Transport modeling of the DIII-D high $${{\\beta}_{p}}$$ scenario and extrapolations to ITER steady-state operation

DOE PAGES

McClenaghan, Joseph; Garofalo, Andrea M.; Meneghini, Orso; ...

2017-08-03

In this study, transport modeling of a proposed ITER steady-state scenario based on DIII-D high poloidal-beta (more » $${{\\beta}_{p}}$$ ) discharges finds that ITB formation can occur with either sufficient rotation or a negative central shear q-profile. The high $${{\\beta}_{p}}$$ scenario is characterized by a large bootstrap current fraction (80%) which reduces the demands on the external current drive, and a large radius internal transport barrier which is associated with excellent normalized confinement. Modeling predictions of the electron transport in the high $${{\\beta}_{p}}$$ scenario improve as $${{q}_{95}}$$ approaches levels similar to typical existing models of ITER steady-state and the ion transport is turbulence dominated. Typical temperature and density profiles from the non-inductive high $${{\\beta}_{p}}$$ scenario on DIII-D are scaled according to 0D modeling predictions of the requirements for achieving a $Q=5$ steady-state fusion gain in ITER with 'day one' heating and current drive capabilities. Then, TGLF turbulence modeling is carried out under systematic variations of the toroidal rotation and the core q-profile. A high bootstrap fraction, high $${{\\beta}_{p}}$$ scenario is found to be near an ITB formation threshold, and either strong negative central magnetic shear or rotation in a high bootstrap fraction are found to successfully provide the turbulence suppression required to achieve $Q=5$.« less

18. Detail view of central pivot pier, drive gear rack, ...

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

18. Detail view of central pivot pier, drive gear rack, and stabilizing wheel, looking southwest - India Point Railroad Bridge, Spanning Seekonk River between Providence & East Providence, Providence, Providence County, RI

Perceptual load in different regions of the visual scene and its relevance for driving.

PubMed

Marciano, Hadas; Yeshurun, Yaffa

2015-06-01

The aim of this study was to better understand the role played by perceptual load, at both central and peripheral regions of the visual scene, in driving safety. Attention is a crucial factor in driving safety, and previous laboratory studies suggest that perceptual load is an important factor determining the efficiency of attentional selectivity. Yet, the effects of perceptual load on driving were never studied systematically. Using a driving simulator, we orthogonally manipulated the load levels at the road (central load) and its sides (peripheral load), while occasionally introducing critical events at one of these regions. Perceptual load affected driving performance at both regions of the visual scene. Critically, the effect was different for central versus peripheral load: Whereas load levels on the road mainly affected driving speed, load levels on its sides mainly affected the ability to detect critical events initiating from the roadsides. Moreover, higher levels of peripheral load impaired performance but mainly with low levels of central load, replicating findings with simple letter stimuli. Perceptual load has a considerable effect on driving, but the nature of this effect depends on the region of the visual scene at which the load is introduced. Given the observed importance of perceptual load, authors of future studies of driving safety should take it into account. Specifically, these findings suggest that our understanding of factors that may be relevant for driving safety would benefit from studying these factors under different levels of load at different regions of the visual scene. © 2014, Human Factors and Ergonomics Society.

Advances in transient (pulsed) eddy current for inspection of multi-layer aluminum structures in the presence of ferrous fasteners

NASA Astrophysics Data System (ADS)

Desjardins, D. R.; Vallières, G.; Whalen, P. P.; Krause, T. W.

2012-05-01

An experimental investigation of the electromagnetic processes underlying transient (pulsed) eddy current inspection of aircraft wing structures in the vicinity of ferrous fasteners is performed. The separate effects of transient excitation of ferrous fastener and eddy currents induced in the surrounding aluminum structure are explored using a transmit-receive configuration with transient excitation of a steel rod, an aluminum plate with a bore hole and a steel rod through the bore hole. Observations are used to interpret results from a coupled driving and differential coil sensing unit applied to detect fatigue cracks emanating from bolt holes in aluminum structures with ferrous fasteners present. In particular, it is noted that abrupt magnetization of the fastener, by the probe's central driving unit, can transfer flux and consequently, induce strong eddy current responses deep within the aluminum structure in the vicinity of the bore hole. Rotation of the probe, centered over the fastener, permits detection of subsurface discontinuities, such as cracks, by the pair of differentially connected pickup coils.

Effects of confinement and electron transport on magnetic switching in single Co nanoparticles

PubMed Central

Jiang, W.; Birk, F. T.; Davidović, D.

2013-01-01

This work reports the first study of current-driven magnetization noise in a single, nanometerscale, ferromagnetic (Co) particle, attached to normal metal leads by high-resistance tunneling junctions. As the tunnel current increases at low temperature, the magnetic switching field decreases, its probability distribution widens, while the temperature of the environment remains nearly constant. These observations demonstrate nonequilibrium magnetization noise. A classical model of the noise is provided, where the spin-orbit interaction plays a central role in driving magnetic tunneling transitions. PMID:23383370

Concepts of magnetospheric convection

NASA Technical Reports Server (NTRS)

Vasyliunas, V. M.

1975-01-01

The paper describes the basic theoretical notions of convection applicable to magnetospheres in general and discusses the relative importance of convective and corrotational motions, with particular reference to the comparison of the earth and Jupiter. The basic equations relating the E, B, and J fields and the bulk plasma velocity are given for the three principal regions in magnetosphere dynamics, namely, the central object and its magnetic field, the space surrounding the central object, and the external medium outside the magnetosphere. The notion of driving currents of magnetospheric convection and their closure is explained, while consideration of the added effects of the rotation of the central body completes the basic theoretical picture. Flow topology is examined for the two cases where convection dominates over corotation and vice versa.

Measurements of dynamo effect on double-CHI pulse ST plasmas on HIST

NASA Astrophysics Data System (ADS)

Ito, K.; Hanao, T.; Ishihara, M.; Matsumoto, K.; Higashi, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

2011-10-01

Coaxial Helicity injection (CHI) is an efficient current-drive method used in spheromak and spherical torus (ST) experiments. An anticipated issue for CHI is achieving good energy confinement, since it relies on the magnetic relaxation and dynamo. This is essentially because CHI cannot drive a dynamo directly inside a closed magnetic flux surface. Thus, it is an important issue to investigate dynamo effect to explore CHI current drive mechanisms in a new approach such as Multi-pulsing CHI method. To study the dynamo model with two-fluid Hall effects, we have started from the generalized Ohm law. We have measured each MHD dynamo term and Hall dynamo term separately by using Mach probe and Hall probe involving 3-axis magnetic pick-up coils. The result shows that the induced electric field due to MHD dynamo is large enough to sustain the mean toroidal current against resistive decay in the core region. In the other hand, the anti-dynamo effect in the MHD dynamo term is observed in the central open flux column (OFC) region. From the viewpoint of two-fluid theory, ion diamagnetic drift is opposite to the electron diamagnetic drift, maybe resulting in the anti-dynamo effect. Hall dynamo may arise from the fluctuating electron diamagnetic current due to high electron density gradient which is large in the OFC region.

Advanced tokamak investigations in full-tungsten ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Bock, A.; Doerk, H.; Fischer, R.; Rittich, D.; Stober, J.; Burckhart, A.; Fable, E.; Geiger, B.; Mlynek, A.; Reich, M.; Zohm, H.; ASDEX Upgrade Team

2018-05-01

The appropriate tailoring of the q-profile is the key to accessing Advanced Tokamak (AT) scenarios, which are of great benefit to future all-metal fusion power plants. Such scenarios depend on low collisionality ν* which permits efficient external current drive and high amounts of intrinsic bootstrap current. At constant pressure, lowering of the electron density ne leads to a strong decrease in the collisionality with increasing electron temperature ν* ˜ Te-3 . Simultaneously, the conditions for low ne also benefit impurity accumulation. This paper reports on how radiative collapses due to central W accumulation were overcome by improved understanding of the changes to recycling and pumping, substantially expanded ECRH capacities for both heating and current drive, and a new solid W divertor capable of withstanding the power loads at low ne. Furthermore, it reports on various improvements to the reliability of the q-profile reconstruction. A candidate steady state scenario for ITER/DEMO (q95 = 5.3, βN = 2.7, fbs > 40%) is presented. The ion temperature profiles are steeper than predicted by TGLF, but nonlinear electromagnetic gyro-kinetic analyses with GENE including fast particle effects matched the experimental heat fluxes. A fully non-inductive scenario at higher q95 = 7.1 for current drive model validation is also discussed. The results show that non-inductive operation is principally compatible with full-metal machines.

ROSTRUM IN MEMORIAL SECTION ALONG CENTRAL DRIVE, WITH BIVOUAC OF ...

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

ROSTRUM IN MEMORIAL SECTION ALONG CENTRAL DRIVE, WITH BIVOUAC OF THE DEAD MONUMENT AT FAR LEFT. VIEW TO EAST. - Baton Rouge National Cemetery, 220 North 19th Street, Baton Rouge, East Baton Rouge Parish, LA

OVERALL VIEW OF CEMETERY SECTIONS SOUTH OF CENTRAL DRIVE, SHOWING ...

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

OVERALL VIEW OF CEMETERY SECTIONS SOUTH OF CENTRAL DRIVE, SHOWING SECTION MARKER AT BASE OF TREE. VIEW TO SOUTH. - Baton Rouge National Cemetery, 220 North 19th Street, Baton Rouge, East Baton Rouge Parish, LA

Status of the ITER Electron Cyclotron Heating and Current Drive System

NASA Astrophysics Data System (ADS)

Darbos, Caroline; Albajar, Ferran; Bonicelli, Tullio; Carannante, Giuseppe; Cavinato, Mario; Cismondi, Fabio; Denisov, Grigory; Farina, Daniela; Gagliardi, Mario; Gandini, Franco; Gassmann, Thibault; Goodman, Timothy; Hanson, Gregory; Henderson, Mark A.; Kajiwara, Ken; McElhaney, Karen; Nousiainen, Risto; Oda, Yasuhisa; Omori, Toshimichi; Oustinov, Alexander; Parmar, Darshankumar; Popov, Vladimir L.; Purohit, Dharmesh; Rao, Shambhu Laxmikanth; Rasmussen, David; Rathod, Vipal; Ronden, Dennis M. S.; Saibene, Gabriella; Sakamoto, Keishi; Sartori, Filippo; Scherer, Theo; Singh, Narinder Pal; Strauß, Dirk; Takahashi, Koji

2016-01-01

The electron cyclotron (EC) heating and current drive (H&CD) system developed for the ITER is made of 12 sets of high-voltage power supplies feeding 24 gyrotrons connected through 24 transmission lines (TL), to five launchers, four located in upper ports and one at the equatorial level. Nearly all procurements are in-kind, following general ITER philosophy, and will come from Europe, India, Japan, Russia and the USA. The full system is designed to couple to the plasma 20 MW among the 24 MW generated power, at the frequency of 170 GHz, for various physics applications such as plasma start-up, central H&CD and magnetohydrodynamic (MHD) activity control. The design takes present day technology and extends toward high-power continuous operation, which represents a large step forward as compared to the present state of the art. The ITER EC system will be a stepping stone to future EC systems for DEMO and beyond.

Central Mechanisms in the Maintenance of Chronic Widespread Noninflammatory Muscle Pain

PubMed Central

DeSantana, Josimari M.; Sluka, Kathleen A.

2009-01-01

Chronic widespread pain (CWP) conditions such as fibromyalgia and myofascial syndromes are characterized by generalized pain, tenderness, morning stiffness, disturbed sleep, and pronounced fatigue. However, CWP pathophysiology is still unclear. A number of hypotheses have been proposed as the underlying pathophysiology of CWP: muscular dysfunction/ischemia, central sensitization, and a deficit in endogenous pain-modulating systems. This article reviews the current and emerging literature about the pathophysiology and neurobiology of chronic widespread musculoskeletal pain. Widespread musculoskeletal pain results in changes in the central nervous system in human subjects and animal models. These changes likely reflect alterations in supraspinal modulation of nociception, and include increases in excitatory and decreases in inhibitory modulation pathways. These alterations in excitation and inhibition likely drive changes observed in the spinal cord to result in central sensitization, and the consequent pain and hyperalgesia. PMID:18765138

High performance advanced tokamak regimes in DIII-D for next-step experiments

NASA Astrophysics Data System (ADS)

Greenfield, C. M.; Murakami, M.; Ferron, J. R.; Wade, M. R.; Luce, T. C.; Petty, C. C.; Menard, J. E.; Petrie, T. W.; Allen, S. L.; Burrell, K. H.; Casper, T. A.; DeBoo, J. C.; Doyle, E. J.; Garofalo, A. M.; Gorelov, I. A.; Groebner, R. J.; Hobirk, J.; Hyatt, A. W.; Jayakumar, R. J.; Kessel, C. E.; La Haye, R. J.; Jackson, G. L.; Lohr, J.; Makowski, M. A.; Pinsker, R. I.; Politzer, P. A.; Prater, R.; Strait, E. J.; Taylor, T. S.; West, W. P.; DIII-D Team

2004-05-01

Advanced Tokamak (AT) research in DIII-D [K. H. Burrell for the DIII-D Team, in Proceedings of the 19th Fusion Energy Conference, Lyon, France, 2002 (International Atomic Energy Agency, Vienna, 2002) published on CD-ROM] seeks to provide a scientific basis for steady-state high performance operation in future devices. These regimes require high toroidal beta to maximize fusion output and poloidal beta to maximize the self-driven bootstrap current. Achieving these conditions requires integrated, simultaneous control of the current and pressure profiles, and active magnetohydrodynamic stability control. The building blocks for AT operation are in hand. Resistive wall mode stabilization via plasma rotation and active feedback with nonaxisymmetric coils allows routine operation above the no-wall beta limit. Neoclassical tearing modes are stabilized by active feedback control of localized electron cyclotron current drive (ECCD). Plasma shaping and profile control provide further improvements. Under these conditions, bootstrap supplies most of the current. Steady-state operation requires replacing the remaining Ohmic current, mostly located near the half radius, with noninductive external sources. In DIII-D this current is provided by ECCD, and nearly stationary AT discharges have been sustained with little remaining Ohmic current. Fast wave current drive is being developed to control the central magnetic shear. Density control, with divertor cryopumps, of AT discharges with edge localized moding H-mode edges facilitates high current drive efficiency at reactor relevant collisionalities. A sophisticated plasma control system allows integrated control of these elements. Close coupling between modeling and experiment is key to understanding the separate elements, their complex nonlinear interactions, and their integration into self-consistent high performance scenarios. Progress on this development, and its implications for next-step devices, will be illustrated by results of recent experiment and simulation efforts.

Linear mass actuator

NASA Technical Reports Server (NTRS)

Holloway, Sidney E., III (Inventor); Crossley, Edward A., Jr. (Inventor); Jones, Irby W. (Inventor); Miller, James B. (Inventor); Davis, C. Calvin (Inventor); Behun, Vaughn D. (Inventor); Goodrich, Lewis R., Sr. (Inventor)

1992-01-01

A linear mass actuator includes an upper housing and a lower housing connectable to each other and having a central passageway passing axially through a mass that is linearly movable in the central passageway. Rollers mounted in the upper and lower housings in frictional engagement with the mass translate the mass linearly in the central passageway and drive motors operatively coupled to the roller means, for rotating the rollers and driving the mass axially in the central passageway.

Effects of fexofenadine and hydroxyzine on brake reaction time during car-driving with cellular phone use.

PubMed

Tashiro, Manabu; Horikawa, Etsuo; Mochizuki, Hideki; Sakurada, Yumiko; Kato, Motohisa; Inokuchi, Takatoshi; Ridout, Fran; Hindmarch, Ian; Yanai, Kazuhiko

2005-10-01

Antihistamines are a mainstay treatment for allergic rhinitis; however, many older agents cause adverse events, including sedation and central nervous system (CNS) impairment. Research has shown sedating effects of antihistamines on driving; currently, no known study has examined whether cellular phone usage while driving further compounds impairment in individuals administered antihistamines. The aim of this study was to examine this endpoint. In a randomized, double-blind, placebo-controlled, three-way crossover study, healthy volunteers received fexofenadine HCl 120 mg, hydroxyzine HCl 30 mg and placebo. Brake reaction time (BRT) was used to examine driving performance across four conditions: driving only; driving while completing simple calculations; complex calculations; and conversing on a cellular phone. Subjective sedation assessments were also conducted. Brake reaction time with and without cellular phone usage in fexofenadine-treated subjects did not differ significantly from placebo in any condition. In contrast, hydroxyzine-treated subjects were significantly more sedated and had slower BRTs, suggesting slower hazard recognition and brake application, compared with the fexofenadine and placebo groups in all conditions. Importantly, cellular phone operation was an additive factor, increasing BRTs in hydroxyzine-treated volunteers. Fexofenadine did not impair CNS function in subjects involved in a divided attention task of driving and cellular phone operation. Copyright (c) 2005 John Wiley & Sons, Ltd.

The effects of driver identity on driving safety in a retrospective feedback system.

PubMed

Zhao, Guozhen; Wu, Changxu

2012-03-01

Retrospective feedback that provides detailed information on a driver's performance in critical driving situations at the end of a trip enhances his/her driving behaviors and safe driving habits. Although this has been demonstrated by a previous study, retrospective feedback can be further improved and applied to non-critical driving situations, which is needed for transportation safety. To propose a new retrospective feedback system that uses driver identity (i.e., a driver's name) and to experimentally study its effects on measures of driving performance and safety in a driving simulator. We conducted a behavioral experimental study with 30 participants. "Feedback type" was a between-subject variable with three conditions: no feedback (control group), feedback without driver identity, and feedback with driver identity. We measured multiple aspects of participants' driving behavior. To control for potential confounds, factors that were significantly correlated with driving behavior (e.g., age and driving experience) were all entered as covariates into a multivariate analysis of variance. To examine the effects of speeding on collision severity in driving simulation studies, we also developed a new index - momentum of potential collision - with a set of equations. Subjects who used a feedback system with driver identity had the fewest speeding violations and central-line crossings, spent the least amount of time speeding and crossing the central line, had the lowest speeding and central-line crossing magnitude, ran the fewest red lights, and had the smallest momentum of potential collision compared to the groups with feedback without driver identity and without feedback (control group). The new retrospective feedback system with driver identity has the potential to enhance a person's driving safety (e.g., speeding, central-line crossing, momentum of potential collision), which is an indication of the valence of one's name in a feedback system design. Copyright © 2011 Elsevier Ltd. All rights reserved.

The interaction of psychological and physiological homeostatic drives and role of general control principles in the regulation of physiological systems, exercise and the fatigue process - The Integrative Governor theory.

PubMed

St Clair Gibson, A; Swart, J; Tucker, R

2018-02-01

Either central (brain) or peripheral (body physiological system) control mechanisms, or a combination of these, have been championed in the last few decades in the field of Exercise Sciences as how physiological activity and fatigue processes are regulated. In this review, we suggest that the concept of 'central' or 'peripheral' mechanisms are both artificial constructs that have 'straight-jacketed' research in the field, and rather that competition between psychological and physiological homeostatic drives is central to the regulation of both, and that governing principles, rather than distinct physical processes, underpin all physical system and exercise regulation. As part of the Integrative Governor theory we develop in this review, we suggest that both psychological and physiological drives and requirements are underpinned by homeostatic principles, and that regulation of the relative activity of each is by dynamic negative feedback activity, as the fundamental general operational controller. Because of this competitive, dynamic interplay, we propose that the activity in all systems will oscillate, that these oscillations create information, and comparison of this oscillatory information with either prior information, current activity, or activity templates create efferent responses that change the activity in the different systems in a similarly dynamic manner. Changes in a particular system are always the result of perturbations occurring outside the system itself, the behavioural causative 'history' of this external activity will be evident in the pattern of the oscillations, and awareness of change occurs as a result of unexpected rather than planned change in physiological activity or psychological state.

Oscillatory nonohomic current drive for maintaining a plasma current

DOEpatents

Fisch, N.J.

1984-01-01

Apparatus and methods are described for maintaining a plasma current with an oscillatory nonohmic current drive. Each cycle of operation has a generation period in which current driving energy is applied to the plasma, and a relaxation period in which current driving energy is removed. Plasma parameters, such as plasma temperature or plasma average ionic charge state, are modified during the generation period so as to oscillate plasma resistivity in synchronism with the application of current driving energy. The invention improves overall current drive efficiencies.

Oscillatory nonhmic current drive for maintaining a plasma current

DOEpatents

Fisch, Nathaniel J.

1986-01-01

Apparatus and method of the invention maintain a plasma current with an oscillatory nonohmic current drive. Each cycle of operation has a generation period in which current driving energy is applied to the plasma, and a relaxation period in which current driving energy is removed. Plasma parameters, such as plasma temperature or plasma average ionic charge state, are modified during the generation period so as to oscillate plasma resistivity in synchronism with the application of current driving energy. The invention improves overall current drive efficiencies.

CENTRAL DRIVE RUNNING PAST THE GARAGE AND TERMINATING AT THE ...

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

CENTRAL DRIVE RUNNING PAST THE GARAGE AND TERMINATING AT THE BARN. The barn’s primary entrance is through the central double doors with chamfered corners on the west façade. The garage was used both as a mechanic shop and to park vehicles. The hipped roof of the pump house can be seen behind the garage. - Kineth Farm, Barn, 19162 STATE ROUTE 20, Coupeville, Island County, WA

Vehicle systems design optimization study

NASA Technical Reports Server (NTRS)

Gilmour, J. L.

1980-01-01

The optimum vehicle configuration and component locations are determined for an electric drive vehicle based on using the basic structure of a current production subcompact vehicle. The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current internal combustion engine vehicles. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages, one at front under the hood and a second at the rear under the cargo area, in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passenger and cargo space for a given size vehicle.

Mean PB To Failure - Initial results from a long-term study of disk storage patterns at the RACF

NASA Astrophysics Data System (ADS)

Caramarcu, C.; Hollowell, C.; Rao, T.; Strecker-Kellogg, W.; Wong, A.; Zaytsev, S. A.

2015-12-01

The RACF (RHIC-ATLAS Computing Facility) has operated a large, multi-purpose dedicated computing facility since the mid-1990’s, serving a worldwide, geographically diverse scientific community that is a major contributor to various HEPN projects. A central component of the RACF is the Linux-based worker node cluster that is used for both computing and data storage purposes. It currently has nearly 50,000 computing cores and over 23 PB of storage capacity distributed over 12,000+ (non-SSD) disk drives. The majority of the 12,000+ disk drives provide a cost-effective solution for dCache/XRootD-managed storage, and a key concern is the reliability of this solution over the lifetime of the hardware, particularly as the number of disk drives and the storage capacity of individual drives grow. We report initial results of a long-term study to measure lifetime PB read/written to disk drives in the worker node cluster. We discuss the historical disk drive mortality rate, disk drive manufacturers' published MPTF (Mean PB to Failure) data and how they are correlated to our results. The results help the RACF understand the productivity and reliability of its storage solutions and have implications for other highly-available storage systems (NFS, GPFS, CVMFS, etc) with large I/O requirements.

Driving When You Have Parkinson's Disease

MedlinePlus

Driving When You Have Parkinson’s Disease DRIVEWELL You have been a safe driver for years. For you, driving means freedom and control. As you get older, ... mental health can affect how safely you drive. Parkinson’s disease is a disorder of the central nervous system ...

The role of biotic forces in driving macroevolution: beyond the Red Queen

PubMed Central

Voje, Kjetil L.; Holen, Øistein H.; Liow, Lee Hsiang; Stenseth, Nils Chr.

2015-01-01

A multitude of hypotheses claim that abiotic factors are the main drivers of macroevolutionary change. By contrast, Van Valen's Red Queen hypothesis is often put forward as the sole representative of the view that biotic forcing is the main evolutionary driver. This imbalance of hypotheses does not reflect our current knowledge: theoretical work demonstrates the plausibility of biotically driven long-term evolution, whereas empirical work suggests a central role for biotic forcing in macroevolution. We call for a more pluralistic view of how biotic forces may drive long-term evolution that is compatible with both phenotypic stasis in the fossil record and with non-constant extinction rates. Promising avenues of research include contrasting predictions from relevant theories within ecology and macroevolution, as well as embracing both abiotic and biotic proxies while modelling long-term evolutionary data. By fitting models describing hypotheses of biotically driven macroevolution to data, we could dissect their predictions and transcend beyond pattern description, possibly narrowing the divide between our current understanding of micro- and macroevolution. PMID:25948685

Local atmospheric forcing driving an unexpected California Current System response during the 2015-2016 El Niño

NASA Astrophysics Data System (ADS)

Frischknecht, Martin; Münnich, Matthias; Gruber, Nicolas

2017-01-01

The 2015-2016 El Niño contributed to large anomalies across the California Current System (CalCS), but these anomalies ceased unexpectedly in late 2015. Here we use a suite of three hindcast simulations with the Regional Oceanic Modeling System to assess the responsible mechanisms for this development. We find that the early buildup was primarily driven by the early onset of this event in the tropical Pacific, driving anomalies in the CalCS through the propagation of coastally trapped waves. In contrast, the abrupt end in the central CalCS was caused by the unusual onset of upwelling favorable winds in the fall of 2015, which offset the continuing remote forcing through the coastal waveguide. Nevertheless, low-nutrient anomalies persisted, causing anomalously low phytoplankton abundance in the upwelling season of 2016. This is a recurring pattern for all El Niño events over the last 37 years, suggesting predictive skill on seasonal timescales.

Major results from the first plasma campaign of the Wendelstein 7-X stellarator

DOE PAGES

Wolf, R. C.; Ali, A.; Alonso, A.; ...

2017-07-27

Here, after completing the main construction phase of Wendelstein 7-X (W7-X) and successfully commissioning the device, first plasma operation started at the end of 2015. Integral commissioning of plasma start-up and operation using electron cyclotron resonance heating (ECRH) and an extensive set of plasma diagnostics have been completed, allowing initial physics studies during the first operational campaign. Both in helium and hydrogen, plasma breakdown was easily achieved. Gaining experience with plasma vessel conditioning, discharge lengths could be extended gradually. Eventually, discharges lasted up to 6 s, reaching an injected energy of 4 MJ, which is twice the limit originally agreedmore » for the limiter configuration employed during the first operational campaign. At power levels of 4 MW central electron densities reached 3 × 10 19 m –3, central electron temperatures reached values of 7 keV and ion temperatures reached just above 2 keV. Important physics studies during this first operational phase include a first assessment of power balance and energy confinement, ECRH power deposition experiments, 2nd harmonic O-mode ECRH using multi-pass absorption, and current drive experiments using electron cyclotron current drive. As in many plasma discharges the electron temperature exceeds the ion temperature significantly, these plasmas are governed by core electron root confinement showing a strong positive electric field in the plasma centre.« less

Major results from the first plasma campaign of the Wendelstein 7-X stellarator

NASA Astrophysics Data System (ADS)

Wolf, R. C.; Ali, A.; Alonso, A.; Baldzuhn, J.; Beidler, C.; Beurskens, M.; Biedermann, C.; Bosch, H.-S.; Bozhenkov, S.; Brakel, R.; Dinklage, A.; Feng, Y.; Fuchert, G.; Geiger, J.; Grulke, O.; Helander, P.; Hirsch, M.; Höfel, U.; Jakubowski, M.; Knauer, J.; Kocsis, G.; König, R.; Kornejew, P.; Krämer-Flecken, A.; Krychowiak, M.; Landreman, M.; Langenberg, A.; Laqua, H. P.; Lazerson, S.; Maaßberg, H.; Marsen, S.; Marushchenko, M.; Moseev, D.; Niemann, H.; Pablant, N.; Pasch, E.; Rahbarnia, K.; Schlisio, G.; Stange, T.; Pedersen, T. Sunn; Svensson, J.; Szepesi, T.; Trimino Mora, H.; Turkin, Y.; Wauters, T.; Weir, G.; Wenzel, U.; Windisch, T.; Wurden, G.; Zhang, D.; Abramovic, I.; Äkäslompolo, S.; Aleynikov, P.; Aleynikova, K.; Alzbutas, R.; Anda, G.; Andreeva, T.; Ascasibar, E.; Assmann, J.; Baek, S.-G.; Banduch, M.; Barbui, T.; Barlak, M.; Baumann, K.; Behr, W.; Benndorf, A.; Bertuch, O.; Biel, W.; Birus, D.; Blackwell, B.; Blanco, E.; Blatzheim, M.; Bluhm, T.; Böckenhoff, D.; Bolgert, P.; Borchardt, M.; Borsuk, V.; Boscary, J.; Böttger, L.-G.; Brand, H.; Brandt, Ch.; Bräuer, T.; Braune, H.; Brezinsek, S.; Brunner, K.-J.; Brünner, B.; Burhenn, R.; Buttenschön, B.; Bykov, V.; Calvo, I.; Cannas, B.; Cappa, A.; Carls, A.; Carraro, L.; Carvalho, B.; Castejon, F.; Charl, A.; Chernyshev, F.; Cianciosa, M.; Citarella, R.; Ciupiński, Ł.; Claps, G.; Cole, M.; Cole, M. J.; Cordella, F.; Cseh, G.; Czarnecka, A.; Czermak, A.; Czerski, K.; Czerwinski, M.; Czymek, G.; da Molin, A.; da Silva, A.; Dammertz, G.; Danielson, J.; de la Pena, A.; Degenkolbe, S.; Denner, P.; Dhard, D. P.; Dostal, M.; Drevlak, M.; Drewelow, P.; Drews, Ph.; Dudek, A.; Dundulis, G.; Durodie, F.; van Eeten, P.; Effenberg, F.; Ehrke, G.; Endler, M.; Ennis, D.; Erckmann, E.; Esteban, H.; Estrada, T.; Fahrenkamp, N.; Feist, J.-H.; Fellinger, J.; Fernandes, H.; Fietz, W. H.; Figacz, W.; Fontdecaba, J.; Ford, O.; Fornal, T.; Frerichs, H.; Freund, A.; Führer, M.; Funaba, T.; Galkowski, A.; Gantenbein, G.; Gao, Y.; García Regaña, J.; Garcia-Munoz, M.; Gates, D.; Gawlik, G.; Geiger, B.; Giannella, V.; Gierse, N.; Gogoleva, A.; Goncalves, B.; Goriaev, A.; Gradic, D.; Grahl, M.; Green, J.; Grosman, A.; Grote, H.; Gruca, M.; Guerard, C.; Haiduk, L.; Han, X.; Harberts, F.; Harris, J. H.; Hartfuß, H.-J.; Hartmann, D.; Hathiramani, D.; Hein, B.; Heinemann, B.; Heitzenroeder, P.; Henneberg, S.; Hennig, C.; Hernandez Sanchez, J.; Hidalgo, C.; Hölbe, H.; Hollfeld, K. P.; Hölting, A.; Höschen, D.; Houry, M.; Howard, J.; Huang, X.; Huber, M.; Huber, V.; Hunger, H.; Ida, K.; Ilkei, T.; Illy, S.; Israeli, B.; Ivanov, A.; Jablonski, S.; Jagielski, J.; Jelonnek, J.; Jenzsch, H.; Junghans, P.; Kacmarczyk, J.; Kaliatka, T.; Kallmeyer, J.-P.; Kamionka, U.; Karalevicius, R.; Kasahara, H.; Kasparek, W.; Kenmochi, N.; Keunecke, M.; Khilchenko, A.; Kinna, D.; Kleiber, R.; Klinger, T.; Knaup, M.; Kobarg, Th.; Köchl, F.; Kolesnichenko, Y.; Könies, A.; Köppen, M.; Koshurinov, J.; Koslowski, R.; Köster, F.; Koziol, R.; Krämer, M.; Krampitz, R.; Kraszewsk, P.; Krawczyk, N.; Kremeyer, T.; Krings, Th.; Krom, J.; Krzesinski, G.; Ksiazek, I.; Kubkowska, M.; Kühner, G.; Kurki-Suonio, T.; Kwak, S.; Lang, R.; Langish, S.; Laqua, H.; Laube, R.; Lechte, C.; Lennartz, M.; Leonhardt, W.; Lewerentz, L.; Liang, Y.; Linsmeier, Ch.; Liu, S.; Lobsien, J.-F.; Loesser, D.; Loizu Cisquella, J.; Lore, J.; Lorenz, A.; Losert, M.; Lubyako, L.; Lücke, A.; Lumsdaine, A.; Lutsenko, V.; Majano-Brown, J.; Marchuk, O.; Mardenfeld, M.; Marek, P.; Massidda, S.; Masuzaki, S.; Maurer, D.; McCarthy, K.; McNeely, P.; Meier, A.; Mellein, D.; Mendelevitch, B.; Mertens, Ph.; Mikkelsen, D.; Mishchenko, O.; Missal, B.; Mittelstaedt, J.; Mizuuchi, T.; Mollen, A.; Moncada, V.; Mönnich, T.; Morizaki, T.; Munk, R.; Murakami, S.; Musielok, F.; Náfrádi, G.; Nagel, M.; Naujoks, D.; Neilson, H.; Neubauer, O.; Neuner, U.; Ngo, T.; Nocentini, R.; Nührenberg, C.; Nührenberg, J.; Obermayer, S.; Offermanns, G.; Ogawa, K.; Ongena, J.; Oosterbeek, J. W.; Orozco, G.; Otte, M.; Pacios Rodriguez, L.; Pan, W.; Panadero, N.; Panadero Alvarez, N.; Panin, A.; Papenfuß, D.; Paqay, S.; Pavone, A.; Pawelec, E.; Pelka, G.; Peng, X.; Perseo, V.; Peterson, B.; Pieper, A.; Pilopp, D.; Pingel, S.; Pisano, F.; Plaum, B.; Plunk, G.; Povilaitis, M.; Preinhaelter, J.; Proll, J.; Puiatti, M.-E.; Sitjes, A. Puig; Purps, F.; Rack, M.; Récsei, S.; Reiman, A.; Reiter, D.; Remppel, F.; Renard, S.; Riedl, R.; Riemann, J.; Rimkevicius, S.; Riße, K.; Rodatos, A.; Röhlinger, H.; Romé, M.; Rong, P.; Roscher, H.-J.; Roth, B.; Rudischhauser, L.; Rummel, K.; Rummel, T.; Runov, A.; Rust, N.; Ryc, L.; Ryosuke, S.; Sakamoto, R.; Samartsev, A.; Sanchez, M.; Sano, F.; Satake, S.; Satheeswaran, G.; Schacht, J.; Schauer, F.; Scherer, T.; Schlaich, A.; Schlüter, K.-H.; Schmitt, J.; Schmitz, H.; Schmitz, O.; Schmuck, S.; Schneider, M.; Schneider, W.; Scholz, M.; Scholz, P.; Schrittwieser, R.; Schröder, M.; Schröder, T.; Schroeder, R.; Schumacher, H.; Schweer, B.; Shanahan, B.; Shikhovtsev, I. V.; Sibilia, M.; Sinha, P.; Sipliä, S.; Skodzik, J.; Slaby, C.; Smith, H.; Spiess, W.; Spong, D. A.; Spring, A.; Stadler, R.; Standley, B.; Stephey, L.; Stoneking, M.; Stridde, U.; Sulek, Z.; Surko, C.; Suzuki, Y.; Szabó, V.; Szabolics, T.; Szökefalvi-Nagy, Z.; Tamura, N.; Terra, A.; Terry, J.; Thomas, J.; Thomsen, H.; Thumm, M.; von Thun, C. P.; Timmermann, D.; Titus, P.; Toi, K.; Travere, J. M.; Traverso, P.; Tretter, J.; Tsuchiya, H.; Tsujimura, T.; Tulipán, S.; Turnyanskiy, M.; Unterberg, B.; Urban, J.; Urbonavicius, E.; Vakulchyk, I.; Valet, S.; van Millingen, B.; Vela, L.; Velasco, J.-L.; Vergote, M.; Vervier, M.; Vianello, N.; Viebke, H.; Vilbrandt, R.; Vorkörper, A.; Wadle, S.; Wagner, F.; Wang, E.; Wang, N.; Warmer, F.; Wegener, L.; Weggen, J.; Wei, Y.; Wendorf, J.; Werner, A.; Wiegel, B.; Wilde, F.; Winkler, E.; Winters, V.; Wolf, S.; Wolowski, J.; Wright, A.; Xanthopoulos, P.; Yamada, H.; Yamada, I.; Yasuhara, R.; Yokoyama, M.; Zajac, J.; Zarnstorff, M.; Zeitler, A.; Zhang, H.; Zhu, J.; Zilker, M.; Zimbal, A.; Zocco, A.; Zoletnik, S.; Zuin, M.

2017-10-01

After completing the main construction phase of Wendelstein 7-X (W7-X) and successfully commissioning the device, first plasma operation started at the end of 2015. Integral commissioning of plasma start-up and operation using electron cyclotron resonance heating (ECRH) and an extensive set of plasma diagnostics have been completed, allowing initial physics studies during the first operational campaign. Both in helium and hydrogen, plasma breakdown was easily achieved. Gaining experience with plasma vessel conditioning, discharge lengths could be extended gradually. Eventually, discharges lasted up to 6 s, reaching an injected energy of 4 MJ, which is twice the limit originally agreed for the limiter configuration employed during the first operational campaign. At power levels of 4 MW central electron densities reached 3  ×  1019 m-3, central electron temperatures reached values of 7 keV and ion temperatures reached just above 2 keV. Important physics studies during this first operational phase include a first assessment of power balance and energy confinement, ECRH power deposition experiments, 2nd harmonic O-mode ECRH using multi-pass absorption, and current drive experiments using electron cyclotron current drive. As in many plasma discharges the electron temperature exceeds the ion temperature significantly, these plasmas are governed by core electron root confinement showing a strong positive electric field in the plasma centre.

Major results from the first plasma campaign of the Wendelstein 7-X stellarator

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

Wolf, R. C.; Ali, A.; Alonso, A.

Here, after completing the main construction phase of Wendelstein 7-X (W7-X) and successfully commissioning the device, first plasma operation started at the end of 2015. Integral commissioning of plasma start-up and operation using electron cyclotron resonance heating (ECRH) and an extensive set of plasma diagnostics have been completed, allowing initial physics studies during the first operational campaign. Both in helium and hydrogen, plasma breakdown was easily achieved. Gaining experience with plasma vessel conditioning, discharge lengths could be extended gradually. Eventually, discharges lasted up to 6 s, reaching an injected energy of 4 MJ, which is twice the limit originally agreedmore » for the limiter configuration employed during the first operational campaign. At power levels of 4 MW central electron densities reached 3 × 10 19 m –3, central electron temperatures reached values of 7 keV and ion temperatures reached just above 2 keV. Important physics studies during this first operational phase include a first assessment of power balance and energy confinement, ECRH power deposition experiments, 2nd harmonic O-mode ECRH using multi-pass absorption, and current drive experiments using electron cyclotron current drive. As in many plasma discharges the electron temperature exceeds the ion temperature significantly, these plasmas are governed by core electron root confinement showing a strong positive electric field in the plasma centre.« less

Reconfigurable Drive Current System

NASA Technical Reports Server (NTRS)

Alhorn, Dean C. (Inventor); Dutton, Kenneth R. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

2017-01-01

A reconfigurable drive current system includes drive stages, each of which includes a high-side transistor and a low-side transistor in a totem pole configuration. A current monitor is coupled to an output of each drive stage. Input channels are provided to receive input signals. A processor is coupled to the input channels and to each current monitor for generating at least one drive signal using at least one of the input signals and current measured by at least one of the current monitors. A pulse width modulation generator is coupled to the processor and each drive stage for varying the drive signals as a function of time prior to being supplied to at least one of the drive stages.

Sympatho-renal axis in chronic disease.

PubMed

Sobotka, Paul A; Mahfoud, Felix; Schlaich, Markus P; Hoppe, Uta C; Böhm, Michael; Krum, Henry

2011-12-01

Essential hypertension, insulin resistance, heart failure, congestion, diuretic resistance, and functional renal disease are all characterized by excessive central sympathetic drive. The contribution of the kidney's somatic afferent nerves, as an underlying cause of elevated central sympathetic drive, and the consequences of excessive efferent sympathetic signals to the kidney itself, as well as other organs, identify the renal sympathetic nerves as a uniquely logical therapeutic target for diseases linked by excessive central sympathetic drive. Clinical studies of renal denervation in patients with resistant hypertension using an endovascular radiofrequency ablation methodology have exposed the sympathetic link between these conditions. Renal denervation could be expected to simultaneously affect blood pressure, insulin resistance, sleep disorders, congestion in heart failure, cardiorenal syndrome and diuretic resistance. The striking epidemiologic evidence for coexistence of these disorders suggests common causal pathways. Chronic activation of the sympathetic nervous system has been associated with components of the metabolic syndrome, such as blood pressure elevation, obesity, dyslipidemia, and impaired fasting glucose with hyperinsulinemia. Over 50% of patients with essential hypertension are hyperinsulinemic, regardless of whether they are untreated or in a stable program of treatment. Insulin resistance is related to sympathetic drive via a bidirectional mechanism. In this manuscript, we review the data that suggests that selective impairment of renal somatic afferent and sympathetic efferent nerves in patients with resistant hypertension both reduces markers of central sympathetic drive and favorably impacts diseases linked through central sympathetics-insulin resistance, heart failure, congestion, diuretic resistance, and cardiorenal disorders.

Solenoid-free plasma start-up in spherical tokamaks

NASA Astrophysics Data System (ADS)

Raman, R.; Shevchenko, V. F.

2014-10-01

The central solenoid is an intrinsic part of all present-day tokamaks and most spherical tokamaks. The spherical torus (ST) confinement concept is projected to operate at high toroidal beta and at a high fraction of the non-inductive bootstrap current as required for an efficient reactor system. The use of a conventional solenoid in a ST-based fusion nuclear facility is generally believed to not be a possibility. Solenoid-free plasma start-up is therefore an area of extensive worldwide research activity. Solenoid-free plasma start-up is also relevant to steady-state tokamak operation, as the central transformer coil of a conventional aspect ratio tokamak reactor would be located in a high radiation environment but would be needed only during the initial discharge initiation and current ramp-up phases. Solenoid-free operation also provides greater flexibility in the selection of the aspect ratio and simplifies the reactor design. Plasma start-up methods based on induction from external poloidal field coils, helicity injection and radio frequency current drive have all made substantial progress towards meeting this important need for the ST. Some of these systems will now undergo the final stages of test in a new generation of large STs, which are scheduled to begin operations during the next two years. This paper reviews research to date on methods for inducing the initial start-up current in STs without reliance on the conventional central solenoid.

Bilastine: a new antihistamine with an optimal benefit-to-risk ratio for safety during driving.

PubMed

Jáuregui, Ignacio; Ramaekers, Johannes G; Yanai, Kazuhiko; Farré, Magí; Redondo, Esther; Valiente, Román; Labeaga, Luis

2016-01-01

Rational selection of a second-generation H1-antihistamine requires efficacy and safety considerations, particularly regarding central nervous system (CNS) effects (cognitive and psychomotor function), potential for driving impairment, minimal sedative effects and a lack of interactions. This review evaluates the key safety features of the non-sedating antihistamine, bilastine, during driving and in preventing road traffic accidents. Among the second-generation H1-antihistamines, sedative effects which can affect cognitive and psychomotor performance, and possibly driving ability, may not be similar. Bilastine is absorbed rapidly, undergoes no hepatic metabolism or cytochrome P450 interaction (minimal drug-drug interaction potential), and is a substrate for P-glycoprotein (limiting CNS entry). Positron emission tomography showed that, compared with other second-generation H1-antihistamines, bilastine has the lowest cerebral histamine H1-receptor occupancy. Bilastine 20 mg once daily (therapeutic dose) is non-sedating, does not enhance the effects of alcohol or CNS sedatives, does not impair driving performance and has at least similar efficacy as other second-generation H1-antihistamines in the treatment of allergic rhinoconjunctivitis and urticaria. Current evidence shows that bilastine has an optimal benefit-to-risk ratio, meeting all conditions for contributing to safety in drivers who need antihistamines, and hence for being considered as an antihistamine of choice for drivers.

Maintenance of Wakefulness Test scores and driving performance in sleep disorder patients and controls.

PubMed

Philip, Pierre; Chaufton, Cyril; Taillard, Jacques; Sagaspe, Patricia; Léger, Damien; Raimondi, Monika; Vakulin, Andrew; Capelli, Aurore

2013-08-01

Sleepiness at the wheel is a risk factor for traffic accidents. Past studies have demonstrated the validity of the Maintenance of Wakefulness Test (MWT) scores as a predictor of driving impairment in untreated patients with obstructive sleep apnea syndrome (OSAS), but there is limited information on the validity of the maintenance of wakefulness test by MWT in predicting driving impairment in patients with hypersomnias of central origin (narcolepsy or idiopathic hypersomnia). The aim of this study was to compare the MWT scores with driving performance in sleep disorder patients and controls. 19 patients suffering from hypersomnias of central origin (9 narcoleptics and 10 idiopathic hypersomnia), 17 OSAS patients and 14 healthy controls performed a MWT (4×40-minute trials) and a 40-minute driving session on a real car driving simulator. Participants were divided into 4 groups defined by their MWT sleep latency scores. The groups were pathological (sleep latency 0-19 min), intermediate (20-33 min), alert (34-40 min) and control (>34 min). The main driving performance outcome was the number of inappropriate line crossings (ILCs) during the 40 minute drive test. Patients with pathological MWT sleep latency scores (0-19 min) displayed statistically significantly more ILC than patients from the intermediate, alert and control groups (F (3, 46)=7.47, p<0.001). Pathological sleep latencies on the MWT predicted driving impairment in patients suffering from hypersomnias of central origin as well as in OSAS patients. MWT is an objective measure of daytime sleepiness that appears to be useful in estimating the driving performance in sleepy patients. Copyright © 2013 Elsevier B.V. All rights reserved.

2. VIEW OF TECHWOOD DORMITORY LOOKING EAST FROM TECHWOOD DRIVE, ...

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

2. VIEW OF TECHWOOD DORMITORY LOOKING EAST FROM TECHWOOD DRIVE, SHOWING WEST FRONT OF NORTH WING, WEST FRONT OF CENTER WING AND CENTRAL COURTYARD. - Techwood Homes, McDaniel Dormitory, 581-587 Techwood Drive, Atlanta, Fulton County, GA

3. VIEW OF TECHWOOD DORMITORY LOOKING EAST FROM TECHWOOD DRIVE, ...

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

3. VIEW OF TECHWOOD DORMITORY LOOKING EAST FROM TECHWOOD DRIVE, SHOWING CENTRAL COURTYARD, WEST FRONT OF CENTER WING, AND WEST FRONT OF SOUTH WING. - Techwood Homes, McDaniel Dormitory, 581-587 Techwood Drive, Atlanta, Fulton County, GA

ADX: a high field, high power density, advanced divertor and RF tokamak

NASA Astrophysics Data System (ADS)

LaBombard, B.; Marmar, E.; Irby, J.; Terry, J. L.; Vieira, R.; Wallace, G.; Whyte, D. G.; Wolfe, S.; Wukitch, S.; Baek, S.; Beck, W.; Bonoli, P.; Brunner, D.; Doody, J.; Ellis, R.; Ernst, D.; Fiore, C.; Freidberg, J. P.; Golfinopoulos, T.; Granetz, R.; Greenwald, M.; Hartwig, Z. S.; Hubbard, A.; Hughes, J. W.; Hutchinson, I. H.; Kessel, C.; Kotschenreuther, M.; Leccacorvi, R.; Lin, Y.; Lipschultz, B.; Mahajan, S.; Minervini, J.; Mumgaard, R.; Nygren, R.; Parker, R.; Poli, F.; Porkolab, M.; Reinke, M. L.; Rice, J.; Rognlien, T.; Rowan, W.; Shiraiwa, S.; Terry, D.; Theiler, C.; Titus, P.; Umansky, M.; Valanju, P.; Walk, J.; White, A.; Wilson, J. R.; Wright, G.; Zweben, S. J.

2015-05-01

The MIT Plasma Science and Fusion Center and collaborators are proposing a high-performance Advanced Divertor and RF tokamak eXperiment (ADX)—a tokamak specifically designed to address critical gaps in the world fusion research programme on the pathway to next-step devices: fusion nuclear science facility (FNSF), fusion pilot plant (FPP) and/or demonstration power plant (DEMO). This high-field (⩾6.5 T, 1.5 MA), high power density facility (P/S ˜ 1.5 MW m-2) will test innovative divertor ideas, including an ‘X-point target divertor’ concept, at the required performance parameters—reactor-level boundary plasma pressures, magnetic field strengths and parallel heat flux densities entering into the divertor region—while simultaneously producing high-performance core plasma conditions that are prototypical of a reactor: equilibrated and strongly coupled electrons and ions, regimes with low or no torque, and no fuelling from external heating and current drive systems. Equally important, the experimental platform will test innovative concepts for lower hybrid current drive and ion cyclotron range of frequency actuators with the unprecedented ability to deploy launch structures both on the low-magnetic-field side and the high-magnetic-field side—the latter being a location where energetic plasma-material interactions can be controlled and favourable RF wave physics leads to efficient current drive, current profile control, heating and flow drive. This triple combination—advanced divertors, advanced RF actuators, reactor-prototypical core plasma conditions—will enable ADX to explore enhanced core confinement physics, such as made possible by reversed central shear, using only the types of external drive systems that are considered viable for a fusion power plant. Such an integrated demonstration of high-performance core-divertor operation with steady-state sustainment would pave the way towards an attractive pilot plant, as envisioned in the ARC concept (affordable, robust, compact) (Sorbom et al 2015 Fusion Eng. Des. submitted (arXiv:1409.3540)) that makes use of high-temperature superconductor technology—a high-field (9.25 T) tokamak the size of the Joint European Torus that produces 270 MW of net electricity.

High Field Side Lower Hybrid Current Drive Launcher Design for DIII-D

NASA Astrophysics Data System (ADS)

Wallace, G. M.; Leccacori, R.; Doody, J.; Vieira, R.; Shiraiwa, S.; Wukitch, S. J.; Holcomb, C.; Pinsker, R. I.

2017-10-01

Efficient off-axis current drive scalable to reactors is a key enabling technology for a steady-state tokamak. Simulations of DIII-D discharges have identified high performance scenarios with excellent lower hybrid (LH) wave penetration, single pass absorption and high current drive efficiency. The strategy was to adapt known launching technology utilized in previous experiments on C-Mod (poloidal splitter) and Tore Supra (bi-junction) and remain within power density limits established in JET and Tore Supra. For a 2 MW source power antenna, the launcher consists of 32 toroidal apertures and 4 poloidal rows. The aperture is 60 mm x 5 mm with 1 mm septa and the peak n| | is 2.7+/-0.2 for 90□ phasing. Eight WR187 waveguides are routed from the R-1 port down under the lower cryopump, under the existing divertor, and up the central column with the long waveguide dimension along the vacuum vessel. Above the inner strike point region, each waveguide is twisted to orient the long dimension perpendicular to the vacuum vessel and splits into 4 toroidal apertures via bi-junctions. To protect the waveguide, the inner wall radius will need to increase by 2.5 cm. RF, disruption, and thermal analysis of the latest design will be presented. Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using User Facility DIII-D, under Award Number DE-FC02-04ER54698 and by MIT PSFC cooperative agreement DE-SC0014264.

Modifications to the edge current profile with auxiliary edge current drive and improved confinement in a reversed-field pinch

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

Chapman, B.E.; Biewer, T.M.; Chattopadhyay, P.K.

2000-09-01

Auxiliary edge current drive is routinely applied in the Madison Symmetric Torus [R.N. Dexter, D. W. Kerst, T.W. Lovell et.al., Fusion Technol. 19, 131 (1991)] with the goal of modifying the parallel current profile to reduce current- driven magnetic fluctuations and the associated particle and energy transport. Provided by an inductive electric field, the current drive successfully reduces energy transport. First-time measurements of the modified edge current profile reveal that, relative to discharges without auxiliary current drive, the edge current density decreases. This decrease is explicable in terms of newly measured reductions in the dynamo (fluctuation-based) electric field and themore » electrical conductivity. Induced by the current drive, these two changes to the edge plasma play as much of a role in determining the resultant edge current profile as does the current drive itself.« less

Emerging Role for Methylation in Multiple Sclerosis: Beyond DNA.

PubMed

Webb, Lindsay M; Guerau-de-Arellano, Mireia

2017-06-01

Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. The inflammatory and neurodegenerative pathways driving MS are modulated by DNA, lysine, and arginine methylation, as evidenced by studies made possible by novel tools for methylation detection or loss of function. We present evidence that MS is associated with genetic variants and metabolic changes that impact on methylation. Further, we comprehensively review current understanding of how methylation can impact on central nervous system (CNS) resilience and neuroregenerative potential, as well as inflammatory versus regulatory T helper (Th) cell balance. These findings are discussed in the context of therapeutic relevance for MS, with broad implications in other neurologic and immune-mediated diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Resistive instabilities in tokamaks

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

Rutherford, P.H.

1985-10-01

Low-m tearing modes constitute the dominant instability problem in present-day tokamaks. In this lecture, the stability criteria for representative current profiles with q(0)-values slightly less than unit are reviewed; ''sawtooth'' reconnection to q(0)-values just at, or slightly exceeding, unity is generally destabilizing to the m = 2, n = 1 and m = 3, n = 2 modes, and severely limits the range of stable profile shapes. Feedback stabilization of m greater than or equal to 2 modes by rf heating or current drive, applied locally at the magnetic islands, appears feasible; feedback by island current drive is much moremore » efficient, in terms of the radio-frequency power required, then feedback by island heating. Feedback stabilization of the m = 1 mode - although yielding particularly beneficial effects for resistive-tearing and high-beta stability by allowing q(0)-values substantially below unity - is more problematical, unless the m = 1 ideal-MHD mode can be made positively stable by strong triangular shaping of the central flux surfaces. Feedback techniques require a detectable, rotating MHD-like signal; the slowing of mode rotation - or the excitation of non-rotating modes - by an imperfectly conducting wall is also discussed.« less

On the Drive Specificity of Freudian Drives for the Generation of SEEKING Activities: The Importance of the Underestimated Imperative Motor Factor

PubMed Central

Kirsch, Michael; Mertens, Wolfgang

2018-01-01

Doubters of Freud’s theory of drives frequently mentioned that his approach is outdated and therefore cannot be useful for solving current problems in patients with mental disorders. At present, many scientists believe that affects rather than drives are of utmost importance for the emotional life and the theoretical framework of affective neuroscience, developed by Panksepp, strongly underpinned this view. Panksepp evaluated seven so-called command systems and the SEEKING system is therein of central importance. Panksepp used Pankseppian drives as inputs for the SEEKING system but noted the missing explanation of drive-specific generation of SEEKING activities in his description. Drive specificity requires dual action of the drive: the activation of a drive-specific brain area and the release of the neurotransmitter dopamine. Noticeably, as Freud claimed drive specificity too, it was here analyzed whether a Freudian drive can evoke the generation of drive-specific SEEKING activities. Special importance was addressed to the imperative motor factor in Freud’s drive theory because Panksepp’s formulations focused on neural pathways without specifying underlying neurotransmitter/endocrine factors impelling motor activity. As Panksepp claimed sleep as a Pankseppian drive, we firstly had to classified sleep as a Freudian drive by using three evaluated criteria for a Freudian drive. After that it was possible to identify the imperative motor factors of hunger, thirst, sex, and sleep. Most importantly, all of these imperative motor factors can both activate a drive-specific brain area and release dopamine from dopaminergic neurons, i.e., they can achieve the so-called drive specificity. Surprisingly, an impaired Freudian drive can alter via endocrinological pathways the concentration of the imperative motor factor of a second Freudian drive, obviously in some independence to the level of the metabolic deficit, thereby offering the possibility to modulate the generation of SEEKING activities of this second Freudian drive. This novel possibility might help to refine the general understanding of the action of Freudian drives. As only imperative motor factors of Freudian drives can guarantee drive specificity for the generation of SEEKING activities, the impact of Freud’s construct Eros (with its constituents hunger, thirst, sex, and sleep) should be revisited. PMID:29774002

Modifications to the edge current profile with auxiliary edge current drive and improved confinement in a reversed-field pinch

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

Chapman, B. E.; Biewer, T. M.; Chattopadhyay, P. K.

2000-09-01

Auxiliary edge current drive is routinely applied in the Madison Symmetric Torus [R. N. Dexter, D. W. Kerst, T. W. Lovell et al., Fusion Technol. 19, 131 (1991)] with the goal of modifying the parallel current profile to reduce current-driven magnetic fluctuations and the associated particle and energy transport. Provided by an inductive electric field, the current drive successfully reduces fluctuations and transport. First-time measurements of the modified edge current profile reveal that, relative to discharges without auxiliary current drive, the edge current density decreases. This decrease is explicable in terms of newly measured reductions in the dynamo (fluctuation-based) electricmore » field and the electrical conductivity. Induced by the current drive, these two changes to the edge plasma play as much of a role in determining the resultant edge current profile as does the current drive itself. (c) 2000 American Institute of Physics.« less

Control of plasma profiles and stability through localised Electron Cyclotron Current Drive

NASA Astrophysics Data System (ADS)

Merkulov, Oleksiy

2006-06-01

The work presented in this thesis addresses several topics from the physics of the magnetically confined plasma inside a tokamak. At the moment, the tokamak is the most successful concept for becoming a future thermonuclear reactor. However, there are plenty of physics and engineering problems to surpass before the prototype can become an economically and environmentally feasible device. The plasma in the tokamak experiences periodic oscillations of the central temperature and density when the safety factor, q, drops below unity on-axis. These oscillations are called the sawtooth instability and are the subject of the first part of this thesis. The sawtooth oscillations are characterised by the relatively slow rise phase, when the central temperature increases, and a following crash phase, when the central temperature drops. The energy, particles and plasma current are redistributed during the sawtooth crash. Obviously, this leads to a confinement degradation and moreover, the sawtooth instability can trigger potentially other more dangerous instabilities, such as a neoclassical tearing mode. The sawtooth period control is realised on the basis of the sawtooth trigger model, derived by Porcelli. The main idea of this model is that the sawtooth crash is triggered when the magnetic shear at the q=1 surface, s1, reaches a critical value which depends on the local plasma parameters. The magnetic shear, s, is a measure for the rate of change in the direction of the field line as a function of the position in the plasma. The sawtooth period can be changed by affecting the evolution of s1. The effects of the electron cyclotron current drive (ECCD) on the shear evolution are studied with a simple model for the poloidal field evolution. The results of the model are summarised in a form of a criterion for the amount of the non-inductive current drive required for sawtooth period control. The effects of the ECCD have been studied in the TEXTOR tokamak in order to confirm the outcome of the model. The observations are complicated by the unavoidable presence of concurrent heating, which also affects the sawtooth period. The effects of additional heating have been separated from the effects of current drive by normalising the sawtooth period, as a function of the power deposition radius, to a case with heating only. The results are in qualitative agreement with the predictions of the theory and confirm that the shear around the q=1 surface determines the moment of the sawtooth crash. The next topic addresses the current diffusion in the presence of the ECCD. It is known that the synergy between non-inductively driven current and the ohmic current can affect the current penetration. However, the standard method of calculations, which assumes neoclassical plasma resistivity, cannot describe the synergistic effects. We propose a model which combines a Fokker-Planck code and magnetic diffusion calculation in a self-consistent manner; where the plasma resistivity is approximated from the Fokker-Planck code at every time step. In this way the parallel electric field is no longer a constant input profile for the Fokker-Planck code, but is a result of calculations of the magnetic diffusion. This model allowed us to identify situations where the synergy between the driven and the ohmic currents becomes significant and affects the current penetration. Both the ECCD power and the electron density have been varied over a wide range of parameters, thus changing the well known non-linearity criterion for ECCD after Harvey. This criterion indicates the non-linear behaviour of the current drive efficiency and also appears to be a good predictor for the synergistic effects. The results are compared with the standard method of calculations which were supplied by the ASTRA transport code. The standard method and the Fokker-Planck code with the self-consistent electric field show similar results in the absence of the synergy and therefore for low values of the Harvey parameter. For co-ECCD and high values of the Harvey parameter substantial synergy between ECCD and the ohmic current is observed and leads to the generation of a large population of suprathermal electrons and slows down the current penetration. The synergy between counter-ECCD and the inductive current results in a decrease of the total driven current and a much smaller population of suprathermal electrons. Another plasma stability problem has been studied during the current ramp-up phase. Quiet and MHD free current ramp-up is a necessary requirement for a long and efficient flat-top phase. The current penetration in the plasma scenarios with various plasma ramp-up rates has been modelled with the ASTRA transport code. It is shown that in the absence of MHD activity the predictions of the ASTRA code are in a agreement with the experimental results.

Low backlash direct drive actuator

DOEpatents

Kuklo, Thomas C.

1994-01-01

A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw.

A mechanism for the dynamo terms to sustain closed-flux current, including helicity balance, by driving current which crosses the magnetic field

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

Jarboe, T. R.; Nelson, B. A.; Sutherland, D. A.

2015-07-15

An analysis of imposed dynamo current drive (IDCD) [T.R. Jarboe et al., Nucl. Fusion 52 083017 (2012)] reveals: (a) current drive on closed flux surfaces seems possible without relaxation, reconnection, or other flux-surface-breaking large events; (b) the scale size of the key physics may be smaller than is often computationally resolved; (c) helicity can be sustained across closed flux; and (d) IDCD current drive is parallel to the current which crosses the magnetic field to produce the current driving force. In addition to agreeing with spheromak data, IDCD agrees with selected tokamak data.

The new 34-meter antenna

NASA Technical Reports Server (NTRS)

Pompa, M. F.

1986-01-01

The new 34-m high efficiency Azimuth - Elevation antenna configuration, including its features, dynamic characteristics and performance at 8.4-GHz frequencies is described. The current-technology features of this antenna produce a highly reliable configuration by incorporation of a main wheel and track azimuth support, central pintle pivot bearing, close tolerance surface panels and all-welded construction. Also described are basic drive controls that, as slaved to three automatic microprocessors, provide accurate and safe control of the antenna's steering tasks. At this time antenna installations are completed at Goldstone and Canberra and have operationally supported the Voyager - Uranus encounter. A third installation is being constructed currently in Madrid and is scheduled for completion in late 1986.

Driving habits in older patients with central vision loss.

PubMed

Sengupta, Sabyasachi; van Landingham, Suzanne W; Solomon, Sharon D; Do, Diana V; Friedman, David S; Ramulu, Pradeep Y

2014-03-01

To determine if central visual loss is associated with driving cessation, driving restriction, or other-driver preference. Cross-sectional study. Sixty-four subjects with bilateral visual loss (<20/32 in better eye) or severe unilateral visual loss (<20/200) from age-related macular degeneration (AMD) and 58 normally sighted controls between 60 and 80 years of age. Participants self-reported driving habits. Other-driver preference was defined as preferring that another drive when there is more than 1 driver in the car. Subjects reporting 2 or more driving limitations were considered to have restricted their driving. Self-reported driving cessation, other-driver preference, and driving restriction. Age-related macular degeneration subjects were older (74.7 vs. 69.7 years), had worse visual acuity (VA; mean better-eye VA, 0.43 vs. 0.08 logarithm of minimum angle of resolution [logMAR]) and contrast sensitivity (CS; 1.4 vs. 1.9 log units of CS [logCS]), and were more likely to be white when compared with controls (P<0.001 for all). Drivers with AMD-related vision loss were more likely to avoid driving over longer distances, beyond 1 hour, at night, and in unfamiliar conditions (P < 0.05 for all). In multivariate models, driving cessation was associated with worse better-eye VA (odds ratio [OR], 1.5 per 1-line decrement in VA; P<0.001) and worse binocular CS (OR, 1.36 per 0.1 logCS increment; P = 0.005); however, AMD group status was not associated with driving cessation (OR, 1.9; P = 0.35). Factors predicting driving restriction were AMD (OR, 9.0; P = 0.004), worse vision (OR, 2.5 per line of VA loss; P<0.001), lower CS (OR, 2.2 per 0.1-logCS increment; P<0.001), and female gender (OR, 27.9; P = 0.002). Other-driver preference was more common with worse vision (OR, 1.6 per 0.1-logMAR increment; P = 0.003), female gender (OR, 4.5; P = 0.02), and being married (OR, 3.8; P = 0.04). Most patients with AMD-related central vision loss continue to drive, but demonstrate significant driving restrictions, especially with more severe VA and CS loss. Future work should determine which driving adaptations the visually impaired best balance safety and independence. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

High Harmonic Fast Wave Damping on an Ion Beam: NSTX and DIII-D Regimes Compared

NASA Astrophysics Data System (ADS)

Pinsker, R. I.; Choi, C. C.; Petty, C. C.; Porkolab, M.; Wilson, J. R.; Murakami, M.; Harvey, R. W.

2004-11-01

Both NSTX and DIII-D use the combination of fast Alfven waves (FW) and neutral beam injection (NBI) for central electron heating and current drive. Damping of the fast wave on the beam ions at moderate to high harmonics (4th--20th) of the beam ion cyclotron frequency represents a loss process. In DIII-D current drive experiments at low density in which 4th and 8th harmonics were compared, damping at the 8th harmonic damping was much weaker than at the 4th [1]. However, recent simulations have predicted that in higher density and higher beam power regimes (of interest to the Advanced Tokamak program) the beam ion absorption will transition to the unmagnetized ion regime, where the damping is significant and essentially independent of harmonic number. In the present work, the transition from magnetized to unmagnetized ion regimes for the NSTX and DIII-D HHFW experiments is studied theoretically, with a combination of simple semi-analytic models and numerical models. \\vspace0.25 em [1] C.C. Petty, et al., Plasma Phys. and Contr. Fusion 43, 1747 (2001).

High-speed low-power voltage-programmed driving scheme for AMOLED displays

NASA Astrophysics Data System (ADS)

Xingheng, Xia; Weijing, Wu; Xiaofeng, Song; Guanming, Li; Lei, Zhou; Lirong, Zhang; Miao, Xu; Lei, Wang; Junbiao, Peng

2015-12-01

A new voltage-programmed driving scheme named the mixed parallel addressing scheme is presented for AMOLED displays, in which one compensation interval can be divided into the first compensation frame and the consequent N -1 post-compensation frames without periods of initialization and threshold voltage detection. The proposed driving scheme has the advantages of both high speed and low driving power due to the mixture of the pipeline technology and the threshold voltage one-time detection technology. Corresponding to the proposed driving scheme, we also propose a new voltage-programmed compensation pixel circuit, which consists of five TFTs and two capacitors (5T2C). In-Zn-O thin-film transistors (IZO TFTs) are used to build the proposed 5T2C pixel circuit. It is shown that the non-uniformity of the proposed pixel circuit is considerably reduced compared with that of the conventional 2T1C pixel circuit. The number of frames (N) preserved in the proposed driving scheme are measured and can be up to 35 with the variation of the OLED current remaining in an acceptable range. Moreover, the proposed voltage-programmed driving scheme can be more valuable for an AMOLED display with high resolution, and may also be applied to other compensation pixel circuits. Project supported by the State Key Development Program for Basic Research of China (No. 2015CB655000) the National Natural Science Foundation of China (Nos. 61204089, 61306099, 61036007, 51173049, U1301243), and the Fundamental Research Funds for the Central Universities (Nos. 2013ZZ0046, 2014ZZ0028).

Computing at DESY — current setup, trends and strategic directions

NASA Astrophysics Data System (ADS)

Ernst, Michael

1998-05-01

Since the HERA experiments H1 and ZEUS started data taking in '92, the computing environment at DESY has changed dramatically. Running a mainframe centred computing for more than 20 years, DESY switched to a heterogeneous, fully distributed computing environment within only about two years in almost every corner where computing has its applications. The computing strategy was highly influenced by the needs of the user community. The collaborations are usually limited by current technology and their ever increasing demands is the driving force for central computing to always move close to the technology edge. While DESY's central computing has a multidecade experience in running Central Data Recording/Central Data Processing for HEP experiments, the most challenging task today is to provide for clear and homogeneous concepts in the desktop area. Given that lowest level commodity hardware draws more and more attention, combined with the financial constraints we are facing already today, we quickly need concepts for integrated support of a versatile device which has the potential to move into basically any computing area in HEP. Though commercial solutions, especially addressing the PC management/support issues, are expected to come to market in the next 2-3 years, we need to provide for suitable solutions now. Buying PC's at DESY currently at a rate of about 30/month will otherwise absorb any available manpower in central computing and still will leave hundreds of unhappy people alone. Though certainly not the only region, the desktop issue is one of the most important one where we need HEP-wide collaboration to a large extent, and right now. Taking into account that there is traditionally no room for R&D at DESY, collaboration, meaning sharing experience and development resources within the HEP community, is a predominant factor for us.

Views and practices of Australian optometrists regarding driving for patients with central visual impairment.

PubMed

Oberstein, Sharon L; Boon, Mei Ying; Chu, Byoung Sun; Wood, Joanne M

2016-09-01

Eye-care practitioners are often required to make recommendations regarding their patients' visual fitness for driving, including patients with visual impairment. This study aimed to understand the perspectives and management strategies adopted by optometrists regarding driving for their patients with central visual impairment. Optometrists were invited to participate in an online survey (from April to June 2012). Items were designed to explore the views and practices adopted by optometrists regarding driving for patients with central visual impairment (visual acuity [VA] poorer than 6/12, normal visual fields, cognitive and physical health), including conditional driver's licences and bioptic telescopes. Closed- and open-ended questions were used. The response rate was 14 per cent (n = 300 valid responses were received). Most respondents (83 per cent) reported that they advised their patients with visual impairment to 'always' or 'sometimes' stop driving. Most were confident in interpreting the visual licensing standards (78 per cent) and advising on legal responsibilities concerning driving (99 per cent). Respondents were familiar with VA requirements for unconditional licensing (98 per cent); however, the median response VA of 6/15 as the poorest VA suggested for conditional licences differed from international practice and Australian medical guidelines released a month prior to the survey's launch. Few respondents reported prescribing bioptic telescopes (two per cent). While 97 per cent of respondents stated that they discussed conditional licences with their patients with visual impairment, relatively few (28 per cent) reported having completed conditional licence applications for such individuals in the previous year. Those who had completed applications were more experienced in years of practice (p = 0.02) and spent more time practising in rural locations (p = 0.03) than those who had not. The majority of Australian optometrists were receptive to the possibilities of driving options for individuals with central visual impairment, although management approaches varied with respect to conditional licensing. © 2016 Optometry Australia.

The alpha-motoneuron pool as transmitter of rhythmicities in cortical motor drive.

PubMed

Stegeman, Dick F; van de Ven, Wendy J M; van Elswijk, Gijs A; Oostenveld, Robert; Kleine, Bert U

2010-10-01

Investigate the effectiveness and frequency dependence of central drive transmission via the alpha-motoneuron pool to the muscle. We describe a model for the simulation of alpha-motoneuron firing and the EMG signal as response to central drive input. The transfer in the frequency domain is investigated. Coherence between stochastical central input and EMG is also evaluated. The transmission of central rhythmicities to the EMG signal relates to the spectral content of the latter. Coherence between central input to the alpha-motoneuron pool and the EMG signal is significant whereby the coupling strength hardly depends on the frequency in a range from 1 to 100 Hz. Common central input to pairs of alpha-motoneurons strongly increases the coherence levels. The often-used rectification of the EMG signal introduces a clear frequency dependence. Oscillatory phenomena are strongly transmitted via the alpha-motoneuron pool. The motoneuron firing frequencies do play a role in the transmission gain, but do not influence the coherence levels. Rectification of the EMG signal enhances the transmission gain, but lowers coherence and introduces a strong frequency dependency. We think that it should be avoided. Our findings show that rhythmicities are translated into alpha-motoneuron activity without strong non-linearities. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Noninductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta

DOE PAGES

Schlossberg, David J.; Bodner, Grant M.; Bongard, Michael W.; ...

2017-07-01

Access to and characterization of sustained, toroidally confined plasmas with a very high plasma-to-magnetic pressure ratio (β t), low internal inductance, high elongation, and nonsolenoidal current drive is a central goal of present tokamak plasma research. Stable access to this desirable parameter space is demonstrated in plasmas with ultralow aspect ratio and high elongation. Local helicity injection provides nonsolenoidal sustainment, low internal inductance, and ion heating. Equilibrium analyses indicate β t up to ~100% with a minimum |B| well spanning up to ~50% of the plasma volume.

Noninductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta.

PubMed

Schlossberg, D J; Bodner, G M; Bongard, M W; Burke, M G; Fonck, R J; Perry, J M; Reusch, J A

2017-07-21

Access to and characterization of sustained, toroidally confined plasmas with a very high plasma-to-magnetic pressure ratio (β_{t}), low internal inductance, high elongation, and nonsolenoidal current drive is a central goal of present tokamak plasma research. Stable access to this desirable parameter space is demonstrated in plasmas with ultralow aspect ratio and high elongation. Local helicity injection provides nonsolenoidal sustainment, low internal inductance, and ion heating. Equilibrium analyses indicate β_{t} up to ∼100% with a minimum |B| well spanning up to ∼50% of the plasma volume.

Observation of odd toroidal Alfvén eigenmodes.

PubMed

Kramer, G J; Sharapov, S E; Nazikian, R; Gorelenkov, N N; Budny, R V

2004-01-09

Experimental evidence is presented for the existence of the theoretically predicted odd toroidicity induced Alfvén eigenmode (TAE) from the simultaneous appearance of odd and even TAEs in a normal shear discharge of the joint European torus. The modes are observed in low central magnetic shear plasmas created by injecting lower hybrid current drive. A fast ion population was created by applying ion cyclotron heating at the high-field side to excite the TAEs. The odd TAEs were identified from their frequency, mode number, and timing relative to the even TAEs.

Heating and current drive on NSTX

NASA Astrophysics Data System (ADS)

Wilson, J. R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C. K.; Rogers, J. H.; Schilling, G.

1997-04-01

Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (˜45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation.

Equatorward moving arcs and substorm onset

NASA Astrophysics Data System (ADS)

Haerendel, Gerhard

2010-07-01

Key observations of phenomena during the growth phase of a substorm are being reviewed with particular attention to the equatorward motion of the hydrogen and electron arcs. The dynamic role of the electron, the so-called growth phase arc, is analyzed. It is part of a current system of type II that is instrumental in changing the dominantly equatorward convection from the polar cap into a sunward convection along the auroral oval. A quantitative model of the arc and associated current system allows determining the energy required for the flow change. It is suggested that high-β plasma outflow from the central current sheet of the tail creates the current generator. Assessment of the energy supplied in this process proves its sufficiency for driving the arc system. The equatorward motion of the arcs is interpreted as a manifestation of the shrinkage of the near-Earth transition region (NETR) between the dipolar magnetosphere and the highly stretched tail. This shrinkage is caused by returning magnetic flux to the dayside magnetosphere as partial replacement of the flux eroded by frontside reconnection. As the erosion of the NETR is proceeding, more and more magnetic flux is demanded from the central current sheet of the near-Earth tail until highly accelerated plasma outflow causes the current sheet to collapse. Propagation of the collapse along the tail triggers reconnection and initiates the substorm.

Power Balance Modeling and Validation for ST Startup Using Local Helicity Injection

NASA Astrophysics Data System (ADS)

Barr, J. L.; Bodner, G. M.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Hinson, E. T.; Perry, J. M.; Reusch, J. A.; Schlossberg, D. J.

2015-11-01

Local Helicity Injection (LHI) uses localized current injectors for routine Ip<0.18 MA non-solenoidal startup on the Pegasus ST. A power-balance model is under development for predictive Ip t using helicity-balance to quantify LHI's effective current drive, Veff. Analytic formulas for low-A plasma inductance and vertical field are used to account for the inductive effects of dynamic shape evolution. These formulas are being validated against magnetic reconstructions of LHI discharges with varied shape evolutions. Initial results match experimental Ip t within 20 kA with assumed shaping and average resistivity (Spitzer, Te = 60 eV). Geometric effects and inductive drive provide 2.0 V along with Veff = 0.3 V to balance 1.1 V of resistive losses and 1.2 V inductive reactance to ramping Ip. The model is especially sensitive to resistivity when Te<150 eV. Initial Thomson Scattering results give core Te = 72 +/-22 eV, and at times suggest higher central electron energies. Spatial and temporal scans are underway to quantify LHI plasma resistivity and transport. MA-class startup in NSTX-U will require increased area (Ainj >= 40 cm2) LHI systems that play a larger role in current drive than geometric effects, with Veff dropping from >10 V to on-par with inductive effects. This regime is accessed in Pegasus at Ip ≅ 300 kA. Work supported by US DOE grants DE-FG02-96ER54375 and DE-SC0006928.

Advanced Tokamak Investigations in Full-Tungsten ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Bock, Alexander

2017-10-01

The tailoring of the q-profile is the foundation of Advanced Tokamak (AT) scenarios. It depends on low collisionality ν* which permits efficient external current drive and high amounts of intrinsic bootstrap current. At constant pressure, lowering ne leads to a strong decrease of ν* Te - 3 . After the conversion of ASDEX Upgrade to fully W-coated plasma facing components, radiative collapses of H-modes with little gas puffing due to central W accumulation could only be avoided partially with central ECRH. Also, operation at high β with low ne presented a challenge for the divertor. Together, these issues prevented meaningful AT investigations. To overcome this, several major feats have been accomplished: Access to lower ne was achieved through a better understanding of the changes to recycling and pumping, and optionally the density pump-out phenomenon due to RMPs. ECRH capacities were substantially expanded for both heating and current drive, and a solid W divertor capable of withstanding the power loads was installed. A major overhaul improved the reliability of the current profile diagnostics. This contribution will detail the efforts needed to re-access AT scenarios and report on the development of candidate steady state scenarios for ITER/DEMO. Starting from the `hybrid scenario,' a non-inductive scenario (q95 = 5.3 , βN = 2.7 , fbs > 40 %) was developed. It can be sustained for many τE, limited only by technical boundaries, and is also independent of the ramp-up scenario. The β-limit is set by ideal modes that convert into NTMs. The Ti-profiles are steeper than predicted by TGLF, but nonlinear electromagnetic gyro-kinetic analyses with GENE including fast particle effects matched the experimental heat fluxes. We will also report on scenarios at higher q95, similar to the EAST/DIII-D steady state scenario. The extrapolation of these scenarios to ITER/DEMO will be discussed.

Apparatus and method for reducing inductive coupling between levitation and drive coils within a magnetic propulsion system

DOEpatents

Post, Richard F.

2001-01-01

An apparatus and method is disclosed for reducing inductive coupling between levitation and drive coils within a magnetic levitation system. A pole array has a magnetic field. A levitation coil is positioned so that in response to motion of the magnetic field of the pole array a current is induced in the levitation coil. A first drive coil having a magnetic field coupled to drive the pole array also has a magnetic flux which induces a parasitic current in the levitation coil. A second drive coil having a magnetic field is positioned to attenuate the parasitic current in the levitation coil by canceling the magnetic flux of the first drive coil which induces the parasitic current. Steps in the method include generating a magnetic field with a pole array for levitating an object; inducing current in a levitation coil in response to motion of the magnetic field of the pole array; generating a magnetic field with a first drive coil for propelling the object; and generating a magnetic field with a second drive coil for attenuating effects of the magnetic field of the first drive coil on the current in the levitation coil.

Electrical current nanogeneration driven by spontaneous nanofluidic oscillations.

PubMed

Gimenez, R; Mercuri, M; Berli, C L A; Bellino, M G

2018-02-15

Exploiting natural phenomena is a central route for providing electricity to sustainably drive wearable electronics. Here we report a nano-scale water-driven energy generator that produces tiny electrical currents from spontaneous wetting-drying oscillations in mesoporous thin films. The system was fabricated with a wormlike mesoporous silica film, which was packed in between Cu and silicon contacts. The nanogenerator runs autonomously when a water droplet is laid over the film close to the Cu electrode, as water infiltration into the film under the electrode produces a direct-current. Wetting-drying cycles, which are spontaneously triggered by water evaporation, are perfectly correlated to the generated electrical current. The autonomous water displacement through the film yields a sustained energy conversion until the droplet reservoir vanishes. This novel water-driven nanogenerator opens new alternatives for versatile, mobile and cost-effective self-powering of nanosystems and nanodevices.

Passive runaway electron suppression in tokamak disruptions

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

Smith, H. M.; Helander, P.; Boozer, A. H.

2013-07-15

Runaway electrons created in disruptions pose a serious problem for tokamaks with large current. It would be desirable to have a runaway electron suppression method which is passive, i.e., a method that does not rely on an uncertain disruption prediction system. One option is to let the large electric field inherent in the disruption drive helical currents in the wall. This would create ergodic regions in the plasma and increase the runaway losses. Whether these regions appear at a suitable time and place to affect the formation of the runaway beam depends on disruption parameters, such as electron temperature andmore » density. We find that it is difficult to ergodize the central plasma before a beam of runaway current has formed. However, the ergodic outer region will make the Ohmic current profile contract, which can lead to instabilities that yield large runaway electron losses.« less

Hanbury Brown and Twiss noise correlations in a topological superconductor beam splitter

NASA Astrophysics Data System (ADS)

Jonckheere, T.; Rech, J.; Zazunov, A.; Egger, R.; Martin, T.

2017-02-01

We study Hanbury Brown and Twiss current cross-correlations in a three-terminal junction where a central topological superconductor (TS) nanowire, bearing Majorana bound states at its ends, is connected to two normal leads. Relying on a nonperturbative Green function formalism, our calculations allow us to provide analytical expressions for the currents and their correlations at subgap voltages, while also giving exact numerical results valid for arbitrary external bias. We show that when the normal leads are biased at voltages V1 and V2 smaller than the gap, the sign of the current cross-correlations is given by -sgn(V1V2) . In particular, this leads to positive cross-correlations for opposite voltages, a behavior in stark contrast with the one of a standard superconductor, which provides direct evidence of the presence of the Majorana zero mode at the edge of the TS. We further extend our results, varying the length of the TS (leading to an overlap of the Majorana bound states) as well as its chemical potential (driving it away from half-filling), generalizing the boundary TS Green function to those cases. In the case of opposite bias voltages, sgn(V1V2)=-1 , driving the TS wire through the topological transition leads to a sign change of the current cross-correlations, providing yet another signature of the physics of the Majorana bound state.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2006-03-14

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2008-03-25

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Low backlash direct drive actuator

DOEpatents

Kuklo, T.C.

1994-10-25

A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw. 10 figs.

Keeping fit and fit to drive : an experimental intervention to explore the impact of physical exercise on older adults' driving.

DOT National Transportation Integrated Search

2013-06-01

With the aging of the population has come increased attention to the importance of helping older : adults retain their mobility. For many older adults, driving is central to their senses of identity : and autonomy, and some research has shown that dr...

Strongly-sheared wind-forced currents in the nearshore regions of the central Southern California Bight

USGS Publications Warehouse

Noble, Marlene A.; Rosenberger, Kurt; Robertson, George L.

2015-01-01

Contrary to many previous reports, winds do drive currents along the shelf in the central portion of the Southern California Bight (SCB). Winds off Huntington Beach CA are the dominant forcing for currents over the nearshore region of the shelf (water depths less than 20 m). Winds control about 50–70% of the energy in nearshore alongshelf surface currents. The wind-driven current amplitudes are also anomalously high. For a relatively weak 1 dyne/cm2 wind stress, the alongshelf surface current amplitudes in this region can reach 80 cm/s or more. Mid-depth current amplitudes for the same wind stress are around 30–40 cm/s. These wind-driven surface current amplitudes are much larger than previously measured over other nearshore shelf regions, perhaps because this program is one of the few that measured currents within a meter of the surface. The near-bed cross-shelf currents over the nearshore region of the Huntington Beach shelf have an Ekman response to winds in that they upwell (downwell) for down (up) coast winds. This response disappears further offshore. Hence, there is upwelling in the SCB, but it does not occur across the entire shelf. Subthermocline water in the nearshore region that may contain nutrients and plankton move onshore when winds are southeastward, but subthermocline water over the shelf break is not transported to the beach. The currents over the outer shelf are not predominately controlled by winds, consistent with previous reports. Instead, they are mainly driven by cross-shelf pressure gradients that are independent of local wind stress.

Concepts for Multi-Speed Rotorcraft Drive System - Status of Design and Testing at NASA GRC

NASA Technical Reports Server (NTRS)

Stevens, Mark A.; Lewicki, David G.; Handschuh, Robert F.

2015-01-01

In several studies and on-going developments for advanced rotorcraft, the need for variable multi-speed capable rotors has been raised. Speed changes of up to 50 have been proposed for future rotorcraft to improve vehicle performance. A rotor speed change during operation not only requires a rotor that can perform effectively over the operating speedload range, but also requires a propulsion system possessing these same capabilities. A study was completed investigating possible drive system arrangements that can accommodate up to a 50 speed change. Key drivers were identified from which simplicity and weight were judged as central. This paper presents the current status of two gear train concepts coupled with the first of two clutch types developed and tested thus far with focus on design lessons learned and areas requiring development. Also, a third concept is presented, a dual input planetary differential as leveraged from a simple planetary with fixed carrier.

Photodrive of magnetic bubbles via magnetoelastic waves

PubMed Central

Ogawa, Naoki; Koshibae, Wataru; Beekman, Aron Jonathan; Nagaosa, Naoto; Kubota, Masashi; Kawasaki, Masashi; Tokura, Yoshinori

2015-01-01

Precise control of magnetic domain walls continues to be a central topic in the field of spintronics to boost infotech, logic, and memory applications. One way is to drive the domain wall by current in metals. In insulators, the incoherent flow of phonons and magnons induced by the temperature gradient can carry the spins, i.e., spin Seebeck effect, but the spatial and time dependence is difficult to control. Here, we report that coherent phonons hybridized with spin waves, magnetoelastic waves, can drive magnetic bubble domains, or curved domain walls, in an iron garnet, which are excited by ultrafast laser pulses at a nonabsorbing photon energy. These magnetoelastic waves were imaged by time-resolved Faraday microscopy, and the resultant spin transfer force was evaluated to be larger for domain walls with steeper curvature. This will pave a path for the rapid spatiotemporal control of magnetic textures in insulating magnets. PMID:26150487

Photodrive of magnetic bubbles via magnetoelastic waves.

PubMed

Ogawa, Naoki; Koshibae, Wataru; Beekman, Aron Jonathan; Nagaosa, Naoto; Kubota, Masashi; Kawasaki, Masashi; Tokura, Yoshinori

2015-07-21

Precise control of magnetic domain walls continues to be a central topic in the field of spintronics to boost infotech, logic, and memory applications. One way is to drive the domain wall by current in metals. In insulators, the incoherent flow of phonons and magnons induced by the temperature gradient can carry the spins, i.e., spin Seebeck effect, but the spatial and time dependence is difficult to control. Here, we report that coherent phonons hybridized with spin waves, magnetoelastic waves, can drive magnetic bubble domains, or curved domain walls, in an iron garnet, which are excited by ultrafast laser pulses at a nonabsorbing photon energy. These magnetoelastic waves were imaged by time-resolved Faraday microscopy, and the resultant spin transfer force was evaluated to be larger for domain walls with steeper curvature. This will pave a path for the rapid spatiotemporal control of magnetic textures in insulating magnets.

ICRF fast wave current drive and mode conversion current drive in EAST tokamak

NASA Astrophysics Data System (ADS)

Yin, L.; Yang, C.; Gong, X. Y.; Lu, X. Q.; Du, D.; Chen, Y.

2017-10-01

Fast wave in the ion-cyclotron resonance frequency (ICRF) range is a promising candidate for non-inductive current drive (CD), which is essential for long pulse and high performance operation of tokamaks. A numerical study on the ICRF fast wave current drive (FWCD) and mode-conversion current drive (MCCD) in the Experimental Advanced Superconducting Tokamak (EAST) is carried out by means of the coupled full wave and Ehst-Karney parameterization methods. The results show that FWCD efficiency is notable in two frequency regimes, i.e., f ≥ 85 MHz and f = 50-65 MHz, where ion cyclotron absorption is effectively avoided, and the maximum on-axis driven current per unit power can reach 120 kA/MW. The sensitivity of the CD efficiency to the minority ion concentration is confirmed, owing to fast wave mode conversion, and the peak MCCD efficiency is reached for 22% minority-ion concentration. The effects of the wave-launch position and the toroidal wavenumber on the efficiency of current drive are also investigated.

Radio-frequency current drive efficiency in the presence of ITBs and a dc electric field

NASA Astrophysics Data System (ADS)

Rosa, P. R. da S.; Mourão, R.; Ziebell, L. F.

2009-05-01

This paper discusses the current drive efficiency by the combined action of EC and LH waves in the presence of a dc electric field and transport, with an internal transport barrier. The transport is assumed to be produced by magnetic fluctuations. The study explores the different barrier parameters and their influence on the current drive efficiency. We study the subject by numerically solving the Fokker-Planck equation. Our main result is that the barrier depth and barrier width are important to determine the correct shape of the current density profile but not to determine the current drive efficiency, which is very little influenced by these parameters. We also found similar results for the influence of the level of magnetic fluctuations on the current density profile and on the current drive efficiency.

4. VIEW LOOKING EAST INTO CENTRAL COURTYARD OF TECHWOOD DORMITORY, ...

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

4. VIEW LOOKING EAST INTO CENTRAL COURTYARD OF TECHWOOD DORMITORY, SHOWING WEST FRONT OF CENTRAL WING. ORIGINAL CASEMENT WINDOWS HAVE BEEN REPLACED WITH SASH WINDOWS, SOME WITH SCREENS. - Techwood Homes, McDaniel Dormitory, 581-587 Techwood Drive, Atlanta, Fulton County, GA

Organization of the central control of muscles of facial expression in man

PubMed Central

Root, A A; Stephens, J A

2003-01-01

Surface EMGs were recorded simultaneously from ipsilateral pairs of facial muscles while subjects made three different common facial expressions: the smile, a sad expression and an expression of horror, and three contrived facial expressions. Central peaks were found in the cross-correlograms of EMG activity recorded from the orbicularis oculi and zygomaticus major during smiling, the corrugator and depressor anguli oris during the sad look and the frontalis and mentalis during the horror look. The size of the central peak was significantly greater between the orbicularis oculi and zygomaticus major during smiling. It is concluded that co-contraction of facial muscles during some facial expressions are accompanied by the presence of common synaptic drive to the motoneurones supplying the muscles involved. Central peaks were found in the cross-correlograms of EMG activity recorded from the frontalis and depressor anguli oris during a contrived expression. However, no central peaks were found in the cross-correlograms of EMG activity recorded from the frontalis and orbicularis oculi or from the frontalis and zygomaticus major during the other two contrived expressions. It is concluded that a common synaptic drive is not present between all possible facial muscle pairs and suggests a functional role for the synergy. The origin of the common drive is discussed. It is concluded that activity in branches of common stem last-order presynaptic input fibres to motoneurones innervating the different facial muscles and presynaptic synchronization of input activity to the different motoneurone pools is involved. The former probably contributes more to the drive to the orbicularis oculi and zygomaticus major during smiling, while the latter is probably more prevalent in the corrugator and depressor anguli oris during the sad look, the frontalis and mentalis during the horror look and the frontalis and depressor anguli oris during one of the contrived expressions. The strength of common synaptic drive is inversely related to the degree of separate control that can be exhibited by the facial muscles involved. PMID:12692176

Optimization of current waveform tailoring for magnetically driven isentropic compression experiments

NASA Astrophysics Data System (ADS)

Waisman, E. M.; Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Cuneo, M. E.; Haill, T. A.; Davis, J.-P.; Brown, J. L.; Seagle, C. T.; Spielman, R. B.

2016-06-01

The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called "bricks," that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.-Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel "current-adder" architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L2 norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.

Optimization of current waveform tailoring for magnetically driven isentropic compression experiments.

PubMed

Waisman, E M; Reisman, D B; Stoltzfus, B S; Stygar, W A; Cuneo, M E; Haill, T A; Davis, J-P; Brown, J L; Seagle, C T; Spielman, R B

2016-06-01

The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called "bricks," that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.-Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel "current-adder" architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L2 norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.

Experiments Using Local Helicity Injectors in the Lower Divertor Region as the Majority Current Drive in a Tokamak Plasma

NASA Astrophysics Data System (ADS)

Perry, Justin M.

Local helicity injection (LHI) is a non-solenoidal current drive capable of achieving high-Ip tokamak startup with a relatively compact and non-invasive array of current injectors in the plasma scrape-off layer. The choice of injector location within the edge region is flexible, but has a profound influence on the nature of the current drive in LHI discharges. Past experiments on the Pegasus ST with injection on the low-field-side near the outboard midplane produced plasmas dominated by inductive drive resulting primarily from plasma geometry evolution over the discharge. Recent experiments with injection on the high-field- side in the lower divertor region produce plasmas dominated by helicity injection current drive, with relatively static plasma geometry, and thus negligible inductive drive. Plasma current up to 200 kA is driven with helicity injection as the dominant current drive using a pair of 4 cm2 area injectors sourcing 8 kA of total injected current. Steady sustainment with LHI current drive alone is demonstrated, with 100 kA sustained for 18 ms. Maximum achievable plasma current is found to scale approximately linearly with a plasma-geometry- normalized form of the effective loop voltage from LHI, Vnorm = AinjVinj/Rinj, where A inj is the total injector area, Vinj is the injector bias voltage, and Rinj is the major radius of the injectors. A newly-discovered MHD regime for LHI-driven plasmas is described, in which the large-amplitude n = 1 fluctuations at 20-50 kHz which are generally dominant during LHI are abruptly reduced by an order of magnitude on the outboard side. High frequency fluctuations ( f > 400 kHz) increase inside the plasma edge at the same time. This regime results in improved plasma current and pervasive changes to plasma behavior, and may suggest short wavelength turbulence as a current drive mechanism during LHI.

On current drive by Ohkawa mechanism of electron cyclotron wave in large inverse aspect ratio tokamaks

NASA Astrophysics Data System (ADS)

Zheng, Pingwei; Gong, Xueyu; Lu, Xingqiang; He, Lihua; Cao, Jingjia; Huang, Qianhong; Deng, Sheng

2018-03-01

A localized and efficient current drive method in the outer-half region of the tokamak with a large inverse aspect ratio is proposed via the Ohkawa mechanism of electron cyclotron (EC) waves. Further off-axis Ohkawa current drive (OKCD) via EC waves was investigated in high electron beta β e HL-2M-like tokamaks with a large inverse aspect ratio, and in EAST-like tokamaks with a low inverse aspect ratio. OKCD can be driven efficiently, and the driven current profile is spatially localized in the radial region, ranging from 0.62 to 0.85, where the large fraction of trapped electrons provides an excellent advantage for OKCD. Furthermore, the current drive efficiency increases with an increase in minor radius, and then drops when the minor radius beyond a certain value. The effect of trapped electrons greatly enhances the current driving capability of the OKCD mechanism. The highest current drive efficiency can reach 0.183 by adjusting the steering mirror to change the toroidal and poloidal incident angle, and the total driven current by OKCD can reach 20-32 kA MW-1 in HL-2M-like tokamaks. The current drive is less efficient for the EAST-like scenario due to the lower inverse aspect ratio. The results show that OKCD may be a valuable alternative current drive method in large inverse aspect ratio tokamaks, and the potential capabilities of OKCD can be used to suppress some important magnetohydrodynamics instabilities in the far off-axis region.

One- and two-dimensional modeling of argon K-shell emission from gas-puff Z-pinch plasmas

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

Thornhill, J. W.; Chong, Y. K.; Apruzese, J. P.

2007-06-15

In this paper, a theoretical model is described and demonstrated that serves as a useful tool for understanding K-shell radiating Z-pinch plasma behavior. Such understanding requires a self-consistent solution to the complete nonlocal thermodynamic equilibrium kinetics and radiation transport in order to realistically model opacity effects and the high-temperature state of the plasma. For this purpose, we have incorporated into the MACH2 two-dimensional magnetohydrodynamic (MHD) code [R. E. Peterkin et al., J. Comput. Phys. 140, 148 (1998)] an equation of state, called the tabular collisional radiative equilibrium (TCRE) model [J. W. Thornhill et al., Phys. Plasmas 8, 3480 (2001)], thatmore » provides reasonable approximations to the plasma's opacity state. MACH2 with TCRE is applied toward analyzing the multidimensional implosion behavior that occurred in Decade Quad (DQ) [D. Price et al., Proceedings of the 12th IEEE Pulsed Power Conference, Monterey, CA, edited by C. Stallings and H. Kirbie (IEEE, New York, 1999), p. 489] argon gas puff experiments that employed a 12 cm diameter nozzle with and without a central gas jet on axis. Typical peak drive currents and implosion times in these experiments were {approx}6 MA and {approx}230 ns. By using Planar Laser Induced Fluorescence measured initial density profiles as input to the calculations, the effect these profiles have on the ability of the pinch to efficiently produce K-shell emission can be analyzed with this combined radiation-MHD model. The calculated results are in agreement with the experimental result that the DQ central-jet configuration is superior to the no-central-jet experiment in terms of producing more K-shell emission. These theoretical results support the contention that the improved operation of the central-jet nozzle is due to the better suppression of instabilities and the higher-density K-shell radiating conditions that the central-jet configuration promotes. When we applied the model toward projecting argon K-shell yield behavior for Sandia National Laboratories' ZR machine ({approx}25 MA peak drive currents, {approx}100 ns implosion times) [D. McDaniel et al., Proceedings of the 5th International Conference on Dense Z-Pinches, Albuquerque, NM, 2002, edited by J. Davis, C. Deeney, and N. R. Pereira (American Institute of Physics, New York, 2002), Vol. 651, p. 23] for experiments that utilize the 12 cm diameter central-jet nozzle configuration, it predicts over 1 MJ of K-shell emission is attainable.« less

Peripheral chemoreceptors tune inspiratory drive via tonic expiratory neuron hubs in the medullary ventral respiratory column network.

PubMed

Segers, L S; Nuding, S C; Ott, M M; Dean, J B; Bolser, D C; O'Connor, R; Morris, K F; Lindsey, B G

2015-01-01

Models of brain stem ventral respiratory column (VRC) circuits typically emphasize populations of neurons, each active during a particular phase of the respiratory cycle. We have proposed that "tonic" pericolumnar expiratory (t-E) neurons tune breathing during baroreceptor-evoked reductions and central chemoreceptor-evoked enhancements of inspiratory (I) drive. The aims of this study were to further characterize the coordinated activity of t-E neurons and test the hypothesis that peripheral chemoreceptors also modulate drive via inhibition of t-E neurons and disinhibition of their inspiratory neuron targets. Spike trains of 828 VRC neurons were acquired by multielectrode arrays along with phrenic nerve signals from 22 decerebrate, vagotomized, neuromuscularly blocked, artificially ventilated adult cats. Forty-eight of 191 t-E neurons fired synchronously with another t-E neuron as indicated by cross-correlogram central peaks; 32 of the 39 synchronous pairs were elements of groups with mutual pairwise correlations. Gravitational clustering identified fluctuations in t-E neuron synchrony. A network model supported the prediction that inhibitory populations with spike synchrony reduce target neuron firing probabilities, resulting in offset or central correlogram troughs. In five animals, stimulation of carotid chemoreceptors evoked changes in the firing rates of 179 of 240 neurons. Thirty-two neuron pairs had correlogram troughs consistent with convergent and divergent t-E inhibition of I cells and disinhibitory enhancement of drive. Four of 10 t-E neurons that responded to sequential stimulation of peripheral and central chemoreceptors triggered 25 cross-correlograms with offset features. The results support the hypothesis that multiple afferent systems dynamically tune inspiratory drive in part via coordinated t-E neurons. Copyright © 2015 the American Physiological Society.

Peripheral chemoreceptors tune inspiratory drive via tonic expiratory neuron hubs in the medullary ventral respiratory column network

PubMed Central

Segers, L. S.; Nuding, S. C.; Ott, M. M.; Dean, J. B.; Bolser, D. C.; O'Connor, R.; Morris, K. F.

2014-01-01

Models of brain stem ventral respiratory column (VRC) circuits typically emphasize populations of neurons, each active during a particular phase of the respiratory cycle. We have proposed that “tonic” pericolumnar expiratory (t-E) neurons tune breathing during baroreceptor-evoked reductions and central chemoreceptor-evoked enhancements of inspiratory (I) drive. The aims of this study were to further characterize the coordinated activity of t-E neurons and test the hypothesis that peripheral chemoreceptors also modulate drive via inhibition of t-E neurons and disinhibition of their inspiratory neuron targets. Spike trains of 828 VRC neurons were acquired by multielectrode arrays along with phrenic nerve signals from 22 decerebrate, vagotomized, neuromuscularly blocked, artificially ventilated adult cats. Forty-eight of 191 t-E neurons fired synchronously with another t-E neuron as indicated by cross-correlogram central peaks; 32 of the 39 synchronous pairs were elements of groups with mutual pairwise correlations. Gravitational clustering identified fluctuations in t-E neuron synchrony. A network model supported the prediction that inhibitory populations with spike synchrony reduce target neuron firing probabilities, resulting in offset or central correlogram troughs. In five animals, stimulation of carotid chemoreceptors evoked changes in the firing rates of 179 of 240 neurons. Thirty-two neuron pairs had correlogram troughs consistent with convergent and divergent t-E inhibition of I cells and disinhibitory enhancement of drive. Four of 10 t-E neurons that responded to sequential stimulation of peripheral and central chemoreceptors triggered 25 cross-correlograms with offset features. The results support the hypothesis that multiple afferent systems dynamically tune inspiratory drive in part via coordinated t-E neurons. PMID:25343784

Extrapolation of the DIII-D high poloidal beta scenario to ITER steady-state using transport modeling

NASA Astrophysics Data System (ADS)

McClenaghan, J.; Garofalo, A. M.; Meneghini, O.; Smith, S. P.

2016-10-01

Transport modeling of a proposed ITER steady-state scenario based on DIII-D high βP discharges finds that the core confinement may be improved with either sufficient rotation or a negative central shear q-profile. The high poloidal beta scenario is characterized by a large bootstrap current fraction( 80%) which reduces the demands on the external current drive, and a large radius internal transport barrier which is associated with improved normalized confinement. Typical temperature and density profiles from the non-inductive high poloidal beta scenario on DIII-D are scaled according to 0D modeling predictions of the requirements for achieving Q=5 steady state performance in ITER with ``day one'' H&CD capabilities. Then, TGLF turbulence modeling is carried out under systematic variations of the toroidal rotation and the core q-profile. Either strong negative central magnetic shear or rotation are found to successfully provide the turbulence suppression required to maintain the temperature and density profiles. This work supported by the US Department of Energy under DE-FC02-04ER54698.

Current Drive

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

Faulconer, D.W

2004-03-15

Certain devices aimed at magnetic confinement of thermonuclear plasma rely on the steady flow of an electric current in the plasma. In view of the dominant place it occupies in both the world magnetic-confinement fusion effort and the author's own activity, the tokamak toroidal configuration is selected as prototype for discussing the question of how such a current can be maintained. Tokamaks require a stationary toroidal plasma current, this being traditionally provided by a pulsed magnetic induction which drives the plasma ring as the secondary of a transformer. Since this mechanism is essentially transient, and steady-state fusion reactor operation hasmore » manifold advantages, significant effort is now devoted to developing alternate steady-state means of generating toroidal current. These methods are classed under the global heading of 'noninductive current drive' or simply 'current drive', generally, though not exclusively, employing the injection of waves and/or toroidally directed particle beams. In what follows we highlight the physical mechanisms underlying surprisingly various approaches to driving current in a tokamak, downplaying a number of practical and technical issues. When a significant data base exists for a given method, its experimental current drive efficiency and future prospects are detailed.« less

Transition From High Harmonic Fast Wave to Whistler/Helicon Regime in Tokamaks

NASA Astrophysics Data System (ADS)

Harris, S. P.; Pinsker, R. I.; Porkolab, M.

2014-10-01

Experiments are being prepared1 on DIII-D in which fast waves (FWs) at 0.5 GHz will be used to drive current noninductively in the mid-radius region. Previous DIII-D experiments used FWs at ~0.1 GHz to drive central current; in this work we examine the frequency dependence of wave propagation and damping in the 0.1-1.0 GHz range with the goal of identifying the optimum frequency range for a particular application. Strongly enhanced electron damping and reduced ion damping at higher frequencies must be weighed against increasing coupling difficulties at higher frequencies and more restrictive wave accessibility at low toroidal field. Wave propagation and accessibility is studied with ray tracing models in slab, cylindrical, and fully toroidal geometries. Analytic expressions for electron and ion damping will be derived with an emphasis on understanding the transition from the moderate-to-high ion cyclotron harmonic regime to the very high harmonic or ``whistler''/``helicon''/lower hybrid FW regime. Work supported in part by the National Undergraduate Fellowship Program in Plasma Physics and Fusion Energy Sciences and the US Department of Energy under DE-FC02-04ER54698.

Driving in unheard silence: Disability and the politics of shutting up.

PubMed

Lourens, Heidi

2018-03-01

The politics of silence is central to disability experience and the field of disability studies. In this analytical autoethnography, I write about my silences as a visually impaired woman. I explore and make sense of personal life stories through a theoretical perspective. The analysis of these personal experiences lead me to argue that disability-related silences are mostly created through the confluence of inaccessible physical and social environments and the psychological internalisation of these worlds. I also discuss the ways in which I am currently regaining my voice. Further research on resistance by disabled persons is recommended.

Long Pulse Operation on Tore-Supra: Towards Steady State

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

Moreau, P.; Bucalossi, J.; Brosset, C.

The experimental programme of Tore Supra is devoted to the study of technology and physics issues associated to long-duration high performance discharges. This new domain of operation requires simultaneously and in steady state: heat removal capability, particle exhaust, fully non-inductive current drive, advanced technology integration and real time plasma control. The long discharge allows for addressing new time scale physic such as the wall particle retention and erosion. Moreover, the physics of fully non-inductive discharges is full of novelty, namely: the MHD stability, the slow spontaneous oscillation of the central electron temperature or the outstanding inward particle pinch.

NIMROD Simulations of the HIT-SI and HIT-SI3 Devices

NASA Astrophysics Data System (ADS)

Morgan, Kyle; Jarboe, Tom; Hossack, Aaron; Chandra, Rian; Everson, Chris

2017-10-01

The Helicity Injected Torus with Steady Inductive helicity injection (HIT-SI) experiment uses a set of inductively driven helicity injectors to apply non-axisymmetric current drive on the edge of the plasma, driving an axisymmetric spheromak equilibrium in a central confinement volume. Significant improvements have been made to extended MHD modeling of HIT-SI, with both the resolution of disagreement at high injector frequencies in HIT-SI in addition to successes with the new upgraded HIT-SI3 device. Previous numerical studies of HIT-SI, using a zero-beta eMHD model, focused on operations with a drive frequency of 14.5 kHz, and found reduced agreement with both the magnetic profile and current amplification at higher frequencies (30-70 kHz). HIT-SI3 has three helicity injectors which are able to operate with different mode structures of perturbations through the different relative temporal phasing of the injectors. Simulations that allow for pressure gradients have been performed in the parameter regimes of both devices using the NIMROD code and show improved agreement with experimental results, most notably capturing the observed Shafranov-shift due to increased beta observed at higher finj in HIT-SI and the variety of toroidal perturbation spectra available in HIT-SI3. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Award Number DE-FG02- 96ER54361.

3. DETAIL VIEW OF DIRECT DRIVE STERLING 'DOLPHIN T' MODEL ...

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

3. DETAIL VIEW OF DIRECT DRIVE STERLING 'DOLPHIN T' MODEL 4 CYLINDER, GASOLINE TRACTOR-TYPE ENGINE WITH FALKBIBBY FLEXIBLE COUPLING - Central Railroad of New Jersey, Newark Bay Lift Bridge, Spanning Newark Bay, Newark, Essex County, NJ

Electrical motor/generator drive apparatus and method

DOEpatents

Su, Gui Jia

2013-02-12

The present disclosure includes electrical motor/generator drive systems and methods that significantly reduce inverter direct-current (DC) bus ripple currents and thus the volume and cost of a capacitor. The drive methodology is based on a segmented drive system that does not add switches or passive components but involves reconfiguring inverter switches and motor stator winding connections in a way that allows the formation of multiple, independent drive units and the use of simple alternated switching and optimized Pulse Width Modulation (PWM) schemes to eliminate or significantly reduce the capacitor ripple current.

Characteristics of on-road driving performance of persons with central vision loss who use bioptic telescopes.

PubMed

Wood, Joanne M; McGwin, Gerald; Elgin, Jennifer; Searcey, Karen; Owsley, Cynthia

2013-05-01

To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. Participants included 23 persons (mean age = 33 ± 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age = 33 ± 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation.

Isotopic effect in experiments on lower hybrid current drive in the FT-2 tokamak

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

Lashkul, S. I., E-mail: Serguey.lashkul@mail.ioffe.ru; Altukhov, A. B.; Gurchenko, A. D., E-mail: aleksey.gurchenko@mail.ioffe.ru

To analyze factors influencing the limiting value of the plasma density at which lower hybrid (LH) current drive terminates, the isotopic factor (the difference in the LH resonance densities in hydrogen and deuterium plasmas) was used for the first time in experiments carried out at the FT-2 tokamak. It is experimentally found that the efficiency of LH current drive in deuterium plasma is appreciably higher than that in hydrogen plasma. The significant role of the parametric decay of the LH pumping wave, which hampers the use of the LH range of RF waves for current drive at high plasma densities,more » is confirmed. It is demonstrated that the parameters characterizing LH current drive agree well with the earlier results obtained at large tokamaks.« less

Universal power transistor base drive control unit

DOEpatents

Gale, Allan R.; Gritter, David J.

1988-01-01

A saturation condition regulator system for a power transistor which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition.

Universal power transistor base drive control unit

DOEpatents

Gale, A.R.; Gritter, D.J.

1988-06-07

A saturation condition regulator system for a power transistor is disclosed which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition. 2 figs.

Generation of spin currents by surface plasmon resonance

PubMed Central

Uchida, K.; Adachi, H.; Kikuchi, D.; Ito, S.; Qiu, Z.; Maekawa, S.; Saitoh, E.

2015-01-01

Surface plasmons, free-electron collective oscillations in metallic nanostructures, provide abundant routes to manipulate light–electron interactions that can localize light energy and alter electromagnetic field distributions at subwavelength scales. The research field of plasmonics thus integrates nano-photonics with electronics. In contrast, electronics is also entering a new era of spintronics, where spin currents play a central role in driving devices. However, plasmonics and spin-current physics have so far been developed independently. Here we report the generation of spin currents by surface plasmon resonance. Using Au nanoparticles embedded in Pt/BiY2Fe5O12 bilayer films, we show that, when the Au nanoparticles fulfill the surface-plasmon-resonance conditions, spin currents are generated across the Pt/BiY2Fe5O12 interface. This spin-current generation cannot be explained by conventional heating effects, requiring us to introduce nonequilibrium magnons excited by surface-plasmon-induced evanescent electromagnetic fields in BiY2Fe5O12. This plasmonic spin pumping integrates surface plasmons with spin-current physics, opening the door to plasmonic spintronics. PMID:25569821

Bootstrap and fast wave current drive for tokamak reactors

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

Ehst, D.A.

1991-09-01

Using the multi-species neoclassical treatment of Hirshman and Sigmar we study steady state bootstrap equilibria with seed currents provided by low frequency (ICRF) fast waves and with additional surface current density driven by lower hybrid waves. This study applies to reactor plasmas of arbitrary aspect ratio. IN one limit the bootstrap component can supply nearly the total equilibrium current with minimal driving power (< 20 MW). However, for larger total currents considerable driving power is required (for ITER: I{sub o} = 18 MA needs P{sub FW} = 15 MW, P{sub LH} = 75 MW). A computational survey of bootstrap fractionmore » and current drive efficiency is presented. 11 refs., 8 figs.« less

National direct-drive program on OMEGA and the National Ignition Facility

NASA Astrophysics Data System (ADS)

Goncharov, V. N.; Regan, S. P.; Campbell, E. M.; Sangster, T. C.; Radha, P. B.; Myatt, J. F.; Froula, D. H.; Betti, R.; Boehly, T. R.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Glebov, V. Yu; Harding, D. R.; Hu, S. X.; Igumenshchev, I. V.; Marshall, F. J.; McCrory, R. L.; Michel, D. T.; Seka, W.; Shvydky, A.; Stoeckl, C.; Theobald, W.; Gatu-Johnson, M.

2017-01-01

A major advantage of the laser direct-drive (DD) approach to ignition is the increased fraction of laser drive energy coupled to the hot spot and relaxed hot-spot requirements for the peak pressure and convergence ratios relative to the indirect-drive approach at equivalent laser energy. With the goal of a successful ignition demonstration using DD, the recently established national strategy has several elements and involves multiple national and international institutions. These elements include the experimental demonstration on OMEGA cryogenic implosions of hot-spot conditions relevant for ignition at MJ-scale energies available at the National Ignition Facility (NIF) and developing an understanding of laser-plasma interactions and laser coupling using DD experiments on the NIF. DD designs require reaching central stagnation pressures in excess of 100 Gbar. The current experiments on OMEGA have achieved inferred peak pressures of 56 Gbar (Regan et al 2016 Phys. Rev. Lett. 117 025001). Extensive analysis of the cryogenic target experiments and two- and three-dimensional simulations suggest that power balance, target offset, and target quality are the main limiting factors in target performance. In addition, cross-beam energy transfer (CBET) has been identified as the main mechanism reducing laser coupling. Reaching the goal of demonstrating hydrodynamic equivalence on OMEGA includes improving laser power balance, target position, and target quality at shot time. CBET must also be significantly reduced and several strategies have been identified to address this issue.

ECRH System For ITER

NASA Astrophysics Data System (ADS)

Darbos, C.; Henderson, M.; Albajar, F.; Bigelow, T.; Bomcelli, T.; Chavan, R.; Denisov, G.; Farina, D.; Gandini, F.; Heidinger, R.; Goodman, T.; Hogge, J. P.; Kajiwara, K.; Kasugai, A.; Kern, S.; Kobayashi, N.; Oda, Y.; Ramponi, G.; Rao, S. L.; Rasmussen, D.; Rzesnicki, T.; Saibene, G.; Sakamoto, K.; Sauter, O.; Scherer, T.; Strauss, D.; Takahashi, K.; Zohm, H.

2009-11-01

A 26 MW Electron Cyclotron Heating and Current Drive (EC H&CD) system is to be installed for ITER. The main objectives are to provide, start-up assist, central H&CD and control of MHD activity. These are achieved by a combination of two types of launchers, one located in an equatorial port and the second type in four upper ports. The physics applications are partitioned between the two launchers, based on the deposition location and driven current profiles. The equatorial launcher (EL) will access from the plasma axis to mid radius with a relatively broad profile useful for central heating and current drive applications, while the upper launchers (ULs) will access roughly the outer half of the plasma radius with a very narrow peaked profile for the control of the Neoclassical Tearing Modes (NTM) and sawtooth oscillations. The EC power can be switched between launchers on a time scale as needed by the immediate physics requirements. A revision of all injection angles of all launchers is under consideration for increased EC physics capabilities while relaxing the engineering constraints of both the EL and ULs. A series of design reviews are being planned with the five parties (EU, IN, JA, RF, US) procuring the EC system, the EC community and ITER Organization (IO). The review meetings qualify the design and provide an environment for enhancing performances while reducing costs, simplifying interfaces, predicting technology upgrades and commercial availability. In parallel, the test programs for critical components are being supported by IO and performed by the Domestic Agencies (DAs) for minimizing risks. The wide participation of the DAs provides a broad representation from the EC community, with the aim of collecting all expertise in guiding the EC system optimization. Still a strong relationship between IO and the DA is essential for optimizing the design of the EC system and for the installation and commissioning of all ex-vessel components when several teams from several DAs will be involved together in the tests on the ITER site.

Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep.

PubMed

Randerath, Winfried; Verbraecken, Johan; Andreas, Stefan; Arzt, Michael; Bloch, Konrad E; Brack, Thomas; Buyse, Bertien; De Backer, Wilfried; Eckert, Danny Joel; Grote, Ludger; Hagmeyer, Lars; Hedner, Jan; Jennum, Poul; La Rovere, Maria Teresa; Miltz, Carla; McNicholas, Walter T; Montserrat, Josep; Naughton, Matthew; Pepin, Jean-Louis; Pevernagie, Dirk; Sanner, Bernd; Testelmans, Dries; Tonia, Thomy; Vrijsen, Bart; Wijkstra, Peter; Levy, Patrick

2017-01-01

The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a "marker" of disease severity or a "mediator" of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation. Copyright ©ERS 2017.

Brief Report: Driving and Young Adults with ASD--Parents' Experiences

ERIC Educational Resources Information Center

Cox, Neill Broderick; Reeve, Ronald E.; Cox, Stephany M.; Cox, Daniel J.

2012-01-01

A paucity of research exists regarding driving skills and individuals with Autism Spectrum Disorders (ASD). The current study sought to gain a better understanding of driving and ASD by surveying parents/caregivers of adolescents/young adults with ASD who were currently attempting, or had previously attempted, to learn to drive. Respondents…

Gender differences in highway driving performance after administration of sleep medication: a review of the literature.

PubMed

Verster, Joris C; Roth, Thomas

2012-01-01

It is generally assumed that there are minimal gender differences in the safety and efficacy of central nervous system drugs, as is evidenced by men and women receiving the same drug dosage. There is, however, evidence that drugs may have a differential effect on performance in men and women, given reported differences in pharmacokinetics as well as the presence or absence and severity of adverse effects. It is especially important to verify whether gender differences in performance exist in case of activities that have potentially dangerous outcomes such as driving a car. This review summarizes the current scientific evidence on gender differences in driving performance after treatment with hypnotic drugs. A literature search was conducted to obtain all studies that conducted on-road driving tests to examine the effects hypnotic drugs on driving. Cross-references were checked and technical reports and raw data were obtained, if possible. Fourteen studies were evaluated. Many studies did not allow analyses of gender effects because only women were included. Others did not report data on gender analyses. Technical reports and additional data analyses revealed significant gender differences in driving performance the morning following bedtime administration of flurazepam (30 mg) and after middle-of-the-night administration of zolpidem (10 mg). No significant gender differences were found for ramelteon (8 mg), lormetazepam (1 and 2 mg), zaleplon (10 and 20 mg), and zopiclone (7.5 mg). Although the available data are limited, the results show that significant gender differences have been found for some drugs but not others. Therefore, in the future more research is needed to reveal potential gender differences and to determine what mediates them.

An overview of Ireland's National Radon Policy.

PubMed

Long, S; Fenton, D

2011-05-01

In Ireland radon is a significant public health issue and is linked to 150-200 lung cancer deaths each year. Irish National Radon Policy aims to reduce individual risk by identifying and remediating buildings with high radon concentrations and also to reduce collective dose through radon prevention as required by revised building regulations. Achievements to date are significant and include the completion of the National Radon Survey, the testing of every school in Ireland, the on-going testing of social housing, collaboration between the public health and radiation protection authorities and the inclusion of radon in inspections of workplaces. However, this work now needs to be drawn together centrally to comprehensively address the radon problem. The RPII and the relevant central governing department, the Department of Environment, Heritage and Local Government are currently working to constitute a group of key experts from relevant public authorities to drive the development of a National Radon Control Strategy.

Plasma heating and current drive using intense, pulsed microwaves

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

Cohen, B.I.; Cohen, R.H.; Nevins, W.M.

1988-01-01

The use of powerful new microwave sources, e.g., free-electron lasers and relativistic gyrotrons, provide unique opportunities for novel heating and current-drive schemes in the electron-cyclotron and lower-hybrid ranges of frequencies. These high-power, pulsed sources have a number of technical advantages over conventional, low-intensity sources; and their use can lead to improved current-drive efficiencies and better penetration into a reactor-grade plasma in specific cases. The Microwave Tokamak Experiment at Lawrence Livermore National Laboratory will provide a test for some of these new heating and current-drive schemes. This paper reports theoretical progress both in modeling absorption and current drive for intense pulsesmore » and in analyzing some of the possible complications that may arise, e.g., parametric instabilities and nonlinear self-focusing. 22 refs., 9 figs., 1 tab.« less

O-regime dynamics and modeling in Tore Supra

NASA Astrophysics Data System (ADS)

Turco, F.; Giruzzi, G.; Imbeaux, F.; Udintsev, V. S.; Artaud, J. F.; Barana, O.; Dumont, R.; Mazon, D.; Ségui, J.-L.

2009-06-01

The regime of nonlinear temperature oscillations (O-regime), characteristic of noninductive discharges on Tore Supra [Équipe Tore Supra, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 9], is investigated in its triggering and suppressing mechanism. This regime can be described by two nonlinearly coupled equations for the current density j(r ) and the electron temperature Te(r) where the equation coefficients are functions of j and Te themselves. Both the integrated modeling code CRONOS [V. Basiuk et al., Nucl. Fusion 43, 822 (2003)] and a two-patch predator-prey system with diffusion and noise have been used and results have been compared to the experimental observations of the O-regime. A database of discharges is analyzed which features monotonic, flat, and reversed safety factor (q) profiles in order to characterize the action of external actuators on the regime dynamics with the widest generality. Electron cyclotron current drive and neutral beam injections have been used in order to induce localized perturbations in the total current profile j(r ) as well as to change the plasma confinement conditions in the central region. Magnetic shear perturbations and modifications of the heat transport turn out to be the central parameters governing the dynamics of the O-regime.

Sensorless optimal sinusoidal brushless direct current for hard disk drives

NASA Astrophysics Data System (ADS)

Soh, C. S.; Bi, C.

2009-04-01

Initiated by the availability of digital signal processors and emergence of new applications, market demands for permanent magnet synchronous motors have been surging. As its back-emf is sinusoidal, the drive current should also be sinusoidal for reducing the torque ripple. However, in applications like hard disk drives, brushless direct current (BLDC) drive is adopted instead of sinusoidal drive for simplification. The adoption, however, comes at the expense of increased harmonics, losses, torque pulsations, and acoustics. In this paper, we propose a sensorless optimal sinusoidal BLDC drive. First and foremost, the derivation for an optimal sinusoidal drive is presented, and a power angle control scheme is proposed to achieve an optimal sinusoidal BLDC. The scheme maintains linear relationship between the motor speed and drive voltage. In an attempt to execute the sensorless drive, an innovative power angle measurement scheme is devised, which takes advantage of the freewheeling diodes and measures the power angle through the detection of diode voltage drops. The objectives as laid out will be presented and discussed in this paper, supported by derivations, simulations, and experimental results. The proposed scheme is straightforward, brings about the benefits of sensorless sinusoidal drive, negates the need for current sensors by utilizing the freewheeling diodes, and does not incur additional cost.

Modelling of minority ion cyclotron current drive during the activated phase of ITER

NASA Astrophysics Data System (ADS)

Laxåback, M.; Hellsten, T.

2005-12-01

Neoclassical tearing modes, triggered by the long-period sawteeth expected in tokamaks with large non-thermal α-particle populations, may impose a severe β limit on experiments with large fusion yields and on reactors. Sawtooth destabilization by localized current drive could relax the β limit and improve plasma performance. 3He minority ion cyclotron current drive around the sawtooth inversion radius has been planned for ITER. Several ion species, including beam injected D ions and fusion born α particles, are however also resonant in the plasma and may represent a parasitic absorption of RF power. Modelling of minority ion cyclotron current drive in an ITER-FEAT-like plasma is presented, including the effects of ion trapping, finite ion drift orbit widths, wave-induced radial transport and the coupled evolution of wave fields and resonant ion distributions. The parasitic absorption of RF power by the other resonant species is concluded to be relatively small, but the 3He minority current drive is nevertheless negligible due to the strong collisionality of the 3He ions and the drag current by toroidally counter-rotating background ions and co-rotating electrons. H minority current drive is found to be a significantly more effective alternative.

Oscillating field current drive experiments in the Madison Symmetric Torus

NASA Astrophysics Data System (ADS)

Blair, Arthur P., Jr.

Oscillating Field Current Drive (OFCD) is an inductive current drive method for toroidal pinches. To test OFCD, two 280 Hz 2 MVA oscillators were installed in the toroidal and poloidal magnetic field circuits of the Madison Symmetric Torus (MST) Reversed Field Pinch (RFP.) Partial sustainment experiments were conducted where the two voltage oscillations were superimposed on the standard MST power supplies. Supplementary current drive of about 10% has been demonstrated, comparable to theoretical predictions. However, maximum current drive does not coincide with maximum helicity injection rate - possibly due to an observed dependence of core and edge tearing modes on the relative phase of the oscillators. A dependence of wall interactions on phase was also observed, the largest interaction coinciding with negative current drive. Experiments were conducted at 280 and 530 Hz. 530 Hz proved to be too high and yielded little or no net current drive. Experiments at 280 Hz proved more fruitful. A 1D relaxed state model was used to predict the effects of voltage amplitudes, frequencies, and waveforms on performance and to optimize the design of OFCD hardware. Predicted current drive was comparable to experimental values, though the aforementioned phase dependence was not. Comparisons were also made with a more comprehensive 3D model which proved to be a more accurate predictor of current drive. Both 1D and 3D models predicted the feasability of full sustainment via OFCD. Experiments were also conducted with only the toroidal field oscillator applied. An entrainment of the natural sawtooth frequency to our applied oscillation was observed as well as a slow modulation of the edge tearing mode amplitudes. A large modulation (20 to 80 eV) of the ion temperature was also observed that can be partially accounted for by collisional heating via magnetic pumping. Work is in progress to increase the power of the existing OFCD hardware.

Turbulent current drive mechanisms

NASA Astrophysics Data System (ADS)

McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

2017-08-01

Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

Electromobility concept for racing cars based on lithium-ion batteries and supercapacitors

NASA Astrophysics Data System (ADS)

Frenzel, B.; Kurzweil, P.; Rönnebeck, H.

For the construction of an all-electric race car, all aspects from engineering design over cost estimation up to the road capability are illuminated. From the most promising batteries for electric vehicle propulsion, the state-of-the art and commercial availability of lithium-ion secondary batteries is critically discussed with respect to cycle-life and unfavorable charge-discharge conditions. A market-overview is given with respect to a small electric car. Different combinations of electric motors and a recuperation system have been investigated. Weight aspects of central drive systems were considered and compared with decentralized wheel-hub drives. As a result, a centralized high-speed drive train based on a permanent-magnet synchronous engine with high-energy magnets seems to be superior due to limited space for assembly.

Reliable, responsive pacemaking and pattern generation with minimal cell numbers: the crustacean cardiac ganglion.

PubMed

Cooke, Ian M

2002-04-01

Investigations of the electrophysiology of crustacean cardiac ganglia over the last half-century are reviewed for their contributions to elucidating the cellular mechanisms and interactions by which a small (as few as nine cells) neuronal network accomplishes extremely reliable, rhythmical, patterned activation of muscular activity-in this case, beating of the neurogenic heart. This ganglion is thus a model for pacemaking and central pattern generation. Favorable anatomy has permitted voltage- and space-clamp analyses of voltage-dependent ionic currents that endow each neuron with the intrinsic ability to respond with rhythmical, patterned impulse activity to nonpatterned stimulation. The crustacean soma and initial axon segment do not support impulse generation but integrate input from stretch-sensitive dendrites and electrotonic and chemically mediated synapses on axonal processes in neuropils. The soma and initial axon produce a depolarization-activated, calcium-mediated, sustained potential, the "driver potential," so-called because it drives a train of impulses at the "trigger zone" of the axon. Extreme reliability results from redundancy and the electrotonic coupling and synaptic interaction among all the neurons. Complex modulation by central nervous system inputs and by neurohormones to adjust heart pumping to physiological demands has long been demonstrated, but much remains to be learned about the cellular and molecular mechanisms of action. The continuing relevance of the crustacean cardiac ganglion as a relatively simple model for pacemaking and central pattern generation is confirmed by the rapidly widening documentation of intrinsic potentials such as plateau potentials in neurons of all major animal groups. The suite of ionic currents (a slowly inactivating calcium current and various potassium currents, with variations) observed for the crustacean cardiac ganglion have been implicated in or proven to underlie a majority of the intrinsic potentials of neurons involved in pattern generation.

Modafinil improves real driving performance in patients with hypersomnia: a randomized double-blind placebo-controlled crossover clinical trial.

PubMed

Philip, Pierre; Chaufton, Cyril; Taillard, Jacques; Capelli, Aurore; Coste, Olivier; Léger, Damien; Moore, Nicholas; Sagaspe, Patricia

2014-03-01

Patients with excessive daytime sleepiness (EDS) are at high risk for driving accidents, and physicians are concerned by the effect of alerting drugs on driving skills of sleepy patients. No study has up to now investigated the effect of modafinil (a reference drug to treat EDS in patients with hypersomnia) on on-road driving performance of patients suffering from central hypersomnia. The objective is to evaluate in patients with central hypersomnia the effect of a wake-promoting drug on real driving performance and to assess the relationship between objective sleepiness and driving performance. Randomized, crossover, double-blind placebo-controlled trial conducted among 13 patients with narcolepsy and 14 patients with idiopathic hypersomnia. Patients were randomly assigned to receive modafinil (400 mg) or placebo for 5 days prior to the driving test. Each condition was separated by at least 3 weeks of washout. Mean number of Inappropriate Line Crossings, Standard Deviation of Lateral Position of the vehicle and mean sleep latency in the Maintenance of Wakefulness Test were assessed. Modafinil reduced the mean number of Inappropriate Line Crossings and Standard Deviation of Lateral Position of the vehicle compared to placebo (F(1,25) = 4.88, P < 0.05 and F(1,25) = 3.87, P = 0.06 tendency). Mean sleep latency at the Maintenance of Wakefulness Test significantly correlated with the mean number of Inappropriate Line Crossings (r = -0.41, P < 0.001). Modafinil improves driving performance in patients with narcolepsy and idiopathic hypersomnia. The Maintenance of Wakefulness Test is a suitable clinical tool to assess fitness to drive in this population.

Prospects for Off-axis Current Drive via High Field Side Lower Hybrid Current Drive in DIII-D

NASA Astrophysics Data System (ADS)

Wukitch, S. J.; Shiraiwa, S.; Wallace, G. M.; Bonoli, P. T.; Holcomb, C.; Park, J. M.; Pinsker, R. I.

2017-10-01

An outstanding challenge for an economical, steady state tokamak is efficient off-axis current drive scalable to reactors. Previous studies have focused on high field side (HFS) launch of lower hybrid waves for current drive (LHCD) in double null configurations in reactor grade plasmas. The goal of this work is to find a HFS LHCD scenario for DIII-D that balances coupling, power penetration and damping. The higher magnetic field on the HFS improves wave accessibility, which allows for lower n||waves to be launched. These waves penetrate farther into the plasma core before damping at higher Te yielding a higher current drive efficiency. Utilizing advanced ray tracing and Fokker Planck simulation tools (GENRAY+CQL3D), wave penetration, absorption and drive current profiles in high performance DIII-D H-Mode plasmas were investigated. We found LH scenarios with single pass absorption, excellent wave penetration to r/a 0.6-0.8, FWHM r/a=0.2 and driven current up to 0.37 MA/MW coupled. These simulations indicate that HFS LHCD has potential to achieve efficient off-axis current drive in DIII-D and the latest results will be presented. Work supported by U.S. Dept. of Energy, Office of Science, Office of Fusion Energy Sciences, using User Facility DIII-D, under Award No. DE-FC02-04ER54698 and Contract No. DE-FC02-01ER54648 under Scientific Discovery through Advanced Computing Initiative.

The drink driving situation in Vietnam.

PubMed

Ngoc, Luu Bich; Thieng, Nguyen Thi; Huong, Nguyen Lan

2012-01-01

To identify the extent and nature of the problem and the main contributing factors to drink driving crashes; determine the current mechanisms in place, particularly in terms of legislation and its enforcement; and identify baseline data and relevant stakeholders. The situational assessment was based on the collection of secondary data from available reports and documents, in-depth interviews with key representatives at a central level, and field surveys in provinces. Vietnam has experienced phenomenal growth in motor vehicles, especially motorcycles, in the last decade (400%). This initially led to an increase in deaths from road crashes, but since 2006 the number has stayed fairly level according to police statistics. However, comparisons with health data suggest that the number of deaths is much higher and there are clearly a number of problems with the relevant data systems. Data on the percentage of drivers exceeding legal limits are not available, but police statistics indicated that drinking alcohol was a contributory factor in 7 percent of motor vehicle crashes. This is likely to be an underestimate, because the police and health services do not have the equipment to measure the blood alcohol concentration (BAC) levels of all drivers in crashes. Motorcycle riders and young people are in the high-risk groups. There are strict BAC limits starting at over zero and severe punishments for drunk drivers involved in serious crashes. However, the police do not have adequate manpower or equipment to conduct regular and frequent roadside checking for drivers who have been drinking. There have also been a number of education programs on road safety including drinking and driving, but these have not included sustained and intensive campaigns targeting the high-risk groups. The National Traffic Safety Committee (NTSC) is responsible for coordinating the relevant agencies but there is still a problem with lack of information sharing between agencies. This study completed a comprehensive situational assessment that examined the problem of drinking and driving and identified some of the weaknesses in the current prevention system. Vietnam currently has 2 international projects on road safety and it is hoped that these together with support from the International Center for Alcohol Policies (ICAP) Global Actions program will provide opportunities for strengthening drinking and drive prevention initiatives by improving the road crash and injury database, building the capacity of the key organizations, strengthening the coordination mechanisms, and implementing and evaluating trial drink-drive interventions. Copyright © 2012 Taylor & Francis Group, LLC

Characteristics of On-Road Driving Performance of Persons With Central Vision Loss Who Use Bioptic Telescopes

PubMed Central

Wood, Joanne M.; McGwin, Gerald; Elgin, Jennifer; Searcey, Karen; Owsley, Cynthia

2013-01-01

Purpose. To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. Methods. Participants included 23 persons (mean age = 33 ± 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age = 33 ± 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use. Results. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. Conclusions. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation. PMID:23640044

Interior, central sunporch behind living room, looking northeast U.S. ...

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

Interior, central sunporch behind living room, looking northeast - U.S. Veterans Hospital, Jefferson Barracks, Medical Officer in Charge Residence, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

Plasma Confinement in the UCLA Electric Tokamak.

NASA Astrophysics Data System (ADS)

Taylor, Robert J.

2001-10-01

The main goal of the newly constructed large Electric Tokamak (R = 5 m, a = 1 m, BT < 0.25 T) is to access an omnigeneous, unity beta(S.C. Cowley, P.K. Kaw, R.S. Kelly, R.M. Kulsrud, Phys. fluids B 3 (1991) 2066.) plasma regime. The design goal was to achieve good confinement at low magnetic fields, consistent with the high beta goal. To keep the program cost down, we adopted the use of ICRF as the primary heating source. Consequently, antenna surfaces covering 1/2 of the surface of the tokamak has been prepared for heating and current drive. Very clean hydrogenic plasmas have been achieved with loop voltage below 0.7 volt and densities 3 times above the Murakami limit, n(0) > 8 x 10^12 cm-3 when there is no MHD activity. The electron temperature, derived from the plasma conductivity is > 250 eV with a central electron energy confinement time > 350 msec in ohmic conditions. The sawteeth period is 50 msec. Edge plasma rotation is induced by plasma biasing via electron injection in an analogous manner to that seen in CCT(R.J. Taylor, M.L. Brown, B.D. Fried, H. Grote, J.R. Liberati, G.J. Morales, P. Pribyl, D. Darrow, and M. Ono. Phys. Rev Lett. 63 2365 1989.) and the neoclassical bifurcation is close to that described by Shaing et al(K.C. Shaing and E.C. Crume, Phys. Rev. Lett. 63 2369 (1989).). In the ohmic phase the confinement tends to be MHD limited. The ICRF heating eliminates the MHD disturbances. Under second harmonic heating conditions, we observe an internal confinement peaking characterized by doubling of the core density and a corresponding increase in the central electron temperature. Charge exchange data, Doppler data in visible H-alpha light, and EC radiation all indicate that ICRF heating works much better than expected. The major effort is focused on increasing the power input and controlling the resulting equilibrium. This task appears to be easy since our current pulses are approaching the 3 second mark without RF heating or current drive. Our initial experience with current profile control, needed for high beta plasma equilibrium, will be also discussed.

Visual function and fitness to drive.

PubMed

Kotecha, Aachal; Spratt, Alexander; Viswanathan, Ananth

2008-01-01

Driving is recognized to be a visually intensive task and accordingly there is a legal minimum standard of vision required for all motorists. The purpose of this paper is to review the current United Kingdom (UK) visual requirements for driving and discuss the evidence base behind these legal rules. The role of newer, alternative tests of visual function that may be better indicators of driving safety will also be considered. Finally, the implications of ageing on driving ability are discussed. A search of Medline and PubMed databases was performed using the following keywords: driving, vision, visual function, fitness to drive and ageing. In addition, papers from the Department of Transport website and UK Royal College of Ophthalmologists guidelines were studied. Current UK visual standards for driving are based upon historical concepts, but recent advances in technology have brought about more sophisticated methods for assessing the status of the binocular visual field and examining visual attention. These tests appear to be better predictors of driving performance. Further work is required to establish whether these newer tests should be incorporated in the current UK visual standards when examining an individual's fitness to drive.

The Caenorhabditis elegans Q neuroblasts: A powerful system to study cell migration at single-cell resolution in vivo.

PubMed

Rella, Lorenzo; Fernandes Póvoa, Euclides E; Korswagen, Hendrik C

2016-04-01

During development, cell migration plays a central role in the formation of tissues and organs. Understanding the molecular mechanisms that drive and control these migrations is a key challenge in developmental biology that will provide important insights into disease processes, including cancer cell metastasis. In this article, we discuss the Caenorhabditis elegans Q neuroblasts and their descendants as a tool to study cell migration at single-cell resolution in vivo. The highly stereotypical migration of these cells provides a powerful system to study the dynamic cytoskeletal processes that drive migration as well as the evolutionarily conserved signaling pathways (including different Wnt signaling cascades) that guide the cells along their specific trajectories. Here, we provide an overview of what is currently known about Q neuroblast migration and highlight the live-cell imaging, genome editing, and quantitative gene expression techniques that have been developed to study this process. © 2016 Wiley Periodicals, Inc.

Concepts for Multi-Speed Rotorcraft Drive System - Status of Design and Testing at NASA GRC

NASA Technical Reports Server (NTRS)

Stevens, Mark A.; Lewicki, David G.; Handschuh, Robert F.

2015-01-01

In several studies and on-going developments for advanced rotorcraft, the need for variable/multi-speed capable rotors has been raised. Speed changes of up to 50 percent have been proposed for future rotorcraft to improve vehicle performance. A rotor speed change during operation not only requires a rotor that can perform effectively over the operating speed/load range, but also requires a propulsion system possessing these same capabilities. A study was completed investigating possible drive system arrangements that can accommodate up to a 50 percent speed change. Key drivers were identified from which simplicity and weight were judged as central. This paper presents the current status of two gear train concepts coupled with the first of two clutch types developed and tested thus far with focus on design lessons learned and areas requiring development. Also, a third concept is presented, a dual input planetary differential as leveraged from a simple planetary with fixed carrier.

Differential segregation in a cell-cell contact interface: the dynamics of the immunological synapse.

PubMed Central

Burroughs, Nigel John; Wülfing, Christoph

2002-01-01

Receptor-ligand couples in the cell-cell contact interface between a T cell and an antigen-presenting cell form distinct geometric patterns and undergo spatial rearrangement within the contact interface. Spatial segregation of the antigen and adhesion receptors occurs within seconds of contact, central aggregation of the antigen receptor then occurring over 1-5 min. This structure, called the immunological synapse, is becoming a paradigm for localized signaling. However, the mechanisms driving its formation, in particular spatial segregation, are currently not understood. With a reaction diffusion model incorporating thermodynamics, elasticity, and reaction kinetics, we examine the hypothesis that differing bond lengths (extracellular domain size) is the driving force behind molecular segregation. We derive two key conditions necessary for segregation: a thermodynamic criterion on the effective bond elasticity and a requirement for the seeding/nucleation of domains. Domains have a minimum length scale and will only spontaneously coalesce/aggregate if the contact area is small or the membrane relaxation distance large. Otherwise, differential attachment of receptors to the cytoskeleton is required for central aggregation. Our analysis indicates that differential bond lengths have a significant effect on synapse dynamics, i.e., there is a significant contribution to the free energy of the interaction, suggesting that segregation by differential bond length is important in cell-cell contact interfaces and the immunological synapse. PMID:12324401

Microscopic Car Modeling for Intelligent Traffic and Scenario Generation in the UCF Driving Simulator : Year 2

DOT National Transportation Integrated Search

2000-01-01

A multi-year project was initiated to introduce autonomous vehicles in the University of Central Florida (UCF) Driving Simulator for real-time interaction with the simulator vehicle. This report describes the progress during the second year. In the f...

Turbulent current drive mechanisms

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

McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm’s law, and hence provide an ideal means for driving deviationsmore » from neoclassical predictions.« less

Turbulent current drive mechanisms

DOE PAGES

McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

2017-07-01

Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm’s law, and hence provide an ideal means for driving deviationsmore » from neoclassical predictions.« less

Interior, first floor, central lobby, detail of dedication plaque of ...

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

Interior, first floor, central lobby, detail of dedication plaque of terrazzo floor, looking west - U.S. Veterans Hospital, Jefferson Barracks, Admissions Building, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

8. VIEW LOOKING SOUTHEAST INTO CENTRAL COURTYARD OF TECHWOOD DORMITORY, ...

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

8. VIEW LOOKING SOUTHEAST INTO CENTRAL COURTYARD OF TECHWOOD DORMITORY, SHOWING WEST FRONT OF CENTER WING AND PART OF NORTH SIDE OF SOUTH WING. - Techwood Homes, McDaniel Dormitory, 581-587 Techwood Drive, Atlanta, Fulton County, GA

The surveillance state of behavioral automation

PubMed Central

Schaefer, Andreas T; Claridge-Chang, Adam

2012-01-01

Genetics’ demand for increased throughput is driving automatization of behavior analysis far beyond experimental workhorses like circadian monitors and the operant conditioning box. However, the new automation is not just faster: it is also allowing new kinds of experiments, many of which erase the boundaries of the traditional neuroscience disciplines (psychology, ethology and physiology) while producing insight into problems that were otherwise opaque. Ironically, a central theme of current automatization is to improve observation of animals in increasingly naturalistic environments. This is not just a return to 19th century priorities: the new observational methods provide unprecedented quantitation of actions and ever-closer integration with experimentation. PMID:22119142

Toward a deeper characterization of the social phenotype of Williams syndrome: the association between personality and social drive

PubMed Central

Ng, Rowena; Järvinen, Anna; Bellugi, Ursula

2014-01-01

Previous research has robustly established a Williams syndrome (WS) specific personality profile, predominantly characterized a gregarious, people-oriented, and tense predisposition. Extending this work, the aims of the current, cross-sectional study were two-fold: (1) to elucidate the stability of personality characteristics in individuals with WS and typically developing (TD) comparisons across development, and (2) to explore the personality attributes that may be related to the respective profiles of social functioning characterizing the two groups, which is currently poorly understood. The sample comprised of participants with WS and TD matched on chronological age. The test battery included the Multidimensional Personality Questionnaire (MPQ) and the Salk Institute Sociability Questionnaire (SISQ), an index of real-life social behavior. The main results showed that compared to the TD individuals, the WS group were consistently rated higher in Social Closeness, and this trait remained stable across development. Interpersonal behaviors were best predicted by Social Closeness in WS and by Social Potency in TD. Regression analysis highlighted that while a central motive underlying the increased drive toward social interaction in individuals with WS pertains to a desire to form affectionate relationships, TD individuals by contrast are motivated by a desire to exert social influence over others (leadership, social-dominance) and Well-Being (positive emotional disposition). In conclusion, these findings provide novel insight into social motivational factors underpinning the WS social behavior in real life, and contribute toward a deeper characterization of the WS affiliative drive. We suggest potential areas for behavioral intervention targeting improved social adjustment in individuals with WS. PMID:24794322

One central oscillatory drive is compatible with experimental motor unit behaviour in essential and Parkinsonian tremor

NASA Astrophysics Data System (ADS)

Dideriksen, Jakob L.; Gallego, Juan A.; Holobar, Ales; Rocon, Eduardo; Pons, Jose L.; Farina, Dario

2015-08-01

Objective. Pathological tremors are symptomatic to several neurological disorders that are difficult to differentiate and the way by which central oscillatory networks entrain tremorogenic contractions is unknown. We considered the alternative hypotheses that tremor arises from one oscillator (at the tremor frequency) or, as suggested by recent findings from the superimposition of two separate inputs (at the tremor frequency and twice that frequency). Approach. Assuming one central oscillatory network we estimated analytically the relative amplitude of the harmonics of the tremor frequency in the motor neuron output for different temporal behaviors of the oscillator. Next, we analyzed the bias in the relative harmonics amplitude introduced by superimposing oscillations at twice the tremor frequency. These findings were validated using experimental measurements of wrist angular velocity and surface electromyography (EMG) from 22 patients (11 essential tremor, 11 Parkinson’s disease). The ensemble motor unit action potential trains identified from the EMG represented the neural drive to the muscles. Main results. The analytical results showed that the relative power of the tremor harmonics in the analytical models of the neural drive was determined by the variability and duration of the tremor bursts and the presence of the second oscillator biased this power towards higher values. The experimental findings accurately matched the analytical model assuming one oscillator, indicating a negligible functional role of secondary oscillatory inputs. Furthermore, a significant difference in the relative power of harmonics in the neural drive was found across the patient groups, suggesting a diagnostic value of this measure (classification accuracy: 86%). This diagnostic power decreased substantially when estimated from limb acceleration or the EMG. Signficance. The results indicate that the neural drive in pathological tremor is compatible with one central network providing neural oscillations at the tremor frequency. Moreover, the regularity of this neural oscillation varies across tremor pathologies, making the relative amplitude of tremor harmonics a potential biomarker for diagnostic use.

One central oscillatory drive is compatible with experimental motor unit behaviour in essential and Parkinsonian tremor.

PubMed

Dideriksen, Jakob L; Gallego, Juan A; Holobar, Ales; Rocon, Eduardo; Pons, Jose L; Farina, Dario

2015-08-01

Pathological tremors are symptomatic to several neurological disorders that are difficult to differentiate and the way by which central oscillatory networks entrain tremorogenic contractions is unknown. We considered the alternative hypotheses that tremor arises from one oscillator (at the tremor frequency) or, as suggested by recent findings from the superimposition of two separate inputs (at the tremor frequency and twice that frequency). Assuming one central oscillatory network we estimated analytically the relative amplitude of the harmonics of the tremor frequency in the motor neuron output for different temporal behaviors of the oscillator. Next, we analyzed the bias in the relative harmonics amplitude introduced by superimposing oscillations at twice the tremor frequency. These findings were validated using experimental measurements of wrist angular velocity and surface electromyography (EMG) from 22 patients (11 essential tremor, 11 Parkinson's disease). The ensemble motor unit action potential trains identified from the EMG represented the neural drive to the muscles. The analytical results showed that the relative power of the tremor harmonics in the analytical models of the neural drive was determined by the variability and duration of the tremor bursts and the presence of the second oscillator biased this power towards higher values. The experimental findings accurately matched the analytical model assuming one oscillator, indicating a negligible functional role of secondary oscillatory inputs. Furthermore, a significant difference in the relative power of harmonics in the neural drive was found across the patient groups, suggesting a diagnostic value of this measure (classification accuracy: 86%). This diagnostic power decreased substantially when estimated from limb acceleration or the EMG. SIGNFICANCE: The results indicate that the neural drive in pathological tremor is compatible with one central network providing neural oscillations at the tremor frequency. Moreover, the regularity of this neural oscillation varies across tremor pathologies, making the relative amplitude of tremor harmonics a potential biomarker for diagnostic use.

What Motivates the Motivators? An Examination of Sports Coaches

ERIC Educational Resources Information Center

McLean, Kristy N.; Mallett, Clifford J.

2012-01-01

Background: Motivation is central to successful performance. In the case of sports coaches, drive is a prerequisite to sustained successful engagement in a complex, dynamic, and turbulent work environment. What fuels these coaches' drive to pursue this vocational activity? Coach motivation has been underrepresented in previous research which has…

The Central Coherence Account of Autism Revisited: Evidence from the ComFor Study

ERIC Educational Resources Information Center

Noens, Ilse L. J.; van Berckelaer-Onnes, Ina A.

2008-01-01

According to the central coherence account, people with autism have a tendency to focus on local rather than global processing. However, there is considerable controversy about the locus of the weak drive for central coherence. Some studies support enhanced bottom-up processing, whereas others claim reduced top-down feedback. The results of the…

High-harmonic fast magnetosonic wave coupling, propagation, and heating in a spherical torus plasma

NASA Astrophysics Data System (ADS)

Menard, J.; Majeski, R.; Kaita, R.; Ono, M.; Munsat, T.; Stutman, D.; Finkenthal, M.

1999-05-01

A novel rotatable two-strap antenna has been installed in the current drive experiment upgrade (CDX-U) [T. Jones, Ph.D. thesis, Princeton University (1995)] in order to investigate high-harmonic fast wave coupling, propagation, and electron heating as a function of strap angle and strap phasing in a spherical torus plasma. Radio-frequency-driven sheath effects are found to fit antenna loading trends at very low power and become negligible above a few kilowatts. At sufficiently high power, the measured coupling efficiency as a function of strap angle is found to agree favorably with cold plasma wave theory. Far-forward microwave scattering from wave-induced density fluctuations in the plasma core tracks the predicted fast wave loading as the antenna is rotated. Signs of electron heating during rf power injection have been observed in CDX-U with central Thomson scattering, impurity ion spectroscopy, and Langmuir probes. While these initial results appear promising, damping of the fast wave on thermal ions at high ion-cyclotron-harmonic number may compete with electron damping at sufficiently high ion β—possibly resulting in a significantly reduced current drive efficiency and production of a fast ion population. Preliminary results from ray-tracing calculations which include these ion damping effects are presented.

Design of an RF System for Electron Bernstein Wave Studies in MST

NASA Astrophysics Data System (ADS)

Kauffold, J. X.; Seltzman, A. H.; Anderson, J. K.; Nonn, P. D.; Forest, C. B.

2010-11-01

Motivated by the possibility of current profile control a 5.5GHz RF system for EBW is being developed. The central component is a standard radar Klystron with 1.2MW peak power and 4μs typical pulse length. Meaningful experiments require RF pulse lengths similar to the characteristic electron confinement times in MST necessitating the creation of a power supply providing 80kV at 40A for 10ms. A low inductance IGBT network switches power at 20kHz from an electrolytic capacitor bank into the primary of a three-phase resonant transformer system that is then rectified and filtered. The system uses three magnetically separate transformers with microcrystalline iron cores to provide suitable volt-seconds and low hysteresis losses. Each phase has a secondary with a large leakage inductance and a parallel capacitor providing a boost ratio greater than 60:1 with a physical turns ratio of 13.5:1. A microprocessor feedback control system varies the drive frequency around resonance to regulate the boost ratio and provide a stable output as the storage bank discharges. The completed system will deliver RF to the plasma boundary where coupling to the Bernstein mode and subsequent heating and current drive can occur.

Branches of electrostatic turbulence inside solitary plasma structures in the auroral ionosphere

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

Golovchanskaya, Irina V.; Kozelov, Boris V.; Chernyshov, Alexander A.

2014-08-15

The excitation of electrostatic turbulence inside space-observed solitary structures is a central topic of this exposition. Three representative solitary structures observed in the topside auroral ionosphere as large-amplitude nonlinear signatures in the electric field and magnetic-field-aligned current on the transverse scales of ∼10{sup 2}–10{sup 3} m are evaluated by the theories of electrostatic wave generation in inhomogeneous background configurations. A quantitative analysis shows that the structures are, in general, effective in destabilizing the inhomogeneous energy-density-driven (IEDD) waves, as well as of the ion acoustic waves modified by a shear in the parallel drift of ions. It is demonstrated that the dominatingmore » branch of the electrostatic turbulence is determined by the interplay of various driving sources inside a particular solitary structure. The sources do not generally act in unison, so that their common effect may be inhibiting for excitation of electrostatic waves of a certain type. In the presence of large magnetic-field-aligned current, which is not correlated to the inhomogeneous electric field inside the structure, the ion-acoustic branch becomes dominating. In other cases, the IEDD instability is more central.« less

On the forces that drive and resist deformation of the south-central Mediterranean: a mechanical model study

NASA Astrophysics Data System (ADS)

Nijholt, Nicolai; Govers, Rob; Wortel, Rinus

2018-04-01

The geodynamics of the Mediterranean comprises a transitional setting in which slab rollback and plate convergence compete to shape the region. In the central Mediterranean, where the balance of driving and resisting forces changes continuously and rapidly since the Miocene, both kinematic and seismo-tectonic observations display a strong variation in deformation style and, therefore possibly, lithospheric forces. We aim to understand the current kinematics in southern Italy and Sicily in terms of lithospheric forces that cause them. The strong regional variation of geodetic velocities appears to prohibit such simple explanation. We use mechanical models to quantify the deformation resulting from large-scale Africa-Eurasia convergence, ESE retreat of the Calabrian subduction zone, pull by the Aegean slab, and regional variations in gravitational potential energy (topography). A key model element is the resistance to slip on major regional fault zones. We show that geodetic velocities, seismicity and sense of slip on regional faults can be understood to result from lithospheric forces. Our most important new finding is that regional variations in resistive tractions are required to fit the observations, with notably very low tractions on the Calabrian subduction contact, and a buildup towards a significant earthquake in the Calabrian fore-arc. We also find that the Calabrian net slab pull force is strongly reduced (compared to the value possible in view of the slab's dimensions) and that trench suction tractions are negligible. Such very small contributions to the present-day force balance in the south-central Mediterranean suggest that the Calabrian arc is now further transitioning towards a setting dominated by Africa-Eurasia plate convergence, whereas during the past 30 Myrs slab retreat continually was the dominant factor.

Numerical analysis on the synergy between electron cyclotron current drive and lower hybrid current drive in tokamak plasmas

NASA Astrophysics Data System (ADS)

Chen, S. Y.; Hong, B. B.; Liu, Y.; Lu, W.; Huang, J.; Tang, C. J.; Ding, X. T.; Zhang, X. J.; Hu, Y. J.

2012-11-01

The synergy between electron cyclotron current drive (ECCD) and lower hybrid current drive (LHCD) is investigated numerically with the parameters of the HL-2A tokamak. Based on the understanding of the synergy mechanisms, a high current driven efficiency or a desired radial current profile can be achieved through properly matching the parameters of ECCD and LHCD due to the flexibility of ECCD. Meanwhile, it is found that the total current driven by the electron cyclotron wave (ECW) and the lower hybrid wave (LHW) simultaneously can be smaller than the sum of the currents driven by the ECW and LHW separately, when the power of the ECW is much larger than the LHW power. One of the reasons leading to this phenomenon (referred to as negative synergy in this context) is that fast current-carrying electrons tend to be trapped, when the perpendicular velocity driven by the ECW is large and the parallel velocity decided by the LHW is correspondingly small.

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

Harvey, R. W.

This DOE grant supported fusion energy research, a potential long-term solution to the world's energy needs. Magnetic fusion, exemplified by confinement of very hot ionized gases, i.e., plasmas, in donut-shaped tokamak vessels is a leading approach for this energy source. Thus far, a mixture of hydrogen isotopes has produced 10's of megawatts of fusion power for seconds in a tokamak reactor at Princeton Plasma Physics Laboratory in New Jersey. The research grant under consideration, ER54684, uses computer models to aid in understanding and projecting efficacy of heating and current drive sources in the National Spherical Torus Experiment, a tokamak variant,more » at PPPL. The NSTX experiment explores the physics of very tight aspect ratio, almost spherical tokamaks, aiming at producing steady-state fusion plasmas. The current drive is an integral part of the steady-state concept, maintaining the magnetic geometry in the steady-state tokamak. CompX further developed and applied models for radiofrequency (rf) heating and current drive for applications to NSTX. These models build on a 30 year development of rf ray tracing (the all-frequencies GENRAY code) and higher dimensional Fokker-Planck rf-collisional modeling (the 3D collisional-quasilinear CQL3D code) at CompX. Two mainline current-drive rf modes are proposed for injection into NSTX: (1) electron Bernstein wave (EBW), and (2) high harmonic fast wave (HHFW) modes. Both these current drive systems provide a means for the rf to access the especially high density plasma--termed high beta plasma--compared to the strength of the required magnetic fields. The CompX studies entailed detailed modeling of the EBW to calculate the efficiency of the current drive system, and to determine its range of flexibility for driving current at spatial locations in the plasma cross-section. The ray tracing showed penetration into NSTX bulk plasma, relatively efficient current drive, but a limited ability to produce current over the whole radial plasma cross-section. The actual EBW experiment will cost several million dollars, and remains in the proposal stage. The HHFW current drive system has been experimentally implemented on NSTX, and successfully drives substantial current. The understanding of the experiment is to be accomplished in terms of general concepts of rf current drive, and also detailed modeling of the experiment which can discern the various competing processes which necessarily occur simultaneously in the experiment. An early discovery of the CompX codes, GENRAY and CQL3D, was that there could be significant interference between the neutral beam injection fast ions in the machine (injected for plasma heating) and the HHFW energy. Under many NSTX experimental conditions, power which could go to the fast ions would then be unavailable for current drive by the desired HHFW interaction with electrons. This result has been born out by experiments; the modeling helps in understanding difficulties with HHFW current drive, and has enabled adjustment of the experiment to avoid interaction with neutral beam injected fast ions thereby achieving stronger HHFW current drive. The detailed physics modeling of the various competing processes is almost always required in fusion energy plasma physics, to ensure a reasonably accurate and certain interpretation of the experiment, enabling the confident design of future, more advanced experiments and ultimately a commercial fusion reactor. More recent work entails detailed investigation of the interaction of the HHFW radiation for fast ions, accounting for the particularly large radius orbits in NSTX, and correlations between multiple HHFW-ion interactions. The spherical aspect of the NSTX experiment emphasized particular physics such as the large orbits which are present to some degree in all tokamaks, but gives clearer clues on the resulting physics phenomena since competing physics effects are reduced.« less

Optimization of current waveform tailoring for magnetically driven isentropic compression experiments

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

Waisman, E. M.; Reisman, D. B.; Stoltzfus, B. S.

2016-06-15

The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called “bricks,” that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.–Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state,more » material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel “current-adder” architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L{sub 2} norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.« less

Comparison of shelf currents off central California prior to and during the 1997-1998 El Nino

USGS Publications Warehouse

Ryan, H.F.; Noble, M.A.

2005-01-01

Moored current, temperature, salinity, and pressure data were collected at three sites that transect the narrow continental shelf offshore of Davenport, CA, starting in August 1996 and continuing to the spring of 1998. This data set allowed a comparison of oceanographic conditions prior to (8/96-3/97) and during (8/97-3/98) the last major El Nin??o. During this El Nin??o, mean temperatures over the 8-month time period were about 3??C warmer than during the prior year at all of the sites. Correlations between near-surface and near-bottom temperatures, and between near-surface temperature and wind stress decreased during the El Nin??o compared to conditions the year before. The mean alongshore currents were more strongly poleward during El Nin??o at sites over the mid-shelf and near the shelf break. There was a general tendency for the energy in alongshore currents to move toward lower frequencies during the El Nin??o, particularly at the sites farther offshore. The processes that forced the shelf flows changed in relative importance throughout the study. The local alongshore wind stress was less important in driving shelf currents during the El Nin??o when much of the wind-induced upwelling was confined to less than 5 km of the coast. The observed strong poleward shelf currents on the mid- to outer-shelf were not clearly tied to local forcing, but were remotely driven, most likely by slope currents. The response of the Davenport shelf to an El Nin??o event may differ from other areas since the shelf is narrow, the wind forcing is weaker than areas to the north and south, and the shelf may be at times isolated by fronts that form at strong upwelling centers. In the winter, strong storm-related winds are important in driving currents at periods not only in the synoptic wind band, but also for periods on the order of 20 d and longer.

Advances in the steady-state hybrid regime in DIII-D – a fully non-inductive, ELM-suppressed scenario for ITER

DOE PAGES

Petty, Craig C.; Nazikian, Raffi; Park, Jin Myung; ...

2017-07-19

Here, the hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated with ELM suppression by applying an odd parity n=3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in the DIII-D tokamak with high beta (β ≤ 2.8%) and high confinement (98y2 ≤ 1.4) in the ITER similar shape have achieved zero surface loop voltage for up to two current relaxation times using efficient central current drive from ECCD and NBCD. The n=3 RMP causes surprisingly little increase in thermal transport during ELM suppression. Poloidal magnetic flux pumping in hybridmore » plasmas maintains q above 1 without loss of current drive efficiency, except that experiments show that extremely peaked ECCD profiles can create sawteeth. During ECCD, Alfvén eigenmode (AE) activity is replaced by a more benign fishbone-like mode, reducing anomalous beam ion diffusion by a factor of 2. While the electron and ion thermal diffusivities substantially increase with higher ECCD power, the loss of confinement can be offset by the decreased fast ion transport resulting from AE suppression. Extrapolations from DIII-D along a dimensionless parameter scaling path as well as those using self-consistent theory-based modeling show that these ELM-suppressed, fully non-inductive hybrids can achieve the Q = 5 ITER steady-state mission.« less

Feasibility planning study for a behavior database. Volume III Appendix B, Compendium of survey questions on drinking and driving and occupant restraints

DOT National Transportation Integrated Search

1987-04-01

The general objective of the project was to determine the feasibility of and the general requirements for a centralized database on driver behavior and attitudes related to drunk driving and occupant restraints. Volume III is a compendium of question...

77 FR 73475 - Changes in Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

...- December 24, 2012 270156 (12-05-1144P). ReNae Bowman, Douglas Drive team.com/starr/ Mayor, City of North, Crystal, LOMR/Pages/ Crystal, 4141 MN 55422. RegionV.aspx. Douglas Drive North, Crystal, MN 55422. Nevada... Grand Las Vegas, NV Central Parkway, 89155. Las Vegas, NV 89155. Douglas Unincorporated The Honorable...

Feasibility planning study for a behavior database. Volume 2 Appendix A, Summary information on the drinking and driving and occupant restraint surveys

DOT National Transportation Integrated Search

1987-04-24

The general objective of the project was to determine the feasibility of and the general requirements for a centralized database on driver behavior and attitudes related to drunk driving and occupant restraints. Volume I assesses the extent of pertin...

Driving Objectives and High-level Requirements for KP-Lab Technologies

ERIC Educational Resources Information Center

Lakkala, Minna; Paavola, Sami; Toikka, Seppo; Bauters, Merja; Markannen, Hannu; de Groot, Reuma; Ben Ami, Zvi; Baurens, Benoit; Jadin, Tanja; Richter, Christoph; Zoserl, Eva; Batatia, Hadj; Paralic, Jan; Babic, Frantisek; Damsa, Crina; Sins, Patrick; Moen, Anne; Norenes, Svein Olav; Bugnon, Alexandra; Karlgren, Klas; Kotzinons, Dimitris

2008-01-01

One of the central goals of the KP-Lab project is to co-design pedagogical methods and technologies for knowledge creation and practice transformation in an integrative and reciprocal manner. In order to facilitate this process user tasks, driving objectives and high-level requirements have been introduced as conceptual tools to mediate between…

Central neural control of thermoregulation and brown adipose tissue

PubMed Central

Morrison, Shaun F.

2016-01-01

Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation. PMID:26924538

Central neural control of thermoregulation and brown adipose tissue.

PubMed

Morrison, Shaun F

2016-04-01

Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation. Copyright © 2016 Elsevier B.V. All rights reserved.

5. VIEW LOOKING NORTHEAST INTO CENTRAL COURTYARD OF TECHWOOD DORMITORY, ...

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

5. VIEW LOOKING NORTHEAST INTO CENTRAL COURTYARD OF TECHWOOD DORMITORY, SHOWING WEST FRONT OF CENTER WING AND PART OF SOUTH SIDE OF NORTH WING. MIDTOWN SKYLINE VISIBLE IN BACKGROUND. - Techwood Homes, McDaniel Dormitory, 581-587 Techwood Drive, Atlanta, Fulton County, GA

Current-drive by lower hybrid waves in the presence of energetic alpha-particles

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

Fisch, N.J.; Rax, J.M.

1991-10-01

Many experiments have now proved the effectiveness of lower hybrid waves for driving toroidal current in tokamaks. The use of these waves, however, to provide all the current in a reactor is thought to be uncertain because the waves may not penetrate the center of the more energetic reactor plasma, and, if they did, the wave power may be absorbed by alpha particles rather than by electrons. This paper explores the conditions under which lower-hybrid waves might actually drive all the current. 26 refs.

Modafinil Improves Real Driving Performance in Patients with Hypersomnia: A Randomized Double-Blind Placebo-Controlled Crossover Clinical Trial

PubMed Central

Philip, Pierre; Chaufton, Cyril; Taillard, Jacques; Capelli, Aurore; Coste, Olivier; Léger, Damien; Moore, Nicholas; Sagaspe, Patricia

2014-01-01

Study Objective: Patients with excessive daytime sleepiness (EDS) are at high risk for driving accidents, and physicians are concerned by the effect of alerting drugs on driving skills of sleepy patients. No study has up to now investigated the effect of modafinil (a reference drug to treat EDS in patients with hypersomnia) on on-road driving performance of patients suffering from central hypersomnia. The objective is to evaluate in patients with central hypersomnia the effect of a wake-promoting drug on real driving performance and to assess the relationship between objective sleepiness and driving performance. Design and Participants: Randomized, crossover, double-blind placebo-controlled trial conducted among 13 patients with narcolepsy and 14 patients with idiopathic hypersomnia. Patients were randomly assigned to receive modafinil (400 mg) or placebo for 5 days prior to the driving test. Each condition was separated by at least 3 weeks of washout. Measurements: Mean number of Inappropriate Line Crossings, Standard Deviation of Lateral Position of the vehicle and mean sleep latency in the Maintenance of Wakefulness Test were assessed. Results: Modafinil reduced the mean number of Inappropriate Line Crossings and Standard Deviation of Lateral Position of the vehicle compared to placebo (F(1,25) = 4.88, P < 0.05 and F(1,25) = 3.87, P = 0.06 tendency). Mean sleep latency at the Maintenance of Wakefulness Test significantly correlated with the mean number of Inappropriate Line Crossings (r = -0.41, P < 0.001). Conclusions: Modafinil improves driving performance in patients with narcolepsy and idiopathic hypersomnia. The Maintenance of Wakefulness Test is a suitable clinical tool to assess fitness to drive in this population. Citation: Philip P; Chaufton C; Taillard J; Capelli A; Coste O; Léger D; Moore N; Sagaspe P. Modafinil improves real driving performance in patients with hypersomnia: a randomized double-blind placebo-controlled crossover clinical trial. SLEEP 2014;37(3):483-487. PMID:24587570

Fully non-inductive plasma start-up with lower-hybrid waves using the outboard-launch and top-launch antennas on the TST-2 spherical tokamak

NASA Astrophysics Data System (ADS)

Tsujii, Naoto; Takase, Yuichi; Ejiri, Akira; Shinya, Takahiro; Yajima, Satoru; Yamazaki, Hibiki; Togashi, Hiro; Moeller, Charles P.; Roidl, Benedikt; Takahashi, Wataru; Toida, Kazuya; Yoshida, Yusuke

2017-10-01

Removal of the central solenoid is essential to realize an economical spherical tokamak fusion reactor, but non-inductive plasma start-up is a challenge. On the TST-2 spherical tokamak, non-inductive plasma start-up using lower-hybrid (LH) waves has been investigated. Using the capacitively-coupled combline (CCC) antenna installed at the outboard midplane, fully non-inductive plasma current ramp-up up to a quarter of that of the typical Ohmic discharges has been achieved. Although it was desirable to keep the density low during the plasma current ramp-up to avoid the LH density limit, it was recognized that there was a maximum current density that could be carried by a given electron density. Since the density needed to increase as the plasma current was ramped-up, the achievable plasma current was limited by the maximum operational toroidal field of TST-2. The top-launch CCC antenna was installed to access higher density with up-shift of the parallel index of refraction. Numerical analysis of LH current drive with the outboard-launch and top-launch antennas was performed and the results were qualitatively consistent with the experimental observations.

Base drive circuit for a four-terminal power Darlington

DOEpatents

Lee, Fred C.; Carter, Roy A.

1983-01-01

A high power switching circuit which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.

Current Research Activities in Drive System Technology in Support of the NASA Rotorcraft Program

NASA Technical Reports Server (NTRS)

Handschuh, Robert F.; Zakrajsek, James J.

2006-01-01

Drive system technology is a key area for improving rotorcraft performance, noise/vibration reduction, and reducing operational and manufacturing costs. An overview of current research areas that support the NASA Rotorcraft Program will be provided. Work in drive system technology is mainly focused within three research areas: advanced components, thermal behavior/emergency lubrication system operation, and diagnostics/prognostics (also known as Health and Usage Monitoring Systems (HUMS)). Current research activities in each of these activities will be presented. Also, an overview of the conceptual drive system requirements and possible arrangements for the Heavy Lift Rotorcraft program will be reviewed.

Influence of driving frequency on discharge modes in a dielectric-barrier discharge with multiple current pulses

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

Jiang, Weiman; Tang, Jie; Wang, Yishan

2013-07-15

A one-dimensional self-consistent fluid model was employed to investigate the effect of the driving frequency on the discharge modes in atmospheric-pressure argon discharge with multiple current pulses. The discharge mode was discussed in detail not only at current peaks but also between two adjacent peaks. The simulation results show that different transitions between the Townsend and glow modes during the discharge take place with the driving frequency increased. A complicated transition from the Townsend mode, through glow, Townsend, and glow, and finally back to the Townsend one is found in the discharge with the driving frequency of 8 kHz. Theremore » is a tendency of transition from the Townsend to glow mode for the discharge both at the current peaks and troughs with the increasing frequency. The discharge in the half period can all along operate in the glow mode with the driving frequency high enough. This is resulted from the preservation of more electrons in the gas gap and acquisition of more electron energy from the swiftly varying electric field with the increase in driving frequency. Comparison of the spatial and temporal evolutions of the electron density at different driving frequencies indicates that the increment of the driving frequency allows the plasma chemistry to be enhanced. This electrical characteristic is important for the applications, such as surface treatment and biomedical sterilization.« less

Aging baby boomers--a blessing or challenge for driver licensing authorities.

PubMed

Dobbs, Bonnie M

2008-08-01

In less than 5 years, the first wave of baby boomers will begin turning 65, with the last wave of boomers entering their senior years in January 2029. Currently, boomers make up a significant percentage of the population in Canada, the United States, and other developed countries. The baby boom generation has had a profound impact on our society over the last six decades, and this large cohort will continue to exert its influence for several decades to come. Central to this article is the rapid growth in the number of persons 65 years of age and older, beginning in 2011, with a corresponding increase in the number of older drivers. The demographic shift has important implications for licensing authorities, the regulatory bodies charged with licensing and 'fitness to drive' decisions. The objectives of this paper are to summarize the published scientific literature on licensing policies and procedures currently in use for older drivers, discuss their limitations, and provide recommendations for meeting the upcoming challenges of an aging baby boomer population of drivers. Online searches were conducted using the following databases: PsycINFO, MEDLINE, Scopus, and TRIS. Google and Google Scholar also were searched for scientific articles. References identified from database and online searches were examined for relevant articles. A number of studies have investigated the utility of different licensing policies and procedures for identifying older drivers who may be at risk for impaired driving performance. Overall, results suggest that current policies and procedures are ineffective in identifying high-risk older drivers. The results also emphasize the need for a different approach for the identification of high risk older drivers by licensing agencies. Recommendations to assist with that goal are provided. The aging of the baby boomer population, combined with the projected high crash rates for this cohort of drivers as it moves through the senior years, underscores the need for cost-effective, accurate, and efficient methods for identifying and assessing the subgroup of older drivers whose driving has declined to an unsafe level. That subgroup consists of individuals with medical conditions (and treatments) affecting driving performance. The demographic shift has been a blessing for licensing authorities in that it has created awareness of the need for a reexamination of licensing policies and procedures designed to identify those older drivers who may no longer be safe to drive. If that awareness becomes translated into effective policies and procedures that appropriately target the medically at-risk/impaired older driver rather than the older driver per se, the result will be an increase in the safety and mobility of the older driving population and increased public safety overall. However, a continued focus on older drivers rather than medically at-risk drivers will result in a costly, ineffective, and overburdened system.

Student motorcyclists' mobile phone use while driving in Vientiane, Laos.

PubMed

Phommachanh, Sysavanh; Ichikawa, Masao; Nakahara, Shinji; Mayxay, Mayfong; Kimura, Akio

2017-06-01

To investigate mobile phone use while driving among student motorcyclists in Laos, we conducted a school-based questionnaire survey in central Vientiane in May 2014. Of the 883 high school students who reported to drive motorcycles at least once a week, 40% have ever used phones while driving motorcycles in both sexes. Those phone users had longer driving exposures than non-users, with about half engaging in phone use while driving at least 2 days a week and 70% engaging for 1 min or longer on an average day. They reported not just talking on the phone while driving but operating the phone such as dialling and text-messaging. In some instances, phone use was reportedly involved in their past crash experiences. To formulate a sound policy on this emerging distracting behaviour among motorcyclists, its contribution to the occurrence of overall crashes among motorcyclists should be investigated.

From systems biology to systems biomedicine.

PubMed

Antony, Paul M A; Balling, Rudi; Vlassis, Nikos

2012-08-01

Systems Biology is about combining theory, technology, and targeted experiments in a way that drives not only data accumulation but knowledge as well. The challenge in Systems Biomedicine is to furthermore translate mechanistic insights in biological systems to clinical application, with the central aim of improving patients' quality of life. The challenge is to find theoretically well-chosen models for the contextually correct and intelligible representation of multi-scale biological systems. In this review, we discuss the current state of Systems Biology, highlight the emergence of Systems Biomedicine, and highlight some of the topics and views that we think are important for the efficient application of Systems Theory in Biomedicine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Organization and dynamics of the actin cytoskeleton during dendritic spine morphological remodeling.

PubMed

Chazeau, Anaël; Giannone, Grégory

2016-08-01

In the central nervous system, most excitatory post-synapses are small subcellular structures called dendritic spines. Their structure and morphological remodeling are tightly coupled to changes in synaptic transmission. The F-actin cytoskeleton is the main driving force of dendritic spine remodeling and sustains synaptic plasticity. It is therefore essential to understand how changes in synaptic transmission can regulate the organization and dynamics of actin binding proteins (ABPs). In this review, we will provide a detailed description of the organization and dynamics of F-actin and ABPs in dendritic spines and will discuss the current models explaining how the actin cytoskeleton sustains both structural and functional synaptic plasticity.

Impacts of second-generation biofuel feedstock production in the central U.S. on the hydrologic cycle and global warming mitigation potential

NASA Astrophysics Data System (ADS)

Harding, K. J.; Twine, T. E.; VanLoocke, A.; Bagley, J. E.; Hill, J.

2016-10-01

Biofuel feedstocks provide a renewable energy source that can reduce fossil fuel emissions; however, if produced on a large scale they can also impact local to regional water and carbon budgets. Simulation results for 2005-2014 from a regional weather model adapted to simulate the growth of two perennial grass biofuel feedstocks suggest that replacing at least half the current annual cropland with these grasses would increase water use efficiency and drive greater rainfall downwind of perturbed grid cells, but increased evapotranspiration (ET) might switch the Mississippi River basin from having a net warm-season surplus of water (precipitation minus ET) to a net deficit. While this scenario reduces land required for biofuel feedstock production relative to current use for maize grain ethanol production, it only offsets approximately one decade of projected anthropogenic warming and increased water vapor results in greater atmospheric heat content.

New Technique of AC drive in Tokamak using Permanent Magnets

NASA Astrophysics Data System (ADS)

Matteucci, Jackson; Zolfaghari, Ali

2013-10-01

This study investigates a new technique of capturing the rotational energy of alternating permanent magnets in order to inductively drive an alternating current in tokamak devices. The use of rotational motion bypasses many of the pitfalls seen in typical inductive and non-inductive current drives. Three specific designs are presented and assessed in the following criteria: the profile of the current generated, the RMS loop voltage generated as compared to the RMS power required to maintain it, the system's feasibility from an engineering perspective. All of the analysis has been done under ideal E&M conditions using the Maxwell 3D program. Preliminary results indicate that it is possible to produce an over 99% purely toroidal current with a RMS d Φ/dt of over 150 Tm2/s, driven by 20 MW or less of rotational power. The proposed mechanism demonstrates several key advantages including an efficient mechanical drive system, the generation of pure toroidal currents, and the potential for a quasi-steady state fusion reactor. The following quantities are presented for various driving frequencies and magnet strengths: plasma current generated, loop voltage, torque and power required. This project has been supported by DOE Funding under the SULI program.

Competing in an International Era: Preparing the Workforce for the Global Economy. In Depth.

ERIC Educational Resources Information Center

Harmon, Robert, Ed.

2000-01-01

During the past decade, countries in Asia, Latin America, and Central Europe have been experiencing a number of converging factors that drive economic growth, propelling them toward greater economic competitiveness with the economies of the United States (U.S.), Japan, and Western Europe. A major driving force behind this global economic growth is…

Stepping responses to treadmill perturbations vary with severity of motor deficits in human SCI.

PubMed

Chu, Virginia Way Tong; Hornby, T George; Schmit, Brian D

2018-04-18

In this study, we investigated the responses to tread perturbations during human stepping on a treadmill. Our approach was to test the effects of perturbations to a single leg using a split-belt treadmill in healthy participants and in participants with varying severity of spinal cord injury (SCI). We recruited 11 people with incomplete SCI and 5 noninjured participants. As participants walked on an instrumented treadmill, the belt on one side was stopped or accelerated briefly during mid to late stance. A majority of participants initiated an unnecessary swing when the treadmill was stopped in mid stance, although the likelihood of initiating a step was decreased in participants with more severe SCI. Accelerating or decelerating one belt of the treadmill during stance altered the characteristics of swing. We observed delayed swing initiation when the belt was decelerated (i.e. the hip was in a more flexed position at time of swing) and advanced swing initiation with acceleration (i.e. hip extended at swing initiation). Further, the timing and leg posture of heel strike appeared to remain constant, reflected by a sagittal plane hip angle at heel strike that remained the same regardless of the perturbation. In summary, our results supported the current understanding of the role of sensory feedback and central drive in the control of stepping in participants with incomplete SCI and noninjured participants. In particular, the observation of unnecessary swing during a stop perturbation highlights the interdependence of central and sensory drive in walking control.

Impacts of the IOD-associated temperature and salinity anomalies on the intermittent equatorial undercurrent anomalies

NASA Astrophysics Data System (ADS)

Li, Junde; Liang, Chujin; Tang, Youmin; Liu, Xiaohui; Lian, Tao; Shen, Zheqi; Li, Xiaojing

2017-11-01

The study of Equatorial Undercurrent (EUC) has attracted a broad attention in recent years due to its strong response and feedback to the Indian Ocean Dipole. In this paper, we first produce a high-quality simulation of three-dimensional temperature, salinity and zonal current simulation from 1982 to 2014, using a high-resolution ocean general circulation model. On this basis, with two sensitivity experiments, we investigate the role of temperature and salinity anomalies in driving and enhancing the EUC during the positive IOD events by examining the variation of the EUC seasonal cycle and diagnosing the zonal momentum budget along the equatorial Indian Ocean. Our results show that during January-March, the EUC can appear along the entire equatorial Indian Ocean in all years, but during August-November, the EUC can appear and reach the eastern Indian Ocean only during the positive IOD events. The zonal momentum budget analysis indicates that the pressure gradient force contributes most to the variation of the eastward acceleration of zonal currents in the subsurface. During the positive IOD events, strong negative subsurface temperature anomalies exist in the eastern Indian Ocean, with negative surface salinity anomalies in the central and eastern Indian Ocean, resulting in a large pressure gradient force to drive EUC during the August-November. Further, the results of two sensitivity experiments indicate that the temperature anomalies significantly impact the pressure gradient force, playing a leading role in driving the EUC, while the surface salinity anomalies can secondarily help to intensify the eastward EUC through increasing the zonal density gradient in the eastern Indian Ocean and impacting the vertical momentum advection in the subsurface.

Toward a deeper characterization of the social phenotype of Williams syndrome: The association between personality and social drive.

PubMed

Ng, Rowena; Järvinen, Anna; Bellugi, Ursula

2014-08-01

Previous research has robustly established a Williams syndrome (WS) specific personality profile, predominantly characterized a gregarious, people-oriented, and tense predisposition. Extending this work, the aims of the current, cross-sectional study were two-fold: (1) to elucidate the stability of personality characteristics in individuals with WS and typically developing (TD) comparisons across development, and (2) to explore the personality attributes that may be related to the respective profiles of social functioning characterizing the two groups, which is currently poorly understood. The sample comprised of participants with WS and TD matched on chronological age. The test battery included the Multidimensional Personality Questionnaire (MPQ) and the Salk Institute Sociability Questionnaire (SISQ), an index of real-life social behavior. The main results showed that compared to the TD individuals, the WS group were consistently rated higher in Social Closeness, and this trait remained stable across development. Interpersonal behaviors were best predicted by Social Closeness in WS and by Social Potency in TD. Regression analysis highlighted that while a central motive underlying the increased drive toward social interaction in individuals with WS pertains to a desire to form affectionate relationships, TD individuals by contrast are motivated by a desire to exert social influence over others (leadership, social-dominance) and Well-Being (positive emotional disposition). In conclusion, these findings provide novel insight into social motivational factors underpinning the WS social behavior in real life, and contribute toward a deeper characterization of the WS affiliative drive. We suggest potential areas for behavioral intervention targeting improved social adjustment in individuals with WS. Copyright © 2014 Elsevier Ltd. All rights reserved.

Drive Control System for Pipeline Crawl Robot Based on CAN Bus

NASA Astrophysics Data System (ADS)

Chen, H. J.; Gao, B. T.; Zhang, X. H.; Deng2, Z. Q.

2006-10-01

Drive control system plays important roles in pipeline robot. In order to inspect the flaw and corrosion of seabed crude oil pipeline, an original mobile pipeline robot with crawler drive unit, power and monitor unit, central control unit, and ultrasonic wave inspection device is developed. The CAN bus connects these different function units and presents a reliable information channel. Considering the limited space, a compact hardware system is designed based on an ARM processor with two CAN controllers. With made-to-order CAN protocol for the crawl robot, an intelligent drive control system is developed. The implementation of the crawl robot demonstrates that the presented drive control scheme can meet the motion control requirements of the underwater pipeline crawl robot.

Kisspeptin as a master player in the central control of reproduction in mammals: an overview of kisspeptin research in domestic animals.

PubMed

Okamura, Hiroaki; Yamamura, Takashi; Wakabayashi, Yoshihiro

2013-05-01

The hypothalamo-pituitary-gonadal (HPG) axis is the regulatory system for reproduction in mammals. Because secretion of gonadotropin-releasing hormone (GnRH) into the portal vessels is the final step at which the brain controls gonadal activities, the GnRH neuronal system had been thought to be central to the HPG axis. A newly discovered neural peptide, kisspeptin, has opened a new era in reproductive neuroendocrinology. As shown in a variety of mammals, kisspeptin is a potent endogenous secretagogue of GnRH, and the kisspeptin neuronal system governs both the pulsatile GnRH secretion that drives folliculogenesis, spermatogenesis and steroidogenesis, and the GnRH surge that triggers ovulation in females. The kisspeptin neuronal system is therefore considered a master player in the central control of mammalian reproduction, and kisspeptin and related substances could therefore be valuable for the development of novel strategies for the management of fertility in farm animals. To this end, the present review aimed to summarize the current research on kisspeptin signaling with a focus on domestic animals such as sheep, goats, cattle, pigs and horses. © 2013 Japanese Society of Animal Science.

Pulse-Width-Modulating Driver for Brushless dc Motor

NASA Technical Reports Server (NTRS)

Salomon, Phil M.

1991-01-01

High-current pulse-width-modulating driver for brushless dc motor features optical coupling of timing signals from low-current control circuitry to high-current motor-driving circuitry. Provides high electrical isolation of motor-power supply, helping to prevent fast, high-current motor-driving pulses from being coupled through power supplies into control circuitry, where they interfere with low-current control signals.

Power-control switch

NASA Technical Reports Server (NTRS)

Kessler, L. L.

1976-01-01

Constant-current source creates drive current independent of input-voltage variations, 50% reduction in power loss in base drive circuitry, maintains essentially constant charge rate, and improves rise-time consistency over input voltage range.

Using AORSA to simulate helicon waves in DIII-D

NASA Astrophysics Data System (ADS)

Lau, C.; Jaeger, E. F.; Bertelli, N.; Berry, L. A.; Blazevski, D.; Green, D. L.; Murakami, M.; Park, J. M.; Pinsker, R. I.; Prater, R.

2015-12-01

Recent efforts have shown that helicon waves (fast waves at > 20ωci) may be an attractive option for driving efficient off-axis current drive during non-inductive tokamak operation for DIII-D, ITER and DEMO. For DIII-D scenarios, the ray tracing code, GENRAY, has been extensively used to study helicon current drive efficiency and location as a function of many plasma parameters. The full wave code, AORSA, which is applicable to arbitrary Larmor radius and can resolve arbitrary ion cyclotron harmonic order, has been recently used to validate the ray tracing technique at these high cyclotron harmonics. If the SOL is ignored, it will be shown that the GENRAY and AORSA calculated current drive profiles are comparable for the envisioned high beta advanced scenarios for DIII-D, where there is high single pass absorption due to electron Landau damping and minimal ion damping. AORSA is also been used to estimate possible SOL effects on helicon current drive coupling and SOL absorption due to collisional and slow wave effects.

CENTRAL PORTION OF THE CARPORT HOUSING LAUNDRY AND STORAGE FOR ...

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

CENTRAL PORTION OF THE CARPORT HOUSING LAUNDRY AND STORAGE FOR BOTH UNITS AS WELL AS ADDED TRASH ENCLOSURE - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, M-Shaped Four-Bedroom Duplex Type 5, Birch Circle, Cedar Drive, Pearl City, Honolulu County, HI

Self-consistent modeling of the dynamic evolution of magnetic island growth in the presence of stabilizing electron-cyclotron current drive

NASA Astrophysics Data System (ADS)

Chatziantonaki, Ioanna; Tsironis, Christos; Isliker, Heinz; Vlahos, Loukas

2013-11-01

The most promising technique for the control of neoclassical tearing modes in tokamak experiments is the compensation of the missing bootstrap current with an electron-cyclotron current drive (ECCD). In this frame, the dynamics of magnetic islands has been studied extensively in terms of the modified Rutherford equation (MRE), including the presence of a current drive, either analytically described or computed by numerical methods. In this article, a self-consistent model for the dynamic evolution of the magnetic island and the driven current is derived, which takes into account the island's magnetic topology and its effect on the current drive. The model combines the MRE with a ray-tracing approach to electron-cyclotron wave-propagation and absorption. Numerical results exhibit a decrease in the time required for complete stabilization with respect to the conventional computation (not taking into account the island geometry), which increases by increasing the initial island size and radial misalignment of the deposition.

Sensorless Sinusoidal Drives for Fan and Pump Motors by V/f Control

NASA Astrophysics Data System (ADS)

Kiuchi, Mitsuyuki; Ohnishi, Tokuo

This paper proposes sensorless sinusoidal driving methods of permanent magnet synchronous motors for fans and pumps by V/f control. The proposed methods are simple methods that control the motor peak current constant by voltage or frequency control, and are characterized by DC link current detection using a single shunt resistor at carrier wave signal bottom timing. As a result of the dumping factor from square torque load characteristics of fan and pump motors, it is possible to control stable starting and stable steady state by V/f control. In general, pressure losses as a result of the fluid pass of fan and pump systems are nearly constant; therefore, the flow rate and motor torque are determined by revolutions. Accordingly, high efficiency driving is possible by setting corresponding currents to q-axis currents (torque currents) at target revolutions. Because of the simple current detection and motor control methods, the proposed methods are optimum for fan and pump motor driving systems of home appliances.

Lower hybrid current drive experiments in the HT-6M tokamak

NASA Astrophysics Data System (ADS)

Jiang, Tongwen; Liu, Yuexiu; Guo, Wenkang; Zhang, Xuelei; Luo, Jiarong

1987-07-01

Lower hybrid current drive (LHCD) experiments with a multijunction grill have been performed in the HT-6M tokamak. When the RF power pulse with 15ms risetime is injected into the plasma, the toroidal current amplitude is raised, but the temporal variation of the loop voltage does not have measurable change. The efficiency of current drive is Irf/Prf=0.57kA/kW at bar ne=3 × 1012cm-3 and Bt=8KG. It seems that the multijunction grill has the same efficiency as the ordinary grill on the LHCD experiments.

Examining the Direct and Indirect Effects of Fear and Anger on Criminal Decision Making Among Known Offenders.

PubMed

Bouffard, Jeff A

2015-12-01

Deterrence represents the central theoretical core of the American criminal justice system, yet relatively little attention has been paid to how emotions like fear and anger may relate to deterrence. Psychological research has debated whether negative emotions each have similar impacts on decision making (valence approaches) or if distinct emotions have unique impacts (appraisal tendency approaches). This study explores the direct and indirect influences of fear and anger on hypothetical drunk driving likelihood, including their impact on cost perceptions. Surveys were administered to 1,013 male and female incarcerated felony offenders in the Southwestern United States. Using a multivariate path model and controlling for a number of other individual factors, current fear related to increased cost perceptions and anger to decreased costs. Anger also maintained a direct influence on drunk driving, whereas fear did not. Despite their shared negative valence, fear and anger appear to have dissimilar influences on cost perceptions and criminal decision making. A better understanding of these processes may lead to improved crime prevention approaches. © The Author(s) 2014.

Analytical approaches to optimizing system "Semiconductor converter-electric drive complex"

NASA Astrophysics Data System (ADS)

Kormilicin, N. V.; Zhuravlev, A. M.; Khayatov, E. S.

2018-03-01

In the electric drives of the machine-building industry, the problem of optimizing the drive in terms of mass-size indicators is acute. The article offers analytical methods that ensure the minimization of the mass of a multiphase semiconductor converter. In multiphase electric drives, the form of the phase current at which the best possible use of the "semiconductor converter-electric drive complex" for active materials is different from the sinusoidal form. It is shown that under certain restrictions on the phase current form, it is possible to obtain an analytical solution. In particular, if one assumes the shape of the phase current to be rectangular, the optimal shape of the control actions will depend on the width of the interpolar gap. In the general case, the proposed algorithm can be used to solve the problem under consideration by numerical methods.

Assessment Drives Learning: The Effect of Central Exit Exams on Curricular Knowledge and Mathematical Literacy

ERIC Educational Resources Information Center

Jurges, Hendrik; Schneider, Kerstin; Senkbeil, Martin; Carstensen, Claus H.

2012-01-01

In this paper, we use data from the German PISA 2003 sample to study the effects of central exit examinations on student performance and student attitudes. Unlike earlier studies we use (i) a value-added measure to pin down the effect of central exit exams on learning in the last year before the exam and (ii) separate test scores for mathematical…

Volume serving and media management in a networked, distributed client/server environment

NASA Technical Reports Server (NTRS)

Herring, Ralph H.; Tefend, Linda L.

1993-01-01

The E-Systems Modular Automated Storage System (EMASS) is a family of hierarchical mass storage systems providing complete storage/'file space' management. The EMASS volume server provides the flexibility to work with different clients (file servers), different platforms, and different archives with a 'mix and match' capability. The EMASS design considers all file management programs as clients of the volume server system. System storage capacities are tailored to customer needs ranging from small data centers to large central libraries serving multiple users simultaneously. All EMASS hardware is commercial off the shelf (COTS), selected to provide the performance and reliability needed in current and future mass storage solutions. All interfaces use standard commercial protocols and networks suitable to service multiple hosts. EMASS is designed to efficiently store and retrieve in excess of 10,000 terabytes of data. Current clients include CRAY's YMP Model E based Data Migration Facility (DMF), IBM's RS/6000 based Unitree, and CONVEX based EMASS File Server software. The VolSer software provides the capability to accept client or graphical user interface (GUI) commands from the operator's console and translate them to the commands needed to control any configured archive. The VolSer system offers advanced features to enhance media handling and particularly media mounting such as: automated media migration, preferred media placement, drive load leveling, registered MediaClass groupings, and drive pooling.

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,…

Driving reduction and cessation : transitioning to not driving.

DOT National Transportation Integrated Search

2009-09-01

This project examined the process of driving reduction and cessation from the perspective of older adults (current and former drivers) and adult children. The objectives were to identify common markers of the process of driving cessation and to gain ...

Hybrid indirect-drive/direct-drive target for inertial confinement fusion

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

Perkins, Lindsay John

A hybrid indirect-drive/direct drive for inertial confinement fusion utilizing laser beams from a first direction and laser beams from a second direction including a central fusion fuel component; a first portion of a shell surrounding said central fusion fuel component, said first portion of a shell having a first thickness; a second portion of a shell surrounding said fusion fuel component, said second portion of a shell having a second thickness that is greater than said thickness of said first portion of a shell; and a hohlraum containing at least a portion of said fusion fuel component and at leastmore » a portion of said first portion of a shell; wherein said hohlraum is in a position relative to said first laser beam and to receive said first laser beam and produce X-rays that are directed to said first portion of a shell and said fusion fuel component; and wherein said fusion fuel component and said second portion of a shell are in a position relative to said second laser beam such that said second portion of a shell and said fusion fuel component receive said second laser beam.« less

Anomalous-viscosity current drive

DOEpatents

Stix, T.H.; Ono, M.

1986-04-25

The present invention relates to a method and apparatus for maintaining a steady-state current for magnetically confining the plasma in a toroidal magnetic confinement device using anomalous viscosity current drive. A second aspect of this invention relates to an apparatus and method for the start-up of a magnetically confined toroidal plasma.

2010 Carl Ludwig Distinguished Lectureship of the APS Neural Control and Autonomic Regulation Section: Central neural pathways for thermoregulatory cold defense

PubMed Central

2011-01-01

Central neural circuits orchestrate the homeostatic repertoire to maintain body temperature during environmental temperature challenges and to alter body temperature during the inflammatory response. This review summarizes the research leading to a model representing our current understanding of the neural pathways through which cutaneous thermal receptors alter thermoregulatory effectors: the cutaneous circulation for control of heat loss, and brown adipose tissue, skeletal muscle, and the heart for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific core efferent pathways within the central nervous system (CNS) that share a common peripheral thermal sensory input. The thermal afferent circuit from cutaneous thermal receptors includes neurons in the spinal dorsal horn projecting to lateral parabrachial nucleus neurons that project to the medial aspect of the preoptic area. Within the preoptic area, warm-sensitive, inhibitory output neurons control heat production by reducing the discharge of thermogenesis-promoting neurons in the dorsomedial hypothalamus. The rostral ventromedial medulla, including the raphe pallidus, receives projections form the dorsomedial hypothalamus and contains spinally projecting premotor neurons that provide the excitatory drive to spinal circuits controlling the activity of thermogenic effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a platform for further understanding of the functional organization of central thermoregulation. PMID:21270352

Central circuitries for body temperature regulation and fever.

PubMed

Nakamura, Kazuhiro

2011-11-01

Body temperature regulation is a fundamental homeostatic function that is governed by the central nervous system in homeothermic animals, including humans. The central thermoregulatory system also functions for host defense from invading pathogens by elevating body core temperature, a response known as fever. Thermoregulation and fever involve a variety of involuntary effector responses, and this review summarizes the current understandings of the central circuitry mechanisms that underlie nonshivering thermogenesis in brown adipose tissue, shivering thermogenesis in skeletal muscles, thermoregulatory cardiac regulation, heat-loss regulation through cutaneous vasomotion, and ACTH release. To defend thermal homeostasis from environmental thermal challenges, feedforward thermosensory information on environmental temperature sensed by skin thermoreceptors ascends through the spinal cord and lateral parabrachial nucleus to the preoptic area (POA). The POA also receives feedback signals from local thermosensitive neurons, as well as pyrogenic signals of prostaglandin E(2) produced in response to infection. These afferent signals are integrated and affect the activity of GABAergic inhibitory projection neurons descending from the POA to the dorsomedial hypothalamus (DMH) or to the rostral medullary raphe region (rMR). Attenuation of the descending inhibition by cooling or pyrogenic signals leads to disinhibition of thermogenic neurons in the DMH and sympathetic and somatic premotor neurons in the rMR, which then drive spinal motor output mechanisms to elicit thermogenesis, tachycardia, and cutaneous vasoconstriction. Warming signals enhance the descending inhibition from the POA to inhibit the motor outputs, resulting in cutaneous vasodilation and inhibited thermogenesis. This central thermoregulatory mechanism also functions for metabolic regulation and stress-induced hyperthermia.

Enhanced Control for Local Helicity Injection on the Pegasus ST

NASA Astrophysics Data System (ADS)

Pierren, C.; Bongard, M. W.; Fonck, R. J.; Lewicki, B. T.; Perry, J. M.

2017-10-01

Local helicity injection (LHI) experiments on Pegasus rely upon programmable control of a 250 MVA modular power supply system that drives the electromagnets and helicity injection systems. Precise control of the central solenoid is critical to experimental campaigns that test the LHI Taylor relaxation limit and the coupling efficiency of LHI-produced plasmas to Ohmic current drive. Enhancement and expansion of the present control system is underway using field programmable gate array (FPGA) technology for digital logic and control, coupled to new 10 MHz optical-to-digital transceivers for semiconductor level device communication. The system accepts optical command signals from existing analog feedback controllers, transmits them to multiple devices in parallel H-bridges, and aggregates their status signals for fault detection. Present device-level multiplexing/de-multiplexing and protection logic is extended to include bridge-level protections with the FPGA. An input command filter protects against erroneous and/or spurious noise generated commands that could otherwise cause device failures. Fault registration and response times with the FPGA system are 25 ns. Initial system testing indicates an increased immunity to power supply induced noise, enabling plasma operations at higher working capacitor bank voltage. This can increase the applied helicity injection drive voltage, enable longer pulse lengths and improve Ohmic loop voltage control. Work supported by US DOE Grant DE-FG02-96ER54375.

Advances in the steady-state hybrid regime in DIII-D—a fully non-inductive, ELM-suppressed scenario for ITER

NASA Astrophysics Data System (ADS)

Petty, C. C.; Nazikian, R.; Park, J. M.; Turco, F.; Chen, Xi; Cui, L.; Evans, T. E.; Ferraro, N. M.; Ferron, J. R.; Garofalo, A. M.; Grierson, B. A.; Holcomb, C. T.; Hyatt, A. W.; Kolemen, E.; La Haye, R. J.; Lasnier, C.; Logan, N.; Luce, T. C.; McKee, G. R.; Orlov, D.; Osborne, T. H.; Pace, D. C.; Paz-Soldan, C.; Petrie, T. W.; Snyder, P. B.; Solomon, W. M.; Taylor, N. Z.; Thome, K. E.; Van Zeeland, M. A.; Zhu, Y.

2017-11-01

The hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated with ELM suppression by applying an odd parity n  =  3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in the DIII-D tokamak with high beta (≤ft< β \\right>   ⩽  2.8%) and high confinement (H98y2  ⩽  1.4) in the ITER similar shape have achieved zero surface loop voltage for up to two current relaxation times using efficient central current drive from ECCD and NBCD. The n  =  3 RMP causes surprisingly little increase in thermal transport during ELM suppression. Poloidal magnetic flux pumping in hybrid plasmas maintains q above 1 without loss of current drive efficiency, except that experiments show that extremely peaked ECCD profiles can create sawteeth. During ECCD, Alfvén eigenmode (AE) activity is replaced by a more benign fishbone-like mode, reducing anomalous beam ion diffusion by a factor of 2. While the electron and ion thermal diffusivities substantially increase with higher ECCD power, the loss of confinement can be offset by the decreased fast ion transport resulting from AE suppression. Extrapolations from DIII-D along a dimensionless parameter scaling path as well as those using self-consistent theory-based modeling show that these ELM-suppressed, fully non-inductive hybrids can achieve the Q fus  =  5 ITER steady-state mission.

Alcohol and Traffic Safety.

ERIC Educational Resources Information Center

Dickman, Frances Baker, Ed.

1988-01-01

Seven papers discuss current issues and applied social research concerning alcohol traffic safety. Prevention, policy input, methodology, planning strategies, anti-drinking/driving programs, social-programmatic orientations of Mothers Against Drunk Driving, Kansas Driving Under the Influence Law, New Jersey Driving While Impaired Programs,…

Learning to Leverage Student Thinking: What Novice Approximations Teach Us about Ambitious Practice

ERIC Educational Resources Information Center

Singer-Gabella, Marcy; Stengel, Barbara; Shahan, Emily; Kim, Min-Joung

2016-01-01

Central to ambitious teaching is a constellation of practices we have come to call "leveraging student thinking." In leveraging, teachers position students' understanding and reasoning as a central means to drive learning forward. While leveraging typically is described as a feature of mature practice, in this article we examine…

Continuing Education: Blueprint for Excellence.

ERIC Educational Resources Information Center

Herder, Dale M.; Standridge, Larry A.

Educational programs in learning centers away from a central campus can tap a largely forgotten "market" of community college students, especially in times of higher energy costs when many suburban or rural adults may not wish to drive to a central campus. However, in order for these programs to be effective, sound management is essential. An…

High speed, high current pulsed driver circuit

DOEpatents

Carlen, Christopher R.

2017-03-21

Various technologies presented herein relate to driving a LED such that the LED emits short duration pulses of light. This is accomplished by driving the LED with short duration, high amplitude current pulses. When the LED is driven by short duration, high amplitude current pulses, the LED emits light at a greater amplitude compared to when the LED is driven by continuous wave current.

T cell costimulation via the integrin VLA-4 inhibits the actin-dependent centralization of signaling microclusters containing the adaptor SLP-76.

PubMed

Nguyen, Ken; Sylvain, Nicholas R; Bunnell, Stephen C

2008-06-01

Antigen-dependent T cell activation drives the formation of signaling microclusters containing the adaptor SLP-76. Costimulatory integrins regulate SLP-76 phosphorylation and could influence SLP-76 microclusters in the integrin-rich periphery of the immune synapse. We report that costimulation by the integrin VLA-4 (alpha4beta1) required SLP-76 domains implicated in microcluster assembly. Pro-adhesive ligands enlarged the contact and increased the number of SLP-76 microclusters regardless of their costimulatory potential. Costimulatory VLA-4 ligands also prevented the centralization of SLP-76, promoted microcluster persistence, prolonged lateral interactions between SLP-76 and its upstream kinase, ZAP-70, and retained SLP-76 in tyrosine-phosphorylated peripheral structures. SLP-76 centralization was driven by dynamic actin polymerization and was correlated with inward actin flows. VLA-4 ligation retarded these flows, even in the absence of SLP-76. These data suggest a widely applicable model of costimulation, in which integrins promote sustained signaling by attenuating cytoskeletal movements that drive the centralization and inactivation of SLP-76 microclusters.

Mesencephalic stimulation elicits inhibition of phrenic nerve activity in cat.

PubMed Central

Gallman, E A; Lawing, W L; Millhorn, D E

1991-01-01

1. Previous work from this laboratory has indicated that the mesencephalon is the anatomical substrate for a mechanism capable of inhibiting central respiratory drive in glomectomized cats for periods of up to 1 h or more following brief exposure to systemic hypoxia; phrenic nerve activity was used as an index of central respiratory drive. 2. The present study was undertaken to further localize the region responsible for the observed post-hypoxic inhibition of respiratory drive. We studied the phrenic nerve response to stimulations of the mesencephalon in anaesthetized, paralysed peripherally chemo-denervated cats with end-expired PCO2 and body temperature servo-controlled. 3. Stimulations of two types were employed. Electrical stimulation allowed rapid determination of sites from which phrenic inhibition could be elicited. Microinjections of excitatory amino acids were used subsequently in order to confine excitation to neuronal cell bodies and not axons of passage. 4. Stimulation of discrete regions of the ventromedial aspect of the mesencephalon in the vicinity of the red nucleus produced substantial inhibition of phrenic activity which lasted up to 45 min. Stimulation of other areas of the mesencephalon either produced no phrenic inhibition or resulted in a slight stimulation of phrenic activity. 5. The results are discussed in the context of the central respiratory response to hypoxia. PMID:1676420

Antihistamines in drivers, aircrew and occupations of risk.

PubMed

Jáuregui, I; Ferrer, M; Montoro, J; Dávila, I; Bartra, J; del Cuvillo, A; Mullol, J; Sastre, J; Valero, A

2013-01-01

The most commonly occurring allergic diseases can involve a daytime drowsiness associated with the condition itself. The antihistamines used in their treatment can also have central effects and affect certain occupations concerned with risk, road safety and maritime and air navigation. Cognitive tests, experimental studies and epidemiological data recommend avoiding 1st generation antihistamines for people who must drive regularly and/or professions concerned with safety. Although there are no comparative studies on real driving between 1st and 2nd generation antihistamines, in this type of patients there should be a preference for prescribing those with least possible central effect, especially those which are a good substrate for transmembrane transporter pumps such as P-glycoprotein and therefore have a low capacity for crossing the hematoencephalic barrier, thus allowing a broader window for therapy. In this sense, bilastine is a good P-glycoprotein substrate and shows good tolerance at CNS level, in both psychometric trials and real driving test protocols, even at double the dose recommended in the technical file.

Reduced ion bootstrap current drive on NTM instability

NASA Astrophysics Data System (ADS)

Qu, Hongpeng; Wang, Feng; Wang, Aike; Peng, Xiaodong; Li, Jiquan

2018-05-01

The loss of bootstrap current inside magnetic island plays a dominant role in driving the neoclassical tearing mode (NTM) instability in tokamak plasmas. In this work, we investigate the finite-banana-width (FBW) effect on the profile of ion bootstrap current in the island vicinity via an analytical approach. The results show that even if the pressure gradient vanishes inside the island, the ion bootstrap current can partly survive due to the FBW effect. The efficiency of the FBW effect is higher when the island width becomes smaller. Nevertheless, even when the island width is comparable to the ion FBW, the unperturbed ion bootstrap current inside the island cannot be largely recovered by the FBW effect, and thus the current loss still exists. This suggests that FBW effect alone cannot dramatically reduce the ion bootstrap current drive on NTMs.

Fuel magnetization without external field coils (AutoMag)

NASA Astrophysics Data System (ADS)

Slutz, Stephen; Jennings, Christopher; Awe, Thomas; Shipley, Gabe; Lamppa, Derek; McBride, Ryan

2016-10-01

Magnetized Liner Inertial Fusion (MagLIF) has produced fusion-relevant plasma conditions on the Z accelerator where the fuel was magnetized using external field coils. We present a novel concept that does not need external field coils. This concept (AutoMag) magnetizes the fuel during the early part of the drive current by using a composite liner with helical conduction paths separated by insulating material. The drive is designed so the current rises slowly enough to avoid electrical breakdown of the insulators until a sufficiently strong magnetic field is established. Then the current rises more quickly, which causes the insulators to break down allowing the drive current to follow an axial path and implode the liner. Low inductance magnetically insulated power feeds can be used with AutoMag to increase the drive current without interfering with diagnostic access. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Radially Focused Eddy Current Sensor for Detection of Longitudinal Flaws in Metallic Tubes

NASA Technical Reports Server (NTRS)

Wincheski, Russell A. (Inventor); Simpson, John W. (Inventor); Fulton, James P. (Inventor); Nath, Shridhar C. (Inventor); Todhunter, Ronald G. (Inventor); Namkung, Min (Inventor)

1999-01-01

A radially focused eddy current sensor detects longitudinal flaws in a metal tube. A drive coil induces eddy currents within the wall of the metal tube. A pick-up cod is spaced apart from the drive coil along the length of the metal tube. The pick@up coil is positioned with one end thereof lying adjacent the wall of the metal tube such that the pick-up coil's longitudinal axis is perpendicular to the wall of the metal tube. To isolate the pick-up coil from the magnetic flux of the drive coil and the flux from the induced eddy currents. except the eddy currents diverted by a longitudinal flaw. an electrically conducting material high in magnetic permeability surrounds all of the pick-up coil except its one end that is adjacent the walls of the metal tube. The electrically conducting material can extend into and through the drive coil in a coaxial relationship therewith.

Sensor-less pseudo-sinusoidal drive for a permanent-magnet brushless ac motor

NASA Astrophysics Data System (ADS)

Liu, Li-Hsiang; Chern, Tzuen-Lih; Pan, Ping-Lung; Huang, Tsung-Mou; Tsay, Der-Min; Kuang, Jao-Hwa

2012-04-01

The precise rotor-position information is required for a permanent-magnet brushless ac motor (BLACM) drive. In the conventional sinusoidal drive method, either an encoder or a resolver is usually employed. For position sensor-less vector control schemes, the rotor flux estimation and torque components are obtained by complicated coordinate transformations. These computational intensive methods are susceptible to current distortions and parameter variations. To simplify the method complexity, this work presents a sensor-less pseudo-sinusoidal drive scheme with speed control for a three-phase BLACM. Based on the sinusoidal drive scheme, a floating period of each phase current is inserted for back electromotive force detection. The zero-crossing point is determined directly by the proposed scheme, and the rotor magnetic position and rotor speed can be estimated simultaneously. Several experiments for various active angle periods are undertaken. Furthermore, a current feedback control is included to minimize and compensate the torque fluctuation. The experimental results show that the proposed method has a competitive performance compared with the conventional drive manners for BLACM. The proposed scheme is straightforward, bringing the benefits of sensor-less drive and negating the need for coordinate transformations in the operating process.

Using AORSA to simulate helicon waves in DIII-D

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

Lau, C., E-mail: lauch@ornl.gov; Blazevski, D.; Green, D. L.

2015-12-10

Recent efforts have shown that helicon waves (fast waves at > 20ω{sub ci}) may be an attractive option for driving efficient off-axis current drive during non-inductive tokamak operation for DIII-D, ITER and DEMO. For DIII-D scenarios, the ray tracing code, GENRAY, has been extensively used to study helicon current drive efficiency and location as a function of many plasma parameters. The full wave code, AORSA, which is applicable to arbitrary Larmor radius and can resolve arbitrary ion cyclotron harmonic order, has been recently used to validate the ray tracing technique at these high cyclotron harmonics. If the SOL is ignored,more » it will be shown that the GENRAY and AORSA calculated current drive profiles are comparable for the envisioned high beta advanced scenarios for DIII-D, where there is high single pass absorption due to electron Landau damping and minimal ion damping. AORSA is also been used to estimate possible SOL effects on helicon current drive coupling and SOL absorption due to collisional and slow wave effects.« less

Using AORSA to simulate helicon waves in DIII-D

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

Lau, Cornwall H; Jaeger, E. F.; Bertelli, Nicola

2015-01-01

Recent efforts have shown that helicon waves (fast waves at >20 omega(ci)) may be an attractive option for driving efficient off-axis current drive during non-inductive tokamak operation for DIII-D, ITER and DEMO. For DIII-D scenarios, the ray tracing code, GENRAY, has been extensively used to study helicon current drive efficiency and location as a function of many plasma parameters. The full wave code, AORSA, which is applicable to arbitrary Larmor radius and can resolve arbitrary ion cyclotron harmonic order, has been recently used to validate the ray tracing technique at these high cyclotron harmonics. If the SOL is ignored, itmore » will be shown that the GENRAY and AORSA calculated current drive profiles are comparable for the envisioned high beta advanced scenarios for DIII-D, where there is high single pass absorption due to electron Landau damping and minimal ion damping. AORSA is also been used to estimate possible SOL effects on helicon current drive coupling and SOL absorption due to collisional and slow wave effects.« less

Standard operation procedures for conducting the on-the-road driving test, and measurement of the standard deviation of lateral position (SDLP)

PubMed Central

Verster, Joris C; Roth, Thomas

2011-01-01

This review discusses the methodology of the standardized on-the-road driving test and standard operation procedures to conduct the test and analyze the data. The on-the-road driving test has proven to be a sensitive and reliable method to examine driving ability after administration of central nervous system (CNS) drugs. The test is performed on a public highway in normal traffic. Subjects are instructed to drive with a steady lateral position and constant speed. Its primary parameter, the standard deviation of lateral position (SDLP), ie, an index of ‘weaving’, is a stable measure of driving performance with high test–retest reliability. SDLP differences from placebo are dose-dependent, and do not depend on the subject’s baseline driving skills (placebo SDLP). It is important that standard operation procedures are applied to conduct the test and analyze the data in order to allow comparisons between studies from different sites. PMID:21625472

Standard operation procedures for conducting the on-the-road driving test, and measurement of the standard deviation of lateral position (SDLP).

PubMed

Verster, Joris C; Roth, Thomas

2011-01-01

This review discusses the methodology of the standardized on-the-road driving test and standard operation procedures to conduct the test and analyze the data. The on-the-road driving test has proven to be a sensitive and reliable method to examine driving ability after administration of central nervous system (CNS) drugs. The test is performed on a public highway in normal traffic. Subjects are instructed to drive with a steady lateral position and constant speed. Its primary parameter, the standard deviation of lateral position (SDLP), ie, an index of 'weaving', is a stable measure of driving performance with high test-retest reliability. SDLP differences from placebo are dose-dependent, and do not depend on the subject's baseline driving skills (placebo SDLP). It is important that standard operation procedures are applied to conduct the test and analyze the data in order to allow comparisons between studies from different sites.

LETTER: Investigation of the effect of Alfven resonance mode conversion on fast wave current drive in ITER

NASA Astrophysics Data System (ADS)

Alava, M. J.; Heikkinen, J. A.; Hellsten, T.

1995-07-01

In order to reduce or to avoid ion cyclotron damping, the use of frequencies below the ion cyclotron frequency of minority ion species or the second harmonic of majority ion species has been proposed for fast wave current drive based on direct electron absorption. For these scenarios, the Alfven or ion-ion hybrid resonance can appear on the high field side of a tokamak. The presence of these resonances causes parasitic absorption, competing with the electron Landau damping and transit time magnetic pumping responsible for the fast wave current drive. In the present study, neglecting effects from toroidicity, the mode conversion at the Alfven resonance is shown to be of the order of 5 to 10% in the current drive scenarios for the planned ITER experiment. If the single pass absorption in the centre can be made sufficiently high, the conversion at the Alfven resonance becomes negligible

Investigation of the effect of Alfven resonance absorption on fast wave current drive in ITER

NASA Astrophysics Data System (ADS)

Alava, M. J.; Heikkinen, J. A.; Hellsten, T.

The use of frequencies below the ion cyclotron frequency of minority ion species or second harmonic of majority species has been proposed for fast wave current drive in order to reduce or to avoid ion cyclotron damping. For these scenarios, the Alfven resonance can appear on the high field side of a tokamak. The presence of this resonance causes parasitic absorption competing with the electron Landau damping and transit time magnetic pumping responsible for the fast wave current drive. In the present study, the mode conversion at the Alfven resonance is shown to be of the order of 5 to 10 percent in the current drive scenarios for the planned International Thermonuclear Experimental Reactor (ITER) experiment. However, if the single pass absorption in the center can be made sufficiently high, the conversion at the Alfven resonance becomes negligible.

An Inverter Packaging Scheme for an Integrated Segmented Traction Drive System

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

Su, Gui-Jia; Tang, Lixin; Ayers, Curtis William

The standard voltage source inverter (VSI), widely used in electric vehicle/hybrid electric vehicle (EV/HEV) traction drives, requires a bulky dc bus capacitor to absorb the large switching ripple currents and prevent them from shortening the battery s life. The dc bus capacitor presents a significant barrier to meeting inverter cost, volume, and weight requirements for mass production of affordable EVs/HEVs. The large ripple currents become even more problematic for the film capacitors (the capacitor technology of choice for EVs/HEVs) in high temperature environments as their ripple current handling capability decreases rapidly with rising temperatures. It is shown in previous workmore » that segmenting the VSI based traction drive system can significantly decrease the ripple currents and thus the size of the dc bus capacitor. This paper presents an integrated packaging scheme to reduce the system cost of a segmented traction drive.« less

Glaucomatous retinal nerve fiber layer thickness loss is associated with slower reaction times under a divided attention task.

PubMed

Tatham, Andrew J; Boer, Erwin R; Rosen, Peter N; Della Penna, Mauro; Meira-Freitas, Daniel; Weinreb, Robert N; Zangwill, Linda M; Medeiros, Felipe A

2014-11-01

To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving. Cross-sectional observational study. Hamilton Glaucoma Center, University of California San Diego. Total of 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls. Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium, or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measure retinal nerve fiber layer (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire. Reaction times to the driving simulator divided attention task. The mean reaction times to the low-contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls, respectively, during curve negotiation (P < .001), and 1.19 s and 0.77 s (P = .025), respectively, during car following. There was a nonlinear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability, and central driving task performance. Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving. Copyright © 2014 Elsevier Inc. All rights reserved.

Health Care Provided by Military Treatment Facilities to Contractors in Southwest Asia

DTIC Science & Technology

2009-05-04

UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Department of Defense Inspector General,ODIG-AUD,400 Army Navy Drive,Arlington,VA...Department of Defense Inspector General 400 Army Navy Drive (Room 801) Arlington, VA 22202-4704 Acronyms ASD(HA...Central Command USD(AT&L) Under Secretary of Defense (Acquisition, Technology, and Logistics) INSPECTOR GENERAL DEPARTMENT OF DEFENSE 400 ARMY NAVY

Optical analysis of time-averaged multiscale Bessel beams generated by a tunable acoustic gradient index of refraction lens.

PubMed

McLeod, Euan; Arnold, Craig B

2008-07-10

Current methods for generating Bessel beams are limited to fixed beam sizes or, in the case of conventional adaptive optics, relatively long switching times between beam shapes. We analyze the multiscale Bessel beams created using an alternative rapidly switchable device: a tunable acoustic gradient index (TAG) lens. The shape of the beams and their nondiffracting, self-healing characteristics are studied experimentally and explained theoretically using both geometric and Fourier optics. By adjusting the electrical driving signal, we can tune the ring spacings, the size of the central spot, and the working distance of the lens. The results presented here will enable researchers to employ dynamic Bessel beams generated by TAG lenses.

Processing of central and reflex vagal drives by rat cardiac ganglion neurones: an intracellular analysis

PubMed Central

McAllen, Robin M; Salo, Lauren M; Paton, Julian F R; Pickering, Anthony E

2011-01-01

Abstract Cardiac vagal tone is an important indicator of cardiovascular health, and its loss is an independent risk factor for arrhythmias and mortality. Several studies suggest that this loss of vagal tone can occur at the cardiac ganglion but the factors affecting ganglionic transmissionin vivoare poorly understood. We have employed a novel approach allowing intracellular recordings from functionally connected cardiac vagal ganglion cells in the working heart–brainstem preparation. The atria were stabilisedin situpreserving their central neural connections, and ganglion cells (n = 32) were impaled with sharp microelectrodes. Cardiac ganglion cells with vagal synaptic inputs (spontaneous, n = 10; or electrically evoked from the vagus, n = 3) were identified as principal neurones and showed tonic firing responses to current injected to their somata. Cells lacking vagal inputs (n = 19, presumed interneurones) were quiescent but showed phasic firing responses to depolarising current. In principal cells the ongoing action potentials and EPSPs exhibited respiratory modulation, with peak frequency in post-inspiration. Action potentials arose from unitary EPSPs and autocorrelation of those events showed that each ganglion cell received inputs from a single active preganglionic source. Peripheral chemoreceptor, arterial baroreceptor and diving response activation all evoked high frequency synaptic barrages in these cells, always from the same single preganglionic source. EPSP amplitudes showed frequency dependent depression, leading to more spike failures at shorter inter-event intervals. These findings indicate that rather than integrating convergent inputs, cardiac vagal postganglionic neurones gate preganglionic inputs, so regulating the proportion of central parasympathetic tone that is transmitted on to the heart. PMID:22005679

Comparison of SAR and induced current densities in adults and children exposed to electromagnetic fields from electronic article surveillance devices

NASA Astrophysics Data System (ADS)

Martínez-Búrdalo, M.; Sanchis, A.; Martín, A.; Villar, R.

2010-02-01

Electronic article surveillance (EAS) devices are widely used in most stores as anti-theft systems. In this work, the compliance with international guidelines in the human exposure to these devices is analysed by using the finite-difference time-domain (FDTD) method. Two sets of high resolution numerical phantoms of different size (REMCOM/Hershey and Virtual Family), simulating adult and child bodies, are exposed to a 10 MHz pass-by panel-type EAS consisting of two overlapping current-carrying coils. Two different relative positions between the EAS and the body (frontal and lateral exposures), which imply the exposure of different parts of the body at different distances, have been considered. In all cases, induced current densities in tissues of the central nervous system and specific absorption rates (SARs) are calculated to be compared with the limits from the guidelines. Results show that induced current densities are lower in the case of adult models as compared with those of children in both lateral and frontal exposures. Maximum SAR values calculated in lateral exposure are significantly lower than those calculated in frontal exposure, where the EAS-body distance is shorter. Nevertheless, in all studied cases, with an EAS driving current of 4 A rms, maximum induced current and SAR values are below basic restrictions.

Comparison of SAR and induced current densities in adults and children exposed to electromagnetic fields from electronic article surveillance devices.

PubMed

Martínez-Búrdalo, M; Sanchis, A; Martín, A; Villar, R

2010-02-21

Electronic article surveillance (EAS) devices are widely used in most stores as anti-theft systems. In this work, the compliance with international guidelines in the human exposure to these devices is analysed by using the finite-difference time-domain (FDTD) method. Two sets of high resolution numerical phantoms of different size (REMCOM/Hershey and Virtual Family), simulating adult and child bodies, are exposed to a 10 MHz pass-by panel-type EAS consisting of two overlapping current-carrying coils. Two different relative positions between the EAS and the body (frontal and lateral exposures), which imply the exposure of different parts of the body at different distances, have been considered. In all cases, induced current densities in tissues of the central nervous system and specific absorption rates (SARs) are calculated to be compared with the limits from the guidelines. Results show that induced current densities are lower in the case of adult models as compared with those of children in both lateral and frontal exposures. Maximum SAR values calculated in lateral exposure are significantly lower than those calculated in frontal exposure, where the EAS-body distance is shorter. Nevertheless, in all studied cases, with an EAS driving current of 4 A rms, maximum induced current and SAR values are below basic restrictions.

Perceptual load in central and peripheral regions and its effects on driving performance: advertizing billboards.

PubMed

Marciano, Hadas; Yeshurun, Yaffa

2012-01-01

A broadened version of the perceptual load model was utilized to explore systematically the influence of four variables on driver's behavior: a. levels of load on the road; b. levels of load at the sides of the road; c. event's initial location (on the road vs. at the sides of the road); and d. the presence and size of advertizing billboards. 18 participants participated in two experimental sessions in a driving simulator. One of the sessions contained advertizing billboards and the other session did not. The results indicated that billboards can have a considerable effect on various aspects of driving like the time required responding to a potentially dangerous event or simply the number of accidents occurring during driving, but importantly the effect of billboards on driving was modulated by the levels of perceptual load.

Active lamp pulse driver circuit. [optical pumping of laser media

NASA Technical Reports Server (NTRS)

Logan, K. E. (Inventor)

1983-01-01

A flashlamp drive circuit is described which uses an unsaturated transistor as a current mode switch to periodically subject a partially ionized gaseous laser excitation flashlamp to a stable, rectangular pulse of current from an incomplete discharge of an energy storage capacitor. A monostable multivibrator sets the pulse interval, initiating the pulse in response to a flash command by providing a reference voltage to a non-inverting terminal of a base drive amplifier; a tap on an emitter resistor provides a feedback signal sensitive to the current amplitude to an inverting terminal of amplifier, thereby controlling the pulse amplitude. The circuit drives the flashlamp to provide a squarewave current flashlamp discharge.

Renal sympathetic denervation in uncontrolled arterial hypertension after successful repair for aortic coarctation.

PubMed

Lurz, Philipp; Okon, Thomas; Riede, Thomas; Wagner, Robert; Schuler, Gerhard; Daehnert, Ingo; Desch, Steffen

2016-01-01

Uncontrolled arterial hypertension is a frequent problem after successful repair of CoA and has been attributed to increased central sympathetic drive as well as a blunted baroreceptor reflex. RSD is a promising therapy to reduce central sympathetic drive and improve baroreflex sensitivity. 8 patients (age: 27±6 years) with previous surgical and/or percutaneous repair of CoA, absence of any relevant restenosis (invasive gradient across the site of previous treatment 3±4 mmHg) and resistant arterial hypertension (daytime SBP≥140 mmHg on 24 hour ambulatory blood pressure measurements [ABPM] in spite of the concurrent use of 3 antihypertensive agents of different classes or intolerance to BP medications) were included. Bilateral RSD was performed using the Symplicity Flex™ catheter (Medtronic, MN, USA). RSD was successful in all patients with no procedural complications and no evidence for renal artery stenosis 6 months post procedure. From baseline to 6 month follow-up, RSD was followed by a significant reduction in average daytime systolic BP (150.4±7.8 to 143.1±8.0 mmHg; p=0.0117) as well as systolic BP throughout 24 h (146.8±7.3 vs. 140.5±7.8, p=0.04). The BP reductions observed in these patients justify engaging in a larger clinical trial on the efficacy of RSD in this specific type of secondary hypertension and bares the hope that RSD might extend the currently very limited armory against arterial hypertension in young adults with previous repair of CoA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Coaxial test fixture

DOEpatents

Praeg, Walter F.

1986-01-01

An assembly is provided for testing one or more contact material samples in a vacuum environment. The samples are positioned as an inner conductive cylinder assembly which is mounted for reciprocal vertical motion as well as deflection from a vertical axis. An outer conductive cylinder is coaxially positioned around the inner cylinder and test specimen to provide a vacuum enclosure therefor. A power source needed to drive test currents through the test specimens is connected to the bottom of each conductive cylinder, through two specially formed conductive plates. The plates are similar in form, having a plurality of equal resistance current paths connecting the power source to a central connecting ring. The connecting rings are secured to the bottom of the inner conductive assembly and the outer cylinder, respectively. A hydraulic actuator is also connected to the bottom of the inner conductor assembly to adjust the pressure applied to the test specimens during testing. The test assembly controls magnetic forces such that the current distribution through the test samples is symmetrical and that contact pressure is not reduced or otherwise disturbed.

Impact of New Regulations On Assessing Driving Status (INROADS): a South Australian seizure clinic cohort.

PubMed

Hafner, Jessica; Horn, Sharon; Robinson, Martin; Purdie, Grant; Jannes, Jim

2014-11-01

The ability to drive is important to patients and driving restriction often leads to restriction of employment and social opportunities. In March 2012, Austroads released revised Assessing Fitness to Drive Guidelines (AFTDG) with significant changes for drivers with seizures and epilepsy. Our study aimed to assess the impact of the 2012 AFTDG on a Seizure Clinic cohort compared to the previous 2003 AFTDG and an individual's current driving status. We also aimed to quantify the difference in AFTDG interpretation between expert and non-expert doctors. We performed a retrospective observational audit of case notes for all patients managed in a public hospital outpatient Seizure Clinic between 1 March 2010 and 1 March 2012. A total of 142 patients were included in the analysis. Comparison between the 2003 and 2012 AFTDG resulted in reduced eligibility to drive a private vehicle by 2.1% (52.5% versus 50.4%) and commercial vehicle by 2.2% (4.5% versus 2.3%). The proportion of those currently driving against guideline recommendations increased (private 8.8% versus 19%; commercial 50% versus 100%) and the non-expert assessor was more likely to agree with the experts with the 2012 AFTDG. In summary, the 2012 AFTDG has had a measurable impact on driving eligibility in individuals with seizure although it is easier to interpret for non-expert doctors. Greater awareness of the 2012 AFTDG is required to reduce the proportion of patients driving against current recommendations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neoclassical Current Drive by Waves with a Symmetric Spectrum

NASA Astrophysics Data System (ADS)

Helander, Per

2000-10-01

It is well known that plasma waves can produce electric currents if the waves have an asymmetric spectrum, so that they either interact preferentially with electrons travelling in one direction along the magnetic field or impart net parallel momentum to the electrons [1]. This directionality creates an asymmetry in the electron distribution function and thereby produces a current parallel to the field. We demonstrate, somewhat surprisingly, that in a plasma confined by a curved magnetic field no such spectral asymmetry is necessary for current drive if the effect of collisions is properly taken into account. For instance, in a toroidal plasma a current can be produced by a spectrally symmetric wave field if this field is instead up-down asymmetric, which is frequently the case for electron cyclotron current drive (ECCD) in tokamaks. We have calculated the resulting current drive efficiency and found it to be smaller than that of the conventional current drive mechanism in the banana regime, but not insignificant in the plateau regime. The results will be compared with experiments in DIII-D, where the measured efficiency exceeds the classical prediction [2]. Our calculations are focused on this case of ECCD in tokamaks, but the basic physical mechanism is much more general. It is of a universal neoclassical nature and applies to all wave-particle interaction in curved magnetic fields. [1] N.J. Fisch, Rev. Mod. Phys. 59, 175 (1987). [2] Y. R. Lin-Liu et al., 26th EPS Conf. on Contr. Fusion and Plasma Phys.(European Phys. Soc. Paris, 1999) Vol. 23J, p 1245.

Contribution of peripheral and central chemoreceptors to sympatho‐excitation in heart failure

PubMed Central

Toledo, Camilo; Andrade, David C.; Lucero, Claudia; Schultz, Harold D.; Marcus, Noah; Retamal, Mauricio; Madrid, Carlos

2016-01-01

Abstract Chronic heart failure (CHF) is a major public health problem. Tonic hyper‐activation of sympathetic neural outflow is commonly observed in patients with CHF. Importantly, sympatho‐excitation in CHF exacerbates its progression and is strongly related to poor prognosis and high mortality risk. Increases in both peripheral and central chemoreflex drive are considered markers of the severity of CHF. The principal peripheral chemoreceptors are the carotid bodies (CBs) and alteration in their function has been described in CHF. Mainly, during CHF the CB chemosensitivity is enhanced leading to increases in ventilation and sympathetic outflow. In addition to peripheral control of breathing, central chemoreceptors (CCs) are considered a dominant mechanism in ventilatory regulation. Potentiation of the ventilatory and sympathetic drive in response to CC activation has been shown in patients with CHF as well as in animal models. Therefore, improving understanding of the contribution of the peripheral and central chemoreflexes to augmented sympathetic discharge in CHF could help in developing new therapeutic approaches intended to attenuate the progression of CHF. Accordingly, the main focus of this review is to discuss recent evidence that peripheral and central chemoreflex function are altered in CHF and that they contribute to autonomic imbalance and progression of CHF. PMID:27218485

Sequential Dependencies in Driving

ERIC Educational Resources Information Center

Doshi, Anup; Tran, Cuong; Wilder, Matthew H.; Mozer, Michael C.; Trivedi, Mohan M.

2012-01-01

The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find…

Derivation of dynamo current drive in a closed-current volume and stable current sustainment in the HIT-SI experiment

DOE PAGES

Hossack, A. C.; Sutherland, D. A.; Jarboe, T. R.

2017-02-01

A derivation is given showing that the current inside a closed-current volume can be sustained against resistive dissipation by appropriately phased magnetic perturbations. Imposed-dynamo current drive (IDCD) theory is used to predict the toroidal current evolution in the HIT-SI experiment as a function of magnetic fluctuations at the edge. Analysis of magnetic fields from a HIT-SI discharge shows that the injector-imposed fluctuations are sufficient to sustain the measured toroidal current without instabilities whereas the small, plasma-generated magnetic fluctuations are not sufficiently large to sustain the current.

Derivation of dynamo current drive in a closed-current volume and stable current sustainment in the HIT-SI experiment

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

Hossack, A. C.; Sutherland, D. A.; Jarboe, T. R.

A derivation is given showing that the current inside a closed-current volume can be sustained against resistive dissipation by appropriately phased magnetic perturbations. Imposed-dynamo current drive (IDCD) theory is used to predict the toroidal current evolution in the HIT-SI experiment as a function of magnetic fluctuations at the edge. Analysis of magnetic fields from a HIT-SI discharge shows that the injector-imposed fluctuations are sufficient to sustain the measured toroidal current without instabilities whereas the small, plasma-generated magnetic fluctuations are not sufficiently large to sustain the current.

Anxiety, Sedation, and Simulated Driving in Binge Drinkers

PubMed Central

Aston, Elizabeth R.; Shannon, Erin E.; Liguori, Anthony

2014-01-01

The current study evaluated the relationships among trait anxiety, subjective response to alcohol, and simulated driving following a simulated alcohol binge. Sixty drinkers with a binge history completed the State Trait Anxiety Inventory (STAI), the Alcohol Use Questionnaire, and subsequently completed a driving simulation. Participants were then administered 0.2 g/kg ethanol at 30 minute intervals (cumulative dose 0.8 g/kg). Following alcohol consumption, the Biphasic Alcohol Effects Scale (BAES) and visual analog scales of subjective impairment and driving confidence were administered, after which simulated driving was re-assessed. Due to the emphasis on simulated driving after drinking in the current study, subjective response to alcohol (i.e., self-reported sedation, stimulation, impairment, and confidence in driving ability) was assessed once following alcohol consumption, as this is the time when drinkers tend to make decisions regarding legal driving ability. Alcohol increased driving speed, speeding tickets, and collisions. Sedation following alcohol predicted increased subjective impairment and decreased driving confidence. Subjective impairment was not predicted by sensitivity to stimulation or trait anxiety. High trait anxiety predicted low driving confidence after drinking and this relationship was mediated by sedation. Increased speed after alcohol was predicted by sedation, but not by trait anxiety or stimulation. Anxiety, combined with the sedating effects of alcohol, may indicate when consumption should cease. However, once driving is initiated, sensitivity to sedation following alcohol consumption is positively related to simulated driving speed. PMID:24955664

Nonuniform Changes in the Distribution of Visual Attention from Visual Complexity and Action: A Driving Simulation Study.

PubMed

Park, George D; Reed, Catherine L

2015-02-01

Researchers acknowledge the interplay between action and attention, but typically consider action as a response to successful attentional selection or the correlation of performance on separate action and attention tasks. We investigated how concurrent action with spatial monitoring affects the distribution of attention across the visual field. We embedded a functional field of view (FFOV) paradigm with concurrent central object recognition and peripheral target localization tasks in a simulated driving environment. Peripheral targets varied across 20-60 deg eccentricity at 11 radial spokes. Three conditions assessed the effects of visual complexity and concurrent action on the size and shape of the FFOV: (1) with no background, (2) with driving background, and (3) with driving background and vehicle steering. The addition of visual complexity slowed task performance and reduced the FFOV size but did not change the baseline shape. In contrast, the addition of steering produced not only shrinkage of the FFOV, but also changes in the FFOV shape. Nonuniform performance decrements occurred in proximal regions used for the central task and for steering, independent of interference from context elements. Multifocal attention models should consider the role of action and account for nonhomogeneities in the distribution of attention. © 2015 SAGE Publications.

Counting abilities in autism: possible implications for central coherence theory.

PubMed

Jarrold, C; Russell, J

1997-02-01

We examined the claim that children with autism have a "weak drive for central coherence" which biases them towards processing information at an analytic rather than global level. This was done by investigating whether children with autism would rapidly and automatically enumerate a number of dots presented in a canonical form, or count each dot individually to obtain the total. The time taken to count stimuli was compared across three participant groups: children with autism, children with moderate learning difficulties, and normally developing children. There were 22 children in each group, and individuals were matched across groups on the basis of verbal mental age. Results implied that children with autism did show a tendency towards an analytic level of processing. However, though the groups differed on measures of counting speeds, the number or children showing patterns of global or analytic processing did not differ significantly across the groups. Whether these results implicate a weak drive for central coherence in autism, which is both specific to, and pervasive in the disorder, is discussed.

Application of drive circuit based on L298N in direct current motor speed control system

NASA Astrophysics Data System (ADS)

Yin, Liuliu; Wang, Fang; Han, Sen; Li, Yuchen; Sun, Hao; Lu, Qingjie; Yang, Cheng; Wang, Quanzhao

2016-10-01

In the experiment of researching the nanometer laser interferometer, our design of laser interferometer circuit system is up to the wireless communication technique of the 802.15.4 IEEE standard, and we use the RF TI provided by Basic to receive the data on speed control system software. The system's hardware is connected with control module and the DC motor. However, in the experiment, we found that single chip microcomputer control module is very difficult to drive the DC motor directly. The reason is that the DC motor's starting and braking current is larger than the causing current of the single chip microcomputer control module. In order to solve this problem, we add a driving module that control board can transmit PWM wave signal through I/O port to drive the DC motor, the driving circuit board can come true the function of the DC motor's positive and reversal rotation and speed adjustment. In many various driving module, the L298N module's integrated level is higher compared with other driver module. The L298N model is easy to control, it not only can control the DC motor, but also achieve motor speed control by modulating PWM wave that the control panel output. It also has the over-current protection function, when the motor lock, the L298N model can protect circuit and motor. So we use the driver module based on L298N to drive the DC motor. It is concluded that the L298N driver circuit module plays a very important role in the process of driving the DC motor in the DC motor speed control system.

Factors associated with driving in teens with autism spectrum disorders.

PubMed

Huang, Patty; Kao, Trudy; Curry, Allison E; Durbin, Dennis R

2012-01-01

To compare the characteristics of driving and nondriving teens and explore the driving outcomes for teens with higher functioning autism spectrum disorders. Parents of teens aged 15 to 18 years with a parent-reported diagnosis of an autism spectrum disorder enrolled in Interactive Autism Network, an online research registry, were eligible for this cross-sectional study. An online survey was used for data collection. A total of 297 parents completed the survey. Sixty-three percent of teens currently drive or plan to drive. Twenty-nine percent of the teens who are age-eligible to drive currently drive. Compared with age-eligible but nondriving teens, a greater proportion of driving teens were in full-time regular education (p < .005), planned to attend college (p < .001), and held a paid job (p = .008). A greater proportion of parents of driving teens had taught ≥1 teen to drive previously (p < .001). There were no differences in gender, autism subtype, attention deficit/hyperactivity disorder diagnosis, parental age or education, or access to public transportation. Driving predictors included individualized education plans with driving goals, indicators of functional status (classroom placement, college aspiration, and job experience), and parent experience with teaching teens to drive. Twelve percent of teens received driving citations, and 12% of teens had been involved in a motor vehicle crash. Although a significant proportion of teens with higher functioning autism spectrum disorders were driving or learning to drive, the fact that most driving teens' individualized education plans did not include driving goals suggests an area of opportunity for improvement in transition planning. Driving teens were more frequently in regular education settings with college aspirations, which could help schools identify potential drivers.

Dynamic changes in phrenic motor output following high cervical hemisection in the decerebrate rat.

PubMed

Ghali, Michael George Zaki; Marchenko, Vitaliy

2015-09-01

Hemisection of the spinal cord at C2 eliminates ipsilateral descending drive to the phrenic nucleus and causes hemidiaphragmatic paralysis in rats. Phrenic nerve (PhN) or diaphragmatic activity ipsilateral to hemisection can occasionally be induced acutely following hemisection by respiratory stressors (i.e., hypercapnia, asphyxia, contralateral phrenicotomy) and becomes spontaneously active days-to-weeks later. These investigations, however, are potentially confounded by the use of anesthesia, which may suppress spontaneously-active crossed phrenic pathways. Experiments were performed on vecuronium-paralyzed, unanesthetized, decerebrate adult male rats and whole PhN activity recorded continuously before, during, and after high cervical hemisection at the C1 spinal level. Crossed phrenic activity recovered spontaneously over minutes-to-hours with maximal recovery of 11.8 ± 3.1% (m ± SE) in the PhN ipsilateral to hemisection. Additionally, there was a significant increase in PhN activity contralateral to hemisection of 221.0 ± 4 0.4% (m ± SE); since animals were artificially-ventilated, these changes likely represent an increase in central respiratory drive. These results underscore the state-dependence of crossed bulbophrenic projections and suggest that unanesthetized models may be more sensitive in detecting acute recovery of respiratory output following spinal cord injury (SCI). Additionally, our results may suggest an important role for a group of C1-C2 neurons exhibiting respiratory-related activity, spared by the higher level of hemisection. These units may function as relays of polysynaptic bulbophrenic pathways and/or provide excitatory drive to phrenic motoneurons. Our findings provide a new model for investigating acute respiratory recovery following cervical SCI, the high C1-hemisected unanesthetized decerebrate rat and suggest a centrally-mediated increase in central respiratory drive in response to high cervical SCI. Copyright © 2015. Published by Elsevier Inc.

Astrocytic TYMP and VEGFA drive blood–brain barrier opening in inflammatory central nervous system lesions

PubMed Central

Chapouly, Candice; Tadesse Argaw, Azeb; Horng, Sam; Castro, Kamilah; Zhang, Jingya; Asp, Linnea; Loo, Hannah; Laitman, Benjamin M.; Mariani, John N.; Straus Farber, Rebecca; Zaslavsky, Elena; Nudelman, German; Raine, Cedric S.

2015-01-01

In inflammatory central nervous system conditions such as multiple sclerosis, breakdown of the blood–brain barrier is a key event in lesion pathogenesis, predisposing to oedema, excitotoxicity, and ingress of plasma proteins and inflammatory cells. Recently, we showed that reactive astrocytes drive blood–brain barrier opening, via production of vascular endothelial growth factor A (VEGFA). Here, we now identify thymidine phosphorylase (TYMP; previously known as endothelial cell growth factor 1, ECGF1) as a second key astrocyte-derived permeability factor, which interacts with VEGFA to induce blood–brain barrier disruption. The two are co-induced NFκB1-dependently in human astrocytes by the cytokine interleukin 1 beta (IL1B), and inactivation of Vegfa in vivo potentiates TYMP induction. In human central nervous system microvascular endothelial cells, VEGFA and the TYMP product 2-deoxy-d-ribose cooperatively repress tight junction proteins, driving permeability. Notably, this response represents part of a wider pattern of endothelial plasticity: 2-deoxy-d-ribose and VEGFA produce transcriptional programs encompassing angiogenic and permeability genes, and together regulate a third unique cohort. Functionally, each promotes proliferation and viability, and they cooperatively drive motility and angiogenesis. Importantly, introduction of either into mouse cortex promotes blood–brain barrier breakdown, and together they induce severe barrier disruption. In the multiple sclerosis model experimental autoimmune encephalitis, TYMP and VEGFA co-localize to reactive astrocytes, and correlate with blood–brain barrier permeability. Critically, blockade of either reduces neurologic deficit, blood–brain barrier disruption and pathology, and inhibiting both in combination enhances tissue preservation. Suggesting importance in human disease, TYMP and VEGFA both localize to reactive astrocytes in multiple sclerosis lesion samples. Collectively, these data identify TYMP as an astrocyte-derived permeability factor, and suggest TYMP and VEGFA together promote blood–brain barrier breakdown. PMID:25805644

An Imposed Dynamo Current Drive Experiment: Demonstration of Confinement

NASA Astrophysics Data System (ADS)

Jarboe, Thomas; Hansen, Chris; Hossack, Aaron; Marklin, George; Morgan, Kyle; Nelson, Brian; Sutherland, Derek; Victor, Brian

2014-10-01

An experiment for studying and developing the efficient sustainment of a spheromak with sufficient confinement (current-drive power heats the plasma to its stability β-limit) and in the keV temperature range is discussed. A high- β spheromak sustained by imposed dynamo current drive (IDCD) is justified because: previous transient experiments showed sufficient confinement in the keV range with no external toroidal field coil; recent results on HIT-SI show sustainment with sufficient confinement at low temperature; the potential of IDCD of solving other fusion issues; a very attractive reactor concept; and the general need for efficient current drive in magnetic fusion. The design of a 0.55 m minor radius machine with the required density control, wall loading, and neutral shielding for a 2 s pulse is presented. Peak temperatures of 1 keV and toroidal currents of 1.35 MA and 16% wall-normalized plasma beta are envisioned. The experiment is large enough to address the key issues yet small enough for rapid modification and for extended MHD modeling of startup and code validation.

Glaucomatous Retinal Nerve Fiber Layer Thickness Loss is associated with Slower Reaction Times under a Divided Attention Task

PubMed Central

Tatham, Andrew J.; Boer, Erwin R.; Rosen, Peter N.; Penna, Mauro Della; Meira-Freitas, Daniel; Weinreb, Robert N.; Zangwill, Linda M.; Medeiros, Felipe A.

2014-01-01

Purpose To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving. Design Cross-sectional observational study. Methods Setting Hamilton Glaucoma Center, University of California San Diego. Patient Population 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls. Observation Procedure Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measured retinal nerve fiber (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire. Main outcome measures Reaction times to the driving simulator divided attention task. Results The mean reaction times to the low contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls respectively during curve negotiation (P <0.001), and 1.19 s and 0.77 s (P = 0.025) respectively during car following. There was a non-linear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability and central driving task performance. Conclusions Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving. PMID:25068641

SIMULATIONS OF ALFVÉN AND KINK WAVE DRIVING OF THE SOLAR CHROMOSPHERE: EFFICIENT HEATING AND SPICULE LAUNCHING

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

Brady, C. S.; Arber, T. D., E-mail: c.s.brady@warwick.ac.uk

2016-10-01

Two of the central problems in our understanding of the solar chromosphere are how the upper chromosphere is heated and what drives spicules. Estimates of the required chromospheric heating, based on radiative and conductive losses, suggest a rate of ∼0.1 erg cm{sup −3} s{sup −1} in the lower chromosphere and drops to ∼10{sup −3} erg cm{sup −3} s{sup −1} in the upper chromosphere. The chromosphere is also permeated by spicules, higher density plasma from the lower atmosphere propelled upwards at speeds of ∼10–20 km s{sup −1}, for so-called Type I spicules, which reach heights of ∼3000–5000 km above the photosphere.more » A clearer understanding of chromospheric dynamics, its heating, and the formation of spicules is thus of central importance to solar atmospheric science. For over 30 years it has been proposed that photospheric driving of MHD waves may be responsible for both heating and spicule formation. This paper presents results from a high-resolution MHD treatment of photospheric driven Alfvén and kink waves propagating upwards into an expanding flux tube embedded in a model chromospheric atmosphere. We show that the ponderomotive coupling from Alfvén and kink waves into slow modes generates shocks, which both heat the upper chromosphere and drive spicules. These simulations show that wave driving of the solar chromosphere can give a local heating rate that matches observations and drive spicules consistent with Type I observations all within a single coherent model.« less

Fivefold confinement time increase in the Madison Symmetric Torus using inductive poloidal current drive

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

Stoneking, M.R.; Lanier, N.E.; Prager, S.C.

1996-12-01

Current profile control is employed in the Madison Symmetric Torus reversed field pinch to reduce the magnetic fluctuations responsible for anomalous transport. An inductive poloidal electric field pulse is applied in the sense to flatten the parallel current profile, reducing the dynamo fluctuation amplitude required to sustain the equilibrium. This technique demonstrates a substantial reduction in fluctuation amplitude (as much as 50%), and improvement in energy confinement (from 1 ms to 5 ms); a record low fluctuation (0.8%) and record high temperature (615 eV) for this device were observed simultaneously during current drive experiments. Plasma beta increases by 50% andmore » the Ohmic input power is three times lower. Particle confinement improves and plasma impurity contamination is reduced. The results of the transient current drive experiments provide motivation for continuing development of steady-state current profile control strategies for the reversed field pinch.« less

Marijuana and actual driving performance

DOT National Transportation Integrated Search

1993-11-01

This report concerns the effects of marijuana smoking on actual driving performance. It presents the results of one pilot and three actual driving studies. The pilot study's major purpose was to establish the THC dose current marijuana users smoke to...

Expanding Role of T Cells in Human Autoimmune Diseases of the Central Nervous System

PubMed Central

Pilli, Deepti; Zou, Alicia; Tea, Fiona; Dale, Russell C.; Brilot, Fabienne

2017-01-01

It is being increasingly recognized that a dysregulation of the immune system plays a vital role in neurological disorders and shapes the treatment of the disease. Aberrant T cell responses, in particular, are key in driving autoimmunity and have been traditionally associated with multiple sclerosis. Yet, it is evident that there are other neurological diseases in which autoreactive T cells have an active role in pathogenesis. In this review, we report on the recent progress in profiling and assessing the functionality of autoreactive T cells in central nervous system (CNS) autoimmune disorders that are currently postulated to be primarily T cell driven. We also explore the autoreactive T cell response in a recently emerging group of syndromes characterized by autoantibodies against neuronal cell-surface proteins. Common methodology implemented in T cell biology is further considered as it is an important determinant in their detection and characterization. An improved understanding of the contribution of autoreactive T cells expands our knowledge of the autoimmune response in CNS disorders and can offer novel methods of therapeutic intervention. PMID:28638382

Structural Elements Regulating AAA+ Protein Quality Control Machines.

PubMed

Chang, Chiung-Wen; Lee, Sukyeong; Tsai, Francis T F

2017-01-01

Members of the ATPases Associated with various cellular Activities (AAA+) superfamily participate in essential and diverse cellular pathways in all kingdoms of life by harnessing the energy of ATP binding and hydrolysis to drive their biological functions. Although most AAA+ proteins share a ring-shaped architecture, AAA+ proteins have evolved distinct structural elements that are fine-tuned to their specific functions. A central question in the field is how ATP binding and hydrolysis are coupled to substrate translocation through the central channel of ring-forming AAA+ proteins. In this mini-review, we will discuss structural elements present in AAA+ proteins involved in protein quality control, drawing similarities to their known role in substrate interaction by AAA+ proteins involved in DNA translocation. Elements to be discussed include the pore loop-1, the Inter-Subunit Signaling (ISS) motif, and the Pre-Sensor I insert (PS-I) motif. Lastly, we will summarize our current understanding on the inter-relationship of those structural elements and propose a model how ATP binding and hydrolysis might be coupled to polypeptide translocation in protein quality control machines.

Electron Cyclotron Radiation, Related Power Loss, and Passive Current Drive in Tokamaks: A Review

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

Fidone, Ignazio; Giruzzi, Gerardo; Granata, Giovanni

2001-01-15

A critical review on emission of weakly damped, high-harmonics electron cyclotron radiation, the related synchrotron power loss, and passive current drive in tokamaks with a fish-scale first wall is presented. First, the properties of overlapping harmonics are discussed using general analytical formulas and numerical applications. Next, the radiation power loss and efficiency of passive current drive in tokamak reactors are derived for the asymmetric fish-scale first wall. The radiation power loss is determined by the direction-averaged reflection coefficient {sigma}{sub 0} and the passive current drive by the differential reflectivity {delta}{sigma}/(1 - {sigma}{sub 0}). Finally, the problem of experimental investigations ofmore » the high harmonics radiation spectra, of {sigma}{sub 0} and {delta}{sigma}/(1 - {sigma}{sub 0}) in existing and next-step tokamaks, is discussed. Accurate measurements of the radiation spectra and the fish-scale reflectivity can be performed at arbitrary electron temperature using a partial fish-scale structure located near the tokamak equatorial plane.« less

Restraining for switching effects in an AC driving pixel circuit of the OLED-on-silicon

NASA Astrophysics Data System (ADS)

Liu, Yan-Yan; Geng, Wei-Dong; Dai, Yong-Ping

2010-03-01

The AC driving scheme for OLEDs, which uses the pixel circuit with two transistors and one capacitor (2T1C), can extend the lifetime of the active matrix organic light-emitting diode (AMOLED) on silicon, but there are switching effects during the switch of AC signals, which result in the voltage variation on the storage capacitor and cause the current glitch in OLED. That would decrease the gray scale of the OLED. This paper proposes a novel pixel circuit consisting of three transistors and one capacitor to realize AC driving for the OLED-on-silicon while restraining the switching effects. Simulation results indicate that the proposed circuit is less sensitive to switching effects. Also, another pixel circuit is proposed to further reduce the driving current to meet the current constraints for the OLED-on-silicon.

Driving experience and special skills reflected in eye movements

NASA Astrophysics Data System (ADS)

Paeglis, Roberts; Bluss, Kristaps; Atvars, Aigars

2011-10-01

When driving a vehicle, people use the central vision both to plan ahead and monitor their performance feedback (research by Donges, 1978 [1], and after). Discussion is ongoing if making eye movements do more than gathering information. Moving eyes may also prepare the following body movements like steering. Different paradigms exist to explore vision in driving. Our perspective was to quantify eye movements and fixation patterns of different proficiency individuals, a driving learner, a novice, an experienced driver and a European level car racer. Thus for safety reasons we started by asking them to follow a video tour through a known city, remote from an infrared eye tracker sampling at 250 Hz. We report that gaze strategy of an experienced driver differs qualitatively from that of an automobile sports master. Quantitative differences only were found between the latter and a driving learner or a novice driver. Experience in a motor action provides skills different from sports training. We are aiming at testing this finding in real world driving.

Deducing noninductive current profile from surface voltage evolution

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

Litwin, C.; Wukitch, S.; Hershkowitz, N.

Solving the resistive diffusion equation in the presence of a noninductive current source determines the time-evolution of the surface voltage. By inverting the problem the current drive profile can be determined from the surface voltage evolution. We show that under wide range of conditions the deduced profile is unique. If the conductivity profile is known, this method can be employed to infer the noninductive current profile, and, ipso facto, the profile of the total current. We discuss the application of this method to analyze the Alfven wave current drive experiments in Phaedrus-T.

Cross-shaped torsional spring

DOEpatents

Williamson, Matthew M.; Pratt, Gill A.

1999-06-08

The invention provides an elastic actuator consisting of a motor and a motor drive transmission connected at an output of the motor. An elastic element is connected in series with the motor drive transmission, and this elastic element is positioned to alone support the full weight of any load connected at an output of the actuator. A single force transducer is positioned at a point between a mount for the motor and an output of the actuator. This force transducer generates a force signal, based on deflection of the elastic element, that indicates force applied by the elastic element to an output of the actuator. An active feedback force control loop is connected between the force transducer and the motor for controlling the motor. This motor control is based on the force signal to deflect the elastic element an amount that produces a desired actuator output force. The produced output force is substantially independent of load motion. The invention also provides a torsional spring consisting of a flexible structure having at least three flat sections each connected integrally with and extending radially from a central section. Each flat section extends axially along the central section from a distal end of the central section to a proximal end of the central section.

Status of the ITER Electron Cyclotron Heating and Current Drive System

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

Darbos, Caroline; Albajar, Ferran; Bonicelli, Tullio

2015-10-07

We present that the electron cyclotron (EC) heating and current drive (H&CD) system developed for the ITER is made of 12 sets of high-voltage power supplies feeding 24 gyrotrons connected through 24 transmission lines (TL), to five launchers, four located in upper ports and one at the equatorial level. Nearly all procurements are in-kind, following general ITER philosophy, and will come from Europe, India, Japan, Russia and the USA. The full system is designed to couple to the plasma 20 MW among the 24 MW generated power, at the frequency of 170 GHz, for various physics applications such as plasmamore » start-up, central H&CD and magnetohydrodynamic (MHD) activity control. The design takes present day technology and extends toward high-power continuous operation, which represents a large step forward as compared to the present state of the art. The ITER EC system will be a stepping stone to future EC systems for DEMO and beyond.The development of the EC system is facing significant challenges, which includes not only an advanced microwave system but also compliance with stringent requirements associated with nuclear safety as ITER became the first fusion device licensed as basic nuclear installations as of 9 November 2012. Finally, since the conceptual design of the EC system was established in 2007, the EC system has progressed to a preliminary design stage in 2012 and is now moving forward toward a final design.« less

Hepatopulmonary syndrome: update on pathogenesis and clinical features.

PubMed

Zhang, Junlan; Fallon, Michael B

2012-09-01

Hepatopulmonary syndrome (HPS) is a serious vascular complication of liver disease that occurs in 5-32% of patients with cirrhosis. The presence of HPS markedly increases mortality. No effective medical therapies are currently available and liver transplantation is the only established treatment option for HPS. The definition and diagnosis of HPS are established by the presence of a triad of liver disease with intrapulmonary vascular dilation that causes abnormal arterial gas exchange. Experimental biliary cirrhosis induced by common bile duct ligation in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and serves as a pertinent animal model. Pulmonary microvascular dilation and angiogenesis are two central pathogenic features that drive abnormal pulmonary gas exchange in experimental HPS, and thus might underlie HPS in humans. Defining the mechanisms involved in the microvascular alterations of HPS has the potential to lead to effective medical therapies. This Review focuses on the current understanding of the pathogenesis, clinical features and management of HPS.

Simulation of Trolleybus Traction Induction Drive With Supercapacitor Energy Storage System

NASA Astrophysics Data System (ADS)

Brazis, V.; Latkovskis, L.; Grigans, L.

2010-01-01

The article considers the possibilities of saving the regenerative braking energy in Škoda 24Tr type trolleybuses by installing the onboard supercapacitor energy storage system (ESS) and improving its performance with automated switching to the autonomous traction mode. Proposed is an ESS control system with constant DC bus voltage in the supercapacitor charging mode and supercapacitor current proportional to the AC drive current in the discharging mode. The authors investigate stability of the trolleybus ESS control system operating together with AC traction drive in various overhead voltage failure modes. The co-simulation of ESS operation was done by Matlab/Simulink AC drive and PSIM ESS continuous models.

Integral Sensor Fault Detection and Isolation for Railway Traction Drive.

PubMed

Garramiola, Fernando; Del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

2018-05-13

Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive.

Integral Sensor Fault Detection and Isolation for Railway Traction Drive

PubMed Central

del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

2018-01-01

Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive. PMID:29757251

Diplopia and driving: a problematic issue.

PubMed

Righi, Stefano; Boffano, Paolo; Guglielmi, Valeria; Rossi, Paolo; Martorina, Massimo

2014-10-01

The aim of this article was to review the literature regarding diplopia and driving license and to review the West European legislations about this topic, in order to obtain appropriate indications for hospitals specialists and patients. A systematic review of articles published about diplopia and driving was performed. In addition a review of West European national legislations about driving license regulations for medical illnesses was performed, in addition to the European Union Directive on driving licenses. In the literature, the presence of diplopia has not been considered a reliable predictor of the safety of driving behavior, or it has not appeared to be a contraindication for driving according to some authors who were unable to demonstrate significant differences on driving simulator performance between subjects with chronic stable diplopia and control subjects. Nevertheless, in all western European legislations, acute diplopia constitutes an important limitation for driving, thus making the knowledge of current regulations fundamental for specialists involved in managing patients with diplopia. Ophthalmologists and maxillofacial/head and neck surgeons, may advise patients before hospital discharge about current legislations in their respective countries. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Relativistic theory of radiofrequency current drive

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

Balescu, R.; Metens, T.

1991-05-01

A fully relativistic kinetic theory of rf current drive in a tokamak is developed for both the lower hybrid and the electron cyclotron mechanisms. The problem is treated as a generalization of the classical transport equations, in which the thermodynamic forces are modified by the addition of a rf-source term. In the limit of weak rf amplitude and neglecting toroidal effects (such as particle trapping), explicit analytical expressions are obtained for the rf-generated current, the dissipated power, and the current drive efficiency. These expressions are fully relativistic and are valid over the whole admissible range of frequencies and for allmore » electron temperatures. The relation between efficiency and parallel relativistic transport coefficients is exhibited. The most important relativistic effect is a dramatic broadening of the frequency range over which the rf-generated current is significantly different from zero.« less

On the application of frequency selective common mode feedback for multifrequency EIT.

PubMed

Langlois, Peter J; Wu, Yu; Bayford, Richard H; Demosthenous, Andreas

2015-06-01

Common mode voltages are frequently a problem in electrical impedance tomography (EIT) and other bioimpedance applications. To reduce their amplitude common mode feedback is employed. Formalised analyses of both current and voltage feedback is presented in this paper for current drives. Common mode effects due to imbalances caused by the current drives, the electrode connections to the body load and the introduction of the body impedance to ground are considered. Frequency selective narrowband common mode feedback previously proposed to provide feedback stability is examined. As a step towards multifrequency applications the use of narrowband feedback is experimentally demonstrated for two simultaneous current drives. Measured results using standard available components show a reduction of 62 dB for current feedback and 31 dB for voltage feedback. Frequencies ranged from 50 kHz to 1 MHz.

Nonlinear MHD simulation of current drive by multi-pulsed coaxial helicity injection in spherical torus

NASA Astrophysics Data System (ADS)

Kanki, Takashi; Nagata, Masayoshi; Kagei, Yasuhiro

2011-10-01

The dynamics of structures of magnetic field, current density, and plasma flow generated during multi-pulsed coaxial helicity injection in spherical torus is investigated by 3-D nonlinear MHD simulations. During the driven phase, the flux and current amplifications occur due to the merging and magnetic reconnection between the preexisting plasma in the confinement region and the ejected plasma from the gun region involving the n = 1 helical kink distortion of the central open flux column (COFC). Interestingly, the diamagnetic poloidal flow which tends toward the gun region is then observed due to the steep pressure gradients of the COFC generated by ohmic heating through an injection current winding around the inboard field lines, resulting in the formation of the strong poloidal flow shear at the interface between the COFC and the core region. This result is consistent with the flow shear observed in the HIST. During the decay phase, the configuration approaches the axisymmetric MHD equilibrium state without flow because of the dissipation of magnetic fluctuation energy to increase the closed flux surfaces, suggesting the generation of ordered magnetic field structure. The parallel current density λ concentrated in the COFC then diffuses to the core region so as to reduce the gradient in λ, relaxing in the direction of the Taylor state.

Investigating the decision-making processes that contribute to impaired driving.

DOT National Transportation Integrated Search

2015-08-01

Alcohol-impaired (AI) driving continues to cause a disproportionate number of fatalities within the college and : young adult populations, indicating optimal prevention programs for AI driving have yet to be developed. The : current study tested the ...

Alcohol & drug use among drivers : British Columbia roadside survey 2008

DOT National Transportation Integrated Search

2009-01-01

Following two decades of progress dealing with alcoholimpaired : driving, greater attention is now being : directed toward the issue of driving while impaired by : drugs. Currently, there is far less information related to drug-impaired : driving tha...

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 other driving training methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

Resonance fluorescence from an atom in a squeezed vacuum

NASA Astrophysics Data System (ADS)

Carmichael, H. J.; Lane, A. S.; Walls, D. F.

1987-06-01

The fluorescent spectrum for a two-level atom which is damped by a squeezed vacuum shows striking differences from the spectrum for ordinary resonance fluorescence. For strong coherent driving fields the Mollow triplet depends on the relative phase of the driving field and the squeezed vacuum field. The central peak may have either subnatural linewidth or supernatural linewidth depending on this phase. The mean atomic polarization also shows a phase sensitivity.

Derivation of dynamo current drive in a closed-current volume and stable current sustainment in the HIT-SI experiment

NASA Astrophysics Data System (ADS)

Hossack, A. C.; Sutherland, D. A.; Jarboe, T. R.

2017-02-01

A derivation is given showing that the current inside a closed-current volume can be sustained against resistive dissipation by appropriately phased magnetic perturbations. Imposed-dynamo current drive theory is used to predict the toroidal current evolution in the helicity injected torus with steady inductive helicity injection (HIT-SI) experiment as a function of magnetic fluctuations at the edge. Analysis of magnetic fields from a HIT-SI discharge shows that the injector-imposed fluctuations are sufficient to sustain the measured toroidal current without instabilities whereas the small, plasma-generated magnetic fluctuations are not sufficiently large to sustain the current.

Incorporating diverse data and realistic complexity into demographic estimation procedures for sea otters

USGS Publications Warehouse

Tinker, M. Timothy; Doak, Daniel F.; Estes, James A.; Hatfield, Brian B.; Staedler, Michelle M.; Gross, Arthur

2006-01-01

Reliable information on historical and current population dynamics is central to understanding patterns of growth and decline in animal populations. We developed a maximum likelihood-based analysis to estimate spatial and temporal trends in age/sex-specific survival rates for the threatened southern sea otter (Enhydra lutris nereis), using annual population censuses and the age structure of salvaged carcass collections. We evaluated a wide range of possible spatial and temporal effects and used model averaging to incorporate model uncertainty into the resulting estimates of key vital rates and their variances. We compared these results to current demographic parameters estimated in a telemetry-based study conducted between 2001 and 2004. These results show that survival has decreased substantially from the early 1990s to the present and is generally lowest in the north-central portion of the population's range. The greatest temporal decrease in survival was for adult females, and variation in the survival of this age/sex class is primarily responsible for regulating population growth and driving population trends. Our results can be used to focus future research on southern sea otters by highlighting the life history stages and mortality factors most relevant to conservation. More broadly, we have illustrated how the powerful and relatively straightforward tools of information-theoretic-based model fitting can be used to sort through and parameterize quite complex demographic modeling frameworks. ?? 2006 by the Ecological Society of America.

Novel CRISPR/Cas9 gene drive constructs reveal insights into mechanisms of resistance allele formation and drive efficiency in genetically diverse populations

PubMed Central

Liu, Chen

2017-01-01

A functioning gene drive system could fundamentally change our strategies for the control of vector-borne diseases by facilitating rapid dissemination of transgenes that prevent pathogen transmission or reduce vector capacity. CRISPR/Cas9 gene drive promises such a mechanism, which works by converting cells that are heterozygous for the drive construct into homozygotes, thereby enabling super-Mendelian inheritance. Although CRISPR gene drive activity has already been demonstrated, a key obstacle for current systems is their propensity to generate resistance alleles, which cannot be converted to drive alleles. In this study, we developed two CRISPR gene drive constructs based on the nanos and vasa promoters that allowed us to illuminate the different mechanisms by which resistance alleles are formed in the model organism Drosophila melanogaster. We observed resistance allele formation at high rates both prior to fertilization in the germline and post-fertilization in the embryo due to maternally deposited Cas9. Assessment of drive activity in genetically diverse backgrounds further revealed substantial differences in conversion efficiency and resistance rates. Our results demonstrate that the evolution of resistance will likely impose a severe limitation to the effectiveness of current CRISPR gene drive approaches, especially when applied to diverse natural populations. PMID:28727785

Remotely controllable mixing system

NASA Technical Reports Server (NTRS)

Belew, R. R. (Inventor)

1986-01-01

This invention relates to a remotely controllable mixing system in which a plurality of mixing assemblies are arranged in an annular configuration, and wherein each assembly employs a central chamber and two outer, upper and lower chambers. Valves are positioned between chambers, and these valves for a given mixing assembly are operated by upper and lower control rotors, which in turn are driven by upper and lower drive rotors. Additionally, a hoop is compressed around upper control rotors and a hoop is compressed around lower control rotors to thus insure constant frictional engagement between all control rotors and drive rotors. The drive rollers are driven by a motor.

Radiation Oncology in the Developing Economies of Central and Eastern Europe.

PubMed

Esiashvili, Natia

2017-04-01

Eastern Europe is represented by 22 countries of significant variability in population density and degree of economic development. They have been affected by past geopolitical isolation due to their association with the "Soviet Block." Currently, all Eastern European countries except Slovenia are low- or middle-income level and 10 of them are part of European Union. Health care systems in Central and Eastern Europe have been influenced by the legacy of centralized soviet-era governance; however, most countries, particularly in European Union zone, have gone through health care reforms directed toward modernizing infrastructure and staffing. The level of health financing available through health insurance has increased in the region, although still lags behind the Western European levels. After adjusting for differing population age structures, overall incidence rates in both sexes are lower in Eastern and Central Europe compared with the Northern and Western European countries; however, mortality remains higher. There is an ongoing shortage of oncology services in Eastern Europe, including radiotherapy equipment and personnel. Eastern European radiotherapy field is highly diverse with large differences among countries regarding staffing structure, training, accreditation, and defined roles and responsibilities. The rapid diffusion of technological innovations has been identified as one of the most important factors driving the escalating health care expenses, and the need for better cost-effective solutions applicable to the local health care systems and levels of economic development. Copyright © 2017 Elsevier Inc. All rights reserved.

Models of anxiety: responses of mice to novelty and open spaces in a 3D maze.

PubMed

Ennaceur, A; Michalikova, S; van Rensburg, R; Chazot, P L

2006-11-01

The present report describes the emotional responses of different strains of mice to exposure to a novel open space model of anxiety using a 3D spatial navigation task. The 3D maze is modification of the radial maze with flexible arms that can be raised above or lowered below the horizontal level of a central platform. To access the arms animals need to cross a bridge linking the arms to the central platform. In this model, mice are exposed to novelty in an unfamiliar open space setting with no safe alternative. Fear from novelty is compounded with the need to explore. The drive to escape and the drive to approach are intermingled making this open space model radically different from the current models of anxiety which provide animals with the choice between safe and anxiogenic spaces. In a series of experiments, we examined the behaviour of different groups of mice from C57, C3H, CD1 and Balb/c strains. In the first experiment, different groups of C57 mice were tested in one of the three arms configurations. In the second experiment, C57 mice were compared to C3H mice. In the third experiment, C57 mice were compared to CD1 and Balb/c mice in the raised arm configuration over three successive sessions. In the fourth experiment, we examined the behaviour of C57 mice in the lowered arm configuration with an open and an enclosed central. In the final experiment, we examined the difference between C57 and C3H mice of both genders. Using several spatio-temporal parameters of the transition responses between central platform, bridges and arms, we have been able to show consistent results demonstrating significant differences between C57 and C3H mice, and between Balb/c and both C57 and CD1 mice. C3H appear more anxious than C57 mice, and Balb/c mice seem more anxious than C57 and CD1 mice. We also observed significant differences between sexes in C3H mice but not in C57 mice. C3H male mice appear more anxious than C3H female mice and than both C57 male and female mice. In the lowered arm configuration with an enclosed central platform, C57 mice took longer time to make a first entry to an arm, made more visits to bridges before first entry to an arm and required longer time between re-entries to arms, spent longer time on the central platform and shorter time on arms compared to mice in the other arm configurations. They also made frequent entries to the centre and bridges compared to mice in the lowered arm with an open central platform. These results demonstrate not only the sensitivity of the parameters of the test but also the consistencies and concordances of the results which make this 3D maze a valuable new tool in the study of the underlying neural mechanisms of anxiety responses in addition to learning and memory, and in assessing the effects of potential anxiolytic drugs. In this report we examine methodological issues related to the design of animal behavioural paradigms and question the value and the construct validity of the current models of human anxiety.

Alternating-Current Motor Drive for Electric Vehicles

NASA Technical Reports Server (NTRS)

Krauthamer, S.; Rippel, W. E.

1982-01-01

New electric drive controls speed of a polyphase as motor by varying frequency of inverter output. Closed-loop current-sensing circuit automatically adjusts frequency of voltage-controlled oscillator that controls inverter frequency, to limit starting and accelerating surges. Efficient inverter and ac motor would give electric vehicles extra miles per battery charge.

Underwater noise reduction of marine pile driving using a double pile.

DOT National Transportation Integrated Search

2015-12-01

Impact pile driving of steel piles in marine environments produces extremely high sound levels in the water. : It has been shown that current pile driving noise attenuation techniques, such as bubble curtains and : cofferdams, provide limited noise r...

Choice and Control Within Family Relationships: The Lived Experience of Adults With Intellectual Disability.

PubMed

Curryer, Bernadette; Stancliffe, Roger J; Dew, Angela; Wiese, Michele Y

2018-06-01

Increased choice and control is a driving force of current disability policy in Australia for people with disability and their families. Yet little is known of how adults with intellectual disability (ID) actually experience choice and control within their family relationships. We used interpretative phenomenological analysis of individual, semistructured interviews conducted with 8 Australian adults with ID to understand the meaning given to their experience of family support received around choice and decision making. Three themes were identified: (1) centrality of family, (2) experience of self-determination, and (3) limitations to choice and control. The participants identified trusted family members from whom guidance around choice and decision making was both sought and received, often involving mutual decision making and limitations to control.

Pumping up the volume - vacuole biogenesis in Arabidopsis thaliana.

PubMed

Krüger, Falco; Schumacher, Karin

2017-07-08

Plant architecture follows the need to collect CO 2, solar energy, water and mineral nutrients via large surface areas. It is by the presence of a central vacuole that fills much of the cell volume that plants manage to grow at low metabolic cost. In addition vacuoles buffer the fluctuating supply of essential nutrients and help to detoxify the cytosol when plants are challenged by harmful molecules. Despite their large size and multiple important functions, our knowledge of vacuole biogenesis and the machinery underlying their amazing dynamics is still fragmentary. In this review, we try to reconcile past and present models for vacuole biogenesis with the current knowledge of multiple parallel vacuolar trafficking pathways and the molecular machineries driving membrane fusion and organelle shape. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stabilizing effect of helical current drive on tearing modes

NASA Astrophysics Data System (ADS)

Yuan, Y.; Lu, X. Q.; Dong, J. Q.; Gong, X. Y.; Zhang, R. B.

2018-01-01

The effect of helical driven current on the m = 2/n = 1 tearing mode is studied numerically in a cylindrical geometry using the method of reduced magneto-hydro-dynamic simulation. The results show that the local persistent helical current drive from the beginning time can be applied to control the tearing modes, and will cause a rebound effect called flip instability when the driven current reaches a certain value. The current intensity threshold value for the occurrence of flip instability is about 0.00087I0. The method of controlling the development of tearing mode with comparative economy is given. If the local helical driven current is discontinuous, the magnetic island can be controlled within a certain range, and then, the tearing modes stop growing; thus, the flip instability can be avoided. We also find that the flip instability will become impatient with delay injection of the driven current because the high order harmonics have been developed in the original O-point. The tearing mode instability can be controlled by using the electron cyclotron current drive to reduce the gradient of the current intensity on the rational surfaces.

Impact of gender, organized athletics, and video gaming on driving skills in novice drivers

PubMed Central

Miller, Gregory A.

2018-01-01

Given that novice drivers tend to be young, and teenagers and young adult drivers are involved in the greatest number of accidents, it is important that we understand what factors impact the driving skills of this population of drivers. The primary aim of the present study was to understand the impact of gender, organized athletics, and video gaming on driving skills of novice drivers under real-world driving conditions. Novice driving students having less than five hours driving experience previous to a normal driving lesson were evaluated on their self-confidence (self-reported) prior to the lesson and driving skill evaluated by their instructor during the course of the lesson. Information was collected about gender, age, whether or not the students were involved in organized athletics, and the extent of their video game playing. There was no impact of gender or extent of video game playing on driving skills. Females were significantly less self-confident with driving than males, but this did not translate to gender differences in driving skills. Being involved in organized athletics—either currently or in the past—significantly enhanced driving skills in both females and males. Finally, novice drivers’ age was negatively correlated with driving skills. That is, younger novice drivers (especially males) had better driving skills than older novice drivers. This is counter to popular belief that young drivers lack technical driving skills because they have less experience behind the wheel. Based on the results of the current study, we hypothesize that the relatively high accident rate of younger drivers (especially male drivers) is most likely due to inattention to safety considerations rather than lack of technical driving ability. PMID:29364957

Impact of gender, organized athletics, and video gaming on driving skills in novice drivers.

PubMed

Wayne, Nancy L; Miller, Gregory A

2018-01-01

Given that novice drivers tend to be young, and teenagers and young adult drivers are involved in the greatest number of accidents, it is important that we understand what factors impact the driving skills of this population of drivers. The primary aim of the present study was to understand the impact of gender, organized athletics, and video gaming on driving skills of novice drivers under real-world driving conditions. Novice driving students having less than five hours driving experience previous to a normal driving lesson were evaluated on their self-confidence (self-reported) prior to the lesson and driving skill evaluated by their instructor during the course of the lesson. Information was collected about gender, age, whether or not the students were involved in organized athletics, and the extent of their video game playing. There was no impact of gender or extent of video game playing on driving skills. Females were significantly less self-confident with driving than males, but this did not translate to gender differences in driving skills. Being involved in organized athletics-either currently or in the past-significantly enhanced driving skills in both females and males. Finally, novice drivers' age was negatively correlated with driving skills. That is, younger novice drivers (especially males) had better driving skills than older novice drivers. This is counter to popular belief that young drivers lack technical driving skills because they have less experience behind the wheel. Based on the results of the current study, we hypothesize that the relatively high accident rate of younger drivers (especially male drivers) is most likely due to inattention to safety considerations rather than lack of technical driving ability.

Vision screening of older drivers for preventing road traffic injuries and fatalities.

PubMed

Desapriya, Ediriweera; Harjee, Rahana; Brubacher, Jeffrey; Chan, Herbert; Hewapathirane, D Sesath; Subzwari, Sayed; Pike, Ian

2014-02-21

Demographic data in North America, Europe, Asia, Australia and New Zealand suggest a rapid growth in the number of persons over the age of 65 years as the baby boomer generation passes retirement age. As older adults make up an increasing proportion of the population, they are an important consideration when designing future evidence-based traffic safety policies, particularly those that lead to restrictions or cessation of driving. Research has shown that cessation of driving among older drivers can lead to negative emotional consequences such as depression and loss of independence. Older adults who continue to drive tend to do so less frequently than other demographic groups and are more likely to be involved in a road traffic crash, possibly due to what is termed the "low mileage bias". Available research suggests that older driver crash risk estimates based on traditional exposure measures are prone to bias. When annual driving distances are taken in to consideration, older drivers with low driving distances have an increased crash risk, while those with average or high driving distances tend to be safer drivers when compared to other age groups. In addition, older drivers with lower distance driving tend to drive in urban areas which, due to more complex and demanding traffic patterns, tend to be more accident-prone. Failure to control for actual annual driving distances and driving locations among older drivers is referred to as "low mileage bias" in older driver mobility research. It is also important to note that older drivers are more vulnerable to serious injury and death in the event of a traffic crash due to changes in physiology associated with normal ageing. Vision, cognition, and motor functions or skills (e.g., strength, co-ordination, and flexibility) are three key domains required for safe driving. To drive safely, an individual needs to be able to see road signs, road side objects, traffic lights, roadway markings, other vulnerable road users, and other vehicles on the road, among many other cues-all while moving, and under varying light and weather conditions. It is equally important that drivers must have appropriate peripheral vision to monitor objects and movement to identify possible threats in the driving environment. It is, therefore, not surprising that there is agreement among researchers that vision plays a significant role in driving performance. Several age-related processes/conditions impair vision, thus it follows that vision testing of older drivers is an important road safety issue. The components of visual function essential for driving are acuity, static acuity, dynamic acuity, visual fields, visual attention, depth perception, and contrast sensitivity. These indices are typically not fully assessed by licensing agencies. Also, current vision screening regulations and cut-off values required to pass a licensing test vary from country to country. Although there is a clear need to develop evidence-based and validated tools for vision screening for driving, the effectiveness of existing vision screening tools remains unclear. This represents an important and highly warranted initiative to increase road safety worldwide. To assess the effects of vision screening interventions for older drivers to prevent road traffic injuries and fatalities. For the update of this review we searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP) and ISI Web of Science: (CPCI-S & SSCI). The searches were conducted up to 26 September 2013. Randomised controlled trials (RCTs) and controlled before and after studies comparing vision screening to non-screening of drivers aged 55 years and older, and which assessed the effect on road traffic crashes, injuries, fatalities and any involvement in traffic law violations. Two review authors independently screened the reference lists for eligible articles and independently assessed the articles for inclusion against the criteria. If suitable trials had been available, two review authors would have independently extracted data using a standardised extraction form. No studies were found that met the inclusion criteria for this review. Most countries require a vision screening test for the renewal of an individual's driver's licence. There is, however, lack of methodologically sound studies to assess the effects of vision screening tests on subsequent motor vehicle crash reduction. There is a need to develop valid and reliable tools of vision screening that can predict driving performance.

SMART: The Future of Spaceflight Avionics

NASA Technical Reports Server (NTRS)

Alhorn, Dean C.; Howard, David E.

2010-01-01

A novel avionics approach is necessary to meet the future needs of low cost space and lunar missions that require low mass and low power electronics. The current state of the art for avionics systems are centralized electronic units that perform the required spacecraft functions. These electronic units are usually custom-designed for each application and the approach compels avionics designers to have in-depth system knowledge before design can commence. The overall design, development, test and evaluation (DDT&E) cycle for this conventional approach requires long delivery times for space flight electronics and is very expensive. The Small Multi-purpose Advanced Reconfigurable Technology (SMART) concept is currently being developed to overcome the limitations of traditional avionics design. The SMART concept is based upon two multi-functional modules that can be reconfigured to drive and sense a variety of mechanical and electrical components. The SMART units are key to a distributed avionics architecture whereby the modules are located close to or right at the desired application point. The drive module, SMART-D, receives commands from the main computer and controls the spacecraft mechanisms and devices with localized feedback. The sensor module, SMART-S, is used to sense the environmental sensors and offload local limit checking from the main computer. There are numerous benefits that are realized by implementing the SMART system. Localized sensor signal conditioning electronics reduces signal loss and overall wiring mass. Localized drive electronics increase control bandwidth and minimize time lags for critical functions. These benefits in-turn reduce the main processor overhead functions. Since SMART units are standard flight qualified units, DDT&E is reduced and system design can commence much earlier in the design cycle. Increased production scale lowers individual piece part cost and using standard modules also reduces non-recurring costs. The benefit list continues, but the overall message is already evident: the SMART concept is an evolution in spacecraft avionics. SMART devices have the potential to change the design paradigm for future satellites, spacecraft and even commercial applications.

Impacts of Thermal Atomic Layer-Deposited AlN Passivation Layer on GaN-on-Si High Electron Mobility Transistors.

PubMed

Zhao, Sheng-Xun; Liu, Xiao-Yong; Zhang, Lin-Qing; Huang, Hong-Fan; Shi, Jin-Shan; Wang, Peng-Fei

2016-12-01

Thermal atomic layer deposition (ALD)-grown AlN passivation layer is applied on AlGaN/GaN-on-Si HEMT, and the impacts on drive current and leakage current are investigated. The thermal ALD-grown 30-nm amorphous AlN results in a suppressed off-state leakage; however, its drive current is unchanged. It was also observed by nano-beam diffraction method that thermal ALD-amorphous AlN layer barely enhanced the polarization. On the other hand, the plasma-enhanced chemical vapor deposition (PECVD)-deposited SiN layer enhanced the polarization and resulted in an improved drive current. The capacitance-voltage (C-V) measurement also indicates that thermal ALD passivation results in a better interface quality compared with the SiN passivation.

Stable Spheromaks with Profile Control

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

Fowler, T K; Jayakumar, R

A spheromak equilibrium with zero edge current is shown to be stable to both ideal MHD and tearing modes that normally produce Taylor relaxation in gun-injected spheromaks. This stable equilibrium differs from the stable Taylor state in that the current density j falls to zero at the wall. Estimates indicate that this current profile could be sustained by non-inductive current drive at acceptable power levels. Stability is determined using the NIMROD code for linear stability analysis. Non-linear NIMROD calculations with non-inductive current drive could point the way to improved fusion reactors.

Drivers' and non-drivers' performance in a change detection task with static driving scenes: is there a benefit of experience?

PubMed

Zhao, Nan; Chen, Wenfeng; Xuan, Yuming; Mehler, Bruce; Reimer, Bryan; Fu, Xiaolan

2014-01-01

The 'looked-but-failed-to-see' phenomenon is crucial to driving safety. Previous research utilising change detection tasks related to driving has reported inconsistent effects of driver experience on the ability to detect changes in static driving scenes. Reviewing these conflicting results, we suggest that drivers' increased ability to detect changes will only appear when the task requires a pattern of visual attention distribution typical of actual driving. By adding a distant fixation point on the road image, we developed a modified change blindness paradigm and measured detection performance of drivers and non-drivers. Drivers performed better than non-drivers only in scenes with a fixation point. Furthermore, experience effect interacted with the location of the change and the relevance of the change to driving. These results suggest that learning associated with driving experience reflects increased skill in the efficient distribution of visual attention across both the central focus area and peripheral objects. This article provides an explanation for the previously conflicting reports of driving experience effects in change detection tasks. We observed a measurable benefit of experience in static driving scenes, using a modified change blindness paradigm. These results have translational opportunities for picture-based training and testing tools to improve driver skill.

Sleep driving: sleepwalking variant or misuse of z-drugs?

PubMed

Pressman, Mark R

2011-10-01

Sleep driving is most often classified as a variant of sleepwalking, but should be distinguished from impaired driving due to misuse or abuse of sedative/hypnotic drugs. Z-drugs; zolpidem and zopiclone in particular, have been associated with the majority of reported cases of impaired driving. Numerous studies have found z-drugs in driving under influence (DUI) related police stops, arrests and accidents. Impaired drivers are reported to have 1) blood levels of z-drugs that exceed therapeutic ranges 2) failed to take the medication at the correct time or remain in bed for sufficient time and/or 3) combined z-drugs with other central nervous system (CNS) depressants and/or alcohol. Consistent with CNS depression, z-drug-impaired drivers may demonstrate cognitive function at low levels with drivers still able to understand and respond to questions while sleepwalkers are completely unable to understand or interact with police. Z-drug-impaired drivers are often severely physically impaired, unable to stand up or maintain balance while sleepwalkers are able to stand and walk unaided. Sleep driving and impaired driving due to z-drugs may overlap. Sleep driving and drug-impaired driving are statistically rare events, but due to the billions of doses prescribed each year may still result in numerous DUI related arrests and accidents. Copyright © 2010 Elsevier Ltd. All rights reserved.

Reading the Freudian theory of sexual drives from a functional neuroimaging perspective

PubMed Central

Stoléru, Serge

2014-01-01

One of the essential tasks of neuropsychoanalysis is to investigate the neural correlates of sexual drives. Here, we consider the four defining characteristics of sexual drives as delineated by Freud: their pressure, aim, object, and source. We systematically examine the relations between these characteristics and the four-component neurophenomenological model that we have proposed based on functional neuroimaging studies, which comprises a cognitive, a motivational, an emotional and an autonomic/neuroendocrine component. Functional neuroimaging studies of sexual arousal (SA) have thrown a new light on the four fundamental characteristics of sexual drives by identifying their potential neural correlates. While these studies are essentially consistent with the Freudian model of drives, the main difference emerging between the functional neuroimaging perspective on sexual drives and the Freudian theory relates to the source of drives. From a functional neuroimaging perspective, sources of sexual drives, conceived by psychoanalysis as processes of excitation occurring in a peripheral organ, do not seem, at least in adult subjects, to be an essential part of the determinants of SA. It is rather the central processing of visual or genital stimuli that gives to these stimuli their sexually arousing and sexually pleasurable character. Finally, based on functional neuroimaging results, some possible improvements to the psychoanalytic theory of sexual drives are suggested. PMID:24672467

Evaluation of semiconductor devices for Electric and Hybrid Vehicle (EHV) ac-drive applications, volume 1

NASA Technical Reports Server (NTRS)

Lee, F. C.; Chen, D. Y.; Jovanovic, M.; Hopkins, D. C.

1985-01-01

The results of evaluation of power semiconductor devices for electric hybrid vehicle ac drive applications are summarized. Three types of power devices are evaluated in the effort: high power bipolar or Darlington transistors, power MOSFETs, and asymmetric silicon control rectifiers (ASCR). The Bipolar transistors, including discrete device and Darlington devices, range from 100 A to 400 A and from 400 V to 900 V. These devices are currently used as key switching elements inverters for ac motor drive applications. Power MOSFETs, on the other hand, are much smaller in current rating. For the 400 V device, the current rating is limited to 25 A. For the main drive of an electric vehicle, device paralleling is normally needed to achieve practical power level. For other electric vehicle (EV) related applications such as battery charger circuit, however, MOSFET is advantageous to other devices because of drive circuit simplicity and high frequency capability. Asymmetrical SCR is basically a SCR device and needs commutation circuit for turn off. However, the device poses several advantages, i.e., low conduction drop and low cost.

Amplitude-frequency effect of Y-cut langanite and langatate.

PubMed

Kim, Yoonkee

2003-12-01

Amplitude-frequency effect of a Y-cut langanite (LGN) resonator and a Y-cut langatate (LGT) resonator were measured. The frequency shifts from the baseline frequency with 1 mA were measured as a function of drive currents up to 28 mA. High-drive current shifted the frequency, but it also heated the crystal locally, causing temperature-related frequency changes. The local heat transfer and its influence on the frequency were analyzed. The amplitude-frequency shift was effectively measured, and was not affected by the temperature-related frequency changes. The 3rd, 5th, and 7th overtones (OT's) were found to behave as soft springs, i.e., resonant frequency decreases as drive current increases. The drive sensitivity coefficients of the 3rd and 5th OT's are in the vicinity of -2 ppb/mA2 for both resonators. The 7th OT's are higher than the other OT's: -5 approximately -7 ppb/mA2. The lowest drive sensitivity is -1.2 ppb/mA2 on the 5th OT of the LGT.

Cognitive deficits are associated with poorer simulated driving in older adults with heart failure

PubMed Central

2013-01-01

Background Cognitive impairment is prevalent in older adults with heart failure (HF) and associated with reduced functional independence. HF patients appear at risk for reduced driving ability, as past work in other medical samples has shown cognitive dysfunction to be an important contributor to driving performance. The current study examined whether cognitive dysfunction was independently associated with reduced driving simulation performance in a sample of HF patients. Methods 18 persons with HF (67.72; SD = 8.56 year) completed echocardiogram and a brief neuropsychological test battery assessing global cognitive function, attention/executive function, memory and motor function. All participants then completed the Kent Multidimensional Assessment Driving Simulation (K-MADS), a driving simulator scenario with good psychometric properties. Results The sample exhibited an average Mini Mental State Examination (MMSE) score of 27.83 (SD = 2.09). Independent sample t-tests showed that HF patients performed worse than healthy adults on the driving simulation scenario. Finally, partial correlations showed worse attention/executive and motor function were independently associated with poorer driving simulation performance across several indices reflective of driving ability (i.e., centerline crossings, number of collisions, % of time over the speed limit, among others). Conclusion The current findings showed that reduced cognitive function was associated with poor simulated driving performance in older adults with HF. If replicated using behind-the-wheel testing, HF patients may be at elevated risk for unsafe driving and routine driving evaluations in this population may be warranted. PMID:24499466

Experiment to investigate current drive by fast Alfven waves in a small tokamak

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

Gahl, J.; Ishihara, O.; Wong, K.

1985-07-01

An experiment has been carried out to study current generation by Doppler shifted cyclotron resonance heating of minority ions with a unidirectional wave in the small tokamak at Texas Tech University. One of the objectives of the experiment is to understand in detail the wave-particle interactions through which fast (compressional) Alfven waves in the ion cyclotron range of frequencies drive currents in toroidal devices.

Base drive for paralleled inverter systems

NASA Technical Reports Server (NTRS)

Nagano, S. (Inventor)

1980-01-01

In a paralleled inverter system, a positive feedback current derived from the total current from all of the modules of the inverter system is applied to the base drive of each of the power transistors of all modules, thereby to provide all modules protection against open or short circuit faults occurring in any of the modules, and force equal current sharing among the modules during turn on of the power transistors.

AORSA full wave calculations of helicon waves in DIII-D and ITER

NASA Astrophysics Data System (ADS)

Lau, C.; Jaeger, E. F.; Bertelli, N.; Berry, L. A.; Green, D. L.; Murakami, M.; Park, J. M.; Pinsker, R. I.; Prater, R.

2018-06-01

Helicon waves have been recently proposed as an off-axis current drive actuator for DIII-D, FNSF, and DEMO tokamaks. Previous ray tracing modeling using GENRAY predicts strong single pass absorption and current drive in the mid-radius region on DIII-D in high beta tokamak discharges. The full wave code AORSA, which is valid to all order of Larmor radius and can resolve arbitrary ion cyclotron harmonics, has been used to validate the ray tracing technique. If the scrape-off-layer (SOL) is ignored in the modeling, AORSA agrees with GENRAY in both the amplitude and location of driven current for DIII-D and ITER cases. These models also show that helicon current drive can possibly be an efficient current drive actuator for ITER. Previous GENRAY analysis did not include the SOL. AORSA has also been used to extend the simulations to include the SOL and to estimate possible power losses of helicon waves in the SOL. AORSA calculations show that another mode can propagate in the SOL and lead to significant (~10%–20%) SOL losses at high SOL densities. Optimizing the SOL density profile can reduce these SOL losses to a few percent.

AORSA full wave calculations of helicon waves in DIII-D and ITER

DOE PAGES

Lau, Cornwall; Jaeger, E.F.; Bertelli, Nicola; ...

2018-04-11

Helicon waves have been recently proposed as an off-axis current drive actuator for DIII-D, FNSF, and DEMO tokamaks. Previous ray tracing modeling using GENRAY predicts strong single pass absorption and current drive in the mid-radius region on DIII-D in high beta tokamak discharges. The full wave code AORSA, which is valid to all order of Larmor radius and can resolve arbitrary ion cyclotron harmonics, has been used to validate the ray tracing technique. If the scrape-off-layer (SOL) is ignored in the modeling, AORSA agrees with GENRAY in both the amplitude and location of driven current for DIII-D and ITER cases.more » These models also show that helicon current drive can possibly be an efficient current drive actuator for ITER. Previous GENRAY analysis did not include the SOL. AORSA has also been used to extend the simulations to include the SOL and to estimate possible power losses of helicon waves in the SOL. AORSA calculations show that another mode can propagate in the SOL and lead to significant (~10-20%) SOL losses at high SOL densities. Optimizing the SOL density profile can reduce these SOL losses to a few percent.« less

AORSA full wave calculations of helicon waves in DIII-D and ITER

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

Lau, Cornwall; Jaeger, E.F.; Bertelli, Nicola

Helicon waves have been recently proposed as an off-axis current drive actuator for DIII-D, FNSF, and DEMO tokamaks. Previous ray tracing modeling using GENRAY predicts strong single pass absorption and current drive in the mid-radius region on DIII-D in high beta tokamak discharges. The full wave code AORSA, which is valid to all order of Larmor radius and can resolve arbitrary ion cyclotron harmonics, has been used to validate the ray tracing technique. If the scrape-off-layer (SOL) is ignored in the modeling, AORSA agrees with GENRAY in both the amplitude and location of driven current for DIII-D and ITER cases.more » These models also show that helicon current drive can possibly be an efficient current drive actuator for ITER. Previous GENRAY analysis did not include the SOL. AORSA has also been used to extend the simulations to include the SOL and to estimate possible power losses of helicon waves in the SOL. AORSA calculations show that another mode can propagate in the SOL and lead to significant (~10-20%) SOL losses at high SOL densities. Optimizing the SOL density profile can reduce these SOL losses to a few percent.« less

Pushing Particles with Waves: Current Drive and α-Channeling

DOE PAGES

FISCH, Nathaniel J.

2016-01-01

It can be advantageous to push particles with waves in tokamaks or other magnetic confinement devices, relying on wave-particle resonances to accomplish specific goals. Waves that damp on electrons or ions in toroidal fusion devises can drive currents if the waves are launched with toroidal asymmetry. Theses currents are important for tokamaks, since they operate in the absence of an electric field with curl, enabling steady state operation. The lower hybrid wave and the electron cyclotron wave have been demonstrated to drive significant currents. Non-inductive current also stabilizes deleterious tearing modes. Waves can also be used to broker the energymore » transfer between energetic alpha particles and the background plasma. Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled instead into useful energy, that heats fuel ions or drives current. Furthermore, an important question is the extent to which these effects can be accomplished together.« less

Two-dimensional Inductive Position Sensing System

NASA Technical Reports Server (NTRS)

Youngquist, Robert C. (Inventor); Starr, Stanley O. (Inventor)

2015-01-01

A two-dimensional inductive position sensing system uses four drive inductors arranged at the vertices of a parallelogram and a sensing inductor positioned within the parallelogram. The sensing inductor is movable within the parallelogram and relative to the drive inductors. A first oscillating current at a first frequency is supplied to a first pair of the drive inductors located at ends of a first diagonal of the parallelogram. A second oscillating current at a second frequency is supplied to a second pair of the drive inductors located at ends of a second diagonal of the parallelogram. As a result, the sensing inductor generates a first output voltage at the first frequency and a second output voltage at the second frequency. A processor determines a position of the sensing inductor relative to the drive inductors using the first output voltage and the second output voltage.

Current challenges in autonomous driving

NASA Astrophysics Data System (ADS)

Barabás, I.; Todoruţ, A.; Cordoş, N.; Molea, A.

2017-10-01

Nowadays the automotive industry makes a quantum shift to a future, where the driver will have smaller and smaller role in driving his or her vehicle ending up being totally excluded. In this paper, we have investigated the different levels of driving automatization, the prospective effects of these new technologies on the environment and traffic safety, the importance of regulations and their current state, the moral aspects of introducing these technologies and the possible scenarios of deploying the autonomous vehicles. We have found that the self-driving technologies are facing many challenges: a) They must make decisions faster in very diverse conditions which can include many moral dilemmas as well; b) They have an important potential in reducing the environmental pollution by optimizing their routes, driving styles by communicating with other vehicles, infrastructures and their environment; c) There is a considerable gap between the self-drive technology level and the current regulations; fortunately, this gap shows a continuously decreasing trend; d) In case of many types of imminent accidents management there are many concerns about the ability of making the right decision. Considering that this field has an extraordinary speed of development, our study is up to date at the submission deadline. Self-driving technologies become increasingly sophisticated and technically accessible, and in some cases, they can be deployed for commercial vehicles as well. According to the current stage of research and development, it is still unclear how the self-driving technologies will be able to handle extreme and unexpected events including their moral aspects. Since most of the traffic accidents are caused by human error or omission, it is expected that the emergence of the autonomous technologies will reduce these accidents in their number and gravity, but the very few currently available test results have not been able to scientifically underpin this issue yet. The increasing trend in automation of vehicles will radically change the composition of car industry players, as mechatronics will not only be a complementary part of the automobile industry but an indispensable part of it. There is a reasonable expectation that automated cars will perform the same or better in all respects than their conventional counterparts. However, it seems that the current regulations do not keep up with the development of technology and sometimes hinder the development and testing of autonomous technologies.

Driving with Mild Cognitive Impairment or Dementia: Cognitive Test Performance and Proxy Report of Daily Life Function in Older Women.

PubMed

Vaughan, Leslie; Hogan, Patricia E; Rapp, Stephen R; Dugan, Elizabeth; Marottoli, Richard A; Snively, Beverly M; Shumaker, Sally A; Sink, Kaycee M

2015-09-01

To investigate associations between proxy report of cognitive and functional limitations and cognitive performance and current or former driving status in older women with mild cognitive impairment (MCI) and all-cause dementia. Cross-sectional data analysis of retrospectively identified older women with adjudicated MCI and all-cause dementia in the Women's Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO). Academic medical center. Women (mean age ± standard deviation 83.7 ± 3.5) adjudicated with MCI or dementia during Year 1, 2, 3, or 4 of the WHIMS-ECHO follow-up period (N = 385). The telephone-administered cognitive battery included tests of attention, verbal learning and memory, verbal fluency, executive function, working memory, and global cognitive function plus self-report measures of depressive symptomatology. The Dementia Questionnaire (DQ) was administered to a knowledgeable proxy (family member, friend). Sixty percent of women with MCI and 40% of those with dementia are current drivers. Proxy reports of functional limitations in instrumental activities of daily living (IADLs) are associated with current driving status in women with MCI, whereas performance-based cognitive tests are not. In women with dementia, proxy reports of functional limitations in IADLs and performance-based cognitive tests are associated with current driving status, as expected. These findings have clinical implications for the importance of evaluating driving concurrently with other instrumental functional abilities in MCI and dementia. Additional work is needed to determine whether proxy report of cognitive and functional impairments should help guide referrals for driving assessment and rehabilitation or counseling for driving transition. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

An Exploratory Investigation: Are Driving Simulators Appropriate to Teach Pre-Driving Skills to Young Adults with Intellectual Disabilities?

ERIC Educational Resources Information Center

Brooks, Johnell O.; Mossey, Mary E.; Tyler, Peg; Collins, James C.

2014-01-01

Research examining driver training for young adults with intellectual disabilities has been limited since the 1970s. The current pilot and exploratory study investigated teaching pre-driving skills (i.e. lane keeping and speed maintenance) to young adults with intellectual disabilities using an interactive driving simulator to provide dynamic and…

VIEW OF THE WEST SIDE OF BUILDING 63, FACING EAST. ...

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

VIEW OF THE WEST SIDE OF BUILDING 63, FACING EAST. - Naval Computer & Telecommunications Area Station, Enlisted Men's Barracks, West corner of Central Street & Midway Drive, Wahiawa, Honolulu County, HI

Visually Impaired Drivers Who Use Bioptic Telescopes: Self-Assessed Driving Skills and Agreement With On-Road Driving Evaluation

PubMed Central

Owsley, Cynthia; McGwin, Gerald; Elgin, Jennifer; Wood, Joanne M.

2014-01-01

Purpose. To compare self-assessed driving habits and skills of licensed drivers with central visual loss who use bioptic telescopes to those of age-matched normally sighted drivers, and to examine the association between bioptic drivers' impressions of the quality of their driving and ratings by a “backseat” evaluator. Methods. Participants were licensed bioptic drivers (n = 23) and age-matched normally sighted drivers (n = 23). A questionnaire was administered addressing driving difficulty, space, quality, exposure, and, for bioptic drivers, whether the telescope was helpful in on-road situations. Visual acuity and contrast sensitivity were assessed. Information on ocular diagnosis, telescope characteristics, and bioptic driving experience was collected from the medical record or in interview. On-road driving performance in regular traffic conditions was rated independently by two evaluators. Results. Like normally sighted drivers, bioptic drivers reported no or little difficulty in many driving situations (e.g., left turns, rush hour), but reported more difficulty under poor visibility conditions and in unfamiliar areas (P < 0.05). Driving exposure was reduced in bioptic drivers (driving 250 miles per week on average vs. 410 miles per week for normally sighted drivers, P = 0.02), but driving space was similar to that of normally sighted drivers (P = 0.29). All but one bioptic driver used the telescope in at least one driving task, and 56% used the telescope in three or more tasks. Bioptic drivers' judgments about the quality of their driving were very similar to backseat evaluators' ratings. Conclusions. Bioptic drivers show insight into the overall quality of their driving and areas in which they experience driving difficulty. They report using the bioptic telescope while driving, contrary to previous claims that it is primarily used to pass the vision screening test at licensure. PMID:24370830

Visually impaired drivers who use bioptic telescopes: self-assessed driving skills and agreement with on-road driving evaluation.

PubMed

Owsley, Cynthia; McGwin, Gerald; Elgin, Jennifer; Wood, Joanne M

2014-01-15

To compare self-assessed driving habits and skills of licensed drivers with central visual loss who use bioptic telescopes to those of age-matched normally sighted drivers, and to examine the association between bioptic drivers' impressions of the quality of their driving and ratings by a "backseat" evaluator. Participants were licensed bioptic drivers (n = 23) and age-matched normally sighted drivers (n = 23). A questionnaire was administered addressing driving difficulty, space, quality, exposure, and, for bioptic drivers, whether the telescope was helpful in on-road situations. Visual acuity and contrast sensitivity were assessed. Information on ocular diagnosis, telescope characteristics, and bioptic driving experience was collected from the medical record or in interview. On-road driving performance in regular traffic conditions was rated independently by two evaluators. Like normally sighted drivers, bioptic drivers reported no or little difficulty in many driving situations (e.g., left turns, rush hour), but reported more difficulty under poor visibility conditions and in unfamiliar areas (P < 0.05). Driving exposure was reduced in bioptic drivers (driving 250 miles per week on average vs. 410 miles per week for normally sighted drivers, P = 0.02), but driving space was similar to that of normally sighted drivers (P = 0.29). All but one bioptic driver used the telescope in at least one driving task, and 56% used the telescope in three or more tasks. Bioptic drivers' judgments about the quality of their driving were very similar to backseat evaluators' ratings. Bioptic drivers show insight into the overall quality of their driving and areas in which they experience driving difficulty. They report using the bioptic telescope while driving, contrary to previous claims that it is primarily used to pass the vision screening test at licensure.

Continental Asymmetry in Climate-Induced Tropical Drought: Driving Mechanisms and Ecosystem Response

NASA Astrophysics Data System (ADS)

Randerson, J. T.; Swann, A. L. S.; Koven, C. D.; Hoffman, F. M.; Chen, Y.

2015-12-01

Current theory does not adequately explain diverging patterns of future drought stress predicted by Earth system models (ESMs) across tropical South America, Africa, and equatorial Asia. By 2100 for the Representative Concentration Pathway 8.5 (RCP8.5) many models predict significant decreases in precipitation across northeastern South America and Central America. In contrast, most models predict increasing levels of precipitation across tropical Africa and equatorial Asia. Using the Community Earth System Model v1.0 with RCP8.5 simulations to 2300, we found that this longitudinal precipitation asymmetry intensified over time and as a consequence, terrestrial carbon losses from the neotropics were considerably higher than those in Africa and Asia. Carbon losses in some areas of the Amazon in a fully coupled simulation exceeded 15 kg C per m2 by 2300, relative to estimates from a biogeochemically-forced simulation in which atmospheric carbon dioxide and other greenhouse gases did not influence the atmospheric radiation budget. Variations in the amount of neotropical drying varied considerably among CMIP5 ESMs, and we used several types of analysis to identify driving mechanisms and to reduce uncertainties associated with these projections. CMIP5 models in general underestimated North Atlantic sea surface temperatures and the strength of the Atlantic meridional overturning circulation (AMOC). Models that more accurately simulated North Atlantic SSTs during the historical era had smaller mean precipitation biases and predicted greater neotropical forest drying than other models. This suggests that future drought stress in northern South America and Central America may be larger than estimates derived from the multi-model mean. Analysis of idealized radiatively coupled, biogeochemically coupled and fully coupled CMIP5 model simulations indicated that the direct effects of atmospheric carbon dioxide on plant physiology also was an important factor driving asymmetric precipitation change across the tropics, and had a similar pattern as changes induced solely from greenhouse gas effects on atmospheric radiation. We conclude by discussing the implications of the continental drought asymmetry for the vulnerability of tropical forests to fire, agriculture, and tree mortality.

The Technique of Changing the Drive Method of Micro Step Drive and Sensorless Drive for Hybrid Stepping Motor

NASA Astrophysics Data System (ADS)

Yoneda, Makoto; Dohmeki, Hideo

The position control system with the advantage large torque, low vibration, and high resolution can be obtained by the constant current micro step drive applied to hybrid stepping motor. However loss is large, in order not to be concerned with load torque but to control current uniformly. As the one technique of a position control system in which high efficiency is realizable, the same sensorless control as a permanent magnet motor is effective. But, it was the purpose that the control method proposed until now controls speed. Then, this paper proposed changing the drive method of micro step drive and sensorless drive. The change of the drive method was verified from the simulation and the experiment. On no load, it was checked not producing change of a large speed at the time of a change by making electrical angle and carrying out zero reset of the integrator. On load, it was checked that a large speed change arose. The proposed system could change drive method by setting up the initial value of an integrator using the estimated result, without producing speed change. With this technique, the low loss position control system, which employed the advantage of the hybrid stepping motor, has been built.

The need for drugged driving per se laws: a commentary.

PubMed

DuPont, Robert L; Voas, Robert B; Walsh, J Michael; Shea, Corinne; Talpins, Stephen K; Neil, Mark M

2012-01-01

Triggered by the new federal commitment announced by the Office of National Drug Control Policy (ONCDP) to encourage states to enact drugged driving per se laws, this article reviews the reasons to establish such laws and the issues that may arise when trying to enforce them. A review of the state of drunk driving per se laws and their implications for drugged driving is presented, with a review of impaired driving enforcement procedures and drug testing technology. Currently, enforcement of drugged driving laws is an adjunct to the enforcement of laws regarding alcohol impairment. Drivers are apprehended when showing signs of alcohol intoxication and only in the relatively few cases where the blood alcohol concentration of the arrested driver does not account for the observed behavior is the possibility of drug impairment pursued. In most states, the term impaired driving covers both alcohol and drug impairment; thus, driver conviction records may not distinguish between the two different sources of impairment. As a result, enforcement statistics do not reflect the prevalence of drugged driving. Based on the analysis presented, this article recommends a number of steps that can be taken to evaluate current drugged driving enforcement procedures and to move toward the enactment of drug per se laws.

Sleep apnea and cardiovascular risk.

PubMed

Floras, John S

2014-01-01

Sleep apnea is evident in approximately 10% of adults in the general population, but in certain cardiovascular diseases, and in particular those characterized by sodium and water retention, its prevalence can exceed 50%. Although sleep apnea is not as yet integrated into formal cardiovascular risk assessment algorithms, there is increasing awareness of its importance in the causation or promotion of hypertension, coronary artery disease, heart failure, atrial arrhythmias, and stroke, and thus, not surprisingly, as a predictor of premature cardiovascular death. Sleep apnea manifests as two principal phenotypes, both characterized by respiratory instability: obstructive (OSA), which arises when sleep-related withdrawal of respiratory drive to the upper airway dilator muscles is superimposed upon a narrow and highly compliant airway predisposed to collapse, and central (CSA), which occurs when the partial pressure of arterial carbon dioxide falls below the apnea threshold, resulting in withdrawal of central drive to respiratory muscles. The present objectives are to: (1) review the epidemiology and patho-physiology of OSA and CSA, with particular emphasis on the role of renal sodium retention in initiating and promoting these processes, and on population studies that reveal the long-term consequences of untreated OSA and CSA; (2) illustrate mechanical, autonomic, chemical, and inflammatory mechanisms by which OSA and CSA can increase cardiovascular risk and event rates by initiating or promoting hypertension, atherosclerosis, coronary artery disease, heart failure, arrhythmias, and stroke; (3) highlight insights from randomized trials in which treating sleep apnea was the specific target of therapy; (4) emphasize the present lack of evidence that treating sleep apnea reduces cardiovascular risk and the current clinical equipoise concerning treatment of asymptomatic patients with sleep apnea; and (5) consider clinical implications and future directions of clinical research and practice. Copyright © 2013. Published by Elsevier Ltd.

Medications and impaired driving.

PubMed

Hetland, Amanda; Carr, David B

2014-04-01

To describe the association of specific medication classes with driving outcomes and provide clinical recommendations. The MEDLINE and EMBASE databases were searched for articles published from January 1973 to June 2013 on classes of medications associated with driving impairment. The search included outcome terms such as automobile driving, motor vehicle crash, driving simulator, and road tests. Only English-language articles that contained findings from observational or interventional designs with ≥ 10 participants were included in this review. Cross-sectional studies, case series, and case reports were excluded. Driving is an important task and activity for the majority of adults. Some commonly prescribed medications have been associated with driving impairment measured by road performance, driving simulation, and/or motor vehicle crashes. This review of 30 studies identified findings with barbiturates, benzodiazepines, hypnotics, antidepressants, opioid and nonsteroidal analgesics, anticonvulsants, antipsychotics, antiparkinsonian agents, skeletal muscle relaxants, antihistamines, anticholinergic medications, and hypoglycemic agents. Additional studies of medication impact on sedation, sleep latency, and psychomotor function, as well as the role of alcohol, are also discussed. Psychotropic agents and those with central nervous system side effects were associated with measures of impaired driving performance. It is difficult to determine if such associations are actually a result of medication use or the medical diagnosis itself. Regardless, clinicians should be aware of the increased risk of impaired driving with specific classes of medications, educate their patients, and/or consider safer alternatives.

Public Data Set: Initiation and Sustainment of Tokamak Plasmas with Local Helicity Injection as the Majority Current Drive

DOE Data Explorer

Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Pachicano, Jessica L. [University of Wisconsin-Madison] (ORCID:0000000207255693); Pierren, Christopher [University of Wisconsin-Madison] (ORCID:0000000228289825); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Rhodes, Alexander T. [University of Wisconsin-Madison] (ORCID:0000000280735714); Richner, Nathan J. [University of Wisconsin-Madison] (ORCID:0000000155443915); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586); Schaefer, Carolyn E. [University of Wisconsin-Madison] (ORCID:0000000248848727); Weberski, Justin D. [University of Wisconsin-Madison] (ORCID:0000000256267914)

2018-05-22

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in J.M. Perry et al., 'Initiation and Sustainment of Tokamak Plasmas with Local Helicity Injection as the Majority Current Drive,' accepted for publication in Nuclear Fusion.

Analysis of electric drive technologies for transit applications : battery-electric, hybrid-electric, and fuel cells.

DOT National Transportation Integrated Search

2005-08-01

This report provides an overview of the current status of electric drive technologies for transit applications, covering battery-electric, hybrid-electric : and fuel cell buses. Based on input from the transit and electric drive industries, the analy...

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

NASA Astrophysics Data System (ADS)

Parke, E.; Anderson, J. K.; Brower, D. L.; Den Hartog, D. J.; Ding, W. X.; Johnson, C. A.; Lin, L.

2016-05-01

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm with neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q0 by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].

Current drive by helicon waves

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

Paul, Manash Kumar; Bora, Dhiraj; ITER Organization, Cadarache Centre-building 519, 131008 St. Paul-Lez-Durance

2009-01-01

Helicity in the dynamo field components of helicon wave is examined during the novel study of wave induced helicity current drive. Strong poloidal asymmetry in the wave magnetic field components is observed during helicon discharges formed in a toroidal vacuum chamber of small aspect ratio. High frequency regime is chosen to increase the phase velocity of helicon waves which in turn minimizes the resonant wave-particle interactions and enhances the contribution of the nonresonant current drive mechanisms. Owing to the strong poloidal asymmetry in the wave magnetic field structures, plasma current is driven mostly by the dynamo-electric-field, which arise due tomore » the wave helicity injection by helicon waves. Small, yet finite contribution from the suppressed wave-particle resonance cannot be ruled out in the operational regime examined. A brief discussion on the parametric dependence of plasma current along with numerical estimations of nonresonant components is presented. A close agreement between the numerical estimation and measured plasma current magnitude is obtained during the present investigation.« less

Off-axis current drive and real-time control of current profile in JT-60U

NASA Astrophysics Data System (ADS)

Suzuki, T.; Ide, S.; Oikawa, T.; Fujita, T.; Ishikawa, M.; Seki, M.; Matsunaga, G.; Hatae, T.; Naito, O.; Hamamatsu, K.; Sueoka, M.; Hosoyama, H.; Nakazato, M.; JT-60 Team

2008-04-01

Aiming at optimization of current profile in high-β plasmas for higher confinement and stability, a real-time control system of the minimum of the safety factor (qmin) using the off-axis current drive has been developed. The off-axis current drive can raise the safety factor in the centre and help to avoid instability that limits the performance of the plasma. The system controls the injection power of lower-hybrid waves, and hence its off-axis driven current in order to control qmin. The real-time control of qmin is demonstrated in a high-β plasma, where qmin follows the temporally changing reference qmin,ref from 1.3 to 1.7. Applying the control to another high-β discharge (βN = 1.7, βp = 1.5) with m/n = 2/1 neo-classical tearing mode (NTM), qmin was raised above 2 and the NTM was suppressed. The stored energy increased by 16% with the NTM suppressed, since the resonant rational surface was eliminated. For the future use for current profile control, current density profile for off-axis neutral beam current drive (NBCD) is for the first time measured, using the motional Stark effect diagnostic. Spatially localized NBCD profile was clearly observed at the normalized minor radius ρ of about 0.6-0.8. The location was also confirmed by multi-chordal neutron emission profile measurement. The total amount of the measured beam driven current was consistent with the theoretical calculation using the ACCOME code. The CD location in the calculation was inward shifted than the measurement.

VIEW OF THE SOUTH AND WEST SIDES OF BUILDING 63, ...

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

VIEW OF THE SOUTH AND WEST SIDES OF BUILDING 63, FACING NORTHEAST. - Naval Computer & Telecommunications Area Station, Enlisted Men's Barracks, West corner of Central Street & Midway Drive, Wahiawa, Honolulu County, HI

VIEW OF THE EAST AND NORTH SIDES OF BUILDING 63, ...

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

VIEW OF THE EAST AND NORTH SIDES OF BUILDING 63, FACING SOUTHWEST. - Naval Computer & Telecommunications Area Station, Enlisted Men's Barracks, West corner of Central Street & Midway Drive, Wahiawa, Honolulu County, HI

Two-motor direct drive control for elevation axis of telescope

NASA Astrophysics Data System (ADS)

Tang, T.; Tan, Y.; Ren, G.

2014-07-01

Two-motor application has become a very attractive filed in important field which high performance is permitted to achieve of position, speed, and acceleration. In the elevation axis of telescope control system, two-motor direct drive is proposed to enhance the high performance of tracking control system. Although there are several dominant strengths such as low size of motors and high torsional structural dynamics, the synchronization control of two motors is a very difficult and important. In this paper, a multi-loop control technique base master-slave current control is used to synchronize two motors, including current control loop, speed control loop and position control loop. First, the direct drive function of two motors is modeled. Compared of single motor direct control system, the resonance frequency of two motor control systems is same; while the anti-resonance frequency of two motors control system is 1.414 times than those of sing motor system. Because of rigid coupling for direct drive, the speed of two motor of the system is same, and the synchronization of torque for motors is critical. The current master-slave control technique is effective to synchronize the torque, which the current loop of the master motors is tracked the other slave motor. The speed feedback into the input of current loop of the master motors. The experiments test the performance of the two motors drive system. The random tracking error is 0.0119" for the line trajectory of 0.01°/s.

New PMOS LTPS TFT pixel for AMOLED to suppress the hysteresis effect on OLED current by employing a reset voltage driving

NASA Astrophysics Data System (ADS)

Lee, Jae-Hoon; Park, Sang-Geun; Han, Sang-Myeon; Han, Min-Koo; Park, Kee-Chan

2008-03-01

New PMOS LTPS (low temperature polycrystalline silicon)-thin film transistor (TFT) pixel circuit, which can suppress an OLED current error caused by the hysteresis of LTPS-TFT for active matrix organic light emitting diode (AMOLED) display, is proposed and fabricated. The proposed pixel circuit employs a reset voltage driving so that the sweep direction of gate voltage in the current driving TFT is not altered by the gate voltage in the previous frame. Our experimental results show that OLED current error of the proposed pixel is successfully suppressed because a reset voltage can enable the starting gate voltage for a desired one not to be varied, while that of the conventional 2-TFT pixel exceeds over 15% due to the hysteresis of LTPS-TFT.

Effect of simulator training on fitness-to-drive after stroke: a 5-year follow-up of a randomized controlled trial.

PubMed

Devos, Hannes; Akinwuntan, Abiodun Emmanuel; Nieuwboer, Alice; Ringoot, Isabelle; Van Berghen, Karen; Tant, Mark; Kiekens, Carlotte; De Weerdt, Willy

2010-01-01

No long-term studies have been reported on the effect of training programs on driving after stroke. The authors' primary aim was to determine the effect of simulator versus cognitive rehabilitation therapy on fitness-to-drive at 5 years poststroke. A second aim was to investigate differences in clinical characteristics between stroke survivors who resumed and stopped driving. In a previously reported randomized controlled trial, 83 stroke survivors received 15 hours of simulator training (n = 42) or cognitive therapy (n = 41). In this 5-year follow-up study, 61 participants were reassessed. Fitness-to-drive decisions were obtained from medical, visual, neuropsychological, and on-road tests; 44 participants (simulator group, n = 21; cognitive group, n = 23) completed all assessments. The primary outcome measures were fitness-to-drive decision and current driving status. The authors found that 5 years after stroke, 18 of 30 participants (60%) in the simulator group were considered fit to drive, compared with 15 of 31 (48%) in the cognitive group (P = .36); 34 of 61 (56%) participants were driving. Current drivers were younger (P = .04), had higher Barthel scores (P = .008), had less comorbidity (P = .01), and were less severely depressed (P = .02) than those who gave up driving. The advantage of simulator-based driving training over cognitive rehabilitation therapy, evident at 6 months poststroke, had faded 5 years later. Poststroke drivers were younger and less severely affected and depressed than nondrivers.

A State-by-State Analysis of Laws Dealing With Driving Under the Influence of Drugs

DOT National Transportation Integrated Search

2009-12-01

This study reviewed each State statute regarding drug-impaired driving as of December 2008. There : is a high degree of variability across the States in the ways they approach drug-impaired driving. : Current laws in many States contain provisions ma...

[Effects of marijuana and amphetamine (and its derivatives on driving performance based on the driving simulator studies].

PubMed

Drabek, Marcin; Andysz, Aleksandra

2011-01-01

This article presents the results of the driving simulator studies of the effects of marijuana and amphetamines on driving performance. The majority of these studies have been focused on identifying the impact of the tested substances on cognitive and psychomotor functions. Most of the findings on marijuana reveal its modest effect on driving ability that increases with the increasing frequency of its use and when used in conjuction with other drugs and alcohol. Similarly, small doses of amphetamines can cause a positive stimulating effect, improving certain cognitive functions, such as vigilance, but it decreases when they are overused and combined with alcohol. The results of the research on drivers' behavior under the influence of amphetamines also indicate deficits in their cognitive functions and tendency to recklessness on the road. The authors also discuss strong and weak points of simulation studies of the effects of psychoactive substances on the driving ability. An attempt was also made to clarify certain ambiguities, which occur in this field of research. A central role of the ethical and methodological limitations of simulation studies were discussed as well.

Integrated Eye Tracking and Neural Monitoring for Enhanced Assessment of Mild TBI

DTIC Science & Technology

2015-04-01

virtual reality driving simulator data acquisition. Data collection for the pilot study is nearly complete and data analyses are currently under way...Training for primary study procedures including neuropsychological testing, eye- tracking, virtual reality driving simulator, and EEG data acquisition is...the virtual reality driving simulator. Participants are instructed to drive along a coastal highway while performing the target detection task

Cross-shaped torsional spring

DOEpatents

Williamson, M.M.; Pratt, G.A.

1999-06-08

The invention provides an elastic actuator consisting of a motor and a motor drive transmission connected at an output of the motor. An elastic element is connected in series with the motor drive transmission, and this elastic element is positioned to alone support the full weight of any load connected at an output of the actuator. A single force transducer is positioned at a point between a mount for the motor and an output of the actuator. This force transducer generates a force signal, based on deflection of the elastic element, that indicates force applied by the elastic element to an output of the actuator. An active feedback force control loop is connected between the force transducer and the motor for controlling the motor. This motor control is based on the force signal to deflect the elastic element an amount that produces a desired actuator output force. The produced output force is substantially independent of load motion. The invention also provides a torsional spring consisting of a flexible structure having at least three flat sections each connected integrally with and extending radially from a central section. Each flat section extends axially along the central section from a distal end of the central section to a proximal end of the central section. 30 figs.

Elastic actuator for precise force control

DOEpatents

Pratt, G.A.; Williamson, M.M.

1997-07-22

The invention provides an elastic actuator consisting of a motor and a motor drive transmission connected at an output of the motor. An elastic element is connected in series with the motor drive transmission, and this elastic element is positioned to alone support the full weight of any load connected at an output of the actuator. A single force transducer is positioned at a point between a mount for the motor and an output of the actuator. This force transducer generates a force signal, based on deflection of the elastic element, that indicates force applied by the elastic element to an output of the actuator. An active feedback force control loop is connected between the force transducer and the motor for controlling the motor. This motor control is based on the force signal to deflect the elastic element an amount that produces a desired actuator output force. The produced output force is substantially independent of load motion. The invention also provides a torsional spring consisting of a flexible structure having at least three flat sections each connected integrally with and extending radially from a central section. Each flat section extends axially along the central section from a distal end of the central section to a proximal end of the central section. 30 figs.

Elastic actuator for precise force control

DOEpatents

Pratt, Gill A.; Williamson, Matthew M.

1997-07-22

The invention provides an elastic actuator consisting of a motor and a motor drive transmission connected at an output of the motor. An elastic element is connected in series with the motor drive transmission, and this elastic element is positioned to alone support the full weight of any load connected at an output of the actuator. A single force transducer is positioned at a point between a mount for the motor and an output of the actuator. This force transducer generates a force signal, based on deflection of the elastic element, that indicates force applied by the elastic element to an output of the actuator. An active feedback force control loop is connected between the force transducer and the motor for controlling the motor. This motor control is based on the force signal to deflect the elastic element an amount that produces a desired actuator output force. The produced output force is substantially independent of load motion. The invention also provides a torsional spring consisting of a flexible structure having at least three flat sections each connected integrally with and extending radially from a central section. Each flat section extends axially along the central section from a distal end of the central section to a proximal end of the central section.

Agreements between ground-based and satellite-based observations. [of earth magnetospheric currents

NASA Technical Reports Server (NTRS)

Akasofu, S.-I.; Weimer, D.; Iijima, T.; Ahn, B.-H.; Kamide, Y.

1990-01-01

The polar ionospheric parameters obtained by the meridian chain of magnetometers are compared with those obtained by satellites, and a number of ionospheric quantities including the distribution of the electric potential, field-aligned currents, ionospheric currents and their equatorial counterparts, and the relationship between the AE index and the cross-polar cap potential is determined. It is noted that the agreement observed between the ground-based and satellite-based results allows to reduce the search for the driving mechanism of the ionospheric Pedersen current to identifying the driving mechanism of the Pedersen counterpart current in the equatorial plane.

Improving driving advice provided to cardiology patients on discharge.

PubMed

Vusirikala, Amoolya; Backhouse, Mark; Schimansky, Sarah

2018-01-01

Certain cardiac conditions can limit patients' ability to drive. It remains the doctors' responsibility to advise patients of any driving restrictions and is particularly important after certain diagnoses or procedures. We identified that the quality of documented advice was variable and frequently no written driving advice was recorded on discharge. It was apparent that there was a lack of awareness and knowledge of the current Driving and Vehicle Licensing Agency (DVLA) guidance among junior doctors. We therefore designed a quality improvement project using Plan-Do-Study-Act (PDSA) methodology to improve the provision of driving advice on discharge from a cardiology ward by focusing on staff education. After collecting baseline data, we created a template with cardiology-specific DVLA advice. During the second PDSA cycle, we improved the electronic template and also introduced a hard copy on the ward. During the third PDSA cycle, we incorporated information on DVLA guidance in the specialty induction session. We also evaluated junior doctors' confidence of providing driving advice before and after this intervention. Baseline measurements showed that 10% (9/92) of all discharge summaries included driving advice. This improved to 49% (34/69) after the third PDSA cycle. Importantly, after receiving information on driving advice in the induction, junior doctors felt more confident in providing driving advice to cardiology patients on discharge. In conclusion, the provision of driving advice on discharge is an important element of patient safety. However, clinicians' knowledge and awareness of current DVLA guidance is often limited. We demonstrated a significant increase in the provision of driving advice by introducing a standardised template.

Improving driving advice provided to cardiology patients on discharge

PubMed Central

Vusirikala, Amoolya; Backhouse, Mark; Schimansky, Sarah

2018-01-01

Certain cardiac conditions can limit patients’ ability to drive. It remains the doctors' responsibility to advise patients of any driving restrictions and is particularly important after certain diagnoses or procedures. We identified that the quality of documented advice was variable and frequently no written driving advice was recorded on discharge. It was apparent that there was a lack of awareness and knowledge of the current Driving and Vehicle Licensing Agency (DVLA) guidance among junior doctors. We therefore designed a quality improvement project using Plan–Do–Study–Act (PDSA) methodology to improve the provision of driving advice on discharge from a cardiology ward by focusing on staff education. After collecting baseline data, we created a template with cardiology-specific DVLA advice. During the second PDSA cycle, we improved the electronic template and also introduced a hard copy on the ward. During the third PDSA cycle, we incorporated information on DVLA guidance in the specialty induction session. We also evaluated junior doctors’ confidence of providing driving advice before and after this intervention. Baseline measurements showed that 10% (9/92) of all discharge summaries included driving advice. This improved to 49% (34/69) after the third PDSA cycle. Importantly, after receiving information on driving advice in the induction, junior doctors felt more confident in providing driving advice to cardiology patients on discharge. In conclusion, the provision of driving advice on discharge is an important element of patient safety. However, clinicians’ knowledge and awareness of current DVLA guidance is often limited. We demonstrated a significant increase in the provision of driving advice by introducing a standardised template. PMID:29610769

Surface Lagrangian transport in the Adriatic Sea (Mediterranean Sea) from drifters, HF radar and models: implications for fishery and Marine Protected Areas

NASA Astrophysics Data System (ADS)

Griffa, Annalisa; Carlson, Daniel; Berta, Maristella; Sciascia, Roberta; Corgnati, Lorenzo; Mantovani, Carlo; Fredji, Erick; Magaldi, Marcello; Zambianchi, Enrico; Poulain, Pierre Marie; Russo, Aniello; Carniel, Sandro

2017-04-01

Surface transport in the Adriatic Sea is investigated using data from historic drifter data, HF radar and virtual particles computed from a numerical model. Alongshore coastal currents and cyclonic gyres are the primary circulation features that connect regions in the Adriatic Sea. Their strength is highly dependent on the wind, with Southeasterly Sirocco winds driving eastward cross-Adriatic transport from the Italian coasts and Northwesterly Mistral winds enhancing east-to-west transport. Results from the analysis show that Cross-Adriatic connection percentages were higher for east-to-west transport, with westward (eastward) transport observed mostly in the northern (southern) arms of the central and southern gyres. These pathways of patterns influence the connection between Marine Protected Areas (MPAs) and between spawning and nursery areas for small pelagic fish. Percentage connections between MPAs are computed, showing that while the highest percentages occur through boundary currents, significant percentages also occur through cross-gyre transport, suggesting the concept of cell-based ecosystems. The nursery area of the Manfredonia Gulf has limited retention properties, and eggs and larvae are likely to reach the Gulf mostly from remote spawning areas through current transport

Characteristics of On-Road Driving by Persons with Central Vision Loss: Learning to Drive with a Bioptic Telescope

PubMed Central

Wood, Joanne M.; Elgin, Jennifer; McGwin, Gerald; Owsley, Cynthia

2016-01-01

There is limited research on the driving performance and safety of bioptic drivers and even less regarding the driving skills that are most challenging for those learning to drive with bioptic telescopes. This research consisted of case studies of five trainee bioptic drivers whose driving skills were compared with those of a group of licensed bioptic drivers (n=23) while they drove along city, suburban, and controlled-access highways in an instrumented dual-brake vehicle. A certified driver rehabilitation specialist was positioned in the front passenger seat to monitor safety and two backseat evaluators independently rated driving using a standardized scoring system. Other aspects of performance were assessed through vehicle instrumentation and video recordings. Results demonstrate that while sign recognition, lane keeping, steering steadiness, gap judgments and speed choices were significantly worse in trainees, some driving behaviors and skills, including pedestrian detection and traffic light recognition were not significantly different to those of the licensed drivers. These data provide useful insights into the skill challenges encountered by a small sample of trainee bioptic drivers which, while not generalizable because of the small sample size, provide valuable insights beyond that of previous studies and can be used as a basis to guide training strategies. PMID:26480232

Characteristics of on-road driving by persons with central vision loss: Learning to drive with a bioptic telescope.

PubMed

Wood, Joanne M; Elgin, Jennifer; McGwin, Gerald; Owsley, Cynthia

2016-01-01

There is limited research on the driving performance and safety of bioptic drivers and even less regarding the driving skills that are most challenging for those learning to drive with bioptic telescopes. This research consisted of case studies of five trainee bioptic drivers whose driving skills were compared with those of a group of licensed bioptic drivers (n = 23) while they drove along city, suburban, and controlled-access highways in an instrumented dual-brake vehicle. A certified driver rehabilitation specialist was positioned in the front passenger seat to monitor safety and two backseat evaluators independently rated driving using a standardized scoring system. Other aspects of performance were assessed through vehicle instrumentation and video recordings. Results demonstrate that while sign recognition, lane keeping, steering steadiness, gap judgments, and speed choices were significantly worse in trainees, some driving behaviors and skills, including pedestrian detection and traffic light recognition were not significantly different from those of the licensed drivers. These data provide useful insights into the skill challenges encountered by a small sample of trainee bioptic drivers which, while not generalizable because of the small sample size, provide valuable insights beyond that of previous studies and can be used as a basis to guide training strategies.

Assessing climate impacts

PubMed Central

Wohl, Ellen E.; Pulwarty, Roger S.; Zhang, Jian Yun

2000-01-01

Assessing climate impacts involves identifying sources and characteristics of climate variability, and mitigating potential negative impacts of that variability. Associated research focuses on climate driving mechanisms, biosphere–hydrosphere responses and mediation, and human responses. Examples of climate impacts come from 1998 flooding in the Yangtze River Basin and hurricanes in the Caribbean and Central America. Although we have limited understanding of the fundamental driving-response interactions associated with climate variability, increasingly powerful measurement and modeling techniques make assessing climate impacts a rapidly developing frontier of science. PMID:11027321

Drive-train dynamics technology - State-of-the-art and design of a test facility for advanced development

NASA Technical Reports Server (NTRS)

Badgley, R. H.; Fleming, D. P.; Smalley, A. J.

1975-01-01

A program for the development and verification of drive-train dynamic technology is described along with its basis and the results expected from it. A central feature of this program is a drive-train test facility designed for the testing and development of advanced drive-train components, including shaft systems, dampers, and couplings. Previous efforts in designing flexible dynamic drive-train systems are reviewed, and the present state of the art is briefly summarized. The design of the test facility is discussed with major attention given to the formulation of the test-rig concept, dynamic scaling of model shafts, and the specification of design parameters. Specific efforts envisioned for the test facility are briefly noted, including evaluations of supercritical test shafts, stability thresholds for various sources and types of instabilities that can exist in shaft systems, effects of structural flexibility on the dynamic performance of dampers, and methods for vibration control in two-level and three-level flexible shaft systems.

Alternative Shapes and Shaping Techniques for Enhanced Transformer Ratios in Beam Driven Techniques

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

Lemery, F.; Piot, P.

The transformer ration of collinear beam-driven techniques can be significantly improved by shaping the current profile of the drive bunch. To date, several current shapes have been proposed to increase the transformer ratio and produce quasi-uniform energy loss within the drive bunch. Some of these tailoring techniques are possible as a results of recent beam-dynamics advances, e.g., transverse-to-longitudinal emittance exchanger. In ths paper, we propose an alternative class of longitudinal shapes that enable high transformer ratio and uniform energy loss across the drive bunch. We also suggest a simple method based on photocathode-laser shaping and passive shaping in wakefield structuremore » to realize shape close to the theoretically optimized current profiles.« less

Driving while alcohol impaired : a preliminary exploration of the issues and possible approaches.

DOT National Transportation Integrated Search

1989-01-01

Under current Virginia law, a driver who has been drinking but does not have a BAC of 0.10% will likely not be arrested even if his/her driving ability is visibly impaired. A "driving while alcohol impaired" (DWAI) statute would provide law enforceme...

Development of a National Item Bank for Tests of Driving Knowledge.

ERIC Educational Resources Information Center

Pollock, William T.; McDole, Thomas L.

Materials intended for driving knowledge test development use by operational licensing and education agencies were prepared. Candidate test items were developed, using literature and operational practice sources, to reflect current state-of-knowledge with respect to principles of safe, efficient driving, to legal regulations, and to traffic…

Self-organized stationary states of inductively driven tokamaks

NASA Astrophysics Data System (ADS)

Jardin, S. C.; Ferraro, N.; Krebs, I.; Chen, J.

2014-10-01

We report on a mechanism for preventing the current and temperature profiles from peaking in a stationary state tokamak. For certain parameters, regardless of the initial state, the plasma profiles will evolve into a self-organized state with the safety factor q slightly above 1 and constant in a central volume. This large shear free region is unstable to interchange modes for any pressure gradient, and the instability drives a strong (1,1) helical flow. This flow has the property that V × B is the gradient of a potential, so it does not affect the magnetic field evolution. However, the driven flow appears in the temperature evolution equation and dominates over the thermal conductivity in the center of the discharge. The net effect is to keep the central temperature (and resistivity) profiles flat so that the resistive steady state preserves the self organized state with q slightly above 1 and constant in the central volume. This mechanism was discovered with the M3D-C1 toroidal 3D MHD code, and could possibly explain the mechanism at play in non-sawtoothing discharges with q0 just above 1 such as hybrid modes in DIII-D and ASDEX-U and long-lived modes in NSTX and MAST. This work was supported by US DOE Contract No. DE-AC02-09CHI1446, MPPC, and SciDAC CEMM.

Hydro-economic analysis of groundwater pumping for irrigated agriculture in California's Central Valley, USA

NASA Astrophysics Data System (ADS)

Medellín-Azuara, Josué; MacEwan, Duncan; Howitt, Richard E.; Koruakos, George; Dogrul, Emin C.; Brush, Charles F.; Kadir, Tariq N.; Harter, Thomas; Melton, Forrest; Lund, Jay R.

2015-09-01

As in many places, groundwater in California (USA) is the major alternative water source for agriculture during drought, so groundwater's availability will drive some inevitable changes in the state's water management. Currently, agricultural, environmental, and urban uses compete for groundwater, resulting in substantial overdraft in dry years with lowering of water tables, which in turn increases pumping costs and reduces groundwater pumping capacity. In this study, SWAP (an economic model of agricultural production and water use in California) and C2VISim (the California Department of Water Resources groundwater model for California's Central Valley) are connected. This paper examines the economic costs of pumping replacement groundwater during drought and the potential loss of pumping capacity as groundwater levels drop. A scenario of three additional drought years continuing from 2014 show lower water tables in California's Central Valley and loss of pumping capacity. Places without access to groundwater and with uncertain surface-water deliveries during drought are the most economically vulnerable in terms of crop revenues, employment and household income. This is particularly true for Tulare Lake Basin, which relies heavily on water imported from the Sacramento-San Joaquin Delta. Remote-sensing estimates of idle agricultural land between 2012 and 2014 confirm this finding. Results also point to the potential of a portfolio approach for agriculture, in which crop mixing and conservation practices have substantial roles.

6. Interior, rear offices: operations assistant office looking north toward ...

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

6. Interior, rear offices: operations assistant office looking north toward security operations officer's office. - Ellsworth Air Force Base, Rushmore Air Force Station, Security Central Control Building, Quesada Drive, Blackhawk, Meade County, SD

Freight 2055 : roundtable discussion.

DOT National Transportation Integrated Search

2015-07-08

JULY 8, 2015 : North Central Texas Council of Governments : Transportation Council Room : 616 Six Flags Drive, Arlington, TX 76011 : The Texas A&M Transportation Institute (TTI) and the Center for Transportation Research (CTR) invite you to a Roundta...

36 CFR 1253.6 - Records Centers.

Code of Federal Regulations, 2011 CFR

2011-07-01

...., Chicago, IL 60629-5898. The telephone number is 773-948-9000. (h) NARA—Central Plains Region (Lee's Summit, MO) is located at 200 Space Center Drive, Lee's Summit, MO 64064-1182. The telephone number is 816...

77 FR 4276 - National Urban and Community Forestry Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

... Drive SW., Washington, DC 20250; Phone: (202) 205-7829. FOR FURTHER INFORMATION CONTACT: Nancy Stremple, 201 14th Street SW., Yates Building (1 Central) MS-1151, Washington, DC 20250-1151, phone (202) 205...

Plasma response to sustainment with imposed-dynamo current drive in HIT-SI and HIT-SI3

NASA Astrophysics Data System (ADS)

Hossack, A. C.; Jarboe, T. R.; Chandra, R. N.; Morgan, K. D.; Sutherland, D. A.; Penna, J. M.; Everson, C. J.; Nelson, B. A.

2017-07-01

The helicity injected torus—steady inductive (HIT-SI) program studies efficient, steady-state current drive for magnetic confinement plasmas using a novel experimental method. Stable, high-beta spheromaks have been sustained using steady, inductive current drive. Externally induced loop voltage and magnetic flux are oscillated together so that helicity and power injection are always positive, sustaining the edge plasma current indefinitely. Imposed-dynamo current drive (IDCD) theory further shows that the entire plasma current is sustained. The method is ideal for low aspect ratio, toroidal geometries with closed flux surfaces. Experimental studies of spheromak plasmas sustained with IDCD have shown stable magnetic profiles with evidence of pressure confinement. New measurements show coherent motion of a stable spheromak in response to the imposed perturbations. On the original device two helicity injectors were mounted on either side of the spheromak and the injected mode spectrum was predominantly n  =  1. Coherent, rigid motion indicates that the spheromak is stable and a lack of plasma-generated n  =  1 energy indicates that the maximum q is maintained below 1 during sustainment. Results from the HIT-SI3 device are also presented. Three inductive helicity injectors are mounted on one side of the spheromak flux conserver. Varying the relative injector phasing changes the injected mode spectrum which includes n  =  2, 3, and higher modes.

Steady State Advanced Tokamak (SSAT): The mission and the machine

NASA Astrophysics Data System (ADS)

Thomassen, K.; Goldston, R.; Nevins, B.; Neilson, H.; Shannon, T.; Montgomery, B.

1992-03-01

Extending the tokamak concept to the steady state regime and pursuing advances in tokamak physics are important and complementary steps for the magnetic fusion energy program. The required transition away from inductive current drive will provide exciting opportunities for advances in tokamak physics, as well as important impetus to drive advances in fusion technology. Recognizing this, the Fusion Policy Advisory Committee and the U.S. National Energy Strategy identified the development of steady state tokamak physics and technology, and improvements in the tokamak concept, as vital elements in the magnetic fusion energy development plan. Both called for the construction of a steady state tokamak facility to address these plan elements. Advances in physics that produce better confinement and higher pressure limits are required for a similar unit size reactor. Regimes with largely self-driven plasma current are required to permit a steady-state tokamak reactor with acceptable recirculating power. Reliable techniques of disruption control will be needed to achieve the availability goals of an economic reactor. Thus the central role of this new tokamak facility is to point the way to a more attractive demonstration reactor (DEMO) than the present data base would support. To meet the challenges, we propose a new 'Steady State Advanced Tokamak' (SSAT) facility that would develop and demonstrate optimized steady state tokamak operating mode. While other tokamaks in the world program employ superconducting toroidal field coils, SSAT would be the first major tokamak to operate with a fully superconducting coil set in the elongated, divertor geometry planned for ITER and DEMO.

Current distribution in tissues with conducted electrical weapons operated in drive-stun mode.

PubMed

Panescu, Dorin; Kroll, Mark W; Brave, Michael

2016-08-01

The TASER® conducted electrical weapon (CEW) is best known for delivering electrical pulses that can temporarily incapacitate subjects by overriding normal motor control. The alternative drive-stun mode is less understood and the goal of this paper is to analyze the distribution of currents in tissues when the CEW is operated in this mode. Finite element modeling (FEM) was used to approximate current density in tissues with boundary electrical sources placed 40 mm apart. This separation was equivalent to the distance between drive-stun mode TASER X26™, X26P, X2 CEW electrodes located on the device itself and between those located on the expended CEW cartridge. The FEMs estimated the amount of current flowing through various body tissues located underneath the electrodes. The FEM simulated the attenuating effects of both a thin and of a normal layer of fat. The resulting current density distributions were used to compute the residual amount of current flowing through deeper layers of tissue. Numerical modeling estimated that the skin, fat and skeletal muscle layers passed at least 86% or 91% of total CEW current, assuming a thin or normal fat layer thickness, respectively. The current density and electric field strength only exceeded thresholds which have increased probability for ventricular fibrillation (VFTJ), or for cardiac capture (CCTE), in the skin and the subdermal fat layers. The fat layer provided significant attenuation of drive-stun CEW currents. Beyond the skeletal muscle layer, only fractional amounts of the total CEW current were estimated to flow. The regions presenting risk for VF induction or for cardiac capture were well away from the typical heart depth.

Current drive at plasma densities required for thermonuclear reactors.

PubMed

Cesario, R; Amicucci, L; Cardinali, A; Castaldo, C; Marinucci, M; Panaccione, L; Santini, F; Tudisco, O; Apicella, M L; Calabrò, G; Cianfarani, C; Frigione, D; Galli, A; Mazzitelli, G; Mazzotta, C; Pericoli, V; Schettini, G; Tuccillo, A A

2010-08-10

Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors.

Astrocytic TYMP and VEGFA drive blood-brain barrier opening in inflammatory central nervous system lesions.

PubMed

Chapouly, Candice; Tadesse Argaw, Azeb; Horng, Sam; Castro, Kamilah; Zhang, Jingya; Asp, Linnea; Loo, Hannah; Laitman, Benjamin M; Mariani, John N; Straus Farber, Rebecca; Zaslavsky, Elena; Nudelman, German; Raine, Cedric S; John, Gareth R

2015-06-01

In inflammatory central nervous system conditions such as multiple sclerosis, breakdown of the blood-brain barrier is a key event in lesion pathogenesis, predisposing to oedema, excitotoxicity, and ingress of plasma proteins and inflammatory cells. Recently, we showed that reactive astrocytes drive blood-brain barrier opening, via production of vascular endothelial growth factor A (VEGFA). Here, we now identify thymidine phosphorylase (TYMP; previously known as endothelial cell growth factor 1, ECGF1) as a second key astrocyte-derived permeability factor, which interacts with VEGFA to induce blood-brain barrier disruption. The two are co-induced NFκB1-dependently in human astrocytes by the cytokine interleukin 1 beta (IL1B), and inactivation of Vegfa in vivo potentiates TYMP induction. In human central nervous system microvascular endothelial cells, VEGFA and the TYMP product 2-deoxy-d-ribose cooperatively repress tight junction proteins, driving permeability. Notably, this response represents part of a wider pattern of endothelial plasticity: 2-deoxy-d-ribose and VEGFA produce transcriptional programs encompassing angiogenic and permeability genes, and together regulate a third unique cohort. Functionally, each promotes proliferation and viability, and they cooperatively drive motility and angiogenesis. Importantly, introduction of either into mouse cortex promotes blood-brain barrier breakdown, and together they induce severe barrier disruption. In the multiple sclerosis model experimental autoimmune encephalitis, TYMP and VEGFA co-localize to reactive astrocytes, and correlate with blood-brain barrier permeability. Critically, blockade of either reduces neurologic deficit, blood-brain barrier disruption and pathology, and inhibiting both in combination enhances tissue preservation. Suggesting importance in human disease, TYMP and VEGFA both localize to reactive astrocytes in multiple sclerosis lesion samples. Collectively, these data identify TYMP as an astrocyte-derived permeability factor, and suggest TYMP and VEGFA together promote blood-brain barrier breakdown. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Driving evaluation methods for able-bodied persons and individuals with lower extremity disabilities: a review of assessment modalities

PubMed Central

Greve, Julia Maria D'Andréa; Santos, Luciana; Alonso, Angelica Castilho; Tate, Denise G

2015-01-01

Assessing the driving abilities of individuals with disabilities is often a very challenging task because each medical condition is accompanied by physical impairments and because relative individual functional performance may vary depending on personal characteristics. We identified existing driving evaluation modalities for able-bodied and lower extremity-impaired subjects (spinal cord injury patients and amputees) and evaluated the potential relationships between driving performance and the motor component of driving. An extensive scoping review of the literature was conducted to identify driving assessment tools that are currently used for able-bodied individuals and for those with spinal cord injury or lower extremity amputation. The literature search focused on the assessment of the motor component of driving. References were electronically obtained via Medline from the PubMed, Ovid, Web of Science and Google Scholar databases. This article compares the current assessments of driving performance for those with lower extremity impairments with the assessments used for able-bodied persons. Very few articles were found concerning “Lower Extremity Disabilities,” thus confirming the need for further studies that can provide evidence and guidance for such assessments in the future. Little is known about the motor component of driving and its association with the other driving domains, such as vision and cognition. The available research demonstrates the need for a more evidenced-based understanding of how to best evaluate persons with lower extremity impairment. PMID:26375567

Experimental models of liver fibrosis.

PubMed

Yanguas, Sara Crespo; Cogliati, Bruno; Willebrords, Joost; Maes, Michaël; Colle, Isabelle; van den Bossche, Bert; de Oliveira, Claudia Pinto Marques Souza; Andraus, Wellington; Alves, Venâncio Avancini Ferreira; Leclercq, Isabelle; Vinken, Mathieu

2016-05-01

Hepatic fibrosis is a wound healing response to insults and as such affects the entire world population. In industrialized countries, the main causes of liver fibrosis include alcohol abuse, chronic hepatitis virus infection and non-alcoholic steatohepatitis. A central event in liver fibrosis is the activation of hepatic stellate cells, which is triggered by a plethora of signaling pathways. Liver fibrosis can progress into more severe stages, known as cirrhosis, when liver acini are substituted by nodules, and further to hepatocellular carcinoma. Considerable efforts are currently devoted to liver fibrosis research, not only with the goal of further elucidating the molecular mechanisms that drive this disease, but equally in view of establishing effective diagnostic and therapeutic strategies. The present paper provides a state-of-the-art overview of in vivo and in vitro models used in the field of experimental liver fibrosis research.

Method for producing silicon thin-film transistors with enhanced forward current drive

DOEpatents

Weiner, K.H.

1998-06-30

A method is disclosed for fabricating amorphous silicon thin film transistors (TFTs) with a polycrystalline silicon surface channel region for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs which have the advantages of both amorphous and polycrystalline silicon TFTs, but without problem of leakage current of polycrystalline silicon TFTs. This is accomplished by selectively crystallizing a selected region of the amorphous silicon, using a pulsed excimer laser, to create a thin polycrystalline silicon layer at the silicon/gate-insulator surface. The thus created polysilicon layer has an increased mobility compared to the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent to amorphous silicon. A device made by this method can be used, for example, as a pixel switch in an active-matrix liquid crystal display to improve display refresh rates. 1 fig.

Method for producing silicon thin-film transistors with enhanced forward current drive

DOEpatents

Weiner, Kurt H.

1998-01-01

A method for fabricating amorphous silicon thin film transistors (TFTs) with a polycrystalline silicon surface channel region for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs which have the advantages of both amorphous and polycrystalline silicon TFTs, but without problem of leakage current of polycrystalline silicon TFTs. This is accomplished by selectively crystallizing a selected region of the amorphous silicon, using a pulsed excimer laser, to create a thin polycrystalline silicon layer at the silicon/gate-insulator surface. The thus created polysilicon layer has an increased mobility compared to the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent to amorphous silicon. A device made by this method can be used, for example, as a pixel switch in an active-matrix liquid crystal display to improve display refresh rates.

Gate drive latching circuit for an auxiliary resonant commutation circuit

NASA Technical Reports Server (NTRS)

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

1999-01-01

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

Evaluating the Effectiveness of a Front Windshield Sticker Reminder in Reducing Texting while Driving in Young Adults

PubMed Central

Eriksson, Sven; Metcalf, David

2016-01-01

Texting while driving is a dangerous activity that is on the rise in the United States (U.S.). Since 2011 there has been a 17% increase in the number of people injured in a motor vehicle crash involving a distracted driver. Bans on the act of texting and driving have already taken place in 46 states in the U.S., but studies have shown that they are ineffective. An unstudied method of reducing texting while driving is sticker reminders. Sticker reminders have already been proven to be an effective intervention in the realm of driver safety; one study found that a “Buckle-Up” dashboard sticker doubled the use of safety belts by front seat passengers. In this study, 104 medical students aged 21 - 29, from the University of Central Florida (UCF) College of Medicine were randomly divided into two groups, an interventional group receiving a “Drive in the Moment” windshield sticker, and a control group not receiving the sticker. Both groups took a pre- and post-survey that recorded self-reported texting and driving frequency. The results showed that the sticker intervention significantly reduced reported rates of sending texts while driving, reading texts while driving, and using social media while driving (p < 0.05). The results of this study suggest that a novel sticker-intervention could potentially serve as a point of attack when addressing the growing and dangerous texting while driving the epidemic. PMID:27555989

Parent and teen agreement on driving expectations prior to teen licensure.

PubMed

Hamann, Cara J; Ramirez, Marizen; Yang, Jingzhen; Chande, Vidya; Peek-Asa, Corinne

2014-01-01

To examine pre-licensure agreement on driving expectations and predictors of teen driving expectations among parent-teen dyads. Cross-sectional survey of 163 parent-teen dyads. Descriptive statistics, weighted Kappa coefficients, and linear regression were used to examine expectations about post-licensure teen driving. Teens reported high pre-licensure unsupervised driving (N = 79, 48.5%) and regular access to a car (N = 130, 81.8%). Parents and teens had low agreement on teen driving expectations (eg, after dark, κw = 0.23). Each time teens currently drove to/from school, their expectation of driving in risky conditions post-licensure increased (β = 0.21, p = .02). Pre-licensure improvement of parent-teen agreement on driving expectations are needed to have the greatest impact on preventing teens from driving in high risk conditions.

Dynamics of the exponential integrate-and-fire model with slow currents and adaptation.

PubMed

Barranca, Victor J; Johnson, Daniel C; Moyher, Jennifer L; Sauppe, Joshua P; Shkarayev, Maxim S; Kovačič, Gregor; Cai, David

2014-08-01

In order to properly capture spike-frequency adaptation with a simplified point-neuron model, we study approximations of Hodgkin-Huxley (HH) models including slow currents by exponential integrate-and-fire (EIF) models that incorporate the same types of currents. We optimize the parameters of the EIF models under the external drive consisting of AMPA-type conductance pulses using the current-voltage curves and the van Rossum metric to best capture the subthreshold membrane potential, firing rate, and jump size of the slow current at the neuron's spike times. Our numerical simulations demonstrate that, in addition to these quantities, the approximate EIF-type models faithfully reproduce bifurcation properties of the HH neurons with slow currents, which include spike-frequency adaptation, phase-response curves, critical exponents at the transition between a finite and infinite number of spikes with increasing constant external drive, and bifurcation diagrams of interspike intervals in time-periodically forced models. Dynamics of networks of HH neurons with slow currents can also be approximated by corresponding EIF-type networks, with the approximation being at least statistically accurate over a broad range of Poisson rates of the external drive. For the form of external drive resembling realistic, AMPA-like synaptic conductance response to incoming action potentials, the EIF model affords great savings of computation time as compared with the corresponding HH-type model. Our work shows that the EIF model with additional slow currents is well suited for use in large-scale, point-neuron models in which spike-frequency adaptation is important.

The potential for mode conversion to rail service in Wisconsin.

DOT National Transportation Integrated Search

2016-07-01

The team built upon the Wisconsin Economic Development Corporations study regarding industries that drive the Wisconsin economy, : and complemented the efforts of the Wisconsin Central Group and Wisconsin Manufacturers Commerce by geo-locating shi...

DETAIL ELEVATION VIEW OF EXTERIOR STAIRS ON THE EAST END ...

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

DETAIL ELEVATION VIEW OF EXTERIOR STAIRS ON THE EAST END OF BUILDING 63, FACING SOUTH. - Naval Computer & Telecommunications Area Station, Enlisted Men's Barracks, West corner of Central Street & Midway Drive, Wahiawa, Honolulu County, HI

INTERIOR VIEW OF FIRST FLOOR HALLWAY FROM THE EAST END ...

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

INTERIOR VIEW OF FIRST FLOOR HALLWAY FROM THE EAST END OF BUILDING 63, FACING WEST. - Naval Computer & Telecommunications Area Station, Enlisted Men's Barracks, West corner of Central Street & Midway Drive, Wahiawa, Honolulu County, HI

Computer hardware for radiologists: Part 2.

PubMed

Indrajit, Ik; Alam, A

2010-11-01

Computers are an integral part of modern radiology equipment. In the first half of this two-part article, we dwelt upon some fundamental concepts regarding computer hardware, covering components like motherboard, central processing unit (CPU), chipset, random access memory (RAM), and memory modules. In this article, we describe the remaining computer hardware components that are of relevance to radiology. "Storage drive" is a term describing a "memory" hardware used to store data for later retrieval. Commonly used storage drives are hard drives, floppy drives, optical drives, flash drives, and network drives. The capacity of a hard drive is dependent on many factors, including the number of disk sides, number of tracks per side, number of sectors on each track, and the amount of data that can be stored in each sector. "Drive interfaces" connect hard drives and optical drives to a computer. The connections of such drives require both a power cable and a data cable. The four most popular "input/output devices" used commonly with computers are the printer, monitor, mouse, and keyboard. The "bus" is a built-in electronic signal pathway in the motherboard to permit efficient and uninterrupted data transfer. A motherboard can have several buses, including the system bus, the PCI express bus, the PCI bus, the AGP bus, and the (outdated) ISA bus. "Ports" are the location at which external devices are connected to a computer motherboard. All commonly used peripheral devices, such as printers, scanners, and portable drives, need ports. A working knowledge of computers is necessary for the radiologist if the workflow is to realize its full potential and, besides, this knowledge will prepare the radiologist for the coming innovations in the 'ever increasing' digital future.

Improved motors for utility applications: Volume 6, Squirrel-cage rotor analysis: Final report

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

Griffith, J.W.; McCoy, R.M.

1986-11-01

An analysis of squirrel cage induction motor rotors was undertaken in response to an Industry Assessment Study finding 10% of motor failures to be rotor related. The analysis focuses on evaluating rotor design life. The evaluation combines state-of-the-art electromagnetic, thermal, and structural solution techniques into an integrated analysis and presents a simple summary. Finite element techniques are central tools in the analysis. The analysis is applied to a specific forced draft fan drive design. Fans as a category of application have a higher failure rate than other categories of power station auxiliary motor applications. Forced-draft fan drives are one ofmore » the major fan drives which accelerate a relatively high value of rotor load inertia. Various starting and operating conditions are studied for this forced-draft fan drive motor including a representative application duty cycle.« less

GPS Usage in a Population of Low-Vision Drivers.

PubMed

Cucuras, Maria; Chun, Robert; Lee, Patrick; Jay, Walter M; Pusateri, Gregg

2017-01-01

We surveyed bioptic and non-bioptic low-vision drivers in Illinois, USA, to determine their usage of global positioning system (GPS) devices. Low-vision patients completed an IRB-approved phone survey regarding driving demographics and usage of GPS while driving. Participants were required to be active drivers with an Illinois driver's license, and met one of the following criteria: best-corrected visual acuity (BCVA) less than or equal to 20/40, central or significant peripheral visual field defects, or a combination of both. Of 27 low-vision drivers, 10 (37%) used GPS while driving. The average age for GPS users was 54.3 and for non-users was 77.6. All 10 drivers who used GPS while driving reported increased comfort or safety level. Since non-GPS users were significantly older than GPS users, it is likely that older participants would benefit from GPS technology training from their low-vision eye care professionals.

A comparative approach for the investigation of biological information processing: An examination of the structure and function of computer hard drives and DNA

PubMed Central

2010-01-01

Background The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Methods Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Results Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological systems do not have an external source for a map of their stored information or for an operational instruction set; rather, they must contain an organizational template conserved within their intra-nuclear architecture that "manipulates" the laws of chemistry and physics into a highly robust instruction set. We propose that the epigenetic structure of the intra-nuclear environment and the non-coding RNA may play the roles of a Biological File Allocation Table (BFAT) and biological operating system (Bio-OS) in eukaryotic cells. Conclusions The comparison of functional and structural characteristics of the DNA complex and the computer hard drive leads to a new descriptive paradigm that identifies the DNA as a dynamic storage system of biological information. This system is embodied in an autonomous operating system that inductively follows organizational structures, data hierarchy and executable operations that are well understood in the computer science industry. Characterizing the "DNA hard drive" in this fashion can lead to insights arising from discrepancies in the descriptive framework, particularly with respect to positing the role of epigenetic processes in an information-processing context. Further expansions arising from this comparison include the view of cells as parallel computing machines and a new approach towards characterizing cellular control systems. PMID:20092652

A comparative approach for the investigation of biological information processing: an examination of the structure and function of computer hard drives and DNA.

PubMed

D'Onofrio, David J; An, Gary

2010-01-21

The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological systems do not have an external source for a map of their stored information or for an operational instruction set; rather, they must contain an organizational template conserved within their intra-nuclear architecture that "manipulates" the laws of chemistry and physics into a highly robust instruction set. We propose that the epigenetic structure of the intra-nuclear environment and the non-coding RNA may play the roles of a Biological File Allocation Table (BFAT) and biological operating system (Bio-OS) in eukaryotic cells. The comparison of functional and structural characteristics of the DNA complex and the computer hard drive leads to a new descriptive paradigm that identifies the DNA as a dynamic storage system of biological information. This system is embodied in an autonomous operating system that inductively follows organizational structures, data hierarchy and executable operations that are well understood in the computer science industry. Characterizing the "DNA hard drive" in this fashion can lead to insights arising from discrepancies in the descriptive framework, particularly with respect to positing the role of epigenetic processes in an information-processing context. Further expansions arising from this comparison include the view of cells as parallel computing machines and a new approach towards characterizing cellular control systems.

[Central sleep apnea syndrome].

PubMed

Sanner, B; Schäfer, T

2008-04-01

Central sleep apnea (CSA) is characterized by a lack of drive to inspire for at least 10 sec. In the CSA-syndrome accompanying arousals and desaturations of the arterial blood cause sleep disturbances and sympathetic nerve activations which lead to excessive daytime sleepiness and increase the risk for cardiovascular morbidity. There are six manifestations of CSA: a rare primary or idiopathic form, often in hypocapnic patients with an increased hypercapnic ventilatory drive; Cheyne-Stokes respiration, characterised by periodic CSA and a crescendo/decrescendo breathing pattern, often in patients with severe cardiac or neurological diseases; high altitude-induced periodic breathing (above 4000 m), CSA due to medical or neurological conditions; CSA due to drug or substance use; and primary sleep apnea of infancy. Besides the consequent treatment of the underlying medical conditions therapeutic options include the use of drugs, e. g. acetacolamide or oxygen, as well as non-invasive ventilation, e. g. continuous positive airway pressure (CPAP) or adaptive servo-ventilation.

Survey of heating and current drive for K-DEMO

NASA Astrophysics Data System (ADS)

Mikkelsen, D. R.; Kessel, C. E.; Poli, F. M.; Bertelli, N.; Kim, K.

2018-03-01

We present calculations of heating and current drive by neutral injection and by electromagnetic waves in the ion cyclotron, helicon, lower hybrid, and electron cyclotron frequency ranges for the steady state burn conditions in a K-DEMO configuration with I_p=12.3 MA, a  =  2.1 m, R_o=6.8 m, B_o=7.4 T, \

Drive Beam Shaping and Witness Bunch Generation for the Plasma Wakefield Accelerator

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

England, R. J.; Frederico, J.; Hogan, M. J.

2010-11-04

High transformer ratio operation of the plasma wake field accelerator requires a tailored drive beam current profile followed by a short witness bunch. We discuss techniques for generating the requisite dual bunches and for obtaining the desired drive beam profile, with emphasis on the FACET experiment at SLAC National Accelerator Laboratory.

Interpretation of steam drive pilots in the Belridge Diatomite

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

Johnston, R.M.; Shahin, G.T.

1995-12-31

The South Belridge Diatomite Field contains more than 2.5 billion barrels of oil-in-place. Current primary and waterflood development are estimated to recover only a small fraction of this oil. Despite its low permeability, the diatomite may be a good candidate for the steam drive process, due to its thick oil column (1,000 ft), high porosity (50% to 65%), and high oil saturation (up to 70%). With these attributes, thermal expansion and decreased viscosity of reservoir fluids accelerate oil production, without significant heat loss to cap and base rock. Steam drive pilot operations have been conducted at South Belridge since 1986.more » This paper discusses the pilot projects and the 15-acre steam drive full-scale project currently being installed.« less

Baseline tests of the Kordesh hybrid passenger vehicle

NASA Technical Reports Server (NTRS)

Soltis, R. F.; Bozek, J. M.; Denington, R. J.; Dustin, M. O.

1978-01-01

Performance test results are presented for a four-passenger Austin A40 sedan that was converted to a heat-engine-alternator-and battery-powered hybrid. It is propelled by a conventional, gasoline-fueled, heat-engine-driven alternator and a traction pack powering a series-wound, 10 hp direct-current electric drive motor. The 16 hp gasoline engine drives the 7 kilowatt alternator, which provides electrical power to the drive motor or to the 96 volt traction battery through a rectifier. The propulsion battery consists of eight 12 volt batteries connected in series. The electric motor is coupled to a four-speed standard transmission, which drives the rear wheels. Power to the motor is controlled by a three-step foot throttle, which actuates relays that control armature current and field excitation. Conventional hydraulic brakes are used.

Central Safety Factor and Normalized Beta Control Under Near-Zero Input Torque Constraints in DIII-D

NASA Astrophysics Data System (ADS)

Pajares, Andres; Wehner, William; Schuster, Eugenio; Burrell, Keith; Ferron, John; Walker, Michael; Humphreys, David; Lehigh University Team; Atomics Team, General

2017-10-01

DIII-D experiments have assessed the capability of combined central safety factor (q0) and normalized beta (βN) control under near-zero net torque to facilitate access to QH-mode with reverse Ip and normal Bt. Regulation of q0 and βN can prevent magneto-hydrodynamic instabilities that deteriorate plasma performance in discharges with a monotonically increasing safety-factor profile. Zero-input-torque scenarios are of special interest because future burning plasma tokamaks such as ITER will most likely operate with very low input torque, which makes these scenarios more susceptible to locked modes. To support studies of such scenarios, a controller for simultaneous regulation of q0 and βN has been developed using near-zero net input torque actuators including balanced neutral beam injection (NBI) and electron-cyclotron heating & current drive (ECH/ECCD). Experimental results show that in spite of the presence of locked modes the use of feedback control resulted in good tracking of the commanded q0 and βN when both ECCD/ECH and NBI were available. Supported by the US DOE under DE-SC0010661 and DE-FC02-04ER54698.

Informatics in radiology: automated Web-based graphical dashboard for radiology operational business intelligence.

PubMed

Nagy, Paul G; Warnock, Max J; Daly, Mark; Toland, Christopher; Meenan, Christopher D; Mezrich, Reuben S

2009-11-01

Radiology departments today are faced with many challenges to improve operational efficiency, performance, and quality. Many organizations rely on antiquated, paper-based methods to review their historical performance and understand their operations. With increased workloads, geographically dispersed image acquisition and reading sites, and rapidly changing technologies, this approach is increasingly untenable. A Web-based dashboard was constructed to automate the extraction, processing, and display of indicators and thereby provide useful and current data for twice-monthly departmental operational meetings. The feasibility of extracting specific metrics from clinical information systems was evaluated as part of a longer-term effort to build a radiology business intelligence architecture. Operational data were extracted from clinical information systems and stored in a centralized data warehouse. Higher-level analytics were performed on the centralized data, a process that generated indicators in a dynamic Web-based graphical environment that proved valuable in discussion and root cause analysis. Results aggregated over a 24-month period since implementation suggest that this operational business intelligence reporting system has provided significant data for driving more effective management decisions to improve productivity, performance, and quality of service in the department.

Detrimental and protective fat: body fat distribution and its relation to metabolic disease.

PubMed

Booth, Andrea; Magnuson, Aaron; Foster, Michelle

2014-01-01

Obesity is linked to numerous comorbidities that include, but are not limited to, glucose intolerance, insulin resistance, dyslipidemia, and cardiovascular disease. Current evidence suggests, however, obesity itself is not an exclusive predictor of metabolic dysregulation but rather adipose tissue distribution. Obesity-related adverse health consequences occur predominately in individuals with upper body fat accumulation, the detrimental distribution, commonly associated with visceral obesity. Increased lower body subcutaneous adipose tissue, however, is associated with a reduced risk of obesity-induced metabolic dysregulation and even enhanced insulin sensitivity, thus, storage in this region is considered protective. The proposed mechanisms that causally relate the differential outcomes of adipose tissue distribution are often attributed to location and/or adipocyte regulation. Visceral adipose tissue effluent to the portal vein drains into the liver where hepatocytes are directly exposed to its metabolites and secretory products, whereas the subcutaneous adipose tissue drains systemically. Adipose depots are also inherently different in numerous ways such as adipokine release, immunity response and regulation, lipid turnover, rate of cell growth and death, and response to stress and sex hormones. Proximal extrinsic factors also play a role in the differential drive between adipose tissue depots. This review focuses on the deleterious mechanisms postulated to drive the differential metabolic response between central and lower body adipose tissue distribution.

Effects of memory rehearsal on driver performance: experiment and theoretical account.

PubMed

Salvucci, Dario D; Beltowska, Joanna

2008-10-01

We report an experiment and a theoretical analysis concerning the effects of an exclusively cognitive task, specifically a memory rehearsal task, on driver performance. Although recent work on driver distraction has elucidated the sometimes significant effects of cognitive processing on driver performance, these studies have typically mixed cognitive with perceptual and motor processing, making it difficult to isolate the effects of cognitive processing alone. We asked participants to drive in a driving simulator during only the rehearsal stage of a serial-recall memory task while we measured their ability to maintain a central lane position and respond to the illumination of a lead vehicle's brake lights. Memory rehearsal significantly affected drivers' steering performance as measured by lateral deviation from lane center, and it also significantly affected drivers' response time to the braking stimulus for the higher load memory task. These results lend support to a theoretical account of cognitive distraction provided by threaded cognition theory in terms of a cognitive bottleneck in procedural processing, and they also suggest that consideration of task urgency may be important in accounting for performance trade-offs among concurrent tasks. The experiment augments the current understanding of cognitive driver distraction and suggests that even exclusively cognitive secondary tasks may sometimes affect driver performance.

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

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

Parke, E.; Department of Physics, University of Wisconsin-Madison 1150 University Ave., Madison, Wisconsin 53706; Anderson, J. K.

2016-05-15

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm withmore » neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q{sub 0} by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].« less

Functional and neurochemical characterization of angiotensin type 1A receptor-expressing neurons in the nucleus of the solitary tract of the mouse.

PubMed

Carter, D A; Choong, Y-T; Connelly, A A; Bassi, J K; Hunter, N O; Thongsepee, N; Llewellyn-Smith, I J; Fong, A Y; McDougall, S J; Allen, A M

2017-10-01

Angiotensin II acts via two main receptors within the central nervous system, with the type 1A receptor (AT 1A R) most widely expressed in adult neurons. Activation of the AT 1 R in the nucleus of the solitary tract (NTS), the principal nucleus receiving central synapses of viscerosensory afferents, modulates cardiovascular reflexes. Expression of the AT 1 R occurs in high density within the NTS of most mammals, including humans, but the fundamental electrophysiological and neurochemical characteristics of the AT 1A R-expressing NTS neurons are not known. To address this, we have used a transgenic mouse, in which the AT 1A R promoter drives expression of green fluorescent protein (GFP). Approximately one-third of AT 1A R-expressing neurons express the catecholamine-synthetic enzyme tyrosine hydroxylase (TH), and a subpopulation of these stained for the transcription factor paired-like homeobox 2b (Phox2b). A third group, comprising approximately two-thirds of the AT 1A R-expressing NTS neurons, showed Phox2b immunoreactivity alone. A fourth group in the ventral subnucleus expressed neither TH nor Phox2b. In whole cell recordings from slices in vitro, AT 1A R-GFP neurons exhibited voltage-activated potassium currents, including the transient outward current and the M-type potassium current. In two different mouse strains, both AT 1A R-GFP neurons and TH-GFP neurons showed similar AT 1A R-mediated depolarizing responses to superfusion with angiotensin II. These data provide a comprehensive description of AT 1A R-expressing neurons in the NTS and increase our understanding of the complex actions of this neuropeptide in the modulation of viscerosensory processing. Copyright © 2017 the American Physiological Society.

The Effects of Low Dose-Rate Ionizing Radiation on the Shapes of Transients in the LM124 Operational Amplifier

NASA Technical Reports Server (NTRS)

Buchner, Stephen; McMorrow, Dale; Roche, Nicholas; Dusseau, Laurent; Pease, Ron L.

2008-01-01

Shapes of single event transients (SETs) in a linear bipolar circuit (LM124) change with exposure to total ionizing dose (TID) radiation. SETs shape changes are a direct consequence of TID-induced degradation of bipolar transistor gain. A reduction in transistor gain causes a reduction in the drive current of the current sources in the circuit, and it is the lower drive current that most affects the shapes of large amplitude SETs.

Low-jitter high-power thyristor array pulse driver and generator

DOEpatents

Hanks, Roy L.

2002-01-01

A method and apparatus for generating low-jitter, high-voltage and high-current pulses for driving low impedance loads such as detonator fuses uses a MOSFET driver which, when triggered, discharges a high-voltage pre-charged capacitor into the primary of a toroidal current-multiplying transformer with multiple isolated secondary windings. The secondary outputs are suitable for driving an array of thyristors that discharge a precharged high-voltage capacitor and thus generating the required high-voltage and high-current pulse.

Pile Driving

NASA Technical Reports Server (NTRS)

1987-01-01

Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

Resting state synchrony in long-term abstinent alcoholics: Effects of a current major depressive disorder diagnosis.

PubMed

Fein, George; Camchong, Jazmin; Cardenas, Valerie A; Stenger, Andy

2017-03-01

Alcoholism is characterized by a lack of control over an impulsive and compulsive drive toward excessive alcohol consumption despite significant negative consequences; our previous work demonstrated that successful abstinence is characterized by decreased resting-state synchrony (RSS) as measured with functional magnetic resonance imaging (fMRI), within appetitive drive networks and increased RSS in emotion regulation and inhibitory executive control networks. Our hypothesis is that LTAA (Long-Term Abstinent Alcoholics) with a current major depressive disorder (MDD) drank primarily to deal with the negative affect associated with their MDD and not because of a heightened externalizing diathesis (including heightened appetitive drive), and consequently, in achieving and maintaining abstinence, such individuals would not exhibit the RSS adaptations characteristic of pure alcoholics. We studied 69 NSAC (Non Substance Abusing Controls) and 40 LTAA (8 with current MDD, 32 without a current MDD) using resting-state fMRI and seed based connectivity analyses. In the inhibitory executive control network (nucleus accumbens vs. left dorsolateral prefrontal cortex), LTAA with a current MDD showed increased synchrony compared to NSAC. In the emotion regulation executive control network (subgenual anterior cingulate cortex vs. right dorsolateral prefrontal cortex), LTAA with current MDD did not show increased RSS. In the appetitive drive networks (nucleus accumbens vs, aspects of the caudate nucleus and thalamus), LTAA with a current MDD did not show a reduction of RSS compared to NSAC, but LTAA without a current MDD did. These results suggest different pathways to their alcohol dependence in LTAA with vs. without a current MDD, and different patterns of brain activity in long-term abstinence, suggesting different treatment needs. Copyright © 2016 Elsevier Inc. All rights reserved.

Resting state synchrony in long-term abstinent alcoholics: Effects of a current major depressive disorder diagnosis

PubMed Central

Fein, George; Camchong, Jazmin; Cardenas, Valerie A.; Stenger, Andy

2017-01-01

Alcoholism is characterized by a lack of control over an impulsive and compulsive drive toward excessive alcohol consumption despite significant negative consequences; our previous work demonstrated that successful abstinence is characterized by decreased resting-state synchrony (RSS) as measured with functional magnetic resonance imaging (fMRI), within appetitive drive networks and increased RSS in emotion regulation and inhibitory executive control networks. Our hypothesis is that LTAA (Long-Term Abstinent Alcoholics) with a current major depressive disorder (MDD) drank primarily to deal with the negative affect associated with their MDD and not because of a heightened externalizing diathesis (including heightened appetitive drive), and consequently, in achieving and maintaining abstinence, such individuals would not exhibit the RSS adaptations characteristic of pure alcoholics. We studied 69 NSAC (Non Substance Abusing Controls) and 40 LTAA (8 with current MDD, 32 without a current MDD) using resting-state fMRI and seed based connectivity analyses. In the inhibitory executive control network (nucleus accumbens vs. left dorsolateral prefrontal cortex), LTAA with a current MDD showed increased synchrony compared to NSAC. In the emotion regulation executive control network (subgenual anterior cingulate cortex vs. right dorsolateral prefrontal cortex), LTAA with current MDD did not show increased RSS. In the appetitive drive networks (nucleus accumbens vs, aspects of the caudate nucleus and thalamus), LTAA with a current MDD did not show a reduction of RSS compared to NSAC, but LTAA without a current MDD did. These results suggest different pathways to their alcohol dependence in LTAA with vs. without a current MDD, and different patterns of brain activity in long-term abstinence, suggesting different treatment needs. PMID:28262184

Sleep in heart failure.

PubMed

Naughton, Matthew T; Lorenzi-Filho, Geraldo

2009-01-01

Sleep plays a large role in patients with heart failure. In normal subjects, sleep is usually in a supine position with reduced sympathetic drive, elevated vagal tone and as such a relatively lower cardiac output and minute ventilation, allowing for recuperation. Patients with heart failure may not experience the same degree of autonomic activity change and the supine position may place a large strain on the pulmonary system. More than half of all heart failure patients have one of two types of sleep apnea: either obstructive or central sleep apnea. Some patients have both types. Obstructive sleep apnea is likely to be a cause of heart failure due to large negative intrathoracic pressures, apnea related hypoxemia and hypercapnia, terminated by an arousal and surge in systemic blood pressure associated with endothelial damage and resultant premature atherosclerosis. Reversal of obstructive sleep apnea improves blood pressure, systolic contraction and autonomic dysfunction however mortality studies are lacking. Central sleep apnea with Cheyne Stokes pattern of respiration (CSA-CSR) occurs as a result of increased central controller (brainstem driving ventilation) and plant (ventilation driving CO2) gain in the setting of a delayed feed back (i.e., low cardiac output). It is thought this type of apnea is a result of moderately to severely impaired cardiac function and is possibly indicative of high mortality. Treatment of CSA-CSR is best undertaken by treating the underlying cardiac condition which may include with medications, pacemakers, transplantation or continuous positive airway pressure (CPAP). In such patients CPAP exerts unique effects to assist cardiac function and reduce pulmonary edema. Whether CPAP improves survival in this heart failure population remains to be determined.

Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation.

PubMed

Seven, Yasin B; Mantilla, Carlos B; Sieck, Gary C

2014-12-01

Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P < 0.01). During airway occlusion, central drive was ∼3 times greater, motor units were recruited ∼30 ms earlier (P < 0.01), and motor unit onset discharge frequencies were significantly higher (P < 0.01). Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited <20 ms apart. These results are consistent with DIAm motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. Copyright © 2014 the American Physiological Society.

Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation

PubMed Central

Seven, Yasin B.; Mantilla, Carlos B.

2014-01-01

Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P < 0.01). During airway occlusion, central drive was ∼3 times greater, motor units were recruited ∼30 ms earlier (P < 0.01), and motor unit onset discharge frequencies were significantly higher (P < 0.01). Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited <20 ms apart. These results are consistent with DIAm motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. PMID:25257864

Improved heat tolerance in air drives the recurrent evolution of air-breathing.

PubMed

Giomi, Folco; Fusi, Marco; Barausse, Alberto; Mostert, Bruce; Pörtner, Hans-Otto; Cannicci, Stefano

2014-05-07

The transition to air-breathing by formerly aquatic species has occurred repeatedly and independently in fish, crabs and other animal phyla, but the proximate drivers of this key innovation remain a long-standing puzzle in evolutionary biology. Most studies attribute the onset of air-breathing to the repeated occurrence of aquatic hypoxia; however, this hypothesis leaves the current geographical distribution of the 300 genera of air-breathing crabs unexplained. Here, we show that their occurrence is mainly related to high environmental temperatures in the tropics. We also demonstrate in an amphibious crab that the reduced cost of oxygen supply in air extends aerobic performance to higher temperatures and thus widens the animal's thermal niche. These findings suggest that high water temperature as a driver consistently explains the numerous times air-breathing has evolved. The data also indicate a central role for oxygen- and capacity-limited thermal tolerance not only in shaping sensitivity to current climate change but also in underpinning the climate-dependent evolution of animals, in this case the evolution of air-breathing.

The interface of genomic technologies and nursing.

PubMed

Loescher, Lois J; Merkle, Carrie J

2005-01-01

(a) to summarize views of the interface of technology, genomic technology, and nursing; (b) provide an overview of current and emerging genomic technologies; (c) present clinical exemplars of uses of genomic technology in two disease conditions; and (d) list genomic-focused nursing research on genomic technologies. A discussion of genomic technology in the context of nurses' views of technology, the importance of genomic technology for nurses, linking the central dogma of molecular biology to state-of-the-art tests and assays, and nurses' current use of technologies. Human genome discoveries will continue to be an integral part of disease prevention, diagnosis, treatment, and management. These discoveries also have the potential for being integrated into nursing science. Genomic technologies are becoming a driving force in patient management, so that nurses will be unable to provide quality care without knowledge of the types of genomic technologies, the rationale for their use, and the possible sequelae that can result from genetic diagnosis or treatment. Many nurses already are using genomic technologies to conduct genomic-focused nursing research. The biobehavioral nature of much of this research further indicates the important contributions of nurses in genomics.

Improved heat tolerance in air drives the recurrent evolution of air-breathing

PubMed Central

Giomi, Folco; Fusi, Marco; Barausse, Alberto; Mostert, Bruce; Pörtner, Hans-Otto; Cannicci, Stefano

2014-01-01

The transition to air-breathing by formerly aquatic species has occurred repeatedly and independently in fish, crabs and other animal phyla, but the proximate drivers of this key innovation remain a long-standing puzzle in evolutionary biology. Most studies attribute the onset of air-breathing to the repeated occurrence of aquatic hypoxia; however, this hypothesis leaves the current geographical distribution of the 300 genera of air-breathing crabs unexplained. Here, we show that their occurrence is mainly related to high environmental temperatures in the tropics. We also demonstrate in an amphibious crab that the reduced cost of oxygen supply in air extends aerobic performance to higher temperatures and thus widens the animal's thermal niche. These findings suggest that high water temperature as a driver consistently explains the numerous times air-breathing has evolved. The data also indicate a central role for oxygen- and capacity-limited thermal tolerance not only in shaping sensitivity to current climate change but also in underpinning the climate-dependent evolution of animals, in this case the evolution of air-breathing. PMID:24619438

Protein-linked glycans in periodontal bacteria: prevalence and role at the immune interface.

PubMed

Settem, Rajendra P; Honma, Kiyonobu; Stafford, Graham P; Sharma, Ashu

2013-10-17

Protein modification with complex glycans is increasingly being recognized in many pathogenic and non-pathogenic bacteria, and is now thought to be central to the successful life-style of those species in their respective hosts. This review aims to convey current knowledge on the extent of protein glycosylation in periodontal pathogenic bacteria and its role in the modulation of the host immune responses. The available data show that surface glycans of periodontal bacteria orchestrate dendritic cell cytokine responses to drive T cell immunity in ways that facilitate bacterial persistence in the host and induce periodontal inflammation. In addition, surface glycans may help certain periodontal bacteria protect against serum complement attack or help them escape immune detection through glycomimicry. In this review we will focus mainly on the generalized surface-layer protein glycosylation system of the periodontal pathogen Tannerella forsythia in shaping innate and adaptive host immunity in the context of periodontal disease. In addition, we will also review the current state of knowledge of surface protein glycosylation and its potential for immune modulation in other periodontal pathogens.

Vehicle Test Procedure Driving Schedules

DOT National Transportation Integrated Search

1977-03-01

This report discusses the salient characteristics of driving schedules which are currently being used to determine automotive fuel economy, exhaust emissions, and component characteristics. The analyses discussed and the results reported highlight th...

The Effects of Dextromethorphan on Driving Performance and the Standardized Field Sobriety Test.

PubMed

Perry, Paul J; Fredriksen, Kristian; Chew, Stephanie; Ip, Eric J; Lopes, Ingrid; Doroudgar, Shadi; Thomas, Kelan

2015-09-01

Dextromethorphan (DXM) is abused most commonly among adolescents as a recreational drug to generate a dissociative experience. The objective of the study was to assess driving with and without DXM ingestion. The effects of one-time maximum daily doses of DXM 120 mg versus a guaifenesin 400 mg dose were compared among 40 healthy subjects using a crossover design. Subjects' ability to drive was assessed by their performance in a driving simulator (STISIM® Drive driving simulator software) and by conducting a standardized field sobriety test (SFST) administered 1-h postdrug administration. The one-time dose of DXM 120 mg did not demonstrate driving impairment on the STISIM® Drive driving simulator or increase SFST failures compared to guaifenesin 400 mg. Doses greater than the currently recommended maximum daily dose of 120 mg are necessary to perturb driving behavior. © 2015 American Academy of Forensic Sciences.

75 FR 70023 - Outer Continental Shelf (OCS), Western and Central Planning Areas, Gulf of Mexico (GOM) Oil and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-16

..., November 16, 2010, New Orleans, Louisiana, Hilton New Orleans Airport, 901 Airline Drive Kenner, Louisiana... the Regional Supervisor, Leasing and Environment (MS 5410), Bureau of Ocean Energy Management...

Faster, Better, Cheaper: A Decade of PC Progress.

ERIC Educational Resources Information Center

Crawford, Walt

1997-01-01

Reviews the development of personal computers and how computer components have changed in price and value. Highlights include disk drives; keyboards; displays; memory; color graphics; modems; CPU (central processing unit); storage; direct mail vendors; and future possibilities. (LRW)

What drives interaction strengths in complex food webs? A test with feeding rates of a generalist stream predator.

PubMed

Preston, Daniel L; Henderson, Jeremy S; Falke, Landon P; Segui, Leah M; Layden, Tamara J; Novak, Mark

2018-05-08

Describing the mechanisms that drive variation in species interaction strengths is central to understanding, predicting, and managing community dynamics. Multiple factors have been linked to trophic interaction strength variation, including species densities, species traits, and abiotic factors. Yet most empirical tests of the relative roles of multiple mechanisms that drive variation have been limited to simplified experiments that may diverge from the dynamics of natural food webs. Here, we used a field-based observational approach to quantify the roles of prey density, predator density, predator-prey body-mass ratios, prey identity, and abiotic factors in driving variation in feeding rates of reticulate sculpin (Cottus perplexus). We combined data on over 6,000 predator-prey observations with prey identification time functions to estimate 289 prey-specific feeding rates at nine stream sites in Oregon. Feeding rates on 57 prey types showed an approximately log-normal distribution, with few strong and many weak interactions. Model selection indicated that prey density, followed by prey identity, were the two most important predictors of prey-specific sculpin feeding rates. Feeding rates showed a positive relationship with prey taxon densities that was inconsistent with predator saturation predicted by current functional response models. Feeding rates also exhibited four orders-of-magnitude in variation across prey taxonomic orders, with the lowest feeding rates observed on prey with significant anti-predator defenses. Body-mass ratios were the third most important predictor variable, showing a hump-shaped relationship with the highest feeding rates at intermediate ratios. Sculpin density was negatively correlated with feeding rates, consistent with the presence of intraspecific predator interference. Our results highlight how multiple co-occurring drivers shape trophic interactions in nature and underscore ways in which simplified experiments or reliance on scaling laws alone may lead to biased inferences about the structure and dynamics of species-rich food webs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Safe driving practices and factors associated with motor-vehicle collisions among people with insulin-treated diabetes mellitus: Results from the Diabetes and Driving (DAD) study.

PubMed

Almigbal, Turky H; Alfaifi, Abdullah A; Aleid, Muath A; Billah, Baki; Alramadan, Mohammed J; Sheshah, Eman; AlMogbel, Turki A; Aldekhayel, Ghassan A; Batais, Mohammed Ali

2018-06-01

The aim of this study was to assess the prevalence of people with insulin-treated diabetes mellitus (ITDM) who have discussed issues related to diabetes and driving with their health care providers (HCPs). We also sought to determine the safe driving practices that are currently employed by this group. Finally, we investigated the factors that might increase the risk of motor-vehicle collisions (MVCs) among this group in Saudi Arabia. This cross-sectional study surveyed a representative sample of 429 current male drivers with ITDM using a structured questionnaire in Saudi Arabia. Most of the participants (76.5%) never discussed topics regarding diabetes and driving with their HCPs. The majority of the participants (61.8%) reported at least never doing one of the following: (a) carrying a blood glucose testing kit while driving, (b) testing their blood glucose level before driving or during a journey, or (c) having thought of a specific threshold of blood glucose level that would preclude driving. Three factors were associated with a higher risk of MVCs among participants with ITDM: (a) being on a basal/boluses regimen, (b) never having a discussion regarding diabetes and driving with their HCPs, and (c) having experienced hypoglycemia during driving. The majority of people with ITDM had not had a discussion regarding diabetes and driving with their HCPs, which was reflected by a lack of safe driving practices. People with ITDM should be encouraged to take precautions while driving in order to prevent future MVCs. This research highlights the importance of investing more effort in educating drivers who have diabetes about safe driving practices by their health care providers. Also, it will attracts the attention of policymakers for an urgent need to establish clear policies and procedures for dealing with drivers who have diabetes. Copyright © 2018 National Safety Council and Elsevier Ltd. All rights reserved.

Simulations towards the achievement of non-inductive current ramp-up and sustainment in the National Spherical Torus Experiment Upgrade

DOE PAGES

Poli, F. M.; Andre, R. G.; Bertelli, N.; ...

2015-10-30

One of the goals of the National Spherical Torus Experiment Upgrade (NSTX-U) (Menard et al 2012 Nucl. Fusion 52 083015) is the demonstration of fully non-inductive start-up, current ramp-up and sustainment. This work discusses predictive simulations where the available heating and current drive systems are combined to maximize the non-inductive current and minimize the solenoidal contribution. Radio-frequency waves at harmonics higher than the ion cyclotron resonance (high-harmonic fast waves (HHFW)) and neutral beam injection are used to ramp the plasma current non-inductively starting from an initial Ohmic plasma. An interesting synergy is observed in the simulations between the HHFW andmore » electron cyclotron (EC) wave heating. Furthermore, time-dependent simulations indicate that, depending on the phasing of the HHFW antenna, EC wave heating can significantly increase the effectiveness of the radio-frequency power, by heating the electrons and increasing the current drive efficiency, thus relaxing the requirements on the level of HHFW power that needs to be absorbed in the core plasma to drive the same amount of fast-wave current.« less

Effects of central nervous system drugs on driving: speed variability versus standard deviation of lateral position as outcome measure of the on-the-road driving test.

PubMed

Verster, Joris C; Roth, Thomas

2014-01-01

The on-the-road driving test in normal traffic is used to examine the impact of drugs on driving performance. This paper compares the sensitivity of standard deviation of lateral position (SDLP) and SD speed in detecting driving impairment. A literature search was conducted to identify studies applying the on-the-road driving test, examining the effects of anxiolytics, antidepressants, antihistamines, and hypnotics. The proportion of comparisons (treatment versus placebo) where a significant impairment was detected with SDLP and SD speed was compared. About 40% of 53 relevant papers did not report data on SD speed and/or SDLP. After placebo administration, the correlation between SDLP and SD speed was significant but did not explain much variance (r = 0.253, p = 0.0001). A significant correlation was found between ΔSDLP and ΔSD speed (treatment-placebo), explaining 48% of variance. When using SDLP as outcome measure, 67 significant treatment-placebo comparisons were found. Only 17 (25.4%) were significant when SD speed was used as outcome measure. Alternatively, for five treatment-placebo comparisons, a significant difference was found for SD speed but not for SDLP. Standard deviation of lateral position is a more sensitive outcome measure to detect driving impairment than speed variability.

Computer hardware for radiologists: Part 2

PubMed Central

Indrajit, IK; Alam, A

2010-01-01

Computers are an integral part of modern radiology equipment. In the first half of this two-part article, we dwelt upon some fundamental concepts regarding computer hardware, covering components like motherboard, central processing unit (CPU), chipset, random access memory (RAM), and memory modules. In this article, we describe the remaining computer hardware components that are of relevance to radiology. “Storage drive” is a term describing a “memory” hardware used to store data for later retrieval. Commonly used storage drives are hard drives, floppy drives, optical drives, flash drives, and network drives. The capacity of a hard drive is dependent on many factors, including the number of disk sides, number of tracks per side, number of sectors on each track, and the amount of data that can be stored in each sector. “Drive interfaces” connect hard drives and optical drives to a computer. The connections of such drives require both a power cable and a data cable. The four most popular “input/output devices” used commonly with computers are the printer, monitor, mouse, and keyboard. The “bus” is a built-in electronic signal pathway in the motherboard to permit efficient and uninterrupted data transfer. A motherboard can have several buses, including the system bus, the PCI express bus, the PCI bus, the AGP bus, and the (outdated) ISA bus. “Ports” are the location at which external devices are connected to a computer motherboard. All commonly used peripheral devices, such as printers, scanners, and portable drives, need ports. A working knowledge of computers is necessary for the radiologist if the workflow is to realize its full potential and, besides, this knowledge will prepare the radiologist for the coming innovations in the ‘ever increasing’ digital future. PMID:21423895

Using Social Judgment Theory method to examine how experienced occupational therapy driver assessors use information to make fitness-to-drive recommendations

PubMed Central

Harries, Priscilla; Davies, Miranda

2015-01-01

Introduction As people with a range of disabilities strive to increase their community mobility, occupational therapy driver assessors are increasingly required to make complex recommendations regarding fitness-to-drive. However, very little is known about how therapists use information to make decisions. The aim of this study was to model how experienced occupational therapy driver assessors weight and combine information when making fitness-to-drive recommendations and establish their level of decision agreement. Method Using Social Judgment Theory method, this study examined how 45 experienced occupational therapy driver assessors from the UK, Australia and New Zealand made fitness-to-drive recommendations for a series of 64 case scenarios. Participants completed the task on a dedicated website, and data were analysed using discriminant function analysis and an intraclass correlation coefficient. Results Accounting for 87% of the variance, the cues central to the fitness-to-drive recommendations made by assessors are the client’s physical skills, cognitive and perceptual skills, road law craft skills, vehicle handling skills and the number of driving instructor interventions. Agreement (consensus) between fitness-to-drive recommendations was very high: intraclass correlation coefficient = .97, 95% confidence interval .96–.98). Conclusion Findings can be used by both experienced and novice driver assessors to reflect on and strengthen the fitness-to-drive recommendations made to clients. PMID:26435572

Common drive to the upper airway muscle genioglossus during inspiratory loading

PubMed Central

Woods, Michael J.; Nicholas, Christian L.; Semmler, John G.; Chan, Julia K. M.; Jordan, Amy S.

2015-01-01

Common drive is thought to constitute a central mechanism by which the efficiency of a motor neuron pool is increased. This study tested the hypothesis that common drive to the upper airway muscle genioglossus (GG) would increase with increased respiratory drive in response to an inspiratory load. Respiration, GG electromyographic (EMG) activity, single-motor unit activity, and coherence in the 0–5 Hz range between pairs of GG motor units were assessed for the 30 s before an inspiratory load, the first and second 30 s of the load, and the 30 s after the load. Twelve of twenty young, healthy male subjects provided usable data, yielding 77 pairs of motor units: 2 Inspiratory Phasic, 39 Inspiratory Tonic, 15 Expiratory Tonic, and 21 Tonic. Respiratory and GG inspiratory activity significantly increased during the loads and returned to preload levels during the postload periods (all showed significant quadratic functions over load trials, P < 0.05). As hypothesized, common drive increased during the load in inspiratory modulated motor units to a greater extent than in expiratory/tonic motor units (significant load × discharge pattern interaction, P < 0.05). Furthermore, this effect persisted during the postload period. In conclusion, common drive to inspiratory modulated motor units was elevated in response to increased respiratory drive. The postload elevation in common drive was suggestive of a poststimulus activation effect. PMID:26378207

The cold driver: Cold stress while driving results in dangerous behavior.

PubMed

Morris, Drew M; Pilcher, June J

2016-10-01

Cool vehicle cabin temperatures can induce short-term non-hypothermic cold stress. The current study created a cold condition to examine the impact of cold stress on driving behavior. Forty-four participants drove a high-fidelity driving simulator during a thermal neutral or local torso cooled condition. Participants performed additional tasks to assess attention, psychomotor vigilance, and manual dexterity. Skin temperature was significantly lower in the cold condition while internal temperature was unaffected. Participants who had higher subjective ratings of cold followed lead vehicles closer and started to brake later. Participants in the cold condition followed the lead car 22% (0.82s) closer and started braking 20% (2.35s) later when approaching a stop sign during the car-following task. No change in attention, psychomotor vigilance, or dexterity was observed. The current results suggest that cold environmental conditions can contribute to dangerous driving behaviors. Measures of cold perception were also shown to predict changes in driving behavior. Copyright © 2016 Elsevier B.V. All rights reserved.

Non-inductive current drive and transport in high βN plasmas in JET

NASA Astrophysics Data System (ADS)

Voitsekhovitch, I.; Alper, B.; Brix, M.; Budny, R. V.; Buratti, P.; Challis, C. D.; Ferron, J.; Giroud, C.; Joffrin, E.; Laborde, L.; Luce, T. C.; McCune, D.; Menard, J.; Murakami, M.; Park, J. M.; JET-EFDA contributors

2009-05-01

A route to stationary MHD stable operation at high βN has been explored at the Joint European Torus (JET) by optimizing the current ramp-up, heating start time and the waveform of neutral beam injection (NBI) power. In these scenarios the current ramp-up has been accompanied by plasma pre-heat (or the NBI has been started before the current flat-top) and NBI power up to 22 MW has been applied during the current flat-top. In the discharges considered transient total βN ≈ 3.3 and stationary (during high power phase) βN ≈ 3 have been achieved by applying the feedback control of βN with the NBI power in configurations with monotonic or flat core safety factor profile and without an internal transport barrier (ITB). The transport and current drive in this scenario is analysed here by using the TRANSP and ASTRA codes. The interpretative analysis performed with TRANSP shows that 50-70% of current is driven non-inductively; half of this current is due to the bootstrap current which has a broad profile since an ITB was deliberately avoided. The GLF23 transport model predicts the temperature profiles within a ±22% discrepancy with the measurements over the explored parameter space. Predictive simulations with this model show that the E × B rotational shear plays an important role for thermal ion transport in this scenario, producing up to a 40% increase of the ion temperature. By applying transport and current drive models validated in self-consistent simulations of given reference scenarios in a wider parameter space, the requirements for fully non-inductive stationary operation at JET are estimated. It is shown that the strong stiffness of the temperature profiles predicted by the GLF23 model restricts the bootstrap current at larger heating power. In this situation full non-inductive operation without an ITB can be rather expensive strongly relying on the external non-inductive current drive sources.

Survey of heating and current drive for K-DEMO

DOE PAGES

Mikkelsen, D. R.; Kessel, C. E.; Poli, F. M.; ...

2018-01-22

Here, we present calculations of heating and current drive by neutral injection and by electromagnetic waves in the ion cyclotron, helicon, lower hybrid, and electron cyclotron frequency ranges for the steady state burn conditions in a K-DEMO configuration withmore » $$I_{\\rm p}=12.3$$ MA, a = 2.1 m, $$R_{\\rm o}=6.8$$ m, $$B_{\\rm o}=7.4$$ T, $$ \

Survey of heating and current drive for K-DEMO

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

Mikkelsen, D. R.; Kessel, C. E.; Poli, F. M.

Here, we present calculations of heating and current drive by neutral injection and by electromagnetic waves in the ion cyclotron, helicon, lower hybrid, and electron cyclotron frequency ranges for the steady state burn conditions in a K-DEMO configuration withmore » $$I_{\\rm p}=12.3$$ MA, a = 2.1 m, $$R_{\\rm o}=6.8$$ m, $$B_{\\rm o}=7.4$$ T, $$ \

Stable Spheromaks Sustained by Neutral Beam Injection

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

Fowler, T K; Jayakumar, R; McLean, H S

It is shown that spheromak equilibria, stable at zero-beta but departing from the Taylor state, could be sustained by non-inductive current drive at acceptable power levels. Stability to both ideal MHD and tearing modes is verified using the NIMROD code for linear stability analysis. Non-linear NIMROD calculations with non-inductive current drive and pressure effects could point the way to improved fusion reactors.

Dangers of Texting While Driving

MedlinePlus

... it be shared with students and parents. State laws Currently there is no national ban on texting ... driving, but a number of states have passed laws banning texting or wireless phones or requiring hands- ...

About increasing informativity of diagnostic system of asynchronous electric motor by extracting additional information from values of consumed current parameter

NASA Astrophysics Data System (ADS)

Zhukovskiy, Y.; Korolev, N.; Koteleva, N.

2018-05-01

This article is devoted to expanding the possibilities of assessing the technical state of the current consumption of asynchronous electric drives, as well as increasing the information capacity of diagnostic methods, in conditions of limited access to equipment and incompleteness of information. The method of spectral analysis of the electric drive current can be supplemented by an analysis of the components of the current of the Park's vector. The research of the hodograph evolution in the moment of appearance and development of defects was carried out using the example of current asymmetry in the phases of an induction motor. The result of the study is the new diagnostic parameters of the asynchronous electric drive. During the research, it was proved that the proposed diagnostic parameters allow determining the type and level of the defect. At the same time, there is no need to stop the equipment and taky it out of service for repair. Modern digital control and monitoring systems can use the proposed parameters based on the stator current of an electrical machine to improve the accuracy and reliability of obtaining diagnostic patterns and predicting their changes in order to improve the equipment maintenance systems. This approach can also be used in systems and objects where there are significant parasitic vibrations and unsteady loads. The extraction of useful information can be carried out in electric drive systems in the structure of which there is a power electric converter.

Attentional Differences in a Driving Hazard Perception Task in Adults with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Sheppard, Elizabeth; van Loon, Editha; Underwood, Geoffrey; Ropar, Danielle

2017-01-01

The current study explored attentional processing of social and non-social stimuli in ASD within the context of a driving hazard perception task. Participants watched videos of road scenes and detected hazards while their eye movements were recorded. Although individuals with ASD demonstrated relatively good detection of driving hazards, they were…

Early Life Conditions and Physiological Stress following the Transition to Farming in Central/Southeast Europe: Skeletal Growth Impairment and 6000 Years of Gradual Recovery

PubMed Central

Macintosh, Alison A.; Pinhasi, Ron; Stock, Jay T.

2016-01-01

Early life conditions play an important role in determining adult body size. In particular, childhood malnutrition and disease can elicit growth delays and affect adult body size if severe or prolonged enough. In the earliest stages of farming, skeletal growth impairment and small adult body size are often documented relative to hunter-gatherer groups, though this pattern is regionally variable. In Central/Southeast Europe, it is unclear how early life stress, growth history, and adult body size were impacted by the introduction of agriculture and ensuing long-term demographic, social, and behavioral change. The current study assesses this impact through the reconstruction and analysis of mean stature, body mass, limb proportion indices, and sexual dimorphism among 407 skeletally mature men and women from foraging and farming populations spanning the Late Mesolithic through Early Medieval periods in Central/Southeast Europe (~7100 calBC to 850 AD). Results document significantly reduced mean stature, body mass, and crural index in Neolithic agriculturalists relative both to Late Mesolithic hunter-gatherer-fishers and to later farming populations. This indication of relative growth impairment in the Neolithic, particularly among women, is supported by existing evidence of high developmental stress, intensive physical activity, and variable access to animal protein in these early agricultural populations. Among subsequent agriculturalists, temporal increases in mean stature, body mass, and crural index were more pronounced among Central European women, driving declines in the magnitude of sexual dimorphism through time. Overall, results suggest that the transition to agriculture in Central/Southeast Europe was challenging for early farming populations, but was followed by gradual amelioration across thousands of years, particularly among Central European women. This sex difference may be indicative, in part, of greater temporal variation in the social status afforded to young girls, in their access to resources during growth, and/or in their health status than was experienced by men. PMID:26844892

Low-power transcutaneous current stimulator for wearable applications.

PubMed

Karpul, David; Cohen, Gregory K; Gargiulo, Gaetano D; van Schaik, André; McIntyre, Sarah; Breen, Paul P

2017-10-03

Peripheral neuropathic desensitization associated with aging, diabetes, alcoholism and HIV/AIDS, affects tens of millions of people worldwide, and there is little or no treatment available to improve sensory function. Recent studies that apply imperceptible continuous vibration or electrical stimulation have shown promise in improving sensitivity in both diseased and healthy participants. This class of interventions only has an effect during application, necessitating the design of a wearable device for everyday use. We present a circuit that allows for a low-power, low-cost and small form factor implementation of a current stimulator for the continuous application of subthreshold currents. This circuit acts as a voltage-to-current converter and has been tested to drive + 1 to - 1 mA into a 60 k[Formula: see text] load from DC to 1 kHz. Driving a 60 k[Formula: see text] load with a 2 mA peak-to-peak 1 kHz sinusoid, the circuit draws less than 21 mA from a 9 V source. The minimum operating current of the circuit is less than 12 mA. Voltage compliance is ± 60 V with just 1.02 mA drawn by the high voltage current drive circuitry. The circuit was implemented as a compact 46 mm × 21 mm two-layer PCB highlighting its potential for use in a body-worn device. No design to the best of our knowledge presents comparably low quiescent power with such high voltage compliance. This makes the design uniquely appropriate for low-power transcutaneous current stimulation in wearable applications. Further development of driving and instrumentation circuitry is recommended.

Parents' and peers' contribution to risky driving of male teen drivers.

PubMed

Taubman - Ben-Ari, Orit; Kaplan, Sigal; Lotan, Tsippy; Prato, Carlo Giacomo

2015-05-01

The current study joins efforts devoted to understanding the associations of parents' personality, attitude, and behavior, and to evaluating the added contribution of peers to the driving behavior of young drivers during their solo driving. The study combines data gathered using in-vehicle data recorders from actual driving of parents and their male teen driver with data collected from self-report questionnaires completed by the young drivers. The sample consists of 121 families, who participated in the study for 12 months, beginning with the licensure of the teen driver. The current examination concentrates on the last 3 months of this first year of driving. The experimental design was based on a random control assignment into three treatment groups (with different forms of feedback) and a control group (with no feedback). Findings indicate that the parents' (especially the fathers') sensation seeking, anxiety, and aggression, as well as their risky driving events rate were positively associated with higher risky driving of the young driver. In addition, parents' involvement in the intervention, either by feedback or by training, led to lower risky driving events rate of young drivers compared to the control group. Finally, higher cohesion and adaptability mitigated parents' model for risky driving, and peers norms' of risky driving were associated with higher risk by the teen drivers. We conclude by claiming that there is an unequivocal need to look at a full and complex set of antecedents in parents' personality, attitudes, and behavior, together with the contribution of peers to the young drivers' reckless driving, and address the practical implications for road safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

Driving Method for Compensating Reliability Problem of Hydrogenated Amorphous Silicon Thin Film Transistors and Image Sticking Phenomenon in Active Matrix Organic Light-Emitting Diode Displays

NASA Astrophysics Data System (ADS)

Shin, Min-Seok; Jo, Yun-Rae; Kwon, Oh-Kyong

2011-03-01

In this paper, we propose a driving method for compensating the electrical instability of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs) and the luminance degradation of organic light-emitting diode (OLED) devices for large active matrix OLED (AMOLED) displays. The proposed driving method senses the electrical characteristics of a-Si:H TFTs and OLEDs using current integrators and compensates them by an external compensation method. Threshold voltage shift is controlled a using negative bias voltage. After applying the proposed driving method, the measured error of the maximum emission current ranges from -1.23 to +1.59 least significant bit (LSB) of a 10-bit gray scale under the threshold voltage shift ranging from -0.16 to 0.17 V.

Adolescent Cellphone Use While Driving: An Overview of the Literature and Promising Future Directions for Prevention.

PubMed

Delgado, M Kit; Wanner, Kathryn J; McDonald, Catherine

2016-06-16

Motor vehicle crashes are the leading cause of death in adolescents, and drivers aged 16-19 are the most likely to die in distracted driving crashes. This paper provides an overview of the literature on adolescent cellphone use while driving, focusing on the crash risk, incidence, risk factors for engagement, and the effectiveness of current mitigation strategies. We conclude by discussing promising future approaches to prevent crashes related to cellphone use in adolescents. Handheld manipulation of the phone while driving has been shown to have a 3 to 4-fold increased risk of a near crash or crash, and eye glance duration greater than 2 seconds increases crash risk exponentially. Nearly half of U.S. high school students admit to texting while driving in the last month, but the frequency of use according to vehicle speed and high-risk situations remains unknown. Several risk factors are associated with cell phone use while driving including: parental cellphone use while driving, social norms for quick responses to text messages, and higher levels of temporal discounting. Given the limited effectiveness of current mitigation strategies such as educational campaigns and legal bans, a multi-pronged behavioral and technological approach addressing the above risk factors will be necessary to reduce this dangerous behavior in adolescents.

The choice to text and drive in younger drivers: behavior may shape attitude.

PubMed

Atchley, Paul; Atwood, Stephanie; Boulton, Aaron

2011-01-01

Following a previous study that reported a large number of young adult drivers text and drive, the current study investigated this behavior by looking at patterns of use and driver assessment of the risk of the behavior. The data from the current study converge with and extended the previous work showing 70% of the 348 young adult drivers surveyed report initiating texts while driving while higher numbers reply to texts (81%) and read texts (92%) while driving. Additional drivers also report doing these behaviors, but only while stopped in traffic, showing only 2% never text and drive under any circumstances. The drivers indicated that they perceived these behaviors to be very risky and riskier than talking on a cell phone while driving, but perception of risk was a very weak predictor of behavior (for initiating texts) or had no effect on texting (for replying or reading texts while driving). In addition, a factor analysis of the perception of road conditions while texting revealed that making the choice to engage in texting (initiating) led drivers to perceive road conditions as being safer than if they replied to a text or read a text, suggesting that choosing to engage in the behavior itself changes attitudes toward risk. Copyright © 2010 Elsevier Ltd. All rights reserved.

Adolescent Cellphone Use While Driving: An Overview of the Literature and Promising Future Directions for Prevention

PubMed Central

Delgado, M. Kit; Wanner, Kathryn J.; McDonald, Catherine

2016-01-01

Motor vehicle crashes are the leading cause of death in adolescents, and drivers aged 16–19 are the most likely to die in distracted driving crashes. This paper provides an overview of the literature on adolescent cellphone use while driving, focusing on the crash risk, incidence, risk factors for engagement, and the effectiveness of current mitigation strategies. We conclude by discussing promising future approaches to prevent crashes related to cellphone use in adolescents. Handheld manipulation of the phone while driving has been shown to have a 3 to 4-fold increased risk of a near crash or crash, and eye glance duration greater than 2 seconds increases crash risk exponentially. Nearly half of U.S. high school students admit to texting while driving in the last month, but the frequency of use according to vehicle speed and high-risk situations remains unknown. Several risk factors are associated with cell phone use while driving including: parental cellphone use while driving, social norms for quick responses to text messages, and higher levels of temporal discounting. Given the limited effectiveness of current mitigation strategies such as educational campaigns and legal bans, a multi-pronged behavioral and technological approach addressing the above risk factors will be necessary to reduce this dangerous behavior in adolescents. PMID:27695663

A numerical study on the evolution of the wind-driven circulation in the Yellow Sea in winter

NASA Astrophysics Data System (ADS)

Tak, Y. J.; Cho, Y. K.

2016-02-01

The Yellow Sea is a semi-enclosed marginal sea and its circulation in winter is affected by the winter monsoon. In previous studies, it was found that the circulation of the Yellow Sea in winter consists of downwind and upwind currents. Downwind currents consisting of the Korean Coast Current (KCC) and the Chinese Coast Current (CCC) flow along the boundary of the Yellow Sea, whereas an upwind current consisting of the Yellow Sea Warm Current (YSWC) flows along the central trough of the Yellow Sea. Although some characteristics of such currents and the driving forces of the circulation have been studied by many scientists, the evolution of these currents has received little attention. So, the wind-driven circulation in the Yellow Sea was simulated to explain the changing pattern of these currents in winter and their evolutions were explored by the time-lagged correlation for winter season. According to the lagged correlation, downwind currents occurred in surface layer without a time lag. These downwind currents were more sensitive in the Chinese coast than that in the Korean coast. There is one day time-lag between the wind and the upwind flow developing in the Yellow Sea trough. The YSWC was shifted to the west of the trough after two days and then the KCC strengthened at the same time. It implied the westward shift of the YSWC and the clockwise circulation is developed, two days after the wind blows. The clockwise circulation was one of the reasons that the KCC was stronger than the CCC although the CCC was more sensitive to the wind than the KCC. The clockwise circulation also made the YSWC stronger in the inner YS than it at the entrance of the YS.

Active-Matrix Organic Light Emission Diode Pixel Circuit for Suppressing and Compensating for the Threshold Voltage Degradation of Hydrogenated Amorphous Silicon Thin Film Transistors

NASA Astrophysics Data System (ADS)

Shin, Hee-Sun; Lee, Won-Kyu; Park, Sang-Guen; Kuk, Seung-Hee; Han, Min-Koo

2009-03-01

A new hydrogenated amorphous silicon (a-Si:H) thin film transistor (TFT) pixel circuit for active-matrix organic light emission diodes (AM-OLEDs), which significantly compensates the OLED current degradation by memorizing the threshold voltage of driving TFT and suppresses the threshold voltage shift of a-Si:H TFTs by negative bias annealing, is proposed and fabricated. During the first half of each frame, the driving TFT of the proposed pixel circuit supplies current to the OLED, which is determined by modified data voltage in the compensation scheme. The proposed pixel circuit was able to compensate the threshold voltage shift of the driving TFT as well as the OLED. During the remaining half of each frame, the proposed pixel circuit induces the recovery of the threshold voltage degradation of a-Si:H TFTs owing to the negative bias annealing. The experimental results show that the proposed pixel circuit was able to successfully compensate for the OLED current degradation and suppress the threshold voltage degradation of the driving TFT.

Freud on the Death Drive as Existence Without Tension.

PubMed

O'Connor, Brian

2016-06-01

Freud's notion of the death drive is complex and arguably ambiguous. This paper, however, proposes that Freud's thoughts on our organic dynamic towards tensionlessness provide us with a cohesive path through the diverse characteristics that are attributed to the death drive. The paper shows that Freud is interested in giving expression to a kind of disavowal of personhood that may present itself symptomatically. A tensionless state can be gained by a dynamic release of the individual from the pressures of the ego. This study critically sets out the line of analysis that brought Freud, in Beyond the Pleasure Principle, to introduce the notion of the death drive. The main work of the paper is to examine the meaning of the very idea of death as tensionlessness. A central contention will be that death has a figurative meaning when it is discussed in that context: it is the death of the ego. The idea of death as tensionlessness will be employed to explore a number of clinical interpretations of the relationship between the death drive and neurotic guilt and envy.

National Center for Photovoltaics at NREL

ScienceCinema

VanSant, Kaitlyn; Wilson, Greg; Berry, Joseph; Al-Jassim, Mowafak; Kurtz, Sarah

2018-06-08

The National Center for Photovoltaics at the National Renewable Energy Laboratory (NREL) focuses on technology innovations that drive industry growth in U.S. photovoltaic (PV) manufacturing. The NCPV is a central resource for our nation's capabilities in PV research, development, deployment, and outreach.

Arctic Ice-Ocean Coupling and Gyre Equilibration Observed With Remote Sensing

NASA Astrophysics Data System (ADS)

Dewey, Sarah; Morison, James; Kwok, Ronald; Dickinson, Suzanne; Morison, David; Andersen, Roger

2018-02-01

Model and observational evidence has shown that ocean current speeds in the Beaufort Gyre have increased and recently stabilized. Because these currents rival ice drift speeds, we examine the potential for the Beaufort Gyre's shift from a system in which the wind drives the ice and the ice drives a passive ocean to one in which the ocean often, in the absence of high winds, drives the ice. The resultant stress exerted on the ocean by the ice and the resultant Ekman pumping are reversed, without any change in average wind stress curl. Through these curl reversals, the ice-ocean stress provides a key feedback in Beaufort Gyre stabilization. This manuscript constitutes one of the first observational studies of ice-ocean stress inclusive of geostrophic ocean currents, by making use of recently available remote sensing data.

Long-Life, Lightweight, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration

NASA Technical Reports Server (NTRS)

Klein, Richard C.; Fusaro, Robert L.; Dimofte, Florin

2012-01-01

NASA s initiative for Lunar and Martian exploration will require long lived, robust drive systems for manned vehicles that must operate in hostile environments. The operation of these mechanical drives will pose a problem because of the existing extreme operating conditions. Some of these extreme conditions include operating at a very high or very cold temperature, operating over a wide range of temperatures, operating in very dusty environments, operating in a very high radiation environment, and operating in possibly corrosive environments. Current drive systems use gears with various configurations of teeth. These gears must be lubricated with oil (or grease) and must have some sort of a lubricant resupply system. For drive systems, oil poses problems such as evaporation, becoming too viscous and eventually freezing at cold temperatures, being too thin to lubricate at high temperatures, being degraded by the radiation environment, being contaminated by the regolith (soil), and if vaporized (and not sealed), it will contaminate the regolith. Thus, it may not be advisable or even possible to use oil because of these limitations. An oil-less, compact traction vehicle drive is a drive designed for use in hostile environments like those that will be encountered on planetary surfaces. Initially, traction roller tests in vacuum were conducted to obtain traction and endurance data needed for designing the drives. From that data, a traction drive was designed that would fit into a prototype lunar rover vehicle, and this design data was used to construct several traction drives. These drives were then tested in air to determine their performance characteristics, and if any final corrections to the designs were necessary. A limitation with current speed reducer systems such as planetary gears and harmonic drives is the high-contact stresses that occur at tooth engagement and in the harmonic drive wave generator interface. These high stresses induce high wear of solid lubricant coatings, thus necessitating the use of liquid lubricants for long life.

Driving range estimation for electric vehicles based on driving condition identification and forecast

NASA Astrophysics Data System (ADS)

Pan, Chaofeng; Dai, Wei; Chen, Liao; Chen, Long; Wang, Limei

2017-10-01

With the impact of serious environmental pollution in our cities combined with the ongoing depletion of oil resources, electric vehicles are becoming highly favored as means of transport. Not only for the advantage of low noise, but for their high energy efficiency and zero pollution. The Power battery is used as the energy source of electric vehicles. However, it does currently still have a few shortcomings, noticeably the low energy density, with high costs and short cycle life results in limited mileage compared with conventional passenger vehicles. There is great difference in vehicle energy consumption rate under different environment and driving conditions. Estimation error of current driving range is relatively large due to without considering the effects of environmental temperature and driving conditions. The development of a driving range estimation method will have a great impact on the electric vehicles. A new driving range estimation model based on the combination of driving cycle identification and prediction is proposed and investigated. This model can effectively eliminate mileage errors and has good convergence with added robustness. Initially the identification of the driving cycle is based on Kernel Principal Component feature parameters and fuzzy C referring to clustering algorithm. Secondly, a fuzzy rule between the characteristic parameters and energy consumption is established under MATLAB/Simulink environment. Furthermore the Markov algorithm and BP(Back Propagation) neural network method is utilized to predict the future driving conditions to improve the accuracy of the remaining range estimation. Finally, driving range estimation method is carried out under the ECE 15 condition by using the rotary drum test bench, and the experimental results are compared with the estimation results. Results now show that the proposed driving range estimation method can not only estimate the remaining mileage, but also eliminate the fluctuation of the residual range under different driving conditions.

Demonstration of plasma start-up by Coaxial Helicity Injection

NASA Astrophysics Data System (ADS)

Raman, Roger

2003-10-01

Experimental results on the first successful transfer of a Coaxial-Helicity-Injection- (CHI)-produced discharge to inductive operation are reported. CHI assisted plasma start-up is more robust than inductive-only operation and reduces volt-seconds consumption. After hand-off for inductive operation, the initial 100 kA of CHI-produced current drops to 44 kA, then ramps up to 180 kA, using only 30 mVs, more than 30induction alone. Coupling a CHI-produced discharge to induction from a pre-charged central solenoid has produced record plasma currents of 265kA in HIT-II. CHI discharges can also be generated while the central transformer is in the process of being pre-charged, during which period it induces a negative loop voltage on the CHI discharge. Such capability is believed to be important for a short pulse burning plasma experiment that could contain a solenoid. In the latest results, which improve upon the earlier work (Raman et. al., Phys. Rev. Lett., 90, (2003) 075005-1), no transient coil currents are necessary for the CHI produced closed flux generation. This is particularly important for a reactor in which the poloidal field coils would be located outside blanket structures. Three important results are reported. First, CHI is shown to produce closed flux plasma. Second, it is shown that electrode-based CHI plasmas can be sufficiently clean for fusion research purposes. Finally, it is shown that CHI discharges, in addition to generating useful startup current, improve the performance of inductive discharges. This work was motivated by earlier experiments on HIT-II and NSTX that showed coupling of the inductive drive to the external CHI power supply circuit, instead of to the main plasma discharge. These important results were obtained on the HIT-II spherical torus experiment (R/a of 0.3/0.2m, elongation of 1.5).

Combination spindle-drive system for high precision machining

DOEpatents

Gerth, Howard L.

1977-07-26

A combination spindle-drive is provided for fabrication of optical quality surface finishes. Both the spindle-and-drive utilize the spindle bearings for support, thereby removing the conventional drive-means bearings as a source of vibration. An airbearing spindle is modified to carry at the drive end a highly conductive cup-shaped rotor which is aligned with a stationary stator to produce torque in the cup-shaped rotor through the reaction of eddy currents induced in the rotor. This arrangement eliminates magnetic attraction forces and all force is in the form of torque on the cup-shaped rotor.

Where the Rubber Hits the Road: What Home Healthcare Professionals Need to Know About Driving Safety for Persons With Dementia.

PubMed

Pastor, Diane K; Jones, Andrea; Arms, Tamatha

2017-01-01

Driving cessation for people with dementia is a significant personal safety and public health issue. Home healthcare professionals frequently encounter situations where patients/clients should not continue to drive, and family members are unaware of how to approach the issue. This article will inform readers of the current state of the healthcare driving assessment process, measures and instruments used to assess, and effective strategies and resources when working with families facing the dilemma of how and when to proceed with a driving cessation plan.

Current drive by spheromak injection into a tokamak

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

Brown, M.R.; Bellan, P.M.

1990-04-30

We report the first observation of current drive by injection of a spheromak plasma into a tokamak (Caltech ENCORE small reasearch tokamak) due to the process of helicity injection. After an abrupt 30% increase, the tokamak current decays by a factor of 3 due to plasma cooling caused by the merging of the relatively cold spheromak with the tokamak. The tokamak density profile peaks sharply due to the injected spheromak plasma ({ital {bar n}}{sub 3} increases by a factor of 6) then becomes hollow, suggestive of an interchange instability.

Ocular disease and driving.

PubMed

Wood, Joanne M; Black, Alex A

2016-09-01

As the driving population ages, the number of drivers with visual impairment resulting from ocular disease will increase given the age-related prevalence of ocular disease. The increase in visual impairment in the driving population has a number of implications for driving outcomes. This review summarises current research regarding the impact of common ocular diseases on driving ability and safety, with particular focus on cataract, glaucoma, age-related macular degeneration, hemianopia and diabetic retinopathy. The evidence considered includes self-reported driving outcomes, driving performance (on-road and simulator-based) and various motor vehicle crash indices. Collectively, this review demonstrates that driving ability and safety are negatively affected by ocular disease; however, further research is needed in this area. Older drivers with ocular disease need to be aware of the negative consequences of their ocular condition and in the case where treatment options are available, encouraged to seek these earlier for optimum driving safety and quality of life benefits. © 2016 Optometry Australia.

Electrophysiology of Hypothalamic Magnocellular Neurons In vitro: A Rhythmic Drive in Organotypic Cultures and Acute Slices.

PubMed

Israel, Jean-Marc; Oliet, Stéphane H; Ciofi, Philippe

2016-01-01

Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains.

The Hispanic Americans baseline alcohol survey (HABLAS): DUI rates, birthplace, and acculturation across Hispanic national groups.

PubMed

Caetano, Raul; Ramisetty-Mikler, Suhasini; Rodriguez, Lori A

2008-03-01

This article examines the association between birthplace, acculturation, and self-reported driving under the influence of alcohol (DUI), 12-month and lifetime DUI arrest rates among Mexican Americans, Puerto Ricans, Cuban Americans, and South/Central Americans in the U.S. population. Using a multistage cluster sample design, 5,224 adults (18 years of age or older) were interviewed from households in five metropolitan areas of the United States: Miami, New York, Philadelphia, Houston, and Los Angeles. Birthplace was not associated with DUI, 12-month DUI arrest rates, or lifetime DUI arrest rates. Mexican Americans in the medium- and high-acculturation groups were more likely to engage in DUI. A higher proportion of U.S.-born than foreign-born respondents as well as those in the high-acculturation group, irrespective of national origin, reported having been stopped by police when driving. U.S.-born Cuban Americans, Mexican Americans, and South/Central Americans thought they could consume a higher mean number of drinks before their driving is impaired compared with those who are foreign born. There are considerable differences in DUI-related behavior across Hispanic national groups. U.S.-born Hispanics and those born abroad, but not those at different levels of acculturation, have equal risk of involvement with DUI.

Driving and Epilepsy: a Review of Important Issues.

PubMed

Kang, Joon Y; Mintzer, Scott

2016-09-01

Driving restrictions in people with epilepsy (PWE) is a highly contentious topic. The fundamental difficulty lies in achieving a balance between safety and practicality. The aim of this review is to provide an overview, history, and rationale behind current laws regarding driving restriction in PWE. We also discuss recent findings that may be helpful to practitioners during individual discussions with PWE including seizure recurrence risk after first seizure, recurrent seizure, and anticonvulsant with drawl and driving restrictions in patients with psychogenic non-epileptic seizures (PNES).

[Driving and dementia : An issue for general practice?!

PubMed

Leve, Verena; Ilse, Katharina; Ufert, Marie; Wilm, Stefan; Pentzek, Michael

2017-05-01

With most forms of dementia, the risk of road traffic accidents increases with disease progression. Addressing the issue of fitness to drive at an early stage can help to reduce driving-related risks and simultaneously preserve mobility. General practitioners (GPs) are central contact persons for dementia patients and their relatives in medical and psychosocial matters, and also play a key role in addressing the issue of driving safety. Identification of relevant aspects of managing fitness to drive in dementia, as well as of support requirements for German general practice. Seven focus groups with dementia patients, family caregivers and GPs were conducted in order to define the different requirements for counselling in the general practice setting. The transcribed discussions were analysed by a multiprofessional research team using content analysis. For people with dementia, declining mobility and driving cessation is related to a loss of autonomy. Addressing fitness to drive in dementia is thus a subject of conflict and uncertainty for both family caregivers and GPs. The difficulties include the assessment of fitness to drive in the general practice setting, concerns about compromising the patient-physician relationship by raising the issue of driving fitness, as well as uncertainties about the GP's own role. GPs consider the involvement of caregivers to be important to successfully address the topic of driving safety and organise alternative transport. Support is required in the form of criteria defining the time point at which fitness to drive should be assessed, information on compensation possibilities and mobility alternatives. Resource-oriented and patient-centred development of management strategies for limited mobility is needed in general practice. Finding the correct balance between documentation, adequately informing the patient and establishing patient-centred strategies represents a challenge.

Auto-magnetizing liners for magnetized inertial fusion

DOE PAGES

Slutz, S. A.; Jennings, C. A.; Awe, T. J.; ...

2017-01-20

Here, the MagLIF (Magnetized Liner Inertial Fusion) concept has demonstrated fusion-relevant plasma conditions on the Z accelerator using external field coils to magnetize the fuel before compression. We present a novel concept (AutoMag), which uses a composite liner with helical conduction paths separated by insulating material to provide fuel magnetization from the early part of the drive current, which by design rises slowly enough to avoid electrical breakdown of the insulators. Once the magnetization field is established, the drive current rises more quickly, which causes the insulators to break down allowing the drive current to follow an axial path andmore » implode the liner in the conventional z-pinch manner. There are two important advantages to AutoMag over external field coils for the operation of MagLIF. Low inductance magnetically insulated power feeds can be used to increase the drive current, and AutoMag does not interfere with diagnostic access. Also, AutoMag enables a pathway to energy applications for MagLIF, since expensive field coils will not be damaged each shot. Finally, it should be possible to generate Field Reversed Configurations (FRC) by using both external field coils and AutoMag in opposite polarities. This would provide a means to studying FRC liner implosions on the 100 ns time scale.« less

Application of very high harmonic fast waves for off-axis current drive in the DIII-D and FNSF-AT tokamaks

DOE PAGES

Prater, Ronald; Moeller, Charles P.; Pinsker, Robert I.; ...

2014-06-26

Fast waves at frequencies far above the ion cyclotron frequency and approaching the lower hybrid frequency (also called “helicons” or “whistlers”) have application to off-axis current drive in tokamaks with high electron beta. The high frequency causes the whistler-like behavior of the wave power nearly following field lines, but with a small radial component, so the waves spiral slowly toward the plasma center. The high frequency also contributes to strong damping. Modeling predicts robust off-axis current drive with good efficiency compared to alternatives in high performance discharges in DIII-D and Fusion Nuclear Science Facility (FNSF) when the electron beta ismore » above about 1.8%. Detailed analysis of ray behavior shows that ray trajectories and damping are deterministic (that is, not strongly affected by plasma profiles or initial ray conditions), unlike the chaotic ray behavior in lower frequency fast wave experiments. Current drive was found to not be sensitive to the launched value of the parallel index of refraction n||, so wave accessibility issues can be reduced. Finally, use of a traveling wave antenna provides a very narrow n|| spectrum, which also helps avoid accessibility problems.« less

Electron Cyclotron Current Drive Efficiency in General Tokamak Geometry and Its Application to Advanced Tokamak Plasmas

NASA Astrophysics Data System (ADS)

Lin-Liu, Y. R.; Chan, V. S.; Luce, T. C.; Prater, R.

1998-11-01

Owing to relativistic mass shift in the cyclotron resonance condition, a simple and accurate interpolation formula for estimating the current drive efficiency, such as those(S.C. Chiu et al.), Nucl. Fusion 29, 2175 (1989).^,(D.A. Ehst and C.F.F. Karney, Nucl. Fusion 31), 1933 (1991). commonly used in FWCD, is not available in the case of ECCD. In this work, we model ECCD using the adjoint techniques. A semi-analytic adjoint function appropriate for general tokamak geometry is obtained using Fisch's relativistic collision model. Predictions of off-axis ECCD qualitatively and semi-quantitatively agrees with those of Cohen,(R.H. Cohen, Phys. Fluids 30), 2442 (1987). currently implemented in the raytracing code TORAY. The dependences of the current drive efficiency on the wave launch configuration and the plasma parameters will be presented. Strong absorption of the wave away from the resonance layer is shown to be an important factor in optimizing the off-axis ECCD for application to advanced tokamak operations.

Compact hohlraum configuration with parallel planar-wire-array x-ray sources at the 1.7-MA Zebra generator.

PubMed

Kantsyrev, V L; Chuvatin, A S; Rudakov, L I; Velikovich, A L; Shrestha, I K; Esaulov, A A; Safronova, A S; Shlyaptseva, V V; Osborne, G C; Astanovitsky, A L; Weller, M E; Stafford, A; Schultz, K A; Cooper, M C; Cuneo, M E; Jones, B; Vesey, R A

2014-12-01

A compact Z-pinch x-ray hohlraum design with parallel-driven x-ray sources is experimentally demonstrated in a configuration with a central target and tailored shine shields at a 1.7-MA Zebra generator. Driving in parallel two magnetically decoupled compact double-planar-wire Z pinches has demonstrated the generation of synchronized x-ray bursts that correlated well in time with x-ray emission from a central reemission target. Good agreement between simulated and measured hohlraum radiation temperature of the central target is shown. The advantages of compact hohlraum design applications for multi-MA facilities are discussed.

Chemotaxis in Microfluidic Devices

NASA Astrophysics Data System (ADS)

Wyatt, Danica; Nadkarni, Sharvari; Song, Loling; Voeltz, Camilla; Bodenschatz, Eberhard

2004-03-01

Dictyostelium amoebae use chemical signaling to begin starvation-induced aggregation. Cells generate a complex and dynamic pattern of cyclic AMP that drives their migration toward a central point. While this phenomenon is unique to social amoebae, the signaling pathways of chemotaxis are similar in all eukaryotic cells. Dicty serves as a model organism for imaging these intracellular protein dynamics. To date, chemotaxis has been primarily studied in diffusion-generated gradients in chambers many orders of magnitude larger than a cell. To better quantify which aspects of a gradient trigger a response, we have designed a microfluidic channel that confines cells in an environment where spatiotemporal cAMP concentration can be precisely manipulated. We report results on an early event in the signaling cascade, the translocation of PH domain-containing proteins, which test current models of chemotaxis. This work was supported by the NSF Biocomplexity program and the Nanobiotechnology Center, an STC Program of the NSF under Agreement No. ECS-9876771.

Magnetic flux pumping in 3D nonlinear magnetohydrodynamic simulations

NASA Astrophysics Data System (ADS)

Krebs, I.; Jardin, S. C.; Günter, S.; Lackner, K.; Hoelzl, M.; Strumberger, E.; Ferraro, N.

2017-10-01

A self-regulating magnetic flux pumping mechanism in tokamaks that maintains the core safety factor at q ≈1 , thus preventing sawteeth, is analyzed in nonlinear 3D magnetohydrodynamic simulations using the M3D-C1 code. In these simulations, the most important mechanism responsible for the flux pumping is that a saturated (m =1 ,n =1 ) quasi-interchange instability generates an effective negative loop voltage in the plasma center via a dynamo effect. It is shown that sawtoothing is prevented in the simulations if β is sufficiently high to provide the necessary drive for the (m =1 ,n =1 ) instability that generates the dynamo loop voltage. The necessary amount of dynamo loop voltage is determined by the tendency of the current density profile to centrally peak which, in our simulations, is controlled by the peakedness of the applied heat source profile.

MECHANISMS OF APNEA

PubMed Central

Eckert, Danny J.; Malhotra, Atul; Jordan, Amy S.

2009-01-01

This article focuses on the underlying mechanisms contributing to sleep-disordered breathing. Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by repetitive narrowing or collapse of the pharyngeal airway during sleep. Conversely, central sleep apnea (CSA), highly prevalent in congestive heart failure, is distinguished by a lack of drive to breathe during sleep resulting in repetitive periods of insufficient ventilation. Both lead to compromised gas exchange, impaired sleep continuity, catecholamine surges and are associated with major co-morbidities including excessive daytime sleepiness and increased risk of cardiovascular disease. While OSA and CSA exist on a spectrum of sleep-disordered breathing, the two entities have overlap in their underlying pathophysiologies. This brief review summarizes the etiology and current understanding of OSA and CSA pathophysiology, the role of the cardiovascular system may play in contributing to disease pathology and, highlights the likely substantial overlap that exists between the various forms of sleep-disordered breathing. PMID:19110133

A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems

USGS Publications Warehouse

Scholz, Nathaniel L.; Fleishman, Erica; Brown, Larry; Werner, Inge; Johnson, Michael L.; Brooks, Marjorie L.; Mitchelmore, Carys L.; Schlenk, Daniel

2012-01-01

Pesticides applied on land are commonly transported by runoff or spray drift to aquatic ecosystems, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of ecosystem processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the cumulative effects of pesticides on species or ecological functions has been difficult for historical, legal, conceptual, and practical reasons. To explore these challenges, we examine current-use (modern) pesticides and their potential connections to the abundances of fishes in the San Francisco Estuary (California). Declines in delta smelt (Hypomesus transpacificus), Chinook salmon (Oncorhynchus tshawytscha), and other species have triggered mandatory and expensive management actions in the urbanizing estuary and agriculturally productive Central Valley. Our inferences are transferable to other situations in which toxics may drive changes in ecological status and trends.

Effect of water activity on rates of serpentinization of olivine.

PubMed

Lamadrid, Hector M; Rimstidt, J Donald; Schwarzenbach, Esther M; Klein, Frieder; Ulrich, Sarah; Dolocan, Andrei; Bodnar, Robert J

2017-07-14

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth's surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and H 2 O activity decreases.

Effect of water activity on rates of serpentinization of olivine

NASA Astrophysics Data System (ADS)

Lamadrid, Hector M.; Rimstidt, J. Donald; Schwarzenbach, Esther M.; Klein, Frieder; Ulrich, Sarah; Dolocan, Andrei; Bodnar, Robert J.

2017-07-01

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth's surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and H2O activity decreases.

The Role of Metal Halide Perovskites in Next-Generation Lighting Devices.

PubMed

Lozano, Gabriel

2018-06-28

The development of smart illumination sources represents a central challenge of the current technology. In this context, the quest for novel materials that enable efficient light generation is essential. Metal halide compounds with perovskite crystalline structure (ABX3) have gained tremendous interest in the last five years since they come as easy-to-prepare high performance semiconductors. Perovskite absorbers are driving the power-conversion-efficiencies of thin film photovoltaics to unprecedented values. Nowadays, mixed-cation mixed-halide lead perovskite solar cells reach efficiencies consistently over 20% and promise to get close to 30% in multi-junction devices when combined with silicon cells at no surcharge. Nonetheless, perovskites' fame extends further since extensive research on these novel semiconductors has also revealed their brightest side. Soon after their irruption in the photovoltaic scenario, demonstration of efficient color tunable -with high color purity- perovskite emitters has opened new avenues for light generation applications that are timely to discuss herein.

Biogeography of photoautotrophs in the high polar biome

PubMed Central

Pointing, Stephen B.; Burkhard Büdel; Convey, Peter; Gillman, Len N.; Körner, Christian; Leuzinger, Sebastian; Vincent, Warwick F.

2015-01-01

The global latitudinal gradient in biodiversity weakens in the high polar biome and so an alternative explanation for distribution of Arctic and Antarctic photoautotrophs is required. Here we identify how temporal, microclimate and evolutionary drivers of biogeography are important, rather than the macroclimate features that drive plant diversity patterns elsewhere. High polar ecosystems are biologically unique, with a more central role for bryophytes, lichens and microbial photoautotrophs over that of vascular plants. Constraints on vascular plants arise mainly due to stature and ontogenetic barriers. Conversely non-vascular plant and microbial photoautotroph distribution is correlated with favorable microclimates and the capacity for poikilohydric dormancy. Contemporary distribution also depends on evolutionary history, with adaptive and dispersal traits as well as legacy influencing biogeography. We highlight the relevance of these findings to predicting future impacts on diversity of polar photoautotrophs and to the current status of plants in Arctic and Antarctic conservation policy frameworks. PMID:26442009

Emerging targets and therapeutic approaches for the treatment of osteoarthritis pain.

PubMed

Rahman, Wahida; Dickenson, Anthony H

2015-06-01

Osteoarthritis is a complex and often painful disease that is inadequately controlled with current analgesics. This review discusses emerging targets and therapeutic approaches that may lead to the development of better analgesics. Aberrant excitability in peripheral and central pain pathways drives osteoarthritis pain, reversing this via modulation of nerve growth factor, voltage-gated sodium channel, voltage-gated calcium channel and transient receptor potential vanilloid one activity, and increasing inhibitory mechanisms through modulation of cannabinoid and descending modulatory systems hold promise for osteoarthritis pain therapy. Somatosensory phenotyping of chronic pain patients, as a surrogate of putative pain generating mechanisms, may predict patient response to treatment. Identification of new targets will inform and guide future research, aiding the development of more effective analgesics. Future clinical trial designs should implement sensory phenotyping of patients, as an inclusion or stratification criterion, in order to establish an individualized, mechanism-based treatment of osteoarthritis pain.

Magnetic flux pumping in 3D nonlinear magnetohydrodynamic simulations

DOE PAGES

Krebs, I.; Jardin, S. C.; Gunter, S.; ...

2017-09-27

A self-regulating magnetic flux pumping mechanism in tokamaks that maintains the core safety factor at q≈1, thus preventing sawteeth, is analyzed in nonlinear 3D magnetohydrodynamic simulations using the M3D-C1 code. In these simulations, the most important mechanism responsible for the flux pumping is that a saturated (m=1,n=1) quasi-interchange instability generates an effective negative loop voltage in the plasma center via a dynamo effect. It is shown that sawtoothing is prevented in the simulations if β is sufficiently high to provide the necessary drive for the (m=1,n=1) instability that generates the dynamo loop voltage. In conclusion, the necessary amount of dynamomore » loop voltage is determined by the tendency of the current density profile to centrally peak which, in our simulations, is controlled by the peakedness of the applied heat source profile.« less

Electron cyclotron resonance plasma reactor for production of carbon stripper foil

NASA Astrophysics Data System (ADS)

Faith Romero, Camille; Kanamori, Keita; Kinsho, Michikazu; Yoshimoto, Masahiro; Wada, Motoi

2018-01-01

A graphite antenna for the production of carbon-containing hydrogen plasmas is being developed to prepare impurity-free charge exchange foils for high-energy synchrotrons. Microwave power at 2.45 GHz frequency drives a coaxial structure antenna with a 12-mm-diameter central graphite cylinder and a tapered surrounding cylinder serving as the ground electrode. The antenna was placed in a linear magnetic field to investigate how it performs under an electron cyclotron resonance (ECR) condition. A clear resonance phenomenon was observed in plasma luminosity, microwave power absorption, and microwave power reflection when the induction current used to produce a linear magnetic field was changed. The antenna realized the best microwave coupling to the plasma with the ECR zone formed 5 mm from the end of the center electrode. The antenna realized stable operation for more than 5 h with 100 W input microwave power and with operating hydrogen pressure from 0.5 to 50 Pa.

Economists, capitalists, and the making of globalization: North American free trade in comparative-historical perspective.

PubMed

Fairbrother, Malcolm

2014-03-01

Why did globalization happen? Current explanations point to a variety of conditions under which states have made the free market policy changes driving international economic integration since the 1980s. Such accounts disagree, however, about the key actors involved. This article provides a reconciliation, showing how two different combinations of actors, and two different political economic pathways, have led to globalization in recent decades. In developed countries, mobilization by business has been central; elsewhere, technocrats both constrained and empowered by international finance have pursued globalization more independently of business. In both contexts, economists' technical authority has helped legitimate liberalization, despite the limited diffusion of their ideas. The article validates and elaborates this model using a comparative-historical study of how the United States, Canada, and Mexico proposed, negotiated, and ratified agreements for free trade in North America.

The Role of Magnetic Reconnection in Solar Activity

NASA Technical Reports Server (NTRS)

Antiochos, Spiro; DeVore, C. R.

2008-01-01

The central challenge in solar/heliospheric physics is to understand how the emergence and transport of magnetic flux at the photosphere drives the structure and dynamics that we observe in the corona and heliosphere. This presentation focuses on the role of magnetic reconnection in determining solar/heliospheric activity. We demonstrate that two generic properties of the photospheric magnetic and velocity fields are responsible for the ubiquitous reconnection in the corona. First, the photospheric velocities are complex, which leads to the injection of energy and helicity into the coronal magnetic fields and to the efficient, formation of small-scale structure. Second, the flux distribution at the photosphere is multi-polar, which implies that topological discontinuities and, consequently, current sheets, must be present in the coronal magnetic field. We: present numerical simulations showing that photospherically-driven reconnection is responsible for the heating and dynamics of coronal plasma, and for the topology of the coronal/heliospheric magnetic field.

Effect of water activity on rates of serpentinization of olivine

PubMed Central

Lamadrid, Hector M.; Rimstidt, J. Donald; Schwarzenbach, Esther M.; Klein, Frieder; Ulrich, Sarah; Dolocan, Andrei; Bodnar, Robert J.

2017-01-01

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth’s surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and H2O activity decreases. PMID:28706268

Bipedal vs. unipedal: a comparison between one-foot and two-foot driving in a driving simulator.

PubMed

Wang, Dong-Yuan Debbie; Richard, F Dan; Cino, Cullen R; Blount, Trevin; Schmuller, Joseph

2017-04-01

Is it better to drive with one foot or with two feet? Although two-foot driving has fostered interminable debate in the media, no scientific and systematic research has assessed this issue and federal and local state governments have provided no answers. The current study compared traditional unipedal (one-foot driving, using the right foot to control the accelerator and the brake pedal) with bipedal (two-foot driving, using the right foot to control the accelerator and the left foot to control the brake pedal) responses to a visual stimulus in a driving simulator study. Each of 30 undergraduate participants drove in a simulated driving scenario. They responded to a STOP sign displayed on the centre of the screen by bringing their vehicle to a complete stop. Brake RT was shorter under the bipedal condition, while throttle RT showed advantage under the unipedal condition. Stopping time and distance showed a bipedal advantage, however. We discuss further limitations of the current study and implications in a driving task. Before drawing any conclusions from the simulator study, further on-road driving tests are necessary to confirm these obtained bipedal advantages. Practitioner Summary: Traditional unipedal (using the right foot to control the accelerator and the brake pedal) with bipedal (using the right foot to control the accelerator and the left foot to control the brake pedal) responses to a visual stimulus in a driving simulator were compared. Our results showed a bipedal advantage. Promotion: Although two-foot driving has fostered interminable debate in the media, no scientific and systematic research has assessed this issue and federal and local state governments have provided no answers. Traditional (one-foot driving, using the right foot to control the accelerator and the brake pedal) with bipedal (using the right foot to control the accelerator and the left foot to control the brake pedal) responses to a visual stimulus in a simulated driving study were compared. Throttle reaction time was faster in the unipedal condition whereas brake reaction time, stopping time and stopping distance showed a bipedal advantage. We discuss further theoretical issues and implications in a driving task.

The centrality of guilt: working with ultra-orthodox Jewish patients in Israel.

PubMed

Hess, Esther

2014-09-01

The ultra-orthodox Jewish (Haredi) community in Israel is characterized by strict observance of the requirements of orthodox Jewish life. Psychoanalytic psychotherapy within this community brings us into contact with guilt as a central emotion throughout the therapeutic process. The exposure to new concepts, ways of thought and a previously unknown space, together with increased awareness of internal wishes and drives, are experienced as forbidden areas that arouse an awakening of conscience and a sense of guilt. The author's cases illustrate these conflicts.

Recent results from the electron cyclotron heated plasmas in Tokamak à Configuration Variable (TCV)

NASA Astrophysics Data System (ADS)

Henderson, M. A.; Alberti, S.; Angioni, C.; Arnoux, G.; Behn, R.; Blanchard, P.; Bosshard, P.; Camenen, Y.; Coda, S.; Condrea, I.; Goodman, T. P.; Hofmann, F.; Hogge, J.-Ph.; Karpushov, A.; Manini, A.; Martynov, An.; Moret, J.-M.; Nikkola, P.; Nelson-Melby, E.; Pochelon, A.; Porte, L.; Sauter, O.; Ahmed, S. M.; Andrèbe, Y.; Appert, K.; Chavan, R.; Degeling, A.; Duval, B. P.; Etienne, P.; Fasel, D.; Fasoli, A.; Favez, J.-Y.; Furno, I.; Horacek, J.; Isoz, P.; Joye, B.; Klimanov, I.; Lavanchy, P.; Lister, J. B.; Llobet, X.; Magnin, J.-C.; Marlétaz, B.; Marmillod, P.; Martin, Y.; Mayor, J.-M.; Mylnar, J.; Paris, P. J.; Perez, A.; Peysson, Y.; Pitts, R. A.; Raju, D.; Reimerdes, H.; Scarabosio, A.; Scavino, E.; Seo, S. H.; Siravo, U.; Sushkov, A.; Tonetti, G.; Tran, M. Q.; Weisen, H.; Wischmeier, M.; Zabolotsky, A.; Yhuang, G.

2003-05-01

In noninductively driven discharges, 0.9 MW second harmonic (X2) off-axis co-electron cyclotron current drive deposition is combined with 0.45 MW X2 central heating to create an electron internal transport barrier (eITB) in steady plasma conditions resulting in a 1.6-fold increase of the confinement time (τEe) over ITER-98L-mode scaling. The eITB is associated with a reversed shear current profile enhanced by a large bootstrap current fraction (up to 80%) and is sustained for up to 10 current redistribution times. A linear dependence of the confinement improvement on the product of the global shear reversal factor (q0/qmin) and the reversed shear volume (ρq-min2) is shown. In other discharges heated with X2 the sawteeth are destabilized (respectively stabilized) when heating just inside (respectively outside) the q=1 surface. Control of the sawteeth may allow the avoidance of neoclassical tearing modes that can be seeded by the sawtooth instability. Results on H-mode and highly elongated plasmas using the newly completed third harmonic (X3) system and achieving up to 100% absorption are also discussed, along with comparison of experimental results with the TORAY-GA ray tracing code [K. Matsuda, IEEE Trans. Plasma Sci. PS-17, 6 (1989); R. H. Cohen, Phys. Fluids 30, 2442 (1987)].

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2010-11-10

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Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

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Prevalence and correlates of drink driving within patrons of Australian night-time entertainment precincts.

PubMed

Curtis, Ashlee; Coomber, Kerri; Hyder, Shannon; Droste, Nic; Pennay, Amy; Jenkinson, Rebecca; Mayshak, Richelle; Miller, Peter G

2016-10-01

Drink driving is a significant public health concern, and contributes to many road fatalities worldwide. The current study is the first to examine the prevalence and correlates of drink driving behavior in a sample of night-time entertainment precinct attendees in Australia. Interviews were conducted with 4214 night-time entertainment precinct attendees in two metropolitan and three regional cities in Australia. Seven correlates of self-reported drink driving were examined: gender, age, occupation, blood alcohol concentration (BAC), alcohol consumed prior to attending a licensed venue, energy drink consumption, and other drug consumption. Fourteen percent of night-time entertainment precinct attendees reported drink driving in the past three months. Bivariate logistic regression models indicated that males were significantly more likely than females to report drink driving in the past three months. Blue-collar workers and sales/clerical/administrative workers were significantly more likely to report drink driving behavior in the past three months than white-collar workers. The likelihood of reporting drink driving during the three months prior to interview significantly increased as BAC on the current night out increased, and when patrons reported engaging in pre-drinking or other drug use. The multivariate model presented a similar pattern of results, however BAC and pre-drinking on the night of the interview were no longer independent significant predictors. Males, blue collar/sales/clerical/administrative workers, and illicit drug consumers were more likely to report engaging in drink driving behavior than their counterparts. Interventions should focus on addressing the considerable proportion night-time entertainment precinct attendees who report engaging in drink driving behavior. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mild Cognitive Impairment and driving: Does in-vehicle distraction affect driving performance?

PubMed

Beratis, Ion N; Pavlou, Dimosthenis; Papadimitriou, Eleonora; Andronas, Nikolaos; Kontaxopoulou, Dionysia; Fragkiadaki, Stella; Yannis, George; Papageorgiou, Sokratis G

2017-06-01

In-vehicle distraction is considered to be an important cause of road accidents. Drivers with Mild Cognitive Impairment (MCI), because of their attenuated cognitive resources, may be vulnerable to the effects of distraction; however, previous relevant research is lacking. The main objective of the current study was to explore the effect of in-vehicle distraction on the driving performance of MCI patients, by assessing their reaction time at unexpected incidents and accident probability. Thirteen patients with MCI (age: 64.5±7.2) and 12 cognitively intact individuals (age: 60.0±7.7), all active drivers were introduced in the study. The driving simulator experiment included three distraction conditions: (a) undistracted driving, (b) conversing with passenger and (c) conversing through a hand-held mobile phone. The mixed ANOVA models revealed a greater effect of distraction on MCI patients. Specifically, the use of mobile phone induced a more pronounced impact on reaction time and accident probability in the group of patients, as compared to healthy controls. On the other hand, in the driving condition "conversing with passenger" the interaction effects regarding reaction time and accident probability were not significant. Notably, the aforementioned findings concerning the MCI patients in the case of the mobile phone were observed despite the effort of the drivers to apply a compensatory strategy by reducing significantly their speed in this driving condition. Overall, the current findings indicate, for the first time, that a common driving practice, such as the use of mobile phone, may have a detrimental impact on the driving performance of individuals with MCI. Copyright © 2017. Published by Elsevier Ltd.

Drive beam stabilisation in the CLIC Test Facility 3

NASA Astrophysics Data System (ADS)

Malina, L.; Corsini, R.; Persson, T.; Skowroński, P. K.; Adli, E.

2018-06-01

The proposed Compact Linear Collider (CLIC) uses a high intensity, low energy drive beam to produce the RF power needed to accelerate a lower intensity main beam with 100 MV/m gradient. This scheme puts stringent requirements on drive beam stability in terms of phase, energy and current. The consequent experimental work was carried out in CLIC Test Facility CTF3. In this paper, we present a novel analysis technique in accelerator physics to find beam drifts and their sources in the vast amount of the continuously gathered signals. The instability sources are identified and adequately mitigated either by hardware improvements or by implementation and commissioning of various feedbacks, mostly beam-based. The resulting drive beam stability is of 0.2°@ 3 GHz in phase, 0.08% in relative beam energy and about 0.2% beam current. Finally, we propose a stabilisation concept for CLIC to guarantee the main beam stability.

System and method for determining stator winding resistance in an AC motor using motor drives

DOEpatents

Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

2013-02-26

A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

Improvement in Brightness Uniformity by Compensating for the Threshold Voltages of Both the Driving Thin-Film Transistor and the Organic Light-Emitting Diode for Active-Matrix Organic Light-Emitting Diode Displays

NASA Astrophysics Data System (ADS)

Ching-Lin Fan,; Hui-Lung Lai,; Jyu-Yu Chang,

2010-05-01

In this paper, we propose a novel pixel design and driving method for active-matrix organic light-emitting diode (AM-OLED) displays using low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs). The proposed threshold voltage compensation circuit, which comprised five transistors and two capacitors, has been verified to supply uniform output current by simulation work using the automatic integrated circuit modeling simulation program with integrated circuit emphasis (AIM-SPICE) simulator. The driving scheme of this voltage programming method includes four periods: precharging, compensation, data input, and emission. The simulated results demonstrate excellent properties such as low error rate of OLED anode voltage variation (<1%) and high output current. The proposed pixel circuit shows high immunity to the threshold voltage deviation characteristics of both the driving poly-Si TFT and the OLED.

Making sense of ocean biota: how evolution and biodiversity of land organisms differ from that of the plankton.

PubMed

Smetacek, Victor

2012-09-01

The oceans cover 70% of the planet's surface, and their planktonic inhabitants generate about half the global primary production, thereby playing a key role in modulating planetary climate via the carbon cycle. The ocean biota have been under scientific scrutiny for well over a century, and yet our understanding of the processes driving natural selection in the pelagic environment - the open water inhabited by drifting plankton and free-swimming nekton - is still quite vague. Because of the fundamental differences in the physical environment, pelagic ecosystems function differently from the familiar terrestrial ecosystems of which we are a part. Natural selection creates biodiversity but understanding how this quality control of random mutations operates in the oceans - which traits are selected for under what circumstances and by which environmental factors, whether bottom-up or top-down - is currently a major challenge. Rapid advances in genomics are providing information, particularly in the prokaryotic realm, pertaining not only to the biodiversity inventory but also functional groups. This essay is dedicated to the poorly understood tribes of planktonic protists (unicellular eukaryotes) that feed the ocean's animals and continue to run the elemental cycles of our planet. It is an attempt at developing a conceptually coherent framework to understand the course of evolution by natural selection in the plankton and contrast it with the better-known terrestrial realm. I argue that organism interactions, in particular co-evolution between predators and prey (the arms race), play a central role in driving evolution in the pelagic realm. Understanding the evolutionary forces shaping ocean biota is a prerequisite for harnessing plankton for human purposes and also for protecting the oceanic ecosystems currently under severe stress from anthropogenic pressures.

Characterizing wave- and current- induced bottom shear stress: U.S. middle Atlantic continental shelf

USGS Publications Warehouse

Dalyander, P. Soupy; Butman, Bradford; Sherwood, Christopher R.; Signell, Richard P.; Wilkin, John L.

2013-01-01

Waves and currents create bottom shear stress, a force at the seabed that influences sediment texture distribution, micro-topography, habitat, and anthropogenic use. This paper presents a methodology for assessing the magnitude, variability, and driving mechanisms of bottom stress and resultant sediment mobility on regional scales using numerical model output. The analysis was applied to the Middle Atlantic Bight (MAB), off the U.S. East Coast, and identified a tidally-dominated shallow region with relatively high stress southeast of Massachusetts over Nantucket Shoals, where sediment mobility thresholds are exceeded over 50% of the time; a coastal band extending offshore to about 30 m water depth dominated by waves, where mobility occurs more than 20% of the time; and a quiescent low stress region southeast of Long Island, approximately coincident with an area of fine-grained sediments called the “Mud Patch”. The regional high in stress and mobility over Nantucket Shoals supports the hypothesis that fine grain sediment winnowed away in this region maintains the Mud Patch to the southwest. The analysis identified waves as the driving mechanism for stress throughout most of the MAB, excluding Nantucket Shoals and sheltered coastal bays where tides dominate; however, the relative dominance of low-frequency events varied regionally, and increased southward toward Cape Hatteras. The correlation between wave stress and local wind stress was lowest in the central MAB, indicating a relatively high contribution of swell to bottom stress in this area, rather than locally generated waves. Accurate prediction of the wave energy spectrum was critical to produce good estimates of bottom shear stress, which was sensitive to energy in the long period waves.

Understanding Peripheral Bat Populations Using Maximum-Entropy Suitability Modeling

PubMed Central

Barnhart, Paul R.; Gillam, Erin H.

2016-01-01

Individuals along the periphery of a species distribution regularly encounter more challenging environmental and climatic conditions than conspecifics near the center of the distribution. Due to these potential constraints, individuals in peripheral margins are expected to change their habitat and behavioral characteristics. Managers typically rely on species distribution maps when developing adequate management practices. However, these range maps are often too simplistic and do not provide adequate information as to what fine-scale biotic and abiotic factors are driving a species occurrence. In the last decade, habitat suitability modelling has become widely used as a substitute for simplistic distribution mapping which allows regional managers the ability to fine-tune management resources. The objectives of this study were to use maximum-entropy modeling to produce habitat suitability models for seven species that have a peripheral margin intersecting the state of North Dakota, according to current IUCN distributions, and determine the vegetative and climatic characteristics driving these models. Mistnetting resulted in the documentation of five species outside the IUCN distribution in North Dakota, indicating that current range maps for North Dakota, and potentially the northern Great Plains, are in need of update. Maximum-entropy modeling showed that temperature and not precipitation were the variables most important for model production. This fine-scale result highlights the importance of habitat suitability modelling as this information cannot be extracted from distribution maps. Our results provide baseline information needed for future research about how and why individuals residing in the peripheral margins of a species’ distribution may show marked differences in habitat use as a result of urban expansion, habitat loss, and climate change compared to more centralized populations. PMID:27935936

Corruption drives the emergence of civil society.

PubMed

Abdallah, Sherief; Sayed, Rasha; Rahwan, Iyad; Leveck, Brad L; Cebrian, Manuel; Rutherford, Alex; Fowler, James H

2014-04-06

Centralized sanctioning institutions have been shown to emerge naturally through social learning, displace all other forms of punishment and lead to stable cooperation. However, this result provokes a number of questions. If centralized sanctioning is so successful, then why do many highly authoritarian states suffer from low levels of cooperation? Why do states with high levels of public good provision tend to rely more on citizen-driven peer punishment? Here, we consider how corruption influences the evolution of cooperation and punishment. Our model shows that the effectiveness of centralized punishment in promoting cooperation breaks down when some actors in the model are allowed to bribe centralized authorities. Counterintuitively, a weaker centralized authority is actually more effective because it allows peer punishment to restore cooperation in the presence of corruption. Our results provide an evolutionary rationale for why public goods provision rarely flourishes in polities that rely only on strong centralized institutions. Instead, cooperation requires both decentralized and centralized enforcement. These results help to explain why citizen participation is a fundamental necessity for policing the commons.

Time-Dependent Simulations of Fast-Wave Heated High-Non-Inductive-Fraction H-Mode Plasmas in the National Spherical Torus Experiment Upgrade

NASA Astrophysics Data System (ADS)

Taylor, Gary; Bertelli, Nicola; Gerhardt, Stefan P.; Hosea, Joel C.; Mueller, Dennis; Perkins, Rory J.; Poli, Francesca M.; Wilson, James R.; Raman, Roger

2017-10-01

30 MHz fast-wave heating may be an effective tool for non-inductively ramping low-current plasmas to a level suitable for initiating up to 12 MW of neutral beam injection on the National Spherical Tokamak Experiment Upgrade (NSTX-U). Previously on NSTX 30 MHz fast wave heating was shown to efficiently and rapidly heat electrons; at the NSTX maximum axial toroidal magnetic field (BT(0)) of 0.55 T, 1.4 MW of 30 MHz heating increased the central electron temperature from 0.2 to 2 keV in 30 ms and generated an H-mode plasma with a non-inductive fraction (fNI) ˜ 0.7 at a plasma current (Ip) of 300 kA. NSTX-U will operate at BT(0) up to 1 T, with up to 4 MW of 30 MHz power (Prf). Predictive TRANSP free boundary transport simulations, using the TORIC full wave spectral code to calculate the fast-wave heating and current drive, have been run for NSTX-U Ip = 300 kA H-mode plasmas. Favorable scaling of fNI with 30 MHz heating power is predicted, with fNI ≥ 1 for Prf ≥ 2 MW.

Assessment of driving-related performance in chronic whiplash using an advanced driving simulator.

PubMed

Takasaki, Hiroshi; Treleaven, Julia; Johnston, Venerina; Rakotonirainy, Andry; Haines, Andrew; Jull, Gwendolen

2013-11-01

Driving is often nominated as problematic by individuals with chronic whiplash associated disorders (WAD), yet driving-related performance has not been evaluated objectively. The purpose of this study was to test driving-related performance in persons with chronic WAD against healthy controls of similar age, gender and driving experience to determine if driving-related performance in the WAD group was sufficiently impaired to recommend fitness to drive assessment. Driving-related performance was assessed using an advanced driving simulator during three driving scenarios; freeway, residential and a central business district (CBD). Total driving duration was approximately 15min. Five driving tasks which could cause a collision (critical events) were included in the scenarios. In addition, the effect of divided attention (identify red dots projected onto side or rear view mirrors) was assessed three times in each scenario. Driving performance was measured using the simulator performance index (SPI) which is calculated from 12 measures. z-Scores for all SPI measures were calculated for each WAD subject based on mean values of the control subjects. The z-scores were then averaged for the WAD group. A z-score of ≤-2 indicated a driving failing grade in the simulator. The number of collisions over the five critical events was compared between the WAD and control groups as was reaction time and missed response ratio in identifying the red dots. Seventeen WAD and 26 control subjects commenced the driving assessment. Demographic data were comparable between the groups. All subjects completed the freeway scenario but four withdrew during the residential and eight during the CBD scenario because of motion sickness. All scenarios were completed by 14 WAD and 17 control subjects. Mean z-scores for the SPI over the three scenarios was statistically lower in the WAD group (-0.3±0.3; P<0.05) but the score was not below the cut-off point for safe driving. There were no differences in the reaction time and missed response ratio in divided attention tasks between the groups (All P>0.05). Assessment of driving in an advanced driving simulator for approximately 15min revealed that driving-related performance in chronic WAD was not sufficiently impaired to recommend the need for fitness to drive assessment. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Quality and Accuracy of Mobile Apps to Prevent Driving After Drinking Alcohol.

PubMed

Wilson, Hollie; Stoyanov, Stoyan R; Gandabhai, Shailen; Baldwin, Alexander

2016-08-08

Driving after the consumption of alcohol represents a significant problem globally. Individual prevention countermeasures such as personalized mobile app aimed at preventing such behavior are widespread, but there is little research on their accuracy and evidence base. There has been no known assessment investigating the quality of such apps. This study aimed to determine the quality and accuracy of apps for drink driving prevention by conducting a review and evaluation of relevant mobile apps. A systematic app search was conducted following PRISMA guidelines. App quality was assessed using the Mobile App Rating Scale (MARS). Apps providing blood alcohol calculators (hereafter "calculators") were reviewed against current alcohol advice for accuracy. A total of 58 apps (30 iOS and 28 Android) met inclusion criteria and were included in the final analysis. Drink driving prevention apps had significantly lower engagement and overall quality scores than alcohol management apps. Most calculators provided conservative blood alcohol content (BAC) time until sober calculations. None of the apps had been evaluated to determine their efficacy in changing either drinking or driving behaviors. This novel study demonstrates that most drink driving prevention apps are not engaging and lack accuracy. They could be improved by increasing engagement features, such as gamification. Further research should examine the context and motivations for using apps to prevent driving after drinking in at-risk populations. Development of drink driving prevention apps should incorporate evidence-based information and guidance, lacking in current apps.

The Quality and Accuracy of Mobile Apps to Prevent Driving After Drinking Alcohol

PubMed Central

Stoyanov, Stoyan R; Gandabhai, Shailen; Baldwin, Alexander

2016-01-01

Background Driving after the consumption of alcohol represents a significant problem globally. Individual prevention countermeasures such as personalized mobile apps aimed at preventing such behavior are widespread, but there is little research on their accuracy and evidence base. There has been no known assessment investigating the quality of such apps. Objective This study aimed to determine the quality and accuracy of apps for drink driving prevention by conducting a review and evaluation of relevant mobile apps. Methods A systematic app search was conducted following PRISMA guidelines. App quality was assessed using the Mobile App Rating Scale (MARS). Apps providing blood alcohol calculators (hereafter “calculators”) were reviewed against current alcohol advice for accuracy. Results A total of 58 apps (30 iOS and 28 Android) met inclusion criteria and were included in the final analysis. Drink driving prevention apps had significantly lower engagement and overall quality scores than alcohol management apps. Most calculators provided conservative blood alcohol content (BAC) time until sober calculations. None of the apps had been evaluated to determine their efficacy in changing either drinking or driving behaviors. Conclusions This novel study demonstrates that most drink driving prevention apps are not engaging and lack accuracy. They could be improved by increasing engagement features, such as gamification. Further research should examine the context and motivations for using apps to prevent driving after drinking in at-risk populations. Development of drink driving prevention apps should incorporate evidence-based information and guidance, lacking in current apps. PMID:27502956

TFT-Directed Electroplating of RGB Luminescent Films without a Vacuum or Mask toward a Full-Color AMOLED Pixel Matrix.

PubMed

Wang, Rong; Zhang, Donglian; Xiong, You; Zhou, Xuehong; Liu, Cao; Chen, Weifeng; Wu, Weijing; Zhou, Lei; Xu, Miao; Wang, Lei; Liu, Linlin; Peng, Junbiao; Ma, Yuguang; Cao, Yong

2018-05-30

The thin-film transistor (TFT) driving circuit is a separate electronic component embedded within the panel itself to switch the current for each pixel in active-matrix organic light-emitting diode displays. We reported a TFT-directed dye electroplating method to fabricate pixels; this would be a new method to deposit films on prepatterned electrode for organic full-color display, where TFT driving circuit provide a switching current signal to drive and direct dye depositing on selected RGB pixels. A prototype patterned color pixel matrix was achieved, as high-quality light-emitting films with uniform morphology, pure RGB chromaticity, and stable output.

Electric machine and current source inverter drive system

DOEpatents

Hsu, John S

2014-06-24

A drive system includes an electric machine and a current source inverter (CSI). This integration of an electric machine and an inverter uses the machine's field excitation coil for not only flux generation in the machine but also for the CSI inductor. This integration of the two technologies, namely the U machine motor and the CSI, opens a new chapter for the component function integration instead of the traditional integration by simply placing separate machine and inverter components in the same housing. Elimination of the CSI inductor adds to the CSI volumetric reduction of the capacitors and the elimination of PMs for the motor further improve the drive system cost, weight, and volume.

Modelling of piezoelectric actuator dynamics for active structural control

NASA Technical Reports Server (NTRS)

Hagood, Nesbitt W.; Chung, Walter H.; Von Flotow, Andreas

1990-01-01

The paper models the effects of dynamic coupling between a structure and an electrical network through the piezoelectric effect. The coupled equations of motion of an arbitrary elastic structure with piezoelectric elements and passive electronics are derived. State space models are developed for three important cases: direct voltage driven electrodes, direct charge driven electrodes, and an indirect drive case where the piezoelectric electrodes are connected to an arbitrary electrical circuit with embedded voltage and current sources. The equations are applied to the case of a cantilevered beam with surface mounted piezoceramics and indirect voltage and current drive. The theoretical derivations are validated experimentally on an actively controlled cantilevered beam test article with indirect voltage drive.

Weber electrodynamics, part I. general theory, steady current effects

NASA Astrophysics Data System (ADS)

Wesley, J. P.

1990-10-01

The original Weber action at a distance theory, valid for slowly varying effects, is extended to time-retarded fields, valid for rapidly varying effects including radiation. A new law for the force on a charge moving in this field is derived (replacing the Lorentz force which violates Newton's third law). The limitations of the Maxwell theory are discussed. The Weber theory, in addition to predicting all of the usual electrodynamic results, predicts the following crucial results for slowly varying effects (where Maxwell theory fails): 1) the force on Ampere's bridge in agreement with the measurements of Moyssides and Pappas, 2) the tension required to rupture current carrying wires as observed by Graneau, 3) the force to drive the Graneau-Hering submarine, 4) the force to drive the mercury in Hering's pump, and 5) the force to drive the oscillations in a current carrying mercury wedge as observed by Phipps.

Ultrafast probing of magnetic field growth inside a laser-driven solenoid

NASA Astrophysics Data System (ADS)

Goyon, C.; Pollock, B. B.; Turnbull, D. P.; Hazi, A.; Divol, L.; Farmer, W. A.; Haberberger, D.; Javedani, J.; Johnson, A. J.; Kemp, A.; Levy, M. C.; Grant Logan, B.; Mariscal, D. A.; Landen, O. L.; Patankar, S.; Ross, J. S.; Rubenchik, A. M.; Swadling, G. F.; Williams, G. J.; Fujioka, S.; Law, K. F. F.; Moody, J. D.

2017-03-01

We report on the detection of the time-dependent B-field amplitude and topology in a laser-driven solenoid. The B-field inferred from both proton deflectometry and Faraday rotation ramps up linearly in time reaching 210 ± 35 T at the end of a 0.75-ns laser drive with 1 TW at 351 nm. A lumped-element circuit model agrees well with the linear rise and suggests that the blow-off plasma screens the field between the plates leading to an increased plate capacitance that converts the laser-generated hot-electron current into a voltage source that drives current through the solenoid. ALE3D modeling shows that target disassembly and current diffusion may limit the B-field increase for longer laser drive. Scaling of these experimental results to a National Ignition Facility (NIF) hohlraum target size (˜0.2 cm3 ) indicates that it is possible to achieve several tens of Tesla.

Ultrafast probing of magnetic field growth inside a laser-driven solenoid.

PubMed

Goyon, C; Pollock, B B; Turnbull, D P; Hazi, A; Divol, L; Farmer, W A; Haberberger, D; Javedani, J; Johnson, A J; Kemp, A; Levy, M C; Grant Logan, B; Mariscal, D A; Landen, O L; Patankar, S; Ross, J S; Rubenchik, A M; Swadling, G F; Williams, G J; Fujioka, S; Law, K F F; Moody, J D

2017-03-01

We report on the detection of the time-dependent B-field amplitude and topology in a laser-driven solenoid. The B-field inferred from both proton deflectometry and Faraday rotation ramps up linearly in time reaching 210 ± 35 T at the end of a 0.75-ns laser drive with 1 TW at 351 nm. A lumped-element circuit model agrees well with the linear rise and suggests that the blow-off plasma screens the field between the plates leading to an increased plate capacitance that converts the laser-generated hot-electron current into a voltage source that drives current through the solenoid. ALE3D modeling shows that target disassembly and current diffusion may limit the B-field increase for longer laser drive. Scaling of these experimental results to a National Ignition Facility (NIF) hohlraum target size (∼0.2cm^{3}) indicates that it is possible to achieve several tens of Tesla.

Turbidity Currents With Equilibrium Basal Driving Layers: A Mechanism for Long Runout

NASA Astrophysics Data System (ADS)

Luchi, R.; Balachandar, S.; Seminara, G.; Parker, G.

2018-02-01

Turbidity currents run out over 100 km in lakes and reservoirs, and over 1,000 km in the ocean. They do so without dissipating themselves via excess entrainment of ambient water. Existing layer-averaged formulations cannot capture this. We use a numerical model to describe the temporal evolution of a turbidity current toward steady state under condition of zero net sediment flux at the bed. The flow self-partitions itself into two layers. The lower "driving layer" approaches an invariant flow thickness, velocity profile, and suspended sediment concentration profile that sequesters nearly all of the suspended sediment. This layer can continue indefinitely at steady state over a constant bed slope. The upper "driven layer" contains a small fraction of the suspended sediment. The devolution of the flow into these two layers likely allows the driving layer to run out long distances.

Whistlers, helicons, and lower hybrid waves: The physics of radio frequency wave propagation and absorption for current drive via Landau damping

DOE PAGES

Pinsker, Robert I.

2015-09-24

This introductory-level tutorial article describes the application of plasma waves in the lower hybrid range of frequencies for current drive in tokamaks. Wave damping mechanisms in a nearly collisionless hot magnetized plasma are briefly described, and the connections between the properties of the damping mechanisms and the optimal choices of wave properties (mode, frequency, wavelength) are explored. The two wave modes available for current drive in the lower hybrid range of frequencies (LHRF) are described and compared. The terms applied to these waves in different applications of plasma physics are elucidated. Here, the character of the ray paths of thesemore » waves in the LHRF is illustrated in slab and toroidal geometries. An upcoming experiment on one of these two wave modes, the “helicon” or “whistler”, to be carried out on the DIII-D tokamak, is described.« less

Recent experimental results of KSTAR RF heating and current drive

NASA Astrophysics Data System (ADS)

Wang, S. J.; Kim, J.; Jeong, J. H.; Kim, H. J.; Joung, M.; Bae, Y. S.; Kwak, J. G.

2015-12-01

The overview of KSTAR activities on ICRH, LHCD and ECH/CD including the last experimental results and future plan aiming for long-pulse high-beta plasma will be presented. Recently we achieved reasonable coupling of ICRF power to H-mode plasma through several efforts to increase system reliability. Power balance will be discussed on this experiment. LHCD is still struggling in the low power regime. Review of antenna spectrum for the higher coupling in H-mode plasma will be tried. ECH/CD provides 41 sec, 0.8 MW of heating power to support high-performance long-pulse discharge. Also, 170 GHz ECH system is integrated with the Plasma Control System (PCS) for the feedback controlling of NTM. Status and plan of ECH/CD will be discussed. Finally, helicon current drive is being prepared for the next stage of KSTAR operation. The hardware preparation and the calculation results of helicon current drive in KSTAR plasma will be discussed.

Redundant drive current imbalance problem of the Automatic Radiator Inspection Device (ARID)

NASA Technical Reports Server (NTRS)

Latino, Carl D.

1992-01-01

The Automatic Radiator Inspection Device (ARID) is a 4 Degree of Freedom (DOF) robot with redundant drive motors at each joint. The device is intended to automate the labor intensive task of space shuttle radiator inspection. For safety and redundancy, each joint is driven by two independent motor systems. Motors driving the same joint, however, draw vastly different currents. The concern was that the robot joints could be subjected to undue stress. It was the objective of this summer's project to determine the cause of this current imbalance. In addition it was to determine, in a quantitative manner, what was the cause, how serious the problem was in terms of damage or undue wear to the robot and find solutions if possible. It was concluded that most problems could be resolved with a better motor control design. This document discusses problems encountered and possible solutions.

Ultra-Compact Multitip Scanning Probe Microscope with an Outer Diameter of 50 mm

NASA Astrophysics Data System (ADS)

Cherepanov, Vasily; Zubkov, Evgeny; Junker, Hubertus; Korte, Stefan; Blab, Marcus; Coenen, Peter; Voigtländer, Bert

We present a multitip scanning tunneling microscope (STM) where four independent STM units are integrated on a diameter of 50 mm. The coarse positioning of the tips is done under the control of an optical microscope or an SEM in vacuum. The heart of this STM is a new type of piezoelectric coarse approach called Koala Drive which can have a diameter greater than 2.5 mm and a length smaller than 10 mm. Alternating movements of springs move a central tube which holds the STM tip or AFM sensor. This new operating principle provides a smooth travel sequence and avoids shaking which is intrinsically present for nanopositioners based on inertial motion with saw tooth driving signals. Inserting the Koala Drive in a piezo tube for xyz-scanning integrates a complete STM inside a 4 mm outer diameter piezo tube of <10 mm length. The use of the Koala Drive makes the scanning probe microscopy design ultra-compact and accordingly leads to a high mechanical stability. The drive is UHV, low temperature, and magnetic field compatible. The compactness of the Koala Drive allows building a four-tip STM as small as a single-tip STM with a drift of <0.2 nm/min and lowest resonance frequencies of 2.5 (xy) and 5.5 kHz (z). We present examples of the performance of the multitip STM designed using the Koala Drive.

--No Title--

Science.gov Websites

when his car went into a ravine due to high waters. 8/8/2013 MO Jane McDonald 69 F Road Driving Brush Road Driving Appears victim tried to drive through high water on a road, but stalled. Got out to try the flooded area of a street when his car was swept away by the forceful current off of the road and

Design and Implementation of a Hall Effect Sensor Array Applied to Recycling Hard Drive Magnets

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

Kisner, Roger; Lenarduzzi, Roberto; Killough, Stephen M

Rare earths are an important resource for many electronic components and technologies. Examples abound including Neodymium magnets used in mobile devices and computer hard drives (HDDs), and a variety of renewable energy technologies (e.g., wind turbines). Approximately 21,000 metric tons of Neodymium is processed annually with less than 1% being recycled. An economic system to assist in the recycling of magnet material from post-consumer goods, such as Neodymium Iron Boron magnets commonly found in hard drives is presented. A central component of this recycling measurement system uses an array of 128 Hall Effect sensors arranged in two columns to detectmore » the magnetic flux lines orthogonal to the HDD. Results of using the system to scan planar shaped objects such as hard drives to identify and spatially locate rare-earth magnets for removal and recycling from HDDs are presented. Applications of the sensor array in other identification and localization of magnetic components and assemblies will be presented.« less

Ultra-High Intensity Magnetic Field Generation in Dense Plasma

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

Fisch, Nathaniel J.

2014-01-08

The main objective of this grant proposal was to explore the efficient generation of intense currents. Whereas the efficient generation of electric current in low-­energy-­density plasma has occupied the attention of the magnetic fusion community for several decades, scant attention has been paid to carrying over to high-­energy-­density plasma the ideas for steady-­state current drive developed for low-­energy-­density plasma, or, for that matter, to inventing new methodologies for generating electric current in high-­energy-­density plasma. What we proposed to do was to identify new mechanisms to accomplish current generation, and to assess the operation, physics, and engineering basis of new formsmore » of current drive in regimes appropriate for new fusion concepts.« less

Are selective serotonin reuptake inhibitors safe for drivers? What is the evidence?

PubMed

Ravera, Silvia; Ramaekers, Johannes G; de Jong-van den Berg, Lolkje T W; de Gier, Johan J

2012-05-01

Selective serotonin reuptake inhibitors (SSRIs) are widely used medications to treat several psychiatric diseases and, above all, depression. They seem to be as effective as older antidepressants but have a different adverse effect profile. Despite their favorable safety profile, little is known about their influence on traffic safety. To conduct a literature review to summarize the current evidence on the role of SSRIs in traffic safety, particularly concerning undesirable effects that could potentially impair fitness to drive, experimental and pharmacoepidemiologic studies on driving impairment, 2 existing categorization systems for driving-impairing medications, and the European legislative procedures for assessing fitness to drive before issuing a driver's license and driving under the influence of medicines. The article search was performed in the following electronic databases: MEDLINE, PsycINFO, ScienceDirect, and SafetyLit. The English-language scientific literature was searched using key words such as SSRIs and psychomotor performance, car crash or traffic accident, and adverse effects. For inclusion in this review, papers had to be full-text articles, refer to possible driving-related adverse effects, and be experimental or pharmacoepidemiologic studies on SSRIs and traffic accident risks. No restrictions concerning publication year were applied. Ten articles were selected as background information on driving-related adverse effects, and 15 articles were selected regarding experimental and pharmacoepidemiologic work. Regarding SSRI adverse effects, the most reported undesirable effects referring to driving impairment were anxiety, agitation, sleep disturbances, headache, increased risk of suicidal behavior, and deliberate self-harm. Regarding the remaining issues addressed in this article, inconsistencies were found between the outcomes of the selected experimental and epidemiologic studies and between the 2 existing categorization systems under evaluation. Some pitfalls of the current legislative scenario were identified as well. Based on the current evidence, it was concluded that more experimental and epidemiologic research is needed to elucidate the relationship between SSRI use and traffic safety. Furthermore, a revision of the existing categorization systems and harmonized European legislation in the field of medication use and driving were highly recommended. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

The effects of electron cyclotron heating and current drive on toroidal Alfvén eigenmodes in tokamak plasmas

NASA Astrophysics Data System (ADS)

Sharapov, S. E.; Garcia-Munoz, M.; Van Zeeland, M. A.; Bobkov, B.; Classen, I. G. J.; Ferreira, J.; Figueiredo, A.; Fitzgerald, M.; Galdon-Quiroga, J.; Gallart, D.; Geiger, B.; Gonzalez-Martin, J.; Johnson, T.; Lauber, P.; Mantsinen, M.; Nabais, F.; Nikolaeva, V.; Rodriguez-Ramos, M.; Sanchis-Sanchez, L.; Schneider, P. A.; Snicker, A.; Vallejos, P.; the AUG Team; the EUROfusion MST1 Team

2018-01-01

Dedicated studies performed for toroidal Alfvén eigenmodes (TAEs) in ASDEX-Upgrade (AUG) discharges with monotonic q-profiles have shown that electron cyclotron resonance heating (ECRH) can make TAEs more unstable. In these AUG discharges, energetic ions driving TAEs were obtained by ion cyclotron resonance heating (ICRH). It was found that off-axis ECRH facilitated TAE instability, with TAEs appearing and disappearing on timescales of a few milliseconds when the ECRH power was switched on and off. On-axis ECRH had a much weaker effect on TAEs, and in AUG discharges performed with co- and counter-current electron cyclotron current drive (ECCD), the effects of ECCD were found to be similar to those of ECRH. Fast ion distributions produced by ICRH were computed with the PION and SELFO codes. A significant increase in T e caused by ECRH applied off-axis is found to increase the fast ion slowing-down time and fast ion pressure causing a significant increase in the TAE drive by ICRH-accelerated ions. TAE stability calculations show that the rise in T e causes also an increase in TAE radiative damping and thermal ion Landau damping, but to a lesser extent than the fast ion drive. As a result of the competition between larger drive and damping effects caused by ECRH, TAEs become more unstable. It is concluded, that although ECRH effects on AE stability in present-day experiments may be quite significant, they are determined by the changes in the plasma profiles and are not particularly ECRH specific.

Recording and automated analysis of naturalistic bioptic driving.

PubMed

Luo, Gang; Peli, Eli

2011-05-01

People with moderate central vision loss are legally permitted to drive with a bioptic telescope in 39 US states and the Netherlands, but the safety of bioptic driving remains highly controversial. There is no scientific evidence about bioptic use and its impact on safety. We propose searching for evidence by recording naturalistic driving activities in patients' cars. In a pilot study we used an analogue video system to record two bioptic drivers' daily driving activities for 10 and 5 days, respectively. In this technical report, we also describe our novel digital system that collects vehicle manoeuvre information and enables recording over more extended periods, and discuss our approach to analyzing the vast amount of data. Our observations of telescope use by the pilot subjects were quite different from their reports in a previous survey. One subject used the telescope only seven times in nearly 6 h of driving. For the other subject, the average interval between telescope use was about 2 min, and Mobile (cell) phone use in one trip extended the interval to almost 5 min. We demonstrate that computerized analysis of lengthy recordings based on video, GPS, acceleration, and black box data can be used to select informative segments for efficient off-line review of naturalistic driving behaviours. The inconsistency between self reports and objective data as well as infrequent telescope use underscores the importance of recording bioptic driving behaviours in naturalistic conditions over extended periods. We argue that the new recording system is important for understanding bioptic use behaviours and bioptic driving safety. © 2011 The College of Optometrists.

Recording and automated analysis of naturalistic bioptic driving

PubMed Central

Luo, Gang; Peli, Eli

2011-01-01

Purpose People with moderate central vision loss are legally permitted to drive with a bioptic telescope in 39 US states and the Netherlands, but the safety of bioptic driving remains highly controversial. There is no scientific evidence about bioptic use and its impact on safety. We propose searching for evidence by recording naturalistic driving activities in patients' cars. Methods In a pilot study we used an analogue video system to record two bioptic drivers' daily driving activities for 10 and 5 days, respectively. In this technical report, we also describe our novel digital system that collects vehicle maneuver information and enables recording over more extended periods, and discuss our approach to analyzing the vast amount of data. Results Our observations of telescope use by the pilot subjects were quite different from their reports in a previous survey. One subject used the telescope only 7 times in nearly 6 hours of driving. For the other subject, the average interval between telescope use was about 2 minutes, and cell phone use in one trip extended the interval to almost 5 minutes. We demonstrate that computerized analysis of lengthy recordings based on video, GPS, acceleration, and black box data can be used to select informative segments for efficient off-line review of naturalistic driving behaviors. Conclusions The inconsistency between self reports and objective data as well as infrequent telescope use underscores the importance of recording bioptic driving behaviors in naturalistic conditions over extended periods. We argue that the new recording system is important for understanding bioptic use behaviors and bioptic driving safety. PMID:21410498

State-changes in the swimmeret system: a neural circuit that drives locomotion

PubMed Central

Tschuluun, N.; Hall, W. M.; Mulloney, B.

2009-01-01

Summary The crayfish swimmeret system undergoes transitions between a silent state and an active state. In the silent state, no patterned firing occurs in swimmeret motor neurons. In the active state, bursts of spikes in power stroke motor neurons alternate periodically with bursts of spikes in return stroke motor neurons. In preparations of the isolated crayfish central nervous system (CNS), the temporal structures of motor patterns expressed in the active state are similar to those expressed by the intact animal. These transitions can occur spontaneously, in response to stimulation of command neurons, or in response to application of neuromodulators and transmitter analogues. We used single-electrode voltage clamp of power-stroke exciter and return-stroke exciter motor neurons to study changes in membrane currents during spontaneous transitions and during transitions caused by bath-application of carbachol or octopamine (OA). Spontaneous transitions from silence to activity were marked by the appearance of a standing inward current and periodic outward currents in both types of motor neurons. Bath-application of carbachol also led to the development of these currents and activation of the system. Using low Ca2+–high Mg2+ saline to block synaptic transmission, we found that the carbachol-induced inward current included a direct response by the motor neuron and an indirect component. Spontaneous transitions from activity to silence were marked by disappearance of the standing inward current and the periodic outward currents. Bath-application of OA led promptly to the disappearance of both currents, and silenced the system. OA also acted directly on both types of motor neurons to cause a hyperpolarizing outward current that would contribute to silencing the system. PMID:19880720

State-changes in the swimmeret system: a neural circuit that drives locomotion.

PubMed

Tschuluun, N; Hall, W M; Mulloney, B

2009-11-01

The crayfish swimmeret system undergoes transitions between a silent state and an active state. In the silent state, no patterned firing occurs in swimmeret motor neurons. In the active state, bursts of spikes in power stroke motor neurons alternate periodically with bursts of spikes in return stroke motor neurons. In preparations of the isolated crayfish central nervous system (CNS), the temporal structures of motor patterns expressed in the active state are similar to those expressed by the intact animal. These transitions can occur spontaneously, in response to stimulation of command neurons, or in response to application of neuromodulators and transmitter analogues. We used single-electrode voltage clamp of power-stroke exciter and return-stroke exciter motor neurons to study changes in membrane currents during spontaneous transitions and during transitions caused by bath-application of carbachol or octopamine (OA). Spontaneous transitions from silence to activity were marked by the appearance of a standing inward current and periodic outward currents in both types of motor neurons. Bath-application of carbachol also led to the development of these currents and activation of the system. Using low Ca(2+)-high Mg(2+) saline to block synaptic transmission, we found that the carbachol-induced inward current included a direct response by the motor neuron and an indirect component. Spontaneous transitions from activity to silence were marked by disappearance of the standing inward current and the periodic outward currents. Bath-application of OA led promptly to the disappearance of both currents, and silenced the system. OA also acted directly on both types of motor neurons to cause a hyperpolarizing outward current that would contribute to silencing the system.

Local wind forcing of the Monterey Bay area inner shelf

USGS Publications Warehouse

Drake, P.T.; McManus, M.A.; Storlazzi, C.D.

2005-01-01

Wind forcing and the seasonal cycles of temperature and currents were investigated on the inner shelf of the Monterey Bay area of the California coast for 460 days, from June 2001 to September 2002. Temperature measurements spanned an approximate 100 km stretch of coastline from a bluff just north of Monterey Bay south to Point Sur. Inner shelf currents were measured at two sites near the bay's northern shore. Seasonal temperature variations were consistent with previous observations from the central California shelf. During the spring, summer and fall, a seasonal mean alongshore current was observed flowing northwestward in the northern bay, in direct opposition to a southeastward wind stress. A barotropic alongshore pressure gradient, potentially driving the northwestward flow, was needed to balance the alongshore momentum equation. With the exception of the winter season, vertical profiles of mean cross-shore currents were consistent with two-dimensional upwelling and existing observations from upwelling regions with poleward subsurface flow. At periods of 15-60 days, temperature fluctuations were coherent both throughout the domain and with the regional wind field. Remote wind forcing was minimal. During the spring upwelling season, alongshore currents and temperatures in the northern bay were most coherent with winds measured at a nearby land meteorological station. This wind site showed relatively low correlations to offshore buoy wind stations, indicating localized wind effects are important to the circulation along this stretch of Monterey Bay's inner shelf. ?? 2004 Elsevier Ltd. All rights reserved.

Current Sensor Fault Reconstruction for PMSM Drives

PubMed Central

Huang, Gang; Luo, Yi-Ping; Zhang, Chang-Fan; He, Jing; Huang, Yi-Shan

2016-01-01

This paper deals with a current sensor fault reconstruction algorithm for the torque closed-loop drive system of an interior PMSM. First, sensor faults are equated to actuator ones by a new introduced state variable. Then, in αβ coordinates, based on the motor model with active flux linkage, a current observer is constructed with a specific sliding mode equivalent control methodology to eliminate the effects of unknown disturbances, and the phase current sensor faults are reconstructed by means of an adaptive method. Finally, an αβ axis current fault processing module is designed based on the reconstructed value. The feasibility and effectiveness of the proposed method are verified by simulation and experimental tests on the RT-LAB platform. PMID:26840317

Exact Large-Deviation Statistics for a Nonequilibrium Quantum Spin Chain

NASA Astrophysics Data System (ADS)

Žnidarič, Marko

2014-01-01

We consider a one-dimensional XX spin chain in a nonequilibrium setting with a Lindblad-type boundary driving. By calculating large-deviation rate function in the thermodynamic limit, a generalization of free energy to a nonequilibrium setting, we obtain a complete distribution of current, including closed expressions for lower-order cumulants. We also identify two phase-transition-like behaviors in either the thermodynamic limit, at which the current probability distribution becomes discontinuous, or at maximal driving, when the range of possible current values changes discontinuously. In the thermodynamic limit the current has a finite upper and lower bound. We also explicitly confirm nonequilibrium fluctuation relation and show that the current distribution is the same under mapping of the coupling strength Γ→1/Γ.

The influence of cognitive impairment with no dementia on driving restriction and cessation in older adults.

PubMed

Kowalski, Kristina; Love, Janet; Tuokko, Holly; MacDonald, Stuart; Hultsch, David; Strauss, Esther

2012-11-01

Cognitively impaired older adults may be at increased risk of unsafe driving. Individuals with insight into their own impairments may minimize their risk by restricting or stopping driving. The purpose of this study was to examine the influence of cognitive impairment on driving status and driving habits and intentions. Participants were classified as cognitively impaired, no dementia single (CIND-single), CIND-multiple, or not cognitively impaired (NCI) and compared on their self-reported driving status, habits, and intentions to restrict or quit driving in the future. The groups differed significantly in driving status, but not in whether they restricted their driving or reduced their driving frequency. CIND-multiple group also had significantly higher intention to restrict/stop driving than the NCI group. Reasons for restricting and quitting driving were varied and many individuals reported multiple reasons, both external and internal, for their driving habits and intentions. Regardless of cognitive status, none of the current drivers were seriously thinking of restricting or quitting driving in the next 6 months. It will be important to determine, in future research, how driving practices change over time and what factors influence decisions to restrict or stop driving for people with cognitive impairment. Copyright © 2011. Published by Elsevier Ltd.

Is the useful field of view a good predictor of at-fault crash risk in elderly Japanese drivers?

PubMed

Sakai, Hiroyuki; Uchiyama, Yuji; Takahara, Miwa; Doi, Shun'ichi; Kubota, Fumiko; Yoshimura, Takayoshi; Tachibana, Atsumichi; Kurahashi, Tetsuo

2015-05-01

Although age-related decline in the useful field of view (UFOV) is well recognized as a risk factor for at-fault crash involvement in elderly drivers, there is still room to study its applicability to elderly Japanese drivers. In the current study, we thus examined the relationship between UFOV and at-fault crash history in an elderly Japanese population. We also explored whether potential factors that create awareness of reduced driving fitness could be a trigger for the self-regulation of driving in elderly drivers. We measured UFOV and at-fault crash history from 151 community-dwelling Japanese aged 60 years or older, and compared UFOV of at-fault crash-free and crash-involved drivers. We also measured self-evaluated driving style using a questionnaire. UFOV in crash-involved drivers was significantly lower than that in crash-free drivers. No significant difference was found in self-evaluated driving style between crash-free and crash-involved drivers. In addition, there was no significant association between UFOV and self-evaluated driving style. The present study showed that UFOV is a good predictor of at-fault crash risk in elderly Japanese drivers. Furthermore, our data imply that it might be difficult for elderly drivers to adopt appropriate driving strategies commensurate with their current driving competence. © 2014 Japan Geriatrics Society.

Update LADOTD policy on pile driving vibration management.

DOT National Transportation Integrated Search

2012-02-01

The main objective of this project was to update the current Louisiana Department of Transportation and Development (LADOTD) policy on pile driving vibration risk management with a focus on how to determine an appropriate vibration monitoring area. T...

Useful field of view in simulated driving: Reaction times and eye movements of drivers

PubMed Central

Seya, Yasuhiro; Nakayasu, Hidetoshi; Yagi, Tadasu

2013-01-01

To examine the spatial distribution of a useful field of view (UFOV) in driving, reaction times (RTs) and eye movements were measured in simulated driving. In the experiment, a normal or mirror-reversed letter “E” was presented on driving images with different eccentricities and directions from the current gaze position. The results showed significantly slower RTs in the upper and upper left directions than in the other directions. The RTs were significantly slower in the left directions than in the right directions. These results suggest that the UFOV in driving may be asymmetrical among the meridians in the visual field. PMID:24349688

Spine-fan reconnection. The influence of temporal and spatial variation in the driver

NASA Astrophysics Data System (ADS)

Wyper, P. F.; Jain, R.; Pontin, D. I.

2012-09-01

Context. From observations, the atmosphere of the Sun has been shown to be highly dynamic with perturbations of the magnetic field often lacking temporal or spatial symmetry. Despite this, studies of the spine-fan reconnection mode at 3D nulls have so far focused on the very idealised case with symmetric driving of a fixed spatial extent. Aims: We investigate the spine-fan reconnection process for less idealised cases, focusing on asymmetric driving and drivers with different length scales. We look at the initial current sheet formation and whether the scalings developed in the idealised models are robust in more realistic situations. Methods: The investigation was carried out by numerically solving the resistive compressible 3D magnetohydrodynamic equations in a Cartesian box containing a linear null point. The spine-fan collapse was driven at the null through tangential boundary driving of the spine foot points. Results: We find significant differences in the initial current sheet formation with asymmetric driving. Notable is the displacement of the null point position as a function of driving velocity and resistivity (η). However, the scaling relations developed in the idealised case are found to be robust (albeit at reduced amplitudes) despite this extra complexity. Lastly, the spatial variation is also shown to play an important role in the initial current sheet formation through controlling the displacement of the spine foot points. Conclusions: We conclude that during the early stages of spine-fan reconnection both the temporal and spatial nature of the driving play important roles, with the idealised symmetrically driven case giving a "best case" for the rate of current development and connectivity change. As the most interesting eruptive events occur in relatively short time frames this work clearly shows the need for high temporal and spatial knowledge of the flows for accurate interpretation of the reconnection scenario. Lastly, since the scalings developed in the idealised case remain robust with more complex driving we can be more confident of their use in interpreting reconnection in complex magnetic field structures.

[A literature review on epidemiologic research on sleep disturbances in the elderly].

PubMed

Doi, Yuriko

2015-06-01

One of the issues facing our super-aging society of Japan is to secure the elderly's safety and health. According to the latest 10-year statistics of the National Police Agency, the number of elderly driving deaths 75 years of age and over has risen 1.3 times from 2003 to 2013, whereas driving deaths decreased by less than half among the people under age 75 during the same period of time. This paper reviews the current literature on epidemiologic studies investigating the associations of sleep disturbances with adverse driving events and driving practice among elderly drivers. The results suggest a cognitive behavioral therapy for insomnia as a promising method for improving their driving capacity. Key words: elderly driving, epidemiology, sleep disturbances

Virtual groundwater transfers from overexploited aquifers in the United States

PubMed Central

Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J.

2015-01-01

The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km3, 9.18 km3, and 6.81 km3, respectively, which is comparable to the capacity of Lake Mead (35.7 km3), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use. PMID:26124137

The role of the Hippo pathway in human disease and tumorigenesis

PubMed Central

2014-01-01

Understanding the molecular nature of human cancer is essential to the development of effective and personalized therapies. Several different molecular signal transduction pathways drive tumorigenesis when deregulated and respond to different types of therapeutic interventions. The Hippo signaling pathway has been demonstrated to play a central role in the regulation of tissue and organ size during development. The deregulation of Hippo signaling leads to a concurrent combination of uncontrolled cellular proliferation and inhibition of apoptosis, two key hallmarks in cancer development. The molecular nature of this pathway was first uncovered in Drosophila melanogaster through genetic screens to identify regulators of cell growth and cell division. The pathway is strongly conserved in humans, rendering Drosophila a suitable and efficient model system to better understand the molecular nature of this pathway. In the present study, we review the current understanding of the molecular mechanism and clinical impact of the Hippo pathway. Current studies have demonstrated that a variety of deregulated molecules can alter Hippo signaling, leading to the constitutive activation of the transcriptional activator YAP or its paralog TAZ. Additionally, the Hippo pathway integrates inputs from a number of growth signaling pathways, positioning the Hippo pathway in a central role in the regulation of tissue size. Importantly, deregulated Hippo signaling is frequently observed in human cancers. YAP is commonly activated in a number of in vitro and in vivo models of tumorigenesis, as well as a number of human cancers. The common activation of YAP in many different tumor types provides an attractive target for potential therapeutic intervention. PMID:25097728

Phenotypic Mismatches Reveal Escape from Arms-Race Coevolution

PubMed Central

Hanifin, Charles T; Brodie, Edmund D; Brodie, Edmund D

2008-01-01

Because coevolution takes place across a broad scale of time and space, it is virtually impossible to understand its dynamics and trajectories by studying a single pair of interacting populations at one time. Comparing populations across a range of an interaction, especially for long-lived species, can provide insight into these features of coevolution by sampling across a diverse set of conditions and histories. We used measures of prey traits (tetrodotoxin toxicity in newts) and predator traits (tetrodotoxin resistance of snakes) to assess the degree of phenotypic mismatch across the range of their coevolutionary interaction. Geographic patterns of phenotypic exaggeration were similar in prey and predators, with most phenotypically elevated localities occurring along the central Oregon coast and central California. Contrary to expectations, however, these areas of elevated traits did not coincide with the most intense coevolutionary selection. Measures of functional trait mismatch revealed that over one-third of sampled localities were so mismatched that reciprocal selection could not occur given current trait distributions. Estimates of current locality-specific interaction selection gradients confirmed this interpretation. In every case of mismatch, predators were “ahead” of prey in the arms race; the converse escape of prey was never observed. The emergent pattern suggests a dynamic in which interacting species experience reciprocal selection that drives arms-race escalation of both prey and predator phenotypes at a subset of localities across the interaction. This coadaptation proceeds until the evolution of extreme phenotypes by predators, through genes of large effect, allows snakes to, at least temporarily, escape the arms race. PMID:18336073

Virtual groundwater transfers from overexploited aquifers in the United States.

PubMed

Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J

2015-07-14

The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km(3), 9.18 km(3), and 6.81 km(3), respectively, which is comparable to the capacity of Lake Mead (35.7 km(3)), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.

Phase-noise influence on coherent transients and hole burning

NASA Astrophysics Data System (ADS)

Shakhmuratov, R. N.; Szabo, Alex

1998-10-01

Resonant excitation of an inhomogeneously broadened ensemble of two-level atoms (TLA) by a stochastic field with phase noise is theoretically investigated. Free-induction decay (FID), hole burning (HB), and transient nutation (TN) are studied. We consider two kinds of driving fields, one with a free walking phase and another with the phase locked in a limited domain. It is shown that the resonant excitation behavior depends strongly on the noise property. Noise induced by a walking phase gives a simple contribution to the dephasing time, T2, of two-level atoms whereas phase locking qualitatively changes the laser-atom interaction. In the latter case, it is shown that even when the central part of the driving field spectrum is narrower than homogeneous absorption line of the TLA, the wide, low intensity wings of the spectrum (sidebands produced by the locked phase noise), have a strong effect on the FID, TN, and HB induced by the central, narrow part of the spectrum. The influence of sidebands on photon echoes is also discussed.