Sample records for control rod trip

  1. 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.

  2. TREAT Reactor Control and Protection System

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

    Lipinski, W.C.; Brookshier, W.K.; Burrows, D.R.

    1985-01-01

    The main control algorithm of the Transient Reactor Test Facility (TREAT) Automatic Reactor Control System (ARCS) resides in Read Only Memory (ROM) and only experiment specific parameters are input via keyboard entry. Prior to executing an experiment, the software and hardware of the control computer is tested by a closed loop real-time simulation. Two computers with parallel processing are used for the reactor simulation and another computer is used for simulation of the control rod system. A monitor computer, used as a redundant diverse reactor protection channel, uses more conservative setpoints and reduces challenges to the Reactor Trip System (RTS).more » The RTS consists of triplicated hardwired channels with one out of three logic. The RTS is automatically tested by a digital Dedicated Microprocessor Tester (DMT) prior to the execution of an experiment. 6 refs., 5 figs., 1 tab.« less

  3. DR Reactor VSR channel damage

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

    Kempf, F.J.; Rawlins, J.K.

    1961-10-30

    On July 11, 1961 the Ball 3X System at DR Reactor was inadventently tripped. All vertical safety rods dropped and all channels were filled with balls. This report has the twofold purpose of documenting borescope observations of ten vertical rod channels at DR Reactor and recording the estimated extent of graphite damage resulting from the above incident. Channel damage data are presented on appended drawings. With suitable notations, the tracings of these drawings may be revised to reflect any future graphite damage. All vertical rod channels at DR Reactor were visually examined with a closed circuit television system during ballmore » removal efforts. Typical photographs of trapped balls and ledges, as viewed on the television monitor, are shown. Photographs of typical graphite damage, obtained through the borescope are also included in this report. 3 refs., 8 figs., 1 tab.« less

  4. Cobalt Chrome Spinal Constructs Trigger Airport Security Screening in 24% of Pediatric Patients.

    PubMed

    Woon, Regina P; Andras, Lindsay M; Barrett, Kody K; Skaggs, David L

    2015-03-01

    Retrospective study. To determine whether pediatric patients undergo additional airport security screening after posterior spinal fusion. Airport security has expanded to include body scanners as well as traditional metal detectors. Families frequently ask whether spinal implants will trigger airport security, but there is limited information on modern implants and screening methods. The researchers conducted a survey of 50 pediatric patients after posterior spinal fusion from 2004 to 2013. Inclusion criteria were posterior instrumentation, pedicle screws for at least 80% of anchors, and at least 1 trip through an American airport after surgery. Charts and radiographs were reviewed for metal type, number of levels fused, number of anchors, and rod diameter. A total of 16% of patients (8 of 50) were detected by body scan or metal detector and all had cobalt chrome (CoCr) rods. No patients with stainless-steel (SS) rods were detected. The CoCr rods triggered additional screening in 24% of children (8 of 33), compared with none of 17 with SS rods (p = .03). For patients with CoCr rods, the detection rate was 18% (5 of 28) by metal detector and 17% (3 of 18) by body scanner. For patients with CoCr rods, there was no significant difference between detection rates and levels fused (p = .30), number of anchors (p = .15), or rod diameter (p = .17). In this series, CoCr constructs were more likely to incur additional airport security compared with more traditional SS constructs. Copyright © 2015 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

  5. Core Dynamics Analysis for Reactivity Insertion and Loss of Coolant Flow Tests Using the High Temperature Engineering Test Reactor

    NASA Astrophysics Data System (ADS)

    Takamatsu, Kuniyoshi; Nakagawa, Shigeaki; Takeda, Tetsuaki

    Safety demonstration tests using the High Temperature Engineering Test Reactor (HTTR) are in progress to verify its inherent safety features and improve the safety technology and design methodology for High-temperature Gas-cooled Reactors (HTGRs). The reactivity insertion test is one of the safety demonstration tests for the HTTR. This test simulates the rapid increase in the reactor power by withdrawing the control rod without operating the reactor power control system. In addition, the loss of coolant flow tests has been conducted to simulate the rapid decrease in the reactor power by tripping one, two or all out of three gas circulators. The experimental results have revealed the inherent safety features of HTGRs, such as the negative reactivity feedback effect. The numerical analysis code, which was named-ACCORD-, was developed to analyze the reactor dynamics including the flow behavior in the HTTR core. We have modified this code to use a model with four parallel channels and twenty temperature coefficients. Furthermore, we added another analytical model of the core for calculating the heat conduction between the fuel channels and the core in the case of the loss of coolant flow tests. This paper describes the validation results for the newly developed code using the experimental results. Moreover, the effect of the model is formulated quantitatively with our proposed equation. Finally, the pre-analytical result of the loss of coolant flow test by tripping all gas circulators is also discussed.

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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)

  16. 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.

  17. 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.

  18. 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)

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. 46 CFR 62.35-50 - Tabulated monitoring and safety control requirements for specific systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Status Main (Propulsion steam) turbine (2) (2) (2) (4, 5) Manual trip Main propulsion, diesel (1) (1) (1... Temperature High Generators Ship service (1) (1) Starting pressure/voltage Low Tripped Emergency (5) (5) (5) Turbogenerator (1,6) (1,6) (6) Manual trip Diesel (1,7) (1,7) (7) (5) Manual trip Auxiliary boiler Run Trip (12...

  4. CRDM with separate SCRAM latch engagement and locking

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

    Dodd, Christopher D.; DeSantis, Paul K.; Stambaugh, Kevin J.

    A control rod drive mechanism (CRDM) configured to latch onto the lifting rod of a control rod assembly and including separate latch engagement and latch holding mechanisms. A CRDM configured to latch onto the lifting rod of a control rod assembly and including a four-bar linkage closing the latch, wherein the four-bar linkage biases the latch closed under force of gravity.

  5. 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

  6. 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.

  7. POSITIONING DEVICE

    DOEpatents

    McCorkle, W.H.

    1959-07-14

    A positioner for a control rod for a nuclear reactor is described. The positioner includes a spur gear and rack for adjusting the control rod slowly and in small ainounts as well as a piston and cylinder for moving the control rod rapidly thrcugh larger distances. The positioner also has associsted with it a worm wheel and gear for rotating it out of engagement with the control rod.

  8. 49 CFR 236.531 - Trip arm; height and distance from rail.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Trip arm; height and distance from rail. 236.531... Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.531 Trip arm; height and distance from rail. Trip arm of automatic train stop device when in the stop position shall be...

  9. 49 CFR 236.531 - Trip arm; height and distance from rail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Trip arm; height and distance from rail. 236.531... Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.531 Trip arm; height and distance from rail. Trip arm of automatic train stop device when in the stop position shall be...

  10. 49 CFR 236.531 - Trip arm; height and distance from rail.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Trip arm; height and distance from rail. 236.531... Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.531 Trip arm; height and distance from rail. Trip arm of automatic train stop device when in the stop position shall be...

  11. 49 CFR 236.531 - Trip arm; height and distance from rail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Trip arm; height and distance from rail. 236.531... Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.531 Trip arm; height and distance from rail. Trip arm of automatic train stop device when in the stop position shall be...

  12. 49 CFR 236.531 - Trip arm; height and distance from rail.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Trip arm; height and distance from rail. 236.531... Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Roadway § 236.531 Trip arm; height and distance from rail. Trip arm of automatic train stop device when in the stop position shall be...

  13. 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.

  14. Using a Field Trip Inventory to Determine If Listening to Elementary School Students' Conversations, While on a Zoo Field Trip, Enhances Preservice Teachers' Abilities to Plan Zoo Field Trips

    NASA Astrophysics Data System (ADS)

    Patrick, Patricia; Mathews, Cathy; Tunnicliffe, Sue Dale

    2013-10-01

    This study investigated whether listening to spontaneous conversations of elementary students and their teachers/chaperones, while they were visiting a zoo, affected preservice elementary teachers' conceptions about planning a field trip to the zoo. One hundred five preservice elementary teachers designed field trips prior to and after listening to students' conversations during a field trip to the zoo. In order to analyze the preservice teachers' field trip designs, we conducted a review of the literature on field trips to develop the field trip inventory (FTI). The FTI focussed on three major components of field trips: cognitive, procedural, and social. Cognitive components were subdivided into pre-visit, during-visit, and post-visit activities and problem-solving. Procedural components included information about the informal science education facility (the zoo) and the zoo staff and included advanced organizers. Social components on student groups, fun, control during the zoo visit, and control of student learning. The results of the investigation showed that (a) the dominant topic in conversations among elementary school groups at the zoo was management, (b) procedural components were mentioned least often, (c) preservice teachers described during-visit activities more often than any other characteristic central to field trip design, (d) seven of the nine characteristics listed in the FTI were noted more frequently in the preservice teachers' field trip designs after they listened to students' conversations at the zoo, and (e) preservice teachers thought that students were not learning and that planning was important.

  15. 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...

  16. A robust and high-performance queue management controller for large round trip time networks

    NASA Astrophysics Data System (ADS)

    Khoshnevisan, Ladan; Salmasi, Farzad R.

    2016-05-01

    Congestion management for transmission control protocol is of utmost importance to prevent packet loss within a network. This necessitates strategies for active queue management. The most applied active queue management strategies have their inherent disadvantages which lead to suboptimal performance and even instability in the case of large round trip time and/or external disturbance. This paper presents an internal model control robust queue management scheme with two degrees of freedom in order to restrict the undesired effects of large and small round trip time and parameter variations in the queue management. Conventional approaches such as proportional integral and random early detection procedures lead to unstable behaviour due to large delay. Moreover, internal model control-Smith scheme suffers from large oscillations due to the large round trip time. On the other hand, other schemes such as internal model control-proportional integral and derivative show excessive sluggish performance for small round trip time values. To overcome these shortcomings, we introduce a system entailing two individual controllers for queue management and disturbance rejection, simultaneously. Simulation results based on Matlab/Simulink and also Network Simulator 2 (NS2) demonstrate the effectiveness of the procedure and verify the analytical approach.

  17. 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.

  18. 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)

  19. 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

  20. NUCLEAR REACTOR

    DOEpatents

    Moore, R.V.; Bowen, J.H.; Dent, K.H.

    1958-12-01

    A heterogeneous, natural uranium fueled, solid moderated, gas cooled reactor is described, in which the fuel elements are in the form of elongated rods and are dlsposed within vertical coolant channels ln the moderator symmetrically arranged as a regular lattice in groups. This reactor employs control rods which operate in vertical channels in the moderator so that each control rod is centered in one of the fuel element groups. The reactor is enclosed in a pressure vessel which ls provided with access holes at the top to facilitate loading and unloadlng of the fuel elements, control rods and control rod driving devices.

  1. 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)

  2. 77 FR 46940 - Airworthiness Directives; Glasflugel Gliders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... condition as corrosion damage to the elevator control rod that could lead to failure of the elevator control... into the elevator control rod through a control bore hole and resulted in corrosion damage. The investigation concluded as well that the corrosion cannot be detected from outside the elevator control rod...

  3. 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.

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

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

    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

  5. 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.

  6. 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)

  7. 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 was 27% of control (p<0.001) and 180% of CoCr (p<0.01). Conclusions PEEK rods decreased flexibility versus noninstumented controls, and increased flexibility versus metal rods. Smaller increases in ROM at proximal and distal adjacent motion segments occurred with PEEK compared to metal rods, which may help decrease junctional kyphosis. Flexible growing rods may eventually help improve treatment options for young patients with severe deformity. PMID:25810752

  8. 49 CFR 236.586 - Daily or after trip test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.586 Daily or after trip test..., each locomotive equipped with an automatic cab signal or train stop or train control device operating...

  9. 49 CFR 236.586 - Daily or after trip test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.586 Daily or after trip test..., each locomotive equipped with an automatic cab signal or train stop or train control device operating...

  10. 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.

  11. 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.

  12. 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.

  13. ADAPTATION AND GENERALIZATION TO OPPOSING PERTURBATIONS IN WALKING

    PubMed Central

    Bhatt, T.; Wang, T.-Y.; Yang, F.; Pai, Y.-C.

    2013-01-01

    Little is known on how the CNS would select its movement options when a person faces a novel or recurring perturbation of two opposing types (slip or trip) while walking. The purposes of this study were (1) to determine whether young adults’ adaptation to repeated slips would interfere with their recovery from a novel trip, and (2) to investigate the generalized strategies after they were exposed to a mixed training with both types of perturbation. Thirty-two young adults were assigned to either the training group, which first underwent repeated-slip training before encountering a novel, unannounced trip while walking, or to the control group, which only experienced the same novel, unannounced trip. The former group would then experience a mix of repeated trips and slips. The results indicated that prior adaptation to slips had only limited interference during the initial phase of trip recovery. In fact, the prior repeated-slip exposure had primed their reaction, which mitigated any error resulting from early interference. As a result, they did not have to take a longer compensatory step for trip recovery than did the controls. After the mixed training, subjects were able to converge effectively the motion state of their center of mass (in its position and velocity space) to a stable and generalized “middle ground” steady-state. Such movement strategies not only further strengthened their robust reactive control of stability, but also reduced the CNS’ overall reliance on accurate context prediction and on feedback correction of perturbation-induced movement error. PMID:23603517

  14. 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.)

  15. 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.

  16. 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

  17. 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.

  18. Hybrid intelligent monironing systems for thermal power plant trips

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader; Ismail, Firas Basim

    2012-11-01

    Steam boiler is one of the main equipment in thermal power plants. If the steam boiler trips it may lead to entire shutdown of the plant, which is economically burdensome. Early boiler trips monitoring is crucial to maintain normal and safe operational conditions. In the present work two artificial intelligent monitoring systems specialized in boiler trips have been proposed and coded within the MATLAB environment. The training and validation of the two systems has been performed using real operational data captured from the plant control system of selected power plant. An integrated plant data preparation framework for seven boiler trips with related operational variables has been proposed for IMSs data analysis. The first IMS represents the use of pure Artificial Neural Network system for boiler trip detection. All seven boiler trips under consideration have been detected by IMSs before or at the same time of the plant control system. The second IMS represents the use of Genetic Algorithms and Artificial Neural Networks as a hybrid intelligent system. A slightly lower root mean square error was observed in the second system which reveals that the hybrid intelligent system performed better than the pure neural network system. Also, the optimal selection of the most influencing variables performed successfully by the hybrid intelligent system.

  19. NEUTRONIC REACTORS

    DOEpatents

    Anderson, H.L.

    1958-10-01

    The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

  20. 2010 Annual Health Physics Report for the HEU Transparency Program

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

    Radev, Radoslav

    2011-05-16

    During the 2010 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. LLNL also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2010, there were 141 person-trips that required dose monitoring of the U.S. monitors. Of the 141 person-trips, 129 person-trips were Special Monitoring Visits (SMVs) and 12 person-trips were Transparency Monitoring Office (TMO) trips. In 8 of these TMO trips the TMO monitors participated also in the UEIE SMVs and in 2 TMOmore » trips the TMO monitors participated in UEIE and MPA SMVs. There were three monitoring visits (source changes) that were back-to-back SMVs with a total of 25 monitors. LLNL’s Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors.« less

  1. Experimental Evaluation of Field Trips on Instruction in Vocational Agriculture.

    ERIC Educational Resources Information Center

    McCaslin, Norval L.

    To determine the effect of field trips on student achievement in each of four subject matter areas in vocational agriculture, 12 schools offering approved programs were randomly selected and divided into a treatment group and a control group. Uniform teaching outlines and reference materials were provided to each group. While no field trips were…

  2. 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.

  3. 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.

  4. 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.)

  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. Optimal Navigation of Self-Propelled Colloids in Microstructured Mazes

    NASA Astrophysics Data System (ADS)

    Yang, Yuguang; Bevan, Michael

    Controlling navigation of self-propelled microscopic `robots' subject to random Brownian motion in complex microstructured environments (e.g., porous media, tumor vasculature) is important to many emerging applications (e.g., enhanced oil recovery, drug delivery). In this work, we design an optimal feedback policy to navigate an active self-propelled colloidal rod in complex mazes with various obstacle types. Actuation of the rods is modelled based on a light-controlled osmotic flow mechanism, which produces different propulsion velocities along the rod's long axis. Actuator-parameterized Langevin equations, with soft rod-obstacle repulsive interactions, are developed to describe the system dynamics. A Markov decision process (MDP) framework is used for optimal policy calculations with design goals of colloidal rods reaching target end points in minimum time. Simulations show that optimal MDP-based policies are able to control rod trajectories to reach target regions order-of-magnitudes faster than uncontrolled rods, which diverges as maze complexity increases. An efficient multi-graph based implementation for MDP is also presented, which scales linearly with the maze dimension.

  7. 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.

  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. The Effect of Planetarium Trip on Pre-Service Science Teachers' Metaphorical Perceptions about Planetariums

    ERIC Educational Resources Information Center

    Bozdogan, Aykut Emre

    2016-01-01

    The study aimed at examining the effect of the planetarium trip on metaphors developed by the pre-service science teachers about the concept of planetarium. Within this context of the study, a trip was organized to Ondokuz Mayis University (OMU) Planetarium. Pretest-posttest control group design, one of the experimental designs, was used in the…

  10. 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

  11. 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

  12. Can a Lifestyle Intervention Increase Active Transportation in Women Aged 55-70 years? Secondary Outcomes From a Pilot Randomized Controlled Trial.

    PubMed

    Gray, Samantha M; Chen, Peggy; Fleig, Lena; Gardiner, Paul A; McAllister, Megan M; Puyat, Joseph H; Sims-Gould, Joanie; McKay, Heather A; Winters, Meghan; Ashe, Maureen C

    2018-06-01

    Physical activity confers many health benefits to older adults, and adopting activity into daily life routines may lead to better uptake. The purpose of this study was to test the effect of a lifestyle intervention to increase daily physical activity in older women through utilitarian walking and use of public transportation. In total, 25 inactive women with mean age (SD) of 64.1 (4.6) years participated in this pilot randomized controlled trial [intervention (n = 13) and control (n = 12)]. Seven-day travel diaries (trips per week) and the International Physical Activity Questionnaire (minutes per week) were collected at baseline, 3, and 6 months. At 3 months, intervention participants reported 9 walking trips per week and 643.5 minutes per week of active transportation, whereas control participants reported 4 walking trips per week and 49.5 minutes per week of active transportation. Adjusting for baseline values, there were significant group differences favoring Everyday Activity Supports You for walking trips per week [4.6 (0.5 to 9.4); P = .04] and active transportation minutes per week [692.2 (36.1 to 1323.5); P = .05]. At 6 months, significant group differences were observed in walking trips per week [6.1 (1.9 to 11.4); P = .03] favoring the intervention (9 vs 2 trips per week). Given these promising findings, the next step is to test Everyday Activity Supports You model's effectiveness to promote physical activity in older women within a larger study.

  13. Method for producing solid or hollow spherical particles of chosen chemical composition and of uniform size

    DOEpatents

    Hendricks, Charles D.

    1988-01-01

    A method is provided for producing commercially large quantities of high melting temperature solid or hollow spherical particles of a predetermined chemical composition and having a uniform and controlled size distribution. An end (18, 50, 90) of a solid or hollow rod (20, 48, 88) of the material is rendered molten by a laser beam (14, 44, 82). Because of this, there is no possibility of the molten rod material becoming contaminated with extraneous material. In various aspects of the invention, an electric field is applied to the molten rod end (18, 90), and/or the molten rod end (50, 90) is vibrated. In a further aspect of the invention, a high-frequency component is added to the electric field applied to the molten end of the rod (90). By controlling the internal pressure of the rod, the rate at which the rod is introduced into the laser beam, the environment of the process, the vibration amplitude and frequency of the molten rod end, the electric field intensity applied to the molten rod end, and the frequency and intensity of the component added to the electric field, the uniformity and size distribution of the solid or hollow spherical particles (122) produced by the inventive method is controlled. The polarity of the electric field applied to the molten rod end can be chosen to eliminate backstreaming electrons, which tend to produce run-away heating in the rod, from the process.

  14. 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.

  15. POSITIONING DEVICE

    DOEpatents

    Wall, R.R.; Peterson, D.L.

    1959-09-15

    A positioner is described for a vertical reactor-control rod. The positioner comprises four grooved friction rotatable members that engage the control rod on all sides and shift it longitudinally. The four friction members are drivingly interconnected for conjoint rotation and comprise two pairs of coaxial members. The members of each pair are urged toward one another by hydraulic or pneumatic pressure and thus grip the control rod so as to hold it in any position or adjust it. Release of the by-draulic or pneumatic pressure permits springs between the friction members of each pair to force them apart, whereby the control rod moves quickly by gravity into the reactor.

  16. QUICK RELEASABLE DRIVE

    DOEpatents

    Dickson, J.J.

    1958-07-01

    A quick releasable mechanical drive system suitable for use in a nuclear reactor is described. A small reversible motor positions a control rod by means of a worm and gear speed reducer, a magnetic torque clutch, and a bell crank. As the control rod is raised to the operating position, a heavy coil spring is compressed. In the event of an emergency indicated by either a''scram'' signal or a power failure, the current to the magnetic clutch is cut off, thereby freeing the coil spring and the bell crank positioner from the motor and speed reduction gearing. The coil spring will immediately act upon the bell crank to cause the insertion of the control rod. This arrangement will allow the slow, accurate positioning of the control rod during reactor operation, while providing an independent force to rapidly insert the rod in the event of an emergency.

  17. 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.

  18. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

  19. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

  20. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

  1. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

  2. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

  3. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and.... Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  4. Geology of the National Capital Region: field trip guidebook

    USGS Publications Warehouse

    Burton, William; Southworth, Scott

    2004-01-01

    The 2004 Joint Northeast-Southeast Section Meeting of the Geological Society of America is the fourth such meeting and the third to be held in or near Washington, D.C. This guidebook and the field trips presented herein are intended to provide meeting participants, as well as other interested readers, a means to understand and enjoy the rich geological and historical legacy of the National Capital Region. The field trips cover all of the major physiographic and geologic provinces of the central Appalachians in the Mid-Atlantic region. Trip 1 outlines the tectonic history of northern Virginia along an east-to-west transect from the Coastal Plain province to the Blue Ridge province, whereas the other field trips each focus on a specific province. From west to east, these excursions investigate the paleoclimate controls on the stratigraphy of the Paleozoic rocks of the Allegheny Plateau and Valley and Ridge province in West Virginia, Pennsylvania, and Maryland (Trip 3); Eocene volcanic rocks that intrude Paleozoic rocks in the westernmost Valley and Ridge province in Virginia and West Virginia (Trip 4); age, petrology, and structure of Mesoproterozoic gneisses and granitoids located in the Blue Ridge province within and near Shenandoah National Park, Virginia (Trip 2); the use of argon data to unravel the complex structural and thermal history of the metamorphic rocks of the eastern Piedmont province in Maryland and Virginia (Trip 5); the use of cosmogenic isotopes to understand the timing of bedrock incision and formation of terraces along the Potomac River in the eastern Piedmont province near Great Falls, Virginia and Maryland (Trip 6); the nature of the boundary between rocks of the Goochland and Chopawamsic terranes in the eastern Piedmont of Virginia (Trip 7); the role of bluffs and fluvial terraces of the Coastal Plain in the Civil War Battle of Fredericksburg, Virginia (Trip 8); and the Tertiary lithology and paleontology of Coastal Plain strata around the Chesapeake Bay of Virginia and Maryland (Trip 9). Some of the field trips present new geochronological research that uses isotopic techniques to unravel Earth history and processes, including U-Pb dating to determine the timing of metamorphism and igneous activity associated with the Mesoproterozoic Grenville orogeny (Trip 2); argon (4DAr/39Ar) analysis to understand the complex Paleozoic history of deformation and metamorphism in the Piedmont (Trip 5); and cosmogenic beryllium-10 data to derive exposure ages of landforms and deposits of the Potomac River valley (Trip 6). Several trips shed insight on significant or enigmatic geologic features of the region. Trip 3 presents evidence for global paleoclimate controls on the Paleozoic stratigraphy of the Appalachian basin, including evidence for Late Devonian glacial deposits. Trip 4 investigates unusual Eocene igneous rocks in the Eastern United States, and Trip 2 visits several local ductile high-strain zones, offering geologists opportunities to consider the importance of such structures relative to the poorly understood Rockfish Valley fault zone in the Blue Ridge province. In the Piedmont province, Trip 7 focuses on a controversial terrane boundary, whereas Trip 5 crosses several lithologic belts with distinct thermotectonic histories that suggest terrane boundaries. Trip 6 sheds new light on the erosional history of a major river gorge cut into crystalline rocks in the Fall Zone.Four trips are recommended for Earth science teachers and are cosponsored by the National Association of Geologic Teachers (NAGT). These trips focus on the tectonic history of northern Virginia (Trip 1), terraces of the Potomac River at Great Falls and cosmogenic isotope analysis to date the terraces and the incision history (Trip 6), and Tertiary lithology and paleontology of the Chesapeake Bay region (Trip 9). Trip 8 takes advantage of the rich Civil War history of this region to look at the role that geology played in the strategies and outcome of the Battle of Fredericksburg. This guidebook is the result of much hard work by many individuals. The editors wish to thank the field trip leaders and authors, the technical reviewers, and Nancy Stamm of ths USGS Geologic Names Committee. We also owe a very special thanks to Linda Gundersen, Chief Scientist, Geologic Discipline, USGS, who provided funding for the guidebook.

  5. Fimbria-Fornix Lesions Disrupt the Dead Reckoning (Homing) Component of Exploratory Behavior in Mice

    PubMed Central

    Gorny, Joanna H.; Gorny, Bogdan; Wallace, Douglas G.; Whishaw, Ian Q.

    2002-01-01

    Exploration is the primary way in which rodents gather information about their spatial surroundings. Thus, spatial theories propose that damage to the hippocampus, a structure thought to play a fundamental role in spatial behavior, should disrupt exploration. Exploration in rats is organized. The animals create home bases that are central to exploratory excursions and returns, and hippocampal formation damage alters the organization of exploration by disrupting returns. Mice do not appear to readily establish home bases in novel environments, thus, for this species, it is more difficult to establish the contribution of the hippocampus to exploration. The purpose of the present study was threefold: develop a task in which mice center their exploration from a home base, determine whether the exploratory behavior is organized, and evaluate the role of fimbria-fornix lesions on exploration. Mice were given a novel exploratory task in which their nesting material was placed on a large circular table. Video records of control and fimbria-fornix mice were made in both light and dark (infrared light) conditions. Exploration patterns (outward trips, stops, and homeward trips) were reconstructed from the video records. Control mice centered their activity on their bedding, from which they made circuitous outward trips marked by many stops, and periodic direct returns. The bedding-centered behavior and outward trips of the fimbria-fornix mice were similar to those of the control mice, but significantly fewer direct return trips occurred. The direct homeward trips observed under light and dark conditions were consistent with a dead-reckoning strategy, in which an animal computes its present position and homeward trajectory from self-movement cues generated on the outward trip. Because the fimbria-fornix lesions disrupted the homeward component of exploratory trips, we conclude that the fimbria-fornix may contribute to dead reckoning in mice. The results also show that the home-bedding methodology facilitates the establishment of a home base by mice, thus providing a useful methodology for studies with mice. PMID:12464698

  6. The Effects of Autonomy-Supportive vs. Controlling Guidance on Learners' Motivational and Cognitive Achievement in a Structured Field Trip

    ERIC Educational Resources Information Center

    Basten, Melanie; Meyer-Ahrens, Inga; Fries, Stefan; Wilde, Matthias

    2014-01-01

    Field trips can provide unique opportunities for authentic, meaningful, and self-determined learning. Capitalizing on these opportunities requires that field trips be structured. A common way to do this is through the use of educational materials such as worksheets. The extent to which the guide's or teacher's autonomy-supportive or…

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.; Babcock, Dale F.; Menegus, Robert L.

    1983-01-01

    A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

  13. 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.

  14. Elementary school children's science learning from school field trips

    NASA Astrophysics Data System (ADS)

    Glick, Marilyn Petty

    This research examines the impact of classroom anchoring activities on elementary school students' science learning from a school field trip. Although there is prior research demonstrating that students can learn science from school field trips, most of this research is descriptive in nature and does not examine the conditions that enhance or facilitate such learning. The current study draws upon research in psychology and education to create an intervention that is designed to enhance what students learn from school science field trips. The intervention comprises of a set of "anchoring" activities that include: (1) Orientation to context, (2) Discussion to activate prior knowledge and generate questions, (3) Use of field notebooks during the field trip to record observations and answer questions generated prior to field trip, (4) Post-visit discussion of what was learned. The effects of the intervention are examined by comparing two groups of students: an intervention group which receives anchoring classroom activities related to their field trip and an equivalent control group which visits the same field trip site for the same duration but does not receive any anchoring classroom activities. Learning of target concepts in both groups was compared using objective pre and posttests. Additionally, a subset of students in each group were interviewed to obtain more detailed descriptive data on what children learned through their field trip.

  15. 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.)

  16. Layered reactive particles with controlled geometries, energies, and reactivities, and methods for making the same

    DOEpatents

    Fritz, Gregory M.; Weihs, Timothy P.; Grzyb, Justin A.

    2016-07-05

    An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

  17. Layered reactive particles with controlled geometries, energies, and reactivities, and methods for making the same

    DOEpatents

    Fritz, Gregory M; Knepper, Robert Allen; Weihs, Timothy P; Gash, Alexander E; Sze, John S

    2013-04-30

    An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

  18. 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)

  19. 2007 Annual Health Physics Report for the HEU Transparency Program

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

    Radev, R

    2008-04-09

    During the 2007 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection and technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2007, there were 172 person-trips that required dose monitoring of the U.S. monitors. Of the 172 person-trips, 160 person-trips were SMVs and 12 person-trips were Transparency Monitoring Office (TMO) trips. There were 12 monitoring visits by TMO monitors to facilities other than UEIE and 10 to UEIE itself. There were two monitoring visits (sourcemore » changes) that were back to back with 14 monitors. LLNL's Hazard Control Division laboratories provided the dosimetry services for the HEU Transparency monitors.« less

  20. Study on the Strain Hardening Behaviors of TWIP/TRIP Steels

    NASA Astrophysics Data System (ADS)

    Huang, T. T.; Dan, W. J.; Zhang, W. G.

    2017-10-01

    Due to the complex coupling of twinning-induced plasticity (TWIP), transformation-induced plasticity (TRIP), and dislocation glide in TWIP/TRIP steels, it is difficult as well as essential to build a comprehensive strain hardening model to describe the interactions between different deformation mechanisms ( i.e., deformation twinning, martensitic transformation, and dislocation glide) and the resulted strain hardening behaviors. To address this issue, a micromechanical model is established in this paper to predict the deformation process of TWIP/TRIP steels considering both TWIP and TRIP effects. In the proposed model, the generation of deformation twinning and martensitic transformation is controlled by the stacking fault energy (SFE) of the material. In the thermodynamic calculation of SFE, deformation temperature, chemical compositions, microstrain, and temperature rise during deformation are taken into account. Varied by experimental results, the developed model can predict the stress-strain response and strain hardening behaviors of TWIP/TRIP steels precisely. In addition, the improved strength and enhanced strain hardening in Fe-Mn-C TWIP/TRIP steels due to the increased carbon content is also analyzed, which consists with literature.

  1. Using Vessel Monitoring System Data to Identify and Characterize Trips Made by Fishing Vessels in the United States North Pacific

    PubMed Central

    Haynie, Alan C.

    2016-01-01

    Time spent fishing is the effort metric often studied in fisheries but it may under-represent the effort actually expended by fishers. Entire fishing trips, from the time vessels leave port until they return, may prove more useful for examining trends in fleet dynamics, fisher behavior, and fishing costs. However, such trip information is often difficult to resolve. We identified ~30,000 trips made by vessels that targeted walleye pollock (Gadus chalcogrammus) in the Eastern Bering Sea from 2008–2014 by using vessel monitoring system (VMS) and landings data. We compared estimated trip durations to observer data, which were available for approximately half of trips. Total days at sea were estimated with < 1.5% error and 96.4% of trip durations were either estimated with < 5% error or they were within expected measurement error. With 99% accuracy, we classified trips as fishing for pollock, for another target species, or not fishing. This accuracy lends strong support to the use of our method with unobserved trips across North Pacific fisheries. With individual trips resolved, we examined potential errors in datasets which are often viewed as “the truth.” Despite having > 5 million VMS records (timestamps and vessel locations), this study was as much about understanding and managing data errors as it was about characterizing trips. Missing VMS records were pervasive and they strongly influenced our approach. To understand implications of missing data on inference, we simulated removal of VMS records from trips. Removal of records straightened (i.e., shortened) vessel trajectories, and travel distances were underestimated, on average, by 1.5–13.4% per trip. Despite this bias, VMS proved robust for trip characterization and for improved quality control of human-recorded data. Our scrutiny of human-reported and VMS data advanced our understanding of the potential utility and challenges facing VMS users globally. PMID:27788174

  2. Using Vessel Monitoring System Data to Identify and Characterize Trips Made by Fishing Vessels in the United States North Pacific.

    PubMed

    Watson, Jordan T; Haynie, Alan C

    2016-01-01

    Time spent fishing is the effort metric often studied in fisheries but it may under-represent the effort actually expended by fishers. Entire fishing trips, from the time vessels leave port until they return, may prove more useful for examining trends in fleet dynamics, fisher behavior, and fishing costs. However, such trip information is often difficult to resolve. We identified ~30,000 trips made by vessels that targeted walleye pollock (Gadus chalcogrammus) in the Eastern Bering Sea from 2008-2014 by using vessel monitoring system (VMS) and landings data. We compared estimated trip durations to observer data, which were available for approximately half of trips. Total days at sea were estimated with < 1.5% error and 96.4% of trip durations were either estimated with < 5% error or they were within expected measurement error. With 99% accuracy, we classified trips as fishing for pollock, for another target species, or not fishing. This accuracy lends strong support to the use of our method with unobserved trips across North Pacific fisheries. With individual trips resolved, we examined potential errors in datasets which are often viewed as "the truth." Despite having > 5 million VMS records (timestamps and vessel locations), this study was as much about understanding and managing data errors as it was about characterizing trips. Missing VMS records were pervasive and they strongly influenced our approach. To understand implications of missing data on inference, we simulated removal of VMS records from trips. Removal of records straightened (i.e., shortened) vessel trajectories, and travel distances were underestimated, on average, by 1.5-13.4% per trip. Despite this bias, VMS proved robust for trip characterization and for improved quality control of human-recorded data. Our scrutiny of human-reported and VMS data advanced our understanding of the potential utility and challenges facing VMS users globally.

  3. Passenger vehicle idling in Vermont, Phase II.

    DOT National Transportation Integrated Search

    2014-08-01

    While trip-start and trip-end idling, including idling at intermediary stops along a route, cannot be completely eliminated, the duration of these discretionary idling events is largely controlled by the driver and can be considered part of travel or...

  4. 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

  5. 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

  6. 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)

  7. 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.

  8. Innovative workover/drilling rigs to utilize hydraulics

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

    Noran, D.

    1975-09-29

    While Western Gear Corp., Everett, Wash., is currently building 2 models of a hydraulic workover/drilling rig (one offshore and the other a trailer-mounted land rig), Bender Co., Bakersfield, Calif., already has an all-hydraulic servicing/drilling rig undergoing tests. The rigs are similar in that they eliminate the traveling block, crown block, draw works, chains, and sprockets found on the conventional rig. The major design innovation on the Western Gear model is the 260,000-lb-capacity hoisting system in which 2 hydraulic rams are anchored to the rig floor and carry all the pipe weight, thus eliminating the danger of the derrick's being pulledmore » in. Other changes involve the tripping system, a power swivel/elevator, and the control valves. Maintenance and labor cost reductions are expected to be substantial. The Bender Co. rig has a single-section mast that is a lever-lift-type derrick which serves as a guide for the rams and a support for the pipe-racking platform. Hoisting capacity depends on the number and size of the lifting rods (which support the crown sheaves) and the hydraulic pressure applied. Manufacturing and operating costs are expected to be less than for conventional rigs.« less

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Simulation of parameters of hydraulic drive with volumetric type controller

    NASA Astrophysics Data System (ADS)

    Mulyukin, V. L.; Boldyrev, A. V.; Karelin, D. L.; Belousov, A. M.

    2017-09-01

    The article presents a mathematical model of volumetric type hydraulic drive controller that allows to calculate the parameters of forward and reverse motion. According to the results of simulation static characteristics of rod’s speed and the force of the hydraulic cylinder rod were built and the influence of the angle of swash plate of the controller at the characteristics profile is shown. The results analysis showed that the proposed controller allows steplessly adjust the speed□ц of hydraulic cylinder’s rod motion and the force developed on the rod without the use of flow throttling.

  14. Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe.

    PubMed

    Giechaskiel, Barouch; Vlachos, Theodoros; Riccobono, Francesco; Forni, Fausto; Colombo, Rinaldo; Montigny, Francois; Le-Lijour, Philippe; Carriero, Massimo; Bonnel, Pierre; Weiss, Martin

    2016-12-04

    Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given.

  15. Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

    PubMed Central

    Giechaskiel, Barouch; Vlachos, Theodoros; Riccobono, Francesco; Forni, Fausto; Colombo, Rinaldo; Montigny, Francois; Le-Lijour, Philippe; Carriero, Massimo; Bonnel, Pierre; Weiss, Martin

    2016-01-01

    Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given. PMID:28060306

  16. Neural net controlled tag gas sampling system for nuclear reactors

    DOEpatents

    Gross, Kenneth C.; Laug, Matthew T.; Lambert, John D. B.; Herzog, James P.

    1997-01-01

    A method and system for providing a tag gas identifier to a nuclear fuel rod and analyze escaped tag gas to identify a particular failed nuclear fuel rod. The method and system include disposing a unique tag gas composition into a plenum of a nuclear fuel rod, monitoring gamma ray activity, analyzing gamma ray signals to assess whether a nuclear fuel rod has failed and is emitting tag gas, activating a tag gas sampling and analysis system upon sensing tag gas emission from a failed nuclear rod and evaluating the escaped tag gas to identify the particular failed nuclear fuel rod.

  17. Pulsed ultrasonic stir welding method

    NASA Technical Reports Server (NTRS)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

  18. 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.

  19. 77 FR 36137 - Airworthiness Directives; AGUSTA S.p.A. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... the upper end of collective control rod C2 to torque tube C3 is properly installed. This AD is... prevent separation of the collective control rod from the torque tube, loss of control of the collective... helicopters because the production quality control procedures did not require recording the applied torque on...

  20. 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.

  1. Changes in toe clearance during treadmill walking after long-duration spaceflight.

    PubMed

    Miller, Christopher A; Peters, Brian T; Brady, Rachel R; Richards, Jason R; Ploutz-Snyder, Robert J; Mulavara, Ajitkumar P; Bloomberg, Jacob J

    2010-10-01

    Astronauts exhibit sensorimotor changes upon return from long-duration spaceflight that can result in altered gait kinematics and possibly an increased risk of tripping. Toe trajectory during locomotion is a precise motor control task involving both legs, thus providing a composite metric of locomotor control. The purpose of this study was to determine whether astronauts are at an increased risk of tripping after their return from long-duration spaceflight. This was accomplished by assessing the pre- to postflight changes in toe clearance during treadmill walking. Ten crewmembers walked on a treadmill while performing a visual-acuity task pre- and postflight. In the three subjects on whom landing day data were available, each exhibited a characteristic of increased tripping risk on landing day: either a decreased median toe clearance or an increased interquartile range (a measure of variance). For all crewmembers, toe clearance median and interquartile range were not significantly different from preflight for the other postflight sessions (the earliest being 1 d after landing). A follow-up analysis showed that changes in foot pitch, ankle dorsiflexion, and pelvis roll angles were significant predictors of changes in toe clearance. The landing-day observations indicated an increased risk of tripping, which may pose a hazard during locomotion immediately upon return to Earth, especially in an emergency scenario. However, tripping risk on subsequent days was not different than preflight. The joint angle analysis suggested that the crewmembers tried to reestablish their normal walking pattern postflight, instead of developing a new motor control strategy.

  2. Adaptive control reduces trip-induced forward gait instability among young adults.

    PubMed

    Wang, Ting-Yun; Bhatt, Tanvi; Yang, Feng; Pai, Yi-Chung

    2012-04-30

    A vital functional plasticity of humans is their ability to adapt to threats to posture stability. The purpose of this study was to investigate adaptation to repeated trips in walking. Sixteen young adults were recruited and exposed to the sudden (electronic-mechanical) release of an obstacle, 11-cm in height, in the path of over ground walking during the mid-to-late left swing phase. Although none of the subjects fell on the first of eight unannounced, consecutive trips, all of them had to rely on compensatory step with a step length significantly longer than their regular to reduce their instability. In the subsequent trials, they were able to rapidly make adaptive adjustments in the control of their center-of-mass (COM) stability both proactively and reactively (i.e., before and after hitting or crossing the obstacle), such that the need for taking compensatory step was substantially diminished. The proactive adaptations included a reduced forward COM velocity that lessened forward instability in mid-to-late stance and an elevated toe clearance that reduced the likelihood of obstacle contact. The reactive adjustments were characterized by improved trunk control (by reducing its forward rotation) and limb support (by increasing hip height), and reduced forward instability (by both the posterior COM shift and the reduction in its forward velocity). These findings suggest that young adults can adapt appropriately to repeated trip perturbations and to reduce trip-induced excessive instability in both proactive and reactive manners. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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.

  5. 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

  6. Ambient and microenvironmental particles and exhaled nitric oxide before and after a group bus trip.

    PubMed

    Adar, Sara Dubowsky; Adamkiewicz, Gary; Gold, Diane R; Schwartz, Joel; Coull, Brent A; Suh, Helen

    2007-04-01

    Airborne particles have been linked to pulmonary oxidative stress and inflammation. Because these effects may be particularly great for traffic-related particles, we examined associations between particle exposures and exhaled nitric oxide (FE(NO)) in a study of 44 senior citizens, which involved repeated trips aboard a diesel bus. Samples of FE(NO) collected before and after the trips were regressed against microenvironmental and ambient particle concentrations using mixed models controlling for subject, day, trip, vitamins, collection device, mold, pollen, room air nitric oxide, apparent temperature, and time to analysis. Although ambient concentrations were collected at a fixed location, continuous group-level personal samples characterized microenvironmental exposures throughout facility and trip periods. In pre-trip samples, both microenvironmental and ambient exposures to fine particles were positively associated with FE(NO). For example, an interquartile increase of 4 microg/m(3) in the daily microenvironmental PM(2.5) concentration was associated with a 13% [95% confidence interval (CI), 2-24%) increase in FE(NO). After the trips, however, FE(NO) concentrations were associated pre-dominantly with microenvironmental exposures, with significant associations for concentrations measured throughout the whole day. Associations with exposures during the trip also were strong and statistically significant with a 24% (95% CI, 15-34%) increase in FE(NO) predicted per interquartile increase of 9 microg/m(3) in PM(2.5). Although pre-trip findings were generally robust, our post-trip findings were sensitive to several influential days. Fine particle exposures resulted in increased levels of FE(NO) in elderly adults, suggestive of increased airway inflammation. These associations were best assessed by microenvironmental exposure measurements during periods of high personal particle exposures.

  7. Ambient and Microenvironmental Particles and Exhaled Nitric Oxide Before and After a Group Bus Trip

    PubMed Central

    Adar, Sara Dubowsky; Adamkiewicz, Gary; Gold, Diane R.; Schwartz, Joel; Coull, Brent A.; Suh, Helen

    2007-01-01

    Objectives Airborne particles have been linked to pulmonary oxidative stress and inflammation. Because these effects may be particularly great for traffic-related particles, we examined associations between particle exposures and exhaled nitric oxide (FENO) in a study of 44 senior citizens, which involved repeated trips aboard a diesel bus. Methods Samples of FENO collected before and after the trips were regressed against microenvironmental and ambient particle concentrations using mixed models controlling for subject, day, trip, vitamins, collection device, mold, pollen, room air nitric oxide, apparent temperature, and time to analysis. Although ambient concentrations were collected at a fixed location, continuous group-level personal samples characterized microenvironmental exposures throughout facility and trip periods. Results In pre-trip samples, both microenvironmental and ambient exposures to fine particles were positively associated with FENO. For example, an interquartile increase of 4 μg/m3 in the daily microenvironmental PM2.5 concentration was associated with a 13% [95% confidence interval (CI), 2–24%) increase in FENO. After the trips, however, FENO concentrations were associated pre-dominantly with microenvironmental exposures, with significant associations for concentrations measured throughout the whole day. Associations with exposures during the trip also were strong and statistically significant with a 24% (95% CI, 15–34%) increase in FENO predicted per interquartile increase of 9 μg/m3 in PM2.5. Although pre-trip findings were generally robust, our post-trip findings were sensitive to several influential days. Conclusions Fine particle exposures resulted in increased levels of FENO in elderly adults, suggestive of increased airway inflammation. These associations were best assessed by microenvironmental exposure measurements during periods of high personal particle exposures. PMID:17450216

  8. 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)

  9. A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects.

    PubMed

    Li, Q; Morimoto, K; Kobayashi, M; Inagaki, H; Katsumata, M; Hirata, Y; Hirata, K; Shimizu, T; Li, Y J; Wakayama, Y; Kawada, T; Ohira, T; Takayama, N; Kagawa, T; Miyazaki, Y

    2008-01-01

    We previously reported that forest bathing trips enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after the trip in male subjects. In the present study, we investigated the effect of forest bathing trip on human NK activity in female subjects. Thirteen healthy nurses, age 25-43 years, professional career 4-18 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields. On day 1, the subjects walked for two hours in the afternoon in a forest field; on day 2, they walked for two hours each in the morning and afternoon in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire. Blood and urine were sampled on the second and third days during the trip, and on days 7 and 30 after the trip. NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, the concentrations of estradiol and progesterone in serum, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the trip on a normal working day. The concentrations of phytoncides in the forests were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air. These findings indicate that a forest bathing trip also increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins in female subjects, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.

  10. Neural net controlled tag gas sampling system for nuclear reactors

    DOEpatents

    Gross, K.C.; Laug, M.T.; Lambert, J.B.; Herzog, J.P.

    1997-02-11

    A method and system are disclosed for providing a tag gas identifier to a nuclear fuel rod and analyze escaped tag gas to identify a particular failed nuclear fuel rod. The method and system include disposing a unique tag gas composition into a plenum of a nuclear fuel rod, monitoring gamma ray activity, analyzing gamma ray signals to assess whether a nuclear fuel rod has failed and is emitting tag gas, activating a tag gas sampling and analysis system upon sensing tag gas emission from a failed nuclear rod and evaluating the escaped tag gas to identify the particular failed nuclear fuel rod. 12 figs.

  11. 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).

  12. 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.)

  13. 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.

  14. Integrated head package for top mounted nuclear instrumentation

    DOEpatents

    Malandra, Louis J.; Hornak, Leonard P.; Meuschke, Robert E.

    1993-01-01

    A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted. The shroud forms a structural element of sufficient strength to support the vessel head, the control rod guide mechanism and the instrumentation tube structure, and includes radiation shielding material for limiting passage of radiation from retracted instrumentation tubes. The shroud is thicker at the bottom adjacent the vessel head, where the more irradiated lower ends of retracted sensors reside. The vessel head, shroud and contents thus can be removed from the reactor as a unit and rested safely and securely on a support.

  15. 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

  16. Brief Report: A Gaming Approach to the Assessment of Attention Networks in Autism Spectrum Disorder and Typical Development.

    PubMed

    Mash, Lisa E; Klein, Raymond M; Townsend, Jeanne

    2018-06-12

    Attentional impairments are among the earliest identifiable features of autism spectrum disorders (ASDs). Three attention networks have been extensively studied using the attention network test (ANT), but this long and repetitive task may pose challenges for individuals with ASDs. The AttentionTrip was developed as a more engaging measure of attention network efficiency. In 20 adults with ASDs and 20 typically developing controls, both tasks produced typical network scores (all p < .003, all Cohen's d > 0.78). Reaction time was less variable in the AttentionTrip than the ANT, possibly reflecting improved task engagement. Although the AttentionTrip elicited more consistent responses throughout an experimental session, anomalously low split-half reliability for its executive control network suggests that some changes may be needed.

  17. 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.

  18. 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)

  19. 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.

  20. 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

  1. Effectiveness of the Treatment Readiness and Induction Program for Increasing Adolescent Motivation for Change

    PubMed Central

    Becan, Jennifer E.; Knight, Danica K.; Crawley, Rachel D.; Joe, George W.; Flynn, Patrick M.

    2014-01-01

    Success in substance abuse treatment is improved by problem recognition, desire to seek help, and readiness to engage in treatment, all of which are important aspects of motivation. Interventions that facilitate these at treatment induction for adolescents are especially needed. The purpose of this study is to assess the effectiveness of TRIP (Treatment Readiness and Induction Program) in promoting treatment motivation. Data represent 519 adolescents from 6 residential programs who completed assessments at treatment intake (Time 1) and 35 days after admission (Time 2). The design consisted of a comparison sample (n = 281) that had enrolled in treatment prior to implementation of TRIP (standard operating practice) and a sample of clients that had entered treatment after TRIP began and received standard operating practice enhanced by TRIP (n = 238). Repeated measures ANCOVAs were conducted using each Time 2 motivation scale as a dependent measure. Motivation scales were conceptualized as representing sequential stages of change. LISREL was used to test a structural model involving TRIP participation, gender, drug use severity, juvenile justice involvement, age, race-ethnicity, prior treatment, and urgency as predictors of the stages of treatment motivation. Compared to standard practice, adolescents receiving TRIP demonstrated greater gains in problem recognition, even after controlling for the other variables in the model. The model fit was adequate, with TRIP directly affecting problem recognition and indirectly affecting later stages of change (desire for help and treatment readiness). Future studies should examine which specific components of TRIP affect change in motivation. PMID:25456094

  2. 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.

  3. 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 techniques have been demonstrated for classical block copolymers, the pi conjugation in the rod blocks allow for additional control mechanisms. Liquid crystals are traditionally aligned in magnetic fields. Here, it is demonstrated that if the rod-like blocks are aligned unidirectionally, the block copolymer interfaces follow to create macroscopic alignment of the nanostructures. Organic Light Emitting Diodes (OLEDs) are generally composed of electron transporting and hole transporting moieties to balance charge recombination. Here, a new multifunctional bipolar rod-coil block copolymer containing the hole transporting and electron transporting materials is synthesized. Self-assembly of this new block copolymer results in 15nm lamellae oriented in grains both parallel and perpendicula to the anode. The self-assembled block copolymer shows superior device performance to controls consisting of a luminescent, analogous homopolymer, and a blend of the two component homopolymers. The effects of the morphologies and chemical structure on photovoltaics is explored with a rod-coil block copolymer, (poly(3-hexylthiophene-b-acrylic perylene)). By varying the kinetics of self-assembly through processing, the block copolymer can be disordered, ordered with only short range registry between the nanodomains, or with long-range order. The short range ordered samples showed the best device performance suggesting that the connectivity that is a biproduct of poor order is beneficial for device performance.

  4. 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.

  5. Impact of the World Trade Organization TRIPS agreement on the pharmaceutical industry in Thailand.

    PubMed Central

    Supakankunti, S.; Janjaroen, W. S.; Tangphao, O.; Ratanawijitrasin, S.; Kraipornsak, P.; Pradithavanij, P.

    2001-01-01

    The 1994 World Trade Organization (WTO) Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) established minimum universal standards in all areas of intellectual property. It is intended to implement these standards globally through a WTO enforcement mechanism. The present article proposes a strategy for alleviating the potentially negative impact of TRIPS in Thailand in relation to the following: purchasers; prescribers and dispensers; producers; products; price control; patent-to-third-party; parallel imports; power of the customer; patentable new drugs; personnel; and prevention policies. The following TRIPS provisions are pertinent to the pharmaceutical industry in Thailand: the limited term of product and process patents; the conditions of protection; and the broad scope for compulsory licensing and enforcement procedures in the national patent system. PMID:11417042

  6. Reactivity control assembly for nuclear reactor. [LMFBR

    DOEpatents

    Bollinger, L.R.

    1982-03-17

    This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

  7. 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

  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. Additive Benefits of Twice Forest Bathing Trips in Elderly Patients with Chronic Heart Failure.

    PubMed

    Mao, Gen Xiang; Cao, Yong Bao; Yang, Yan; Chen, Zhuo Mei; Dong, Jian Hua; Chen, Sha Sha; Wu, Qing; Lyu, Xiao Ling; Jia, Bing Bing; Yan, Jing; Wang, Guo Fu

    2018-02-01

    Chronic heart failure (CHF), a clinical syndrome resulting from the consequences of various cardiovascular diseases (CVDs), is increasingly becoming a global cause of morbidity and mortality. We had earlier demonstrated that a 4-day forest bathing trip can provide an adjunctive therapeutic influence on patients with CHF. To further investigate the duration of the impact and the optimal frequency of forest bathing trips in patients with CHF, we recruited those subjects who had experienced the first forest bathing trip again after 4 weeks and randomly categorized them into two groups, namely, the urban control group (city) and the forest bathing group (forest). After a second 4-day forest bathing trip, we observed a steady decline in the brain natriuretic peptide levels, a biomarker of heart failure, and an attenuated inflammatory response as well as oxidative stress. Thus, this exploratory study demonstrated the additive benefits of twice forest bathing trips in elderly patients with CHF, which could further pave the way for analyzing the effects of such interventions in CVDs. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  10. Measuring the relationship between sportfishing trip expenditures and anglers’ species preferences

    USGS Publications Warehouse

    Long, James M.; Melstrom, Richard T.

    2016-01-01

    We examined the relationship between fishing trip expenditures and anglers’ species preferences from a survey of Oklahoma resident anglers conducted in 2014. Understanding patterns in fishing trip expenditures is important because a significant share of state wildlife agency revenue comes from taxes on purchases of fishing equipment. Presently, there is little research that addresses the question of how spending levels vary within groups of sportspersons, including anglers. We used regression analysis to identify a relationship between trip spending and several preference variables, and included controls for other characteristics of fishing trips, such as location, party size, and duration. We received 780 surveys for a response rate of 26%, but only 506 were useable due to missing data or nonfishing responses. Average trip expenditures were approximately US$140, regardless of species preferences, but anglers who preferred to fish for trout and black bass tended to spend more than those who preferred to fish for catfish and panfish. These results were even more pronounced when location was considered, those who last fished at lakes spending more than those who fished at rivers or ponds. The results underscore the differences in spending among anglers with different preferred species and fishing locations.

  11. Daily Variations in Spring Break Alcohol and Sexual Behaviors Based on Intentions, Perceived Norms, and Daily Trip Context

    PubMed Central

    Patrick, Megan E.; Lee, Christine M.

    2012-01-01

    Objective: Given the known risks of alcohol use and sexual behavior for college students on Spring Break, this study was designed to document the behaviors and correlates associated with being on a Spring Break trip on a given day (controlling for average time on a trip). Method: Participants were undergraduate students (n = 261; 55% women) who reported that they planned to go on a Spring Break trip. Web-based survey responses before and after Spring Break documented perceived norms, intentions, and actual behavior on each of the 10 days of Spring Break. Results: Students who went on longer trips, who previously engaged in more heavy episodic drinking, or who had greater pre–Spring Break intentions to drink reported greater alcohol use during Spring Break. Similarly, students with greater pre–Spring Break intentions to have sex, greater perceived norms for sex, or more previoussexual partners had greater odds of having sex. On days students were on trips, they had a greater likelihood of having sex, drinking to higher estimated blood alcohol concentrations, consuming more drinks, and reporting perceived drunkenness than on nontrip days, especially if they had intentions to have sex and drink alcohol (and, for models predicting sexual behavior and drunkenness, had greater perceived norms for sex and drinking). Conclusions: Students who went on Spring Break trips engaged in more risk behaviors. In addition, the context of being on a trip on a given day was associated with increased risk, especially if they had stronger intentions and, in some cases, higher perceived norms. Further research is needed to describe the contexts of Spring Break trips and how to intervene effectively. PMID:22630797

  12. 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.

  13. 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.

  14. NUT SCREW MECHANISMS

    DOEpatents

    Glass, J.A.F.

    1958-07-01

    A reactor control mechanism is described wherein the control is achieved by the partial or total withdrawal of the fissile material which is in the form of a fuel rod. The fuel rod is designed to be raised and lowered from the reactor core area by means of two concentric ball nut and screw assemblies that may telescope one within the other. These screw mechanisms are connected through a magnetic clutch to a speed reduction gear and an accurately controllable prime motive source. With the clutch energized, the fuel rod may be moved into the reactor core area, and fine adjustments may be made through the reduction gearing. However, in the event of a power failure or an emergency signal, the magnetic clutch will become deenergized, and the fuel rod will drop out of the core area by the force of gravity, thus shutting down the operation of the reactor.

  15. 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

  16. Visiting a forest, but not a city, increases human natural killer activity and expression of anti-cancer proteins.

    PubMed

    Li, Q; Morimoto, K; Kobayashi, M; Inagaki, H; Katsumata, M; Hirata, Y; Hirata, K; Suzuki, H; Li, Y J; Wakayama, Y; Kawada, T; Park, B J; Ohira, T; Matsui, N; Kagawa, T; Miyazaki, Y; Krensky, A M

    2008-01-01

    We previously reported that a forest bathing trip enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes. In the present study, we investigated how long the increased NK activity lasts and compared the effect of a forest bathing trip on NK activity with a trip to places in a city without forests. Twelve healthy male subjects, age 35-56 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields and to a city, in which activity levels during both trips were matched. On day 1, subjects walked for two hours in the afternoon in a forest field; and on day 2, they walked for two hours in the morning and afternoon, respectively, in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood samples and completing the questionnaire. Blood and urine were sampled on the second and third days during the trips, and on days 7 and 30 after the trip, and NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trips on a normal working day as the control. Phytoncide concentrations in forest and city air were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzyme A/B-expressing cells and significantly decreased the concentration of adrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. In contrast, a city tourist visit did not increase NK activity, numbers of NK cells, nor the expression of selected intracellular anti-cancer proteins, and did not decrease the concentration of adrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air, but almost not in city air. These findings indicate that a forest bathing trip increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone may partially contribute to the increased NK activity.

  17. Apparatus for Controlling Low Power Voltages in Space Based Processing Systems

    NASA Technical Reports Server (NTRS)

    Petrick, David J. (Inventor)

    2017-01-01

    A low power voltage control circuit for use in space missions includes a switching device coupled between an input voltage and an output voltage. The switching device includes a control input coupled to an enable signal, wherein the control input is configured to selectively turn the output voltage on or off based at least in part on the enable signal. A current monitoring circuit is coupled to the output voltage and configured to produce a trip signal, wherein the trip signal is active when a load current flowing through the switching device is determined to exceed a predetermined threshold and is inactive otherwise. The power voltage control circuit is constructed of space qualified components.

  18. Fabrication of light water reactor tritium targets

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

    Pilger, J.P.

    1991-11-01

    The mission of the Fabrication Development Task of the Tritium Target Development Project is: to produce a documented technology basis, including specifications and procedures for target rod fabrication; to demonstrate that light water tritium targets can be manufactured at a rate consistent with tritium production requirements; and to develop quality control methods to evaluate target rod components and assemblies, and establish correlations between evaluated characteristics and target rod performance. Many of the target rod components: cladding tubes, end caps, plenum springs, etc., have similar counterparts in LWR fuel rods. High production rate manufacture and inspection of these components has beenmore » adequately demonstrated by nuclear fuel rod manufacturers. This summary describes the more non-conventional manufacturing processes and inspection techniques developed to fabricate target rod components whose manufacturability at required production rates had not been previously demonstrated.« less

  19. 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.

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

    Hannan, N. A.; Matos, J. E.; Stillman, J. A.

    At the request of the Czech Technical University (CTU) in Prague, ANL has performed independent verification calculations using the MCNP Monte Carlo code for three core configurations of the VR-1 reactor: a current core configuration B1 with HEU (36%) IRT-3M fuel assemblies and planned core configurations C1 and C2 with LEU (19.7%) IRT-4M fuel assemblies. Details of these configurations were provided to ANL by CTU. For core configuration B1, criticality calculations were performed for two sets of control rod positions provided to ANL by CTU. Fore core configurations C1 and C2, criticality calculations were done for cases with all controlmore » rods at the top positions, all control rods at the bottom positions, and two critical states of the reactor for different control rod positions. In addition, sensitivity studies for variation of the {sup 235}U mass in each fuel assembly and variation of the fuel meat and cladding thicknesses in each of the fuel tubes were doe for the C1 core configuration. The reactivity worth of the individual control rods was calculated for the B1, C1, and C2 core configurations. Finally, the reactivity feedback coefficients, the prompt neutron lifetime, and the total effective delay neutron fraction were calculated for each of the three cores.« less

  1. Controlling Tensegrity Robots through Evolution using Friction based Actuation

    NASA Technical Reports Server (NTRS)

    Kothapalli, Tejasvi; Agogino, Adrian K.

    2017-01-01

    Traditional robotic structures have limitations in planetary exploration as their rigid structural joints are prone to damage in new and rough terrains. In contrast, robots based on tensegrity structures, composed of rods and tensile cables, offer a highly robust, lightweight, and energy efficient solution over traditional robots. In addition tensegrity robots can be highly configurable by rearranging their topology of rods, cables and motors. However, these highly configurable tensegrity robots pose a significant challenge for locomotion due to their complexity. This study investigates a control pattern for successful locomotion in tensegrity robots through an evolutionary algorithm. A twelve-rod hardware model is rapidly prototyped to utilize a new actuation method based on friction. A web-based physics simulation is created to model the twelve-rod tensegrity ball structure. Square-waves are used as control policies for the actuators of the tensegrity structure. Monte Carlo trials are run to find the most successful number of amplitudes for the square-wave control policy. From the results, an evolutionary algorithm is implemented to find the most optimized solution for locomotion of the twelve-rod tensegrity structure. The software pattern coupled with the new friction based actuation method can serve as the basis for highly efficient tensegrity robots in space exploration.

  2. Effectiveness of the Treatment Readiness and Induction Program for increasing adolescent motivation for change.

    PubMed

    Becan, Jennifer E; Knight, Danica K; Crawley, Rachel D; Joe, George W; Flynn, Patrick M

    2015-03-01

    Success in substance abuse treatment is improved by problem recognition, desire to seek help, and readiness to engage in treatment, all of which are important aspects of motivation. Interventions that facilitate these at treatment induction for adolescents are especially needed. The purpose of this study is to assess the effectiveness of TRIP (Treatment Readiness and Induction Program) in promoting treatment motivation. Data represent 519 adolescents from 6 residential programs who completed assessments at treatment intake (time 1) and 35 days after admission (time 2). The design consisted of a comparison sample (n=281) that had enrolled in treatment prior to implementation of TRIP (standard operating practice) and a sample of clients that had entered treatment after TRIP began and received standard operating practice enhanced by TRIP (n=238). Repeated measures ANCOVAs were conducted using each time 2 motivation scale as a dependent measure. Motivation scales were conceptualized as representing sequential stages of change. LISREL was used to test a structural model involving TRIP participation, gender, drug use severity, juvenile justice involvement, age, race-ethnicity, prior treatment, and urgency as predictors of the stages of treatment motivation. Compared to standard practice, adolescents receiving TRIP demonstrated greater gains in problem recognition, even after controlling for the other variables in the model. The model fit was adequate, with TRIP directly affecting problem recognition and indirectly affecting later stages of change (desire for help and treatment readiness). Future studies should examine which specific components of TRIP affect change in motivation. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Solid State Welding Development at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Ding, Robert J.; Walker, Bryant

    2012-01-01

    What is TSW and USW? TSW is a solid state weld process consisting of an induction coil heating source, a stir rod, and non-rotating containment plates Independent heating, stirring and forging controls Decouples the heating, stirring and forging process elements of FSW. USW is a solid state weld process consisting of an induction coil heating source, a stir rod, and a non-rotating containment plate; Ultrasonic energy integrated into non-rotating containment plate and stir rod; Independent heating, stirring and forging controls; Decouples the heating, stirring and forging process elements of FSW.

  4. Bounded parametric control of plane motions of space tethered system

    NASA Astrophysics Data System (ADS)

    Bezglasnyi, S. P.; Mukhametzyanova, A. A.

    2018-05-01

    This paper is focused on the problem of control of plane motions of a space tethered system (STS). The STS is modeled as a heavy rod with two point masses. Point masses are fixed on the rod. A third point mass can move along the rod. The control is realized as a continuous change of the distance from the centre of mass of the tethered system to the movable mass. New limited control laws processes of excitation and damping are built. Diametric reorientation and gravitational stabilization to the local vertical of an STS were obtained. The problem is solved by the method of Lyapunov's functions of the classical theory of stability. The theoretical results are confirmed by numerical calculations.

  5. 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.

  6. Key Differences in Operating a Rover on the Moon vs. Mars

    NASA Technical Reports Server (NTRS)

    Trimble, Jay

    2017-01-01

    The command and control model for spacecraft operations, as well as the distribution of tasks between ground assets and in space assets, whether with a crew or solely robotic, is fundamentally constrained by the round trip light time between the space asset and the control facility (presumably on Earth, though not required). For an asset on Mars, the round trip light time varies, from roughly fourteen minutes to up to forty minutes. For a Lunar asset the round-trip light time is measured in only a few seconds, but current communications systems may more than double the latency with system overhead. For a Lunar Asset the total command latency may range from six seconds to more than forty, depending on communications overhead and data rates. Further, these variables are not always predictable, thus complicating operations. There are several differentiating factors for Lunar vs. Mars operations, Round trip light time/Atmosphere/Lighting and ShadowsTerrain type and knowledge/Round trip light time has implications for the distribution of tasks between ground and in space assets. Even at Lunar Distances, the combination of round trip light time plus communications systems overhead does not enable joy stick driving of a rover. The best that can be done, if driving from Earth, is near real time command and control. By 2030, driving from in space may be possible. Productivity on Mars requires either long operational sequences of commands, as is done for current rovers such as Curiosity, significant autonomous capability or, as may be possible by 2030, command and control support from space. Another implication of the long round trip light time from Earth to Mars, is that flight software functions must be resident on the in space asset. On the Moon, there is considerably more flexibility, enabling processing functions, to be resident on Earth or in space. This provides the opportunity to take advantage of the considerable processing power available on the ground, but may be constrained by data rates. On the Moon, for practical operational purposes, there is no atmosphere. Hence there is no scattering of light in the shadows. This has implications for image interpretation and driving near the poles. The Moon has permanently shadowed regions (PSR), unique terrain with unknown surface properties. With no scattering of light in shadows, driving on the Moon, particularly at the poles, where we have strong evidence of water, may prove to be hazardous and complex, requiring non-optical sensors, such as LIDAR.

  7. 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-photon responses are smaller due to coupling, but the signal-to-noise ratio for a dim (multiphoton) light response is increased at night because of signal averaging between coupled rods. PMID:25616058

  8. 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.)

  9. 75 FR 68548 - Airworthiness Directives; Airbus Model A318, A319, A320, and A321 Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ...: One case of elevator servo-control disconnection has been experienced on an aeroplane of the A320 family. Investigation has revealed that the failure occurred at the servo-control rod eye-end. Further to... servo-control rod eye-ends. In several cases, both actuators of the same elevator surface were affected...

  10. 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.

  11. A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects.

    PubMed

    Li, Qing; Kobayashi, M; Inagaki, H; Hirata, Y; Li, Y J; Hirata, K; Shimizu, T; Suzuki, H; Katsumata, M; Wakayama, Y; Kawada, T; Ohira, T; Matsui, N; Kagawa, T

    2010-01-01

    We previously reported that 2-night/3-day trips to forest parks enhanced human NK activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that this increased NK activity lasted for more than 7 days after the trip in both male and female subjects. In the present study, we investigated the effect of a day trip to a forest park on human NK activity in male subjects. Twelve healthy male subjects, aged 35-53 years, were selected after giving informed consent. The subjects experienced a day trip to a forest park in the suburbs of Tokyo. They walked for two hours in the morning and afternoon, respectively, in the forest park on Sunday. Blood and urine were sampled in the morning of the following day and 7 days after the trip, and the NK activity, numbers of NK and T cells, and granulysin, perforin, and granzyme A/B-expressing lymphocytes, the concentration of cortisol in blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trip on a weekend day as the control. Phytoncide concentrations in the forest were measured. The day trip to the forest park significantly increased NK activity and the numbers of CD16(+) and CD56(+) NK cells, perforin, granulysin, and granzyme A/B-expressing NK cells and significantly decreased CD4(+) T cells, the concentrations of cortisol in the blood and adrenaline in urine. The increased NK activity lasted for 7 days after the trip. Phytoncides, such as isoprene, alpha-pinene, and beta-pinene, were detected in the forest air. These findings indicate that the day trip to the forest park also increased the NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted for at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.

  12. Stability and optimised H∞ control of tripped and untripped vehicle rollover

    NASA Astrophysics Data System (ADS)

    Jin, Zhilin; Zhang, Lei; Zhang, Jiale; Khajepour, Amir

    2016-10-01

    Vehicle rollover is a serious traffic accident. In order to accurately evaluate the possibility of untripped and some special tripped vehicle rollovers, and to prevent vehicle rollover under unpredictable variations of parameters and harsh driving conditions, a new rollover index and an anti-roll control strategy are proposed in this paper. Taking deflections of steering and suspension induced by the roll at the axles into consideration, a six degrees of freedom dynamic model is established, including lateral, yaw, roll, and vertical motions of sprung and unsprung masses. From the vehicle dynamics theory, a new rollover index is developed to predict vehicle rollover risk under both untripped and special tripped situations. This new rollover index is validated by Carsim simulations. In addition, an H-infinity controller with electro hydraulic brake system is optimised by genetic algorithm to improve the anti-rollover performance of the vehicle. The stability and robustness of the active rollover prevention control system are analysed by some numerical simulations. The results show that the control system can improve the critical speed of vehicle rollover obviously, and has a good robustness for variations in the number of passengers and longitude position of the centre of gravity.

  13. 2009 Annual Health Physics Report for the HEU Transparency Program

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

    Radev, R

    2010-04-14

    During the 2009 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. LLNL also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2009, there were 159 person-trips that required dose monitoring of the U.S. monitors. Of the 159 person-trips, 149 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 4 monitoring visits by TMO monitors to facilities other than UEIE and 10 to UEIE itself. LLNL's Hazard Control Departmentmore » laboratories provided the dosimetry services for the HEU Transparency monitors. In 2009, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency Program now has over fifteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.« less

  14. Development of an ATCA IPMI controller mezzanine board to be used in the ATCA developments for the ATLAS Liquid Argon upgrade

    NASA Astrophysics Data System (ADS)

    Dumont Dayot, Nicolas

    2012-01-01

    In the context of the LHC upgrade, we develop a new Read Out Driver (ROD) for the ATLAS Liquid Argon (LAr) community. ATCA and μTCA (Advanced/Micro Telecom Computing Architecture) is becoming a standard in high energy physics and a strong candidate to be used for boards and crates. We work to master ATCA and to integrate a large number of high speed links (96 links at 8.5 Gbps) on a ROD evaluation ATCA board. A versatile ATCA IPMI controller for ATCA boards which is FPGA Mezzanine Card (FMC) compliant has been developed to control the ROD evaluation board.

  15. A dynamic parking charge optimal control model under perspective of commuters' evolutionary game behavior

    NASA Astrophysics Data System (ADS)

    Lin, XuXun; Yuan, PengCheng

    2018-01-01

    In this research we consider commuters' dynamic learning effect by modeling the trip mode choice behavior from a new perspective of dynamic evolutionary game theory. We explore the behavior pattern of different types of commuters and study the evolution path and equilibrium properties under different traffic conditions. We further establish a dynamic parking charge optimal control (referred to as DPCOC) model to alter commuters' trip mode choice while minimizing the total social cost. Numerical tests show. (1) Under fixed parking fee policy, the evolutionary results are completely decided by the travel time and the only method for public transit induction is to increase the parking charge price. (2) Compared with fixed parking fee policy, DPCOC policy proposed in this research has several advantages. Firstly, it can effectively turn the evolutionary path and evolutionary stable strategy to a better situation while minimizing the total social cost. Secondly, it can reduce the sensitivity of trip mode choice behavior to traffic congestion and improve the ability to resist interferences and emergencies. Thirdly, it is able to control the private car proportion to a stable state and make the trip behavior more predictable for the transportation management department. The research results can provide theoretical basis and decision-making references for commuters' mode choice prediction, dynamic setting of urban parking charge prices and public transit induction.

  16. 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 POS was observed in both normal (p<.05) and osteoporotic (p<.05) bone. Back out and reinsertion of the screw resulted in no significant difference in mean POS, stiffness, and work energy to failure (p>.05). In circumstances where a rod is not fully seated within the pedicle screw, the use of a rod persuasion device decreases the overall POS and work energy to failure of the screw or results in outright failure. Further rod contouring or correction of pedicle screw depth of insertion may be warranted to allow for appropriate alignment of the longitudinal rods. Published by Elsevier Inc.

  17. 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.

  18. 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

  19. 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.

  20. COUPLING

    DOEpatents

    Hawke, B.C.

    1963-02-26

    This patent relates to a releasable coupling connecting a control rod to a control rod drive. This remotely operable coupling mechanism can connect two elements which are laterally and angviarly misaligned, and provides a means for sensing the locked condition of the elements. The coupling utilizes a spherical bayonet joint which is locked against rotation by a ball detent lock. (AEC)

  1. Time-delay control of a magnetic levitated linear positioning system

    NASA Technical Reports Server (NTRS)

    Tarn, J. H.; Juang, K. Y.; Lin, C. E.

    1994-01-01

    In this paper, a high accuracy linear positioning system with a linear force actuator and magnetic levitation is proposed. By locating a permanently magnetized rod inside a current-carrying solenoid, the axial force is achieved by the boundary effect of magnet poles and utilized to power the linear motion, while the force for levitation is governed by Ampere's Law supplied with the same solenoid. With the levitation in a radial direction, there is hardly any friction between the rod and the solenoid. The high speed motion can hence be achieved. Besides, the axial force acting on the rod is a smooth function of rod position, so the system can provide nanometer resolution linear positioning to the molecule size. Since the force-position relation is highly nonlinear, and the mathematical model is derived according to some assumptions, such as the equivalent solenoid of the permanently magnetized rod, so there exists unknown dynamics in practical application. Thus 'robustness' is an important issue in controller design. Meanwhile the load effect reacts directly on the servo system without transmission elements, so the capability of 'disturbance rejection; is also required. With the above consideration, a time-delay control scheme is chosen and applied. By comparing the input-output relation and the mathematical model, the time-delay controller calculates an estimation of unmodeled dynamics and disturbances and then composes the desired compensation into the system. Effectiveness of the linear positioning system and control scheme are illustrated with simulation results.

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

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

    At The request of the Czech Technical University in Prague, ANL has performed independent verification calculations using the MCNP Monte Carlo code for three core configurations of the VR-1 reactor: a current core configuration B1 with HEU (36%) IRT-3M fuel assemblies and planned core configurations C1 and C2 with LEU (19.7%) IRT-4M fuel assemblies. Details of these configurations were provided to ANL by CTU. For core configuration B1, criticality calculations were performed for two sets of control rod positions provided to ANL by CTU. For core configurations C1 and C2, criticality calculations were done for cases with all control rodsmore » at the top positions, all control rods at the bottom positions, and two critical states of the reactor for different control rod positions. In addition, sensitivity studies for variation of the {sup 235}U mass in each fuel assembly and variation of the fuel meat and cladding thicknesses in each of the fuel tubes were done for the C1 core configuration. Finally the reactivity worth of the individual control rods was calculated for the B1, C1, and C2 core configurations.« less

  3. The Effects of Diabetic Retinopathy and Pan-Retinal Photocoagulation on Photoreceptor Cell Function as Assessed by Dark Adaptometry

    PubMed Central

    Bavinger, J. Clay; Dunbar, Grace E.; Stem, Maxwell S.; Blachley, Taylor S.; Kwark, Leon; Farsiu, Sina; Jackson, Gregory R.; Gardner, Thomas W.

    2016-01-01

    Purpose The pathophysiology of vision loss in persons with diabetic retinopathy (DR) is complex and incompletely defined. We hypothesized that retinal pigment epithelium (RPE) and rod and cone photoreceptor dysfunction, as measured by dark adaptometry, would increase with severity of DR, and that pan-retinal photocoagulation (PRP) would exacerbate this dysfunction. Methods Dark adaptation (DA) was measured in subjects with diabetes mellitus and healthy controls. Dark adaptation was measured at 5° superior to the fovea following a flash bleach, and the data were analyzed to yield cone and rod sensitivity curves. Retinal layer thicknesses were quantified using spectral-domain optical coherence tomography (OCT). Results The sample consisted of 23 controls and 73 diabetic subjects. Subjects with moderate nonproliferative diabetic retinopathy (NPDR) exhibited significant impairment of rod recovery rate compared with control subjects (P = 0.04). Cone sensitivity was impaired in subjects with proliferative diabetic retinopathy (PDR) (type 1 diabetes mellitus [T1DM]: P = 0.0047; type 2 diabetes mellitus [T2DM]: P < 0.001). Subjects with untreated PDR compared with subjects treated with PRP exhibited similar rod recovery rates and cone sensitivities. Thinner RPE as assessed by OCT was associated with slower rod recovery and lower cone sensitivity, and thinner photoreceptor inner segment/outer segment layer was associated with lower cone sensitivity. Conclusions The results suggest that RPE and photoreceptor cell dysfunction, as assessed by cone sensitivity level and rod- and RPE-mediated dark adaptation, progresses with worsening DR, and rod recovery dysfunction occurs earlier than cone dysfunction. Function was preserved following PRP. The findings suggest multiple defects in retinoid function and provide potential points to improve visual function in persons with PDR. PMID:26803796

  4. Specific features of the control systems of new-modification 310-330-MW steam turbines manufactured by PAO turboatom

    NASA Astrophysics Data System (ADS)

    Shvetsov, V. L.; Babaev, I. N.

    2017-07-01

    Principal engineering solutions taken by PAO Turboatom when developing the control systems of the 310-325-MW turbines for thermal power stations are set forth. A schematic diagram of the control system is presented and the designs of the retrofitted basic mechanisms, viz., high-pressure steam-distribution unit and the cutoff valve, are described. It is noted that the accepted principles of designing the control systems allow retaining the following advantages of the latter: use of the condensate as a cheap nonflammable working fluid, valveless switches to control the locking servomotors, a mechanical ring-type turbine trip mechanism (TTM) in combination with an actuator fitted with two double-seated actuator valves to control the pressure in the pulse security lines, and a rotary valve to block the triggering of the actuator valves during successive testing of the TTM rings by filling the oil during the operation of the turbine and the subsequent raising of the above valves. The control systems of the new-modification turbines are based on microprocessor hardware using electromechanical converters to drive every cutoff valve as a universal solution that is not oriented towards a particular manufacturer of the control system electronics. Application of a mechanical turbine trip mechanism is acknowledged as indispensable for unconditional guarantee of the safe operation of the turbines irrespective of the presence of the electronic turbine trip mechanism.

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

    NASA Astrophysics Data System (ADS)

    Yilmaz, Mine Ozdemir

    The purpose of this research was to develop a burnup dependent fuel thermal conductivity model within Pennsylvania State University, Reactor Dynamics and Fuel Management Group (RDFMG) version of the subchannel thermal-hydraulics code COBRA-TF (CTF). The model takes into account first, the degradation of fuel thermal conductivity with high burnup; and second, the fuel thermal conductivity dependence on the Gadolinium content for both UO2 and MOX fuel rods. The modified Nuclear Fuel Industries (NFI) model for UO2 fuel rods and Duriez/Modified NFI Model for MOX fuel rods were incorporated into CTF and fuel centerline predictions were compared against Halden experimental test data and FRAPCON-3.4 predictions to validate the burnup dependent fuel thermal conductivity model in CTF. Experimental test cases from Halden reactor fuel rods for UO2 fuel rods at Beginning of Life (BOL), through lifetime without Gd2O3 and through lifetime with Gd 2O3 and a MOX fuel rod were simulated with CTF. Since test fuel rod and FRAPCON-3.4 results were based on single rod measurements, CTF was run for a single fuel rod surrounded with a single channel configuration. Input decks for CTF were developed for one fuel rod located at the center of a subchannel (rod-centered subchannel approach). Fuel centerline temperatures predicted by CTF were compared against the measurements from Halden experimental test data and the predictions from FRAPCON-3.4. After implementing the new fuel thermal conductivity model in CTF and validating the model with experimental data, CTF model was applied to steady state and transient calculations. 4x4 PWR fuel bundle configuration from Purdue MOX benchmark was used to apply the new model for steady state and transient calculations. First, one of each high burnup UO2 and MOX fuel rods from 4x4 matrix were selected to carry out single fuel rod calculations and fuel centerline temperatures predicted by CTF/TORT-TD were compared against CTF /TORT-TD /FRAPTRAN 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.

  6. A method to simulate motor control strategies to recover from perturbations: application to a stumble recovery during gait.

    PubMed

    Forner-Cordero, Arturo; Ackermann, Marko; de Lima Freitas, Mateus

    2011-01-01

    Perturbations during human gait such as a trip or a slip can result in a fall, especially among frail populations such as the elderly. In order to recover from a trip or a stumble during gait, humans perform different types of recovery strategies. It is very useful to uncover the mechanisms of the recovery to improve training methods for populations at risk of falling. Moreover, human recovery strategies could be applied to implement controllers for bipedal robot walker, as an application of biomimetic design. A biomechanical model of the response to a trip during gait might uncover the control mechanisms underlying the different recovery strategies and the adaptation of the responses found during the execution of successive perturbation trials. This paper introduces a model of stumble in the multibody system framework. This model is used to assess different feedforward strategies to recover from a trip. First of all, normal gait patterns for the musculoskeletal system model are obtained by solving an optimal control problem. Secondly, the reference gait is perturbed by the application of forces on the swinging foot in different ways: as an instantaneous inelastic collision of the foot with an obstacle, as an impulsive horizontal force or using a force curve measured experimentally during gait perturbation experiments. The influence of the type of perturbation, the timing of the collision with respect to the gait cycle, as well as of the coefficient of restitution was investigated previously. Finally, in order to test the effects of different muscle excitation levels on the initial phases of the recovery response, several muscle excitations were added to selected muscles of the legs, thus providing a simulation of the recovery reactions. These results pave the way for future analysis and modeling of the control mechanisms of gait.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. NUCLEAR REACTOR FUEL ELEMENT

    DOEpatents

    Currier, E.L. Jr.; Nicklas, J.H.

    1963-06-11

    A fuel plate is designed for incorporation into control rods of the type utilized in high-flux test reactors. The fuel plate is designed so that the portion nearest the poison section of the control rod contains about one-half as much fissionable material as in the rest of the plate, thereby eliminating dangerous flux peaking in that portion. (AEC)

  14. 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.

  15. Modulation of thalamocortical oscillations by TRIP8b, an auxiliary subunit for HCN channels.

    PubMed

    Zobeiri, Mehrnoush; Chaudhary, Rahul; Datunashvili, Maia; Heuermann, Robert J; Lüttjohann, Annika; Narayanan, Venu; Balfanz, Sabine; Meuth, Patrick; Chetkovich, Dane M; Pape, Hans-Christian; Baumann, Arnd; van Luijtelaar, Gilles; Budde, Thomas

    2018-04-01

    Hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels have important functions in controlling neuronal excitability and generating rhythmic oscillatory activity. The role of tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b) in regulation of hyperpolarization-activated inward current, I h , in the thalamocortical system and its functional relevance for the physiological thalamocortical oscillations were investigated. A significant decrease in I h current density, in both thalamocortical relay (TC) and cortical pyramidal neurons was found in TRIP8b-deficient mice (TRIP8b -/- ). In addition basal cAMP levels in the brain were found to be decreased while the availability of the fast transient A-type K + current, I A , in TC neurons was increased. These changes were associated with alterations in intrinsic properties and firing patterns of TC neurons, as well as intrathalamic and thalamocortical network oscillations, revealing a significant increase in slow oscillations in the delta frequency range (0.5-4 Hz) during episodes of active-wakefulness. In addition, absence of TRIP8b suppresses the normal desynchronization response of the EEG during the switch from slow-wave sleep to wakefulness. It is concluded that TRIP8b is necessary for the modulation of physiological thalamocortical oscillations due to its direct effect on HCN channel expression in thalamus and cortex and that mechanisms related to reduced cAMP signaling may contribute to the present findings.

  16. Summary of the thermal evaluation of LWBR (LWBR Development Program)

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

    Lerner, S.; McWilliams, K.D.; Stout, J.W.

    1980-03-01

    This report describes the thermal evaluation of the core for the Shippingport Light Water Breeder Reactor. This core contains unique thermal-hydraulic features such as (1) close rod-to-rod proximity, (2) an open-lattice array of fuel rods with two different diameters and rod-to-rod spacings in the same flow region, (3) triplate orifices located at both the entrance and exit of fuel modules and (4) a hydraulically-balanced movable-fuel system coupled with (5) axial-and-radial fuel zoning for reactivity control. Performance studies used reactor thermal principles such as the hot-and-nominal channel concept and related nuclear/engineering design allowances. These were applied to models of three-dimensional roddedmore » arrays comprising the core fuel regions.« less

  17. Landing gear energy absorption system

    NASA Technical Reports Server (NTRS)

    Hansen, Christopher P. (Inventor)

    1994-01-01

    A landing pad system is described for absorbing horizontal and vertical impact forces upon engagement with a landing surface where circumferentially arranged landing struts respectively have a clevis which receives a slidable rod member and where the upper portion of a slidable rod member is coupled to the clevis by friction washers which are force fit onto the rod member to provide for controlled constant force energy absorption when the rod member moves relative to the clevis. The lower end of the friction rod is pivotally attached by a ball and socket to a support plate where the support plate is arranged to slide in a transverse direction relative to a housing which contains an energy absorption material for absorbing energy in a transverse direction.

  18. OVERALL CONTROL SYSTEM FOR HIGH FLUX PILE

    DOEpatents

    Newson, H.W.; Durham, N.C.; Wigner, E.P.; Princeton, N.J.; Epler, E.P.

    1961-05-23

    A control system is given for a high fiux reactor incorporating an anti- scram control feature whereby a neutron absorbing control rod acts as a fine adjustment while a neutron absorbing shim rod, actuated upon a command received from reactor period and level signals, has substantially greater effect on the neutron level and is moved prior to scram conditions to alter the reactor activity before a scram condition is created. Thus the probability that a scram will have to be initiated is substantially decreased.

  19. Approaches to Golden Algae Control: In-Lake Mesocosm Experiments

    DTIC Science & Technology

    2012-04-01

    P. parvum population density (b), and cyanobacteria biomass (c) from monthly sampling trips performed in Lake Granbury where trips spanned five...zooplankton and pathogenic effects of virus (Schwierzke et al. 2010). In addition, some cyanobacteria may inhibit P. parvum blooms (Grover et al...toxins released by P. parvum may behave as weak bases in aqueous solutions. These results suggest that targeted reductions of pH can reduce the

  20. 2011 Annual Health Physics Report for the HEU transparency Program

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

    Radev, R

    2012-04-30

    During the 2008 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. They also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2008, there were 158 person-trips that required dose monitoring of the U.S. monitors. Of the 158 person-trips, 148 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 6 monitoring visits by TMO monitors to facilities other than UEIE and 8 to UEIE itself. There were three monitoringmore » visits (source changes) that were back-to-back with a total of 24 monitors. LLNL's Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors. In 2008, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency now has thirteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.« less

  1. 2008 Annual Health Physics Report for the HEU Transparency Program

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

    Radev, R.

    2009-03-24

    During the 2008 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. They also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2008, there were 158 person-trips that required dose monitoring of the U.S. monitors. Of the 158 person-trips, 148 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 6 monitoring visits by TMO monitors to facilities other than UEIE and 8 to UEIE itself. There were three monitoringmore » visits (source changes) that were back-to-back with a total of 24 monitors. LLNL’s Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors. In 2008, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency now has thirteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.« less

  2. Biomechanical risk factors for tripping during obstacle--Crossing with the trailing limb in patients with type II diabetes mellitus.

    PubMed

    Hsu, Wei-Chun; Liu, Ming-Wei; Lu, Tung-Wu

    2016-03-01

    People with type II diabetes mellitus (DM) are at a high risk of falling especially during more challenging locomotor tasks such as obstacle-crossing. The current study aimed to identify the risk factors for tripping in these patients during trailing-limb obstacle-crossing. Fourteen patients with type II DM with or without mild peripheral neuropathy (PN) and 14 healthy controls walked and crossed obstacles of three different heights while their motion data were measured using a motion capture system and two forceplates. The DM group was found to cross obstacles with significantly reduced trailing toe clearance (p<0.05), increasing the probability of the foot hitting the obstacle, and thus the risk of tripping. This altered end-point control was associated with significantly reduced knee flexion and hip adduction of the trailing swing limb (p<0.05), as well as significantly increased ankle plantarflexor moments in the leading stance limb (p<0.05). Therefore, reduced knee flexion and hip adduction of the swing limb are identified as risk factors for tripping during obstacle-crossing. Increased mechanical demands on the ankle plantarflexors suggest that weakness of these muscles may further reduce the already compromised performance of obstacle-crossing in these patients. The current results showed that obstacle-crossing can be used to detect gait deviations and to identify the associated risk of tripping in patients with type II DM without or at an early stage of PN. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Defect scriber

    DOEpatents

    Russell, Harold C.

    1979-01-01

    This disclosure describes a device for repeatably scribing a V-shaped scratch having sharply defined dimensions on the interior surface of a nuclear reactor fuel rod tube. A cutting tool having a V-shaped cutting tip is supported within the fuel rod tube so that the V-shaped cutting tip can be pivoted about an axis and scribe a scratch on the interior surface of the fuel rod tube. Lengthwise the scratch runs parallel to a line drawn through the axis of the fuel rod tube and is in the shape of an arc, and widthwise the scratch is V-shaped. This shape is used because the dimensions of the scratch can be plugged into appropriate formulas to calculate stress intensity of cracks in fuel rod tubes. Since the fuel rod tubes which are to be scribed may be radioactive, the scratching assembly is designed for use in a fixture which allows it to be operated in a cave by remote control handling devices.

  4. 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.

  5. 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

  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. 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

  8. 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.

  9. Power controller 28Vdc load switching (N. O. SPST). Final report, 31 August 1977-21 January 1980

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

    McMackin, J.B.

    1980-01-21

    A solid state power controller has been designed in four ratings to switch 28Vdc power to selected loads upon remote command. The four ratings trip out at currents of 10, 5, 2 and 1/2 amps. The design allows for wide variations in load and supply voltage and will not trip out on short load transients of up to 1000% of rated load current. In case of failure of the controller circuitry, an internal fuse protects the load from excessive current. The control current which operates the controller also provides a sensing function so that the state of the controller canmore » be determined remotely. The controllers are designed to operate over a case temperature range of -54 C to 120 C. A quantity of 100 units have been fabricated, tested, and supplied to the Navy.« less

  10. Bringing Grand Canyon to the College Campus: Assessment of Student Learning in the Geosciences Through Virtual Field Trip Games for Mobile Smart-Devices

    NASA Astrophysics Data System (ADS)

    Bursztyn, N.; Walker, A.; Shelton, B.; Pederson, J. L.

    2015-12-01

    Geoscience educators have long considered field trips to be the most effective way of attracting students into the discipline. A solution for bringing student-driven, engaging, kinesthetic field experiences to a broader audience lies in ongoing advances in mobile-communication technology. This NSF-TUES funded project developed three virtual field trip experiences for smartphones and tablets (on geologic time, geologic structures, and hydrologic processes), and then tested their performance in terms of student interest in geoscience as well as gains in learning. The virtual field trips utilize the GPS capabilities of smartphones and tablets, requiring the students to navigate outdoors in the real world while following a map on their smart device. This research, involving 873 students at five different college campuses, used analysis of covariance (ANCOVA) and multiple regression for statistical methods. Gains in learning across all participants are minor, and not statistically different between intervention and control groups. Predictors of gains in content comprehension for all three modules are the students' initial interest in the subject and their base level knowledge. For the Geologic Time and Structures modules, being a STEM major is an important predictor of student success. Most pertinent for this research, for Geologic Time and Hydrologic Processes, gains in student learning can be predicted by having completed those particular virtual field trips. Gender and race had no statistical impact, indicating that the virtual field trip modules have broad reach across student demographics. In related research, these modules have been shown to increase student interest in the geosciences more definitively than the learning gains here. Thus, future work should focus on improving the educational impact of mobile-device field trips, as their eventual incorporation into curricula is inevitable.

  11. 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.

  12. 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.

  13. Lake Holloman Recreational Area Development Environmental Assessment

    DTIC Science & Technology

    2009-08-01

    facilities Total daily trips are applied to the following factors depending on the corresponding years. Year 2005 through 2009: VOCE = .016...Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022...Trips COE = .262 * Trips To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 NOx (tons/yr) = NOxE * DPYII/2000

  14. A new mouse model for stationary night blindness with mutant Slc24a1 explains the pathophysiology of the associated human disease

    PubMed Central

    Vinberg, Frans; Wang, Tian; Molday, Robert S.; Chen, Jeannie; Kefalov, Vladimir J.

    2015-01-01

    Mutations that affect calcium homeostasis (Ca2+) in rod photoreceptors are linked to retinal degeneration and visual disorders such as retinitis pigmentosa and congenital stationary night blindness (CSNB). It is thought that the concentration of Ca2+ in rod outer segments is controlled by a dynamic balance between influx via cGMP-gated (CNG) channels and extrusion via Na+/Ca2+, K+ exchangers (NCKX1). The extrusion-driven lowering of rod [Ca2+]i following light exposure controls their light adaptation and response termination. Mutant NCKX1 has been linked to autosomal-recessive stationary night blindness. However, whether NCKX1 contributes to light adaptation has not been directly tested and the mechanisms by which human NCKX1 mutations cause night blindness are not understood. Here, we report that the deletion of NCKX1 in mice results in malformed outer segment disks, suppressed expression and function of rod CNG channels and a subsequent 100-fold reduction in rod responses, while preserving normal cone responses. The compensating loss of CNG channel function in the absence of NCKX1-mediated Ca2+ extrusion may prevent toxic Ca2+ buildup and provides an explanation for the stationary nature of the associated disorder in humans. Surprisingly, the lack of NCKX1 did not compromise rod background light adaptation, suggesting additional Ca2+-extruding mechanisms exist in these cells. PMID:26246500

  15. Navy Explosive Ordnance Disposal School Master Development Plan for Test Area D-51 Final Environmental Assessment

    DTIC Science & Technology

    2008-01-01

    Year 2005 through 2009: VOCE = .016 * Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips...NOxE = .013 * Trips PM10E = .0022 * Trips COE = .262 * Trips To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII

  16. 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.

  17. Randomized Controlled Trial of a Spring Break Intervention to Reduce High-Risk Drinking

    PubMed Central

    Lee, Christine M.; Neighbors, Clayton; Lewis, Melissa A.; Kaysen, Debra; Mittmann, Angela; Geisner, Irene M.; Atkins, David C.; Zheng, Cheng; Garberson, Lisa A.; Kilmer, Jason R.; Larimer, Mary E.

    2014-01-01

    Objective While recent studies have documented high-risk drinking occurring during Spring Break (SB), particularly on SB trips with friends, published intervention studies are few. The present study evaluated the efficacy of Event Specific Prevention (ESP) strategies for reducing SB drinking among college students, compared to general prevention strategies and an assessment-only control group, as well as evaluated inclusion of peers in interventions and mode of intervention delivery (in-person vs. web). Method Participants included 783 undergraduates (56.1% women, average age 20.5) intending to go on a SB trip with friends as well as to drink heavily on at least one day of SB. Participants completed assessments prior to SB and were randomized to one of five intervention conditions: SB in-person BASICS, SB web BASICS, SB in-person BASICS with friend, SB web BASICS with friend, general BASICS, or an attention control condition. Follow-up assessment was completed one week after SB. Results While the SB web BASICS (with and without friends) and general BASICS interventions were not effective at reducing SB drinking, results indicated significant intervention effects for SB in-person BASICS in reducing SB drinking, particularly on trip days. Follow-up analyses indicated change in descriptive norms mediated treatment effect and reductions in drinking, while SB drinking intentions and positive expectancies did not. Conclusions Overall, results suggest an in-person SB-specific intervention is effective at reducing SB drinking, especially during trips. In contrast, interventions that contain non-SB related content, are web-based, or seek to involve friends may be less effective at reducing SB drinking. PMID:24491072

  18. 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.

  19. Final Environmental Assessment for the Military Family Housing Privatization Initiative Columbus Air Force Base, Mississippi

    DTIC Science & Technology

    2005-05-03

    daily trips are applied to the following factors depending on the corresponding years. Year 2005 through 2009: VOCE = .016 * Trips NOxE = .015...Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE...262 * Trips To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 NOx (tons/yr) = NOxE * DPYII/2000 PM10 (tons/yr

  20. Final Environmental Assessment for the Okaloosa Regional Airport Expansion at Eglin Air Force Base, FL

    DTIC Science & Technology

    2006-06-01

    construction Total daily trips are then applied to the following factors depending on the corresponding years. Year 2005 through 2009: VOCE ...016 * Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E...0022 * Trips COE = .262 * Trips To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 Nox (tons/yr) = NOxE

  1. Identifying walking trips from GPS and accelerometer data in adolescent females

    PubMed Central

    Rodriguez, Daniel; Cho, GH; Elder, John; Conway, Terry; Evenson, Kelly R; Ghosh-Dastidar, Bonnie; Shay, Elizabeth; Cohen, Deborah A; Veblen-Mortenson, Sarah; Pickrell, Julie; Lytle, Leslie

    2013-01-01

    Background Studies that have combined accelerometers and global positioning systems (GPS) to identify walking have done so in carefully controlled conditions. This study tested algorithms for identifying walking trips from accelerometer and GPS data in free-living conditions. The study also assessed the accuracy of the locations where walking occurred compared to what participants reported in a diary. Methods A convenience sample of high school females was recruited (N=42) in 2007. Participants wore a GPS unit and an accelerometer, and recorded their out-of-school travel for six days. Split-sample validation was used to examine agreement in the daily and total number of walking trips with Kappa statistics and count regression models, while agreement in locations visited by walking was examined with geographic information systems. Results Agreement varied based on the parameters of the algorithm, with algorithms exhibiting moderate to substantial agreement with self-reported daily (Kappa = 0.33–0.48) and weekly (Kappa = 0.41–0.64) walking trips. Comparison of reported locations reached by walking and GPS data suggest that reported locations are accurate. Conclusions The use of GPS and accelerometers is promising for assessing the number of walking trips and the walking locations of adolescent females. PMID:21934163

  2. Development of a Trip Energy Estimation Model Using Real-World Global Positioning System Driving Data: Preprint

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

    Holden, Jacob; Wood, Eric W; Zhu, Lei

    A data-driven technique for estimation of energy requirements for a proposed vehicle trip has been developed. Based on over 700,000 miles of driving data, the technique has been applied to generate a model that estimates trip energy requirements. The model uses a novel binning approach to categorize driving by road type, traffic conditions, and driving profile. The trip-level energy estimations can easily be aggregated to any higher-level transportation system network desired. The model has been tested and validated on the Austin, Texas, data set used to build this model. Ground-truth energy consumption for the data set was obtained from Futuremore » Automotive Systems Technology Simulator (FASTSim) vehicle simulation results. The energy estimation model has demonstrated 12.1 percent normalized total absolute error. The energy estimation from the model can be used to inform control strategies in routing tools, such as change in departure time, alternate routing, and alternate destinations, to reduce energy consumption. The model can also be used to determine more accurate energy consumption of regional or national transportation networks if trip origin and destinations are known. Additionally, this method allows the estimation tool to be tuned to a specific driver or vehicle type.« less

  3. 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.

  4. A preliminary investigation of shape memory alloys in the surgical correction of scoliosis.

    PubMed

    Sanders, J O; Sanders, A E; More, R; Ashman, R B

    1993-09-15

    Nitinol, a shape memory alloy, is flexible at low temperatures but retains its original shape when heated. This offers interesting possibilities for scoliosis correction. Of the shape memory alloys, nitinol is the most promising medically because of biocompatibility and the ability to control transition temperature. In vivo: Six goats with experimental scoliosis were instrumented with 6-mm nitinol rods. The rods were transformed, and the scoliosis corrected, in the awakened goats by 450-kHz radio frequency induction heating. The curves averaged 41 degrees before instrumentation, 33 degrees after instrumentation, and 11 degrees after rod transformation. The animals tolerated the heating without discomfort, neurologic injury, or evidence of thermal injury to the tissues or the spinal cord. In vitro: Nitinol rods were tested under both constant deflection and constant loading conditions and plotted temperature versus either force or displacement. The 6-mm rod generated forces of 200 N. The 9-mm rod generated up to 500 N. We safely coupled shape memory alloy transformation to the spine and corrected an experimental spinal deformity in awake animals. The forces generated can be estimated by the rod's curvature and temperature. The use of shape memory alloys allows continuous neurologic monitoring during awake correction, true rotational correction by rod torsion, and the potential option of periodic correction to take advantage of spinal viscoelasticity and the potential of true rotational correction by rod torsion.

  5. 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.

  6. 46 CFR 62.10-1 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... control means a function of an automatic control system to restrict operation to a specified operating... automatic or manual control. Safety trip control system means a manually or automatically operated system... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Terms Used...

  7. 46 CFR 62.10-1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... control means a function of an automatic control system to restrict operation to a specified operating... automatic or manual control. Safety trip control system means a manually or automatically operated system... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Terms Used...

  8. 46 CFR 62.10-1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... control means a function of an automatic control system to restrict operation to a specified operating... automatic or manual control. Safety trip control system means a manually or automatically operated system... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Terms Used...

  9. 46 CFR 62.10-1 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... control means a function of an automatic control system to restrict operation to a specified operating... automatic or manual control. Safety trip control system means a manually or automatically operated system... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Terms Used...

  10. 46 CFR 62.10-1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... control means a function of an automatic control system to restrict operation to a specified operating... automatic or manual control. Safety trip control system means a manually or automatically operated system... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Terms Used...

  11. How to Conduct a Research Field Trip

    ERIC Educational Resources Information Center

    Wacker, David G.

    1974-01-01

    Discusses the three phases of a three-day intensive research study field trip: planning and pre-trip training; actual trip; and post-trip report, research and data organization, and final trip evaluation. Included is a sample program of the limnology field trip taken by the Grafton High School, Wisconsin. (CC)

  12. Mechatronic Aeropendulum: Demonstration of Linear and Nonlinear Feedback Control Principles with MATLAB/Simulink Real-Time Windows Target

    ERIC Educational Resources Information Center

    Enikov, E. T.; Campa, G.

    2012-01-01

    This paper presents a low-cost hands-on experiment for a classical undergraduate controls course for non-electrical engineering majors. The setup consists of a small dc electrical motor attached to one of the ends of a light rod. The motor drives a 2-in propeller and allows the rod to swing. Angular position is measured by a potentiometer attached…

  13. 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.

  14. Parametric Analysis of a Turbine Trip Event in a BWR Using a 3D Nodal Code

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

    Gorzel, A.

    2006-07-01

    Two essential thermal hydraulics safety criteria concerning the reactor core are that even during operational transients there is no fuel melting and not-permissible cladding temperatures are avoided. A common concept for boiling water reactors is to establish a minimum critical power ratio (MCPR) for steady state operation. For this MCPR it is shown that only a very small number of fuel rods suffers a short-term dryout during the transient. It is known from experience that the limiting transient for the determination of the MCPR is the turbine trip with blocked bypass system. This fast transient was simulated for a Germanmore » BWR by use of the three-dimensional reactor analysis transient code SIMULATE-3K. The transient behaviour of the hot channels was used as input for the dryout calculation with the transient thermal hydraulics code FRANCESCA. By this way the maximum reduction of the CPR during the transient could be calculated. The fast increase in reactor power due to the pressure increase and to an increased core inlet flow is limited mainly by the Doppler effect, but automatically triggered operational measures also can contribute to the mitigation of the turbine trip. One very important method is the short-term fast reduction of the recirculation pump speed which is initiated e. g. by a pressure increase in front of the turbine. The large impacts of the starting time and of the rate of the pump speed reduction on the power progression and hence on the deterioration of CPR is presented. Another important procedure to limit the effects of the transient is the fast shutdown of the reactor that is caused when the reactor power reaches the limit value. It is shown that the SCRAM is not fast enough to reduce the first power maximum, but is able to prevent the appearance of a second - much smaller - maximum that would occur around one second after the first one in the absence of a SCRAM. (author)« less

  15. Weld Nugget Temperature Control in Thermal Stir Welding

    NASA Technical Reports Server (NTRS)

    Ding, R. Jeffrey (Inventor)

    2014-01-01

    A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

  16. Final Environmental Assessment: For Construction of an Addition to the Joint Strike Fighter Reprogramming Facility, Building 614, on Eglin Air Force Base, Florida

    DTIC Science & Technology

    2007-01-01

    VOCE = .016 * Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013...Trips PM10E = .0022 * Trips COE = .262 * Trips E = emissions To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 lbs

  17. 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

  18. Formation of gold nanorods by a stochastic "popcorn" mechanism.

    PubMed

    Edgar, Jonathan A; McDonagh, Andrew M; Cortie, Michael B

    2012-02-28

    Gold nanorods have significant technological potential and are of broad interest to the nanotechnology community. The discovery of the seeded, wet-chemical synthetic process to produce them may be regarded as a landmark in the control of metal nanoparticle shape. However, the mechanism by which the initial spherical gold seeds acquire anisotropy is a critical, yet poorly understood, factor. Here we examine the very early stages of rod growth using a combination of techniques including cryogenic transmission electron microscopy, optical spectroscopy, and computational modeling. Reconciliation of the available experimental observations can only be achieved by invoking a stochastic, "popcorn"-like mechanism of growth, in which individual seeds lie quiescent for some time before suddenly and rapidly growing into rods. This is quite different from the steady, concurrent growth of nanorods that has been previously generally assumed. Furthermore we propose that the shape is controlled by the ratio of surface energy of rod sides to rod ends, with values of this quantity in the range of 0.3-0.8 indicated for typical growth solutions.

  19. An analytical approach to thermal modeling of Bridgman-type crystal growth. I - One-dimensional analysis

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1982-01-01

    A relatively simple one-dimensional thermal model of the Bridgman growth process has been developed which is applicable to the growth of small diameter samples with conductivities similar to those of metallic alloys. The heat flow in a translating rod is analyzed in a way that is applicable to Biot numbers less than unity. The model accommodates an adiabatic zone, different heat transfer coefficients in the hot and cold zones, and changes in sample material properties associated with phase change. The analysis is applied to several simplified cases. The effect of the rod's motion is studied in a three-zone furnace for a rod sufficiently long that end effects can be neglected; end effects are then investigated for a motionless rod. Finally, the addition of a fourth zone, an independently controlled booster heater between the main heater and the adiabatic zone, is evaluated for its ability to increase the gradient in the sample at the melt interface and to control the position of the interface.

  20. 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

  1. 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.

  2. Final Environmental Assessment for Construction of a Precision Measurement Equipment Laboratory Facility on Eglin Air Force Base, FL

    DTIC Science & Technology

    2006-10-01

    daily trips are then applied to the following factors depending on the corresponding years. Year 2005 through 2009: VOCE = .016 * Trips NOxE...015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE...262 * Trips E = emissions To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 lbs/ton NOx (tons/yr) = NOxE * DPYII

  3. Mitigation of Remedial Action Schemes by Decentralized Robust Governor Control

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

    Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Lian, Jianming

    This paper presents transient stability improvement by a new distributed hierarchical control architecture (DHC). The integration of remedial action schemes (RAS) to the distributed hierarchical control architecture is studied. RAS in power systems are designed to maintain stability and avoid undesired system conditions by rapidly switching equipment and/or changing operating points according to predetermined rules. The acceleration trend relay currently in use in the US western interconnection is an example of RAS that trips generators to maintain transient stability. The link between RAS and DHC is through fast acting robust turbine/governor control that can also improve transient stability. In thismore » paper, the influence of the decentralized robust turbine/governor control on the design of RAS is studied. Benefits of combining these two schemes are increasing power transfer capability and mitigation of RAS generator tripping actions; the later benefit is shown through simulations.« less

  4. Vortical flow management for improved configuration aerodynamics: Recent experiences

    NASA Technical Reports Server (NTRS)

    Rao, D. M.

    1983-01-01

    Recent progress in vortex-control applications for alleviating the adverse consequences of three dimensional separation and vortical interactions on slender body/swept wing configurations is reported. Examples include helical separation trip to alleviate the side force due to forebody vortex asymmetry; hinged strakes to avoid vortex breakdown effects; compartmentation of swept leading edge separation to delay the pitch-up instability; under wing vortex trip and vortex trip and vortex flaps for drag reduction at high lift; and an apex-flap trimmer to fully utilize the lift capability of trailing-edge flaps for take off and landing of delta wings. Experimental results on generic wind-tunnel models are presented to illustrate the vortex-management concepts involved and to indicate their potential for enhancing the subsonic aerodynamics of supersonic-cruise type vehicles.

  5. METHOD FOR SENSING DEGREE OF FLUIDIZATION IN FLUIDIZED BED

    DOEpatents

    Levey, R.P. Jr.; Fowler, A.H.

    1961-12-12

    A method is given for detecting, indicating, and controlling the degree of fluidization in a fluid-bed reactor into which powdered material is fed. The method comprises admitting of gas into the reactor, inserting a springsupported rod into the powder bed of the reactor, exciting the rod to vibrate at its resonant frequency, deriving a signal responsive to the amplitude of vibi-ation of the rod and spring, the signal being directiy proportional to the rate of flow of the gas through the reactor, displaying the signal to provide an indication of the degree of fluidization within the reactor, and controlling the rate of gas flow into the reactor until said signal stabilizes at a constant value to provide substantially complete fluidization within the reactor. (AEC)

  6. Shaw Air Force Base Infrastructure Project Environmental Assessment

    DTIC Science & Technology

    2008-09-01

    are the applied to the following factors depending on the corresponding years. Year 2009: VOCE = .016 * Trips NOXE = .015 * Trips PM10E...0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOXE = .013 * Trips PM10E = .0022 * Trips COE = .262 * Trips To...convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 Nox (tons/yr) = NOxE * DPYII/2000 PM10(tons/yr) = PM10E

  7. NEUTRONIC REACTOR MANIPULATING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1962-08-01

    A cable connecting a control rod in a reactor with a motor outside the reactor for moving the rod, and a helical conduit in the reactor wall, through which the cable passes are described. The helical shape of the conduit prevents the escape of certain harmful radiations from the reactor. (AEC)

  8. 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

  9. 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.

  10. 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

  11. Pm-1 Reactor Core Final Design Report

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

    Bagley, R. O.; Cox, F. H.; Carnasale, A.

    1962-01-01

    The PM-1 water cooled and moderated core contains 741 highly enriched stainless steel cermet tubular fuel elements and 90 lumped B stainless steel burnable poison elements, and it is controlled by 6 Y-shaped europium titanate movable control rods. The core has a lifetime of 1.95 years when operated at its design power level of 9.37 mw of thermal energy. The control of the core is designed so that there is a positive shutdown margin at all times with either one rod stuck completely out or the core or with two rods stuck in the operating condition. The core power ismore » removed by 2125 gpm of pressurized water at an average temperature of 463 deg F and pressure of 1300 psia. In reactors of this type, the core is stable with a negative temperature coefficient of approximately 2.5 x 10/sup -4/ DELTA K/K/ deg F.« less

  12. Trip Reports. Hazardous Waste Minimization and Control at Army Depots

    DTIC Science & Technology

    1989-08-01

    Cdcs Statement A per telecon Eric Hangeland Dist Av f CETIA-TS-D s AG, MD 21010-5401 NW 1-29-92 A-1 iii _ TABLES Number 1 Hazardous waste generation...Chief, Building 114; Major Robert Ronne; and Ken Rollins, Section Chief, Building 409. The purpose of this trip report Is to document the Information...hazardous. 6. Wf-TIM WOR Feosbility of a suitable p-etresaent f waste cuttins oil and sulleln coolant loach as 4iltratlan to remove metals. removal

  13. A novel plant protection strategy for transient reactors

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Samit K.; Lipinski, Walter C.; Hanan, Nelson A.

    The present plant protection system (PPS) has been defined for use in the TREAT-upgrade (TU) reactor for controlled transient operation of reactor-fuel behavior testing under simulated reactor-accident conditions. A PPS with energy-dependent trip set points lowered worst-case clad temperatures by as much as 180 K, relative to the use of conventional fixed-level trip set points. The multilayered multilevel protection strategy represents the state-of-the-art in terrestrial transient reactor protection systems, and should be applicable to multi-MW space reactors.

  14. 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.

  15. 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.

  16. Thermionic switched self-actuating reactor shutdown system

    DOEpatents

    Barrus, Donald M.; Shires, Charles D.; Brummond, William A.

    1989-01-01

    A self-actuating reactor shutdown system incorporating a thermionic switched electromagnetic latch arrangement which is responsive to reactor neutron flux changes and to reactor coolant temperature changes. The system is self-actuating in that the sensing thermionic device acts directly to release (scram) the control rod (absorber) without reference or signal from the main reactor plant protective and control systems. To be responsive to both temperature and neutron flux effects, two detectors are used, one responsive to reactor coolant temperatures, and the other responsive to reactor neutron flux increase. The detectors are incorporated into a thermionic diode connected electrically with an electromagnetic mechanism which under normal reactor operating conditions holds the the control rod in its ready position (exterior of the reactor core). Upon reaching either a specified temperature or neutron flux, the thermionic diode functions to short-circuit the electromagnetic mechanism causing same to lose its holding power and release the control rod, which drops into the reactor core region under gravitational force.

  17. Forest bathing enhances human natural killer activity and expression of anti-cancer proteins.

    PubMed

    Li, Q; Morimoto, K; Nakadai, A; Inagaki, H; Katsumata, M; Shimizu, T; Hirata, Y; Hirata, K; Suzuki, H; Miyazaki, Y; Kagawa, T; Koyama, Y; Ohira, T; Takayama, N; Krensky, A M; Kawada, T

    2007-01-01

    In order to explore the effect of forest bathing on human immune function, we investigated natural killer (NK) activity; the number of NK cells, and perforin, granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields. Twelve healthy male subjects, age 37-55 years, were selected with informed consent from three large companies in Tokyo, Japan. The subjects experienced a three-day/two-night trip in three different forest fields. On the first day, subjects walked for two hours in the afternoon in a forest field; and on the second day, they walked for two hours in the morning and afternoon, respectively, in two different forest fields. Blood was sampled on the second and third days, and NK activity; proportions of NK, T cells, granulysin, perforin, and granzymes A/B-expressing cells in PBL were measured. Similar measurements were made before the trip on a normal working day as the control. Almost all of the subjects (11/12) showed higher NK activity after the trip (about 50 percent increased) compared with before. There are significant differences both before and after the trip and between days 1 and 2 in NK activity. The forest bathing trip also significantly increased the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells. Taken together, these findings indicate that a forest bathing trip can increase NK activity, and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins.

  18. Environmental Assessment for the Construction of a Three-Bay Multi-Aircraft Hangar Tinker Air Force Base, Oklahoma

    DTIC Science & Technology

    2008-01-01

    Years 2005 through 2009: VOCE = .016 * Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Appendix A: Air Quality January 2008...Final EA for the Construction of a Three-Bay Multi-Aircraft Hangar Page A-9 Tinker Air Force Base, Oklahoma Years 2010 and beyond: VOCE = .012...Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE = .262 * Trips To convert from pounds per day to tons per year: VOC (tons/year) = VOCE

  19. Aspects of IVHS architecture design

    DOT National Transportation Integrated Search

    1991-09-17

    IVHS systems influence four kinds of decisions that drivers make during their trip. The : corresponding tasks that IVHS systems carry out are route and flow control, congestion : control, vehicle coordination, and spacing. A comparison of two scenari...

  20. 46 CFR 32.65-20 - Pumprooms-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... bulkhead between the pumproom and the pump-engine compartment may be pierced by fixed lights, drive shaft and pump-engine control rods, provided that the shafts and rods are fitted with stuffing boxes where... their cargo pumps isolated from all sources of vapor ignition by gastight bulkheads. Totally enclosed...

  1. 46 CFR 32.65-20 - Pumprooms-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... bulkhead between the pumproom and the pump-engine compartment may be pierced by fixed lights, drive shaft and pump-engine control rods, provided that the shafts and rods are fitted with stuffing boxes where... their cargo pumps isolated from all sources of vapor ignition by gastight bulkheads. Totally enclosed...

  2. 46 CFR 32.65-20 - Pumprooms-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... bulkhead between the pumproom and the pump-engine compartment may be pierced by fixed lights, drive shaft and pump-engine control rods, provided that the shafts and rods are fitted with stuffing boxes where... their cargo pumps isolated from all sources of vapor ignition by gastight bulkheads. Totally enclosed...

  3. 46 CFR 32.65-20 - Pumprooms-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... bulkhead between the pumproom and the pump-engine compartment may be pierced by fixed lights, drive shaft and pump-engine control rods, provided that the shafts and rods are fitted with stuffing boxes where... their cargo pumps isolated from all sources of vapor ignition by gastight bulkheads. Totally enclosed...

  4. 46 CFR 32.65-20 - Pumprooms-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... bulkhead between the pumproom and the pump-engine compartment may be pierced by fixed lights, drive shaft and pump-engine control rods, provided that the shafts and rods are fitted with stuffing boxes where... their cargo pumps isolated from all sources of vapor ignition by gastight bulkheads. Totally enclosed...

  5. 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

  6. 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 increases during a time course of tens of seconds, gradually extending the operating range of the rod. In Rv-/- rods, this mechanism is also deleted, steady-state currents are already larger and rods saturate at brighter intensities. We argue that neither (i) nor (ii) can be caused by modulation of rhodopsin phosphorylation but may instead be produced by direct modulation of phophodiesterase-6 (PDE6), the phototransduction effector enzyme. We propose that recoverin in dark-adapted rods keeps the integration time long and the spontaneous PDE6 rate relatively high to improve sensitivity. In background light, the integration time is decreased to facilitate detection of change and motion and the spontaneous PDE6 rate decreases to augment the rod working range. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

  7. Multi-destination trip patterns

    Treesearch

    Susan I. Stewart; Christine A. Vogt

    1996-01-01

    In a 1993 article in Annals, Leu, Crompton, and Fesenmaier (LCF) presented a model of multi-destination pleasure trips. In the article, they question the practice of modeling pleasure trips as single destination trips, and put forward conceptual arguments suggesting that most trips "are not simple origin-destination trips: (1993:291) but...

  8. Revised Final Environmental Review for the Construction of a New Base Exchange at Kadena Air Base, Okinawa, Japan

    DTIC Science & Technology

    2007-05-01

    factors depending on the corresponding years. Year 2005 through 2009: VOCE = .016 * Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262...Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE = .262 * Trips To convert from pounds per day to...tons per year: VOC (tons/yr) = VOCE * DPYII/2000 Nox (tons/yr) = NOxE * DPYII/2000 PM10(tons/yr) = PM10E * DPYII/2000 CO (tons/yr) = COE * DPYII

  9. Navy Explosive Ordnance Disposal School Master Development Plan for Test Area D-51, Eglin Air Force Base, Florida

    DTIC Science & Technology

    2008-01-25

    depending on the corresponding years. Year 2005 through 2009: VOCE = .016 * Trips NOxE = .015 * Trips PM10E = .0022 * Trips COE = .262 * Trips Year...2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE = .262 * Trips To convert from pounds per day to tons per year...VOC (tons/yr) = VOCE * DPYII/2000 NOx (tons/yr) = NOxE * DPYII/2000 PM10 (tons/yr) = PM10E * DPYII/2000 CO (tons/yr) = COE * DPYII/2000

  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. Clip gage attachment for frictionless measurement of displacement during high-temperature mechanical testing

    DOEpatents

    Alexander, David J.

    1994-01-01

    An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical.

  12. 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.

  13. Single-Mode WGM Resonators Fabricated by Diamond Turning

    NASA Technical Reports Server (NTRS)

    Grudinin, Ivan; Maleki, Lute; Savchenkov, Anatoliy; Matsko, Andrewy; Strekalov, Dmitry; Iltchenko, Vladimir

    2008-01-01

    A diamond turning process has made possible a significant advance in the art of whispering-gallery-mode (WGM) optical resonators. By use of this process, it is possible to fashion crystalline materials into WGM resonators that have ultrahigh resonance quality factors (high Q values), are compact (ranging in size from millimeters down to tens of microns), and support single electromagnetic modes. This development combines and extends the developments reported in "Few- Mode Whispering-Gallery-Mode Resonators" (NPO-41256), NASA Tech Briefs, Vol. 30, No. 1 (January 2006), page 16a and "Fabrication of Submillimeter Axisymmetric Optical Components" (NPO-42056), NASA Tech Briefs, Vol. 31, No. 5 (May 2007), page 10a. To recapitulate from the first cited prior article: A WGM resonator of this special type consists of a rod, made of a suitable transparent material, from which protrudes a thin circumferential belt of the same material. The belt is integral with the rest of the rod and acts as a circumferential waveguide. If the depth and width of the belt are made appropriately small, then the belt acts as though it were the core of a single-mode optical fiber: the belt and the rod material adjacent to it support a single, circumferentially propagating mode or family of modes. To recapitulate from the second cited prior article: A major step in the fabrication of a WGM resonator of this special type is diamond turning or computer numerically controlled machining of a rod of a suitable transparent crystalline material on an ultrahigh-precision lathe. During the rotation of a spindle in which the rod is mounted, a diamond tool is used to cut the rod. A computer program is used to control stepping motors that move the diamond tool, thereby controlling the shape cut by the tool. Because the shape can be controlled via software, it is possible to choose a shape designed to optimize a resonator spectrum, including, if desired, to limit the resonator to supporting a single mode. After diamond turning, a resonator can be polished to increase its Q. By virtue of its largely automated, computer-controlled nature, the process is suitable for mass production of nominally identical single-mode WGM resonators. In a demonstration of the capabilities afforded by this development, a number of WGM resonators of various designs were fabricated side by side on the surface of a single CaF2 rod (see figure).

  14. The influence of artificially increased trunk stiffness on the balance recovery after a trip.

    PubMed

    van der Burg, J C E; Pijnappels, M; van Dieën, J H

    2007-07-01

    Falls occur frequently in the growing population of elderly. Since trunk control is critical for maintaining balance, the higher trunk stiffness in elderly people compared to the general population has been associated with their increased fall-risk. Theoretically, trunk stiffness may be beneficial for balance recovery in walking, i.e. after a trip. A stiff joint may provide a torque that restricts the perturbation effects and thereby reduces the probability of a fall. The aim of this study was to test whether trunk stiffness impaired or assisted balance recovery after a trip during walking. An orthopedic corset was used to simulate trunk stiffness in 11 young male adults. Subjects walked over a platform, with or without the corset on, and were occasionally tripped over a hidden obstacle. Kinematics of the tripping reaction were measured. Initial trunk accelerations were significantly attenuated by the corset, which indicates a positive effect of the stiffening corset. However, no subsequent effects on peak trunk inclination and on the peak moment arm of gravity on the trunk were found. The pattern of trunk motion allowed ample time for triggered or voluntary muscle responses to be generated, before a substantial inclination occurred. It appears that such active responses were sufficient in the young subjects tested to obtain a similar net effect with or without the increased trunk stiffness induced by the corset.

  15. Walk Score, Transportation Mode Choice, and Walking Among French Adults: A GPS, Accelerometer, and Mobility Survey Study.

    PubMed

    Duncan, Dustin T; Méline, Julie; Kestens, Yan; Day, Kristen; Elbel, Brian; Trasande, Leonardo; Chaix, Basile

    2016-06-20

    Few studies have used GPS data to analyze the relationship between Walk Score, transportation choice and walking. Additionally, the influence of Walk Score is understudied using trips rather than individuals as statistical units. The purpose of this study is to examine associations at the trip level between Walk Score, transportation mode choice, and walking among Paris adults who were tracked with GPS receivers and accelerometers in the RECORD GPS Study. In the RECORD GPS Study, 227 participants were tracked during seven days with GPS receivers and accelerometers. Participants were also surveyed with a GPS-based web mapping application on their activities and transportation modes for all trips (6969 trips). Walk Score, which calculates neighborhood walkability, was assessed for each origin and destination of every trip. Multilevel logistic and linear regression analyses were conducted to estimate associations between Walk Score and walking in the trip or accelerometry-assessed number of steps for each trip, after adjustment for individual/neighborhood characteristics. The mean overall Walk Scores for trip origins were 87.1 (SD = 14.4) and for trip destinations 87.1 (SD = 14.5). In adjusted trip-level associations between Walk Score and walking only in the trip, we found that a walkable neighborhood in the trip origin and trip destination was associated with increased odds of walking in the trip assessed in the survey. The odds of only walking in the trip were 3.48 (95% CI: 2.73 to 4.44) times higher when the Walk Score for the trip origin was "Walker's Paradise" compared to less walkable neighborhoods (Very/Car-Dependent or Somewhat Walkable), with an identical independent effect of trip destination Walk Score on walking. The number of steps per 10 min (as assessed with accelerometry) was cumulatively higher for trips both originating and ending in walkable neighborhoods (i.e., "Very Walkable"). Walkable neighborhoods were associated with increases in walking among adults in Paris, as documented at the trip level. Creating walkable neighborhoods (through neighborhood design increased commercial activity) may increase walking trips and, therefore, could be a relevant health promotion strategy to increase physical activity.

  16. Walk Score, Transportation Mode Choice, and Walking Among French Adults: A GPS, Accelerometer, and Mobility Survey Study

    PubMed Central

    Duncan, Dustin T.; Méline, Julie; Kestens, Yan; Day, Kristen; Elbel, Brian; Trasande, Leonardo; Chaix, Basile

    2016-01-01

    Background: Few studies have used GPS data to analyze the relationship between Walk Score, transportation choice and walking. Additionally, the influence of Walk Score is understudied using trips rather than individuals as statistical units. The purpose of this study is to examine associations at the trip level between Walk Score, transportation mode choice, and walking among Paris adults who were tracked with GPS receivers and accelerometers in the RECORD GPS Study. Methods: In the RECORD GPS Study, 227 participants were tracked during seven days with GPS receivers and accelerometers. Participants were also surveyed with a GPS-based web mapping application on their activities and transportation modes for all trips (6969 trips). Walk Score, which calculates neighborhood walkability, was assessed for each origin and destination of every trip. Multilevel logistic and linear regression analyses were conducted to estimate associations between Walk Score and walking in the trip or accelerometry-assessed number of steps for each trip, after adjustment for individual/neighborhood characteristics. Results: The mean overall Walk Scores for trip origins were 87.1 (SD = 14.4) and for trip destinations 87.1 (SD = 14.5). In adjusted trip-level associations between Walk Score and walking only in the trip, we found that a walkable neighborhood in the trip origin and trip destination was associated with increased odds of walking in the trip assessed in the survey. The odds of only walking in the trip were 3.48 (95% CI: 2.73 to 4.44) times higher when the Walk Score for the trip origin was “Walker’s Paradise” compared to less walkable neighborhoods (Very/Car-Dependent or Somewhat Walkable), with an identical independent effect of trip destination Walk Score on walking. The number of steps per 10 min (as assessed with accelerometry) was cumulatively higher for trips both originating and ending in walkable neighborhoods (i.e., “Very Walkable”). Conclusions: Walkable neighborhoods were associated with increases in walking among adults in Paris, as documented at the trip level. Creating walkable neighborhoods (through neighborhood design increased commercial activity) may increase walking trips and, therefore, could be a relevant health promotion strategy to increase physical activity. PMID:27331818

  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. 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.

  1. High frequency magnetostrictive transducers for waveguide applications

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

    Daw, Joshua Earl; Taylor, Steven Cheney; Rempe, Joy Lynn

    A high frequency magnetostrictive transducer includes a magnetostrictive rod or wire inserted co-axially into a driving coil, wherein the driving coil includes a coil arrangement with a plurality of small coil segments along the magnetostrictive rod or wire; wherein frequency operation of the high frequency magnetostrictive transducer is controlled by a length of the small coil segments and a material type of the magnetostrictive rod or wire. This design of the high frequency magnetostrictive transducer retains the beneficial aspects of the magnetostrictive design, while reducing its primary drawback, lower frequency operation.

  2. Report: EPA Travel Program Lacks Necessary Controls

    EPA Pesticide Factsheets

    Report #10-P-0078, March 9, 2010. The EPA travel program, which comprises EPA policies and GovTrip, lacks necessary control procedures to assure all travel authorizations were necessary and in the best interest of the government.

  3. Building a Community of Experience.

    ERIC Educational Resources Information Center

    Matthews, Kelly

    2002-01-01

    Discusses how field trips can build a community of experience in preschool settings. Focuses on what to consider when planning field trips, how to reduce field trip costs, adjustments to be made during the trip, and ways to bring the trip to the preschool setting. Suggests activities after the field trip, and destinations related to the arts,…

  4. Older adults who have previously fallen due to a trip walk differently than those who have fallen due to a slip.

    PubMed

    Wright, Rachel L; Peters, Derek M; Robinson, Paul D; Watt, Thomas N; Hollands, Mark A

    2015-01-01

    Studying the relationships between centre of mass (COM) and centre of pressure (COP) during walking has been shown to be useful in determining movement stability. The aim of the current study was to compare COM-COP separation measures during walking between groups of older adults with no history of falling, and a history of falling due to tripping or slipping. Any differences between individuals who have fallen due to a slip and those who have fallen due to a trip in measures of dynamic balance could potentially indicate differences in the mechanisms responsible for falls. Forty older adults were allocated into groups based on their self-reported fall history during walking. The non-faller group had not experienced a fall in at least the previous year. Participants who had experienced a fall were split into two groups based on whether a trip or slip resulted in the fall(s). A Vicon system was used to collect full body kinematic trajectories. Two force platforms were used to measure ground reaction forces. The COM was significantly further ahead of the COP at heel strike for the trip (14.3 ± 2.7 cm) and slip (15.3 ± 1.1 cm) groups compared to the non-fallers (12.0 ± 2.7 cm). COM was significantly further behind the COP at foot flat for the slip group (-14.9 ± 3.6 cm) compared to the non-fallers (-10.3 ± 3.9 cm). At mid-swing, the COM of the trip group was ahead of the COP (0.9 ± 1.6 cm), whereas for the slip group the COM was behind the COP (-1.2 ± 2.2 cm). These results show identifiable differences in dynamic balance control of walking between older adults with a history of tripping or slipping and non-fallers. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Security, protection, and control of power systems with large-scale wind power penetration

    NASA Astrophysics Data System (ADS)

    Acharya, Naresh

    As the number of wind generation facilities in the utility system is fast increasing, many issues associated with their integration into the power system are beginning to emerge. Of the various issues, this dissertation deals with the development of new concepts and computational methods to handle the transmission issues and voltage issues caused by large-scale integration of wind turbines. This dissertation also formulates a probabilistic framework for the steady-state security assessment of wind power incorporating the forecast uncertainty and correlation. Transmission issues are mainly related to the overloading of transmission lines, when all the wind power generated cannot be delivered in full due to prior outage conditions. To deal with this problem, a method to curtail the wind turbine outputs through Energy Management System facilities in the on-line operational environment is proposed. The proposed method, which is based on linear optimization, sends the calculated control signals via the Supervisory Control and Data Acquisition system to wind farm controllers. The necessary ramping of the wind farm outputs is implemented either by the appropriate blade pitch angle control at the turbine level or by switching a certain number of turbines. The curtailment strategy is tested with an equivalent system model of MidAmerican Energy Company. The results show that the line overload in high wind areas can be alleviated by controlling the outputs of the wind farms step-by-step over an allowable period of time. A low voltage event during a system fault can cause a large number of wind turbines to trip, depending on voltages at the wind turbine terminals during the fault and the under-voltage protection setting of wind turbines. As a result, an N-1 contingency may evolve into an N-(K+1) contingency, where K is the number of wind farms tripped due to low voltage conditions. Losing a large amount of wind power following a line contingency might lead to system instabilities. It is important for the system operator to be aware of such limiting events during system operation and be prepared to take proper control actions. This can be achieved by incorporating the wind farm tripping status for each contingency as part of the static security assessment. A methodology to calculate voltages at the wind farm buses during a worst case line fault is proposed, which, along with the protection settings of wind turbines, can be used to determine the tripping of wind farms. The proposed algorithm is implemented in MATLAB and tested with MidAmerican Energy reduced network. The result shows that a large amount of wind capacity can be tripped due to a fault in the lines. Therefore, the technique will find its application in the static security assessment where each line fault can be associated with the tripping of wind farms as determined from the proposed method. A probabilistic framework to handle the uncertainty in day-ahead forecast error in order to correctly assess the steady-state security of the power system is presented. Stochastic simulations are conducted by means of Latin hypercube sampling along with the consideration of correlations. The correlation is calculated from the historical distribution of wind power forecast errors. The results from the deterministic simulation based on point forecast and the stochastic simulation show that security assessment based solely on deterministic simulations can lead to incorrect assessment of system security. With stochastic simulations, each outcome can be assigned a probability and the decision regarding control actions can be made based on the associated probability.

  6. 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

  7. 26 CFR 49.4264(e)-1 - Round trips.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... two separate trips, i.e., one trip from the point of departure to the destination and a second trip in... followed on the return trip from the destination to the point of departure as was taken on the going trip... destination but with one or more intermediate stops en route) the point farthest from the point of departure...

  8. Implementation of an unmanned aerial vehicle for new generation Peterbilt trucks

    NASA Astrophysics Data System (ADS)

    Srinivasan K, Venkatesh

    As science and technology continue to advance, innovative developments in transportation can enhance product safety and security for the benefit and welfare of society. The federal government requires every commercial truck to be inspected before each trip. This pre-trip inspection ensures the safe mechanical condition of each vehicle before it is used. An Unmanned Aerial Vehicle (UAV) could be used to provide an automated inspection, thus reducing driver workload, inspection costs and time while increasing inspection accuracy. This thesis develops a primary component of the algorithm that is required to implement UAV pre-trip inspections for commercial trucks using an android-based application. Specifically, this thesis provides foundational work of providing stable height control in an outdoor environment using a laser sensor and an android flight control application that includes take-off, landing, throttle control, and real-time video transmission. The height algorithm developed is the core of this thesis project. Phantom 2 Vision+ uses a pressure sensor to calculate the altitude of the drone for height stabilization. However, these altitude readings do not provide the precision required for this project. Rather, the goal of autonomously controlling height with great precision necessitated the use of a laser rangefinder sensor in the development of the height control algorithm. Another major contribution from this thesis research is to extend the limited capabilities of the DJI software development kit in order to provide more sophisticated control goals without modifying the drone dynamics. The results of this project are also directly applicable to a number of additional uses of drones in the transportation industry.

  9. Questionnaire-based person trip visualization and its integration to quantitative measurements in Myanmar

    NASA Astrophysics Data System (ADS)

    Kimijiama, S.; Nagai, M.

    2016-06-01

    With telecommunication development in Myanmar, person trip survey is supposed to shift from conversational questionnaire to GPS survey. Integration of both historical questionnaire data to GPS survey and visualizing them are very important to evaluate chronological trip changes with socio-economic and environmental events. The objectives of this paper are to: (a) visualize questionnaire-based person trip data, (b) compare the errors between questionnaire and GPS data sets with respect to sex and age and (c) assess the trip behaviour in time-series. Totally, 345 individual respondents were selected through random stratification to assess person trip using a questionnaire and GPS survey for each. Conversion of trip information such as a destination from the questionnaires was conducted by using GIS. The results show that errors between the two data sets in the number of trips, total trip distance and total trip duration are 25.5%, 33.2% and 37.2%, respectively. The smaller errors are found among working-age females mainly employed with the project-related activities generated by foreign investment. The trip distant was yearly increased. The study concluded that visualization of questionnaire-based person trip data and integrating them to current quantitative measurements are very useful to explore historical trip changes and understand impacts from socio-economic events.

  10. Variable gas leak rate valve

    DOEpatents

    Eernisse, Errol P.; Peterson, Gary D.

    1976-01-01

    A variable gas leak rate valve which utilizes a poled piezoelectric element to control opening and closing of the valve. The gas flow may be around a cylindrical rod with a tubular piezoelectric member encircling the rod for seating thereagainst to block passage of gas and for reopening thereof upon application of suitable electrical fields.

  11. Inhibitory masking controls the threshold sensitivity of retinal ganglion cells

    PubMed Central

    Pan, Feng; Toychiev, Abduqodir; Zhang, Yi; Atlasz, Tamas; Ramakrishnan, Hariharasubramanian; Roy, Kaushambi; Völgyi, Béla; Akopian, Abram

    2016-01-01

    Key points Retinal ganglion cells (RGCs) in dark‐adapted retinas show a range of threshold sensitivities spanning ∼3 log units of illuminance.Here, we show that the different threshold sensitivities of RGCs reflect an inhibitory mechanism that masks inputs from certain rod pathways.The masking inhibition is subserved by GABAC receptors, probably on bipolar cell axon terminals.The GABAergic masking inhibition appears independent of dopaminergic circuitry that has been shown also to affect RGC sensitivity.The results indicate a novel mechanism whereby inhibition controls the sensitivity of different cohorts of RGCs. This can limit and thereby ensure that appropriate signals are carried centrally in scotopic conditions when sensitivity rather than acuity is crucial. Abstract The responses of rod photoreceptors, which subserve dim light vision, are carried through the retina by three independent pathways. These pathways carry signals with largely different sensitivities. Retinal ganglion cells (RGCs), the output neurons of the retina, show a wide range of sensitivities in the same dark‐adapted conditions, suggesting a divergence of the rod pathways. However, this organization is not supported by the known synaptic morphology of the retina. Here, we tested an alternative idea that the rod pathways converge onto single RGCs, but inhibitory circuits selectively mask signals so that one pathway predominates. Indeed, we found that application of GABA receptor blockers increased the sensitivity of most RGCs by unmasking rod signals, which were suppressed. Our results indicate that inhibition controls the threshold responses of RGCs under dim ambient light. This mechanism can ensure that appropriate signals cross the bottleneck of the optic nerve in changing stimulus conditions. PMID:27350405

  12. 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 © 2011 Elsevier Ltd. All rights reserved.

  13. Microstructure Evolution and Mechanical Behavior of a Hot-Rolled High-Manganese Dual-Phase Transformation-Induced Plasticity/Twinning-Induced Plasticity Steel

    NASA Astrophysics Data System (ADS)

    Fu, Liming; Shan, Mokun; Zhang, Daoda; Wang, Huanrong; Wang, Wei; Shan, Aidang

    2017-05-01

    The microstructures and deformation behavior were studied in a high-temperature annealed high-manganese dual-phase (28 vol pct δ-ferrite and 72 vol pct γ-austenite) transformation-induced plasticity/twinning-induced plasticity (TRIP/TWIP) steel. The results showed that the steel exhibits a special Lüders-like yielding phenomenon at room temperature (RT) and 348 K (75 °C), while it shows continuous yielding at 423 K, 573 K and 673 K (150 °C, 300 °C and 400 °C) deformation. A significant TRIP effect takes place during Lüders-like deformation at RT and 348 K (75 °C) temperatures. Semiquantitative analysis of the TRIP effect on the Lüders-like yield phenomenon proves that a softening effect of the strain energy consumption of strain-induced transformation is mainly responsible for this Lüders-like phenomenon. The TWIP mechanism dominates the 423 K (150 °C) deformation process, while the dislocation glide controls the plasticity at 573 K (300 °C) deformation. The delta-ferrite, as a hard phase in annealed dual-phase steel, greatly affects the mechanical stability of austenite due to the heterogeneous strain distribution between the two phases during deformation. A delta-ferrite-aided TRIP effect, i.e., martensite transformation induced by localized strain concentration of the hard delta-ferrite, is proposed to explain this kind of Lüders-like phenomenon. Moreover, the tensile curve at RT exhibits an upward curved behavior in the middle deformation stage, which is principally attributed to the deformation twinning of austenite retained after Lüders-like deformation. The combination of the TRIP effect during Lüders-like deformation and the subsequent TWIP effect greatly enhances the ductility in this annealed high-manganese dual-phase TRIP/TWIP steel.

  14. 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.

  15. 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

  16. The MAGEC system for spinal lengthening in children with scoliosis: A NICE Medical Technology Guidance.

    PubMed

    Jenks, Michelle; Craig, Joyce; Higgins, Joanne; Willits, Iain; Barata, Teresa; Wood, Hannah; Kimpton, Christine; Sims, Andrew

    2014-12-01

    Scoliosis-structural lateral curvature of the spine-affects around four children per 1,000. The MAGEC system comprises a magnetically distractible spinal rod implant and an external remote controller, which lengthens the rod; this system avoids repeated surgical lengthening. Rod implants brace the spine internally and are lengthened as the child grows, preventing worsening of scoliosis and delaying the need for spinal fusion. The Medical Technologies Advisory Committee at the National Institute for Health and Care Excellence (NICE) selected the MAGEC system for evaluation in a NICE medical technologies guidance. Six studies were identified by the sponsor (Ellipse Technologies Inc.) as being relevant to the decision problem. Meta-analysis was used to compare the clinical evidence results with those of one conventional growth rod study, and equal efficacy of the two devices was concluded. The key weakness was selection of a single comparator study. The External Assessment Centre (EAC) identified 16 conventional growth rod studies and undertook meta-analyses of relevant outcomes. Its critique highlighted limitations around study heterogeneity and variations in baseline characteristics and follow-up duration, precluding the ability to draw firm conclusions. The sponsor constructed a de novo costing model showing that MAGEC rods generated cost savings of £9,946 per patient after 6 years, compared with conventional rods. The EAC critiqued and updated the model structure and inputs, calculating robust cost savings of £12,077 per patient with MAGEC rods compared with conventional rods over 6 years. The year of valuation was 2012. NICE issued a positive recommendation as supported by the evidence (Medical Technologies Guidance 18).

  17. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  18. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1998-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  19. Internal trip capture estimator for mixed-use developments.

    DOT National Transportation Integrated Search

    2007-12-01

    This report describes a spreadsheet tool for estimating trip generation for mixed-use developments, : accounting for internal trip capture. Internal trip capture is the portion of trips generated by a mixed-use : development that both begin and end w...

  20. Final Environmental Assessment: To Relocate Air Force Explosive Ordnance Disposal Administrative Complex at Eglin Air Force Base

    DTIC Science & Technology

    2006-10-01

    Trips PM10E = .0022 * Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE...Air Force Base, Florida To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000 NOx (tons/yr) = NOxE * DPYII/2000

  1. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... against unintentional operation and have the individual operator's hand controls arranged by design and... trip the press. (b) The control system shall be designed to permit an adjustment which will require... shall incorporate an antirepeat feature. (d) The control systems shall be designed to require release of...

  2. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... against unintentional operation and have the individual operator's hand controls arranged by design and... trip the press. (b) The control system shall be designed to permit an adjustment which will require... shall incorporate an antirepeat feature. (d) The control systems shall be designed to require release of...

  3. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... against unintentional operation and have the individual operator's hand controls arranged by design and... trip the press. (b) The control system shall be designed to permit an adjustment which will require... shall incorporate an antirepeat feature. (d) The control systems shall be designed to require release of...

  4. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... against unintentional operation and have the individual operator's hand controls arranged by design and... trip the press. (b) The control system shall be designed to permit an adjustment which will require... shall incorporate an antirepeat feature. (d) The control systems shall be designed to require release of...

  5. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... against unintentional operation and have the individual operator's hand controls arranged by design and... trip the press. (b) The control system shall be designed to permit an adjustment which will require... shall incorporate an antirepeat feature. (d) The control systems shall be designed to require release of...

  6. The sex and age of older adults influence the outcome of induced trips.

    PubMed

    Pavol, M J; Owings, T M; Foley, K T; Grabiner, M D

    1999-02-01

    Falls are a significant source of morbidity and mortality in older adults, with up to 53% of these falls due to tripping. To aid in fall prevention, there is a need to identify the factors that determine whether a trip is recoverable and those factors that increase an older adult's risk of falling. Trips were induced during gait in 79 healthy, community-dwelling, safety-harnessed older adults (50 women) using a concealed, mechanical obstacle. Trip outcomes were graded as recoveries, falls, rope-assists, or misses. Kinematics were recorded during normal gait, without and with the safety harness. Selected gait parameters were compared to determine whether the experimental conditions affected gait at the time of the trip. Thirty-nine trip outcomes were classified as recoveries, 10 as falls, 12 as rope-assists, and 18 as misses. Women fell more than four times as frequently as men. Women younger than 70 years fell more than three times as frequently as those older. Trip outcomes in the men were essentially unaffected by age. The foot obstructed to induce the trip did not affect the trip outcome. The presence of the safety harness had almost no effect on gait. The length of the stride preceding the trip did not differ from normal. The majority of trips in healthy older adults did not result in falls. Older women were more likely than men to fall following a trip. The likelihood of falling from a trip was greatest in the youngest older women.

  7. Combining Telephone Surveys and Fishing Catches Self-Report: The French Sea Bass Recreational Fishery Assessment

    PubMed Central

    Rocklin, Delphine; Levrel, Harold; Drogou, Mickaël; Herfaut, Johanna; Veron, Gérard

    2014-01-01

    Fisheries statistics are known to be underestimated, since they are mainly based on information about commercial fisheries. However, various types of fishing activities exist and evaluating them is necessary for implementing effective management plans. This paper assesses the characteristics and catches of the French European sea bass recreational fishery along the Atlantic coasts, through the combination of large-scale telephone surveys and fishing diaries study. Our results demonstrated that half of the total catches (mainly small fish) were released at sea and that the mean length of a kept sea bass was 46.6 cm. We highlighted different patterns of fishing methods and type of gear used. Catches from boats were greater than from the shore, both in abundance and biomass, considering mean values per fishing trip as well as CPUE. Spearfishers caught the highest biomass of sea bass per fishing trip, but the fishing rod with lure was the most effective type of gear in terms of CPUE. Longlines had the highest CPUE value in abundance but not in biomass: they caught numerous but small sea bass. Handlines were less effective, catching few sea bass in both abundance and biomass. We estimated that the annual total recreational sea bass catches was 3,173 tonnes of which 2,345 tonnes were kept. Since the annual commercial catches landings were evaluated at 5,160 tonnes, recreational landings represent 30% of the total fishing catches on the Atlantic coasts of France. Using fishers' self-reports was a valuable way to obtain new information on data-poor fisheries. Our results underline the importance of evaluating recreational fishing as a part of the total amount of fisheries catches. More studies are critically needed to assess overall fish resources caught in order to develop effective fishery management tools. PMID:24489885

  8. Combining telephone surveys and fishing catches self-report: the French sea bass recreational fishery assessment.

    PubMed

    Rocklin, Delphine; Levrel, Harold; Drogou, Mickaël; Herfaut, Johanna; Veron, Gérard

    2014-01-01

    Fisheries statistics are known to be underestimated, since they are mainly based on information about commercial fisheries. However, various types of fishing activities exist and evaluating them is necessary for implementing effective management plans. This paper assesses the characteristics and catches of the French European sea bass recreational fishery along the Atlantic coasts, through the combination of large-scale telephone surveys and fishing diaries study. Our results demonstrated that half of the total catches (mainly small fish) were released at sea and that the mean length of a kept sea bass was 46.6 cm. We highlighted different patterns of fishing methods and type of gear used. Catches from boats were greater than from the shore, both in abundance and biomass, considering mean values per fishing trip as well as CPUE. Spearfishers caught the highest biomass of sea bass per fishing trip, but the fishing rod with lure was the most effective type of gear in terms of CPUE. Longlines had the highest CPUE value in abundance but not in biomass: they caught numerous but small sea bass. Handlines were less effective, catching few sea bass in both abundance and biomass. We estimated that the annual total recreational sea bass catches was 3,173 tonnes of which 2,345 tonnes were kept. Since the annual commercial catches landings were evaluated at 5,160 tonnes, recreational landings represent 30% of the total fishing catches on the Atlantic coasts of France. Using fishers' self-reports was a valuable way to obtain new information on data-poor fisheries. Our results underline the importance of evaluating recreational fishing as a part of the total amount of fisheries catches. More studies are critically needed to assess overall fish resources caught in order to develop effective fishery management tools.

  9. Clip gage attachment for frictionless measurement of displacement during high-temperature mechanical testing

    DOEpatents

    Alexander, D.J.

    1994-01-04

    An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature is described. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical. 1 figure.

  10. Study of feasibility of solid-state electric switch gear for aircraft and spacecraft

    NASA Technical Reports Server (NTRS)

    Buchanan, E.; Waddington, D.

    1973-01-01

    The design of a solid-state circuit breaker that can be interconnected to a second breaker to form a transfer switch is presented. The breaker operates on a nominal 270-V dc circuit and controls power to loads of up to 15 A. Automatic overload trip is provided as a function of excess energy measured through the breaker and/or excess current through the breaker. After an overload trip, up to nine preprogrammable attempts to reclose may be tried with programmable delays between each attempt. The breaker or switch is remotely controllable. Test data on performance in the laboratory over temperatures from -45 to 100 C are provided. The feasibility of solid-state switch gear has been established.

  11. Back Propagation Artificial Neural Network and Its Application in Fault Detection of Condenser Failure in Thermo Plant

    NASA Astrophysics Data System (ADS)

    Ismail, Firas B.; Thiruchelvam, Vinesh

    2013-06-01

    Steam condenser is one of the most important equipment in steam power plants. If the steam condenser trips it may lead to whole unit shutdown, which is economically burdensome. Early condenser trips monitoring is crucial to maintain normal and safe operational conditions. In the present work, artificial intelligent monitoring systems specialized in condenser outages has been proposed and coded within the MATLAB environment. The training and validation of the system has been performed using real operational measurements captured from the control system of selected steam power plant. An integrated plant data preparation scheme for condenser outages with related operational variables has been proposed. Condenser outages under consideration have been detected by developed system before the plant control system"

  12. Investigation of the cross-ship comparison monitoring method of failure detection in the HIMAT RPRV. [digital control techniques using airborne microprocessors

    NASA Technical Reports Server (NTRS)

    Wolf, J. A.

    1978-01-01

    The Highly maneuverable aircraft technology (HIMAT) remotely piloted research vehicle (RPRV) uses cross-ship comparison monitoring of the actuator RAM positions to detect a failure in the aileron, canard, and elevator control surface servosystems. Some possible sources of nuisance trips for this failure detection technique are analyzed. A FORTRAN model of the simplex servosystems and the failure detection technique were utilized to provide a convenient means of changing parameters and introducing system noise. The sensitivity of the technique to differences between servosystems and operating conditions was determined. The cross-ship comparison monitoring method presently appears to be marginal in its capability to detect an actual failure and to withstand nuisance trips.

  13. 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.

  14. 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.

  15. Evaluation of anticipatory signal to steam generator pressure control program for 700 MWe Indian pressurized heavy water reactor

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

    Pahari, S.; Hajela, S.; Rammohan, H. P.

    2012-07-01

    700 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is horizontal channel type reactor with partial boiling at channel outlet. Due to boiling, it has a large volume of vapor present in the primary loops. It has two primary loops connected with the help of pressurizer surge line. The pressurizer has a large capacity and is partly filled by liquid and partly by vapor. Large vapor volume improves compressibility of the system. During turbine trip or load rejection, pressure builds up in Steam Generator (SG). This leads to pressurization of Primary Heat Transport System (PHTS). To control pressurization of SG andmore » PHTS, around 70% of the steam generated in SG is dumped into the condenser by opening Condenser Steam Dump Valves (CSDVs) and rest of the steam is released to the atmosphere by opening Atmospheric Steam Discharge Valves (ASDVs) immediately after sensing the event. This is accomplished by adding anticipatory signal to the output of SG pressure controller. Anticipatory signal is proportional to the thermal power of reactor and the proportionality constant is set so that SG pressure controller's output jacks up to ASDV opening range when operating at 100% FP. To simulate this behavior for 700 MWe IPHWR, Primary and secondary heat transport system is modeled. SG pressure control and other process control program have also been modeled to capture overall plant dynamics. Analysis has been carried out with 3-D neutron kinetics coupled thermal hydraulic computer code ATMIKA.T to evaluate the effect of the anticipatory signal on PHT pressure and over all plant dynamics during turbine trip in 700 MWe IPHWR. This paper brings out the results of the analysis with and without considering anticipatory signal in SG pressure control program during turbine trip. (authors)« less

  16. Nonlinear stability research on the hydraulic system of double-side rolling shear.

    PubMed

    Wang, Jun; Huang, Qingxue; An, Gaocheng; Qi, Qisong; Sun, Binyu

    2015-10-01

    This paper researches the stability of the nonlinear system taking the hydraulic system of double-side rolling shear as an example. The hydraulic system of double-side rolling shear uses unsymmetrical electro-hydraulic proportional servo valve to control the cylinder with single piston rod, which can make best use of the space and reduce reversing shock. It is a typical nonlinear structure. The nonlinear state-space equations of the unsymmetrical valve controlling cylinder system are built first, and the second Lyapunov method is used to evaluate its stability. Second, the software AMEsim is applied to simulate the nonlinear system, and the results indicate that the system is stable. At last, the experimental results show that the system unsymmetrical valve controlling the cylinder with single piston rod is stable and conforms to what is deduced by theoretical analysis and simulation. The construction and application of Lyapunov function not only provide the theoretical basis for using of unsymmetrical valve controlling cylinder with single piston rod but also develop a new thought for nonlinear stability evaluation.

  17. Nonlinear stability research on the hydraulic system of double-side rolling shear

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Huang, Qingxue; An, Gaocheng; Qi, Qisong; Sun, Binyu

    2015-10-01

    This paper researches the stability of the nonlinear system taking the hydraulic system of double-side rolling shear as an example. The hydraulic system of double-side rolling shear uses unsymmetrical electro-hydraulic proportional servo valve to control the cylinder with single piston rod, which can make best use of the space and reduce reversing shock. It is a typical nonlinear structure. The nonlinear state-space equations of the unsymmetrical valve controlling cylinder system are built first, and the second Lyapunov method is used to evaluate its stability. Second, the software AMEsim is applied to simulate the nonlinear system, and the results indicate that the system is stable. At last, the experimental results show that the system unsymmetrical valve controlling the cylinder with single piston rod is stable and conforms to what is deduced by theoretical analysis and simulation. The construction and application of Lyapunov function not only provide the theoretical basis for using of unsymmetrical valve controlling cylinder with single piston rod but also develop a new thought for nonlinear stability evaluation.

  18. 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

  19. A Preliminary Model for Spacecraft Propulsion Performance Analysis Based on Nuclear Gain and Subsystem Mass-Power Balances

    NASA Technical Reports Server (NTRS)

    Chakrabarti, Suman; Schmidt, George R.; Thio, Y. C.; Hurst, Chantelle M.

    1999-01-01

    A preliminary model for spacecraft propulsion performance analysis based on nuclear gain and subsystem mass-power balances are presented in viewgraph form. For very fast missions with straight-line trajectories, it has been shown that mission trip time is proportional to the cube root of alpha. Analysis of spacecraft power systems via a power balance and examination of gain vs. mass-power ratio has shown: 1) A minimum gain is needed to have enough power for thruster and driver operation; and 2) Increases in gain result in decreases in overall mass-power ratio, which in turn leads to greater achievable accelerations. However, subsystem mass-power ratios and efficiencies are crucial: less efficient values for these can partially offset the effect of nuclear gain. Therefore, it is of interest to monitor the progress of gain-limited subsystem technologies and it is also possible that power-limited systems with sufficiently low alpha may be competitive for such ambitious missions. Topics include Space flight requirements; Spacecraft energy gain; Control theory for performance; Mission assumptions; Round trips: Time and distance; Trip times; Vehicle acceleration; and Minimizing trip times.

  20. Self-guided field trips for students of environments

    NASA Astrophysics Data System (ADS)

    Moore, G.; Kerr, Roger; Hadgraft, Roger

    2011-05-01

    In many learning institutions around the world, there is a trend towards larger classes, more flexible learning pathways and reduced teaching resources. Experiential learning is often used in the form of site visits or field trips for students studying engineering, natural resource management, geography and similar disciplines. Providing opportunities for students to undertake field trips without the traditional support mechanism is one of the more challenging issues for subject designers. How can large cohorts of students gain practical exposure to various aspects of the natural or built environment? Although this is typically done using traditional site visits and fieldwork with a high staff/student ratio, the goal has been to use action research to design and develop resources to enable small groups (three or four) to make self-guided visits to sites close to campus. Multimedia resources to examine and interpret aspects of the site that relate to their on-campus learning guide the students. One critical issue in the success of these activities has been proper risk assessment and control procedures. The outcome of this research is a framework to provide a safe, active learning experience by way of self-guided field trips that is suitable for implementation with large classes.

  1. The effect of boron and gadolinium burnable poisons on the hot-to-cold reactivity swing of a pressurized water reactor assembly

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

    Galperin, A.; Segev, M.; Radkowsky, A.

    1986-11-01

    Control requirements for advanced pressurized water reactor designs must be met with heavy loadings of burnable poison rods, the required reactivity hold-down typically amounting to 30% or more in a poisoned subassembly. Two apparent choices for poisons are natural boron rods and natural gadolinium rods. Studied and analyzed is the effect of these two poisons on the hot-to-cold reactivity upswing. Compared with an upswing of 2.9% in a nonpoisoned assembly, the upswing in the gadolinium-poisoned assembly is 3.0%, and the upswing in the boron-poisoned assembly is 8.8%. Thus the hot-to-cold control penalty is almost nil for the choice of gadoliniummore » and is considerable for the choice of boron.« less

  2. A Method of Efficient Inclination Changes for Low-thrust Spacecraft

    NASA Technical Reports Server (NTRS)

    Falck, Robert; Gefert, Leon

    2002-01-01

    The evolution of low-thrust propulsion technologies has reached a point where such systems have become an economical option for many space missions. The development of efficient, low trip time control laws has received an increasing amount of attention in recent years, though few studies have examined the subject of inclination changing maneuvers in detail. A method for performing economical inclination changes through the use of an efficiency factor is derived front Lagrange's planetary equations. The efficiency factor can be used to regulate propellant expenditure at the expense of trip time. Such a method can be used for discontinuous-thrust transfers that offer reduced propellant masses and trip-times in comparison to continuous thrust transfers, while utilizing thrusters that operate at a lower specific impulse. Performance comparisons of transfers utilizing this approach with continuous-thrust transfers are generated through trajectory simulation and are presented in this paper.

  3. Modelling dynamic fronto-parietal behaviour during minimally invasive surgery--a Markovian trip distribution approach.

    PubMed

    Leff, Daniel Richard; Orihuela-Espina, Felipe; Leong, Julian; Darzi, Ara; Yang, Guang-Zhong

    2008-01-01

    Learning to perform Minimally Invasive Surgery (MIS) requires considerable attention, concentration and spatial ability. Theoretically, this leads to activation in executive control (prefrontal) and visuospatial (parietal) centres of the brain. A novel approach is presented in this paper for analysing the flow of fronto-parietal haemodynamic behaviour and the associated variability between subjects. Serially acquired functional Near Infrared Spectroscopy (fNIRS) data from fourteen laparoscopic novices at different stages of learning is projected into a low-dimensional 'geospace', where sequentially acquired data is mapped to different locations. A trip distribution matrix based on consecutive directed trips between locations in the geospace reveals confluent fronto-parietal haemodynamic changes and a gravity model is applied to populate this matrix. To model global convergence in haemodynamic behaviour, a Markov chain is constructed and by comparing sequential haemodynamic distributions to the Markov's stationary distribution, inter-subject variability in learning an MIS task can be identified.

  4. Verification of Spin Magnetic Attitude Control System using air-bearing-based attitude control simulator

    NASA Astrophysics Data System (ADS)

    Ousaloo, H. S.; Nodeh, M. T.; Mehrabian, R.

    2016-09-01

    This paper accomplishes one goal and it was to verify and to validate a Spin Magnetic Attitude Control System (SMACS) program and to perform Hardware-In-the-Loop (HIL) air-bearing experiments. A study of a closed-loop magnetic spin controller is presented using only magnetic rods as actuators. The magnetic spin rate control approach is able to perform spin rate control and it is verified with an Attitude Control System (ACS) air-bearing MATLAB® SIMULINK® model and a hardware-embedded LABVIEW® algorithm that controls the spin rate of the test platform on a spherical air bearing table. The SIMULINK® model includes dynamic model of air-bearing, its disturbances, actuator emulation and the time delays caused by on-board calculations. The air-bearing simulator is employed to develop, improve, and carry out objective tests of magnetic torque rods and spin rate control algorithm in the experimental framework and to provide a more realistic demonstration of expected performance of attitude control as compared with software-based architectures. Six sets of two torque rods are used as actuators for the SMACS. It is implemented and simulated to fulfill mission requirement including spin the satellite up to 12 degs-1 around the z-axis. These techniques are documented for the full nonlinear equations of motion of the system and the performances of these techniques are compared in several simulations.

  5. TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors

    PubMed Central

    Cheong, Jit Kong; Gunaratnam, Lakshman; Zang, Zhi Jiang; Yang, Christopher M; Sun, Xiaoming; Nasr, Susan L; Sim, Khe Guan; Peh, Bee Keow; Rashid, Suhaimi Bin Abdul; Bonventre, Joseph V; Salto-Tellez, Manuel; Hsu, Stephen I

    2009-01-01

    Background Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2). Methods Oncogenic potential of TRIP-Br2 was demonstrated by (1) inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2) comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs). Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Results Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA) knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. Conclusion This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer. PMID:19152710

  6. Thresholds and noise limitations of colour vision in dim light.

    PubMed

    Kelber, Almut; Yovanovich, Carola; Olsson, Peter

    2017-04-05

    Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod-cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones.This article is part of the themed issue 'Vision in dim light'. © 2017 The Author(s).

  7. Retinal Degeneration in a Rodent Model of Smith-Lemli-Opitz Syndrome

    PubMed Central

    Fliesler, Steven J.; Peachey, Neal S.; Richards, Michael J.; Nagel, Barbara A.; Vaughan, Dana K.

    2010-01-01

    Objective To assess the electrophysiologic, histologic, and biochemical features of an animal model of Smith-Lemli-Opitz syndrome (SLOS). Methods Sprague-Dawley rats were treated with AY9944, a selective inhibitor of 3β-hydroxysterol-Δ7-reductase (the affected enzyme in SLOS). Dark- and light-adapted electroretinograms were obtained from treated and control animals. From each animal, 1 retina was analyzed by microscopy, and the contralateral retina plus serum samples were analyzed for sterol composition. The main outcome measures were rod and cone electroretinographic amplitudes and implicit times, outer nuclear layer (ONL) thickness, rod outer segment length, pyknotic ONL nucleus counts, and the 7-dehydrocholesterol/ cholesterol mole ratio in the retina and serum. Results By 10 weeks’ postnatal age, rod and cone electroretinographic wave amplitudes in AY9944-treated animals were significantly reduced and implicit times were significantly increased relative to controls. Maximal rod photoresponse and gain values were reduced approximately 2-fold in treated animals relative to controls. The ONL thickness and average rod outer segment length were reduced by approximately 18% and 33%, respectively, and ONL pyknotic nucleus counts were approximately 4.5-fold greater in treated animals relative to controls. The retinal pigment epithelium of treated animals contained massive amounts of membranous/lipid inclusions not routinely observed in controls. The 7-dehydrocholesterol/cholesterol mole ratios in treated retinas and serum samples were approximately 5:1 and 9:1, respectively, whereas the ratios in control tissues were essentially zero. Conclusions This rodent model exhibits the key biochemical hallmarks associated with SLOS and displays electrophysiologic deficits comparable to or greater than those observed in the human disease. Clinical Relevance These results predict retinal degeneration in patients with SLOS, particularly those with the more severe (type II) form of the disease, and may be more broadly relevant to other inborn errors of cholesterol biosynthesis. This animal model may also be of use in evaluating therapeutic treatments for SLOS and in understanding the slow phototransduction kinetics observed in patients with SLOS. PMID:15302661

  8. Quick release latch for reactor scram

    DOEpatents

    Johnson, Melvin L.; Shawver, Bruce M.

    1976-01-01

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

  9. Quick release latch for reactor scram

    DOEpatents

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

    1975-09-16

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

  10. Field Trips. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Cartwright, Sally; Aronson, Susan S.; Stacey, Susan; Winbush, Olga

    2001-01-01

    Five articles highlight benefits and organization of field trips: (1) "Field Trips Promote Child Learning at Its Best"; (2) "Planning for Maximum Benefit, Minimum Risk"; (3) "Coaching Community Hosts"; (4) "The Story of a Field Trip: Trash and Its Place within Children's Learning and Community"; and (5) "Field Trip Stories and Perspectives" (from…

  11. 50 CFR 622.43 - Commercial trip limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Reef Fish Resources of the Gulf of Mexico § 622.43 Commercial trip limits. Commercial trip limits are limits on the... with any trip or possession limit applicable to state waters. A species subject to a trip limit...

  12. 28 CFR 570.42 - Non-medical escorted trips.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Non-medical escorted trips. 570.42... RELEASE COMMUNITY PROGRAMS Escorted Trips § 570.42 Non-medical escorted trips. (a) Non-medical escorted trips allow an inmate to leave the institution under staff escort for approved, non-medical reasons...

  13. 28 CFR 570.41 - Medical escorted trips.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Medical escorted trips. 570.41 Section... COMMUNITY PROGRAMS Escorted Trips § 570.41 Medical escorted trips. (a) Medical escorted trips are intended to provide an inmate with medical treatment not available within the institution. There are two types...

  14. 28 CFR 570.41 - Medical escorted trips.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Medical escorted trips. 570.41 Section... COMMUNITY PROGRAMS Escorted Trips § 570.41 Medical escorted trips. (a) Medical escorted trips are intended to provide an inmate with medical treatment not available within the institution. There are two types...

  15. 2004 Annual Health Physics Report for the HEU Transparency Program

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

    Radev, R

    2005-04-01

    During the 2004 calendar year, LLNL provided health physics support for the Highly Enriched Uranium Transparency Implementation Program (HEU-TIP) in external and internal radiation protection and technical expertise into matters related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2004, there were 200 person-trips that required dose monitoring of the U.S. monitors. Of the 200 person-trips, 183 person-trips were SMVs and 17 person-trips were Transparency Monitoring Office (TMO) trips. Eight person-trips from the SMV trips were continuation trips of TMO monitors to facilities other than UEIP. The LLNL Safety Laboratories' Division provided the dosimetrymore » services for the HEU-TIP monitors.« less

  16. Impacts of energy consumption and emissions on the trip cost without late arrival at the equilibrium state

    NASA Astrophysics Data System (ADS)

    Tang, Tie-Qiao; Wang, Tao; Chen, Liang; Shang, Hua-Yan

    2017-08-01

    In this paper, we apply a car-following model, fuel consumption model, emission model and electricity consumption model to explore the influences of energy consumption and emissions on each commuter's trip costs without late arrival at the equilibrium state. The numerical results show that the energy consumption and emissions have significant impacts on each commuter's trip cost without late arrival at the equilibrium state. The fuel cost and emission cost prominently enhance each commuter's trip cost and the trip cost increases with the number of vehicles, which shows that considering the fuel cost and emission cost in the trip cost will destroy the equilibrium state. However, the electricity cost slightly enhances each commuter's trip cost, but the trip cost is still approximately a constant, which indicates that considering the electricity cost in the trip cost does not destroy the equilibrium state.

  17. 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 guidelines for abrasion resistance rod-like microstructures in composites with high volume fraction of brittle minerals or ceramics with tailored performance for specific applications.

  18. A description of a staff development program: Preparing the elementary school classroom teacher to lead environmental field trips and to use an integrated subject approach to environmental education

    NASA Astrophysics Data System (ADS)

    Egana, John Joseph

    This study of the Field Trip Specialist Program (FTS) described how a professional development plan fostered change in the traditional roles of third and fourth grade teachers. Teachers that volunteered were prepared to become interpretive guides for their class on environmental field trips, integrate their basic subject areas lessons into an environmental science context, and develop their self-perception as professional educators. This qualitative study made use of quantitative data and drew on information collected over four years from surveys, interviews, classroom observations, field trip and workshop observations, focus groups, journals and assessments performed in Florida. The FTS Program attracted teachers who thought it was important for all students to understand environmental issues, and these teachers believed in integrated instruction. These beliefs were inconsistent with many aspects of school culture. FTS invited the participation of these teachers and encouraged them to take control of the program by serving as instructors and program developers. Teachers described themselves as prepared to deliver the FTS Program with a high level of motivation and relevance. They also credited the program as beneficial in preparation for the Florida Comprehensive Assessment Tests (FCAT). Teachers reported that their responsibility as field trip leaders was the primary factor motivating them to provide conscientious presentation of pre- and post-field trip lessons and thorough integration of environmental topics in basic subject area instruction. Despite the impact of the field trip leadership factor, I could not find another program in the State of Florida that required teachers to lead their own field trips. Other influential factors specific to this program were: Voluntary participation, on-site field instruction, peer instructors and program developers, high quality and task specific materials, and pre- and post-assessments for students. Factors were identified in the FTS staff development plan that could be generalized to all staff development programs. I applied the "stages of concern" from the "Concerns Based Adoption Model"(CBAM) and found FTS to be a participantcentered plan. In addition FTS set demonstrable goals that were understood and desirable for all participants. Finally FTS offered teachers opportunities to adopt leadership roles in their own staff development program.

  19. Language Travel or Language Tourism: Have Educational Trips Changed So Much?

    ERIC Educational Resources Information Center

    Laborda, Jesus Garcia

    2007-01-01

    This article points out the changes in organization, students and language learning that language trips, as contrasted with educational trips (of which language trips are a subgroup) have gone through in the last years. The article emphasizes the need to differentiate between language trips and language tourism based on issues of additional…

  20. Teachers as Secondary Players: Involvement in Field Trips to Natural Environments

    ERIC Educational Resources Information Center

    Alon, Nirit Lavie; Tal, Tali

    2017-01-01

    This study focused on field trips to natural environments where the teacher plays a secondary role alongside a professional guide. We investigated teachers' and field trip guides' views of the teacher's role, the teacher's actual function on the field trip, and the relationship between them. We observed field trips, interviewed teachers and…

  1. Field Trips Put Chemistry in Context for Non-Science Majors

    ERIC Educational Resources Information Center

    Peterman, Keith E.

    2008-01-01

    Field trips can provide excellent real-world learning situations for students in non-science major chemistry courses. The field trips described in this article are accessible, most trips can be completed within a scheduled three-hour laboratory time period, and they can be conducted at minimal cost. These field trips significantly enhanced student…

  2. Field Trips as Valuable Learning Experiences in Geography Courses

    ERIC Educational Resources Information Center

    Krakowka, Amy Richmond

    2012-01-01

    Field trips have been acknowledged as valuable learning experiences in geography. This article uses Kolb's (1984) experiential learning model to discuss how students learn and how field trips can help enhance learning. Using Kolb's experiential learning theory as a guide in the design of field trips helps ensure that field trips contribute to…

  3. 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.

  4. TRIP13 impairs mitotic checkpoint surveillance and is associated with poor prognosis in multiple myeloma

    PubMed Central

    Song, Dongliang; Hu, Liangning; Xie, Bingqian; Wang, Houcai; Gao, Lu; Gao, Minjie; Xu, Hongwei; Xu, Zhijian; Wu, Xiaosong; Zhang, Yiwen; Zhu, Weiliang; Zhan, Fenghuang; Shi, Jumei

    2017-01-01

    AAA-ATPase TRIP13 is one of the chromosome instability gene recently established in multiple myeloma (MM), the second most common and incurable hematological malignancy. However, the specific function of TRIP13 in MM is largely unknown. Using sequential gene expression profiling, we demonstrated that high TRIP13 expression levels were positively correlated with progression, disease relapse, and poor prognosis in MM patients. Overexpressing human TRIP13 in myeloma cells prompted cell growth and drug resistance, and overexpressing murine TRIP13, which shares 93% sequence identity with human TRIP13, led to colony formation of NIH/3T3 fibroblasts in vitro and tumor formation in vivo. Meanwhile, the knockdown of TRIP13 inhibited myeloma cell growth, induced cell apoptosis, and reduced tumor burden in xenograft MM mice. Mechanistically, we observed that the overexpression of TRIP13 abrogated the spindle checkpoint and induced proteasome-mediated degradation of MAD2 primarily through the Akt pathway. Thus, our results demonstrate that TRIP13 may serve as a biomarker for MM disease development and prognosis, making it a potential target for future therapies. PMID:28157697

  5. Trade, TRIPS, and pharmaceuticals.

    PubMed

    Smith, Richard D; Correa, Carlos; Oh, Cecilia

    2009-02-21

    The World Trade Organization's Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) set global minimum standards for the protection of intellectual property, substantially increasing and expanding intellectual-property rights, and generated clear gains for the pharmaceutical industry and the developed world. The question of whether TRIPS generates gains for developing countries, in the form of increased exports, is addressed in this paper through consideration of the importance of pharmaceuticals in health-care trade, outlining the essential requirements, implications, and issues related to TRIPS, and TRIPS-plus, in which increased restrictions are imposed as part of bilateral free-trade agreements. TRIPS has not generated substantial gains for developing countries, but has further increased pharmaceutical trade in developed countries. The unequal trade between developed and developing countries (ie, exporting and importing high-value patented drugs, respectively) raises the issue of access to medicines, which is exacerbated by TRIPS-plus provisions, although many countries have not even enacted provision for TRIPS flexibilities. Therefore this paper focuses on options that are available to the health community for negotiation to their advantage under TRIPS, and within the presence of TRIPS-plus.

  6. 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.

  7. Getting out and about in older adults: the nature of daily trips and their association with objectively assessed physical activity.

    PubMed

    Davis, Mark G; Fox, Kenneth R; Hillsdon, Melvyn; Coulson, Jo C; Sharp, Debbie J; Stathi, Afroditi; Thompson, Janice L

    2011-10-21

    A key public health objective is increasing health-enhancing physical activity (PA) for older adults (OAs). Daily trip frequency is independently associated with objectively assessed PA volumes (OAs). Little is known about correlates and these trips' transport mode, and how these elements relate to PA. to describe the frequency, purpose, and travel mode of daily trips in OAs, and their association with participant characteristics and objectively-assessed PA. Participants (n = 214, aged 78.1 SD 5.7 years), completed a seven-day trips log recording daily-trip frequency, purpose and transport mode. Concurrently participants wore an accelerometer which provided mean daily steps (steps·d-1), and minutes of moderate to vigorous PA (MVPA·d-1). Participants' physical function (PF) was estimated and demographic, height and weight data obtained. Trip frequency was associated with gender, age, physical function, walking-aid use, educational attainment, number of amenities within walking distance and cars in the household. Participants reported 9.6 (SD 4.2) trips per week (trips·wk-1). Most trips (61%) were by car (driver 44%, passenger 17%), 30% walking or cycling (active) and 9% public transport/other. Driving trips·wk-1 were more common in participants who were males (5.3 SD 3.6), well-educated (5.0 SD 4.3), high functioning (5.1 SD 4.6), younger (5.6 SD 4.9), affluent area residents (5.1 SD 4.2) and accessing > one car (7.2 SD 4.7). Active trips·wk-1 were more frequent in participants who were males (3.4 SD 3.6), normal weight (3.2 SD 3.4), not requiring walking aids (3.5 SD 3.3), well-educated (3.7 SD 0.7), from less deprived neighbourhoods (3.9 SD 3.9) and with ≥ 8 amenities nearby (4.4 SD 3.8).Public transport, and active trip frequency, were significantly associated with steps·d-1 (p < 0.001), even after adjustment for other trip modes and potential confounders. Public transport, active, or car driving trips were independently associated with minutes MVPA·d-1 (p < 0.01). Daily trips are associated with objectively-measured PA as indicated by daily MVPA and steps. Public transport and active trips are associated with greater PA than those by car, especially as a car passenger. Strategies encouraging increased trips, particularly active or public transport trips, in OAs can potentially increase their PA and benefit public health.

  8. Addressing legal and political barriers to global pharmaceutical access: options for remedying the impact of the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) and the imposition of TRIPS-plus standards.

    PubMed

    Cohen-Kohler, Jillian Clare; Forman, Lisa; Lipkus, Nathaniel

    2008-07-01

    Despite myriad programs aimed at increasing access to essential medicines in the developing world, the global drug gap persists. This paper focuses on the major legal and political constraints preventing implementation of coordinated global policy solutions - particularly, the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) and bilateral and regional free trade agreements. We argue that several policy and research routes should be taken to mitigate the restrictive impact of TRIPS and TRIPS-plus rules, including greater use of TRIPS flexibilities, advancement of human rights, and an ethical framework for essential medicines distribution, and a broader campaign that debates the legitimacy of TRIPS and TRIPS-plus standards themselves.

  9. HTR-PROTEUS Pebble Bed Experimental Program Cores 1, 1A, 2, and 3: Hexagonal Close Packing with a 1:2 Moderator-to-Fuel Pebble Ratio

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

    John D. Bess; Barbara H. Dolphin; James W. Sterbentz

    2013-03-01

    In its deployment as a pebble bed reactor (PBR) critical facility from 1992 to 1996, the PROTEUS facility was designated as HTR-PROTEUS. This experimental program was performed as part of an International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on the Validation of Safety Related Physics Calculations for Low Enriched HTGRs. Within this project, critical experiments were conducted for graphite moderated LEU systems to determine core reactivity, flux and power profiles, reaction-rate ratios, the worth of control rods, both in-core and reflector based, the worth of burnable poisons, kinetic parameters, and the effects of moisture ingress on these parameters.more » Four benchmark experiments were evaluated in this report: Cores 1, 1A, 2, and 3. These core configurations represent the hexagonal close packing (HCP) configurations of the HTR-PROTEUS experiment with a moderator-to-fuel pebble ratio of 1:2. Core 1 represents the only configuration utilizing ZEBRA control rods. Cores 1A, 2, and 3 use withdrawable, hollow, stainless steel control rods. Cores 1 and 1A are similar except for the use of different control rods; Core 1A also has one less layer of pebbles (21 layers instead of 22). Core 2 retains the first 16 layers of pebbles from Cores 1 and 1A and has 16 layers of moderator pebbles stacked above the fueled layers. Core 3 retains the first 17 layers of pebbles but has polyethylene rods inserted between pebbles to simulate water ingress. The additional partial pebble layer (layer 18) for Core 3 was not included as it was used for core operations and not the reported critical configuration. Cores 1, 1A, 2, and 3 were determined to be acceptable benchmark experiments.« less

  10. HTR-PROTEUS Pebble Bed Experimental Program Cores 1, 1A, 2, and 3: Hexagonal Close Packing with a 1:2 Moderator-to-Fuel Pebble Ratio

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

    John D. Bess; Barbara H. Dolphin; James W. Sterbentz

    2012-03-01

    In its deployment as a pebble bed reactor (PBR) critical facility from 1992 to 1996, the PROTEUS facility was designated as HTR-PROTEUS. This experimental program was performed as part of an International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on the Validation of Safety Related Physics Calculations for Low Enriched HTGRs. Within this project, critical experiments were conducted for graphite moderated LEU systems to determine core reactivity, flux and power profiles, reaction-rate ratios, the worth of control rods, both in-core and reflector based, the worth of burnable poisons, kinetic parameters, and the effects of moisture ingress on these parameters.more » Four benchmark experiments were evaluated in this report: Cores 1, 1A, 2, and 3. These core configurations represent the hexagonal close packing (HCP) configurations of the HTR-PROTEUS experiment with a moderator-to-fuel pebble ratio of 1:2. Core 1 represents the only configuration utilizing ZEBRA control rods. Cores 1A, 2, and 3 use withdrawable, hollow, stainless steel control rods. Cores 1 and 1A are similar except for the use of different control rods; Core 1A also has one less layer of pebbles (21 layers instead of 22). Core 2 retains the first 16 layers of pebbles from Cores 1 and 1A and has 16 layers of moderator pebbles stacked above the fueled layers. Core 3 retains the first 17 layers of pebbles but has polyethylene rods inserted between pebbles to simulate water ingress. The additional partial pebble layer (layer 18) for Core 3 was not included as it was used for core operations and not the reported critical configuration. Cores 1, 1A, 2, and 3 were determined to be acceptable benchmark experiments.« less

  11. Collaborative Research: Bringing Problem Solving in the Field into the Classroom: Developing and Assessing Virtual Field Trips for Teaching Sedimentary and Introductory Geology

    NASA Astrophysics Data System (ADS)

    Wang, P.; Caldwell, M.

    2012-12-01

    Coastal Florida offers a unique setting for the facilitation of learning about a variety of modern sedimentary environments. Despite the conflicting concept of "virtual" and "actual" field trip, and the uncertainties associated with the implementation and effectiveness, virtual trips provide likely the only way to reach a large diversified student population and eliminate travel time and expenses. In addition, with rapidly improving web and visualization technology, field trips can be simulated virtually. It is therefore essential to systematically develop and assess the educational effectiveness of virtual field trips. This project is developing, implementing, and assessing a series of virtual field trips for teaching undergraduate sedimentary geology at a large four-year research university and introductory geology at a large two-year community college. The virtual field trip is based on a four-day actual field trip for a senior level sedimentary geology class. Two versions of the virtual field trip, one for advanced class and one for introductory class, are being produced. The educational outcome of the virtual field trip will be compared to that from actual field trip. This presentation summarizes Year 1 achievements of the three-year project. The filming, editing, and initial production of the virtual field trip have been completed. Formative assessments were conducted by the Coalition for Science Literacy at the University of South Florida. Once tested and refined, the virtual field trips will be disseminated through broadly used web portals and workshops at regional and national meetings.

  12. Personal and trip characteristics associated with safety equipment use by injured adult bicyclists: a cross-sectional study

    PubMed Central

    2012-01-01

    Background The aim of this study was to estimate use of helmets, lights, and visible clothing among cyclists and to examine trip and personal characteristics associated with their use. Methods Using data from a study of transportation infrastructure and injuries to 690 adult cyclists in Toronto and Vancouver, Canada, we examined the proportion who used bike lights, conspicuous clothing on the torso, and helmets on their injury trip. Multiple logistic regression was used to examine associations between personal and trip characteristics and each type of safety equipment. Results Bike lights were the least frequently used (20% of all trips) although they were used on 77% of trips at night. Conspicuous clothing (white, yellow, orange, red) was worn on 33% of trips. Helmets were used on 69% of trips, 76% in Vancouver where adult helmet use is required by law and 59% in Toronto where it is not. Factors positively associated with bike light use included night, dawn and dusk trips, poor weather conditions, weekday trips, male sex, and helmet use. Factors positively associated with conspicuous clothing use included good weather conditions, older age, and more frequent cycling. Factors positively associated with helmet use included bike light use, longer trip distances, hybrid bike type, not using alcohol in the 6 hours prior to the trip, female sex, older age, higher income, and higher education. Conclusions In two of Canada’s largest cities, helmets were the most widely used safety equipment. Measures to increase use of visibility aids on both daytime and night-time cycling trips may help prevent crashes. PMID:22966752

  13. Designed synthesis and supramolecular architectures of furan-substituted perylene diimide.

    PubMed

    Yu, Yanwen; Li, Yongjun; Qin, Zhihong; Jiang, Runsheng; Liu, Huibiao; Li, Yuliang

    2013-06-01

    Novel furan-substituted perylene diimides are successfully synthesized and an efficient supramolecular architecture approach to construct zero/one-dimensional nano- and micro-structures by controlling solvents has been demonstrated. The aggregate structure conversion in different molecular structures can be controlled in the form of sphere-like, rod-like, and vesicle-like structures. As expected, these solid supramolecular rod-like architectures displayed interesting optical waveguide behavior, which indicates the aggregate structure materials of furan-substituted perylene diimides have the potential application as micro-scale photonic elements. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Study on Locally Confined Deposition of Si Nanocrystals in High-Aspect-Ratio Si Nano-Pillar Arrays for Nano-Electronic and Nano-Photonic Applications II

    DTIC Science & Technology

    2010-12-03

    photoluminescence characteristics of equivalent-size controlled silicon quantum dots by employing a nano-porous aluminum oxide membrane as the template for growing...synthesis of Si quantum dots (Si-QDs) embedded in low-temperature (500oC) annealed Si-rich SiOx nano-rod deposited in nano-porous anodic aluminum oxide ...characteristics of the equivalent-size controlled Si-QDs by employing the nano-porous AAO membrane as the template for growing Si-rich SiOx nano-rods

  15. Analysis of electric vehicle's trip cost allowing late arrival

    NASA Astrophysics Data System (ADS)

    Leng, Jun-Qiang; Liu, Wei-Yi; Zhao, Lin

    2017-05-01

    In this paper, we use a car-following model to study each electric vehicle's trip cost and the total trip cost allowing late arrival. The numerical result show that the electricity cost has great effects on each commuter's trip cost and the total trip costs and that these effects are dependent on each commuter's time headway at the origin, but the electricity cost has no prominent impacts on the minimum value of total trip cost under each commuter's different time headway at the origin.

  16. Analysis of electric vehicle's trip cost without late arrival

    NASA Astrophysics Data System (ADS)

    Leng, Jun-Qiang; Zhao, Lin

    2017-03-01

    In this paper, we use a car-following model to study each electric vehicle's trip cost and the corresponding total trip cost without late arrival. The numerical result show that the electricity cost has significant effects on each electric vehicle's trip cost and the corresponding total trip costs and that the effects are dependent on its time headway at the origin, but the electricity cost has no prominent effects on the minimum value of the system's total trip cost.

  17. 46 CFR 111.106-13 - Cargo handling devices or cargo pump rooms handling flammable or combustible cargoes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... pierced by fixed lights, drive shafts, and pump-engine control rods, provided that the shafts and rods are... 46 Shipping 4 2014-10-01 2014-10-01 false Cargo handling devices or cargo pump rooms handling... OSVs § 111.106-13 Cargo handling devices or cargo pump rooms handling flammable or combustible cargoes...

  18. EPA Concurrence/Approval of Federal Facility Proposed Plans and Records of Decision and other Documents

    EPA Pesticide Factsheets

    The purpose of this memorandum is to ensure that EPA Regions scrutinize all proposed plans, draft and final RODs, and post-ROD documents that address institutional controls (ICs) in order to verify that they adequately document the objectives of the ICs and clearly identify who has responsibility for implementation, monitoring, reporting, and enforcement of the IC.

  19. Surface decarburization behavior and its adverse effects of air-cooled forging steel C70S6 for fracture splitting connecting rod

    NASA Astrophysics Data System (ADS)

    Zhang, Chao-lei; Xie, li-yao; Liu, Guang-lei; Chen, lie; Liu, Ya-zheng; Li, Jian

    2016-09-01

    Surface decarburization behavior and its adverse effects of air-cooled forging steel C70S6 for automobile engine fracture splitting connecting rod were investigated comprehensively by mechanical properties, microstructure and fracture morphology analysis. The results show that the surface decarburization in the outer surface of the fracture splitting at the big end bore and the micro-cracks in the decarburized layer are result in the uneven and spalling fracture surfaces of the waster connecting rod product. Besides, partial decarburization is produced between 900 °C and 1250 °C for heating 2 h, and decarburization sensitivity reach maximum at 1150 °C, but no complete decarburization forms for heating 2 h at 650-1250 °C. The decarburized depth follows a parabolic law with the increase of the heating time from 0.5 h to 12 h, and the decarburization sensitivity coefficient is 2.05×10-5 m·s-1/2 at 1200 °C. For the connecting rod manufacturing, surface decarburization must be under effective control during the hot forging process but not the control cooling process.

  20. 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

  1. Open the Door Let's Explore: Neighborhood Field Trips for Young Children.

    ERIC Educational Resources Information Center

    Redleaf, Rhoda

    Designed as a resource for teachers and parents, this guide contains activities to help children from 2 to 8 years old learn from neighborhood walks and field trips. Information is presented on: field trips as an approach to learning, learning processes of children, and techniques to make trips meaningful. Teaching material for each trip includes…

  2. A Field Trip without Buses: Connecting Your Students to Scientists through a Virtual Visit

    ERIC Educational Resources Information Center

    Adedokun, Omolola; Parker, Loran Carleton; Loizzo, Jamie; Burgess, Wilella; Robinson, J. Paul

    2011-01-01

    One school offers zipTrips as an alternative to actual field trips taken outside of school. ZipTrips are web- and broadcast-delivered electronic field trips that include online videos, lesson plans, and a live, 45-minute interactive program consisting of four core components: an in-studio audience, live interaction with scientists, prerecorded…

  3. Field Trips: Tradition in Jeopardy

    ERIC Educational Resources Information Center

    Wheeler, Ginger

    2011-01-01

    The school field trip: something fun, different, exciting, exhausting--a break from the school day grind. But the field trip has ramifications beyond just getting out of school for the day. For students, the field trip is to the classroom what the big game is to athletes. For museums and other attractions, the field trip is a way to cultivate…

  4. 30 CFR 250.514 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... uppermost BOP; (2) A well-control, fluid-volume measuring device for determining fluid volumes when filling the hole on trips; and (3) A recording mud-pit-level indicator to determine mud-pit-volume gains and... the hole with drill pipe, the annulus shall be filled with well-control fluid before the change in...

  5. Phase-locked loop with controlled phase slippage

    DOEpatents

    Mestha, Lingappa K.

    1994-01-01

    A system for synchronizing a first subsystem controlled by a changing frequency sweeping from a first frequency to a second frequency, with a second subsystem operating at a steady state second frequency. Trip plan parameters are calculated in advance to determine the phase relationship between the frequencies of the first subsystem and second subsystem in order to obtain synchronism at the end of the frequency sweep of the first subsystem. During the time in which the frequency of the first subsystem is sweeping from the first frequency to the second frequency, the phase locked system compares the actual phase difference with the trip plan phase difference and incrementally changes the sweep frequency in a manner so that phase lock is achieved when the first subsystem reaches a frequency substantially identical to that of the second subsystem.

  6. Microprocessor tester for the treat upgrade reactor trip system

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

    Lenkszus, F.R.; Bucher, R.G.

    1984-01-01

    The upgrading of the Transient Reactor Test (TREAT) Facility at ANL-Idaho has been designed to provide additional experimental capabilities for the study of core disruptive accident (CDA) phenomena. In addition, a programmable Automated Reactor Control System (ARCS) will permit high-power transients up to 11,000 MW having a controlled reactor period of from 15 to 0.1 sec. These modifications to the core neutronics will improve simulation of LMFBR accident conditions. Finally, a sophisticated, multiply-redundant safety system, the Reactor Trip System (RTS), will provide safe operation for both steady state and transient production operating modes. To insure that this complex safety systemmore » is functioning properly, a Dedicated Microprocessor Tester (DMT) has been implemented to perform a thorough checkout of the RTS prior to all TREAT operations.« less

  7. Cold Vacuum Drying (CVD) Set Point Determination

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

    PHILIPP, B.L.

    2000-03-21

    The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated, would result in a safety event. Specifically, actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO on high tempered water MCO inlet temperature. For the MCO isolation and purge, the SCIC receives signals from MCO pressure (both positive pressure and vacuum), helium flow rate, bay high temperature switches, seismic trips and time under vacuum trips.

  8. Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response.

    PubMed

    Barrionuevo, Pablo A; Cao, Dingcai

    2016-09-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals. We first analyzed the light adaptation behavior of melanopsin activation and rod and cones signals. Second, we determined how melanopsin is integrated with postreceptoral signals by testing with cone luminance, chromatic blue-yellow, and chromatic red-green stimuli that were processed by magnocellular (MC), koniocellular (KC), and parvocellular (PC) pathways, respectively. A combined rod and melanopsin response was also measured. The relative phase of the postreceptoral signals was varied with respect to the melanopsin phase. The results showed that light adaptation behavior for all conditions was weaker than typical Weber adaptation. Melanopsin activation combined linearly with luminance, S-cone, and rod inputs, suggesting the locus of integration with MC and KC signals was retinal. The melanopsin contribution to phasic pupil responses was lower than luminance contributions, but much higher than S-cone contributions. Chromatic red-green modulation interacted with melanopsin activation nonlinearly as described by a "winner-takes-all" process, suggesting the integration with PC signals might be mediated by a postretinal site.

  9. Using Virtual Field Trips to Connect Students with University Scientists: Core Elements and Evaluation of zipTrips[TM

    ERIC Educational Resources Information Center

    Adedokun, Omolola A.; Hetzel, Kristin; Parker, Loran Carleton; Loizzo, Jamie; Burgess, Wilella D.; Robinson, J. Paul

    2012-01-01

    Physical field trips to scientists' work places have been shown to enhance student perceptions of science, scientists and science careers. Although virtual field trips (VFTs) have emerged as viable alternatives (or supplements) to traditional physical fieldtrips, little is known about the potential of virtual field trips to provide the same or…

  10. Cybertrips in Social Studies. Online Field Trips for All Ages.

    ERIC Educational Resources Information Center

    Mandel, Scott

    The Internet can take students on virtual field trips to anywhere earth, under the seas, out in space, or back in time. This book demonstrates how teachers can use the Internet to take students on field trips. Composed of two parts, part 1, "Preparing for the Trip," discusses the background of virtual field trips what they are, and why…

  11. SP-100 Control System Design

    NASA Astrophysics Data System (ADS)

    Shukla, Jaikaran N.; Halfen, Frank J.; Brynsvold, Glen V.; Syed, Akbar; Jiang, Thomas J.; Wong, Kwok K.; Otwell, Robert L.

    1994-07-01

    Recent work in lower power generic early applications for the SP-100 have resulted in control system design simplification for a 20 kWe design with thermoelectric power conversion. This paper presents the non-mission-dependent control system features for this design. The control system includes a digital computer based controller, dual purpose control rods and drives, temperature sensors, and neutron flux monitors. The thaw system is mission dependent and can be either electrical or based on NaK trace lines. Key features of the control system and components are discussed. As was the case for higher power applications, the initial on-orbit approach to criticality involves the relatively fast withdrawal of the control-rods to a near-critical position followed by slower movement through critical and into the power range. The control system performs operating maneuvers as well as providing for automatic startup, shutdown, restart, and reactor protection.

  12. 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.

  13. Thresholds and noise limitations of colour vision in dim light

    PubMed Central

    Yovanovich, Carola

    2017-01-01

    Colour discrimination is based on opponent photoreceptor interactions, and limited by receptor noise. In dim light, photon shot noise impairs colour vision, and in vertebrates, the absolute threshold of colour vision is set by dark noise in cones. Nocturnal insects (e.g. moths and nocturnal bees) and vertebrates lacking rods (geckos) have adaptations to reduce receptor noise and use chromatic vision even in very dim light. In contrast, vertebrates with duplex retinae use colour-blind rod vision when noisy cone signals become unreliable, and their transition from cone- to rod-based vision is marked by the Purkinje shift. Rod–cone interactions have not been shown to improve colour vision in dim light, but may contribute to colour vision in mesopic light intensities. Frogs and toads that have two types of rods use opponent signals from these rods to control phototaxis even at their visual threshold. However, for tasks such as prey or mate choice, their colour discrimination abilities fail at brighter light intensities, similar to other vertebrates, probably limited by the dark noise in cones. This article is part of the themed issue 'Vision in dim light’. PMID:28193810

  14. 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

  15. Echoes from the Field: An Ethnographic Investigation of Outdoor Science Field Trips

    NASA Astrophysics Data System (ADS)

    Boxerman, Jonathan Zvi

    As popular as field trips are, one might think they have been well-studied. Nonetheless, field trips have not been heavily studied, and little research has mapped what actually transpires during field trips. Accordingly, to address this research gap, I asked two related research questions. The first question is a descriptive one: What happens on field trips? The second question is explanatory: What field trip events are memorable and why? I employed design research and ethnographic methodologies to study learning in naturally occurring contexts. I collaborated with middle-school science teachers to design and implement more than a dozen field trips. The field trips were nested in particular biology and earth sciences focal units. Students were tasked with making scientific observations in the field and then analyzing this data during classroom activities. Audio and video recording devices captured what happened during the field trips, classroom activities and discussions, and the interviews. I conducted comparative microanalysis of videotaped interactions. I observed dozens of events during the field trips that reverberated across time and place. I characterize the features of these events and the objects that drew interest. Then, I trace the residue across contexts. This study suggests that field trips could be more than one-off experiences and have the potential to be resources to seed and enrich learning and to augment interest in the practice of science.

  16. Thyroid hormone receptor interactor 13 (TRIP13) overexpression associated with tumor progression and poor prognosis in lung adenocarcinoma.

    PubMed

    Li, Wei; Zhang, Gengyan; Li, Xiaojun; Wang, Xiaojing; Li, Qing; Hong, Lei; Shen, Yuangbing; Zhao, Chenling; Gong, Xiaomeng; Chen, Yuqing; Zhou, Jihong

    2018-05-15

    Thyroid hormone receptor interactor 13 (TRIP13) is an AAA + -ATPase that plays a key role in mitotic checkpoint complex inactivation and is associated with the progression of several cancers. However, its role in lung adenocarcinogenesis remains unknown. Here, we report that TRIP13 is highly overexpressed in multiple lung adenocarcinoma cell lines and tumor tissues. Clinically, TRIP13 expression is positively associated with tumor size, T-stage, and N-stage, and Kaplan-Meier analysis revealed that heightened TRIP13 expression is associated with lower overall survival. TRIP13 promotes lung adenocarcinoma cell proliferation, clonogenicity, and migration while inhibiting apoptosis and G2/M phase shift in vitro. Accordingly, TRIP13-silenced xenograft tumors displayed significant growth inhibition in vivo. Bioinformatics analysis demonstrated that TRIP13 interacts with a protein network associated with dsDNA break repair and PI3K/Akt signaling. TRIP13 upregulatesAkt Ser473 and downregulatesAkt Thr308 /mTOR Ser2448 activity, which suppresses accurate dsDNA break repair. TRIP13 also downregulates pro-apoptotic Bad Ser136 and cleaved caspase-3 while upregulating survivin. In conclusion, heightened TRIP13 expression appears to promote lung adenocarcinoma tumor progression and displays potential as a therapeutic target or biomarker for lung adenocarcinoma. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. 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.

  18. 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

  19. Fundus-controlled two-color dark adaptometry with the Microperimeter MP1.

    PubMed

    Bowl, Wadim; Stieger, Knut; Lorenz, Birgit

    2015-06-01

    The aim of this study was to provide fundus-controlled two-color adaptometry with an existing device. A quick and easy approach extends the application possibilities of a commercial fundus-controlled perimeter. An external filter holder was placed in front the objective lens of the MP1 (Nidek, Italy) and fitted with filters to modify background, stimulus intensity, and color. Prior to dark adaptometry, the subject's visual sensitivity profile was measured for red and blue stimuli to determine whether rods or cones or both mediated the absolute threshold. After light adaptation, 20 healthy subjects were investigated with a pattern covering six spots at the posterior pole of the retina up to 45 min of dark adaptation. Thresholds were determined using a 200 ms red Goldmann IV and a blue Goldmann II stimulus. The pre-test sensitivity showed a typical distribution of values along the meridian, with high peripheral light increment sensitivity (LIS) and low central LIS for rods and the reverse for cones. After bleach, threshold recovery had a classic biphasic shape. The absolute threshold was reached after approximately 10 min for the red and 15 min for the blue stimulus. Two-color fundus-controlled adaptometry with a commercial MP1 without internal changes to the device provides a quick and easy examination of rod and cone function during dark adaptation at defined retinal loci of the posterior pole. This innovative method will be helpful to measure rod vs. cone function at known loci of the posterior pole in early stages of retinal degenerations.

  20. Vibration Method for Tracking the Resonant Mode and Impedance of a Microwave Cavity

    NASA Technical Reports Server (NTRS)

    Barmatz, M.; Iny, O.; Yiin, T.; Khan, I.

    1995-01-01

    A vibration technique his been developed to continuously maintain mode resonance and impedance much between a constant frequency magnetron source and resonant cavity. This method uses a vibrating metal rod to modulate the volume of the cavity in a manner equivalent to modulating an adjustable plunger. A similar vibrating metal rod attached to a stub tuner modulates the waveguide volume between the source and cavity. A phase sensitive detection scheme determines the optimum position of the adjustable plunger and stub turner during processing. The improved power transfer during the heating of a 99.8% pure alumina rod was demonstrated using this new technique. Temperature-time and reflected power-time heating curves are presented for the cases of no tracking, impedance tracker only, mode tracker only and simultaneous impedance and mode tracking. Controlled internal melting of an alumina rod near 2000 C using both tracking units was also demonstrated.

  1. 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.

  2. Trip Energy Estimation Methodology and Model Based on Real-World Driving Data for Green Routing Applications: Preprint

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

    Holden, Jacob; Van Til, Harrison J; Wood, Eric W

    A data-informed model to predict energy use for a proposed vehicle trip has been developed in this paper. The methodology leverages nearly 1 million miles of real-world driving data to generate the estimation model. Driving is categorized at the sub-trip level by average speed, road gradient, and road network geometry, then aggregated by category. An average energy consumption rate is determined for each category, creating an energy rates look-up table. Proposed vehicle trips are then categorized in the same manner, and estimated energy rates are appended from the look-up table. The methodology is robust and applicable to almost any typemore » of driving data. The model has been trained on vehicle global positioning system data from the Transportation Secure Data Center at the National Renewable Energy Laboratory and validated against on-road fuel consumption data from testing in Phoenix, Arizona. The estimation model has demonstrated an error range of 8.6% to 13.8%. The model results can be used to inform control strategies in routing tools, such as change in departure time, alternate routing, and alternate destinations to reduce energy consumption. This work provides a highly extensible framework that allows the model to be tuned to a specific driver or vehicle type.« less

  3. Guilt Trips and Love Withdrawal: Does Mothers' Use of Psychological Control Predict Depressive Symptoms among African American Adolescents?

    ERIC Educational Resources Information Center

    Mandara, Jelani; Pikes, Crysta L.

    2008-01-01

    This study examined the effects of maternal psychological control on the depressive symptoms of 152 lower socioeconomic status African American adolescents. After controlling for the effects of other parenting practices, psychological control had a strong positive relationship with girls' depressive symptoms, but none for boys, even though the 2…

  4. How Combined Trip Purposes Are Associated with Transport Choice for Short Distance Trips. Results from a Cross-Sectional Study in the Netherlands

    PubMed Central

    Scheepers, Eline; Slinger, Minke; Wendel-Vos, Wanda; Schuit, Jantine

    2014-01-01

    Background One way to increase physical activity is to stimulate a shift from car use to walking or cycling. In single-purpose trips, purpose was found to be an important predictor of transport choice. However, as far as known, no studies have been conducted to see how trips with combined purposes affect this decision. This study was designed to provide insight into associations between combined purposes and transport choice. Methods An online questionnaire (N = 3,663) was used to collect data concerning transport choice for four primary purposes: shopping, going to public natural spaces, sports, and commuting. Per combination of primary trip purpose and transport choice, participants were asked to give examples of secondary purposes that they combine with the primary purpose. Logistic regression analyses were used to model the odds of both cycling and walking versus car use. Results Primary trip purposes combined with commuting, shopping, visiting private contacts or medical care were more likely to be made by car than by cycling or walking. Combinations with visiting catering facilities, trips to social infrastructure facilities, recreational outings, trips to facilities for the provision of daily requirements or private contacts during the trip were more likely to be made by walking and/or cycling than by car. Conclusion Combined trip purposes were found to be associated with transport choice. When stimulating active transport focus should be on the combined-trip purposes which were more likely to be made by car, namely trips combined with commuting, other shopping, visiting private contacts or medical care. PMID:25474653

  5. Predictive Trip Detection for Nuclear Power Plants

    NASA Astrophysics Data System (ADS)

    Rankin, Drew J.; Jiang, Jin

    2016-08-01

    This paper investigates the use of a Kalman filter (KF) to predict, within the shutdown system (SDS) of a nuclear power plant (NPP), whether safety parameter measurements have reached a trip set-point. In addition, least squares (LS) estimation compensates for prediction error due to system-model mismatch. The motivation behind predictive shutdown is to reduce the amount of time between the occurrence of a fault or failure and the time of trip detection, referred to as time-to-trip. These reductions in time-to-trip can ultimately lead to increases in safety and productivity margins. The proposed predictive SDS differs from conventional SDSs in that it compares point-predictions of the measurements, rather than sensor measurements, against trip set-points. The predictive SDS is validated through simulation and experiments for the steam generator water level safety parameter. Performance of the proposed predictive SDS is compared against benchmark conventional SDS with respect to time-to-trip. In addition, this paper analyzes: prediction uncertainty, as well as; the conditions under which it is possible to achieve reduced time-to-trip. Simulation results demonstrate that on average the predictive SDS reduces time-to-trip by an amount of time equal to the length of the prediction horizon and that the distribution of times-to-trip is approximately Gaussian. Experimental results reveal that a reduced time-to-trip can be achieved in a real-world system with unknown system-model mismatch and that the predictive SDS can be implemented with a scan time of under 100ms. Thus, this paper is a proof of concept for KF/LS-based predictive trip detection.

  6. Analysis of the equilibrium trip cost accounting for the fuel cost in a single-lane traffic system without late arrival

    NASA Astrophysics Data System (ADS)

    Tang, Tie-Qiao; Wang, Tao; Chen, Liang; Huang, Hai-Jun

    2018-01-01

    In this paper, we introduce the fuel cost into each commuter's trip cost, define a new trip cost without late arrival and its corresponding equilibrium state, and use a car-following model to explore the impacts of the fuel cost on each commuter's departure time, departure interval, arrival time, arrival interval, traveling time, early arrival time and trip cost at the above equilibrium state. The numerical results show that considering the fuel cost in each commuter's trip cost has positive impacts on his trip cost and fuel cost, and the traffic situation in the system without late arrival, i.e., each commuter should explicitly consider the fuel cost in his trip cost.

  7. Analysis of the trip costs of a traffic corridor with two entrances and one exit under car-following model

    NASA Astrophysics Data System (ADS)

    Tang, Tie-Qiao; Wang, Tao; Chen, Liang; Shang, Hua-Yan

    2017-11-01

    In this paper, we first define each commuter's first, second and third trip costs, and then apply the full velocity difference model and the VT-Micro model to explore each commuter's three trip costs and the system's corresponding total trip costs in a traffic corridor with two entrances and one exit. The numerical results show that one entrance has prominent effects on the commuter's three trip costs and the system's corresponding total trip cost and that the impacts are directly related to the commuter's departure interval at this entrance. The results can provide some suggestions for reducing the commuters' trip costs in a traffic corridor with two entrances and one exit.

  8. 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.

  9. VMT-based traffic impact assessment : development of a trip length model.

    DOT National Transportation Integrated Search

    2010-06-01

    This report develops models that relate the trip-lengths to the land-use characteristics at : the trip-ends (both production- and attraction-ends). Separate models were developed by trip : purpose. The results indicate several statistically significa...

  10. Trip internalization in multi-use developments.

    DOT National Transportation Integrated Search

    2014-04-01

    Internal trip capture refers to how the number trips to and from a development are reduced by the proximity of : complementary land uses within the development (e.g., residential to retail). Internal trips occur within the : development and do not en...

  11. Trip Planning State of the Practice.

    DOT National Transportation Integrated Search

    2002-07-01

    Automated trip planning is one of the easiest ways for transit users to identify their best choice of routes using the Internet. Trip planners use an input form to obtain information on desired trip characteristics then automatically generate an itin...

  12. Towards ultra-high ductility TRIP-assisted multiphase steels controlled by strain gradient plasticity effects

    NASA Astrophysics Data System (ADS)

    Hatami, M. K.; Pardoen, T.; Lacroix, G.; Berke, P.; Jacques, P. J.; Massart, T. J.

    2017-01-01

    TRansformation Induced Plasticity (TRIP) is a very effective mechanism to increase the strain hardening capacity of multiphase steels containing a fraction of metastable austenite, leading to both high strength and large uniform elongation. Excellent performances have been reached in the past 20 years, with recent renewed interest through the development of the 3rd generation of high strength steels often involving a TRIP effect. The microstructure and composition optimization is complex due to the interplay of coupled effects on the transformation kinetics and work hardening such as phase stability, size of retained austenite grains, temperature and loading path. In particular, recent studies have shown that the TRIP effect can only be quantitatively captured for realistic microstructures if strain gradient plasticity effects are taken into account, although direct experimental validation of this claim is missing. Here, an original computational averaging scheme is developed for predicting the elastoplastic response of TRIP aided multiphase steels based on a strain gradient plasticity model. The microstructure is represented by an aggregate of many elementary unit cells involving each a fraction of retained austenite with a specified stability. The model parameters, involving the transformation kinetics, are identified based on experimental tensile tests performed at different temperatures. The model is further assessed towards original experiments, involving temperature changes during deformation. A classical size independent plasticity model is shown unable to capture the TRIP effect on the mechanical response. Conversely, the strain gradient formulation properly predicts substantial variations of the strain hardening with deformation and temperature, hence of the uniform elongation in good agreement with the experiments. A parametric study is performed to get more insight on the effect of the material length scale as well as to determine optimum transformation kinetics to reach the highest possible strength-ductility balance. It is shown that the uniform elongation can potentially be increased by 50% or more, paving the way towards future microstructure engineering efforts.

  13. 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 propose that the increased responses are caused by stray light stimulating the peripheral retina, thereby allowing peripheral rod-driven function to be studied using the triple silent substitution technique at photopic luminances. The method is effective in studying impaired peripheral rod- and cone- function in RP patients.

  14. 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.

  15. Real Students and Virtual Field Trips

    NASA Astrophysics Data System (ADS)

    de Paor, D. G.; Whitmeyer, S. J.; Bailey, J. E.; Schott, R. C.; Treves, R.; Scientific Team Of Www. Digitalplanet. Org

    2010-12-01

    Field trips have always been one of the major attractions of geoscience education, distinguishing courses in geology, geography, oceanography, etc., from laboratory-bound sciences such as nuclear physics or biochemistry. However, traditional field trips have been limited to regions with educationally useful exposures and to student populations with the necessary free time and financial resources. Two-year or commuter colleges serving worker-students cannot realistically insist on completion of field assignments and even well-endowed universities cannot take students to more than a handful of the best available field localities. Many instructors have attempted to bring the field into the classroom with the aid of technology. So-called Virtual Field Trips (VFTs) cannot replace the real experience for those that experience it but they are much better than nothing at all. We have been working to create transformative improvements in VFTs using four concepts: (i) self-drive virtual vehicles that students use to navigate the virtual globe under their own control; (ii) GigaPan outcrops that reveal successively more details views of key locations; (iii) virtual specimens scanned from real rocks, minerals, and fossils; and (iv) embedded assessment via logging of student actions. Students are represented by avatars of their own choosing and travel either together in a virtual field vehicle, or separately. When they approach virtual outcrops, virtual specimens become collectable and can be examined using Javascript controls that change magnification and orientation. These instructional resources are being made available via a new server under the domain name www.DigitalPlanet.org. The server will log student progress and provide immediate feedback. We aim to disseminate these resources widely and welcome feedback from instructors and students.

  16. Boundary Layer Control for Hypersonic Airbreathing Vehicles

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; Nowak, Robert J.; Horvath, Thomas J.

    2004-01-01

    Active and passive methods for tripping hypersonic boundary layers have been examined in NASA Langley Research Center wind tunnels using a Hyper-X model. This investigation assessed several concepts for forcing transition, including passive discrete roughness elements and active mass addition (or blowing), in the 20-Inch Mach 6 Air and the 31-Inch Mach 10 Air Tunnels. Heat transfer distributions obtained via phosphor thermography, shock system details, and surface streamline patterns were measured on a 0.333-scale model of the Hyper-X forebody. The comparisons between the active and passive methods for boundary layer control were conducted at test conditions that nearly match the Hyper-X nominal Mach 7 flight test-point of an angle-of-attack of 2-deg and length Reynolds number of 5.6 million. For passive roughness, the primary parametric variation was a range of trip heights within the calculated boundary layer thickness for several trip concepts. The passive roughness study resulted in a swept ramp configuration, scaled to be roughly 0.6 of the calculated boundary layer thickness, being selected for the Mach 7 flight vehicle. For the active blowing study, the manifold pressure was systematically varied (while monitoring the mass flow) for each configuration to determine the jet penetration height, with schlieren, and transition movement, with the phosphor system, for comparison to the passive results. All the blowing concepts tested, which included various rows of sonic orifices (holes), two- and three-dimensional slots, and random porosity, provided transition onset near the trip location with manifold stagnation pressures on the order of 40 times the model surface static pressure, which is adequate to ensure sonic jets. The present results indicate that the jet penetration height for blowing was roughly half the height required with passive roughness elements for an equivalent amount of transition movement.

  17. Fuel Cell Electric Vehicle Composite Data Products | Hydrogen and Fuel

    Science.gov Websites

    Ambient Temperature CDP FCEV 35, 2/19/16 Time Between Trips CDP FCEV 36, 5/1/16 Time Between Trips and Trip Ambient Temperature CDP FCEV 37, 5/1/16 Trips per Hour CDP FCEV 38, 2/19/16 Trips per Hour by Fuel Vehicle Miles Between Fills by Month CDP FCEV 56, 3/1/16 Reliability Maintenance Causes and Effects-Stack

  18. Using a Field Trip Inventory to Determine If Listening to Elementary School Students' Conversations, While on a Zoo Field Trip, Enhances Preservice Teachers' Abilities to Plan Zoo Field Trips

    ERIC Educational Resources Information Center

    Patrick, Patricia; Mathews, Cathy; Tunnicliffe, Sue Dale

    2013-01-01

    This study investigated whether listening to spontaneous conversations of elementary students and their teachers/chaperones, while they were visiting a zoo, affected preservice elementary teachers' conceptions about planning a field trip to the zoo. One hundred five preservice elementary teachers designed field trips prior to and after…

  19. 30 CFR 250.514 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-control, fluid-volume measuring device for determining fluid volumes when filling the hole on trips; and... shall include both a visual and an audible warning device. (c) When coming out of the hole with drill... collars that may be pulled prior to filling the hole and the equivalent well-control fluid volume shall be...

  20. Galvanizability of Advanced High-Strength Steels 1180TRIP and 1180CP

    NASA Astrophysics Data System (ADS)

    Kim, M. S.; Kwak, J. H.; Kim, J. S.; Liu, Y. H.; Gao, N.; Tang, N.-Y.

    2009-08-01

    In general, Si-bearing advanced high-strength steels (AHSS) possess excellent mechanical properties but poor galvanizability. The galvanizability of a transformation-induced plasticity (TRIP) steel 1180TRIP containing 2.2 pct Mn and 1.7 pct Si and a complex phase steel 1180CP containing 2.7 pct Mn and 0.2 pct Si was extensively studied using a galvanizing simulator. The steel coupons were annealed at fixed dew points in the simulator. The surface features of the as-annealed steel coupons, together with galvanized and galvannealed coatings, were carefully examined using a variety of advanced analysis techniques. It was found that various oxides formed on the surface of these steels, depending on the steel composition and on the dew point control. Coating quality was good at 0 °C dew point but deteriorated as the dew point decreased to -35 °C and -65 °C. Based on the findings, guidance was provided for improving galvanizability by adjusting the Mn:Si ratio in steel compositions according to the dew point.

  1. Flight crew fatigue III: North Sea helicopter air transport operations.

    PubMed

    Gander, P H; Barnes, R M; Gregory, K B; Graeber, R C; Connell, L J; Rosekind, M R

    1998-09-01

    We studied 32 helicopter pilots before, during, and after 4-5 d trips from Aberdeen, Scotland, to service North Sea oil rigs. On duty days, subjects awoke 1.5 h earlier than pretrip or posttrip, after having slept nearly an hour less. Subjective fatigue was greater posttrip than pretrip. By the end of trip days, fatigue was greater and mood more negative than by the end of pretrip days. During trips, daily caffeine consumption increased 42%, reports of headache doubled, reports of back pain increased 12-fold, and reports of burning eyes quadrupled. In the cockpits studied, thermal discomfort and high vibration levels were common. Subjective workload during preflight, taxi, climb, and cruise was related to the crewmembers' ratings of the quality of the aircraft systems. During descent and approach, workload was affected by weather at the landing site. During landing, it was influenced by the quality of the landing site and air traffic control. Beginning duty later, and greater attention to aircraft comfort and maintenance, should reduce fatigue in these operations.

  2. Thermo-mechanical Processing of TRIP-Aided Steels

    NASA Astrophysics Data System (ADS)

    Ranjan, Ravi; Beladi, Hossein; Singh, Shiv Brat; Hodgson, Peter D.

    2015-07-01

    The effects of the partial replacement of Si with Al and the addition of P on the microstructure and mechanical properties of experimental TRIP-aided steels subjected to different thermo-mechanical cycles were studied. Based on the available literature and thermodynamics-based calculations, three steels with different compositions were designed to obtain optimum results from a relatively low number of experiments. Different combinations of microstructure were developed through three different kinds of thermo-mechanical-controlled processing (TMCP) routes, and the corresponding tensile properties were evaluated. The results indicated that partial replacement of Si with Al improved the strength-ductility balance along with providing an improved variation in the incremental change in the strain-hardening exponent. However, the impact of the P addition was found to depend more on the final microstructure obtained by the different TMCP cycles. It has also been shown that an increase in the volume fraction of the retained austenite () or its carbon content () resulted in an improved strength-ductility balance, which can be attributed to better exploitation of the TRIP effect.

  3. Solid-state power controller

    NASA Technical Reports Server (NTRS)

    Fox, D. A.; Fullemann, J. S.

    1980-01-01

    Compact, solid state, electric-power controller switches power on and off at remote load, limits current drawn by load, and shuts off (with 2- to 3- second trip time) in case of short circuit. Lightweight efficient hybrid unit operates at 28 volts dc and at maximum currents of from 3 to 2 amperes.

  4. 77 FR 729 - Airworthiness Directives; Enstrom Helicopter Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... subsequent loss of control of the helicopter. DATES: This AD becomes effective January 23, 2012. The Director... Program Manager, FAA, Chicago Aircraft Certification Office, 2300 East Devon Avenue, Room 107, Des Plaines... the circuit breaker to trip before any significant loss of control occurs. After the trim actuator...

  5. Trip attraction rates of shopping centers in Northern New Castle County, Delaware.

    DOT National Transportation Integrated Search

    2004-07-01

    This report presents the trip attraction rates of the shopping centers in Northern New : Castle County in Delaware. The study aims to provide an alternative to ITE Trip : Generation Manual (1997) for computing the trip attraction of shopping centers ...

  6. High-Powered, Ultrasonically Assisted Thermal Stir Welding

    NASA Technical Reports Server (NTRS)

    Ding, Robert

    2013-01-01

    This method is a solid-state weld process capable of joining metallic alloys without melting. The weld workpieces to be joined by thermal stir welding (TSW) are drawn, by heavy forces, between containment plates past the TSW stir tool that then causes joining of the weld workpiece. TSW is similar to friction stir welding (FSW) in that material is heated into a plastic state (not melted) and stirred using a stir rod. The FSW pin tool is an integrated geometrical structure consisting of a large-diameter shoulder, and a smaller-diameter stir pin protruding from the shoulder. When the pin is plunged into a weld workpiece, the shoulder spins on the surface of the weld workpiece, thus inducing frictional heat into the part. The pin stirs the fraying surfaces of the weld joint, thus joining the weld workpiece into one structure. The shoulder and stir pin of the FSW pin tool must rotate together at a desired rotational speed. The induced frictional energy control and stir pin control of the pin tool cannot be de-coupled. The two work as one integrated unit. TSW, on the other hand, de-couples the heating and stirring of FSW, and allows for independent control of each process element. A uniquely designed induction coil heats the weld workpiece to a desired temperature, and once heated, the part moves into a stir rod whose RPM is also independently controlled. As the weld workpiece moves into the stir rod, the piece is positioned, or sandwiched, between upper and lower containment plates. The plate squeezes together, thus compressing the upper and lower surfaces of the weld workpiece. This compressive force, also called consolidation force, consolidates the plastic material within the weld nugget material as it is being stirred by the stir rod. The stir rod is positioned through the center of the top containment plate and protrudes midway through the opposite lower containment plate where it is mechanically captured. The upper and lower containment plates are separated by a distance equal to the thickness of the material being welded. The TSW process can be significantly improved by reducing the draw forces. This can be achieved by reducing the friction forces between the weld workpieces and the containment plates. High-power ultrasonic (HPU) vibrations of the containment plates achieve friction reduction in the TSW process. Furthermore, integration of the HPU energy into the TSW stir rod can increase tool life of the stir rod, and can reduce shear forces to which the stir rod is subjected during the welding process. TSW has been used to successfully join 0.500-in (˜13-mm) thick commercially pure (CP) titanium, titanium 6AL- 4V, and titanium 6AL-4V ELI in weld joint lengths up to 9 ft (˜2.75-m) long. In addition, the TSW process was used to fabricate a sub-scale hexagonally shaped gun turret component for the U.S. Navy. The turret is comprised of six 0.5000-in (˜13-mm) thick angled welds. Each angled weld joint was prepared by machining the mating surfaces to 120deg. The angled weld joint was then fixtured using an upper and lower containment plate of the same geometry of the angled weld joint. The weld joint was then stirred by the stir rod as it and the upper and lower containment plates traverse through the angled joint prep.

  7. Nuclear reactor with low-level core coolant intake

    DOEpatents

    Challberg, Roy C.; Townsend, Harold E.

    1993-01-01

    A natural-circulation boiling-water reactor has skirts extending downward from control rod guide tubes to about 10 centimeters from the reactor vessel bottom. The skirts define annular channels about control rod drive housings that extend through the reactor vessel bottom. Recirculating water is forced in through the low-level entrances to these channels, sweeping bottom water into the channels in the process. The sweeping action prevents cooler water from accumulating at the bottom. This in turn minimizes thermal shock to bottom-dwelling components as would occur when accumulated cool water is swept away and suddenly replaced by warmer water.

  8. The importance of holiday trips for people with chronic mental health problems.

    PubMed

    Pols, Jeannette; Kroon, Hans

    2007-02-01

    Although research findings point to the importance of leisure activities for people with severe mental illness, there is no research into the specific effects of holiday trips. This Open Forum describes the experience of going on holiday trips for people with chronic mental health problems in the Netherlands. A qualitative research design was used. Material for the research was collected by participant observation on two trips and in-depth interviews of 11 travelers and four psychiatric nurses who accompanied the travelers. The trips contributed to rehabilitation by promoting and supporting, among other things, community participation, social relations, skill development, and new perceptions of identity. The trips also helped travelers to maintain balance in everyday life. For the nurses the trips provided a learning environment outside of medical institutions.

  9. Forwardly-placed firearm fire control assembly

    DOEpatents

    Frickey, Steven J.

    2001-12-22

    A firearm fire control assembly for disposition in a forwardly placed support-hand operative relationship within a firearm having a combination of a firing pin and a firearm hammer adapted to engage and fire a cartridge, a sear assembly to alternately engage and disengage the combination of the firearm hammer and firing pin, and a trigger assembly including a movable trigger mechanism that is operable to engage the sear assembly to cause the firearm hammer firing pin combination to fire the firearm, a fire control assembly including a fire control depression member and a fire control rod operably connected to the depression member, and being positioned in a forward disposition disposed within a forestock of the firearm, and the depression member adapted to be operably engaged and depressed by the user's conventional forwardly placed support hand to maneuver the fire control rod to provide firing control of the firing of the firearm.

  10. Phase-locked loop with controlled phase slippage

    DOEpatents

    Mestha, L.K.

    1994-03-29

    A system for synchronizing a first subsystem controlled by a changing frequency sweeping from a first frequency to a second frequency, with a second subsystem operating at a steady state second frequency is described. Trip plan parameters are calculated in advance to determine the phase relationship between the frequencies of the first subsystem and second subsystem in order to obtain synchronism at the end of the frequency sweep of the first subsystem. During the time in which the frequency of the first subsystem is sweeping from the first frequency to the second frequency, the phase locked system compares the actual phase difference with the trip plan phase difference and incrementally changes the sweep frequency in a manner so that phase lock is achieved when the first subsystem reaches a frequency substantially identical to that of the second subsystem. 10 figures.

  11. Survey on how fluctuating petrol prices are affecting Malaysian large city dwellers in changing their trip patterns

    NASA Astrophysics Data System (ADS)

    Rohani, M. M.; Pahazri, N.

    2018-04-01

    Rising fuel prices shocks have a significant impact on the way of life of most Malaysians. Due to the rising of oil prices, the costs of travel for private vehicle users are therefore increasing. The study was conducted based on the objective of studying the impact of rising fuel prices on three types of trip patterns of Malaysians who are living in the city areas. The three types of trip patterns are, workplaces trip, leisure trip and personal purposes trip during the weekdays. This study was conducted by distributing questionnaires to respondents of private vehicle users in selected city such as Johor Bahru, Kuala Lumpur, Putrajaya, Melaka, Perak, Selangor and Kelantan. This study, found that the trip patterns of those who were using their own vehicles had changed after the rising of fuel prices. The changes showed that many private vehicle users were taking steps to save money on petrol by adjusting their trips.

  12. TRIP13 promotes error-prone nonhomologous end joining and induces chemoresistance in head and neck cancer

    PubMed Central

    Banerjee, Rajat; Russo, Nickole; Liu, Min; Basrur, Venkatesha; Bellile, Emily; Palanisamy, Nallasivam; Scanlon, Christina S.; van Tubergen, Elizabeth; Inglehart, Ronald C.; Metwally, Tarek; Mani, Ram-Shankar; Yocum, Anastasia; Nyati, Mukesh K.; Castilho, Rogerio M.; Varambally, Sooryanarayana; Chinnaiyan, Arul M.

    2014-01-01

    Head and neck cancer (SCCHN) is a common, aggressive, treatment-resistant cancer with a high recurrence rate and mortality, but the mechanism of treatment-resistance remains unclear. Here we describe a mechanism where the AAA-ATPase TRIP13 promotes treatment-resistance. Overexpression of TRIP13 in non-malignant cells results in malignant transformation. High expression of TRIP13 in SCCHN leads to aggressive, treatment-resistant tumors and enhanced repair of DNA damage. Using mass spectrometry, we identify DNA-PKcs complex proteins that mediate non homologous end joining (NHEJ), as TRIP13 binding partners. Using repair-deficient reporter systems, we show that TRIP13 promotes NHEJ, even when homologous recombination is intact. Importantly, overexpression of TRIP13 sensitizes SCCHN to an inhibitor of DNA-PKcs. Thus, this study defines a new mechanism of treatment resistance in SCCHN and underscores the importance of targeting NHEJ to overcome treatment failure in SCCHN and potentially in other cancers that overexpress TRIP13. PMID:25078033

  13. 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.

  14. ETR CRITICAL FACILITY, TRA654. SCIENTISTS STAND AT EDGE OF TANK ...

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

    ETR CRITICAL FACILITY, TRA-654. SCIENTISTS STAND AT EDGE OF TANK AND LIFT REMOVABLE BRIDGE ABOVE THE REACTOR. CONTROL RODS AND FUEL RODS ARE BELOW ENOUGH WATER TO SHIELD WORKERS ABOVE. NOTE CRANE RAILS ALONG WALLS, PUMICE BLOCK WALLS. INL NEGATIVE NO. 57-3690. R.G. Larsen, Photographer, 7/29/1957 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  15. The AAA+ ATPase TRIP13 remodels HORMA domains through N-terminal engagement and unfolding

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

    Ye, Qiaozhen; Kim, Dong Hyun; Dereli, Ihsan

    Proteins of the conserved HORMA domain family, including the spindle assembly checkpoint protein MAD2 and the meiotic HORMADs, assemble into signaling complexes by binding short peptides termed “closure motifs”. The AAA+ ATPase TRIP13 regulates both MAD2 and meiotic HORMADs by disassembling these HORMA domain–closure motif complexes, but its mechanisms of substrate recognition and remodeling are unknown. Here, we combine X-ray crystallography and crosslinking mass spectrometry to outline how TRIP13 recognizes MAD2 with the help of the adapter protein p31comet. We show that p31comet binding to the TRIP13 N-terminal domain positions the disordered MAD2 N-terminus for engagement by the TRIP13 “poremore » loops”, which then unfold MAD2 in the presence of ATP. N-terminal truncation of MAD2 renders it refractory to TRIP13 action in vitro, and in cells causes spindle assembly checkpoint defects consistent with loss of TRIP13 function. Similar truncation of HORMAD1 in mouse spermatocytes compromises its TRIP13-mediated removal from meiotic chromosomes, highlighting a conserved mechanism for recognition and disassembly of HORMA domain–closure motif complexes by TRIP13.« less

  16. A case study of urban student and teacher experiences surrounding an outdoor environmental science field trip

    NASA Astrophysics Data System (ADS)

    Preusch, Peggy L.

    2009-12-01

    Field trips provide opportunities for students to experience many different contexts beyond the classroom, and are a popular choice of K-12 teachers in the US. Recent interest in learning that occurs at informal science education centers such as museums, zoos and aquariums has stimulated studies of the relationship between learning in and outside of schools. Although many studies focus on the teachers, the contexts, and/or the students during the field trip, only a few look at the entire process of learning by including the classroom setting before and after the field trip. This study was designed to develop understandings of the student process of learning during and surrounding an environmental science field trip to an outdoor setting. John Dewey's extensive writings on the relationship between experience and learning informed the analysis, creating a focus on active and passive elements of the experience, continuity within and across contexts, the interactive nature of the experience and the importance of subject matter. An exploration of environmental education (EE), environmental science (ES), and nature study as content revealed the complexities of the subject matter of the field trip that make its presentation problematic. An urban school was chosen to contribute to the research literature about urban student learning in outdoor environments. During the field trip, the students' active engagement with each other and the environment supported meaningful remembrances of the field trip experiences during interviews after the field trip. The students accurately described plants and animals they had observed in different habitats during the field trip. They also made connections with their home life and prior experiences in the outdoors as they discussed the field trip and drew pictures that represented their experiences. One student integrated his outdoor experience with a language arts assignment as he reflected deeply on the field trip. One implication of this study is that educational experiences in outdoor natural environments are complex in ways that contribute to lack of continuity between science lessons in an elementary classroom and environmental science field trip. Long term relationships between schools and informal settings that recognize the strengths of both contexts in terms of student learning processes surrounding field trip experiences are needed to strengthen the educative process for field trip participants.

  17. Examining the Role of Trip Length in Commuter Decisions to Use Public Transportation

    DOT National Transportation Integrated Search

    2010-06-01

    Traveler trip length has for years been used as a fundamental indicator of the best mix of transit modes and user perceptions of travel cost for transit versus auto. This study examines traveler trip lengths across transit modes, work trip duration f...

  18. 30 CFR 57.14162 - Trip lights.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trip lights. 57.14162 Section 57.14162 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Devices and Maintenance Requirements § 57.14162 Trip lights. On underground rail haulage, trip lights...

  19. 30 CFR 57.14162 - Trip lights.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Trip lights. 57.14162 Section 57.14162 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Devices and Maintenance Requirements § 57.14162 Trip lights. On underground rail haulage, trip lights...

  20. 30 CFR 57.14162 - Trip lights.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Trip lights. 57.14162 Section 57.14162 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Devices and Maintenance Requirements § 57.14162 Trip lights. On underground rail haulage, trip lights...

  1. 30 CFR 57.14162 - Trip lights.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Trip lights. 57.14162 Section 57.14162 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Devices and Maintenance Requirements § 57.14162 Trip lights. On underground rail haulage, trip lights...

  2. 30 CFR 57.14162 - Trip lights.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Trip lights. 57.14162 Section 57.14162 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Devices and Maintenance Requirements § 57.14162 Trip lights. On underground rail haulage, trip lights...

  3. Food-purchasing patterns for home: a grocery store-intercept survey.

    PubMed

    Yoo, Sunmi; Baranowski, Tom; Missaghian, Mariam; Baranowski, Janice; Cullen, Karen; Fisher, Jennifer O; Watson, Kathy; Zakeri, Issa F; Nicklas, Theresa

    2006-05-01

    To identify the most common frequency of food-purchasing patterns and relate this pattern to characteristics of individuals and families. A customer-intercept survey was conducted in the greater Houston area, Texas, USA, in 2002. The frequency of food shopping at supermarkets, convenience stores and restaurants to buy food for eating at home was assessed. A total of 823 adults (78.5% female; mean age 37.4 years) who went to any of several grocery or convenience stores, including European, Hispanic and African Americans, and Asian/Pacific Islanders. Major food-shopping patterns were a weekly big trip with a few small trips (34.9%), biweekly big trips with a few small trips (21.9%), no big shopping trips (15.4%), a weekly big trip without small trips (13.9%), a monthly big trip (8.3%), and biweekly big trips without small trips (6.4%). While 61.1% of participants never went to convenience stores to buy fruit and vegetables (F&V) for eating at home, 67% went to restaurants for F&V. African American families shopped for food least frequently, while Asian American families shopped for food most frequently. Educational level was negatively associated with the use of convenience stores and positively associated with take-away from restaurants. There is substantial variability in the frequency of food shopping. Future research on food shopping should incorporate this variable.

  4. Conceptual design study of improved 1985 remote lift-fan V/STOL commercial transports

    NASA Technical Reports Server (NTRS)

    Cavage, R. L.

    1975-01-01

    A design study was conducted for a remote lift-fan commercial V/STOL transport for the 1985 time period. The investigation centered on the commercial short haul transportation application to carry 100 passengers over trip distances of 400 nautical miles from a vertical takeoff and landing, and 800 nautical miles after a 1600 foot STOL takeoff. The study included investigation of alternate numbers and arrangements of lift fans and gas generators, fan control margins, and structural concepts. The sensitivity of direct operating costs to major airframe parameters, airframe costs, propulsion costs, yearly aircraft utilization rate, and trip distances are evaluated.

  5. Anticipatory control of xenon in a pressurized water reactor

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

    Impink, A.J. Jr.

    1987-02-10

    A method is described for automatically dampening xenon-135 spatial transients in the core of a pressurized water reactor having control rods which regulate reactor power level, comprising the steps of: measuring the neutron flu in the reactor core at a plurality of axially spaced locations on a real-time, on-line basis; repetitively generating from the neutron flux measurements, on a point-by-point basis, signals representative of the current axial distribution of xenon-135, and signals representative of the current rate of change of the axial distribution of xenon-135; generating from the xenon-135 distribution signals and the rate of change of xenon distribution signals,more » control signals for reducing the xenon transients; and positioning the control rods as a function of the control signals to dampen the xenon-135 spatial transients.« less

  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. The Use of Field Trips in Air-Photo Interpretation and Remote-Sensing Classes.

    ERIC Educational Resources Information Center

    Giardino, John Richard; Fish, Ernest Bertley

    1986-01-01

    Advocates the use of field trips for improving students' image-interpretation abilities. Presents guidelines for developing a field trip for an aerial-photo interpretation class or a remote-sensing class. Reviews methodology employed, content emphasis, and includes an exercise that was used on a trip. (ML)

  8. 50 CFR 622.278 - Commercial trip limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.278 Commercial trip limits. Commercial trip limits are... in this section with any trip or possession limit applicable to state waters. A species subject to a...

  9. 50 CFR 622.278 - Commercial trip limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.278 Commercial trip limits. Commercial trip limits are... in this section with any trip or possession limit applicable to state waters. A species subject to a...

  10. Multiple Stages of Weekend Field Trips To Expose Students to Nature: Emphasis on Discovery and Awareness.

    ERIC Educational Resources Information Center

    Krupa, James J.

    2002-01-01

    Describes the three stages of a field trip and reviews stage 1, weekend field trips, which focuses on an organism's morphology, behavior, and ecology. Presents activities on salamanders, small mammals, fish, birds, and bats. Explains the difficulties of weekend trips. (YDS)

  11. Actual and Virtual Reality: Making the Most of Field Trips.

    ERIC Educational Resources Information Center

    Bellan, Jennifer Marie; Scheurman, Geoffrey

    1998-01-01

    Argues that a virtual field trip can complement and enhance a real one. Discusses the benefits and pitfalls of both types of field trips. Outlines a series of student and teacher activities combining an actual field trip and a virtual one to Fort Snelling in St. Paul, Minnesota. (MJP)

  12. 78 FR 53486 - Addition of Round-Trip Mailer Product to the Competitive Product List

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... POSTAL SERVICE Addition of Round-Trip Mailer Product to the Competitive Product List AGENCY... request with the Postal Regulatory Commission to add a product called ``Round-Trip Mailer'' to the...] filed with the Postal Regulatory Commission (Commission) a request to add a ``Round-Trip Mailer...

  13. 28 CFR 570.45 - Violation of escorted trip.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Violation of escorted trip. 570.45 Section 570.45 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE COMMUNITY PROGRAMS AND RELEASE COMMUNITY PROGRAMS Escorted Trips § 570.45 Violation of escorted trip. (a) Staff shall process as...

  14. Material test machine for tension-compression tests at high temperature

    DOEpatents

    Cioletti, Olisse C.

    1988-01-01

    Apparatus providing a device for testing the properties of material specimens at high temperatures and pressures in controlled water chemistries includes, inter alia, an autoclave housing the specimen which is being tested. The specimen is connected to a pull rod which couples out of the autoclave to an external assembly which includes one or more transducers, a force balance chamber and a piston type actuator. The pull rod feeds through the force balance chamber and is compensated thereby for the pressure conditions existing within the autoclave and tending to eject the pull rod therefrom. The upper end of the push rod is connected to the actuator through elements containing a transducer comprising a linear variable differential transformer (LVDT). The housing and coil assembly of the LVDT is coupled to a tube which runs through a central bore of the pull rod into the autoclave where it is connected to one side of the specimen. The movable core of the LVDT is coupled to a stem which runs through the tube where it is then connected to the other side of the specimen through a coupling member. A transducer in the form of a load cell including one or more strain gages is located on a necked-down portion of the upper part of the pull rod intermediate the LVDT and force balance chamber.

  15. 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.

  16. 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.

  17. 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.

  18. 10 CFR 55.41 - Written examination: Operators.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... elements, control rods, core instrumentation, and coolant flow. (3) Mechanical components and design..., and functions of reactivity control mechanisms and instrumentation. (7) Design, components, and functions of control and safety systems, including instrumentation, signals, interlocks, failure modes, and...

  19. 10 CFR 55.41 - Written examination: Operators.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... elements, control rods, core instrumentation, and coolant flow. (3) Mechanical components and design..., and functions of reactivity control mechanisms and instrumentation. (7) Design, components, and functions of control and safety systems, including instrumentation, signals, interlocks, failure modes, and...

  20. Reactivity control assembly for nuclear reactor

    DOEpatents

    Bollinger, Lawrence R.

    1984-01-01

    Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.

  1. Fast-spectrum space-power-reactor concepts using boron control devices

    NASA Technical Reports Server (NTRS)

    Mayo, W.

    1973-01-01

    Several fast-spectrum space power reactor concepts that use boron carbide control devices were examined to determine the neutronic feasibility of the designs. The designs considered were (1) a 199-fuel-pin, 12-poison-reflector-control-drum reactor; (2) a 232-fuel-pin reactor with 12 reflector drums and three in-core control rods; (3) a 337-fuel-pin design with 12 incore control rods; and a 181-fuel-pin design with six drums closely coupled to the core to increase reactivity per drum. Adequate reactivity control and excess reactivity could be obtained for each concept, and the goals of 50,000 hours at 2.17 thermal megawatts with a lithium-7 coolant outlet temperature of 1222 K could be met without exceeding the 1-percent-clad-creep criterion. Heating rates in the boron carbide were calculated, but a heat transfer analysis was not done.

  2. 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.

  3. A technique for efficiently generating bimetallic clusters

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

    Wagner, R.L.; Vann, W.D.; Castleman, A.W. , Jr.

    1997-08-01

    Reactivities of bimetallic clusters can be controlled by varying their composition, making them potentially valuable as catalysts and for use in elucidating the reactivities of such subnanoscale surfaces. A dual rod laser vaporization source coupled to a fast flow reactor is developed for the study of bimetallic clusters and their reactions. In order to establish the versatility of the technique, the results of studies are presented in which Nb/Al clusters are formed in two plasmas induced by the second harmonic (532 nm photons) of a single Nd:YAG laser and then detected by a quadrupole mass spectrometer. The beam from themore » laser is split and then focused onto each rod, allowing the mixing ratio within the cluster to vary by altering the laser fluence on each rod. With a low fluence on the Nb rod and a high fluence on the Al rod, an Al rich cluster distribution is formed, NbAl{sub m}{sup {minus}} (m=2{endash}20), and Al{sub m}{sup {minus}} (m=5{endash}31). By increasing the fluence on the Nb rod and decreasing the fluence on the Al rod, a Nb rich cluster distribution is formed, Nb{sub n}Al{sub m}{sup {minus}} (n=3{endash}8 and m=1{endash}3), Nb{sub n}OAl{sub m}{sup {minus}} (n=3{endash}8 and m=1{endash}5), and Nb{sub n}O{sup {minus}} (n=3{endash}8). Additional characterization is also performed on V/Al clusters. {copyright} {ital 1997 American Institute of Physics.}« less

  4. 28 CFR 570.43 - Inmates requiring a high degree of control and supervision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Inmates requiring a high degree of control and supervision. 570.43 Section 570.43 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE COMMUNITY PROGRAMS AND RELEASE COMMUNITY PROGRAMS Escorted Trips § 570.43 Inmates requiring a high degree of control and supervision. Only the...

  5. Development of testing and training simulator for CEDMCS in KSNP

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

    Nam, C. H.; Park, C. Y.; Nam, J. I.

    2006-07-01

    This paper presents a newly developed testing and training simulator (TTS) for automatically diagnosing and tuning the Control Element Drive Mechanism Control System (CEDMCS). TTS includes a new automatic, diagnostic, method for logic control cards and a new tuning method for phase synchronous pulse cards. In Korea Standard Nuclear Power Plants (KSNP). reactor trips occasionally occur due to a damaged logic control card in CEDMCS. However, there is no pre-diagnostic tester available to detect a damaged card in CEDMCS before it causes a reactor trip. Even after the reactor trip occurs, it is difficult to find the damaged card. Tomore » find the damaged card. ICT is usually used. ICT is an automated, computer-controlled testing system with measurement capabilities for testing active and passive components, or clusters of components, on printed circuit boards (PCB) and/or assemblies. However, ICT cannot detect a time dependent fault correctly and requires removal of the waterproof mating to perform the test. Therefore, the additional procedure of re-coating the PCB card is required after the test. TTS for CEDMCS is designed based on real plant conditions, both electrically and mechanically. Therefore, the operator can operate the Control Element Drive Mechanism (CEDM), which is mounted on the closure head of the reactor vessel (RV) using the soft control panel in ITS, which duplicates the Main Control Board (MCB) in the Main Control Room (MCR). However, during the generation of electric power in a nuclear power plant, it is difficult to operate the CEDM so a CEDM and Control Element Assembly (CEA) mock-up facility was developed to simulate a real plant CEDM. ITS was used for diagnosing and tuning control logic cards in CEDMCS in the Ulchin Nuclear Power Plant No. 4 during the plant overhaul period. It exhibited good performance in detecting the damaged cards and tuning the phase synchronous pulse cards. In addition, TTS was useful in training the CEDMCS operator by supplying detail signal information from the logic cards. (authors)« less

  6. An Experimental Study of Fan Inflow Distortion Tone Noise

    NASA Technical Reports Server (NTRS)

    Koch, L. Danielle

    2010-01-01

    The tone noise generated when a fan ingests circumferentially distorted flow was studied by an experiment conducted with the Advanced Noise Control Fan at the NASA Glenn Research Center. The inflow was distorted by inserting cylindrical rods radially into the duct. The rods were arranged in circumferentially irregular patterns in three of the five configurations tested. Rods were held in place using a mounting ring with 30 equally spaced holes placed at an axial location one rotor chordlength upstream of the fan. Acoustic pressure was measured in the inlet and exhaust duct of the fan using the Rotating Rake fan tone measurement system. Sound power levels, calculated from the measured data, were plotted as a function of circumferential mode. An analytic description of the unsteady pressure distribution at the interaction plane between the stationary rods and the fan rotor is presented in a form suitable for representing the circumferentially irregularly placed rods. Terms in the analytical description for sound power were proven to be useful in determining the dominant circumferential modes measured in the experiment and the differences in mode power level between the configurations tested. Insight gained through this work will be useful in the development of tools to compute fan inflow distortion tone noise.

  7. 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 be considered for future research.

  8. 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 current generation technologies should be considered for future research. PMID:29588607

  9. In-flight sleep, pilot fatigue and Psychomotor Vigilance Task performance on ultra-long range versus long range flights.

    PubMed

    Gander, Philippa H; Signal, T Leigh; van den Berg, Margo J; Mulrine, Hannah M; Jay, Sarah M; Jim Mangie, Captain

    2013-12-01

    This study evaluated whether pilot fatigue was greater on ultra-long range (ULR) trips (flights >16 h on 10% of trips in a 90-day period) than on long range (LR) trips. The within-subjects design controlled for crew complement, pattern of in-flight breaks, flight direction and departure time. Thirty male Captains (mean age = 54.5 years) and 40 male First officers (mean age = 48.0 years) were monitored on commercial passenger flights (Boeing 777 aircraft). Sleep was monitored (actigraphy, duty/sleep diaries) from 3 days before the first study trip to 3 days after the second study trip. Karolinska Sleepiness Scale, Samn-Perelli fatigue ratings and a 5-min Psychomotor Vigilance Task were completed before, during and after every flight. Total sleep in the 24 h before outbound flights and before inbound flights after 2-day layovers was comparable for ULR and LR flights. All pilots slept on all flights. For each additional hour of flight time, they obtained an estimated additional 12.3 min of sleep. Estimated mean total sleep was longer on ULR flights (3 h 53 min) than LR flights (3 h 15 min; P(F) = 0.0004). Sleepiness ratings were lower and mean reaction speed was faster at the end of ULR flights. Findings suggest that additional in-flight sleep mitigated fatigue effectively on longer flights. Further research is needed to clarify the contributions to fatigue of in-flight sleep versus time awake at top of descent. The study design was limited to eastward outbound flights with two Captains and two First Officers. Caution must be exercised when extrapolating to different operations. © 2013 European Sleep Research Society.

  10. Reduced Collagen Deposition in Infarcted Myocardium Facilitates Induced Pluripotent Stem Cell Engraftment and Angiomyogenesis for Improvement of Left Ventricular Function

    PubMed Central

    Dai, Bo; Huang, Wei; Xu, Meifeng; Millard, Ronald W.; Gao, Mei Hua; Hammond, H. Kirk; Menick, Donald R.; Ashraf, Muhammad; Wang, Yigang

    2012-01-01

    Objectives The purpose of this study was to assess the effect of scar tissue composition on engraftment of progenitor cells into infarcted myocardium. Background Scar tissue formation after myocardial infarction creates a barrier that severely compromises tissue regeneration, limiting potential functional recovery. Methods In vitro: A tricell patch (Tri-P) was created from peritoneum seeded and cultured with induced pluripotent stem cell–derived cardiomyocytes, endothelial cells, and mouse embryonic fibroblasts. The expression of fibrosis-related molecules from mouse embryonic fibroblasts and infarcted heart was measured by Western blot and quantitative reverse transcriptase polymerase chain reaction. In vivo: A Tri-P was affixed over the entire infarcted area 7 days after myocardial infarction in mice overexpressing adenylyl cyclase 6 (AC6). Engraftment efficiency of progenitor cells in hearts of AC6 mice was compared with that of control wild-type (WT) mice using a combination of in vivo bioluminescence imaging, post-mortem ex vivo tissue analysis, and the number of green fluorescent protein–positive cells. Echocardiography of left ventricular (LV) function was performed weekly. Hearts were harvested for analysis 4 weeks after Tri-P application. Mouse embryonic fibroblasts were stimulated with forskolin before an anoxia/reoxygenation protocol. Fibrosis-related molecules were analyzed. Results In AC6 mice, infarcted hearts treated with Tri-P showed significantly higher bioluminescence imaging intensity and numbers of green fluorescent protein–positive cells than in WT mice. LV function improved progressively in AC6 mice from weeks 2 to 4 and was associated with reduced LV fibrosis. Conclusions Application of a Tri-P in AC6 mice resulted in significantly higher induced pluripotent stem cell engraftment accompanied by angiomyogenesis in the infarcted area and improvement in LV function. PMID:22051336

  11. 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

  12. Application of a hurdle negative binomial count data model to demand for bass fishing in the southeastern United States.

    PubMed

    Bilgic, Abdulbaki; Florkowski, Wojciech J

    2007-06-01

    This paper identifies factors that influence the demand for a bass fishing trip taken in the southeastern United States using a hurdle negative binomial count data model. The probability of fishing for a bass is estimated in the first stage and the fishing trip frequency is estimated in the second stage for individuals reporting bass fishing trips in the Southeast. The applied approach allows the decomposition of the effects of factors responsible for the decision to take a trip and the trip number. Calculated partial and total elasticities indicate a highly inelastic demand for the number of fishing trips as trip costs increase. However, the demand can be expected to increase if anglers experience a success measured by the number of caught fish or their size. Benefit estimates based on alternative estimation methods differ substantially, suggesting the need for testing each modeling approach applied in empirical studies.

  13. Reduce Fraud Risk in Your District with Stronger Internal Controls

    ERIC Educational Resources Information Center

    Okrzesik, Daryl J.; Nuehring, Bert G.

    2011-01-01

    Internal accounts offer schools a faster, more convenient way to handle the income and expenses that result from student fees, school clubs and organizations, field trips, fund-raising, and similar activities. But this convenience also incurs the added risk of fraud. Fortunately, there are proven ways to strengthen internal controls and reduce…

  14. 46 CFR 111.51-3 - Protection of vital equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... plant configurations. (b)Overcurrent protective devices must be installed so that: (1) A short-circuit on a circuit that is not vital to the propulsion, control, or safety of the vessel does not trip equipment that is vital; and (2) A short-circuit on a circuit that is vital to the propulsion, control, or...

  15. Global Research in an Age of Export Controls

    ERIC Educational Resources Information Center

    Monastersky, Richard

    2008-01-01

    When a jury convicted a Tennessee professor this month of illegally exporting information to foreign countries via his graduate students and a trip to China, it sent a message to colleges that they need to scrupulously monitor their faculty members' research and their compliance with the often confusing universe of export-control regulations. In…

  16. 30 CFR 250.1623 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., (2) A well-control fluid-volume measuring device for determining fluid volumes when filling the hole on trips, and (3) A recording mud-pit-level indicator to determine mud-pit-volume gains and losses... the change in fluid level decreases the hydrostatic pressure 75 psi or every five stands of drill pipe...

  17. 49 CFR 1510.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... that is not a round trip. Origin point means the location at which a trip on a complete air travel... accumulated travel mileage credits in a customer loyalty program, whether or not the term frequent flyer is... Administration by an air carrier as required by this part. Round trip means a trip on an air travel itinerary...

  18. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Contact element, mechanical trip type; location... Instructions; Locomotives § 236.560 Contact element, mechanical trip type; location with respect to rail. Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  19. Tourism, Field Trips and Geographic Education.

    ERIC Educational Resources Information Center

    Dilsaver, Lary M.

    In university level geography education, both a market and a need exist for "learning trips" combining the elements of a field trip with those of a commercial tour. Planning such trips involves four steps. The first of these is to establish the conditions of the tour, including identification of the topical focus, specific destinations and sites…

  20. Teachers' Sources of Knowledge for Field Trip Practices

    ERIC Educational Resources Information Center

    Rebar, Bryan M.

    2012-01-01

    Teachers draw from many personal and professional experiences when organising and leading field trips. In order to identify the influences on teachers' field trip practices, I used surveys, interviews, artifacts and observations gathered from teachers who led trips to an aquarium. Findings clarified the types of influence and the impact that these…

  1. Geography via Aerial Field Trips: Do It This Way, 6.

    ERIC Educational Resources Information Center

    Richason, Benjamin F., Jr.; Guell, Carl E.

    To provide guidance for geography teachers, this booklet presents information on how to plan and execute aerial field trips. The aerial field trip can be employed as an effective visual aid technique in the teaching of geography, especially for presenting earth generalizations and interrelationships. The benefits of an aerial field trip are…

  2. Revisiting Virtual Field Trips: Perspectives of College Science Instructors

    ERIC Educational Resources Information Center

    Lei, Simon A.

    2015-01-01

    Field trips are an important component of upper undergraduate and graduate-level science courses, especially in the fields of biology, geoscience, and environmental science. Field trips can provide a new perspective to a course's content and quality. Science field trips can facilitate active student learning, yet often can be constrained by time,…

  3. Flow in Rotating Serpentine Coolant Passages With Skewed Trip Strips

    NASA Technical Reports Server (NTRS)

    Tse, David G.N.; Steuber, Gary

    1996-01-01

    Laser velocimetry was utilized to map the velocity field in serpentine turbine blade cooling passages with skewed trip strips. The measurements were obtained at Reynolds and Rotation numbers of 25,000 and 0.24 to assess the influence of trips, passage curvature and Coriolis force on the flow field. The interaction of the secondary flows induced by skewed trips with the passage rotation produces a swirling vortex and a corner recirculation zone. With trips skewed at +45 deg, the secondary flows remain unaltered as the cross-flow proceeds from the passage to the turn. However, the flow characteristics at these locations differ when trips are skewed at -45 deg. Changes in the flow structure are expected to augment heat transfer, in agreement with the heat transfer measurements of Johnson, et al. The present results show that trips are skewed at -45 deg in the outward flow passage and trips are skewed at +45 deg in the inward flow passage maximize heat transfer. Details of the present measurements were related to the heat transfer measurements of Johnson, et al. to relate fluid flow and heat transfer measurements.

  4. An experimental investigation of energy absorption in TRIP steel under impact three-point bending deformation

    NASA Astrophysics Data System (ADS)

    Pham, Hang; Iwamoto, Takeshi

    2015-09-01

    TRIP (Transformation-induced Plasticity) steel is nowadays in widespread use in the automobile industry because of their favorable mechanical properties such as high strength, excellent formability and toughness because of strain-induced martensitic transformation. Moreover, when TRIP steel is applied to the components of the vehicles, it is expected that huge amount of kinetic energy will be absorbed into both plastic deformation and martensitic transformation during the collision. Basically, bending deformation due to buckling is one of the major crash deformation modes of automobile structures. Thus, an investigation of energy absorption during bending deformation at high impact velocity for TRIP steel is indispensable. Although TRIP steel have particularly attracted the recent interest of the scientific community, just few studies can be found on the energy absorption characteristic of TRIP steel, especially at impact loading condition. In present study, experimental investigations of bending deformation behaviors of TRIP steel are conducted in the three-point bending tests for both smooth and pre-cracked specimen. Then, energy absorption characteristic during plastic deformation and fracture process at high impact velocity in TRIP steel will be discussed.

  5. Mineralization and growth of cultured embryonic skeletal tissue in microgravity

    NASA Technical Reports Server (NTRS)

    Klement, B. J.; Spooner, B. S.

    1999-01-01

    Microgravity provides a unique environment in which to study normal and pathological phenomenon. Very few studies have been done to examine the effects of microgravity on developing skeletal tissue such as growth plate formation and maintenance, elongation of bone primordia, or the mineralization of growth plate cartilage. Embryonic mouse premetatarsal triads were cultured on three space shuttle flights to study cartilage growth, differentiation, and mineralization, in a microgravity environment. The premetatarsal triads that were cultured in microgravity all formed cartilage rods and grew in length. However, the premetatarsal cartilage rods cultured in microgravity grew less in length than the ground control cartilage rods. Terminal chondrocyte differentiation also occurred during culture in microgravity, as well as in the ground controls, and the matrix around the hypertrophied chondrocytes was capable of mineralizing in both groups. The same percentage of premetatarsals mineralized in the microgravity cultures as mineralized in the ground control cultures. In addition, the sizes of the mineralized areas between the two groups were very similar. However, the amount of 45Ca incorporated into the mineralized areas was significantly lower in the microgravity cultures, suggesting that the composition or density of the mineralized regions was compromised in microgravity. There was no significant difference in the amount of 45Ca liberated from prelabeled explants in microgravity or in the ground controls.

  6. Urban commuting: crowdedness and catecholamine excretion.

    PubMed

    Lundberg, U

    1976-09-01

    Male passengers regularly commuting by train on the Stockholm-Nynäshamn line were investigated on two morning trips to Stockholm. These trips were made under different levels of crowding, before (Trip 1) and after (Trip 2) a period of gas rationing during the oil crisis in 1974. However, seats were available for almost everyone during both trips. One group of subjects boarded the train at its first stop (Nynäshamn), the other midway on its route (Västerhaninge). Physiological reactions were assessed from the rate of catecholamine excretion in urine and subjective experiences were measured by self-ratings. The results showed that feelings of discomfort grew more intense as the train approached Stockholm and the number of passengers increased. Perceived crowdedness increased as the square of the number of passengers. During both trips the subjects from Nynäshamn (longer trip) had a lower rate of adrenaline and noradrenaline excretion on the train than those from Västerhaninge. Furthermore, it was found that the rate of adrenaline excretion was higher for both groups during Trip 2, when the train was more crowded. The results support previous findings indicating that the stress involved in travelling by train varies more with the social and ecological conditions of the trip than with its length or duration.

  7. Bonding of TRIP-Steel/Al2O3-(3Y)-TZP Composites and (3Y)-TZP Ceramic by a Spark Plasma Sintering (SPS) Apparatus

    PubMed Central

    Miriyev, Aslan; Grützner, Steffen; Krüger, Lutz; Kalabukhov, Sergey; Frage, Nachum

    2016-01-01

    A combination of the high damage tolerance of TRIP-steel and the extremely low thermal conductivity of partially stabilized zirconia (PSZ) can provide controlled thermal-mechanical properties to sandwich-shaped composite specimens comprising these materials. Sintering the (TRIP-steel-PSZ)/PSZ sandwich in a single step is very difficult due to differences in the sintering temperature and densification kinetics of the composite and the ceramic powders. In the present study, we successfully applied a two-step approach involving separate SPS consolidation of pure (3Y)-TZP and composites containing 20 vol % TRIP-steel, 40 vol % Al2O3 and 40 vol % (3Y)-TZP ceramic phase, and subsequent diffusion joining of both sintered components in an SPS apparatus. The microstructure and properties of the sintered and bonded specimens were characterized. No defects at the interface between the TZP and the composite after joining in the 1050–1150 °C temperature range were observed. Only limited grain growth occurred during joining, while crystallite size, hardness, shear strength and the fraction of the monoclinic phase in the TZP ceramic virtually did not change. The slight increase of the TZP layer’s fracture toughness with the joining temperature was attributed to the effect of grain size on transformation toughening. PMID:28773680

  8. Design and fabrication of a basic mass analyzer and vacuum system

    NASA Technical Reports Server (NTRS)

    Judson, C. M.; Josias, C.; Lawrence, J. L., Jr.

    1977-01-01

    A two-inch hyperbolic rod quadrupole mass analyzer with a mass range of 400 to 200 amu and a sensitivity exceeding 100 packs per billion has been developed and tested. This analyzer is the basic hardware portion of a microprocessor-controlled quadrupole mass spectrometer for a Gas Analysis and Detection System (GADS). The development and testing of the hyperbolic-rod quadrupole mass spectrometer and associated hardware are described in detail.

  9. 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 surgery in the CoCr MRC group. However, 55.5% (5/9) of PJK developed over 12 months after surgery in the Ti TRC group. Increasing the rod stiffness by the use of cobalt chrome rod and can prevent rod breakage but adversely affects the occurrence and the time of PJK. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Field trips and their effect on student achievement in and attitudes toward science: A comparison of a physical versus a virtual field trip to the Indian River Lagoon

    NASA Astrophysics Data System (ADS)

    Garner, Lesley Cochran

    The purpose of this study was to determine the effect of physical and virtual field trips on students' achievement in estuarine ecology and their attitudes toward science. The study also assessed the effect of students' learning styles, the interaction between group membership and learning styles, and the effect of group membership on students' ability to answer questions at different levels of Bloom's (1956) taxonomy. Working with a convenient sample of 67 freshmen and sophomore non-science majors, students were randomly assigned to one of two treatment groups (physical, n = 32 and virtual, n = 35). Prior to treatment, students' learning styles were determined, students were pre-assessed on the two targeted measures, and all students attended four consecutive, in-class, 75-minute lectures on estuarine ecology and the Indian River Lagoon (IRL). Pre-assessed data indicated no significant differences between the groups on the two dependent measures. On the weekend following the lecture series, the physical field trip group engaged in a set of predetermined activities at the IRL for 2 hours in the morning. Later that afternoon, the virtual field trip group participated in a 2-hour virtual trip to the IRL that exactly matched the physical field trip activities. This virtual trip incorporated the CD-ROM The Living Lagoon: An Electronic Field Trip. Following each trip, students were post-assessed using the same pre-assessment instruments. MANCOVA results indicated no significant differences on all research factors (i.e., group membership, learning style, and group-learning style interaction). Data analysis also revealed that there was no significant effect of group membership on students' ability to answer questions at different levels of Bloom's taxonomy. These findings imply that educators can integrate virtual field trips that are structured in the same manner as their corresponding physical field trips without significantly impacting student achievement or attitudes.

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

    Wang, Hong; Wang, Jy-An John

    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

  12. 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.

  13. 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

  14. 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.

  15. Echoes from the Field: An Ethnographic Investigation of Outdoor Science Field Trips

    ERIC Educational Resources Information Center

    Boxerman, Jonathan Zvi

    2013-01-01

    As popular as field trips are, one might think they have been well-studied. Nonetheless, field trips have not been heavily studied, and little research has mapped what actually transpires during field trips. Accordingly, to address this research gap, I asked two related research questions. The first question is a descriptive one: What happens on…

  16. 26 CFR 49.4264(e)-1 - Round trips.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Round trips. 49.4264(e)-1 Section 49.4264(e)-1... TAXES FACILITIES AND SERVICES EXCISE TAXES Transportation of Persons § 49.4264(e)-1 Round trips. (a) In general. For purposes of the regulations in this subpart, a round trip shall be considered to consist of...

  17. 26 CFR 49.4264(e)-1 - Round trips.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Round trips. 49.4264(e)-1 Section 49.4264(e)-1... TAXES FACILITIES AND SERVICES EXCISE TAXES Transportation of Persons § 49.4264(e)-1 Round trips. (a) In general. For purposes of the regulations in this subpart, a round trip shall be considered to consist of...

  18. 26 CFR 49.4264(e)-1 - Round trips.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Round trips. 49.4264(e)-1 Section 49.4264(e)-1... TAXES FACILITIES AND SERVICES EXCISE TAXES Transportation of Persons § 49.4264(e)-1 Round trips. (a) In general. For purposes of the regulations in this subpart, a round trip shall be considered to consist of...

  19. A Contingent Trip Model for Estimating Rail-trail Demand

    Treesearch

    Carter J. Betz; John C. Bergstrom; J. Michael Bowker

    2003-01-01

    The authors develop a contingent trip model to estimate the recreation demand for and value of a potential rail-trail site in north-east Georgia. The contingent trip model is an alternative to travel cost modelling useful for ex ante evaluation of proposed recreation resources or management alternatives. The authors estimate the empirical demand for trips using a...

  20. Valuation of travel time savings in viewpoint of WTA.

    PubMed

    Shao, Chang-Qiao; Liu, Yang; Liu, Xiao-Ming

    2014-01-01

    In order to investigate the issues in measurement of value of travel time savings (VTTS), the willingness-to-accept (WTA) for the private car owner is studied by using surveyed data. It is convincing that trip purpose, trip length, time savings, cost savings, income, and allowance from employee have effects on the WTA. Moreover, influences of these variables are not the same for different trip purposes. For commuting trips, effects of income and allowance from employee are significant while time savings and cost savings are dominated for leisure and shopping trips. It is also found that WTA is much higher than expected which implies that there are a group of drivers who are not prone to switching to other trip modes other than passenger car.

  1. Ultrasonic Stir Welding

    NASA Technical Reports Server (NTRS)

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  2. W-026, transuranic waste restricted waste management (TRU RWM) glovebox operational test report

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

    Leist, K.J.

    1998-02-18

    The TRU Waste/Restricted Waste Management (LLW/PWNP) Glovebox 401 is designed to accept and process waste from the Transuranic Process Glovebox 302. Waste is transferred to the glovebox via the Drath and Schraeder Bagless Transfer Port (DO-07401) on a transfer stand. The stand is removed with a hoist and the operator inspects the waste (with the aid of the Sampling and Treatment Director) to determine a course of action for each item. The waste is separated into compliant and non compliant. One Trip Port DO-07402A is designated as ``Compliant``and One Trip Port DO-07402B is designated as ``Non Compliant``. As the processingmore » (inspection, bar coding, sampling and treatment) of the transferred items takes place, residue is placed in the appropriate One Trip port. The status of the waste items is tracked by the Data Management System (DMS) via the Plant Control System (PCS) barcode interface. As an item is moved for sampling or storage or it`s state altered by treatment, the Operator will track an items location using a portable barcode reader and entry any required data on the DMS console. The Operational Test Procedure (OTP) will perform evolutions (described here) using the Plant Operating Procedures (POP) in order to verify that they are sufficient and accurate for controlled glovebox operation.« less

  3. 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.

  4. A Comparison of Active and Passive Methods for Control of Hypersonic Boundary Layers on Airbreathing Configurations

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; Nowak, Robert J.

    2003-01-01

    Active and passive methods for control of hypersonic boundary layers have been experimentally examined in NASA Langley Research Center wind tunnels on a Hyper-X model. Several configurations for forcing transition using passive discrete roughness elements and active mass addition, or blowing, methods were compared in two hypersonic facilities, the 20-Inch Mach 6 Air and the 31-Inch Mach 10 Air tunnels. Heat transfer distributions, obtained via phosphor thermography, shock system details, and surface streamline patterns were measured on a 0.333-scale model of the Hyper-X forebody. The comparisons between the active and passive methods for boundary layer control were conducted at test conditions that nearly match the nominal Mach 7 flight trajectory of an angle-of-attack of 2-deg and length Reynolds number of 5.6 million. For the passive roughness examination, the primary parametric variation was a range of trip heights within the calculated boundary layer thickness for several trip concepts. The prior passive roughness study resulted in a swept ramp configuration being selected for the Mach 7 flight vehicle that was scaled to be roughly 0.6 of the calculated boundary layer thickness. For the active jet blowing study, the blowing manifold pressure was systematically varied for each configuration, while monitoring the mass flow, to determine the jet penetration height with schlieren and transition movement with the phosphor system for comparison to the passive results. All the blowing concepts tested were adequate for providing transition onset near the trip location with manifold stagnation pressures on the order of 40 times the model static pressure or higher.

  5. Cranking Out Adventure: A Bike Leader's Guide to Trial and Error Touring.

    ERIC Educational Resources Information Center

    Rohnke, Karl

    The product of a 3,355 mile bicycle trip involving a co-ed group of teenagers and a leader (N=12), this guide to bike riding trips presents practical and philosophical insights gained by the Project Adventure leader who conducted the trip. Detailed lists of pre- and on-trip requirements are presented. Specifically, there are sections devoted to…

  6. Affective and cognitive effects of information use over the course of a vacation

    Treesearch

    Christine A. Vogt; Susan I. Stewart

    1998-01-01

    From pre-trip planning through post-trip remembering, vacations unfold over long periods of time. Through the course of a trip the same travel information may be used repeatedly but with different levels of success and satisfaction. These experiential fluctuations over time were examined in a study of trip planners, who collected information from a chamber of commerce...

  7. Field trip guide to the 2010 Schultz Fire Burn Area

    Treesearch

    Karen Koestner; Anne Youberg; Daniel G. Neary

    2011-01-01

    This field trip guide was created for a September 18th, 2011, field trip to the 2010 Schultz Fire burn area northeast of Flagstaff, Arizona, as part of the Arizona Hydrological Society's Annual Symposium. The guide provides background information on the 2010 Schultz Fire and aftermath (Section 1), site-specific information for each stop on the field trip (Section...

  8. The Effectiveness of a Virtual Field Trip (VFT) Module in Learning Biology

    ERIC Educational Resources Information Center

    Haris, Norbaizura; Osman, Kamisah

    2015-01-01

    Virtual Field Trip is a computer aided module of science developed to study the Colonisation and Succession in Mangrove Swamps, as an alternative to the real field trip in Form for Biology. This study is to identify the effectiveness of the Virtual Field Trip (VFT) module towards the level of achievement in the formative test for this topic. This…

  9. Relationship between Objectively Measured Transportation Behaviors and Health Characteristics in Older Adults.

    PubMed

    Takemoto, Michelle; Carlson, Jordan A; Moran, Kevin; Godbole, Suneeta; Crist, Katie; Kerr, Jacqueline

    2015-10-30

    This study used objective Global Positioning Systems (GPS) to investigate the relationship between pedestrian and vehicle trips to physical, cognitive, and psychological functioning in older adults living in retirement communities. Older adults (N = 279; mean age = 83 ± 6 years) wore a GPS and accelerometer for 6 days. Participants completed standard health measures. The Personal Activity and Location Measurement System (PALMS) was used to calculate the average daily number of trips, distance, and minutes traveled for pedestrian and vehicle trips from the combined GPS and accelerometer data. Linear mixed effects regression models explored relationships between these transportation variables and physical, psychological and cognitive functioning. Number, distance, and minutes of pedestrian trips were positively associated with physical and psychological functioning but not cognitive functioning. Number of vehicle trips was negatively associated with fear of falls; there were no other associations between the vehicle trip variables and functioning. Vehicle travel did not appear to be related to functioning in older adults in retirement communities except that fear of falling was related to number of vehicle trips. Pedestrian trips had moderate associations with multiple physical and psychological functioning measures, supporting a link between walking and many aspects of health in older adults.

  10. JPRS Report Science and Technology, Japan: Atomic Energy Society 1989 Annual Meeting.

    DTIC Science & Technology

    1989-10-13

    Control Rod Hole in VHTRC-1 Core [F, Akino, T, Yamane, et al.] ,,, 5 Measurement of MEU [Medium Enriched Uranium ] Fuel Element Characteristics in...K. Yoshida, K. Kobayashi, I. Kimura , C. Yamanaka, and S. Nakai, Laser Laboratory,, Osaka University. Nuclear Reactor Laboratory, Kyoto University...1 core loaded with 278 fuel rods (4 percent enriched uranium ). The PNS target was placed at the back center of the 1/2 assembly on the fixed side

  11. Thermal control of high energy nuclear waste, space option. [mathematical models

    NASA Technical Reports Server (NTRS)

    Peoples, J. A.

    1979-01-01

    Problems related to the temperature and packaging of nuclear waste material for disposal in space are explored. An approach is suggested for solving both problems with emphasis on high energy density waste material. A passive cooling concept is presented which utilized conduction rods that penetrate the inner core. Data are presented to illustrate the effectiveness of the rods and the limit of their capability. A computerized thermal model is discussed and developed for the cooling concept.

  12. Tamoxifen and vitamin E treatments delay symptoms in the mouse model of Niemann-Pick C.

    PubMed

    Bascuñan-Castillo, Eric C; Erickson, Robert P; Howison, Christy M; Hunter, Robert J; Heidenreich, Randall H; Hicks, Chad; Trouard, Theodore P; Gillies, Robert J

    2004-01-01

    Niemann-Pick C disease (NPC) is an irreversible neurodegenerative disorder without current treatment. It is the result of deficient intracellular cholesterol movement. We investigated the effects of tamoxifen and vitamin E (D-alpha tocopherol) treatment on patterns of weight loss and motor function in the mouse model of Niemann-Pick C disease (Npc1-/- mice). Tamoxifen has multiple metabolic effects, including reducing oxidative damage, while vitamin E primarily has this property. Npc1-/- mice were identified and treatment was initiated at an approximate age of 21 days. Tamoxifen suspended in peanut oil was administered via intraperitoneal injection (weekly, at a dose calculated to deliver 0.023 microg/g/day). Vitamin E (25 IU) was administered orally via gavage once a week. Weight loss and Rota-Rod performance were analyzed by using Kaplan-Meyer survival curves. Tamoxifen treatment by itself significantly delayed weight loss (an endpoint of neurodegeneration) in male and female mice compared to untreated controls. Motor function was evaluated by performance on a Rota-Rod. Tamoxifen maintained Rota-Rod performance for about an extra week. Vitamin E treatment significantly delayed weight loss in females only. Rota-Rod performance was maintained slightly longer in mice treated with vitamin E. Simultaneous use of both treatments did not delay weight loss longer than tamoxifen-only treatment but had a greater effect than either treatment alone on Rota-Rod performance and demonstrated a significant positive effect on the early "learning curve" portion of the Rota-Rod evaluations. We found significant but relatively small improvements in rate of disease progression by treating Npc1-/- mice with tamoxifen and/or vitamin E. Some sex differences in response and an early improvement in Rota-Rod performance suggest areas for further study.

  13. 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.

  14. Surviving bacterial sibling rivalry: inducible and reversible phenotypic switching in Paenibacillus dendritiformis.

    PubMed

    Be'er, Avraham; Florin, E-L; Fisher, Carolyn R; Swinney, Harry L; Payne, Shelley M

    2011-01-01

    Natural habitats vary in available nutrients and room for bacteria to grow, but successful colonization can lead to overcrowding and stress. Here we show that competing sibling colonies of Paenibacillus dendritiformis bacteria survive overcrowding by switching between two distinct vegetative phenotypes, motile rods and immotile cocci. Growing colonies of the rod-shaped bacteria produce a toxic protein, Slf, which kills cells of encroaching sibling colonies. However, sublethal concentrations of Slf induce some of the rods to switch to Slf-resistant cocci, which have distinct metabolic and resistance profiles, including resistance to cell wall antibiotics. Unlike dormant spores of P. dendritiformis, the cocci replicate. If cocci encounter conditions that favor rods, they secrete a signaling molecule that induces a switch to rods. Thus, in contrast to persister cells, P. dendritiformis bacteria adapt to changing environmental conditions by inducible and reversible phenotypic switching. In favorable environments, species may face space and nutrient limits due to overcrowding. Bacteria provide an excellent model for analyzing principles underlying overcrowding and regulation of density in nature, since their population dynamics can be easily and accurately assessed under controlled conditions. We describe a newly discovered mechanism for survival of a bacterial population during overcrowding. When competing with sibling colonies, Paenibacillus dendritiformis produces a lethal protein (Slf) that kills cells at the interface of encroaching colonies. Slf also induces a small proportion of the cells to switch from motile, rod-shaped cells to nonmotile, Slf-resistant, vegetative cocci. When crowding is reduced and nutrients are no longer limiting, the bacteria produce a signal that induces cocci to switch back to motile rods, allowing the population to spread. Genes encoding components of this phenotypic switching pathway are widespread among bacterial species, suggesting that this survival mechanism is not unique to P. dendritiformis.

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

    Chen Shuguang, E-mail: hustcsg@sohu.com; Zeng Kai; Li Haibin

    Dispersed rhombohedral NiS rods with high aspect ratios and rhombic dodecahedron-like cubic NiS{sub 2} crystals were prepared by solvothermal routes using NiCl{sub 2}.6H{sub 2}O and Na{sub 2}S{sub 2}O{sub 3}.5H{sub 2}O as reagents and ethylenediamine as a solvent, and 3D blossoming flower-like rhombohedral NiS microstructures were synthesized using different sulfur sources of thiourea. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersion spectrometry and selected area electronic diffraction. All the products were pure and had good single crystalline nature. The synthesis parameters were of great importance on the purity and morphology of themore » products. The possible growth mechanisms have been discussed based on the analyses of the effects of sulfur sources and solvent on the crystal structures and detailed configurations of the products. The present work is likely to help the phase-controlled synthesis of other metal chalcogenides. - Graphical abstract: Rhombohedral NiS dispersed rods and 3D flower-like microstructures are evolved from dispersed nucleus and aggregate of nucleus, respectively, and the cross-sections of such rods are in equilateral triangle-like shape. Highlights: > 3D blossoming flower-like r-NiS microstructures are obtained. > Equilateral triangle-like cross-sections of r-NiS rods are observed. > Approach based on XRD analysis to phase-controlled synthesis is presented.« less

  16. 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

  17. 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 photoreceptors. PMID:10051522

  18. Autonomous motion of metallic microrods propelled by ultrasound.

    PubMed

    Wang, Wei; Castro, Luz Angelica; Hoyos, Mauricio; Mallouk, Thomas E

    2012-07-24

    Autonomously moving micro-objects, or micromotors, have attracted the attention of the scientific community over the past decade, but the incompatibility of phoretic motors with solutions of high ionic strength and the use of toxic fuels have limited their applications in biologically relevant media. In this letter we demonstrate that ultrasonic standing waves in the MHz frequency range can levitate, propel, rotate, align, and assemble metallic microrods (2 μm long and 330 nm diameter) in water as well as in solutions of high ionic strength. Metallic rods levitated to the midpoint plane of a cylindrical cell when the ultrasonic frequency was tuned to create a vertical standing wave. Fast axial motion of metallic microrods at ~200 μm/s was observed at the resonant frequency using continuous or pulsed ultrasound. Segmented metal rods (AuRu or AuPt) were propelled unidirectionally with one end (Ru or Pt, respectively) consistently forward. A self-acoustophoresis mechanism based on the shape asymmetry of the metallic rods is proposed to explain this axial propulsion. Metallic rods also aligned and self-assembled into long spinning chains, which in the case of bimetallic rods had a head-to-tail alternating structure. These chains formed ring or streak patterns in the levitation plane. The diameter or distance between streaks was roughly half the wavelength of the ultrasonic excitation. The ultrasonically driven movement of metallic rods was insensitive to the addition of salt to the solution, opening the possibility of driving and controlling metallic micromotors in biologically relevant media using ultrasound.

  19. Interference of two codirectional exclusion processes in the presence of a static bottleneck: A biologically motivated model

    NASA Astrophysics Data System (ADS)

    Mishra, Bhavya; Chowdhury, Debashish

    2017-06-01

    We develop a two-species exclusion process with a distinct pair of entry and exit sites for each species of rigid rods. The relatively slower forward stepping of the rods in an extended bottleneck region, located in between the two entry sites, controls the extent of interference of the codirectional flow of the two species of rods. The relative positions of the sites of entry of the two species of rods with respect to the location of the bottleneck are motivated by a biological phenomenon. However, the primary focus of the study here is to explore the effects of the interference of the flow of the two species of rods on their spatiotemporal organization and the regulations of this interference by the extended bottleneck. By a combination of mean-field theory and computer simulation, we calculate the flux of both species of rods and their density profiles as well as the composite phase diagrams of the system. If the bottleneck is sufficiently stringent, then some of the phases become practically unrealizable, although not ruled out on the basis of any fundamental physical principle. Moreover, the extent of suppression of flow of the downstream entrants by the flow of the upstream entrants can also be regulated by the strength of the bottleneck. We speculate on the possible implications of the results in the context of the biological phenomenon that motivated the formulation of the theoretical model.

  20. Prevention of Disease in Travel from the Perspective of Iranian Traditional Medicine.

    PubMed

    Motavasselian, Fatemeh; Hashemi, Monireh Seyed; Emtiazy, Majid

    2016-05-01

    Due to the high volume of travel and the spread of various diseases as well as disorders during a trip, one of the major concerns for travelers is the issues related to disease spread, control, and prevention. The approach of philosophers and traditional physicians along with hygiene measures were noted as trip recommendations in their textbooks. Considering negligence in disease prevention and the lack of dedicated and systematic discussion on this topic, this article aims at collecting their experiences as a practical reference point. This qualitative study, review articles in the field of traditional medicine and search in authentic books on traditional medicine. The gathered data were initially analyzed and then categorized. Results were described in several sub-categories, including general recommendation, food and drinking recommendations during travel, prevention of dehydration in warm and cold conditions, poisoned and polluted air recommendations, management of sea passengers, fatigue due to travel, and the prevention of skin diseases. These measures are efficient interventions and cost-effective, which provide guidelines for traveler's health during a trip.

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