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Sample records for driver beams forheavy

  1. BEAM SIMULATIONS USING VIRTUAL DIAGNOSTICS FOR THE DRIVER LINAC

    SciTech Connect

    R. C. York; X. Wu; Q. Zhao

    2011-12-21

    End-to-end beam simulations for the driver linac have shown that the design meets the necessary performance requirements including having adequate transverse and longitudinal acceptances. However, to achieve reliable operational performance, the development of appropriate beam diagnostic systems and control room procedures are crucial. With limited R&D funding, beam simulations provide a cost effective tool to evaluate candidate beam diagnostic systems and to provide a critical basis for developing early commissioning and later operational activities. We propose to perform beam dynamic studies and engineering analyses to define the requisite diagnostic systems of the driver linac and through simulation to develop and test commissioning and operational procedures.

  2. Beam Simulations for IRE and Driver-Status and Strategy

    SciTech Connect

    Friedman, A.; Grote, D.P.; Lee, E.P.; Sonnendrucker, E.

    2000-03-01

    The methods and codes employed in the U.S. Heavy Ion Fusion program to simulate the beams in an Integrated Research Experiments (IRE) facility and a fusion driver are presented in overview. A new family of models incorporating accelerating module impedance, multi-beam, and self-magnetic effects is described, and initial WARP3d particle simulations of beams using these models are presented. Finally, plans for streamlining the machine-design simulation sequence, and for simulating beam dynamics from the source to the target in a consistent and comprehensive manner, are described.

  3. Beam Simulations for IRE and Driver - Status and Strategy

    SciTech Connect

    Friedman, A; Grote, D P; Lee, E P

    2001-03-13

    The methods and codes employed in the U.S. Heavy Ion Fusion program to simulate the beams in an Integrated Research Experiments (IRE) facility and a fusion driver are presented in overview. A new family of models incorporating accelerating module impedance, multi-beam, and self-magnetic effects is described, and initial WARP3d particle simulations of beams using these models are presented. Finally, plans for streamlining the machine-design simulation sequence, and for simulating beam dynamics from the source to the target in a consistent and comprehensive manner, are described.

  4. Nonlinear transmission line based electron beam driver

    SciTech Connect

    French, David M.; Hoff, Brad W.; Tang Wilkin; Heidger, Susan; Shiffler, Don; Allen-Flowers, Jordan

    2012-12-15

    Gated field emission cathodes can provide short electron pulses without the requirement of laser systems or cathode heating required by photoemission or thermionic cathodes. The large electric field requirement for field emission to take place can be achieved by using a high aspect ratio cathode with a large field enhancement factor which reduces the voltage requirement for emission. In this paper, a cathode gate driver based on the output pulse train from a nonlinear transmission line is experimentally demonstrated. The application of the pulse train to a tufted carbon fiber field emission cathode generates short electron pulses. The pulses are approximately 2 ns in duration with emission currents of several mA, and the train contains up to 6 pulses at a frequency of 100 MHz. Particle-in-cell simulation is used to predict the characteristic of the current pulse train generated from a single carbon fiber field emission cathode using the same technique.

  5. Microfabricated Ion Beam Drivers for Magnetized Target Fusion

    NASA Astrophysics Data System (ADS)

    Persaud, Arun; Seidl, Peter; Ji, Qing; Ardanuc, Serhan; Miller, Joseph; Lal, Amit; Schenkel, Thomas

    2015-11-01

    Efficient, low-cost drivers are important for Magnetized Target Fusion (MTF). Ion beams offer a high degree of control to deliver the required mega joules of driver energy for MTF and they can be matched to several types of magnetized fuel targets, including compact toroids and solid targets. We describe an ion beam driver approach based on the MEQALAC concept (Multiple Electrostatic Quadrupole Array Linear Accelerator) with many beamlets in an array of micro-fabricated channels. The channels consist of a lattice of electrostatic quadrupoles (ESQ) for focusing and of radio-frequency (RF) electrodes for ion acceleration. Simulations with particle-in-cell and beam envelope codes predict >10x higher current densities compared to state-of-the-art ion accelerators. This increase results from dividing the total ion beam current up into many beamlets to control space charge forces. Focusing elements can be biased taking advantage of high breakdown electric fields in sub-mm structures formed using MEMS techniques (Micro-Electro-Mechanical Systems). We will present results on ion beam transport and acceleration in MEMS based beamlets. Acknowledgments: This work is supported by the U.S. DOE under Contract No. DE-AC02-05CH11231.

  6. A driver linac for the Advanced Exotic Beam Laboratory : physics design and beam dynamics simulations.

    SciTech Connect

    Ostroumov, P. N.; Mustapha, B.; Nolen, J.; Physics

    2007-01-01

    The Advanced Exotic Beam Laboratory (AEBL) being developed at ANL consists of an 833 MV heavy-ion driver linac capable of producing uranium ions up to 200 MeV/u and protons to 580 MeV with 400 kW beam power. We have designed all accelerator components including a two charge state LEBT, an RFQ, a MEBT, a superconducting linac, a stripper station and chicane. We present the results of an optimized linac design and end-to-end simulations including machine errors and detailed beam loss analysis. The Advanced Exotic Beam Laboratory (AEBL) has been proposed at ANL as a reduced scale of the original Rare Isotope Accelerator (RIA) project with about half the cost but the same beam power. AEBL will address 90% or more of RIA physics but with reduced multi-users capabilities. The focus of this paper is the physics design and beam dynamics simulations of the AEBL driver linac. The reported results are for a multiple charge state U{sup 238} beam.

  7. Effect of the transverse parasitic mode on beam performance for the ADS driver linac in China

    NASA Astrophysics Data System (ADS)

    Cheng, Peng; Pei, Shi-Lun; Wang, Jiu-Qing; Li, Zhi-Hui

    2015-05-01

    The ADS (Accelerator Driven subcritical System) driver linac in China is designed to run in CW (Continuous Wave) mode with 10 mA designed beam current. In this scenario, the beam-induced parasitic modes in the ADS driver linac may make the beam unstable or deteriorate the beam performance. To evaluate the parasitic mode effect on the beam dynamics systematically, simulation studies using the ROOT-based numerical code SMD have been conducted. The longitudinal beam instability induced by the HOMs (High Order Modes) and SOMs (Same Order Modes) has little effect on the longitudinal beam performance for the current ADS driver linac design based on the 10 MeV/325 MHz injector I from previous studies. Here the transverse parasitic mode (i.e., dipole HOM) effect on the transverse beam performance at the ADS driver linac exit is investigated. To more reasonably quantify the dipole mode effect, the multi-bunch effective emittance is introduced in this paper.

  8. Error analysis in post linac to driver linac transport beam line of RAON

    NASA Astrophysics Data System (ADS)

    Kim, Chanmi; Kim, Eun-San

    2016-07-01

    We investigated the effects of magnet errors in the beam transport line connecting the post linac to the driver linac (P2DT) in the Rare Isotope Accelerator in Korea (RAON). The P2DT beam line is bent by 180-degree to send the radioactive Isotope Separation On-line (ISOL) beams accelerated in Linac-3 to Linac-2. This beam line transports beams with multi-charge state 132Sn45,46,47. The P2DT beam line includes 42 quadrupole, 4 dipole and 10 sextupole magnets. We evaluate the effects of errors on the trajectory of the beam by using the TRACK code, which includes the translational and the rotational errors of the quadrupole, dipole and sextupole magnets in the beam line. The purpose of this error analysis is to reduce the rate of beam loss in the P2DT beam line. The distorted beam trajectories can be corrected by using six correctors and seven monitors.

  9. Evaluation of Negative-Ion-Beam Driver Concepts for Heavy Ion Fusion

    SciTech Connect

    Grisham, Larry R.

    2003-03-15

    The feasibility of producing and using atomically neutral heavy ion beams produced from negative ions as drivers for an inertial confinement fusion reactor is evaluated. Bromine and iodine appear to be the most attractive elements for the driver beams. Fluorine and chlorine appear to be the most appropriate feedstocks for initial tests of extractable negative-ion current densities. With regard to ion sources, photodetachment neutralizers, and vacuum requirements for accelerators and beam transport, this approach appears feasible within existing technology, and the vacuum requirements are essentially identical to those for positive-ion drivers except in the target chamber. The principal constraint is that this approach requires harder vacuums in the target chamber than do space-charge-neutralized positive-ion drivers. With realistic (but perhaps pessimistic) estimates of the total ionization cross section, limiting the ionization of a neutral beam to <5% while traversing a 3-m path would require a chamber pressure of no more than 1.3 x 10{sup -5} torr. However, it appears that substantial improvements in the beam spot size on target might be achieved at pressures a factor of 10 or more higher than this. Alternatively, even at still higher chamber pressures that would strongly ionize atomically neutral beams, the negative-ion approach may still have significant appeal, since it precludes the possibly challenging problem of electron contamination of a positive-ion beam during acceleration, drift compression, and focusing.

  10. Evaluation of Negative-Ion-Beam Driver Concepts for Heavy Ion Fusion

    SciTech Connect

    Larry R. Grisham

    2002-01-14

    We evaluate the feasibility of producing and using atomically neutral heavy ion beams produced from negative ions as drivers for an inertial confinement fusion reactor. Bromine and iodine appear to be the most attractive elements for the driver beams. Fluorine and chlorine appear to be the most appropriate feedstocks for initial tests of extractable negative ion current densities. With regards to ion sources, photodetachment neutralizers, and vacuum requirements for accelerators and beam transport, this approach appears feasible within existing technology, and the vacuum requirements are essentially identical to those for positive ion drivers except in the target chamber. The principal constraint is that this approach requires harder vacuums in the target chamber than do space-charge-neutralized positive ion drivers. With realistic (but perhaps pessimistic) estimates of the total ionization cross section, limiting the ionization of a neutral beam to less than 5% while traversing a four -meter path would require a chamber pressure of no more than 5 x 10{sup -5} torr. Alternatively, even at chamber pressures that are too high to allow propagation of atomically neutral beams, the negative ion approach may still have appeal, since it precludes the possibly serious problem of electron contamination of a positive ion beam during acceleration, drift compression, and focusing.

  11. Design of post linac to driver linac transport beam line in rare isotope accelerator

    NASA Astrophysics Data System (ADS)

    Kim, Chanmi; Kim, Eun-San

    2015-07-01

    We investigated the design of a beam transport line connecting the post linac to the driver linac (P2DT) in the Rare Isotope Accelerator (RAON). P2DT beam line is designed by 180° bending scheme to send the radioactive isotope separation on-line (ISOL) beams accelerated in the Linac-3 to Linac-2. The beam line is designed as a 180° bend for the transport of a multi-charge state 132Sn+45,+46,+47 beam. We used the TRACE 3-D, TRACK, and ORBIT codes to design the optics system, which also includes two bunchers and ten sextupole magnets for chromaticity compensation. The transverse emittance growth is minimized by adopting mirror symmetric optics and by correcting second-order aberrations using sextupoles. We report on the multi-charge state beam transport performance of the designed beam line. The main characteristics of the P2DT line are to minimize beam loss and the growth of emittance, and for charge stripping. Beam optics for P2DT is optimized for reducing beam loss and charge stripping. As Linac-3 may accelerate the stable beam and radioactive beam simultaneously, P2DT line also transports the stable beam and radioactive beam simultaneously. Thus, we need a RF switchyard to send the stable beam to the ISOL target and the radioactive beam to the high-energy experimental area in Linac-2 end.

  12. Design of post linac to driver linac transport beam line in rare isotope accelerator.

    PubMed

    Kim, Chanmi; Kim, Eun-San

    2015-07-01

    We investigated the design of a beam transport line connecting the post linac to the driver linac (P2DT) in the Rare Isotope Accelerator (RAON). P2DT beam line is designed by 180° bending scheme to send the radioactive isotope separation on-line (ISOL) beams accelerated in the Linac-3 to Linac-2. The beam line is designed as a 180° bend for the transport of a multi-charge state (132)Sn(+45,+46,+47) beam. We used the TRACE 3-D, TRACK, and ORBIT codes to design the optics system, which also includes two bunchers and ten sextupole magnets for chromaticity compensation. The transverse emittance growth is minimized by adopting mirror symmetric optics and by correcting second-order aberrations using sextupoles. We report on the multi-charge state beam transport performance of the designed beam line. The main characteristics of the P2DT line are to minimize beam loss and the growth of emittance, and for charge stripping. Beam optics for P2DT is optimized for reducing beam loss and charge stripping. As Linac-3 may accelerate the stable beam and radioactive beam simultaneously, P2DT line also transports the stable beam and radioactive beam simultaneously. Thus, we need a RF switchyard to send the stable beam to the ISOL target and the radioactive beam to the high-energy experimental area in Linac-2 end.

  13. Beam Simulation Studies of the LEBT for RIA Driver Linac

    SciTech Connect

    Zhao, Q.; Wu, X.; Andreev, V.; Balabin, A.; Doleans, M.; Gorelov, D.; Grimm, T.L.; Hartung, W.; Marti, F.; Schriber, S.O.; York, R.C.; Leitner, D.; Lyneis, C.M.

    2005-03-15

    The low energy beam transport (LEBT) system in the front-end of the Rare Isotope Accelerator (RIA) uses a 70 kV platform to pre-accelerate the ion beam from a 30 kV Electron Cyclotron Resonance (ECR) ion source, followed by an achromatic charge selection system. The selected beam is then pre-bunched and matched into the entrance of a Radio Frequency Quadrupole (RFQ) with a multi-harmonic buncher. To meet the beam power requirements for heavy ions, high current (several mA), multi-species beams will be extracted from the ECR. Therefore, it is crucial to control space charge effects in order to obtain the low emittance beam required for RIA. The PARMELA code is used to perform the LEBT simulations for the multi-species beams with 3D space charge calculations. The results of the beam dynamics simulations are presented, and the key issues of emittance growth in the LEBT and its possible compensation are discussed.

  14. Beam Loss Studies for Rare Isotope Driver Linacs Final Report

    SciTech Connect

    Wangler, T P; Kurennoy, S S; Billen, J H; Crandall, K R; Qiang, J; Ryne, R D; Mustapha, B; Ostroumov, P; Zhao, Q; York, and R. C.

    2008-03-26

    The Fortran 90 RIAPMTQ/IMPACT code package is a pair of linked beam-dynamics simulation codes that have been developed for end-to-end computer simulations of multiple-charge-state heavy-ion linacs for future exotic-beam facilities. These codes have multiple charge-state capability, and include space-charge forces. The simulations can extend from the low-energy beam-transport line after an ECR ion source to the end of the linac. The work has been performed by a collaboration including LANL, LBNL, ANL, and MSU. The code RIAPMTQ simulates the linac front-end beam dynamics including the LEBT, RFQ, and MEBT. The code IMPACT simulates the beam dynamics of the main superconducting linac. The codes have been benchmarked for rms beam properties against previously existing codes at ANL and MSU. The codes allow high-statistics runs on parallel supercomputing platforms, particularly at NERSC at LBNL, for studies of beam losses. The codes also run on desktop PC computers for low-statistics work. The code package is described in more detail in a recent publication [1] in the Proceedings of PAC07 (2007 US Particle Accelerator Conference). In this report we describe the main activities for the FY07 beam-loss studies project using this code package.

  15. Numerical analysis corresponding with experiment in compact beam simulator for heavy ion inertial fusion driver

    NASA Astrophysics Data System (ADS)

    Kikuchi, T.; Sakai, Y.; Komori, T.; Sato, T.; Hasegawa, J.; Horioka, K.; Takahashi, K.; Sasaki, T.; Harada, Nob

    2016-05-01

    Tune depression in a compact beam equipment is estimated, and numerical simulation results are compared with an experimental one for the compact beam simulator in a driver of heavy ion inertial fusion. The numerical simulation with multi-particle tracking is carried out, corresponding to the experimental condition, and the result is discussed with the experimental one. It is expected that the numerical simulation developed in this paper is useful tool to investigate the beam dynamics in the experiment with the compact beam simulator.

  16. Proof-of-Concept Experiments for Negative Ion Driver Beams for Heavy Ion Fusion

    SciTech Connect

    L.R. Grisham; S.K. Hahto; S.T. Hahto; J.W. Kwan; K.N. Leung

    2003-05-06

    Negative halogen ion beams have recently been proposed as heavy ion fusion drivers. They would avoid the problem of electron accumulation in positive ion beams, and could be efficiently photo-detached to neutrals if desired. Initial experiments using chlorine produced a current density of 45 mA/cm{sup 2} of 99.5% atomic negative Cl with an e/Cl- ratio as low as 7:1 and good emittance.

  17. Beam intensity expectations for a 200 MeV/u 400 kW radioactive beam driver accelerator.

    SciTech Connect

    Back, B. B.; Jiang, C. L.; Physics

    2006-12-31

    The expected radioactive ion production rate for a 200 MeV/u 400 kW driver linac using four different production methods is discussed. For each isotope the optimum method is identified and the rate is calculated based on different model assumptions, empirical observation and extrapolations. The results are compared to the rates expected for a 550 MeV proton driver machine with a beam power of 50 kW, as well as the full RIA facility with a 400 MeV/u 400 kW production linac.

  18. BANSHEE: High-voltage repetitively pulsed electron-beam driver

    SciTech Connect

    VanHaaften, F.

    1992-01-01

    BANSHEE (Beam Accelerator for a New Source of High-Energy Electrons) this is a high-voltage modulator is used to produce a high-current relativistic electron beam for high-power microwave tube development. The goal of the BANSHEE research is first to achieve a voltage pulse of 700--750 kV with a 1-{mu}s pulse width driving a load of {approximately}100 {Omega}, the pulse repetition frequency (PRF) of a few hertz. The ensuing goal is to increase the pulse amplitude to a level approaching 1 MV. We conducted tests using half the modulator with an output load of 200 {Omega}, up to a level of {approximately}650 kV at a PRF of 1 Hz and 525 kV at a PRF of 5 Hz. We then conducted additional testing using the complete system driving a load of {approximately}100 {Omega}.

  19. BANSHEE: High-voltage repetitively pulsed electron-beam driver

    SciTech Connect

    VanHaaften, F.

    1992-08-01

    BANSHEE (Beam Accelerator for a New Source of High-Energy Electrons) this is a high-voltage modulator is used to produce a high-current relativistic electron beam for high-power microwave tube development. The goal of the BANSHEE research is first to achieve a voltage pulse of 700--750 kV with a 1-{mu}s pulse width driving a load of {approximately}100 {Omega}, the pulse repetition frequency (PRF) of a few hertz. The ensuing goal is to increase the pulse amplitude to a level approaching 1 MV. We conducted tests using half the modulator with an output load of 200 {Omega}, up to a level of {approximately}650 kV at a PRF of 1 Hz and 525 kV at a PRF of 5 Hz. We then conducted additional testing using the complete system driving a load of {approximately}100 {Omega}.

  20. Linear beam raster magnet driver based on H-bridge technique

    DOEpatents

    Sinkine, Nikolai I.; Yan, Chen; Apeldoorn, Cornelis; Dail, Jeffrey Glenn; Wojcik, Randolph Frank; Gunning, William

    2006-06-06

    An improved raster magnet driver for a linear particle beam is based on an H-bridge technique. Four branches of power HEXFETs form a two-by-two switch. Switching the HEXFETs in a predetermined order and at the right frequency produces a triangular current waveform. An H-bridge controller controls switching sequence and timing. The magnetic field of the coil follows the shape of the waveform and thus steers the beam using a triangular rather than a sinusoidal waveform. The system produces a raster pattern having a highly uniform raster density distribution, eliminates target heating from non-uniform raster density distributions, and produces higher levels of beam current.

  1. New Capabilities for Modeling Intense Beams in Heavy Ion Fusion Drivers

    SciTech Connect

    Friedman, A; Barnard, J J; Bieniosek, F M; Celata, C M; Cohen, R H; Davidson, R C; Grote, D P; Haber, I; Henestroza, E; Lee, E P; Lund, S M; Qin, H; Sharp, W M; Startsev, E; Vay, J L

    2003-09-09

    Significant advances have been made in modeling the intense beams of heavy-ion beam-driven Inertial Fusion Energy (Heavy Ion Fusion). In this paper, a roadmap for a validated, predictive driver simulation capability, building on improved codes and experimental diagnostics, is presented, as are examples of progress. The Mesh Refinement and Particle-in-Cell methods were integrated in the WARP code; this capability supported an injector experiment that determined the achievable current rise time, in good agreement with calculations. In a complementary effort, a new injector approach based on the merging of {approx}100 small beamlets was simulated, its basic feasibility established, and an experimental test designed. Time-dependent 3D simulations of the High Current Experiment (HCX) were performed, yielding voltage waveforms for an upcoming study of bunch-end control. Studies of collective beam modes which must be taken into account in driver designs were carried out. The value of using experimental data to tomographically ''synthesize'' a 4D beam particle distribution and so initialize a simulation was established; this work motivated further development of new diagnostics which yield 3D projections of the beam phase space. Other developments, including improved modeling of ion beam focusing and transport through the fusion chamber environment and onto the target, and of stray electrons and their effects on ion beams, are briefly noted.

  2. Beam dynamics studies in the driver LINAC pre-Stripper section of the RIA facility.

    SciTech Connect

    Lessner, E. S.; Ostroumov, P. N.

    2003-07-10

    The RIA facility driver linac consists of about 400 superconducting (SC) independently phased rf cavities. The linac is designed to accelerate simultaneously several-charge-state beams to generate as much as 400 kW of uranium beam power. The linac beam dynamics is most sensitive to the focusing and accelerating-structure parameters of the prestripper section, where the uranium beam is accelerated from 0.17 keV/u to 9.4 MeV/u. This section is designed to accept and accelerate 2 charge states (28 and 29) of uranium beam from an ECR ion source. The prestripper section must be designed to minimize the beam emittance distortion of this two-charge-state beam. In particular, the inter-cryostat spaces must be minimized and beam parameters near transitions of the accelerating and focusing lattices must be matched carefully. Several sources of possible effective emittance growth are considered in the design of the prestripper section and a tolerance budget is established. Numerical beam dynamics studies include realistic electric and magnetic 3-dimensional field distributions in the SC rf cavities and SC solenoids. Error effects in the longitudinal beam parameters are studied.

  3. StarDriver: Recent results on beam smoothing and LPI mitigation

    NASA Astrophysics Data System (ADS)

    Eimerl, D.; Skupsky, S.; Campbell, E. M.

    2016-05-01

    StarDriver was recently proposed as a highly flexible laser driver for inertial confinement fusion and high energy density physics. It envisions a laser drive consisting of very many beams at an aperture and energy where the optical technology is well-developed, used in concert to create a large scale laser driver system. In this paper we describe a StarDriver-class laser with 5120 physical beamlets disposed about the target chamber in 80 evenly spaced ports, each port containing 64 beamlets, each beamlet having about ∼1.5THz of 2D SSD bandwidth and suitable phase plates, an aperture of ∼65mm, an energy of 80J, and frequency-converted to ∼351nm.many beamlets at an aperture where optical technology is well-developed, and each beamlet has energy ∼100J in a several times diffraction limited beam. The ensemble of beamlets has frequency bandwidth 2%-10%, thereby providing significant control of both hydrodynamic and laser-plasma instabilities The drive at the target is ∼400kJ, has a well-behaved low L-mode spectrum, and smooths very rapidly, reaching an asymptotic smoothness of <1% in less than Ins.

  4. Experimental Investigation of Multibunch, Multipass Beam Breakup in the Jefferson Laboratory Free Electron Laser Upgrade Driver

    SciTech Connect

    Christopher Tennant; David Douglas; Kevin Jordan; Nikolitsa Merminga; Eduard Pozdeyev; Haipeng Wang; Todd I. Smith; Stefan Simrock; Ivan Bazarov; Georg Hoffstaetter

    2006-03-24

    In recirculating accelerators, and in particular energy recovery linacs (ERLs), the maximum current can be limited by multipass, multibunch beam breakup (BBU), which occurs when the electron beam interacts with the higher-order modes (HOMs) of an accelerating cavity on the accelerating pass and again on the energy recovering pass. This effect is of particular concern in the design of modern high average current energy recovery accelerators utilizing superconducting RF technology. Experimental characterization and observations of the instability at the Jefferson Laboratory 10 kW Free Electron Laser (FEL) are presented. Measurements of the threshold current for the instability are made under a variety of beam conditions and compared to the predictions of several BBU simulation codes. This represents the first time in which the codes have been experimentally benchmarked. With BBU posing a threat to high current beam operation in the FEL Driver, several suppression schemes were developed.

  5. Space charge and beam stability issues of the Fermilab proton driver in Phase I

    SciTech Connect

    K. Y. Ng

    2001-08-24

    Issues concerning beam stability of the proposed Fermilab Proton Driver are studied in its Phase I. Although the betatron tune shifts are dominated by space charge, these shifts are less than 0.25 and will therefore not drive the symmetric and antisymmetric modes of the beam envelope into instability. The longitudinal space charge force is large and inductive inserts may be needed to compensate for the distortion of the rf potential. Although the longitudinal impedance is space charge dominated, it will not drive any microwave instability, unless the real part of the impedance coming from the inductive inserts and wall resistivity of the beam tube are large enough. The design of the beam tube is therefore very important in order to limit the flow of eddy current and keep wall resistivity low. The transverse impedance is also space charge dominated. With the Proton Driver operated at an imaginary transition gamma, however, Landau damping will never be canceled and beam stability can be maintained with negative chromaticities.

  6. Beam loss and collimation in the Fermilab 16 GeV proton driver

    SciTech Connect

    Alexandr I. Drozhdin, Oleg E. Krivosheev and Nikolai V. Mokhov

    2001-07-20

    A high beam power of 1.15 MW in the proposed 16-GeV Proton Driver [1] implies serious constraints on beam losses in the machine. The main concerns are the hands-on maintenance and ground-water activation. Only with a very efficient beam collimation system can one reduce uncontrolled beam losses to an allowable level. The results on tolerable beam loss and on a proposed beam collimation system are summarized in this paper. A multi-turn particle tracking in the accelerator defined by all lattice components with their realistic strengths and aperture restrictions, and halo interactions with the collimators is done with the STRUCT code [2]. Full-scale Monte Carlo hadronic and electromagnetic shower simulations in the lattice elements, shielding, tunnel and surrounding dirt with realistic geometry, materials and magnetic field are done with the MARS14 code [3]. It is shown that the proposed 3-stage collimation system, allows localization of more than 99% of beamloss in a special straight section. Beam loss in the rest of the accelerator is 0.2 W/m on average.

  7. Modeling of direct beam extraction for a high-charge-state fusion driver

    NASA Astrophysics Data System (ADS)

    Anderson, O. A.; Grant Logan, B.

    A newly proposed type of multicharged ion source offers the possibility of an economically advantageous high-charge-state fusion driver. Multiphoton absorption in an intense uniform laser focus can give multiple charge states of high purity, simplifying or eliminating the need for charge-state separation downstream. Very large currents (hundreds of amperes) can be extracted from this type of source. Several arrangements are possible. For example, the laser plasma could be tailored for storage in a magnetic bucket, with beam extracted from the bucket. A different approach, described in this report, is direct beam extraction from the expanding laser plasma. We discuss extraction and focusing for the particular case of a 4.1 MV beam of Xe 16+ ions. The maximum duration of the beam pulse is limited by the total charge in the plasma, while the practical pulse length is determined by the range of plasma radii over which good beam optics can be achieved. The extraction electrode contains a solenoid for beam focusing. Our design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from our initial model showed that hundreds of amperes could be extracted, but that most of this current missed the solenoid entrance or was intercepted by the wall and that only a few amperes were able to pass through. We conclude with an improved design which increases the surviving beam to more than 70 A.

  8. The solenoidal transport option: IFE drivers, near term research facilities, and beam dynamics

    SciTech Connect

    Lee, E.P.; Briggs, R.J.

    1997-09-01

    Solenoidal magnets have been used as the beam transport system in all the high current electron induction accelerators that have been built in the past several decades. They have also been considered for the front end transport system for heavy ion accelerators for Inertial Fusion Energy (IFE) drivers, but this option has received very little attention in recent years. The analysis reported here was stimulated mainly by the recent effort to define an affordable {open_quotes}Integrated Research Experiment{close_quotes} (IRE) that can meet the near term needs of the IFE program. The 1996 FESAC IFE review panel agreed that an integrated experiment is needed to fully resolve IFE heavy ion driver science and technology issues; specifically, {open_quotes}the basic beam dynamics issues in the accelerator, the final focusing and transport issues in a reactor-relevant beam parameter regime, and the target heating phenomenology{close_quotes}. The development of concepts that can meet these technical objectives and still stay within the severe cost constraints all new fusion proposals will encounter is a formidable challenge. Solenoidal transport has a very favorable scaling as the particle mass is decreased (the main reason why it is preferred for electrons in the region below 50 MeV). This was recognized in a recent conceptual study of high intensity induction linac-based proton accelerators for Accelerator Driven Transmutation Technologies, where solenoidal transport was chosen for the front end. Reducing the ion mass is an obvious scaling to exploit in an IRE design, since the output beam voltage will necessarily be much lower than that of a full scale driver, so solenoids should certainly be considered as one option for this experiment as well.

  9. Effect of Driver Impedance on Dense Plasma Focus Z-Pinch Neutron Yield and Beam Acceleration

    NASA Astrophysics Data System (ADS)

    Sears, J.; Link, A.; Ellsworth, J.; Falabella, S.; Rusnak, B.; Tang, V.; Schmidt, A.; Welch, D.

    2014-10-01

    We explore the effect of driver characteristics on dense plasma focus (DPF) neutron yield and beam acceleration using particle-in-cell (PIC) simulations of a kJ-scale DPF. Our PIC simulations are fluid for the run-down phase and transition to fully kinetic for the pinch phase. The anode-cathode boundary is driven by a circuit model of the capacitive driver, including system inductance, the load of the railgap switches, the guard resistors, and the coaxial transmission line parameters. Simulations are benchmarked to measurements of a table top kJ DPF experiment with neutron yield measured with He3-based detectors. Simulated neutron yield scales approximately with the fourth power of peak current, I4. We also probe the accelerating fields by measuring the acceleration of a 4 MeV deuteron beam and by measuring the DPF self-generated beam energy distribution, finding gradients higher than 50 MV/m. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and supported by the Laboratory Directed Research and Development Program (11-ERD-063) at LLNL.

  10. Overview of proton drivers for neutrino super beams and neutrino factories

    SciTech Connect

    Chou, W.; /Fermilab

    2006-06-01

    There has been a world-wide interest in Proton Drivers in the past decade. Numerous design proposals have been presented in Asia, Europe and North America, ranging from low energy rapid cycling synchrotrons, normal or superconducting linacs to high energy slow cycling synchrotrons and FFAGs. One thing in common is that all these machines provide MW beam power and are used primarily for neutrino experiments. This paper gives an overview of these activities. In the last section the author expresses his personal opinion on the future of this field.

  11. BEAM DYNAMICS STUDIES OF A HIGH-REPETITION RATE LINAC-DRIVER FOR A 4TH GENERATION LIGHT SOURCE

    SciTech Connect

    Ventturini, M.; Corlett, J.; Emma, P.; Papadopoulos, C.; Penn, G.; Placidi, M.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Sun, C.; Wells, R.

    2012-05-18

    We present recent progress toward the design of a super-conducting linac driver for a high-repetition rate FEL-based soft x-ray light source. The machine is designed to accept beams generated by the APEX photo-cathode gun operating with MHz-range repetition rate and deliver them to an array of SASE and seeded FEL beamlines. We review the current baseline design and report results of beam dynamics studies.

  12. Heavy-Ion Driver Linac for the RIA Facility and the Feasibility of Producing Multi-Megawatt Beams

    SciTech Connect

    Ostroumov, P.N.; Nolen, J.A.; Shepard, K.W.

    2005-06-08

    The Rare-Isotope Accelerator (RIA) facility is a top priority project in the U.S. RIA is a next generation facility for basic research with radioactive beams that utilizes both standard isotope-separator on-line and in-flight fragmentation methods with novel approaches to handle high primary-beam power and remove existing limitations in the extraction of short-lived isotopes. A versatile primary accelerator, a 1.4-GV, CW superconducting linac, will provide beams from protons at 1 GeV to uranium at 400 MeV/u at power levels of 400 kW. Novel features include the acceptance of two charge states of heavy ions from the ion source and the acceleration of five charge states following the stripper foils. To achieve these goals, comprehensive beam dynamics studies have been performed to optimize the design of the driver linac. Recently we have investigated the feasibility of increasing the currents of light ions to deliver megawatts of beam power. This option is entirely possible from the beam dynamics point of view. It would require higher power from the rf system, as well as, increased shielding at the beam loss points with respect to the existing baseline design. Preliminary indications of the limitations of beam power for this class of CW superconducting linac for light ion beams will be presented.

  13. Heavy-ion driver linac for the RIA facility and the feasibility of producing multi-megawatt beams.

    SciTech Connect

    Ostroumov, P. N.; Nolen, J. A.; Shepard, K. W.; Physics

    2005-01-01

    The Rare-Isotope Accelerator (RIA) facility is a top priority project in the U.S. RIA is a next generation facility for basic research with radioactive beams that utilizes both standard isotope-separator on-line and in-flight fragmentation methods with novel approaches to handle high primary-beam power and remove existing limitations in the extraction of short-lived isotopes. A versatile primary accelerator, a 1.4-GV, CW superconducting linac, will provide beams from protons at 1 GeV to uranium at 400 MeV/u at power levels of 400 kW. Novel features include the acceptance of two charge states of heavy ions from the ion source and the acceleration of five charge states following the stripper foils. To achieve these goals, comprehensive beam dynamics studies have been performed to optimize the design of the driver linac. Recently we have investigated the feasibility of increasing the currents of light ions to deliver megawatts of beam power. This option is entirely possible from the beam dynamics point of view. It would require higher power from the rf system, as well as, increased shielding at the beam loss points with respect to the existing baseline design. Preliminary indications of the limitations of beam power for this class of CW superconducting linac for light ion beams will be presented.

  14. Differential acceleration in the final beam lines of a Heavy Ion Fusion driver

    SciTech Connect

    Friedman, Alex

    2013-10-19

    A long-standing challenge in the design of a Heavy Ion Fusion power plant is that the ion beams entering the target chamber, which number of order a hundred, all need to be routed from one or two multi-beam accelerators through a set of transport lines. The beams are divided into groups, which each have unique arrival times and may have unique kinetic energies. It is also necessary to arrange for each beam to enter the target chamber from a prescribed location on the periphery of that chamber. Furthermore, it has generally been assumed that additional constraints must be obeyed: that the path lengths of the beams in a group must be equal, and that any delay of \\main-pulse" beams relative to \\foot-pulse" beams must be provided by the insertion of large delay-arcs in the main beam transport lines. Here we introduce the notion of applying \\di erential acceleration" to individual beams or sets of beam at strategic stages of the transport lines. That is, by accelerating some beams \\sooner" and others \\later," it is possible to simplify the beam line con guration in a number of cases. For example, the time delay between the foot and main pulses can be generated without resorting to large arcs in the main-pulse beam lines. It is also possible to use di erential acceleration to e ect the simultaneous arrival on target of a set of beams ( e.g., for the foot-pulse) without requiring that their path lengths be precisely equal. We illustrate the technique for two model con gurations, one corresponding to a typical indirect-drive scenario requiring distinct foot and main energies, and the other to an ion-driven fast-ignition scenario wherein the foot and main beams share a common energy.

  15. Differential acceleration in the final beam lines of a Heavy Ion Fusion driver

    DOE PAGES

    Friedman, Alex

    2013-10-19

    A long-standing challenge in the design of a Heavy Ion Fusion power plant is that the ion beams entering the target chamber, which number of order a hundred, all need to be routed from one or two multi-beam accelerators through a set of transport lines. The beams are divided into groups, which each have unique arrival times and may have unique kinetic energies. It is also necessary to arrange for each beam to enter the target chamber from a prescribed location on the periphery of that chamber. Furthermore, it has generally been assumed that additional constraints must be obeyed: thatmore » the path lengths of the beams in a group must be equal, and that any delay of \\main-pulse" beams relative to \\foot-pulse" beams must be provided by the insertion of large delay-arcs in the main beam transport lines. Here we introduce the notion of applying \\di erential acceleration" to individual beams or sets of beam at strategic stages of the transport lines. That is, by accelerating some beams \\sooner" and others \\later," it is possible to simplify the beam line con guration in a number of cases. For example, the time delay between the foot and main pulses can be generated without resorting to large arcs in the main-pulse beam lines. It is also possible to use di erential acceleration to e ect the simultaneous arrival on target of a set of beams ( e.g., for the foot-pulse) without requiring that their path lengths be precisely equal. We illustrate the technique for two model con gurations, one corresponding to a typical indirect-drive scenario requiring distinct foot and main energies, and the other to an ion-driven fast-ignition scenario wherein the foot and main beams share a common energy.« less

  16. Impact of beam transport method on chamber and driver design for heavy ion inertial fusion energy

    SciTech Connect

    Rose, D.V.; Welch, D.R.; Olson, C.L.; Yu, S.S.; Neff, S.; Sharp, W.M.

    2002-12-01

    In heavy ion inertial fusion energy systems, intense beams of ions must be transported from the exit of the final focus magnet system through the target chamber to hit millimeter spot sizes on the target. In this paper, we examine three different modes of beam propagation: neutralized ballistic transport, assisted pinched transport, and self-pinched transport. The status of our understanding of these three modes is summarized, and the constraints imposed by beam propagation upon the chamber environment, as well as their compatibility with various chamber and target concepts, are considered. We conclude that, on the basis of our present understanding, there is a reasonable range of parameter space where beams can propagate in thick-liquid wall, wetted-wall, and dry-wall chambers.

  17. Parametic Study of the current limit within a single driver-scaletransport beam line of an induction Linac for Heavy Ion Fusion

    SciTech Connect

    Prost, Lionel Robert

    2004-01-01

    The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program that explores heavy-ion beam as the driver option for fusion energy production in an Inertial Fusion Energy (IFE) plant. The HCX is a beam transport experiment at a scale representative of the low-energy end of an induction linear accelerator driver. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density ~0.2 μC/m) over long pulse durations (4 μs) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo and, electron and gas cloud effects. We present the results for a coasting 1 MeV K+ ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase-space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor (~80%) is achieved with acceptable emittance growth and beam loss. We achieved good envelope control, and re-matching may only be needed every ten lattice periods (at 80% fill factor) in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

  18. Two-frequency acousto-optic modulator driver to improve the beam pointing stability during intensity ramps

    SciTech Connect

    Froehlich, B.; Lahaye, T.; Kaltenhaeuser, B.; Kuebler, H.; Mueller, S.; Koch, T.; Fattori, M.; Pfau, T.

    2007-04-15

    We report on a scheme to improve the pointing stability of the first order beam diffracted by an acousto-optic modulator (AOM). Due to thermal effects inside the crystal, the angular position of the beam can change by as much as 1 mrad when the radio-frequency power in the AOM is reduced to decrease the first order beam intensity. This is done, for example, to perform forced evaporative cooling in ultracold atom experiments using far-off-resonant optical traps. We solve this problem by driving the AOM with two radio frequencies f{sub 1} and f{sub 2}. The power of f{sub 2} is adjusted relative to the power of f{sub 1} to keep the total power constant. Using this, the beam displacement is decreased by a factor of 20. The method is simple to implement in existing experimental setups, without any modification of the optics.

  19. Older Drivers

    MedlinePlus

    ... Affects Driving Tips for Safe Driving Making Your Vehicle Safe Regulations Affecting Older Drivers When Driving Skills ... Like drivers of any age, they use their vehicles to go shopping, do errands, and visit the ...

  20. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    DOE PAGES

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; Schenkel, Thomas; Barnard, John; Friedman, Alex; Eder, David; Fisher, Aaron; Masters, Nathan

    2016-03-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as wellmore » as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.« less

  1. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    NASA Astrophysics Data System (ADS)

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; Schenkel, Thomas; Barnard, John; Friedman, Alex; Eder, David; Fisher, Aaron; Masters, Nathan

    2016-03-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as well as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.

  2. Workshop on transport for a common ion driver

    SciTech Connect

    Olson, C.C.; Lee, E.; Langdon, B.

    1994-12-31

    This report contains research in the following areas related to beam transport for a common ion driver: multi-gap acceleration; neutralization with electrons; gas neutralization; self-pinched transport; HIF and LIF transport, and relevance to common ion driver; LIF and HIF reactor concepts and relevance to common ion driver; atomic physics for common ion driver; code capabilities and needed improvement.

  3. Driver circuit

    NASA Technical Reports Server (NTRS)

    Matsumoto, Raymond T. (Inventor); Higashi, Stanley T. (Inventor)

    1976-01-01

    A driver circuit which has low power requirements, a relatively small number of components and provides flexibility in output voltage setting. The driver circuit comprises, essentially, two portions which are selectively activated by the application of input signals. The output signal is determined by which of the two circuit portions is activated. While each of the two circuit portions operates in a manner similar to silicon controlled rectifiers (SCR), the circuit portions are on only when an input signal is supplied thereto.

  4. Studies of Energy Recovery Linacs at Jefferson Laboratory: 1 GeV Demonstration of Energy Recovery at CEBAF and Studies of the Multibunch, Multipass Beam Breakup Instability in the 10 kW FEL Upgrade Driver

    SciTech Connect

    Tennant, Christopher D.

    2006-10-01

    An energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. Two primary physics challenges exist in pushing the frontier of ERL performance. The first is energy recovering a high energy beam while demonstrating operational control of two coupled beams in a common transport channel. The second is controlling the high average current effects in ERLs, specifically a type of beam instability called multipass beam breakup (BBU). This work addresses both of these issues. A successful 1 GeV energy recovery demonstration with a maximum-to-injection energy ratio of 51:1 was carried out on the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory in an effort to address issues related to beam quality preservation in a large scale system. With a 1.3 km recirculation length and containing 312 superconducting radio frequency (SRF) cavities, this experiment has demonstrated energy recovery on the largest scale, and through the largest SRF environment, to date. The BBU instability imposes a potentially severe limitation to the average current that can be accelerated in an ERL. Simulation results for Jefferson Laboratory's 10 kW free electron laser (FEL) Upgrade Driver predict the occurrence of BBU below the nominal operating current. Measurements of the threshold current are described and shown to agree to within 10% of predictions from BBU simulation codes. This represents the first time the codes have been benchmarked with experimental data. With BBU limiting the beam current, several suppression schemes were developed. These include direct damping of the higher-order mode using two different cavity-based feedbacks and modifying the electron beam optics to reduce the coupling between the beam and mode. Specifically the effect of implementing (1) point-to-point focusing (2

  5. Electron cloud considerations for HIF drivers

    NASA Astrophysics Data System (ADS)

    Cohen, R. H.

    2014-01-01

    We review some previous results on electron-cloud dynamics and accumulation and the impact of electron clouds on ion beam dynamics, and assess these in the context of a magnetic-quadrupole-based heavy-ion fusion driver. We present a new analysis which exploits analytic solution of linearized envelope equations between accelerating gaps to derive a set of mapping equations which we use to extrapolate from previously obtained particle-simulation results for a beam transport system to an HIF driver.

  6. The RIA driver linac.

    SciTech Connect

    Shepard, K. W.

    2002-09-23

    The driver linac for the U.S. RIA project will be a 1.4 GV superconducting linac capable of accelerating the full mass range of ions from 900 MeV protons to 400 MeV/u uranium, and delivering a cw beam of 400 kW shared by at least two targets simultaneously. Elements of the linac are being developed at several U.S. laboratories. The current status of linac design and development is reviewed with emphasis on changes in the baseline design since the last linac conference.

  7. Teaching Driver Education Technology to Novice Drivers.

    ERIC Educational Resources Information Center

    Young, Anthony

    A cybernetic unit in driver education was developed to help grade 10 students develop the skills needed to acquire and process driver education information and prepare for the driving phase of driver education in grade 11. Students used a simulator to engage in a series of scenarios designed to promote development of social, behavioral, and mental…

  8. Driver Education Saves Gas.

    ERIC Educational Resources Information Center

    American Automobile Association, Falls Church, VA. Traffic Engineering and Safety Dept.

    The argument that driver education should be dropped because driver education cars use gas is shortsighted. High school driver education is an excellent vehicle for teaching concepts of energy conservation. A small investment in fuel now can result in major savings of gasoline over a student's lifetime. In addition good driver education courses…

  9. A Superconducting Linac Proton Driver at Fermilab

    NASA Astrophysics Data System (ADS)

    Foster, G. William

    2004-05-01

    A proton driver has emerged as the leading candidate for Fermilab's next near-term accelerator project. The preferred technical solution is an 8 GeV superconducting linac based on technology developed for TESLA and the Spallation Neutron Source (SNS). Its primary mission is to serve as a single-stage H- injector to prepare 2 MW "Super-Beams" for Neutrino experiments using the Fermilab Main Injector. The linac can also accelerate electrons, protons, and relativistic muons, permitting future applications such as a driver for an FEL, a long-pulse spallation source, the driver for an intense 8 GeV neutrino or kaon program, and potential applications to a neutrino factory or muon collider. The technical design of the 8 GeV linac, as well as the design of an alternative synchrotron based proton driver, will be described along with plans for project proposal and construction.

  10. LANL GPIB Driver

    SciTech Connect

    2004-04-15

    This driver code adds a GPIB infrastructure and API features to 2.6 series Linux kernels. Currently supported hardware is National Instruments PCI-GPIB cards built on either the TNT4882 controller chip, or the TNT5004 controller chip. This driver is an improvement over previous GPIB drivers in Linux because it has all the features of the GPL, high performance DMA, supports Linux 2.6 and the new driver model, and has a cleaner API than the previous drivers. GPIB is the "general purpose interface bus", commonly used to control oscilloscopes, digital multimeters, function generators, and other electronic test equipment.

  11. LANL GPIB Driver

    2004-04-15

    This driver code adds a GPIB infrastructure and API features to 2.6 series Linux kernels. Currently supported hardware is National Instruments PCI-GPIB cards built on either the TNT4882 controller chip, or the TNT5004 controller chip. This driver is an improvement over previous GPIB drivers in Linux because it has all the features of the GPL, high performance DMA, supports Linux 2.6 and the new driver model, and has a cleaner API than the previous drivers.more » GPIB is the "general purpose interface bus", commonly used to control oscilloscopes, digital multimeters, function generators, and other electronic test equipment.« less

  12. Summary of sessions B and F: High intensity linacs and frontend & proton drivers

    SciTech Connect

    Ferdinand, R.; Chou, W.; Galambos, J.; /Oak Ridge

    2005-01-01

    This paper summarizes the sessions B&F of the 33rd ICFA Advanced Beam Dynamics Workshop on High Intensity & High Brightness Hadron Beams held in Bensheim, Germany. It covers high intensity linacs, front ends and proton driver topics.

  13. Design of the driver linac for the Rare Isotope Accelerator.

    SciTech Connect

    Ostroumov, P. N.; Nolen, J. A.; Shepard, K. W.; Physics

    2006-01-01

    The proposed design of the Rare Isotope Accelerator (RIA) driver linac is a cw, fully superconducting, 1.4 GV linac capable of accelerating uranium ions up to 400 MeV/u and protons to 1 GeV with 400 kW beam power. An extensive research and development effort has resolved many technical issues related to the construction of the driver linac and other systems of the RIA facility. In particular, record intensities of heavy ion beams have been demonstrated with the ECR ion source VENUS at LBNL, the driver front end systems including two-charge-state Low Energy Beam Transport (LEBT) and RFQ are being tested, and a set of SC accelerating structures to cover velocity range from 0.02c to 0.7c have been developed and prototyped. Newly developed high-performance SC cavities will provide the required voltage for the driver linac using 300 cavities designed for six different geometrical betas.

  14. Thermally Activated Driver

    NASA Technical Reports Server (NTRS)

    Kinard, William H.; Murray, Robert C.; Walsh, Robert F.

    1987-01-01

    Space-qualified, precise, large-force, thermally activated driver (TAD) developed for use in space on astro-physics experiment to measure abundance of rare actinide-group elements in cosmic rays. Actinide cosmic rays detected using thermally activated driver as heart of event-thermometer (ET) system. Thermal expansion and contraction of silicone oil activates driver. Potential applications in fluid-control systems where precise valve controls are needed.

  15. A Simple Wave Driver

    ERIC Educational Resources Information Center

    Temiz, Burak Kagan; Yavuz, Ahmet

    2015-01-01

    This study was done to develop a simple and inexpensive wave driver that can be used in experiments on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be used to produce string waves at a fixed frequency. The working principle of the apparatus is as follows: shortly after the car is turned on, the…

  16. Help Wanted: Drivers.

    ERIC Educational Resources Information Center

    Hoober, Scott

    1999-01-01

    A booming economy and low unemployment make it harder than ever before to lure and retain good school-bus drivers. Lack of money for good wages has prompted some innovative recruitment and retention tactics. Chicago has turned to the rolls of people going off welfare as a source of bus-driver candidates. The Trans Group, headquartered in Chestnut…

  17. Synchrotron based proton drivers

    SciTech Connect

    Weiren Chou

    2002-09-19

    Proton drivers are the proton sources that produce intense short proton bunches. They have a wide range of applications. This paper discusses the proton drivers based on high-intensity proton synchrotrons. It gives a review of the high-intensity proton sources over the world and a brief report on recent developments in this field in the U.S. high-energy physics (HEP) community. The Fermilab Proton Driver is used as a case study for a number of challenging technical design issues.

  18. A cryomodule for the RIA driver linac.

    SciTech Connect

    Fuerst, J. D.; Shepard, K. W.

    2002-10-25

    We present a cryomodule design for the superconducting linacs for the proposed Rare Isotope Accelerator Facility (RIA). This paper discusses the design of a cryomodule for all the drift-tube-loaded superconducting cavities required for the machine. The same basic design will be used for the low and medium velocity sections of the driver linac and also for sections of the radioactive ion beam (RIB) linac. Fundamental design choices such as separate vs. common beam and insulating vacuum spaces are driven by the clean fabrication techniques required for optimum cavity performance. The design can be adapted to a variety of cavity geometries.

  19. High-acceleration mass drivers

    NASA Technical Reports Server (NTRS)

    Oneill, G. K.; Kolm, H. H.

    1979-01-01

    High-acceleration mass drivers are discussed including the MD2 model of axial geometry, with individually powered drive coils of 13.1 cm diameter. Timing is derived through the interruption of light beams by the moving armature (bucket). Electric power is provided by the resonant discharge of sector capacitor banks through silicon-controlled rectifiers in a two-phase, quadrature circuit. The bucket flies in vacuum, guided by passive dynamic eddy-current magnetic forces, those currents flowing in strip conductors lining the inside of a nonconducting vacuum pipe. Quantitative measurements are obtained with a solid bucket carrying two superconducting coils with a current density of 25 kA/sq cm. A cryogenic station for cooling the bucket to liquid helium temperature is connected to the vacuum pipe.

  20. Mass drivers. 3: Engineering

    NASA Technical Reports Server (NTRS)

    Arnold, W.; Bowen, S.; Cohen, S.; Fine, K.; Kaplan, D.; Kolm, M.; Kolm, H.; Newman, J.; Oneill, G. K.; Snow, W.

    1979-01-01

    The last of a series of three papers by the Mass-Driver Group of the 1977 Ames Summer Study is presented. It develops the engineering principles required to implement the basic mass-driver. Optimum component mass trade-offs are derived from a set of four input parameters, and the program used to design a lunar launcher. The mass optimization procedures is then incorporated into a more comprehensive mission optimization program called OPT-4, which evaluates an optimized mass-driver reaction engine and its performance in a range of specified missions. Finally, this paper discusses, to the extent that time permitted, certain peripheral problems: heating effects in buckets due to magnetic field ripple; an approximate derivation of guide force profiles; the mechanics of inserting and releasing payloads; the reaction mass orbits; and a proposed research and development plan for implementing mass drivers.

  1. Square pulse linear transformer driver

    NASA Astrophysics Data System (ADS)

    Kim, A. A.; Mazarakis, M. G.; Sinebryukhov, V. A.; Volkov, S. N.; Kondratiev, S. S.; Alexeenko, V. M.; Bayol, F.; Demol, G.; Stygar, W. A.

    2012-04-01

    The linear transformer driver (LTD) technological approach can result in relatively compact devices that can deliver fast, high current, and high-voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture [A. A. Kim, M. G. Mazarakis, V. A. Sinebryukhov, B. M. Kovalchuk, V. A. Vizir, S. N Volkov, F. Bayol, A. N. Bastrikov, V. G. Durakov, S. V. Frolov, V. M. Alexeenko, D. H. McDaniel, W. E. Fowler, K. LeCheen, C. Olson, W. A. Stygar, K. W. Struve, J. Porter, and R. M. Gilgenbach, Phys. Rev. ST Accel. Beams 12, 050402 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050402; M. G. Mazarakis, W. E. Fowler, A. A. Kim, V. A. Sinebryukhov, S. T. Rogowski, R. A. Sharpe, D. H. McDaniel, C. L. Olson, J. L. Porter, K. W. Struve, W. A. Stygar, and J. R. Woodworth, Phys. Rev. ST Accel. Beams 12, 050401 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050401] provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling) top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks. A voltage adder made out of a square pulse cavity linear array will produce the same shape output pulses provided that the timing of each cavity is synchronized with the propagation of the electromagnetic pulse.

  2. Drivers license display system

    NASA Astrophysics Data System (ADS)

    Prokoski, Francine J.

    1997-01-01

    Carjackings are only one of a growing class of law enforcement problems associated with increasingly violent crimes and accidents involving automobiles plays weapons, drugs and alcohol. Police traffic stops have become increasingly dangerous, with an officer having no information about a vehicle's potentially armed driver until approaching him. There are 15 million alcoholics in the US and 90 percent of them have drivers licenses. Many of them continue driving even after their licenses have ben revoked or suspended. There are thousands of unlicensed truck drivers in the country, and also thousands who routinely exceed safe operating periods without rest; often using drugs in an attempt to stay alert. MIKOS has developed the Drivers License Display Systems to reduce these and other related risks. Although every state requires the continuous display of vehicle registration information on every vehicle using public roads, no state yet requires the display of driver license information. The technology exists to provide that feature as an add-on to current vehicles for nominal cost. An initial voluntary market is expected to include: municipal, rental, and high value vehicles which are most likely to be mis-appropriated. It is anticipated that state regulations will eventually require such systems in the future, beginning with commercial vehicles, and then extending to high risk drivers and eventually all vehicles. The MIKOS system offers a dual-display approach which can be deployed now, and which will utilize all existing state licenses without requiring standardization.

  3. Graduated Driver Licensing

    PubMed Central

    Bates, Lyndel J.; Allen, Siobhan; Armstrong, Kerry; Watson, Barry; King, Mark J.; Davey, Jeremy

    2014-01-01

    Graduated driver licensing (GDL) aims to gradually increase the exposure of new drivers to more complex driving situations and typically consists of learner, provisional and open licence phases. The first phase, the learner licence, is designed to allow novice drivers to obtain practical driving experience in lower risk situations. The learner licence can delay licensure, encourage novice drivers to learn under supervision, mandate the number of hours of practice required to progress to the next phase and encourage parental involvement. The second phase, the provisional licence, establishes various driving restrictions and thereby reduces exposure to situations of higher risk, such as driving at night, with passengers or after drinking alcohol. Parental involvement with a GDL system appears essential in helping novices obtain sufficient practice and in enforcing compliance with restrictions once the new driver obtains a provisional licence. Given the significant number of young drivers involved in crashes within Oman, GDL is one countermeasure that may be beneficial in reducing crash risk and involvement for this group. PMID:25364543

  4. Commercial Driver Medical Examinations

    PubMed Central

    Moffitt, Gary; Hanowski, Richard J.; Kales, Stefanos N.; Porter, Richard J.; Hegmann, Kurt T.

    2015-01-01

    Objective: The objective of this study was to assess relationships between body mass index (BMI) and comorbid conditions within a large sample of truck drivers. Methods: Commercial driver medical examination data from 88,246 commercial drivers between 2005 and 2012 were analyzed for associations between BMI, medical disorders, and driver certification. Results: Most drivers were obese (53.3%, BMI >30.0 kg/m2) and morbidly obese (26.6%, BMI >35.0 kg/m2), higher than prior reports. Obese drivers were less likely to be certified for 2 years and more likely to report heart disease, hypertension, diabetes mellitus, nervous disorders, sleep disorders, and chronic low back pain (all P < 0.0001). There are relationships between multiple potentially disqualifying conditions and increasing obesity (P < 0.0001). Morbid obesity prevalence increased 8.9% and prevalence of three or more multiple conditions increased fourfold between 2005 and 2012. Conclusions: Obesity is related to multiple medical factors as well as increasing numbers of conditions that limit driving certification. PMID:25710607

  5. Driver Improvement Training and Evaluation.

    ERIC Educational Resources Information Center

    Whittenburg, John A.; And Others

    The last phase of the NHTSA-U.S. Coast Guard Driver Improvement Training and Evaluation Project is described. Begun in July 1970, the project had two basic objectives. The first was to determine whether or not driver training programs do, in fact, significantly reduce driver errors and accidents and improve overall driver efficiency. The second…

  6. Acoustic Levitation With One Driver

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Rudnick, I.; Elleman, D. D.; Stoneburner, J. D.

    1985-01-01

    Report discusses acoustic levitation in rectangular chamber using one driver mounted at corner. Placement of driver at corner enables it to couple effectively to acoustic modes along all three axes. Use of single driver reduces cost, complexity and weight of levitation system below those of three driver system.

  7. Optimization of steering elements in the RIA driver linac.

    SciTech Connect

    Lessner, E. S.; Aseev, V. S.; Ostroumov, P. N.; Physics

    2005-01-01

    The driver linac of the projected RIA facility is a versatile accelerator, a 1.4-GV, CW superconducting (SC) linac designed to simultaneously accelerate several heavy-ion charge states, providing beams from proton to uranium at 400 MeV/u at power levels at a minimum of 100 kW and up to 400 kW for most beams. Acceleration of multiple-charge-state uranium beams places stringent requirements on the linac design. A steering algorithm was derived that fulfilled the driver's real estate requirements, such as placement of steering dipole coils on SC solenoids and of beam position monitors outside cryostats, and beam-dynamics requirements, such as coupling effects induced by the focusing solenoids. The algorithm has been fully integrated into the tracking code TRACK and it is used to study and optimize the number and position of steering elements that minimize the multiple-beam centroid oscillations and preserve the beam emittance under misalignments of accelerating and transverse focusing elements in the driver linac.

  8. The accuracy of drivers' judgments of the effects of headlight glare on their own visual acuity.

    PubMed

    Stafford Sewall, Ashley A; Whetsel Borzendowski, Stephanie A; Tyrrell, Richard A

    2014-01-01

    Drivers' judgments of the magnitude of disability glare caused by high-beam headlights may not match actual declines in visual performance. This study investigated younger and older drivers' beliefs about their own visual performance in the presence of headlight glare. Eleven older drivers and seventeen younger drivers judged the distance at which they would just be able to recognize the orientation of a white Landolt C if it were present adjacent to the headlamps of a stationary opposing vehicle at night. The younger participants were generally accurate in their estimates of the recognition distance of the stimulus, while older participants significantly overestimated both their own acuity and the effect of glare on their vision. From this study, we see that older drivers' judgments about the disabling effects of oncoming headlights may be systematically inaccurate. These misperceptions about headlight glare may help explain why drivers tend to underuse high beams. PMID:25638936

  9. Forced Vibrations of a Cantilever Beam

    ERIC Educational Resources Information Center

    Repetto, C. E.; Roatta, A.; Welti, R. J.

    2012-01-01

    The theoretical and experimental solutions for vibrations of a vertical-oriented, prismatic, thin cantilever beam are studied. The beam orientation is "downwards", i.e. the clamped end is above the free end, and it is subjected to a transverse movement at a selected frequency. Both the behaviour of the device driver and the beam's weak-damping…

  10. Driver distraction and driver inattention: definition, relationship and taxonomy.

    PubMed

    Regan, Michael A; Hallett, Charlene; Gordon, Craig P

    2011-09-01

    There is accumulating evidence that driver distraction and driver inattention are leading causes of vehicle crashes and incidents. However, as applied psychological constructs, they have been inconsistently defined and the relationship between them remains unclear. In this paper, driver distraction and driver inattention are defined and a taxonomy is presented in which driver distraction is distinguished from other forms of driver inattention. The taxonomy and the definitions provided are intended (a) to provide a common framework for coding different forms of driver inattention as contributing factors in crashes and incidents, so that comparable estimates of their role as contributing factors can be made across different studies, and (b) to make it possible to more accurately interpret and compare, across studies, the research findings for a given form of driver inattention.

  11. Systems modeling and analysis of heavy ion drivers for inertial fusion energy

    SciTech Connect

    Meier, W. R.

    1998-06-03

    A computer model for systems analysis of heavy ion drivers based on induction linac technology has been used to evaluate driver designs for inertial fusion energy (IFE). Design parameters and estimated costs have been determined for drivers with various ions, different charge states, different front-end designs, with and without beam merging, and various pulse compression and acceleration schedules. We have examined the sensitivity of the results to variations in component cost assumptions, design constraints, and selected design parameters

  12. Seven Performance Drivers.

    ERIC Educational Resources Information Center

    Ross, Linda

    2003-01-01

    Recent work with automotive e-commerce clients led to the development of a performance analysis methodology called the Seven Performance Drivers, including: standards, incentives, capacity, knowledge and skill, measurement, feedback, and analysis. This methodology has been highly effective in introducing and implementing performance improvement.…

  13. Assessment of older drivers.

    PubMed

    Reuben, D B

    1993-05-01

    As concern increases about the safety of the aging driver, it is clear that the principal goal of assessment is to identify the unsafe driver and provide effective medical and rehabilitative services to enable the resumption of safe driving. When adequate restorative therapy is not possible, it is necessary to restrict or revoke the privilege of driving. Assessment also can reassure the safe older driver that he or she can continue operating a motor vehicle without restrictions. The process of assessing the older driver is best accomplished through the collaboration of health professionals and governmental agencies. The former identify and treat, if possible, medical conditions that may pose threats to safe driving; the latter establish guidelines of competency for driving tasks. These roles are complementary, although the settings and methods for these assessments are different. Moreover, the responsibilities of the physician and other health care professionals extend beyond the decision regarding driving and must consider the individual needs for driving, as well as the ramifications associated with its cessation. PMID:8504391

  14. The Bicycle Driver's Guide.

    ERIC Educational Resources Information Center

    Pennsylvania State Dept. of Education, Harrisburg. Bureau of Curriculum Services.

    Designed to emphasize the concept of the bicycle driver vs. the popular term, bicycle rider, this manual contains guidelines on bicycle safety, addressing itself both to parents and children. The main section topics are: (1) parent responsibility; (2) choosing a bicycle, fitting it to the child, and learning to drive; (3) bicycle equipment,…

  15. Florida Driver Education Handbook.

    ERIC Educational Resources Information Center

    Mick, Susan H.

    This student edition contains the same basic information as the official Florida Driver Handbook, but the reading difficulty of the material has been sharply reduced. It also provides activity-oriented exercises and review tests on this material. Introductory materials include a complete listing of all activities given, some vocabulary exercises…

  16. A high power accelerator driver system for spallation neutron sources

    SciTech Connect

    Jason, A.; Blind, B.; Channell, P.

    1996-07-01

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). For several years, the Los Alamos Meson Physics Facility (LAMPF) and the Proton Storage Ring (PSR) have provided a successful driver for the nearly 100-kW Los Alamos Neutron Scattering Center (LANSCE) source. The authors have studied an upgrade to this system. The goal of this effort was to establish a credible design for the accelerator driver of a next-generation source providing 1-MW of beam power. They have explored a limited subset of the possible approaches to a driver and have considered only the low 1-MW beam power. The next-generation source must utilize the optimum technology and may require larger neutron intensities than they now envision.

  17. Solid state laser driver for Extreme Ultraviolet Lithography. Revision 1

    SciTech Connect

    Zapata, L.E.; Honig, J.; Reichert, P.; Hackel, L.A.

    1994-05-01

    We describe the design and initial performance of a Nd:YAG laser master oscillator/phase conjugated power amplifier as a driver for extreme ultraviolet lithography. The design provides 0.5 to 1 joule per pulse with about 5 ns pulse width and excellent beam quality up through 1.5 kHz repetition frequency.

  18. Earning a driver's license.

    PubMed Central

    Williams, A F

    1997-01-01

    Teenage drivers in the United States have greatly elevated crash rates, primarily a result of qualities associated with immaturity and lack of driving experience. State licensing systems vary substantially, but most have allowed quick and easy access to driving with full privileges at a young age, contributing to the crash problem. Formal driver education has not been an effective crash prevention measure. Following the introduction of graduated licensing in New Zealand, Australia, and Canada, this system has been considered in many states and has been implemented in some. Graduated systems phase in full privilege driving, requiring initial experience to be gained under conditions of lower risk. The author describes the first five multistage graduated systems enacted in the United States in 1996 and 1997. Factors that will influence the acceptability and effectiveness of these new licensing systems are discussed. Images p[452]-a p454-a p456-a p457-a p460-a PMID:10822470

  19. Earning a driver's license.

    PubMed

    Williams, A F

    1997-01-01

    Teenage drivers in the United States have greatly elevated crash rates, primarily a result of qualities associated with immaturity and lack of driving experience. State licensing systems vary substantially, but most have allowed quick and easy access to driving with full privileges at a young age, contributing to the crash problem. Formal driver education has not been an effective crash prevention measure. Following the introduction of graduated licensing in New Zealand, Australia, and Canada, this system has been considered in many states and has been implemented in some. Graduated systems phase in full privilege driving, requiring initial experience to be gained under conditions of lower risk. The author describes the first five multistage graduated systems enacted in the United States in 1996 and 1997. Factors that will influence the acceptability and effectiveness of these new licensing systems are discussed.

  20. A novel collinear optical system with annulus mirrors for holographic disc driver

    NASA Astrophysics Data System (ADS)

    Wang, Ye

    2008-12-01

    This paper focus on a novel collinear lens system with annulus mirrors for holographic disc driver, both information beam and reference beam are use same laser beam. The expanded and parallel laser beam, center part of it as the information beam then through Fourier transform lens, the beam around center part as a reference beam. On this axis, the ring reference beam reflected by two annulus shaped mirrors, then became a convergent beam, together with the information beam which through the first Fourier transform lens then produce holographic pattern to be write into the holographic disc behind of them, this lens system with two mirrors made the angle between information beam and reference beam more wide, can improved the multiplex level of holographic storage. Pair of Fourier transform lens with advance performance is designed in this paper.

  1. Drivers, Trends and Mitigation

    SciTech Connect

    Blanco, Arthur S.; Gerlagh, Reyer; Suh, Sangwon; Barrett, John A.; de Coninck, Heleen; Diaz Morejon, Cristobal Felix; Mathur, Ritu; Nakicenovic, Nebojsa; Ahenkorah, Alfred Ofosu; Pan, Jiahua; Pathak, Himanshu; Rice, Jake; Richels, Richard G.; Smith, Steven J.; Stern, David; Toth, Ferenc L.; Zhou, Peter

    2014-12-01

    Chapter 5 analyzes the anthropogenic greenhouse gas (GHG) emission trends until the present and the main drivers that explain those trends. The chapter uses different perspectives to analyze past GHG-emissions trends, including aggregate emissions flows and per capita emissions, cumulative emissions, sectoral emissions, and territory-based vs. consumption-based emissions. In all cases, global and regional trends are analyzed. Where appropriate, the emission trends are contextualized with long-term historic developments in GHG emissions extending back to 1750.

  2. Robotic Intelligence Kernel: Driver

    SciTech Connect

    2009-09-16

    The INL Robotic Intelligence Kernel-Driver is built on top of the RIK-A and implements a dynamic autonomy structure. The RIK-D is used to orchestrate hardware for sensing and action as well as software components for perception, communication, behavior and world modeling into a single cognitive behavior kernel that provides intrinsic intelligence for a wide variety of unmanned ground vehicle systems.

  3. Relativistic particle beams for interstellar propulsion

    NASA Astrophysics Data System (ADS)

    Nordley, Gerald D.

    1993-04-01

    The concept of pellet-stream propulsion proposed by Singer (1980) is extended to particle beams and relativistic velocities. A simple relativistic mission study is presented, and it is shown how certain technological developments might enhance the concept. In particular, considerations discussed include beam drivers; beam cooling, steering, and focusing; beam driven mission mechanics; and the radiation problem. The energy issues are also briefly considered.

  4. Heavy ion induction linac drivers for inertial confinement fusion

    SciTech Connect

    Lee, E.P.; Hovingh, J.

    1988-10-01

    Intense beams of high energy heavy ions (e.g., 10 GeV Hg) are an attractive option for an ICF driver because of their favorable energy deposition characteristics. The accelerator systems to produce the beams at the required power level are a development from existing technologies of the induction linac, rf linac/storage ring, and synchrotron. The high repetition rate of the accelerator systems, and the high efficiency which can be realized at high current make this approach especially suitable for commercial ICF. The present report gives a summary of the main features of the induction linac driver system, which is the approach now pursued in the USA. The main subsystems, consisting of injector, multiple beam accelerator at low and high energy, transport and pulse compression lines, and final focus are described. Scale relations are given for the current limits and other features of these subsystems. 17 refs., 1 fig., 1 tab.

  5. Progress in heavy-ion drivers for inertial fusion

    SciTech Connect

    Friedman, A.; Bangerter, R.O.; Herrmannsfeldt, W.B.

    1994-12-22

    Heavy-ion induction accelerators are being developed as fusion drivers for ICF power production in the US Inertial Fusion Energy (IFE) program, in the Office of Fusion Energy of the US Department of Energy. In addition, they represent an attractive driver option for a high-yield microfusion facility for defense research. This paper describes recent progress in induction drivers for Heavy-Ion Fusion (HIF), and plans for future work. It presents research aimed at developing drivers having reduced cost and size, specifically advanced induction linacs and recirculating induction accelerators (recirculators). The goals and design of the Elise accelerator being built at Lawrence Berkeley Laboratory (LBL), as the first stage of the ILSE (Induction Linac Systems Experiments) program, are described. Elise will accelerate, for the first time, space-charge-dominated ion beams which are of full driver scale in line-charge density and diameter. Elise will be a platform on which the critical beam manipulations of the induction approach can be explored. An experimental program at Lawrence Livermore National Laboratory (LLNL) exploring the recirculator principle on a small scale is described in some detail; it is expected that these studies will result ultimately in an operational prototype recirculating induction accelerator. In addition, other elements of the US HIF program are described.

  6. Sandia Material Model Driver

    2005-09-28

    The Sandia Material Model Driver (MMD) software package allows users to run material models from a variety of different Finite Element Model (FEM) codes in a standalone fashion, independent of the host codes. The MMD software is designed to be run on a variety of different operating system platforms as a console application. Initial development efforts have resulted in a package that has been shown to be fast, convenient, and easy to use, with substantialmore » growth potential.« less

  7. Reliability and availability studies in the RIA driver linac.

    SciTech Connect

    Lessner, E. S.; Ostroumov, P. N.; Physics

    2005-01-01

    The Rare Isotope Accelerator (RIA) facility will include various complex systems and must provide radioactive beams to many users simultaneously. The availability of radioactive beams for most experiments at the fully-commissioned facility should be as high as possible within design cost limitations. To make a realistic estimate of the achievable reliability a detailed analysis is required. The RIA driver linac is a complex machine containing a large number of superconducting (SC) resonators and capable of accelerating multiple-charge-state beams [1]. At the pre-CDR stage of the design it is essential to identify critical facility subsystem failures that can prevent the driver linac from operating. The reliability and availability of the driver linac were studied using expert information and data from operating machines such as ATLAS, APS, JLab, and LANL. Availability studies are performed with a Monte-Carlo simulation code previously applied to availability assessments of the NLC facility [2] and the results used to identify subsystem failures that most affect the availability and reliability of the RIA driver, and guide design iterations and component specifications to address identified problems.

  8. Simulation of ionization effects for high-density positron drivers in future plasma wakefield experiments

    SciTech Connect

    Bruhwiler, D.L.; Dimitrov, D.A.; Cary, J.R.; Esarey, E.; Leemans, W.P.

    2003-05-12

    The plasma wakefield accelerator (PWFA) concept has been proposed as a potential energy doubler for present or future electron-positron colliders. Recent particle-in-cell (PIC) simulations have shown that the self-fields of the required electron beam driver can tunnel ionize neutral Li, leading to plasma wake dynamics differing significantly from that of a preionized plasma. It has also been shown, for the case of a preionized plasma, that the plasma wake of a positron driver differs strongly from that of an electron driver. We will present new PIC simulations, using the OOPIC code, showing the effects of tunneling ionization on the plasma wake generated by high-density positron drivers. The results will be compared to previous work on electron drivers with tunneling ionization and positron drivers without ionization. Parameters relevant to the energy doubler and the upcoming E-164x experiment at the Stanford Linear Accelerator Center will be considered.

  9. Counter-driver shock tube

    NASA Astrophysics Data System (ADS)

    Tamba, T.; Nguyen, T. M.; Takeya, K.; Harasaki, T.; Iwakawa, A.; Sasoh, A.

    2015-11-01

    A "counter-driver" shock tube was developed. In this device, two counter drivers are actuated with an appropriate delay time to generate the interaction between a shock wave and a flow in the opposite direction which is induced by another shock wave. The conditions for the counter drivers can be set independently. Each driver is activated by a separate electrically controlled diaphragm rupture device, in which a pneumatic piston drives a rupture needle with a temporal jitter of better than 1.1 ms. Operation demonstrations were conducted to evaluate the practical performance.

  10. Driver behaviour at roadworks.

    PubMed

    Walker, Guy; Calvert, Malcolm

    2015-11-01

    There is an incompatibility between how transport engineers think drivers behave in roadworks and how they actually behave. As a result of this incompatibility we are losing approximately a lane's worth of capacity in addition to those closed by the roadworks themselves. The problem would have little significance were it not for the fact a lane of motorway costs approx. £30 m per mile to construct and £43 k a year to maintain, and that many more roadworks are planned as infrastructure constructed 40 or 50 years previously reaches a critical stage in its lifecycle. Given current traffic volumes, and the sensitivity of road networks to congestion, the effects of roadworks need to be accurately assessed. To do this requires a new ergonomic approach. A large-scale observational study of real traffic conditions was used to identify the issues and impacts, which were then mapped to the ergonomic knowledge-base on driver behaviour, and combined to developed practical guidelines to help in modelling future roadworks scenarios with greater behavioural accuracy. Also stemming from the work are novel directions for the future ergonomic design of roadworks themselves.

  11. Fast SCR Thyratron Driver

    SciTech Connect

    Nguyen, M.N.; /SLAC

    2007-06-18

    As part of an improvement project on the linear accelerator at SLAC, it was necessary to replace the original thyratron trigger generator, which consisted of two chassis, two vacuum tubes, and a small thyratron. All solid-state, fast rise, and high voltage thyratron drivers, therefore, have been developed and built for the 244 klystron modulators. The rack mounted, single chassis driver employs a unique way to control and generate pulses through the use of an asymmetric SCR, a PFN, a fast pulse transformer, and a saturable reactor. The resulting output pulse is 2 kV peak into 50 {Omega} load with pulse duration of 1.5 {mu}s FWHM at 180 Hz. The pulse risetime is less than 40 ns with less than 1 ns jitter. Various techniques are used to protect the SCR from being damaged by high voltage and current transients due to thyratron breakdowns. The end-of-line clipper (EOLC) detection circuit is also integrated into this chassis to interrupt the modulator triggering in the event a high percentage of line reflections occurred.

  12. Driver behaviour at roadworks.

    PubMed

    Walker, Guy; Calvert, Malcolm

    2015-11-01

    There is an incompatibility between how transport engineers think drivers behave in roadworks and how they actually behave. As a result of this incompatibility we are losing approximately a lane's worth of capacity in addition to those closed by the roadworks themselves. The problem would have little significance were it not for the fact a lane of motorway costs approx. £30 m per mile to construct and £43 k a year to maintain, and that many more roadworks are planned as infrastructure constructed 40 or 50 years previously reaches a critical stage in its lifecycle. Given current traffic volumes, and the sensitivity of road networks to congestion, the effects of roadworks need to be accurately assessed. To do this requires a new ergonomic approach. A large-scale observational study of real traffic conditions was used to identify the issues and impacts, which were then mapped to the ergonomic knowledge-base on driver behaviour, and combined to developed practical guidelines to help in modelling future roadworks scenarios with greater behavioural accuracy. Also stemming from the work are novel directions for the future ergonomic design of roadworks themselves. PMID:26154200

  13. High Power Operation of the JLab IR FEL Driver Accelerator

    SciTech Connect

    Kevin Beard; Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Christopher Gould; Albert Grippo; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; J. Hovater; Kevin Jordan; John Klopf; Rui Li; Steven Moore; George Neil; Benard Poelker; Thomas Powers; Joseph Preble; Robert Rimmer; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Gwyn Williams; Shukui Zhang

    2007-08-01

    Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

  14. Design and characteristics of a high-precision chopper wheel motor driver

    SciTech Connect

    Gu Xibin; Guo Ying; Chan, Henry; Kawamura, Ed; Kaiser, Ralf I.

    2005-11-15

    The circuit diagram and design principles of a high-stability chopper wheel motor driver are presented. Experimental results show that this unit can be interfaced to molecular-beam machines to generate supersonic beams with extremely stable root-mean-square and peak velocities fluctuating on a day-to-day basis by less than 0.2%.

  15. Idaho Driver Education Instructional Guide. Revised.

    ERIC Educational Resources Information Center

    Idaho State Dept. of Education, Boise.

    This driver education instructional safety guide is organized in three sections: Driver Education; Motorcycle Education; and Driver Education for the Handicapped. The driver education section contains 10 units dealing with the following topics: parent orientation; student orientation; basic control skills; driver performance; driving regulations;…

  16. Beam-Beam Interactions

    SciTech Connect

    Sramek, Christopher

    2003-09-05

    At the interaction point of a particle accelerator, various phenomena occur which are known as beam-beam effects. Incident bunches of electrons (or positrons) experience strong electromagnetic fields from the opposing bunches, which leads to electron deflection, beamstrahlung and the creation of electron/positron pairs and hadrons due to two-photon exchange. In addition, the beams experience a ''pinch effect'' which focuses each beam and results in either a reduction or expansion of their vertical size. Finally, if a beam's disruption parameter is too large, the beam can develop a sinusoidal distortion, or two-stream (kink) instability. This project simulated and studied these effects as they relate to luminosity, deflection angles and energy loss in order to optimize beam parameters for the Next Linear Collider (NLC). Using the simulation program Guinea-Pig, luminosity, deflection angle and beam energy data was acquired for different levels of beam offset and distortion. Standard deflection curves and luminosity plots agreed with theoretical models but also made clear the difficulties of e-e- feedback. Simulations emphasizing kink instability in modulated and straight beam collisions followed qualitative behavioral predictions and roughly fit recent analytic calculations. Finally, a study of e-e- collisions under design constraints for the NLC provided new estimates of how luminosity, beamstrahlung energy loss, upsilon parameter and deflection curve width scale with beam spotsizes.

  17. Improving School Bus Driver Performance.

    ERIC Educational Resources Information Center

    Farmer, Ernest

    This reference source is intended to assist the school bus driver training instructor in course preparation. Instructional units for program planning each contain pertinent course questions, a summary, and evaluation questions. Unit 1, "Introduction to the School Bus Driver Training Program," focuses on basic course objectives and requirements and…

  18. The older adult driver.

    PubMed

    Carr, D B

    2000-01-01

    More adults aged 65 and older will be driving in the next few decades. Many older drivers are safe behind the wheel and do not need intensive testing for license renewal. Others, however, have physiologic or cognitive impairments that can affect their mobility and driving safety. When an older patient's driving competency is questioned, a comprehensive, step-by-step assessment is recommended. Many diseases that impair driving ability can be detected and treated effectively by family physicians. Physicians should take an active role in assessing and reducing the risk for injury in a motor vehicle and, when possible, prevent or delay driving cessation in their patients. Referral to other health care professionals, such as an occupational or physical therapist, may be helpful for evaluation and treatment. When an older patient is no longer permitted or able to drive, the physician should counsel the patient about using alternative methods of transportation. PMID:10643955

  19. Laser-Beam-Alignment Controller

    NASA Technical Reports Server (NTRS)

    Krasowski, M. J.; Dickens, D. E.

    1995-01-01

    In laser-beam-alignment controller, images from video camera compared to reference patterns by fuzzy-logic pattern comparator. Results processed by fuzzy-logic microcontroller, which sends control signals to motor driver adjusting lens and pinhole in spatial filter.

  20. BEAM-BEAM 2003 SUMMARY.

    SciTech Connect

    FISCHER,W.SEN,T.

    2003-05-19

    This paper summarizes the presentations and discussions of the Beam-Beam'03 workshop, held in Montauk, Long Island, from May 19 to 23, 2003. Presentations and discussions focused on halo generation from beam-beam interactions; beam-beam limits, especially coherent limits and their effects on existing and future hadron colliders; beam-beam compensation techniques, particularly for long-range interactions; and beam-beam study tools in theory, simulation, and experiment.

  1. Progress in bright ion beams for industry, medicine and fusion at LBNL

    SciTech Connect

    Kwan, Joe W.

    2002-05-31

    Recent progresses at LBNL in developing ion beams for industry, radiation therapy and inertial fusion applications were discussed. The highlights include ion beam lithography, boron neutron capture therapy (BNCT), and heavy ion fusion (HIF) drivers using multiple linacs.

  2. PROTON BEAM REQUIREMENTS FOR A NEUTRINO FACTORY AND MUON COLLIDER

    SciTech Connect

    Zisman, Michael S.

    2009-12-11

    Both a Neutrino Factory and a Muon Collider place stringent demands on the proton beam used to generate the desired beam of muons. Here we discuss the advantages and challenges of muon accelerators and the rationale behind the requirements on proton beam energy, intensity, bunch length, and repetition rate. Example proton driver configurations that have been considered in recent years are also briefly indicated.

  3. Inertially confined fusion using heavy ion drivers

    SciTech Connect

    Herrmannsfeldt, W.B.; Bangerter, R.O.; Bock, R.; Hogan, W.J.; Lindl, J.D.

    1991-10-01

    The various technical issues of HIF will be briefly reviewed in this paper. It will be seen that there are numerous areas in common in all the approaches to HIF. In the recent International Symposium on Heavy Ion Inertial Fusion, the attendees met in specialized workshop sessions to consider the needs for research in each area. Each of the workshop groups considered the key questions of this report: (1) Is this an appropriate time for international collaboration in HIF? (2) Which problems are most appropriate for such collaboration? (3) Can the sharing of target design information be set aside until other driver and systems issues are better resolved, by which time it might be supposed that there could be a relaxation of classification of target issues? (4) What form(s) of collaboration are most appropriate, e.g., bilateral or multilateral? (5) Can international collaboration be sensibly attempted without significant increases in funding for HIF? The authors of this report share the conviction that collaboration on a broad scale is mandatory for HIF to have the resources, both financial and personnel, to progress to a demonstration experiment. Ultimately it may be possible for a single driver with the energy, power, focusibility, and pulse shape to satisfy the needs of the international community for target physics research. Such a facility could service multiple experimental chambers with a variety of beam geometries and target concepts.

  4. Inertially confined fusion using heavy ion drivers

    SciTech Connect

    Herrmannsfeldt, W.B. ); Bangerter, R.O. ); Bock, R. ); Hogan, W.J.; Lindl, J.D. )

    1991-10-01

    The various technical issues of HIF will be briefly reviewed in this paper. It will be seen that there are numerous areas in common in all the approaches to HIF. In the recent International Symposium on Heavy Ion Inertial Fusion, the attendees met in specialized workshop sessions to consider the needs for research in each area. Each of the workshop groups considered the key questions of this report: (1) Is this an appropriate time for international collaboration in HIF (2) Which problems are most appropriate for such collaboration (3) Can the sharing of target design information be set aside until other driver and systems issues are better resolved, by which time it might be supposed that there could be a relaxation of classification of target issues (4) What form(s) of collaboration are most appropriate, e.g., bilateral or multilateral (5) Can international collaboration be sensibly attempted without significant increases in funding for HIF The authors of this report share the conviction that collaboration on a broad scale is mandatory for HIF to have the resources, both financial and personnel, to progress to a demonstration experiment. Ultimately it may be possible for a single driver with the energy, power, focusibility, and pulse shape to satisfy the needs of the international community for target physics research. Such a facility could service multiple experimental chambers with a variety of beam geometries and target concepts.

  5. Proton driver power supply system

    SciTech Connect

    C. Jach and D. Wolff

    2002-06-03

    This paper describes magnet power supply system for a proposed Proton Driver at Fermilab. The magnet power supply system consists of resonant dipole/quadrupole power supply system, quadrupole tracking, dipole correction (horizontal and vertical) and sextupole power supply systems. This paper also describes preliminary design of the power distribution system supplying 13.8 kV power to all proton Driver electrical systems.

  6. Review of a Spoke-Cavity Design Option for the RIA Driver Linac

    SciTech Connect

    Petr Ostroumov; Kenneth Shepard; Jean Delayen

    2005-05-16

    A design option for the 1.4 GV, multiple-charge-state driver linac required for the U. S. Rare Isotope Accelerator Project based on 345 MHz, 3-cell spoke-loaded cavities has been previously discussed [1]. This paper updates consideration of design options for the RIA driver, including recent results from numerically-modeling the multi-charge-state beam dynamics and also cold test results for prototype superconducting niobium 3-cell spoke-loaded cavities.

  7. Review of a spoke-cavity design option for the RIA driver linac.

    SciTech Connect

    Ostroumov, P. N.; Shepard, K. W.; Delayen, J. R.; Physics; Thomas Jefferson National Accel. Facility

    2005-01-01

    A design option for the 1.4 GV, multiple-charge-state driver linac required for the U.S. Rare Isotope Accelerator Project based on 345 MHz, 3-cell spoke-loaded cavities has been previously discussed [1]. This paper updates consideration of design options for the RIA driver, including recent results from numerically-modeling the multi-charge-state beam dynamics and also cold test results for prototype superconducting niobium three-spoke-loaded cavities.

  8. Beam dynamics for induction accelerators

    NASA Astrophysics Data System (ADS)

    Lee, Edward P.

    2014-01-01

    An induction linac uses pulsed power that is applied directly, without any intervening resonant cavities, to accelerate a charged particle pulse. This approach can accommodate a large multiple-beam focusing lattice capable of transporting a large total beam current with a long pulse duration, which may be compressed while accelerating as well as afterward. The mean accelerating gradient is relatively low (less than about 1.5 MV/m), but the potential efficiency of energy transfer can be large up to about 50%. A multiple-beam induction linac is therefore a natural candidate accelerator for a heavy ion fusion (HIF) driver. However, the accelerated beams must meet stringent requirements on occupied phase space volume in order to be focused accurately and with small radius onto the fusion target. Dynamical considerations in the beam injector and linac, as well as in the final compression, final focus, and the fusion chamber, determine the quality of the driver beams as they approach the target. Requirements and tolerances derived from beam dynamics strongly influence the linac configuration and component design.

  9. How do drivers overtake cyclists?

    PubMed

    Dozza, Marco; Schindler, Ron; Bianchi-Piccinini, Giulio; Karlsson, Johan

    2016-03-01

    In Europe, the number of road crashes is steadily decreasing every year. However, the incidence of bicycle crashes is not declining as fast as that of car crashes. In Sweden, cyclists are the most frequently injured road users. Collisions between bicycles and motorized vehicles are of particular concern because the high speed and large mass of motorized vehicles create a high risk of serious injury to cyclists. In Sweden's urban areas, bicycle lanes keep bicycles separated from motorized vehicles, but on rural roads bicycle lanes are often absent, requiring drivers to interact with cyclists-usually by overtaking them. During this maneuver, drivers regulate speed and lateral position, negotiating with potential oncoming traffic to stay within their comfort zones while approaching and passing cyclists. In this study an instrumented bicycle recorded 145 overtaking maneuvers performed by car and truck drivers on public rural roads in Sweden. The bicycle was equipped with a LIDAR and two cameras to assess how drivers approached and circumvented the bicycle. The collected data allowed us to identify four overtaking phases and quantify the corresponding driver comfort zones. The presence of an oncoming vehicle was the factor that most influenced the maneuver, whereas neither vehicle speed, lane width, shoulder width nor posted speed limit significantly affected the driver comfort zone or the overtaking dynamics. PMID:26717348

  10. How do drivers overtake cyclists?

    PubMed

    Dozza, Marco; Schindler, Ron; Bianchi-Piccinini, Giulio; Karlsson, Johan

    2016-03-01

    In Europe, the number of road crashes is steadily decreasing every year. However, the incidence of bicycle crashes is not declining as fast as that of car crashes. In Sweden, cyclists are the most frequently injured road users. Collisions between bicycles and motorized vehicles are of particular concern because the high speed and large mass of motorized vehicles create a high risk of serious injury to cyclists. In Sweden's urban areas, bicycle lanes keep bicycles separated from motorized vehicles, but on rural roads bicycle lanes are often absent, requiring drivers to interact with cyclists-usually by overtaking them. During this maneuver, drivers regulate speed and lateral position, negotiating with potential oncoming traffic to stay within their comfort zones while approaching and passing cyclists. In this study an instrumented bicycle recorded 145 overtaking maneuvers performed by car and truck drivers on public rural roads in Sweden. The bicycle was equipped with a LIDAR and two cameras to assess how drivers approached and circumvented the bicycle. The collected data allowed us to identify four overtaking phases and quantify the corresponding driver comfort zones. The presence of an oncoming vehicle was the factor that most influenced the maneuver, whereas neither vehicle speed, lane width, shoulder width nor posted speed limit significantly affected the driver comfort zone or the overtaking dynamics.

  11. 49 CFR 380.109 - Driver testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....109 Driver testing. (a) Testing methods. The driver-student must pass knowledge and skills tests in... an LCV driver-training program as specified in subpart B of this part. The written knowledge test may be administered by any qualified driver-instructor. The skills tests, based on actual operation of...

  12. Electron Cloud Measurements in Heavy-Ion Driver for HEDP and Inertial Fusion Energy

    SciTech Connect

    Covo, M K; Molvik, A W; Friedman, A; Cohen, R; Vay, J; Bieniosek, F; Baca, D; Seidl, P A; Logan, G; Vujic, J L

    2006-08-16

    The High Current Experiment (HCX) at LBNL is a driver scale single beam injector that provides a 1 MeV K+ ion beam current of 0.18 A for 5 {micro}s. It transports high-current beams with large fill factor (ratio of the maximum beam envelope radius to the beam pipe radius) and low emittance growth that are required to keep the cost of the power plant competitive and to satisfy the target requirements of focusing ion beams to high-power density. Beam interaction with the background gas and walls desorbs electrons that can multiply and accumulate, creating an electron cloud. This ubiquitous effect grows at higher fill factors and degrades the quality of the beam. We review simulations and diagnostics tools used to measure electron production, accumulation and its properties.

  13. The Role of the Driver Circuit in the Neutron Yield of the Plasma Focus

    NASA Astrophysics Data System (ADS)

    Sears, Jason; Schmidt, Andrea; Link, Anthony; Welch, Dale

    2015-11-01

    Emperical observations have suggested that dense plasma focus (DPF) neutron yield increases with driver impedance. Using the particle-in-cell code LSP, we reproduce this trend in a kJ DPF, and demonstrate in detail how driver impedance is coupled to neutron output. We implement a 2-D model of the plasma focus including self-consistent circuit-driven boundary conditions. We show that m=0 growth is central to beam formation and is a chaotic, non-deterministic process. Neutrons are produced when high, short-lived electric fields in the low-density cavity of an m=0 mode accelerate a beam of ions into the dense downstream pinch region. Neutron yield is highest when the ion beam is generated within 50 ns of the pinch formation on axis, because at that time the pinch (target) density is highest. High driver impedance contributes to prompt beam formation in two ways. First, the high impedance driver, losing less energy to run-down, has a faster run-in velocity and hence larger Rayleigh-Taylor features that more readily seed the m=0 instability. Second, the shorter anode of the high-impedance driver retains less trailing mass in the run-down region and thus exhibits fewer and less parasitic restrikes. Prepared by LLNL under Contract DE-AC52-07NA27344.

  14. Sexual behavior among truck drivers.

    PubMed

    Singh, Rajiv Kumar; Joshi, Hari Shankar

    2012-01-01

    A cross-sectional study was conducted on Lucknow highway in Bareilly district of Uttar Pradesh to study the knowledge of truck drivers about HIV transmission and prevention and to study the sexual behaviour of these drivers with reference to HIV/AIDS. Age, marital status, education, income, drinking alcohol, length of stay away from home, knowledge about transmission and prevention of HIV, and HIV-prone behavior of truck drivers were studied. Chi-square, mean, and SD were calculated. In all, 289 (97.6%) drivers had heard about HIV/AIDS. Only 242 (81.8%) were aware of HIV transmission by heterosexual route. Misconceptions such as HIV transmission by mosquito bites, living in same room, shaking hands, and sharing food were found. Out of 174 (58.8%) who visited Commercial Sex Workers (CSW), 146 (83.9%) used a condom. 38 (12.8%) visited more than 5 CSW in the last 3 months. Time away from home on the road, marital status, alcohol use, and income class were associated with visiting CSW. High-risk behavior was established in the study population. Safe sex and use of condoms need to be promoted among the truck drivers and better condom availability needs to be assured on highways.

  15. Key drivers of airline loyalty

    PubMed Central

    Dolnicar, Sara; Grabler, Klaus; Grün, Bettina; Kulnig, Anna

    2011-01-01

    This study investigates drivers of airline loyalty. It contributes to the body of knowledge in the area by investigating loyalty for a number of a priori market segments identified by airline management and by using a method which accounts for the multi-step nature of the airline choice process. The study is based on responses from 687 passengers. Results indicate that, at aggregate level, frequent flyer membership, price, the status of being a national carrier and the reputation of the airline as perceived by friends are the variables which best discriminate between travellers loyal to the airline and those who are not. Differences in drivers of airline loyalty for a number of segments were identified. For example, loyalty programs play a key role for business travellers whereas airline loyalty of leisure travellers is difficult to trace back to single factors. For none of the calculated models satisfaction emerged as a key driver of airline loyalty. PMID:27064618

  16. Drivers of the primate thalamus

    PubMed Central

    Rovó, Zita; Ulbert, István; Acsády, László

    2012-01-01

    The activity of thalamocortical neurons is largely determined by giant excitatory terminals, called drivers. These afferents may arise from neocortex or from subcortical centers; however their exact distribution, segregation or putative absence in given thalamic nuclei are unknown. To unravel the nucleus-specific composition of drivers, we mapped the entire macaque thalamus utilizing vesicular glutamate transporters 1 and 2 to label cortical and subcortical afferents, respectively. Large thalamic territories were innervated exclusively either by giant vGLUT2- or vGLUT1-positive boutons. Co-distribution of drivers with different origin was not abundant. In several thalamic regions, no giant terminals of any type could be detected at light microscopic level. Electron microscopic observation of these territories revealed either the complete absence of large multisynaptic excitatory terminals (basal ganglia-recipient nuclei) or the presence of both vGLUT1- and vGLUT2-positive terminals, which were significantly smaller than their giant counterparts (intralaminar nuclei, medial pulvinar). In the basal ganglia-recipient thalamus, giant inhibitory terminals replaced the excitatory driver inputs. The pulvinar and the mediodorsal nucleus displayed subnuclear heterogeneity in their driver assemblies. These results show that distinct thalamic territories can be under pure subcortical or cortical control; however there is significant variability in the composition of major excitatory inputs in several thalamic regions. Since thalamic information transfer depends on the origin and complexity of the excitatory inputs, this suggests that the computations performed by individual thalamic regions display considerable variability. Finally, the map of driver distribution may help to resolve the morphological basis of human diseases involving different parts of the thalamus. PMID:23223308

  17. UWB dual burst transmit driver

    SciTech Connect

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Zumstein, James M.; Vigars, Mark L.; Romero, Carlos E.

    2012-04-17

    A dual burst transmitter for ultra-wideband (UWB) communication systems generates a pair of precisely spaced RF bursts from a single trigger event. An input trigger pulse produces two oscillator trigger pulses, an initial pulse and a delayed pulse, in a dual trigger generator. The two oscillator trigger pulses drive a gated RF burst (power output) oscillator. A bias driver circuit gates the RF output oscillator on and off and sets the RF burst packet width. The bias driver also level shifts the drive signal to the level that is required for the RF output device.

  18. Emittance growth and instability induced by space charge effect during final beam bunching in HIF accelerator system

    NASA Astrophysics Data System (ADS)

    Kikuchi, T.; Someya, T.; Kawata, S.; Nakajima, M.; Horioka, K.

    2006-06-01

    Beam dynamics and emittance growth are investigated by using particle-in-cell simulations during a final beam bunching for a driver system of inertial fusion driven by intense heavy ion beams. Space-charge-dominated beams are transported by a transverse confinement lattice with longitudinal compression, and the emittance increases along the longitudinal beam bunching. Dipole oscillations are excited due to the initial displacement of the beam center. The displacement causes the additional emittance growth during the final beam bunching.

  19. Children's Understanding of Drivers' Intentions

    ERIC Educational Resources Information Center

    Foot, Hugh C.; Thomson, James A.; Tolmie, Andrew K.; Whelan, Kirstie M.; Morrison, Sheila; Sarvary, Penelope

    2006-01-01

    To become more skilled as pedestrians, children need to acquire a view of the traffic environment as one in which road users are active agents with different intentions and objectives. This paper describes a simulation study designed to explore children's understanding of drivers' intentions. It also investigated the effect of training children's…

  20. Transporting Handicapped Students: Driver Manual.

    ERIC Educational Resources Information Center

    Turner, Dayton Ray

    The document offers guidelines for van or bus drivers transporting handicapped students to and from school. Part 1 offers an overview of adaptive transportation services and gives specifics on providing services to the blind/visually impaired, hearing impaired, mentally retarded, physically handicapped, behaviorally disordered, learning disabled,…

  1. Teaching French via Driver Education.

    ERIC Educational Resources Information Center

    Berwald, Jean-Pierre

    1980-01-01

    Driver instruction through the medium of a foreign language is useful in teaching vocabulary, grammar, and culture. The maps, driving manuals, and cars stimulate discussion and communication. Course techniques can include Asher's concept of Total Physical Response wherein students act in response to commands in the foreign language. (PMJ)

  2. Fuel-Cell Drivers Wanted

    ERIC Educational Resources Information Center

    Clark, Todd; Jones, Rick

    2004-01-01

    While the political climate seems favorable for the development of fuel-cell vehicles for personal transportation, the market's demand may not be so favorable. Nonetheless, middle level students will be the next generation of drivers and voters, and they need to be able to make informed decisions regarding the nation's energy and transportation…

  3. Older Drivers: A Closer Look.

    ERIC Educational Resources Information Center

    Goggin, Noreen L.; Keller, M. Jean

    1996-01-01

    Cognitive and decision-making capabilities and motor responses were assessed for 24 older adults using 15 videotaped driving scenarios. Older drivers performed better on the simulation than the written test. Men performed better, drove more miles per year, and did more highway driving, differences attributed to handgrip strength or sex-role…

  4. 49 CFR 380.109 - Driver testing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SPECIAL TRAINING....109 Driver testing. (a) Testing methods. The driver-student must pass knowledge and skills tests...

  5. 49 CFR 380.109 - Driver testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SPECIAL TRAINING....109 Driver testing. (a) Testing methods. The driver-student must pass knowledge and skills tests...

  6. 49 CFR 380.109 - Driver testing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SPECIAL TRAINING....109 Driver testing. (a) Testing methods. The driver-student must pass knowledge and skills tests...

  7. 49 CFR 380.109 - Driver testing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SPECIAL TRAINING....109 Driver testing. (a) Testing methods. The driver-student must pass knowledge and skills tests...

  8. Space Charge Waves in Mismatched Beams

    SciTech Connect

    Poole, B R; Blackfield, D T; Chen, Y; Harris, J R; O'Shea, P G

    2009-04-17

    Mismatch oscillations resulting from the propagation of space charge waves in intense beams may lead to halo generation, beam loss, and modification of longitudinal beam properties. These oscillations have amplitudes and frequencies different from that of the main beam and are particularly important in machines such as the University of Maryland Electron Ring (UMER), in which the beam dynamics scales to parameters associated with heavy ion fusion drivers. To study these effects, we use the particle in cell code LSP [1] to simulate space charge wave dynamics in an intense electron beam propagating in a smooth focusing channel with 2-D cylindrical symmetry. We examine the evolution of linear and nonlinear density perturbations for both matched and mismatched beams. Comparisons between LSP simulations and numerical models are presented.

  9. RF parameter curves for a proton driver synchrotron

    SciTech Connect

    James A. MacLachlan, Z. Qian and J.E. Griffin

    2001-07-12

    High average beam power proton synchrotrons in the medium energy range are under consideration at several laboratories for intense and specialized secondary particle sources like muon colliders and {nu} factories. A 12-16 GeV machine with a 15 Hz cycle and 3 {center_dot} 10{sup 13} p/pulse capability called the Proton Driver (PD) has been studied as a replacement for the Fermilab Booster and as a base for future facilities.[1] A staged development is proposed, initially using 20 modified 53 MHz Booster cavities in 12 GeV operation.[2] A second stage would allow 16 GeV top energy using a 7.5 MHz rf system consisting of 100 15 kV low-Q cavities.[3] This paper discusses the choices of rf system parameters made in the design study. The limited number of existing Booster cavities has led to consideration for stage 1 of an inductive insert in the ring to aid initial beam capture by compensating longitudinal space charge, an admittedly speculative expedient requiring followup with further calculation and some beam experiments. This report is one of nineteen papers at this conference by members of the Proton Driver design team; it relies on these others to help establish the general context.

  10. The multiple-pulse driver line on the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Kosc, T. Z.; Kelly, J. H.; Hill, E. M.; Dorrer, C.; Waxer, L. J.; Donaldson, W. R.

    2015-02-01

    The multiple-pulse driver line (MPD) provides on-shot co-propagation of two separate pulse shapes in all 60 OMEGA beams at the Laboratory for Laser Energetics (LLE). The two co-propagating pulse shapes would typically be (1) a series of 100-ps "picket" pulses followed by (2) a longer square or shaped "drive" pulse. Smoothing by spectral dispersion (SSD), which increases the laser bandwidth, can be applied to either one of the two pulse shapes. Therefore, MPD allows for dynamic bandwidth reduction, where the bandwidth is applied only to the picket portion of a pulse shape. Since the use of SSD decreases the efficiency of frequency conversion from the IR to the UV, dynamic bandwidth reduction provides an increase in the drive-pulse energy. The design of the MPD required careful consideration of beam combination as well as the minimum pulse separation for two pulses generated by two separate sources. A new combined-pulse-shape diagnostic needed to be designed and installed after the last grating used for SSD. This new driver-line flexibility is built into the OMEGA front end as one component of the initiative to mitigate cross-beam energy transfer on target and to demonstrate hydro-equivalent ignition on the OMEGA laser at LLE.

  11. Quasiperiodic behavior in beam-driven strong Langmuir turbulence

    NASA Technical Reports Server (NTRS)

    Robinson, P. A.; Newman, D. L.

    1989-01-01

    The evolution of unmagnetized beam-driven strong Langmuir turbulence is studied in two dimensions by numerically integrating the Zakharov equations for systems pumped by monochromatic and broadband negative-damping drivers with nonzero central wavenumber. Long-time statistically steady states are reached for which the dependence of the evolution on the driver wavenumber, growth rate, and bandwidth is examined in detail. For monochromatic drivers, a quasiperiodic cycle is found to develop if the driver wavenumber is sufficiently large. The characteristic frequency of the quasiperiodic cycle and the average system energy are both approximately proportional to the growth rate. Broadening of the driver in wavenumber tends to degrade the system-wide coherence of the cycle, but its main features appear to survive on the scale of the coherence length of the driver.

  12. Eaton AF5000+Genesis Communication Driver

    1995-05-25

    Communication driver allows the Genesis Control Series software to interact with Eaton AF5000+ frequency drives via RS-232 communications. All Eaton AF5000+ parameters that support communications are supported by the Genesis driver. Multidrop addressing to multiple units is available with the Genesis communication driver.

  13. Driver Education and the Learning Disabled.

    ERIC Educational Resources Information Center

    Wirths, Claudine G.; Leonard, Steven

    1982-01-01

    A project of the University of Maryland has developed a driver education curriculum for the learning disabled. Several states are making efforts to improve driver education, including rewriting materials and providing oral tests for drivers' licenses. Options for future safety programs include parent-student seminars, multidiscipline teaching, and…

  14. Yb:YAG ceramic-based laser driver for Inertial Fusion Energy (IFE)

    NASA Astrophysics Data System (ADS)

    Vetrovec, John; Copeland, Drew A.; Litt, Amardeep S.

    2016-03-01

    We report on a new class of laser amplifiers for inertial confinement fusion (ICF) drivers based on a Yb:YAG ceramic disk in an edge-pumped configuration and cooled by a high-velocity gas flow. The Yb lasant offers very high efficiency and low waste heat. The ceramic host material has a thermal conductivity nearly 15-times higher than the traditionally used glass and it is producible in sizes suitable for a typical 10- to 20-kJ driver beam line. The combination of high lasant efficiency, low waste heat, edge-pumping, and excellent thermal conductivity of the host, enable operation at 10 to 20 Hz at over 20% wall plug efficiency while being comparably smaller and less costly than recently considered face-pumped alternative drivers using Nd:glass, Yb:S-FAP, and cryogenic Yb:YAG. Scalability of the laser driver over a broad range of sizes is presented.

  15. Physics design and scaling of recirculating induction accelerators: from benchtop prototypes to drivers

    SciTech Connect

    Barnard, J.J.; Cable, M.D.; Callahan, D.A.

    1996-02-06

    Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all of the critical beam dynamics issues that have been raised. We review the design equations for recirculators and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion/extraction, vacuum requirements, and emittance growth, scale from small-prototype to driver-size accelerator.

  16. PLASMA WAKE EXCITATION BY LASERS OR PARTICLE BEAMS

    SciTech Connect

    Schroeder, Carl B.; Esarey, Eric; Benedetti, Carlo; Toth, Csaba; Geddes, Cameron; Leemans, Wim

    2011-04-01

    Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. Plasma wake excitation driven by lasers or particle beams is examined, and the implications of the different physical excitation mechanisms for accelerator design are discussed. Plasma-based accelerators have attracted considerable attention owing to the ultrahigh field gradients sustainable in a plasma wave, enabling compact accelerators. These relativistic plasma waves are excited by displacing electrons in a neutral plasma. Two basic mechanisms for excitation of plasma waves are actively being researched: (i) excitation by the nonlinear ponderomotive force (radiation pressure) of an intense laser or (ii) excitation by the space-charge force of a dense charged particle beam. There has been significant recent experimental success using lasers and particle beam drivers for plasma acceleration. In particular, for laser-plasma accelerators (LPAs), the demonstration at LBNL in 2006 of high-quality, 1 GeV electron beams produced in approximately 3 cm plasma using a 40 TW laser. In 2007, for beam-driven plasma accelerators, or plasma-wakefield accelerators (PWFAs), the energy doubling over a meter to 42 GeV of a fraction of beam electrons on the tail of an electron beam by the plasma wave excited by the head was demonstrated at SLAC. These experimental successes have resulted in further interest in the development of plasma-based acceleration as a basis for a linear collider, and preliminary collider designs using laser drivers and beam drivers are being developed. The different physical mechanisms of plasma wave excitation, as well as the typical characteristics of the drivers, have implications for accelerator design. In the following, we identify the similarities and differences between wave excitation by lasers and particle beams. The field structure of the plasma wave driven by lasers or particle beams is discussed, as well as the

  17. Factors Contributing to Crashes among Young Drivers.

    PubMed

    Bates, Lyndel J; Davey, Jeremy; Watson, Barry; King, Mark J; Armstrong, Kerry

    2014-08-01

    Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures.

  18. Visualization drivers for Geant4

    SciTech Connect

    Beretvas, Andy; /Fermilab

    2005-10-01

    This document is on Geant4 visualization tools (drivers), evaluating pros and cons of each option, including recommendations on which tools to support at Fermilab for different applications. Four visualization drivers are evaluated. They are OpenGL, HepRep, DAWN and VRML. They all have good features, OpenGL provides graphic output without an intermediate file. HepRep provides menus to assist the user. DAWN provides high quality plots and even for large files produces output quickly. VRML uses the smallest disk space for intermediate files. Large experiments at Fermilab will want to write their own display. They should proceed to make this display graphics independent. Medium experiment will probably want to use HepRep because of it's menu support. Smaller scale experiments will want to use OpenGL in the spirit of having immediate response, good quality output and keeping things simple.

  19. Global desertification: Drivers and feedbacks

    NASA Astrophysics Data System (ADS)

    D'Odorico, Paolo; Bhattachan, Abinash; Davis, Kyle F.; Ravi, Sujith; Runyan, Christiane W.

    2013-01-01

    Desertification is a change in soil properties, vegetation or climate, which results in a persistent loss of ecosystem services that are fundamental to sustaining life. Desertification affects large dryland areas around the world and is a major cause of stress in human societies. Here we review recent research on the drivers, feedbacks, and impacts of desertification. A multidisciplinary approach to understanding the drivers and feedbacks of global desertification is motivated by our increasing need to improve global food production and to sustainably manage ecosystems in the context of climate change. Classic desertification theories look at this process as a transition between stable states in bistable ecosystem dynamics. Climate change (i.e., aridification) and land use dynamics are the major drivers of an ecosystem shift to a “desertified” (or “degraded”) state. This shift is typically sustained by positive feedbacks, which stabilize the system in the new state. Desertification feedbacks may involve land degradation processes (e.g., nutrient loss or salinization), changes in rainfall regime resulting from land-atmosphere interactions (e.g., precipitation recycling, dust emissions), or changes in plant community composition (e.g., shrub encroachment, decrease in vegetation cover). We analyze each of these feedback mechanisms and discuss their possible enhancement by interactions with socio-economic drivers. Large scale effects of desertification include the emigration of “environmental refugees” displaced from degraded areas, climatic changes, and the alteration of global biogeochemical cycles resulting from the emission and long-range transport of fine mineral dust. Recent research has identified some possible early warning signs of desertification, which can be used as indicators of resilience loss and imminent shift to desert-like conditions. We conclude with a brief discussion on some desertification control strategies implemented in different

  20. The drivers of tropical speciation.

    PubMed

    Smith, Brian Tilston; McCormack, John E; Cuervo, Andrés M; Hickerson, Michael J; Aleixo, Alexandre; Cadena, Carlos Daniel; Pérez-Emán, Jorge; Burney, Curtis W; Xie, Xiaoou; Harvey, Michael G; Faircloth, Brant C; Glenn, Travis C; Derryberry, Elizabeth P; Prejean, Jesse; Fields, Samantha; Brumfield, Robb T

    2014-11-20

    Since the recognition that allopatric speciation can be induced by large-scale reconfigurations of the landscape that isolate formerly continuous populations, such as the separation of continents by plate tectonics, the uplift of mountains or the formation of large rivers, landscape change has been viewed as a primary driver of biological diversification. This process is referred to in biogeography as vicariance. In the most species-rich region of the world, the Neotropics, the sundering of populations associated with the Andean uplift is ascribed this principal role in speciation. An alternative model posits that rather than being directly linked to landscape change, allopatric speciation is initiated to a greater extent by dispersal events, with the principal drivers of speciation being organism-specific abilities to persist and disperse in the landscape. Landscape change is not a necessity for speciation in this model. Here we show that spatial and temporal patterns of genetic differentiation in Neotropical birds are highly discordant across lineages and are not reconcilable with a model linking speciation solely to landscape change. Instead, the strongest predictors of speciation are the amount of time a lineage has persisted in the landscape and the ability of birds to move through the landscape matrix. These results, augmented by the observation that most species-level diversity originated after episodes of major Andean uplift in the Neogene period, suggest that dispersal and differentiation on a matrix previously shaped by large-scale landscape events was a major driver of avian speciation in lowland Neotropical rainforests.

  1. The drivers of tropical speciation.

    PubMed

    Smith, Brian Tilston; McCormack, John E; Cuervo, Andrés M; Hickerson, Michael J; Aleixo, Alexandre; Cadena, Carlos Daniel; Pérez-Emán, Jorge; Burney, Curtis W; Xie, Xiaoou; Harvey, Michael G; Faircloth, Brant C; Glenn, Travis C; Derryberry, Elizabeth P; Prejean, Jesse; Fields, Samantha; Brumfield, Robb T

    2014-11-20

    Since the recognition that allopatric speciation can be induced by large-scale reconfigurations of the landscape that isolate formerly continuous populations, such as the separation of continents by plate tectonics, the uplift of mountains or the formation of large rivers, landscape change has been viewed as a primary driver of biological diversification. This process is referred to in biogeography as vicariance. In the most species-rich region of the world, the Neotropics, the sundering of populations associated with the Andean uplift is ascribed this principal role in speciation. An alternative model posits that rather than being directly linked to landscape change, allopatric speciation is initiated to a greater extent by dispersal events, with the principal drivers of speciation being organism-specific abilities to persist and disperse in the landscape. Landscape change is not a necessity for speciation in this model. Here we show that spatial and temporal patterns of genetic differentiation in Neotropical birds are highly discordant across lineages and are not reconcilable with a model linking speciation solely to landscape change. Instead, the strongest predictors of speciation are the amount of time a lineage has persisted in the landscape and the ability of birds to move through the landscape matrix. These results, augmented by the observation that most species-level diversity originated after episodes of major Andean uplift in the Neogene period, suggest that dispersal and differentiation on a matrix previously shaped by large-scale landscape events was a major driver of avian speciation in lowland Neotropical rainforests. PMID:25209666

  2. Progress in heavy ion drivers inertial fusion energy: From scaled experiments to the integrated research experiment

    SciTech Connect

    Barnard, J.J.; Ahle, L.E.; Baca, D.; Bangerter, R.O.; Bieniosek, F.M.; Celata, C.M.; Chacon-Golcher, E.; Davidson, R.C.; Faltens, A.; Friedman, A.; Franks, R.M.; Grote, D.P.; Haber, I.; Henestroza, E.; de Hoon, M.J.L.; Kaganovich, I.; Karpenko, V.P.; Kishek, R.A.; Kwan, J.W.; Lee, E.P.; Logan, B.G.; Lund, S.M.; Meier, W.R.; Molvik, A.W.; Olson, C.; Prost, L.R.; Qin, H.; Rose, D.; Sabbi, G.-L.; Sangster, T.C.; Seidl, P.A.; Sharp, W.M.; Shuman, D.; Vay, J.-L.; Waldron, W.L.; Welch, D.; Yu, S.S.

    2001-03-01

    The promise of inertial fusion energy driven by heavy ion beams requires the development of accelerators that produce ion currents ({approx}100's Amperes/beam) and ion energies ({approx}1-10 GeV) that have not been achieved simultaneously in any existing accelerator. The high currents imply high generalized perveances, large tune depressions, and high space charge potentials of the beam center relative to the beam pipe. Many of the scientific issues associated with ion beams of high perveance and large tune depression have been addressed over the last two decades on scaled experiments at Lawrence Berkeley and Lawrence Livermore National Laboratories, the University of Maryland, and elsewhere. The additional requirement of high space charge potential (or equivalently high line charge density) gives rise to effects (particularly the role of electrons in beam transport) which must be understood before proceeding to a large scale accelerator. The first phase of a new series of experiments in Heavy Ion Fusion Virtual National Laboratory (HIF VNL), the High Current Experiments (HCX), is now being constructed at LBNL. The mission of the HCX will be to transport beams with driver line charge density so as to investigate the physics of this regime, including constraints on the maximum radial filling factor of the beam through the pipe. This factor is important for determining both cost and reliability of a driver scale accelerator. The HCX will provide data for design of the next steps in the sequence of experiments leading to an inertial fusion energy power plant. The focus of the program after the HCX will be on integration of all of the manipulations required for a driver. In the near term following HCX, an Integrated Beam Experiment (IBX) of the same general scale as the HCX is envisioned. The step which bridges the gap between the IBX and an engineering test facility for fusion has been designated the Integrated Research Experiment (IRE). The IRE (like the IBX) will

  3. Illumination non-uniformity of spirally wobbling beam in heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Noguchi, K.; Kurosaki, T.; Barada, D.; Kawata, S.; Ma, Y. Y.; Ogoyski, A. I.

    2016-03-01

    In inertial confinement fusion, the driver beam illumination non-uniformity leads a degradation of fusion energy output. The illumination non-uniformity allowed is less than a few percent in inertial fusion target implosion. Heavy ion beam (HIB) accelerator provides a capability to oscillate a beam axis with a high frequency. The wobbling beams may provide a new method to reduce or smooth the beam illumination non-uniformity. In this paper the HIBs wobbling illumination scheme was optimized.

  4. Study of CSR Effects in the Jefferson Laboratory FEL Driver

    SciTech Connect

    Hall, C. C.; Biedron, S.; Burleson, Theodore A.; Milton, Stephen V.; Morin, Auralee L.; Benson, Stephen V.; Douglas, David R.; Evtushenko, Pavel E.; Hannon, Fay E.; Li, Rui; Tennant, Christopher D.; Zhang, Shukui; Carlsten, Bruce E.; Lewellen, John W.

    2013-08-01

    In a recent experiment conducted on the Jefferson Laboratory IR FEL driver the effects of Coherent Synchrotron Radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR chicane. This experiment also provides a valuable opportunity to benchmark existing CSR models in a system that may not be fully represented by a 1-D CSR model. Here we present results from this experiment and compare to initial simulations of CSR in the magnetic compression chicane of the machine. Finally, we touch upon the possibility for CSR induced microbunching gain in the magnetic compression chicane, and show that parameters in the machine are such that it should be thoroughly damped.

  5. Anomalous intense driver (AID) concept

    SciTech Connect

    Thode, L.E.

    1980-03-01

    An optimized electron bunching mechanism is utilized to efficiently couple the energy of a 5 to 100 MeV, 1 to 30 TW electron beam into a 3 to 50 cm/sup 3/ plasma of electron density 10/sup 17/ to 10/sup 20/ cm-/sup 3/. An efficient coupling of beam energy and momentum to the plasma is possible due to the relativistic nature of the beam dynamics combined with the short wavelength of the bunching mechanism in a high-density plasma. The rapidly produced multi-kilovolt plasma can be used directly to develop a pulsed neutron and x-ray source. Alternatively, the plasma can be used to drive a hierarchy of inertial confinement or x-ray devices. Utilizing this novel concept, controlled thermonuclear fusion may be achievable within present or near term relativistic electron beam technology.

  6. Car drivers' attitudes towards motorcyclists: a survey.

    PubMed

    Crundall, David; Bibby, Peter; Clarke, David; Ward, Patrick; Bartle, Craig

    2008-05-01

    Motorcyclists are over-represented in UK traffic accident statistics. Many car-motorcycle accidents are however due to the inappropriate actions of car drivers. It is predicted that car drivers at risk of collision with motorcycles have divergent attitudes and beliefs about motorcyclists compared to safer drivers, which may lead to a deficient mental model guiding their interactions with motorcyclists. To assess car drivers' attitudes towards motorcyclists, a survey was undertaken. Respondents filled in 26 general and motorcycle-related items and the 24 items of the reduced Driver Behaviour Questionnaire. Compared to an experienced dual driver group (who both drive cars and ride motorcycles), all other drivers showed divergent beliefs and attitudes. Four factors were extracted from the motorcycle items: negative attitudes, empathic attitudes, awareness of perceptual problems, and spatial understanding. Car drivers with a moderate amount of experience (between 2 and 10 years driving) held the most negative views and reported the most violations. The results have lead to several suggestions for interventions aimed at decreasing the divergence between drivers' perceptions of motorcyclists, and the perceptions of experienced dual drivers.

  7. Effect of driver impedance on dense plasma focus Z-pinch neutron yield

    SciTech Connect

    Sears, Jason E-mail: schmidt36@llnl.gov; Link, Anthony E-mail: schmidt36@llnl.gov; Schmidt, Andrea E-mail: schmidt36@llnl.gov; Welch, Dale

    2014-12-15

    The Z-pinch phase of a dense plasma focus (DPF) heats the plasma by rapid compression and accelerates ions across its intense electric fields, producing neutrons through both thermonuclear and beam-target fusion. Driver characteristics have empirically been shown to affect performance, as measured by neutron yield per unit of stored energy. We are exploring the effect of driver characteristics on DPF performance using particle-in-cell (PIC) simulations of a kJ scale DPF. In this work, our PIC simulations are fluid for the run-down phase and transition to fully kinetic for the pinch phase, capturing kinetic instabilities, anomalous resistivity, and beam formation during the pinch. The anode-cathode boundary is driven by a circuit model of the capacitive driver, including system inductance, the load of the railgap switches, the guard resistors, and the coaxial transmission line parameters. It is known that the driver impedance plays an important role in the neutron yield: first, it sets the peak current achieved at pinch time; and second, it affects how much current continues to flow through the pinch when the pinch inductance and resistance suddenly increase. Here we show from fully kinetic simulations how total neutron yield depends on the impedance of the driver and the distributed parameters of the transmission circuit. Direct comparisons between the experiment and simulations enhance our understanding of these plasmas and provide predictive design capability for neutron source applications.

  8. Effect of driver impedance on dense plasma focus Z-pinch neutron yield

    NASA Astrophysics Data System (ADS)

    Sears, Jason; Link, Anthony; Schmidt, Andrea; Welch, Dale

    2014-12-01

    The Z-pinch phase of a dense plasma focus (DPF) heats the plasma by rapid compression and accelerates ions across its intense electric fields, producing neutrons through both thermonuclear and beam-target fusion. Driver characteristics have empirically been shown to affect performance, as measured by neutron yield per unit of stored energy. We are exploring the effect of driver characteristics on DPF performance using particle-in-cell (PIC) simulations of a kJ scale DPF. In this work, our PIC simulations are fluid for the run-down phase and transition to fully kinetic for the pinch phase, capturing kinetic instabilities, anomalous resistivity, and beam formation during the pinch. The anode-cathode boundary is driven by a circuit model of the capacitive driver, including system inductance, the load of the railgap switches, the guard resistors, and the coaxial transmission line parameters. It is known that the driver impedance plays an important role in the neutron yield: first, it sets the peak current achieved at pinch time; and second, it affects how much current continues to flow through the pinch when the pinch inductance and resistance suddenly increase. Here we show from fully kinetic simulations how total neutron yield depends on the impedance of the driver and the distributed parameters of the transmission circuit. Direct comparisons between the experiment and simulations enhance our understanding of these plasmas and provide predictive design capability for neutron source applications.

  9. The Facility for Rare Isotope Beams

    NASA Astrophysics Data System (ADS)

    Wrede, C.

    2015-05-01

    The Facility for Rare Isotope Beams (FRIB) is a United States Department of Energy user facility currently under construction on the campus of Michigan State University. Based on a 400 kW, 200 MeV/u heavy-ion driver linac, FRIB will deliver high-quality fast, thermalized, and re-accelerated beams of rare isotopes with unprecedented intensities to a variety of experimental areas and equipment. New science opportunities at the frontiers of nuclear structure, nuclear astrophysics, fundamental symmetries, and societal applications will be enabled by this future world-leading rare-isotope beam facility.

  10. Recent developments in mass drivers

    NASA Technical Reports Server (NTRS)

    Oneill, G. K.

    1981-01-01

    In the past eight months a new mass driver concept has been explored through calculation and inductance model verification. It retains the linear synchronous principle and freedom from arcs, plasmas or physical contact between the accelerated bucket and accelerator. However, it discards passive magnetic flight and obtains transverse focussing from strong off-axis restoring forces produced by drive coils operating in a pull-only mode. This paper gives the reasoning on which the new concept is based, and applies the concept to a lunar catapult design.

  11. Drug use by tractor-trailer drivers.

    PubMed

    Lund, A K; Preusser, D F; Blomberg, R D; Williams, A F

    1988-05-01

    Blood or urine samples or both were obtained from 317 of 359 randomly selected tractor-trailer drivers asked to participate in a driver health survey conducted at a truck weighing station on Interstate 40 in Tennessee. Altogether, 29% of the drivers had evidence of alcohol, marijuana, cocaine, prescription or nonprescription stimulants, or some combination of these, in either blood or urine. Cannabinoids were found in 15% of the drivers' blood or urine; nonprescription stimulants such as phenylpropanolamine were found in 12%; prescription stimulants such as amphetamine were found in 5%; cocaine metabolites were found in 2%; and alcohol was found in less than 1%. These results provide the first objective information about the use of potentially abusive drugs by tractor-trailer drivers. The extent of driver impairment attributable to the observed drugs is uncertain because of the complex relationship between performance and drug concentrations.

  12. Monitoring Car Drivers' Condition Using Image Processing

    NASA Astrophysics Data System (ADS)

    Adachi, Kazumasa; Yamamto, Nozomi; Yamamoto, Osami; Nakano, Tomoaki; Yamamoto, Shin

    We have developed a car driver monitoring system for measuring drivers' consciousness, with which we aim to reduce car accidents caused by drowsiness of drivers. The system consists of the following three subsystems: an image capturing system with a pulsed infrared CCD camera, a system for detecting blinking waveform by the images using a neural network with which we can extract images of face and eye areas, and a system for measuring drivers' consciousness analyzing the waveform with a fuzzy inference technique and others. The third subsystem extracts three factors from the waveform first, and analyzed them with a statistical method, while our previous system used only one factor. Our experiments showed that the three-factor method we used this time was more effective to measure drivers' consciousness than the one-factor method we described in the previous paper. Moreover, the method is more suitable for fitting parameters of the system to each individual driver.

  13. Psychological reactions of drivers to railway suicide.

    PubMed

    Tranah, T; Farmer, R D

    1994-02-01

    Around 90 London Underground train drivers experience a person jumping or falling in front of their train each year. The majority of these incidents are suicides or attempted suicides. 76 drivers were interviewed in order to assess the range of responses to these incidents. The following psychometric instruments were used: Present State Examination (PSE9); Post-Traumatic Stress Disorder (PTSD) Interview; General Health Questionnaire (GHQ-28); Impact of Events Scale (IES); Post-Traumatic Symptom Scale; Recent Difficulties/Events scale; Perceived Stress Scale and Eysenck Personality Questionnaire (EPQ). When interviewed 1 month after the incident 13 (17.11%) drivers presented with PTSD. Diagnoses other than PTSD e.g. neurotic depression and phobic state were present in 24 (31.58%) drivers (including 12 of the 13 PTSD cases who had one additional diagnosis). On the basis of diagnoses three groups were identified: Group 1 drivers had PTSD and in most cases an additional PSE9 diagnosis; Group 2 drivers had a PSE9 diagnosis only; Group 3 drivers were not cases. 56 drivers were again interviewed 6 months after the incident to assess duration of caseness and/or symptoms and to identify any cases of delayed onset. Two drivers were still cases at 6 months (neurotic depression and phobic state), no driver presented with PTSD at 6 months. At 6 months there was a significant drop in symptom scores compared with measures taken at 1 month. These results suggest that although approximately one-third of drivers suffered a severe psychological reaction following a railway suicide, when interviewed again 6 months after the incident most drivers reported a marked reduction in symptoms. PMID:8153752

  14. Beam diagnostics

    SciTech Connect

    Bogaty, J.; Clifft, B.E.; Zinkann, G.P.; Pardo, R.C.

    1995-08-01

    The ECR-PII injector beam line is operated at a fixed ion velocity. The platform high voltage is chosen so that all ions have a velocity of 0.0085c at the PII entrance. If a previous tune configuration for the linac is to be used, the beam arrival time must be matched to the previous tune as well. A nondestructive beam-phase pickup detector was developed and installed at the entrance to the PII linac. This device provides continuous phase and beam current information and allows quick optimization of the beam injected into PII. Bunches traverse a short tubular electrode thereby inducing displacement currents. These currents are brought outside the vacuum interface where a lumped inductance resonates electrode capacitance at one of the bunching harmonic frequencies. This configuration yields a basic sensitivity of a few hundred millivolts signal per microampere of beam current. Beam-induced radiofrequency signals are summed against an offset frequency generated by our master oscillator. The resulting kilohertz difference frequency conveys beam intensity and bunch phase information which is sent to separate processing channels. One channel utilizes a phase locked loop which stabilizes phase readings if beam is unstable. The other channel uses a linear full wave active rectifier circuit which converts kilohertz sine wave signal amplitude to a D.C. voltage representing beam current. A prototype set of electronics is now in use with the detector and we began to use the system in operation to set the arrival beam phase. A permanent version of the electronics system for the phase detector is now under construction. Additional nondestructive beam intensity and phase monitors at the {open_quotes}Booster{close_quotes} and {open_quotes}ATLAS{close_quotes} linac sections are planned as well as on some of the high-energy beam lines. Such a monitor will be particularly useful for FMA experiments where the primary beam hits one of the electric deflector plates.

  15. Rf-driver linear colliders

    SciTech Connect

    Wilson, P.B.

    1987-05-01

    The next generation of linear collider after the SLC (Stanford Linear Collider) will probably have an energy in the range 300 GeV-1 TeV per linac. A number of exotic accelerating schemes, such as laser and plasma acceleration, have been proposed for linear colliders of the far future. However, the technology which is most mature and which could lead to a collider in the above energy range in the relatively near future is the rf-driven linac, in which externally produced rf is fed into a more or less conventional metallic accelerating structure. Two basic technologies have been proposed for producing the required high peak rf power: discrete microwave power sources, and various two-beam acceleration schemes in which the rf is produced by a high current driving beam running parallel to the main accelerator. The current status of experimental and analytic work on both the discrete source and the two-beam methods for producing rf is discussed. The implications of beam-beam related effects (luminosity, disruption and beamstrahlung) for the design of rf-driven colliders are also considered.

  16. Economic drivers of mineral supply

    USGS Publications Warehouse

    Wagner, Lorie A.; Sullivan, Daniel E.; Sznopek, John L.

    2003-01-01

    The debate over the adequacy of future supplies of mineral resources continues in light of the growing use of mineral-based materials in the United States. According to the U.S. Geological Survey, the quantity of new materials utilized each year has dramatically increased from 161 million tons2 in 1900 to 3.2 billion tons in 2000. Of all the materials used during the 20th century in the United States, more than half were used in the last 25 years. With the Earth?s endowment of natural resources remaining constant, and increased demand for resources, economic theory states that as depletion approaches, prices rise. This study shows that many economic drivers (conditions that create an economic incentive for producers to act in a particular way) such as the impact of globalization, technological improvements, productivity increases, and efficient materials usage are at work simultaneously to impact minerals markets and supply. As a result of these economic drivers, the historical price trend of mineral prices3 in constant dollars has declined as demand has risen. When price is measured by the cost in human effort, the price trend also has been almost steadily downward. Although the United States economy continues its increasing mineral consumption trend, the supply of minerals has been able to keep pace. This study shows that in general supply has grown faster than demand, causing a declining trend in mineral prices.

  17. Optimization of a 3x3 focusing array for heavy ion drivers

    SciTech Connect

    Martovetsky, N N; Meinke, R B

    2005-08-08

    A heavy ion driver for inertial fusion will accelerate an array of beams through common induction cores and then direct the beams onto the DT target. An array of quadrupole focusing magnets is used to prevent beam expansion from space charge forces. In the array, the magnet fields from the coils embracing the beams are coupled, which reduces the cost of superconductor and increases the focusing power. The challenges in designing such an array are meeting the strict requirements for the quadrupole field inside the beam pipes and preventing stray fields outside. We report our optimization effort on designing such an array and show that 3 x 3 or larger arrays are feasible and practical to build with flat racetrack coils.

  18. Can we estimate plasma density in ICP driver through electrical parameters in RF circuit?

    SciTech Connect

    Bandyopadhyay, M. Sudhir, Dass Chakraborty, A.

    2015-04-08

    To avoid regular maintenance, invasive plasma diagnostics with probes are not included in the inductively coupled plasma (ICP) based ITER Neutral Beam (NB) source design. Even non-invasive probes like optical emission spectroscopic diagnostics are also not included in the present ITER NB design due to overall system design and interface issues. As a result, negative ion beam current through the extraction system in the ITER NB negative ion source is the only measurement which indicates plasma condition inside the ion source. However, beam current not only depends on the plasma condition near the extraction region but also on the perveance condition of the ion extractor system and negative ion stripping. Nevertheless, inductively coupled plasma production region (RF driver region) is placed at distance (∼ 30cm) from the extraction region. Due to that, some uncertainties are expected to be involved if one tries to link beam current with plasma properties inside the RF driver. Plasma characterization in source RF driver region is utmost necessary to maintain the optimum condition for source operation. In this paper, a method of plasma density estimation is described, based on density dependent plasma load calculation.

  19. Rare isotope beams at ISAC—target & ion source systems

    NASA Astrophysics Data System (ADS)

    Bricault, Pierre G.; Ames, Friedhelm; Dombsky, Marik; Kunz, Peter; Lassen, Jens

    2014-01-01

    The present status of the ISAC facility for rare isotopes beams after its first 10 years of operation is presented. Planning for the ISAC facility started in 1985 with the Parksville workshop on radioactive ion beams (Buchmann and D'Auria 1985). It was put on halt by the KAON proposal and planning was only resumed in 1993 after the cancellation of KAON. The ISAC facility was built to satisfy the scientific need for accelerated beams of rare isotopes for use in applications such as nuclear physics, nuclear astrophysics, atomic and condensed matter physics as well as medicine. At the time of the ISAC proposal submission, a number of facilities were either planned or under construction. In order to have an impact in the field, the requirements and specifications for the driver beam intensity on target was set to 100 μA, 500 MeV protons, which for ISAC results in a driver beam power of 50 kW.

  20. Plans for a proton driver at Fermilab

    SciTech Connect

    Kephart, R.D.; /Fermilab

    2005-01-01

    , and will certainly have important implications for our understanding of cosmology and the evolution of the early Universe. The current Fermilab Program is an important part of the world-wide accelerator based effort to explore and understand the physics of neutrino oscillations. By early 2005, with both MINOS and MiniBooNE taking data, Fermilab will be able to answer some of the most pressing first-round questions raised by the discovery that neutrinos have mass. Fermilab's high-intensity neutrino beams are derived from 8- and 120-GeV proton beams. MiniBooNE is currently taking data using 8 GeV Protons from the Booster. The 120 GeV NuMI beam will start to operate in early 2005 using a 0.25 MW proton beam power from the Main Injector. Future neutrino programs will build on these existing facilities. New short and long baseline experiments have been proposed. There are proposals to increase the available number of protons at 8 and 120 GeV with the goal of addressing the full range of questions presented by neutrino oscillations. Key to that vision is a new intense proton source that usually is referred to as the Proton Driver.

  1. Multiple beam induction accelerators for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Seidl, Peter A.; Barnard, John J.; Faltens, Andris; Friedman, Alex; Waldron, William L.

    2014-01-01

    Induction accelerators are appealing for heavy-ion driven inertial fusion energy (HIF) because of their high efficiency and their demonstrated capability to accelerate high beam current (≥10 kA in some applications). For the HIF application, accomplishments and challenges are summarized. HIF research and development has demonstrated the production of single ion beams with the required emittance, current, and energy suitable for injection into an induction linear accelerator. Driver scale beams have been transported in quadrupole channels of the order of 10% of the number of quadrupoles of a driver. We review the design and operation of induction accelerators and the relevant aspects of their use as drivers for HIF. We describe intermediate research steps that would provide the basis for a heavy-ion research facility capable of heating matter to fusion relevant temperatures and densities, and also to test and demonstrate an accelerator architecture that scales well to a fusion power plant.

  2. Overview of linac applications at future radioactive beam facilities

    SciTech Connect

    Nolen, J.A.

    1996-11-01

    There is considerable interest worldwide in the research which could be done at a next generation, advanced radioactive beam facility. To generate high quality, intense beams of accelerated radionuclides via the {open_quotes}isotope separator on-line{close_quotes} (ISOL) method requires two major accelerator components: a high power (100 kW) driver device to produce radionuclides in a production target/ion source complex, and a secondary beam accelerator to produce beams of radioactive ions up to energies on the order of 10 MeV per nucleon over a broad mass range. In reviewing the technological challenges of such a facility, several types of modem linear accelerators appear well suited. This paper reviews the properties of the linacs currently under construction and those proposed for future facilities for use either as the driver device or the radioactive beam post-accelerator. Other choices of accelerators, such as cyclotrons, for either the driver or secondary beam devices of a radioactive beam complex will also be compared. Issues to be addressed for the production accelerator include the choice of ion beam types to be used for cost-effective production of radionuclides. For the post-accelerator the choice of ion source technology is critical and dictates the charge-to-mass requirements at the injection stage.

  3. Graduated Driver Licensing: The New Zealand Experience.

    ERIC Educational Resources Information Center

    Begg, Dorothy; Stephenson, Shaun

    2003-01-01

    Evaluates the graduated driver-licensing (GDL) system in New Zealand. Describes driver licensing and crash fatality rates before and after the implementation of GDL in 1987. Reports that GDL has contributed to a reduction in crashes among young people. (Contains 2 figures and 6 references.) (AUTHOR/WFA)

  4. Tractor Trailer Driver's Training Programs. Performance Report.

    ERIC Educational Resources Information Center

    New Hampshire Vocational Technical Coll., Nashua.

    This document describes a project to develop a 320-hour tractor trailer driver training program and a 20-hour commercial driver licensing upgrade training program. Of 34 graduates from the training program, 28 secured employment in the trucking industry. From August 1989 to June 1990, 725 students were trained in the upgrade training program with…

  5. New method of designing CCD driver

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Yu, Daoyin; Zhang, Yimo

    1993-04-01

    A new method of designing CCD driver circuits is introduced in this paper. Some kinds of programmable logic device (PLD) chips including generic array logic (GAL) and EPROM are used to drive a CCD sensor. The driver runs stably and reliably. It is widely applied in many fields with its good interchangeability, small size, and low cost.

  6. School Bus Driver Instructional Program. Instructor's Guide.

    ERIC Educational Resources Information Center

    Department of Transportation, Washington, DC. National Highway Safety Bureau.

    A standardized and comprehensive school bus driver instructional program has been developed under contract with the Federal Government. The course has been organized to provide in one package a program for developing the minimum skills and knowledge needed by the school bus driver instructor, as well as those supplemental skills and knowledge…

  7. Prevalence of hypertension in bus drivers.

    PubMed

    Ragland, D R; Winkleby, M A; Schwalbe, J; Holman, B L; Morse, L; Syme, S L; Fisher, J M

    1987-06-01

    This paper reports the results of a cross-sectional study conducted to evaluate the prevalence of hypertension in 1500 black and white male bus drivers from a large urban transit system in the US. Data for this study were compiled from the files of an occupational health clinic which conducts biennial medical examinations for drivers' license renewal. To test whether prevalence of hypertension was higher among bus drivers than among employed individuals in general, drivers were compared to three groups: individuals from both a national and local health survey and individuals undergoing baseline health examinations prior to employment as bus drivers. After adjustment for age and race, hypertension rates for bus drivers were significantly greater than rates for each of the three comparison groups. These findings support previous results from international studies of bus drivers suggesting that exposure to the occupation of driving a bus may carry increased health risk. This research has expanded into an on-going study which has the goals of clarifying the extent of hypertension in bus drivers and identifying specific behavioural and occupational factors that may be responsible for increased risk of cardiovascular disease.

  8. California's Bus Driver's Training Course. Instructor's Manual.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    This instructor's manual was designed to help graduates of the California Bus Driver Instructor Course provide effective instruction to school bus driver trainees. It contains enough material for 20-30 hours of classroom training. The information is organized in 12 instructional units that cover the following topics: introduction to the course;…

  9. Hallways to Highways. Driver Education 1982.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Education, Oklahoma City.

    The purpose of this guide is to provide direction and assistance to driver education instructors and school administrators as they plan and implement quality programs of traffic safety instruction. Materials are divided into seven chapters conveying: (1) the organization and administration of driver and traffic safety education, (2) the driving…

  10. Evaluation of Driver Education and Training Programs.

    ERIC Educational Resources Information Center

    Harman, Harry H.; And Others

    What contributions do driver education and training programs make to the Nation's highway safety program? An answer to this question was sought through a synthesis of four feasibility studies concerning the effectiveness of current or proposed driver education programs. These preliminary investigations failed to identify any clear proof that…

  11. Physics at an upgraded Fermilab proton driver

    SciTech Connect

    Geer, S.; /Fermilab

    2005-07-01

    In 2004 the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future, primarily motivated by the recent exciting developments in neutrino physics. Over the last few months a physics study has developed the physics case for the Fermilab Proton Driver. The potential physics opportunities are discussed.

  12. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  13. Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams

    SciTech Connect

    Schroeder, C. B.; Esarey, E.; Benedetti, C.; Toth, Cs.; Geddes, C. G. R.; Leemans, W.P.

    2010-06-01

    Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator design and the different physical mechanisms of laser-driven and beam-driven plasma acceleration are discussed. Driver propagation is examined, as well as the effects of the excited plasma wave phase velocity. The driver coupling to subsequent plasma accelerator stages for high-energy physics applications is addressed.

  14. Passive and active plasma deceleration for the compact disposal of electron beams

    SciTech Connect

    Bonatto, A.; Schroeder, C. B.; Vay, J.-L.; Geddes, C. G. R.; Benedetti, C.; Esarey, E.; Leemans, W. P.

    2015-08-15

    Plasma-based decelerating schemes are investigated as compact alternatives for the disposal of high-energy beams (beam dumps). Analytical solutions for the energy loss of electron beams propagating in passive and active (laser-driven) schemes are derived. These solutions, along with numerical modeling, are used to investigate the evolution of the electron distribution, including energy chirp and total beam energy. In the active beam dump scheme, a laser-driver allows a more homogeneous beam energy extraction and drastically reduces the energy chirp observed in the passive scheme. These concepts could benefit applications requiring overall compactness, such as transportable light sources, or facilities operating at high beam power.

  15. Stability analysis of automobile driver steering control

    NASA Technical Reports Server (NTRS)

    Allen, R. W.

    1981-01-01

    In steering an automobile, the driver must basically control the direction of the car's trajectory (heading angle) and the lateral deviation of the car relative to a delineated pathway. A previously published linear control model of driver steering behavior which is analyzed from a stability point of view is considered. A simple approximate expression for a stability parameter, phase margin, is derived in terms of various driver and vehicle control parameters, and boundaries for stability are discussed. A field test study is reviewed that includes the measurement of driver steering control parameters. Phase margins derived for a range of vehicle characteristics are found to be generally consistent with known adaptive properties of the human operator. The implications of these results are discussed in terms of driver adaptive behavior.

  16. Driver drowsiness detection using multimodal sensor fusion

    NASA Astrophysics Data System (ADS)

    Andreeva, Elena O.; Aarabi, Parham; Philiastides, Marios G.; Mohajer, Keyvan; Emami, Majid

    2004-04-01

    This paper proposes a multi-modal sensor fusion algorithm for the estimation of driver drowsiness. Driver sleepiness is believed to be responsible for more than 30% of passenger car accidents and for 4% of all accident fatalities. In commercial vehicles, drowsiness is blamed for 58% of single truck accidents and 31% of commercial truck driver fatalities. This work proposes an innovative automatic sleep-onset detection system. Using multiple sensors, the driver"s body is studied as a mechanical structure of springs and dampeners. The sleep-detection system consists of highly sensitive triple-axial accelerometers to monitor the driver"s upper body in 3-D. The subject is modeled as a linear time-variant (LTV) system. An LMS adaptive filter estimation algorithm generates the transfer function (i.e. weight coefficients) for this LTV system. Separate coefficients are generated for the awake and asleep states of the subject. These coefficients are then used to train a neural network. Once trained, the neural network classifies the condition of the driver as either awake or asleep. The system has been tested on a total of 8 subjects. The tests were conducted on sleep-deprived individuals for the sleep state and on fully awake individuals for the awake state. When trained and tested on the same subject, the system detected sleep and awake states of the driver with a success rate of 95%. When the system was trained on three subjects and then retested on a fourth "unseen" subject, the classification rate dropped to 90%. Furthermore, it was attempted to correlate driver posture and sleepiness by observing how car vibrations propagate through a person"s body. Eight additional subjects were studied for this purpose. The results obtained in this experiment proved inconclusive which was attributed to significant differences in the individual habitual postures.

  17. Beam dynamics studies for the relativistic klystron two-beam accelerator experiment

    SciTech Connect

    Lidia, Steven M.

    2001-06-22

    Two-beam accelerators based upon relativistic klystron s (RK s) have been proposed as power sources for future generation linear electron-positron colliders. These drivers are known to suffer from several transverse beam break-up (BBU) instabilities. A program to study a particular technique (the betatron node scheme ) for ameliorating the high frequency BBU is under way at LBNL. Central to this study are the pillbox RF cavities and RF beam position monitors (BPM s) employed. This paper describes the design, fabrication, and testing of the RF components. Performance details during operation are also discussed.

  18. Comparison of electric and magnetic quadrupole focusing for the low energy end of an induction-linac-ICF (Inertial-Confinement-Fusion) driver

    SciTech Connect

    Kim, C.H.

    1987-04-01

    This report compares two physics designs of the low energy end of an induction linac-ICF driver: one using electric quadrupole focusing of many parallel beams followed by transverse combining; the other using magnetic quadrupole focusing of fewer beams without beam combining. Because of larger head-to-tail velocity spread and a consequent rapid current amplification in a magnetic focusing channel, the overall accelerator size of the design using magnetic focusing is comparable to that using electric focusing.

  19. A Linear Magnetic Field Scan Driver

    PubMed Central

    QUINE, RICHARD W.; CZECHOWSKI, TOMASZ; EATON, GARETH R.

    2009-01-01

    A linear magnetic field scan driver was developed to provide a rapidly scanning magnetic field for use in electron paramagnetic resonance (EPR) spectroscopy. The driver consists of two parts: a digitally synthesized ramp waveform generator and a power amplifier to drive the magnetic field coils. Additionally, the driver provides a trigger signal to a data collection digitizer that is synchronized to the ramp waveform. The driver can also drive an arbitrary current waveform supplied from an external source. The waveform generator is computer controlled through a serial data interface. Additional functions are controlled by the user from the driver front panel. The frequency and amplitude of the waveform are each separately controlled with 12-bit resolution (one part in 4,096). Several versions of the driver have been built with different frequency and amplitude ranges. Frequencies range from 500 to 20,000 Hz. Field sweep amplitudes range up to 80 Gpp. This article also gives a brief description of the field coils that are driven by the driver. PMID:19838315

  20. Does advanced driver training improve situational awareness?

    PubMed

    Walker, Guy H; Stanton, Neville A; Kazi, Tara A; Salmon, Paul M; Jenkins, Daniel P

    2009-07-01

    Over 70 years of experiential evidence suggests that a specific form of advanced driver training, one based on an explicit system of car control, improves driver situation awareness (SA). Five experimental hypotheses are developed. They propose that advanced driving should increase the number of information elements in the driver's working memory, increase the interconnection between those elements, increase the amount of 'new' information in memory as well as the prominence of existing information, and that finally, it should stimulate behaviours that help drivers evolve better situations to be aware of. An approach to SA based on Neisser's perceptual cycle theory is anchored to a network based methodology. This is applied within the context of a longitudinal on-road study involving three groups of 25 drivers, all of whom were measured pre- and post-intervention. One experimental group was subject to advanced driver training and two further groups provided control for time and for being accompanied whilst driving. Empirical support is found for all five hypotheses. Advanced driving does improve driver SA but not necessarily in the way that existing situation focused, closed loop models of the concept might predict. PMID:18675387

  1. [Drivers license qualification for epileptics].

    PubMed

    Egli, M; Hartmann, H; Hess, R

    1977-03-26

    The question whether a person with epilepsy qualified for a driving licence must be examined from the point of view of the individual as well as that of the community. The general public should be protected against unduly high risks from epileptic drivers, whereas the patient has a right to live as normal a life as possible, which includes driving an automobile. Too rigid criteria for obtaining the license increase the number of persons who evade medical control and drive "illegally". To require physicians to report their epileptic patients to the authorities would be counterproductive; it would also destroy the personal confidence between physician and patient which is so essential for successful treatment. Epileptic persons endanger safety on the road only slightly: 0.1-0.3% of all traffic accidents are due to epileptic seizures. In contrast, abuse of alcohol plays a major role in 6-9% of all accidents, whereas 80-90% are attributable to evident mistakes by the driver. Epileptic patients under regular medical supervision who are licenced on grounds of approved criteria do not cause more accidents than the general population. A dangerous group are, however, those with mental alterations (organic or reactive) and particularly patients with aggressive and expansive-compensatory traits, as well as those driving without permission. Prognostic criteria as to the further course of the disease are paramount for the assessment of qualification for the licence. The following rules have proved their worth: 2 years freedom from seizures (with or without therapy), no abnormalities specific for epilepsy in the EEG, no serious mental changes, regular medical supervision and treatment mus be guaranteed. Departures from these rules should be confined to exceptional cases with the consent of a physician specialized in epileptology. The same holds for admission to higher categories of driving licence, the only practical eventuality being category D (lorries), and even this only in

  2. Beam tuning

    SciTech Connect

    Pardo, R.C.; Zinkann, G.P.

    1995-08-01

    A program for configuring the linac, based on previously run configurations for any desired beam was used during the past year. This program uses only a small number of empirical tunes to scale resonator fields to properly accelerate a beam with a different charge-to-mass (q/A) ratio from the original tune configuration. The program worked very well for the PII linac section where we can easily match a new beam`s arrival phase and velocity to the tuned value. It was also fairly successful for the Booster and ATLAS sections of the linac, but not as successful as for the PII linac. Most of the problems are associated with setting the beam arrival time correctly for each major linac section. This problem is being addressed with the development of the capacitive pickup beam phase monitor discussed above. During the next year we expect to improve our ability to quickly configure the linac for new beams and reduce the time required for linac tuning. Already the time required for linac tuning as a percentage of research hours has decreased from 22% in FY 1993 to 15% in the first quarter of FY 1995.

  3. Measurement of driver calibration and the impact of feedback on drivers' estimates of performance.

    PubMed

    Roberts, Shannon C; Horrey, William J; Liang, Yulan

    2016-03-01

    Recent studies focused on driver calibration show that drivers are often miscalibrated, either over confident or under confident, and the magnitude of this miscalibration changes under different conditions. Previous work has demonstrated behavioral and performance benefits of feedback, yet these studies have not explicitly examined the issue of calibration. The objective of this study was to examine driver calibration, i.e., the degree to which drivers are accurately aware of their performance, and determine whether feedback alters driver calibration. Twenty-four drivers completed a series of driving tasks (pace clocks, traffic light, speed maintenance, and traffic cones) on a test track. Drivers drove three different blocks around the test track: (1) baseline block, where no participants received feedback; (2) feedback block, where half of the participants received performance feedback while the other half received no feedback; (3) a no feedback block, where no participants received feedback. Results indicated that across two different calibration measures, drivers were sufficiently calibrated to the pace clocks, traffic light, and traffic cone tasks. Drivers were not accurately aware of their performance regarding speed maintenance, though receiving feedback on this task improved calibration. Proper and accurate measurements of driver calibration are needed before designing performance feedback to improve calibration as these feedback systems may not always yield the intended results.

  4. Approaches of truck drivers and non-truck drivers toward reckless on-road behavior.

    PubMed

    Rosenbloom, Tova; Eldror, Ehud; Shahar, Amit

    2009-07-01

    The purpose of the study was to compare the reported approaches of truck drivers to those of non-truck drivers toward reckless on-road behaviors. One hundred and sixty-seven adult males, including 70 non-truck drivers, completed the questionnaires voluntarily. The truck drivers were employees of a concrete manufacturing company working at various company plants throughout Israel. Seventy were professional mixer truckers and 27 were tip-truckers. The participants completed the Reckless Driving Self-Report Scale based on Taubman Ben-Ari et al. [Taubman Ben-Ari, O., Florian, V., Mikulincer, M., 1999. The impact of mortality salience on reckless driving: a test of terror management mechanisms. Journal of Personality and Social Psychology 76, 35-45], adapted for truck drivers for this study. It was expected that non-professional, as compared to professional (truck) drivers, would be more permissive regarding reckless driving, since driving risks are less prominent in their daily driving experience. An ANOVA performed on mean reckless-driving scores yielded significant results. The post hoc Schéffe test indicated significantly higher reckless-driving scores for automobile drivers as compared to both mixer-truck driver scores and tip-truck driver scores. In addition, the reckless-driving scores for mixer-truck drivers were significantly higher than the tip-truck driver scores. We discuss various explanations for the findings and consider possible implications for training strategies in organizations as well as for media campaigns focused on mutual safe road use of truck drivers and private vehicle drivers.

  5. Approaches of truck drivers and non-truck drivers toward reckless on-road behavior.

    PubMed

    Rosenbloom, Tova; Eldror, Ehud; Shahar, Amit

    2009-07-01

    The purpose of the study was to compare the reported approaches of truck drivers to those of non-truck drivers toward reckless on-road behaviors. One hundred and sixty-seven adult males, including 70 non-truck drivers, completed the questionnaires voluntarily. The truck drivers were employees of a concrete manufacturing company working at various company plants throughout Israel. Seventy were professional mixer truckers and 27 were tip-truckers. The participants completed the Reckless Driving Self-Report Scale based on Taubman Ben-Ari et al. [Taubman Ben-Ari, O., Florian, V., Mikulincer, M., 1999. The impact of mortality salience on reckless driving: a test of terror management mechanisms. Journal of Personality and Social Psychology 76, 35-45], adapted for truck drivers for this study. It was expected that non-professional, as compared to professional (truck) drivers, would be more permissive regarding reckless driving, since driving risks are less prominent in their daily driving experience. An ANOVA performed on mean reckless-driving scores yielded significant results. The post hoc Schéffe test indicated significantly higher reckless-driving scores for automobile drivers as compared to both mixer-truck driver scores and tip-truck driver scores. In addition, the reckless-driving scores for mixer-truck drivers were significantly higher than the tip-truck driver scores. We discuss various explanations for the findings and consider possible implications for training strategies in organizations as well as for media campaigns focused on mutual safe road use of truck drivers and private vehicle drivers. PMID:19540960

  6. Camera-based driver assistance systems

    NASA Astrophysics Data System (ADS)

    Grimm, Michael

    2013-04-01

    In recent years, camera-based driver assistance systems have taken an important step: from laboratory setup to series production. This tutorial gives a brief overview on the technology behind driver assistance systems, presents the most significant functionalities and focuses on the processes of developing camera-based systems for series production. We highlight the critical points which need to be addressed when camera-based driver assistance systems are sold in their thousands, worldwide - and the benefit in terms of safety which results from it.

  7. Studies of a Linac Driver for a High Repetition Rate X-Ray FEL

    SciTech Connect

    Venturini, M.; Corlett, J.; Doolittle, L.; Filippetto, D.; Papadopoulos, C.; Penn, G.; Prosnitz, D.; Qiang, J.; Reinsch, M.; Ryne, R.; Sannibale, F.; Staples, J.; Wells, R.; Wurtele, J.; Zolotorev, M.; Zholents, A.

    2011-06-01

    We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a pointdesign for a 1.8 GeV machine tuned for 300 pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.

  8. Food consumption trends and drivers

    PubMed Central

    Kearney, John

    2010-01-01

    A picture of food consumption (availability) trends and projections to 2050, both globally and for different regions of the world, along with the drivers largely responsible for these observed consumption trends are the subject of this review. Throughout the world, major shifts in dietary patterns are occurring, even in the consumption of basic staples towards more diversified diets. Accompanying these changes in food consumption at a global and regional level have been considerable health consequences. Populations in those countries undergoing rapid transition are experiencing nutritional transition. The diverse nature of this transition may be the result of differences in socio-demographic factors and other consumer characteristics. Among other factors including urbanization and food industry marketing, the policies of trade liberalization over the past two decades have implications for health by virtue of being a factor in facilitating the ‘nutrition transition’ that is associated with rising rates of obesity and chronic diseases such as cardiovascular disease and cancer. Future food policies must consider both agricultural and health sectors, thereby enabling the development of coherent and sustainable policies that will ultimately benefit agriculture, human health and the environment. PMID:20713385

  9. An AGS experiment to test bunching for the proton driver of the muon collider.

    SciTech Connect

    Norem, J.

    1998-04-27

    The proton driver for the muon collider must produce short pulses of protons in order to facilitate muon cooling and operation with polarized beams. In order to test methods of producing these bunches they have operated the AGS near transition and studied procedures which involved moving the transition energy {gamma} to the beam energy. They were able to produce stable bunches with RMS widths of {sigma} = 2.2-2.7 ns for longitudinal bunch areas of {minus}1.5 V-s, in addition to making measurements of the lowest two orders of the momentum compaction factor.

  10. Cavities and Cryomodules for the RIA Driver Linac

    SciTech Connect

    Fuerst, J.D.; Shepard, K.W.; Kedzie, M.; Kelly, M.P.

    2004-06-23

    We describe cavities, cryomodules, and associated subsystem concepts for the Rare Isotope Accelerator (RIA) driver linac baseline design. Some alternative concepts are also presented. Beams from protons to uranium are accelerated with superconducting RF cavities operating from 57.5 MHz to 805 MHz. Substantial cost reduction over the baseline design may be achieved by replacing three classes of elliptical cell structures operating at 2 K by two classes of three-spoke drift tube structures. Cavity count and tunnel length are reduced while efficient cooling at 4.5 K for all linac structures may be possible. Issues include RF power requirements, microphonics, clean handling techniques, separate cavity and insulating vacuum systems, and heat load.

  11. Beam-beam deflection and signature curves for elliptic beams

    SciTech Connect

    Ziemann, V.

    1990-10-22

    In this note we will present closed expressions for the beam-beam deflection angle for arbitrary elliptic beams including tilt. From these expressions signature curves, i.e., systematic deviations from the round beam deflection curve due to ellipticity or tilt are derived. In the course of the presentation we will prove that it is generally impossible to infer individual beam sizes from beam-beam deflection scans. 3 refs., 2 figs.

  12. Beam losses and beam halos in accelerators for new energy sources

    SciTech Connect

    Jameson, R.A.

    1995-12-31

    Large particle accelerators are proposed as drivers for new ways to produce electricity from nuclear fusion and fission reactions. The accelerators must be designed to deliver large particle beam currents to a target facility with very little beam spill along the accelerator itself, in order that accelerator maintenance can be accomplished without remote manipulators. Typically, particle loss is preceded by the formation of a tenuous halo of particles around the central beam core, caused by beam dynamics effects, often coupled with the slight imperfections inevitable in a practical design. If the halo becomes large enough, particles may be scraped off along the accelerator. The tolerance for beam spill in different applications is discussed, halo mechanisms and recent work to explore and understand their dynamics are reviewed, and possible directions for future investigation are outlined. 17 refs., 10 figs.

  13. Driver circuit for solid state light sources

    DOEpatents

    Palmer, Fred; Denvir, Kerry; Allen, Steven

    2016-02-16

    A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

  14. Top 3 Mistakes Teen Drivers Make

    MedlinePlus

    ... those crashes, according to the American Automobile Association (AAA). "Involved parents really can help save lives, so ... to avoid other common mistakes," Bill Van Tassel, AAA's manager of driver training operations, said in a ...

  15. Physics at a new Fermilab proton driver

    SciTech Connect

    Geer, Steve; /Fermilab

    2006-04-01

    In 2004, motivated by the recent exciting developments in neutrino physics, the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future. At the end of 2004 the APS ''Study on the Physics of Neutrinos'' concluded that the future US neutrino program should have, as one of its components, ''A proton driver in the megawatt class or above and neutrino superbeam with an appropriate very large detector capable of observing Cp violation and measuring the neutrino mass-squared differences and mixing parameters with high precision''. The presently proposed Fermilab Proton Driver is designed to accomplish these goals, and is based on, and would help develop, Linear Collider technology. In this paper the Proton Driver parameters are summarized, and the potential physics program is described.

  16. Drinking histories of fatally injured drivers

    PubMed Central

    Baker, S; Braver, E; Chen, L; Li, G; Williams, A

    2002-01-01

    Context: About 30% of drivers killed in crashes have high blood alcohol concentrations (BACs) of 0.10+ g/dl. There is a question about whether these drivers primarily are problem drinkers who chronically drink and drive—the so-called hard core drinking drivers. Objective: To investigate drinking histories of fatally injured drivers in relation to their BACs. Design and participants: Retrospective cohort study of 818 fatally injured drivers who were included in the 1993 National Mortality Followback Survey (a national sample of US deaths in which next of kin were interviewed) and whose BACs were recorded by the Fatality Analysis Reporting System, a census of US traffic deaths. Main outcome measure: Problem drinking indicators. Results: At least one indicator of potential problem drinking, primarily heavy drinking, was reported for 68% of drivers with very high BACs (0.15+ g/dl), 41% with BACs of 0.10–0.14 g/dl, 32% with BACs of 0.01–0.09 g/dl, and 7% with zero BACs. Spouses provided more credible responses than other relatives: they were more likely to report at least occasional drinking and driving among deceased drivers with high BACs. For the most direct signs of problem drinking (described as a problem drinker during the last month of life or frequently driving after having five or more drinks), spousal reports suggested the prevalence of problem drinking among drivers with very high BACs was 22% (having both indicators), 32% (frequently driving after having five or more drinks), 44% (described as problem drinker), or 57% (having either indicator). Conclusions: Drivers with BACs of 0.10+ g/dl were far more likely than sober drivers to be described as having markers of problem drinking. However, many did not have indicators suggestive of problem drinking. In addition to programs focused on repeat offenders or problem drinkers, countermeasures such as sobriety checkpoints that target a broader spectrum of drinking drivers are appropriate. PMID:12226120

  17. High Brightness Beam Applications: Energy Recovered Linacs

    SciTech Connect

    Geoffrey A. Krafft

    2005-09-01

    In the first part of the paper some general statements are made regarding applications suitable for utilizing energy recovered linacs (ERLs) by contrasting their potential performance to that of single pass linacs and storage rings. As a result of their potential for extremely good beam quality in combination with high average beam current, ERLs have been used and considered as drivers of both free electron laser and partially coherent photon sources, from THz through X-rays; as a suitable technology for high energy electron cooling; and as a continuous or semi-continuous electron beam source for high energy colliders. At present, beam requirements tend to be highly matched to end use requirements. By reviewing some of the many examples which have either been reduced to practice, or are being explored presently, one can develop an appreciation for the wide range of parameters being considered in ERL applications.

  18. Oscillations of end loaded cantilever beams

    NASA Astrophysics Data System (ADS)

    Macho-Stadler, E.; Elejalde-García, M. J.; Llanos-Vázquez, R.

    2015-09-01

    This article presents several simple experiments based on changing transverse vibration frequencies in a cantilever beam, when acted on by an external attached mass load at the free end. By using a mechanical wave driver, available in introductory undergraduate laboratories, we provide various experimental results for end loaded cantilever beams that fit reasonably well into a linear equation. The behaviour of the cantilever beam’s weak-damping resonance response is studied for the case of metal resonance strips. As the mass load increases, a more pronounced decrease occurs in the fundamental frequency of beam vibration. It is important to note that cantilever construction is often used in architectural design and engineering construction projects but current analysis also predicts the influence of mass load on the sound generated by musical free reeds with boundary conditions similar to a cantilever beam.

  19. Multi-beam RFQ linac structure for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Hayashizaki, Noriyosu; Ishibashi, Takuya; Ito, Taku; Hattori, Toshiyuki

    2009-07-01

    Both the RF linear accelerator (linac) and the linear induction accelerator have been considered as injectors in a driver system for heavy ion fusion (HIF). In order to relax beam defocusing by space charge effect in the low-energy region, the accelerating beams that were merged and had their beam currents increased by the funnel tree system are injected into storage rings. A multi-beam linac that accelerates multiple beams in an accelerator cavity has the advantages of cost reduction and downsizing of the system. We modeled the multi-beam Interdigital-H type radio frequency quadruple (IH-RFQ) cavities with the different beam numbers and evaluated the electromagnetic characteristics by simulation. As a result, the reasonable ranges of their configuration were indicated for a practical use.

  20. Muon-decay medium-baseline neutrino beam facility

    NASA Astrophysics Data System (ADS)

    Cao, Jun; He, Miao; Hou, Zhi-Long; Jing, Han-Tao; Li, Yu-Feng; Li, Zhi-Hui; Song, Ying-Peng; Tang, Jing-Yu; Wang, Yi-Fang; Wu, Qian-Fan; Yuan, Ye; Zheng, Yang-Heng

    2014-09-01

    Neutrino beam with about 300 MeV in energy, high-flux and medium baseline is considered a rational choice for measuring CP violation before the more powerful Neutrino Factory is to be built. Following this concept, a unique neutrino beam facility based on muon-decayed neutrinos is proposed. The facility adopts a continuous-wave proton linac of 1.5 GeV and 10 mA as the proton driver, which can deliver an extremely high beam power of 15 MW. Instead of pion-decayed neutrinos, unprecedentedly intense muon-decayed neutrinos are used for better background discrimination. The schematic design for the facility is presented here, including the proton driver, the assembly of a mercury-jet target and capture superconducting solenoids, a pion /muon beam transport line, a long muon decay channel of about 600 m and the detector concept. The physics prospects and the technical challenges are also discussed.

  1. Drivers of desertification and their impact

    NASA Astrophysics Data System (ADS)

    Mantel, S.; Van Lynden, G. V. L.; Karavitis, C. A.; Kosmas, C.; Van der Werff ten Bosch, M. J.

    2012-04-01

    Drivers of desertification and their impact An inventory was made of drivers of desertification and how they impact on the degradation process. The major drivers of desertification were analysed and compared between 16 sites around the globe. For each of these sites factors were scored with a perceived influence on desertification. Most of these factors, from the socio-cultural, environmental, and economic dimensions, appeared to be related to land management and planning and to (de-)population. They cause a number of temporary or permanent changes in the landscape, which, by themselves or in combination, lead to degradation of vegetation and soils. Most sites have several forms of land degradation occurring in and around their study area of which erosion by water is the dominant one. Other degradation types occurring in sites were: wind erosion, soil salinization, seawater intrusion in the groundwater, vegetation and biodiversity decline, groundwater depletion, decreased productivity/ carrying capacity, soil fertility decline, water logging and water pollution. As a first step, data and information was gathered on policies, desertification status and processes and on socio-economic conditions. The DPSIR framework (Driving force, Pressure, State, Impact, Response) provides a structure for assessment of the impact of past measures on the status of the environment or to formulate effective measures. In analysing the data, the different data items were structured in and formulated to elements fitting the DPSIR chain. Then possible connections between these different aspects were analysed. In our analysis nine major drivers were reported for the various sites, of which one was environmental, three drivers were related to land management, one driver was related to planning and policies, three drivers were related to socio-economic conditions, and one driver related to legal land status. Depending on the specific desertification process, factors may be positively or

  2. Missing Drivers with Dementia: Antecedents and Recovery

    PubMed Central

    Rowe, Meredeth A.; Greenblum, Catherine A.; Boltz, Marie; Galvin, James E.

    2013-01-01

    OBJECTIVES To determine the circumstance in which persons with dementia become lost while driving, how missing drivers are found, and how Silver Alert notificationsare instrumental in those discoveries. DESIGN A retrospective, descriptive study. SETTING Retrospective record review. PARTICIPANTS Conducted using 156 records from the Florida Silver Alert program for the time period October, 2008 through May 2010. These alerts were issued in Florida for a missing driver with dementia. MEASUREMENTS Information derived from the reports on characteristics of the missing driver, antecedents to missing event and discovery of a missing driver. RESULTS and CONCLUSION The majority of missing drivers were males, with ages ranging from 58’94, who were being cared for by a spouse. Most drivers became lost on routine, caregiver-sanctioned trips to usual locations. Only 15% were in the act of driving when found with most being found in or near a parked car and the large majority were found by law enforcement officers. Only 40% were found in the county they went missing and 10% were found in a different state. Silver Alert notifications were most effective for law enforcement; citizen alerts resulted in a few discoveries. There was a 5% mortality rate in the study population with those living alone more likely to be found dead than alive. An additional 15% were found in dangerous situations such as stopped on railroad tracks. Thirty-two percent had documented driving or dangerous errors such as, driving thewrong way or into secluded areas, or walking in or near roadways. PMID:23134069

  3. SSL Luminaire with Novel Driver Architecture

    SciTech Connect

    Heikman, Sten; Robinson, Clark

    2011-07-07

    Cree has developed a new high-efficiency light emitting diode (LED) technology platform capable of providing low-cost, high performance luminaires that can be adopted across a variety of SSL applications. This development is built on Cree’s high brightness LED platform to design a novel LED chip that enables a high-efficiency driver architecture to improve the overall luminaire system efficacy. These system efficiency gains were realized using an integrated approach tailoring the LED chip characteristics to allow for the high-efficiency driver technology platform. The reliability of the new LED design was robust at the component level under accelerated testing conditions. Luminaires were assembled integrating the novel LED and driver technology to demonstrate the system improvement. Cree has successfully completed this project by developing a novel LED architecture that enables a new driver design with 93% efficiency. This technology was showcased in an LED luminaire that produced 725 lumens at an efficacy of 87.4 lumens per watt (LPW). The correlated color temperature (CCT) of the luminaire was 2708 K with a color rendering index (CRI) of 91. The novel LEDs and driver led to a 9% system performance improvement compared to the standard LEDs and driver scheme.

  4. Simulations of longitudinal beam dynamics of space-charge dominated beams for heavy ion fusion

    SciTech Connect

    Miller, D.A.C.

    1994-12-01

    The longitudinal instability has potentially disastrous effects on the ion beams used for heavy ion driven inertial confinement fusion. This instability is a {open_quotes}resistive wall{close_quotes} instability with the impedance coining from the induction modules in the accelerator used as a driver. This instability can greatly amplify perturbations launched from the beam head and can prevent focusing of the beam onto the small spot necessary for fusion. This instability has been studied using the WARPrz particle-in-cell code. WARPrz is a 2 1/2 dimensional electrostatic axisymmetric code. This code includes a model for the impedance of the induction modules. Simulations with resistances similar to that expected in a driver show moderate amounts of growth from the instability as a perturbation travels from beam head to tail as predicted by cold beam fluid theory. The perturbation reflects off the beam tail and decays as it travels toward the beam head. Nonlinear effects cause the perturbation to steepen during reflection. Including the capacitive component of the, module impedance. has a partially stabilizing effect on the longitudinal instability. This reduction in the growth rate is seen in both cold beam fluid theory and in simulations with WARPrz. Instability growth rates for warm beams measured from WARPrz are lower than cold beam fluid theory predicts. Longitudinal thermal spread cannot account for this decrease in the growth rate. A mechanism for coupling the transverse thermal spread to decay of the longitudinal waves is presented. The longitudinal instability is no longer a threat to the heavy ion fusion program. The simulations in this thesis have shown that the growth rate for this instability will not be as large as earlier calculations predicted.

  5. Beam Dynamics in the Cebaf Superconducting Cavities.

    NASA Astrophysics Data System (ADS)

    Li, Zenghai

    1995-01-01

    This work is a study of beam dynamics in the CEBAF superconducting cavities under the influence of the fields generated by externally applied RF and beam particles. A full 3-D modeling of the CEBAF 5-cell superconducting cavity is carried out. Details of the modeling with MAFIA are discussed. Multipole fields due to the asymmetric couplers are studied by means of 3-D Fourier transforms. The cavity steering and focusing of the multipole fields are studied. Experimental measurements of these effects are performed to validate the modeling. Evaluation of the cavity misalignment is discussed. The emittance degradation effects in the CEBAF superconducting linacs and an FEL driver linac due to the head-tail effects of the cavity steering and the x - y coupling effects of the multipole fields are studied. The beam-cavity interactions for cases of v _{s}, v_{t} not= c are studied. The Lindman boundary condition is implemented to accommodate simulation of infinite long beam pipes of the beam line. A fourth-order finite-difference algorithm is derived in cylindrical coordinates to reduce the frequency dependent truncation errors, which were discovered in the process of calculating wake fields of very short bunches, of the second-order Yee algorithm. The effects of the slippage between the source particle and the test particle are considered in the wake function calculations. Radial scaling relations are obtained for calculating the wake functions on the axis from the integrated value at the beam pipe radius. The scaling found not only depends on the beam energy but also depends on the bunch length of the beam and the opening of the cavity. The conditions for the validity of the ultrarelativistic treatment of the wakefield are discussed. The emittance growth and the energy spread due to the combined effects of the cavity multipole fields and the wakefields in a 40 MeV IR FEL driver linac are studied.

  6. 77 FR 60956 - State Graduated Driver Licensing Incentive Grant

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... the minimum qualification criteria for the State Graduated Driver Licensing (GDL) Incentive Grant... grants for States that implement multi-stage licensing systems that require novice drivers younger than... multi-staged process for issuing driver's licenses to young, novice drivers. During the first stage,...

  7. 49 CFR 391.63 - Multiple-employer drivers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Multiple-employer drivers. 391.63 Section 391.63... AND LONGER COMBINATION VEHICLE (LCV) DRIVER INSTRUCTORS Limited Exemptions § 391.63 Multiple-employer drivers. (a) If a motor carrier employs a person as a multiple-employer driver (as defined in § 390.5...

  8. 49 CFR 395.8 - Driver's record of duty status.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shall be shown on the driver's record of duty status. (g) Graph grid. The following graph grid must be... 49 Transportation 5 2014-10-01 2014-10-01 false Driver's record of duty status. 395.8 Section 395... SERVICE OF DRIVERS § 395.8 Driver's record of duty status. (a) Except for a private motor carrier...

  9. 49 CFR 395.8 - Driver's record of duty status.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shall be shown on the driver's record of duty status. (g) Graph grid. The following graph grid must be... 49 Transportation 5 2011-10-01 2011-10-01 false Driver's record of duty status. 395.8 Section 395... SERVICE OF DRIVERS § 395.8 Driver's record of duty status. (a) Except for a private motor carrier...

  10. 49 CFR 395.8 - Driver's record of duty status.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shall be shown on the driver's record of duty status. (g) Graph grid. The following graph grid must be... 49 Transportation 5 2013-10-01 2013-10-01 false Driver's record of duty status. 395.8 Section 395... SERVICE OF DRIVERS § 395.8 Driver's record of duty status. (a) Except for a private motor carrier...

  11. 49 CFR 395.8 - Driver's record of duty status.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shall be shown on the driver's record of duty status. (g) Graph grid. The following graph grid must be... 49 Transportation 5 2012-10-01 2012-10-01 false Driver's record of duty status. 395.8 Section 395... SERVICE OF DRIVERS § 395.8 Driver's record of duty status. (a) Except for a private motor carrier...

  12. Physics of beam self-modulation in plasma wakefield accelerators

    SciTech Connect

    Lotov, K. V.

    2015-10-15

    The self-modulation instability is a key effect that makes possible the usage of nowadays proton beams as drivers for plasma wakefield acceleration. Development of the instability in uniform plasmas and in plasmas with a small density up-step is numerically studied with the focus at nonlinear stages of beam evolution. The step parameters providing the strongest established wakefield are found, and the mechanism of stable bunch train formation is identified.

  13. Beam loss

    NASA Astrophysics Data System (ADS)

    VanGinneken, A.; Edwards, D.; Harrison, M.

    1989-04-01

    This paper presents results from simulations of beam losses during the operation of a superconducting accelerator. The calculations use a combination of hadron/electromagnetic cascade plus elastic scattering codes with accelerator tracking routines. These calculations have been used in conjunction with the design of the Fermilab Tevatron. First accelerator geometry is described. The rest of the paper discusses a detailed attempt to simulate a fast extraction cycle, essentially in chronological order. Beginning with an unperturbed beam, the simulation generates proton phase-space distributions incident on the electrostatic septum. These interact either elastically or inelastically with the septum wires, and the products of these interactions are traced through the machine. Where these leave the accelerator, energy deposition levels in the magnets are calculated together with the projected response of the beam-loss monitors in this region. Finally, results of the calculation are compared with experimental data. (AIP)

  14. Factors associated with self-reported driver sleepiness and incidents in city bus drivers.

    PubMed

    Anund, Anna; Ihlström, Jonas; Fors, Carina; Kecklund, Göran; Filtness, Ashleigh

    2016-08-01

    Driver fatigue has received increased attention during recent years and is now considered to be a major contributor to approximately 15-30% of all crashes. However, little is known about fatigue in city bus drivers. It is hypothesized that city bus drivers suffer from sleepiness, which is due to a combination of working conditions, lack of health and reduced sleep quantity and quality. The overall aim with the current study is to investigate if severe driver sleepiness, as indicated by subjective reports of having to fight sleep while driving, is a problem for city based bus drivers in Sweden and if so, to identify the determinants related to working conditions, health and sleep which contribute towards this. The results indicate that driver sleepiness is a problem for city bus drivers, with 19% having to fight to stay awake while driving the bus 2-3 times each week or more and nearly half experiencing this at least 2-4 times per month. In conclusion, severe sleepiness, as indicated by having to fight sleep during driving, was common among the city bus drivers. Severe sleepiness correlated with fatigue related safety risks, such as near crashes.

  15. Factors associated with self-reported driver sleepiness and incidents in city bus drivers

    PubMed Central

    ANUND, Anna; IHLSTRÖM, Jonas; FORS, Carina; KECKLUND, Göran; FILTNESS, Ashleigh

    2016-01-01

    Driver fatigue has received increased attention during recent years and is now considered to be a major contributor to approximately 15–30% of all crashes. However, little is known about fatigue in city bus drivers. It is hypothesized that city bus drivers suffer from sleepiness, which is due to a combination of working conditions, lack of health and reduced sleep quantity and quality. The overall aim with the current study is to investigate if severe driver sleepiness, as indicated by subjective reports of having to fight sleep while driving, is a problem for city based bus drivers in Sweden and if so, to identify the determinants related to working conditions, health and sleep which contribute towards this. The results indicate that driver sleepiness is a problem for city bus drivers, with 19% having to fight to stay awake while driving the bus 2–3 times each week or more and nearly half experiencing this at least 2–4 times per month. In conclusion, severe sleepiness, as indicated by having to fight sleep during driving, was common among the city bus drivers. Severe sleepiness correlated with fatigue related safety risks, such as near crashes. PMID:27098307

  16. Novice drivers' individual trajectories of driver behavior over the first three years of driving.

    PubMed

    Roman, Gabriela D; Poulter, Damian; Barker, Edward; McKenna, Frank P; Rowe, Richard

    2015-09-01

    Identifying the changes in driving behavior that underlie the decrease in crash risk over the first few months of driving is key to efforts to reduce injury and fatality risk in novice drivers. This study represented a secondary data analysis of 1148 drivers who participated in the UK Cohort II study. The Driver Behavior Questionnaire was completed at 6 months and 1, 2 and 3 years after licensure. Linear latent growth models indicated significant increases across development in all four dimensions of aberrant driving behavior under scrutiny: aggressive violations, ordinary violations, errors and slips. Unconditional and conditional latent growth class analyses showed that the observed heterogeneity in individual trajectories was explained by the presence of multiple homogeneous groups of drivers, each exhibiting specific trajectories of aberrant driver behavior. Initial levels of aberrant driver behavior were important in identifying sub-groups of drivers. All classes showed positive slopes; there was no evidence of a group of drivers whose aberrant behavior decreased over time that might explain the decrease in crash involvement observed over this period. Male gender and younger age predicted membership of trajectories with higher levels of aberrant behavior. These findings highlight the importance of early intervention for improving road safety. We discuss the implications of our findings for understanding the behavioral underpinnings of the decrease in crash involvement observed in the early months of driving.

  17. Beam loss studies in high-intensity heavy-ion linacs

    NASA Astrophysics Data System (ADS)

    Ostroumov, P. N.; Aseev, V. N.; Mustapha, B.

    2004-09-01

    The proposed Rare Isotope Accelerator (RIA) Facility, an innovative exotic-beam facility for the production of high-quality beams of short-lived isotopes, consists of a fully superconducting 1.4GV driver linac and a 140MV postaccelerator. To produce sufficient intensities of secondary beams the driver linac will provide 400kW primary beams of any ion from hydrogen to uranium. Because of the high intensity of the primary beams the beam losses must be minimized to avoid radioactivation of the accelerator equipment. To keep the power deposited by the particles lost on the accelerator structures below 1 W/m, the relative beam losses per unit length should be less than 10-5, especially along the high-energy section of the linac. A new beam dynamics simulation code TRACK has been developed and used for beam loss studies in the RIA driver linac. In the TRACK code, ions are tracked through the three-dimensional electromagnetic fields of every element of the linac starting from the electron cyclotron resonance (ECR) ion source to the production target. The simulation starts with a multicomponent dc ion beam extracted from the ECR. The space charge forces are included in the simulations. They are especially important in the front end of the driver linac. Beam losses are studied by tracking a large number of particles (up to 106) through the whole linac considering all sources of error such us element misalignments, rf field errors, and stripper thickness fluctuations. For each configuration of the linac, multiple sets of error values have been randomly generated and used in the calculations. The results are then combined to calculate important beam parameters, estimate beam losses, and characterize the corresponding linac configuration. To track a large number of particles for a comprehensive number of error sets (up to 500), the code TRACK was parallelized and run on the Jazz computer cluster at ANL.

  18. Redesign of Transjakarta Bus Driver's Cabin

    NASA Astrophysics Data System (ADS)

    Mardi Safitri, Dian; Azmi, Nora; Singh, Gurbinder; Astuti, Pudji

    2016-02-01

    Ergonomic risk at work stations with type Seated Work Control was one of the problems faced by Transjakarta bus driver. Currently “Trisakti” type bus, one type of bus that is used by Transjakarta in corridor 9, serving route Pinang Ranti - Pluit, gained many complaints from drivers. From the results of Nordic Body Map questionnaires given to 30 drivers, it was known that drivers feel pain in the neck, arms, hips, and buttocks. Allegedly this was due to the seat position and the button/panel bus has a considerable distance range (1 meter) to be achieved by drivers. In addition, preliminary results of the questionnaire using Workstation Checklist identified their complaints about uncomfortable cushion, driver's seat backrest, and the exact position of the AC is above the driver head. To reduce the risk level of ergonomics, then did research to design the cabin by using a generic approach to designing products. The risk analysis driver posture before the design was done by using Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), and Quick Exposure Checklist (QEC), while the calculation of the moment the body is done by using software Mannequin Pro V10.2. Furthermore, the design of generic products was done through the stages: need metric-matrix, house of quality, anthropometric data collection, classification tree concept, concept screening, scoring concept, design and manufacture of products in the form of two-dimensional. While the design after design risk analysis driver posture was done by using RULA, REBA, and calculation of moments body as well as the design visualized using software 3DMax. From the results of analysis before the draft design improvements cabin RULA obtained scores of 6, REBA 9, and the result amounted to 57.38% QEC and moment forces on the back is 247.3 LbF.inch and on the right hip is 72.9 LbF.in. While the results of the proposed improvements cabin design RULA obtained scores of 3, REBA 4, and the moment of force on

  19. Road accidents caused by drivers falling asleep.

    PubMed

    Sagberg, F

    1999-11-01

    About 29600 Norwegian accident-involved drivers received a questionnaire about the last accident reported to their insurance company. About 9200 drivers (31%) returned the questionnaire. The questionnaire contained questions about sleep or fatigue as contributing factors to the accident. In addition, the drivers reported whether or not they had fallen asleep some time whilst driving. and what the consequences had been. Sleep or drowsiness was a contributing factor in 3.9% of all accidents, as reported by drivers who were at fault for the accident. This factor was strongly over-represented in night-time accidents (18.6%), in running-off-the-road accidents (8.3%), accidents after driving more than 150 km on one trip (8.1%), and personal injury accidents (7.3%). A logistic regression analysis showed that the following additional factors made significant and independent contributions to increasing the odds of sleep involvement in an accident: dry road, high speed limit, driving one's own car, not driving the car daily, high education, and few years of driving experience. More male than female drivers were involved in sleep-related accidents, but this seems largely to be explained by males driving relatively more than females on roads with high speed limits. A total of 10% of male drivers and 4% of females reported to have fallen asleep while driving during the last 12 months. A total of 4% of these events resulted in an accident. The most frequent consequence of falling asleep--amounting to more than 40% of the reported incidents--was crossing of the right edge-line before awaking, whereas crossing of the centreline was reported by 16%. Drivers' lack of awareness of important precursors of falling asleep--like highway hypnosis, driving without awareness, and similar phenomena--as well as a reluctance to discontinue driving despite feeling tired are pointed out as likely contributors to sleep-related accidents. More knowledge about the drivers' experiences immediately

  20. The Proton Driver for the μμ Collider

    NASA Astrophysics Data System (ADS)

    Norem, J.; Ankenbrandt, C.; Griffin, J.; Johnstone, C.; Mills, F.; Moretti, A.; Noble, R.; Popovic, M.; Qian, Z.; Brennan, M.; Roser, T.; Trbojevic, D.; Wei, J.

    1997-05-01

    The proton driver for the μμ collider would operate at about 15 Hz and produce four bunches of 2.5 \\cdot 10^13 protons/bunch at 10 GeV (or half that number at 20 - 30 GeV) with a bunch length of σ ~ 1 ns. A number of options have been considered to produce these bunches using: a) simple bunch rotation, b) energy slewing near γt followed by a fast increase of γt which permits bunching, and c) change of rf frequency in a ring to ring transfer. Flexible Momentum Compaction (FMC), or similar, lattices seem to offer control of γt even on short timescales. The large momentum spread, space charge tune shift and rapid bunching would tend to stabilize short, intense bunches, although I_pk ~ 1600 A. Both active (harmonic cavities) and passive (inductance in the wall) solutions have been considered to minimize high current beam effects. Magnet and vacuum systems would be similar to other high current designs, however beam losses require special attention.

  1. Front end design of the RIA driver LINAC.

    SciTech Connect

    Kolomiets, A. A.; Asseev, V. N.; Ostroumov, P. N.; Pardo, R. C.; Physics; ITEP

    2003-01-01

    This paper describes the front end design for the RIA driver linac which is able to select, separate and accelerate in the RFQ the required ion species of one- or two-charge states. The front end consists of an ECR ion source located on a 100 kV platform, LEBT, RFQ and MEBT. The first section of the LEBT is an achromatic bending system for charge-to-mass analysis and selection. For the heaviest ions with masses above 180, the transport system is able to deliver to the entrance of the first buncher a two-charge-state beam with similar Twiss parameters for both charge states. In order to match two-charge-state ions with different mass to charge ratios, the straight section of the LEBT upstream of the RFQ will be placed on a high-voltage platform. A voltage /spl sim/30 kV is required in order to match velocities of ions with mass to charge ratio less than the design value and to maintain the possibility accelerating two charge states simultaneously. Several beam matching schemes in the transitions LEBT-RFQ and RFQ-MEBT have been studied.

  2. Proton Driver Linac for the Frankfurt Neutron Source

    SciTech Connect

    Wiesner, C.; Chau, L. P.; Dinter, H.; Droba, M.; Heilmann, M.; Joshi, N.; Maeder, D.; Metz, A.; Meusel, O.; Noll, D.; Podlech, H.; Ratzinger, U.; Reichau, H.; Schempp, A.; Schmidt, S.; Schweizer, W.; Volk, K.; Wagner, C.; Mueller, I.

    2010-08-04

    The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum (FRANZ) will deliver high neutron fluxes in the energy range of 1 to 500 keV. The Activation Mode provides a high averaged neutron flux created by a cw proton beam of up to 5 mA, while in the Compressor Mode intense neutron pulses of 1 ns length are formed with a repetition rate of up to 250 kHz. The Compressor Mode is well-suited for energy-dependent neutron capture measurements using the Time-of-Flight method in combination with a 4{pi} BaF{sub 2} detector array. The design of the proton driver linac for both operation modes is presented. This includes the volume type ion source, the ExB chopper located in the low energy section, the RFQ-IH combination for beam acceleration and the bunch compressor. Finally, the neutron production at the lithium-7 target and the resulting energy spectrum is described.

  3. Railway suicide: the psychological effects on drivers.

    PubMed

    Farmer, R; Tranah, T; O'Donnell, I; Catalan, J

    1992-05-01

    People have jumped (or fallen) in front of trains on the London Underground system in increasing numbers throughout the twentieth century. During the past decade there have been about 100 such incidents each year, of which around 90 would involve the train driver witnessing his train strike the person on the track. Most are suicides or attempts at suicide. They represent major unexpected and violent events in the lives of the train drivers and it might be expected that some of them would respond by developing a post-traumatic stress reaction of the type identified by Horowitz (1976) or other adverse psychological reactions or both. The research reported in this paper was designed to characterize the range of responses of drivers to the experiences of killing or injuring members of the public during the course of their daily work. It was found that 16.3% of the drivers involved in incidents did develop post-traumatic stress disorder and that other diagnoses, e.g. depression and phobic states, were present in 39.5% of drivers when interviewed one month after the incident. PMID:1615108

  4. Drivers of the virtual water trade

    NASA Astrophysics Data System (ADS)

    Tamea, S.; Carr, J. A.; Laio, F.; Ridolfi, L.

    2014-01-01

    Through the international trade of food commodities, countries virtually export or import the water used for food production, known as "virtual water." The international trade network thus implies a network of virtual water flows from exporting to importing countries. The purpose of this study is to identify some controlling factors of the virtual water network by means of multivariate regression analyses, or gravity laws, as often named in economics. Starting from the FAOSTAT database, we reconstruct 25 years (1986-2010) of international virtual water trade values; we then analyze the dependence of the exchanged fluxes on: population, gross domestic product, arable land, virtual water embedded in agricultural production and dietary demand, and geographical distance between countries. Significant drivers are identified for each country considering separately export and import fluxes; temporal trends are outlined and the relative importance of drivers is assessed by a commonality analysis. Results indicate that population, gross domestic product and geographical distance are the major drivers of virtual water fluxes, with a minor (nonnegligible) contribution given by the agricultural production of exporting countries. Such drivers have become relevant for an increasing number of countries throughout the years, with an increasing variance explained by the distance between countries and a decreasing role of the gross domestic product. The worldwide adjusted coefficient of determination of fitted gravity-law model is 0.57 (in 2010), and it has increased in time, confirming the good descriptive capability of selected drivers for the virtual water trade.

  5. Driver Module for Noise Cancellation System

    NASA Astrophysics Data System (ADS)

    Shirvani, Mir S.

    2002-12-01

    The Driver module is an integral part of the noise cancellation system, which was my primary objective to research, design, and prototype during the tenure in NASA Langley research center. The function of the driver module is to actuate a panel that is constructed with a smart material and invented in NASA-LaRC. The bandwidth and amplitude of the actuation of the panel correlates the undesirable structural bandwidth and amplitude of the applied object. The undesirable structural bandwidth is relatively narrow and the undesirable amplitude is relatively large. A highly stable, low distortion, linear monolithic integrated circuit was used as a variable frequency and amplitude function generator. In order to elevate the amplitude of the output waveform of the generator to a sufficient magnitude a pair of high voltage monolithic MOSFET operational amplifiers were implemented. The amplifiers connected in a bipolar bridge configuration for a higher efficiency. In order to reduce the required external Supply voltages and make the driver capable to be operated by a battery a pair of ultra miniature high-output voltage dc to dc converters are also used. The driver module tested with the noise cancellation panel, the required data was acquired, and the result was promising. After examining all the options the driver module was designed and prototyped.

  6. Directing driver attention with augmented reality cues

    PubMed Central

    Rusch, Michelle L.; Schall, Mark C.; Gavin, Patrick; Lee, John D.; Dawson, Jeffrey D.; Vecera, Shaun; Rizzo, Matthew

    2013-01-01

    This simulator study evaluated the effects of augmented reality (AR) cues designed to direct the attention of experienced drivers to roadside hazards. Twenty-seven healthy middle-aged licensed drivers with a range of attention capacity participated in a 54 mile (1.5 hour) drive in an interactive fixed-base driving simulator. Each participant received AR cues to potential roadside hazards in six simulated straight (9 mile long) rural roadway segments. Drivers were evaluated on response time for detecting a potentially hazardous event, detection accuracy for target (hazard) and non-target objects, and headway with respect to the hazards. Results showed no negative outcomes associated with interference. AR cues did not impair perception of non-target objects, including for drivers with lower attentional capacity. Results showed near significant response time benefits for AR cued hazards. AR cueing increased response rate for detecting pedestrians and warning signs but not vehicles. AR system false alarms and misses did not impair driver responses to potential hazards. PMID:24436635

  7. Driver anger on the information superhighway: A content analysis of online complaints of offensive driver behaviour.

    PubMed

    Wickens, Christine M; Wiesenthal, David L; Hall, Ashley; Roseborough, James E W

    2013-03-01

    In recent years, several websites have been developed allowing drivers to post their complaints about other motorists online. These websites allow drivers to describe the nature of the offensive behaviour and to identify the offending motorist by vehicle type, colour, and license plate number. Some websites also ask drivers to list the location where the event took place and the exact date and time of the offence. The current study was a content analysis of complaints posted to RoadRagers.com between 1999 and 2007 (N=5624). The purpose of the study was to: (1) assess the research value of this novel data source; (2) demonstrate the value of content analysis to the study of driver behaviour; (3) further validate an existing coding scheme; (4) determine whether this new data source would replicate previous research findings regarding the most frequent types of driver complaints and temporal distribution of these reports; (5) provide recommendations for improved driver training and public safety initiatives based on these data. A coding scheme that was originally developed for an assessment of complaints submitted to the Ontario Provincial Police (OPP) (Wickens et al., 2005) was revised to accommodate the new dataset. The inter-rater reliability of the revised coding scheme as applied to the website complaints was very good (kappa=.85). The most frequently reported improper driver behaviours were cutting/weaving, speeding, perceived displays of hostility, and tailgating. Reports were most frequent on weekdays and during the morning and afternoon rush hour. The current study replicated several findings from the analysis of reports to the OPP, but possible differences in the sample and data collection method also produced some differences in findings. The value of content analysis to driver behaviour research and of driver complaint websites as a data source was demonstrated. Implications for driver safety initiatives and future research will be discussed. PMID:23201756

  8. Determinants and Drivers of Infectious Disease Threat Events in Europe.

    PubMed

    Semenza, Jan C; Lindgren, Elisabet; Balkanyi, Laszlo; Espinosa, Laura; Almqvist, My S; Penttinen, Pasi; Rocklöv, Joacim

    2016-04-01

    Infectious disease threat events (IDTEs) are increasing in frequency worldwide. We analyzed underlying drivers of 116 IDTEs detected in Europe during 2008-2013 by epidemic intelligence at the European Centre of Disease Prevention and Control. Seventeen drivers were identified and categorized into 3 groups: globalization and environment, sociodemographic, and public health systems. A combination of >2 drivers was responsible for most IDTEs. The driver category globalization and environment contributed to 61% of individual IDTEs, and the top 5 individual drivers of all IDTEs were travel and tourism, food and water quality, natural environment, global trade, and climate. Hierarchical cluster analysis of all drivers identified travel and tourism as a distinctly separate driver. Monitoring and modeling such disease drivers can help anticipate future IDTEs and strengthen control measures. More important, intervening directly on these underlying drivers can diminish the likelihood of the occurrence of an IDTE and reduce the associated human and economic costs. PMID:26982104

  9. Determinants and Drivers of Infectious Disease Threat Events in Europe

    PubMed Central

    Lindgren, Elisabet; Balkanyi, Laszlo; Espinosa, Laura; Almqvist, My S.; Penttinen, Pasi; Rocklöv, Joacim

    2016-01-01

    Infectious disease threat events (IDTEs) are increasing in frequency worldwide. We analyzed underlying drivers of 116 IDTEs detected in Europe during 2008–2013 by epidemic intelligence at the European Centre of Disease Prevention and Control. Seventeen drivers were identified and categorized into 3 groups: globalization and environment, sociodemographic, and public health systems. A combination of >2 drivers was responsible for most IDTEs. The driver category globalization and environment contributed to 61% of individual IDTEs, and the top 5 individual drivers of all IDTEs were travel and tourism, food and water quality, natural environment, global trade, and climate. Hierarchical cluster analysis of all drivers identified travel and tourism as a distinctly separate driver. Monitoring and modeling such disease drivers can help anticipate future IDTEs and strengthen control measures. More important, intervening directly on these underlying drivers can diminish the likelihood of the occurrence of an IDTE and reduce the associated human and economic costs. PMID:26982104

  10. DEVICE CONTROL TOOL FOR CEBAF BEAM DIAGNOSTICS SOFTWARE

    SciTech Connect

    Pavel Chevtsov

    2008-02-11

    Continuously monitoring the beam quality in the CEBAF accelerator, a variety of beam diagnostics software created at Jefferson Lab makes a significant contribution to very high availability of the machine for nuclear physics experiments. The interface between this software and beam instrumentation hardware components is provided by a device control tool, which is optimized for beam diagnostics tasks. As a part of the device/driver development framework at Jefferson Lab, this tool is very easy to support and extend to integrate new beam instrumentation components. All device control functions are based on the configuration (ASCII text) files that completely define the used hardware interface standards (CAMAC, VME, RS-232, GPIB, etc.) and communication protocols. The paper presents the main elements of the device control tool for beam diagnostics software at Jefferson Lab.

  11. Simulation Studies of Temperature Anisotropy Instability in Intense Charged Particle Beams for IBX Parameters

    NASA Astrophysics Data System (ADS)

    Startsev, E. A.; Davidson, R. C.; Qin, H.

    2003-10-01

    The Integrated Beam Experiment (IBX) is a proof-of-principal experiment for heavy ion fusion designed to test source-to-target beam physics using a single beam of K^+ ions of duration 0.2 - 1.5 μ s, accelerated to energies 5-10 MeV, and driver-scale normalized perviance in the range 10-5 -10-3. An important physics issue to be addressed by IBX is the effect of longitudinal-transverse coupling on the beam transport and focusibility of the driver. Our previous numerical and theoretical studies of intense charged particle beams with large temperature anisotropy [E. A. Startsev, R. C. Davidson and H. Qin, Phys. Plasmas 9, 3138, 2002] demonstrated that a fast, electrostatic, Harris-like instability may develop. This paper reports the results of recent simulations of the temperature anisotropy instability using the Beam Equilibrium Stability Transport (BEST) code for IBX parameters.

  12. Linear transformer driver for pulse generation

    DOEpatents

    Kim, Alexander A; Mazarakis, Michael G; Sinebryukhov, Vadim A; Volkov, Sergey N; Kondratiev, Sergey S; Alexeenko, Vitaly M; Bayol, Frederic; Demol, Gauthier; Stygar, William A

    2015-04-07

    A linear transformer driver includes at least one ferrite ring positioned to accept a load. The linear transformer driver also includes a first power delivery module that includes a first charge storage devices and a first switch. The first power delivery module sends a first energy in the form of a first pulse to the load. The linear transformer driver also includes a second power delivery module including a second charge storage device and a second switch. The second power delivery module sends a second energy in the form of a second pulse to the load. The second pulse has a frequency that is approximately three times the frequency of the first pulse. The at least one ferrite ring is positioned to force the first pulse and the second pulse to the load by temporarily isolating the first pulse and the second pulse from an electrical ground.

  13. A model of Beijing drivers' scrambling behaviors.

    PubMed

    Shi, Jing; Bai, Yun; Tao, Li; Atchley, Paul

    2011-07-01

    A major, but unstudied, cause of crashes in China is drivers that "scramble" to gain the right of way in violation of traffic regulations. The motivation of this study is to explore the features of drivers' scrambling behaviors and the attitudes and driving skills that influence them. In this study, we established a scrambling behavior scale, and developed a driving attitude scale and a driving skill scale using factor analysis of an Internet survey of 486 drivers in Beijing. A structural equation model of scrambling behavior toward cars and pedestrians/cyclists was developed with attitudes and skills as predictors of behavior. Skills and attitudes of approval toward violations of traffic rules did not predict scrambling behaviors, while the motivation for safety and attitudes against violating traffic rules led to reduced scrambling behaviors. The current work highlights this peculiar aspect of Chinese roads and suggests methods to reduce the behavior.

  14. Drivers' perceptions and reactions to roadside memorials.

    PubMed

    Tay, Richard

    2009-07-01

    Despite their growing popularity in North America, little research has been conducted on understanding the effects of roadside memorials on drivers' behaviour. In this study, an online survey of 810 drivers found that public opinions on the policy options as well as drivers' self-reported reactions to the presence of roadside memorials were fairly divided. In addition, an on-road experiment was conducted to examine the short term effects of roadside memorials at two intersections. Our results showed that the number of red light violations was reduced by 16.7% in the 6 weeks after the installation of the mock memorials compared to the 6 weeks before whereas the number of violations at two comparison sites experienced an increase of 16.8%.

  15. Living dangerously: driver distraction at high speed.

    PubMed

    Johnson, Mark B; Voas, Robert B; Lacey, John H; McKnight, A Scott; Lange, James E

    2004-03-01

    Recent research indicates that cell phone use can distract drivers from safe vehicle operation. However, estimates of the prevalence of cell phone use while driving have been limited to daytime hours and low-speed roadways. This paper describes the results of a study to estimate rates of cell phone use and other distractions by examining approximately 40,000 high-quality digital photographs of vehicles and drivers on the New Jersey Turnpike. The photographs, which originally were collected as part of a separate study, were taken both during the day and during the night and at different locations across the span of the Turnpike. A radar gun linked to the camera recorded the speeds of vehicles as they passed. This provided us with the speeds of every vehicle photographed, and allowed us to determine population counts of vehicles. A panel of three trained coders examined each photograph and recorded the presence of cell phone use by the drivers or any other distracting behavior. Demographic information on the driver was obtained during previous examinations of the photographs for an unrelated study. A rating was considered reliable when two out of the three coders agreed. Population estimates (and confidence intervals) of cell phone use and other distractions were estimated by weighting the cases by the inverse probability of vehicle selection. Logistic regression was used to predict cell phone use from demographic and situational factors. The results indicated that the most frequent distraction was cell phone use: 1.5% of the drivers on the Turnpike were using cell phones compared to the 3 to 4% use rates reported in the National Occupant Protection Use Survey (NOPUS) surveys conducted during the daytime on lower speed roadways. The Turnpike survey indicated that cell phones were used less on weekends and at night, and when the driver was exceeding the speed limit or had a passenger in the car.

  16. Laser-seeded modulation instability in a proton driver plasma wakefield accelerator

    SciTech Connect

    Siemon, Carl; Khudik, Vladimir; Austin Yi, S.; Shvets, Gennady; Pukhov, Alexander

    2013-10-15

    A new method for initiating the modulation instability (MI) of a proton beam in a proton driver plasma wakefield accelerator using a short laser pulse preceding the beam is presented. A diffracting laser pulse is used to produce a plasma wave that provides a seeding modulation of the proton bunch with the period equal to that of the plasma wave. Using the envelope description of the proton beam, this method of seeding the MI is analytically compared with the earlier suggested seeding technique that involves an abrupt truncation of the proton bunch. The full kinetic simulation of a realistic proton bunch is used to validate the analytic results. It is further used to demonstrate that a plasma density ramp placed in the early stages of the laser-seeded MI leads to its stabilization, resulting in sustained accelerating electric fields (of order several hundred MV/m) over long propagation distances (∼100–1000 m)

  17. Communications Interface Driver (CID) test plan

    NASA Astrophysics Data System (ADS)

    Bratton, Thomas; Davis, James; Dudas, Charles; Livings, Jeffrey G.; Schoenthal, Mark

    1990-09-01

    This test plan for the Communications Interface Driver (CID) systems will be used to evaluate and accept the CID. The CID system is a test tool whose purpose is to supply or receive a capacity level of communication (comm) messages to and from the air traffic control (ATC) and non-ATC ports of the Mode Select (Mode S) sensor. The primary concern of the CID test plan is written to establish the detailed test requirements, criteria, and methods to achieve the evaluation of the CID against the requirements set forth in the report, Functional Requirements of the Communications Interface Driver (CID), DOT/FAA/CT-TN87/41.

  18. Validation of the Driver Behaviour Questionnaire in a representative sample of drivers in Australia.

    PubMed

    Stephens, A N; Fitzharris, M

    2016-01-01

    The Driver Behaviour Questionnaire (DBQ) is a widely used measure of driving behaviours that may increase a driver's risk of crash involvement. However, there are several different versions of the DBQ varying in terms of number of items and factor structure. The aim of the current research was to assess the construct validity of the popular 28-item four-factor DBQ solution in a representative sample of drivers in Australia. A further aim was to test the factorial invariance of the measure across gender, age and also between fleet and non-fleet drivers using multigroup confirmatory factor analyses. Data on a range of attitudes towards road safety were collected using an online survey. A stratified sampling procedure was undertaken to ensure the age, gender and location distributions of participants were representative of the Australian population. A total of 2771 responses were obtained from fully licensed motor vehicle drivers (male: 46%). Confirmatory factor analysis supported the 28-item four-factor DBQ in the Australian sample. The DBQ was also found to be gender-invariant and strong partial measurement invariance was found for drivers aged from 26 to 64, but not for younger (17-25) or older (65-75) drivers. Modifications to the DBQ suggest how the DBQ can be improved for use in these two age groups. PMID:26584016

  19. Reproducible and controllable induction voltage adder for scaled beam experiments

    NASA Astrophysics Data System (ADS)

    Sakai, Yasuo; Nakajima, Mitsuo; Horioka, Kazuhiko

    2016-08-01

    A reproducible and controllable induction adder was developed using solid-state switching devices and Finemet cores for scaled beam compression experiments. A gate controlled MOSFET circuit was developed for the controllable voltage driver. The MOSFET circuit drove the induction adder at low magnetization levels of the cores which enabled us to form reproducible modulation voltages with jitter less than 0.3 ns. Preliminary beam compression experiments indicated that the induction adder can improve the reproducibility of modulation voltages and advance the beam physics experiments.

  20. Reproducible and controllable induction voltage adder for scaled beam experiments.

    PubMed

    Sakai, Yasuo; Nakajima, Mitsuo; Horioka, Kazuhiko

    2016-08-01

    A reproducible and controllable induction adder was developed using solid-state switching devices and Finemet cores for scaled beam compression experiments. A gate controlled MOSFET circuit was developed for the controllable voltage driver. The MOSFET circuit drove the induction adder at low magnetization levels of the cores which enabled us to form reproducible modulation voltages with jitter less than 0.3 ns. Preliminary beam compression experiments indicated that the induction adder can improve the reproducibility of modulation voltages and advance the beam physics experiments. PMID:27587112

  1. External Beam Therapy (EBT)

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z External Beam Therapy (EBT) External beam therapy (EBT) is a ... follow-up should I expect? What is external beam therapy and how is it used? External beam ...

  2. EC Driver - 41" Stroke Hydraulic Cylinder

    SciTech Connect

    Jaques, A.; /Fermilab

    1990-05-24

    It was decided to use a hydraulic cylinder resting on the floor of the argon spill trough in the EC carriage to drive the EC's motion on the center beam. Space was limited due to the spill bellows and their required support and containment system. The 0.0. of the cylinder had to be limited to 3 to 3-1/2 inches, maximum. The weight of a wet EC and carriage is estimated to be 320 tons. The rolling coefficient of friction of the Tychoway rollers chosen to guide the EC and carriage along the hardened centerbeam ways is claimed to be less than 0.0025. The driver will also need to overcome the forces produced by moving (rotating) the numerous bayonets located at the top of the cryostats in the many piping systems. These forces were conservatively estimated at 1000 lbs. The drive force required to overcome these forces was then calculated to be: 320(2,000) x 0.0025 + 1,000 = 2.600 lbs. (min. required). Due to the uncertainty in the actual roller coefficient of friction and the various unknowns in estimating the resistive forces contained in the piping and cabling systems attached to the cryostat, a conservative design factor of 5 was chosen. This should account for any uncertainty in our estimation of the minimum required drive force and also leaves us with a reserve to fall back on in case any unforeseen problems might arise. Thus the desired capacity of the driver was set at: (2,600) x 5 = 13,000 lbs. (design capacity). Assuming a 3 inch O.D. cylinder with a 1/2 inch wall (2 inch bore), we first analyzed a 1-3/8 inch diameter piston rod. Using Shigley & Mischke's 'Mechanical Engineering Design' (5th Ed.) and it's formulas for long columns with central loading, it was determined that a 1-3/8 inch diameter rod would not suffice, given our safety factor of 2. Increasing the piston rod diameter to 1-1/2 inches proved to be sufficient. The maximum allowable load came out to be approximately 17,000 lbs., which is greater than the 13,000 lbs. design capacity. With a 1-1/2 inch

  3. FRIB - Facility for Rare Isotope Beams

    SciTech Connect

    Bollen, G.

    2010-04-30

    FRIB, the US's 'Facility for Rare Isotope Beams' to be built at Michigan State University (MSU), will be based on a 400 kW, 200 MeV/u heavy ion driver linac. Once completed, FRIB will offer world-unique opportunities for rare isotope science. It will provide a wide variety of high-quality beams of unstable isotopes at unprecedented intensities, opening exciting research perspectives with fast, stopped, and reaccelerated beams. New experiments will become possible to explore nuclear structure very far from stability and to provide information critical for the explanation of the element abundances observed in the universe. Special isotopes that are important for the study of fundamental symmetries and to allow for new applications of isotopes to meet societal needs will at become available at high intensities.

  4. Active control of flexural vibrations in beams

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.

    1987-01-01

    The feasibility of using piezoelectric actuators to control the flexural oscillations of large structures in space is investigated. Flexural oscillations are excited by impulsive loads. The vibratory response can degrade the pointing accuracy of cameras and antennae, and can cause high stresses at structural node points. Piezoelectric actuators have the advantage of exerting localized bending moments. In this way, vibration is controlled without exciting rigid body modes. The actuators are used in collocated sensor/driver pairs to form a feedback control system. The sensor produces a voltage that is proportional to the dynamic stress at the sensor location, and the driver produces a force that is proportional to the voltage applied to it. The analog control system amplifies and phase shifts the sensor signal to produce the voltage signal that is applied to the driver. The feedback control is demonstrated to increase the first mode damping in a cantilever beam by up to 100 percent, depending on the amplifier gain. The damping efficiency of the control system when the piezoelectrics are not optimally positioned at points of high stress in the beam is evaluated.

  5. Energy Efficiency Handbook for Driver's Education.

    ERIC Educational Resources Information Center

    Berlowitz, Dan; And Others

    Presented are suggestions to help the automobile driver attain the saving of fuel and money. Discussed are starting and stopping; anticipation of traffic conditions; use of accessories; trip planning; and accomodation of pedestrians and cyclists. Additional topics covered include systematic car maintenance and safety considerations. (RE)

  6. 49 CFR 177.816 - Driver training.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... employee who will operate a motor vehicle has been trained in the applicable requirements of 49 CFR parts... 49 CFR part 383. Specialized training shall include the following: (1) Operation of emergency control... 49 Transportation 2 2010-10-01 2010-10-01 false Driver training. 177.816 Section...

  7. 49 CFR 177.816 - Driver training.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cause to be transported, a hazardous material unless each hazmat employee who will operate a motor vehicle has been trained in the applicable requirements of 49 CFR parts 390 through 397 and the procedures... have the appropriate State-issued commercial driver's license required by 49 CFR part 383....

  8. Driver Education Program. Administrative and Curriculum Guide.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

    This administrative and curriculum guide is designed for use in establishing and teaching a driver education course for high school students. The first section of the guide, a discussion of program administration, deals with various aspects of program management as well as the roles and responsibilities of the key practitioners involved in driver…

  9. Wisconsin Bicycle Driver Training Course. Instructor's Handbook.

    ERIC Educational Resources Information Center

    Thompson, Ronald L.

    Designed for use by trained and certified instructors of a voluntary bicycle driver training course, this handbook provides materials for eight one-hour sessions for beginners or experienced bicyclists. Part 1, Instructor's Guidelines, discusses course objectives, organization, and content; instruction methods; and audiovisual materials. Part 2…

  10. Who's Driving This Bus Anyway? Empowering Drivers.

    ERIC Educational Resources Information Center

    Allen, J. D.

    1997-01-01

    In 1977, a school transportation director developed a policy giving school bus drivers authority to discipline unruly student behavior via a system of graduated warnings and suspension of riding privileges. Most parents have been supportive and expect their kids to behave on the bus. In the interest of safety, school administrators should support…

  11. Toms River Drivers Manual 1984-1985.

    ERIC Educational Resources Information Center

    Thomas, Patricia

    The procedures in this manual are designed to establish stability and continuity within the student transportation department of the Toms River Regional Schools in New Jersey. The manual is divided into three sections. Section 1 provides driver and aide specific information. It includes directives related to time clock, spare buses, and…

  12. What Are Drivers for Informal Learning?

    ERIC Educational Resources Information Center

    Schürmann, Eva; Beausaert, Simon

    2016-01-01

    Purpose: The topic of informal learning at work has received increasing attention in the past years. The purpose of this study is to explore in which informal learning activities employees engage and what are the drivers for informal learning. Design/Methodology/Approach: Semi-structured interviews were taken from ten human resources (HR) and ten…

  13. Mathematical model to predict drivers' reaction speeds.

    PubMed

    Long, Benjamin L; Gillespie, A Isabella; Tanaka, Martin L

    2012-02-01

    Mental distractions and physical impairments can increase the risk of accidents by affecting a driver's ability to control the vehicle. In this article, we developed a linear mathematical model that can be used to quantitatively predict drivers' performance over a variety of possible driving conditions. Predictions were not limited only to conditions tested, but also included linear combinations of these tests conditions. Two groups of 12 participants were evaluated using a custom drivers' reaction speed testing device to evaluate the effect of cell phone talking, texting, and a fixed knee brace on the components of drivers' reaction speed. Cognitive reaction time was found to increase by 24% for cell phone talking and 74% for texting. The fixed knee brace increased musculoskeletal reaction time by 24%. These experimental data were used to develop a mathematical model to predict reaction speed for an untested condition, talking on a cell phone with a fixed knee brace. The model was verified by comparing the predicted reaction speed to measured experimental values from an independent test. The model predicted full braking time within 3% of the measured value. Although only a few influential conditions were evaluated, we present a general approach that can be expanded to include other types of distractions, impairments, and environmental conditions. PMID:22431214

  14. Levitation With a Single Acoustic Driver

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.; Allen, J. L.

    1986-01-01

    Pair of reports describes acoustic-levitation systems in which only one acoustic resonance mode excited, and only one driver needed. Systems employ levitation chambers of rectangular and cylindrical geometries. Reports first describe single mode concept and indicate which modes used to levitate sample without rotation. Reports then describe systems in which controlled rotation of sample introduced.

  15. Multi-Phase Driver Education Teaching Guide.

    ERIC Educational Resources Information Center

    Hurst-Euless-Bedford Independent School District, Hurst, TX.

    For use in planning and conducting functional multi-phase driver education programs, this teacher's guide consists of four phases of instruction: classroom activities, simulated application, in-car range practice, and in-car public practice. Contents are divided into three instructional sections, with the first combining the classroom activities…

  16. Evasive and Emergency Curriculum for Driver Education.

    ERIC Educational Resources Information Center

    1976

    An advanced course to increase the student's driving ability and knowledge of the automobile is presented in this curriculum guide for use by high school driver education instructors. The course is designed for students who have been driving for 6 to 12 months or who have mastered basic driving skills. Focus is on advanced driving techniques,…

  17. Driver and Traffic Safety Education Policies.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Div. of General Education.

    The policy statement outlines New York State standards regarding: (1) the driver's education program; (2) vehicles in the program; (3) administration, supervision, and organization of summer school programs; (4) teachers in the program; and (5) pupils in the program. A glossary defines terms and instructional objectives. Program policies…

  18. Driver Education for Motorcycle Operation. Final Report.

    ERIC Educational Resources Information Center

    Council, Forrest M.; And Others

    A three-year pilot project was conducted to evaluate the feasibility of implementing a statewide off-road motorcycle training program for beginning drivers in North Carolina. The first year of the program involved approximately 422 students from five locations, the second year involved seven sites across the State. The three basic criteria for the…

  19. Mathematical model to predict drivers' reaction speeds.

    PubMed

    Long, Benjamin L; Gillespie, A Isabella; Tanaka, Martin L

    2012-02-01

    Mental distractions and physical impairments can increase the risk of accidents by affecting a driver's ability to control the vehicle. In this article, we developed a linear mathematical model that can be used to quantitatively predict drivers' performance over a variety of possible driving conditions. Predictions were not limited only to conditions tested, but also included linear combinations of these tests conditions. Two groups of 12 participants were evaluated using a custom drivers' reaction speed testing device to evaluate the effect of cell phone talking, texting, and a fixed knee brace on the components of drivers' reaction speed. Cognitive reaction time was found to increase by 24% for cell phone talking and 74% for texting. The fixed knee brace increased musculoskeletal reaction time by 24%. These experimental data were used to develop a mathematical model to predict reaction speed for an untested condition, talking on a cell phone with a fixed knee brace. The model was verified by comparing the predicted reaction speed to measured experimental values from an independent test. The model predicted full braking time within 3% of the measured value. Although only a few influential conditions were evaluated, we present a general approach that can be expanded to include other types of distractions, impairments, and environmental conditions.

  20. CEBAF beam loss accounting

    SciTech Connect

    Ursic, R.; Mahoney, K.; Hovater, C.; Hutton, A.; Sinclair, C.

    1995-12-31

    This paper describes the design and implementation of a beam loss accounting system for the CEBAF electron accelerator. This system samples the beam curent throughout the beam path and measures the beam current accurately. Personnel Safety and Machine Protection systems use this system to turn off the beam when hazardous beam losses occur.

  1. Studies Of Coherent Synchrotron Radiation And Longitudinal Space Charge In The Jefferson Lab FEL Driver

    SciTech Connect

    Tennant, Christopher D.; Douglas, David R.; Li, Rui; Tsai, C.-Y.

    2014-12-01

    The Jefferson Laboratory IR FEL Driver provides an ideal test bed for studying a variety of beam dynamical effects. Recent studies focused on characterizing the impact of coherent synchrotron radiation (CSR) with the goal of benchmarking measurements with simulation. Following measurements to characterize the beam, we quantitatively characterized energy extraction via CSR by measuring beam position at a dispersed location as a function of bunch compression. In addition to operating with the beam on the rising part of the linac RF waveform, measurements were also made while accelerating on the falling part. For each, the full compression point was moved along the backleg of the machine and the response of the beam (distribution, extracted energy) measured. Initial results of start-to-end simulations using a 1D CSR algorithm show remarkably good agreement with measurements. A subsequent experiment established lasing with the beam accelerated on the falling side of the RF waveform in conjunction with positive momentum compaction (R56) to compress the bunch. The success of this experiment motivated the design of a modified CEBAF-style arc with control of CSR and microbunching effects.

  2. Use of Multipass Recirculation and Energy Recovery In CW SRF X-FEL Driver Accelerators

    SciTech Connect

    Douglas, David; Akers, Walt; Benson, Stephen V.; Biallas, George; Blackburn, Keith; Boyce, James; Bullard, Donald; Coleman, James; Dickover, Cody; Ellingsworth, Forrest; Evtushenko, Pavel; Fisk, Sally; Gould, Christopher; Gubeli, Joseph; Hannon, Fay; Hardy, David; Hernandez-Garcia, Carlos; Jordan, Kevin; Klopf, John; Kortze, J.; Legg, Robert; Li, Rui; Marchlik, Matthew; Moore, Steven W.; Neil, George; Powers, Thomas; Sexton, Daniel; Shin, Ilkyoung; Shinn, Michelle D.; Tennant, Christopher; Terzic, Balsa; Walker, Richard; Williams, Gwyn P.; Wilson, G.; Zhang, Shukui

    2010-08-01

    We discuss the use of multipass recirculation and energy recovery in CW SRF drivers for short wavelength FELs. Benefits include cost management (through reduced system footprint, required RF and SRF hardware, and associated infrastructure - including high power beam dumps and cryogenic systems), ease in radiation control (low drive beam exhaust energy), ability to accelerate and deliver multiple beams of differing energy to multiple FELs, and opportunity for seamless integration of multistage bunch length compression into the longitudinal matching scenario. Issues include all those associated with ERLs compounded by the challenge of generating and preserving the CW electron drive beam brightness required by short wavelength FELs. We thus consider the impact of space charge, BBU and other environmental wakes and impedances, ISR and CSR, potential for microbunching, intra-beam and beam-residual gas scattering, ion effects, RF transients, and halo, as well as the effect of traditional design, fabrication, installation and operational errors (lattice aberrations, alignment, powering, field quality). Context for the discussion is provided by JLAMP, the proposed VUV/X-ray upgrade to the existing Jefferson Lab FEL.

  3. OPERATION AND COMMISSIONING OF THE JEFFERSON LAB UV FEL USING AN SRF DRIVER ERL

    SciTech Connect

    R. Legg; S. Benson; G. Biallas; K. Blackburn; J. Boyce; D. Bullard; J. Coleman; C. Dickover; D. Douglas; F. Ellingsworth; P. Evtushenko; F. Hannon; C. Hernandez-Garcia; C. Gould; J. Gubeli; D. Hardy; K. Jordan; M. Klopf; J. Kortze; M. Marchlik; W. Moore; G. Neil; T. Powers; D. Sexton; Michelle D. Shinn; C. Tennant; R. Walker; G. Wilson

    2011-03-01

    We describe the operation and commissioning of the Jefferson Lab UV FEL using a CW SRF ERL driver. Based on the same 135 MeV linear accelerator as the Jefferson Lab 10 kW IR Upgrade FEL, the UV driver ERL uses a bypass geometry to provide transverse phase space control, bunch length compression, and nonlinear aberration compensation necessitating a unique set of commissioning and operational procedures. Additionally, a novel technique to initiate lasing is described. To meet these constraints and accommodate a challenging installation schedule, we adopted a staged commissioning plan with alternating installation and operation periods. This report addresses these issues and presents operational results from on-going beam operations.

  4. JLAMP: AN AMPLIFIER-BASED FEL IN THE JLAB SRF ERL DRIVER

    SciTech Connect

    Kevin Jordan; Stephen V. Benson; David Douglas; Pavel Evtushenko; Carlos Hernandez-Garcia; George R. Neil

    2007-06-13

    Notional designs for energy-recovering linac (“ERL”) -driven high average power free electron lasers (“FEL”s) often invoke amplifier-based architectures. To date, however, amplifier FELs have been limited in average power output to values several orders of magnitude lower than those demonstrated in optical-resonator based systems; this is due at least in part to the limited electron beam powers available from their driver accelerators. In order to directly contrast the performance available from amplifiers to that provided by high-power cavity-based resonators, we have developed a scheme to test an amplifier FEL in the JLab SRF ERL driver. We describe an accelerator system design that can seamlessly and non-invasively integrate a 10 m wiggler into the existing system and which provides, at least in principle, performance that would support high-efficiency lasing in an amplifier configuration. Details of the design and an accelerator performance analysis will be presented

  5. Towards a general theory of driver behaviour.

    PubMed

    Fuller, Ray

    2005-05-01

    Taylor [Taylor, D.H., 1964. Drivers' galvanic skin response and the risk of accident. Ergonomics 7, 439-451] argued that drivers attempt to maintain a constant level of anxiety when driving which Wilde [Wilde, G.J.S., 1982. The theory of risk homeostasis: implications for safety and health. Risk Anal. 2, 209-225] interpreted to be coupled to subjective estimates of the probability of collision. This theoretical paper argues that what drivers attempt to maintain is a level of task difficulty. Naatanen and Summala [Naatanen, R., Summala, H., 1976. Road User Behaviour and Traffic Accidents. North Holland/Elsevier, Amsterdam, New York] similarly rejected the concept of statistical risk as a determinant of driver behaviour, but in so doing fell back on the learning process to generate a largely automatised selection of appropriate safety margins. However it is argued here that driver behaviour cannot be acquired and executed principally in such S-R terms. The concept of task difficulty is elaborated within the framework of the task-capability interface (TCI) model, which describes the dynamic interaction between the determinants of task demand and driver capability. It is this interaction which produces different levels of task difficulty. Implications of the model are discussed regarding variation in performance, resource allocation, hierarchical decision-making and the interdependence of demand and capability. Task difficulty homeostasis is proposed as a key sub-goal in driving and speed choice is argued to be the primary solution to the problem of keeping task difficulty within selected boundaries. The relationship between task difficulty and mental workload and calibration is clarified. Evidence is cited in support of the TCI model, which clearly distinguishes task difficulty from estimates of statistical risk. However, contrary to expectation, ratings of perceived risk depart from ratings of statistical risk but track difficulty ratings almost perfectly. It now

  6. 77 FR 12361 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications; Vision... Federal vision standard applicable to interstate truck and bus drivers and the reasons for the denials. FMCSA has statutory authority to exempt individuals from the vision requirement if the...

  7. 75 FR 22175 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-27

    ... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications; Vision... Federal vision standard applicable to interstate truck and bus drivers and the reasons for the denials. FMCSA has statutory authority to exempt individuals from the vision requirement if the...

  8. 76 FR 25763 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications; Vision... Federal vision standard applicable to interstate truck and bus drivers and the reasons for the denials. FMCSA has statutory authority to exempt individuals from the vision requirement if the...

  9. 78 FR 76394 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications; Vision... Federal vision standard applicable to interstate truck and bus drivers and the reasons for the denials. FMCSA has statutory authority to exempt individuals from the vision requirement if the...

  10. A UNIX device driver for a Translink II Transputer board

    SciTech Connect

    Wiley, J.C.

    1991-01-01

    A UNIX device driver for a TransLink II Transputer board is described. A complete listing of the code is presented. The device driver allows a transputer array to be used with the A/UX operating system.

  11. 78 FR 63295 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... individuals for exemptions from the prohibition against persons with insulin- treated diabetes mellitus (ITDM... individual assessment of drivers with diabetes mellitus, and be consistent with the criteria described in... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications;...

  12. 78 FR 63280 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... exemptions from the prohibition against persons with insulin- treated diabetes mellitus (ITDM) operating... drivers with diabetes mellitus, and be consistent with the criteria described in section 4018 of the... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications;...

  13. 78 FR 63298 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... individuals for exemptions from the prohibition against persons with insulin- treated diabetes mellitus (ITDM... must provide for individual assessment of drivers with diabetes mellitus, and be consistent with the... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications;...

  14. Cardiovascular Risk Factors of Taxi Drivers.

    PubMed

    Elshatarat, Rami Azmi; Burgel, Barbara J

    2016-06-01

    In the United States (U.S.), cardiovascular disease (CVD) is a major leading cause of death. Despite the high mortality rate related to CVD, little is known about CVD risk factors among urban taxi drivers in the U.S. A cross-sectional design was used to identify the predictors of high cardiovascular risk factors among taxi drivers. Convenience sampling method was used to recruit 130 taxi drivers. A structured questionnaire was used to obtain the data. The sample was male (94 %), age mean (45 ± 10.75) years, married (54 %), born outside of the USA (55 %), had some college or below (61.5 %), night drivers (50.8 %), and driving on average 9.7 years and 41 h/week. About 79 % of them were eligible for CVD prevention, and 35.4 % had high CVD risk factors (4-9 risk factors). A CVD high-risk profile had a significant relationship with the subjects who were ≥55 years old; had hypertension, diabetes, or hyperlipidemia; were drinking alcohol ≥2 times/week; and had insufficient physical activity. Subjects who worked as a taxi driver for more than 10 years (OR 4.37; 95 % CI 1.82, 10.50) and had mental exertion from cab driving >5 out of 10 (OR 2.63; 95 % CI 1.05, 6.57) were more likely to have a CVD high-risk profile. As a conclusion, system-level or worksite interventions include offering healthy food at taxi dispatching locations, creating a work culture of frequent walking breaks, and interventions focusing on smoking, physical activity, and weight management. Improving health insurance coverage for this group of workers is recommended. PMID:27151321

  15. Aggregate driver model to enable predictable behaviour

    NASA Astrophysics Data System (ADS)

    Chowdhury, A.; Chakravarty, T.; Banerjee, T.; Balamuralidhar, P.

    2015-09-01

    The categorization of driving styles, particularly in terms of aggressiveness and skill is an emerging area of interest under the broader theme of intelligent transportation. There are two possible discriminatory techniques that can be applied for such categorization; a microscale (event based) model and a macro-scale (aggregate) model. It is believed that an aggregate model will reveal many interesting aspects of human-machine interaction; for example, we may be able to understand the propensities of individuals to carry out a given task over longer periods of time. A useful driver model may include the adaptive capability of the human driver, aggregated as the individual propensity to control speed/acceleration. Towards that objective, we carried out experiments by deploying smartphone based application to be used for data collection by a group of drivers. Data is primarily being collected from GPS measurements including position & speed on a second-by-second basis, for a number of trips over a two months period. Analysing the data set, aggregate models for individual drivers were created and their natural aggressiveness were deduced. In this paper, we present the initial results for 12 drivers. It is shown that the higher order moments of the acceleration profile is an important parameter and identifier of journey quality. It is also observed that the Kurtosis of the acceleration profiles stores major information about the driving styles. Such an observation leads to two different ranking systems based on acceleration data. Such driving behaviour models can be integrated with vehicle and road model and used to generate behavioural model for real traffic scenario.

  16. Older Emergency Department Drivers: Patterns, Behaviors, and Willingness to Enroll in a Safe Driver Program

    PubMed Central

    Stiffler, Kirk A.; Wilber, Scott T.

    2011-01-01

    Objective: Our objective was to assess the reported driving patterns of older emergency department (ED) drivers and the factors that might lead them to enroll in a safe driving program. Methods: We conducted a prospective, cross-sectional survey of a convenience sample of ED patients 65-years-old and up regarding their driving patterns, behaviors and willingness to enroll in a safe driving program. Results: We surveyed 138 patients. Most (73%) reported driving within the last year, and 88% of these believe they could not manage without driving. Eleven percent of ED older drivers have been in a motor vehicle crash (MVC) in the past year (95% CI 6–20%), compared to 2.5% of all seniors. Our survey findings suggest that 88% of older ED drivers avoid at least some high-risk driving situations and 65% are unwilling to enroll in a safe driver program unless it lowers their automobile insurance rates. At the same time, most older ED drivers underestimate their risk of being involved in (75%) or dying from (74%) a MVC. Conclusion: Overall, there are a significant number of older people for whom driving remains a vital yet risky daily function. Most of these drivers have little interest in information regarding safe driving programs while in the ED. Those willing to learn about such programs would prefer to take home the information regarding the program rather than have any staff member discuss it while in the ED. PMID:21691472

  17. Recent U.S. advances in ion-beam-driven high energy densityphysics and heavy ion fusion

    SciTech Connect

    Logan, B.G.; Bieniosek, F.M.; Celata, C.M.; Coleman, J.; Greenway, W.; Henestroza, E.; Kwan, J.W.; Lee, E.P.; Leitner, M.; Roy,P.K.; Seidl, P.A.; Vay, J-L.; Waldron, W.L.; Yu, S.S.; Barnard, J.J.; Cohen, R.H.; Friedman, A.; Grote, D.P.; Kireeff Covo, M.; Molvik, A.W.; Lund, S.M.; Meier, W.R.; Sharp, W.; Davidson, R.C.; Efthimion, P.C.; Gilson, E.P.; Grisham, L.; Kaganovich, Qin H.; Sefkow, A.B.; Startsev,E.A.; Welch, D.; Olson, C.

    2006-07-05

    During the past two years, significant experimental and theoretical progress has been made in the US heavy ion fusion science program in longitudinal beam compression, ion-beam-driven warm dense matter, beam acceleration, high brightness beam transport; and advanced theory and numerical simulations. Innovations in longitudinal compression of intense ion beams by > 50 X propagating through background plasma enable initial beam target experiments in warm dense matter to begin within the next two years. They are assessing how these new techniques might apply to heavy ion fusion drivers for inertial fusion energy.

  18. Highway Safety Program Manual: Volume 4: Driver Education:

    ERIC Educational Resources Information Center

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

    Volume 4 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on driver education. The purpose and specific objectives of the driver education program and general policies regarding driver education derived from the Federal standard are described.…

  19. Highway Safety Program Manual: Volume 5: Driver Licensing.

    ERIC Educational Resources Information Center

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

    Volume 5 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on driver licensing. The purpose and specific objectives of the driver licensing program are outlined. Federal authority in the area of driver licensing and general policies of a licensing…

  20. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Driver and bus monitor training. 1310.17 Section... START PROGRAM HEAD START TRANSPORTATION Transportation Requirements § 1310.17 Driver and bus monitor... records as necessary. (c) Drivers must also receive instruction on the topics listed in 45 CFR...

  1. 49 CFR 391.53 - Driver investigation history file.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver...

  2. 49 CFR 391.53 - Driver investigation history file.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver...

  3. 49 CFR 391.53 - Driver investigation history file.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver...

  4. 49 CFR 391.53 - Driver investigation history file.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver...

  5. 49 CFR 383.23 - Commercial driver's license.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Commercial driver's license. 383.23 Section 383.23... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS COMMERCIAL DRIVER'S LICENSE STANDARDS; REQUIREMENTS AND PENALTIES Single License Requirement § 383.23 Commercial driver's license....

  6. Truck Safety. Information on Driver Training. Report to Congressional Requesters.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. Resources, Community, and Economic Development Div.

    The General Accounting Office examined the types of training available for tractor-trailer drivers, focusing on the Federal Highway Administration's (FHWA's) efforts to establish minimum federal standards for training tractor-trailer drivers, the driver training curriculum offered by various private and public schools, and the trucking industry's…

  7. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER...—bus and driver. Each bus and driver providing service shall be identified in a manner visible...

  8. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER...—bus and driver. Each bus and driver providing service shall be identified in a manner visible...

  9. 49 CFR 395.8 - Driver's record of duty status.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 3:30 p.m. at which time the driver started driving again. Upon arrival at Cherry Hill, New Jersey... driver resumed driving again. At 7 p.m. the driver arrived at the company's terminal in Newark, New... this section may be combined with any company forms. The previously approved format of the Daily...

  10. Texas Driver and Traffic Safety Education Teacher Preparation Guide.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin. Div. of Curriculum Development.

    This guide contains detailed descriptions of four university courses designed to give basic driver and traffic safety education preparation to prospective driver education teachers. The basic courses are as follows: Safety Education (general safety education concepts with emphasis on nontraffic areas); Driver and Traffic Safety Education I…

  11. Tips on Car Care & Safety for Deaf Drivers.

    ERIC Educational Resources Information Center

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

    Primarily intended for the deaf or hard of hearing driver, this booklet contains many tips useful to all drivers. It is divided into two sections: Signs of Car Trouble and What to Do, and Safe Driving Tips and Special Situations. The rationale for section 1 is that a hearing driver can often tell that his car is not running properly or that some…

  12. Teenaged Drivers and Fatal Crash Responsibility. Preliminary Report.

    ERIC Educational Resources Information Center

    Williams, Allan F.; Karpf, Ronald S.

    According to data obtained for the year 1978 from the Fatal Accident Reporting System (FARS) and from state governments under contract to the National Highway Traffic Safety Administration, teenaged drivers (especially males) have much higher rates of fatal crash involvement than older drivers. In addition, teenaged drivers are more likely than…

  13. Cooperative Driver Education Manual for the High School EMR Student.

    ERIC Educational Resources Information Center

    Kenel, Francis C., Ed.; Krueger, Emily A., Ed.

    The manual covers high school driver education for the educable mentally retarded (EMR) student. Guidelines are given for an instructional program offered prior to enrollment in a regular driver education course, to familiarize EMR students with the general content areas. The driving task is analyzed and general objectives for driver education…

  14. The effects of driver training on simulated driving performance.

    PubMed

    Dorn, Lisa; Barker, David

    2005-01-01

    Given that the beneficial effects of driver training on accident risk may not be an appropriate criterion measure, this study investigates whether professionally trained and experienced drivers exhibit safer driving behaviour in a simulated driving task compared with drivers without professional driver training. A sample of 54 police trained drivers and a sample of 56 non-police trained drivers were required to complete two tasks. Firstly to overtake a slow-moving bus on a hazardous stretch of single-lane road with bends and hills and secondly to follow a lead vehicle travelling at 55mph in a built-up section with a speed limit of 30mph. Results showed that in comparison with non-police trained drivers, police drivers were significantly less likely to cross the central division of the road at unsafe locations during the overtaking task and reduced their speed on approach to pedestrians at the roadside in the following task to a greater extent. Police drivers also adopted a more central lane position compared with non-police trained drivers on urban roads and at traffic lights during the following task. Driver group differences in simulated driving performance are discussed with reference to the implications for driver training assessment and skill development. PMID:15607276

  15. 49 CFR 383.23 - Commercial driver's license.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Commercial driver's license. 383.23 Section 383.23... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS COMMERCIAL DRIVER'S LICENSE STANDARDS; REQUIREMENTS AND PENALTIES Single License Requirement § 383.23 Commercial driver's license....

  16. Beam geometry selection using sequential beam addition

    SciTech Connect

    Popple, Richard A. Brezovich, Ivan A.; Fiveash, John B.

    2014-05-15

    Purpose: The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. Methods: The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. Results: In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. Conclusions: For situations in which beam geometry has a significant effect on the objective function, SBA can identify

  17. An analysis of grazing incidence metal mirrors in a laser ICF reactor driver

    SciTech Connect

    Bieri, R.; Guinan, M.

    1991-07-12

    Grazing incidence metal mirrors (GIMMs) are examined to replace dielectric mirrors for the final elements in a laser beam line for an inertial confinement fusion reactor. For a laser driver with a wavelength from 250 to 500 nm in a 10-ms pulse, irradiated mirrors made of Al, Al alloys, or Mg were found to have calculated laser damage limits of 0.3--2.3 J/cm{sup 2} of beam energy and neutron lifetime fluence limits of over 5 {times} 10{sup 20} 14 MeV n/cm{sup 2} when used at grazing incidence and operated at room temperature or at 77 K. A final focusing system including mirrors made of Al alloy 7475 at room temperature or at liquid nitrogen temperatures used with a driver which delivers 5 MJ of beam energy in 32 beams would require 32 mirrors of roughly 10 m{sup 2} each. This chapter includes calculations of damage limits for GIMMs and discusses critical issues relevant to the integrity and lifetime of such mirrors in a reactor environment. The reflectivities of various metals are calculated from measured optical constants at room temperature and at cryogenic temperatures for 250- to 500-nm light at both normal and grazing incidence. Then, for the mirrors in a representative system, the thermal absorption and conduction rates of the best candidate metals are used with the maximum allowable cyclic thermal stress to give the maximum allowed surface-temperature rise and surface thermal load. The allowed surface thermal load and surface reflectivity give the maximum beam energy density and the minimum size for each mirror. For mirrors made of aluminum alloy 7475 and initially operated at room temperature, the resulting optical damage threshold and allowable temperature rise give a required mirror size for each final mirror. Critical issues relevant to the integrity and lifetime of such mirrors in a reactor environment are briefly discussed.

  18. Beam-Bem interactions

    SciTech Connect

    Kim, Hyung Jin; /Fermilab

    2011-12-01

    In high energy storage-ring colliders, the nonlinear effect arising from beam-beam interactions is a major source that leads to the emittance growth, the reduction of beam life time, and limits the collider luminosity. In this paper, two models of beam-beam interactions are introduced, which are weak-strong and strong-strong beam-beam interactions. In addition, space-charge model is introduced.

  19. Design study of low-energy beam transport for multi-charge beams at RAON

    NASA Astrophysics Data System (ADS)

    Bahng, Jungbae; Qiang, Ji; Kim, Eun-San

    2015-12-01

    The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

  20. Occupational Fatalities Among Driver/Sales Workers and Truck Drivers in the United States, 2003–2008

    PubMed Central

    Chen, Guang X.; Amandus, Harlan E.; Wu, Nan

    2015-01-01

    Background This study provides a national profile of occupational fatalities among truck drivers and driver-sales workers. Methods Data from the 2003–2008 Census of Fatal Occupational Injuries were used. Cases were extracted specifically for occupational subcategories included in the Driver/Sales Workers and Truck Drivers occupational category: Driver/Sales Workers, Heavy and Tractor-Trailer Truck Drivers, and Light Truck or Delivery Services Drivers. Results In 2003–2008, the group Driver/Sales Workers and Truck Drivers had 5,568 occupational fatalities, representing 17% of all occupational fatalities in the United States. The majority of these fatalities were in the subgroup Heavy and Tractor-Trailer Truck Drivers (85%) and due to transportation incidents (80%). Older and male drivers had higher fatality rates than their counterparts. Conclusions Findings suggest a need for targeted interventions to reduce highway fatalities among heavy truck drivers. Better employment data are needed to separate the three occupational subcategories by worker characteristic and employment history for use in research and prevention efforts. PMID:24811905

  1. Flow processes in electric discharge drivers

    NASA Technical Reports Server (NTRS)

    Baganoff, D.

    1975-01-01

    The performance of an electric discharge shock tube is discussed from the point of view that the conditions at the sonic station are the primary controlling variables (likewise in comparing designs), and that the analysis of the flow on either side of the sonic station should be done separately. The importance of considering mass-flow rate in matching a given driver design to the downstream flow required for a particular shock-wave speed is stressed. It is shown that a driver based on the principle of liquid injection (of H2) is superior to one based on the Ludwieg tube, because of the greater mass-flow rate and the absence of a massive diaphragm.

  2. Schedule tightness among tractor-trailer drivers.

    PubMed

    Beilock, Richard

    2003-06-01

    The extent to which schedules are sufficiently tight to encourage violations of Hours-of-Service Regulations, speed limits, or both was investigated through a survey of over 1,600 tractor-trailer drivers. The focus was on drivers with refrigerated trailers. The results indicate high incidence levels of tight schedules. For example, assuming average speed limits of 65 mph, 24% had violation-inducing schedules with regard to the movement they were making at the time of the interviews. Incorporating information about previous driving, the incidence of violation-inducing schedules rose to 40%. Comparison with an earlier study suggests that, despite increases in speed limits which would tend to loosen schedules, schedules have become tighter over the past decade. The implications of these findings for reforms of Hours-of-Service Regulations are briefly discussed.

  3. Data Fusion for Driver Behaviour Analysis

    PubMed Central

    Carmona, Juan; García, Fernando; Martín, David; de la Escalera, Arturo; Armingol, José María

    2015-01-01

    A driver behaviour analysis tool is presented. The proposal offers a novel contribution based on low-cost hardware and advanced software capabilities based on data fusion. The device takes advantage of the information provided by the in-vehicle sensors using Controller Area Network Bus (CAN-BUS), an Inertial Measurement Unit (IMU) and a GPS. By fusing this information, the system can infer the behaviour of the driver, providing aggressive behaviour detection. By means of accurate GPS-based localization, the system is able to add context information, such as digital map information, speed limits, etc. Several parameters and signals are taken into account, both in the temporal and frequency domains, to provide real time behaviour detection. The system was tested in urban, interurban and highways scenarios. PMID:26473875

  4. Electromagnetic propulsion alternatives. [in mass drivers

    NASA Technical Reports Server (NTRS)

    Kolm, H.; Fine, K.; Mongeau, P.; Williams, F.

    1979-01-01

    Mass drivers can serve to propel massive objects by expelling any available material as reaction mass, however, mass driver engines have several limitations such as relatively large payload size and dynamic stability problems. A number of alternative acceleration mechanisms exist which offer advantages for certain applications, such as higher acceleration at a sacrifice in efficiency, smaller possible size and decreased complexity at a sacrifice in service life, etc. The alternative concepts include several variants of the railgun, a family of superconducting slingshot oscillators, a momentum transformer, an impulse induction motor, and a family of hybrid synchronous accelerators. A potential application of considerable interest is the earth-based launching of space cargo or nuclear waste by using off-peak generating capacity to accelerate one ton cargo cylinders at intervals of several minutes.

  5. Data fusion for driver behaviour analysis.

    PubMed

    Carmona, Juan; García, Fernando; Martín, David; Escalera, Arturo de la; Armingol, José María

    2015-10-14

    A driver behaviour analysis tool is presented. The proposal offers a novel contribution based on low-cost hardware and advanced software capabilities based on data fusion. The device takes advantage of the information provided by the in-vehicle sensors using Controller Area Network Bus (CAN-BUS), an Inertial Measurement Unit (IMU) and a GPS. By fusing this information, the system can infer the behaviour of the driver, providing aggressive behaviour detection. By means of accurate GPS-based localization, the system is able to add context information, such as digital map information, speed limits, etc. Several parameters and signals are taken into account, both in the temporal and frequency domains, to provide real time behaviour detection. The system was tested in urban, interurban and highways scenarios.

  6. Social capital, health, and elderly driver status.

    PubMed

    Isbel, Stephen T; Berry, Helen L

    2016-03-01

    Driving a car enables many people to engage in meaningful activities that, in turn, help develop and maintain personal social capital. Social capital, a combination of community participation and social cohesion, is important in maintaining well-being. This paper argues that social capital can provide a framework for investigating the general role of transportation and driving a car specifically to access activities that contribute to connectedness and well-being among older people. This paper proposes theoretically plausible and empirically testable hypotheses about the relationship between driver status, social capital, and well-being. A longitudinal study may provide a new way of understanding, and thus of addressing, the well-being challenges that occur when older people experience restrictions to, or loss of, their driver's license.

  7. Cell-intrinsic drivers of dendrite morphogenesis

    PubMed Central

    Puram, Sidharth V.; Bonni, Azad

    2013-01-01

    The proper formation and morphogenesis of dendrites is fundamental to the establishment of neural circuits in the brain. Following cell cycle exit and migration, neurons undergo organized stages of dendrite morphogenesis, which include dendritic arbor growth and elaboration followed by retraction and pruning. Although these developmental stages were characterized over a century ago, molecular regulators of dendrite morphogenesis have only recently been defined. In particular, studies in Drosophila and mammalian neurons have identified numerous cell-intrinsic drivers of dendrite morphogenesis that include transcriptional regulators, cytoskeletal and motor proteins, secretory and endocytic pathways, cell cycle-regulated ubiquitin ligases, and components of other signaling cascades. Here, we review cell-intrinsic drivers of dendrite patterning and discuss how the characterization of such crucial regulators advances our understanding of normal brain development and pathogenesis of diverse cognitive disorders. PMID:24255095

  8. Data fusion for driver behaviour analysis.

    PubMed

    Carmona, Juan; García, Fernando; Martín, David; Escalera, Arturo de la; Armingol, José María

    2015-01-01

    A driver behaviour analysis tool is presented. The proposal offers a novel contribution based on low-cost hardware and advanced software capabilities based on data fusion. The device takes advantage of the information provided by the in-vehicle sensors using Controller Area Network Bus (CAN-BUS), an Inertial Measurement Unit (IMU) and a GPS. By fusing this information, the system can infer the behaviour of the driver, providing aggressive behaviour detection. By means of accurate GPS-based localization, the system is able to add context information, such as digital map information, speed limits, etc. Several parameters and signals are taken into account, both in the temporal and frequency domains, to provide real time behaviour detection. The system was tested in urban, interurban and highways scenarios. PMID:26473875

  9. Social capital, health, and elderly driver status.

    PubMed

    Isbel, Stephen T; Berry, Helen L

    2016-03-01

    Driving a car enables many people to engage in meaningful activities that, in turn, help develop and maintain personal social capital. Social capital, a combination of community participation and social cohesion, is important in maintaining well-being. This paper argues that social capital can provide a framework for investigating the general role of transportation and driving a car specifically to access activities that contribute to connectedness and well-being among older people. This paper proposes theoretically plausible and empirically testable hypotheses about the relationship between driver status, social capital, and well-being. A longitudinal study may provide a new way of understanding, and thus of addressing, the well-being challenges that occur when older people experience restrictions to, or loss of, their driver's license. PMID:27505020

  10. Laser dazzling impacts on car driver performance

    NASA Astrophysics Data System (ADS)

    Steinvall, Ove; Sandberg, Stig; Hörberg, Ulf; Persson, Rolf; Berglund, Folke; Karslsson, Kjell; Öhgren, Johan; Yu, Zhaohua; Söderberg, Per

    2013-10-01

    A growing problem for the Police and Security Forces has been to prevent potentially hostile individuals to pass a checkpoint, without using lethatl violence. Therefore the question has been if there is a laser or any other strong light source that could be used as a warning and dazzling device, without lethal or long term effects. To investigate the possibilities a field trial has been performed at a motor-racing track. A green CW laser with an irradiance on the eye of maximum 0.5 MPE, as defined by ICNIRP [1] and the ANZI standard [2], was used as a dazzle source. Ten drivers have been driving with dipped headlights through a course of three lines with orange cones. In every line there has been only one gate wide enough to pass without hitting the cones. The time through the course, the choice of gates and the number of cones hit have been measured. For every second trial drive through the track, the driver was exposed to the laser dazzler. The background illuminances ranged from a thousand lux in daylight to about ten millilux in darkness. The protective effect of the sun-visor of the car was investigated. The drives visual system was carefully examined before and after experimental driving and a few weeks after the experimental driving to verify that no pathological effects, that could potentially be induced by the laser exposure, pre-existed or occurred after the laser exposure. An analysis of variance for a within subjects design has been used for evaluation. It was found that green laser light can have an obvious warning effect in daylight. Dazzling does reduce the drivers ability to make judgments and manouver the car in twilight and darkness. A sun-visor can reduce the glare and give the driver an improved control, but that perception can be unjustified. No damage to the visual system was observed.

  11. Voltage-Boosting Driver For Switching Regulator

    NASA Technical Reports Server (NTRS)

    Trump, Ronald C.

    1990-01-01

    Driver circuit assures availability of 10- to 15-V gate-to-source voltage needed to turn on n-channel metal oxide/semiconductor field-effect transistor (MOSFET) acting as switch in switching voltage regulator. Includes voltage-boosting circuit efficiently providing gate voltage 10 to 15 V above supply voltage. Contains no exotic parts and does not require additional power supply. Consists of NAND gate and dual voltage booster operating in conjunction with pulse-width modulator part of regulator.

  12. Drivers of chronic rhinosinusitis: Inflammation versus infection.

    PubMed

    Hamilos, Daniel L

    2015-12-01

    Studies of the underlying cause or causes of chronic rhinosinusitis (CRS) over the past 20 or more years have expanded from a focus on systemic immune and allergic mechanisms to an intense search for the underlying drivers of mucosal inflammation. These drivers involve mucosal inflammatory pathways that become activated by allergens, microbial stimuli, or poorly understood exogenous or endogenous stimuli. The holy grail in the study of CRS is to identify specific drivers of mucosal inflammation and translate these into more effective treatment for CRS. Certain deficiencies in local innate immunity have been described in patients with CRS that predispose to increased sinus mucosal bacterial colonization/infection, including deficient local production of antimicrobial lactoferrin and deficient functioning of the bitter taste receptor TAS2R38. Conversely, certain innate factors, namely IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), are elaborated by sinus epithelial cells in response to microbial stimulation or airway injury and promote local TH2 inflammation. The precise physiologic role of these factors in innate or adaptive immunity is unclear, although IL-33 might function as an alarmin triggered by damage-associated molecular patterns. The cytokines IL-25 and TSLP, similarly promote proinflammatory tissue responses. Another feature of epithelial dysregulation in patients with CRS is overproduction of eosinophil-promoting C-C chemokines by sinus epithelium, perhaps driven in part through innate stimuli, as well as TH2 cytokines, such as IL-13. Strategies to reduce the microbial stimulation of maladaptive TH2 inflammation or to suppress the local elaboration of TH2-promoting epithelial factors, such as IL-33, have potential therapeutic benefit in patients with CRS, although the extent to which this is realized in patient care remains limited at present. This rostrum will summarize my views on the major microbial drivers of mucosal inflammation and

  13. Enhanced tiredness among young impaired male nighttime drivers.

    PubMed

    Corfitsen, M T

    1996-03-01

    This study focuses on the incidence and amount of tiredness among young impaired male nighttime drivers during the hours between midnight and 6 a.m. One hundred and twenty impaired drivers, aged 18-30 years, with an average blood alcohol concentration of 1.54 g/l (range 0.81-2.99 g/l) are compared to 240 sober drivers of similar age stopped by the police in roadside surveys. A questionnaire shows that the increase in median awake period during the six observation hours is gradual and directly proportional to the time of the night for both groups, while the average awake period is significantly longer and that the average previous sleep period is significantly shorter for the impaired drivers. Self-assessment of tiredness shows 30 "rested," 68 "tired," and 22 "very tired" impaired drivers and 123 "rested," 105 "tired," and 12 "very tired" sober control drivers. This difference in level of "tiredness" is also significant. The questionnaire and the results of a simple visual reaction time test show individual differences for the drivers in both groups, but the difference in mean reaction time between the impaired drivers and the sober drivers is significant. Sub-division of the impaired drivers according to their self-assessed level of "tiredness" also shows significant differences in mean reaction time. The findings of the present study support the hypothesis that tiredness is an inherent and common accident risk factor among young male impaired drivers in nighttime traffic. PMID:8703273

  14. Older drivers' risks of at-fault motor vehicle collisions.

    PubMed

    Ichikawa, Masao; Nakahara, Shinji; Taniguchi, Ayako

    2015-08-01

    In aging societies, increasing numbers of older drivers are involved in motor vehicle collisions (MVCs), and preserving their safety is a growing concern. In this study, we focused on whether older drivers were more likely to cause MVCs and injuries than drivers in other age groups. To do so we compared at-fault MVC incidence and resulting injury risks by drivers' ages, using data from Japan, a country with a rapidly aging population. The at-fault MVC incidence was calculated based on distance traveled made for non-commercial purposes, and the injury risks posed to at-fault drivers and other road users per at-fault MVCs. We used MVC data for 2010 from the National Police Agency of Japan and driving exposure data from the Nationwide Person Trip Survey conducted by a Japanese governmental ministry in 2010. The at-fault MVC incidence showed a U-shaped curve across the drivers' ages, where teenage and the oldest drivers appeared to be the highest risk groups in terms of causing MVCs, and the incidence was higher for female drivers after age 25. The injury risk older drivers posed to other vehicle occupants because of their at-fault MVCs was lower than for drivers in other age groups, while their own injury risk appeared much higher. As the number of older drivers is increasing, efforts to reduce their at-fault MVCs appear justified.

  15. Driver steering model for closed-loop steering function analysis

    NASA Astrophysics Data System (ADS)

    Bolia, Pratiksh; Weiskircher, Thomas; Müller, Steffen

    2014-05-01

    In this paper, a two level preview driver steering control model for the use in numerical vehicle dynamics simulation is introduced. The proposed model is composed of cascaded control loops: The outer loop is the path following layer based on potential field framework. The inner loop tries to capture the driver's physical behaviour. The proposed driver model allows easy implementation of different driving situations to simulate a wide range of different driver types, moods and vehicle types. The expediency of the proposed driver model is shown with the help of developed driver steering assist (DSA) function integrated with a conventional series production (Electric Power steering System with rack assist servo unit) system. With the help of the DSA assist function, the driver is prevented from over saturating the front tyre forces and loss of stability and controllability during cornering. The simulation results show different driver reactions caused by the change in the parameters or properties of the proposed driver model if the DSA assist function is activated. Thus, the proposed driver model is useful for the advanced driver steering and vehicle stability assist function evaluation in the early stage of vehicle dynamics handling and stability evaluation.

  16. The Integrated Beam Experiment-- The Next Step for Heavy Ion Fusion

    NASA Astrophysics Data System (ADS)

    Celata, C. M.; Kwan, J. W.; Lee, E. P.; Leitner, M. A.; Logan, B. G.; Vay, J.-L.; Waldron, W. L.; Yu, S. S.; Barnard, J. J.; Cohen, R. H.; Friedman, A.; Grote, D. P.; Molvik, A. W.; Sharp, W. M.; Rose, D. V.; Welch, D. R.; Davidson, R. C.; Kaganovich, Igor D.; Qin, H.; Startsev, Edward A.

    2003-10-01

    The U.S. Heavy Ion Fusion Program is completing a 2-decade effort of small-scale experiments and analysis to explore the beam manipulations and non-neutral plasma physics of the intense beams necessary for a driver. The next step, a proof-of-principle experiment called the "Integrated Beam Experiment" (IBX) is in the design stage. It would integrate, for a single beam, all the beam physics from source to target, including beam production, acceleration, interaction with electrons and gas, compression, neutralization, and final focus. Present designs call for a K+ beam accelerated in an induction linac to 5-10 MeV. We present design studies, including PIC code studies of beam behavior.

  17. Parenting and the Young Driver Problem

    PubMed Central

    Simons-Morton, Bruce G.; Ouimet, Marie Claude; Catalano, Richard F.

    2008-01-01

    Crash rates increase sharply at the age teenagers begin to drive and remain elevated relative to adult levels well into the twenties. Parents have important roles to play in managing the risk for teenage drivers before and after licensure. Parents can be involved in their teenagers’ driving, allowing them to test for permit and licensure, supervising practice driving, providing access to a vehicle, and setting and enforcing limits on driving privileges after licensure. However, the management practices of many parents may not be sufficient to provide safety effects. The literature indicates that the two most important decisions parents can make to reduce teenagers driving risk is to delay licensure and impose limits on high-risk driving conditions (such as driving at night and with teenage passengers) during the first year of licensure. Two intervention programs have been shown to increase parent limit setting as a means of reducing risky driving behaviors and improving driving performance among novice teenage drivers. This article describes the contexts of and opportunities for parent involvement in teenage driving and the efficacy of interventions to increase and improve parental management of young drivers. PMID:18702985

  18. Driver behavior following an automatic steering intervention.

    PubMed

    Fricke, Nicola; Griesche, Stefan; Schieben, Anna; Hesse, Tobias; Baumann, Martin

    2015-10-01

    The study investigated driver behavior toward an automatic steering intervention of a collision mitigation system. Forty participants were tested in a driving simulator and confronted with an inevitable collision. They performed a naïve drive and afterwards a repeated exposure in which they were told to hold the steering wheel loosely. In a third drive they experienced a false alarm situation. Data on driving behavior, i.e. steering and braking behavior as well as subjective data was assessed in the scenarios. Results showed that most participants held on to the steering wheel strongly or counter-steered during the system intervention during the first encounter. Moreover, subjective data collected after the first drive showed that the majority of drivers was not aware of the system intervention. Data from the repeated drive in which participants were instructed to hold the steering wheel loosely, led to significantly more participants holding the steering wheel loosely and thus complying with the instruction. This study seems to imply that without knowledge and information of the system about an upcoming intervention, the most prevalent driving behavior is a strong reaction with the steering wheel similar to an automatic steering reflex which decreases the system's effectiveness. Results of the second drive show some potential for countermeasures, such as informing drivers shortly before a system intervention in order to prevent inhibiting reactions.

  19. Driver behavior following an automatic steering intervention.

    PubMed

    Fricke, Nicola; Griesche, Stefan; Schieben, Anna; Hesse, Tobias; Baumann, Martin

    2015-10-01

    The study investigated driver behavior toward an automatic steering intervention of a collision mitigation system. Forty participants were tested in a driving simulator and confronted with an inevitable collision. They performed a naïve drive and afterwards a repeated exposure in which they were told to hold the steering wheel loosely. In a third drive they experienced a false alarm situation. Data on driving behavior, i.e. steering and braking behavior as well as subjective data was assessed in the scenarios. Results showed that most participants held on to the steering wheel strongly or counter-steered during the system intervention during the first encounter. Moreover, subjective data collected after the first drive showed that the majority of drivers was not aware of the system intervention. Data from the repeated drive in which participants were instructed to hold the steering wheel loosely, led to significantly more participants holding the steering wheel loosely and thus complying with the instruction. This study seems to imply that without knowledge and information of the system about an upcoming intervention, the most prevalent driving behavior is a strong reaction with the steering wheel similar to an automatic steering reflex which decreases the system's effectiveness. Results of the second drive show some potential for countermeasures, such as informing drivers shortly before a system intervention in order to prevent inhibiting reactions. PMID:26310799

  20. A Landscape of Driver Mutations in Melanoma

    PubMed Central

    Hodis, Eran; Watson, Ian R.; Kryukov, Gregory V.; Arold, Stefan T.; Imielinski, Marcin; Theurillat, Jean-Philippe; Nickerson, Elizabeth; Auclair, Daniel; Li, Liren; Place, Chelsea; DiCara, Daniel; Ramos, Alex H.; Lawrence, Michael S.; Cibulskis, Kristian; Sivachenko, Andrey; Voet, Douglas; Saksena, Gordon; Stransky, Nicolas; Onofrio, Robert C.; Winckler, Wendy; Ardlie, Kristin; Wagle, Nikhil; Wargo, Jennifer; Chong, Kelly; Morton, Donald L.; Stemke-Hale, Katherine; Chen, Guo; Noble, Michael; Meyerson, Matthew; Ladbury, John E.; Davies, Michael A.; Gershenwald, Jeffrey E.; Wagner, Stephan N.; Hoon, Dave S.B.; Schadendorf, Dirk; Lander, Eric S.; Gabriel, Stacey B.; Getz, Gad; Garraway, Levi A.; Chin, Lynda

    2012-01-01

    SUMMARY Despite recent insights into melanoma genetics, systematic surveys for driver mutations are challenged by an abundance of passenger mutations caused by carcinogenic ultraviolet (UV) light exposure. We developed a permutation-based framework to address this challenge, employing mutation data from intronic sequences to control for passenger mutational load on a per gene basis. Analysis of large-scale melanoma exome data by this approach discovered six novel melanoma genes (PPP6C, RAC1, SNX31, TACC1, STK19 and ARID2), three of which - RAC1, PPP6C and STK19 - harbored recurrent and potentially targetable mutations. Integration with chromosomal copy number data contextualized the landscape of driver mutations, providing oncogenic insights in BRAF- and NRAS-driven melanoma as well as those without known NRAS/BRAF mutations. The landscape also clarified a mutational basis for RB and p53 pathway deregulation in this malignancy. Finally, the spectrum of driver mutations provided unequivocal genomic evidence for a direct mutagenic role of UV light in melanoma pathogenesis. PMID:22817889

  1. Design of a fast diaphragmless shock tube driver

    NASA Astrophysics Data System (ADS)

    Mejia-Alvarez, R.; Wilson, B.; Leftwich, M. C.; Martinez, A. A.; Prestridge, K. P.

    2015-11-01

    In this paper, we developed a one-dimensional compressible flow model to study the behavior of various diaphragmless drivers numerically. We determined that the diameter ratio, β d, for the discharge orifice of the back chamber controls driver actuation. Driver performance is optimized by accelerating the barrier element before breaching to minimize the opening time of the driver. Our new two-body driver outperforms various designs and exhibits opening times comparable to those of aluminum burst diaphragms. Experimental results verify the effectiveness of the new driver and show that it closely follows the pressure-Mach curve for the ideal case. Planar laser-induced fluorescence images and pressure traces confirm the consistent formation of shock waves about 41 diameters from the driver.

  2. Simple beam profile monitor

    SciTech Connect

    Gelbart, W.; Johnson, R. R.; Abeysekera, B.

    2012-12-19

    An inexpensive beam profile monitor is based on the well proven rotating wire method. The monitor can display beam position and shape in real time for particle beams of most energies and beam currents up to 200{mu}A. Beam shape, position cross-section and other parameters are displayed on a computer screen.

  3. Compact hadron driver for cancer therapies using continuous energy sweep scanning

    NASA Astrophysics Data System (ADS)

    Wah, Leo Kwee; Monma, Takumi; Adachi, Toshikazu; Kawakubo, Tadamichi; Dixit, Tanuja; Takayama, Ken

    2016-04-01

    A design of a compact hadron driver for future cancer therapies based on the induction synchrotron concept is presented. To realize a slow extraction technique in a fast-cycling synchrotron, which allows energy sweep beam scanning, a zero momentum-dispersion D (s ) region and a high flat D (s ) region are necessary. The proposed design meets both requirements. The lattice has two-fold symmetry with a circumference of 52.8 m, a 2-m dispersion-free straight section, and a 3-m-long large flat dispersion straight section. Assuming a 1.5-T bending magnet, the ring can deliver heavy ions (200 MeV /u ) at 10 Hz. A beam fraction is dropped from the barrier bucket at the desired timing, and the increasing negative momentum deviation of this beam fraction becomes large enough for the fraction to fall in the electrostatic septum extraction gap, which is placed at the large D (s ) region. The programmed energy sweep extraction enables scanning beam irradiation on a cancer site in depth without an energy degrader, avoiding the production of secondary particles and the degradation of emittance. Details of the lattice parameters and computer simulations for slow extraction are discussed. An example extraction scenario is presented. Qualities of the spilled beam such as emittance and momentum spread are discussed, as well as necessary functions and parameters required for the extraction system.

  4. A Thermal-beam Calcium Interferometer

    NASA Astrophysics Data System (ADS)

    Erickson, Christopher; van Zjill, Marshall; Washburn, Matthew; Archibald, James; Christensen, Dan; Birrell, Jeremiah; Burdett, Adam; Durfee, Dallin

    2007-06-01

    We report on the construction of a next-generation atom interferometer. Our research includes developing passive stabilization techniques, low-noise laser current drivers, high-speed scan-balancing lock circuits, and high-speed low-noise photo-detecting units. Our efforts have lead to developing an extremely stable laser locked to an ultra-high finesse optical cavity for use in a Ramsey-Bord'e interferometer scheme. The interferometer itself is based on a thermal calcium beam and will be upgraded in the future to a dual species Ca/Sr interferometer sensitive enough to improve measurements of possible time variance of the fine structure constant.

  5. Effectiveness evaluation of simulative workshops for newly licensed drivers.

    PubMed

    Rosenbloom, Tova; Eldror, Ehud

    2014-02-01

    The current study set to examine the effects of simulator use in driving instruction on newly licensed drivers, comparing the road safety knowledge and reported intended behavior, as well as the actual driving performance of new drivers. Participants consisted of 280 newly licensed driver, of which 140 whose drivers license training included additional simulator-based lessons, and 140 drivers whose training precluded simulator-based lessons. All drivers answered questionnaires pertaining to their intended safe driving behaviors (according to Ajzen's (2000) theory of planned behavior), and to their traffic safety knowledge. Of the initial sample, 40 drivers received actual driving performance evaluation by an expert driving instructor, as well as by in-vehicle data recorders (IVDRs). We assumed that safer drivers report safer driving intentions, demonstrate greater traffic safety knowledge, evaluated as safer drivers by the driving instructor, and display lower and stable driving parameters on the IVDRs. We hypothesized that theoretical driving studies combined with practical training on simulators will elevate the safety level of novices driving. Hierarchical regression analyses on driving intentions indicated that drivers who did not receive simulator-based lessons demonstrated safer driving intentions compared to drivers who received simulator-based lessons. This pattern possibly indicating the drivers who received simulator-based lessons felt more confident in their driving abilities compared to drivers who did not receive simulated training. No significant difference was found in traffic safety knowledge, or in the evaluation of the expert driving instructor. IDVR data comparisons indicated drivers who received simulator-based lessons braked more often and were less prone to headway events, suggesting a more responsive driving style. These findings do not point to any significant advantage or disadvantage of the current simulator-based driving training over

  6. Vision-based method for detecting driver drowsiness and distraction in driver monitoring system

    NASA Astrophysics Data System (ADS)

    Jo, Jaeik; Lee, Sung Joo; Jung, Ho Gi; Park, Kang Ryoung; Kim, Jaihie

    2011-12-01

    Most driver-monitoring systems have attempted to detect either driver drowsiness or distraction, although both factors should be considered for accident prevention. Therefore, we propose a new driver-monitoring method considering both factors. We make the following contributions. First, if the driver is looking ahead, drowsiness detection is performed; otherwise, distraction detection is performed. Thus, the computational cost and eye-detection error can be reduced. Second, we propose a new eye-detection algorithm that combines adaptive boosting, adaptive template matching, and blob detection with eye validation, thereby reducing the eye-detection error and processing time significantly, which is hardly achievable using a single method. Third, to enhance eye-detection accuracy, eye validation is applied after initial eye detection, using a support vector machine based on appearance features obtained by principal component analysis (PCA) and linear discriminant analysis (LDA). Fourth, we propose a novel eye state-detection algorithm that combines appearance features obtained using PCA and LDA, with statistical features such as the sparseness and kurtosis of the histogram from the horizontal edge image of the eye. Experimental results showed that the detection accuracies of the eye region and eye states were 99 and 97%, respectively. Both driver drowsiness and distraction were detected with a success rate of 98%.

  7. Testing a structural model of young driver willingness to uptake Smartphone Driver Support Systems.

    PubMed

    Kervick, Aoife A; Hogan, Michael J; O'Hora, Denis; Sarma, Kiran M

    2015-10-01

    There is growing interest in the potential value of using phone applications that can monitor driver behaviour (Smartphone Driver Support Systems, 'SDSSs') in mitigating risky driving by young people. However, their value in this regard will only be realised if young people are willing to use this technology. This paper reports the findings of a study in which a novel structural model of willingness to use SDSSs was tested. Grounded in the driver monitoring and Technology Acceptance (TA) research literature, the model incorporates the perceived risks and gains associated with potential SDSS usage and additional social cognitive factors, including perceived usability and social influences. A total of 333 smartphone users, aged 18-24, with full Irish driving licenses completed an online questionnaire examining willingness or Behavioural Intention (BI) to uptake a SDSS. Following exploratory and confirmatory factor analyses, structural equation modelling indicated that perceived gains and social influence factors had significant direct effects on BI. Perceived risks and social influence also had significant indirect effects on BI, as mediated by perceived gains. Overall, this model accounted for 72.5% of the variance in willingness to uptake SDSSs. Multi-group structural models highlighted invariance of effects across gender, high and low risk drivers, and those likely or unlikely to adopt novel phone app technologies. These findings have implications for our understanding of the willingness of young drivers to adopt and use SDSSs, and highlight potential factors that could be targeted in behavioural change interventions seeking to improve usage rates. PMID:26277411

  8. Testing a structural model of young driver willingness to uptake Smartphone Driver Support Systems.

    PubMed

    Kervick, Aoife A; Hogan, Michael J; O'Hora, Denis; Sarma, Kiran M

    2015-10-01

    There is growing interest in the potential value of using phone applications that can monitor driver behaviour (Smartphone Driver Support Systems, 'SDSSs') in mitigating risky driving by young people. However, their value in this regard will only be realised if young people are willing to use this technology. This paper reports the findings of a study in which a novel structural model of willingness to use SDSSs was tested. Grounded in the driver monitoring and Technology Acceptance (TA) research literature, the model incorporates the perceived risks and gains associated with potential SDSS usage and additional social cognitive factors, including perceived usability and social influences. A total of 333 smartphone users, aged 18-24, with full Irish driving licenses completed an online questionnaire examining willingness or Behavioural Intention (BI) to uptake a SDSS. Following exploratory and confirmatory factor analyses, structural equation modelling indicated that perceived gains and social influence factors had significant direct effects on BI. Perceived risks and social influence also had significant indirect effects on BI, as mediated by perceived gains. Overall, this model accounted for 72.5% of the variance in willingness to uptake SDSSs. Multi-group structural models highlighted invariance of effects across gender, high and low risk drivers, and those likely or unlikely to adopt novel phone app technologies. These findings have implications for our understanding of the willingness of young drivers to adopt and use SDSSs, and highlight potential factors that could be targeted in behavioural change interventions seeking to improve usage rates.

  9. Fusion of Optimized Indicators from Advanced Driver Assistance Systems (ADAS) for Driver Drowsiness Detection

    PubMed Central

    Daza, Iván G.; Bergasa, Luis M.; Bronte, Sebastián; Yebes, J. Javier; Almazán, Javier; Arroyo, Roberto

    2014-01-01

    This paper presents a non-intrusive approach for monitoring driver drowsiness using the fusion of several optimized indicators based on driver physical and driving performance measures, obtained from ADAS (Advanced Driver Assistant Systems) in simulated conditions. The paper is focused on real-time drowsiness detection technology rather than on long-term sleep/awake regulation prediction technology. We have developed our own vision system in order to obtain robust and optimized driver indicators able to be used in simulators and future real environments. These indicators are principally based on driver physical and driving performance skills. The fusion of several indicators, proposed in the literature, is evaluated using a neural network and a stochastic optimization method to obtain the best combination. We propose a new method for ground-truth generation based on a supervised Karolinska Sleepiness Scale (KSS). An extensive evaluation of indicators, derived from trials over a third generation simulator with several test subjects during different driving sessions, was performed. The main conclusions about the performance of single indicators and the best combinations of them are included, as well as the future works derived from this study. PMID:24412904

  10. Fusion of optimized indicators from Advanced Driver Assistance Systems (ADAS) for driver drowsiness detection.

    PubMed

    Daza, Iván García; Bergasa, Luis Miguel; Bronte, Sebastián; Yebes, Jose Javier; Almazán, Javier; Arroyo, Roberto

    2014-01-09

    This paper presents a non-intrusive approach for monitoring driver drowsiness using the fusion of several optimized indicators based on driver physical and driving performance measures, obtained from ADAS (Advanced Driver Assistant Systems) in simulated conditions. The paper is focused on real-time drowsiness detection technology rather than on long-term sleep/awake regulation prediction technology. We have developed our own vision system in order to obtain robust and optimized driver indicators able to be used in simulators and future real environments. These indicators are principally based on driver physical and driving performance skills. The fusion of several indicators, proposed in the literature, is evaluated using a neural network and a stochastic optimization method to obtain the best combination. We propose a new method for ground-truth generation based on a supervised Karolinska Sleepiness Scale (KSS). An extensive evaluation of indicators, derived from trials over a third generation simulator with several test subjects during different driving sessions, was performed. The main conclusions about the performance of single indicators and the best combinations of them are included, as well as the future works derived from this study.

  11. Multiple Electron Stripping of Heavy Ion Beams

    SciTech Connect

    D. Mueller; L. Grisham; I. Kaganovich; R. L. Watson; V. Horvat; K. E. Zaharakis; Y. Peng

    2002-06-25

    One approach being explored as a route to practical fusion energy uses heavy ion beams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ion beams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters.

  12. Laser beam monitoring system

    DOEpatents

    Weil, Bradley S.; Wetherington, Jr., Grady R.

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  13. Relativistic electron beam generator

    DOEpatents

    Mooney, L.J.; Hyatt, H.M.

    1975-11-11

    A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

  14. A learning-based autonomous driver: emulate human driver's intelligence in low-speed car following

    NASA Astrophysics Data System (ADS)

    Wei, Junqing; Dolan, John M.; Litkouhi, Bakhtiar

    2010-04-01

    In this paper, an offline learning mechanism based on the genetic algorithm is proposed for autonomous vehicles to emulate human driver behaviors. The autonomous driving ability is implemented based on a Prediction- and Cost function-Based algorithm (PCB). PCB is designed to emulate a human driver's decision process, which is modeled as traffic scenario prediction and evaluation. This paper focuses on using a learning algorithm to optimize PCB with very limited training data, so that PCB can have the ability to predict and evaluate traffic scenarios similarly to human drivers. 80 seconds of human driving data was collected in low-speed (< 30miles/h) car-following scenarios. In the low-speed car-following tests, PCB was able to perform more human-like carfollowing after learning. A more general 120 kilometer-long simulation showed that PCB performs robustly even in scenarios that are not part of the training set.

  15. Design and operation of the multiple-pulse driver line on the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Kosc, T. Z.; Kelly, J. H.; Hill, E. M.; Waxer, L. J.

    2016-05-01

    The multiple-pulse driver line (MPD) provides on-shot co-propagation of two separately generated pulse shapes in all 60 OMEGA beams at the Laboratory for Laser Energetics. Smoothing by spectral dispersion (SSD), which increases the laser bandwidth, can be applied to either one of the two pulse shapes, thereby enabling dynamic bandwidth reduction. The design of the MPD required careful consideration of beam combination as well as the minimum pulse separation for two pulses generated by two separate seed sources. A new combined-pulse-shape diagnostic needed to be designed and installed after the last SSD grating. The capability of MPD to reduce dynamic bandwidth has been used on a series of campaigns on OMEGA and the performance data are presented.

  16. Beam imaging sensor

    DOEpatents

    McAninch, Michael D.; Root, Jeffrey J.

    2016-07-05

    The present invention relates generally to the field of sensors for beam imaging and, in particular, to a new and useful beam imaging sensor for use in determining, for example, the power density distribution of a beam including, but not limited to, an electron beam or an ion beam. In one embodiment, the beam imaging sensor of the present invention comprises, among other items, a circumferential slit that is either circular, elliptical or polygonal in nature.

  17. NK Muon Beam

    SciTech Connect

    Koizumi, G.

    1988-09-28

    The NK Muon Beam will be a modified version of the existing NT beam line. The decision to employ a modified version of the NT beam line was made based on considerations of cost and availability of the beam line. Preliminary studies considered use of other beam lines, e.g., the NW beam line, and even of moving the bubble chamber with its superconducting coils but were rejected for reasons such as cost, personnel limitations, and potential conflicts with other users.

  18. Tunable beam displacer

    SciTech Connect

    Salazar-Serrano, Luis José; Valencia, Alejandra; Torres, Juan P.

    2015-03-15

    We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.

  19. Simulated driving performance under alcohol: effects on driver-risk versus driver-skill

    PubMed Central

    Laude, Jennifer R.; Fillmore, Mark T.

    2015-01-01

    Background Those who place their vehicles closer to others on the roadway are said to have high risk acceptance, and this contributes to motor vehicle crashes. However, the effect of alcohol on this risky driving behavior is understudied. Behavioral mechanisms that contribute to risky driving are also not well understood. Further, whether increased risk-taking behavior in a driver co-occurs with pronounced impairment in the driver’s skill is unknown. Methods The study examined the effect of alcohol on risk and skill-relevant driving and whether riskier drivers were also those who showed high skill impairment. The relationship between driving behavior and inhibitory control was also tested. Participants completed two driving simulations. In the first drive test, risky driving was encouraged and in the second test, skill-relevant driving was emphasized. The cued go/no-go task provided a measure inhibitory control. Tests were completed under a 0.65 g/kg alcohol and 0.0 g/kg (placebo) dose of alcohol. Results Alcohol impaired a measure of driving skill and increased driver risk taking. It was also found that riskier drivers were not necessarily those who showed the greatest impairments in skill. Poorer inhibitory control was associated with greater driver risk in the sober state. Conclusions Alcohol-induced risk-taking behaviors can be dissociable from impairing effects on driver skill and poor inhibitory control is selectively related to risky driving. As such, a distinction between skill and risk-related driving needs to be made in the investigation of problems concerning DUI-related accidents and fatalities in future research. PMID:26231663

  20. Space-Charge Waves and Instabilities in Intense Beams

    NASA Astrophysics Data System (ADS)

    Wang, J. G.

    1997-11-01

    Advancced accelerator applications, such as drivers for heavy ion inertial fusion, high-intensity synchrotrons for spallation neutron sources, high energy boosters, free electron lasers, high-power microwave generators, etc., require ever-increasing beam intensity. An important beam dynamics issue in such beams is the collective behavior of charged particles due to their space charge effects. This includes the phenomena of space-charge waves and instabilities excited on beams by external perturbations. It is very crucial to fully understand these phenomena in order to develop advanced accelerators for various applications. At the University of Maryland we have been conducting experimental programs to study space-charge waves and longitudinal instabilities by employing low-energy, high-current, space-charge dominated electron beams. Localized perturbations on the beams are generated from a gridded electron gun. In a conducting transport channel focused by short solenoids, these perturbations evolve into space-charge waves propagating on the beams. The wave speed is measured and many beam parameters are determined with this technique. The reflection of space-charge waves at the shoulder of an initially rectangular beam bunch is also observed. In a resistive-wall channel focused by a uniform long solenoid, the space-charge waves suffer longitudinal instability. The properties of the instabilities are studied in detail in the long wavelength range. In this talk we review our experimental results on the waves and instabilities and compare with theory.

  1. Using Shadow Page Cache to Improve Isolated Drivers Performance

    PubMed Central

    Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

    2015-01-01

    With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much. PMID:25815373

  2. Static Anthropometric Characteristics of Bangladeshi Vehicle Driver: A Case Study

    PubMed Central

    Sarker, E.

    2016-01-01

    Background. Inappropriate design of sitting furniture and working equipment causes the serious musculoskeletal injuries and various pains as well as reducing working efficiency. Uncomfortable sitting posture in prolonged driving in Bangladesh is an issue to be solved immediately. Therefore, anthropometric databank of user population is significantly essential for the suitable dimensional design for avoiding these remarkable problems. Methods. This study analyses the anthropometric data of the Bangladeshi male vehicle driver aged between 30 and 60 years. A total of 210 Bangladeshi healthy drivers are considered for 15 anthropometric measurements and compared with the similar anthropometrics of other nationalities. Results. The mean stature and sitting height erect of Bangladeshi driver are 1645 mm and 843 mm, respectively. The mean of body mass index (BMI) of the drivers is 26.09 kg/m2, which indicates that the drivers are overweight. The mean stature of Bangladeshi driver is 17 mm shorter than the driver of Korea and 115 mm shorter than the driver of Iran. Conclusion. There are substantial differences between the body dimensions of Bangladeshi driver and similar dimensions of other countries. In comparison, Bangladeshi driver is found to be the shortest compared with the sample of other nationalities. PMID:27579216

  3. Using shadow page cache to improve isolated drivers performance.

    PubMed

    Zheng, Hao; Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

    2015-01-01

    With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much. PMID:25815373

  4. Analysis of driver casualty risk for different work zone types.

    PubMed

    Weng, Jinxian; Meng, Qiang

    2011-09-01

    Using driver casualty data from the Fatality Analysis Report System, this study examines driver casualty risk and investigates the risk contributing factors in the construction, maintenance and utility work zones. The multiple t-tests results show that the driver casualty risk is statistically different depending on the work zone type. Moreover, construction work zones have the largest driver casualty risk, followed by maintenance and utility work zones. Three separate logistic regression models are developed to predict driver casualty risk for the three work zone types because of their unique features. Finally, the effects of risk factors on driver casualty risk for each work zone type are examined and compared. For all three work zone types, five significant risk factors including road alignment, truck involvement, most harmful event, vehicle age and notification time are associated with increased driver casualty risk while traffic control devices and restraint use are associated with reduced driver casualty risk. However, one finding is that three risk factors (light condition, gender and day of week) exhibit opposing effects on the driver casualty risk in different types of work zones. This may largely be due to different work zone features and driver behavior in different types of work zones.

  5. Static Anthropometric Characteristics of Bangladeshi Vehicle Driver: A Case Study.

    PubMed

    Halder, P K; Sarker, E

    2016-01-01

    Background. Inappropriate design of sitting furniture and working equipment causes the serious musculoskeletal injuries and various pains as well as reducing working efficiency. Uncomfortable sitting posture in prolonged driving in Bangladesh is an issue to be solved immediately. Therefore, anthropometric databank of user population is significantly essential for the suitable dimensional design for avoiding these remarkable problems. Methods. This study analyses the anthropometric data of the Bangladeshi male vehicle driver aged between 30 and 60 years. A total of 210 Bangladeshi healthy drivers are considered for 15 anthropometric measurements and compared with the similar anthropometrics of other nationalities. Results. The mean stature and sitting height erect of Bangladeshi driver are 1645 mm and 843 mm, respectively. The mean of body mass index (BMI) of the drivers is 26.09 kg/m(2), which indicates that the drivers are overweight. The mean stature of Bangladeshi driver is 17 mm shorter than the driver of Korea and 115 mm shorter than the driver of Iran. Conclusion. There are substantial differences between the body dimensions of Bangladeshi driver and similar dimensions of other countries. In comparison, Bangladeshi driver is found to be the shortest compared with the sample of other nationalities. PMID:27579216

  6. BEAM INSTRUMENTATION FOR HIGH POWER HADRON BEAMS

    SciTech Connect

    Aleksandrov, Alexander V

    2013-01-01

    This presentation will describe developments in the beam diagnostics which support the understanding and operation of high power hadron accelerators. These include the measurement of large dynamic range transverse and longitudinal beam profiles, beam loss detection, and non-interceptive diagnostics.

  7. Propagation-invariant beams with quantum pendulum spectra: from Bessel beams to Gaussian beam-beams.

    PubMed

    Dennis, Mark R; Ring, James D

    2013-09-01

    We describe a new class of propagation-invariant light beams with Fourier transform given by an eigenfunction of the quantum mechanical pendulum. These beams, whose spectra (restricted to a circle) are doubly periodic Mathieu functions in azimuth, depend on a field strength parameter. When the parameter is zero, pendulum beams are Bessel beams, and as the parameter approaches infinity, they resemble transversely propagating one-dimensional Gaussian wave packets (Gaussian beam-beams). Pendulum beams are the eigenfunctions of an operator that interpolates between the squared angular momentum operator and the linear momentum operator. The analysis reveals connections with Mathieu beams, and insight into the paraxial approximation.

  8. 55+ Drivers: Needs and Problems of Older Drivers: Survey Results and Recommendations. Proceedings of the Older Driver Colloquium (Orlando, Florida, February 4-7, 1985).

    ERIC Educational Resources Information Center

    Malfetti, James L., Ed.

    These proceedings include 11 background papers that were presented by a panel of authorities in traffic safety and/or gerontology who were professionally concerned with older drivers and pedestrians. Papers focus on the needs and problems of older drivers and on what can and should be done to deal with them. Recommendations to improve safety for…

  9. Preliminary result of rapid solenoid for controlling heavy-ion beam parameters of laser ion source

    DOE PAGES

    Okamura, M.; Sekine, M.; Ikeda, S.; Kanesue, T.; Kumaki, M.; Fuwa, Y.

    2015-03-13

    To realize a heavy ion inertial fusion driver, we have studied a possibility of laser ion source (LIS). A LIS can provide high current high brightness heavy ion beams, however it was difficult to manipulate the beam parameters. To overcome the issue, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The rapid ramping magnetic field could enhance limited time slice of the current and simultaneously the beam emittance changed accordingly. This approach may also useful to realize an ion source for HIF power plant.

  10. The fast beam condition monitor BCM1F backend electronics upgraded MicroTCA-based architecture

    NASA Astrophysics Data System (ADS)

    Zagozdzinska, Agnieszka A.; Bell, Alan; Dabrowski, Anne E.; Guthoff, Moritz; Hempel, Maria; Henschel, Hans; Karacheban, Olena; Lange, Wolfgang; Lohmann, Wolfgang; Lokhovitskiy, Arkady; Leonard, Jessica L.; Loos, Robert; Miraglia, Marco; Penno, Marek; Pozniak, Krzysztof T.; Przyborowski, Dominik; Stickland, David; Trapani, Pier Paolo; Romaniuk, Ryszard; Ryjov, Vladimir; Walsh, Roberval

    2014-11-01

    The Beam Radiation Instrumentation and Luminosity Project of the CMS experiment, consists of several beam monitoring systems. One system, the upgraded Fast Beams Condition Monitor, is based on 24 single crystal CVD diamonds with a double-pad sensor metallization and a custom designed readout. Signals for real-time monitoring are transmitted to the counting room, where they are received and processed by new back-end electronics designed to extract information on LHC collision, beam induced background and activation products. The Slow Control Driver is designed for the front-end electronics configuration and control. The system architecture and the upgrade status will be presented.

  11. INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS

    SciTech Connect

    Sharp, W. M.; Friedman, A.; Grote, D. P.; Barnard, J. J.; Cohen, R. H.; Dorf, M. A.; Lund, S. M.; Perkins, L. J.; Terry, M. R.; Logan, B. G.; Bieniosek, F. M.; Faltens, A.; Henestroza, E.; Jung, J. Y.; Kwan, J. W.; Lee, E. P.; Lidia, S. M.; Ni, P. A.; Reginato, L. L.; Roy, P. K.; Seidl, P. A.; Takakuwa, J. H.; Vay, J.-L.; Waldron, W. L.; Davidson, R. C.; Gilson, E. P.; Kaganovich, I. D.; Qin, H.; Startsev, E.; Haber, I.; Kishek, R. A.; Koniges, A. E.

    2011-03-31

    Intense heavy-ion beams have long been considered a promising driver option for inertial-fusion energy production. This paper briefly compares inertial confinement fusion (ICF) to the more-familiar magnetic-confinement approach and presents some advantages of using beams of heavy ions to drive ICF instead of lasers. Key design choices in heavy-ion fusion (HIF) facilities are discussed, particularly the type of accelerator. We then review experiments carried out at Lawrence Berkeley National Laboratory (LBNL) over the past thirty years to understand various aspects of HIF driver physics. A brief review follows of present HIF research in the US and abroad, focusing on a new facility, NDCX-II, being built at LBNL to study the physics of warm dense matter heated by ions, as well as aspects of HIF target physics. Future research directions are briefly summarized.

  12. Global drivers, sustainable manufacturing and systems ergonomics.

    PubMed

    Siemieniuch, C E; Sinclair, M A; Henshaw, M J deC

    2015-11-01

    This paper briefly explores the expected impact of the 'Global Drivers' (such as population demographics, food security; energy security; community security and safety), and the role of sustainability engineering in mitigating the potential effects of these Global Drivers. The message of the paper is that sustainability requires a significant input from Ergonomics/Human Factors, but the profession needs some expansion in its thinking in order to make this contribution. Creating a future sustainable world in which people experience an acceptable way of life will not happen without a large input from manufacturing industry into all the Global Drivers, both in delivering products that meet sustainability criteria (such as durability, reliability, minimised material requirement and low energy consumption), and in developing sustainable processes to deliver products for sustainability (such as minimum waste, minimum emissions and low energy consumption). Appropriate changes are already being implemented in manufacturing industry, including new business models, new jobs and new skills. Considerable high-level planning around the world is in progress and is bringing about these changes; for example, there is the US 'Advanced Manufacturing National Program' (AMNP)', the German 'Industrie 4.0' plan, the French plan 'la nouvelle France industrielle' and the UK Foresight publications on the 'Future of Manufacturing'. All of these activities recognise the central part that humans will continue to play in the new manufacturing paradigms; however, they do not discuss many of the issues that systems ergonomics professionals acknowledge. This paper discusses a number of these issues, highlighting the need for some new thinking and knowledge capture by systems ergonomics professionals. Among these are ethical issues, job content and skills issues. Towards the end, there is a summary of knowledge extensions considered necessary in order that systems ergonomists can be fully

  13. Muscle computer interfaces for driver distraction reduction.

    PubMed

    Khushaba, Rami N; Kodagoda, Sarath; Liu, Diaki; Dissanayake, Gamini

    2013-05-01

    Driver distraction is regarded as a significant contributor to motor-vehicle crashes. One of the important factors contributing to driver distraction was reported to be the handling and reaching of in-car electronic equipment and controls that usually requires taking the drivers' hands off the wheel and eyes off the road. To minimize the amount of such distraction, we present a new control scheme that senses and decodes the human muscles signals, denoted as Electromyogram (EMG), associated with different fingers postures/pressures, and map that to different commands to control external equipment, without taking hands off the wheel. To facilitate such a scheme, the most significant step is the extraction of a set of highly discriminative feature set that can well separate between the different EMG-based actions and to do so in a computationally efficient manner. In this paper, an accurate and efficient method based on Fuzzy Neighborhood Discriminant Analysis (FNDA), is proposed for discriminant feature extraction and then extended to the channel selection problem. Unlike existing methods, the objective of the proposed FNDA is to preserve the local geometrical and discriminant structures, while taking into account the contribution of the samples to the different classes. The method also aims to efficiently overcome the singularity problems of classical LDA by employing the QR-decomposition. Practical real-time experiments with eight EMG sensors attached on the human forearm of eight subjects indicated that up to fourteen classes of fingers postures/pressures can be classified with <7% error on average, proving the significance of the proposed method.

  14. An electromagnetic pneumatic blood pump driver.

    PubMed

    Whalen, R L; Briskman, R N

    1988-01-01

    An electromagnetic pneumatic pump driver has been developed with the goals of enhanced mechanical reliability and simplicity of operation. The new driver eliminates failure prone components such as solenoid valves or pressure regulators common to conventional pneumatic drive systems, has only a single moving part, and provides for closed-loop operation in which stroke volume and dP/dT are controlled on each beat in real time. Power is provided by a high force (178 N) electromagnetic linear actuator. This assembly uses a high energy density neodymium-iron-boron permanent magnet, low loss vanadium alloy pole pieces, and an energized moving coil. The nominal stroke length of the actuator is 1.7 cm. During operation, the moving coil always remains within a fixed annular air gap, resulting in a measured force output versus applied power linearity of better than 92% over its stroke range. The coil is directly attached to the free end of a 10 cm diameter, 21 convolution, welded titanium metal bellows that forms the gas containing element of the system. The comparatively low pressure gradients across the bellows in this application result in a predicted life for the bellows in excess of 10(9) cycles. Bellows position and internal pressure are monitored continuously to control the pneumatic output. The linear actuator total excursion and velocity are adjusted on each beat using a closed-loop servo system. This results in a pump driver with no operator required adjustment of drive pressure. Instead, there are user selected settings of stroke volume, operating mode, and fill sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Drivers for animal welfare policies in Europe.

    PubMed

    Dalla Villa, P; Matthews, L R; Alessandrini, B; Messori, S; Migliorati, G

    2014-04-01

    The European region has been, and remains, a global leader in the development of animal welfare policies. The region has a great diversity of cultures and religions, different levels of socio-economic development, and varied legislation, policies and practices. Nevertheless, there are common drivers for animal welfare policy based on a history of animal welfare ethics and obligations to animal users and society in general. A unifying goal of countries in the region is to achieve sustainable compliance with the World Organisation for Animal Health (OIE) standards on animal health and welfare. Ethics isthe overarching driver, supported by the actions of governmental, inter-governmental and non-governmental activities, markets and trade, science and knowledge. Historically, organisations involved in promoting animal welfare have tended to act in isolation. For example, non-governmental organisations (NGOs) have run campaigns to influence retailers and the welfare policies of their farmer suppliers. Increasingly, different organisations with common or complementary goals are working together. For example, competent authorities, inter-governmental bodies and NGOs have combined their efforts to address dog population control across several countries in the region. Also, animal welfare is becoming integrated into the corporate social responsibility targets of private companies. Science and knowledge, as drivers and tools, are assisting with the harmonisation of welfare standards, e.g. by providing a common basis for measuring welfare impacts through animal-based measures and widespread sharing of this information. Current trends suggest that there will be greater collaboration among the organisations driving change, and increasing convergence of animal welfare strategies and welfare assessment tools. The result will be increased harmonisation of animal welfare standards throughout the region. PMID:25000776

  16. Drivers for animal welfare policies in Europe.

    PubMed

    Dalla Villa, P; Matthews, L R; Alessandrini, B; Messori, S; Migliorati, G

    2014-04-01

    The European region has been, and remains, a global leader in the development of animal welfare policies. The region has a great diversity of cultures and religions, different levels of socio-economic development, and varied legislation, policies and practices. Nevertheless, there are common drivers for animal welfare policy based on a history of animal welfare ethics and obligations to animal users and society in general. A unifying goal of countries in the region is to achieve sustainable compliance with the World Organisation for Animal Health (OIE) standards on animal health and welfare. Ethics isthe overarching driver, supported by the actions of governmental, inter-governmental and non-governmental activities, markets and trade, science and knowledge. Historically, organisations involved in promoting animal welfare have tended to act in isolation. For example, non-governmental organisations (NGOs) have run campaigns to influence retailers and the welfare policies of their farmer suppliers. Increasingly, different organisations with common or complementary goals are working together. For example, competent authorities, inter-governmental bodies and NGOs have combined their efforts to address dog population control across several countries in the region. Also, animal welfare is becoming integrated into the corporate social responsibility targets of private companies. Science and knowledge, as drivers and tools, are assisting with the harmonisation of welfare standards, e.g. by providing a common basis for measuring welfare impacts through animal-based measures and widespread sharing of this information. Current trends suggest that there will be greater collaboration among the organisations driving change, and increasing convergence of animal welfare strategies and welfare assessment tools. The result will be increased harmonisation of animal welfare standards throughout the region.

  17. Global drivers, sustainable manufacturing and systems ergonomics.

    PubMed

    Siemieniuch, C E; Sinclair, M A; Henshaw, M J deC

    2015-11-01

    This paper briefly explores the expected impact of the 'Global Drivers' (such as population demographics, food security; energy security; community security and safety), and the role of sustainability engineering in mitigating the potential effects of these Global Drivers. The message of the paper is that sustainability requires a significant input from Ergonomics/Human Factors, but the profession needs some expansion in its thinking in order to make this contribution. Creating a future sustainable world in which people experience an acceptable way of life will not happen without a large input from manufacturing industry into all the Global Drivers, both in delivering products that meet sustainability criteria (such as durability, reliability, minimised material requirement and low energy consumption), and in developing sustainable processes to deliver products for sustainability (such as minimum waste, minimum emissions and low energy consumption). Appropriate changes are already being implemented in manufacturing industry, including new business models, new jobs and new skills. Considerable high-level planning around the world is in progress and is bringing about these changes; for example, there is the US 'Advanced Manufacturing National Program' (AMNP)', the German 'Industrie 4.0' plan, the French plan 'la nouvelle France industrielle' and the UK Foresight publications on the 'Future of Manufacturing'. All of these activities recognise the central part that humans will continue to play in the new manufacturing paradigms; however, they do not discuss many of the issues that systems ergonomics professionals acknowledge. This paper discusses a number of these issues, highlighting the need for some new thinking and knowledge capture by systems ergonomics professionals. Among these are ethical issues, job content and skills issues. Towards the end, there is a summary of knowledge extensions considered necessary in order that systems ergonomists can be fully

  18. How human drivers control their vehicle

    NASA Astrophysics Data System (ADS)

    Wagner, P.

    2006-08-01

    The data presented here show that human drivers apply a discrete noisy control mechanism to drive their vehicle. A car-following model built on these observations, together with some physical limitations (crash-freeness, acceleration), lead to non-Gaussian probability distributions in the speed difference and distance which are in good agreement with empirical data. All model parameters have a clear physical meaning and can be measured. Despite its apparent complexity, this model is simple to understand and might serve as a starting point to develop even quantitatively correct models.

  19. Antenna Beam Coverage Concepts

    NASA Technical Reports Server (NTRS)

    Estabrook, Polly; Motamedi, Masoud

    1990-01-01

    The strawman Personal Access Satellite System (PASS) design calls for the use of a CONUS beam for transmission between the supplier and the satellite and for fixed beams for transmission between the basic personal terminal and the satellite. The satellite uses a 3 m main reflector for transmission at 20 GHz and a 2 m main reflector for reception at 30 GHz. There are several types of spot beams under consideration for the PASS system besides fixed beams. The beam pattern of a CONUS coverage switched beam is shown along with that of a scanning beam. A switched beam refers to one in which the signal from the satellite is connected alternatively to various feed horns. Scanning beams are taken to mean beams whose footprints are moved between contiguous regions in the beam's coverage area. The advantages and disadvantages of switched and/or scanning beams relative to fixed beams. The consequences of using switched/scanning in lieu of fixed beams in the PASS design and attempts are made to evaluate the listed advantages and disadvantages. Two uses of switched/scanning beams are examined. To illustrate the implications of switched beams use on PASS system design, operation at two beam scan rates is explored.

  20. Driver linac design for a femtosecond head-on inverse Compton scatteringX-ray source

    NASA Astrophysics Data System (ADS)

    Huang, N. Y.; Lau, W. K.; Liang, C. C.; Lee, A. P.; Cheng, W. C.; Yang, S. S.

    2011-05-01

    The feasibility of generating an ultra-short relativistic electron beam with a thermionic cathode rf gun driver linac for a femtosecond head-on inverse Compton scattering (ICS) X-ray source has been examined by space charge tracking throughout the entire beamline, from the cathode to the interaction point. It has been determined that GHz-repetition-rate electron pulses as short as 49 fs can be produced by compressing the energy-chirped beam from a 2998-MHz, 1.5-cell rf gun with an alpha magnet and an rf linac operating at the injection phase near the zero crossing. These electron pulses, with a 42-pC bunch charge, are accelerated to 27 MeV with an S-band traveling-wave constant-gradient linac structure for the ICS in an interaction chamber located downstream. The driver linac design that allows the operation of an ultra-short ICS X-ray source at a 0.7-Å wavelength, with a peak photon flux of 9.08×1017 photons/s, is presented in this paper.

  1. Neutrino oscillations with a proton driver upgrade and an off-axis detector: A Case study

    SciTech Connect

    Barenboim, Gabriela; De Gouvea, Andre; Szleper, Michal; Velasco, Mayda

    2002-04-01

    We study the physics capabilities of the NuMI beamline with an off-axis highly-segmented iron scintillator detector and with the inclusion of the currently under study proton driver upgrade. We focus on the prospects for the experimental determination of the remaining neutrino oscillation parameters, assuming different outcomes for experiments under way or in preparation. An optimization of the beam conditions and detector location for the detection of the nu_mu to nu_e transitions is discussed. Different physics scenarios were considered, depending on the actual solution of the solar neutrino puzzle. If KamLAND measures Delta m^2_solar, we find it possible to measure both |U_{e3}|^2 and the CP violating phase delta within a viable exposure time, assuming a realistic detector and a complete data analysis. Exposure to both neutrino and antineutrino beams is necessary. We can, in addition, shed light on Delta m^2_solar if its value is at the upper limit of KamLAND sensitivity (i.e. the precise value of Delta m^2_solar remains unknown even after KamLAND). If the solar neutrino solution is not in the LMA region, we can measure |U_{e3}|^2 and determine the neutrino mass hierarchy. The existence of the proton driver is vital for the feasibility of most of these measurements.

  2. Design of Accumulator and Compressor Rings for the Project-X Based Proton Driver

    SciTech Connect

    Alexahin, Y.; Neuffer, D.; /Fermilab

    2012-05-01

    A Muon Collider (MC) and a Neutrino Factory (NF) - which may be considered as a step towards a MC - both require a high-power ({approx}4 MW) proton driver providing short (<1 m r.m.s. length) bunches for muon production. However, the driver repetition rates required for these two machines are different: {approx}15 Hz for MC and {approx}60 Hz for NF. This difference suggests employing two separate rings: one for accumulation of the proton beam from the Project-X linac in a few (e.g. 4) long bunches, the other for bunch compression - one by one for NF or all at a time for MC with simultaneous delivery to the target. The lattice requirements for these two rings are different: the momentum compaction factor in the accumulator ring should be large (and possibly negative) to avoid the microwave instability, while the compressor ring can be nearly isochronous in order to limit the required RF voltage and reduce the dispersion contribution to the beam size. In the present report we consider ring lattice designs which achieve these goals.

  3. High current, high bandwidth laser diode current driver

    NASA Technical Reports Server (NTRS)

    Copeland, David J.; Zimmerman, Robert K., Jr.

    1991-01-01

    A laser diode current driver has been developed for free space laser communications. The driver provides 300 mA peak modulation current and exhibits an optical risetime of less than 400 ps. The current and optical pulses are well behaved and show minimal ringing. The driver is well suited for QPPM modulation at data rates up to 440 Mbit/s. Much previous work has championed current steering circuits; in contrast, the present driver is a single-ended on/off switch. This results in twice the power efficiency as a current steering driver. The driver electrical efficiency for QPPM data is 34 percent. The high speed switch is realized with a Ku-band GaAsFET transistor, with a suitable pre-drive circuit, on a hybrid microcircuit adjacent to the laser diode.

  4. Health on the road: issues faced by female truck drivers.

    PubMed

    Reed, Deborah B; Cronin, Jennifer Skeeters

    2003-03-01

    Nearly 3 million long haul truck drivers transport goods across America. Truck driving is rated as the nation's third largest growth occupation. Between 174,000 and 290,000 drivers are women and the percentage of women in trucking is growing. A descriptive study was conducted to identify health conditions, health care access, and driving environments of female drivers. Analyses of the 284 surveys showed only 77.8% had a usual place of health care. One of five had no insurance coverage and only 35 respondents had paid sick leave. Drivers reported substantial prevalence of sinus problems, back pain, migraine headaches, and hypertension. Drivers ignored symptoms or self medicated when working. More than 40% expressed dissatisfaction with health care while "on the road." Occupational health nurses may be in positions to address the special needs of drivers through websites, trucker health clinics, or special programs delivered where truckers congregate. PMID:12670099

  5. Video surveillance for monitoring driver's fatigue and distraction

    NASA Astrophysics Data System (ADS)

    Jiménez-Moreno, R.; Orjuela, S. A.; Van Hese, P.; Prieto, F. A.; Grisales, V. H.; Philips, W.

    2012-06-01

    Fatigue and distraction effects in drivers represent a great risk for road safety. For both types of driver behavior problems, image analysis of eyes, mouth and head movements gives valuable information. We present in this paper a system for monitoring fatigue and distraction in drivers by evaluating their performance using image processing. We extract visual features related to nod, yawn, eye closure and opening, and mouth movements to detect fatigue as well as to identify diversion of attention from the road. We achieve an average of 98.3% and 98.8% in terms of sensitivity and specificity for detection of driver's fatigue, and 97.3% and 99.2% for detection of driver's distraction when evaluating four video sequences with different drivers.

  6. Improved gauge driver for the generalized harmonic Einstein system

    SciTech Connect

    Lindblom, Lee; Szilagyi, Bela

    2009-10-15

    A new gauge driver is introduced for the generalized harmonic (GH) representation of Einstein's equation. This new driver allows a rather general class of gauge conditions to be implemented in a way that maintains the hyperbolicity of the combined evolution system. This driver is more stable and effective and, unlike previous drivers, allows stable evolutions using the dual-frame evolution technique. Appropriate boundary conditions for this new gauge driver are constructed, and a new boundary condition for the 'gauge' components of the spacetime metric in the GH Einstein system is introduced. The stability and effectiveness of this new gauge driver are demonstrated through numerical tests, which impose a new damped-wave gauge condition on the evolutions of single black-hole spacetimes.

  7. Implications of HARP Results for the Energy of the Proton Driver for a Neutrino Factory and Muon Collider

    SciTech Connect

    Strait, J.; Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2010-06-09

    Cross-section data from the HARP experiment for pion production by protons from a tantalum target have been convoluted with the acceptance of the front-end channel for the proposed neutrino factory or muon collider and integrated over the full phase space measured by HARP, to determine the beam-energy dependence of the muon yield. This permits a determination of the optimal beam energy for the proton driver for these projects. The cross-section data are corrected for the beam-energy dependent 'amplification' due to the development of hadronic showers in a thick target. The conclusion is that, for constant beam power, the yield is maximum for a beam energy of about 7 GeV, but it is within 10% of this maximum for 4 < T{sub beam} < 11 GeV, and within 20% of the maximum for T{sub beam} as low as 2 GeV. This result is insensitive to which of the two HARP groups results are used, and to which pion generator is used to compute the thick target effects.

  8. Comorbidities and Crash Involvement among Younger and Older Drivers

    PubMed Central

    Papa, Michela; Boccardi, Virginia; Prestano, Raffaele; Angellotti, Edith; Desiderio, Manuela; Marano, Luigi; Rizzo, Maria Rosaria; Paolisso, Giuseppe

    2014-01-01

    Previous studies identified comorbidities as predictors of older driver performance and driving pattern, while the direct impact of comorbidities on road crash risk in elderly drivers is still unknown. The present study is a cross-sectional aimed at investigating the association between levels of comorbidity and crash involvement in adult and elderly drivers. 327 drivers were stratified according to age range in two groups: elderly drivers (age ≥70 years old, referred as older) and adult drivers (age <70 years old, referred as younger). Driving information was obtained through a driving questionnaire. Distance traveled was categorized into low, medium and high on the basis of kilometers driven in a year. CIRS-illness severity (IS) and CIRS-comorbidity indices (CI) in all populations were calculated. Older drivers had a significantly higher crash involvements rate (p = .045) compared with the younger group based on the number of licensed drivers. Dividing comorbidity indices into tertiles among all licensed subjects, the number of current drivers significantly decreased (p<.0001) with increasing level of comorbidity. The number of current drivers among older subjects significantly decreased with increasing comorbidity level (p = .026) while no difference among younger group was found (p = .462). Among younger drivers with increasing comorbidity level, the number of road accidents significantly increased (p = .048) and the logistic regression analysis showed that comorbidity level significantly associated with crash involvement independent of gender and driving exposure. Older subjects with high level of comorbidity are able to self-regulate driving while comorbidity burden represents a significant risk factor for crash involvements among younger drivers. PMID:24722619

  9. Advanced beam-dynamics simulation tools for RIA.

    SciTech Connect

    Garnett, R. W.; Wangler, T. P.; Billen, J. H.; Qiang, J.; Ryne, R.; Crandall, K. R.; Ostroumov, P.; York, R.; Zhao, Q.; Physics; LANL; LBNL; Tech Source; Michigan State Univ.

    2005-01-01

    We are developing multi-particle beam-dynamics simulation codes for RIA driver-linac simulations extending from the low-energy beam transport (LEBT) line to the end of the linac. These codes run on the NERSC parallel supercomputing platforms at LBNL, which allow us to run simulations with large numbers of macroparticles. The codes have the physics capabilities needed for RIA, including transport and acceleration of multiple-charge-state beams, beam-line elements such as high-voltage platforms within the linac, interdigital accelerating structures, charge-stripper foils, and capabilities for handling the effects of machine errors and other off-normal conditions. This year will mark the end of our project. In this paper we present the status of the work, describe some recent additions to the codes, and show some preliminary simulation results.

  10. Possibilities for Beam Stripping Solutions at a Rare Isotope Accelerator (RIA)

    SciTech Connect

    Greife, Uwe

    2006-08-29

    As part of the DOE RIA R&D effort we investigated the possibilities and problems of beam strippers in the different heavy ion accelerator components of a possible Rare Isotope Accelerator (RIA) facility. We focused on two beam stripping positions in the RIA heavy ion driver where benchmark currents of up to 5 particle μA 238-U were projected at energies of 10.5 MeV/u and 85 MeV/u respectively. In order to select feasible stripper materials, data from experiments with Uranium beams at Texas A&M and GSI were evaluated. Based on these results thermal estimates for a possible design were calculated and cooling simulations with commercially available software performed. Additionally, we performed simulations with the GEANT4 code on evaluating the radiation environment for our beam stripping solution at the 85 MeV/u position in the RIA driver.

  11. Current density compression of intense ion beams

    NASA Astrophysics Data System (ADS)

    Sefkow, Adam Bennett

    Current density compression of intense ion beams in space and time is required for heavy ion fusion, in order to achieve the necessary intensities to implode an inertial confinement fusion target. Longitudinal compression to high current in a short pulse is achieved by imposing a velocity tilt upon the space-charge-dominated charge bunch, and a variety of means exist for simultaneous transverse focusing to a coincident focal plane. Compression to the desired levels requires sufficient neutralization of the beam by a pre-formed plasma during final transport. The physics of current density compression is studied in scaled experiments relevant for the operating regime of a heavy ion driver, and related theory and advanced particle-in-cell simulations provide valuable insight into the physical and technological limitations involved. A fast Faraday cup measures longitudinal compression ratios greater than 50 with pulse durations less than 5 ns, in excellent agreement with reduced models and sophisticated simulations, which account for many experimental parameters and effects. The detailed physics of achieving current density compression in the laboratory is reviewed. Quantitative examples explore the dependency of longitudinal compression on effects such as the finite-size acceleration gap, voltage waveform accuracy, variation in initial beam temperature, pulse length, intended fractional velocity tilt, and energy uncertainty, as well as aberration within focusing elements and plasma neutralization processes. In addition, plasma evolution in experimental sources responsible for the degree of beam neutralization is studied numerically, since compression stagnation occurs under inadequate neutralization conditions, which may excite nonlinear collective excitations due to beam-plasma interactions. The design of simultaneous focusing experiments using both existing and upgraded hardware is provided, and parametric variations important for compression physics are

  12. Feasibility of a driver performance data acquisition system

    SciTech Connect

    Carter, R.J.; Spelt, P.F.; Goodman, M.J.

    1994-06-01

    The National Highway Traffic Safety Administration (NHTSA) envisions many future situations in which the effectiveness and consequences of new intelligent vehicle-highway systems technologies will need to be studied in actual production vehicles. Such studies will enable evaluations in vehicles which are familiar to drivers. These studies would be future enhanced by the availability of an instrumentation package that can be easily installed in these vehicles to enable specific vehicle configurations of interest to be evaluated, thereby increasing the variety of vehicle options that are available for study. Ideally, an approach is needed that would allow data collection from a variety of vehicle models and types, and would address the issue of driver familiarity. Such an approach is embodied in the concept of a driver performance data acquisition system that could be installed in a wide range of vehicles within a relatively short period of time. As a universally adaptable system, it would provide researchers with the ability to manually input data as well as directly record information on driver, vehicle, roadway, and environmental parameters. Furthermore, it would enable the measurement of driver performance in the driver`s own vehicle, thereby ensuring vehicle familiarity. In addition, it would be possible to measure driver performance in relation to any vehicle design characteristic at relatively little expense and effort, and would make it easy to update existing models of driver/vehicle behavior to reflect performance characteristics in vehicles of current manufacture.

  13. Improving drivers' knowledge of road rules using digital games.

    PubMed

    Li, Qing; Tay, Richard

    2014-04-01

    Although a proficient knowledge of the road rules is important to safe driving, many drivers do not retain the knowledge acquired after they have obtained their licenses. Hence, more innovative and appealing methods are needed to improve drivers' knowledge of the road rules. This study examines the effect of game based learning on drivers' knowledge acquisition and retention. We find that playing an entertaining game that is designed to impart knowledge of the road rules not only improves players' knowledge but also helps them retain such knowledge. Hence, learning by gaming appears to be a promising learning approach for driver education.

  14. Car drivers' perceptions of electronic stability control (ESC) systems.

    PubMed

    Vadeby, Anna; Wiklund, Mats; Forward, Sonja

    2011-05-01

    As a way to reduce the number of car crashes different in-car safety devices are being introduced. In this paper one such application is being investigated, namely the electronic stability control system (ESC). The study used a survey method, including 2000 private car drivers (1000 driving a car with ESC and 1000 driving a car without ESC). The main objective was to investigate the effect of ESC on driver behaviour. Results show that drivers report that they drive even more carelessly when they believe that they have ESC, than when they do not. Men are more risk prone than women and young drivers more than older drivers. Using the theory of planned behaviour the results show that attitude, subjective norm and perceived control explain between 62% and 67% of driver's variation of intentions to take risks. When descriptive norm was added to the model a small but statistically significant increase was found. The study also shows that more than 35% erroneously believe that their car is equipped with an ESC system. These findings may suggest that driver behaviour could reduce the positive effect ESC has on accidents. It also shows that drivers who purchase a new car are not well informed about what kind of safety devices the car is equipped with. These findings highlight the need for more targeted information to drivers.

  15. A multinomial choice model approach for dynamic driver vision transitions.

    PubMed

    Huang, Shih-Hsuan; Wong, Jinn-Tsai

    2015-01-01

    Exploring the continual process of drivers allocating their attention under varying conditions could be vital for preventing motor vehicle crashes. This study aims to model visual behaviors and to estimate the effects of various contributing factors on driver's vision transitions. A visual attention allocation framework, based on certain contributing attributes related to driving tasks and environmental conditions, has been developed. The associated logit type models for determining driver choices for focal points were successfully formulated and estimated by using naturalistic glance data from the 100-car event database. The results offer insights into driver visual behavior and patterns of visual attention allocation. The three focal points that drivers most frequently rely on and glance at are the forward, left and rear view mirror. The sample drivers were less likely to demonstrate troublesome transition patterns, particularly in mentally demanding situations. Additionally, instead of shifting vision directly between two non-forward focal points, the sample drivers frequently had an intermediate forward glance. Thus, seemingly unrelated paths could be grouped into explanatory patterns of driver attention allocation. Finally, in addition to the vision-transition patterns, the potential pitfalls of such patterns and possible countermeasures to improving safety are illustrated, focusing on situations when drivers are distracted, traveling at high speeds and approaching intersections.

  16. Car drivers' perceptions of electronic stability control (ESC) systems.

    PubMed

    Vadeby, Anna; Wiklund, Mats; Forward, Sonja

    2011-05-01

    As a way to reduce the number of car crashes different in-car safety devices are being introduced. In this paper one such application is being investigated, namely the electronic stability control system (ESC). The study used a survey method, including 2000 private car drivers (1000 driving a car with ESC and 1000 driving a car without ESC). The main objective was to investigate the effect of ESC on driver behaviour. Results show that drivers report that they drive even more carelessly when they believe that they have ESC, than when they do not. Men are more risk prone than women and young drivers more than older drivers. Using the theory of planned behaviour the results show that attitude, subjective norm and perceived control explain between 62% and 67% of driver's variation of intentions to take risks. When descriptive norm was added to the model a small but statistically significant increase was found. The study also shows that more than 35% erroneously believe that their car is equipped with an ESC system. These findings may suggest that driver behaviour could reduce the positive effect ESC has on accidents. It also shows that drivers who purchase a new car are not well informed about what kind of safety devices the car is equipped with. These findings highlight the need for more targeted information to drivers. PMID:21376858

  17. Telecommunication using muon beams

    DOEpatents

    Arnold, Richard C.

    1976-01-01

    Telecommunication is effected by generating a beam of mu mesons or muons, varying a property of the beam at a modulating rate to generate a modulated beam of muons, and detecting the information in the modulated beam at a remote location.

  18. Design of the SRF Driver ERL for the Jefferson Lab UV FEL

    SciTech Connect

    Douglas, David R; Benson, Stephen; Biallas, George; Blackburn, Keith; Boyce, James; Bullard, Donald; Coleman, James; Dickover, Cody; Ellingsworth, Forrest; Evtushenko, Pavel; Gould, Christopher; Gubeli, Joseph; Hannon, Fay; Hardy, David; Hernandez-Garcia, Carlos; Jordan, Kevin; Klopf, Michael; Kortze, James; Marchlik, Matthew; Moore, Steven; Neil, George; Powers, Thomas; Sexton, Daniel; Shinn, Michelle D; Tennant, Christopher; Walker, Richard; Wilson, Frederick; Zhang, Shukui

    2011-03-01

    We describe the design of the SRF Energy-Recovering Linac (ERL) providing the CW electron drive beam at the Jefferson Lab UV FEL. Based on the same 135 MeV linear accelerator as and sharing portions of the recirculator with the Jefferson Lab 10 kW IR Upgrade FEL, the UV driver ERL uses a novel bypass geometry to provide transverse phase space control, bunch length compression, and nonlinear aberration compensation (including correction of RF curvature effects) without the use of magnetic chicanes or harmonic RF. Stringent phase space requirements at the wiggler, low beam energy, high beam current, and use of a pre-existing facility and legacy hardware subject the design to numerous constraints. These are imposed not only by the need for both transverse and longitudinal phase space management, but also by the potential impact of collective phenomena (space charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation (CSR)), and by interactions between the FEL and the accelerator RF system. This report addresses these issues and presents the accelerator design solution that is now in operation.

  19. Does attention capacity moderate the effect of driver distraction in older drivers?

    PubMed

    Cuenen, Ariane; Jongen, Ellen M M; Brijs, Tom; Brijs, Kris; Lutin, Mark; Van Vlierden, Karin; Wets, Geert

    2015-04-01

    With age, a decline in attention capacity may occur and this may impact driving performance especially while distracted. Although the effect of distraction on driving performance of older drivers has been investigated, the moderating effect of attention capacity on driving performance during distraction has not been investigated yet. Therefore, the aim was to investigate whether attention capacity has a moderating effect on older drivers' driving performance during visual distraction (experiment 1) and cognitive distraction (experiment 2). In a fixed-based driving simulator, older drivers completed a driving task without and with visual distraction (experiment 1, N=17, mean age 78 years) or cognitive distraction (experiment 2, N=35, mean age 76 years). Several specific driving measures of varying complexity (i.e., speed, lane keeping, following distance, braking behavior, and crashes) were investigated. In addition to these objective driving measures, subjective measures of workload and driving performance were also included. In experiment 1, crash occurrence increased with visual distraction and was negatively related to attention capacity. In experiment 2, complete stops at stop signs decreased, initiation of braking at pedestrian crossings was later, and crash occurrence increased with cognitive distraction. Interestingly, for a measure of lane keeping (i.e., standard deviation of lateral lane position (SDLP)), effects of both types of distraction were moderated by attention capacity. Despite the decrease of driving performance with distraction, participants estimated their driving performance during distraction as good. These results imply that attention capacity is important for driving. Driver assessment and training programs might therefore focus on attention capacity. Nonetheless, it is crucial to eliminate driver distraction as much as possible given the deterioration of performance on several driving measures in those with low and high attention capacity.

  20. Real-time driver drowsiness feedback improves driver alertness and self-reported driving performance.

    PubMed

    Aidman, Eugene; Chadunow, Carolyn; Johnson, Kayla; Reece, John

    2015-08-01

    Driver drowsiness has been implicated as a major causal factor in road accidents. Tools that allow remote monitoring and management of driver fatigue are used in the mining and road transport industries. Increasing drivers' own awareness of their drowsiness levels using such tools may also reduce risk of accidents. The study examined the effects of real-time blink-velocity-derived drowsiness feedback on driver performance and levels of alertness in a military setting. A sample of 15 Army Reserve personnel (1 female) aged 21-59 (M=41.3, SD=11.1) volunteered to being monitored by an infra-red oculography-based Optalert Alertness Monitoring System (OAMS) while they performed their regular driving tasks, including on-duty tasks and commuting to and from duty, for a continuous period of 4-8 weeks. For approximately half that period, blink-velocity-derived Johns Drowsiness Scale (JDS) scores were fed back to the driver in a counterbalanced repeated-measures design, resulting in a total of 419 driving periods under "feedback" and 385 periods under "no-feedback" condition. Overall, the provision of real-time feedback resulted in reduced drowsiness (lower JDS scores) and improved alertness and driving performance ratings. The effect was small and varied across the 24-h circadian cycle but it remained robust after controlling for time of day and driving task duration. Both the number of JDS peaks counted for each trip and their duration declined in the presence of drowsiness feedback, indicating a dynamic pattern that is consistent with a genuine, entropy-reducing feedback mechanism (as distinct from random re-alerting) behind the observed effect. Its mechanisms and practical utility have yet to be fully explored. Direct examination of the alternative, random re-alerting explanation of this feedback effect is an important step for future research.

  1. Drivers of Pontocaspian Biodiversity Rise and Demise

    NASA Astrophysics Data System (ADS)

    Wesselingh, Frank; Flecker, Rachel; Wilke, Thomas; Leroy, Suzanne; Krijgsman, Wout; Stoica, Marius

    2015-04-01

    In the past two million years, the region of the Black Sea Basin, Caspian Basin and adjacent Anatolia and the Balkans were the stage of the evolution of a unique brackish water fauna, the so-called Pontocaspian fauna. The fauna is the result of assembly of genera with a Paratethyan origin and Anatolian origins during the Early Pleistocene. The rapid diversification of the Pontocaspian fauna is the result of the very dynamic nature of the lakes (the Caspian Sea is technically a lake) and seas in the region in the past two million years. In most times the various lake basins were isolated (like today), but in other episodes connections existed. Regional and global climate as well as the regional tectonic regimes were main drivers of lake basin evolution. Over the past 80 years a major biodiversity crisis is hitting the Pontocaspian faunas due to environmental degradation, pollution and invasive species. In the new EU-ETN PRIDE (Drivers of Pontocaspian Biodiversity Rise and Demise)we will be documenting the geological context of past diversifications and turnover events. We present examples of rapid turnover (biodiversity crises) in the Quaternary, assess driving forces and draw implications for the nature of the current human-mediated biodiversity crisis in the region.

  2. THE OLDER ADULT DRIVER WITH COGNITIVE IMPAIRMENT

    PubMed Central

    Carr, David B.; Ott, Brian R.

    2010-01-01

    Although automobiles remain the transportation of choice for older adults, late life cognitive impairment and dementia often impair the ability to drive safely. There is, however, no commonly utilized method of assessing dementia severity in relation to driving, no consensus on the assessment of older drivers with cognitive impairment, and no gold standard for determining driving fitness. Yet, clinicians are called upon by patients, their families, other health professionals, and often the Department of Motor Vehicles (DMV) to assess their patients' fitness-to-drive and to make recommendations about driving privileges. Using the case of Mr W, we describe the challenges of driving with cognitive impairment for both the patient and caregiver, summarize the literature on dementia and driving, discuss evidenced-based assessment of fitness-to-drive, and address important ethical and legal issues. We describe the role of physician assessment, referral to neuropsychology, functional screens, dementia severity tools, driving evaluation clinics, and DMV referrals that may assist with evaluation. Finally, we discuss mobility counseling (eg, exploration of transportation alternatives) since health professionals need to address this important issue for older adults who lose the ability to drive. The application of a comprehensive, interdisciplinary approach to the older driver with cognitive impairment will have the best opportunity to enhance our patients' social connectedness and quality of life, while meeting their psychological and medical needs and maintaining personal and public safety. PMID:20424254

  3. Induction linac drivers: Prospects for the future

    SciTech Connect

    Keefe, D.

    1988-06-01

    This review is intended to place in perspective our current view of the parameter ranges for induction linac drivers that lead to attractive scenarios for civilian electrical power plants; there is a surprising degree of choice (a factor of two or so in most parameters) before any significant impact on the cost of energy results. The progress and goals of the US Heavy Ion Accelerator Research (HIFAR) program are reviewed. The step between the realization of the HIFAR goals and a full-scale driver is seen to be very large indeed and will require one or more significant intermediate steps which can be justified only by a commitment to advance the HIF method towards a true fusion goal. Historical anomalies in the way that fusion programs for both military and civilian applications are administered will need to be resolved; the absence of any presently perceived energy crisis results in little current sense of urgency to develop vigorous long-term energy solutions. 12 refs., 3 figs., 1 tab.

  4. Convenience food products. Drivers for consumption.

    PubMed

    Brunner, Thomas A; van der Horst, Klazine; Siegrist, Michael

    2010-12-01

    Convenience is one of the big trends in the food business. The demand for convenience food products is steadily increasing; therefore, understanding convenience food consumption is an important issue. Despite being vital properties of convenience food, saving time and effort have not been very successful constructs for predicting convenience food consumption. To examine a wide range of possible drivers for convenience food consumption, the present study uses a convenience food frequency questionnaire that asks about consumption behavior. A paper-and-pencil questionnaire was sent out to a representative sample of people in German-speaking Switzerland and yielded N = 918 complete datasets from persons mainly responsible for buying and preparing food in the household. The various convenience food products could be categorized into four groups, which we labeled as highly processed food items, moderately processed food items, single components, and salads. Fifteen drivers were found to have a significant impact either on total convenience consumption or on one of the identified categories. Strong predictors were age, concern about naturalness, nutrition knowledge, and cooking skills. PMID:20832437

  5. The Jefferson lab FEL driver ERLs

    SciTech Connect

    Douglas, David R.; Tennant, Christopher D.

    2013-11-01

    Jefferson Lab has - for over a decade - been operating high power IR and UV FELs using CW energy recovering linacs based on DC photocathode electron sources and CEBAF SRF technology. These machines have unique combinations of beam quality, power, and operational flexibility, and thus offer significant opportunity for experiments that use low and medium energy (several tens - few hundreds of MeV) electron beams. We will describe the systems and detail their present and near-term (potential) performance. Recent internal-target analysis and validation testing will be discussed, and schemes for single- and two-pass fixed target operation described. An introduction to subsequent discussions of beam quality and upgrade paths to polarized operation/higher energy will be given.

  6. Study of a final focus system for high intensity beams

    SciTech Connect

    Henestroza, Enrique; Eylon, Shmuel; Roy, Prabir K.; Yu, Simon S.; Bieniosek, Frank M.; Shuman, Derek B.; Waldron, William L.

    2004-06-01

    The NTX experiment at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high perveance heavy ion beams. The final focus scenario in an HIF driver consists of several large aperture quadrupole magnets followed by a drift section in which the beam space charge is neutralized by a plasma. This beam is required to hit a millimeter-sized target spot at the end of the drift section. The objective of the NTX experiments and associated theory and simulations is to study the various physical mechanisms that determine the final spot size (radius r{sub s}) at a given distance (f) from the end of the last quadrupole. In a fusion driver, f is the standoff distance required to keep the chamber wall and superconducting magnets properly protected. The NTX final quadrupole focusing system produces a converging beam at the entrance to the neutralized drift section where it focuses to a small spot. The final spot is determined by the conditions of the beam entering the quadrupole section, the beam dynamics in the magnetic lattice, and the plasma neutralization dynamics in the drift section. The main issues are the control of emittance growth due to high order fields from magnetic multipoles and image fields. In this paper, we will describe the theoretical and experimental aspects of the beam dynamics in the quadrupole lattice, and how these physical effects influence the final beam size. In particular, we present theoretical and experimental results on the dependence of final spot size on geometric aberrations and perveance.

  7. Data acquisition system for KOMAC beam monitoring using EPICS middleware

    NASA Astrophysics Data System (ADS)

    Song, Young-Gi

    2015-10-01

    The beam diagnostics instrument used to measure the beam properties is one of the important devices for the 100-MeV proton linear accelerator of the KOrea Multi-purpose Accelerator Complex (KOMAC). A data acquisition system (DAQ) is required to collect the output beam signals conditioned in the analog front-end circuitry of a beam loss monitor (BLM) and a beam position monitor (BPM). The electrical beam signal must be digitized, and the sampling has to be synchronized to a global timing system that produces a pulse signal for the pulsed beam operation. The digitized data must be accessible by the experimental physics and industrial control system (EPICS)-based control system, which manages all accelerator control. An input output controller (IOC), which runs Linux on a central process unit (CPU) module with a peripheral component interconnect (PCI) express-based Analog-to-digital converter (ADC) card, has been adopted to satisfy the requirements. An associated Linux driver and EPICS device support module have also been developed. The IOC meets the requirements, and the development and maintenance of software for the IOC is very efficient. In this paper, the details of the DAQ system for the BLM and the BPM with the introduction of the KOMAC beam-diagnostics devices, along with the performance, are described.

  8. Parabolic scaling beams.

    PubMed

    Gao, Nan; Xie, Changqing

    2014-06-15

    We generalize the concept of diffraction free beams to parabolic scaling beams (PSBs), whose normalized intensity scales parabolically during propagation. These beams are nondiffracting in the circular parabolic coordinate systems, and all the diffraction free beams of Durnin's type have counterparts as PSBs. Parabolic scaling Bessel beams with Gaussian apodization are investigated in detail, their nonparaxial extrapolations are derived, and experimental results agree well with theoretical predictions.

  9. Automated beam builder

    NASA Technical Reports Server (NTRS)

    Muench, W. K.

    1980-01-01

    Requirements for the space fabrication of large space structures are considered with emphasis on the design, development, manufacture, and testing of a machine which automatically produces a basic building block aluminum beam. Particular problems discussed include those associated with beam cap forming; brace storage, dispensing, and transporting; beam component fastening; and beam cut-off. Various critical process tests conducted to develop technology for a machine to produce composite beams are also discussed.

  10. SUMMARY OF BEAM BEAM OBSERVATIONS DURING STORES IN RHIC.

    SciTech Connect

    FISCHER,W.

    2003-05-19

    During stores, the beam-beam interaction has a significant impact on the beam and luminosity lifetimes in RHIC. This was observed in heavy ion, and even more pronounced in proton collisions. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. In addition, RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. Coherent beam-beam modes were observed, and suppressed by tune changes. In this article we summarize the most important beam-beam observations made during stores so far.

  11. How Drivers Respond to Alarms Adapted to Their Braking Behaviour?

    NASA Astrophysics Data System (ADS)

    Abe, Genya; Itoh, Makoto

    Determining appropriate alarm timing for Forward Collision Warning Systems (FCWS) may play an important role in enhancing system acceptance by drivers. It is not always true that a common alarm trigger logic is suitable for all drivers, because presented alarms may be differently viewed for each driver, i.e., paying attention or requiring appropriate actions. The current study focused on adaptive alarm timing which was adjusted in response to braking behaviour for collision avoidance for the individual. In Experiment I, the braking performance of individual driver was measured repeatedly to assess the variation of each performance. We utilised the following two indices: elapsed time from the deceleration of the lead car to release of the accelerator (accelerator release time) and elapsed time to application of the brakes (braking response time). Two alarm timings were then determined based on these two indices: (i) the median of the accelerator release time of the driver and (ii) the median of the braking response time of the driver. Experiment II compared the two alarm timings for each driver in order to investigate which timing is more appropriate for enhancing driver trust in the driver-adaptive FCWS and the system effectiveness. The results showed that the timing of the accelerator release time increased the trust ratings more than the timing of braking response. The timing of the braking response time induced a longer response time to application of the brakes. Moreover, the degree to which the response time was longer depended on alarm timing preference of the driver. The possible benefit and drawback of driver-adaptive alarm timing are discussed.

  12. Accelerators for the advanced exotic beam facility in the U.S.

    SciTech Connect

    Ostroumov, P. N.; Fuerst, J. D.; Kelly, M. P.; Mustapha, B.; Nolen, J. A.; Shepard, K. W.; Physics

    2007-01-01

    The Office of Science of the Department of Energy is currently considering options for an advanced radioactive beam facility in the U.S which is a reduced scale version of the Rare Isotope Accelerator (RIA) project [1,2]. This facility will have unique capabilities compared with others both existing and planned elsewhere. As envisioned at ANL, the facility, called the Advanced Exotic Beam Laboratory (AEBL), would consist of a heavy-ion driver linac, a post-accelerator and experimental areas. Secondary beams of rare isotopes will be available as high quality reaccelerated or stopped beams from a gas catcher and high power ISOL targets, as well as, high energy beams following in-flight fragmentation or fission of heavy ions. The proposed design of the AEBL driver linac is a cw, fully superconducting, 833 MV linac capable of accelerating uranium ions up to 200 MeV/u and protons to 580 MeV with 400 kW beam power. An extensive research and development effort has resolved many technical issues related to the construction of the driver linac and other systems required for AEBL. This paper presents the status of planning, some options for such a facility, as well as, progress in related R&D.

  13. Beam dynamics in resonant plasma wakefield acceleration at SPARC_LAB

    NASA Astrophysics Data System (ADS)

    Romeo, S.; Anania, M. P.; Chiadroni, E.; Croia, M.; Ferrario, M.; Marocchino, A.; Pompili, R.; Vaccarezza, C.

    2016-09-01

    Strategies to mitigate the increase of witness emittance and energy spread in beam driven plasma wakefield acceleration are investigated. Starting from the proposed resonant wakefield acceleration scheme in quasi-non-linear regime that is going to be carried out at SPARC_LAB, we performed systematic scans of the parameters to be used for drivers. The analysis will show that one of the main requirements to preserve witness quality during the acceleration is to have accelerating and focusing fields that are very stable during all the accelerating length. The difference between the dynamics of the leading bunch and the trailing bunch is pointed out. The classical condition on bunch length kpσz =√{ 2 } seems to be an ideal condition for the first driver within long accelerating lengths. The other drivers show to follow different longitudinal matching conditions. In the end a new method for the investigation of the matching for the first driver is introduced.

  14. Pulsed power drivers for ICF and high energy density physics

    NASA Astrophysics Data System (ADS)

    Ramirez, Juan J.; Matzen, M. Keith; McDaniel, Dillon H.

    Nanosecond Pulsed Power Science and Technology has its origins in the 1960s and over the past decade has matured into a flexible and robust discipline capable of addressing key physics issues of importance to Inertial Confinement Fusion (ICF) and high Energy Density Physics. The major leverage provided by pulsed power is its ability to generate and deliver high energy and high power at low cost and high efficiency. A low-cost, high-efficiency driver is important because of the very large capital investment required for multi-megajoule ignition-class systems. High efficiency is of additional importance for a commercially viable inertial fusion energy option. Nanosecond pulsed power has been aggressively and successfully developed at Sandia over the past twenty years. This effort has led to the development of unique multi-purpose facilities supported by highly capable diagnostic, calculational and analytic capabilities. The Sandia Particle-beam Fusion Program has evolved as part of an integrated national ICF Program. It applies the low-cost, high-efficiency leverage provided by nanosecond pulsed power systems to the longer-term goals of the national program, i.e., the Laboratory Microfusion Facility and Inertial Fusion Energy. A separate effort has led to the application of nanosecond pulsed power to the generation of intense, high-energy laboratory x-ray sources for application to x-ray laser and radiation effects science research. Saturn is the most powerful of these sources to date. It generates (approximately) 500 kilojoules of x-rays from a magnetically driven implosion (Z-pinch). This paper describes results of x-ray physics experiments performed on Saturn, plans for a new Z-pinch drive capability for PBFA-2, and a design concept for the proposed (approximately) 15 MJ Jupiter facility. The opportunities for ICF-relevant research using these facilities will also be discussed.

  15. Tevatron beam-beam compensation project progress

    SciTech Connect

    Shiltsev, V.; Zhang, X.L.; Kuznetsov, G.; Pfeffer, H.; Saewert, G.; Zimmermann, F.; Tiunov, M.; Bishofberger, K.; Bogdanov, I.; Kashtanov, E.; Kozub, S.; Sytnik, V.; Tkachenko, L.; /Serpukhov, IHEP

    2005-05-01

    In this paper, we report the progress of the Tevatron Beam-Beam Compensation (BBC) project [1]. Electron beam induced proton and antiproton tuneshifts have been reported in [2], suppression of an antiproton emittance growth has been observed, too [1]. Currently, the first electron lens (TEL1) is in operational use as the Tevatron DC beam cleaner. We have made a lot of the upgrades to improve its stability [3]. The 2nd Tevatron electron lens (TEL2) is under the final phase of development and preparation for installation in the Tevatron.

  16. ION BEAM COLLIMATOR

    DOEpatents

    Langsdorf, A.S. Jr.

    1957-11-26

    A device is described for defining a beam of high energy particles wherein the means for defining the beam in the horizontal and vertical dimension are separately adjustable and the defining members are internally cooled. In general, the device comprises a mounting block having a central opening through which the beam is projected, means for rotatably supporting two pairs of beam- forming members, passages in each member for the flow of coolant; the beam- forming members being insulated from each other and the block, and each having an end projecting into the opening. The beam-forming members are adjustable and may be cooperatively positioned to define the beam passing between the end of the members. To assist in projecting and defining the beam, the member ends have individual means connected thereto for indicating the amount of charge collected thereon due to beam interception.

  17. Drivers and Interpretations of Doctoral Education Today: National Comparisons

    ERIC Educational Resources Information Center

    Andres, Lesley; Bengtsen, Søren S. E.; del Pilar Gallego Castaño, Liliana; Crossouard, Barbara; Keefer, Jeffrey M.; Pyhältö, Kirsi

    2015-01-01

    In the last decade, doctoral education has undergone a sea change with several global trends increasingly apparent. Drivers of change include massification and professionalization of doctoral education and the introduction of quality assurance systems. The impact of these drivers, and the forms that they take, however, are dependent on doctoral…

  18. 29 CFR 541.504 - Drivers who sell.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DELIMITING THE EXEMPTIONS FOR EXECUTIVE, ADMINISTRATIVE, PROFESSIONAL, COMPUTER AND OUTSIDE SALES EMPLOYEES Outside Sales Employees § 541.504 Drivers who sell. (a) Drivers who deliver products and also sell such products may qualify as exempt outside sales employees only if the employee has a primary duty of...

  19. 49 CFR 384.234 - Driver medical certification recordkeeping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Driver medical certification recordkeeping. 384.234 Section 384.234 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Compliance by States § 384.234 Driver medical certification recordkeeping. The State must meet the...

  20. 49 CFR 384.234 - Driver medical certification recordkeeping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Driver medical certification recordkeeping. 384.234 Section 384.234 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Compliance by States § 384.234 Driver medical certification recordkeeping. The State must meet the...

  1. 49 CFR 384.234 - Driver medical certification recordkeeping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Driver medical certification recordkeeping. 384.234 Section 384.234 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Compliance by States § 384.234 Driver medical certification recordkeeping. The State must meet the...

  2. Bicycles in Traffic. A North Carolina Driver Education Handbook.

    ERIC Educational Resources Information Center

    East Carolina Univ., Greenville, NC.

    This unit is designed to provide driver educators with information for teaching automobile drivers about the traffic-mix problem between bicycles and motor vehicles on roadways. The purpose of the unit is to improve the safety of bicyclists on North Carolina highways and help to decrease the number of bicycle deaths and injuries caused by traffic…

  3. 49 CFR 383.51 - Disqualification of drivers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Disqualification of drivers. 383.51 Section 383.51... STANDARDS; REQUIREMENTS AND PENALTIES Driver Disqualifications and Penalties § 383.51 Disqualification of...) of this section (Table 1 to § 383.51) after 10 years, if that person has voluntarily entered...

  4. Volunteer Drivers: Their Contributions to Older Adults and to Themselves

    ERIC Educational Resources Information Center

    Kerschner, Helen; Rousseau, Marie-Helene

    2008-01-01

    In 2004 and 2005 the Beverly Foundation surveyed volunteer drivers in an effort to better understand how and why they support older adults. The sample comprised 714 volunteer drivers from 367 communities, representing 40 states, who responded to the survey. Their responses provided qualitative and quantitative information about who they are, why…

  5. 49 CFR 391.53 - Driver investigation history file.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY...

  6. Driver Aid and Education Test Project. Final Report.

    ERIC Educational Resources Information Center

    Shadis, W.; Soucek, S. J.

    A driver education project tested the hypothesis that measurable improvements in fleet fuel economy can be achieved by driver awareness training in fuel-efficient driving techniques and by a manifold vacuum gauge, used individually or in combination with each other. From April 1976 through December 1977 data were collected in the Las Vegas,…

  7. A novel active heads-up display for driver assistance.

    PubMed

    Doshi, Anup; Cheng, Shinko Yuanhsien; Trivedi, Mohan Manubhai

    2009-02-01

    In this paper, we introduce a novel laser-based wide-area heads-up windshield display which is capable of actively interfacing with a human as part of a driver assistance system. The dynamic active display (DAD) is a unique prototype interface that presents safety-critical visual icons to the driver in a manner that minimizes the deviation of his or her gaze direction without adding to unnecessary visual clutter. As part of an automotive safety system, the DAD presents alerts in the field of view of the driver only if necessary, which is based upon the state and pose of the driver, vehicle, and environment. This paper examines the effectiveness of DAD through a comprehensive comparative experimental evaluation of a speed compliance driver assistance system, which is implemented on a vehicular test bed. Three different types of display protocols for assisting a driver to comply with speed limits are tested on actual roadways, and these are compared with a conventional dashboard display. Given the inclination, drivers who are given an overspeed warning alert reduced the time required to slow down to the speed limit by 38% (p < 0.01) as compared with the drivers not given the alert. Additionally, certain alerts decreased distraction levels by reducing the time spent looking away from the road by 63% (p < 0.01). Ultimately, these alerts demonstrate the utility and promise of the DAD system.

  8. Self-reported wayfinding ability of older drivers.

    PubMed

    Bryden, Kelly J; Charlton, Judith L; Oxley, Jennifer A; Lowndes, Georgia J

    2013-10-01

    Some older drivers experience difficulties driving whilst wayfinding in unfamiliar areas. Difficulties in wayfinding have been associated with poorer driving performance and reduced driving mobility. The objective of the current study was to identify cognitive and demographic predictors in older drivers of perceived wayfinding difficulty, avoidance of unfamiliar areas and the use of wayfinding strategies. Five hundred and thirty-four drivers aged 65 years and over (excluding those with dementia or Parkinson's disease) completed a mail-out survey. Drivers commonly reported difficulties with wayfinding, with 59.5% reporting their abilities as poor or fair rather than good. Those significantly more likely to report difficulty were older, reported poorer health and cognition, and had less driving experience. A small proportion of drivers reported regularly avoiding unfamiliar areas (13.8%); these drivers were significantly more likely to be female and to report poorer wayfinding abilities. The most common wayfinding strategies regularly used by older drivers were using a street directory whilst driving (61.9%) and pulling over to check the map (55.1%). Regular passenger guidance (23.9%) or use of a navigation system (9.9%) was less common. The implications of this study are wide and include collecting further information about: (1) the role of cognitive processes in wayfinding ability; (2) the relationship between perceived wayfinding difficulty and restriction of driving in unfamiliar areas; and (3) older drivers' preferences for different wayfinding strategies. PMID:23845406

  9. 76 FR 26681 - Hours of Service of Drivers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-09

    ... Federal Motor Carrier Safety Administration 49 CFR Parts 385, 386, 390, and 395 RIN 2126-AB26 Hours of Service of Drivers AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice... service (HOS) for commercial motor vehicle drivers. The Agency is reopening the comment period on the...

  10. 78 FR 72149 - Qualification of Drivers; Application for Exemptions; Hearing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... hearing loss in the better ear greater than 40 decibels at 500 Hz, 1,000 Hz, and 2,000 Hz with or without... allow drivers to be qualified under this standard while wearing a hearing aid, 35 FR 6458, 6463 (April... Federal Motor Carrier Safety Administration Qualification of Drivers; Application for Exemptions;...

  11. 78 FR 26417 - Qualification of Drivers; Application for Exemptions; Hearing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... hearing loss in the better ear greater than 40 decibels at 500 Hz, 1,000 Hz, and 2,000 Hz with or without... allow drivers to be qualified under this standard while wearing a hearing aid, 35 FR 6458, 6463 (April... Federal Motor Carrier Safety Administration Qualification of Drivers; Application for Exemptions;...

  12. Driving Procedures. A Resource Guide for Driver Education Teachers.

    ERIC Educational Resources Information Center

    Texas State Dept. of Public Safety, Austin.

    Designed to provide instructors with resource materials for driver education, this book contains mainly materials on established safe driving procedures. An introduction defines a procedure as describing ways in which a driver can comply with the law to do something extra that will increase his/her safety and prevent congestion and collision.…

  13. Hazard prediction discriminates between novice and experienced drivers.

    PubMed

    Crundall, David

    2016-01-01

    Typical hazard perception tests often confound multiple processes in their responses. The current study tested hazard prediction in isolation to assess whether this component can discriminate between novice and experienced drivers. A variant of the hazard perception test, based on the Situation Awareness Global Assessment Technique, found experienced drivers to outperform novices across three experiments suggesting that the act of predicting an imminent hazard is a crucial part of the hazard-perception process. Furthermore three additional hypotheses were tested in these experiments. First, performance was compared across clips of different length. There was marginal evidence that novice drivers' performance suffered with the longest clips, but experienced drivers' performance did not, suggesting that experienced drivers find hazard prediction less effortful. Secondly, predictive accuracy was found to be dependent on the temporal proximity of visual precursors to the hazard. Thirdly the relationship between the hazard and its precursor was found to be important, with less obvious precursors improving the discrimination between novice and experience drivers. These findings demonstrate that a measure of hazard prediction, which is less confounded by the influence of risk appraisal than simple response time measures, can still discriminate between novice and experienced drivers. Application of this methodology under different conditions can produce insights into the underlying processes that may be at work, whilst also providing an alternative test of driver skill in relation to the detection of hazards. PMID:26513336

  14. 49 CFR 384.234 - Driver medical certification recordkeeping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Driver medical certification recordkeeping. 384.234 Section 384.234 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Compliance by States § 384.234 Driver medical certification recordkeeping. The State must meet the...

  15. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... records as necessary. (c) Drivers must also receive instruction on the topics listed in 45 CFR 1304.52(k... with Disabilities (45 CFR 1308) relating to transportation services for children with disabilities. (d... 45 Public Welfare 4 2010-10-01 2010-10-01 false Driver and bus monitor training. 1310.17...

  16. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... records as necessary. (c) Drivers must also receive instruction on the topics listed in 45 CFR 1304.52(k... with Disabilities (45 CFR 1308) relating to transportation services for children with disabilities. (d... 45 Public Welfare 4 2011-10-01 2011-10-01 false Driver and bus monitor training. 1310.17...

  17. Lane-changing model with dynamic consideration of driver's propensity

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyuan; Wang, Jianqiang; Zhang, Jinglei; Ban, Xuegang Jeff

    2015-07-01

    Lane-changing is the driver's selection result of the satisfaction degree in different lane driving conditions. There are many different factors influencing lane-changing behavior, such as diversity, randomicity and difficulty of measurement. So it is hard to accurately reflect the uncertainty of drivers' lane-changing behavior. As a result, the research of lane-changing models is behind that of car-following models. Driver's propensity is her/his emotion state or the corresponding preference of a decision or action toward the real objective traffic situations under the influence of various dynamic factors. It represents the psychological characteristics of the driver in the process of vehicle operation and movement. It is an important factor to influence lane-changing. In this paper, dynamic recognition of driver's propensity is considered during simulation based on its time-varying discipline and the analysis of the driver's psycho-physic characteristics. The Analytic Hierarchy Process (AHP) method is used to quantify the hierarchy of driver's dynamic lane-changing decision-making process, especially the influence of the propensity. The model is validated using real data. Test results show that the developed lane-changing model with the dynamic consideration of a driver's time-varying propensity and the AHP method are feasible and with improved accuracy.

  18. Defensive Tips in the War against Drunk Drivers.

    ERIC Educational Resources Information Center

    Penkivich, Robert R.

    The purpose of this book, written by a retired law enforcement officer, is to educate the public about drunk drivers, drinking drivers, and high-speed driving, in an effort to prevent injury, death, and suffering. It is intended to be an instructional manual and a practical, common-sense survival guide for the average individual. National…

  19. Determining older driver crash responsibility from police and insurance data.

    PubMed

    Langford, Jim; Koppel, Sjaanie; Andrea, Dale; Fildes, Brian

    2006-12-01

    This study aimed to determine the extent to which older drivers can be considered responsible for their crashes, to identify key factors in those crashes for which older drivers have been judged responsible, and to assess the extent to which older drivers' extra crash responsibility contributes to the road toll. Insurance claims from the State of Tasmania, Australia, for 1998-2002 were linked with police records for crashes involving drivers aged either 41-55 years or 65 years or older. Insurance and police data sets contained independent judgments of crash responsibility. There was a high level of agreement between the two sets of judgments, with older drivers judged around 1.5 times more likely to be responsible for their crashes than middle-aged drivers and, conversely, older drivers were around 0.6 as likely to be absolved from crash responsibility. It was concluded that older drivers' additional crash responsibility while valuable in explaining "what went wrong," currently makes only a small contribution to the overall road toll.

  20. 49 CFR 391.15 - Disqualification of drivers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... vehicle under the influence of a 21 CFR 1308.11 Schedule I identified controlled substance, an amphetamine...) Transportation, possession, or unlawful use of a 21 CFR 1308.11 Schedule I identified controlled substance... § 391.15 Disqualification of drivers. (a) General. A driver who is disqualified shall not drive...

  1. 49 CFR 391.15 - Disqualification of drivers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... vehicle under the influence of a 21 CFR 1308.11 Schedule I identified controlled substance, an amphetamine...) Transportation, possession, or unlawful use of a 21 CFR 1308.11 Schedule I identified controlled substance... § 391.15 Disqualification of drivers. (a) General. A driver who is disqualified shall not drive...

  2. 49 CFR 391.15 - Disqualification of drivers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... vehicle under the influence of a 21 CFR 1308.11 Schedule I identified controlled substance, an amphetamine...) Transportation, possession, or unlawful use of a 21 CFR 1308.11 Schedule I identified controlled substance... § 391.15 Disqualification of drivers. (a) General. A driver who is disqualified shall not drive...

  3. 49 CFR 391.15 - Disqualification of drivers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... vehicle under the influence of a 21 CFR 1308.11 Schedule I identified controlled substance, an amphetamine...) Transportation, possession, or unlawful use of a 21 CFR 1308.11 Schedule I identified controlled substance... § 391.15 Disqualification of drivers. (a) General. A driver who is disqualified shall not drive...

  4. 32 CFR 634.10 - Remedial driver training programs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Remedial driver training programs. 634.10 Section 634.10 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Privileges § 634.10 Remedial driver training programs. (a)...

  5. Visual attention and the transition from novice to advanced driver.

    PubMed

    Underwood, G

    2007-08-01

    Inexperienced drivers are particularly vulnerable to road traffic accidents, and inattention emerges as a factor in these accidents. What do these drivers attend to and how can their observation skills be developed? When drivers scan the road around them, differences are observed as function of driving experience and training, with experienced drivers increasing their visual scanning on roadways of increasing complexity. Trained police drivers showed this effect of increased scanning even more than experienced drivers. This suggests that the driver's understanding of the task develops with experience, such that roads that demand increased monitoring (e.g. interweaving traffic on a multi-lane highway) receive more extensive scanning than roads that are simpler (e.g. light traffic on a straight rural road). Novice drivers do not show this sensitivity to road complexity, suggesting that they fail to attend to potential dangers involving the behaviour of other road users. Encouragingly, a simple training intervention can increase the visual scanning of novices. PMID:17558667

  6. Student Drivers Will Find This Defensive Course Difficult

    ERIC Educational Resources Information Center

    Nation's Schools, 1972

    1972-01-01

    Map and description of 40-acre defensive driving range being built for secondary school driver education programs in the Burke County Public Schools of North Carolina. Features include a beginner course, streets, driveways, expressway, gravel road, a driver education building, and an emergency skid area. (Author/DN)

  7. 77 FR 27842 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM) operating..., 2003 (68 FR 52441).\\1\\ The revision must provide for individual assessment of drivers with diabetes... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications;...

  8. 49 CFR 383.21 - Number of drivers' licenses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Number of drivers' licenses. 383.21 Section 383.21 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... STANDARDS; REQUIREMENTS AND PENALTIES Single License Requirement § 383.21 Number of drivers' licenses....

  9. 49 CFR 383.21 - Number of drivers' licenses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Number of drivers' licenses. 383.21 Section 383.21 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... STANDARDS; REQUIREMENTS AND PENALTIES Single License Requirement § 383.21 Number of drivers' licenses....

  10. 49 CFR 384.225 - CDLIS driver recordkeeping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of the CDLIS driver record: (1) All convictions, disqualifications and other licensing actions for... weight, or vehicle defect violations) committed in any type of vehicle. (2) The following medical certification status information: (i) Driver self-certification for the type of driving operations provided...

  11. 75 FR 34209 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... driver with a very healthy right eye, normal color vision and normal peripheral vision. I do not consider... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications; Vision... exemption from the vision requirement in the Federal Motor Carrier Safety Regulations. If granted,...

  12. 75 FR 44049 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... general population. The diabetes rule provides that ``A person is physically qualified to drive a..., received education related to diabetes management, and is on a stable insulin regimen. These drivers report... Federal Motor Carrier Safety Administration Qualification of Drivers; Exemption Applications;...

  13. Glia as drivers of abnormal neuronal activity

    PubMed Central

    Robel, Stefanie; Sontheimer, Harald

    2016-01-01

    Reactive astrocytes have been proposed to become incompetent bystanders in epilepsy as a result of cellular changes rendering them unable to perform important housekeeping functions. Indeed, successful surgical treatment of mesiotemporal lobe epilepsy hinges on the removal of the glial scar. New research now extends the role of astrocytes, suggesting that they may drive the disease process by impairing the inhibitory action of neuronal GABA receptors. Here we discuss studies that include hyperexcitability resulting from impaired supply of astrocytic glutamine for neuronal GABA synthesis, and epilepsy resulting from genetically induced astrogliosis or malignant transformation, both of which render the inhibitory neurotransmitter GABA excitatory. In these examples, glial cells alter the expression or function of neuronal proteins involved in excitability. Although epilepsy has traditionally been thought of as a disease caused by changes in neuronal properties exclusively, these new findings challenge us to consider the contribution of glial cells as drivers of epileptogenesis in acquired epilepsies. PMID:26713746

  14. Synergies among extinction drivers under global change.

    PubMed

    Brook, Barry W; Sodhi, Navjot S; Bradshaw, Corey J A

    2008-08-01

    If habitat destruction or overexploitation of populations is severe, species loss can occur directly and abruptly. Yet the final descent to extinction is often driven by synergistic processes (amplifying feedbacks) that can be disconnected from the original cause of decline. We review recent observational, experimental and meta-analytic work which together show that owing to interacting and self-reinforcing processes, estimates of extinction risk for most species are more severe than previously recognised. As such, conservation actions which only target single-threat drivers risk being inadequate because of the cascading effects caused by unmanaged synergies. Future work should focus on how climate change will interact with and accelerate ongoing threats to biodiversity, such as habitat degradation, overexploitation and invasive species.

  15. Social capital, health, and elderly driver status

    PubMed Central

    Isbel, Stephen T.; Berry, Helen L.

    2016-01-01

    Driving a car enables many people to engage in meaningful activities that, in turn, help develop and maintain personal social capital. Social capital, a combination of community participation and social cohesion, is important in maintaining well-being. This paper argues that social capital can provide a framework for investigating the general role of transportation and driving a car specifically to access activities that contribute to connectedness and well-being among older people. This paper proposes theoretically plausible and empirically testable hypotheses about the relationship between driver status, social capital, and well-being. A longitudinal study may provide a new way of understanding, and thus of addressing, the well-being challenges that occur when older people experience restrictions to, or loss of, their driver’s license. PMID:27505020

  16. Active gated imaging in driver assistance system

    NASA Astrophysics Data System (ADS)

    Grauer, Yoav

    2014-04-01

    In this paper, we shall present the active gated imaging system (AGIS) in relation to the automotive field. AGIS is based on a fast-gated camera and pulsed illuminator, synchronized in the time domain to record images of a certain range of interest. A dedicated gated CMOS imager sensor and near infra-red (NIR) pulsed laser illuminator, is presented in this paper to provide active gated technology. In recent years, we have developed these key components and learned the system parameters, which are most beneficial to nighttime (in all weather conditions) driving in terms of field of view, illumination profile, resolution, and processing power. We shall present our approach of a camera-based advanced driver assistance systems (ADAS) named BrightEye™, which makes use of the AGIS technology in the automotive field.

  17. An examination of the environmental, driver and vehicle factors associated with the serious and fatal crashes of older rural drivers.

    PubMed

    Thompson, J P; Baldock, M R J; Mathias, J L; Wundersitz, L N

    2013-01-01

    Motor vehicle crashes involving rural drivers aged 75 years and over are more than twice as likely to result in a serious or fatal injury as those involving their urban counterparts. The current study examined some of the reasons for this using a database of police-reported crashes (2004-2008) to identify the environmental (lighting, road and weather conditions, road layout, road surface, speed limit), driver (driver error, crash type), and vehicle (vehicle age) factors that are associated with the crashes of older rural drivers. It also determined whether these same factors are associated with an increased likelihood of serious or fatal injury in younger drivers for whom frailty does not contribute to the resulting injury severity. A number of environmental (i.e., undivided, unsealed, curved and inclined roads, and areas with a speed limit of 100km/h or greater) and driver (i.e., collision with a fixed object and rolling over) factors were more frequent in the crashes of older rural drivers and additionally associated with increased injury severity in younger drivers. Moreover, when these environmental factors were entered into a logistic regression model to predict whether older drivers who were involved in crashes did or did not sustain a serious or fatal injury, it was found that each factor independently increased the likelihood of a serious or fatal injury. Changes, such as the provision of divided and sealed roads, greater protection from fixed roadside objects, and reduced speed limits, appear to be indicated in order to improve the safety of the rural driving environment for drivers of all ages. Additionally, older rural drivers should be encouraged to reduce their exposure to these risky circumstances.

  18. Driver state examination--Treading new paths.

    PubMed

    Wascher, Edmund; Getzmann, Stephan; Karthaus, Melanie

    2016-06-01

    A large proportion of crashes in road driving can be attributed to driver fatigue. Several types of fatigue are discussed, comprising sleep-related fatigue, active task-related fatigue (as a consequence of workload in demanding driving situations) as well as passive task-related fatigue (as related to monotonous driving situations). The present study investigated actual states of fatigue in a monotonous driving situation, using EEG measures and a long-lasting driving simulation experiment, in which drivers had to keep the vehicle on track by compensating crosswind of different strength. Performance data and electrophysiological correlates of mental fatigue (EEG Alpha and Theta power, Inter Trial Coherence (ITC), and auditory event-related potentials to short sound stimuli) were analyzed. Driving errors and driving lane variability increased with time on task and with increasing crosswind. The posterior Alpha and Theta power also increased with time on task, but decreased with stronger crosswind. The P3a to sound stimuli decreased with time on task when the crosswind was weak, but remained stable when the crosswind was strong. The analysis of ITC revealed less frontal Alpha and Theta band synchronization with time on task, but no effect of crosswind. The results suggest that Alpha power in monotonous driving situations reflects boredom or attentional withdrawal due to monotony rather than the decline of processing abilities as a consequence of high mental effort. A more valid indicator of declining mental resources with increasing time on task seems to be provided by brain oscillatory synchronization measures and event-related activity. PMID:26986022

  19. Global Greening Is Firm, Drivers Are Mixed

    NASA Astrophysics Data System (ADS)

    Kauppi, P.; Meyfroidt, P.; Ausubel, J. H.; Graven, H. D.; Birdsey, R.; Posch, M.; Wernick, I.; Myneni, R. B.; Stenberg, P.

    2015-12-01

    Evidence for global greening is converging, asserting an increase in CO2 uptake and biomass of the terrestrial biosphere. Global greening refers to global net increases in the area of green canopy, stocks of carbon, and the duration of the growing season. The growing seasons in general have prolonged while the stock of biomass carbon has increased and the rate of deforestation has decelerated, although these trends are mixed in the Tropics. Evidence for these trends comes from firm empirical data obtained through atmospheric CO2 observations, remote sensing, forest inventories and land use statistics. The drivers of global greening cannot be assessed based only on unambiguous empirical measurements. They include spatially and temporally heterogeneous combinations of changing land use and management - including green revolution and increasing yields, afforestation, forest protection and management, and abandonment of agricultural land -, changes in the global environment (increased CO2, warmer temperatures and longer growing seasons in the northern latitudes, acceleration of the global nitrogen cycle), and shifts in demand for forest and farm products. The global trade of biomass-derived commodities affects the link between consumption patterns and the land cover impact. Global greening confirms the immediacy of global change and may be associated with more or less biodiversity and diverse environmental and human consequences depending on local circumstances. Understanding causes, mechanisms, and implications of global greening requires integrated analyses spanning land use and management, demand for products of the terrestrial biosphere, and the atmosphere and climate. Understanding the pace and drivers of global greening matters crucially for assessing the future of the terrestrial C sink; ecological, economic, social, and cultural assessments of the bio-economy; and the preservation of ecosystems.

  20. Racial Disparities in Survival Among Injured Drivers

    PubMed Central

    Haskins, Amy E.; Clark, David E.; Travis, Lori L.

    2013-01-01

    Prior studies on racial and ethnic disparities in survival after motor vehicle crashes have examined only population-based death rates or have been restricted to hospitalized patients. In the current study, we examined 3 components of crash survival by race/ethnicity: survival overall, survival to reach a hospital, and survival among those hospitalized. Nine years of data (from 2000 through 2008) from the National Automotive Sampling System Crashworthiness Data System were used to examine white non-Hispanic, black non-Hispanic, and Hispanic drivers aged ≥15 years with serious injuries (injury severity scores of ≥9). By using multivariable logistic regression, we found that a driver's race/ethnicity was not significantly associated with overall survival after being injured in a crash (for blacks, odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.36, 1.32; for Hispanics, OR = 1.00, 95% CI: 0.59, 1.72), and blacks and Hispanics were equally likely to survive to be treated at a hospital compared with whites (for blacks, OR = 1.00, 95% CI: 0.52, 1.93; for Hispanics, OR = 1.13, 95% CI: 0.71, 1.79). However, among patients who were treated at a hospital, blacks were 50% less likely to survive 30 days compared with whites (OR = 0.50, 95% CI: 0.33, 0.76). The disparity in survival after serious traffic injuries among blacks appears to occur after hospitalization, not in prehospital survival. PMID:23371352

  1. Influences of Vehicle Size and Mass and Selected Driver Factors on Odds of Driver Fatality

    PubMed Central

    Padmanaban, Jeya

    2003-01-01

    Research was undertaken to determine vehicle size parameters influencing driver fatality odds, independent of mass, in two-vehicle collisions. Forty vehicle parameters were evaluated for 1,500 vehicle groupings. Logistic regression analyses show driver factors (belt use, age, drinking) collectively contribute more to fatality odds than vehicle factors, and that mass is the most important vehicular parameter influencing fatality odds for all crash configurations. In car crashes, other vehicle parameters with statistical significance had a second order effect compared to mass. In light truck-to-car crashes, “vehicle type-striking vehicle is light truck” was the most important parameter after mass, followed by vehicle height and bumper height, with second order effect. To understand the importance of “vehicle type” variable, further investigation of vehicle “stiffness” and other passenger car/light truck differentiating parameters is warranted. PMID:12941244

  2. Driver face recognition as a security and safety feature

    NASA Astrophysics Data System (ADS)

    Vetter, Volker; Giefing, Gerd-Juergen; Mai, Rudolf; Weisser, Hubert

    1995-09-01

    We present a driver face recognition system for comfortable access control and individual settings of automobiles. The primary goals are the prevention of car thefts and heavy accidents caused by unauthorized use (joy-riders), as well as the increase of safety through optimal settings, e.g. of the mirrors and the seat position. The person sitting on the driver's seat is observed automatically by a small video camera in the dashboard. All he has to do is to behave cooperatively, i.e. to look into the camera. A classification system validates his access. Only after a positive identification, the car can be used and the driver-specific environment (e.g. seat position, mirrors, etc.) may be set up to ensure the driver's comfort and safety. The driver identification system has been integrated in a Volkswagen research car. Recognition results are presented.

  3. Automatic Fatigue Detection of Drivers through Yawning Analysis

    NASA Astrophysics Data System (ADS)

    Azim, Tayyaba; Jaffar, M. Arfan; Ramzan, M.; Mirza, Anwar M.

    This paper presents a non-intrusive fatigue detection system based on the video analysis of drivers. The focus of the paper is on how to detect yawning which is an important cue for determining driver's fatigue. Initially, the face is located through Viola-Jones face detection method in a video frame. Then, a mouth window is extracted from the face region, in which lips are searched through spatial fuzzy c-means (s-FCM) clustering. The degree of mouth openness is extracted on the basis of mouth features, to determine driver's yawning state. If the yawning state of the driver persists for several consecutive frames, the system concludes that the driver is non-vigilant due to fatigue and is thus warned through an alarm. The system reinitializes when occlusion or misdetection occurs. Experiments were carried out using real data, recorded in day and night lighting conditions, and with users belonging to different race and gender.

  4. Effect of aftermarket automobile window tinting films on driver vision.

    PubMed

    LaMotte, J; Ridder, W; Yeung, K; De Land, P

    2000-01-01

    This study was conducted to determine the level of automobile window tint that causes a significant reduction of vision for automobile drivers. Contrast sensitivity was measured on 20 participants, of whom 10 were age 20 to 29 years and 10 were age 60 to 69 years, through a stock automobile window (control) and two windows darkened with plastic film. For the younger drivers, a car window with 37% transmittance did not significantly reduce contrast sensitivity, but a darker tint of 18% transmittance reduced contrast sensitivity at higher spatial frequencies. For the older drivers, a tint of 37% transmittance significantly reduced mid-to- high spatial frequency contrast sensitivity. The typical state standard (no tint with less than 35% transmittance) would thus seem to be appropriate for younger drivers; however, further examination of the standard may be necessary in regard to older drivers. Actual or potential applications of this research include guidelines and regulations regarding tinting of automobile windows. PMID:11022888

  5. Beam position monitor

    DOEpatents

    Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

    2003-07-22

    An apparatus for determining the position of an x-ray beam relative to a desired beam axis. Where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in an a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

  6. Pyramid beam splitter

    DOEpatents

    McKeown, Mark H.; Beason, Steven C.; Fairer, George

    1992-01-01

    The apparatus of the present invention provides means for obtaining accurate, dependable, measurement of bearings and directions for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. In operation, a laser beam is projected along a reference bearing. A pyramid is mounted such that the laser beam is parallel to the pyramid axis and can impinge on the apex of the pyramid thus splitting the beam several ways into several beams at right angles to each other and at right angles to the reference beam. The pyramid is also translatable and rotatable in a plane perpendicular to the reference beam.

  7. De Novo Discovery of Mutated Driver Pathways in Cancer

    NASA Astrophysics Data System (ADS)

    Vandin, Fabio; Upfal, Eli; Raphael, Benjamin J.

    Next-generation DNA sequencing technologies are enabling genome-wide measurements of somatic mutations in large numbers of cancer patients. A major challenge in interpretation of this data is to distinguish functional driver mutations that are important for cancer development from random, passenger mutations. A common approach to identify driver mutations is to find genes that are mutated at significant frequency in a large cohort of cancer genomes. This approach is confounded by the observation that driver mutations target multiple cellular signaling and regulatory pathways. Thus, each cancer patient may exhibit a different combination of mutations that are sufficient to perturb the necessary pathways. However, the current understanding of the somatic mutational process of cancer [3,5,6] places two additional constraints on the expected patterns of somatic mutations in a cancer pathway. First, an important cancer pathway should be perturbed in a large number of patients. Thus we expect that with genome-wide measurements of somatic mutations a driver pathway will exhibit high coverage, where most patients will have a mutation in some gene in the pathway. Second, since driver mutations are relatively rare and typically a single driver mutation is sufficient to perturb a pathway, a reasonable assumption is that most patients have a single driver mutation in a pathway. Thus, the genes in a driver pathway exhibit a pattern of mutually exclusive driver mutations, where driver mutations are observed in exactly one gene in the pathway in each patient. There are numerous examples of sets of mutually exclusive mutations [5,6].

  8. Do Restricted Driver's Licenses Lower Crash Risk among Older Drivers? A Survival Analysis of Insurance Data from British Columbia

    ERIC Educational Resources Information Center

    Nasvadi, Glenyth Caragata; Wister, Andrew

    2009-01-01

    Purpose: Faced with an aging driving population, interest is increasing in the use of restricted licenses or "graduated delicensing" for older drivers to allow them to safely retain a driver's license. The primary purpose of this study was to determine whether restricted licenses are successful at mitigating number of crashes per year and whether…

  9. 77 FR 40142 - Applications for Exemption: Commercial Driver's License (CDL) and Hours-of-Service (HOS) of Drivers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... individual, filed a joint application seeking relief for 20 CMV drivers who transport jet fuel in tank CMVs... FMCSRs to determine if there are any practical alternatives that would allow it to conduct its motor... alternatives available to it, including hiring U.S. CDL drivers. A copy of the denial letter has been placed...

  10. Can Active Navigation Be as Good as Driving? A Comparison of Spatial Memory in Drivers and Backseat Drivers

    ERIC Educational Resources Information Center

    von Stulpnagel, Rul; Steffens, Melanie C.

    2012-01-01

    When driving a vehicle, either the driver or a passenger (henceforth: backseat driver) may be responsible for navigation. Research on active navigation, primarily addressed in virtual environments, suggests that controlling navigation is more central for spatial learning than controlling movement. To test this assumption in a real-world scenario,…

  11. Successful Beam-Beam Tuneshift Compensation

    SciTech Connect

    Bishofberger, Kip Aaron

    2005-01-01

    The performance of synchrotron colliders has been limited by the beam-beam limit, a maximum tuneshift that colliding bunches could sustain. Due to bunch-to-bunch tune variation and intra-bunch tune spread, larger tuneshifts produce severe emittance growth. Breaking through this constraint has been viewed as impossible for several decades. This dissertation introduces the physics of ultra-relativistic synchrotrons and low-energy electron beams, with emphasis placed on the limits of the Tevatron and the needs of a tuneshift-compensation device. A detailed analysis of the Tevatron Electron Lens (TEL) is given, comparing theoretical models to experimental data whenever possible. Finally, results of Tevatron operations with inclusion of the TEL are presented and analyzed. It is shown that the TEL provides a way to shatter the previously inescapable beam-beam limit.

  12. BEAMS3D Neutral Beam Injection Model

    SciTech Connect

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  13. Final report to US Department of Energy: Cyclotron autoresonance accelerator for electron beam dry scrubbing of flue gases

    SciTech Connect

    Hirshfield, J.L.

    2001-05-25

    Several designs have been built and operated of microwave cyclotron autoresonance accelerators (CARA's) with electron beam parameters suitable for remediation of pollutants in flue gas emissions from coal-burning power plants. CARA designs have also been developed with a TW-level 10.6 micron laser driver for electron acceleration from 50 to 100 MeV, and with UHF drivers for proton acceleration to over 500 MeV. Dose requirements for reducing SO2, NOx, and particulates in flue gas emissions to acceptable levels have been surveyed, and used to optimize the design of an electron beam source to deliver this dose.

  14. Anomalous beam diffusion near beam-beam synchrobetatron resonances

    NASA Astrophysics Data System (ADS)

    Sen, Tanaji

    2012-10-01

    The diffusion process near low order synchrobetatron resonances driven by beam-beam interactions at a crossing angle is investigated. Macroscopic observables such as beam emittance, lifetime, and beam profiles are calculated. These are followed with detailed studies of microscopic quantities such as the evolution of the variance at several transverse amplitudes and single particle probability distribution functions. We present evidence to show that the observed diffusion is anomalous and the dynamics follows a non-Markovian continuous time random walk process. We derive a modified master equation to replace the Chapman-Kolmogorov equation in action-angle space and a fractional diffusion equation to describe the density evolution for this class of processes.

  15. Beam Dynamics Experiments in Support of Relativistic Klystrons

    SciTech Connect

    Houck, T; Lidia, S

    2001-06-03

    Experiments to study beam dynamics for Relativistic Klystrons (RK) are being performed with a 1-MeV, 600-A induction accelerator beam. The RK is a RF Power source based on induction accelerator technology and conventional resonant output structures. Capable of generating 100's of MW/m at frequencies up to K-band, the RK has been proposed as a driver for a future linear collider in one version of a Two-Beam Accelerator. A critical feasibility issue remaining to be demonstrated is suppression of the transverse instability of the drive beam. This kiloampere beam must transit about a hundred resonance output structures and many hundreds of induction accelerator cavities for the RK to achieve competitive efficiency and cost with respect to other proposed power sources. The RK's strong focusing used to contain the beam in the small aperture resonant structures, repetitive geometry, and reacceleration allow the resonant output structures to be spaced at a betatron phase advance of 360{sup o}. This phase advance (or any integral multiple of 180{sup o}) is beneficial in linear accelerators as the instability growth changes from exponential to linear. In our experiment the beam is contained in a solenoidal focusing channel, RF cavities are spaced every 60 cm, and growth in the transverse motion is measured as a function of phase advance. Details of the experiments and results are presented.

  16. Beam Extraction from Laser Driven Multi-Charged Ion Source

    SciTech Connect

    Anderson, O A; Logan, B G

    2001-03-19

    A newly proposed type of multicharged ion source offers the possibility of an economically advantageous high-charge-state fusion driver. Multiphoton absorption in an intense uniform laser focus can give multiple charge states of high purity, simplifying or eliminating the need for charge-state separation downstream. Very large currents (hundreds of amperes) can be extracted from this type of source. Several arrangements are possible. For example, the laser plasma could be tailored for storage in a magnetic bucket, with beam extracted from the bucket. A different approach, described in this report, is direct beam extraction from the expanding laser plasma. They discuss extraction and focusing for the particular case of a 4.1-MV beam of Xe{sup 16+} ions. The maximum duration of the beam pulse is limited by the total charge in the plasma, while the practical pulse length is determined by the range of plasma radii over which good beam optics can be achieved. The extraction electrode contains a solenoid for beam focusing. The design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from the initial model showed that hundreds of amperes could be extracted, but that most of this current missed the solenoid entrance or was intercepted by the wall and that only a few amperes were able to pass through. They conclude with an improved design which increases the surviving beam to more than 70 amperes.

  17. What happens when drivers face hazards on the road?

    PubMed

    Ventsislavova, Petya; Gugliotta, Andres; Peña-Suarez, Elsa; Garcia-Fernandez, Pedro; Eisman, Eduardo; Crundall, David; Castro, Candida

    2016-06-01

    The current study aims to obtain knowledge about the nature of the processes involved in Hazard Perception, using measurement techniques to separate and independently quantify these suspected sub-processes: Sensation, Situation Awareness (recognition, location and projection) and decision-making. It applies Signal Detection Theory analysis to Hazard Perception and Prediction Tasks. To enable the calculation of Signal Detection Theory parameters, video-recorded hazardous vs. quasi-hazardous situations were presented to the participants. In the hazardous situations it is necessary to perform an evasive action, for instance, braking or swerving abruptly, while the quasi-hazardous situations do not require the driver to make any evasive manoeuvre, merely to carry on driving at the same speed and following the same trajectory. A first Multiple Choice Hazard Perception and Prediction test was created to measure participants' performance in a What Happens Next? Task. The sample comprised 143 participants, 47 females and 94 males. Groups of non-offender drivers (learner, novice and experienced) and offender drivers (novice and experienced) were recruited. The Multiple Choice Hazard Perception and Prediction test succeeded in finding differences between drivers according to their driving experience. In fact, differences exist with regard to the level of hazard discrimination (d' prime) by drivers with different experience (learner, novice and experienced drivers) and profile (offenders and non-offenders) and these differences emerge from Signal Detection Theory analysis. In addition, it was found that experienced drivers show higher Situation Awareness than learner or novice drivers. On the other hand, although offenders do worse than non-offenders on the hazard identification question, they do just as well when their Situation Awareness is probed (in fact, they are as aware as non-offenders of what the obstacles on the road are, where they are and what will happen next

  18. Psychoactive substances in seriously injured drivers in Denmark.

    PubMed

    Wiese Simonsen, K; Steentoft, A; Bernhoft, I M; Hels, T; Rasmussen, B S; Linnet, K

    2013-01-10

    This study assesses the presence of a number of psychoactive substances, including alcohol, based on blood samples from 840 seriously injured drivers admitted to five selected hospitals located in five different regions of Denmark. The study was a part of the EU 6th framework program DRUID (Driving Under the Influence of Drugs, Alcohol and Medicines). Blood samples were screened for 30 illegal and legal psychoactive substances and metabolites as well as ethanol. Danish legal limits were used to evaluate the frequency of drivers violating the Danish legislation while limit of quantification (LOQ) was used for monitoring positive drivers. Tramadol is not included in the Danish legislation therefore the general cut off, as decided in the DRUID project was used. Overall, ethanol (18%) was the most frequently identified compound (alone or in combination with other drugs) exceeding the legal limit, which is 0.53g/l in Denmark. The percentage of seriously injured drivers testing positive for medicinal drugs at levels above the Danish legal limit was 6.8%. Benzodiazepines and Z-drugs (6.4%) comprised the majority of this group. One or more illegal drugs (primarily amphetamines and cannabis) were found to be above the Danish legal limit in 4.9% of injured drivers. Young men (median age 31 years) were over-represented among injured drivers who violated Danish law for alcohol and drugs. Diazepam (4.4%), tramadol (3.2%), and clonazepam (3.0%) were the medicinal drugs most frequently detected at levels above LOQ, whereas amphetamines (5.4%) (amphetamine [5.2%] and methamphetamine [1.5%]), tetrahydrocannabinol (3.7%), and cocaine (3.3%), including the metabolite benzoylecgonine, were the most frequently detected illegal drugs. A driver could be positive for more than one substance; therefore, percentages are not mutually exclusive. Poly-drug use was observed in 112 (13%) seriously injured drivers. Tramadol was detected above DRUID cutoffs in 2.1% of seriously injured drivers

  19. High energy beam lines

    NASA Astrophysics Data System (ADS)

    Marchetto, M.; Laxdal, R. E.

    2014-01-01

    The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

  20. Electron Beam Freeform Fabrication

    NASA Video Gallery

    Electron Beam Freeform Fabrication (EBF3) is a process by which NASA hopes to build metal parts in zero gravity environments. It's a layer-additive process that uses an electron beam and a solid wi...

  1. Intra-beam scattering

    NASA Astrophysics Data System (ADS)

    Piwinski, A.

    Intra-beam scattering is analysed and the rise times or damping times of the beam dimensions are derived. The theoretical results are compared with experimental values obtained on the CERN AA and SPS machines.

  2. Laser-Beam Separator

    NASA Technical Reports Server (NTRS)

    Mcdermid, I. S.

    1984-01-01

    Train of prisms and optical stop separate fundamental beam of laser from second and higher order harmonics of beam produced in certain crystals and by stimulated Raman scattering in gases and liquids.

  3. A lateral driver model for vehicle-driver closed-loop simulation at the limits of handling

    NASA Astrophysics Data System (ADS)

    Joa, Eunhyek; Yi, Kyongsu; Kim, Kilsoo

    2015-09-01

    This paper presents a lateral driver model for vehicle-driver closed-loop simulation at the limits of handling. An appropriate driver model can be used to evaluate the performance of vehicle chassis control systems via computer simulations before vehicle tests which incurs expenses especially at the limits of handling. The driver model consists of two parts. The first part is an upper-level controller employing force-based approach to reduce the number of unknown vehicle parameters. The feedforward part of the upper controller has been designed by using the centre of percussion. The feedback part aims to minimise 'tangential error', defined as the sum of body slip angle and yaw error, to match vehicle direction and road heading angle. The part is designed to regenerate an appropriate skid motion similar to that of a professional driver at the limits. The second part is a lower-level controller which converts the desired front lateral force to steering wheel angle. The lower-level controller also consists of feedforward and feedback parts. A two-degree-of-freedom bicycle model-based feedforward part provides nominal steering wheel angle, and the feedback part aims to eliminate unmodelled error. The performance of the lateral driver model has been investigated via computer simulations. It has been shown that the steering behaviours of the proposed driver model are quite close to those of a professional driver at the limits. Compared with the previously developed lateral driver models, the proposed lateral driver model shows good tracking performance at the limits of handling.

  4. Electron beam focusing system

    SciTech Connect

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  5. Beam Dynamics for ARIA

    SciTech Connect

    Ekdahl, Carl August Jr.

    2014-10-14

    Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

  6. PARTICLE BEAM TRACKING CIRCUIT

    DOEpatents

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  7. Confinement of bunched beams

    NASA Astrophysics Data System (ADS)

    Hess, Mark; Chen, Chiping

    2001-05-01

    The non-relativistic motion is analyzed for a highly bunched beam propagating through a perfectly conducting cylindrical pipe confined radially by a constant magnetic field parallel to the conductor axis, using a Green's function technique and Hamiltonian dynamics analysis. It is shown that for the confinement of beams with the same charge per unit length, the maximum value of the effective self-field parameter for a highly bunched beam is significantly lower than the Brillouin density limit for an unbunched beam.

  8. Study of beam-beam effects in eRHIC

    SciTech Connect

    Hao, Y.; Litvinenko, V.; Ptitsyn, V.

    2010-05-23

    Beam-beam effects in eRHIC have a number of unique features, which distinguish them from both hadron and lepton colliders. Due to beam-beam interaction, both electron and hadron beams would suffer quality degradation or beam loss from without proper treatments. Those features need novel study and dedicate countermeasures. We study the beam dynamics and resulting luminosity of the characteristics, including mismatch, disruption and pinch effects on electron beam, in additional to their consequences on the opposing beam as a wake field and other incoherent effects of hadron beam. We also carry out countermeasures to prevent beam quality degrade and coherent instability.

  9. Dual beam optical interferometer

    NASA Technical Reports Server (NTRS)

    Gutierrez, Roman C. (Inventor)

    2003-01-01

    A dual beam interferometer device is disclosed that enables moving an optics module in a direction, which changes the path lengths of two beams of light. The two beams reflect off a surface of an object and generate different speckle patterns detected by an element, such as a camera. The camera detects a characteristic of the surface.

  10. ATA beam director experiment

    SciTech Connect

    Lee, E.P.; Younger, F.C.; Cruz, G.E.; Nolting, E.

    1986-06-23

    This report describes beam director elements for an experiment at the Advanced Test Accelerator. The elements described include a vernier magnet for beam aiming, an achromat magnet, and an isolation system for the beam interface. These components are built at small scale for concept testing. (JDH)

  11. Cooling of stored beams

    SciTech Connect

    Mills, F.E.

    1986-10-15

    Beam cooling methods developed for the accumulation of antiprotons are being employed to assist in the performance of experiments in Nuclear and Particle Physics with ion beams stored in storage rings. The physics of beam cooling, and the ranges of utility of stochastic and electron cooling are discussed in this paper.

  12. Beam injection into RHIC

    SciTech Connect

    Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N.; Zhang, W.

    1997-07-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.

  13. Electron beam device

    DOEpatents

    Beckner, E.H.; Clauser, M.J.

    1975-08-12

    This patent pertains to an electron beam device in which a hollow target is symmetrically irradiated by a high energy, pulsed electron beam about its periphery and wherein the outer portion of the target has a thickness slightly greater than required to absorb the electron beam pulse energy. (auth)

  14. Older drivers' insight into their hazard perception ability.

    PubMed

    Horswill, Mark S; Anstey, Kaarin J; Hatherly, Christopher; Wood, Joanne M; Pachana, Nancy A

    2011-11-01

    Even though the driving ability of older adults may decline with age, there is evidence that some individuals attempt to compensate for these declines using strategies such as restricting their driving exposure. Such compensatory mechanisms rely on drivers' ability to evaluate their own driving performance. This paper focuses on one key aspect of driver ability that is associated with crash risk and has been found to decline with age: hazard perception. Three hundred and seven drivers, aged 65-96, completed a validated video-based hazard perception test. There was no significant relationship between hazard perception test response latencies and drivers' ratings of their hazard perception test performance, suggesting that their ability to assess their own test performance was poor. Also, age-related declines in hazard perception latency were not reflected in drivers' self-ratings. Nonetheless, ratings of test performance were associated with self-reported regulation of driving, as was self-rated driving ability. These findings are consistent with the proposal that, while self-assessments of driving ability may be used by drivers to determine the degree to which they restrict their driving, the problem is that drivershave little insight into their own driving ability. This may impact on the potential road safety benefits of self-restriction of driving because drivers may not have the information needed to optimally self-restrict. Strategies for addressing this problem are discussed.

  15. Large reductions are possible in older driver crashes at intersections.

    PubMed

    Samuel, Siby; Yamani, Yusuke; Fisher, Donald L

    2016-09-01

    Among all crash types, the largest percentage of older driver fatalities occur at intersections. Many explanations have been offered for older drivers' increased risks of crashing at intersections; however, only recently was it determined that older drivers were much less likely to glance for latent threats after entering an intersection than middle-aged drivers. In response, training programmes were designed to increase the frequency of such glances. The programmes have proven effective, doubling the frequency of these glances for up to a period of two years post-training. The programmes take only an hour to administer and are not directly targeted at remediating any of the underlying declines in cognitive, visual or motor function that can explain the decrease in the frequency of glances for threat vehicles among older drivers. The first question we addressed was, what are the basic declines that can explain the decrease in glances for threat vehicles? The second question we addressed was, how did the training programme achieve the results it did without directly addressing these declines? We hypothesise that drivers are learning to decouple hand, foot and head movements in the training programmes and that this serialisation of behaviour essentially sidesteps the major declines in cognitive, visual and motor functions. We provide evidence that the assumptions of the decoupling hypothesis about the capabilities of older drivers when the movements are decoupled, are consistent with the evidence from existing experiments. More research is needed to evaluate this hypothesis. PMID:27523785

  16. Regime Shifts in the Anthropocene: Drivers, Risks, and Resilience

    PubMed Central

    Rocha, Juan Carlos; Peterson, Garry D.; Biggs, Reinette

    2015-01-01

    Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers. PMID:26267896

  17. Towards an understanding of driver inattention: taxonomy and theory.

    PubMed

    Regan, Michael A; Strayer, David L

    2014-01-01

    There is little agreement in the scientific literature about what the terms "driver distraction" and "driver inattention" mean, and what the relationship is between them. In 2011, Regan, Hallett and Gordon proposed a taxonomy of driver inattention in which driver distraction is conceptualized as just one of several processes that give rise to driver inattention. Since publication of that paper, two other papers have emerged that bear on the taxonomy. In one, the Regan et al taxonomy was used, for the first time, to classify data from an in-depth crash investigation in Australia. In the other, another taxonomy of driver inattention was proposed and described. In this paper we revisit the original taxonomy proposed by Regan et al. in light of these developments, and make recommendations for how the original taxonomy might be improved to make it more useful as a tool for classifying and coding crash and critical incident data. In addition, we attempt to characterize, theoretically, the processes within each category of the original taxonomy that are assumed to give rise to driver inattention. Recommendations are made for several lines of research: to further validate the original taxonomy; to understand the impact of each category of inattention in the taxonomy on driving performance, crash type and crash risk; and to revise and align with the original taxonomy existing crash and incident investigation protocols, so that they provide more comprehensive, reliable and consistent information regarding the contribution of inattention to crashes of all types.

  18. Bifurcation analysis of a car and driver model

    NASA Astrophysics Data System (ADS)

    Della Rossa, Fabio; Gobbi, Massimiliano; Mastinu, Gianpiero; Piccardi, Carlo; Previati, Giorgio

    2014-05-01

    The bifurcation analysis of a simple mathematical model describing a road vehicle with a driver is presented. The mechanical model of the car has two degrees of freedom and the related equations of motion contain the nonlinear tyre characteristics. The driver is described by a well-known model proposed in the literature. The road vehicle model has been validated in a case study. Bifurcation analysis is adopted as the proper procedure for analysing both steady-state cornering and straight ahead motion at different speeds. The importance of properly computing steady-state equilibria is highlighted. The effect of a skilled driver is to broaden the basin of attraction of stable equilibria and, in some cases, to stabilise originally unstable behaviours. A subcritical Hopf bifurcation is normally found which limits the forward speed of either understeering or oversteering vehicles. A three-parameter bifurcation analysis is performed to understand the influence on stability of driver gain, of driver prediction time, of vehicle speed. It turns out, as expected from practice, that an oversteering vehicle is more challenging to be controlled than an understeering one. The paper proposes an insight into vehicle-driver interaction. The stabilising or de-stabilising effect of the driver is ultimately explained referring to the existence of a Hopf bifurcation.

  19. Risky attitudes towards road use in pre-drivers.

    PubMed

    Waylen, Andrea E; McKenna, Frank P

    2008-05-01

    Motor vehicle accidents are one of the principal causes of adolescent disability or mortality and male drivers are more likely to be involved in road accidents than female drivers. In part such associations between driver age and sex have been linked to differences in risky behaviour (e.g. speed, violations) and individual characteristics (e.g. sensation seeking, deviant behaviour). The aim of this research is to determine whether associations between risky road user behaviour and individual characteristics are a function of driver behaviour or whether they are intrinsic and measurable in individuals too young to drive. Five hundred and sixty-seven pre-driver students aged 11-16 from three secondary schools completed questionnaires measuring enthusiasm for speed, sensation seeking, deviant behaviour and attitudes towards driver violations. Boys reported more risky attitudes than girls for all measures. Associations between sensation seeking, deviant behaviour and attitudes towards risky road use were present from early adolescence and were strongest around age 14, before individuals learn to drive. Risky attitudes towards road use are associated with individual characteristics and are observed in adolescents long before they learn to drive. Safe attitudes towards road use and driver behaviour should be promoted from childhood in order to be effective.

  20. Regime shifts in the anthropocene: drivers, risks, and resilience.

    PubMed

    Rocha, Juan Carlos; Peterson, Garry D; Biggs, Reinette

    2015-01-01

    Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers.

  1. Regime shifts in the anthropocene: drivers, risks, and resilience.

    PubMed

    Rocha, Juan Carlos; Peterson, Garry D; Biggs, Reinette

    2015-01-01

    Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers. PMID:26267896

  2. Towards an Understanding of Driver Inattention: Taxonomy and Theory

    PubMed Central

    Regan, Michael. A.; Strayer, David. L.

    2014-01-01

    There is little agreement in the scientific literature about what the terms “driver distraction” and “driver inattention” mean, and what the relationship is between them. In 2011, Regan, Hallett and Gordon proposed a taxonomy of driver inattention in which driver distraction is conceptualized as just one of several processes that give rise to driver inattention. Since publication of that paper, two other papers have emerged that bear on the taxonomy. In one, the Regan et al taxonomy was used, for the first time, to classify data from an in-depth crash investigation in Australia. In the other, another taxonomy of driver inattention was proposed and described. In this paper we revisit the original taxonomy proposed by Regan et al. in light of these developments, and make recommendations for how the original taxonomy might be improved to make it more useful as a tool for classifying and coding crash and critical incident data. In addition, we attempt to characterize, theoretically, the processes within each category of the original taxonomy that are assumed to give rise to driver inattention. Recommendations are made for several lines of research: to further validate the original taxonomy; to understand the impact of each category of inattention in the taxonomy on driving performance, crash type and crash risk; and to revise and align with the original taxonomy existing crash and incident investigation protocols, so that they provide more comprehensive, reliable and consistent information regarding the contribution of inattention to crashes of all types. PMID:24776222

  3. Visual Fitness of Public Vehicle Drivers in Southeast of Iran

    PubMed Central

    Sharifi, Ali; Sharifi, Hamid; Karamouzian, Mohammad; Daneshtalab, Elham; Daneshtalab, Ali

    2013-01-01

    Background: Although visual impairment of drivers is a very important risk factor for car accident, a few published papers have explored this issue in Iran. This study aims to evaluate the visual fitness of public vehicle drivers in Kerman province, southeast of Iran. Methods: A total of 4,003 public vehicle drivers were examined by one ophthalmologist for visual fitness in Kerman province between January 2009 and June 2010. Data are presented as Mean±SD or percentage, and with 95% confidence intervals (CIs). Pearson Chi-square and McNemmar tests along with crude odds ratio (OR) were used to compare vision deficit between groups. Results: Almost 361 drivers (9.0%; 95% CI: 8.1-9.9) had insufficient vision to drive public vehicles before the refractive errors (RE) correction and this number, was reduced to 68 drivers (1.7%; 95% CI: 1.3-2.1) after the correction. A number of them including 200 drivers (5.0%; 95% CI: 4.3-5.7) had insufficient vision to drive personal vehicles before the correction and this was reduced to 30 thereafter (0.8%; 95% CI: 0.5-1.0). We also found out that the vision status got worse with aging, and RE was the most prevalent cause of sight defects. Conclusion: It seems that visual fitness of public vehicle drivers is a point of real concerns which might somewhat explain the high rate of car accidents in Iran. PMID:23930189

  4. A high power beam-on-target test of liquid lithium target for RIA.

    SciTech Connect

    Nolen, J.; Reed, C.; Novick, V.; Specht, J.; Plotkin, P.; Momozaki,Y.; Gomes, I.

    2005-08-29

    Experiments were conducted to demonstrate the stable operation of a windowless liquid lithium target under extreme thermal loads that are equivalent to uranium beams from the proposed Rare Isotope Accelerator (RIA) driver linac. The engineering and safety issues accompanying liquid lithium systems are first discussed. The liquid metal technology knowledge base generated primarily for fast reactors, and liquid metal cooled fusion reactors, was applied to the development of these systems in a nuclear physics laboratory setting. The use of a high energy electron beam for simulating a high power uranium beam produced by the RIA driver linac is also described. Calculations were performed to obtain energy deposition profiles produced by electron beams at up to a few MeV to compare with expected uranium beam energy deposition profiles. It was concluded that an experimental simulation using a 1-MeV electron beam would be a valuable tool to assess beam-jet interaction. In the experiments, the cross section of the windowless liquid lithium target was 5 mm x 10 mm, which is a 1/3rd scale prototype target, and the velocity of the liquid lithium was varied up to 6 m/s. Thermal loads up to 20 kW within a beam spot diameter of 1mm were applied on the windowless liquid lithium target by the 1-MeV electron beam. The calculations showed that the maximum power density and total power deposited within the target, from the electron beam, was equivalent to that of a 200-kW, 400-MeV/u uranium beam. It was demonstrated that the windowless liquid lithium target flowing at velocities as low as 1.8 m/s stably operated under beam powers up to 20 kW without disruption or excessive vaporization.

  5. Prevalence of drug use in commercial tractor-trailer drivers.

    PubMed

    Couper, Fiona J; Pemberton, Melissa; Jarvis, Anjanette; Hughes, Marty; Logan, Barry K

    2002-05-01

    An enforcement emphasis project, "Operation Trucker Check," was established in order to determine the extent to which commercial tractor-trailer drivers were operating their vehicles while impaired by drugs. A total of 1079 drivers and their vehicles were assessed for driver and equipment violations, and drivers additionally underwent preliminary field sobriety tests conducted by drug recognition expert (DRE) officers. Anonymous urine specimens for drug analysis were requested, and 822 urine specimens were obtained in total. Compliance with the drug-testing portion was voluntary, and there was a 19% refusal rate. Overall, 21% of the urine specimens tested positive for either illicit, prescription, and/or over-the-counter drugs, and 7% tested positive for more than one drug. Excluding caffeine and nicotine, the largest number of positive findings (9.5%) were for CNS stimulants, such as methamphetamine, amphetamine, phentermine, ephedrine/pseudoephedrine, and cocaine. The second most frequently encountered drug class were the cannabinoids, with 4.3% of drivers testing positive for marijuana metabolites. Only 11 drivers (1.3%) were positive for alcohol. Sixteen truck drivers (1.6%) were charged with driving under the influence of drugs after a full DRE evaluation was conducted. The results indicate that in spite of comprehensive drug testing in the trucking industry, some tractor-trailer drivers are continuing to take illicit and other drugs with the potential of having a negative effect on their driving ability. On the other hand, only a few drivers were, in fact, deemed to be under the influence of drugs at the time of driving when evaluated by DRE officers.

  6. Effectiveness of Taxicab Security Equipment in Reducing Driver Homicide Rates

    PubMed Central

    Menéndez, Cammie K.C.; Amandus, Harlan E.; Damadi, Parisa; Wu, Nan; Konda, Srinivas; Hendricks, Scott A.

    2015-01-01

    Background Taxicab drivers historically have had one of the highest work-related homicide rates of any occupation. In 2010 the taxicab driver homicide rate was 7.4 per 100,000 drivers, compared to the overall rate of 0.37 per 100,000 workers. Purpose Evaluate the effectiveness of taxicab security cameras and partitions on citywide taxicab driver homicide rates. Methods Taxicab driver homicide rates were compared in 26 major cities in the U.S. licensing taxicabs with security cameras (n=8); bullet-resistant partitions (n=7); and cities where taxicabs were not equipped with either security cameras or partitions (n=11). News clippings of taxicab driver homicides and the number of licensed taxicabs by city were used to construct taxicab driver homicide rates spanning 15 years (1996–2010). Generalized estimating equations were constructed to model the Poisson-distributed homicide rates on city-specific safety equipment installation status, controlling for city homicide rate and the concurrent decline of homicide rates over time. Data were analyzed in 2012. Results Cities with cameras experienced a threefold reduction in taxicab driver homicides compared with control cities (RR=0.27; 95% CI=0.12, 0.61; p=0.002). There was no difference in homicide rates for cities with partitions compared with control cities (RR=1.15; 95% CI=0.80, 1.64; p=0.575). Conclusions Municipal ordinances and company policies mandating security cameras appear to be highly effective in reducing taxicab driver deaths due to workplace violence. PMID:23790983

  7. Prevalence of drug use in commercial tractor-trailer drivers.

    PubMed

    Couper, Fiona J; Pemberton, Melissa; Jarvis, Anjanette; Hughes, Marty; Logan, Barry K

    2002-05-01

    An enforcement emphasis project, "Operation Trucker Check," was established in order to determine the extent to which commercial tractor-trailer drivers were operating their vehicles while impaired by drugs. A total of 1079 drivers and their vehicles were assessed for driver and equipment violations, and drivers additionally underwent preliminary field sobriety tests conducted by drug recognition expert (DRE) officers. Anonymous urine specimens for drug analysis were requested, and 822 urine specimens were obtained in total. Compliance with the drug-testing portion was voluntary, and there was a 19% refusal rate. Overall, 21% of the urine specimens tested positive for either illicit, prescription, and/or over-the-counter drugs, and 7% tested positive for more than one drug. Excluding caffeine and nicotine, the largest number of positive findings (9.5%) were for CNS stimulants, such as methamphetamine, amphetamine, phentermine, ephedrine/pseudoephedrine, and cocaine. The second most frequently encountered drug class were the cannabinoids, with 4.3% of drivers testing positive for marijuana metabolites. Only 11 drivers (1.3%) were positive for alcohol. Sixteen truck drivers (1.6%) were charged with driving under the influence of drugs after a full DRE evaluation was conducted. The results indicate that in spite of comprehensive drug testing in the trucking industry, some tractor-trailer drivers are continuing to take illicit and other drugs with the potential of having a negative effect on their driving ability. On the other hand, only a few drivers were, in fact, deemed to be under the influence of drugs at the time of driving when evaluated by DRE officers. PMID:12051337

  8. Design of the ILC Prototype FONT4 Digital Intra-Train Beam-Based Feedback System

    SciTech Connect

    Burrows, P.; Christian, G.B.; Hartin, A.F.; Dabiri Khah, H.; White, G.R.; Clarke, C.C.; Perry, C.; Kalinin, A.; McCormick, D.J.; Molloy, S.; Ross, M.C.; /SLAC

    2007-04-16

    We present the design of the FONT4 digital intra-train beam position feedback system prototype and preliminary results of initial beam tests at the Accelerator Test Facility (ATF) at KEK. The feedback system incorporates a fast analogue beam position monitor (BPM) front-end signal processor, a digital feedback board, and a kicker driver amplifier. The short bunchtrain, comprising 3 electron bunches separated by c. 150ns, in the ATF extraction line was used to test components of the prototype feedback system.

  9. Note: An improved solenoid driver valve for miniature shock tubes.

    PubMed

    Lynch, P T

    2016-05-01

    A solenoid driver valve has been built to improve the operating performance of diaphragmless shock tubes, which are used for high pressure, high temperature chemical kinetics, and fluid mechanics studies. For shock tube driver application, the most important characteristics are those of sealing, strength, and quality of the generated shock waves and repeatability of opening characteristics and therefore subsequent post-shock conditions. The main features of the new driver valve are a face o-ring sealing design of the valve, the large internal volume, and through inserts near the solenoid core: adjustable opening characteristics of the valve. PMID:27250485

  10. Simulator for Measuring Elderly Driver's Visual Performances While Driving

    NASA Astrophysics Data System (ADS)

    Nakano, Tomoaki; Yamada, Muneo; Takagi, Yoshiya; Yamamoto, Osami; Yamamoto, Shin

    Aging goes on rapidly in Japan and traffic accidents of elderly driver are increasing year by year. It is a main cause of the accidents that most elderly drivers are not aware of the reduction in their visual performances. The purpose of this research is to develop the system that measures the elderly visual perceptions necessary for safe driving and improves their perceptions by education and training. This paper describes the simulator for measuring the most important visual perceptions; visual field, dynamic visual acuity and depth perception while driving. This paper also presents the measurement results of the visual perceptions for older drivers.

  11. Fatal Traffic Crashes Involving Drinking Drivers: What have we Learned?

    PubMed Central

    Fell, James C.; Tippetts, A. Scott; Voas, Robert B.

    2009-01-01

    Alcohol involvement in fatal crashes (any driver with a blood alcohol concentration [BAC] = .01g/dL or greater) in 2007 was more than three times higher at night (6 p.m.–6 a.m.) than during the day (6 a.m.–6 p.m.) (62% versus 19%). Alcohol involvement was 35% during weekdays compared to 54% on weekends. Nearly one in four drivers (23%) of personal vehicles (e.g., passenger cars or light trucks) and more than one in four motorcyclists (27%) in fatal crashes were intoxicated (i.e., had a BAC equal to or greater than the .08 g/dL illegal limit in the United States). In contrast, only 1% of the commercial drivers of heavy trucks had BACs equal to .08 g/dL or higher. More than a quarter (26%) of the drivers with high BACs (≥.15 g/dL) did not have valid licenses. The 21- to 24-age group had the highest proportion (35%) of drivers with BACs≥.08 g/dL, followed by the 25- to 34-age group (29%). The oldest and the youngest drivers had the lowest percentages of BACs≥ .08 g/dL: those aged 75 or older were at 4%, and those aged 16 to 20 were at 17%. Utah had the lowest rate of intoxicated drivers in fatal crashes at one in every eight drivers (12%), followed by Kentucky, Indiana, Iowa, New Hampshire, and Kansas, all at 17%. Montana (31%), South Carolina (31%), and North Dakota (39%) all had more than 3 in 10 drivers in fatal crashes who were intoxicated in 2007. The United States enjoyed a remarkable downward trend in alcohol-related crashes between 1982 and 1995, which has since leveled off. That trend coincided with a period during which per capita national alcohol consumption declined, the number of young drivers decreased, and the proportion of female drivers increased. Those factors alone, however, did not appear to account for the overall reduction. This provides further evidence that impaired-driving laws and safety program activity may have been responsible for at least some of the decline. However, there was a general worldwide decline in alcohol

  12. Fatal traffic crashes involving drinking drivers: what have we learned?

    PubMed

    Fell, James C; Tippetts, A Scott; Voas, Robert B

    2009-10-01

    Alcohol involvement in fatal crashes (any driver with a blood alcohol concentration [BAC] = .01g/dL or greater) in 2007 was more than three times higher at night (6 p.m.-6 a.m.) than during the day (6 a.m.-6 p.m.) (62% versus 19%). Alcohol involvement was 35% during weekdays compared to 54% on weekends. Nearly one in four drivers (23%) of personal vehicles (e.g., passenger cars or light trucks) and more than one in four motorcyclists (27%) in fatal crashes were intoxicated (i.e., had a BAC equal to or greater than the .08 g/dL illegal limit in the United States). In contrast, only 1% of the commercial drivers of heavy trucks had BACs equal to .08 g/dL or higher. More than a quarter (26%) of the drivers with high BACs (>or=.15 g/dL) did not have valid licenses. The 21- to 24-age group had the highest proportion (35%) of drivers with BACs>or=.08 g/dL, followed by the 25- to 34-age group (29%). The oldest and the youngest drivers had the lowest percentages of BACs>or= .08 g/dL: those aged 75 or older were at 4%, and those aged 16 to 20 were at 17%. Utah had the lowest rate of intoxicated drivers in fatal crashes at one in every eight drivers (12%), followed by Kentucky, Indiana, Iowa, New Hampshire, and Kansas, all at 17%. Montana (31%), South Carolina (31%), and North Dakota (39%) all had more than 3 in 10 drivers in fatal crashes who were intoxicated in 2007. The United States enjoyed a remarkable downward trend in alcohol-related crashes between 1982 and 1995, which has since leveled off. That trend coincided with a period during which per capita national alcohol consumption declined, the number of young drivers decreased, and the proportion of female drivers increased. Those factors alone, however, did not appear to account for the overall reduction. This provides further evidence that impaired-driving laws and safety program activity may have been responsible for at least some of the decline. However, there was a general worldwide decline in alcohol

  13. BEAM CONTROL PROBE

    DOEpatents

    Chesterman, A.W.

    1959-03-17

    A probe is described for intercepting a desired portion of a beam of charged particles and for indicating the spatial disposition of the beam. The disclosed probe assembly includes a pair of pivotally mounted vanes moveable into a single plane with adjacent edges joining and a calibrated mechanical arrangement for pivoting the vancs apart. When the probe is disposed in the path of a charged particle beam, the vanes may be adjusted according to the beam current received in each vane to ascertain the dimension of the beam.

  14. Beams for kaon research

    SciTech Connect

    Pile, P.H.

    1985-01-01

    A proposed 1-2 GeV/c kaon beam line for BNL, designed to deliver momentum analyzed negative kaon beams with intensities above 10/sup 6/ per spill, is discussed. The beam intensity is expected to be about an order of magnitude greater than presently available and it is expected to be a clean beam with no more than 1:1 (..pi../sup -/,..mu../sup -/,e/sup -/)/K/sup -/. The beam line will allow a detailed investigation of strangeness -2 systems as well as continued investigations of strangeness -1 systems.

  15. Neutral beam monitoring

    DOEpatents

    Fink, Joel H.

    1981-08-18

    Method and apparatus for monitoring characteristics of a high energy neutral beam. A neutral beam is generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange neutralizes the high energy ion beam. The neutral beam is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are further identified.

  16. Generalized drivers in the mammalian endangerment process.

    PubMed

    González-Suárez, Manuela; Revilla, Eloy

    2014-01-01

    An important challenge for conservation today is to understand the endangerment process and identify any generalized patterns in how threats occur and aggregate across taxa. Here we use a global database describing main current external threats in mammals to evaluate the prevalence of distinct threatening processes, primarily of anthropogenic origin, and to identify generalized drivers of extinction and their association with vulnerability status and intrinsic species' traits. We detect several primary threat combinations that are generally associated with distinct species. In particular, large and widely distributed mammals are affected by combinations of direct exploitation and threats associated with increasing landscape modification that go from logging to intense human land-use. Meanwhile, small, narrowly distributed species are affected by intensifying levels of landscape modification but are not directly exploited. In general more vulnerable species are affected by a greater number of threats, suggesting increased extinction risk is associated with the accumulation of external threats. Overall, our findings show that endangerment in mammals is strongly associated with increasing habitat loss and degradation caused by human land-use intensification. For large and widely distributed mammals there is the additional risk of being hunted.

  17. Global coccolithophore diversity: Drivers and future change

    NASA Astrophysics Data System (ADS)

    O'Brien, Colleen J.; Vogt, Meike; Gruber, Nicolas

    2016-01-01

    We use the MAREDAT global compilation of coccolithophore species distribution and combine them with observations of climatological environmental conditions to determine the global-scale distribution of coccolithophore species diversity, its underlying drivers, and potential future changes. To this end, we developed a feed-forward neural network, which predicts 78% of the observed variance in coccolithophore diversity from environmental input variables (temperature, PAR, nitrate, silicic acid, mixed layer depth, excess phosphate (P∗) and chlorophyll). Light and temperature are the strongest predictors of coccolithophore diversity. Coccolithophore diversity is highest in the low latitudes, where coccolithophores are a relatively dominant component of the total phytoplankton community. Particularly high diversity is predicted in the western equatorial Pacific and the southern Indian Ocean, with additional peaks at approximately 30°N and 30°S. The global, zonal mean pattern is dominated by the Pacific Ocean, which shows a clear latitudinal gradient with diversity peaking at the equator, whereas in the Atlantic Ocean diversity is highest in the subtropics. We find a unimodal relationship between coccolithophore diversity and biomass, as has previously been observed for total phytoplankton assemblages. In contrast, diversity shows a negative relationship with total chlorophyll. Applying our diversity model to projections from the CMIP5 climate models, we project an increase in the diversity of coccolithophore assemblages by the end of this century.

  18. Global drivers of future river flood risk

    NASA Astrophysics Data System (ADS)

    Winsemius, Hessel C.; Aerts, Jeroen C. J. H.; van Beek, Ludovicus P. H.; Bierkens, Marc F. P.; Bouwman, Arno; Jongman, Brenden; Kwadijk, Jaap C. J.; Ligtvoet, Willem; Lucas, Paul L.; van Vuuren, Detlef P.; Ward, Philip J.

    2016-04-01

    Understanding global future river flood risk is a prerequisite for the quantification of climate change impacts and planning effective adaptation strategies. Existing global flood risk projections fail to integrate the combined dynamics of expected socio-economic development and climate change. We present the first global future river flood risk projections that separate the impacts of climate change and socio-economic development. The projections are based on an ensemble of climate model outputs, socio-economic scenarios, and a state-of-the-art hydrologic river flood model combined with socio-economic impact models. Globally, absolute damage may increase by up to a factor of 20 by the end of the century without action. Countries in Southeast Asia face a severe increase in flood risk. Although climate change contributes significantly to the increase in risk in Southeast Asia, we show that it is dwarfed by the effect of socio-economic growth, even after normalization for gross domestic product (GDP) growth. African countries face a strong increase in risk mainly due to socio-economic change. However, when normalized to GDP, climate change becomes by far the strongest driver. Both high- and low-income countries may benefit greatly from investing in adaptation measures, for which our analysis provides a basis.

  19. Greening of the Earth and its drivers

    DOE PAGES

    Zhu, Zaichun; Piao, Shilong; Myneni, Ranga B.; Huang, Mengtian; Zeng, Zhenzhong; Canadell, Josep G.; Ciais, Philippe; Sitch, Stephen; Friedlingstein, Pierre; Arneth, Almut; et al

    2016-04-25

    Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system and provision of ecosystem services1, 2. Yet how global vegetation is responding to the changing environment is not well established. Here we use three long-term satellite leaf area index (LAI) records and ten global ecosystem models to investigate four key drivers of LAI trends during 1982 2009. We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning).more » Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend, followed by nitrogen deposition (9%), climate change (8%) and land cover change (LCC) (4%). CO2 fertilization effects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau. LCC contributed most to the regional greening observed in southeast China and the eastern United States. In conclusion, the regional effects of unexplained factors suggest that the next generation of ecosystem models will need to explore the impacts of forest demography, differences in regional management intensities for cropland and pastures, and other emerging productivity constraints such as phosphorus availability.« less

  20. Greening of the Earth and its drivers

    NASA Astrophysics Data System (ADS)

    Zhu, Zaichun; Piao, Shilong; Myneni, Ranga B.; Huang, Mengtian; Zeng, Zhenzhong; Canadell, Josep G.; Ciais, Philippe; Sitch, Stephen; Friedlingstein, Pierre; Arneth, Almut; Cao, Chunxiang; Cheng, Lei; Kato, Etsushi; Koven, Charles; Li, Yue; Lian, Xu; Liu, Yongwen; Liu, Ronggao; Mao, Jiafu; Pan, Yaozhong; Peng, Shushi; Peñuelas, Josep; Poulter, Benjamin; Pugh, Thomas A. M.; Stocker, Benjamin D.; Viovy, Nicolas; Wang, Xuhui; Wang, Yingping; Xiao, Zhiqiang; Yang, Hui; Zaehle, Sönke; Zeng, Ning

    2016-08-01

    Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system and provision of ecosystem services. Yet how global vegetation is responding to the changing environment is not well established. Here we use three long-term satellite leaf area index (LAI) records and ten global ecosystem models to investigate four key drivers of LAI trends during 1982-2009. We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend, followed by nitrogen deposition (9%), climate change (8%) and land cover change (LCC) (4%). CO2 fertilization effects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau. LCC contributed most to the regional greening observed in southeast China and the eastern United States. The regional effects of unexplained factors suggest that the next generation of ecosystem models will need to explore the impacts of forest demography, differences in regional management intensities for cropland and pastures, and other emerging productivity constraints such as phosphorus availability.