance with 212.1 F g-1 even at 30 A g-1, and outstanding cyclic stability with 96% capacitance retention after 10,000 cycles at 5 A g-1. Furthermore, TC supercapacitor devices can deliver an energy density of 31.3 Wh kg-1 at 0.5 A g-1 and power density of 11.8 kW kg-1 at 15 A g-1. Therefore, this novel concept of tobacco use, namely tobacco rods from cigarette (the harmful) to high-performance carbon for supercapacitors (the beneficial), is an extremely promising strategy for developing high-performance carbon from renewable sources, and supporting the tobacco control.

  5. Air- coupled ultrasonic testing of CFRP rods by means of guided waves

    NASA Astrophysics Data System (ADS)

    Kažys, Rymantas; Raišutis, Renaldas; Žukauskas, Egidijus; Mažeika, Liudas; Vladišauskas, Alfonsas

    2010-01-01

    One of the most important parts of the gliders is a lightweight longeron reinforcement made of carbon fibre reinforced plastics (CFRP) rods. These small diameter (a few millimetres) rods during manufacturing are glued together in epoxy filled matrix in order to build the arbitrary spar profile. However, the defects presenting in the rods such as brake of fibres, lack of bonding, reduction of density affect essentially the strength of the construction and are very complicated in repairing. Therefore, appropriate non-destructive testing techniques of carbon fibber rods should be applied before gluing them together. The objective of the presented work was development of NDT technique of CFRP rods used for aerospace applications, which is based on air- coupled excitation/reception of guided waves. The regularities of ultrasonic guided waves propagating in both circular and rectangular cross-section CFRP rods immersed into water were investigated and it was shown that the guided waves propagating along sample of the rod create leaky waves which are radiated into a surrounding medium. The ultrasonic receiver scanned over the rod enables to pick-up the leaky waves and to determine the non-uniformities of propagation caused by the defects. Theoretical investigations were carried out by means of numerical simulations based on a 2D and 3D finite differences method. By modelling and experimental investigations it was demonstrated that presence of any type of the defect disturbs the leaky wave and enables to detect them. So, the spatial position of defects can be determined also. It was shown that such important defects as a disbond of the plies essentially reduce or even completely suppress the leaky wave, so they can be detected quit easily.

  6. Payload Safety: Risk and Characteristic-Based Control of Engineered Nanomaterials

    NASA Astrophysics Data System (ADS)

    Abou, Seraphin Chally; Saad, Maarouf

    2013-09-01

    In the last decade progress has been made to assist organizations that are developing payloads intended for flight on the International Space Station (ISS) and/or Space Shuttle. Collaboration programs for comprehensive risk assessment have been initiated between the U.S. and the European Union to generate requirements and data needed to comply with payloads safety and to perform risk assessment and controls guidance. Yet, substantial research gaps remain, as do challenges in the translation of these research findings to control for exposure to nanoscale material payloads, and the health effects. Since nanomaterial structures are different from traditional molecules, some standard material properties can change at size of 50nm or less. Changes in material properties at this scale challenge our understanding of hazards posed by nanomaterial payloads in the ISS realistic exposure conditions, and our ability to anticipate, evaluate, and control potential health issues, and safety. The research question addressed in this framework is: what kind of descriptors can be developed for nanomaterial payloads risks assessment? Methods proposed incorporate elements of characteristic- based risk an alysis: (1) to enable characterization of anthropogenic nanomaterials which can result in incidental from natural nanoparticles; and (2) to better understand safety attributes in terms of human health impacts from exposure to varying types of engineered nanomaterials.

  7. Critical review of controlled release packaging to improve food safety and quality.

    PubMed

    Chen, Xi; Chen, Mo; Xu, Chenyi; Yam, Kit L

    2018-03-19

    Controlled release packaging (CRP) is an innovative technology that uses the package to release active compounds in a controlled manner to improve safety and quality for a wide range of food products during storage. This paper provides a critical review of the uniqueness, design considerations, and research gaps of CRP, with a focus on the kinetics and mechanism of active compounds releasing from the package. Literature data and practical examples are presented to illustrate how CRP controls what active compounds to release, when and how to release, how much and how fast to release, in order to improve food safety and quality.

  8. An analytical model for inductively coupled implantable biomedical devices with ferrite rods.

    PubMed

    Theilmann, P T; Asbeck, P M

    2009-02-01

    Using approximations applicable to near field coupled implants simplified expressions for the complex mutual inductance of coaxial aligned coils with and without a cylindrical ferrite rod are derived. Experimental results for ferrite rods of various sizes and permeabilities are presented to verify the accuracy of this expression. An equivalent circuit model for the inductive link between an implant and power coil is then presented and used to investigate how ferrite size, permeability and loss affect the power available to the implant device. Enhancements in coupling provided by high frequency, low permeability nickel zinc rods are compared with low frequency high permeability manganese zinc rods.

  9. Fission control system for nuclear reactor

    DOEpatents

    Conley, G.H.; Estes, G.P.

    Control system for nuclear reactor comprises a first set of reactivity modifying rods fixed in a reactor core with their upper ends stepped in height across the core, and a second set of reactivity modifying rods movable vertically within the reactor core and having their lower ends stepped to correspond with the stepped arrangement of the first set of rods, pairs of the rods of the first and second sets being in coaxial alignment.

  10. Power ramp induced iodine and cesium redistribution in LWR fuel rods

    NASA Astrophysics Data System (ADS)

    Sontheimer, F.; Vogl, W.; Ruyter, I.; Markgraf, J.

    1980-01-01

    Volatile fission product migration in LWR fuel rods which are power ramped above a certain threshold beyond the envelope of their previous power history, plays an important role in stress corrosion cracking of Zircaloy. This may cause fuel rods to fail already at stresses below the yield strength. In the HFR, Petten, many power ramp experiments have been performed with subsequent examination of the ramped rods for fission product distribution. This study describes the measurement of iodine and cesium distribution using γ-spectroscopy of I-131 and Cs-137. An evaluation method is presented which makes the determination of absolute amounts of I/Cs feasible. It is shown that a threshold for I/Cs redistribution exists beyond which it depends strongly on local fuel rod power and fuel type.

  11. Measurement of liquid film flow on nuclear rod bundle in micro-scale by using very high speed camera system

    NASA Astrophysics Data System (ADS)

    Pham, Son; Kawara, Zensaku; Yokomine, Takehiko; Kunugi, Tomoaki

    2012-11-01

    Playing important roles in the mass and heat transfer as well as the safety of boiling water reactor, the liquid film flow on nuclear fuel rods has been studied by different measurement techniques such as ultrasonic transmission, conductivity probe, etc. Obtained experimental data of this annular two-phase flow, however, are still not enough to construct the physical model for critical heat flux analysis especially at the micro-scale. Remain problems are mainly caused by complicated geometry of fuel rod bundles, high velocity and very unstable interface behavior of liquid and gas flow. To get over these difficulties, a new approach using a very high speed digital camera system has been introduced in this work. The test section simulating a 3×3 rectangular rod bundle was made of acrylic to allow a full optical observation of the camera. Image data were taken through Cassegrain optical system to maintain the spatiotemporal resolution up to 7 μm and 20 μs. The results included not only the real-time visual information of flow patterns, but also the quantitative data such as liquid film thickness, the droplets' size and speed distributions, and the tilt angle of wavy surfaces. These databases could contribute to the development of a new model for the annular two-phase flow. Partly supported by the Global Center of Excellence (G-COE) program (J-051) of MEXT, Japan.

  12. Dark-Adapted Chromatic Perimetry for Measuring Rod Visual Fields in Patients with Retinitis Pigmentosa

    PubMed Central

    Bennett, Lea D.; Klein, Martin; Locke, Kirsten G.; Kiser, Kelly; Birch, David G.

    2017-01-01

    Purpose Although rod photoreceptors are initially affected in retinitis pigmentosa (RP), the full-field of rod vision is not routinely characterized due to the unavailability of commercial devices detecting rod sensitivity. The purpose of this study was to quantify rod-mediated vision in the peripheral field from patients with RP using a new commercially available perimeter. Methods Participants had one eye dilated and dark-adapted for 45 minutes. A dark-adapted chromatic (DAC) perimeter tested 80 loci 144° horizontally and 72° vertically with cyan stimuli. The number of rod-mediated loci (RML) were analyzed based on normal cone sensitivity (method 1) and associated with full-field electroretinography (ERG) responses by Pearson's r correlation and linear regression. In a second cohort of patients with RP, RML were identified by two-color perimetry (cyan and red; method 2). The two methods for ascribing rod function were compared by Bland-Altman analysis. Results Method 1 RML were correlated with responses to the 0.01 cd.s/m2 flash (P < 0.001), while total sensitivity to the cyan stimulus showed correlation with responses to the 3.0 cd.s/m2 flash (P < 0.0001). Method 2 detected a mean of 10 additional RML compared to method 1. Conclusions Scotopic fields measured with the DAC detected rod sensitivity across the full visual field, even in some patients who had nondetectable rod ERGs. Two-color perimetry is warranted when sensitivity to the cyan stimulus is reduced to ≤20 dB to get a true estimation of rod function. Translational Relevance Many genetic forms of retinitis pigmentosa (RP) are caused by mutations in rod-specific genes. However, treatment trials for patients with RP have relied primarily on photopic (cone-mediated) tests as outcome measures because there are a limited number of available testing methods designed to evaluate rod function. Thus, efficient methods for quantifying rod-mediated vision are needed for the rapidly increasing numbers of

  13. Safety concerns in composite manufacturing and machining

    NASA Astrophysics Data System (ADS)

    Asmatulu, Eylem; Alonayni, Abdullah; Alamir, Mohammed

    2018-03-01

    Because of the superior properties, composites have been used in many industrial applications, including aerospace, wind turbines, ships, cars, fishing rods, storage tanks, swimming pool panels, and baseball bats. Each application may require different combinations of reinforcements and matrices, which make the manufacturing safety even more challenging while working on these substances. In this study, safety issues in composite manufacturing and machining were investigated in detail, and latest developments were provided for workers. The materials most frequently used in composite manufacturing, such as matrix (polyester, vinylester, phenolic, epoxies, methyl ethyl ketone peroxide, benzoil peroxide, hardeners, and solvents), and reinforcement materials (carbon, glass and Kevlar fibers, honeycomb and foams) can be highly toxic to human body. These materials can also be very toxic to the environment when dumped out uncontrollably, creating major future health and environmental concerns. Throughout the manufacturing process, workers inhale vapors of the liquid matrix, hardeners and solvents / thinners, as well as reinforcement materials (chopped fibers and particles) in airborne. Milling, cutting and machining of the composites can further increase the toxic inhalations of airborne composite particles, resulting in major rashes, irritation, skin disorders, coughing, severe eye and lung injury and other serious illnesses. The major portions of these hazardous materials can be controlled using appropriate personal protective equipment for the chemicals and materials used in composite manufacturing and machining. This study provides best possible safety practices utilized in composite manufacturing facilities for workers, engineers and other participants.

  14. Single- versus dual-rod anterior instrumentation of thoracolumbar curves in adolescent idiopathic scoliosis.

    PubMed

    Nambiar, Mithun; Yang, Yi; Liew, Susan; Turner, Peter L; Torode, Ian P

    2016-10-01

    Single or dual-rod instrumentation can be used for the anterior fixation of the spine in adolescent idiopathic scoliosis (AIS). We aim to compare the complications, radiographic and functional outcomes of patients with AIS who have undergone single and dual-rod instrumentation. This is a multi-centre study involving the Royal Children's, Royal Melbourne and Epworth hospitals. Three primary surgeons were involved to ensure homogeneity of surgical technique and implants. Patients with AIS and thoracolumbar curves (Lenke 5 and 6) undergoing anterior instrumentation from 1st January 2000 to 30th June 2013 were included. Radiographic data were collected from X-rays. The functional outcome was measured through the Scoliosis Research Society questionnaire (SRS-30). The study included 58 patients (38 single-rod and 20 dual-rod patients). Thirty-nine patients were classified with Lenke 5 curves, while 19 patients had Lenke 6 curves. Structural interbody supports were used in 95 % of cases. In the preoperative to postoperative period, patients with single rods had an improvement of 75 and 51 % for primary and secondary curves, respectively, while patients with dual rods had an improvement of 70 and 38 % for primary and secondary curves, respectively. There were no cases of pseudoarthrosis or metalware failure in either group. Two patients (one single-rod and one dual-rod patient) required further unplanned posterior fusion. 91 % of patients were satisfied with the results of their back management. Pseudoarthrosis and metalware failure are rare complications of anterior instrumentation. Our study found no significant difference in functional or radiographic outcome between single and dual-rod instrumentation. Level III.

  15. Characterization of the rod photoresponse isolated from the dark-adapted primate ERG.

    PubMed

    Jamison, J A; Bush, R A; Lei, B; Sieving, P A

    2001-01-01

    The a-wave of the human dark-adapted ERG is thought to derive from activity of rod photoreceptors. However, other sources within the retina could potentially perturb this simple equation. We investigated the extent to which the short-latency dark-adapted rod a-wave of the primate ERG is dominated by the rod photoresponse and the applicability of the phototransduction model to fit the rod a-wave. Dark-adapted Ganzfeld ERGs were elicited over a 5-log-unit intensity range using short bright xenon flashes, and the light-adapted cone responses were subtracted to isolate the rod ERG a-wave. Intravitreal 4-phosphono-butyric acid (APB) and cis-2,3-piperidine-dicarboxylic acid (PDA) were applied to isolate the photoreceptor response. The Hood and Birch version of the phototransduction model, Rmax[1 - e(-I x S x (t-t(eff)))2], was fitted to the a-wave data while allowing Rmax and S to vary. Three principle observations were made: (1) At flash intensities > or =0.77 log sc-td-s the leading edge of the normalized rod ERG a-wave tracks the isolated photoreceptor response across the first 20 ms or up to the point of b-wave intrusion. The rod ERG a-wave was essentially identical to the isolated receptor response for all intensities that produce peak responses within 14 ms after the flash. (2) The best fit of sensitivity (S) was not affected by APB and/or PDA, suggesting that the inner retina contributes very little to the dark-adapted a-wave. (3) APB always reduced the maximum dark-adapted a-wave amplitude (by 15-30%), and PDA always increased it (by 7-15%). Using the phototransduction model, both events can be interpreted as a scaling of the photoreceptor dark current. This suggests that activity of postreceptor cells somehow influences the rod dark current, possibly by feedback through horizontal cells (although currently not demonstrated for the rod system), or by altering the ionic concentrations near the photoreceptors, or by neuromodulator effects mediated by dopamine or

  16. Ultrasonic Structural Health Monitoring to Assess the Integrity of Spinal Growing Rods In Vitro.

    PubMed

    Oetgen, Matthew E; Goodley, Addison; Yoo, Byungseok; Pines, Darryll J; Hsieh, Adam H

    2016-01-01

    Rod fracture is a common complication of growing rods and can result in loss of correction, patient discomfort, and unplanned revision surgery. The ability to quantitate rod integrity at each lengthening would be advantageous to avoid this complication. We investigate the feasibility of applying structural health monitoring to evaluate the integrity of growing rods in vitro. Single-rod titanium 4.5-mm growing rod constructs (n = 9), one screw proximally and one distally connected by in-line connectors, were assembled with pedicle screws fixed in polyethylene blocks. Proximal and distal ends were loaded and constructs subjected to cyclic axial compression (0-100 N at 1 Hz), with incrementally increasing maximum compressive loads of 10 N every 9k cycles until failure. Four piezoceramic transducers (PZTs) were mounted along the length the constructs to interrogate the integrity of the rods with an ultrasonic, guided lamb wave approach. Every 9k cycles, an 80 V excitatory voltage was applied to a PZT to generate high-frequency vibrations, which, after propagating through the construct, was detected by the remaining PZTs. Amplitude differences between pre- and postload waveform signals were calculated until rod failure. Average construct lifetime was 88,991 ± 13,398 cycles. All constructs failed due to rod fracture within 21 mm (mean = 15 ± 4.5 mm) of a screw or connector. Amplitude differences between pre- and postload increased in a stepwise fashion as constructs were cycled. Compared to baseline, we found a 1.8 ± 0.6-fold increase in amplitude 18k cycles before failure, a 2.2 ± 1.0-fold increase in amplitude 9k cycles before failure, and a 2.75 ± 1.5-fold increase in amplitude immediately before rod fracture. We describe a potential method for assessing the structural integrity of growing rods using ultrasonic structural health monitoring. These preliminary data demonstrate the ability of periodic rod assessment to detect structural changes in cycled growing

  17. Biomechanical Evaluation of a Growth-Friendly Rod Construct.

    PubMed

    Galvis, Sarah; Arnold, Josh; Mannen, Erin; Wong, Benjamin; Sis, Hadley; Cadel, Eileen; Anderson, John; Anderson, Dennis; Arnold, Paul; Friis, Elizabeth

    2017-01-01

    Distraction-type rods mechanically stabilize the thorax and improve lung growth and function by applying distraction forces at the rib, spine, pelvis, or a combination of locations. However, the amount of stability the rods provide and the amount the thorax needs is unknown. Five freshly frozen and thawed cadaveric thoracic spine specimens were tested for lateral bending, flexion/extension, and axial rotation in displacement control (1°/sec) to a load limit of ±5 Nm for five cycles after which a growth-friendly unilateral rod was placed in a simulated rib-to-lumbar attachment along the right side. The specimens were tested again in the same modes of bending. From the seven Optotrak Orthopedic Research Pin markers (Northern Digital Inc., Waterloo, Ontario, Canada) inserted into the top potting to denote T1, and the right pedicles at T2, T4, T5, T8, T9, and T11 and the Standard Needle Tip Pressure Transducers (Gaeltech, Isle of Skye, Scotland) inserted into the T4/T5 and T8/T9 discs, motion, stiffness, and pressure data were calculated. Parameters from the third cycle of the intact case and the construct case were compared using two-tailed paired t tests with 0.05 as the level of significance. With the construct attached, the T1-T4 segment showed a 30% increase in neutral zone stiffness during extension (p = .001); the T8-T12 segment experienced a 63% reduction in the in-plane range of motion during flexion (p = .04); and the T8/T9 spinal motion unit had a significant decrease of 24% in elastic zone stiffness during left axial rotation (p = .04). It is clear the device as tested here does not produce large biomechanical changes, but the balance between providing desired changes while preventing complications remains difficult. Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

  18. Coiling of elastic rods from a geometric perspective

    NASA Astrophysics Data System (ADS)

    Jawed, Mohammad; Brun, Pierre-Thomas; Reis, Pedro

    2015-03-01

    We present results from a systematic numerical investigation of the pattern formation of coiling obtained when a slender elastic rod is deployed onto a moving substrate; a system known as the elastic sewing machine (ESM). The Discrete Elastic Rods method is employed to explore the parameter space, construct phase diagrams, identify their phase boundaries and characterize the morphology of the patterns. The nontrivial geometric nonlinearities are described in terms of the gravito-bending length and the deployment height. Our results are interpreted using a reduced geometric model for the evolution of the position of the contact point with the belt and the curvature of the rod in its neighborhood. This geometric model reproduces all of the coiling patterns of the ESM, which allows us to establish a universal link between our elastic problem and the analogous patterns obtained when depositing a viscous thread onto a moving surface; a well-known system referred to as the fluid mechanical sewing machine.

  19. Mechanical energy flow models of rods and beams

    NASA Technical Reports Server (NTRS)

    Wohlever, J. C.; Bernhard, R. J.

    1992-01-01

    It has been proposed that the flow of mechanical energy through a structural/acoustic system may be modeled in a manner similar to that of flow of thermal energy/in a heat conduction problem. If this hypothesis is true, it would result in relatively efficient numerical models of structure-borne energy in large built-up structures. Fewer parameters are required to approximate the energy solution than are required to model the characteristic wave behavior of structural vibration by using traditional displacement formulations. The energy flow hypothesis is tested in this investigation for both longitudinal vibration in rods and transverse flexural vibrations of beams. The rod is shown to behave approximately according to the thermal energy flow analogy. However, the beam solutions behave significantly differently than predicted by the thermal analogy unless locally-space-averaged energy and power are considered. Several techniques for coupling dissimilar rods and beams are also discussed. Illustrations of the solution accuracy of the methods are included.

  20. Pattern formation of microtubules and motors: inelastic interaction of polar rods.

    PubMed

    Aranson, Igor S; Tsimring, Lev S

    2005-05-01

    We derive a model describing spatiotemporal organization of an array of microtubules interacting via molecular motors. Starting from a stochastic model of inelastic polar rods with a generic anisotropic interaction kernel we obtain a set of equations for the local rods concentration and orientation. At large enough mean density of rods and concentration of motors, the model describes orientational instability. We demonstrate that the orientational instability leads to the formation of vortices and (for large density and/or kernel anisotropy) asters seen in recent experiments.

  1. Low-NA single-mode LMA photonic crystal rod fiber amplifier

    NASA Astrophysics Data System (ADS)

    Alkeskjold, Thomas Tanggaard; Laurila, Marko; Scolari, Lara; Broeng, Jes

    2011-02-01

    Enabling Single-Mode (SM) operation in Large-Mode-Area (LMA) fiber amplifiers and lasers is critical, since a SM output ensures high beam quality and excellent pointing stability. In this paper, we demonstrate and test a new design approach for achieving ultra-low NA SM rod fibers by using a spatially Distributed Mode Filter (DMF). This approach achieves SM performance in a short and straight rod fiber and allows preform tolerances to be compensated during draw. A low-NA SM rod fiber amplifier having a mode field diameter of ~60μm at 1064nm and a pump absorption of 27dB/m at 976nm is demonstrated.

  2. Tapered laser rods as a means of minimizing the path length of trapped barrel mode rays

    DOEpatents

    Beach, Raymond J.; Honea, Eric C.; Payne, Stephen A.; Mercer, Ian; Perry, Michael D.

    2005-08-30

    By tapering the diameter of a flanged barrel laser rod over its length, the maximum trapped path length of a barrel mode can be dramatically reduced, thereby reducing the ability of the trapped spontaneous emission to negatively impact laser performance through amplified spontaneous emission (ASE). Laser rods with polished barrels and flanged end caps have found increasing application in diode array end-pumped laser systems. The polished barrel of the rod serves to confine diode array pump light within the rod. In systems utilizing an end-pumping geometry and such polished barrel laser rods, the pump light that is introduced into one or both ends of the laser rod, is ducted down the length of the rod via the total internal reflections (TIRs) that occur when the light strikes the rod's barrel. A disadvantage of using polished barrel laser rods is that such rods are very susceptible to barrel mode paths that can trap spontaneous emission over long path lengths. This trapped spontaneous emission can then be amplified through stimulated emission resulting in a situation where the stored energy available to the desired lasing mode is effectively depleted, which then negatively impacts the laser's performance, a result that is effectively reduced by introducing a taper onto the laser rod.

  3. Numerical Tests for the Problem of U-Pu Fuel Burnup in Fuel Rod and Polycell Models Using the MCNP Code

    NASA Astrophysics Data System (ADS)

    Muratov, V. G.; Lopatkin, A. V.

    An important aspect in the verification of the engineering techniques used in the safety analysis of MOX-fuelled reactors, is the preparation of test calculations to determine nuclide composition variations under irradiation and analysis of burnup problem errors resulting from various factors, such as, for instance, the effect of nuclear data uncertainties on nuclide concentration calculations. So far, no universally recognized tests have been devised. A calculation technique has been developed for solving the problem using the up-to-date calculation tools and the latest versions of nuclear libraries. Initially, in 1997, a code was drawn up in an effort under ISTC Project No. 116 to calculate the burnup in one VVER-1000 fuel rod, using the MCNP Code. Later on, the authors developed a computation technique which allows calculating fuel burnup in models of a fuel rod, or a fuel assembly, or the whole reactor. It became possible to apply it to fuel burnup in all types of nuclear reactors and subcritical blankets.

  4. Crystal phase-controlled synthesis of rod-shaped AgInTe2 nanocrystals for in vivo imaging in the near-infrared wavelength region

    NASA Astrophysics Data System (ADS)

    Kameyama, Tatsuya; Ishigami, Yujiro; Yukawa, Hiroshi; Shimada, Taisuke; Baba, Yoshinobu; Ishikawa, Tetsuya; Kuwabata, Susumu; Torimoto, Tsukasa

    2016-03-01

    Rod-shaped AgInTe2 nanocrystals (NCs) exhibiting intense near-band edge photoluminescence in the near-infrared (NIR) wavelength region, were successfully prepared by the thermal reaction of metal acetates and Te precursors in 1-dodecanethiol. Increasing the reaction temperature resulted in the formation of larger AgInTe2 NCs with crystal structures varying from hexagonal to tetragonal at reaction temperatures of 280 °C or higher. The energy gap was increased from 1.13 to 1.20 eV with a decrease in rod width from 8.3 to 5.6 nm, accompanied by a blue shift in the photoluminescence (PL) peak wavelength from 1097 to 1033 nm. The optimal PL quantum yield was approximately 18% for AgInTe2 NCs with rod widths of 5.6 nm. The applicability of AgInTe2 NCs as a NIR-emitting material for in vivo biological imaging was examined by injecting AgInTe2 NC-incorporated liposomes into the back of a C57BL/6 mouse, followed by in vivo photoluminescence imaging in the NIR region.Rod-shaped AgInTe2 nanocrystals (NCs) exhibiting intense near-band edge photoluminescence in the near-infrared (NIR) wavelength region, were successfully prepared by the thermal reaction of metal acetates and Te precursors in 1-dodecanethiol. Increasing the reaction temperature resulted in the formation of larger AgInTe2 NCs with crystal structures varying from hexagonal to tetragonal at reaction temperatures of 280 °C or higher. The energy gap was increased from 1.13 to 1.20 eV with a decrease in rod width from 8.3 to 5.6 nm, accompanied by a blue shift in the photoluminescence (PL) peak wavelength from 1097 to 1033 nm. The optimal PL quantum yield was approximately 18% for AgInTe2 NCs with rod widths of 5.6 nm. The applicability of AgInTe2 NCs as a NIR-emitting material for in vivo biological imaging was examined by injecting AgInTe2 NC-incorporated liposomes into the back of a C57BL/6 mouse, followed by in vivo photoluminescence imaging in the NIR region. Electronic supplementary information (ESI) available

  5. Between a Map and a Data Rod

    NASA Technical Reports Server (NTRS)

    Teng, William; Rui, Hualan; Strub, Richard; Vollmer, Bruce

    2015-01-01

    A Digital Divide has long stood between how NASA and other satellite-derived data are typically archived (time-step arrays or maps) and how hydrology and other point-time series oriented communities prefer to access those data. In essence, the desired method of data access is orthogonal to the way the data are archived. Our approach to bridging the Divide is part of a larger NASA-supported data rods project to enhance access to and use of NASA and other data by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) and the larger hydrology community. Our main objective was to determine a way to reorganize data that is optimal for these communities. Two related objectives were to optimally reorganize data in a way that (1) is operational and fits in and leverages the existing Goddard Earth Sciences Data and Information Services Center (GES DISC) operational environment and (2) addresses the scaling up of data sets available as time series from those archived at the GES DISC to potentially include those from other Earth Observing System Data and Information System (EOSDIS) data archives. Through several prototype efforts and lessons learned, we arrived at a non-database solution that satisfied our objectivesconstraints. We describe, in this presentation, how we implemented the operational production of pre-generated data rods and, considering the tradeoffs between length of time series (or number of time steps), resources needed, and performance, how we implemented the operational production of on-the-fly (virtual) data rods. For the virtual data rods, we leveraged a number of existing resources, including the NASA Giovanni Cache and NetCDF Operators (NCO) and used data cubes processed in parallel. Our current benchmark performance for virtual generation of data rods is about a years worth of time series for hourly data (9,000 time steps) in 90 seconds. Our approach is a specific implementation of

  6. Between a Map and a Data Rod

    NASA Astrophysics Data System (ADS)

    Teng, W. L.; Rui, H.; Strub, R. F.; Vollmer, B.

    2015-12-01

    A "Digital Divide" has long stood between how NASA and other satellite-derived data are typically archived (time-step arrays or "maps") and how hydrology and other point-time series oriented communities prefer to access those data. In essence, the desired method of data access is orthogonal to the way the data are archived. Our approach to bridging the Divide is part of a larger NASA-supported "data rods" project to enhance access to and use of NASA and other data by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) and the larger hydrology community. Our main objective was to determine a way to reorganize data that is optimal for these communities. Two related objectives were to optimally reorganize data in a way that (1) is operational and fits in and leverages the existing Goddard Earth Sciences Data and Information Services Center (GES DISC) operational environment and (2) addresses the scaling up of data sets available as time series from those archived at the GES DISC to potentially include those from other Earth Observing System Data and Information System (EOSDIS) data archives. Through several prototype efforts and lessons learned, we arrived at a non-database solution that satisfied our objectives/constraints. We describe, in this presentation, how we implemented the operational production of pre-generated data rods and, considering the tradeoffs between length of time series (or number of time steps), resources needed, and performance, how we implemented the operational production of on-the-fly ("virtual") data rods. For the virtual data rods, we leveraged a number of existing resources, including the NASA Giovanni Cache and NetCDF Operators (NCO) and used data cubes processed in parallel. Our current benchmark performance for virtual generation of data rods is about a year's worth of time series for hourly data (~9,000 time steps) in ~90 seconds. Our approach is a specific

  7. Dynamic near-infrared imaging reveals transient phototropic change in retinal rod photoreceptors.

    PubMed

    Lu, Rongwen; Levy, Alexander M; Zhang, Qiuxiang; Pittler, Steven J; Yao, Xincheng

    2013-10-01

    Stiles-Crawford effect (SCE) is exclusively observed in cone photoreceptors, but why the SCE is absent in rod photoreceptors is still a mystery. In this study, we employed dynamic near infrared light imaging to monitor photoreceptor kinetics in freshly isolated frog and mouse retinas stimulated by oblique visible light flashes. It was observed that retinal rods could rapidly (onset: ∼10 ms for frog and 5 ms for mouse; time-to-peak: ∼200 ms for frog and 30 ms for mouse) shift toward the direction of the visible light, which might quickly compensate for the loss of luminous efficiency due to oblique illumination. In contrast, such directional movement was negligible in retinal cones. Moreover, transient rod phototropism could contribute to characteristic intrinsic optical signal (IOS). We anticipate that further study of the transient rod phototropism may not only provide insight into better understanding of the nature of vision but also promise an IOS biomarker for functional mapping of rod physiology at high resolution.

  8. On the lightweighting of automobile engine components : forming sheet metal connecting rod

    NASA Astrophysics Data System (ADS)

    Date, P. P.; Kasture, R. N.; Kore, A. S.

    2017-09-01

    Reducing the inertia of the reciprocating engine components can lead to significant savings on fuel. A lighter connecting rod (for the same functionality and performance) with a lower material input would be an advantage to the user (customer) and the manufacturer alike. Light materials will make the connecting rod much more expensive compared to those made from steel. Non-ferrous metals are amenable to cold forging of engine components to achieve lightweighting. Alternately, one can make a hollow connecting rod formed from steel sheet, thereby making it lighter, and with many advantages over the conventionally hot forged product. The present paper describes the process of forming a connecting rod from sheet metal. Cold forming (as opposed to high energy needs, lower tool life and the need for greater number of operations and finishing processes in hot forming) would be expected to reduce the cost of manufacture by cold forming. Work hardening during forming is also expected to enhance the in-service performance of the connecting rod.

  9. Neutron economic reactivity control system for light water reactors

    DOEpatents

    Luce, Robert G.; McCoy, Daniel F.; Merriman, Floyd C.; Gregurech, Steve

    1989-01-01

    A neutron reactivity control system for a LWBR incorporating a stationary seed-blanket core arrangement. The core arrangement includes a plurality of contiguous hexagonal shaped regions. Each region has a central and a peripheral blanket area juxapositioned an annular seed area. The blanket areas contain thoria fuel rods while the annular seed area includes seed fuel rods and movable thoria shim control rods.

  10. Addressing prehospital patient safety using the science of injury prevention and control.

    PubMed

    Meisel, Zachary F; Hargarten, Stephen; Vernick, Jon

    2008-01-01

    There is inadequate information about the scope and character of adverse events in prehospital care. However, there is ample evidence to suggest that prehospital patient safety hazards are often unique and underrecognized. We first summarize what is currently understood about prehospital patient safety and identify the specific aspects of emergency medical services (EMS) care that may make conventional approaches to the evaluation and improvement of patient safety more difficult. Next we introduce the concept of using injury prevention and control science to analyze prehospital adverse events and to help develop EMS patient safety solutions. Injury prevention and control is a proven public health approach for the study and reduction of both intentional and unintentional injuries. It includes the use of a Haddon phase-factor matrix to identify possible interventions, especially environmental modifications that provide automatic protection. We demonstrate how this method can be used as a complementary approach in efforts to prevent injuries caused by prehospital adverse medical events.

  11. Safety Verification of a Fault Tolerant Reconfigurable Autonomous Goal-Based Robotic Control System

    NASA Technical Reports Server (NTRS)

    Braman, Julia M. B.; Murray, Richard M; Wagner, David A.

    2007-01-01

    Fault tolerance and safety verification of control systems are essential for the success of autonomous robotic systems. A control architecture called Mission Data System (MDS), developed at the Jet Propulsion Laboratory, takes a goal-based control approach. In this paper, a method for converting goal network control programs into linear hybrid systems is developed. The linear hybrid system can then be verified for safety in the presence of failures using existing symbolic model checkers. An example task is simulated in MDS and successfully verified using HyTech, a symbolic model checking software for linear hybrid systems.

  12. Assessment of safety-relevant aspects of Kraftwerk Union's 200-MW(thermal) nuclear district heating plant concept

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Erlenwein, P.; Frisch, W.; Kafka, P.

    Nuclear reactors of 200- to 400-MW(thermal) power for district heating are the subject of increasing interest, and several specific designs are under discussion today. In the Federal Republic of Germany (FRG), the Kraftwerk Union AG has presented a 200-MW(thermal) heating reactor concept. The main safety issues of this design are assessed. In this design, the primary system is fully integrated into the reactor pressure vessel (RPV), which is tightly enclosed by the containment. The low process parameters like pressure, temperature, and power density and the high ratio of coolant volume to thermal power allow the design of simple safety features.more » This is supported by the preference of passive over active components. A special feature is a newly designed hydraulic control and rod drive mechanism, which is also integrated into the RPV. Within the safety assessment an overview of the relevant FRG safety rules and guidelines, developed mainly for large, electricity-generating power plants, is given. Included is a discussion of the extent to which these licensing rules can be applied to the concept of heating reactors.« less

  13. Reflectance Spectra of Peacock Feathers and the Turning Angles of Melanin Rods in Barbules.

    PubMed

    Okazaki, Toshio

    2018-02-01

    I analyzed the association between the reflectance spectra and melanin rod arrangement in barbules of the eyespot of peacock feathers. The reflectance spectra from the yellow-green feather of the eyespot indicated double peaks of 430 and 540 nm. The maximum reflectance spectrum of the blue feather was 480 nm, and that of the dark blue feather was 420 nm. The reflectance spectra from brown feathers indicated double peaks of 490 and 610 nm. Transmission electron microscopic analysis confirmed that melanin rods were arranged fanwise in the outer layer toward the barbule tips. In addition, using polarized light microscope, I attempted to determine whether the turning angles of melanin rods in the barbules reflected different colors. The turning angle of the polarizing axis of the barbules was supported by that of the melanin rods, observed using transmission electron microscopic images. To compare the turning angle of melanin rods in the respective barbules, I calculated the opening width of the fanwise melanin rods by dividing the width of the barbules by the turning angle of the polarizing axis of barbules and obtained a positive correlation between the reflectance spectra and opening width of the fanwise melanin rods. Moreover, the widely spreading reflection from the barbules may occur because of the fanwise melanin rod arrangement.

  14. Failure Wave in DEDF and Soda-Lime Glass During Rod Impact

    NASA Astrophysics Data System (ADS)

    Orphal, Dennis; Behner, Thilo; Anderson, Charles; Templeton, Douglas

    2005-07-01

    Investigations of glass by planar, and classical and symmetric Taylor impact experiments reveal that failure wave velocity U/F depends on impact velocity, geometry, and the type of glass. U/F typically increases with impact velocity to between ˜ 1.4 C/S and C/L (shear and longitudinal wave velocities, respectively). This paper reports the results of direct high-speed photographic measurements of the failure wave for gold rod impact from 1.2 and 2.0 km/s on DEDF glass (C/S = 2.0, C/L =3.5 km/s). The average rod penetration velocity, u, was measured using flash X-rays. Gold rods eliminated penetrator strength effects. U/F for gold rod impact on DEDF is ˜ 1.0-1.2 km/s, which is considerably less than C/S. The increase of u with impact velocity is greater than that of U/F. These results are confirmed by soda-lime glass impact on a gold rod at an impact velocity of 1300 m/s. Similar results are found in``edge-on-impact'' tests; U/F values of 1.4 km/s and 2.4-2.6 km/s in soda-lime glass are reported for W-alloy rod impact, considerably less than C/S (3.2 km/s) [1,2]. [1] Bless, et. al.(1990) AIP Proc. Shock Comp. Cond. Matter---1989, pp. 939-942 (1990) [2] E. L. Zilberbrand, et. al. (1999) Int. J. Impact Engng., 23, 995-1001 (1999).

  15. An improved equivalent circuit model of a four rod deflecting cavity

    NASA Astrophysics Data System (ADS)

    Apsimon, R.; Burt, G.

    2017-03-01

    In this paper we present an improved equivalent circuit model for a four rod deflecting cavity which calculates the frequencies of the first four modes of the cavity as well as the RT/Q for the deflecting mode. Equivalent circuit models of RF cavities give intuition and understanding about how the cavity operates and what changes can be made to modify the frequency, without the need for RF simulations, which can be time-consuming. We parameterise a generic four rod deflecting cavity into a geometry consisting of simple shapes. Equations are derived for the line impedance of the rods and the capacitance between the rods and these are used to calculate the resonant frequency of the deflecting dipole mode as well as the lower order mode and the model is bench-marked against two test cases; the CEBAF separator and the HL-LHC 4-rod LHC crab cavity. CST and the equivalent circuit model agree within 4% for both cavities with the LOM frequency and within 1% for the deflecting frequency. RT/Q differs between the model and CST by 37% for the CEBAF separator and 25% for the HL-LHC 4-rod crab cavity; however this is sufficient for understanding how to optimise the cavity design. The model has then been utilised to suggest a method of separating the modal frequencies in the HL-LHC crab cavity and to suggest design methodologies to optimise the cavity geometries.

  16. Prediction based active ramp metering control strategy with mobility and safety assessment

    NASA Astrophysics Data System (ADS)

    Fang, Jie; Tu, Lili

    2018-04-01

    Ramp metering is one of the most direct and efficient motorway traffic flow management measures so as to improve traffic conditions. However, owing to short of traffic conditions prediction, in earlier studies, the impact on traffic flow dynamics of the applied RM control was not quantitatively evaluated. In this study, a RM control algorithm adopting Model Predictive Control (MPC) framework to predict and assess future traffic conditions, which taking both the current traffic conditions and the RM-controlled future traffic states into consideration, was presented. The designed RM control algorithm targets at optimizing the network mobility and safety performance. The designed algorithm is evaluated in a field-data-based simulation. Through comparing the presented algorithm controlled scenario with the uncontrolled scenario, it was proved that the proposed RM control algorithm can effectively relieve the congestion of traffic network with no significant compromises in safety aspect.

  17. Spontaneous membrane formation and self-encapsulation of active rods in an inhomogeneous motility field

    NASA Astrophysics Data System (ADS)

    Grauer, Jens; Löwen, Hartmut; Janssen, Liesbeth M. C.

    2018-02-01

    We study the collective dynamics of self-propelled rods in an inhomogeneous motility field. At the interface between two regions of constant but different motility, a smectic rod layer is spontaneously created through aligning interactions between the active rods, reminiscent of an artificial, semipermeable membrane. This "active membrane" engulfes rods which are locally trapped in low-motility regions and thereby further enhances the trapping efficiency by self-organization, an effect which we call "self-encapsulation." Our results are gained by computer simulations of self-propelled rod models confined on a two-dimensional planar or spherical surface with a stepwise constant motility field, but the phenomenon should be observable in any geometry with sufficiently large spatial inhomogeneity. We also discuss possibilities to verify our predictions of active-membrane formation in experiments of self-propelled colloidal rods and vibrated granular matter.

  18. Lightweight piston-rod assembly for a reciprocating machine

    DOEpatents

    Corey, John A.; Walsh, Michael M.

    1986-01-01

    In a reciprocating machine, there is provided a hollow piston including a dome portion on one end and a base portion on the opposite end. The base portion includes a central bore into which a rod is hermetically fixed in radial and angular alignment. The extending end of the rod has a reduced diameter portion adapted to fit into the central bore of a second member such as a cross-head assembly, and to be secured thereto in radial and axial alignment with the piston.

  19. Improvement in Jc performance below liquid nitrogen temperature for SmBa2Cu3Oy superconducting films with BaHfO3 nano-rods controlled by low-temperature growth

    NASA Astrophysics Data System (ADS)

    Miura, S.; Yoshida, Y.; Ichino, Y.; Xu, Q.; Matsumoto, K.; Ichinose, A.; Awaji, S.

    2016-01-01

    For use in high-magnetic-field coil-based applications, the critical current density (Jc) of REBa2Cu3Oy (REBCO, where RE = rare earth) coated conductors must be isotropically improved, with respect to the direction of the magnetic field; these improvements must be realized at the operating conditions of these applications. In this study, improvement of the Jc for various applied directions of magnetic field was achieved by controlling the morphology of the BaHfO3 (BHO) nano-rods in a SmBCO film. We fabricated the 3.0 vol. % BHO-doped SmBCO film at a low growth temperature of 720 °C, by using a seed layer technique (Ts = 720 °C film). The low-temperature growth resulted in a morphological change in the BHO nano-rods. In fact, a high number density of (3.1 ± 0.1) × 103 μm-2 of small (diameter: 4 ± 1 nm), discontinuous nano-rods that grew in various directions, was obtained. In Jc measurements, the Jc of the Ts = 720 °C film in all directions of the applied magnetic field was higher than that of the non-doped SmBCO film. The Jcmin (6.4 MA/cm2) of the former was more than 6 times higher than that (1.0 MA/cm2) of the latter at 40 K, under 3 T. The aforementioned results indicated that the discontinuous BHO nano-rods, which occurred with a high number density, exerted a 3D-like flux pinning at the measurement conditions considered. Moreover, at 4.2 K and under 17 T, a flux pinning force density of 1.6 TN/m3 was realized; this value was comparable to the highest value recorded, to date.

  20. Possibilities and limitations of rod-beam theories. [nonlinear distortion tensor and nonlinear stress tensors

    NASA Technical Reports Server (NTRS)

    Peterson, D.

    1979-01-01

    Rod-beam theories are founded on hypotheses such as Bernouilli's suggesting flat cross-sections under deformation. These assumptions, which make rod-beam theories possible, also limit the accuracy of their analysis. It is shown that from a certain order upward terms of geometrically nonlinear deformations contradict the rod-beam hypotheses. Consistent application of differential geometry calculus also reveals differences from existing rod theories of higher order. These differences are explained by simple examples.

  1. Signaling States of Rhodopsin in Rod Disk Membranes Lacking Transducin βγ-Complex

    PubMed Central

    Lomonosova, Elena; Kolesnikov, Alexander V.; Kefalov, Vladimir J.

    2012-01-01

    Purpose. To characterize the possible role of transducin Gtβγ-complex in modulating the signaling properties of photoactivated rhodopsin and its lifetime in rod disc membranes and intact rods. Methods. Rhodopsin photolysis was studied using UV-visible spectroscopy and rapid scanning spectroscopy in the presence of hydroxylamine in highly purified wild-type and Gtγ-deficient mouse rod disc membranes. Complex formation between photoactivated rhodopsin and transducin was measured by extra-metarhodopsin (meta) II assay. Recovery of dark current and flash sensitivity in individual intact wild-type and Gtγ-deficient mouse rods was measured by single-cell suction recordings. Results. Photoconversion of rhodopsin to meta I/meta II equilibrium proceeds normally after elimination of the Gtβγ-complex. The meta I/meta II ratio, the rate of meta II decay, the reactivity of meta II toward hydroxylamine, and the rate of meta III formation in Gtγ-deficient rod disc membranes were identical with those observed in wild-type samples. Under low-intensity illumination, the amount of extra–meta II in Gtγ-deficient discs was significantly reduced. The initial rate of dark current recovery after 12% rhodopsin bleach was three times faster in Gtγ-deficient rods, whereas the rate of the late current recovery was largely unchanged. Mutant rods also exhibited faster postbleach recovery of flash sensitivity. Conclusions. Photoactivation and thermal decay of rhodopsin proceed similarly in wild-type and Gtγ-deficient mouse rods, but the complex formation between photoactivated rhodopsin and transducin is severely compromised in the absence of Gtβγ. The resultant lower transduction activation contributes to faster photoresponse recovery after a moderate pigment bleach in Gtγ-deficient rods. PMID:22266510

  2. Nuclear reactor fuel rod attachment system

    DOEpatents

    Christiansen, David W.

    1982-01-01

    A reusable system for removably attaching a nuclear reactor fuel rod (12) to a support member (14). A locking cap (22) is secured to the fuel rod (12) and a locking strip (24) is fastened to the support member (14). The locking cap (22) has two opposing fingers (24a and 24b) shaped to form a socket having a body portion (26). The locking strip has an extension (36) shaped to rigidly attach to the socket's body portion (26). The locking cap's fingers are resiliently deflectable. For attachment, the locking cap (22) is longitudinally pushed onto the locking strip (24) causing the extension (36) to temporarily deflect open the fingers (24a and 24b) to engage the socket's body portion (26). For removal, the process is reversed.

  3. Instabilities of a rotating helical rod

    NASA Astrophysics Data System (ADS)

    Park, Yunyoung; Ko, William; Kim, Yongsam; Lim, Sookkyung

    2016-11-01

    Bacteria such as Escherichia coli and Vibrio alginolyticus have helical flagellar filament. By rotating a motor, which is located at the bottom end of the flagellar filament embedded in the cell body, CCW or CW, they swim forward or backward. We model a left-handed helix by the Kirchhoff rod theory and use regularized Stokes formulation to study an interaction between the surrounding fluid and the flagellar filament. We perform numerical studies focusing on relations between physical parameters and critical angular frequency of the motor, which separates overwhiring from twirling. We are also interested in the buckling instability of the hook, which is very flexible elastic rod. By measuring buckling angle, which is an angle between rotational axis and helical axis, we observe the effects of physical parameters on buckling of the hook.

  4. [Rod of Asclepius. Symbol of medicine].

    PubMed

    Young, Pablo; Finn, Bárbara C; Bruetman, Julio E; Cesaro Gelos, Jorge; Trimarchi, Hernán

    2013-09-01

    Symbolism is one of the most archaic forms of human thoughts. Symbol derives from the Latin word symbolum, and the latter from the Greek symbolon or symballo, which means "I coincide, I make matches". The Medicine symbol represents a whole series of historical and ethical values. Asclepius Rod with one serpent entwined, has traditionally been the symbol of scientific medicine. In a misconception that has lasted 500 years, the Caduceus of Hermes, entwined by two serpents and with two wings, has been considered the symbol of Medicine. However, the Caduceus is the current symbol of Commerce. Asclepius Rod and the Caduceus of Hermes represent two professions, Medicine and Commerce that, in ethical practice, should not be mixed. Physicians should be aware of their real emblem, its historical origin and meaning.

  5. Spatiotemporal regulation of ATP and Ca2+ dynamics in vertebrate rod and cone ribbon synapses

    PubMed Central

    Johnson, Jerry E.; Perkins, Guy A.; Giddabasappa, Anand; Chaney, Shawntay; Xiao, Weimin; White, Andrew D.; Brown, Joshua M.; Waggoner, Jenna; Ellisman, Mark H.

    2007-01-01

    Purpose In conventional neurons, Ca2+ enters presynaptic terminals during an action potential and its increased local concentration triggers transient exocytosis. In contrast, vertebrate photoreceptors are nonspiking neurons that maintain sustained depolarization and neurotransmitter release from ribbon synapses in darkness and produce light-dependent graded hyperpolarizing responses. Rods transmit single photon responses with high fidelity, whereas cones are less sensitive and exhibit faster response kinetics. These differences are likely due to variations in presynaptic Ca2+ dynamics. Metabolic coupling and cross-talk between mitochondria, endoplasmic reticulum (ER), plasma membrane Ca2+ ATPase (PMCA), and Na+-Ca2+ exchanger (NCX) coordinately control presynaptic ATP production and Ca2+ dynamics. The goal of our structural and functional studies was to determine the spatiotemporal regulation of ATP and Ca2+ dynamics in rod spherules and cone pedicles. Methods Central retina tissue from C57BL/6 mice was used. Laser scanning confocal microscopy (LSCM) experiments were conducted on fixed-frozen vertical sections. Primary antibodies were selected for their tissue/cellular specificity and ability to recognize single, multiple or all splice variants of selected isoforms. Electron microscopy (EM) and 3-D electron tomography (ET) studies used our standard procedures on thin- and thick-sectioned retinas, respectively. Calibrated fluo-3-Ca2+ imaging experiments of dark- and light-adapted rod and cone terminals in retinal slices were conducted. Results Confocal microscopy showed that mitochondria, ER, PMCA, and NCX1 exhibited distinct retinal lamination patterns and differential distribution in photoreceptor synapses. Antibodies for three distinct mitochondrial compartments differentially labeled retinal areas with high metabolic demand: rod and cone inner segments, previously undescribed cone juxtanuclear mitochondria and the two plexiform layers. Rod spherule membranes

  6. Spatiotemporal regulation of ATP and Ca2+ dynamics in vertebrate rod and cone ribbon synapses.

    PubMed

    Johnson, Jerry E; Perkins, Guy A; Giddabasappa, Anand; Chaney, Shawntay; Xiao, Weimin; White, Andrew D; Brown, Joshua M; Waggoner, Jenna; Ellisman, Mark H; Fox, Donald A

    2007-06-15

    In conventional neurons, Ca2+ enters presynaptic terminals during an action potential and its increased local concentration triggers transient exocytosis. In contrast, vertebrate photoreceptors are nonspiking neurons that maintain sustained depolarization and neurotransmitter release from ribbon synapses in darkness and produce light-dependent graded hyperpolarizing responses. Rods transmit single photon responses with high fidelity, whereas cones are less sensitive and exhibit faster response kinetics. These differences are likely due to variations in presynaptic Ca2+ dynamics. Metabolic coupling and cross-talk between mitochondria, endoplasmic reticulum (ER), plasma membrane Ca2+ ATPase (PMCA), and Na+-Ca2+ exchanger (NCX) coordinately control presynaptic ATP production and Ca2+ dynamics. The goal of our structural and functional studies was to determine the spatiotemporal regulation of ATP and Ca2+ dynamics in rod spherules and cone pedicles. Central retina tissue from C57BL/6 mice was used. Laser scanning confocal microscopy (LSCM) experiments were conducted on fixed-frozen vertical sections. Primary antibodies were selected for their tissue/cellular specificity and ability to recognize single, multiple or all splice variants of selected isoforms. Electron microscopy (EM) and 3-D electron tomography (ET) studies used our standard procedures on thin- and thick-sectioned retinas, respectively. Calibrated fluo-3-Ca2+ imaging experiments of dark- and light-adapted rod and cone terminals in retinal slices were conducted. Confocal microscopy showed that mitochondria, ER, PMCA, and NCX1 exhibited distinct retinal lamination patterns and differential distribution in photoreceptor synapses. Antibodies for three distinct mitochondrial compartments differentially labeled retinal areas with high metabolic demand: rod and cone inner segments, previously undescribed cone juxtanuclear mitochondria and the two plexiform layers. Rod spherule membranes uniformly and intensely

  7. Not just signal shutoff: the protective role of arrestin-1 in rod cells.

    PubMed

    Sommer, Martha E; Hofmann, Klaus Peter; Heck, Martin

    2014-01-01

    The retinal rod cell is an exquisitely sensitive single-photon detector that primarily functions in dim light (e.g., moonlight). However, rod cells must routinely survive light intensities more than a billion times greater (e.g., bright daylight). One serious challenge to rod cell survival in daylight is the massive amount of all-trans-retinal that is released by Meta II, the light-activated form of the photoreceptor rhodopsin. All-trans-retinal is toxic, and its condensation products have been implicated in disease. Our recent work has developed the concept that rod arrestin (arrestin-1), which terminates Meta II signaling, has an additional role in protecting rod cells from the consequences of bright light by limiting free all-trans-retinal. In this chapter we will elaborate upon the molecular mechanisms by which arrestin-1 serves as both a single-photon response quencher as well as an instrument of rod cell survival in bright light. This discussion will take place within the framework of three distinct functional modules of vision: signal transduction, the retinoid cycle, and protein translocation.

  8. Apparatus for injection casting metallic nuclear energy fuel rods

    DOEpatents

    Seidel, Bobby R.; Tracy, Donald B.; Griffiths, Vernon

    1991-01-01

    Molds for making metallic nuclear fuel rods are provided which present reduced risks to the environment by reducing radioactive waste. In one embodiment, the mold is consumable with the fuel rod, and in another embodiment, part of the mold can be re-used. Several molds can be arranged together in a cascaded manner, if desired, or several long cavities can be integrated in a monolithic multiple cavity re-usable mold.

  9. Extending calibration-free force measurements to optically-trapped rod-shaped samples

    PubMed Central

    Català, Frederic; Marsà, Ferran; Montes-Usategui, Mario; Farré, Arnau; Martín-Badosa, Estela

    2017-01-01

    Optical trapping has become an optimal choice for biological research at the microscale due to its non-invasive performance and accessibility for quantitative studies, especially on the forces involved in biological processes. However, reliable force measurements depend on the calibration of the optical traps, which is different for each experiment and hence requires high control of the local variables, especially of the trapped object geometry. Many biological samples have an elongated, rod-like shape, such as chromosomes, intracellular organelles (e.g., peroxisomes), membrane tubules, certain microalgae, and a wide variety of bacteria and parasites. This type of samples often requires several optical traps to stabilize and orient them in the correct spatial direction, making it more difficult to determine the total force applied. Here, we manipulate glass microcylinders with holographic optical tweezers and show the accurate measurement of drag forces by calibration-free direct detection of beam momentum. The agreement between our results and slender-body hydrodynamic theoretical calculations indicates potential for this force-sensing method in studying protracted, rod-shaped specimens. PMID:28220855

  10. Simultaneous double-rod rotation technique in posterior instrumentation surgery for correction of adolescent idiopathic scoliosis.

    PubMed

    Ito, Manabu; Abumi, Kuniyoshi; Kotani, Yoshihisa; Takahata, Masahiko; Sudo, Hideki; Hojo, Yoshihiro; Minami, Akio

    2010-03-01

    The authors present a new posterior correction technique consisting of simultaneous double-rod rotation using 2 contoured rods and polyaxial pedicle screws with or without Nesplon tapes. The purpose of this study is to introduce the basic principles and surgical procedures of this new posterior surgery for correction of adolescent idiopathic scoliosis. Through gradual rotation of the concave-side rod by 2 rod holders, the convex-side rod simultaneously rotates with the the concave-side rod. This procedure does not involve any force pushing down the spinal column around the apex. Since this procedure consists of upward pushing and lateral translation of the spinal column with simultaneous double-rod rotation maneuvers, it is simple and can obtain thoracic kyphosis as well as favorable scoliosis correction. This technique is applicable not only to a thoracic single curve but also to double major curves in cases of adolescent idiopathic scoliosis.

  11. Low-cost Engineering of Laser Rods and Slabs with Liquid Phase Epitaxy

    DTIC Science & Technology

    2011-09-01

    SUPPLEMENTARY NOTES 14. ABSTRACT We investigated the use of a liquid phase epitaxial ( LPE ) coating to improve the performance of a rod or slab laser. A...single crystal erbium-doped yttrium aluminum garnet (Er:YAG) rod coated with undoped YAG, and an uncoated sample were procured, then compared on the...the whispering gallery modes, which otherwise would deplete the gain in ~50% of the rod volume. We also investigated LPE growth on a ceramic sample

  12. Detection of Microcracks in Trunnion Rods Using Ultrasonic Guided Waves

    DTIC Science & Technology

    2015-07-01

    49 Figure 40. Larger second echo from PMN-PT vs. PZT transducer. ........................................................ 50...Figure. 41 Nonlinear crack simulations: two polished ends pulled together (top left), fatigued aluminum (bottom left), nut coupled and shims hammered... fatigued rods, can go through opening and closing variations during their deterioration. Microcracked rods need to be detected and quantified

  13. Vibration and Noise Control. Module SH-33. Safety and Health.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This student module on vibration and noise control is one of 50 modules concerned with job safety and health. Following the introduction, nine objectives (each keyed to a page in the text) the student is expected to accomplish are listed (e.g., Compare four strategies for vibration control). Then each objective is taught in detail, sometimes…

  14. Increased proliferation of late-born retinal progenitor cells by gestational lead exposure delays rod and bipolar cell differentiation.

    PubMed

    Chaney, Shawnta Y; Mukherjee, Shradha; Giddabasappa, Anand; Rueda, Elda M; Hamilton, W Ryan; Johnson, Jerry E; Fox, Donald A

    2016-01-01

    Studies of neuronal development in the retina often examine the stages of proliferation, differentiation, and synaptic development, albeit independently. Our goal was to determine if a known neurotoxicant insult to a population of retinal progenitor cells (RPCs) would affect their eventual differentiation and synaptic development. To that end, we used our previously published human equivalent murine model of low-level gestational lead exposure (GLE). Children and animals with GLE exhibit increased scotopic electroretinogram a- and b-waves. Adult mice with GLE exhibit an increased number of late-born RPCs, a prolonged period of RPC proliferation, and an increased number of late-born rod photoreceptors and rod and cone bipolar cells (BCs), with no change in the number of late-born Müller glial cells or early-born neurons. The specific aims of this study were to determine whether increased and prolonged RPC proliferation alters the spatiotemporal differentiation and synaptic development of rods and BCs in early postnatal GLE retinas compared to control retinas. C57BL/6N mouse pups were exposed to lead acetate via drinking water throughout gestation and until postnatal day 10, which is equivalent to the human gestation period for retinal neurogenesis. RT-qPCR, immunohistochemical analysis, and western blots of well-characterized, cell-specific genes and proteins were performed at embryonic and early postnatal ages to assess rod and cone photoreceptor differentiation, rod and BC differentiation and synaptic development, and Müller glial cell differentiation. Real-time quantitative PCR (RT-qPCR) with the rod-specific transcription factors Nrl , Nr2e3 , and Crx and the rod-specific functional gene Rho , along with central retinal confocal studies with anti-recoverin and anti-rhodopsin antibodies, revealed a two-day delay in the differentiation of rod photoreceptors in GLE retinas. Rhodopsin immunoblots supported this conclusion. No changes in glutamine synthetase gene

  15. A study to compare the efficacy of polyether ether ketone rod device with titanium devices in posterior spinal fusion in a canine model.

    PubMed

    Wang, Nanxiang; Xie, Huanxin; Xi, Chunyang; Zhang, Han; Yan, Jinglong

    2017-03-09

    The benefits of posterior lumbar fusion surgery with orthotopic paraspinal muscle-pediculated bone flaps are well established. However, the problem of non-union due to mechanical support is not completely resolved. The aim of the study was to compare the efficacy of polyether ether ketone (PEEK) rod device with conventional titanium devices in the posterior lumbar fusion surgery with orthotopic paraspinal muscle-pediculated bone flaps. This was a randomized controlled study with an experimental animal model. Thirty-two mongrel dogs were randomly divided into two groups-control group (n = 16), which received the titanium device and the treatment group (n = 16), which received PEEK rods. The animals were sacrificed 8 or 16 weeks after surgery. Lumbar spines of dogs in both groups were removed, harvested, and assessed for radiographic, biomechanical, and histological changes. Results in the current study indicated that there was no significant difference in the lumbar spine of the control and treatment groups in terms of radiographic, manual palpation, and gross examination. However, certain parameters of biomechanical testing showed significant differences (p < 0.05) in stiffness and displacement, revealing a better fusion (treatment group showed decreased stiffness with decreased displacement) of the bone graft. Similarly, the histological analysis also revealed a significant fusion mass in both treatment and control groups (p < 0.05). These findings revealed that fixation using PEEK connecting rod could improve the union of the bone graft in the posterior lumbar spine fusion surgery compared with that of the titanium rod fixation.

  16. Intraspinal canal rod migration causing late-onset paraparesis 8 years after scoliosis surgery.

    PubMed

    Obeid, Ibrahim; Vital, Jean-Marc; Aurouer, Nicolas; Hansen, Steve; Gangnet, Nicolas; Pointillart, Vincent; Gille, Olivier; Boissiere, Louis; Quraishi, Nasir A

    2016-07-01

    Complete intraspinal canal rod migration with posterior bone reconstitution has never been described in the adolescent idiopathic scoliosis (AIS) population. We present an unusual but significant delayed neurological complication after spinal instrumentation surgery. A 24-year-old woman presented with lower limb weakness (ASIA D) 8 years after posterior instrumentation from T2 to L4 for AIS. CT scan and MRI demonstrated intra-canal rod migration with complete laminar reconstitution. The C-reactive protein was slightly elevated (fluctuated between 10 and 20 mg/l). Radiographs showed the convex rod had entered the spinal canal. The patient was taken into the operating room for thoracic spinal decompression and removal of the convex rod. This Cotrel-Dubousset rod, which had been placed on the convexity of the thoracic curve had completely entered the canal from T5 to T10 and was totally covered by bone with the eroded laminae entirely healed and closed. There was no pseudarthrosis. Intra-operatively, the fusion mass was opened along the whole length of this rod and the rod carefully removed and the spinal cord decompressed. The bacteriological cultures returned positive for Propionibacterium acnes. The patient recovered fully within 2 months post-operatively. We opine that the progressive laminar erosion with intra-canal rod migration resulted from mechanical and infectious-related factors. The very low virulence of the strain of Propionibacterium acnes is probably involved in this particular presentation where the rod was trapped in the canal, owing to the quite extensive laminar reconstitution.

  17. Melanopsin Phototransduction Contributes to Light-Evoked Choroidal Expansion and Rod L-Type Calcium Channel Function In Vivo.

    PubMed

    Berkowitz, Bruce A; Schmidt, Tiffany; Podolsky, Robert H; Roberts, Robin

    2016-10-01

    In humans, rodents, and pigeons, the dark → light transition signals nonretinal brain tissue to increase choroidal thickness, a major control element of choroidal blood flow, and thus of photoreceptor and retinal pigment epithelium function. However, it is unclear which photopigments in the retina relay the light signal to the brain. Here, we test the hypothesis that melanopsin (Opn4)-regulated phototransduction modulates light-evoked choroidal thickness expansion in mice. Two-month-old C57Bl/6 wild-type (B6), 4- to 5-month-old C57Bl/6/129S6 wild-type (B6 + S6), and 2-month-old melanopsin knockout (Opn4-/-) on a B6 + S6 background were studied. Retinal anatomy was evaluated in vivo by optical coherence tomography and MRI. Choroidal thickness in dark and light were measured by diffusion-weighted MRI. Rod cell L-type calcium channel (LTCC) function in dark and light (manganese-enhanced MRI [MEMRI]) was also measured. Opn4-/- mice did not show the light-evoked expansion of choroidal thickness observed in B6 and B6 + S6 controls. Additionally, Opn4-/- mice had lower than normal rod cell and inner retinal LTCC function in the dark but not in the light. These deficits were not due to structural abnormalities because retinal laminar architecture and thickness, and choroidal thickness in the Opn4-/- mice were similar to controls. First time evidence is provided that melanopsin phototransduction contributes to dark → light control of murine choroidal thickness. The data also highlight a contribution in vivo of melanopsin phototransduction to rod cell and inner retinal depolarization in the dark.

  18. Rapid kinetics of endocytosis at rod photoreceptor synapses depends upon endocytic load and calcium.

    PubMed

    Cork, Karlene M; Thoreson, Wallace B

    2014-05-01

    Release from rods is triggered by the opening of L-type Ca2+ channels that lie beneath synaptic ribbons. After exocytosis, vesicles are retrieved by compensatory endocytosis. Previous work showed that endocytosis is dynamin-dependent in rods but dynamin-independent in cones. We hypothesized that fast endocytosis in rods may also differ from cones in its dependence upon the amount of Ca2+ influx and/or endocytic load. We measured exocytosis and endocytosis from membrane capacitance (C m) changes evoked by depolarizing steps in voltage clamped rods from tiger salamander retinal slices. Similar to cones, the time constant for endocytosis in rods was quite fast, averaging <200 ms. We manipulated Ca2+ influx and the amount of vesicle release by altering the duration and voltage of depolarizing steps. Unlike cones, endocytosis kinetics in rods slowed after increasing Ca2+ channel activation with longer step durations or more strongly depolarized voltage steps. Endocytosis kinetics also slowed as Ca2+ buffering was decreased by replacing BAPTA (10 or 1 mM) with the slower Ca2+ buffer EGTA (5 or 0.5 mM) in the pipette solution. These data provide further evidence that endocytosis mechanisms differ in rods and cones and suggest that endocytosis in rods is regulated by both endocytic load and local Ca2+ levels.

  19. Rapid kinetics of endocytosis at rod photoreceptor synapses depends upon endocytic load and calcium

    PubMed Central

    CORK, KARLENE M.; THORESON, WALLACE B.

    2015-01-01

    Release from rods is triggered by the opening of L-type Ca2+ channels that lie beneath synaptic ribbons. After exocytosis, vesicles are retrieved by compensatory endocytosis. Previous work showed that endocytosis is dynamin-dependent in rods but dynamin-independent in cones. We hypothesized that fast endocytosis in rods may also differ from cones in its dependence upon the amount of Ca2+ influx and/or endocytic load. We measured exocytosis and endocytosis from membrane capacitance (Cm) changes evoked by depolarizing steps in voltage clamped rods from tiger salamander retinal slices. Similar to cones, the time constant for endocytosis in rods was quite fast, averaging <200 ms. We manipulated Ca2+ influx and the amount of vesicle release by altering the duration and voltage of depolarizing steps. Unlike cones, endocytosis kinetics in rods slowed after increasing Ca2+ channel activation with longer step durations or more strongly depolarized voltage steps. Endocytosis kinetics also slowed as Ca2+ buffering was decreased by replacing BAPTA (10 or 1 mM) with the slower Ca2+ buffer EGTA (5 or 0.5 mM) in the pipette solution. These data provide further evidence that endocytosis mechanisms differ in rods and cones and suggest that endocytosis in rods is regulated by both endocytic load and local Ca2+ levels. PMID:24735554

  20. Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment.

    PubMed

    Chávez de Paz, L E; Molander, A; Dahlén, G

    2004-09-01

    To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.