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Sample records for active front steering

  1. Integrated chassis control of active front steering and yaw stability control based on improved inverse nyquist array method.

    PubMed

    Zhu, Bing; Chen, Yizhou; Zhao, Jian

    2014-01-01

    An integrated chassis control (ICC) system with active front steering (AFS) and yaw stability control (YSC) is introduced in this paper. The proposed ICC algorithm uses the improved Inverse Nyquist Array (INA) method based on a 2-degree-of-freedom (DOF) planar vehicle reference model to decouple the plant dynamics under different frequency bands, and the change of velocity and cornering stiffness were considered to calculate the analytical solution in the precompensator design so that the INA based algorithm runs well and fast on the nonlinear vehicle system. The stability of the system is guaranteed by dynamic compensator together with a proposed PI feedback controller. After the response analysis of the system on frequency domain and time domain, simulations under step steering maneuver were carried out using a 2-DOF vehicle model and a 14-DOF vehicle model by Matlab/Simulink. The results show that the system is decoupled and the vehicle handling and stability performance are significantly improved by the proposed method.

  2. Integrated Chassis Control of Active Front Steering and Yaw Stability Control Based on Improved Inverse Nyquist Array Method

    PubMed Central

    2014-01-01

    An integrated chassis control (ICC) system with active front steering (AFS) and yaw stability control (YSC) is introduced in this paper. The proposed ICC algorithm uses the improved Inverse Nyquist Array (INA) method based on a 2-degree-of-freedom (DOF) planar vehicle reference model to decouple the plant dynamics under different frequency bands, and the change of velocity and cornering stiffness were considered to calculate the analytical solution in the precompensator design so that the INA based algorithm runs well and fast on the nonlinear vehicle system. The stability of the system is guaranteed by dynamic compensator together with a proposed PI feedback controller. After the response analysis of the system on frequency domain and time domain, simulations under step steering maneuver were carried out using a 2-DOF vehicle model and a 14-DOF vehicle model by Matlab/Simulink. The results show that the system is decoupled and the vehicle handling and stability performance are significantly improved by the proposed method. PMID:24782676

  3. New approaches to enhance active steering system functionalities: preliminary results

    NASA Astrophysics Data System (ADS)

    Serarslan, Benan

    2014-09-01

    An important development of the steering systems in general is active steering systems like active front steering and steer-by-wire systems. In this paper the current functional possibilities in application of active steering systems are explored. A new approach and additional functionalities are presented that can be implemented to the active steering systems without additional hardware such as new sensors and electronic control units. Commercial active steering systems are controlling the steering angle depending on the driving situation only. This paper introduce methods for enhancing active steering system functionalities depending not only on the driving situation but also vehicle parameters like vehicle mass, tyre and road condition. In this regard, adaptation of the steering ratio as a function of above mentioned vehicle parameters is presented with examples. With some selected vehicle parameter changes, the reduction of the undesired influences on vehicle dynamics of these parameter changes has been demonstrated theoretically with simulations and with real-time driving measurements.

  4. Steering Dynamics of Tilting Narrow Track Vehicle with Passive Front Wheel Design

    NASA Astrophysics Data System (ADS)

    TAN, Jeffrey Too Chuan; ARAKAWA, Hiroki; SUDA, Yoshihiro

    2016-09-01

    In recent years, narrow track vehicle has been emerged as a potential candidate for the next generation of urban transportation system, which is greener and space effective. Vehicle body tilting has been a symbolic characteristic of such vehicle, with the purpose to maintain its stability with the narrow track body. However, the coordination between active steering and vehicle tilting requires considerable driving skill in order to achieve effective stability. In this work, we propose an alternative steering method with a passive front wheel that mechanically follows the vehicle body tilting. The objective of this paper is to investigate the steering dynamics of the vehicle under various design parameters of the passive front wheel. Modeling of a three-wheel tilting narrow track vehicle and multibody dynamics simulations were conducted to study the effects of two important front wheel design parameters, i.e. caster angle and trail toward the vehicle steering dynamics in steering response time, turning radius, steering stability and resiliency towards external disturbance. From the results of the simulation studies, we have verified the relationships of these two front wheel design parameters toward the vehicle steering dynamics.

  5. Deformation effect simulation and optimization for double front axle steering mechanism

    NASA Astrophysics Data System (ADS)

    Wu, Jungang; Zhang, Siqin; Yang, Qinglong

    2013-03-01

    This paper research on tire wear problem of heavy vehicles with Double Front Axle Steering Mechanism from the flexible effect of Steering Mechanism, and proposes a structural optimization method which use both traditional static structural theory and dynamic structure theory - Equivalent Static Load (ESL) method to optimize key parts. The good simulated and test results show this method has high engineering practice and reference value for tire wear problem of Double Front Axle Steering Mechanism design.

  6. Front-End Types. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

    ERIC Educational Resources Information Center

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with automobile front-end types. Covered in the module are three common types of passenger car front suspension systems and their major components as well as two types…

  7. The Physics Performance Of The Front Steering Launcher For The ITER ECRH Upper Port

    SciTech Connect

    Henderson, M.; Chavan, R.; Nikkola, P.; Sanchez, F.; Sauter, O.; Shidara, H.; Ramponi, G.; Saibene, G.; Zohm, H.

    2005-09-26

    The capability of any given e.m.-wave plasma heating system to be utilized for physics applications depends strongly on the technical properties of the launching antenna (or launcher). An effective ECH launcher must project a small mm-wave beam spot size far into the plasma and 'steer' the beam across a large fraction of the plasma cross section (along the resonance surface). Thus the choice in the launcher concept and design may either severely limit or enhance the capability of a heating system to be effectively applied for physics applications, such as sawtooth stabilization, control of the Neoclassical Tearing Mode (NTM), Edge Localized Mode (ELM) control, etc. Presently, two antenna concepts are under consideration for the ITER upper port ECH launcher: front steering (FS) and remote steering (RS) launchers. The RS launcher has the technical advantage of easier maintenance access to the steering mirror, which is isolated from the torus vacuum. The FS launcher places the steering mirror near the plasma increasing the technical challenges, but significantly enhancing the focusing and steering capabilities of the launcher, offering a threefold increase in NTM stabilization efficiency over the RS launcher as well as the potential for application to other critical physics issues such as ELM or sawtooth control.

  8. Front leg movements and tibial motoneurons underlying auditory steering in the cricket (Gryllus bimaculatus deGeer).

    PubMed

    Baden, T; Hedwig, B

    2008-07-01

    Front leg movements in the cricket (Gryllus bimaculatus) were measured during phonotactic steering on a trackball together with electromyogram recordings of the tibial extensor and flexor muscles. Up-down leg movements clearly indicated the step cycle and were independent of auditory stimulation. By contrast, left-right movements of the front leg were dependent on sound direction, with crickets performing rapid steering leg movements towards the active speaker. Steering movements were dependent on the phase of sound relative to the step cycle, and were greatest for sounds occurring during the swing phase. During phonotaxis the slow extensor tibiae motoneuron responded to ipsilateral sounds with a latency of 35-40 ms, whereas the fast flexor tibiae motoneurons were excited by contralateral sound. We made intracellular recordings of two tibial extensor and at least eight flexor motoneurons. The fast extensor tibiae, the slow extensor tibiae and one fast flexor tibiae motoneurons were individually identifiable, but a group of at least four fast flexor tibiae as well as at least three slow flexor tibiae motoneurons of highly similar morphology could not be distinguished. Motoneurons received descending inputs from cephalic ganglia and from local prothoracic networks. There was no overlap between the dendritic fields of the tibial motoneurons and the auditory neuropile. They did not respond to auditory stimulation at rest. Neither extracellular stimulation of descending pathways nor pharmacological activation of prothoracic motor networks changed the auditory responsiveness. Therefore, any auditory input to tibial motoneurons is likely to be indirect, possibly via the brain.

  9. Active learning of Pareto fronts.

    PubMed

    Campigotto, Paolo; Passerini, Andrea; Battiti, Roberto

    2014-03-01

    This paper introduces the active learning of Pareto fronts (ALP) algorithm, a novel approach to recover the Pareto front of a multiobjective optimization problem. ALP casts the identification of the Pareto front into a supervised machine learning task. This approach enables an analytical model of the Pareto front to be built. The computational effort in generating the supervised information is reduced by an active learning strategy. In particular, the model is learned from a set of informative training objective vectors. The training objective vectors are approximated Pareto-optimal vectors obtained by solving different scalarized problem instances. The experimental results show that ALP achieves an accurate Pareto front approximation with a lower computational effort than state-of-the-art estimation of distribution algorithms and widely known genetic techniques.

  10. Boundaries can steer active Janus spheres

    PubMed Central

    Das, Sambeeta; Garg, Astha; Campbell, Andrew I.; Howse, Jonathan; Sen, Ayusman; Velegol, Darrell; Golestanian, Ramin; Ebbens, Stephen J.

    2015-01-01

    The advent of autonomous self-propulsion has instigated research towards making colloidal machines that can deliver mechanical work in the form of transport, and other functions such as sensing and cleaning. While much progress has been made in the last 10 years on various mechanisms to generate self-propulsion, the ability to steer self-propelled colloidal devices has so far been much more limited. A critical barrier in increasing the impact of such motors is in directing their motion against the Brownian rotation, which randomizes particle orientations. In this context, here we report directed motion of a specific class of catalytic motors when moving in close proximity to solid surfaces. This is achieved through active quenching of their Brownian rotation by constraining it in a rotational well, caused not by equilibrium, but by hydrodynamic effects. We demonstrate how combining these geometric constraints can be utilized to steer these active colloids along arbitrary trajectories. PMID:26627125

  11. Boundaries can steer active Janus spheres

    NASA Astrophysics Data System (ADS)

    Das, Sambeeta; Garg, Astha; Campbell, Andrew I.; Howse, Jonathan; Sen, Ayusman; Velegol, Darrell; Golestanian, Ramin; Ebbens, Stephen J.

    2015-12-01

    The advent of autonomous self-propulsion has instigated research towards making colloidal machines that can deliver mechanical work in the form of transport, and other functions such as sensing and cleaning. While much progress has been made in the last 10 years on various mechanisms to generate self-propulsion, the ability to steer self-propelled colloidal devices has so far been much more limited. A critical barrier in increasing the impact of such motors is in directing their motion against the Brownian rotation, which randomizes particle orientations. In this context, here we report directed motion of a specific class of catalytic motors when moving in close proximity to solid surfaces. This is achieved through active quenching of their Brownian rotation by constraining it in a rotational well, caused not by equilibrium, but by hydrodynamic effects. We demonstrate how combining these geometric constraints can be utilized to steer these active colloids along arbitrary trajectories.

  12. Front-Steering Assist Control System Design for a Motorcycle Stabilization during Braking

    NASA Astrophysics Data System (ADS)

    Murakami, Shintaroh; Nishimura, Hidekazu; Zhu, Shaopeng

    In braking situations, it is known that a motorcycle may become unstable. In this paper, a front-steering assist control is designed to stabilize a motorcycle during braking. The rider-motorcycle system with its pitching motions is linearized around an equilibrium point of quasi-steady state straight running with constant deceleration. From the viewpoints of eigenvalues and frequency responses, the linearized model is analyzed and a reduced-order model is obtained to design the control system by using H∞ control theory. By carrying out simulations, it is demonstrated that the control system can stabilize a motorcycle during braking when receiving a sudden disturbance from the front wheel, and its applicable scope is discussed for several situations including different maneuvering of a rider.

  13. Advanced Optics for a Full Quasi-Optical Front Steering ECRH Upper Launcher for ITER

    SciTech Connect

    Moro, A.; Alessi, E.; Bruschi, A.; Platania, P.; Sozzi, C.; Chavan, R.; Collazos, A.; Goodman, T. P.; Udintsev, V. S.; Henderson, M. A.

    2009-11-26

    A full quasi-optical setup for the internal optics of the Front Steering Electron Cyclotron Resonance Heating (ECRH) Upper Launcher for ITER was designed, proving to be feasible and favorable in terms of additional flexibility and cost reduction with respect to the former design. This full quasi-optical solution foresees the replacement of the mitre-bends in the final section of the launcher with dedicated free-space mirrors to realize the last changes of directions in the launcher. A description of the launcher is given and its advantages presented. The parameters of the expected output beams as well as preliminary evaluations of truncation effects with the physical optics GRASP code are shown. Moreover, a study of mitre-bends replacement with single mirrors for multiple beams is described. In principle it could allow the beams to be larger at the mirror locations (with a further decrease of the peak power density due to partial overlapping) and has the additional advantage to get a larger opening with compressed beams to avoid conflicts with side-walls port. Constraints on the setup, arising both from the resulting beam characteristics in the space of free parameters and from mechanical requirements are taken into account in the analysis.

  14. Boundaries steer the contraction of active gels

    NASA Astrophysics Data System (ADS)

    Schuppler, Matthias; Keber, Felix C.; Kröger, Martin; Bausch, Andreas R.

    2016-10-01

    Cells set up contractile actin arrays to drive various shape changes and to exert forces to their environment. To understand their assembly process, we present here a reconstituted contractile system, comprising F-actin and myosin II filaments, where we can control the local activation of myosin by light. By stimulating different symmetries, we show that the force balancing at the boundaries determine the shape changes as well as the dynamics of the global contraction. Spatially anisotropic attachment of initially isotropic networks leads to a self-organization of highly aligned contractile fibres, being reminiscent of the order formation in muscles or stress fibres. The observed shape changes and dynamics are fully recovered by a minimal physical model.

  15. Boundaries steer the contraction of active gels

    PubMed Central

    Schuppler, Matthias; Keber, Felix C.; Kröger, Martin; Bausch, Andreas R.

    2016-01-01

    Cells set up contractile actin arrays to drive various shape changes and to exert forces to their environment. To understand their assembly process, we present here a reconstituted contractile system, comprising F-actin and myosin II filaments, where we can control the local activation of myosin by light. By stimulating different symmetries, we show that the force balancing at the boundaries determine the shape changes as well as the dynamics of the global contraction. Spatially anisotropic attachment of initially isotropic networks leads to a self-organization of highly aligned contractile fibres, being reminiscent of the order formation in muscles or stress fibres. The observed shape changes and dynamics are fully recovered by a minimal physical model. PMID:27739426

  16. Micromachined low-mass RF front-end for beam steering radar

    NASA Astrophysics Data System (ADS)

    Vahidpour, M.; Moallem, M.; East, J.; Sarabandi, K.

    2012-06-01

    Sensors for autonomous small robotic platforms must be low mass, compact size and low power due to the limited space. For such applications, as the dimensions of the structures shrink, standard machining methods are not suitable because of low fabrication tolerances and high cost in assembly. Commonly, the structures show a high degree of fabrication complexity due to error in alignment, air gaps between conductive parts, poor metal contact, inaccuracy in patterning because of non-contact lithography, complex assemblies of various parts, and high number of steps needed for construction. However, micromachining offers high fabrication precision, provides easy fabrication and integration with active devices and hence is suitable for manufacturing high MMW and submillimeter-wave frequency structures. A radar design compatible with micromachining process is developed to fabricate a Y-band high resolution radar structure with a slot-fed patch array antenna. A multi-step silicon DRIE process is developed for the fabrication of the waveguide structure while the slots are suspended on a thin oxide/nitride/oxide membrane to form the top cover of the waveguide trenches and the patch elements are suspended on a thin Parylene membrane. Gold thermocompression bonding and Parylene bonding are used to assemble different parts of the antenna. These processes result in a compact (4.5 cm × 3.5 cm × 1.5 mm) and light-weight (5 g) radar.

  17. Concept for a laser guide beacon Shack-Hartmann wave-front sensor with dynamically steered subapertures.

    PubMed

    Baranec, Christoph J; Bauman, Brian J; Lloyd-Hart, Michael

    2005-04-01

    We describe an innovative implementation of the Shack-Hartmann wave-front sensor that is designed to correct the perspective elongation of a laser guide beacon in adaptive optics. Subapertures are defined by the segments of a deformable mirror rather than by a conventional lenslet array. A bias tilt on each segment separates the beacon images on the sensor's detector. One removes the perspective elongation by dynamically driving each segment with a predetermined open-loop signal that would, in the absence of atmospheric wave-front aberration, keep the corresponding beacon image centered on the subaperture's optical axis.

  18. Active terahertz beam steering by photo-generated graded index gratings in thin semiconductor films.

    PubMed

    Steinbusch, T P; Tyagi, H K; Schaafsma, M C; Georgiou, G; Gómez Rivas, J

    2014-11-01

    We demonstrate active beam steering of terahertz radiation using a photo-excited thin layer of gallium arsenide. A constant gradient of phase discontinuity along the interface is introduced by an spatially inhomogeneous density of free charge carriers that are photo-generated in the GaAs with an optical pump. The optical pump has been spatially modulated to form the shape of a planar blazed grating. The phase gradient leads to an asymmetry between the +1 and -1 transmission diffracted orders of more than a factor two. Optimization of the grating structure can lead to an asymmetry of more than one order of magnitude. Similar to metasurfaces made of plasmonic antennas, the photo-generated grating is a planar structure that can achieve large beam steering efficiency. Moreover, the photo-generation of such structures provides a platform for active THz beam steering. PMID:25401807

  19. Effects of isobutyrate supplementation on ruminal microflora, rumen enzyme activities and methane emissions in Simmental steers.

    PubMed

    Wang, C; Liu, Q; Zhang, Y L; Pei, C X; Zhang, S L; Wang, Y X; Yang, W Z; Bai, Y S; Shi, Z G; Liu, X N

    2015-02-01

    The objective of this study was to evaluate the effects of isobutyrate supplementation on rumen microflora, enzyme activities and methane emissions in Simmental steers consuming a corn stover-based diet. Eight ruminally cannulated Simmental steers were used in a replicated 4 × 4 Latin square experiment. The treatments were control (without isobutyrate), low isobutyrate (LIB), moderate isobutyrate (MIB) and high isobutyrate (HIB) with 8.4, 16.8 and 25.2 g isobutyrate per steer per day respectively. Isobutyrate was hand-mixed into the concentrate portion. Diet consisted of 60% corn stover and 40% concentrate [dry matter (DM) basis]. Dry matter intake (averaged 9 kg/day) was restricted to a maximum of 90% of ad libitum intake. Population of total bacteria, cellulolytic bacteria and anaerobic fungi were linearly increased, whereas that of protozoa and total methanogens was linearly reduced with increasing isobutyrate supplementation. Real-time PCR quantification of population of Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Fibrobacter succinogenes was linearly increased with increasing isobutyrate supplementation. Activities of carboxymethyl cellulase, xylanase and β-glucosidase were linearly increased, whereas that of protease was linearly reduced. Methane production was linearly decreased with increasing isobutyrate supplementation. Effective degradabilities of cellulose and hemicellulose of corn stover were linearly increased, whereas that of crude protein in diet was linearly decreased with increasing isobutyrate supplementation. The present results indicate that isobutyrate supplemented improved microflora, rumen enzyme activities and methane emissions in steers. It was suggested that the isobutyrate stimulated the digestive micro-organisms or enzymes in a dose-dependent manner. In the experimental conditions of this trial, the optimum isobutyrate dose was approximately 16.8 g isobutyrate per steer per day.

  20. Relationships among Ergot Alkaloids, Cytochrome P450 Activity, and Beef Steer Growth

    NASA Astrophysics Data System (ADS)

    Rosenkrans, Charles; Ezell, Nicholas

    2015-03-01

    Determining a grazing animal’s susceptibility to ergot alkaloids has been a research topic for decades. Our objective was to determine if the Promega™ P450-Glo assay could be used to indirectly detect ergot alkaloids or their metabolites in urine of steers. The first experiment validated the effects of ergot alkaloids [0, 20, and 40 μM of ergotamine (ET), dihydroergotamine (DHET), and ergonovine (EN)] on human CYP3A4 using the P450-Glo assay (Promega™ V9800). With this assay, luminescence is directly proportional to CYP450 activity. Relative inhibition of in vitro cytochrome P450 activity was affected (P < 0.001) by an interaction between alkaloids and concentration. That interaction resulted in no concentration effect of EN, but within ET and DHET 20 and 40 µM concentrations inhibited CYP450 activity when compared with controls. In experiment 2, urine was collected from Angus-sired crossbred steers (n = 39; 216 ± 2.6 d of age; 203 ± 1.7 kg) after grazing tall fescue pastures for 105 d. Non-diluted urine was added to the Promega™ P450-Glo assay, and observed inhibition (3.7 % ± 2.7 of control). Urine content of total ergot alkaloids (331.1 ng/mg of creatinine ± 325.7) was determined using enzyme linked immunosorbent assay. Urine inhibition of CYP450 activity and total alkaloids were correlated (r = -0.31; P < 0.05). Steers were genotyped at CYP450 single nucleotide polymorphism, C994G. Steer genotype affected (P < 0.03) inhibition of CYP450 activity by urine; heterozygous steers had the least amount of CYP450 inhibition suggesting that genotyping cattle may be a method of identifying animals that are susceptible to ergot alkaloids. Although, additional research is needed, we demonstrate that the Promega™ P450-Glo assay is sensitive to ergot alkaloids and urine from steers grazing tall fescue. With some refinement the P450-Glo assay has potential as a tool for screening cattle for their exposure to fescue toxins.

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

    NASA Astrophysics Data System (ADS)

    Bolia, Pratiksh; Weiskircher, Thomas; Müller, Steffen

    2014-05-01

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

  2. Simple control-theoretic models of human steering activity in visually guided vehicle control

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.

    1991-01-01

    A simple control theoretic model of human steering or control activity in the lateral-directional control of vehicles such as automobiles and rotorcraft is discussed. The term 'control theoretic' is used to emphasize the fact that the model is derived from a consideration of well-known control system design principles as opposed to psychological theories regarding egomotion, etc. The model is employed to emphasize the 'closed-loop' nature of tasks involving the visually guided control of vehicles upon, or in close proximity to, the earth and to hypothesize how changes in vehicle dynamics can significantly alter the nature of the visual cues which a human might use in such tasks.

  3. Feedlot performance, carcass characteristics, hormones, and metabolites in steers actively immunized against growth hormone-releasing factor.

    PubMed

    Harvey, R W; Armstrong, J D; Heimer, E P; Campbell, R M

    1993-11-01

    Large-framed Simmental and Charolais steers were actively immunized against growth hormone-releasing factor (GRF) to evaluate the effect on growth, carcass characteristics (especially intramuscular fat deposition), and concentrations of somatotropin (ST) and IGF-I. Primary immunizations of 1.5 mg of GRF-(1-29)-Gly-Gly-Cys-NH2 conjugated to 1.5 mg of human serum albumin (GRFi, n = 12) or 1.5 mg of human serum albumin (HSAi, n = 12) were given at approximately 10 mo of age. Booster immunizations of .5 mg of the appropriate antigen were given at d 49 and 125. Weights of steers administered GRFi were less (P < .05) than those given HSAi at 126 d (34.6 kg) or at 262 d (48.2 kg) after treatment. Carcass weights were 28.2 kg less (P < .01) for GRFi than for HSAi steers. Dry matter intake was not affected by immunization treatment, whereas feed efficiency was reduced in GRFi steers. Marbling scores were higher (P < .05) for HSAi than for GRFi steers but similar percentages (83.3) of both treatments graded Low Choice or higher. Rib sections of GRFi steers contained more fat (31.2 vs 25.0%) and less lean (63.3 vs 68.4%) than those of HSAi steers (P < .05). A breed x treatment interaction was observed for percentage of fat within the trimmed longissimus muscle (P < .05); percentage of fat was similar for Charolais and Simmental steers when immunized against HSAi but was higher for Simmental than for Charolais when immunized against GRFi.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Muscle activation of drivers with hemiplegia caused by stroke while driving using a steering wheel or knob.

    PubMed

    Jung, Nam-Hae; Kim, Hwanhee; Chang, Moonyoung

    2015-04-01

    [Purpose] The aim of this study was to investigate three muscle activities of drivers with post-stoke hemiplegia while they were driving using a steering wheel or a spinner knob, and to compare them with those of non-disabled drivers. [Subjects and Methods] The subjects were four non-disabled drivers and five drivers with left hemiplegia. The subjects drove forward in a straight line for 5 m and then turned right or left using the steering wheel or spinner knob with only their right hand. EMG electrodes were placed over the anterior deltoid, biceps and triceps brachii on the right-side. [Results] While differences in muscle activation between the spinner knob and the steering wheel in the control group were not significant, those of the experimental group were significant. Activation of the biceps brachii while the control group turned the vehicle to the right using the spinner knob was significantly lower than when using the steering wheel. Activation of the biceps brachii while the experimental group turned the vehicle to the right using the spinner knob was significantly lower than that of the control group. [Conclusion] The results of this study indicate that a spinner knob requires less activation of the main muscle than a steering wheel, especially in drivers who have had a stroke. The results could be used as basic data when driver rehabilitation specialists prescribe the spinner knob for patients.

  5. Active Gaze Control Improves Optic Flow-Based Segmentation and Steering

    PubMed Central

    Raudies, Florian; Mingolla, Ennio; Neumann, Heiko

    2012-01-01

    An observer traversing an environment actively relocates gaze to fixate objects. Evidence suggests that gaze is frequently directed toward the center of an object considered as target but more likely toward the edges of an object that appears as an obstacle. We suggest that this difference in gaze might be motivated by specific patterns of optic flow that are generated by either fixating the center or edge of an object. To support our suggestion we derive an analytical model that shows: Tangentially fixating the outer surface of an obstacle leads to strong flow discontinuities that can be used for flow-based segmentation. Fixation of the target center while gaze and heading are locked without head-, body-, or eye-rotations gives rise to a symmetric expansion flow with its center at the point being approached, which facilitates steering toward a target. We conclude that gaze control incorporates ecological constraints to improve the robustness of steering and collision avoidance by actively generating flows appropriate to solve the task. PMID:22719889

  6. Vehicle active steering control research based on two-DOF robust internal model control

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Liu, Yahui; Wang, Fengbo; Bao, Chunjiang; Sun, Qun; Zhao, Youqun

    2016-07-01

    Because of vehicle's external disturbances and model uncertainties, robust control algorithms have obtained popularity in vehicle stability control. The robust control usually gives up performance in order to guarantee the robustness of the control algorithm, therefore an improved robust internal model control(IMC) algorithm blending model tracking and internal model control is put forward for active steering system in order to reach high performance of yaw rate tracking with certain robustness. The proposed algorithm inherits the good model tracking ability of the IMC control and guarantees robustness to model uncertainties. In order to separate the design process of model tracking from the robustness design process, the improved 2 degree of freedom(DOF) robust internal model controller structure is given from the standard Youla parameterization. Simulations of double lane change maneuver and those of crosswind disturbances are conducted for evaluating the robust control algorithm, on the basis of a nonlinear vehicle simulation model with a magic tyre model. Results show that the established 2-DOF robust IMC method has better model tracking ability and a guaranteed level of robustness and robust performance, which can enhance the vehicle stability and handling, regardless of variations of the vehicle model parameters and the external crosswind interferences. Contradiction between performance and robustness of active steering control algorithm is solved and higher control performance with certain robustness to model uncertainties is obtained.

  7. Locally excitable Cdc42 signals steer cells during chemotaxis

    PubMed Central

    Meyer, Tobias

    2016-01-01

    Neutrophils and other amoeboid cells chemotax by steering their front towards chemoattractant. While Ras, Rac, Cdc42, and RhoA small GTPases all regulate chemotaxis, it has been unclear how they spatiotemporally control polarization and steering. Using fluorescence biosensors in neutrophil-like PLB-985 cells and photorelease of chemoattractant, we show that local Cdc42 signals, but not those of Rac, RhoA or Ras, precede cell turning during chemotaxis. Furthermore, preexisting local Cdc42 signals in morphologically unpolarized cells predict the future direction of movement upon uniform stimulation. Moreover, inhibition of actin polymerization uncovers recurring local Cdc42 activity pulses, suggesting that Cdc42 has the excitable characteristic of the compass activity proposed in models of chemotaxis. Globally, Cdc42 antagonizes RhoA, and maintains a steep spatial activity gradient during migration, while Ras and Rac form shallow gradients. Thus, chemotactic steering and de novo polarization are both directed by locally excitable Cdc42 signals. PMID:26689677

  8. Effect of two dietary concentrate levels on tenderness, calpain and calpastatin activities, and carcass merit in Waguli and Brahman steers.

    PubMed

    Ibrahim, R M; Goll, D E; Marchello, J A; Duff, G C; Thompson, V F; Mares, S W; Ahmad, H A

    2008-06-01

    The objective of this study was to compare carcass characteristics of a newly introduced breed, the Waguli (Wagyu x Tuli), with the carcass characteristics of the Brahman breed. Brahman cattle are used extensively in the Southwest of the United States because of their tolerance to adverse environmental conditions. However, Brahman carcasses are discounted according to the height of their humps because of meat tenderness issues. The Waguli was developed in an attempt to obtain a breed that retained the heat tolerance of the Brahman but had meat quality attributes similar to the Wagyu. Twenty-four animals were used. Six steers from each breed were fed a 94% concentrate diet and 6 steers from each breed were fed an 86% concentrate diet. Eight steers, 2 from each group, were harvested after 128 d, after 142 d, and after 156 d on feed. Waguli steers had larger LM, greater backfat thickness, greater marbling scores, and greater quality grades than the Brahman steers (P < 0.05). The Japanese Wagyu breed is well known for its highly marbled and tender meat, and these traits are also present in the Waguli. The Waguli had significantly lower Warner-Bratzler shear force values than the Brahman steers after 7 and 10 d of postmortem aging (P < 0.05); this difference decreased after 14 d postmortem (P = 0.2), when tenderness of the slower aging Brahman had increased to acceptable levels. Toughness of the Brahman has been associated with high levels of calpastatin in Brahman muscle, and the Waguli LM had significantly less calpastatin activity (P = 0.02) at 0 h postmortem than the Brahman LM. At 0-h postmortem, the total LM calpain activity did not differ between the Brahman and Waguli (P = 0.57). Neither diet nor days on feed had any significant effect on the 0-h postmortem calpain or at 0-h postmortem calpastatin activity, nor an effect on Warner-Bratzler shear-force values. In conclusion, LM muscle from the Waguli steers had a high degree of marbling, lower shear force values

  9. Effect of two dietary concentrate levels on tenderness, calpain and calpastatin activities, and carcass merit in Waguli and Brahman steers.

    PubMed

    Ibrahim, R M; Goll, D E; Marchello, J A; Duff, G C; Thompson, V F; Mares, S W; Ahmad, H A

    2008-06-01

    The objective of this study was to compare carcass characteristics of a newly introduced breed, the Waguli (Wagyu x Tuli), with the carcass characteristics of the Brahman breed. Brahman cattle are used extensively in the Southwest of the United States because of their tolerance to adverse environmental conditions. However, Brahman carcasses are discounted according to the height of their humps because of meat tenderness issues. The Waguli was developed in an attempt to obtain a breed that retained the heat tolerance of the Brahman but had meat quality attributes similar to the Wagyu. Twenty-four animals were used. Six steers from each breed were fed a 94% concentrate diet and 6 steers from each breed were fed an 86% concentrate diet. Eight steers, 2 from each group, were harvested after 128 d, after 142 d, and after 156 d on feed. Waguli steers had larger LM, greater backfat thickness, greater marbling scores, and greater quality grades than the Brahman steers (P < 0.05). The Japanese Wagyu breed is well known for its highly marbled and tender meat, and these traits are also present in the Waguli. The Waguli had significantly lower Warner-Bratzler shear force values than the Brahman steers after 7 and 10 d of postmortem aging (P < 0.05); this difference decreased after 14 d postmortem (P = 0.2), when tenderness of the slower aging Brahman had increased to acceptable levels. Toughness of the Brahman has been associated with high levels of calpastatin in Brahman muscle, and the Waguli LM had significantly less calpastatin activity (P = 0.02) at 0 h postmortem than the Brahman LM. At 0-h postmortem, the total LM calpain activity did not differ between the Brahman and Waguli (P = 0.57). Neither diet nor days on feed had any significant effect on the 0-h postmortem calpain or at 0-h postmortem calpastatin activity, nor an effect on Warner-Bratzler shear-force values. In conclusion, LM muscle from the Waguli steers had a high degree of marbling, lower shear force values

  10. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... steering linkage shall not exceed the values shown in Table 3. (1) Inspection procedure. Elevate the front... are correctly adjusted. Grasp the front and rear of a tire and attempt to turn the tire and wheel assemble left and right. If the free movement at the front or rear tread of the tire exceeds the...

  11. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... steering linkage shall not exceed the values shown in Table 3. (1) Inspection procedure. Elevate the front... are correctly adjusted. Grasp the front and rear of a tire and attempt to turn the tire and wheel assemble left and right. If the free movement at the front or rear tread of the tire exceeds the...

  12. 49 CFR 570.7 - Steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... not exceed values shown in Table 1. (1) Inspection procedure. With the engine on and the wheels in the straight ahead position, turn the steering wheel in one direction until there is a perceptible movement of a front wheel. If a point on the steering wheel rim moves more than the value shown in Table...

  13. Oceanic density fronts steering bottom-current induced sedimentation deduced from a 50 ka contourite-drift record and numerical modeling (off NW Spain)

    NASA Astrophysics Data System (ADS)

    Hanebuth, Till J. J.; Zhang, Wenyan; Hofmann, Antonia L.; Löwemark, Ludvig A.; Schwenk, Tilmann

    2015-03-01

    How the various bottom-near hydrographic and sedimentary processes control the formation of contourite drifts, i.e. of bottom-current related confined deep-sea depocenters, usually remains widely speculative. This study uses a transect of six sediment cores and a sediment echosounder profile across a whole contourite system off NW Spain to address the sediment dynamics responsible for the depositional pattern. This "mounded patch"-type contourite drift (18 km long, 20 km wide) with a 150-m deep channel (moat) has formed around an 800-m high structural obstacle. Deposition on the contourite drift in the past was characterized by alternating calm and high-energy bottom-flow conditions. Calm conditions (Last Glacial period: 27-17 cal ka BP; late Holocene times: <4 cal ka BP) led to slightly current-influenced deposition of fine-grained sediments (10 μm) in the entire basin. This regime was interrupted by periods of short-lasting waxing-and-waning high-energy conditions (D/O events during Marine Isotope Stage 3; the Deglacial/early Holocene time interval at 17-4 cal ka BP), resulting in the deposition of coarse sediments (70 μm). Process-based numerical modeling demonstrates that pulse-like oceanic density fronts traveling within the transition zone of two water masses (Labrador Sea Water, Mediterranean Outflow Water) provide a powerful mechanism for contouritic deposition, rather than the core of a water mass itself. These gravity-driven density fronts lead to local re-suspension of sands stored inside the drift's moat and to subsequent upward transport towards the drift's crest. Here, the oceanic density fronts produce additional km-scale eddies. These migrating eddies provide an efficient mechanism for further widespread sediment re-distribution. In comparison with paleoceanographic reconstructions, a downward migration or expansion of the Mediterranean Outflow Water by about 300 m led most probably to such temporary contouritic sand deposition. We finally propose

  14. Oceanic Density Fronts Steering Bottom-Current Induced Sedimentation Deduced from a 50 ka Contourite-Drift Record and Numerical Modeling (off NW Spain)

    NASA Astrophysics Data System (ADS)

    Hanebuth, T. J. J.; Zhang, W.; Hofmann, A. L.; Lowemark, L. A.; Schwenk, T.

    2015-12-01

    How bottom-near hydrographic and sedimentary processes control the formation of bottom-current related confined deep-sea depocenters remains widely speculative. The geological approach of this study uses a transect of sediment cores and sediment echosounder profiles across a whole contourite system off NW Spain. This "mounded patch"-type contourite drift (18 km long, 20 km wide) with a 150-m deep moat has formed around an 800-m high structural obstacle. Past deposition was characterized by alternating calm and high-energy bottom-flow conditions. Calm conditions (Last Glacial period: 27-17 cal ka BP; late Holocene times: < 4 cal ka BP) led to slightly current-influenced deposition of fine-grained sediments (10 µm) over the entire basin. In contrast, waxing-and-waning high-energy conditions (D/O events during Marine Isotope Stage 3; the Deglacial/early Holocene time interval at 17-4 cal ka BP) resulted in coarse grained (70 µm) deposition. Process-based numerical modelling demonstrates that pulse-like oceanic density fronts travelling within the transition zone of two water masses (Labrador Sea Water, Mediterranean Outflow Water) provide a powerful mechanism for contouritic deposition, rather than the core of a water mass itself. These gravity-driven density fronts lead to local re-suspension of sand from the moat and to subsequent upward transport over the crest. Here, the oceanic density fronts produce additional km-scale eddies. These migrating eddies provide an efficient mechanism for further widespread sediment re-distribution. In comparison with paleoceanographic reconstructions, a downward migration or expansion of the Mediterranean Outflow Water by about 300 m led most probably to such temporary contouritic sand deposition. We finally propose a conceptual model to explain how seafloor obstacles redirect and perturbate bottom currents. This model proposes water mass transition zone as an important high-energy medium, for oceanic density fronts to travel. On

  15. Implementation of active steering on longer combination vehicles for enhanced lateral performance

    NASA Astrophysics Data System (ADS)

    Kharrazi, Sogol; Lidberg, Mathias; Roebuck, Richard; Fredriksson, Jonas; Odhams, Andrew

    2012-12-01

    A steering-based controller for improving lateral performance of longer combination vehicles (LCVs) is proposed. The controller steers the axles of the towed units to regulate the time span between the driver steering and generation of tyre lateral forces at the towed units and consequently reduces the yaw rate rearward amplification (RWA) and offtracking. The open-loop effectiveness of the controller is evaluated with simulations and its closed loop or driver in the loop effectiveness is verified on a test track with a truck-dolly-semitrailer test vehicle in a series of single- and double-lane change manoeuvres. The developed controller reduces the yaw rate RWA and offtracking considerably without diminishing the manoeuvrability. Furthermore, as a byproduct, it decreases the lateral acceleration RWA moderately. The obtained safety improvements by the proposed controller can promote the use of LCVs in traffic which will result in the reduction of congestion problem as well as environmental and economic benefits.

  16. Front Range Infrastructure Resources Project: water-resources activities

    USGS Publications Warehouse

    Robson, Stanley G.; Heiny, Janet S.

    1998-01-01

    Infrastructure, such as roads, buildings, airports, and dams, is built and maintained by use of large quantities of natural resources such as aggregate (sand and gravel), energy, and water. As urban area expand, local sources of these resource are becoming inaccessible (gravel cannot be mined from under a subdivision, for example), or the cost of recovery of the resource becomes prohibitive (oil and gas drilling in urban areas is costly), or the resources may become unfit for some use (pollution of ground water may preclude its use as a water supply). Governmental land-use decision and environmental mandates can further preclude development of natural resources. If infrastructure resources are to remain economically available. current resource information must be available for use in well-reasoned decisions bout future land use. Ground water is an infrastructure resource that is present in shallow aquifers and deeper bedrock aquifers that underlie much of the 2,450-square-mile demonstration area of the Colorado Front Range Infrastructure Resources Project. In 1996, mapping of the area's ground-water resources was undertaken as a U.S. Geological Survey project in cooperation with the Colorado Department of Natural Resources, Division of Water Resources, and the Colorado Water Conservation Board.

  17. The Impact of Oil and Natural Gas Activity on Ozone Formation in the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Hornbrook, R. S.; Apel, E. C.; Hills, A. J.; Blake, D. R.; Blake, N. J.; Schroeder, J.; Fried, A.; Weibring, P.; Richter, D.; Walega, J.; Mauldin, L.; Cantrell, C. A.; Hall, S. R.; Ullmann, K.; Weinheimer, A. J.; Montzka, D.; Orlando, J. J.; Tyndall, G. S.; Campos, T. L.; Stell, M. H.; Heikes, B.; Treadaway, V.; O'Sullivan, D. W.; Huey, L. G.; Tanner, D.; Cohen, R. C.; Flocke, F. M.; Pfister, G.; Knote, C. J.; Emmons, L. K.

    2014-12-01

    The 2014 Front Range Air Pollution and Photochemistry Experiment (FRAPPE) was a ground-based and airborne field study designed to characterize and understand air quality in the Colorado Front Range, where National Ambient Air Quality Standards (NAAQS) ozone levels are frequently exceeded during summertime. A primary goal of the study was to determine the factors controlling surface ozone in the Front Range. As part of the project, measurements of many trace gases were observed on board the NSF/NCAR C-130 by a suite of instrumentation, including the NCAR Trace Organic Gas Analyzer (TOGA), which made measurements of a set of volatile organic compounds (VOCs). VOCs are crucial for characterizing emissions and photochemical processing in the Front Range, as well as the air transported into the region. During recent years, oil and natural gas (O&NG) activity in the Front Range has been growing rapidly. Ratios of observed aromatic hydrocarbons, butanes and pentanes demonstrate distinct fingerprinting that can be used to distinguish both between different types of O&NG activities and between O&NG extraction regions in the FRAPPE study region and beyond. Using the observed hydrocarbon data along with other trace gas observations, we will compare contributions of O&NG emissions to OH reactivities in different regions in the Front Range, and present box model results demonstrating the impact of O&NG activities on ozone formation.

  18. The Impact of Oil and Natural Gas Activity on Ozone Formation in the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Hornbrook, R. S.; Apel, E. C.; Hills, A. J.; Blake, D. R.; Blake, N. J.; Schroeder, J.; Fried, A.; Weibring, P.; Richter, D.; Walega, J.; Mauldin, L.; Cantrell, C. A.; Hall, S. R.; Ullmann, K.; Weinheimer, A. J.; Montzka, D.; Orlando, J. J.; Tyndall, G. S.; Campos, T. L.; Stell, M. H.; Heikes, B.; Treadaway, V.; O'Sullivan, D. W.; Huey, L. G.; Tanner, D.; Cohen, R. C.; Flocke, F. M.; Pfister, G.; Knote, C. J.; Emmons, L. K.

    2015-12-01

    The 2014 Front Range Air Pollution and Photochemistry Experiment (FRAPPE) was a ground-based and airborne field study designed to characterize and understand air quality in the Colorado Front Range, where National Ambient Air Quality Standards (NAAQS) ozone levels are frequently exceeded during summertime. A primary goal of the study was to determine the factors controlling surface ozone in the Front Range. As part of the project, measurements of many trace gases were observed on board the NSF/NCAR C-130 by a suite of instrumentation, including the NCAR Trace Organic Gas Analyzer (TOGA), which made measurements of a set of volatile organic compounds (VOCs). VOCs are crucial for characterizing emissions and photochemical processing in the Front Range, as well as the air transported into the region. During recent years, oil and natural gas (O&NG) activity in the Front Range has been growing rapidly. Ratios of observed aromatic hydrocarbons, butanes and pentanes demonstrate distinct fingerprinting that can be used to distinguish both between different types of O&NG activities and between O&NG extraction regions in the FRAPPE study region and beyond. Using the observed hydrocarbon data along with other trace gas observations, we will compare contributions of O&NG emissions to OH reactivities in different regions in the Front Range, and present box model results demonstrating the impact of O&NG activities on ozone formation.

  19. The Effects of Surface-Induced Loads on Forearm Muscle Activity During Steering a Bicycle

    PubMed Central

    Arpinar-Avsar, Pinar; Birlik, Gülin; Sezgin, Önder C.; Soylu, Abdullah R.

    2013-01-01

    On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road) and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB) and Mountain Bike (MTB) are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s-2 when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s-2. The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction). During RB trials performed on rough road conditions, rmsEMG (%MVC) values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider can be

  20. Physical changes within a large tropical hydroelectric reservoir induced by wintertime cold front activity

    NASA Astrophysics Data System (ADS)

    Curtarelli, M. P.; Alcântara, E. H.; Rennó, C. D.; Stech, J. L.

    2014-08-01

    We investigated the influence of wintertime cold front activity on the physical processes within a large tropical reservoir located in Brazil. The period chosen for this study consisted of 49 days between 28 April 2010 and 15 July 2010. This period was defined based on information from the Brazilian Center for Weather Forecasting and Climate Studies (CPTEC), data collected in situ and the interpretation of remotely sensed images. To better understand the governing processes that drive changes in the heat balance, differential cooling and mixing dynamics, a simulation was performed that utilized a three-dimensional hydrodynamic model enforced with in situ and remote sensing data. The results showed that during a cold front passage over the reservoir, the sensible and latent heat fluxes were enhanced by approximately 77 and 16%, respectively. The reservoir's daily averaged heat loss was up to 167% higher on the days with cold front activity than on the days without activity. The cold front passage also intensified the differential cooling process; in some cases the difference between the water temperature of the littoral and pelagic zones reached up to 8 °C. The occurrence of cold front passages impacted the diurnal mixed layer (DML), by increasing the turbulent energy input (∼54%) and the DML depth (∼41%). Our results indicate that the cold front events are one of the main meteorological disturbances driving the physical processes within hydroelectric reservoirs located in tropical South America during the wintertime. Hence, cold front activity over these aquatic systems has several implications for water quality and reservoir management in Brazil.

  1. Front motion and localized states in an asymmetric bistable activator-inhibitor system with saturation

    NASA Astrophysics Data System (ADS)

    Yochelis, Arik; Garfinkel, Alan

    2008-03-01

    We study the spatiotemporal properties of coherent states (peaks, holes, and fronts) in a bistable activator-inhibitor system that exhibits biochemical saturated autocatalysis, and in which fronts do not preserve spatial parity symmetry. Using the Gierer-Meinhardt prototype model, we find the conditions in which two distinct pinning regions are formed. The first pinning type is known in the context of variational systems while the second is structurally different due to the presence of a heteroclinic bifurcation between two uniform states. The bifurcation also separates the parameter regions of counterpropagating fronts, leading in turn to the growth or contraction of activator domains. These phenomena expand the range of pattern formation theory and its biomedical applications: activator domain retraction suggests potential therapeutic strategies for patterned pathologies, such as cardiovascular calcification.

  2. Low-frequency wave activity related to dipolarization fronts detected by MMS in the magnetotail

    NASA Astrophysics Data System (ADS)

    Le Contel, O.; Retino, A.; Breuillard, H.; Mirioni, L.; Roux, A.; Chust, T.; Chasapis, A.; Lavraud, B.; Lindqvist, P. A.; Khotyaintsev, Y. V.; Vaivads, A.; Fu, H.; Marklund, G. T.; Nakamura, R.; Burch, J. L.; Torbert, R. B.; Moore, T. E.; Ergun, R.; Goodrich, K.; Needell, J.; Chutter, M.; Rau, D.; Dors, I.; Russell, C. T.; Magnes, W.; Strangeway, R. J.; Le, G.; Bromund, K. R.; Plaschke, F.; Fischer, D.; Leinweber, H. K.; Anderson, B. J.; Argall, M. R.; Slavin, J. A.; Kepko, L.; Baumjohann, W.; Pollock, C. J.; Mauk, B.; Fuselier, S. A.

    2015-12-01

    Dipolarization fronts are often associated to reconnection jets in the magnetotail current sheet and are sites of important energy dissipation and particle energization. Since the launch on March 12th and until the 9th of July 2015, the MMS constellation has been moving from dawn to dusk in a string of pearls formation. Although particle instruments were rarely operating and only FIELDS instrument suite was often gathering data, the MMS spacecraft have detected numerous dipolarization fronts, in particular on May 15th. Since 9th of July, the MMS evolved into a tetrahedral configuration with an average inter-satellite distance of 160 km and was still able to detect dipolarization fronts in the dusk magnetotail. As the Larmor radius of thermal protons is about 500 km in this region and dipolarization fronts have a typical thickness of the order of the Larmor radius, such a separation allows us to investigate in detail the microphysics of dipolarization fronts. In this study, we focus in particular on low-frequency electromagnetic wave activity related to the fronts and discuss possible mechanisms of particle heating and acceleration both at large scales (string of pearls configuration) and at kinetic scales (tetrahedral configuration).

  3. Electronically controlled optical beam-steering by an active phased array of metallic nanoantennas.

    PubMed

    DeRose, C T; Kekatpure, R D; Trotter, D C; Starbuck, A; Wendt, J R; Yaacobi, A; Watts, M R; Chettiar, U; Engheta, N; Davids, P S

    2013-02-25

    An optical phased array of nanoantenna fabricated in a CMOS compatible silicon photonics process is presented. The optical phased array is fed by low loss silicon waveguides with integrated ohmic thermo-optic phase shifters capable of 2π phase shift with ∼ 15 mW of applied electrical power. By controlling the electrical power to the individual integrated phase shifters fixed wavelength steering of the beam emitted normal to the surface of the wafer of 8° is demonstrated for 1 × 8 phased arrays with periods of both 6 and 9 μm. PMID:23482053

  4. Steering system of a vehicle, such as a snow removing machine for airfields

    NASA Astrophysics Data System (ADS)

    Rantalahti, Esko T.

    1991-12-01

    An improved steering system is disclosed for a vehicle comprising a cabin with front wheels, which are steered by a steering wheel, and a rearward portion carrying a drive unit and with driven rear wheels. The rearward portion is journalled about a vertical shaft to the forward portion of the vehicle, and a second separate steering mechanism is provided for steering the rearward portion. The second separate steering mechanism of the rearward portion comprises a control unit whereby it may be synchronized to operate in an opposite turning direction to that of the steering movements of the front wheels. The control unit is adapted to lock the rearward portion in a desired position, so that, for example, the vehicle can be driven diagonally with the side first. The second steering mechanism comprises a separate hydraulic system controlled from the control unit. Sensors are connected for sensing the steering angle of both the steering mechanisms, such that signals from the sensors may cause the steering of the rearward portion to follow the steering of the front wheels. The steering system of the invention is particularly applicable to snow removal machines used on airfields. In such machines, the front and rear wheel shafts are often 10-15 m distant from each other, but the invention enables easy and reliable linkage without the need for heavy shafts. The invention also enables a long snow-removing machine to turn on a very small radius, which speeds up movements and operation when clearing airfields.

  5. Estimation of the front-to-total activity ratio for wire screens using CFD simulation.

    PubMed

    Chen, B; Zhuo, W

    2015-11-01

    Wire screens are widely used for sampling radioactive aerosols. The front-to-total activity ratio is a critical factor in describing the self-shielding effect of the wire screens. In this study, computational fluid dynamic method was applied to simulate the deposition of aerosols on the surface of the wire screens. Four different types of screens were investigated for particle size varying from 1 nm to 10 µm. Experimental verification was carried out in a radon chamber. The results showed good agreement between experimental data interception and the simulation. Significant differences on the front-to-total activity ratio for the different types of screens were observed when the size of particle was <20 nm.

  6. Autotrophic and heterotrophic abundance and activity associated with a nearshore front off the Georgia coast, U.S.A.

    NASA Astrophysics Data System (ADS)

    Jacobsen, T. R.; Pomeroy, L. R.; Blanton, J. O.

    1983-11-01

    The nearshore frontal zone off the coast of Georgia was found to be an area of high phytoplankton and bacterioplankton abundance and activity. Phytoplankton and bacterioplankton populations on the seaward side of the frontal zone had significantly higher photosynthetic and heterotrophic potentials than the nearshore side of the front. Phytoplankton species composition changed across the front, verifying that the front is a barrier to cross shelf mixing. Nearshore, large chain forming diatoms dominated, while smaller single cell diatoms and cyanobacteria dominated the seaward side of the front. Increased bacterioplankton activity was found associated with phytoplankton photosynthetic activity. Light appeared to be the major factor controlling photosynthesis across the frontal zone. Nitrogen, phosphorus and silica were present in similar concentrations, well above levels that would limit photosynthesis, on both sides of the front. Therefore the outflow of nutrients from rivers or estuaries did not influence primary production directly.

  7. Front end optimization for the monolithic active pixel sensor of the ALICE Inner Tracking System upgrade

    NASA Astrophysics Data System (ADS)

    Kim, D.; Aglieri Rinella, G.; Cavicchioli, C.; Chanlek, N.; Collu, A.; Degerli, Y.; Dorokhov, A.; Flouzat, C.; Gajanana, D.; Gao, C.; Guilloux, F.; Hillemanns, H.; Hristozkov, S.; Junique, A.; Keil, M.; Kofarago, M.; Kugathasan, T.; Kwon, Y.; Lattuca, A.; Mager, M.; Sielewicz, K. M.; Marin Tobon, C. A.; Marras, D.; Martinengo, P.; Mazza, G.; Mugnier, H.; Musa, L.; Pham, T. H.; Puggioni, C.; Reidt, F.; Riedler, P.; Rousset, J.; Siddhanta, S.; Snoeys, W.; Song, M.; Usai, G.; Van Hoorne, J. W.; Yang, P.

    2016-02-01

    ALICE plans to replace its Inner Tracking System during the second long shut down of the LHC in 2019 with a new 10 m2 tracker constructed entirely with monolithic active pixel sensors. The TowerJazz 180 nm CMOS imaging Sensor process has been selected to produce the sensor as it offers a deep pwell allowing full CMOS in-pixel circuitry and different starting materials. First full-scale prototypes have been fabricated and tested. Radiation tolerance has also been verified. In this paper the development of the charge sensitive front end and in particular its optimization for uniformity of charge threshold and time response will be presented.

  8. Azobenzene Modified Imidacloprid Derivatives as Photoswitchable Insecticides: Steering Molecular Activity in a Controllable Manner

    NASA Astrophysics Data System (ADS)

    Xu, Zhiping; Shi, Lina; Jiang, Danping; Cheng, Jiagao; Shao, Xusheng; Li, Zhong

    2015-10-01

    Incorporating the photoisomerizable azobenzene into imidacloprid produced a photoswitchable insecticidal molecule as the first neonicotinoid example of remote control insecticide performance with spatiotemporal resolution. The designed photoswitchable insecticides showed distinguishable activity against Musca both in vivo and in vitro upon irradiation. Molecular docking study further suggested the binding difference of the two photoisomers. The generation of these photomediated insecticides provides novel insight into the insecticidal activity facilitating further investigation on the functions of insect nicotinic acetylcholine receptors and opens a novel way to control and study insect behavior on insecticide poisoning using light.

  9. Asymptotic sideslip angle and yaw rate decoupling control in four-wheel steering vehicles

    NASA Astrophysics Data System (ADS)

    Marino, Riccardo; Scalzi, Stefano

    2010-09-01

    This paper shows that, for a four-wheel steering vehicle, a proportional-integral (PI) active front steering control and a PI active rear steering control from the yaw rate error together with an additive feedforward reference signal for the vehicle sideslip angle can asymptotically decouple the lateral velocity and the yaw rate dynamics; that is the control can set arbitrary steady state values for lateral speed and yaw rate at any longitudinal speed. Moreover, the PI controls can suppress oscillatory behaviours by assigning real stable eigenvalues to a widely used linearised model of the vehicle steering dynamics for any value of longitudinal speed in understeering vehicles. In particular, the four PI control parameters are explicitly expressed in terms of the three real eigenvalues to be assigned. No lateral acceleration and no lateral speed measurements are required. The controlled system maintains the well-known advantages of both front and rear active steering controls: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres and improved manoeuvrability. In particular, zero lateral speed may be asymptotically achieved while controlling the yaw rate: in this case comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced. Also zero yaw rate can be asymptotically achieved: in this case additional stable manoeuvres are obtained in obstacle avoidance. Several simulations, including step references and moose tests, are carried out on a standard small SUV CarSim model to explore the robustness with respect to unmodelled effects such as combined lateral and longitudinal tyre forces, pitch, roll and driver dynamics. The simulations confirm the decoupling between the lateral velocity and the yaw rate and show the advantages obtained by the proposed control: reduced lateral speed or reduced yaw rate, suppressed oscillations and new stable manoeuvres.

  10. Active deformation of the northern front of the Eastern Great Caucasus

    NASA Astrophysics Data System (ADS)

    Niviere, Bertrand; Gagala, Lukasz; Callot, Jean-Paul; Regard, Vincent; Ringenbach, Jean-Claude

    2016-04-01

    The Arabia-Eurasia collision involved a mosaic of island arcs and microcontinents. Their accretion to the complex paleogeographic margin of Neotethys was marked by numerous collisional events. The Greater Caucasus constitute the northernmost tectonic element of this tectonic collage, developed as a back arc extensional zone now inverted, which relationships to the onset of Arabia-Eurasia continental collision and/or to the reorganization of the Arabia-Eurasia plate boundary at ˜5 Ma remain controversial. Structurally, the Greater Caucasus are a former continental back arc rift, now the locus of ongoing continental shortening. Modern geodetic observations suggest that in the west, the strain north of the Armenian Plateau is accommodated almost exclusively along the margins of the Greater Caucasus. This differs from regions further east where strain accommodation is distributed across both the Lesser and Greater Caucasus, and within the Greater Caucasus range, with a unique southward vergence. We question here the amount and mechanisms by which the Eastern Greater Caucasus accommodate part of the Arabia-Eurasia convergence. Morphostructural analysis of the folded late Pleistocene marine terrace along the northern slope of the Eastern Greater Caucasus evidences an on going tectonic activity in the area where GPS measurements record no motion. Most of the recent foreland deformation is accommodated by south-vergent folds and thrust, i. e. opposite to the vergence of the Caucasus frontal northern thrust. A progressive unconformity in the folded beds shows that it was already active during the late Pliocene. Cosmogenic dating of the terrace and kinematic restoration of the remnant terrace, linked to the subsurface geology allows for the estimation of a shortening rate ranging from a few mm/yr to 1 cm/yr over the last 5 Myr along the greater Caucasus northern front. Thus more than one third of the shortening between the Kura block / Lesser Caucasus domain and the Stable

  11. Seismic and satellite observations of calving activity at major glacier fronts in Greenland

    NASA Astrophysics Data System (ADS)

    Danesi, Stefania; Salimbeni, Simone; Urbini, Stefano; Pondrelli, Silvia; Margheriti, Lucia

    2016-04-01

    The interaction between oceans and large outlet glaciers in polar regions contributes to the budget of the global water cycle. We have observed the dynamic of sizeable outlet glaciers in Greenland by the analysis of seismic data collected by the regional seismic network Greenland Ice Sheet Monitoring Network (GLISN) trying also to find out correspondence in the glacier tongue evolution derived by the observation of satellite images. By studying the long-period seismic signals at stations located at the mouth of large fjords (e.g. ILULI, NUUG, KULLO), we identify major calving events through the detection of the ground flexure in response to seiche waves generated by iceberg detachments. 
For the time spanning the period between 2010-2014, we fill out calving-event catalogues which can be useful for the estimation of spatial and temporal variations in volume of ice loss at major active fronts in Greenland.

  12. Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758).

    PubMed

    Ferreira, João C P; Fujihara, Caroline J; Fruhvald, Erika; Trevisol, Eduardo; Destro, Flavia C; Teixeira, Carlos R; Pantoja, José C F; Schmidt, Elizabeth M S; Palme, Rupert

    2015-01-01

    Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots' physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3-9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural

  13. Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758)

    PubMed Central

    Ferreira, João C. P.; Fujihara, Caroline J.; Fruhvald, Erika; Trevisol, Eduardo; Destro, Flavia C.; Teixeira, Carlos R.; Pantoja, José C. F.; Schmidt, Elizabeth M. S.; Palme, Rupert

    2015-01-01

    Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots’ physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3–9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural

  14. Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758).

    PubMed

    Ferreira, João C P; Fujihara, Caroline J; Fruhvald, Erika; Trevisol, Eduardo; Destro, Flavia C; Teixeira, Carlos R; Pantoja, José C F; Schmidt, Elizabeth M S; Palme, Rupert

    2015-01-01

    Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots' physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3-9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural

  15. Steering characteristics of motorcycles

    NASA Astrophysics Data System (ADS)

    Fujii, Shigeru; Shiozawa, Souichi; Shinagawa, Akinori; Kishi, Tomoaki

    2012-08-01

    In this study, the results of a steady-state cornering test using a sport-touring motorcycle and the analysis of those test results are presented. This test was conducted as an activity in our efforts to realise a quantitative development method for motorcycles. The measurement data from this test include measurement results for tyre force, tyre moment, and tyre slip angle that have not been practically addressed in the research of motorcycles, in addition to normal measurement results for velocity, steering angle, steering torque, roll angle, etc. Until now research on motorcycle dynamics characteristics has indicated that 'there is a strong relationship between the motorcycle dynamics characteristics and the tyre slip angle'. However, since it is difficult to take highly precise measurements of the motorcycle's tyre slip angle during actual riding, especially when the motorcycle is tilted during cornering, such measurements have been avoided, cf. [H. Ishii and Y. Tezuka, Considerations of turning performance for motorcycle, SETC (1997), pp. 383-389]. Nevertheless, in this research we attempted to measure the tyre slip angle and also attempted to investigate in detail the dynamics characteristics and tyre characteristics during riding. Until now there has not been an adequate investigation conducted under a variety of riding conditions, but it is the aim of this research to show that it is possible to measure the tyre slip angle with a reasonable accuracy. It is our opinion that this will open a new path to a more detailed investigation of the motorcycle's dynamics characteristics. In addition, we conducted measurements using not only the normal rider's lean angle (lean-with posture), but also measurements in the case where the rider's lean angle was intentionally changed, in order to investigate the effects that a change in the rider's posture has on the variation in the measurement results of the motorcycle's dynamics. Furthermore, we then compared these

  16. Responder fast steering mirror

    NASA Astrophysics Data System (ADS)

    Bullard, Andrew; Shawki, Islam

    2013-10-01

    Raytheon Space and Airborne Systems (SAS) has designed, built and tested a 3.3-inch diameter fast steering mirror (FSM) for space application. This 2-axis FSM operates over a large angle (over 10 degree range), has a very high servo bandwidth (over 3.3 Khz closed loop bandwidth), has nanoradian-class noise, and is designed to support microradian class line of sight accuracy. The FSM maintains excellent performance over large temperature ranges (which includes wave front error) and has very high reliability with the help of fully redundant angle sensors and actuator circuits. The FSM is capable of achieving all its design requirements while also being reaction-compensated. The reaction compensation is achieved passively and does not need a separate control loop. The FSM has undergone various environmental testing which include exported forces and torques and thermal vacuum testing that support the FSM design claims. This paper presents the mechanical design and test results of the mechanism which satisfies the rigorous vacuum and space application requirements.

  17. Responder fast steering mirror

    NASA Astrophysics Data System (ADS)

    Bullard, Andrew; Shawki, Islam

    2013-09-01

    Raytheon Space and Airborne Systems (SAS) has designed, built and tested a 3.3-inch diameter fast steering mirror (FSM) for space application. This 2-axis FSM operates over a large angle (over 10 degree range), has a very high servo bandwidth (over 3.3 Khz closed loop bandwidth), has nanoradian-class noise, and is designed to support microradian class line of sight accuracy. The FSM maintains excellent performance over large temperature ranges (which includes wave front error) and has very high reliability with the help of fully redundant angle sensors and actuator circuits. The FSM is capable of achieving all its design requirements while also being reaction-compensated. The reaction compensation is achieved passively and does not need a separate control loop. The FSM has undergone various environmental testing which include exported forces and torques and thermal vacuum testing that support the FSM design claims. This paper presents the mechanical design and test results of the mechanism which satisfies the rigorous vacuum and space application requirements.

  18. Monogamy of quantum steering

    NASA Astrophysics Data System (ADS)

    Milne, Antony; Jennings, David; Jevtic, Sania; Rudolph, Terry; Wiseman, Howard

    The quantum steering ellipsoid formalism naturally extends the Bloch vector picture for qubits to provide a visualisation of two-qubit systems. If Alice and Bob share a correlated state then a local measurement by Bob steers Alice's qubit inside the Bloch sphere; given all possible measurements by Bob, the set of states to which Alice can be steered form her steering ellipsoid. We apply the formalism to a three-party scenario and find that steering ellipsoid volumes obey a simple monogamy relation. This gives us a novel derivation of the well-known CKW (Coffman-Kundu-Wootters) inequality for entanglement monogamy. The geometric perspective also identifies a new measure of quantum correlation, `obesity', and a set of `maximally obese' states that saturate the steering monogamy bound. These states are found to have extremal quantum correlation properties that are significant in the steering ellipsoid picture and for the study of two-qubit states in general.

  19. Report of International NanoSPD Steering Committee and statistics on recent NanoSPD activities

    NASA Astrophysics Data System (ADS)

    2014-08-01

    Abstract. The Université de Lorraine in Metz, France, is the selected site for the 6th International Conference on Nanomaterials by Severe Plastic Deformation (NanoSPD6) following a series of five earlier conferences. This introductory paper reports on several major developments in NanoSPD activities as well as on very recent NanoSPD citation data which confirm the continued growth and expansion of this important research area. Close attention is given to the topics of workshops, conferences and seminars organized during these last three years as well as on books and reviews published prior to the NanoSPD6 conference. A special concern of the committee is in introducing and discussing the appropriate terminology to be applied in this new field of materials science and engineering.

  20. Front structure and dynamics in dense colonies of motile bacteria: Role of active turbulence

    NASA Astrophysics Data System (ADS)

    Chatterjee, Rayan; Joshi, Abhijeet A.; Perlekar, Prasad

    2016-08-01

    We study the spreading of a bacterial colony undergoing turbulentlike collective motion. We present two minimalistic models to investigate the interplay between population growth and coherent structures arising from turbulence. Using direct numerical simulation of the proposed models we find that turbulence has two prominent effects on the spatial growth of the colony: (a) the front speed is enhanced, and (b) the front gets crumpled. Both these effects, which we highlight by using statistical tools, are markedly different in our two models. We also show that the crumpled front structure and the passive scalar fronts in random flows are related in certain regimes.

  1. Front structure and dynamics in dense colonies of motile bacteria: Role of active turbulence.

    PubMed

    Chatterjee, Rayan; Joshi, Abhijeet A; Perlekar, Prasad

    2016-08-01

    We study the spreading of a bacterial colony undergoing turbulentlike collective motion. We present two minimalistic models to investigate the interplay between population growth and coherent structures arising from turbulence. Using direct numerical simulation of the proposed models we find that turbulence has two prominent effects on the spatial growth of the colony: (a) the front speed is enhanced, and (b) the front gets crumpled. Both these effects, which we highlight by using statistical tools, are markedly different in our two models. We also show that the crumpled front structure and the passive scalar fronts in random flows are related in certain regimes. PMID:27627334

  2. Significance of an Active Volcanic Front in the Far Western Aleutian Arc

    NASA Astrophysics Data System (ADS)

    Yogodzinski, G. M.; Kelemen, P. B.; Hoernle, K.

    2015-12-01

    Discovery of a volcanic front west of Buldir Volcano, the western-most emergent Aleutian volcano, demonstrates that the surface expression of Aleutian volcanism falls below sea level just west of 175.9° E longitude, but is otherwise continuous from mainland Alaska to Kamchatka. The newly discovered sites of western Aleutian seafloor volcanism are the Ingenstrem Depression, a 60 km-long structural depression just west of Buldir, and an unnamed area 300 km further west, referred to as the Western Cones. These locations fall along a volcanic front that stretches from Buldir to Piip Seamount near the Komandorsky Islands. Western Aleutian seafloor volcanic rocks include large quantities of high-silica andesite and dacite, which define a highly calc-alkaline igneous series and carry trace element signatures that are unmistakably subduction-related. This indicates that subducting oceanic lithosphere is present beneath the westernmost Aleutian arc. The rarity of earthquakes below depths of 200 km indicates that the subducting plate is unusually hot. Some seafloor volcanoes are 6-8 km wide at the base, and so are as large as many emergent Aleutian volcanoes. The seafloor volcanoes are submerged in water depths >3000 m because they sit on oceanic lithosphere of the Bering Sea. The volcanic front is thus displaced to the north of the ridge of arc crust that underlies the western Aleutian Islands. This displacement, which developed since approximately 6 Ma when volcanism was last active on the islands, must be a consequence of oblique convergence in a system where the subducting plate and large blocks of arc crust are both moving primarily in an arc-parallel sense. The result is a hot-slab system where low subduction rates probably limit advection of hot mantle to the subarc, and produce a relatively cool and perhaps stagnant mantle wedge. The oceanic setting and highly oblique subduction geometry also severely limit rates of sediment subduction, so the volcanic rocks, which

  3. The Effects of Steroid Implant and Dietary Soybean Hulls on Estrogenic Activity of Sera of Steers Grazing Toxic Endophyte-Infected Tall Fescue Pasture

    PubMed Central

    Shappell, Nancy W.; Flythe, Michael D.; Aiken, Glen E.

    2015-01-01

    Soybean hulls (SBHs) have been fed to cattle pasturing on endophyte-infected tall fescue in attempts to increase rate of gain. Literature reports indicated some symptoms associated with fescue toxicosis were ameliorated by the use of steroidal implants containing estradiol (E2) and progesterone [implantation (IMP)], feeding SBHs, or the combination of the two. While the mechanism for amelioration was unclear, the SBHs were postulated as acting as a diluent of the toxic factors of the fescue. Alternatively, estradiol and phytoestrogens of SBHs might be acting through relaxation of the persistent vasoconstriction found in animals ingesting ergot alkaloids of endophyte-infected fescue. If so, estrogenic activity of serum of steers receiving SBHs, IMP, or a combination of the two should be elevated. Using the cellular proliferation assay of estrogenicity (E-Screen), estradiol equivalents (E2Eqs) were determined on both SBHs and the serum of steers from a previously reported study. Range of SBHs was 5.0–8.5 ng Eqs g−1 DM (mean 6.5, n = 4 from different commercial sources of SBHs). At the rate fed, theoretically calculated blood E2Eq could be physiologically relevant (~80 pg mL−1, based on 2.3 kg SBHs d−1, 300 kg steer, 5.7% blood volume, and 10% absorption). Serum E2Eqs did increase in steers (P ≤ 0.05) with steroidal implants or fed SBHs by 56 and 151% over control, respectively, and treatments were additive (211% increase). Serum prolactin was also greatest for the SBH + IMP group (188 ng mL−1, P < 0.05), concentrations comparable to values reported for steers grazing endophyte-free fescue. Prolactin in the SBH group was higher than IMP or control groups (146 versus 76 and 60 ng mL−1, respectively). Still unknown is if additional E2Eqs from dietary phytoestrogens or exogenous sources of estradiol can further reduce symptoms of fescue toxicosis. The E-Screen assay was an effective tool in monitoring serum for estrogenic effects

  4. PLEKHG3 enhances polarized cell migration by activating actin filaments at the cell front.

    PubMed

    Nguyen, Trang Thi Thu; Park, Wei Sun; Park, Byung Ouk; Kim, Cha Yeon; Oh, Yohan; Kim, Jin Man; Choi, Hana; Kyung, Taeyoon; Kim, Cheol-Hee; Lee, Gabsang; Hahn, Klaus M; Meyer, Tobias; Heo, Won Do

    2016-09-01

    Cells migrate by directing Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) activities and by polymerizing actin toward the leading edge of the cell. Previous studies have proposed that this polarization process requires a local positive feedback in the leading edge involving Rac small GTPase and actin polymerization with PI3K likely playing a coordinating role. Here, we show that the pleckstrin homology and RhoGEF domain containing G3 (PLEKHG3) is a PI3K-regulated Rho guanine nucleotide exchange factor (RhoGEF) for Rac1 and Cdc42 that selectively binds to newly polymerized actin at the leading edge of migrating fibroblasts. Optogenetic inactivation of PLEKHG3 showed that PLEKHG3 is indispensable both for inducing and for maintaining cell polarity. By selectively binding to newly polymerized actin, PLEKHG3 promotes local Rac1/Cdc42 activation to induce more local actin polymerization, which in turn promotes the recruitment of more PLEKHG3 to induce and maintain cell front. Thus, autocatalytic reinforcement of PLEKHG3 localization to the leading edge of the cell provides a molecular basis for the proposed positive feedback loop that is required for cell polarization and directed migration. PMID:27555588

  5. PLEKHG3 enhances polarized cell migration by activating actin filaments at the cell front

    PubMed Central

    Nguyen, Trang Thi Thu; Park, Wei Sun; Park, Byung Ouk; Kim, Cha Yeon; Oh, Yohan; Kim, Jin Man; Choi, Hana; Kyung, Taeyoon; Kim, Cheol-Hee; Lee, Gabsang; Hahn, Klaus M.; Meyer, Tobias; Heo, Won Do

    2016-01-01

    Cells migrate by directing Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) activities and by polymerizing actin toward the leading edge of the cell. Previous studies have proposed that this polarization process requires a local positive feedback in the leading edge involving Rac small GTPase and actin polymerization with PI3K likely playing a coordinating role. Here, we show that the pleckstrin homology and RhoGEF domain containing G3 (PLEKHG3) is a PI3K-regulated Rho guanine nucleotide exchange factor (RhoGEF) for Rac1 and Cdc42 that selectively binds to newly polymerized actin at the leading edge of migrating fibroblasts. Optogenetic inactivation of PLEKHG3 showed that PLEKHG3 is indispensable both for inducing and for maintaining cell polarity. By selectively binding to newly polymerized actin, PLEKHG3 promotes local Rac1/Cdc42 activation to induce more local actin polymerization, which in turn promotes the recruitment of more PLEKHG3 to induce and maintain cell front. Thus, autocatalytic reinforcement of PLEKHG3 localization to the leading edge of the cell provides a molecular basis for the proposed positive feedback loop that is required for cell polarization and directed migration. PMID:27555588

  6. Lipogenic activity of intramuscular and subcutaneous adipose tissues from steers produced by different generations of angus sires.

    PubMed

    May, S G; Burney, N S; Wilson, J J; Savell, J W; Herring, A D; Lunt, D K; Baker, J F; Sanders, J O; Smith, S B

    1995-05-01

    Simmental and Hereford cows (n = 74) were inseminated with semen from purebred Angus bulls from the 1960s or with semen from purebred Angus bulls from the 1980s. The F1 calves provided the foundation for two investigations, one addressing growth and carcass characteristics, and another measuring the impact of sire generation on lipid metabolism and adiposity. Calves sired by the 1980s-type bulls had greater (P < .05) birth, weaning, and final live weights and carcass weights. They also had larger (P < .05) hip heights and hip widths at weaning and larger (P < .05) hip heights and lower (P < .05) body condition scores at slaughter. There were no differences (P > .05) in any measure of fatness between groups (adjusted fat thickness, kidney, pelvic, and heart fat, or marbling scores), but yield grade was higher numerically (P < .1) for the 1980s steers. The second aspect of this research addressed the influence of different generations of Angus sires on specific carcass traits and adipose tissue metabolism. A subset of six steers for each generation type (from Simmental cows) were selected and samples were collected at slaughter for measurements in vitro. For both generation types, intramuscular (i.m.) adipocytes had lesser (P < .05) cell volumes than subcutaneous (s.c.) adipose tissue. Correspondingly. i.m. adipose tissue exhibited lower (P < .05) rates of 14C-labeled acetate incorporation into lipids as measured immediately after slaughter. Intramuscular and s.c. adipocytes from 1980s-type steers were smaller (P < .05) than those from the 1960s-types steers, with correspondingly more cells per gram of tissue.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7665362

  7. Probing the wild-type HRas activation mechanism using steered molecular dynamics, understanding the energy barrier and role of water in the activation.

    PubMed

    Sharma, Neeru; Sonavane, Uddhavesh; Joshi, Rajendra

    2014-03-01

    Ras is one of the most common oncogenes in human cancers. It belongs to a family of GTPases that functions as binary conformational switches by timely switching of their conformations from GDP to GTP and vice versa. It attains the final active state structure via an intermediate GTP-bound state. The transition between these states is a millisecond-time-scale event. This makes studying this mechanism beyond the scope of classical molecular dynamics. In the present study, we describe the activation pathway of the HRas protein complex along the distance-based reaction coordinate using steered molecular dynamics. Approximately ~720 ns of MD simulations using CMD and SMD was performed. We demonstrated the change in orientation and arrangement of the two switch regions and the role of various hydrogen bonds during the activation process. The weighted histogram analysis method was also performed, and the potential of mean force was calculated between the inactive and active via the intermediate state (state 1) of HRas. The study indicates that water seems to play a crucial role in the activation process and to transfer the HRas protein from its intermediate state to the fully active state. The implications of our study hereby suggest that the HRas activation mechanism is a multistep process. It starts from the inactive state to an intermediate state 1 followed by trapping of water molecules and flipping of the Thr35 residue to form a fully active state (state 2). This state 2 also comprises Gly60, Thr35, GTP, Mg(2+) and water-forming stable interactions.

  8. Are boundary conditions in surface productivity at the Southern Polar Front reflected in benthic activity?

    NASA Astrophysics Data System (ADS)

    Brandt, Angelika; Vanreusel, Ann; Bracher, Astrid; Jule Marie Hoppe, Clara; Lins, Lidia; Meyer-Löbbecke, Anna; Altenburg Soppa, Mariana; Würzberg, Laura

    2014-10-01

    In austral summer 2012, during the expedition ANT-XXVIII/3 on board RV Polarstern, two sites were sampled 1600 km apart in the South Polar Front area (52°S) at the boundary of different productivity regimes for meio- and macrobenthos using a multiple-corer and an epibenthic sledge, respectively. Patterns in density and abundance data were compared between different size classes of the benthos and interpreted in relation to surface primary productivity data and sediment oxygen consumption. We tested the hypothesis that long-term satellite-derived surface phytoplankton biomass, in situ real time biomass, and productivity measurements at the surface and throughout the euphotic zone are reflected in abyssal benthos densities, abundances and activity. Specifically, we investigated the effect of boundary conditions for lower and higher surface productivity. Surface and integrated to 100 m depth biomass and primary productivity measurements vary stations, with the lowest values at station 85 (0.083 mg Chl-a m-3 at surface, 9 mg Chl-a m-2 and 161 mg C m-2 d-1- integrated over the first 100 m depth), and the highest values at station 86 (2.231 mg Chl-a m-3 at surface, 180 mg Chl-a m-2 and 2587 mg C m-2 d-1 integrated over first 100 m depth). Total meiofaunal densities varied between 102 and 335 individuals/10 cm². Densities were the highest at station 86-30 (335 individuals) and lowest at station 81-13 (102 individuals). Total macrofaunal densities (individuals/1000 m²) varied between 26 individuals at station 81-17 and 194 individuals at station 86-24. However, three EBS hauls were taken at station 86 with a minimum of 80 and a maximum of 194 individuals. Sediment oxygen consumption did not vary significantly between stations from east to west. Bentho-pelagic coupling of meio- and macrobenthic communities could not be observed in the South Polar Front at the boundary conditions from low to high surface productivity between stations 81 and 86.

  9. Extremely reduced motion in front of screens: investigating real-world physical activity of adolescents by accelerometry and electronic diary.

    PubMed

    Streb, Judith; Kammer, Thomas; Spitzer, Manfred; Hille, Katrin

    2015-01-01

    This paper reports accelerometer and electronic dairy data on typical daily activities of 139 school students from grade six and nine. Recordings covered a typical school day for each student and lasted on average for 23 h. Screen activities (watching television and using the computer) are compared to several other activities performed while sitting (e.g., playing, eating, sitting in school, and doing homework). Body movement was continuously recorded by four accelerometers and transformed into a motion sore. Our results show that extremely low motion scores, as if subjects were freezing, emerge to a greater extent in front of screens compared to other investigated activities. Given the substantial amount of time young people spend in front of screens and the rising obesity epidemic, our data suggest a mechanism for the association of screen time and obesity. PMID:25955531

  10. Active Uplift At The Taiwan Belt Front Revealed By River Profiles:the Hsiaomei Anticline Area

    NASA Astrophysics Data System (ADS)

    Chen, R.-F.; Angelier, J.; Hu, J.-C.; Deffontaines, B.; Tsai, H.

    A river profile may reveal tectonic deformation through comparison with a smoothed theoretical function based on simple assumptions, provided that its relationships with the erosion-accumulation phenomena have been deciphered. The Taiwan orogeny re- sults from the collision between the Luzon volcanic arc of the Philippine Sea plate and the Chinese continental margin of the Eurasian plate. As an active collision zone between the Luzon arc and the China continental margin, the Taiwan mountain belt, particularly its south-central part, is undergoing strong crustal shortening and rapid uplift. In the central part of the island, rock uplift rates are matched by erosion rates calculated from sediment yields and exhumation rates. In the foothills of southwestern Taiwan we focus on the longitudinal profiles of twelve rivers near Chiayi area. Based on the fit with mathematical functions, we characterize a significant positive anomaly in terms of shape, amplitude and location. River data from 1/5,000 topographic maps were used to define a set of parameters related to the classical exponential equation of the longitudinal profiles. We obtained an accepted fit for a set of 5-7 parameters of the polynomial exponent, that is, a degree 4-6. The anomaly is spatially consistent and does not show correlation with variations in erosional-depositional phenomena, including variations in lithology of the rock formations. The anomaly thus reflects tectonic uplift, in good agreement with other sources of information, including the GPS data that indicate active E-W shortening of about 1 cm/yr in this area. The posi- tive anomaly detected in ten river profiles diminishes and vanishes in the northernmost and southernmost river profiles. It reflects continuing folding and uplift within an ellip- tic area elongated N-S, which corresponds to the present-day growth of the Hsiaomei anticline at the front of Taiwan belt.

  11. Automotive power steering system

    SciTech Connect

    VanGorder, D.H.; Wilson, K.R.

    1991-04-23

    This patent describes improvement in an automotive power steering system including a pump, a servo-valve, a steering assist fluid motor, a reservoir having a reservoir chamber therein, fluid ducts; a volume of hydraulic oil; a fluid level. The improvement comprises: means defining a fill port; a cover; means connect a gas accumulator.

  12. A study on single lane-change manoeuvres for determining rearward amplification of multi-trailer articulated heavy vehicles with active trailer steering systems

    NASA Astrophysics Data System (ADS)

    Wang, Qiushi; He, Yuping

    2016-01-01

    The Society of Automotive Engineers issued a test procedure, SAE-J2179, to determine the rearward amplification (RA) of multi-trailer articulated heavy vehicles (MTAHVs). Built upon the procedure, the International Organization for Standardization released the test manoeuvres, ISO-14791, for evaluating directional performance of MTAHVs. For the RA measures, ISO-14791 recommends two single lane-change manoeuvres: (1) an open-loop procedure with a single sine-wave steering input; and (2) a closed-loop manoeuvre with a single sine-wave lateral acceleration input. For an articulated vehicle with active trailer steering (ATS), the RA measure in lateral acceleration under the open-loop manoeuvre was not in good agreement with that under the closed-loop manoeuvre. This observation motivates the research on the applicability of the two manoeuvres for the RA measures of MTAHVs with ATS. It is reported that transient response under the open-loop manoeuvre often leads to asymmetric curve of tractor lateral acceleration [Winkler CB, Fancher PS, Bareket Z, Bogard S, Johnson G, Karamihas S, Mink C. Heavy vehicle size and weight - test procedures for minimum safety performance standards. Final technical report, NHTSA, US DOT, contract DTNH22-87-D-17174, University of Michigan Transportation Research Institute, Report No. UMTRI-92-13; 1992]. To explore the effect of the transient response, a multiple cycle sine-wave steering input (MCSSI) manoeuvre is proposed. Simulation demonstrates that the steady-state RA measures of an MTAHV with and without ATS under the MCSSI manoeuvre are in excellent agreement with those under the closed-loop manoeuvre. It is indicated that between the two manoeuvres by ISO-14791, the closed-loop manoeuvre is more applicable for determining the RA measures of MTAHVs with ATS.

  13. Temperature activated absorption during laser-induced damage: The evolution of laser-supported solid-state absorption fronts

    SciTech Connect

    Carr, C W; Bude, J D; Shen, N; Demange, P

    2010-10-26

    Previously we have shown that the size of laser induced damage sites in both KDP and SiO{sub 2} is largely governed by the duration of the laser pulse which creates them. Here we present a model based on experiment and simulation that accounts for this behavior. Specifically, we show that solid-state laser-supported absorption fronts are generated during a damage event and that these fronts propagate at constant velocities for laser intensities up to 4 GW/cm{sup 2}. It is the constant absorption front velocity that leads to the dependence of laser damage site size on pulse duration. We show that these absorption fronts are driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport, and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. In addition to the practical application of selecting an optimal laser for pre-initiation of large aperture optics, this work serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

  14. Method of achieving ultra-wideband true-time-delay beam steering for active electronically scanned arrays

    DOEpatents

    Loui, Hung; Brock, Billy C.

    2016-10-25

    The various embodiments presented herein relate to beam steering an array antenna by modifying intermediate frequency (IF) waveforms prior to conversion to RF signals. For each channel, a direct digital synthesis (DDS) component can be utilized to generate a waveform or modify amplitude, timing and phase of a waveform relative to another waveform, whereby the generation/modification can be performed prior to the IF input port of a mixer on each channel. A local oscillator (LO) signal can be utilized to commonly drive each of the mixers. After conversion at the RF output port of each of the mixers, each RF signal can be transmitted by a respective antenna element in the antenna array. Initiation of transmission of each RF signal can be performed simultaneously at each antenna. The process can be reversed during receive whereby timing, amplitude, and phase of the received can be modified digitally post ADC conversion.

  15. Liquid Crystal-based Beam Steering Technologies for NASA Applications

    NASA Technical Reports Server (NTRS)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip; Lavrentovich, Oleg; Wang, Xinghua; Pishnyak, Oleg; Kreminska, Liubov; Golovin, Andrii

    2006-01-01

    Liquid crystal-based beam steering devices can provide electronic beam scanning to angles above 1 milliradian, sub-microradian beam pointing accuracy, as well as wave-front correction to maintain output optical beam quality. The liquid crystal technology effort will be summarized, and the potential application of the resulting devices to NASA space-based scenarios will be described.

  16. Muscle activation characteristics of the front leg during baseball swings with timing correction for sudden velocity decrease.

    PubMed

    Ohta, Yoichi; Nakamoto, Hiroki; Ishii, Yasumitsu; Ikudome, Sachi; Takahashi, Kyohei; Shima, Norihiro

    2014-01-01

    This study aimed to clarify the activation characteristics of the vastus lateralis muscle in the front leg during timing correction for a sudden decrease in the velocity of a target during baseball swings. Eleven male collegiate baseball players performed coincident timing tasks that comprised constant velocity of 8 m/s (unchanged) and a sudden decrease in velocity from 8 to 4 m/s (decreased velocity). Electromyography (EMG) revealed that the muscle activation was typically monophasic when responding unchanged conditions. The type of muscle activation during swings in response to decreased velocity condition was both monophasic and biphasic. When biphasic activation appeared in response to decreased velocity, the impact time and the time to peak EMG amplitude were significantly prolonged and the timing error was significantly smaller than that of monophasic activation. However, the EMG onset from the target start was consistent both monophasic and biphasic activation in response to conditions of decreased velocity. In addition, batters with small timing errors in response to decreased velocity were more likely to generate biphasic EMG activation. These findings indicated that timing correction for a sudden decrease in the velocity of an oncoming target is achieved by modifying the muscle activation characteristics of the vastus lateralis muscle of front leg from monophasic to biphasic to delay reaching peak muscle activation and thus prolong impact time. Therefore, the present findings suggests that the extent of timing errors in response to decreased velocity is influenced by the ability to correct muscle activation after its initiation rather than by delaying the initiation timing of muscle activation during baseball swings.

  17. Muscle activation characteristics of the front leg during baseball swings with timing correction for sudden velocity decrease.

    PubMed

    Ohta, Yoichi; Nakamoto, Hiroki; Ishii, Yasumitsu; Ikudome, Sachi; Takahashi, Kyohei; Shima, Norihiro

    2014-01-01

    This study aimed to clarify the activation characteristics of the vastus lateralis muscle in the front leg during timing correction for a sudden decrease in the velocity of a target during baseball swings. Eleven male collegiate baseball players performed coincident timing tasks that comprised constant velocity of 8 m/s (unchanged) and a sudden decrease in velocity from 8 to 4 m/s (decreased velocity). Electromyography (EMG) revealed that the muscle activation was typically monophasic when responding unchanged conditions. The type of muscle activation during swings in response to decreased velocity condition was both monophasic and biphasic. When biphasic activation appeared in response to decreased velocity, the impact time and the time to peak EMG amplitude were significantly prolonged and the timing error was significantly smaller than that of monophasic activation. However, the EMG onset from the target start was consistent both monophasic and biphasic activation in response to conditions of decreased velocity. In addition, batters with small timing errors in response to decreased velocity were more likely to generate biphasic EMG activation. These findings indicated that timing correction for a sudden decrease in the velocity of an oncoming target is achieved by modifying the muscle activation characteristics of the vastus lateralis muscle of front leg from monophasic to biphasic to delay reaching peak muscle activation and thus prolong impact time. Therefore, the present findings suggests that the extent of timing errors in response to decreased velocity is influenced by the ability to correct muscle activation after its initiation rather than by delaying the initiation timing of muscle activation during baseball swings. PMID:25918848

  18. Muscle Activation Characteristics of the Front Leg During Baseball Swings with Timing Correction for Sudden Velocity Decrease

    PubMed Central

    Ohta, Yoichi; Nakamoto, Hiroki; Ishii, Yasumitsu; Ikudome, Sachi; Takahashi, Kyohei; Shima, Norihiro

    2015-01-01

    This study aimed to clarify the activation characteristics of the vastus lateralis muscle in the front leg during timing correction for a sudden decrease in the velocity of a target during baseball swings. Eleven male collegiate baseball players performed coincident timing tasks that comprised constant velocity of 8 m/s (unchanged) and a sudden decrease in velocity from 8 to 4 m/s (decreased velocity). Electromyography (EMG) revealed that the muscle activation was typically monophasic when responding unchanged conditions. The type of muscle activation during swings in response to decreased velocity condition was both monophasic and biphasic. When biphasic activation appeared in response to decreased velocity, the impact time and the time to peak EMG amplitude were significantly prolonged and the timing error was significantly smaller than that of monophasic activation. However, the EMG onset from the target start was consistent both monophasic and biphasic activation in response to conditions of decreased velocity. In addition, batters with small timing errors in response to decreased velocity were more likely to generate biphasic EMG activation. These findings indicated that timing correction for a sudden decrease in the velocity of an oncoming target is achieved by modifying the muscle activation characteristics of the vastus lateralis muscle of front leg from monophasic to biphasic to delay reaching peak muscle activation and thus prolong impact time. Therefore, the present findings suggests that the extent of timing errors in response to decreased velocity is influenced by the ability to correct muscle activation after its initiation rather than by delaying the initiation timing of muscle activation during baseball swings. PMID:25918848

  19. Fronts, fish, and predators

    NASA Astrophysics Data System (ADS)

    Belkin, Igor M.; Hunt, George L.; Hazen, Elliott L.; Zamon, Jeannette E.; Schick, Robert S.; Prieto, Rui; Brodziak, Jon; Teo, Steven L. H.; Thorne, Lesley; Bailey, Helen; Itoh, Sachihiko; Munk, Peter; Musyl, Michael K.; Willis, Jay K.; Zhang, Wuchang

    2014-09-01

    Ocean fronts play a key role in marine ecosystems. Fronts shape oceanic landscapes and affect every trophic level across a wide range of spatio-temporal scales, from meters to thousands of kilometers, and from days to millions of years. At some fronts, there is an elevated rate of primary production, whereas at others, plankton is aggregated by advection and by the behavior of organisms moving against gradients in temperature, salinity, light irradiance, hydrostatic pressure and other physico-chemical and biological factors. Lower trophic level organisms - phytoplankton and zooplankton - that are aggregated in sufficient densities, attract organisms from higher trophic levels, from planktivorous schooling fish to squid, large piscivorous fish, seabirds and marine mammals. Many species have critical portions of their life stages or behaviors closely associated with fronts, including spawning, feeding, ontogenetic development, migrations, and other activities cued to frontal dynamics. At different life stages, an individual species or population might be linked to different fronts. The nature and strength of associations between fronts and biota depend on numerous factors such as the physical nature and spatio-temporal scales of the front and the species and their life stages in question. In other words, fronts support many different niches and micro/macro-habitats over a wide range of spatial and temporal scales.

  20. 52. Patent steering gear, hatch and steering compass binnacle, view ...

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

    52. Patent steering gear, hatch and steering compass binnacle, view from starboard looking aft. Photograph by Jet Lowe, April 1988. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  1. Active faulting south of the Himalayan Front: Establishing a new plate boundary

    NASA Astrophysics Data System (ADS)

    Yeats, Robert S.; Thakur, V. C.

    2008-06-01

    New tectonic uplifts south of the Salt Range Thrust and Himalayan Front Thrust (HFT) represent an outward step of the plate boundary from the principal tectonic displacement zone into the Indo-Gangetic Plain. In Pakistan, the Lilla Anticline deforms fine-grained overbank deposits of the Jhelum River floodplain 15 km south of the Salt Range. The anticline is overpressured in Eocambrian non-marine strata. In northwest India south of Dehra Dun, the Piedmont Fault (PF) lies 15 km south of the HFT. Coalescing fans derived from the Himalaya form a piedmont (Old Piedmont Zone) 15-20 km wide east of the Yamuna River. This zone is uplifted as much as 15-20 m near the PF, and bedding is tilted 5-7° northeast. Holocene thermoluminescence-optically-stimulated luminescence dates for sediments in the Old Piedmont Zone suggest that the uplift rate might be as high as several mm/a. The Old Piedmont Zone is traced northwest 200 km and southeast another 200 km to the Nepal border. These structures, analogous to protothrusts in subduction zones, indicate that the Himalayan plate boundary is not a single structure but a series of structures across strike, including reactivated parts of the Main Boundary Thrust north of the range front, the HFT sensu stricto, and stepout structures on the Indo-Gangetic Plain. Displacement rates on all these structures must be added to determine the local India-Himalaya convergence rate.

  2. Linear quadratic game and non-cooperative predictive methods for potential application to modelling driver-AFS interactive steering control

    NASA Astrophysics Data System (ADS)

    Na, Xiaoxiang; Cole, David J.

    2013-02-01

    This paper is concerned with the modelling of strategic interactions between the human driver and the vehicle active front steering (AFS) controller in a path-following task where the two controllers hold different target paths. The work is aimed at extending the use of mathematical models in representing driver steering behaviour in complicated driving situations. Two game theoretic approaches, namely linear quadratic game and non-cooperative model predictive control (non-cooperative MPC), are used for developing the driver-AFS interactive steering control model. For each approach, the open-loop Nash steering control solution is derived; the influences of the path-following weights, preview and control horizons, driver time delay and arm neuromuscular system (NMS) dynamics are investigated, and the CPU time consumed is recorded. It is found that the two approaches give identical time histories as well as control gains, while the non-cooperative MPC method uses much less CPU time. Specifically, it is observed that the introduction of weight on the integral of vehicle lateral displacement error helps to eliminate the steady-state path-following error; the increase in preview horizon and NMS natural frequency and the decline in time delay and NMS damping ratio improve the path-following accuracy.

  3. Steering in bicycles and motorcycles

    NASA Astrophysics Data System (ADS)

    Fajans, J.

    2000-07-01

    Steering a motorcycle or bicycle is counterintuitive; to turn right, you must steer left initially, and vice versa. You can execute this initially counter-directed turn by turning the handlebars explicitly (called counter-steering) or by throwing your hips to the side. Contrary to common belief, gyroscopic forces play only a limited role in balancing and steering [D. E. H. Jones, Phys. Today 23 (4), 34-40 (1970)].

  4. Measuring seeing with a Shack-Hartmann wave-front sensor during an active-optics experiment.

    PubMed

    Zhang, Yong; Yang, Dehua; Cui, Xiangqun

    2004-02-01

    We describe the measurement of atmospheric enclosure seeing along a 120-m light path by use of a Shack-Hartmann wave-front sensor (S-H WFS) for the first time to our knowledge in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) outdoor active-optics experiment system, based on the differential image motion method and a S-H WFS. Seeing estimates that were gained with the S-H WFS were analyzed and found to be in close agreement with the actual seeing conditions, the estimates of refractive-index structure constant, and the thin-mirror active optics results, which usually include the shape sensing precision and the active correction precision of the experimental system. Finally, some countermeasures against poor seeing conditions were considered and adopted.

  5. Microfluidic plug steering using surface acoustic waves.

    PubMed

    Sesen, Muhsincan; Alan, Tuncay; Neild, Adrian

    2015-07-21

    Digital microfluidic systems, in which isolated droplets are dispersed in a carrier medium, offer a method to study biological assays and chemical reactions highly efficiently. However, it's challenging to manipulate these droplets in closed microchannel devices. Here, we present a method to selectively steer plugs (droplets with diameters larger than the channel's width) at a specially designed Y-junction within a microfluidic chip. The method makes use of surface acoustic waves (SAWs) impinging on a multiphase interface in which an acoustic contrast is present. As a result, the liquid-liquid interface is subjected to acoustic radiation forces. These forces are exploited to steer plugs into selected branches of the Y-junction. Furthermore, the input power can be finely tuned to split a plug into two uneven plugs. The steering of plugs as a whole, based on plug volume and velocity is thoroughly characterized. The results indicate that there is a threshold plug volume after which the steering requires elevated electrical energy input. This plug steering method can easily be integrated to existing lab-on-a-chip devices and it offers a robust and active plug manipulation technique in closed microchannels.

  6. Microfluidic plug steering using surface acoustic waves.

    PubMed

    Sesen, Muhsincan; Alan, Tuncay; Neild, Adrian

    2015-07-21

    Digital microfluidic systems, in which isolated droplets are dispersed in a carrier medium, offer a method to study biological assays and chemical reactions highly efficiently. However, it's challenging to manipulate these droplets in closed microchannel devices. Here, we present a method to selectively steer plugs (droplets with diameters larger than the channel's width) at a specially designed Y-junction within a microfluidic chip. The method makes use of surface acoustic waves (SAWs) impinging on a multiphase interface in which an acoustic contrast is present. As a result, the liquid-liquid interface is subjected to acoustic radiation forces. These forces are exploited to steer plugs into selected branches of the Y-junction. Furthermore, the input power can be finely tuned to split a plug into two uneven plugs. The steering of plugs as a whole, based on plug volume and velocity is thoroughly characterized. The results indicate that there is a threshold plug volume after which the steering requires elevated electrical energy input. This plug steering method can easily be integrated to existing lab-on-a-chip devices and it offers a robust and active plug manipulation technique in closed microchannels. PMID:26079216

  7. On the Feasibility of Dynamic Power Steering

    SciTech Connect

    Barker, Kevin J.; Kerbyson, Darren J.; Anger, Eric A.

    2014-11-16

    While high performance has always been the primary constraint behind large-scale system design, future systems will be built with increasing energy efficiency in mind. Mechanisms such as fine-grained power scaling and gating will provide tools to system-software and application developers to ensure the most efficient use of tightly constrained power budgets. Such approaches to-date have been focused on node level optimizations to impact overall system energy efficiency. In this work we introduce Dynamic Power Steering, in which power can be dynamically routed across a system to resources where it will be of most benefit and away from other resources to maintain a near-constant overall power budget. This, a higher level algorithmic approach to improving energy efficiency, considers the whole extent of a system being used by an application. It can be used for applications in which there is load imbalance that varies over its execution. Using two classes of applications, namely those that contain a wave front type processing, and a particle-in-cell, we quantify the benefit of Dynamic Power Steering for a variety of workload characteristics and derive some insight into the ways in which workload behavior affect Power Steering applicability.

  8. Hydrodynamic Instabilities of Acid-Base Reaction Fronts: Active Role of a Color Indicator

    NASA Astrophysics Data System (ADS)

    Riolfo, L. A.; Almarcha, C.; Trevelyan, P. M. J.; El Hasi, C.; Zalts, A.; D'Onofrio, A.; de Wit, A.

    2010-11-01

    Chemical reactions are able to trigger hydrodynamic flows by, for example changing the density of the solutions across the reactive interfaces. In this work we present an experimental and theoretical study of the buoyancy-driven hydrodynamic instabilities that can occur when two miscible reactive solutions of an acid-base system are put in contact in the gravity field. We compare situations where a hydrochloric acid aqueous solution is put on top of a sodium hydroxide aqueous solution with or without a color indicator (Bromocresol Green). We also analyze the situation where a hydrochloric acid is put on top of an aqueous solution of a color indicator without any base. We show that the patterns observed and the instabilities taking place strongly depend on the presence of a color indicator. Using a reaction-diffusion model for the concentrations of all species (including the color indicator) we analyze the different possible sources of destabilization of the acid-base front and explain the various instabilities observed in each experimental system.

  9. Tunable beam steering enabled by graphene metamaterials.

    PubMed

    Orazbayev, B; Beruete, M; Khromova, I

    2016-04-18

    We demonstrate tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential of each graphene layer. This can arbitrarily tailor the spatial distribution of the phase of the transmitted beam, providing mechanisms for active beam steering. Three different beam steerer (BS) designs are discussed: a graded-index (GRIN) graphene-based metamaterial block, an array of metallic waveguides filled with graphene-dielectric metamaterial and an array of planar waveguides created in a graphene-dielectric metamaterial block with a specific spatial profile of graphene sheets doping. The performances of the BSs are numerically analyzed, showing the tunability of the proposed designs for a wide range of output angles (up to approximately 70°). The proposed graphene-based tunable beam steering can be used in tunable transmitter/receiver modules for infrared imaging and sensing.

  10. In-use measurement of the activity, fuel use, and emissions of front-loader refuse trucks

    NASA Astrophysics Data System (ADS)

    Sandhu, Gurdas S.; Frey, H. Christopher; Bartelt-Hunt, Shannon; Jones, Elizabeth

    2014-08-01

    Field measurements were made for six front-loader refuse trucks for over 560 miles (901 km) and 47 h of operation using a portable emissions measurement system, electronic control unit data logger, and global positioning system receivers. Daily activity, fuel use rates, and emission rates are quantified in terms of operating mode bins defined by the U.S. Environmental Protection Agency for the MOVES emission factor model. On average, 44 (±4) percent of time was spent at idle, 5 (±1) percent braking or decelerating, 11 (±2) percent coasting, 23 (±3) percent cruising or accelerating at low speed (up to 25 mph, 40.2 kmph), 10 (±2) percent cruising or accelerating at moderate speed (25-50 mph, 40.2 to 80.4 kmph), and 7 (±3) percent cruising or accelerating at high speed (50 mph, 80.4 kmph or higher). Fuel use and emission rates varied among operating modes by factors of 6-24. The estimated daily activity cycle average fuel economy ranges from 2.3 to 3.2 mpg (0.98-1.4 kmpl). The PM emission rates for trucks with diesel particulate filters are 98 percent lower compared to those without. Variation in truck weight lead to differences in average fuel use and emission rates of 20 percent or less, except for hydrocarbons. The variation in the empirically-based daily activity cycle average rates were highly correlated with MOVES estimates, except for hydrocarbons. The data collected here are useful for quantifying daily activity specific to front-loaders, and for developing fuel use and emission estimates and models for this type of vehicle.

  11. Controlled Structures Technology Steering Committee Workshop

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Viewgraphs on controlled structures technology presented at the steering committee workshop on 22-23 Jan. 1992 are included. Topics addressed include: interferometer testbed; middeck 0-gravity dynamics experiment; middeck active control experiment; multivariable identification for control; strain actuated aeroelastic control; sensor/actuator technology development; input command shaping; and other research projects. A description of the organization and committee are included.

  12. Laser beam steering device

    NASA Technical Reports Server (NTRS)

    Motamedi, M. E.; Andrews, A. P.; Gunning, W. J.

    1993-01-01

    Agile beam steering is a critical requirement for airborne and space based LIDAR and optical communication systems. Design and test results are presented for a compact beam steering device with low inertia which functions by dithering two complementary (positive and negative) binary optic microlens arrays relative to each other in directions orthogonal to the direction of light propagation. The miniaturized system has been demonstrated at scan frequencies as high as 300 Hz, generating a 13 x 13 spot array with a total field of view of 2.4 degrees. The design is readily extendable to a 9.5 degree field of view and a 52 x 52 scan pattern. The system is compact - less than 2 in. on a side. Further size reductions are anticipated.

  13. Comparative analysis of active drag using the MAD system and an assisted towing method in front crawl swimming.

    PubMed

    Formosa, Daniel P; Toussaint, Huub M; Mason, Bruce R; Burkett, Brendan

    2012-12-01

    The measurement of active drag in swimming is a biomechanical challenge. This research compared two systems: (i) measuring active drag (MAD) and (ii) assisted towing method (ATM). Nine intermediate-level swimmers (19.7 ± 4.4 years) completed front crawl trials with both systems during one session. The mean (95% confidence interval) active drag for the two systems, at the same maximum speed of 1.68 m/s (1.40-1.87 m/s), was significantly different (p = .002) with a 55% variation in magnitude. The mean active drag was 82.3 N (74.0-90.6 N) for the MAD system and 148.3 N (127.5-169.1 N) for the ATM system. These differences were attributed to variations in swimming style within each measurement system. The inability to measure the early catch phase and kick, along with the fixed length and depth hand place requirement within the MAD system generated a different swimming technique, when compared with the more natural free swimming ATM protocol. A benefit of the MAD system was the measurement of active drag at various speeds. Conversely, the fixed towing speed of the ATM system allowed a natural self-selected arm stroke (plus kick) and the generation of an instantaneous force-time profile.

  14. Effects of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection, and degree of doneness on the palatability of steaks from limousin steers.

    PubMed

    Wulf, D M; Morgan, J B; Tatum, J D; Smith, G C

    1996-03-01

    Strip loin (longissimus lumborum), sirloin (gluteus medius) and round (semimembranosus) subprimals from 114 purebred and crossbred Limousin steers were used to identify main effects and interactions of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection (5% wt/wt with a 200 mM CaCl2 solution at 48 h postmortem), and degree of doneness on the palatability of cooked beef steaks. Steaks were aged for 14 d, frozen, thawed, cooked to different internal temperature end points, visually scored for degree of doneness, sheared on a Warner-Bratzler shear machine, and evaluated by a trained taste panel. Raw and cooked steaks from carcasses of higher USDA quality grades had higher fat and lower moisture percentages (P < .05). Higher degrees of doneness resulted in lower moisture percentages (P < .05). Lower shear force values were associated with less variation in shear force. Younger slaughter age and lower calpastatin activity both resulted in greater tenderness (P < .05). Shear force was lowest between "medium rare" and "medium" and increased toward both ends of the degree of doneness scale for round and sirloin steaks; however, shear force increased linearly with degree of doneness in strip loin steaks (P < .05). Subprimal cut had the largest effect on taste panel tenderness ratings, and degree of doneness had the largest effect on taste panel juiciness ratings. The improvement in shear force due to CaCl2 injection was greater for strip loin and sirloin steaks than for round steaks (P < .05 for the interaction). Injection with CaCl2 improved all taste panel attributes. In addition, CaCl2 injection reduced the toughening effects of cooking (P < .05).

  15. Analysis of Steering Knuckle of All Terrain Vehicles (ATV) Using Finite Element Analysis

    NASA Astrophysics Data System (ADS)

    Dusane, S. V.; Dipke, M. K.; Kumbhalkar, M. A.

    2016-09-01

    Steering knuckle is the most stress sustaining and critical component of All Terrain Vehicle (ATV). Steering knuckle is the pivot point of the steering and suspension system, which allows the front wheels to turn and also allow the movement of suspension arms motion. The light weight and high strength component is always in demanding for racecar application. Lightweight and optimized design of steering knuckle is proposed to use for a BAJA SAE INDIA off road racecar. Due to the failure in knuckle in terrain vehicle after some instances, it has to be modified for better performance. The 3D CAD model created by using CATIA V5 and static as well as model analysis carried out in ANSYS 12 to understand its behavior under operating conditions. All test for frame was carried out on aluminum alloys 6061-T6 & for spindle EN8. The paper discusses the FE analysis of existing and modified Steering Knuckle.

  16. High-speed optimal steering of a tractor-semitrailer

    NASA Astrophysics Data System (ADS)

    Cheng, Caizhen; Roebuck, Richard; Odhams, Andrew; Cebon, David

    2011-04-01

    A high-speed optimal trailer steering controller for a tractor-semitrailer is discussed. A linear model of a tractor-semitrailer with steered trailer axles is described, and an optimal trailer steering controller is introduced. A path-following controller is derived to minimise the path-tracking error in steady-state manoeuvres using active trailer steering. A roll stability controller is introduced by adding the lateral acceleration of trailer centre of gravity as another objective in the steering controller, so as to improve roll stability in transient manoeuvres. A strategy to switch between these two control modes is demonstrated. Simulation results show that the steering controller can ensure good path tracking of articulated vehicles in steady-state manoeuvres and improve roll stability significantly in transient manoeuvres, while maintaining the path-tracking deviation within an acceptable range. Tests with an experimental tractor-semitrailer equipped with a high-bandwidth active steering system validate the controller design and simulation results. The roll stability controller reduces the measured rearward amplification by 27%.

  17. DNA polymorphisms and transcript abundance of PRKAG2 and phosphorylated AMP-activated protein kinase in the rumen are associated with gain and feed intake in beef steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef steers with variation in feed efficiency phenotypes were evaluated previously on a high density SNP panel. Ten markers from rs110125325-rs41652818 on bovine chromosome 4 were associated with average daily gain (ADG). To identify the gene(s) in this 1.2Mb region responsible for variation in AD...

  18. Adenosine: front and center in linking nutrition and metabolism to neuronal activity

    PubMed Central

    Greene, Robert W.

    2011-01-01

    Many individuals with epilepsy benefit from consuming a ketogenic diet, which is similar to the more commonly known Atkins diet. The underlying molecular reason for this has not been determined. However, in this issue of the JCI, Masino et al. have elucidated the mechanism responsible for the antiepileptic effects of the ketogenic diet in mice. The diet is shown to decrease expression of the enzyme adenosine kinase (Adk), which is responsible for clearing the endogenous antiepileptic agent adenosine (Ado) from the extracellular CNS space. Decreased expression of Adk results in increased extracellular Ado, activation of inhibitory Ado A1 receptors, and decreased seizure generation, the desired therapeutic effect. The authors’ work serves to emphasize the importance of controlling Adk expression, not only as the mechanism of action of the ketogenic diet, but also as a potential target of future therapies. PMID:21701073

  19. A hybrid active optical system for wave front preservation and variable focal distance

    NASA Astrophysics Data System (ADS)

    Cocco, Daniele; Bortoletto, Gianluca; Sergo, Rudi; Sostero, Giovanni; Cudin, Ivan

    2010-05-01

    A new Free Electron Laser (FEL) user facility, named FERMI@Elettra, is under construction at Sincrotrone Trieste (Italy). It is based on a seeded scheme to provide an almost perfect transform limited beam with fully spatial coherence. The wavelength range will be 100-3 nm with fundamental and will go down to 1 nm by using higher harmonics. It will be operative by autumn 2010. The exceptional characteristics of the source must be preserved until the experimental chamber, where a large set of different experiments will be performed. This condition poses very tight requirements to the design of the beamlines and, in particular, to the focusing optics. Here we will present the active optics system developed for Fermi but intended to be used also on the Elettra beamlines. It is based on the adoption of a hybrid active system composed by UHV compatible stepping motors and piezo ceramic actuators. These mirrors are supposed to provide focal distances from 0.8 m to infinity with an angle of incidence up to a few degrees and residual shape errors below 10 or 5 nm (depending on the wavelength). In this way it is possible to work with an almost perfect focused coherent beam as well as with a uniform defocused or unfocused image. The metrology results on the first 400 mm long mirror will be shown and the actuator system described. A strain gauge assembly, calibrated in Elettra by means of a long trace profiler, and controlled by a custom made electronic system developed by us, is used as a direct in situ encoder.

  20. Focusing solenoids for the HINS Linac front end

    SciTech Connect

    Terechkine, I.; Appollinari, G.; Di-Marco, J.; Huang, Y.; Orris, D.; Page, T.; Rabehl, R.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2008-10-01

    The low energy part of a linac for the High Intensity Neutrino Source (HINS) project at Fermilab will use superconducting solenoids as beam focusing elements (lenses). While the lenses for the conventional DTL-type accelerating section of the front end require individual cryostats, in the superconducting accelerating sections solenoids will be installed inside RF cryomodules. Some of the lenses in the conventional and in the superconducting sections are equipped with horizontal and vertical steering dipoles. Lenses for the DTL section are in the stage of production with certification activities ongoing at Fermilab. For the superconducting sections of the linac, a prototype lens has been built and tested. Each lens will be installed in the transport channel of the accelerator so that its magnetic axis is on the beamline. Corresponding technique has been developed at Fermilab and is used during the certification process. This report summarizes design features, parameters, and test results of the focusing lenses.

  1. Steerable THz pulses from thin emitters via optical pulse-front tilt.

    PubMed

    Smith, B C; Whitaker, J F; Rand, S C

    2016-09-01

    A new method of steering THz pulses radiated from a thin emitter excited by tilted optical pulse-fronts has been developed theoretically and validated in a proof-of-concept experiment. This steering technique is potentially efficient and rapid, and it should benefit from a THz-pulse energy that can scale with optical-beam size and magnitude. Conversely, the method employed for measuring the steered THz pulses is also capable of characterizing the pulse-front tilt of an optical beam. PMID:27607678

  2. Laser Beam Steering/shaping for Free Space Optical Communication

    NASA Technical Reports Server (NTRS)

    Wang, Xinghua; Wang, Bin; Bos, Philip J.; Anderson, James E.; Pouch, John; Miranda, Felix; McManamon, Paul F.

    2004-01-01

    The 2-D Optical Phased Array (OPA) antenna based on a Liquid Crystal On Silicon (LCoS) device can be considered for use in free space optical communication as an active beam controlling device. Several examples of the functionality of the device include: beam steering in the horizontal and elevation direction; high resolution wavefront compensation in a large telescope; and beam shaping with the computer generated kinoform. Various issues related to the diffraction efficiency, steering range, steering accuracy as well as the magnitude of wavefront compensation are discussed.

  3. Simplified planar model of a car steering system with rack and pinion and McPherson suspension

    NASA Astrophysics Data System (ADS)

    Knapczyk, J.; Kucybała, P.

    2016-09-01

    The paper presents the analysis and optimization of steering system with rack and pinion and McPherson suspension using spatial model and equivalent simplified planar model. The dimension of the steering linkage that give minimum steering error can be estimated using planar model. The steering error is defined as the difference between the actual angle made by the outer front wheel during steering manoeuvers and the calculated angle for the same wheel based on the Ackerman principle. For a given linear rack displacement, a specified steering arms angular displacements are determined while simultaneously ensuring best transmission angle characteristics (i) without and (ii) with imposing linear correlation between input and output. Numerical examples are used to illustrate the proposed method.

  4. Diesel Technology: Steering and Suspension.

    ERIC Educational Resources Information Center

    Miller, Roger; Scarberry, Terry; Tesch, Carl; Kellum, Mary

    Competency-based teacher and student materials on steering and suspension are provided for a diesel technology curriculum. Eleven units of instruction cover the following topics: chassis, tires, and wheels; steering; and suspension. The materials are based on the curriculum-alignment concept of first stating the objectives, then developing…

  5. Quantum coherence of steered states

    PubMed Central

    Hu, Xueyuan; Milne, Antony; Zhang, Boyang; Fan, Heng

    2016-01-01

    Lying at the heart of quantum mechanics, coherence has recently been studied as a key resource in quantum information theory. Quantum steering, a fundamental notion originally considered by Schödinger, has also recently received much attention. When Alice and Bob share a correlated quantum system, Alice can perform a local measurement to ‘steer’ Bob’s reduced state. We introduce the maximal steered coherence as a measure describing the extent to which steering can remotely create coherence; more precisely, we find the maximal coherence of Bob’s steered state in the eigenbasis of his original reduced state, where maximization is performed over all positive-operator valued measurements for Alice. We prove that maximal steered coherence vanishes for quantum-classical states whilst reaching a maximum for pure entangled states with full Schmidt rank. Although invariant under local unitary operations, maximal steered coherence may be increased when Bob performs a channel. For a two-qubit state we find that Bob’s channel can increase maximal steered coherence if and only if it is neither unital nor semi-classical, which coincides with the condition for increasing discord. Our results show that the power of steering for coherence generation, though related to discord, is distinct from existing measures of quantum correlation. PMID:26781214

  6. Holographic memory using beam steering

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor); Hanan, Jay C. (Inventor); Reyes, George F. (Inventor); Zhou, Hanying (Inventor)

    2007-01-01

    A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

  7. Glycolytic potential and activity of adenosine monophosphate kinase (AMPK), glycogen phosphorylase (GP) and glycogen debranching enzyme (GDE) in steer carcasses with normal (<5.8) or high (>5.9) 24h pH determined in M. longissimus dorsi.

    PubMed

    Apaoblaza, A; Galaz, A; Strobel, P; Ramírez-Reveco, A; Jeréz-Timaure, N; Gallo, C

    2015-03-01

    Muscle glycogen concentration (MGC) and lactate (LA), activity of glycogen debranching enzyme (GDE), glycogen phosphorylase (GP) and adenosine monophosphate kinase (AMPK) were determined at 0.5h (T0) and 24h (T24) post-mortem in Longissimus dorsi samples from 38 steers that produced high pH (>5.9) and normal pH (<5.8) carcasses at 24h postmortem. MGC, LA and glycolytic potential were higher (P<0.05) in normal pH carcasses. GDE activity was similar (P>0.05) in both pH categories. GP activity increased between T0 and T24 only in normal pH carcasses. AMPK activity was four times higher in normal pH v/s high pH carcasses, without changing its activity over time. Results reinforce the idea that differences in postmortem glycogenolytic/glycolytic flow in L. dorsi of steers showing normal v/s high muscle pH at 24h, could be explained not only by the higher initial MGC in normal pH carcasses, but also by a high and sustained activity of AMPK and an increased GP activity at 24h postmortem.

  8. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    NASA Astrophysics Data System (ADS)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession

  9. Steering Bell-diagonal states

    PubMed Central

    Quan, Quan; Zhu, Huangjun; Liu, Si-Yuan; Fei, Shao-Ming; Fan, Heng; Yang, Wen-Li

    2016-01-01

    We investigate the steerability of two-qubit Bell-diagonal states under projective measurements by the steering party. In the simplest nontrivial scenario of two projective measurements, we solve this problem completely by virtue of the connection between the steering problem and the joint-measurement problem. A necessary and sufficient criterion is derived together with a simple geometrical interpretation. Our study shows that a Bell-diagonal state is steerable by two projective measurements iff it violates the Clauser-Horne-Shimony-Holt (CHSH) inequality, in sharp contrast with the strict hierarchy expected between steering and Bell nonlocality. We also introduce a steering measure and clarify its connections with concurrence and the volume of the steering ellipsoid. In particular, we determine the maximal concurrence and ellipsoid volume of Bell-diagonal states that are not steerable by two projective measurements. Finally, we explore the steerability of Bell-diagonal states under three projective measurements. A simple sufficient criterion is derived, which can detect the steerability of many states that are not steerable by two projective measurements. Our study offers valuable insight on steering of Bell-diagonal states as well as the connections between entanglement, steering, and Bell nonlocality. PMID:26911250

  10. Cloud Front

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02171 Cloud Front

    These clouds formed in the south polar region. The faintness of the cloud system likely indicates that these are mainly ice clouds, with relatively little dust content.

    Image information: VIS instrument. Latitude -86.7N, Longitude 212.3E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Levels of steering control: Reproduction of steering-wheel movements

    NASA Technical Reports Server (NTRS)

    Godthelp, H.

    1982-01-01

    A schematic description of the steering control process is presented. It is shown that this process can be described in terms of levels of control. Level of control will depend on driver's skill in making use of 'clever' strategies which may be related to knowledge about the path to follow (input) and/or the vehicle under control. This knowledge may be referred to as an internal model of a particular task element. Internal information, as derived from these internal models will probably be used together with proprioceptive feedback. It is hypothesized that the efficiency of the higher levels of control will be dependent on the accuracy of both the internal and proprioceptive information. Based on this research philosophy a series of experiments is carried out. Two primary experiments were done in order to analyse subjects' ability to reproduce steering-wheel positions and movements without visual feedback. Steering-wheel angle amplitude, steering force and movement frequency were involved as independent variables.

  12. A control theoretic model of driver steering behavior

    NASA Technical Reports Server (NTRS)

    Donges, E.

    1977-01-01

    A quantitative description of driver steering behavior such as a mathematical model is presented. The steering task is divided into two levels: (1) the guidance level involving the perception of the instantaneous and future course of the forcing function provided by the forward view of the road, and the response to it in an anticipatory open-loop control mode; (2) the stabilization level whereby any occuring deviations from the forcing function are compensated for in a closed-loop control mode. This concept of the duality of the driver's steering activity led to a newly developed two-level model of driver steering behavior. Its parameters are identified on the basis of data measured in driving simulator experiments. The parameter estimates of both levels of the model show significant dependence on the experimental situation which can be characterized by variables such as vehicle speed and desired path curvature.

  13. Holographic memory using beam steering

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor); Hanan, Jay C. (Inventor); Reyes, George F. (Inventor); Zhou, Hanying (Inventor)

    2006-01-01

    A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

  14. Managing Contradictions from the Middle: A Cultural Historical Activity Theory Investigation of Front-Line Supervisors' Learning Lives

    ERIC Educational Resources Information Center

    Lord, Ramo J.

    2009-01-01

    This study focused on front-line supervisors in a union shop, steel-production plant and how they learn to successfully negotiate their role with in the corporation's division of labor. Negotiating their role means continued practice in how issues of standpoint, agency, power, oppression, habits, knowledge, related business concerns, mediating…

  15. Identifying cognitive distraction using steering wheel reversal rates.

    PubMed

    Kountouriotis, Georgios K; Spyridakos, Panagiotis; Carsten, Oliver M J; Merat, Natasha

    2016-11-01

    The influence of driver distraction on driving performance is not yet well understood, but it can have detrimental effects on road safety. In this study, we examined the effects of visual and non-visual distractions during driving, using a high-fidelity driving simulator. The visual task was presented either at an offset angle on an in-vehicle screen, or on the back of a moving lead vehicle. Similar to results from previous studies in this area, non-visual (cognitive) distraction resulted in improved lane keeping performance and increased gaze concentration towards the centre of the road, compared to baseline driving, and further examination of the steering control metrics indicated an increase in steering wheel reversal rates, steering wheel acceleration, and steering entropy. We show, for the first time, that when the visual task is presented centrally, drivers' lane deviation reduces (similar to non-visual distraction), whilst measures of steering control, overall, indicated more steering activity, compared to baseline. When using a visual task that required the diversion of gaze to an in-vehicle display, but without a manual element, lane keeping performance was similar to baseline driving. Steering wheel reversal rates were found to adequately tease apart the effects of non-visual distraction (increase of 0.5° reversals) and visual distraction with offset gaze direction (increase of 2.5° reversals). These findings are discussed in terms of steering control during different types of in-vehicle distraction, and the possible role of manual interference by distracting secondary tasks.

  16. Fermilab Steering Group Report

    SciTech Connect

    Steering Group, Fermilab; /Fermilab

    2007-12-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOvA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the industrialization of ILC components

  17. Fermilab Steering Group Report

    SciTech Connect

    Beier, Eugene; Butler, Joel; Dawson, Sally; Edwards, Helen; Himel, Thomas; Holmes, Stephen; Kim, Young-Kee; Lankford, Andrew; McGinnis, David; Nagaitsev, Sergei; Raubenheimer, Tor; /SLAC /Fermilab

    2007-01-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the industrialization of ILC components

  18. 49 CFR 393.209 - Steering wheel systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rotation for manual steering systems, and 30 degrees angular rotation for power steering systems. (c... arm on the steering gear output shaft shall not be loose. Steering wheels shall turn freely...

  19. Front-line ownership: imagine.

    PubMed

    Matlow, Anne

    2013-01-01

    When used in a military context, the term front line refers to the interface between enemies in action on the battlefield. In a non-military context, the front line is the site where the core activity defining a particular industry takes place, and those working there are key to successful operations. In healthcare, the need to improve patient safety has become a global imperative, and an armamentarium of strategies, tools and technological approaches have been adapted or developed for this context. Often neglected, however, have been strategies to engage the healthcare workers, those at the front line, in the cause.In order for healthcare to function error free, we must assume the characteristics of high-reliability organizations. In particular, the ability to bounce back, to be resilient in the face of a catastrophe, is of paramount importance. Those working at the front line may have the answers. We need to create an opportunity for them to be heard.`

  20. Front matter.

    PubMed

    2015-01-01

    has defined four basic areas to be managed in the new care model: address the big data challenges; foster meaningful innovation; understand and address the potential new risks; and support concerted effort to un-silo communities for a virtual care future. The multilateral benefits of pHealth technologies for all stakeholder communities including patients, citizens, health professionals, politicians, healthcare establishments, and companies from the biomedical technology, pharmaceutical, and telecommunications domain gives enormous potential, not only for medical quality improvement and industrial competitiveness, but also for managing health care cost. The pHealth 2015 Conference thankfully benefits from the experience and the lessons learned from the organizing committees of previous pHealth events, particularly 2009 in Oslo, 2010 in Berlin, 2011 in Lyon, 2012 in Porto, 2013 in Tallinn, and 2014 Vienna. The 2009 conference brought up the interesting idea of having special sessions, focusing on a particular topic, and being organized by a mentor/moderator. The Berlin event in 2010 initiated workshops on particular topics prior to the official kick-off of the conference. Lyon in 2011 initiated the launch of socalled dynamic demonstrations allowing the participants to dynamically show software and hardware solutions on the fly without needing a booth. Implementing preconference events, the pHealth 2012 in Porto gave attendees a platform for presenting and discussing recent developments and provocative ideas that helped to animate the sessions. Highlight of pHealth 2013 in Tallinn was the special session on European projects' success stories, but also presentations on the newest paradigm changes and challenges coming up with Big Data, Analytics, Translational and Nano Medicine, etc. Vienna in 2014 focused on lessons learned from international and national R&D activities and practical solutions, and especially from the new EU Framework Program for Research and Innovation

  1. Front matter.

    PubMed

    2015-01-01

    has defined four basic areas to be managed in the new care model: address the big data challenges; foster meaningful innovation; understand and address the potential new risks; and support concerted effort to un-silo communities for a virtual care future. The multilateral benefits of pHealth technologies for all stakeholder communities including patients, citizens, health professionals, politicians, healthcare establishments, and companies from the biomedical technology, pharmaceutical, and telecommunications domain gives enormous potential, not only for medical quality improvement and industrial competitiveness, but also for managing health care cost. The pHealth 2015 Conference thankfully benefits from the experience and the lessons learned from the organizing committees of previous pHealth events, particularly 2009 in Oslo, 2010 in Berlin, 2011 in Lyon, 2012 in Porto, 2013 in Tallinn, and 2014 Vienna. The 2009 conference brought up the interesting idea of having special sessions, focusing on a particular topic, and being organized by a mentor/moderator. The Berlin event in 2010 initiated workshops on particular topics prior to the official kick-off of the conference. Lyon in 2011 initiated the launch of socalled dynamic demonstrations allowing the participants to dynamically show software and hardware solutions on the fly without needing a booth. Implementing preconference events, the pHealth 2012 in Porto gave attendees a platform for presenting and discussing recent developments and provocative ideas that helped to animate the sessions. Highlight of pHealth 2013 in Tallinn was the special session on European projects' success stories, but also presentations on the newest paradigm changes and challenges coming up with Big Data, Analytics, Translational and Nano Medicine, etc. Vienna in 2014 focused on lessons learned from international and national R&D activities and practical solutions, and especially from the new EU Framework Program for Research and Innovation

  2. Front Matter.

    PubMed

    2016-01-01

    On behalf of the Scientific Program Committee, I extend a warm welcome to the IMIA-NI members, students, practitioners, informatics researchers, industry partners, and others interested in health and nursing informatics who have come to attend the NI 2016, 13th International Congress on Nursing Informatics. NI 2016 is a biennial conference of the IMIA-NI and the leading scientific meeting for health and nursing informatics research and practice. NI 2016 presents work not only from the discipline of nursing but also from many other disciplines and specialties including both basic and applied informatics. The theme of NI 2016 is eHealth for all: Every level collaboration - From project to realization. The theme reflects the major challenges we face in healthcare today, that is, the need to collaborate at every level to achieve our goal of Health For All. NI 2016 offers a variety of topics on the conference theme. The mission of the Scientific Program Committee is to solicit for, evaluate and schedule NI 2016 conference program to be consistent with the goal of the IMIA-NI. We received 445 submissions for papers, posters, short communications, panels, workshops, demonstrations, student competitions and tutorials from more than 40 countries. Each submission was reviewed by three reviewers selected from a panel of more than 963 experts. Reviewers' feedback was provided to the authors and every effort was made to ensure the best submissions given the constraints of the conference timetable. In the end, a total of 332 submissions were selected. The result of the Scientific Program Committee's activity is reflected in the Conference Program and Proceedings. The proceedings contain OA full papers, indexed in MEDLINE, and also workshops, panels and posters summaries. The Scientific Program Committee has prepared a wonderful program. We have six keynote speakers addressing the state-of-the-art for health and nursing informatics ranging from data, to healthcare delivery to the

  3. Front Matter.

    PubMed

    2016-01-01

    On behalf of the Scientific Program Committee, I extend a warm welcome to the IMIA-NI members, students, practitioners, informatics researchers, industry partners, and others interested in health and nursing informatics who have come to attend the NI 2016, 13th International Congress on Nursing Informatics. NI 2016 is a biennial conference of the IMIA-NI and the leading scientific meeting for health and nursing informatics research and practice. NI 2016 presents work not only from the discipline of nursing but also from many other disciplines and specialties including both basic and applied informatics. The theme of NI 2016 is eHealth for all: Every level collaboration - From project to realization. The theme reflects the major challenges we face in healthcare today, that is, the need to collaborate at every level to achieve our goal of Health For All. NI 2016 offers a variety of topics on the conference theme. The mission of the Scientific Program Committee is to solicit for, evaluate and schedule NI 2016 conference program to be consistent with the goal of the IMIA-NI. We received 445 submissions for papers, posters, short communications, panels, workshops, demonstrations, student competitions and tutorials from more than 40 countries. Each submission was reviewed by three reviewers selected from a panel of more than 963 experts. Reviewers' feedback was provided to the authors and every effort was made to ensure the best submissions given the constraints of the conference timetable. In the end, a total of 332 submissions were selected. The result of the Scientific Program Committee's activity is reflected in the Conference Program and Proceedings. The proceedings contain OA full papers, indexed in MEDLINE, and also workshops, panels and posters summaries. The Scientific Program Committee has prepared a wonderful program. We have six keynote speakers addressing the state-of-the-art for health and nursing informatics ranging from data, to healthcare delivery to the

  4. Front Matter.

    PubMed

    2016-01-01

    Can bad health informatics kill? A similar question has been asked a decade ago by one of the editors of this book on evidence-based health informatics [1]. And indeed, when informatics methodology and information and communication technology (ICT) are used inappropriately this can cause severe negative effects. On the other hand we will probably all agree with her, when she writes in the same article that it "is evident that the use of modern ICT offers tremendous opportunities to support health care professionals and to increase efficiency, effectiveness and appropriateness of care" [1]. Even earlier, more than 15 years ago, the other editor stated that it "is unfortunately a truism in health care informatics… that evaluation is undertaken rarely and inadequately" and he concludes, among others, that "integrated information systems also give new opportunity to provide effective health care service evaluation, and thus a much more robust future evidence base" [2]. As perspective he writes that "a deeper and longer-term evaluation philosophy is needed which does not stop after the initial confirmation of system functioning, but continues on with a deepening into the effects on the individual clinical services, and then on the host user organisation" [2]. Both colleagues worked during recent years continuously and intensively on how to better evaluate health care processes and outcomes in the context of health information systems, so that informatics tools and information management strategies are not 'just' applied in this context, but that their evidence has also been evaluated according to current good scientific practice. It is probably no surprise to find later joint papers of them on evidence-based health informatics, reporting about their international activities there [3]. Today there is indeed still a discrepancy in making decisions on health information system architectures, infrastructures and tools, related to considerable investments for health care

  5. 33 CFR 401.18 - Steering lights.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Steering lights. 401.18 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.18 Steering lights. Every vessel shall be equipped with: (a) A steering light located on the centerline at or near the stem of...

  6. 33 CFR 401.18 - Steering lights.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Steering lights. 401.18 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.18 Steering lights. Every vessel shall be equipped with: (a) A steering light located on the centerline at or near the stem of...

  7. 46 CFR 169.251 - Steering apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering apparatus. 169.251 Section 169.251 Shipping... Inspection and Certification Inspections § 169.251 Steering apparatus. At each inspection for certification and periodic inspection the steering apparatus is inspected and operationally tested to determine...

  8. 46 CFR 169.251 - Steering apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Steering apparatus. 169.251 Section 169.251 Shipping... Inspection and Certification Inspections § 169.251 Steering apparatus. At each inspection for certification and periodic inspection the steering apparatus is inspected and operationally tested to determine...

  9. Remote manipulator system steering capability for SVDS

    NASA Technical Reports Server (NTRS)

    Martin, D. T.

    1977-01-01

    Details of the remote manipulator system steering capability to be implemented into the space vehicle dynamics simulator are reported. The resolve rate law is included as part of the overall steering capability. The steering model includes three automatic modes, four manual augmented modes, and a single joint rate mode.

  10. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... steering axle wheels in the straight ahead position, turn the steering wheel in one direction until there is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the value shown in Table 1 before perceptible return movement of the wheel under observation, there...

  11. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... steering axle wheels in the straight ahead position, turn the steering wheel in one direction until there is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the value shown in Table 1 before perceptible return movement of the wheel under observation, there...

  12. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... steering axle wheels in the straight ahead position, turn the steering wheel in one direction until there is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the value shown in Table 1 before perceptible return movement of the wheel under observation, there...

  13. 33 CFR 401.18 - Steering lights.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Steering lights. 401.18 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.18 Steering lights. Every vessel shall be equipped with: (a) A steering light located on the centerline at or near the stem of...

  14. 33 CFR 401.18 - Steering lights.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Steering lights. 401.18 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.18 Steering lights. Every vessel shall be equipped with: (a) A steering light located on the centerline at or near the stem of...

  15. 33 CFR 401.18 - Steering lights.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Steering lights. 401.18 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.18 Steering lights. Every vessel shall be equipped with: (a) A steering light located on the centerline at or near the stem of...

  16. Steering magnet design for a limited space

    SciTech Connect

    Okamura,M.; Fite, J.; Lodestro, V.; Raparia, D.; Ritter, J.

    2009-05-04

    We compare two extreme designs of steering magnets. The first one is a very thin steering magnet design which occupies only 6 mm in length and can be additionally installed as needed. The other is realized by applying extra coil windings to a quadrupole magnet and does not consume any length. The properties and the features of these steering magnets are discussed.

  17. Maximal Torque and Muscle Strength is Affected by Seat Distance from the Steering Wheel when Driving

    PubMed Central

    Yoo, Kyung-Tae; An, Ho-Jung; Lee, Sun-Kyung; Choi, Jung-Hyun

    2013-01-01

    [Purpose] This research analyzed how seat distance and gender affect maximal torque and muscle strength when driving to present base data for the optimal driving posture. [Subjects and Methods] The subjects were 27 college students in their 20's, 15 males and 12 females. After had been measured, the subjects sat in front of a steering wheel with the distance between the steering wheel and the seat set in turns. at 50, 70, and 90% their arm length, and the maximal torque and muscle strength were measured. [Results] Both the maximal torque and muscle strength were found to be greater in male subjects than female subjects whether they turned the steering wheel clockwise or counterclockwise. The difference was big enough to be statistically significant. Maximal torque was greatest when the seat distance was 50% of arm length, whether turning the steering wheel clockwise or counterclockwise. There were statistically significant differences in maximal torque between seat distances of 50 and 70% and 90% of the arm length. Muscle strength, in contrast, was found to be the greatest at a seat distance of 70% of arm length. [Conclusion] We conclude that greater torque can be obtained when the steering wheel is nearer the seat while greater muscle strength can be obtained when the seat distance from the steering wheel is 70% of the arm length. PMID:24259937

  18. Objective evaluation method of steering comfort based on movement quality evaluation of driver steering maneuver

    NASA Astrophysics Data System (ADS)

    Yang, Yiyong; Liu, Yahui; Wang, Man; Ji, Run; Ji, Xuewu

    2014-09-01

    The existing research of steering comfort mainly focuses on the subjective evaluation, aiming at designing and optimizing the steering system. In the development of steering system, especially the evaluation of steering comfort, the objective evaluation methods considered the kinematic characteristics of driver steering maneuver are not proposed, which means that the objective evaluation of steering cannot be conducted with the evaluation of kinematic characteristics of driver in steering maneuver. In order to propose the objective evaluation methods of steering comfort, the evaluation of steering movement quality of driver is developed on the basis of the study of the kinematic characteristics of steering maneuver. First, the steering motion trajectories of the driver in both comfortable and certain extreme uncomfortable operation conditions are detected using the Vicon motion capture system. The operation conditions are under the restrictions of the vertical height and horizontal distance between steering wheel center and the H-point of driver, and the steering resisting torque else. Next, the movement quality evaluation of driver steering maneuver is assessed using twelve kinds of evaluation indices based on the kinematic analyses of the steering motion trajectories to propose an objective evaluation method. Finally, an integrated discomfort index of steering maneuver is proposed on the basis of the regression analysis of subjective evaluation rating and the movement quality evaluation indices, including the Jerk, Discomfort and Joint Torque indices. The test results show that the proposed integrated discomfort index gives a good fitting with the subjective evaluation of discomfort, which means it can be used to evaluate or predict the discomfort level of steering maneuver. This paper proposes an objective evaluation method of steering comfort based on the movement quality evaluation of driver steering maneuver.

  19. Radiation beam steering by cyclotron-resonance maser array

    NASA Astrophysics Data System (ADS)

    Kesar, Amit; Jerby, Eli

    1999-02-01

    A concept of power beaming by a cyclotron-resonance maser (CRM) array is presented theoretically. In this scheme, the CRM-array operates as an active phased-array antenna, and radiates directly from its output aperture. The gain and phase of each CRM element in the array are controlled by the voltage and current of its electron gun. The consequent phase difference between the CRM-element outputs enables the steering of the radiation beam in the far field. A simplified linear model is presented for a CRM-array antenna with uncoupled elements. It provides radiation patterns which demonstrate the main feature of power-beam steering. A wide angular steering range (+/-35°) is obtained by an analog electronic control of the CRM array. The feasibility of practical CRM-array antennas is discussed.

  20. Retinal flow is sufficient for steering during observer rotation

    NASA Technical Reports Server (NTRS)

    Li, Li; Warren, William H Jr

    2002-01-01

    How do people control locomotion while their eyes are simultaneously rotating? A previous study found that during simulated rotation, they can perceive a straight path of self-motion from the retinal flow pattern, despite conflicting extraretinal information, on the basis of dense motion parallax and reference objects. Here we report that the same information is sufficient for active control ofjoystick steering. Participants steered toward a target in displays that simulated a pursuit eye movement. Steering was highly inaccurate with a textured ground plane (motion parallax alone), but quite accurate when an array of posts was added (motion parallax plus reference objects). This result is consistent with the theory that instantaneous heading is determined from motion parallax, and the path of self-motion is determined by updating heading relative to environmental objects. Retinal flow is thus sufficient for both perceiving self-motion and controlling self-motion with a joystick; extraretinal and positional information can also contribute, but are not necessary.

  1. Kinematic and dynamic analysis of a heavy truck with individual front suspension

    NASA Astrophysics Data System (ADS)

    Yarmohamadi, Hoda; Berbyuk, Viktor

    2013-06-01

    The main focus of this work is on the characteristics of a commercial vehicle with individual front suspension (IFS). Both kinematic and dynamic properties of the vehicle are investigated through simulations and analytical expressions. Moreover, employing the model of the tractor semitrailer combination, the study presents the results of comparison between the trucks with IFS and rigid front axle with respect to comfort and handling. This is done by analysing the responses of the vehicles to different road and steering inputs. The obtained results show enhanced comfort and steering feeling for the truck with IFS.

  2. Soil inoculation steers restoration of terrestrial ecosystems.

    PubMed

    Wubs, E R Jasper; van der Putten, Wim H; Bosch, Machiel; Bezemer, T Martijn

    2016-01-01

    Many natural ecosystems have been degraded because of human activities(1,2) and need to be restored so that biodiversity is protected. However, restoration can take decades and restoration activities are often unsuccessful(3) because of abiotic constraints (for example, eutrophication, acidification) and unfavourable biotic conditions (for example, competition or adverse soil community composition). A key question is what manageable factors prevent transition from degraded to restored ecosystems and what interventions are required for successful restoration(2,4). Experiments have shown that the soil community is an important driver of plant community development(5-8), suggesting that manipulation of the soil community is key to successful restoration of terrestrial ecosystems(3,9). Here we examine a large-scale, six-year-old field experiment on ex-arable land and show that application of soil inocula not only promotes ecosystem restoration, but that different origins of soil inocula can steer the plant community development towards different target communities, varying from grassland to heathland vegetation. The impact of soil inoculation on plant and soil community composition was most pronounced when the topsoil layer was removed, whereas effects were less strong, but still significant, when the soil inocula were introduced into intact topsoil. Therefore, soil inoculation is a powerful tool to both restore disturbed terrestrial ecosystems and steer plant community development. PMID:27398907

  3. Soil inoculation steers restoration of terrestrial ecosystems.

    PubMed

    Wubs, E R Jasper; van der Putten, Wim H; Bosch, Machiel; Bezemer, T Martijn

    2016-07-11

    Many natural ecosystems have been degraded because of human activities(1,2) and need to be restored so that biodiversity is protected. However, restoration can take decades and restoration activities are often unsuccessful(3) because of abiotic constraints (for example, eutrophication, acidification) and unfavourable biotic conditions (for example, competition or adverse soil community composition). A key question is what manageable factors prevent transition from degraded to restored ecosystems and what interventions are required for successful restoration(2,4). Experiments have shown that the soil community is an important driver of plant community development(5-8), suggesting that manipulation of the soil community is key to successful restoration of terrestrial ecosystems(3,9). Here we examine a large-scale, six-year-old field experiment on ex-arable land and show that application of soil inocula not only promotes ecosystem restoration, but that different origins of soil inocula can steer the plant community development towards different target communities, varying from grassland to heathland vegetation. The impact of soil inoculation on plant and soil community composition was most pronounced when the topsoil layer was removed, whereas effects were less strong, but still significant, when the soil inocula were introduced into intact topsoil. Therefore, soil inoculation is a powerful tool to both restore disturbed terrestrial ecosystems and steer plant community development.

  4. Relationship between antioxidant capacity, oxidative stress, and feed efficiency in beef steers.

    PubMed

    Russell, J R; Sexten, W J; Kerley, M S; Hansen, S L

    2016-07-01

    Feed efficiency (FE) can vary between individuals but sources of variation are not well characterized. Oxidative stress is among the biological mechanisms believed to contribute to variation. The objective of this study was to evaluate the relationship between FE, antioxidant activity, and oxidative stress in feedlot steers representing phenotypic extremes for FE. Crossbred beef steers ( = 181) fed 70-d growing phase (GP) whole-shell corn-based (G-Corn) or rye baleage and soybean hull-based (G-Rough) diets in GrowSafe bunks at the University of Missouri were shipped to Iowa State University where the 12 most feed efficient (HFE) and 12 least feed efficient (LFE) steers from each diet (n = 48; 467 kg [SD 51]) were selected for evaluation. Steers received diets similar to GP diets, and 3 d after arrival, blood was sampled to evaluate antioxidant activity and oxidative stress markers for the GP following transit. Steers were transitioned to finishing phase (FP) cracked corn-based (F-Corn) or dried distillers' grains and soybean hull-based (F-Byp) diets, and on FP d 97, blood samples for the FP were collected. Data for the GP were analyzed as a 2 × 2 factorial, and data for the FP were analyzed as a 2 × 2 × 2 factorial using PROC MIXED of SAS. No GP diet × FP diet, FP diet × FE group, or 3-way interactions were noted ( ≥ 0.11) for FP measures. Steers fed the G-Rough diet had greater ( = 0.04) GP plasma protein carbonyl concentrations. During the GP, HFE steers had greater ( ≤ 0.04) protein carbonyl and ratio of oxidized:reduced blood lysate glutathione concentrations than LFE steers. There were GP diet × FE group interactions ( ≤ 0.03) during the GP and FP. During the GP, total blood lysate superoxide dismutase (SOD) activity was greater ( ≤ 0.03) in G-Rough/LFE steers than in G-Rough/HFE and G-Corn/LFE steers; G-Corn/HFE steers were intermediate. The G-Rough/LFE steers had greater ( < 0.04) glutathione peroxidase (GPX) activity than other groups and

  5. Efficacy and Limitations of Research Steering in Different Disciplines

    ERIC Educational Resources Information Center

    Seeber, Marco

    2013-01-01

    Higher education reforms informed by the managerial paradigm aim at increasing the capability of the university leadership to steer research activity, with no substantial variation across the disciplines. However, literature points out the limitations of universities to act as strategic actors, as well as the differences between the disciplines…

  6. Extracting quantum coherence via steering

    PubMed Central

    Hu, Xueyuan; Fan, Heng

    2016-01-01

    As the precious resource for quantum information processing, quantum coherence can be created remotely if the involved two sites are quantum correlated. It can be expected that the amount of coherence created should depend on the quantity of the shared quantum correlation, which is also a resource. Here, we establish an operational connection between coherence induced by steering and the quantum correlation. We find that the steering-induced coherence quantified by such as relative entropy of coherence and trace-norm of coherence is bounded from above by a known quantum correlation measure defined as the one-side measurement-induced disturbance. The condition that the upper bound saturated by the induced coherence varies for different measures of coherence. The tripartite scenario is also studied and similar conclusion can be obtained. Our results provide the operational connections between local and non-local resources in quantum information processing. PMID:27682450

  7. Driver steering dynamics measured in car simulator under a range of visibility and roadmaking conditions

    NASA Technical Reports Server (NTRS)

    Allen, R. W.; Mcruer, D. T.

    1977-01-01

    A simulation experiment was conducted to determine the effect of reduced visibility on driver lateral (steering) control. The simulator included a real car cab and a single lane road image projected on a screen six feet in front of the driver. Simulated equations of motion controlled apparent car lane position in response to driver steering actions, wind gusts, and road curvature. Six drivers experienced a range of visibility conditions at various speeds with assorted roadmaking configurations (mark and gap lengths). Driver describing functions were measured and detailed parametric model fits were determined. A pursuit model employing a road curvature feedforward was very effective in explaining driver behavior in following randomly curving roads. Sampled-data concepts were also effective in explaining the combined effects of reduced visibility and intermittent road markings on the driver's dynamic time delay. The results indicate the relative importance of various perceptual variables as the visual input to the driver's steering control process is changed.

  8. Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front

    USGS Publications Warehouse

    Sohn, M.F.; Mahan, S.A.; Knott, J.R.; Bowman, D.D.

    2007-01-01

    Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been the subjects of study, but their ages have generally eluded researchers until recently. Most mapping efforts have recognized at least four major relative-age groupings (Q1 (oldest), Q2, Q3, and Q4 (youngest)), using observed changes in surface soils and morphology, relation to the drainage net, and development of desert pavement. Obtaining numerical age determinations for these morphologic stages has proven challenging. We report the first optically stimulated luminescence (OSL) ages for three of these four stages deposited within alluvial-fans along the tectonically active Black Mountains of Death Valley. Deposits showing distinct, remnant bar and swale topography (Q3b) have OSL ages from 7 to 4 ka., whereas those with moderate to poorly developed desert pavement and located farther above the active channel (Q3a) have OSL ages from 17 to 11 ka. Geomorphically older deposits with well-developed desert pavement (Q2d) have OSL ages ???25 ka. Using this OSL-based chronology, we note that alluvial-fan deposition along this tectonically active mountain front corresponds to both wet-to-dry and dry-to-wet climate changes recorded globally and regionally. These findings underscore the influence of climate change on alluvial fan deposition in arid and semi-arid regions. ?? 2007 Elsevier Ltd and INQUA.

  9. 46 CFR 182.610 - Main steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all...

  10. 46 CFR 182.610 - Main steering gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all...

  11. 46 CFR 182.610 - Main steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all...

  12. 46 CFR 182.610 - Main steering gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all...

  13. Detecting genuine multipartite entanglement in steering scenarios

    NASA Astrophysics Data System (ADS)

    Jebaratnam, C.

    2016-05-01

    Einstein-Podolsky-Rosen (EPR) steering is a form of quantum nonlocality which is intermediate between entanglement and Bell nonlocality. EPR steering is a resource for quantum key distribution that is device independent on only one side in that it certifies bipartite entanglement when one party's device is not characterized while the other party's device is fully characterized. In this work, we introduce two types of genuine tripartite EPR steering, and derive two steering inequalities to detect them. In a semi-device-independent scenario where only the dimensions of two parties are assumed, the correlations which violate one of these inequalities also certify genuine tripartite entanglement. It is known that Alice can demonstrate bipartite EPR steering to Bob if and only if her measurement settings are incompatible. We demonstrate that quantum correlations can also detect tripartite EPR steering from Alice to Bob and Charlie, even if Charlie's measurement settings are compatible.

  14. CUMULVS: Providing fault-tolerance, visualization and steering of parallel applications

    SciTech Connect

    Geist, G.A. II; Kohl, J.A.; Papadopoulos, P.M.

    1996-09-01

    The use of visualization and computational steering can often assist scientists in analyzing large-scale scientific applications. Fault-tolerance to failures is of great importance when running on a distributed system. However, the details of implementing these features are complex and tedious, leaving many scientists with inadequate development tools. CUMULVS is a library that enables programmers to easily incorporate interactive visualization and computational steering into existing parallel programs. The library is divided into two pieces: one for the application program and one for the, possibly commercial, visualization and steering front-end. Together these two libraries encompass all the connection and data protocols needed to dynamically attach multiple independent viewer front-ends to a running parallel application. Viewer programs can also steer one or more user-defined parameters to {open_quotes}close the loop{close_quotes} for computational experiments and analyses. CUMULVS allows the programmer to specify user-directed checkpoints for saving important program state in case of failures, and also provides a mechanism to migrate tasks across heterogeneous machine architectures to achieve improved performance. Details of the CUMULVS design goals and compromises as well as future directions are given.

  15. Vehicle Steering control: A model of learning

    NASA Technical Reports Server (NTRS)

    Smiley, A.; Reid, L.; Fraser, M.

    1978-01-01

    A hierarchy of strategies were postulated to describe the process of learning steering control. Vehicle motion and steering control data were recorded for twelve novices who drove an instrumented car twice a week during and after a driver training course. Car-driver describing functions were calculated, the probable control structure determined, and the driver-alone transfer function modelled. The data suggested that the largest changes in steering control with learning were in the way the driver used the lateral position cue.

  16. Driver behavior following an automatic steering intervention.

    PubMed

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

    2015-10-01

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

  17. Classical communication cost of quantum steering

    NASA Astrophysics Data System (ADS)

    Sainz, Ana Belén; Aolita, Leandro; Brunner, Nicolas; Gallego, Rodrigo; Skrzypczyk, Paul

    2016-07-01

    Quantum steering is observed when performing appropriate local measurements on an entangled state. Here we discuss the possibility of simulating classically this effect, using classical communication instead of entanglement. We show that infinite communication is necessary for exactly simulating steering for any pure entangled state, as well as for a class of mixed entangled states. Moreover, we discuss the communication cost of steering for general entangled states, as well as approximate simulation. Our findings reveal striking differences between Bell nonlocality and steering and provide a natural way of measuring the strength of the latter.

  18. Driver behavior following an automatic steering intervention.

    PubMed

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

    2015-10-01

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

  19. Front Matter: Volume 8454

    NASA Astrophysics Data System (ADS)

    SPIE, Proceedings of

    2012-05-01

    This PDF file contains the front matter associated with SPIE Proceedings Volume 8454, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

  20. Auditory orientation in crickets: Pattern recognition controls reactive steering

    NASA Astrophysics Data System (ADS)

    Poulet, James F. A.; Hedwig, Berthold

    2005-10-01

    Many groups of insects are specialists in exploiting sensory cues to locate food resources or conspecifics. To achieve orientation, bees and ants analyze the polarization pattern of the sky, male moths orient along the females' odor plume, and cicadas, grasshoppers, and crickets use acoustic signals to locate singing conspecifics. In comparison with olfactory and visual orientation, where learning is involved, auditory processing underlying orientation in insects appears to be more hardwired and genetically determined. In each of these examples, however, orientation requires a recognition process identifying the crucial sensory pattern to interact with a localization process directing the animal's locomotor activity. Here, we characterize this interaction. Using a sensitive trackball system, we show that, during cricket auditory behavior, the recognition process that is tuned toward the species-specific song pattern controls the amplitude of auditory evoked steering responses. Females perform small reactive steering movements toward any sound patterns. Hearing the male's calling song increases the gain of auditory steering within 2-5 s, and the animals even steer toward nonattractive sound patterns inserted into the speciesspecific pattern. This gain control mechanism in the auditory-to-motor pathway allows crickets to pursue species-specific sound patterns temporarily corrupted by environmental factors and may reflect the organization of recognition and localization networks in insects. localization | phonotaxis

  1. A new model to compute the desired steering torque for steer-by-wire vehicles and driving simulators

    NASA Astrophysics Data System (ADS)

    Fankem, Steve; Müller, Steffen

    2014-05-01

    This paper deals with the control of the hand wheel actuator in steer-by-wire (SbW) vehicles and driving simulators (DSs). A novel model for the computation of the desired steering torque is presented. The introduced steering torque computation does not only aim to generate a realistic steering feel, which means that the driver should not miss the basic steering functionality of a modern conventional steering system such as an electric power steering (EPS) or hydraulic power steering (HPS), and this in every driving situation. In addition, the modular structure of the steering torque computation combined with suitably selected tuning parameters has the objective to offer a high degree of customisability of the steering feel and thus to provide each driver with his preferred steering feel in a very intuitive manner. The task and the tuning of each module are firstly described. Then, the steering torque computation is parameterised such that the steering feel of a series EPS system is reproduced. For this purpose, experiments are conducted in a hardware-in-the-loop environment where a test EPS is mounted on a steering test bench coupled with a vehicle simulator and parameter identification techniques are applied. Subsequently, how appropriate the steering torque computation mimics the test EPS system is objectively evaluated with respect to criteria concerning the steering torque level and gradient, the feedback behaviour and the steering return ability. Finally, the intuitive tuning of the modular steering torque computation is demonstrated for deriving a sportier steering feel configuration.

  2. 46 CFR 169.251 - Steering apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Steering apparatus. 169.251 Section 169.251 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Inspections § 169.251 Steering apparatus. At each inspection for...

  3. 46 CFR 169.251 - Steering apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Steering apparatus. 169.251 Section 169.251 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Inspections § 169.251 Steering apparatus. At each inspection for...

  4. 46 CFR 169.251 - Steering apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Steering apparatus. 169.251 Section 169.251 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Inspections § 169.251 Steering apparatus. At each inspection for...

  5. 46 CFR 176.814 - Steering systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in suitable condition and fit for the service intended. Servo-type power systems, such as orbital... 46 Shipping 7 2011-10-01 2011-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST...) INSPECTION AND CERTIFICATION Material Inspections § 176.814 Steering systems. At each initial and...

  6. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and... 46 Shipping 4 2010-10-01 2010-10-01 false Steering systems. 115.814 Section 115.814 Shipping COAST... Inspections § 115.814 Steering systems. At each initial and subsequent inspection for certification the...

  7. 46 CFR 176.814 - Steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in suitable condition and fit for the service intended. Servo-type power systems, such as orbital... 46 Shipping 7 2010-10-01 2010-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST...) INSPECTION AND CERTIFICATION Material Inspections § 176.814 Steering systems. At each initial and...

  8. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and... 46 Shipping 4 2011-10-01 2011-10-01 false Steering systems. 115.814 Section 115.814 Shipping COAST... Inspections § 115.814 Steering systems. At each initial and subsequent inspection for certification the...

  9. A practical toolkit for computational steering.

    PubMed

    Pickles, S M; Haines, R; Pinning, R L; Porter, A R

    2005-08-15

    Computational steering refers to the real-time interaction of a scientist with their running simulation code. Despite the many benefits associated with computational steering, its uptake to date has been limited. In this paper we discuss the reasons for this and how the computational steering library and associated tools developed as part of the RealityGrid project aim to tackle them. We describe the functionality of the steering library and the use of Grid services in constructing a generic, dynamic architecture for discovering, steering and connecting visualization software to running simulations. The use of on-line visualization for providing feedback to the scientist is described, including the ways in which it may be enhanced through tools such as Chromium and Access Grid. Finally, we illustrate the flexibility of our approach by describing the functionality that has been added to various simulation codes as part of the RealityGrid project.

  10. Quantifying Non-Markovianity with Temporal Steering.

    PubMed

    Chen, Shin-Liang; Lambert, Neill; Li, Che-Ming; Miranowicz, Adam; Chen, Yueh-Nan; Nori, Franco

    2016-01-15

    Einstein-Podolsky-Rosen (EPR) steering is a type of quantum correlation which allows one to remotely prepare, or steer, the state of a distant quantum system. While EPR steering can be thought of as a purely spatial correlation, there does exist a temporal analogue, in the form of single-system temporal steering. However, a precise quantification of such temporal steering has been lacking. Here, we show that it can be measured, via semidefinite programing, with a temporal steerable weight, in direct analogy to the recently proposed EPR steerable weight. We find a useful property of the temporal steerable weight in that it is a nonincreasing function under completely positive trace-preserving maps and can be used to define a sufficient and practical measure of strong non-Markovianity. PMID:26824533

  11. Steering control system for a mobile robot

    NASA Astrophysics Data System (ADS)

    Kolli, Kaylan C.; Hall, Ernest L.

    1997-09-01

    Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe the design of a steering mechanism for an autonomous mobile robot. The steering mechanism replaces a manually turned rack and pinion arrangement with a crank mechanism driven by a linear actuator that in turn is powered by a brushless dc motor. The system was modeled, analyzed, and redesigned to meet the requirements. A 486 computer through a 3-axis motion controller supervises the steering control. The steering motor is a brushless dc motor powered by three phase signals. It is run in current loop mode. The steering control system is supervised by a personal computer through a multi-axis motion controller. Testing of these systems has been done in the lab as well as on an outside test track with positive results.

  12. Investigation of Motorcycle Steering Torque Components

    NASA Astrophysics Data System (ADS)

    Cossalter, V.; Lot, R.; Massaro, M.; Peretto, M.

    2011-10-01

    When driving along a circular path, the rider controls a motorcycle mainly by the steering torque. This work addresses an in-depth analysis of the steady state cornering and in particular the decomposition of the motorcycle steering torque in its main components, such as road-tyre forces, gyroscopic torques, centrifugal and gravity effects. A detailed and experimentally validated multibody model of the motorcycle is used herein to analyze the steering torque components at different speeds and lateral accelerations. First the road tests are compared with the numerical results for three different vehicles and then a numerical investigation is carried out to decompose the steering torque. Finally, the effect of longitudinal acceleration and deceleration on steering torque components is presented.

  13. Negative Ion Density Fronts

    SciTech Connect

    Igor Kaganovich

    2000-12-18

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

  14. Electronically-Controlled Beam-Steering through Vanadium Dioxide Metasurfaces

    NASA Astrophysics Data System (ADS)

    Hashemi, Mohammed Reza M.; Yang, Shang-Hua; Wang, Tongyu; Sepúlveda, Nelson; Jarrahi, Mona

    2016-10-01

    Engineered metamaterials offer unique functionalities for manipulating the spectral and spatial properties of electromagnetic waves in unconventional ways. Here, we report a novel approach for making reconfigurable metasurfaces capable of deflecting electromagnetic waves in an electronically controllable fashion. This is accomplished by tilting the phase front of waves through a two-dimensional array of resonant metasurface unit-cells with electronically-controlled phase-change materials embedded inside. Such metasurfaces can be placed at the output facet of any electromagnetic radiation source to deflect electromagnetic waves at a desired frequency, ranging from millimeter-wave to far-infrared frequencies. Our design does not use any mechanical elements, external light sources, or reflectarrays, creating, for the first time, a highly robust and fully-integrated beam-steering device solution. We demonstrate a proof-of-concept beam-steering metasurface optimized for operation at 100 GHz, offering up to 44° beam deflection in both horizontal and vertical directions. Dynamic control of electromagnetic wave propagation direction through this unique platform could be transformative for various imaging, sensing, and communication applications, among others.

  15. Electronically-Controlled Beam-Steering through Vanadium Dioxide Metasurfaces

    PubMed Central

    Hashemi, Mohammed Reza M.; Yang, Shang-Hua; Wang, Tongyu; Sepúlveda, Nelson; Jarrahi, Mona

    2016-01-01

    Engineered metamaterials offer unique functionalities for manipulating the spectral and spatial properties of electromagnetic waves in unconventional ways. Here, we report a novel approach for making reconfigurable metasurfaces capable of deflecting electromagnetic waves in an electronically controllable fashion. This is accomplished by tilting the phase front of waves through a two-dimensional array of resonant metasurface unit-cells with electronically-controlled phase-change materials embedded inside. Such metasurfaces can be placed at the output facet of any electromagnetic radiation source to deflect electromagnetic waves at a desired frequency, ranging from millimeter-wave to far-infrared frequencies. Our design does not use any mechanical elements, external light sources, or reflectarrays, creating, for the first time, a highly robust and fully-integrated beam-steering device solution. We demonstrate a proof-of-concept beam-steering metasurface optimized for operation at 100 GHz, offering up to 44° beam deflection in both horizontal and vertical directions. Dynamic control of electromagnetic wave propagation direction through this unique platform could be transformative for various imaging, sensing, and communication applications, among others. PMID:27739471

  16. Trip report, Interagency Manufacturing Operations Group (IMOG) Steering Committee meeting, November 29, 1989

    SciTech Connect

    Butterworth, R.R.

    1989-12-06

    As the Subgroup Chairman for the Process Automation Control Technology Subgroup of IMOG, I was requested to attend the annual Steering Committee Meeting held this year at the Allied-Signal Kansas City Plant and summarize the past year's activities of the Subgroup. The next IMOG Steering Committee Meeting will be held November 14 and 15, 1990 in Los Alamos. The next Process Automation Control Technology Subgroup Meeting will be held in June, 1990 in Rocky Flats.

  17. Observation and interpretation of thermal instabilities at the front face of actively cooled limiters in TORE-SUPRA

    SciTech Connect

    Guilhem, D.; Hogan, J.T.; Mitteau, R.; Phillips, V.

    1995-12-01

    In TORE-SUPRA, actively cooled modular limiters (time constant = 2 s) covered with carbon have been used to exhaust the convective heat flux continuously up to 700 kW steady state (design value) without thermal instability, i.e., 4.5 MW/m{sup 2} on average. Steady state surface temperatures in the range 600 C (with 1.45 MW of Lower Hybrid waves) were routinely obtained. However, sudden surface temperature excursions from 600 C to 1,900 C, called ``super-brilliances``, were observed during ohmic or heated plasmas, taking place locally over 20 ms, which led to a new equilibrium. This new equilibrium correspond to a local increased power flux density to the limiter as confirmed by calorimetric measurements. Shot after shot, an increasing number of independent overheated zones (up to 4) were observed on the limiter ridge, the closest location to Last Closed Flux Surface (LCFS). The power extracted by the limiter then was {approximately} 1.1 MW (6.9 MW/m{sup 2} average and 15 MW/m{sup 2} maximum). Experimental data and possible mechanisms leading to a finite increased heat flux to the limiter surface are reviewed and comparisons with modelization are made.

  18. Effects of fluctuations on propagating fronts

    NASA Astrophysics Data System (ADS)

    Panja, Debabrata

    Propagating fronts are seen in varieties of nonequilibrium pattern forming systems in Physics, Chemistry and Biology. In the last two decades, many researchers have contributed to the understanding of the underlying dynamics of the propagating fronts. Of these, the deterministic and mean-field dynamics of the fronts were mostly understood in late 1980s and 1990s. On the other hand, although the earliest work on the effect of fluctuations on propagating fronts dates back to early 1980s, the subject of fluctuating fronts did not reach its adolescence until the mid 1990s. From there onwards the last few years witnessed a surge in activities in the effect of fluctuations on propagating fronts. Scores of papers have been written on this subject since then, contributing to a significant maturity of our understanding, and only recently a full picture of fluctuating fronts has started to emerge. This review is an attempt to collect all the works on fluctuating (propagating) fronts in a coherent and cogent manner in proper perspective. It is based on the idea of making our knowledge in this field available to a broader audience, and it is also expected to help to collect bits and pieces of loose thread-ends together for possible further investigation.

  19. Role of prokaryotic biomasses and activities in carbon and phosphorus cycles at a coastal, thermohaline front and in offshore waters (Gulf of Manfredonia, Southern Adriatic Sea).

    PubMed

    Monticelli, L S; Caruso, G; Decembrini, F; Caroppo, C; Fiesoletti, F

    2014-04-01

    The Western areas of the Adriatic Sea are subjected to inputs of inorganic nutrients and organic matter that can modify the trophic status of the waters and consequently, the microbiological processes involved in the carbon and phosphorus biogeochemical cycles, particularly in shallow coastal environments. To explore this topic, a survey was carried out during the spring of 2003 in a particular hydrodynamic area of the Gulf of Manfredonia, where the potential (P) and real (R) rates of four different microbial exoenzymatic activities (EEA) (α [αG] and ß glucosidases [ßG], leucine aminopeptidase [LAP], and alkaline phosphatase [AP]) as well as the P and R rates of prokaryotic heterotrophic production (PHP), AP as well as the P and R rates of PHP, primary production (PPnet), the prokaryotic and phototrophic stocks and basic hydrological parameters were examined. Three different water masses were found, with a thermohaline front (THF) being detected between the warmer and less saline coastal waters and colder and saltier offshore Adriatic waters. Under the general oligotrophic conditions of the entire Gulf, a decreasing gradient from the coastal toward the offshore areas was detected, with PHP, PPnet, stocks and EEA (αG, ßG, AP) being directly correlated with the temperature and inversely correlated with the salinity, whereas opposite relationships were observed for LAP activity. No enhancement of microbiological activities or stocks was observed at the THF. The use of P or R rates of microbiological activities, which decrease particularly for EEA, could result in discrepancies in interpreting the efficiency of several metabolic processes.

  20. Highly sensitive beam steering with plasmonic antenna

    PubMed Central

    Rui, Guanghao; Zhan, Qiwen

    2014-01-01

    In this work, we design and study a highly sensitive beam steering device that integrates a spiral plasmonic antenna with a subwavelength metallic waveguide. The short effective wavelength of the surface plasmon polaritons (SPPs) mode supported by the metallic waveguide is exploited to dramatically miniaturize the device and improve the sensitivity of the beam steering. Through introducing a tiny displacement of feed point with respect to the geometrical center of the spiral plasmonic antenna, the direction of the radiation can be steered at considerably high angles. Simulation results show that steering angles of 8°, 17° and 34° are obtainable for a displacement of 50 nm, 100 nm and 200 nm, respectively. Benefiting from the reduced device size and the shorter SPP wavelength, the beam steering sensitivity of the beam steering is improved by 10-fold compared with the case reported previously. This miniature plasmonic beam steering device may find many potential applications in quantum optical information processing and integrated photonic circuits. PMID:25091405

  1. MRTF-A steers an epigenetic complex to activate endothelin-induced pro-inflammatory transcription in vascular smooth muscle cells

    PubMed Central

    Yang, Yuyu; Cheng, Xian; Tian, Wenfang; Zhou, Bisheng; Wu, Xiaoyan; Xu, Huihui; Fang, Fei; Fang, Mingming; Xu, Yong

    2014-01-01

    Endothelin (ET-1) was initially identified as a potent vasoconstrictor contributing to the maintenance of vascular rhythm. Later studies have implicated ET-1, when aberrantly up-regulated within the vasculature, in a range of human pathologies associated with disruption of vascular homeostasis. ET-1 has been shown to invoke strong pro-inflammatory response in vascular smooth muscle cells (VSMCs); the underlying mechanism, however, remains elusive. Here, we report that the transcriptional modulator MRTF-A mediates the activation of pro-inflammatory mediators by ET-1 in VSMCs. ET-1 increased nuclear enrichment and activity of MRTF-A in cultured VSMCs. MRTF-A silencing attenuated ET-1 induced synthesis and release of pro-inflammatory mediators including IL-6, MCP-1 and IL-1 likely as a result of diminished NF-κB activity. In addition, MRTF-A was indispensible for the accumulation of active histone modifications on the gene promoters. Of intrigue, MRTF-A interacted with and recruited ASH2, a component of the mammalian histone methyltransferase complex, to transactivate pro-inflammatory genes in response to ET-1 treatment. The chromatin remodeling proteins BRG1 and BRM were also required for ET-1-dependent induction of pro-inflammatory mediators by communicating with ASH2, a process dependent on MRTF-A. In conclusion, our data have identified a novel epigenetic complex responsible for vascular inflammation inflicted by ET-1. PMID:25159611

  2. Beam Steering Devices Reduce Payload Weight

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Scientists have long been able to shift the direction of a laser beam, steering it toward a target, but often the strength and focus of the light is altered. For precision applications, where the quality of the beam cannot be compromised, scientists have typically turned to mechanical steering methods, redirecting the source of the beam by swinging the entire laser apparatus toward the target. Just as the mechanical methods used for turning cars has evolved into simpler, lighter, power steering methods, so has the means by which researchers can direct lasers. Some of the typical contraptions used to redirect lasers are large and bulky, relying on steering gimbals pivoted, rotating supports to shift the device toward its intended target. These devices, some as large and awkward as a piece of heavy luggage, are subject to the same issues confronted by mechanical parts: Components rub, wear out, and get stuck. The poor reliability and bulk not to mention the power requirements to run one of the machines have made mechanical beam steering components less than ideal for use in applications where weight, bulk, and maneuverability are prime concerns, such as on an unmanned aerial vehicle (UAV) or a microscope. The solution to developing reliable, lighter weight, nonmechanical steering methods to replace the hefty steering boxes was to think outside the box, and a NASA research partner did just that by developing a new beam steering method that bends and redirects the beam, as opposed to shifting the entire apparatus. The benefits include lower power requirements, a smaller footprint, reduced weight, and better control and flexibility in steering capabilities. Such benefits are realized without sacrificing aperture size, efficiency, or scanning range, and can be applied to myriad uses: propulsion systems, structures, radiation protection systems, and landing systems.

  3. Simulation Training in Early Emergency Response (STEER).

    PubMed

    Generoso, Jose Roberto; Latoures, Renee Elizabeth; Acar, Yahya; Miller, Dean Scott; Ciano, Mark; Sandrei, Renan; Vieira, Marlon; Luong, Sean; Hirsch, Jan; Fidler, Richard Lee

    2016-06-01

    HOW TO OBTAIN CONTACT HOURS BY READING THIS ISSUE Instructions: 1.3 contact hours will be awarded by Villanova University College of Nursing upon successful completion of this activity. A contact hour is a unit of measurement that denotes 60 minutes of an organized learning activity. This is a learner-based activity. Villanova University College of Nursing does not require submission of your answers to the quiz. A contact hour certificate will be awarded after you register, pay the registration fee, and complete the evaluation form online at http://goo.gl/gMfXaf. In order to obtain contact hours you must: 1. Read the article, "Simulation Training in Early Emergency Response (STEER)," found on pages 255-263, carefully noting any tables and other illustrative materials that are included to enhance your knowledge and understanding of the content. Be sure to keep track of the amount of time (number of minutes) you spend reading the article and completing the quiz. 2. Read and answer each question on the quiz. After completing all of the questions, compare your answers to those provided within this issue. If you have incorrect answers, return to the article for further study. 3. Go to the Villanova website to register for contact hour credit. You will be asked to provide your name, contact information, and a VISA, MasterCard, or Discover card number for payment of the $20.00 fee. Once you complete the online evaluation, a certificate will be automatically generated. This activity is valid for continuing education credit until May 31, 2019. CONTACT HOURS This activity is co-provided by Villanova University College of Nursing and SLACK Incorporated. Villanova University College of Nursing is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation. OBJECTIVES Define the purpose of the Simulation Training in Early Emergency Response (STEER) study. Review the outcome of the STEER study. DISCLOSURE

  4. Automated beam steering using optimal control

    SciTech Connect

    Allen, C. K.

    2004-01-01

    We present a steering algorithm which, with the aid of a model, allows the user to specify beam behavior throughout a beamline, rather than just at specified beam position monitor (BPM) locations. The model is used primarily to compute the values of the beam phase vectors from BPM measurements, and to define cost functions that describe the steering objectives. The steering problem is formulated as constrained optimization problem; however, by applying optimal control theory we can reduce it to an unconstrained optimization whose dimension is the number of control signals.

  5. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  6. 46 CFR 108.641 - Instructions for changing steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  7. 46 CFR 108.641 - Instructions for changing steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  8. 46 CFR 108.641 - Instructions for changing steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  9. Digital Controller For Laser-Beam-Steering Subsystem: Part 2

    NASA Technical Reports Server (NTRS)

    Ansari, Homayoon; Voisinet, Leeann

    1995-01-01

    A report presents additional information about laser-beam-steering apparatus described in "Digital Controller for Laser-Beam-Steering Subsystem" (NPO-19193) and "More About Beam-Steering Subsystem for Laser Communication" (NPO-19381). Reiterates basic principles of operation of beam-steering subsystem, with emphasis on modes of operation, basic design concepts, and initial experiments on partial prototype of apparatus.

  10. 49 CFR 393.209 - Steering wheel systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Steering wheel systems. 393.209 Section 393.209... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems § 393.209 Steering wheel systems. (a) The steering wheel shall be secured and must not have any...

  11. 49 CFR 393.209 - Steering wheel systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Steering wheel systems. 393.209 Section 393.209... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems § 393.209 Steering wheel systems. (a) The steering wheel shall be secured and must not have any...

  12. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  13. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  14. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  15. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  16. LUMINOSITY OPTIMIZATION USING AUTOMATED IR STEERING AT RHIC.

    SciTech Connect

    DREES,A.D'OTTAVIO,T.

    2004-07-05

    The goal of the RHIC 2004 Au-Au run was to maximize the achieved integrated luminosity. One way is to increase beam currents and minimize beam transverse emittances. Another important ingredient is the minimization of time spent on activities postponing the declaration of ''physics conditions'', i.e. stable beam conditions allowing the experimental detectors to take data. Since collision rates are particularly high in the beginning of the store the integrated luminosity benefits considerably from any minute saved early in the store. In the RHIC run 2004 a new IR steering application uses luminosity monitor signals as a feedback for a fully automated steering procedure. This report gives an overview of the used procedure and summarizes the achieved results.

  17. 46 CFR 176.814 - Steering systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS... hydraulic pumps secured....

  18. 46 CFR 176.814 - Steering systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS... hydraulic pumps secured....

  19. 46 CFR 176.814 - Steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS... hydraulic pumps secured....

  20. Laboratory experiments on fronts

    NASA Astrophysics Data System (ADS)

    Chia, F.; Griffiths, R. W.; Linden, P. F.

    We describe a laboratory model of an upwelling front in a two-layer stratification. In the model the interface between the two layers slopes upwards toward a vertical boundary (or coastline) and can intersect the free surface to produce a front. Fluid motion in each layer is density driven and, in the undisturbed state, is in quasi-geostrophic balance. The front is observed to be unstable to (ageostrophic) disturbances with an along-front wavelength proportional to the Rossby radius of deformation. At very large amplitudes these unstable waves form closed circulations. However, in contrast to the behaviour of fronts far from vertical boundaries, where cyclone-anticyclone vortex pairs are formed, the presence of the coastline inhibits formation of anticyclonic eddies in the upper layer and enhances cyclonic rings of upper layer fluid which lie above cyclonic eddies in the lower layer. The cyclones move away from the vertical boundary and (as is also the case when no vertical boundary is present) they appear at the surface as eddies containing lower layer fluid on the seaward side of the mean frontal position.

  1. Daidzein enhances intramuscular fat deposition and improves meat quality in finishing steers

    PubMed Central

    Zhao, Xiang-Hui; Yang, Zhu-Qing; Bao, Lin-Bin; Wang, Can-Yu; -Zhou, Shan; Gong, Jian-Ming; Fu, Chuan-Bian; Xu, Lan-Jiao; Liu, Chan-Juan

    2015-01-01

    An experiment was conducted to determine the effects of soy isoflavone daidzein on carcass characteristics, fat deposition, meat quality, and blood metabolites in finishing steers. Fourteen crossbred steers were used in a 120-d finishing study. These steers were stratified by weight into groups and randomly allotted by group to one of two dietary treatments: (1) control and (2) daidzein (500 mg/kg concentrate). The steers were fed a 90% concentrate diet. Supplemental daidzein did not affect slaughter weight, hot carcass weight, and dressing percentage, but tended to reduce fat proportion (not including intramuscular fat) in carcass and backfat thickness of steers. The carcass bone proportion was greater in steers fed daidzein diets than those fed control diets. Daidzein supplementation reduced pH at 24 h after slaughtered and moisture content and increased isocitrate dehydrogenase activity, fat content (16.28% and 7.94%), marbling score (5.29 and 3.36), redness (a*), and chroma (C*) values in longissimus muscle relative to control treatment. The concentrations of blood metabolites including glucose, blood urea nitrogen, triglyceride, total cholesterol, non-esterified fatty acid, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were all lower in steers fed daidzein diets than those fed control diets. Current results suggest that supplemental daidzein can affect lipid metabolism, increase intramuscular fat content and marbling score, and improve meat quality in finishing steers. Daidzein should be a promising feed additive for production of high-quality beef meat. PMID:25526906

  2. Daidzein enhances intramuscular fat deposition and improves meat quality in finishing steers.

    PubMed

    Zhao, Xiang-Hui; Yang, Zhu-Qing; Bao, Lin-Bin; Wang, Can-Yu; -Zhou, Shan; Gong, Jian-Ming; Fu, Chuan-Bian; Xu, Lan-Jiao; Liu, Chan-Juan; Qu, Mingren

    2015-09-01

    An experiment was conducted to determine the effects of soy isoflavone daidzein on carcass characteristics, fat deposition, meat quality, and blood metabolites in finishing steers. Fourteen crossbred steers were used in a 120-d finishing study. These steers were stratified by weight into groups and randomly allotted by group to one of two dietary treatments: (1) control and (2) daidzein (500 mg/kg concentrate). The steers were fed a 90% concentrate diet. Supplemental daidzein did not affect slaughter weight, hot carcass weight, and dressing percentage, but tended to reduce fat proportion (not including intramuscular fat) in carcass and backfat thickness of steers. The carcass bone proportion was greater in steers fed daidzein diets than those fed control diets. Daidzein supplementation reduced pH at 24 h after slaughtered and moisture content and increased isocitrate dehydrogenase activity, fat content (16.28% and 7.94%), marbling score (5.29 and 3.36), redness (a*), and chroma (C*) values in longissimus muscle relative to control treatment. The concentrations of blood metabolites including glucose, blood urea nitrogen, triglyceride, total cholesterol, non-esterified fatty acid, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were all lower in steers fed daidzein diets than those fed control diets. Current results suggest that supplemental daidzein can affect lipid metabolism, increase intramuscular fat content and marbling score, and improve meat quality in finishing steers. Daidzein should be a promising feed additive for production of high-quality beef meat.

  3. Multipass Steering: A Reference Implementation

    NASA Astrophysics Data System (ADS)

    Hennessey, Michael; Tiefenback, Michael

    2015-10-01

    We introduce a reference implementation of a protocol to compute corrections that bring all beams in one of the CEBAF linear accelerators (linac) to axis, including, with a larger tolerance, the lowest energy pass using measured beam trajectory data. This method relies on linear optics as representation of the system; we treat beamline perturbations as magnetic field errors localized to regions between cryomodules, providing the same transverse momentum kick to each beam. We produce a vector of measured beam position data with which we left-multiply the pseudo-inverse of a coefficient array, A, that describes the transport of the beam through the linac using parameters that include the magnetic offsets of the quadrupole magnets, the instrumental offsets of the BPMs, and the beam initial conditions. This process is repeated using a reduced array to produce values that can be applied to the available correcting magnets and beam initial conditions. We show that this method is effective in steering the beam to a straight axis along the linac by using our values in elegant, the accelerator simulation program, on a model of the linac in question. The algorithms in this reference implementation provide a tool for systematic diagnosis and cataloging of perturbations in the beam line. Supported by Jefferson Lab, Old Dominion University, NSF, DOE.

  4. Liquid Crystal-Based Beam Steering Device Development for NASA Applications

    NASA Technical Reports Server (NTRS)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip; Lavrentovich, Oleg; Wang, Xinghua

    2004-01-01

    The NASA Computing, Information and Communications Technology (CICT) Program is supporting the development of liquid crystal-based beam steering devices. The device would use inexpensive, light-weight, optical components, and it would have the following capabilities: electronic beam scanning to angles above 1 milliradian, and submicroradian beam pointing accuracy. In order to correct for the imperfections resulting from the space-deployable optics, the technique of wave-front correction would be implemented. Hence, the output beam quality would be maintained. The potential applications could include satellite tracking, near-Earth inter-satellite communications, deep-space communications, and optical phased array systems. The status of the beam steering device development based on the liquid crystal technology and its relationship to prospective NASA mission scenarios will be described.

  5. View aft of compartment D23, aft steering station; note steering ...

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

    View aft of compartment D-23, aft steering station; note steering unit with crosshead and shaft bearing supports. Note framing supports for armored protective deck at top of photo. (p60) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  6. Front Range Branch Officers

    NASA Astrophysics Data System (ADS)

    The Front Range Branch of AGU has installed officers for 1990: Ray Noble, National Center for Atmospheric Research, chair; Sherry Oaks, U.S. Geological Survey, chair-elect; Howard Garcia, NOAA, treasurer; Catharine Skokan, Colorado School of Mines, secretary. JoAnn Joselyn of NOAA is past chair. Members at large are Wallace Campbell, NOAA; William Neff, USGS; and Stephen Schneider, NCAR.

  7. Nanoparticle Oscillations and Fronts

    SciTech Connect

    Lagzi, Istvan; Kowalczyk, Bartlomiej; Wang, Dawei; Grzybowski, Bartosz A.

    2010-09-30

    Chemical oscillations can be coupled to the dynamic self-assembly of nanoparticles. Periodic pH changes translate into protonation and deprotonation of the ligands that stabilize the nanoparticles, thus altering repulsive and attractive interparticle forces. In a continuous stirred-tank reactor, rhythmic aggregation and dispersion is observed; in spatially distributed media, propagation of particle aggregation fronts is seen.

  8. Metamaterial Huygens' Surfaces: Tailoring Wave Fronts with Reflectionless Sheets

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Carl; Grbic, Anthony

    2013-05-01

    Huygens’ principle is a well-known concept in electromagnetics that dates back to 1690. Here, it is applied to develop designer surfaces that provide extreme control of electromagnetic wave fronts across electrically thin layers. These reflectionless surfaces, referred to as metamaterial Huygens’ surfaces, provide new beam shaping, steering, and focusing capabilities. The metamaterial Huygens’ surfaces are realized with two-dimensional arrays of polarizable particles that provide both electric and magnetic polarization currents to generate prescribed wave fronts. A straightforward design methodology is demonstrated and applied to develop a beam-refracting surface and a Gaussian-to-Bessel beam transformer. Metamaterial Huygens’ surfaces could find a wide range of applications over the entire electromagnetic spectrum including single-surface lenses, polarization controlling devices, stealth technologies, and perfect absorbers.

  9. Metamaterial Huygens' surfaces: tailoring wave fronts with reflectionless sheets.

    PubMed

    Pfeiffer, Carl; Grbic, Anthony

    2013-05-10

    Huygens' principle is a well-known concept in electromagnetics that dates back to 1690. Here, it is applied to develop designer surfaces that provide extreme control of electromagnetic wave fronts across electrically thin layers. These reflectionless surfaces, referred to as metamaterial Huygens' surfaces, provide new beam shaping, steering, and focusing capabilities. The metamaterial Huygens' surfaces are realized with two-dimensional arrays of polarizable particles that provide both electric and magnetic polarization currents to generate prescribed wave fronts. A straightforward design methodology is demonstrated and applied to develop a beam-refracting surface and a Gaussian-to-Bessel beam transformer. Metamaterial Huygens' surfaces could find a wide range of applications over the entire electromagnetic spectrum including single-surface lenses, polarization controlling devices, stealth technologies, and perfect absorbers. PMID:23705738

  10. Proposal to use vibration analysis steering components and car body to monitor, for example, the state of unbalance wheel

    NASA Astrophysics Data System (ADS)

    Janczur, R.

    2016-09-01

    The results of road tests of car VW Passat equipped with tires of size 195/65 R15, on the influence of the unbalancing front wheel on vibration of the parts of steering system, steering wheel and the body of the vehicle have been presented in this paper. Unbalances wheels made using weights of different masses, placed close to the outer edge of the steel rim and checked on the machine Hunter GSP 9700 for balancing wheels. The recorded waveforms vibration steering components and car body, at different constant driving speeds, subjected to spectral analysis to determine the possibility of isolating vibration caused by unbalanced wheel in various states and coming from good quality asphalt road surface. The results were discussed in terms of the possibility of identifying the state of unbalancing wheels and possible changes in radial stiffness of the tire vibration transmitted through the system driving wheel on the steering wheel. Vibration analysis steering components and car body, also in the longitudinal direction, including information from the CAN bus of the state of motion of the car, can be used to monitor the development of the state of unbalance wheel, tire damage or errors shape of brake discs or brake drums, causing pulsations braking forces.

  11. 9. DETAIL OF INTERIOR OF FRONT PORCH SHOWING FRONT ENTRY ...

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

    9. DETAIL OF INTERIOR OF FRONT PORCH SHOWING FRONT ENTRY (LEFT) AND BLANK WALL (CENTER) CORRESPONDING TO LOCATION OF INTERIOR VAULTS. VIEW TO SOUTHEAST. - Boise Project, Boise Project Office, 214 Broadway, Boise, Ada County, ID

  12. 35. EAST FRONT OF POWERHOUSE AND CAR BARN: East front ...

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

    35. EAST FRONT OF POWERHOUSE AND CAR BARN: East front of powerhouse and car barn. 'Annex' is right end of building. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  13. 4. BARRACKS, WITH PARKING LOT IN FRONT, FRONT AND RIGHT ...

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

    4. BARRACKS, WITH PARKING LOT IN FRONT, FRONT AND RIGHT SIDES, LOOKING SOUTH. - NIKE Missile Base SL-40, Barracks No. 2, North end of base, southeast of Barracks No. 1 & northeast of Mess Hall, Hecker, Monroe County, IL

  14. 1. BARRACKS, WITH PARKING LOT IN FRONT, FRONT, LOOKING SOUTHWEST. ...

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

    1. BARRACKS, WITH PARKING LOT IN FRONT, FRONT, LOOKING SOUTHWEST. - NIKE Missile Base SL-40, Barracks No. 2, North end of base, southeast of Barracks No. 1 & northeast of Mess Hall, Hecker, Monroe County, IL

  15. 3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side ...

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

    3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side elevation. Note gasoline sign post added. Flush store window not altered, 1900 clapboard siding and panelling remaining. - 510 Central Avenue (Commercial Building), Ridgely, Caroline County, MD

  16. Event-related alpha perturbations related to the scaling of steering wheel corrections.

    PubMed

    Brooks, Justin; Kerick, Scott

    2015-10-01

    Previously we derived a new measure relating the driver's steering wheel responses to the vehicle's heading error velocity. This measure, the relative steering wheel compensation (RSWC), changes at times coincident with an alerting stimulus, possibly representing shifts in control strategy as measured by a change in the gain between visual input and motor output. In the present study, we sought to further validate this novel measure by determining the relationship between the RSWC and electroencephalogram (EEG) activity in brain regions associated with sensorimotor transformation processes. These areas have been shown to exhibit event-related spectral perturbation (ERSP) in the alpha frequency band that occurs with the onset of corrective steering wheel maneuvers in response to vehicle perturbations. We hypothesized that these regions would show differential alpha activity depending on whether the RSWC was high or low, reflecting changes in gain between visual input and motor output. Interestingly, we find that low RSWC is associated with significantly less peak desynchronization than larger RSWC. In addition we demonstrate that these differences are not attributable to the amount the steering wheel is turned nor the heading error velocity independently. Collectively these results suggest that neural activity in these sensorimotor regions scales with alertness and may represent differential utilization of multisensory information to control the steering wheel.

  17. Role of thermal noise in tripartite quantum steering

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Gong, Qihuang; Ficek, Zbigniew; He, Qiongyi

    2014-08-01

    The influence of thermal noise on bipartite and tripartite quantum steering induced by a short laser pulse in a hybrid three-mode optomechanical system is investigated. The calculation is carried out under the bad cavity limit, the adiabatic approximation of a slowly varying amplitude of the cavity mode, and with the assumption of driving the cavity mode with a blue detuned strong laser pulse. Under such conditions, explicit expressions of the bipartite and tripartite steering parameters are obtained, and the concept of collective tripartite quantum steering, recently introduced by He and Reid [Phys. Rev. Lett. 111, 250403 (2013), 10.1103/PhysRevLett.111.250403], is clearly explored. It is found that both bipartite and tripartite steering parameters are sensitive functions of the initial state of the modes and distinctly different steering behavior could be observed depending on whether the modes were initially in a thermal state or not. For the modes initially in a vacuum state, the bipartite and tripartite steering occur simultaneously over the entire interaction time. This indicates that collective tripartite steering cannot be achieved. The collective steering can be achieved for the modes initially prepared in a thermal state. We find that the initial thermal noise is more effective in destroying the bipartite rather than the tripartite steering which, on the other hand, can persist even for a large thermal noise. For the initial vacuum state of a steered mode, the tripartite steering exists over the entire interaction time even if the steering modes are in very noisy thermal states. When the steered mode is initially in a thermal state, it can be collectively steered by the other modes. There are thresholds for the average number of the thermal photons above which the existing tripartite steering appears as the collective steering. Finally, we point out that the collective steering may provide a resource in a hybrid quantum network for quantum secret sharing

  18. Data transfer through beam steering using agile lensing

    NASA Astrophysics Data System (ADS)

    Arshad, Muhammad Assad; Reza, Syed Azer; Muhammad, Ahsan

    2016-04-01

    This paper presents a data transfer scheme using multi-focus tunable lenses. The design involves the use of a standard laser source and a variable focus agile lens to steer to the laser beam that passes through the lens. In our proposed system, the beam steer angle depends on an input electrical signal which drives the tunable lens. Therefore the beam steer angle is made to follow the variations in the input electrical drive signal. This is extremely interesting for data transfer applications as the data signal can be used as the input drive signal to the lens. The laser beam is steered according to the input data voltage levels and when the beam is incident on a photo-detector of a finite size, only a fraction of its total incident optical power is received by the photo-detector. This power contribution is proportional to the fraction of the total number of photons per unit area which are incident on the active area of the detector. The remaining photons which are not incident on the photo-detector do not contribute to the received power at the photo-detector. We present the theory of beam steering through a tunable lens and present a theoretical framework which governs data transfer through the proposed method. We also present the transfer function of the proposed system which helps us to calculate its essential theoretical performance parameters such as modulation depth and bit error rates. We also present experimental results to demonstrate efficient data transfer through the proposed method. As tunable lenses are primarily deployed in motion-free multi-focus cameras hence most of the modern portable devices such as cellphones and tablets use these lenses to operate the in-built variable focus cameras that are part of these devices. Because tunable lenses are commonly present in several different portable devices, the proposed method of data transfer between two devices is highly promising as it expands the use of the already deployed tunable lenses with

  19. ARIEL front end

    NASA Astrophysics Data System (ADS)

    Marchetto, M.; Baartman, R. A.; Laxdal, R. E.

    2014-01-01

    The ARIEL project at TRIUMF will greatly expand the variety and availability of radioactive ion beams (RIBs) (Laxdal, Nucl Inst Methods Phys Res B 204:400-409, 2003). The ARIEL front end connects the two ARIEL target stations to the existing ISAC facility to expand delivery to two and eventually three simultaneous RIB beams with up to two simultaneous accelerated beams (Laxdal et al. 2008). The low-energy beam transport lines and mass separators are designed for maximum flexibility to allow a variety of operational modes in order to optimize the radioactive ion beam delivery. A new accelerator path is conceived for high mass delivery from an EBIS charge state breeder. The front-end design utilizes the experience gained in 15 years of ISAC beam delivery.

  20. Unbounded Violation of Quantum Steering Inequalities.

    PubMed

    Marciniak, M; Rutkowski, A; Yin, Z; Horodecki, M; Horodecki, R

    2015-10-23

    We construct steering inequalities that exhibit unbounded violation. The concept was to exploit the relationship between steering violation and the uncertainty relation. To this end, we apply mutually unbiased bases and anticommuting observables, known to exhibit the strongest uncertainty. In both cases, we are able to procure unbounded violations. Our approach is much more constructive and transparent than the operator space theory approach employed to obtain large violation of Bell inequalities. Importantly, using anticommuting observables we are able to obtain a dichotomic steering inequality with unbounded violation. Thus far, there is no analogous result for Bell inequalities. Interestingly, both the dichotomic inequality and one of our inequalities cannot be directly obtained from existing uncertainty relations, which strongly suggest the existence of an unknown kind of uncertainty relation.

  1. Aeroelastic Tailoring via Tow Steered Composites

    NASA Technical Reports Server (NTRS)

    Stanford, Bret K.; Jutte, Christine V.

    2014-01-01

    The use of tow steered composites, where fibers follow prescribed curvilinear paths within a laminate, can improve upon existing capabilities related to aeroelastic tailoring of wing structures, though this tailoring method has received relatively little attention in the literature. This paper demonstrates the technique for both a simple cantilevered plate in low-speed flow, as well as the wing box of a full-scale high aspect ratio transport configuration. Static aeroelastic stresses and dynamic flutter boundaries are obtained for both cases. The impact of various tailoring choices upon the aeroelastic performance is quantified: curvilinear fiber steering versus straight fiber steering, certifiable versus noncertifiable stacking sequences, a single uniform laminate per wing skin versus multiple laminates, and identical upper and lower wing skins structures versus individual tailoring.

  2. Multipass Steering Protocols at Jefferson Lab

    SciTech Connect

    Ryan Bodenstein; Michael Tiefenback

    2007-06-22

    The CEBAF recirculating accelerator consists of two CW superconducting RF linacs, through which an electron beam is accelerated for up to 5 passes. Focusing and steering elements affect each pass differently, requiring a multipass steering protocol to correct the orbits. Perturbations include lens misalignments (including long-term ground motion), BPM offsets, and focusing and steering from RF fields inside the cavities. A previous treatment of this problem assumed all perturbations were localized at the quadrupoles and the absence of x-y coupling. Having analyzed the problem and characterized the solutions, we developed an empirical iterative protocol to compare against previous results in the presence of skew fields and cross-plane coupling. We plan to characterize static and acceleration-dependent components of the beam line perturbations to allow systematic and rapid configuration of the accelerator at different linac energy gains.

  3. Stability analysis of automobile driver steering control

    NASA Technical Reports Server (NTRS)

    Allen, R. W.

    1981-01-01

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

  4. Theory of pinned fronts

    NASA Astrophysics Data System (ADS)

    Weissmann, Haim; Shnerb, Nadav M.; Kessler, David A.

    2016-01-01

    The properties of a front between two different phases in the presence of a smoothly inhomogeneous external field that takes its critical value at the crossing point is analyzed. Two generic scenarios are studied. In the first, the system admits a bistable solution and the external field governs the rate in which one phase invades the other. The second mechanism corresponds to a continuous transition that, in the case of reactive systems, takes the form of a transcritical bifurcation at the crossing point. We solve for the front shape and for the response of competitive fronts to external noise, showing that static properties and also some of the dynamical features cannot discriminate between the two scenarios. A reliable indicator turns out to be the fluctuation statistics. These take a Gaussian form in the bifurcation case and a double-peaked shape in a bistable system. Our results are discussed in the context of biological processes, such as species and communities dynamics in the presence of a resource gradient.

  5. Radiative thermal conduction fronts

    NASA Technical Reports Server (NTRS)

    Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

    1990-01-01

    The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence.

  6. Influence of different shoulder-elbow configurations on steering precision and steering velocity in automotive context.

    PubMed

    Schmidt, Susanne; Seiberl, Wolfgang; Schwirtz, Ansgar

    2015-01-01

    Ergonomic design requirements are needed to develop optimum vehicle interfaces for the driver. The majority of the current specifications consider only anthropometric conditions and subjective evaluations of comfort. This paper examines specific biomechanical aspects to improve the current ergonomic requirements. Therefore, a research which involved 40 subjects was carried out to obtain more knowledge in the field of steering movement while driving a car. Five different shoulder-elbow joint configurations were analyzed using a driving simulator to find optimum posture for driving in respect of steering precision and steering velocity. Therefore, a 20 s precision test and a test to assess maximum steering velocity over a range of 90° steering motion have been conducted. The results show that driving precision, as well as maximum steering velocity, are significantly increased in mid-positions (elbow angles of 95° and 120°) compared to more flexed (70°) or extended (145° and 160°) postures. We conclude that driver safety can be enhanced by implementing these data in the automotive design process because faster and highly precise steering can be important during evasive actions and in accident situations. In addition, subjective comfort rating, analyzed with questionnaires, confirmed experimental results. PMID:25168195

  7. Influence of different shoulder-elbow configurations on steering precision and steering velocity in automotive context.

    PubMed

    Schmidt, Susanne; Seiberl, Wolfgang; Schwirtz, Ansgar

    2015-01-01

    Ergonomic design requirements are needed to develop optimum vehicle interfaces for the driver. The majority of the current specifications consider only anthropometric conditions and subjective evaluations of comfort. This paper examines specific biomechanical aspects to improve the current ergonomic requirements. Therefore, a research which involved 40 subjects was carried out to obtain more knowledge in the field of steering movement while driving a car. Five different shoulder-elbow joint configurations were analyzed using a driving simulator to find optimum posture for driving in respect of steering precision and steering velocity. Therefore, a 20 s precision test and a test to assess maximum steering velocity over a range of 90° steering motion have been conducted. The results show that driving precision, as well as maximum steering velocity, are significantly increased in mid-positions (elbow angles of 95° and 120°) compared to more flexed (70°) or extended (145° and 160°) postures. We conclude that driver safety can be enhanced by implementing these data in the automotive design process because faster and highly precise steering can be important during evasive actions and in accident situations. In addition, subjective comfort rating, analyzed with questionnaires, confirmed experimental results.

  8. A computer algorithm for automatic beam steering

    SciTech Connect

    Drennan, E.

    1992-06-01

    Beam steering is done by modifying the current in a trim or bending magnet. If the current change is the right amount the beam can be made to bend in such a manner that it will hit a swic or BPM downstream from the magnet at a predetermined set point. Although both bending magnets and trim magnets can be used to modify beam angle, beam steering is usually done with trim magnets. This is so because, during beam steering the beam angle is usually modified only by a small amount which can be easily achieved with a trim magnet. Thus in this note, all steering magnets will be assumed to be trim magnets. There are two ways of monitoring beam position. One way is done using a BPM and the other is done using a swic. For simplicity, beam position monitoring in this paper will be referred to being done with a swic. Beam steering can be done manually by changing the current through a trim magnet and monitoring the position of the beam downstream from the magnet with a swic. Alternatively the beam can be positioned automatically using a computer which periodically updates the current through a specific number of trim magnets. The purpose of this note is to describe the steps involved in coming up with such a computer program. There are two main aspects to automatic beam steering. First a relationship between the beam position and the bending magnet is needed. Secondly a beamline setup of swics and trim magnets has to be chosen that will position the beam according to the desired specifications. A simple example will be looked at that will show that once a mathematical relationship between the needed change of the beam position on a swic and the change in trim currents is established, a computer could be programmed to calculate and update the trim currents.

  9. 22. Steering gear box and wheel from starboard side. Mizzen ...

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

    22. Steering gear box and wheel from starboard side. Mizzen boom has been removed for repairs (note boom cradle just forward of steering gear box). - Schooner C.A. THAYER, Hyde Street Pier, San Francisco, San Francisco County, CA

  10. Experimental Quantification of Asymmetric Einstein-Podolsky-Rosen Steering.

    PubMed

    Sun, Kai; Ye, Xiang-Jun; Xu, Jin-Shi; Xu, Xiao-Ye; Tang, Jian-Shun; Wu, Yu-Chun; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can

    2016-04-22

    Einstein-Podolsky-Rosen (EPR) steering describes the ability of one observer to nonlocally "steer" the other observer's state through local measurements. EPR steering exhibits a unique asymmetric property; i.e., the steerability can differ between observers, which can lead to one-way EPR steering in which only one observer obtains steerability in the steering process. This property is inherently different from the symmetric concepts of entanglement and Bell nonlocality, and it has attracted increasing interest. Here, we experimentally demonstrate asymmetric EPR steering for a class of two-qubit states in the case of two measurement settings. We propose a practical method to quantify the steerability. We then provide a necessary and sufficient condition for EPR steering and clearly demonstrate one-way EPR steering. Our work provides new insight into the fundamental asymmetry of quantum nonlocality and has potential applications in asymmetric quantum information processing.

  11. 9 CFR 78.6 - Steers and spayed heifers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.6 Steers and spayed heifers. Steers and spayed heifers may be moved interstate in accordance with 9 CFR part 86 and without...

  12. 102. STEERING GEAR ROOM FORWARD LOOKING AFT ON STARBOARD ...

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

    102. STEERING GEAR ROOM - FORWARD LOOKING AFT ON STARBOARD SIDE SHOWING RUDDER POST, HYDRAULIC RAM, EMERGENCY STEERING PUMP PIPING AND REMOTE OPERATING LINKAGE. - U.S.S. HORNET, Puget Sound Naval Shipyard, Sinclair Inlet, Bremerton, Kitsap County, WA

  13. Pilothouse bridge with steering gear at center, ship's wheel has ...

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

    Pilothouse bridge with steering gear at center, ship's wheel has been removed. Vertical shaft is connected to flying bridge steering wheel. - Purse Seiner SHENANDOAH, Gig Harbor Peninsula Historical Society and Museum, Gig Harbor, Pierce County, WA

  14. Steering in spin tomographic probability representation

    NASA Astrophysics Data System (ADS)

    Man'ko, V. I.; Markovich, L. A.

    2016-09-01

    The steering property known for two-qubit state in terms of specific inequalities for the correlation function is translated for the state of qudit with the spin j = 3 / 2. Since most steering detection inequalities are based on the correlation functions we introduce analogs of such functions for the single qudit systems. The tomographic probability representation for the qudit states is applied. The connection between the correlation function in the two-qubit system and the single qudit is presented in an integral form with an intertwining kernel calculated explicitly in tomographic probability terms.

  15. A steering mechanism for phototaxis in Chlamydomonas.

    PubMed

    Bennett, Rachel R; Golestanian, Ramin

    2015-03-01

    Chlamydomonas shows both positive and negative phototaxis. It has a single eyespot near its equator, and as the cell rotates during the forward motion, the light signal received by the eyespot varies. We use a simple mechanical model of Chlamydomonas that couples the flagellar beat pattern to the light intensity at the eyespot to demonstrate a mechanism for phototactic steering that is consistent with observations. The direction of phototaxis is controlled by a parameter in our model, and the steering mechanism is robust to noise. Our model shows switching between directed phototaxis when the light is on and run-and-tumble behaviour in the dark.

  16. A steering mechanism for phototaxis in Chlamydomonas

    PubMed Central

    Bennett, Rachel R.; Golestanian, Ramin

    2015-01-01

    Chlamydomonas shows both positive and negative phototaxis. It has a single eyespot near its equator, and as the cell rotates during the forward motion, the light signal received by the eyespot varies. We use a simple mechanical model of Chlamydomonas that couples the flagellar beat pattern to the light intensity at the eyespot to demonstrate a mechanism for phototactic steering that is consistent with observations. The direction of phototaxis is controlled by a parameter in our model, and the steering mechanism is robust to noise. Our model shows switching between directed phototaxis when the light is on and run-and-tumble behaviour in the dark. PMID:25589576

  17. THERMAL FRONTS IN SOLAR FLARES

    SciTech Connect

    Karlický, Marian

    2015-12-01

    We studied the formation of a thermal front during the expansion of hot plasma into colder plasma. We used a three-dimensional electromagnetic particle-in-cell model that includes inductive effects. In early phases, in the area of the expanding hot plasma, we found several thermal fronts, which are defined as a sudden decrease of the local electron kinetic energy. The fronts formed a cascade. Thermal fronts with higher temperature contrast were located near plasma density depressions, generated during the hot plasma expansion. The formation of the main thermal front was associated with the return-current process induced by hot electron expansion and electrons backscattered at the front. A part of the hot plasma was trapped by the thermal front while another part, mainly with the most energetic electrons, escaped and generated Langmuir and electromagnetic waves in front of the thermal front, as shown by the dispersion diagrams. Considering all of these processes and those described in the literature, we show that anomalous electric resistivity is produced at the location of the thermal front. Thus, the thermal front can contribute to energy dissipation in the current-carrying loops of solar flares. We estimated the values of such anomalous resistivity in the solar atmosphere together with collisional resistivity and electric fields. We propose that the slowly drifting reverse drift bursts, observed at the beginning of some solar flares, could be signatures of the thermal front.

  18. Thermal Fronts in Solar Flares

    NASA Astrophysics Data System (ADS)

    Karlický, Marian

    2015-12-01

    We studied the formation of a thermal front during the expansion of hot plasma into colder plasma. We used a three-dimensional electromagnetic particle-in-cell model that includes inductive effects. In early phases, in the area of the expanding hot plasma, we found several thermal fronts, which are defined as a sudden decrease of the local electron kinetic energy. The fronts formed a cascade. Thermal fronts with higher temperature contrast were located near plasma density depressions, generated during the hot plasma expansion. The formation of the main thermal front was associated with the return-current process induced by hot electron expansion and electrons backscattered at the front. A part of the hot plasma was trapped by the thermal front while another part, mainly with the most energetic electrons, escaped and generated Langmuir and electromagnetic waves in front of the thermal front, as shown by the dispersion diagrams. Considering all of these processes and those described in the literature, we show that anomalous electric resistivity is produced at the location of the thermal front. Thus, the thermal front can contribute to energy dissipation in the current-carrying loops of solar flares. We estimated the values of such anomalous resistivity in the solar atmosphere together with collisional resistivity and electric fields. We propose that the slowly drifting reverse drift bursts, observed at the beginning of some solar flares, could be signatures of the thermal front.

  19. More About Beam-Steering Subsystem For Laser Communication

    NASA Technical Reports Server (NTRS)

    Page, Norman A.; Chen, Chien-Chu; Hemmati, Hamid; Lesh, James R.

    1995-01-01

    Two reports present additional information about developmental beam-steering subsystem of laser-communication system. Aspects of this subsystem described previously in "Beam-Steering Subsystem for Laser Communication" (NPO-19069) and "Digital Controller for Laser-Beam-Steering Subsystem" (NPO-19193). Reports reiterate basic principles of operation of beam-steering subsystem and of laser-communication system as whole. Also presents some of details of optical and mechanical design of prototype of subsystem, called Optical Communication Demonstrator.

  20. 49 CFR 393.209 - Steering wheel systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... following parameters: Steering wheel diameter Manual steering system Power steering system 406 mm or less (16 inches or less) 51 mm (2 inches) 108 mm (41/4 inches). 457 mm (18 inches) 57 mm (21/4 inches) 121 mm (43/4 inches). 483 mm (19 inches) 60 mm (23/8 inches) 127 mm (5 inches). 508 mm (20 inches) 64...

  1. 49 CFR 393.209 - Steering wheel systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... following parameters: Steering wheel diameter Manual steering system Power steering system 406 mm or less (16 inches or less) 51 mm (2 inches) 108 mm (41/4 inches). 457 mm (18 inches) 57 mm (21/4 inches) 121 mm (43/4 inches). 483 mm (19 inches) 60 mm (23/8 inches) 127 mm (5 inches). 508 mm (20 inches) 64...

  2. 46 CFR 167.65-25 - Steering gear tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means...

  3. 46 CFR 61.20-1 - Steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of...

  4. 46 CFR 61.20-1 - Steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of...

  5. 46 CFR 167.65-25 - Steering gear tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means...

  6. 46 CFR 167.65-25 - Steering gear tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means...

  7. 46 CFR 61.20-1 - Steering gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of...

  8. 46 CFR 167.65-25 - Steering gear tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means...

  9. 46 CFR 61.20-1 - Steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of...

  10. 46 CFR 61.20-1 - Steering gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of...

  11. Digital Controller For Laser-Beam-Steering Subsystem

    NASA Technical Reports Server (NTRS)

    Ansari, Homayoon

    1995-01-01

    Report presents additional information about proposed apparatus described in "Beam-Steering Subsystem for Laser Communication" (NPO-19069). Discusses design of digital beam-steering control subsystem and, in particular, that part of design pertaining to digital compensation for frequency response of steering mirror.

  12. 9 CFR 78.21 - Bison steers and spayed heifers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Bison steers and spayed heifers. 78.21... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.21 Bison steers and spayed heifers. Bison steers and spayed heifers may be moved interstate without restriction under this subpart....

  13. 9 CFR 78.21 - Bison steers and spayed heifers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Bison steers and spayed heifers. 78.21... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.21 Bison steers and spayed heifers. Bison steers and spayed heifers may be moved interstate without restriction under this subpart....

  14. 9 CFR 78.21 - Bison steers and spayed heifers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Bison steers and spayed heifers. 78.21... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.21 Bison steers and spayed heifers. Bison steers and spayed heifers may be moved interstate without restriction under this subpart....

  15. 9 CFR 78.21 - Bison steers and spayed heifers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Bison steers and spayed heifers. 78.21... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.21 Bison steers and spayed heifers. Bison steers and spayed heifers may be moved interstate without further restriction under this subpart....

  16. 9 CFR 78.21 - Bison steers and spayed heifers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Bison steers and spayed heifers. 78.21... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.21 Bison steers and spayed heifers. Bison steers and spayed heifers may be moved interstate without restriction under this subpart....

  17. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Nose/tail wheel steering. 23.745 Section 23.745 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must...

  18. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Nose/tail wheel steering. 23.745 Section 23.745 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must...

  19. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Nose/tail wheel steering. 23.745 Section 23.745 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must...

  20. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Nose/tail wheel steering. 23.745 Section 23.745 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must...

  1. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Nose/tail wheel steering. 23.745 Section 23.745 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must...

  2. 46 CFR 182.620 - Auxiliary means of steering.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Auxiliary means of steering. 182.620 Section 182.620... TONS) MACHINERY INSTALLATION Steering Systems § 182.620 Auxiliary means of steering. (a) Except as provided in paragraph (c) of this section, a vessel must be provided with an auxiliary means of...

  3. 46 CFR 182.620 - Auxiliary means of steering.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Auxiliary means of steering. 182.620 Section 182.620... TONS) MACHINERY INSTALLATION Steering Systems § 182.620 Auxiliary means of steering. (a) Except as provided in paragraph (c) of this section, a vessel must be provided with an auxiliary means of...

  4. Simple front tracking

    SciTech Connect

    Glimm, J.; Grove, J.W.; Li, X.; Zhao, N.

    1999-04-01

    A new and simplified front tracking algorithm has been developed as an aspect of the extension of this algorithm to three dimensions. Here the authors emphasize two main results: (1) a simplified description of the microtopology of the interface, based on interface crossings with cell block edges, and (2) an improved algorithm for the interaction of a tracked contact discontinuity with an untracked shock wave. For the latter question, they focus on the post interaction jump at the contact, which is a purely 1D issue. Comparisons to other methods, including the level set method, are included.

  5. Robust steering control of spacecraft carrier rockets

    NASA Astrophysics Data System (ADS)

    Correa, Adriana Elysa Alimandro; da Rosa, Alex; Ferreira, Henrique Cezar; Ishihara, Joao Yoshiyuki; Borges, Renato Alves; Sheptun, Yuri Dmitrievich

    In the year of 2003 it was established a cooperation agreement between Ukraine and Brazil for utilization of Cyclone-4 launch vehicle at Alcantara Launch Center. The company responsible for the marketing and operation of launch services is the company bi-national Alcantara Cyclone Space (ACS). The Cyclone-4 launch vehicle is the newest version of the Ukrainian Cyclone family launchers developed by Yuzhnoye State Design Office. This family has been used for many successful spacecrafts launches since 1969. This paper is concerned with the yaw stabilization problem around a nominal trajectory for the third stage of a satellite carrier rocket similar to the Cyclone-4. Only the steering machine of the main engine is considered as actuator. The dynamic behavior of the third stage around the nominal trajectory is modeled as a fourthorder time-varying linear system whereas the steering machine is modeled as a linear dynamical system up to third order. The values of the parameters of the steering machine model are unknown, however belonging to known intervals. As the main result, the stabilization problem is solved with a proportional derivative (PD) controller. The proposed tuning approach takes into account the robustness of the controller with respect to the steering machine model uncertainties. The performance of the PD controller is demonstrated by simulation results.

  6. Ultramaneuverable steering control algorithms for terrain transitions

    NASA Astrophysics Data System (ADS)

    Torrie, Mel W.; Koch, Ralf; Bahl, Vikas; Cripps, Don

    1999-07-01

    The Center for Self-Organizing and Intelligent Systems has built several vehicles with ultra-maneuverable steering capability. Each drive wheel on the vehicle can be independently set at any angle with respect to the vehicle body and the vehicles can rotate or translate in any direction. The vehicles are expected to operate on a wide range of terrain surfaces and problems arise in effectively controlling changes in wheel steering angles as the vehicle transitions from one extreme running surface to another. Controllers developed for smooth surfaces may not perform well on rough or 'sticky' surfaces and vice versa. The approach presented involves the development of a model of the steering motor with the static and viscous friction of the steering motor load included. The model parameters are then identified through a series of environmental tests using a vehicle wheel assembly and the model thus obtained is used for control law development. Four different robust controllers were developed and evaluated through simulation and vehicle testing. The findings of this development will be presented.

  7. Control augmentation for lateral control wheel steering

    NASA Technical Reports Server (NTRS)

    Foulkes, R. H., Jr.

    1981-01-01

    Flight control system design for lateral control wheel steering is discussed. Two alternate designs are presented. The first design is a roll-rate command, bank-angle hold system with a wings-level track-hold submode. The second is a curved-track-hold system. Design details and real-time flight simulator results are included.

  8. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Steering systems. 115.814 Section 115.814 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150... capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  9. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Steering systems. 115.814 Section 115.814 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150... capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  10. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Steering systems. 115.814 Section 115.814 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150... capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  11. Demonstration of large-angle nonmechanical laser beam steering based on LC polymer polarization gratings

    NASA Astrophysics Data System (ADS)

    Kim, Jihwan; Miskiewicz, Matthew N.; Serati, Steve; Escuti, Michael J.

    2011-05-01

    Polarization gratings (PGs) as polarization sensitive diffractive optical elements work in broadband (UV to Mid- IR) with nearly 100% diffraction efficiency. We have introduced and utilized the PGs in different types of beam steering modules presented in our previous papers. Here, we describe and demonstrate a nonmechanical beam steering device based on passive gratings, liquid crystal (LC) polymer PGs. The device covers a large-angle Field-Of-Regard (FOR) with high efficiency, and is based on a stack of alternating LC half-wave plates and LC polymer PGs. The half-wave plates are switchable and are used to select the handedness of the circularly polarized input beam. The polymer PGs diffract the input beam to either of the first diffraction orders based on the circular handedness of the beam previously selected. When compared with conventional beam steering methods based on active gratings (ternary and quasi-ternary designs), this technique is experimentally able to steer an equivalent number of angles with similar efficiency, but fewer LC cells, and hence, fewer transparent electrodes and lower absorption. We successfully demonstrate the ability to steer 80° FOR with roughly 2.6° resolution at 1064 nm wavelength.

  12. Wide-angle nonmechanical beam steering using thin liquid crystal polarization gratings

    NASA Astrophysics Data System (ADS)

    Kim, Jihwan; Oh, Chulwoo; Escuti, Michael J.; Hosting, Lance; Serati, Steve

    2008-08-01

    We introduce and demonstrate a compact, nonmechanical beam steering device based on liquid Crystal (LC) Polarization Gratings (PGs). Directional control of collimated light is essential for free-space optical communications, remote sensing, and related technologies. However, current beam steering methods often require moving parts, or are limited to small angle operation, offer low optical throughput, and are constrained by size and weight. We employ multiple layers of LCPGs to achieve wide-angle (> +/-40°), coarse beam steering of 1550 nm light in a remarkably thin package. LCPGs can be made in switchable or polymer materials, and possess a continuous periodic birefringence profile, that renders several compelling properties (experimentally realized): ~ 100% experimental diffraction efficiency into a single order, high polarization sensitivity, and very low scattering. Light may be controlled within and between the zero- and first-diffraction orders by the handedness of the incident light and potentially by voltage applied to the PG itself. We implement a coarse steering device with several LCPGs matched with active halfwave LC variable retarders. Here, we present the preliminary experimental results and discuss the unique capability of this wide-angle steering.

  13. New Front End Technology

    SciTech Connect

    Pennington, D; Jovanovic, I; Comaskey, B J

    2001-02-01

    The next generation of Petawatt class lasers will require the development of new laser technology. Optical parametric chirped pulse amplification (OPCPA) holds a potential to increase the peak power level to >10 PW with existing grating technology through ultrashort pulses. Furthermore, by utilizing a new type of front-end system based on optical parametric amplification, pulses can be produced with substantially higher contrast than with Ti:sapphire regenerative amplifier technology. We performed extensive study of OPCPA using a single crystal-based OPA. We developed a replacement for Ti:sapphire regenerative amplifier for high peak power lasers based on OPCPA, with an output of 30 mJ, at 10 Hz repetition rate and 16.5 nm spectral bandwidth. We developed a 3D numerical model for OPCPA and we performed a theoretical study of influences of pump laser beam quality on optical parametric amplification. Our results indicate that OPCPA represents a valid replacement for Ti:sapphire in the front end of high energy short pulse lasers.

  14. Vehicle front wheel assist drive overspeed control system

    SciTech Connect

    Riehl, D.C.

    1987-01-13

    This patent describes a front wheel drive speed control system for a vehicle having a rear wheel drive and an assisting front wheel drive, comprising: (a) a hydraulic pump means operably connected by a hydraulic circuit to a hydraulic motor at each driven front wheel to cause rotation of that wheel; (b) an overrunning clutch assembly interposed between the motor and each associated wheel, engageable to facilitate rotation of the driven front wheel in both forward and reverse directions; (c) a speed sensing means has main rear wheel drive sensor mounted with a vehicle transmission output to the driven rear wheels thereof operable to provide pulse signals indicative of the speed of rotation of the driven rear wheels; (d) a driven front wheel sensor mounted with the vehicle and operable to provide pulse signals indicative of the speed of rotation of the driven front wheel; (e) a comparator means operable to compare the rate of rear wheel pulse signals with a first predetermined rate to produce a front wheel enabling signal when the rear wheel pulse signals are below the first predetermined rate; and (f) a front wheel drive operating circuit means connected to the comparator means to receive the front wheel enabling signal and operable to activate the hydraulic pump means to cause rotation of the front wheel.

  15. From the front

    SciTech Connect

    Price, Stephen

    2009-01-01

    The causes of recent dynamic thinning of Greenland's outlet glaciers have been debated. Realistic simulations suggest that changes at the marine fronts of these glaciers are to blame, implying that dynamic thinning will cease once the glaciers retreat to higher ground. For the last decade, many outlet glaciers in Greenland that terminate in the ocean have accelerated, thinned, and retreated. To explain these dynamic changes, two hypotheses have been discussed. Atmospheric warming has increased surface melting and may also have increased the amount of meltwater reaching the glacier bed, increasing lubrication at the base and hence the rate of glacier sliding. Alternatively, a change in the delicate balance of forces where the glacier fronts meet the ocean could trigger the changes. Faezeh Nick and colleagues5 present ice-sheet modeling experiments that mimic the observations on Helheim glacier, East Greenland, and suggest that the dynamic behaviour of outlet glaciers follows from perturbations at their marine fronts. Greenland's ice sheet loses mass partly through surface melting and partly through fast flowing outlet glaciers that connect the vast plateau of inland ice with the ocean. Earlier ice sheet models have failed to reproduce the dynamic variability exhibited by ice sheets over time. It has therefore not been possible to distinguish with confidence between basal lubrication from surface meltwater and changes at the glaciers' marine fronts as causes for the observed changes on Greenland's outlet glaciers. But this distinction bears directly on future sea-level rise, the raison d'etre of much of modern-day glaciology: If the recent dynamic mass loss Greenland's outlet glaciers is linked to changing atmospheric temperatures, it may continue for as long as temperatures continue to increase. On the other hand, if the source of the dynamic mass loss is a perturbation at the ice-ocean boundary, these glaciers will lose contact with that perturbation after a finite

  16. Time Line Visualization of Research Fronts.

    ERIC Educational Resources Information Center

    Morris, Steven A.; Yen, G.; Wu, Zheng; Asnake, Benyam

    2003-01-01

    Research fronts, defined as clusters of documents that tend to cite a fixed, time invariant set of base documents, are plotted as time lines for visualization and exploration. Illustrates the construction, exploration, and interpretation of time lines for identifying and visualizing temporal changes in research activity through journal articles.…

  17. Adaptive beam tracking and steering via electrowetting-controlled liquid prism

    SciTech Connect

    Cheng, JT; Chen, CL

    2011-11-07

    We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm -10mm. With 1 wt.% KCl and 1 wt.% Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26 degrees and 26 degrees that can deflect and steer beam within the incidence angle of 0 degrees-15 degrees. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660578

  18. Second messengers and membrane trafficking direct and organize growth cone steering

    PubMed Central

    Tojima, Takuro; Hines, Jacob H.; Henley, John R.; Kamiguchi, Hiroyuki

    2011-01-01

    Graded distributions of extracellular cues guide developing axons toward their targets. A network of second messengers, Ca2+ and cyclic nucleotides, shapes cue-derived information into either attractive or repulsive signals that steer growth cones bidirectionally. Emerging evidence suggests that such guidance signals create a localized imbalance between exocytosis and endocytosis, which in turn redirects membrane, adhesion and cytoskeletal components asymmetrically across the growth cone to bias the direction of axon extension. These recent advances allow us to propose a unifying model of how the growth cone translates shallow gradients of environmental information into polarized activity of the steering machinery for axon guidance. PMID:21386859

  19. Test procedures and performance measures sensitive to automobile steering dynamics. [considering operator/vehicle responses

    NASA Technical Reports Server (NTRS)

    Klein, R. H.; Mcruer, D. T.; Weir, D.

    1975-01-01

    A maneuver complex and related performance measures used to evaluate driver/vehicle system responses as effected by variations in the directional response characteristics of passenger cars are described. The complex consists of normal and emergency maneuvers (including random and discrete disturbances) which, taken as a whole, represent all classes of steering functions and all modes of driver response behavior. Measures of driver/vehicle system response and performance in regulation tasks included direct describing function measurements and rms yaw velocity. In transient maneuvers, measures such as steering activity and cone strikes were used.

  20. Developmental and activity-dependent plasticity of filiform hair receptors in the locust

    PubMed Central

    Pflüger, Hans-Joachim; Wolf, Harald

    2013-01-01

    A group of wind sensitive filiform hair receptors on the locust thorax and head makes contact onto a pair of identified interneuron, A4I1. The hair receptors' central nervous projections exhibit pronounced structural dynamics during nymphal development, for example, by gradually eliminating their ipsilateral dendritic field while maintaining the contralateral one. These changes are dependent not only on hormones controlling development but on neuronal activity as well. The hair-to-interneuron system has remarkably high gain (close to 1) and makes contact to flight steering muscles. During stationary flight in front of a wind tunnel, interneuron A4I1 is active in the wing beat rhythm, and in addition it responds strongly to stimulation of sensory hairs in its receptive field. A role of the hair-to-interneuron in flight steering is thus suggested. This system appears suitable for further study of developmental and activity-dependent plasticity in a sensorimotor context with known connectivity patterns. PMID:23986712

  1. Prototype Development of the GMT Fast Steering Mirror

    NASA Astrophysics Data System (ADS)

    Kim, Young-Soo; Koh, J.; Jung, H.; Jung, H.; Cho, M. K.; Park, W.; Yang, H.; Kim, H.; Lee, K.; Ahn, H.; Park, B.

    2013-06-01

    A Fast Steering Mirror (FSM) is going to be produced as a secondary mirror of the Giant Magellan Telescope (GMT). FSM is 3.2 m in diameter and the focal ratio is 0.65. It is composed of seven circular segments which match with the primary mirror segments. Each segment contains a light-weighted mirror whose diameter is 1.1 m. It also contains tip-tilt actuators which would compensate wind effect and structure jitter. An FSM prototype (FSMP) has been developed, which consists of a full-size off-axis mirror segment and a tip-tilt test-bed. The main purpose of the FSMP development is to achieve key technologies, such as fabrication of highly aspheric off-axis mirror and tip-tilt actuation. The development has been conducted by a consortium of five institutions in Korea and USA, and led by Korea Astronomy and Space Science Institute. The mirror was light-weighted and grinding of the front surface was finished. Polishing is in progress with computer generated hologram tests. The tip-tilt test-bed has been manufactured and assembled. Frequency tests are being performed and optical tilt set-up is arranged for visual demonstration. In this paper, we present progress of the prototype development, and future works.

  2. Bioconvection and front formation of Paramecium tetraurelia

    NASA Astrophysics Data System (ADS)

    Kitsunezaki, So; Komori, Rie; Harumoto, Terue

    2007-10-01

    We have investigated the bioconvection of Paramecium tetraurelia in high-density suspensions made by centrifugal concentration. When a suspension is kept at rest in a Hele-Shaw cell, a crowded front of paramecia is formed in the vicinity of the bottom and it propagates gradually toward the water-air interface. Fluid convection occurs under this front, and it is driven persistently by the upward swimming of paramecia. The roll structures of the bioconvection become turbulent with an increase in the depth of the suspension; they also change rapidly as the density of paramecia increases. Our experimental results suggest that lack of oxygen in the suspension causes the active individual motions of paramecia to induce the formation of this front.

  3. Method of Controlling Steering of a Ground Vehicle

    NASA Technical Reports Server (NTRS)

    Dawson, Andrew D. (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor)

    2016-01-01

    A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

  4. Steering system for a train of rail-less vehicles

    DOEpatents

    Voight, Edward T.

    1983-01-01

    A steering system for use with a multiple vehicle train permits tracking without rails of one vehicle after another. This system is particularly useful for moving conveyor systems into and out of curved paths of room and pillar underground mine installations. The steering system features an elongated steering bar pivotally connected to each of adjacent vehicles at end portions of the bar permitting angular orientation of each vehicle in respect to the steering bar and other vehicles. Each end portion of the steering bar is linked to the near pair of vehicle wheels through wheel yoke pivot arms about king pin type pivots. Movement of the steering bar about its pivotal connection provides proportional turning of the wheels to effect steering and tracking of one vehicle following another in both forward and reverse directions.

  5. On a front line.

    PubMed Central

    Jones, L.

    1995-01-01

    Like the patients, doctors in Sarajevo depend largely on humanitarian aid; everyone in the public sector has worked without pay for almost three years. The hospital is on a front line; yet the psychiatric department continues to function, even conducting large scale studies of psychosocial aspects of war in Bosnia-Hercegovina. The type of inpatient morbidity and treatment patterns have changed. A plethora of psychosocial rehabilitation programmes has emerged, including counselling, drop in centres, and attending to special needs of elderly people, schoolchildren, and women. The most prominent psychological symptoms were exhaustion at the prospect of a third winter of war and bewilderment at the Western stereotype of Bosnians as Muslim fundamentalists. Images p1052-a p1053-a PMID:7728062

  6. Multi-Level Steering and Institution Building: The European Union's Approach to Research Policy

    ERIC Educational Resources Information Center

    Young, Mitchell

    2012-01-01

    Adopting the conception of the university as a primary driver of innovation and economic growth has brought increased pressure for the European Union (EU) to actively steer university-based research policy, despite its being outside of the EU's direct jurisdiction. While the open method of coordination (OMC) was developed for such situations, the…

  7. FACILITY 1042. FRONT OBLIQUE SHOWING ROYAL PALMS LINING FRONT WALK. ...

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

    FACILITY 1042. FRONT OBLIQUE SHOWING ROYAL PALMS LINING FRONT WALK. VIEW FACING SOUTHEAST - U.S. Naval Base, Pearl Harbor, Naval Housing Area Hale Alii, Junior Officers' Quarters Type, 9-10 Hale Alii Avenue, 1-2 Eighth Street, Pearl City, Honolulu County, HI

  8. SPS Beam Steering for LHC Extraction

    SciTech Connect

    Gianfelice-Wendt, Eliana; Bartosik, Hannes; Cornelis, Karel; Norderhaug Drøsdal, Lene; Goddard, Brennan; Kain, Verena; Meddahi, Malika; Papaphilippou, Yannis; Wenninger, Jorg

    2014-07-01

    The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

  9. A steering mechanism for phototaxis in Chlamydomonas

    NASA Astrophysics Data System (ADS)

    Bennett, Rachel; Golestanian, Ramin

    2015-03-01

    Chlamydomonas shows both positive and negative phototaxis. It has a single eyespot near its equator and as the cell rotates during forward motion the light signal received by the eyespot varies. We use a simple mechanical model of Chlamydomonas that couples the flagellar beat pattern to the light intensity at the eyespot to demonstrate a mechanism for phototactic steering that is consistent with observations. The direction of phototaxis is controlled by a parameter in our model and the steering mechanism is robust to noise. In the dark, our model shows emergent run-and-tumble behavior and we see switching between directed phototaxis and run-and-tumble when we switch the light on and off.

  10. Indexing system for optical beam steering

    NASA Technical Reports Server (NTRS)

    Sullivan, Mark T.; Cannon, David M.; Debra, Daniel B.; Young, Jeffrey A.; Mansfield, Joseph A.; Carmichael, Roger E.; Lissol, Peter S.; Pryor, G. M.; Miklosy, Les G.; Lee, Jeffrey H.

    1990-01-01

    This paper describes the design and testing of an indexing system for optical-beam steering. The cryogenic beam-steering mechanism is a 360-degree rotation device capable of discrete, high-precision alignment positions. It uses low-precision components for its rough alignment and kinematic design to meet its stringent repeatability and stability requirements (of about 5 arcsec). The principal advantages of this design include a decoupling of the low-precision, large angular motion from the high-precision alignment, and a power-off alignment position that potentially extends the life or hold time of cryogenic systems. An alternate design, which takes advantage of these attributes while reducing overall motion, is also presented. Preliminary test results show the kinematic mount capable of sub-arc second repeatability.

  11. Pointing Device Performance in Steering Tasks.

    PubMed

    Senanayake, Ransalu; Goonetilleke, Ravindra S

    2016-06-01

    Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface. PMID:27216944

  12. Mirrors Steer NASA in the Right Direction

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Left Hand Design completed the production of the fine-steering mirror technology through 1995 Phase I and 1996 Phase II SBIR contracts with JPL's Interferometric Astronomy group. Presently, the work resulting from the collaboration with NASA represents the company's main line of products for the commercial sector. Aerospace-related applications include: image motion compensation; interceptor seekers for the U.S. Army and Navy; Earth observation and resource monitoring from spacecraft and airborne platforms; space astronomy; helicopter-based surveillance; and interferometric metrology. Left Hand Design's fine-steering mirrors have also penetrated the commercial marketplace with non-aerospace applications, including laser communications, video cameras, infrared inspection, solar observatories, and bathymeters. These cost-effective, commercial mirrors perform a variety of functions, such as scanning, alignment, chopping, tracking, pointing, and beam stabilization. Potential future applications include laser surgery and photolithography.

  13. Influence of rice whole-crop silage diet on growth performance, carcass and meat characteristics and muscle-related gene expression in Japanese Black steers.

    PubMed

    Shibata, Masahiro; Hikino, Yasuko; Imanari, Mai; Matsumoto, Kazunori; Yamamoto, Naoyuki

    2016-07-01

    The present study investigated the influence of a diet largely comprising rice whole-crop silage (rWCS) on growth performance, carcass and meat characteristics, and expression of genes involved in muscle growth of Japanese Black steers. Steers were randomly separated into rWCS-fed (rWCS ad libitum and restricted feeding of concentrate) and concentrate-fed groups. Total digestible nutrient intake and daily gain (DG) decreased in rWCS-fed steers in comparison with concentrate-fed steers, whereas dressed carcass weight and final body weight did not significantly differ between the groups. Decreases in drip loss in the muscle of rWCS-fed steers may be caused by α-tocopherol and β-carotene in muscle. Feeding large amounts of rWCS to steers may maintain quantitative productivity of beef steers equally to a concentrate-based diet, and improve the qualitative productivity. Results of gene expression suggest that activation of skeletal muscle growth in rWCS-fed steers may occur at the late fattening period owing to a decrease in myostatin and increase in myosin heavy chain gene expression. Preadipocyte factor-1 and myostatin genes may be strongly involved in the control of lipid accumulation. This rearing system would allow beef production to switch to rWCS-based diets from concentrate-based diets.

  14. Influence of rice whole-crop silage diet on growth performance, carcass and meat characteristics and muscle-related gene expression in Japanese Black steers.

    PubMed

    Shibata, Masahiro; Hikino, Yasuko; Imanari, Mai; Matsumoto, Kazunori; Yamamoto, Naoyuki

    2016-07-01

    The present study investigated the influence of a diet largely comprising rice whole-crop silage (rWCS) on growth performance, carcass and meat characteristics, and expression of genes involved in muscle growth of Japanese Black steers. Steers were randomly separated into rWCS-fed (rWCS ad libitum and restricted feeding of concentrate) and concentrate-fed groups. Total digestible nutrient intake and daily gain (DG) decreased in rWCS-fed steers in comparison with concentrate-fed steers, whereas dressed carcass weight and final body weight did not significantly differ between the groups. Decreases in drip loss in the muscle of rWCS-fed steers may be caused by α-tocopherol and β-carotene in muscle. Feeding large amounts of rWCS to steers may maintain quantitative productivity of beef steers equally to a concentrate-based diet, and improve the qualitative productivity. Results of gene expression suggest that activation of skeletal muscle growth in rWCS-fed steers may occur at the late fattening period owing to a decrease in myostatin and increase in myosin heavy chain gene expression. Preadipocyte factor-1 and myostatin genes may be strongly involved in the control of lipid accumulation. This rearing system would allow beef production to switch to rWCS-based diets from concentrate-based diets. PMID:26420580

  15. Offshore Deformation Front in Miaoli Area

    NASA Astrophysics Data System (ADS)

    Chiang, P.; Gwo-shyn, S.

    2015-12-01

    Taiwan is located at the junction of the Eurasian Plate and the Philippine Sea Plate. It's because arc-continent collision occurs in the western Taiwan, resulting in the orogeny has formed a fold-and-thrust belt, developing a series of thrusts aligned in north-south direction. The thrust faults, locating in the central island, are the oldest and have almost inactive. Westward to the island, the faults become younger, dipping angles are smaller, and motions were stronger. On the west side, the foot of the Taiwan Western Foothill is considered the youngest thrust faults located along west Taiwan. Scholars recognized them as so-called the deformation front, and they also believed that the deformation front is located in between the compressive terrain uplifted area and the extensional subsidence area. Therefore, this front line is on the boundary of two different tectonic zones. This study investigates the trace of the deformation front in Miaoli area. Previous studies suggested that the west side of Miaoli collision zone should be fault-bounded, and is located in the seabed. However, in the geological map, there is no geologic evidence that appears on land and so-called active faults related with this deformation front. In the near coast seafloor, according to the reflection earthquakes data from the Institute of Oceanography of NTU, we can only see the offshore strata have been uplifted, and the data also shows that seabed is only covered by thin layer of sediments. This study indicates that in offshore place within three kilometers, shallow formations show a special layer of slime which was extruded to be corrugated transversely. Accordingly, we believe that this slime layer should be pressurized and filled with muddy water. Such features should be further investigated with other geological and geophysical survey data to check if they belong to the structural product of the deformation front.

  16. Self-testing through EPR-steering

    NASA Astrophysics Data System (ADS)

    Šupić, Ivan; Hoban, Matty J.

    2016-07-01

    The verification of quantum devices is an important aspect of quantum information, especially with the emergence of more advanced experimental implementations of quantum computation and secure communication. Within this, the theory of device-independent robust self-testing via Bell tests has reached a level of maturity now that many quantum states and measurements can be verified without direct access to the quantum systems: interaction with the devices is solely classical. However, the requirements for this robust level of verification are daunting and require high levels of experimental accuracy. In this paper we discuss the possibility of self-testing where we only have direct access to one part of the quantum device. This motivates the study of self-testing via EPR-steering, an intermediate form of entanglement verification between full state tomography and Bell tests. Quantum non-locality implies EPR-steering so results in the former can apply in the latter, but we ask what advantages may be gleaned from the latter over the former given that one can do partial state tomography? We show that in the case of self-testing a maximally entangled two-qubit state, or ebit, EPR-steering allows for simpler analysis and better error tolerance than in the case of full device-independence. On the other hand, this improvement is only a constant improvement and (up to constants) is the best one can hope for. Finally, we indicate that the main advantage in self-testing based on EPR-steering could be in the case of self-testing multi-partite quantum states and measurements. For example, it may be easier to establish a tensor product structure for a particular party’s Hilbert space even if we do not have access to their part of the global quantum system.

  17. Vertical flight path steering system for aircraft

    NASA Technical Reports Server (NTRS)

    Lambregts, Antonius A. (Inventor)

    1983-01-01

    Disclosed is a vertical flight path angle steering system for aircraft, utilizing a digital flight control computer which processes pilot control inputs and aircraft response parameters into suitable elevator commands and control information for display to the pilot on a cathode ray tube. The system yields desirable airplane control handling qualities and responses as well as improvements in pilot workload and safety during airplane operation in the terminal area and under windshear conditions.

  18. Surface properties of ocean fronts

    NASA Technical Reports Server (NTRS)

    Wolff, P. M.; Hubert, W. E.

    1976-01-01

    Background information on oceanic fronts is presented and the results of several models which were developed to study the dynamics of oceanic fronts and their effects on various surface properties are described. The details of the four numerical models used in these studies are given in separate appendices which contain all of the physical equations, program documentation and running instructions for the models.

  19. Oblique incidence effect on steering efficiency of liquid crystal polarization gratings used for optical phased array beam steering amplification

    NASA Astrophysics Data System (ADS)

    Xiangjie, Zhao; Jiazhu, Duan; Dayong, Zhang; Cangli, Liu; Yongquan, Luo

    2016-10-01

    A liquid crystal polarization grating (LCPG) is proposed that amplifies the steering angle of a liquid crystal optical phased array for non-mechanical beam steering, taking advantage of its high steering efficiency under normal incidence. However, oblique incidence may play an important role in the overall steering efficiency. The effect of oblique incidence on steering efficiency of a LCPG was analyzed by numerically solving the extended Jones matrix and considering propagation crosstalk. The results indicate that the outgoing laser beam is amplitude-modulated under the effect of oblique incidence and behaves as a sinusoidal-modulated amplitude grating, which diffracts certain energies to non-blazed orders. Over-oblique incidence may even eliminate the steering effect of the incident beam. The modulation depth of the induced amplitude grating was found to be proportional to the product of sinusoidal value of oblique incidence angle and the LC layer thickness, and inversely proportional to the periodic pitch length of the LCPG. Both in-plane incidence and out-of-plane incidence behave similarly to influence the steering efficiency. Finally, the overall steering efficiency for cascaded LCPGs was analyzed and a difference of up to 11 % steering efficiency can be induced between different LCPG configurations, even without considering the over-oblique incidence effect. Both the modulation depth and final steering efficiency can be optimized by varying the LC birefringence and layer thickness.

  20. Oblique incidence effect on steering efficiency of liquid crystal polarization gratings used for optical phased array beam steering amplification

    NASA Astrophysics Data System (ADS)

    Xiangjie, Zhao; Jiazhu, Duan; Dayong, Zhang; Cangli, Liu; Yongquan, Luo

    2016-07-01

    A liquid crystal polarization grating (LCPG) is proposed that amplifies the steering angle of a liquid crystal optical phased array for non-mechanical beam steering, taking advantage of its high steering efficiency under normal incidence. However, oblique incidence may play an important role in the overall steering efficiency. The effect of oblique incidence on steering efficiency of a LCPG was analyzed by numerically solving the extended Jones matrix and considering propagation crosstalk. The results indicate that the outgoing laser beam is amplitude-modulated under the effect of oblique incidence and behaves as a sinusoidal-modulated amplitude grating, which diffracts certain energies to non-blazed orders. Over-oblique incidence may even eliminate the steering effect of the incident beam. The modulation depth of the induced amplitude grating was found to be proportional to the product of sinusoidal value of oblique incidence angle and the LC layer thickness, and inversely proportional to the periodic pitch length of the LCPG. Both in-plane incidence and out-of-plane incidence behave similarly to influence the steering efficiency. Finally, the overall steering efficiency for cascaded LCPGs was analyzed and a difference of up to 11 % steering efficiency can be induced between different LCPG configurations, even without considering the over-oblique incidence effect. Both the modulation depth and final steering efficiency can be optimized by varying the LC birefringence and layer thickness.

  1. Snowplow Injection Front Effects

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Chandler, M. O.; Buzulukova, N.; Collinson, G. A.; Kepko, E. L.; Garcia-Sage, K. S.; Henderson, M. G.; Sitnov, M. I.

    2013-01-01

    As the Polar spacecraft apogee precessed through the magnetic equator in 2001, Polar encountered numerous substorm events in the region between geosynchronous orbit and 10 RE geocentric distance; most of them in the plasma sheet boundary layers. Of these, a small number was recorded near the neutral sheet in the evening sector. Polar/Thermal Ion Dynamics Experiment provides a unique perspective on the lowest-energy ion plasma, showing that these events exhibited a damped wavelike character, initiated by a burst of radially outward flow transverse to the local magnetic field at approximately 80 km/s. They then exhibit strongly damped cycles of inward/outward flow with a period of several minutes. After one or two cycles, they culminated in a hot plasma electron and ion injection, quite similar to those observed at geosynchronous orbit. Cold plasmaspheric plasmas comprise the outward flow cycles, while the inward flow cycles contain counterstreaming field-parallel polar wind-like flows. The observed wavelike structure, preceding the arrival of an earthward moving substorm injection front, suggests an outward displacement driven by the inward motion at local times closer to midnight, that is, a "snowplow" effect. The damped in/out flows are consistent with interchange oscillations driven by the arrival at the observed local time by an injection originating at greater radius and local time.

  2. Fronts in Large Marine Ecosystems

    NASA Astrophysics Data System (ADS)

    Belkin, Igor M.; Cornillon, Peter C.; Sherman, Kenneth

    2009-04-01

    Oceanic fronts shape marine ecosystems; therefore front mapping and characterization are among the most important aspects of physical oceanography. Here we report on the first global remote sensing survey of fronts in the Large Marine Ecosystems (LME). This survey is based on a unique frontal data archive assembled at the University of Rhode Island. Thermal fronts were automatically derived with the edge detection algorithm of Cayula and Cornillon (1992, 1995, 1996) from 12 years of twice-daily, global, 9-km resolution satellite sea surface temperature (SST) fields to produce synoptic (nearly instantaneous) frontal maps, and to compute the long-term mean frequency of occurrence of SST fronts and their gradients. These synoptic and long-term maps were used to identify major quasi-stationary fronts and to derive provisional frontal distribution maps for all LMEs. Since SST fronts are typically collocated with fronts in other water properties such as salinity, density and chlorophyll, digital frontal paths from SST frontal maps can be used in studies of physical-biological correlations at fronts. Frontal patterns in several exemplary LMEs are described and compared, including those for: the East and West Bering Sea LMEs, Sea of Okhotsk LME, East China Sea LME, Yellow Sea LME, North Sea LME, East and West Greenland Shelf LMEs, Newfoundland-Labrador Shelf LME, Northeast and Southeast US Continental Shelf LMEs, Gulf of Mexico LME, and Patagonian Shelf LME. Seasonal evolution of frontal patterns in major upwelling zones reveals an order-of-magnitude growth of frontal scales from summer to winter. A classification of LMEs with regard to the origin and physics of their respective dominant fronts is presented. The proposed classification lends itself to comparative studies of frontal ecosystems.

  3. Steering and Suspension Systems. Auto Mechanics Curriculum Guide. Module 5. Instructor's Guide.

    ERIC Educational Resources Information Center

    Rains, Larry

    This module is the fifth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Seventeen units cover: steering system design; diagnosing steering systems problems; inspecting and replacing steering linkage components; manual and power steering gear service; manual and power rack and pinion steering gear service; power…

  4. 78 FR 15062 - Cohen & Steers Real Assets Fund, Inc., et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... COMMISSION Cohen & Steers Real Assets Fund, Inc., et al.; Notice of Application March 4, 2013. AGENCY...: Cohen & Steers Real Assets Fund, Inc. (the ``Corporation''), Cohen & Steers Real Assets Fund, Ltd. (the ``Subsidiary''), and Cohen & Steers Capital Management, Inc. (``Cohen & Steers'' or the ``Advisor'')....

  5. 46 CFR 58.25-80 - Automatic pilots and ancillary steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-80 Automatic pilots and ancillary steering gear. (a) Automatic pilots and ancillary steering gear, and steering-gear control systems, must be arranged to allow immediate resumption of manual operation of the steering-gear control system required...

  6. Certifying single-system steering for quantum-information processing

    NASA Astrophysics Data System (ADS)

    Li, Che-Ming; Chen, Yueh-Nan; Lambert, Neill; Chiu, Ching-Yi; Nori, Franco

    2015-12-01

    Einstein-Podolsky-Rosen (EPR) steering describes how different ensembles of quantum states can be remotely prepared by measuring one particle of an entangled pair. Here, we investigate quantum steering for single quantum d -dimensional systems (qudits) and devise efficient conditions to certify the steerability therein, which we find are applicable both to single-system steering and EPR steering. In the single-system case our steering conditions enable the unambiguous ruling out of generic classical means of mimicking steering. Ruling out "false-steering" scenarios has implications for securing channels against both cloning-based individual attack and coherent attacks when implementing quantum key distribution using qudits. We also show that these steering conditions also have applications in quantum computation, in that they can serve as an efficient criterion for the evaluation of quantum logic gates of arbitrary size. Finally, we describe how the nonlocal EPR variant of these conditions also function as tools for identifying faithful one-way quantum computation, secure entanglement-based quantum communication, and genuine multipartite EPR steering.

  7. 9 CFR 78.6 - Steers and spayed heifers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.6 Steers and spayed heifers....

  8. 9 CFR 78.6 - Steers and spayed heifers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.6 Steers and spayed heifers....

  9. 6. OVERALL VIEW OF THE FRONT AND THE TOWER, LOOKING ...

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

    6. OVERALL VIEW OF THE FRONT AND THE TOWER, LOOKING WEST FROM THE ACTIVE PIER OF BAY SHIP AND YACHT COMPANY. COAST GUARD CUTTER SHERMAN AT RIGHT. - United Engineering Company Shipyard, Crane, 2900 Main Street, Alameda, Alameda County, CA

  10. 46 CFR 131.845 - Instructions for shift of steering gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specify that each steering wheel or lever, and each rudder, must be amidships before any shift of steering gear or steering stations. (d) Each clutch, gear, wheel, lever, valve, or switch used during any...

  11. 46 CFR 131.845 - Instructions for shift of steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... specify that each steering wheel or lever, and each rudder, must be amidships before any shift of steering gear or steering stations. (d) Each clutch, gear, wheel, lever, valve, or switch used during any...

  12. 46 CFR 131.845 - Instructions for shift of steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specify that each steering wheel or lever, and each rudder, must be amidships before any shift of steering gear or steering stations. (d) Each clutch, gear, wheel, lever, valve, or switch used during any...

  13. 46 CFR 131.845 - Instructions for shift of steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... specify that each steering wheel or lever, and each rudder, must be amidships before any shift of steering gear or steering stations. (d) Each clutch, gear, wheel, lever, valve, or switch used during any...

  14. 46 CFR 131.845 - Instructions for shift of steering gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specify that each steering wheel or lever, and each rudder, must be amidships before any shift of steering gear or steering stations. (d) Each clutch, gear, wheel, lever, valve, or switch used during any...

  15. An explanation of unstable wetting fronts in soils

    NASA Astrophysics Data System (ADS)

    Steenhuis, Tammo; Parlange, Jean-Yves; Kung, Samuel; Stoof, Cathelijne; Baver, Christine

    2016-04-01

    Despite the findings of Raats on unstable wetting front almost a half a century ago, simulating wetting fronts in soils is still an area of active research. One of the critical questions currently is whether Darcy law is valid at the wetting front. In this talk, we pose that in many cases for dry soils, Darcy's law does not apply because the pressure field across the front is not continuous. Consequently, the wetting front pressure is not dependent on the pressure ahead of the front but is determined by the radius of water meniscuses and the dynamic contact angle of the water. If we further assume since the front is discontinuous, that water flows at one pore at the time, then by using the modified Hoffman relationship - relating the dynamic contact angle to the pore water velocity - we find the elevated pressures at the wetting front typical for unstable flows that are similar to those observed experimentally in small diameter columns. The theory helps also explain the funnel flow phenomena observed in layered soils.

  16. Steering disturbance rejection using a physics-based neuromusculoskeletal driver model

    NASA Astrophysics Data System (ADS)

    Mehrabi, Naser; Sharif Razavian, Reza; McPhee, John

    2015-10-01

    The aim of this work is to develop a comprehensive yet practical driver model to be used in studying driver-vehicle interactions. Drivers interact with their vehicle and the road through the steering wheel. This interaction forms a closed-loop coupled human-machine system, which influences the driver's steering feel and control performance. A hierarchical approach is proposed here to capture the complexity of the driver's neuromuscular dynamics and the central nervous system in the coordination of the driver's upper extremity activities, especially in the presence of external disturbance. The proposed motor control framework has three layers: the first (or the path planning) plans a desired vehicle trajectory and the required steering angles to perform the desired trajectory; the second (or the musculoskeletal controller) actuates the musculoskeletal arm to rotate the steering wheel accordingly; and the final layer ensures the precision control and disturbance rejection of the motor control units. The physics-based driver model presented here can also provide insights into vehicle control in relaxed and tensed driving conditions, which are simulated by adjusting the driver model parameters such as cognition delay and muscle co-contraction dynamics.

  17. Auto-steering apparatus and method

    DOEpatents

    McKay, Mark D.; Anderson, Matthew O.

    2007-03-13

    A vehicular guidance method involves providing a user interface using which data can be input to establish a contour for a vehicle to follow, the user interface further configured to receive information from a differential global positioning system (DGPS), determining cross track and offset data using information received from the DGPS, generating control values, using at least vehicular kinematics, the cross track, and the offset data, and providing an output to control steering of the vehicle, using the control values, in a direction to follow the established contour while attempting to minimize the cross track and the offset data.

  18. Efficiency of lysine utilization by growing steers.

    PubMed

    Batista, E D; Hussein, A H; Detmann, E; Miesner, M D; Titgemeyer, E C

    2016-02-01

    This study evaluated the efficiency of Lys utilization by growing steers. Five ruminally cannulated Holstein steers (165 ± 8 kg) housed in metabolism crates were used in a 6 × 6 Latin square design; data from a sixth steer was excluded due to erratic feed intake. All steers were limit fed (2.46 kg DM/d), twice daily, diets low in RUP (81% soybean hulls, 8% wheat straw, 6% cane molasses, and 5% vitamins and minerals). Treatments were 0, 3, 6, 9, 12, and 15 g/d of Lys continuously abomasally infused. To prevent AA other than Lys from limiting performance, a mixture providing all essential AA to excess was continuously abomasally infused. Additional continuous infusions included 10 g urea/d, 200 g acetic acid/d, 200 g propionic acid/d, and 50 g butyric acid/d to the rumen and 300 g glucose/d to the abomasum. These infusions provided adequate ruminal ammonia and increased energy supply without increasing microbial protein supply. Each 6-d period included 2 d for adaptation and 4 d for total fecal and urinary collections for measuring N balance. Blood was collected on d 6 (10 h after feeding). Diet OM digestibility was not altered ( ≥ 0.66) by treatment and averaged 73.7%. Urinary N excretion was decreased from 32.3 to 24.3 g/d by increasing Lys supplementation to 9 g/d, with no further reduction when more than 9 g/d of Lys was supplied (linear and quadratic, < 0.01). Changes in total urinary N excretion predominantly were due to changes in urinary urea N. Increasing Lys supply from 0 to 9 g/d increased N retention from 21.4 to 30.7 g/d, with no further increase beyond 9 g/d of Lys (linear and quadratic, < 0.01). Break-point analysis estimated maximal N retention at 9 g/d supplemental Lys. Over the linear response surface of 0 to 9 g/d Lys, the efficiency of Lys utilization for protein deposition was 40%. Plasma urea N tended to be linearly decreased ( = 0.06) by Lys supplementation in agreement with the reduction in urinary urea N excretion. Plasma concentrations

  19. Radiative magnetized thermal conduction fronts

    NASA Technical Reports Server (NTRS)

    Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

    1990-01-01

    The evolution of plane-parallel magnetized thermal conduction fronts in the interstellar medium (ISM) was studied. Separating the coronal ISM phase and interstellar clouds, these fronts have been thought to be the site of the intermediate-temperature regions whose presence was inferred from O VI absorption-line studies. The front evolution was followed numerically, starting from the initial discontinuous temperature distribution between the hot and cold medium, and ending in the final cooling stage of the hot medium. It was found that, for the typical ISM pressure of 4000 K/cu cm and the hot medium temperature of 10 to the 6th K, the transition from evaporation to condensation in a nonmagnetized front occurs when the front thickness is 15 pc. This thickness is a factor of 5 smaller than previously estimated. The O VI column densities in both evaporative and condensation stages agree with observations if the initial hot medium temperature Th exceeds 750,000 K. Condensing conduction fronts give better agreement with observed O VI line profiles because of lower gas temperatures.

  20. Restless rays, steady wave fronts.

    PubMed

    Godin, Oleg A

    2007-12-01

    Observations of underwater acoustic fields with vertical line arrays and numerical simulations of long-range sound propagation in an ocean perturbed by internal gravity waves indicate that acoustic wave fronts are much more stable than the rays comprising these wave fronts. This paper provides a theoretical explanation of the phenomenon of wave front stability in a medium with weak sound-speed perturbations. It is shown analytically that at propagation ranges that are large compared to the correlation length of the sound-speed perturbations but smaller than ranges at which ray chaos develops, end points of rays launched from a point source and having a given travel time are scattered primarily along the wave front corresponding to the same travel time in the unperturbed environment. The ratio of root mean square displacements of the ray end points along and across the unperturbed wave front increases with range as the ratio of ray length to correlation length of environmental perturbations. An intuitive physical explanation of the theoretical results is proposed. The relative stability of wave fronts compared to rays is shown to follow from Fermat's principle and dimensional considerations. PMID:18247745

  1. International Polar Year Youth Steering Committee

    NASA Astrophysics Data System (ADS)

    Baeseman, J. L.; Church, A.; Kuhn, T.; Raymond, M.; Lantuit, H.

    2006-12-01

    The International Youth Steering Committee is made up of youth representatives from around the world, from science, social science, aboriginal and arts backgrounds and ranging in education from new faculty to high school. The YSC serves as a voice for youth on polar issues and empower youth to get involved in issues facing the Polar Regions. YSC is working to draw the World's attention to the poles and act as a force for positive change. An International YSC website has been developed which will provide a forum where youth will be able to communicate with each other globally and get involved in IPY and YSC programs. One of these programs is the International Youth Conference on the Poles (IYCP). This conference, which will take place in May 2008, will bring together youth from around the world to focus on polar issues. Young polar researchers are being recruited to design educational materials based on their work for another YSC project, Polar Contests. YSC has partnered with Students on Ice (SOI), a non-profit organization who will be providing a series of nine SOI- IPY YSC expeditions to the Arctic and Antarctic over the course of IPY, allowing hundreds of students from around the world to experience the Polar Regions first-hand, learn from experts working in these areas and become inspired to work for their continued protection. We are also sponsoring an opportunity for youth from around the world to connect with and interview the participants of the International Geophysical Year (IGY), the results of that will ultimately be presented in book or documentary form at the close of IPY. The YSC has partnered with the science fiction educational book series, Tales of the Wonder Zone, to release Polaris; A Celebration of Polar Science, in which youth and professional authors from around the world submitted stories based on an IPY fifty years in the future. The final part of the YSC is to provide a forum and activities that will allow early career scientists to

  2. 46 CFR 169.826 - Steering, communications and control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Steering, communications and control. 169.826 Section 169.826 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations Tests, Drills, and Inspections § 169.826 Steering, communications and...

  3. 46 CFR 169.826 - Steering, communications and control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering, communications and control. 169.826 Section 169.826 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations Tests, Drills, and Inspections § 169.826 Steering, communications and...

  4. Gaussian quantum steering and its asymmetry in curved spacetime

    NASA Astrophysics Data System (ADS)

    Wang, Jieci; Cao, Haixin; Jing, Jiliang; Fan, Heng

    2016-06-01

    We study Gaussian quantum steering and its asymmetry in the background of a Schwarzschild black hole. We present a Gaussian channel description of quantum state evolution under the influence of Hawking radiation. We find that thermal noise introduced by the Hawking effect will destroy the steerability between an inertial observer Alice and an accelerated observer Bob who hovers outside the event horizon, while it generates steerability between Bob and a hypothetical observer anti-Bob inside the event horizon. Unlike entanglement behaviors in curved spacetime, here the steering from Alice to Bob suffers from a "sudden death" and the steering from anti-Bob to Bob experiences a "sudden birth" with increasing Hawking temperature. We also find that the Gaussian steering is always asymmetric and the maximum steering asymmetry cannot exceed ln 2 , which means the state never evolves to an extremal asymmetry state. Furthermore, we obtain the parameter settings that maximize steering asymmetry and find that (i) s =arccosh cosh/2r 1 -sinh2r is the critical point of steering asymmetry and (ii) the attainment of maximal steering asymmetry indicates the transition between one-way steerability and both-way steerability for the two-mode Gaussian state under the influence of Hawking radiation.

  5. 33 CFR 164.39 - Steering gear: Foreign tankers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Steering gear: Foreign tankers. 164.39 Section 164.39 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.39 Steering gear: Foreign...

  6. 33 CFR 164.39 - Steering gear: Foreign tankers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Steering gear: Foreign tankers. 164.39 Section 164.39 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.39 Steering gear: Foreign...

  7. 33 CFR 164.39 - Steering gear: Foreign tankers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Steering gear: Foreign tankers. 164.39 Section 164.39 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.39 Steering gear: Foreign...

  8. 33 CFR 164.39 - Steering gear: Foreign tankers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Steering gear: Foreign tankers. 164.39 Section 164.39 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.39 Steering gear: Foreign...

  9. 36. View aft to steering wheel (R. H. Dougherty and ...

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

    36. View aft to steering wheel (R. H. Dougherty and Co. of Baltimore) and steering gear box taken from on top of Aft Cabin. - Two-Sail Bateau E. C. COLLIER, Chesapeake Bay Maritime Museum, Mills Street, Saint Michaels, Talbot County, MD

  10. 9 CFR 78.6 - Steers and spayed heifers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Steers and spayed heifers. 78.6 Section 78.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.6 Steers and spayed heifers....

  11. 9 CFR 78.6 - Steers and spayed heifers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Steers and spayed heifers. 78.6 Section 78.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.6 Steers and spayed heifers....

  12. Theory and experimental research on six-track steering vehicles

    NASA Astrophysics Data System (ADS)

    Zongwei, Yao; Guoqiang, Wang; Rui, Guo; Xuefei, Li

    2013-02-01

    The structural characteristics and steering behaviour of a six-track vehicle are described in this paper. Kinematic analysis for skid steering of a six-track vehicle under steady-state conditions on firm ground is conducted, with the relationship between thrust force and speed instantaneous centre of the track-terrain interface taken into consideration. A mechanical model for steady steering of a six-track vehicle is also presented based on the kinematic analysis. In this model, the steering inaccuracy and efficiency are defined to evaluate steering performance. The steering performance of a six-track vehicle is numerically simulated to analyse the effect of the structural parameters and deflection angles on tracks. A virtual prototype model is established based on the multi-body dynamics software RecurDyn for steering simulation and the findings coincide well with theoretical results. The theory and the virtual prototype simulations presented are verified by a power test of a bucket-wheel excavator. The method for analysing the steering performance of a six-track vehicle proposed in this paper provides a basis for designing a six-track vehicle.

  13. Steering into the Curve: Getting Real in the Classroom

    ERIC Educational Resources Information Center

    Uhl, Christopher

    2010-01-01

    Dozens and dozens of little deaths occur in college classrooms each day as teachers, mostly because of fear, steer themselves and their students away from what is alive and real and toward what is dead, safe, and boring. In this paper, I use a collection of stories to describe a practice that enlivens classroom dynamics that I call "Steering Into…

  14. ICESat-2 ATLAS Beam Steering Mechanism (BSM)

    NASA Technical Reports Server (NTRS)

    Hinkle, Matthew

    2015-01-01

    This work covers the design and test of a beam steering mechanism (BSM) used to accurately guide a laser on the Advanced Topographic Laser Altimeter System (ATLAS) down to Earth in order to measure elevation. It describes the main components in the BSM that allows it to perform and meet stringent requirements. Requirements of the BSM include two-axis steering of the transmitted laser beam, +-5000 uRad mechanical motion in each axis, and 1.5 uRad RMS pointing stability among many other requirements. The BSM uses four voice coil actuators in order to locate the mirror at the angle we need. There are four Differential Position Sensors that determine the position and angle of the mirror at all times. These sensors were verified through optical testing in both ambient and thermal conditions. Testing and extensive analyses were performed on the two-axis flexure throughout the program to check flexure thickness, positive margins, and infinite life. The mirror mount design has been modified to eliminate radial preload, while incorporating a titanium wave spring to provide an axial preload of 10.8N. The BSM underwent multiple tests in order to verify all components work as required under various conditions.

  15. Steering a mobile robot in real time

    NASA Astrophysics Data System (ADS)

    Chuah, Mei C.; Fennema, Claude L., Jr.

    1994-10-01

    Using computer vision for mobile robot navigation has been of interest since the 1960s. This interest is evident in even the earliest robot projects: at SRI International (`Shakey') and at the Stanford University (`Stanford Cart'). These pioneering projects provided a foundation for late work but fell far short of providing real time solutions. Since the mid 1980s, the ARPA sponsored ALV and UGV projects have established a need for real time navigation. To achieve the necessary speed, some researchers have focused on building faster hardware; others have turned to the use of new computational architectures, such as neural nets. The work described in this paper uses another approach that has become known as `perceptual servoing.' Previously reported results show that perceptual servoing is both fast and accurate when used to steer vehicles equipped with precise odometers. When the instrumentation on the vehicle does not give precise measurements of distance traveled, as could be the case for a vehicle traveling on ice or mud, new techniques are required to accommodate the reduced ability to make accurate predictions about motion and control. This paper presents a method that computes estimates of distance traveled using landmarks and path information. The new method continues to perform in real time using modest computational facilities, and results demonstrate the effects of the new implementation on steering accuracy.

  16. Effect of early grain feeding of beef steers on postabsorptive metabolism.

    PubMed

    Nayananjalie, W A D; Pike, K L; Wiles, T R; McCann, M A; Scheffler, J M; Greiner, S P; Schramm, H H; Gerrard, D E; Jiang, H; Hanigan, M D

    2015-05-01

    The objective of this study was to determine the effect of early weaning followed by a period of high-grain feeding on plasma acetate kinetics and signaling protein phosphorylation in LM tissue of growing steers. We hypothesized that early grain feeding would result in altered cell signaling and acetate use to support observed improvements in carcass gain and marbling. Fall-born Angus × Simmental steers were weaned at 106 ± 4 d of age (early weaned [EW]; n = 6) and fed a high-grain diet for 148 d or remained with their dams (normal weaned [NW]; n = 6) on pasture until weaning at 251 ± 5 d of age. Both treatments were subsequently combined and grazed on mixed summer pasture to 394 ± 5 d of age followed by a feedlot ration until harvest at 513 ± 5 d of age. Longissimus muscle tissue biopsies were collected at 253 ± 5 and 394 ± 5 d of age and at harvest. Total and phosphorylated forms of 5' adenosine monophosphate-activated protein kinase (AMPK) and downstream proteins of the mammalian target of rapamycin signaling pathway were determined by western blotting. Eight steers were used to assess acetate clearance at different age points via a bolus infusion of acetate (4 mmol/kg of BW). Early weaned steers had greater (P < 0.05) ADG than NW steers during the early grain feeding period. Phosphorylated to total ratios of ribosomal protein S6 (rpS6) and ribosomal protein S6 kinase 1 (S6K1) were significantly different during the early grain feeding period. Phosphorylated to total ratios of S6K1, rpS6, acetyl-CoA carboxylase, and 4E binding protein 1 and the absolute amount of phosphorylated AMPK were correlated with ADG, explaining 46% of the variance. Acetate clearance rates were less (P < 0.05) and synthesis rates were greater (P = 0.06) in EW steers during early grain feeding. Acetate synthesis rates were also greater (P < 0.05) in NW steers at harvest, suggesting a permanent shift in the gut microflora or gut function in response to the treatment. Neither

  17. Io in Front of Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Jupiter's four largest satellites, including Io, the golden ornament in front of Jupiter in this image from NASA's Cassini spacecraft, have fascinated Earthlings ever since Galileo Galilei discovered them in 1610 in one of his first astronomical uses of the telescope.

    Images from Cassini that will be released over the next several days capture each of the four Galilean satellites in their orbits around the giant planet.

    This true-color composite frame, made from narrow angle images taken on Dec. 12, 2000, captures Io and its shadow in transit against the disk of Jupiter. The distance of the spacecraft from Jupiter was 19.5 million kilometers (12.1 million miles). The image scale is 117 kilometers (73 miles) per pixel.

    The entire body of Io, about the size of Earth's Moon, is periodically flexed as it speeds around Jupiter and feels, as a result of its non-circular orbit, the periodically changing gravitational pull of the planet. The heat arising in Io's interior from this continual flexure makes it the most volcanically active body in the solar system, with more than 100 active volcanoes. The white and reddish colors on its surface are due to the presence of different sulfurous materials. The black areas are silicate rocks.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  18. Conclusive quantum steering with superconducting transition edge sensors

    NASA Astrophysics Data System (ADS)

    de Almeida, Marcelo P.; Smith, Devin H.; Gillett, Geo; Branciard, Cyril; Fedrizzi, Alessandro; Weinhold, Till J.; Lita, Adriana; Calkins, Brice; Gertis, Thomas; Nam, Sae Woo; White, Andrew G.

    2012-02-01

    Quantum steering allows two parties to verify shared entanglement even if one measurement device is untrusted. A conclusive demonstration of steering through the violation of a steering inequality is of considerable fundamental interest and opens up applications in quantum communication. To date all experimental tests with single photon states have relied on post-selection, allowing untrusted devices to cheat by hiding unfavorable events in losses. Here we close this ``detection loophole'' by combining a highly efficient source of entangled photon pairs with superconducting transition edge sensors. We achieve an unprecedented ˜62% conditional detection efficiency of entangled photons and violate a steering inequality with the minimal number of measurement settings by 48 standard deviations. Our results provide a clear path to practical applications of steering and to a photonic loophole-free Bell test.

  19. Conclusive quantum steering with superconducting transition-edge sensors

    NASA Astrophysics Data System (ADS)

    Smith, Devin H.; Gillett, Geoff; de Almeida, Marcelo P.; Branciard, Cyril; Fedrizzi, Alessandro; Weinhold, Till J.; Lita, Adriana; Calkins, Brice; Gerrits, Thomas; Wiseman, Howard M.; Nam, Sae Woo; White, Andrew G.

    2012-01-01

    Quantum steering allows two parties to verify shared entanglement even if one measurement device is untrusted. A conclusive demonstration of steering through the violation of a steering inequality is of considerable fundamental interest and opens up applications in quantum communication. To date, all experimental tests with single-photon states have relied on post selection, allowing untrusted devices to cheat by hiding unfavourable events in losses. Here we close this 'detection loophole' by combining a highly efficient source of entangled photon pairs with superconducting transition-edge sensors. We achieve an unprecedented ~62% conditional detection efficiency of entangled photons and violate a steering inequality with the minimal number of measurement settings by 48 s.d.s. Our results provide a clear path to practical applications of steering and to a photonic loophole-free Bell test.

  20. Pentan isomers compound flame front structure

    SciTech Connect

    Mansurov, Z.A.; Mironenko, A.W.; Bodikov, D.U.; Rachmetkaliev, K.N.

    1995-08-13

    The fuels (hexane, pentane, diethyl ether) and conditions investigated in this study are relevant to engine knock in spark- ignition engines. A review is provided of the field of low temperature hydrocarbon oxidation. Studies were made of radical and stable intermediate distribution in the front of cool flames: Maximum concentrations of H atoms and peroxy radicals were observed in the luminous zone of the cool flame front. Peroxy radicals appear before the luminous zone at 430 K due to diffusion. H atoms were found in cool flames of butane and hexane. H atoms diffuses from the luminous zone to the side of the fresh mixture, and they penetrate into the fresh mixture to a small depth. Extension of action sphear of peroxy radicals in the fresh mixture is much greater than that of H atoms due to their small activity and high concentrations.

  1. Electromagnetic energy conversion at reconnection fronts.

    PubMed

    Angelopoulos, V; Runov, A; Zhou, X-Z; Turner, D L; Kiehas, S A; Li, S-S; Shinohara, I

    2013-09-27

    Earth's magnetotail contains magnetic energy derived from the kinetic energy of the solar wind. Conversion of that energy back to particle energy ultimately powers Earth's auroras, heats the magnetospheric plasma, and energizes the Van Allen radiation belts. Where and how such electromagnetic energy conversion occurs has been unclear. Using a conjunction between eight spacecraft, we show that this conversion takes place within fronts of recently reconnected magnetic flux, predominantly at 1- to 10-electron inertial length scale, intense electrical current sheets (tens to hundreds of nanoamperes per square meter). Launched continually during intervals of geomagnetic activity, these reconnection outflow flux fronts convert ~10 to 100 gigawatts per square Earth radius of power, consistent with local magnetic flux transport, and a few times 10(15) joules of magnetic energy, consistent with global magnetotail flux reduction. PMID:24072917

  2. Electromagnetic energy conversion at reconnection fronts.

    PubMed

    Angelopoulos, V; Runov, A; Zhou, X-Z; Turner, D L; Kiehas, S A; Li, S-S; Shinohara, I

    2013-09-27

    Earth's magnetotail contains magnetic energy derived from the kinetic energy of the solar wind. Conversion of that energy back to particle energy ultimately powers Earth's auroras, heats the magnetospheric plasma, and energizes the Van Allen radiation belts. Where and how such electromagnetic energy conversion occurs has been unclear. Using a conjunction between eight spacecraft, we show that this conversion takes place within fronts of recently reconnected magnetic flux, predominantly at 1- to 10-electron inertial length scale, intense electrical current sheets (tens to hundreds of nanoamperes per square meter). Launched continually during intervals of geomagnetic activity, these reconnection outflow flux fronts convert ~10 to 100 gigawatts per square Earth radius of power, consistent with local magnetic flux transport, and a few times 10(15) joules of magnetic energy, consistent with global magnetotail flux reduction.

  3. Genetic markers of body composition and carcass quality in grazing Brangus steers.

    PubMed

    Baeza, M C; Corva, P M; Soria, L A; Rincon, G; Medrano, J F; Pavan, E; Villarreal, E L; Schor, A; Melucci, L; Mezzadra, C; Miquel, M C

    2011-01-01

    The somatotropic axis is a major regulatory pathway of energy metabolism during postnatal growth in mammals. Genes involved in this pathway influence many economically important traits. The association of selected SNPs in these genes with carcass traits was examined in grazing Brangus steers. These traits included final live weight, ultrasound backfat thickness (UBFT), rib-eye area, kidney fat weight, hot carcass weight, and intramuscular fat percentage (%IMF). Genomic DNA (N = 246) was genotyped for a panel of 15 tag SNPs located in the growth hormone receptor (GHR), insulin-like growth factor I, insulin-like growth factor-binding protein 6, pro-melanin-concentrating hormone, suppressor of cytokine signaling 2, and signal transducer and activator of transcription 6 (STAT6) genes. Allelic and haplotype frequencies were compared with those of a sample of European breeds (N = 177 steers). Two tag SNPs in the GHR affected %IMF; one of them (ss86273136) was also strongly associated with UBFT (P < 0.003). The frequency of the most favorable GHR haplotype for %IMF was lower in Brangus steers. Moreover, the haplotype carrying two unfavorable alleles was present at a frequency of 31% in this group. Four tag SNPs on STAT6 had a significant effect on UBFT. One of these, SNP ss115492467, was also associated with %IMF. The STAT6 haplotype, including all the alleles favoring UBFT, was the most abundant variant (34%) in the European cattle, while it had a frequency of 14% in the Brangus steers. The four less favorable variants (absent in the European cattle) were found at a frequency of 38% in the Brangus steers. These results support the association of GHR and STAT6 SNP with carcass traits in composite breeds, such as Brangus, under grazing conditions. PMID:22194170

  4. The Front Line.

    ERIC Educational Resources Information Center

    Unks, Gerald

    1979-01-01

    The author draws an analogy between today's school system and an assembly line, deploring the notion that all children are taught the same thing at the same time, ending in humiliation, disgrace, and failure for some, and nonchallenging academic activities for others. (KC)

  5. Front End Schaltung zur Online Auswertung von EKG-Signalen

    NASA Astrophysics Data System (ADS)

    Ayari, E.; Tielert, R.

    2007-06-01

    Ein mobiles EKG-System zur Online Auswertung von EKG-Signalen wird dargestellt. Die Auswertung beruht auf ein energiesparendes Verfahren, das den Vorteil einer zulässigen Unterabtastung des Signals bietet und eine Interaktion zwischen der messenden Elektronik und dem funkgebundenen Auswertungsrechner ermöglicht. Diese Interaktion besteht darin, sowohl die Front End Schaltung im EKG-Sensor als auch den im ATmega8L eingebetteten A/D-Wandler vom Auswertungsrechner zu steuern und den Datenbedarf des Rechners dynamisch an die Erfordernisse des Analyseprogramms anzupassen. Das entwickelte EKG-System liefert erfolgreiche Charakterisierungen erfasster Elektrokardiogramme. A mobile ecg-system for an online analysis of electrocardiogram signals is presented. The analysis is based on an energy-saving procedure, which offers the advantage of an acceptable undersampling of the signal, and which allows an interaction between the measuring electronic and the radio-bound analysis-computer. In this interaction both the front-end circuit in the ecg-sensor and the A/D converter, which is embedded in the ATmega8L, are steered by the analysis computer. The data requirement of the computer is also dynamically adapted to the requirements of the analysis-program. The developed ecg-system supplies successful characterisations of measured electrocardiograms.

  6. Mechanistic principles of colloidal crystal growth by evaporation-induced convective steering.

    PubMed

    Brewer, Damien D; Allen, Joshua; Miller, Michael R; de Santos, Juan M; Kumar, Satish; Norris, David J; Tsapatsis, Michael; Scriven, L E

    2008-12-01

    We simulate evaporation-driven self-assembly of colloidal crystals using an equivalent network model. Relationships between a regular hexagonally close-packed array of hard, monodisperse spheres, the associated pore space, and selectivity mechanisms for face-centered cubic microstructure propagation are described. By accounting for contact line rearrangement and evaporation at a series of exposed menisci, the equivalent network model describes creeping flow of solvent into and through a rigid colloidal crystal. Observations concerning colloidal crystal growth are interpreted in terms of the convective steering hypothesis, which posits that solvent flow into and through the pore space of the crystal may play a major role in colloidal self-assembly. Aspects of the convective steering and deposition of high-Peclet-number rigid spherical particles at a crystal boundary are inferred from spatially resolved solvent flow into the crystal. Gradients in local flow through boundary channels were predicted due to the channels' spatial distribution relative to a pinned free surface contact line. On the basis of a uniform solvent and particle flux as the criterion for stability of a particular growth plane, these network simulations suggest the stability of a declining {311} crystal interface, a symmetry plane which exclusively propagates fcc microstructure. Network simulations of alternate crystal planes suggest preferential growth front evolution to the declining {311} interface, in consistent agreement with the proposed stability mechanism for preferential fcc microstructure propagation in convective assembly.

  7. Automatic guidance control of an articulated all-wheel-steered vehicle

    NASA Astrophysics Data System (ADS)

    Kim, Young Chol; Yun, Kyong-Han; Min, Kyung-Deuk

    2014-04-01

    This paper presents automatic guidance control of a single-articulated all-wheel-steered vehicle being developed by the Korea Railroad Research Institute. The vehicle has an independent drive motor on each wheel except for the front axle. The guidance controller is designed so that the vehicle follows the given reference path within permissible lateral deviations. We use a three-input/three-output linearised model derived from the nonlinear dynamic model of the vehicle. For the purpose of simplifying the controller and making it tunable, we consider a decentralised control configuration. We first design a second-order decoupling compensator for the two-input/two-output system that is strongly coupled and then design a first-order controller for each decoupled feedback loop by using the characteristic ratio assignment method. The simulation results for the nonlinear dynamic model indicate that the proposed control configuration successfully achieves the design objectives.

  8. The Expression of Adipogenic Genes in Adipose Tissues of Feedlot Steers Fed Supplementary Palm Oil or Soybean Oil

    PubMed Central

    Choi, Seong Ho; Park, Sung Kwon; Choi, Chang Weon; Li, Xiang Zi; Kim, Kyoung Hoon; Kim, Won Young; Jeong, Joon; Johnson, Bradley J.; Zan, Linsen; Smith, Stephen B.

    2016-01-01

    We hypothesized that supplementing finishing diets with palm oil would promote adipogenic gene expression and stearoyl-CoA desaturase (SCD) gene expression in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues of feedlot steers. Eighteen Angus and Angus crossbred steers were assigned to three groups of 6 steers and fed a basal diet (control), with 3% palm oil, or with 3% soybean oil, for 70 d, top-dressed daily. Tailhead s.c. adipose tissue was obtained by biopsy at 14 d before the initiation of dietary treatments and at 35 d of dietary treatments. At slaughter, after 70 d of dietary treatment, tailhead s.c. adipose tissue and i.m. adipose tissue were obtained from the longissimus thoracis muscle. Palm oil increased plasma palmitic acid and soybean oil increased plasma linoleic acid and α-linolenic acid relative to the initial sampling time. Expression of AMP-activated protein kinase alpha (AMPKα) and peroxisome proliferator-activated receptor gamma (PPARγ) increased between the initial and intermediate biopsies and declined thereafter (p<0.03). SCD gene expression did not change between the initial and intermediate biopsies but declined by over 75% by the final period (p = 0.04), and G-coupled protein receptor 43 (GPR43) gene expression was unaffected by diet or time on trial. Soybean oil decreased (p = 0.01) PPARγ gene expression at the intermediate sample time. At the terminal sample time, PPARγ and SCD gene expression was less in i.m. adipose tissue than in s.c. adipose tissue (p<0.05). AMPKα gene expression was less in s.c. adipose tissue of palm oil-fed steers than in control steers (p = 0.04) and CCAAT enhancer binding protein-beta (CEBPβ) gene expression was less in s.c. and i.m. adipose tissues of palm oil-fed steers than in soybean oil-fed steers (p<0.03). Soybean oil decreased SCD gene expression in s.c. adipose tissue (p = 0.05); SCD gene expression in palm oil-fed steers was intermediate between control and soybean oil-fed steers

  9. The Expression of Adipogenic Genes in Adipose Tissues of Feedlot Steers Fed Supplementary Palm Oil or Soybean Oil.

    PubMed

    Choi, Seong Ho; Park, Sung Kwon; Choi, Chang Weon; Li, Xiang Zi; Kim, Kyoung Hoon; Kim, Won Young; Jeong, Joon; Johnson, Bradley J; Zan, Linsen; Smith, Stephen B

    2016-03-01

    We hypothesized that supplementing finishing diets with palm oil would promote adipogenic gene expression and stearoyl-CoA desaturase (SCD) gene expression in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues of feedlot steers. Eighteen Angus and Angus crossbred steers were assigned to three groups of 6 steers and fed a basal diet (control), with 3% palm oil, or with 3% soybean oil, for 70 d, top-dressed daily. Tailhead s.c. adipose tissue was obtained by biopsy at 14 d before the initiation of dietary treatments and at 35 d of dietary treatments. At slaughter, after 70 d of dietary treatment, tailhead s.c. adipose tissue and i.m. adipose tissue were obtained from the longissimus thoracis muscle. Palm oil increased plasma palmitic acid and soybean oil increased plasma linoleic acid and α-linolenic acid relative to the initial sampling time. Expression of AMP-activated protein kinase alpha (AMPKα) and peroxisome proliferator-activated receptor gamma (PPARγ) increased between the initial and intermediate biopsies and declined thereafter (p<0.03). SCD gene expression did not change between the initial and intermediate biopsies but declined by over 75% by the final period (p = 0.04), and G-coupled protein receptor 43 (GPR43) gene expression was unaffected by diet or time on trial. Soybean oil decreased (p = 0.01) PPARγ gene expression at the intermediate sample time. At the terminal sample time, PPARγ and SCD gene expression was less in i.m. adipose tissue than in s.c. adipose tissue (p<0.05). AMPKα gene expression was less in s.c. adipose tissue of palm oil-fed steers than in control steers (p = 0.04) and CCAAT enhancer binding protein-beta (CEBPβ) gene expression was less in s.c. and i.m. adipose tissues of palm oil-fed steers than in soybean oil-fed steers (p<0.03). Soybean oil decreased SCD gene expression in s.c. adipose tissue (p = 0.05); SCD gene expression in palm oil-fed steers was intermediate between control and soybean oil-fed steers

  10. The Expression of Adipogenic Genes in Adipose Tissues of Feedlot Steers Fed Supplementary Palm Oil or Soybean Oil.

    PubMed

    Choi, Seong Ho; Park, Sung Kwon; Choi, Chang Weon; Li, Xiang Zi; Kim, Kyoung Hoon; Kim, Won Young; Jeong, Joon; Johnson, Bradley J; Zan, Linsen; Smith, Stephen B

    2016-03-01

    We hypothesized that supplementing finishing diets with palm oil would promote adipogenic gene expression and stearoyl-CoA desaturase (SCD) gene expression in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues of feedlot steers. Eighteen Angus and Angus crossbred steers were assigned to three groups of 6 steers and fed a basal diet (control), with 3% palm oil, or with 3% soybean oil, for 70 d, top-dressed daily. Tailhead s.c. adipose tissue was obtained by biopsy at 14 d before the initiation of dietary treatments and at 35 d of dietary treatments. At slaughter, after 70 d of dietary treatment, tailhead s.c. adipose tissue and i.m. adipose tissue were obtained from the longissimus thoracis muscle. Palm oil increased plasma palmitic acid and soybean oil increased plasma linoleic acid and α-linolenic acid relative to the initial sampling time. Expression of AMP-activated protein kinase alpha (AMPKα) and peroxisome proliferator-activated receptor gamma (PPARγ) increased between the initial and intermediate biopsies and declined thereafter (p<0.03). SCD gene expression did not change between the initial and intermediate biopsies but declined by over 75% by the final period (p = 0.04), and G-coupled protein receptor 43 (GPR43) gene expression was unaffected by diet or time on trial. Soybean oil decreased (p = 0.01) PPARγ gene expression at the intermediate sample time. At the terminal sample time, PPARγ and SCD gene expression was less in i.m. adipose tissue than in s.c. adipose tissue (p<0.05). AMPKα gene expression was less in s.c. adipose tissue of palm oil-fed steers than in control steers (p = 0.04) and CCAAT enhancer binding protein-beta (CEBPβ) gene expression was less in s.c. and i.m. adipose tissues of palm oil-fed steers than in soybean oil-fed steers (p<0.03). Soybean oil decreased SCD gene expression in s.c. adipose tissue (p = 0.05); SCD gene expression in palm oil-fed steers was intermediate between control and soybean oil-fed steers

  11. Carcass characteristics, the calpain proteinase system, and aged tenderness of Angus and Brahman crossbred steers.

    PubMed

    Pringle, T D; Williams, S E; Lamb, B S; Johnson, D D; West, R L

    1997-11-01

    We used 69 steers of varying percentage Brahman (B) breeding (0% B, n = 11; 25% B, n = 13; 37% B, n = 10; 50% B, n = 12; 75% B, n = 12; 100% B, n = 11) to study the relationship between carcass traits, the calpain proteinase system, and aged meat tenderness in intermediate B crosses. Calpains and calpastatin activities were determined on fresh longissimus muscle samples using anion-exchange chromatography. The USDA yield and quality grade data (24 h) were collected for each carcass. Longissimus steaks were removed and aged for 5 or 14 d for determination of shear force and 5 d for sensory panel evaluation. Even though some yield grade factors were affected by the percentage of B breeding, USDA yield grades did not differ (P > .15) between breed types. Marbling score and USDA quality grade decreased linearly (P < .01) with increasing percentage of B breeding. Shear force after 5 and 14 d of aging was higher (P < .05) in the 100% B steers than in all other breed types, which were not significantly different. Sensory panel tenderness and connective tissue scores decreased linearly (P < .05) with increasing B breeding. A quadratic effect was also noted for tenderness and connective tissue scores; 37% B steers received the highest scores. A similar response was found in mu-calpain activities; the 37% B steers had the highest activities. Conversely, calpastatin activity increased linearly (P < .01) with increasing percentage B breeding. These data show strong linear relationships between calpastatin activity (positive), marbling score (negative), and percentage B breeding, suggesting a possible combined effect of these traits on aged tenderness of intermediate Brahman crosses. PMID:9374310

  12. Carcass characteristics, the calpain proteinase system, and aged tenderness of Angus and Brahman crossbred steers.

    PubMed

    Pringle, T D; Williams, S E; Lamb, B S; Johnson, D D; West, R L

    1997-11-01

    We used 69 steers of varying percentage Brahman (B) breeding (0% B, n = 11; 25% B, n = 13; 37% B, n = 10; 50% B, n = 12; 75% B, n = 12; 100% B, n = 11) to study the relationship between carcass traits, the calpain proteinase system, and aged meat tenderness in intermediate B crosses. Calpains and calpastatin activities were determined on fresh longissimus muscle samples using anion-exchange chromatography. The USDA yield and quality grade data (24 h) were collected for each carcass. Longissimus steaks were removed and aged for 5 or 14 d for determination of shear force and 5 d for sensory panel evaluation. Even though some yield grade factors were affected by the percentage of B breeding, USDA yield grades did not differ (P > .15) between breed types. Marbling score and USDA quality grade decreased linearly (P < .01) with increasing percentage of B breeding. Shear force after 5 and 14 d of aging was higher (P < .05) in the 100% B steers than in all other breed types, which were not significantly different. Sensory panel tenderness and connective tissue scores decreased linearly (P < .05) with increasing B breeding. A quadratic effect was also noted for tenderness and connective tissue scores; 37% B steers received the highest scores. A similar response was found in mu-calpain activities; the 37% B steers had the highest activities. Conversely, calpastatin activity increased linearly (P < .01) with increasing percentage B breeding. These data show strong linear relationships between calpastatin activity (positive), marbling score (negative), and percentage B breeding, suggesting a possible combined effect of these traits on aged tenderness of intermediate Brahman crosses.

  13. Carcass, sensory, and adipose tissue traits of Brangus steers fed casein-formaldehyde-protected starch and/or canola lipid.

    PubMed

    Gilbert, C D; Lunt, D K; Miller, R K; Smith, S B

    2003-10-01

    .m. adipose tissue. Fatty acid synthetase activity tended (P = 0.08) to be higher in s.c. adipose tissue of Marble Plus steers, and NADP-malic dehydrogenase activity was higher (P = 0.03) in i.m. adipose tissue of Canola Lipid steers. We conclude that Marble Plus did not improve carcass quality, but also did not reduce beef sensory attributes. Any differences we observed in carcass characteristics, adipose tissue cellularity, or lipogenesis apparently were caused by the protected lipid rather than the protected starch. PMID:14552372

  14. Design of an Ultra-Efficient GaN High Power Amplifier for Radar Front-Ends Using Active Harmonic Load-Pull

    NASA Technical Reports Server (NTRS)

    Thrivikraman, Tushar; Hoffman, James

    2012-01-01

    This work presents a new measurement technique, mixed-signal active harmonic load-pull (MSALP) developed by Anterverta-mw in partnership with Maury Microwave, that allows for wide-band ultra-high efficiency amplifiers to be designed using GaN technology. An overview of the theory behind active load-pull is presented and why load-pull is important for high-power device characterization. In addition, an example procedure is presented that outlines a methodology for amplifier design using this measurement system. Lastly, measured results of a 10W GaN amplifier are presented. This work aims to highlight the benefit of using this sophisticated measurement systems for to optimize amplifier design for real radar waveforms that in turn will simplify implementation of space-based radar systems

  15. Phase shifter for antenna beam steering

    NASA Astrophysics Data System (ADS)

    Jindal, Ravi; Razban, Tchanguiz

    2016-03-01

    Wide band Array Antenna operates in Ku-band (10.7-12.7 GHz) frequency composed of N×N radiating elements. This antenna aims at the reception of television satellite signals. The goal of this research is to provide better possibility of electronic beam control instead of manual or mechanical control, and design compact and low cost phase shifters to be inserted in the feeding network of this antenna. The electronic control of the phase shifter will allow the control of beam steering. The emphasis of this project will be done at the beginning on the design of a good phase shifter in Ku band. The aim of this research is to define, simulate, release and measure a continuous phase shifter. Better reflection loss, low transmission loss, low Cost of array antennas, large range of phase-shifter, phase flatness and bandwidth will be achieved by providing better gain.

  16. New twist to steering. [Magnus effect rotors

    SciTech Connect

    Borg, J.L.

    1980-06-01

    The new vessel steering system is based on The Magnus Effect which is defined in simplified terms; if a vertical cylinder immersed in water is rotated, it produces a force at right angles to the direction of the water flowing past it. The Magnus Effect rotor needs only sufficient torque to overcome bearing and surface friction forces, so that the power requirements are very low. Further energy savings are realized because the rotor can develop maximum turning force or can return to zero in a few seconds. Tests with these cylindrical rudders have been conducted to verify the hydrodynamic theory. This concept is in the preliminary stages of development. Results are expected soon from field testing on an 1800-hp pushboat working four barges on the Warrior and Tombigbee Rivers in Alabama and Mississippi.

  17. Fast steering mirror for laser communication

    NASA Astrophysics Data System (ADS)

    Langenbach, Harald; Schmid, Manfred

    2005-07-01

    Future multimedia satellites require communication at large bandwidth which can be achieved by means of optical communication links. TESAT Spacecom is currently developing a Laser Communication Terminal (LCT) for such applications under DLR contract. EADS Astrium is developing and building the mechanisms for Pointing, Acquisition and Tracking (PAT) of the laser beam between two Laser Communication Terminals. Based on this development work the development of mechanism H/W to be flown on TerraSar X is currently under way. After a short description of the general arrangement of the Mechanisms inside the LCT, the paper describes the design of the fast steering mirrors (FSM) reflecting the critical requirements and the solutions how to achieve them.

  18. Steering attosecond electron wave packets with light.

    PubMed

    Kienberger, R; Hentschel, M; Uiberacker, M; Spielmann, Ch; Kitzler, M; Scrinzi, A; Wieland, M; Westerwalbesloh, Th; Kleineberg, U; Heinzmann, U; Drescher, M; Krausz, F

    2002-08-16

    Photoelectrons excited by extreme ultraviolet or x-ray photons in the presence of a strong laser field generally suffer a spread of their energies due to the absorption and emission of laser photons. We demonstrate that if the emitted electron wave packet is temporally confined to a small fraction of the oscillation period of the interacting light wave, its energy spectrum can be up- or downshifted by many times the laser photon energy without substantial broadening. The light wave can accelerate or decelerate the electron's drift velocity, i.e., steer the electron wave packet like a classical particle. This capability strictly relies on a sub-femtosecond duration of the ionizing x-ray pulse and on its timing to the phase of the light wave with a similar accuracy, offering a simple and potentially single-shot diagnostic tool for attosecond pump-probe spectroscopy.

  19. ATLAS Beam Steering Mechanism Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Cramer, Alexander K.; Gostin, Alan B.; Hakun, Claef F.; Haney, Paul G.; Hinkle, Matthew R.; Lee, Kenneth Y.; Lugo, Carlos F.; Matuszeski, Adam J.; Morrell, Armando; Armani, Nerses V.; Bonafede, Joseph; Jackson, Molly I.; Steigner, Peter J.; Stromsdorfer, Juan J.

    2016-01-01

    This paper describes the design, testing, and lessons learned during the development of the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM). The BSM is a 2 degree-of-freedom tip-tilt mechanism for the purpose of pointing a flat mirror to tightly control the co-alignment of the transmitted laser and the receiver telescope of the ATLAS instrument. The high resolution needs of the mission resulted in sub-arcsecond pointing and knowledge requirements, which have been met. Development of the methodology to verify performance required significant effort. The BSM will fly as part of the Ice, Cloud, and Elevation Satellite II Mission (ICESat II), which is scheduled to be launched in 2017. The ICESat II primary mission is to map the earth's surface topography for the determination of seasonal changes of ice sheet thickness and vegetation canopy thickness to establish long-term trends.

  20. Beam Steering Mechanism (BSM) Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Cramer, Alexander K.; Gostin, Alan B.; Hakun, Claef F.; Haney, Paul G.; Hinkle, Matthew R.; Lee, Kenneth Y.; Lugo, Carlos F.; Matuszeski, Adam J.; Morell, Armando; Armani, Nerses V.; Bonafede, Joseph; Jackson, Molly I.; Steigner, Peter J.; Stromsdorfer, Juan J.

    2016-01-01

    This paper describes the design, testing, and lessons learned during the development of the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM). The BSM is a 2 degree-of-freedom tip-tilt mechanism for the purpose of pointing a flat mirror to tightly control the co-alignment of the transmitted laser and the receiver telescope of the ATLAS instrument. High resolution needs of the mission resulted in sub-arcsecond pointing and knowledge requirements, which have been met. Development of methodology to verify performance was a significant effortadvancement. The BSM will fly as part of the Ice, Cloud, and Elevation Satellite 2 Mission (ICESat 2), which is scheduled to be launched in 2017. The ICESat 2 primary mission is to map the earths surface topography for the determination of seasonal changes of ice sheet thickness as well as vegetation canopy thickness.

  1. ATLAS Beam Steering Mechanism (BSM) Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Cramer, Alexander K.; Gosten, Alan B.; Hakun, Claef F.; Haney, Paul G.; Hinkle, Matthew R.; Lee, Kenneth Y.; Lugo, Carlos F.; Matuszeski, Adam J.; Morell, Armando; Armani, Nerses V.; Bonafede, Joseph; Jackson, Molly I.; Steigner, Peter J.; Stromsdorfer, Juan J.

    2016-01-01

    This paper describes the design, testing, and lessons learned during the development of the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM). The BSM is a 2 degree-of-freedom tip-tilt mechanism for the purpose of pointing a flat mirror to tightly control the co-alignment of the transmitted laser and the receiver telescope of the ATLAS instrument. The high resolution needs of the mission resulted in sub-arcsecond pointing and knowledge requirements, which have been met. Development of the methodology to verify performance required significant effort. The BSM will fly as part of the Ice, Cloud, and Elevation Satellite II Mission (ICESat II), which is scheduled to be launched in 2017. The ICESat II primary mission is to map the Earth's surface topography for the determination of seasonal changes of ice sheet thickness and vegetation canopy thickness to establish long-term trends.

  2. Adaptive null steering by reflector antennas

    NASA Astrophysics Data System (ADS)

    Cofer, J. W.; Martin, G. P.; Ralph, S. E.

    The feasibility of peforming adaptive null steering by reflector antennas is investigated, and the results are reported. The implementation consists of an array of feed elements located in the focal region. The outputs of all the feeds are weighted in phase and amplitude and summed coherently. After deduction by a receiver, the signal passes to a digital algorithm computer where a decision is made as to how the weights should be adjusted, and interactive perturbational process continues until the system has arrived at an optimal weight combination. The configuration allows for multiple jammers and/or desired signals. Nulls on the order of 35 dB can be achieved with the basic limitation being amplitude and phase balance of the RF weights versus frequency. The system offers simpler, lighter weight more economically than full-phased arrays, much broader bandwidth than sidelobe cancellers, well-understood analysis procedures, and allows cancellation high up on the main beam.

  3. Feeding ecology and activity pattern of black-fronted titi monkeys (Callicebus nigrifrons) in a semideciduous tropical forest of southern Brazil.

    PubMed

    Caselli, Christini Barbosa; Setz, Eleonore Zulnara Freire

    2011-10-01

    Most aspects of the ecology and behavior of Callicebus nigrifrons are still unknown. The information available about this species is mainly based on a few studies that also focused on other Callicebus. We examined the feeding behavior and activity pattern of a free-ranging pair of C. nigrifrons between March and November 2007 in an area of semideciduous tropical forest of southeastern Brazil. The study site is located at the southern limit of the Tropical Zone and is characterized by pronounced seasonality. As observed for other Callicebus monkeys, fruits were the most consumed food resource, accounting for 53% of the diet, which was complemented mainly by leaves (16%) but also by invertebrates and flowers (10% of each). A great variety of plant families (28) and species (62) were included in the diet. The titis spent 35% of their time feeding, distributing the remaining time between resting (30%) and traveling (24%). Data presented here indicate that C. nigrifrons prefer high-quality food items (fruit pulp), adding low-quality food items (such as leaves) as the availability of the higher-quality foods decreases. The amount of time spent traveling and resting did not change between seasons, but the time invested in feeding increased during the lean period. The activity pattern was not related to fruit availability, but in months with lower temperatures, monkeys spent more time feeding. We suggest that the feeding ecology and activity pattern of C. nigrifrons reflect adaptations related to annual fluctuations in food availability and temperature, respectively.

  4. Common underlying steering curves for motorcycles in steady turns

    NASA Astrophysics Data System (ADS)

    Mangaraju Karanam, Venkata; Chatterjee, Anindya

    2011-06-01

    We study the steady turn behaviours of some light motorcycle models on circular paths, using the commercial software package ADAMS-Motorcycle. Steering torque and steering angle are obtained for several path radii and a range of steady forward speeds. For path radii much greater than motorcycle wheelbase, and for all motorcycle parameters including tyre parameters held fixed, dimensional analysis can predict the asymptotic behaviour of steering torque and angle. In particular, steering torque is a function purely of lateral acceleration plus another such function divided by path radius. Of these, the first function is numerically determined, while the second is approximated by an analytically determined constant. Similarly, the steering angle is a function purely of lateral acceleration, plus another such function divided by path radius. Of these, the first is determined numerically while the second is determined analytically. Both predictions are verified through ADAMS simulations for various tyre and geometric parameters. In summary, steady circular motions of a given motorcycle with given tyre parameters can be approximately characterised by just one curve for steering torque and one for steering angle.

  5. The need for speed: global optic flow speed influences steering

    PubMed Central

    Kountouriotis, Georgios K.; Mole, Callum D.; Merat, Natasha

    2016-01-01

    How do animals follow demarcated paths? Different species are sensitive to optic flow and one control solution is to maintain the balance of flow symmetry across visual fields; however, it is unclear whether animals are sensitive to changes in asymmetries when steering along curved paths. Flow asymmetries can alter the global properties of flow (i.e. flow speed) which may also influence steering control. We tested humans steering curved paths in a virtual environment. The scene was manipulated so that the ground plane to either side of the demarcated path produced larger or smaller asymmetries in optic flow. Independent of asymmetries and the locomotor speed, the scene properties were altered to produce either faster or slower globally averaged flow speeds. Results showed that rather than being influenced by changes in flow asymmetry, steering responded to global flow speed. We conclude that the human brain performs global averaging of flow speed from across the scene and uses this signal as an input for steering control. This finding is surprising since the demarcated path provided sufficient information to steer, whereas global flow speed (by itself) did not. To explain these findings, existing models of steering must be modified to include a new perceptual variable: namely global optic flow speed. PMID:27293789

  6. Lagrangian fronts in the ocean

    NASA Astrophysics Data System (ADS)

    Prants, S. V.; Budyansky, M. V.; Uleysky, M. Yu.

    2014-05-01

    We introduce the concept of Lagrangian fronts (LFs) in the ocean and describe their importance for analyzing water mixing and transport and the specific features and differences from hydrological fronts. A method of calculating LFs in a given velocity field is proposed. Based on altimeter velocity fields from AVISO data in the northwestern Pacific, we calculate the Lagrangian synoptic maps and identify LFs of different spatial and temporal scales. Using statistical analysis of saury catches in different years according to the Goskomrybolovstvo (State Fisheries Committee of the Russian Federation), we show that LFs can serve as good indicators of places that are favorable for fishing.

  7. Front tracking for gas dynamics

    SciTech Connect

    Chern, I.L.; Glimm, J.; McBryan, O.; Plohr, B.; Yaniv, S.

    1984-05-01

    Front tracking is an adaptive computational method in which a lower dimensional moving grid is fitted to and follows the dynamical evolution of distinguished waves in a fluid flow. The method takes advantage of known analytic solutions, derived from the Rankine-Hugoniot relations, for idealized discontinuities. In this paper the method is applied to the Euler equations describing compressible gas dynamics. The main thrust here is validation of the front tracking method: we present results on a series of test problems for which comparison answers can be obtained by independent methods.

  8. Front tracking for gas dynamics

    SciTech Connect

    Chern, I.; Glimm, J.; McBryan, O.; Plohr, B.; Yaniv, S.

    1986-01-01

    Front tracking is an adaptive computational method in which a lower dimensional moving grid is fitted to and follows the dynamical evolution of distinguished waves in a fluid flow. The method takes advantage of known analytic solutions, derived from the Rankine-Hugoniot relations, for idealized discontinuities. In this paper the method is applied to the Euler equations describing compressible gas dynamics. The main thrust here is validation of the front tracking method: we present results on a series of test problems for which comparison answers can be obtained by independent methods.

  9. Propagating substorm injection fronts

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Arnoldy, R. L.; Feynman, J.; Hardy, D. A.

    1981-01-01

    It is argued that a series of two-satellite observations leads to a clarification of substorm plasma injection, in which boundary motion plays a major role. Emphasis is put on a type of event characterized by abrupt, dispersionless changes in electron intensity and a coincident perturbation that consists of both a field magnitude increase and a small rotation toward more dipolar orientation. Comparing plasma observations at two points, it is found that in active, preinjection conditions the two most important features of the plasma sheet are: (1) the low-energy convection boundary for near-zero energy particles, determined by the magnitude of the large-scale convection electric field; and (2) the precipitation-flow boundary layer between the hot plasma sheet and the atmospherically contaminated inner plasma sheet.

  10. Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production.

    PubMed

    Van Bibber-Krueger, C L; Miller, K A; Aperce, C C; Alvarado-Gilis, C A; Higgins, J J; Drouillard, J S

    2016-03-01

    .03), with steers consuming 0% menthol having the greatest BW and steers that consumed 0.3% menthol having the lightest BW until d 30. A menthol × day interaction was observed for daily feed deliveries ( < 0.01): cattle fed 0.3% menthol consumed less feed from d 5 through 12. Furthermore, in vitro gas production and VFA concentrations were unaffected by addition of menthol ( > 0.21). In conclusion, menthol supplementation minimally affected blood parameters associated with growth or ruminal fermentative activity. PMID:27065278

  11. Environmental heat stress modulates thyroid status and its response to repeated endotoxin challenge in steers.

    PubMed

    Kahl, S; Elsasser, T H; Rhoads, R P; Collier, R J; Baumgard, L H

    2015-07-01

    The objective of this study was to evaluate in cattle, the effects of acute exposure to a heat stress (HS) environment on the status of the pituitary (thyrotropin, TSH)-thyroid (thyroxine, T4)-peripheral tissue T4 deiodination (type 1 5'-deiodinase [D1]; triiodothyronine [T3]; reverse-triiodothyronine [rT3]) axis, and the further response of this pituitary-thyroid-peripheral tissue axis (PTTA) to perturbation caused by the induction of the proinflammatory innate immune state provoked by the administration of gram-negative bacteria endotoxin (lipopolysaccharide [LPS]). Ten steers (318 ± 49 kg body weight) housed in controlled environment chambers were subjected to either a thermoneutral (TN: constant 19°C) or HS temperature conditions (cyclical daily temperatures: 32.2°C-40.0°C) for a total period of 9 d. To minimize the effects of altered plane of nutrition due to HS, steers in TN were pair-fed to animals in HS conditions. Steers received 2 LPS challenges 3 d apart (LPS1 and LPS2; 0.2 μg/kg body weight, intravenously, Escherichia coli 055:B5) with the first challenge administered on day 4 relative to the start of the environmental conditioning. Jugular blood samples were collected at 0, 1, 2, 4, 7, and 24 h relative to the start of each LPS challenge. Plasma TSH, T4, T3, and rT3 were measured by radioimmunoassay. Liver D1 activity was measured in biopsy samples collected before the LPS1 (0 h) and 24 h after LPS2. Before the start of LPS1, HS decreased (P < 0.01 vs TN) plasma TSH (40%), T4 (45.4%), and T3 (25.9%), but did not affect rT3 concentrations. In TN steers, the LPS1 challenge decreased (P < 0.01 vs 0 h) plasma concentrations of TSH between 1 and 7 h and T4 and T3 at 7 and 24 h. In HS steers, plasma TSH concentrations were decreased at 2 h only (P < 0.05), whereas plasma T3 was decreased at 7 and 24 h (P < 0.01). Whereas plasma T4 concentrations were already depressed in HS steers at 0 h, LPS1 did not further affect the levels. Plasma rT3 concentrations

  12. Upper plate deformation and seismic barrier in front of Nazca subduction zone: The Chololo Fault System and active tectonics along the Coastal Cordillera, southern Peru

    NASA Astrophysics Data System (ADS)

    Audin, Laurence; Lacan, Pierre; Tavera, Hernando; Bondoux, Francis

    2008-11-01

    The South America plate boundary is one of the most active subduction zone. The recent Mw = 8.4 Arequipa 2001 earthquake ruptured the subduction plane toward the south over 400 km and stopped abruptly on the Ilo Peninsula. In this exact region, the subduction seismic crisis induced the reactivation of continental fault systems in the coastal area. We studied the main reactivated fault system that trends perpendicular to the trench by detailed mapping of fault related-geomorphic features. Also, at a longer time scale, a recurrent Quaternary transtensive tectonic activity of the CFS is expressed by offset river gullies and alluvial fans. The presence of such extensional fault systems trending orthogonal to the trench along the Coastal Cordillera in southern Peru is interpreted to reflect a strong coupling between the two plates. In this particular case, stress transfer to the upper plate, at least along the coastal fringe, appears to have induced crustal seismic events that were initiated mainly during and after the 2001 earthquake. The seafloor roughness of the subducting plate is usually thought to be a cause of segmentation along subduction zones. However, after comparing and discussing the role of inherited structures within the upper plate to the subduction zone segmentation in southern Peru, we suggest that the continental structure itself may exert some feedback control on the segmentation of the subduction zone and thus participate to define the rupture pattern of major subduction earthquakes along the southern Peru continental margin.

  13. Simultaneous demultiplexing and steering of multiple orbital angular momentum modes

    PubMed Central

    Li, Shuhui; Wang, Jian

    2015-01-01

    We present a simple scheme to perform simultaneous demultiplexing and steering of multiple orbital angular momentum (OAM) modes using a single complex phase mask. By designing the phase mask, the propagation directions of demultiplexed beams can be arbitrarily steered. System experiments using orthogonal frequency-division multiplexing 32-ary quadrature amplitude modulation (OFDM-32QAM) signals over two OAM modes are carried out by using a two-mode complex phase mask. Moreover, demultiplexing of sixteen OAM modes and arbitrary demultiplexed beam steering are also demonstrated in the experiment. PMID:26503167

  14. Mixture steering law design for control moment gyroscopes

    NASA Astrophysics Data System (ADS)

    Zhang, JingRui; Luo, Yang; Liu, Wei; Zhang, Yao

    2014-01-01

    Focusing on the singularities of a spacecraft using control moment gyros (CMGs) to do the large angle maneuvers, a new mixture steering law is proposed to avoid the singularities. According to this method, if the CMGs are far away from the singularity, the Moore-Penrose pseudo-inverse steering law (MP) is used directly. If the CMGs are close to the singularity, instead of solving the inverse matrix, a set of optimal gimbal angles are sought for the singular measurement to reach the maximum, which can avoid the singularities. Simulations show that the designed steering law enables the spacecraft to carry out the large angle maneuver and avoid the singularities simultaneously.

  15. [Front Block distraction].

    PubMed

    Esnault, Olivier

    2015-03-01

    The contribution of the segmental osteotomies in the ortho-surgical protocols is no longer to demonstrate and found a new lease of life thanks to the combination with the bone distraction techniques. The osteotomy of Köle, initially described to close infraclusies, and then used to level very marked curves of Spee has more recently been used to correct anterior crowding. This support is therefore aimed at patients with an incisor and canine Class 2 but molar Class 1 with an isolated mandibular footprint. With minimal orthodontic preparation we can create in two weeks bilateral diastemas that will then be used to align the incisivocanin crowding without stripping or bicuspid extractions. Dental orthodontic movements can be resumed one month after the end of the distraction. This technique is therefore likely to avoid bicuspid extraction and replace some sagittal osteotomy advancement by correction of the overjet. It also helps to correct a incisors labial or lingual tipping playing on differential activation of the cylinders and the distractor. This segmental surgery can be combined with Le Fort 1 surgeries with correction of the transverse and associated meanings, but in a second time, to a mandibular advancement and/or a genioplasty. PMID:25888045

  16. 46 CFR 196.37-33 - Instructions for changing steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Instructions for changing steering gear. 196.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering engineroom, relating in order, the different steps to be taken in changing to the emergency steering...

  17. 46 CFR 196.37-33 - Instructions for changing steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Instructions for changing steering gear. 196.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering engineroom, relating in order, the different steps to be taken in changing to the emergency steering...

  18. 46 CFR 58.25-55 - Overcurrent protection for steering-gear systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Overcurrent protection for steering-gear systems. 58.25... ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-55 Overcurrent protection for steering-gear systems. (a) Each feeder circuit for steering must be protected by a circuit...

  19. 46 CFR 196.37-33 - Instructions for changing steering gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Instructions for changing steering gear. 196.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering engineroom, relating in order, the different steps to be taken in changing to the emergency steering...

  20. 46 CFR 58.25-10 - Main and auxiliary steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout...

  1. 46 CFR 58.25-40 - Arrangement of the steering-gear compartment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Arrangement of the steering-gear compartment. 58.25-40... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-40 Arrangement of the steering-gear compartment. (a) The steering-gear compartment must— (1) Be readily accessible and, as far as...

  2. 46 CFR 58.25-10 - Main and auxiliary steering gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout...

  3. 46 CFR 130.140 - Steering on OSVs of 100 or more gross tons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hydraulic-helm steering-system in paragraph (b) of this section. (b) Each hydraulic-helm steering-system... normal steering power. (c) For compliance with paragraph (b) of this section, a common piping system for... VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Vessel Control § 130.140 Steering on OSVs of...

  4. 46 CFR 130.140 - Steering on OSVs of 100 or more gross tons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hydraulic-helm steering-system in paragraph (b) of this section. (b) Each hydraulic-helm steering-system... normal steering power. (c) For compliance with paragraph (b) of this section, a common piping system for... VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Vessel Control § 130.140 Steering on OSVs of...

  5. Effect of feeding system on performance and carcass characteristics of yearling steers, steer calves and heifer calves.

    PubMed

    Danner, M L; Fox, D G; Black, J R

    1980-03-01

    Three types of cattle (Angus x Hereford yearling steers, Charolais x British breed steer calves and Hereford heifer calves) were evaluated for their response to different feeding systems utilizing high moisture corn, corn silage and soybean meal as major feed ingredients. Feeding ing systems for steers included: A = 85% concentrate; B = 40% concentrate; C = two phase, with switch from all corn silage to 85% concentrate in the middle of the feeding period; D = same as C except switch occurred late in the feeding period; E = all corn silage continuously. Heifer diets consisted of the following ratios of corn silage to concentrate: low energy = 89:11; medium energy = 67:33; and high energy = 100 fed at a moderate (10.9% for low energy and medium energy, and 11.7% for high energy) and high (13.8%) crude protein level. Treatments within each experiment were terminated at approximately the same final weight. Increasing percentage corn added to the total diet increased ADG in most comparisons. Adjusted to a constant carcass weight, increasing dietary energy increased fat thickness and reduced percentage retail product with no effect on quality grade in yearling steers and heifer calves. In Charolais cross-steer calves, increasing energy level increased quality grade with no effect on yield grade or percentage retail product. Energetic efficiency slightly favored system C in yearling steers while steer calves maximized efficiency on A. Hereford heifers were the most energetically efficient on medium energy diets.

  6. Effect of feeding system on performance and carcass characteristics of yearling steers, steer calves and heifer calves.

    PubMed

    Danner, M L; Fox, D G; Black, J R

    1980-03-01

    Three types of cattle (Angus x Hereford yearling steers, Charolais x British breed steer calves and Hereford heifer calves) were evaluated for their response to different feeding systems utilizing high moisture corn, corn silage and soybean meal as major feed ingredients. Feeding ing systems for steers included: A = 85% concentrate; B = 40% concentrate; C = two phase, with switch from all corn silage to 85% concentrate in the middle of the feeding period; D = same as C except switch occurred late in the feeding period; E = all corn silage continuously. Heifer diets consisted of the following ratios of corn silage to concentrate: low energy = 89:11; medium energy = 67:33; and high energy = 100 fed at a moderate (10.9% for low energy and medium energy, and 11.7% for high energy) and high (13.8%) crude protein level. Treatments within each experiment were terminated at approximately the same final weight. Increasing percentage corn added to the total diet increased ADG in most comparisons. Adjusted to a constant carcass weight, increasing dietary energy increased fat thickness and reduced percentage retail product with no effect on quality grade in yearling steers and heifer calves. In Charolais cross-steer calves, increasing energy level increased quality grade with no effect on yield grade or percentage retail product. Energetic efficiency slightly favored system C in yearling steers while steer calves maximized efficiency on A. Hereford heifers were the most energetically efficient on medium energy diets. PMID:7364676

  7. Effect of protein supplementation on ruminal parameters and microbial community fingerprint of Nellore steers fed tropical forages.

    PubMed

    Bento, C B P; Azevedo, A C; Gomes, D I; Batista, E D; Rufino, L M A; Detmann, E; Mantovani, H C

    2016-01-01

    In tropical regions, protein supplementation is a common practice in dairy and beef farming. However, the effect of highly degradable protein in ruminal fermentation and microbial community composition has not yet been investigated in a systematic manner. In this work, we aimed to investigate the impact of casein supplementation on volatile fatty acids (VFA) production, specific activity of deamination (SAD), ammonia concentration and bacterial and archaeal community composition. The experimental design was a 4×4 Latin square balanced for residual effects, with four animals (average initial weight of 280±10 kg) and four experimental periods, each with duration of 29 days. The diet comprised Tifton 85 (Cynodon sp.) hay with an average CP content of 9.8%, on a dry matter basis. Animals received basal forage (control) or infusions of pure casein (230 g) administered direct into the rumen, abomasum or divided (50 : 50 ratio) in the rumen/abomasum. There was no differences (P>0.05) in ruminal pH and microbial protein concentration between supplemented v. non-supplemented animals. However, in steers receiving ruminal infusion of casein the SAD and ruminal ammonia concentration increased 33% and 76%, respectively, compared with the control. The total concentration of VFA increased (P0.05) in species richness and diversity of γ-proteobacteria, firmicutes and archaea between non-supplemented Nellore steers and steers receiving casein supplementation in the rumen. However, species richness and the Shannon-Wiener index were lower (P<0.05) for the phylum bacteroidetes in steers supplemented with casein in the rumen compared with non-supplemented animals. Venn diagrams indicated that the number of unique bands varied considerably among individual animals and was usually higher in number for non-supplemented steers compared with supplemented animals. These results add new knowledge about the effects of ruminal and postruminal protein supplementation on metabolic activities of

  8. The structure of mountain fronts

    NASA Astrophysics Data System (ADS)

    Vann, I. R.; Graham, R. H.; Hayward, A. B.

    Commonly the part of a mountain front which is visible at the surface consists of foreland-dipping thrust belt rocks elevated above their regional structural position and overlain more or less conformably by molasse. Several explanations for their geometry are possible. (1) Major detachments exist within or beneath the molasse resulting in transport of the foreland basin. Examples of this geometry come from the Swiss Molasse Plain, the Southern Pyrenees and the Mackenzie Mountains of Canada. (2) Displacement is lost on major backthrusts beneath the frontal monocline. Examples cited here are the Rockies of Alberta, the Sulaiman Ranges of Pakistan, the Mackenzies, and the Andes in Peru. (3) Thrust sheets travelled over an old land surface and syntectonic molasse contemporaneously offlaps the topographic high of the thrust front. This phenomenon occurs along the Alpine thrust front in Haute Provence. (4) The frontal fold represents deformation above a large-scale thrust tip. No unequivocal example of tip line strain at this scale has been recorded although this type of deformation may occur in the Brooks Range of Alaska. In many areas mountain fronts show a combination of these idealized geometries.

  9. Advanced RF Front End Technology

    NASA Technical Reports Server (NTRS)

    Herman, M. I.; Valas, S.; Katehi, L. P. B.

    2001-01-01

    The ability to achieve low-mass low-cost micro/nanospacecraft for Deep Space exploration requires extensive miniaturization of all subsystems. The front end of the Telecommunication subsystem is an area in which major mass (factor of 10) and volume (factor of 100) reduction can be achieved via the development of new silicon based micromachined technology and devices. Major components that make up the front end include single-pole and double-throw switches, diplexer, and solid state power amplifier. JPL's Center For Space Microsystems - System On A Chip (SOAC) Program has addressed the challenges of front end miniaturization (switches and diplexers). Our objectives were to develop the main components that comprise a communication front end and enable integration in a single module that we refer to as a 'cube'. In this paper we will provide the latest status of our Microelectromechanical System (MEMS) switches and surface micromachined filter development. Based on the significant progress achieved we can begin to provide guidelines of the proper system insertion for these emerging technologies. Additional information is contained in the original extended abstract.

  10. Align the Front End First.

    ERIC Educational Resources Information Center

    Perry, Jim

    1995-01-01

    Discussion of management styles and front-end analysis focuses on a review of Douglas McGregor's theories. Topics include Theories X, Y, and Z; leadership skills; motivational needs of employees; intrinsic and extrinsic rewards; and faulty implementation of instructional systems design processes. (LRW)

  11. Front instability in stratified media

    NASA Astrophysics Data System (ADS)

    Beltrame, Philippe

    2013-04-01

    Preferential flow in unsaturated soil may due to local heterogeneities like worm burrows but also to front instability leading to unstable finger flow (fingered pattern) in sandy textured soils. This last spontaneous preferential flow cannot be described by the standard Richards equation. Cueto-Felgueroso and Juanes proposed recently a phase field model in order to take into account a macroscopic surface tension effect at the front [1]. Their model simulates successfully the interface instability of an advancing front. We aim at simulating and understanding front instability passing a textural soil discontinuity for which the finger flow is particularly visible. We consider sand layers with different characteristics such as granulometry. Moreover, the wettability is taken into account by adding a hydrophobic term in the free energy of the phase field model. The hydrophobicity part is not only relevant for repellent soil but also to model the ultra-thin films [2]. Therefore, in our framework, this may have an influence at the front because the water saturation is nearly zero. Such a wettability influence on infiltration in porous media has recently been measured in [3]. The governing equation is analogous to the lubrication equation for which we pointed out the specific numerical difficulties [4]. A numerical code to perform time integration and bifurcation analysis was developed in [4] allowing to determine the onset of instability and its resulting dynamics in the parameter space [5]. We compute the parameter range for which the front stops when reaching the layers interface. As in [4], there is two main mechanisms that allow water to cross over the discontinuity. A first mechanism, called «depinning», leads to an intermittent flow and the second one, to a front instability and then to a finger flow. There is a parameter domain where both instabilities are present leading to a complex spatio-temporal dynamics. Finally, it is noteworthy that the wettability

  12. Autonomous collision avoidance system by combined control of steering and braking using geometrically optimised vehicular trajectory

    NASA Astrophysics Data System (ADS)

    Hayashi, Ryuzo; Isogai, Juzo; Raksincharoensak, Pongsathorn; Nagai, Masao

    2012-01-01

    This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.

  13. A null-steering viewpoint of interferometric SAR

    SciTech Connect

    BICKEL,DOUGLAS L.

    2000-05-02

    Interferometric synthetic aperture radar (IFSAR) extends the two-dimensional imaging capability of traditional synthetic aperture radar to three-dimensions by using an aperture in the elevation plane to estimate the 3-D structure of the target. The operation of this additional aperture can be viewed from a null-steering point of view, rather than the traditional phase determination point of view. Knowing that IFSAR can be viewed from the null-steering perspective allows one to take advantage of the mathematical foundation developed for null-steering arrays. In addition, in some problems of interest in IFSAR the null-steering perspective provides better intuition and suggests alternative solutions. One example is the problem of estimating building height where layover is present.

  14. 41. After steering hydraulic mechanism from starboard side. Mechanism built ...

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

    41. After steering hydraulic mechanism from starboard side. Mechanism built by the Superior Iron Works Co., Elizabeth, New Jersey, Lidgerwood Mfg Co. - U.S. Coast Guard Cutter BRAMBLE, Waterfront at Lincoln Avenue, Port Huron, St. Clair County, MI

  15. Micromachined actuators/sensors for intratubular positioning/steering

    DOEpatents

    Lee, A.P.; Krulevitch, P.A.; Northrup, M.A.; Trevino, J.C.

    1998-06-30

    Micromachined thin film cantilever actuators having means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering same through blood vessels, or positioning same within a blood vessel, for example. Such cantilever actuators include tactile sensor arrays mounted on a catheter or guide wire tip for navigation and tissues identification, shape-memory alloy film based catheter/guide wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use the flowing blood itself to help direct the catheter direction through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems. 14 figs.

  16. Micromachined actuators/sensors for intratubular positioning/steering

    DOEpatents

    Lee, Abraham P.; Krulevitch, Peter A.; Northrup, M. Allen; Trevino, Jimmy C.

    1998-01-01

    Micromachined thin film cantilever actuators having means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering same through blood vessels, or positioning same within a blood vessel, for example. Such cantilever actuators include tactile sensor arrays mounted on a catheter or guide wire tip for navigation and tissues identification, shape-memory alloy film based catheter/guide wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use the flowing blood itself to help direct the catheter direction through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems.

  17. Integrated phased array for wide-angle beam steering.

    PubMed

    Yaacobi, Ami; Sun, Jie; Moresco, Michele; Leake, Gerald; Coolbaugh, Douglas; Watts, Michael R

    2014-08-01

    We demonstrate an on-chip optical phased array fabricated in a CMOS compatible process with continuous, fast (100 kHz), wide-angle (51°) beam-steering suitable for applications such as low-cost LIDAR systems. The device demonstrates the largest (51°) beam-steering and beam-spacing to date while providing the ability to steer continuously over the entire range. Continuous steering is enabled by a cascaded phase shifting architecture utilizing, low power and small footprint, thermo-optic phase shifters. We demonstrate these results in the telecom C-band, but the same design can easily be adjusted for any wavelength between 1.2 and 3.5 μm.

  18. View forward of interior of conning tower and steering station; ...

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

    View forward of interior of conning tower and steering station; helmsman or observer viewed action through narrow opening at top of photo. (p57) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  19. View from port side of alternate steering station forward of ...

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

    View from port side of alternate steering station forward of flag house on superstructure deck. (p29) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  20. 54. Starboard profile of steering gear, wood housing has been ...

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

    54. Starboard profile of steering gear, wood housing has been removed showing mechanism. Photograph by Russell Booth, June 1989. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  1. 50. Oblique view aft of saloon skylight with steering gear ...

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

    50. Oblique view aft of saloon skylight with steering gear beyond, mizzen gaff boom above. Photograph by Russell Booth, June 1989. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  2. 42. View forward on afterdeck, showing steering gear box in ...

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

    42. View forward on afterdeck, showing steering gear box in foreground, aft elevation of cabin beyond; weather canopy overhead is not an original or permanent feature - Schooner WAWONA, 1018 Valley Street, Seattle, King County, WA

  3. Reaction front formation in contaminant plumes

    NASA Astrophysics Data System (ADS)

    Cribbin, Laura B.; Winstanley, Henry F.; Mitchell, Sarah L.; Fowler, Andrew C.; Sander, Graham C.

    2014-12-01

    The formation of successive fronts in contaminated groundwater plumes by subsoil bacterial action is a commonly accepted feature of their propagation, but it is not obviously clear from a mathematical standpoint quite how such fronts are formed or propagate. In this paper we show that these can be explained by combining classical reaction-diffusion theory involving just two reactants (oxidant and reductant), and a secondary reaction in which a reactant on one side of such a front is (re-)formed on the other side of the front via diffusion of its product across the front. We give approximate asymptotic solutions for the reactant profiles, and the propagation rate of the front.

  4. Steering and collimating ballistic electrons with amphoteric refraction

    SciTech Connect

    Radu, A.; Dragoman, D.; Iftimie, S.

    2012-07-15

    We show that amphoteric refraction of ballistic electrons, i.e., positive or negative refraction depending on the incidence angle, occurs at an interface between an isotropic and an anisotropic medium and can be employed to steer and collimate electron beams. The steering angle is determined by the materials' parameters, but the degree of collimation can be tuned in a significant range by changing the energy of ballistic electrons.

  5. Active Gaze, Visual Look-Ahead, and Locomotor Control

    ERIC Educational Resources Information Center

    Wilkie, Richard M.; Wann, John P.; Allison, Robert S.

    2008-01-01

    The authors examined observers steering through a series of obstacles to determine the role of active gaze in shaping locomotor trajectories. Participants sat on a bicycle trainer integrated with a large field-of-view simulator and steered through a series of slalom gates. Steering behavior was determined by examining the passing distance through…

  6. Weather fronts and acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Kveton, Vit

    1991-03-01

    Some methodological aspects are discussed of the investigation of acute infarct myocarditis (AIM) in relation to weather fronts. Results of a new method of analysis are given. Data were analysed from about the hour of the onset of symptoms, and led to the diagnosis of AIM either immediately or within a few hours or days (3019 cases observed over 4.5 years during 1982 1986 in Plzen, Czechoslovakia). Weather classification was based on three factors (the type of the foregoing front, the type of the subsequent front, the time section of the time interval demarcated by the passage of the surfaces of the fronts). AIM occurrence increased in particular types of weather fronts: (i) by 30% during 7 12 h after a warm front, if the time span between fronts exceeded 24 h; (ii) by 10% in time at least 36 h distant from the foregoing cold or occlusion front and from the succeeding warm or occlusion front; (iii) by 20% during 0 2 h before the passage of the front, provided the foregoing front was not warm and the interval between fronts exceeded 5 h. AIM occurrence decreased by 15% 20% for time span between fronts > 24 h at times 6 11, 6 23 and 6 35 h before a coming warm or occlusion front (for interfrontal intervals 25 48, 49 72 and possibly > 72 h), and also at 12 23 and possibly 12 35 h before a cold front (for intervals 49 72 and possibly > 72 h), if the foregoing front was cold or an occlusion front.

  7. Multi Front-End Engineering

    NASA Astrophysics Data System (ADS)

    Botterweck, Goetz

    Multi Front-End Engineering (MFE) deals with the design of multiple consistent user interfaces (UI) for one application. One of the main challenges is the conflict between commonality (all front-ends access the same application core) and variability (multiple front-ends on different platforms). This can be overcome by extending techniques from model-driven user interface engineering.We present the MANTRA approach, where the common structure of all interfaces of an application is modelled in an abstract UI model (AUI) annotated with temporal constraints on interaction tasks. Based on these constraints we adapt the AUI, e.g., to tailor presentation units and dialogue structures for a particular platform. We use model transformations to derive concrete, platform-specific UI models (CUI) and implementation code. The presented approach generates working prototypes for three platforms (GUI, web, mobile) integrated with an application core via web service protocols. In addition to static evaluation, such prototypes facilitate early functional evaluations by practical use cases.

  8. Slow slip and the transition from fast to slow fronts in the rupture of frictional interfaces.

    PubMed

    Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Scheibert, Julien; Thøgersen, Kjetil; Amundsen, David Skålid; Malthe-Sørenssen, Anders

    2014-06-17

    The failure of the population of microjunctions forming the frictional interface between two solids is central to fields ranging from biomechanics to seismology. This failure is mediated by the propagation along the interface of various types of rupture fronts, covering a wide range of velocities. Among them are the so-called slow fronts, which are recently discovered fronts much slower than the materials' sound speeds. Despite intense modeling activity, the mechanisms underlying slow fronts remain elusive. Here, we introduce a multiscale model capable of reproducing both the transition from fast to slow fronts in a single rupture event and the short-time slip dynamics observed in recent experiments. We identify slow slip immediately following the arrest of a fast front as a phenomenon sufficient for the front to propagate further at a much slower pace. Whether slow fronts are actually observed is controlled both by the interfacial stresses and by the width of the local distribution of forces among microjunctions. Our results show that slow fronts are qualitatively different from faster fronts. Because the transition from fast to slow fronts is potentially as generic as slow slip, we anticipate that it might occur in the wide range of systems in which slow slip has been reported, including seismic faults. PMID:24889640

  9. Dynamic Steering for Improved Sensor Autonomy and Catalogue Maintenance

    NASA Astrophysics Data System (ADS)

    Hobson, T.; Gordon, N.; Clarkson, I.; Rutten, M.; Bessell, T.

    A number of international agencies endeavour to maintain catalogues of the man-made resident space objects (RSOs) currently orbiting the Earth. Such catalogues are primarily created to anticipate and avoid destructive collisions involving important space assets such as manned missions and active satellites. An agencys ability to achieve this objective is dependent on the accuracy, reliability and timeliness of the information used to update its catalogue. A primary means for gathering this information is by regularly making direct observations of the tens-of-thousands of currently detectable RSOs via networks of space surveillance sensors. But operational constraints sometimes prevent accurate and timely reacquisition of all known RSOs, which can cause them to become lost to the tracking system. Furthermore, when comprehensive acquisition of new objects does not occur, these objects, in addition to the lost RSOs, result in uncorrelated detections when next observed. Due to the rising number of space-missions and the introduction of newer, more capable space-sensors, the number of uncorrelated targets is at an all-time high. The process of differentiating uncorrelated detections caused by once-acquired now-lost RSOs from newly detected RSOs is a difficult and often labour intensive task. Current methods for overcoming this challenge focus on advancements in orbit propagation and object characterisation to improve prediction accuracy and target identification. In this paper, we describe a complementary approach that incorporates increased awareness of error and failed observations into the RSO tracking solution. Our methodology employs a technique called dynamic steering to improve the autonomy and capability of a space surveillance networks steerable sensors. By co-situating each sensor with a low-cost high-performance computer, the steerable sensor can quickly and intelligently decide how to steer itself. The sensor-system uses a dedicated parallel

  10. Observations of gravity waves at atmospheric fronts

    NASA Astrophysics Data System (ADS)

    Abusamah, Azizan B. Hj

    1990-09-01

    An observational study of pressure perturbations associated with the passage of atmospheric fronts over the British Isles using a triangular array of sensitive microbarographs reveals the preponderance of gravity wave activities in the vicinity of the surface cold front (SCF). Examination of the time series of these pressure perturbations in the frequency domain shows an enhancement for frequencies less than the local buoyancy frequency N after the passage of the SCF. The spectral analysis also shows two predominant frequency peaks usually located near N and N/2 s(exp -1). Isolating these frequencies shows that there is a systematic amplitude modulation with an amplification near the SCF and at a region 2-3 hours before and after the SCF passage. The cross-correlation analysis reveals that the gravity waves in the post SCF region propagate towards the SCF. As these waves approach the SCF, the across front component of the phase speed decreases and the direction of propagation of the wave rotates in an anticlockwise manner. It is found that a consistent description of the gravity waves can only be made if first the waves are assumed to be ducted, i.e. there is a reflecting layer aloft, and second that as these waves propagate through the frontal environment, due to the inhomogeneity, they are refracted. A number of conceptual models are then developed to account for the observed wave behavior in a frontal region. In this investigation it is shown that the stable layer associated with the frontal zone can form a good upper reflector for non-hydrostatic gravity waves. It is also argued that the slope of this layer plays an important role in the refraction of the observed gravity waves. A model of wave propagation in a wedge is then used to account for this slope.

  11. Backwards planning approach for rapid attitude maneuvers steering

    NASA Astrophysics Data System (ADS)

    Verbin, D.

    Remote sensing satellites are often built with payloads that do not include line of sight steering mechanisms. In cases, when frequent line of sight retargeting is required, there is a need for efficient actuators and control schemes that would support rapid attitude manoeuvring together with adequate pointing accuracy and stability between the manoeuvres. Within this frame, this research develops the Backwards Planning approach as one of the possible control methods for rapid manoeuvring. The method is based on state feedback and combines time efficient together with straight forward computation flow. Novel efficient methods to execute the Backwards Planning Control in the 3D attitude space are proposed here. The methods refer both for the first saturated control phase of the manoeuvre and for the last braking phase. The actuators used for the spacecraft control in this research are either Reaction Wheels (RWs) or Single Gimbal Control Moments Gyros (SGCMGs) or both of them together. The advantage of the SGCMG is in rapid rotational manoeuvring, but their application for high quality pointing requires very accurate gimbal mechanisms. On the other hand, RWs are usually more suitable for accurate pointing, but their torque to power performance is inferior in manoeuvring. It is shown that the coordination of SGCMGs and RWs together enables to draw more performance from the SGCMGs in terms of agility and meet the pointing requirements between manoeuvres where only the RWs are used. Novel SGCMG steering laws are suggested as well. While the steering laws determine the required angular rate for each gimbal, most steering laws are defined in the angular momentum domain and output the gimbals angular rates to produce a given required torque or angular momentum increment. This research however, practices a novel steering law in the gimbal angles domain. While both steering laws turn to be dynamically equivalent for small control signals, as in the steady state, it is shown

  12. Quantum correlations in Gaussian states via Gaussian channels: steering, entanglement, and discord

    NASA Astrophysics Data System (ADS)

    Wang, Zhong-Xiao; Wang, Shuhao; Li, Qiting; Wang, Tie-Jun; Wang, Chuan

    2016-06-01

    Here we study the quantum steering, quantum entanglement, and quantum discord for Gaussian Einstein-Podolsky-Rosen states via Gaussian channels. And the sudden death phenomena for Gaussian steering and Gaussian entanglement are theoretically observed. We find that some Gaussian states have only one-way steering, which confirms the asymmetry of quantum steering. Also we investigate that the entangled Gaussian states without Gaussian steering and correlated Gaussian states own no Gaussian entanglement. Meanwhile, our results support the assumption that quantum entanglement is intermediate between quantum discord and quantum steering. Furthermore, we give experimental recipes for preparing quantum states with desired types of quantum correlations.

  13. Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots

    NASA Astrophysics Data System (ADS)

    Cox, S. L.; Miller, P. I.; Embling, C. B.; Scales, K. L.; Bicknell, A. W. J.; Hosegood, P. J.; Morgan, G.; Ingram, S. N.; Votier, S. C.

    2016-09-01

    Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems.

  14. Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots

    PubMed Central

    Miller, P. I.; Embling, C. B.; Bicknell, A. W. J.; Hosegood, P. J.; Morgan, G.; Ingram, S. N.

    2016-01-01

    Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems. PMID:27703698

  15. Nanomaterials can dynamically steer cell responses to biological ligands.

    PubMed

    Sharma, Ram I; Schwarzbauer, Jean E; Moghe, Prabhas V

    2011-01-17

    Traditional tissue regeneration approaches to activate cell behaviors on biomaterials rely on the use of extracellular-matrix-based or soluble growth-factor cues. In this article, a novel approach is highlighted to dynamically steer cellular phenomena such as cell motility based on nanoscale substratum features of biological ligands. Albumin-derived nanocarriers (ANCs) with variable nanoscale-size features are functionalized with fibronectin III9-10 matrix ligands, and their effects on primary human keratinocyte activation are investigated. The presentation of fibronectin fragments from ANCs significantly enhances cell migration as compared to free ligands at equivalent concentrations. Notably, cell migration is influenced by the size of the underlying ANCs even for variably sized ANCs covered in comparable levels of fibronectin fragment. For equivalent ligand concentrations, cell migration on the smaller-sized ANCs (30 and 50 nm) is significantly enhanced as compared to that on larger-sized ANCs (75 and 100 nm). In contrast, the enhancement of cell migration on nanocarriers is abolished by the use of immobilized, biofunctionalized ANCs, indicating that "dynamic" nanocarrier internalization events underlie the role of nanocarrier geometry on the differential regulation of cell migration kinetics. Uptake studies using fluorescent ANCs indicate that larger-sized ANCs cause delayed endocytic kinetics and hence could present barriers for internalization during the cell adhesion and motility processes. Motile cells exhibit diminished migration upon exposure to clathrin inhibitors, but not caveolin inhibitors, suggesting the role of clathrin-mediated endocytosis in facilitating cell migratory responsiveness to the nanocarriers. Overall, a monotonic relationship is found between the nanocarrier cytointernalization rate and the cell migration rate, suggesting the possibility of designing biointerfacial features for the dynamic control of cell migration. Thus, the

  16. Controls on channel steering by tectonics in sedimentary basins

    NASA Astrophysics Data System (ADS)

    Paola, C.; Straub, K. M.; Kim, W.

    2009-04-01

    Channel steering refers to the ability of spatial variations in uplift or subsidence to influence the migration, spatial distribution, and/or path direction of channels. We report the results of three experiments on channel steering under conditions of average net deposition. The experiments were done in the University of Minnesota Experimental EarthScape basin, which via its programmable subsiding floor can be used to create a wide variety of patterns of space-time subsidence. Underpinning the experimental program is the idea that the first-order control on tectonic channel steering is a ratio of two fundamental time scales: the time needed for lateral tectonic tilting to produce a slope comparable to the mean streamwise slope of the channel system; and the time needed for the channel system to occupy a fixed, large fraction of the basin surface. The experiments cover a wide range of values of this time-scale ratio, and also include cases with pure deposition (subsidence only) as well as mixed erosion and deposition (relative uplift and subsidence). Lateral tectonic patterns included a simple trough and a more complex geometry patterned after a relay ramp system. Overall, we find that the time scale ratio exerts the expected control: steering is weakest, for either tectonic geometry, when the channels are ‘fast' relative to the tectonics. But steering effects are manifested in different ways, depending on the geometry and possibly the history of the system.

  17. Quantum steering of Gaussian states via non-Gaussian measurements

    NASA Astrophysics Data System (ADS)

    Ji, Se-Wan; Lee, Jaehak; Park, Jiyong; Nha, Hyunchul

    2016-07-01

    Quantum steering—a strong correlation to be verified even when one party or its measuring device is fully untrusted—not only provides a profound insight into quantum physics but also offers a crucial basis for practical applications. For continuous-variable (CV) systems, Gaussian states among others have been extensively studied, however, mostly confined to Gaussian measurements. While the fulfilment of Gaussian criterion is sufficient to detect CV steering, whether it is also necessary for Gaussian states is a question of fundamental importance in many contexts. This critically questions the validity of characterizations established only under Gaussian measurements like the quantification of steering and the monogamy relations. Here, we introduce a formalism based on local uncertainty relations of non-Gaussian measurements, which is shown to manifest quantum steering of some Gaussian states that Gaussian criterion fails to detect. To this aim, we look into Gaussian states of practical relevance, i.e. two-mode squeezed states under a lossy and an amplifying Gaussian channel. Our finding significantly modifies the characteristics of Gaussian-state steering so far established such as monogamy relations and one-way steering under Gaussian measurements, thus opening a new direction for critical studies beyond Gaussian regime.

  18. Quantum steering of Gaussian states via non-Gaussian measurements

    PubMed Central

    Ji, Se-Wan; Lee, Jaehak; Park, Jiyong; Nha, Hyunchul

    2016-01-01

    Quantum steering—a strong correlation to be verified even when one party or its measuring device is fully untrusted—not only provides a profound insight into quantum physics but also offers a crucial basis for practical applications. For continuous-variable (CV) systems, Gaussian states among others have been extensively studied, however, mostly confined to Gaussian measurements. While the fulfilment of Gaussian criterion is sufficient to detect CV steering, whether it is also necessary for Gaussian states is a question of fundamental importance in many contexts. This critically questions the validity of characterizations established only under Gaussian measurements like the quantification of steering and the monogamy relations. Here, we introduce a formalism based on local uncertainty relations of non-Gaussian measurements, which is shown to manifest quantum steering of some Gaussian states that Gaussian criterion fails to detect. To this aim, we look into Gaussian states of practical relevance, i.e. two-mode squeezed states under a lossy and an amplifying Gaussian channel. Our finding significantly modifies the characteristics of Gaussian-state steering so far established such as monogamy relations and one-way steering under Gaussian measurements, thus opening a new direction for critical studies beyond Gaussian regime. PMID:27411853

  19. Development And Test of A Digitally Steered Antenna Array for The Navigator GPS Receiver

    NASA Technical Reports Server (NTRS)

    Pinto, Heitor David; Valdez, Jennifer E.; Winternitz, Luke M. B.; Hassouneh, Munther A.; Price, Samuel R.

    2012-01-01

    Global Positioning System (GPS)-based navigation has become common for low-Earth orbit spacecraft as the signal environment is similar to that on the Earth s surface. The situation changes abruptly, however, for spacecraft whose orbital altitudes exceed that of the GPS constellation. Visibility is dramatically reduced and signals that are present may be very weak and more susceptible to interference. GPS receivers effective at these altitudes require increased sensitivity, which often requires a high-gain antenna. Pointing such an antenna can pose a challenge. One efficient approach to mitigate these problems is the use of a digitally steered antenna array. Such an antenna can optimally allocate gain toward desired signal sources and away from interferers. This paper presents preliminary results in the development and test of a digitally steered antenna array for the Navigator GPS research program at NASA s Goddard Space Flight Center. In particular, this paper highlights the development of an array and front-end electronics, the development and test of a real-time software GPS receiver, and implementation of three beamforming methods for combining the signals from the array. Additionally, this paper discusses the development of a GPS signal simulator which produces digital samples of the GPS L1C/A signals as they would be received by an arbitrary antenna array configuration. The simulator models transmitter and receiver dynamics, near-far and multipath interference, and has been a critical component in both the development and test of the GPS receiver. The GPS receiver system was tested with real and simulated GPS signals. Preliminary results show that performance improvement was achieved in both the weak signal and interference environments, matching analytical predictions. This paper summarizes our initial findings and discusses the advantages and limitations of the antenna array and the various beamforming methods.

  20. Relation between gravitational and arm-movement direction in the mechanism of perception in bimanual steering.

    PubMed

    Sakajiri, Taiji; Tanaka, Yoshihiro; Sano, Akihito

    2013-11-01

    This paper presents the effects of the opposing directions of gravity relative to right- and left-arm movement in bimanual steering. We developed a simulated steering system that permits independent left- and right-hand steering and torque presentations on a single axis, and independent measurements of the steering force exerted by each hand. In a steering force measurement experiment, left and right system units were mechanically combined to function as a single steering unit. Measurements of the force exerted by the participants with their left and right hands revealed that in human bimanual steering, the arm moving with gravity exerts a larger steering force than the one moving against gravity. In a steering force discrimination experiment, the system was mechanically configured to provide independence in both the function of the left and right steering units and the presentation of different left- and right-side steering torques. Each participant was then asked whether the steering force was felt to be larger on the left or the right during bimanual steering. The results of this experiment showed no difference between the left and the right arm in the discrimination threshold, but did reveal a perceptual bias in which the forces exerted in arm movements with gravity were perceived as being smaller than the forces exerted against gravity. Furthermore, there was no significant difference between the measured force and the force that would be predicted from the obtained perceptual bias.

  1. A HIGH FIDELITY SAMPLE OF COLD FRONT CLUSTERS FROM THE CHANDRA ARCHIVE

    SciTech Connect

    Owers, Matt S.; Nulsen, Paul E. J.; Markevitch, Maxim; Couch, Warrick J.

    2009-10-20

    This paper presents a sample of 'cold front' clusters selected from the Chandra archive. The clusters are selected based purely on the existence of surface brightness edges in their Chandra images which are modeled as density jumps. A combination of the derived density and temperature jumps across the fronts is used to select nine robust examples of cold front clusters: 1ES0657 - 558, Abell 1201, Abell 1758N, MS1455.0+2232, Abell 2069, Abell 2142, Abell 2163, RXJ1720.1+2638, and Abell 3667. This sample is the subject of an ongoing study aimed at relating cold fronts to cluster merger activity, and understanding how the merging environment affects the cluster constituents. Here, temperature maps are presented along with the Chandra X-ray images. A dichotomy is found in the sample in that there exists a subsample of cold front clusters which are clearly mergers based on their X-ray morphologies, and a second subsample of clusters which harbor cold fronts, but have surprisingly relaxed X-ray morphologies, and minimal evidence for merger activity at other wavelengths. For this second subsample, the existence of a cold front provides the sole evidence for merger activity at X-ray wavelengths. We discuss how cold fronts can provide additional information which may be used to constrain merger histories, and also the possibility of using cold fronts to distinguish major and minor mergers.

  2. 1. VIEW SOUTHWARD FROM SOUTHWEST CORNER FRONT AND ARCH STREETS ...

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

    1. VIEW SOUTHWARD FROM SOUTHWEST CORNER FRONT AND ARCH STREETS (2. N. Front Street starts at left) - North Front Street Area Study, 2-66 North Front Street (Commercial Buildings), Philadelphia, Philadelphia County, PA

  3. Temperature and frequency compensated array beam steering unit

    NASA Astrophysics Data System (ADS)

    Claborn, K. D.; Bailey, W. C.

    1986-04-01

    Beam pointing errors and sidelobes resulting from temperature variations on the aperture and power divider of a series phased array antenna operating at a plurality of selected operating channel frequencies and having uniformly spaced elements are compensated for by placing a temperature sensor on both the aperture and power divider and converting the respective temperature outputs to digital signals which are fed to a digital beam steering unit. A pair of programmed memories are included in the beam steering unit which respond to an address or pointer corresponding to the digitized temperature values and the selected operating frequency to read out stored digitized beam steering phase gradients and feed phase correction which are combined and sequentially applied at regular intervals to symmetrically located phase shifter pairs. A uniformly compensated beam is thereafter radiated at a predetermined phase angle.

  4. Free energy reconstruction from steered dynamics without post-processing

    SciTech Connect

    Athenes, Manuel; Marinica, Mihai-Cosmin

    2010-09-20

    Various methods achieving importance sampling in ensembles of nonequilibrium trajectories enable one to estimate free energy differences and, by maximum-likelihood post-processing, to reconstruct free energy landscapes. Here, based on Bayes theorem, we propose a more direct method in which a posterior likelihood function is used both to construct the steered dynamics and to infer the contribution to equilibrium of all the sampled states. The method is implemented with two steering schedules. First, using non-autonomous steering, we calculate the migration barrier of the vacancy in Fe-{alpha}. Second, using an autonomous scheduling related to metadynamics and equivalent to temperature-accelerated molecular dynamics, we accurately reconstruct the two-dimensional free energy landscape of the 38-atom Lennard-Jones cluster as a function of an orientational bond-order parameter and energy, down to the solid-solid structural transition temperature of the cluster and without maximum-likelihood post-processing.

  5. Laser steering of particle beams: Refraction and reflection ofparticle beams

    SciTech Connect

    Esarey, Eric; Katsouleas, T.; Mori, W.B.; Dodd, E.; Lee, S.; Hemker, R.; Clayton, C.; Joshi, C.

    1999-11-01

    The co-propagation of an intense particle beam with an ionizing laser beam in a working gas/plasma is considered. When the axes of the laser and particle beam are not aligned, then asymmetric plasma lensing results in a net dipole field acting on the particle beam. The particle beam can be steered or bent (as well as focused) by steering the laser. An analogy is made between the bending of the particle beam by collective effects at a plasma boundary and the refraction or reflection of light at an interface. This mechanism of particle steering may be of interest in applications for which permanent magnets are inconvenient of a fast turn on is required. 3-D particle-in-cell simulations and relevance to a recent experiment are discussed.

  6. Diffraction Efficiency of Thin Film Holographic Beam Steering Devices

    NASA Technical Reports Server (NTRS)

    Titus, Charles M.; Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip J.

    2003-01-01

    Dynamic holography has been demonstrated as a method for correcting aberrations in space deployable optics, and can also be used to achieve high-resolution beam steering in the same environment. In this paper, we consider some of the factors affecting the efficiency of these devices. Specifically, the effect on the efficiency of a highly collimated beam from the number of discrete phase steps per period is considered for a blazed thin film beam steering grating. The effect of the number of discrete phase steps per period on steering resolution is also considered. We also present some result of Finite-Difference Time-Domain (FDTD) calculations of light propagating through liquid crystal "blazed" gratings. Liquid crystal gratings are shown to spatially modulate both the phase and amplitude of the propagating light.

  7. Front and backside processed thin film electronic devices

    DOEpatents

    Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang; Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.

    2012-01-03

    This invention provides thin film devices that have been processed on their front- and backside. The devices include an active layer that is sufficiently thin to be mechanically flexible. Examples of the devices include back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

  8. Marangoni instability in the iodate-arsenous acid reaction front

    NASA Astrophysics Data System (ADS)

    Pópity-Tóth, Éva; Pótári, Gábor; Erdős, István; Horváth, Dezső; Tóth, Ágota

    2014-07-01

    Horizontally propagating chemical fronts leading to the formation of a single stable convection roll are investigated in the iodate-arsenous acid reaction with arsenous acid stoichiometrically limiting, leaving the surface active iodine present in the product mixture. In sufficiently thin solution layers with open upper surface, the contribution of Marangoni instability is significantly enhanced. Acting in the same direction as buoyancy driven instability, it distorts the entire tilted reaction front that becomes 50% more elongated. The corresponding three-dimensional calculations based on the empirical rate-law of the reaction corroborate the experimental findings.

  9. Marangoni instability in the iodate–arsenous acid reaction front

    SciTech Connect

    Pópity-Tóth, Éva; Pótári, Gábor; Erdős, István; Tóth, Ágota; Horváth, Dezső

    2014-07-28

    Horizontally propagating chemical fronts leading to the formation of a single stable convection roll are investigated in the iodate–arsenous acid reaction with arsenous acid stoichiometrically limiting, leaving the surface active iodine present in the product mixture. In sufficiently thin solution layers with open upper surface, the contribution of Marangoni instability is significantly enhanced. Acting in the same direction as buoyancy driven instability, it distorts the entire tilted reaction front that becomes 50% more elongated. The corresponding three-dimensional calculations based on the empirical rate-law of the reaction corroborate the experimental findings.

  10. Volumetric imaging with an amplitude-steered array.

    PubMed

    Frazier, Catherine H; Hughes, W Jack; O'Brien, William D

    2002-12-01

    Volumetric acoustic imaging is desirable for the visualization of underwater objects and structures; however, the implementation of a volumetric imaging system is difficult due to the high channel count of a fully populated two-dimensional array. Recently, a linear amplitude-steered array with a reduced electronics requirement was presented, which is capable of collecting a two-dimensional set of data with a single transmit pulse. In this study, we demonstrate the use of the linear amplitude-steered array and associated image formation algorithms for collecting and displaying volumetric data; that is, proof of principle of the amplitude-steering concept and the associated image formation algorithms is demonstrated. Range and vertical position are obtained by taking advantage of the frequency separation of a vertical linear amplitude-steered array. The third dimension of data is obtained by rotating the array such that the mainlobe is mechanically steered in azimuth. Data are collected in a water tank at the Pennsylvania State University Applied Research Laboratory for two targets: a ladder and three pipes. These data are the first experimental data collected with an amplitude-steered array for the purposes of imaging. The array is 10 cm in diameter and is operated in the frequency range of 80 to 304 kHz. Although the array is small for high-resolution imaging at these frequencies, the rungs of the ladder are recognizable in the images. The three pipes are difficult to discern in two of the projection images; however, the pipes separated in range are clear in the image showing vertical position versus range. The imaging concept is demonstrated on measured data, and the simulations agree well with the experimental results. PMID:12508995

  11. Relating Global Precipitation to Atmospheric Fronts

    NASA Astrophysics Data System (ADS)

    Catto, J. L.; Jakob, C.; Nicholls, N.

    2012-12-01

    Atmospheric fronts are important for the day-to-day variability of weather in the midlatitudes, particularly during winter when extratropical storm-tracks are at their maximum intensity. Fronts are often associated with heavy rain, and strongly affect the local space-time distribution of rainfall. Although global climate models should be expected to represent the baroclinic systems within which the fronts are embedded, the fronts themselves and precipitation processes within them are of much smaller scale. As a consequence, models with the typical horizontal resolution of contemporary climate models do not necessarily accurately capture these features. A recently developed objective front identification method applied to reanalysis data is combined with global rainfall data to investigate how precipitation and extremes of precipitation around the globe are associated with atmospheric fronts. Having established the observed distribution of fronts and their role in producing precipitation and extremes, the occurrence of fronts and the associated precipitation can then be evaluated in state-of-the-art climate models. This provides a process-oriented method of model evaluation where the errors in the model can be decomposed into contributions from errors in front frequency and errors in frontal and non-frontal precipitation intensity. Finally, how fronts and their associated precipitation, may change in the future, especially the extremes, can be investigated.

  12. 49 CFR 571.204 - Standard No. 204; Steering control rearward displacement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... dynamic movement of the upper end of the steering column and shaft during the crash test. S4.2 Vehicles... the maximum dynamic movement of the upper end of the steering column and shaft during the crash...

  13. 49 CFR 571.204 - Standard No. 204; Steering control rearward displacement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... dynamic movement of the upper end of the steering column and shaft during the crash test. S4.2 Vehicles... the maximum dynamic movement of the upper end of the steering column and shaft during the crash...

  14. 49 CFR 571.204 - Standard No. 204; Steering control rearward displacement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... dynamic movement of the upper end of the steering column and shaft during the crash test. S4.2 Vehicles... the maximum dynamic movement of the upper end of the steering column and shaft during the crash...

  15. H∞-control of a rack-assisted electric power steering system

    NASA Astrophysics Data System (ADS)

    Dannöhl, C.; Müller, S.; Ulbrich, H.

    2012-04-01

    Electric power steering (EPS) is more and more in use for passenger cars. Compared with hydraulic steering systems there are many advantages, such as reduced CO2 emissions and the possibility to use the EPS motor torque for advanced driver assistance systems. One task of the steering system is to give the driver an adequate steering feel. This includes providing road feedback and the right level of assistance torque. This article describes the steering torque control of a rack-assisted EPS. The controller's task is to follow a reference steering torque quickly and accurately. First, a mechanical model of the EPS is shown. Then, an H∞-controller is designed, implemented and compared with other steering torque controllers. As steering torque discontinuities are a topic when looking at new control algorithms, the phenomenon and its cause are analysed using a detailed mechanical model. The results of this analysis are considered in the controller design.

  16. Laser-supported solid-state absorption fronts in silica

    NASA Astrophysics Data System (ADS)

    Carr, C. W.; Bude, J. D.; Demange, P.

    2010-11-01

    We develop a model based on simulation and extensive experimentation that explains the behavior of solid-state laser-supported absorption fronts generated in fused silica during high intensity (up to 5GW/cm2 ) laser exposure. Both experiments and simulations show that the absorption front velocity is constant in time and is nearly linear in laser intensity. Further, this model can explain the dependence of laser damage site size on these parameters. We show that these absorption fronts naturally result from the combination of high-temperature-activated deep subband-gap optical absorptivity, free-electron transport, and thermal diffusion in defect-free silica for temperatures up to 15000K and pressures <10GPa . The regime of parameter space critical to this problem spans and extends that measured by other means. It serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

  17. Dynamic Curvature Steering Control for Autonomous Vehicle: Performance Analysis

    NASA Astrophysics Data System (ADS)

    Aizzat Zakaria, Muhammad; Zamzuri, Hairi; Amri Mazlan, Saiful

    2016-02-01

    This paper discusses the design of dynamic curvature steering control for autonomous vehicle. The lateral control and longitudinal control are discussed in this paper. The controller is designed based on the dynamic curvature calculation to estimate the path condition and modify the vehicle speed and steering wheel angle accordingly. In this paper, the simulation results are presented to show the capability of the controller to track the reference path. The controller is able to predict the path and modify the vehicle speed to suit the path condition. The effectiveness of the controller is shown in this paper whereby identical performance is achieved with the benchmark but with extra curvature adaptation capabilites.

  18. Compact holographic memory using E - O beam steering

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Zhou, Hanying; Reyes, George; Hanan, Jay

    2002-01-01

    An innovative holographic memory system has been developed at JPL for high-density and high speed data storage in a space environment. This system ulitlizes a newly developed electro-optic (E-O) beam steering technology for beam steering to enable high-speed random access memory read/write without moving parts. Recently, a compact CD-sized holographic memory broadboard has been developed and demonstrated for holographic data storage adn retrieval. Detail technical progress will be presented in this paper.

  19. The Evolvement of Automobile Steering System Based on TRIZ

    NASA Astrophysics Data System (ADS)

    Zhao, Xinjun; Zhang, Shuang

    Products and techniques pass through a process of birth, growth, maturity, death and quit the stage like biological evolution process. The developments of products and techniques conform to some evolvement rules. If people know and hold these rules, they can design new kind of products and forecast the develop trends of the products. Thereby, enterprises can grasp the future technique directions of products, and make product and technique innovation. Below, based on TRIZ theory, the mechanism evolvement, the function evolvement and the appearance evolvement of automobile steering system had been analyzed and put forward some new ideas about future automobile steering system.

  20. Propagation failures, breathing fronts, and nonannihilation collisions in the ferroin-bromate-pyrocatechol system.

    PubMed

    Harati, Mohammad; Wang, Jichang

    2009-06-01

    The emergence of propagating pulses was investigated with the photosensitive ferroin-bromate-pyrocatechol reaction in capillary tubes, in which various interesting spatiotemporal behaviors such as propagation failure, breathing fronts, and transitions between propagating pulses and fronts have been observed. Rather than a mutual annihilation, the collision of a propagating pulse and a growing front forces the front to recede gradually. A phase diagram in the pyrocatechol-bromate concentration space shows that the pulse instabilities take place throughout the conditions at which the system generates wave activities, suggesting that the presence of coupled autocatalytic feedbacks may facilitate the onset of pulse instabilities.

  1. Light-Front Holographic QCD

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U.

    2012-02-16

    The relation between the hadronic short-distance constituent quark and gluon particle limit and the long-range confining domain is yet one of the most challenging aspects of particle physics due to the strong coupling nature of Quantum Chromodynamics, the fundamental theory of the strong interactions. The central question is how one can compute hadronic properties from first principles; i.e., directly from the QCD Lagrangian. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time. Lattice numerical results follow from computation of frame-dependent moments of distributions in Euclidean space and dynamical observables in Minkowski spacetime, such as the time-like hadronic form factors, are not amenable to Euclidean lattice computations. The Dyson-Schwinger methods have led to many important insights, such as the infrared fixed point behavior of the strong coupling constant, but in practice, the analyses are limited to ladder approximation in Landau gauge. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. New theoretical tools are thus of primary interest for the interpretation of the results expected at the new mass scale and kinematic regions accessible to the JLab 12 GeV Upgrade Project. The AdS/CFT correspondence between gravity or string theory on a higher-dimensional anti-de Sitter (AdS) space and conformal field theories in physical space-time has led to a semiclassical approximation for strongly-coupled QCD, which provides physical insights into its nonperturbative dynamics. The correspondence is holographic in the sense that it determines a duality between theories in different number of space-time dimensions. This geometric approach leads in fact to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light-front

  2. Front propagation and rejuvenation in flipping processes

    SciTech Connect

    Ben-naim, Eli; Krapivsky, P I; Antal, T; Ben - Avrahm, D

    2008-01-01

    We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess {Delta}{sub k} increases logarithmically, {Delta}{sub k} {approx_equal}ln k, with the distance k from the front. Third, the front exhibits ageing -- young fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations.

  3. Condensation Front Migration in a Protoplanetary Nebula

    NASA Technical Reports Server (NTRS)

    Davis, Sanford S.

    2004-01-01

    Condensation front dynamics are investigated in the mid-solar nebula region. A quasi-steady model of the evolving nebula is combined with equilibrium vapor pressure curves to determine evolutionary condensation fronts for selected species. These fronts are found to migrate inwards from the far-nebula to final positions during a period of 10(exp 7) years. The physical process governing this movement is a combination of local viscous heating and luminescent heating from the central star. Two luminescent heating models are used and their effects on the ultimate radial position of the condensation front are discussed. At first the fronts move much faster than the nebular accretion velocity, but after a time the accreting gas and dust overtakes the slowing condensation front.

  4. Progress in front propagation research

    NASA Astrophysics Data System (ADS)

    Fort, Joaquim; Pujol, Toni

    2008-08-01

    We review the progress in the field of front propagation in recent years. We survey many physical, biophysical and cross-disciplinary applications, including reduced-variable models of combustion flames, Reid's paradox of rapid forest range expansions, the European colonization of North America during the 19th century, the Neolithic transition in Europe from 13 000 to 5000 years ago, the description of subsistence boundaries, the formation of cultural boundaries, the spread of genetic mutations, theory and experiments on virus infections, models of cancer tumors, etc. Recent theoretical advances are unified in a single framework, encompassing very diverse systems such as those with biased random walks, distributed delays, sequential reaction and dispersion, cohabitation models, age structure and systems with several interacting species. Directions for future progress are outlined.

  5. The upgraded Tevatron front end

    NASA Astrophysics Data System (ADS)

    Glass, M.; Zagel, J.; Smith, P.; Marsh, W.; Smolucha, J.

    1990-08-01

    We are replacing the computers which support the CAMAC crates in the Fermilab accelerator control system. We want a significant performance increase, but we still want to be able to service scores of different varieties of CAMAC cards in a manner essentially transparent to console applications software. Our new architecture is based on symmetric multiprocessing. Several processors on the same bus, each running identical software, work simultaneously at satisfying different pieces of a console's request for data. We dynamically adjust the load between the processors. We can obtain more processing power by simply plugging in more processors cards and rebooting. We describe in this paper what we believe to be the interesting architectural features of the new front-end computers. We also note how we use some of the advanced features of the Multibus™ II bus and the Intel 80386 processor design to achieve reliability and expandability of both hardware and software.

  6. 46 CFR 97.37-33 - Instructions for changing steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Instructions for changing steering gear. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall...

  7. 46 CFR 35.20-10 - Steering gear test-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Steering gear test-T/ALL. 35.20-10 Section 35.20-10... Steering gear test—T/ALL. On all tankships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means of communication, and the signaling appliances between the bridge...

  8. 46 CFR 35.40-30 - Instructions for changing steering gear-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Instructions for changing steering gear-TB/ALL. 35.40-30... Marking Requirements-TB/ALL. § 35.40-30 Instructions for changing steering gear—TB/ALL. Instructions in at... different steps to be taken in changing to the emergency steering gear. Each clutch, gear wheel,...

  9. 46 CFR 78.47-55 - Instructions for changing steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Instructions for changing steering gear. 78.47-55... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-55 Instructions for changing steering gear..., relating in order, the different steps to be taken in changing to the emergency steering gear. Each...

  10. 46 CFR 97.37-33 - Instructions for changing steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Instructions for changing steering gear. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall...

  11. 46 CFR 97.37-33 - Instructions for changing steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall...

  12. 46 CFR 78.47-55 - Instructions for changing steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Instructions for changing steering gear. 78.47-55... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-55 Instructions for changing steering gear..., relating in order, the different steps to be taken in changing to the emergency steering gear. Each...

  13. 46 CFR 78.47-55 - Instructions for changing steering gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Instructions for changing steering gear. 78.47-55... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-55 Instructions for changing steering gear..., relating in order, the different steps to be taken in changing to the emergency steering gear. Each...

  14. 46 CFR 35.40-30 - Instructions for changing steering gear-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Instructions for changing steering gear-TB/ALL. 35.40-30... Marking Requirements-TB/ALL § 35.40-30 Instructions for changing steering gear—TB/ALL. Instructions in at... different steps to be taken in changing to the emergency steering gear. Each clutch, gear wheel,...

  15. 46 CFR 131.505 - Steering gear, whistle, and means of communication.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Steering gear, whistle, and means of communication. 131... VESSELS OPERATIONS Tests, Drills, and Inspections § 131.505 Steering gear, whistle, and means of... examine and test the steering gear, the whistle, and the means of communication between the pilothouse...

  16. 46 CFR 131.505 - Steering gear, whistle, and means of communication.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Steering gear, whistle, and means of communication. 131... VESSELS OPERATIONS Tests, Drills, and Inspections § 131.505 Steering gear, whistle, and means of... examine and test the steering gear, the whistle, and the means of communication between the pilothouse...

  17. 46 CFR 131.505 - Steering gear, whistle, and means of communication.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Steering gear, whistle, and means of communication. 131... VESSELS OPERATIONS Tests, Drills, and Inspections § 131.505 Steering gear, whistle, and means of... examine and test the steering gear, the whistle, and the means of communication between the pilothouse...

  18. 46 CFR 131.505 - Steering gear, whistle, and means of communication.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, whistle, and means of communication. 131... VESSELS OPERATIONS Tests, Drills, and Inspections § 131.505 Steering gear, whistle, and means of... examine and test the steering gear, the whistle, and the means of communication between the pilothouse...

  19. 46 CFR 131.505 - Steering gear, whistle, and means of communication.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Steering gear, whistle, and means of communication. 131... VESSELS OPERATIONS Tests, Drills, and Inspections § 131.505 Steering gear, whistle, and means of... examine and test the steering gear, the whistle, and the means of communication between the pilothouse...

  20. 46 CFR 130.140 - Steering on OSVs of 100 or more gross tons.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of this chapter; or (2) Requirements for a hydraulic-helm steering-system in paragraph (b) of this section. (b) Each hydraulic-helm steering-system must have the following: (1) A main steering gear of... maximum astern speed. (2) A hydraulic system with a maximum allowable working pressure of not more than...

  1. Enhancement of the acute phase response to lipopolysaccharide (LPS) challenge in steers supplemented with chromium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Twenty steers received a premix that added 0 (control) or 0.2 mg/kg of chromium (KemTRACE®brandChromiumProprionate 0.04%, Kemin Industries) to the total diet on a dry matter basis for 55 d. Steer...

  2. Health measures in beef steers of known genetic background following BVDV challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angus-sired steers (n = 95) born in the spring of 2008 produced from TAMU McGregor Genomics Project cows were evaluated for health measures following challenge to BVD virus. Steers were not vaccinated for BRD prior to trial initiation, and were verified to be BVD-free. Prior to BVDV challenge, steer...

  3. 7 CFR 59.101 - Mandatory daily reporting for steers and heifers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Mandatory daily reporting for steers and heifers. 59... (CONTINUED) LIVESTOCK MANDATORY REPORTING Cattle Reporting § 59.101 Mandatory daily reporting for steers and heifers. (a) In general. The corporate officers or officially designated representatives of each steer...

  4. 7 CFR 59.103 - Mandatory weekly reporting for steers and heifers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Mandatory weekly reporting for steers and heifers. 59... (CONTINUED) LIVESTOCK MANDATORY REPORTING Cattle Reporting § 59.103 Mandatory weekly reporting for steers and heifers. (a) In general. The corporate officers or officially designated representatives of each steer...

  5. 7 CFR 59.101 - Mandatory daily reporting for steers and heifers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Mandatory daily reporting for steers and heifers. 59... (CONTINUED) LIVESTOCK MANDATORY REPORTING Cattle Reporting § 59.101 Mandatory daily reporting for steers and heifers. (a) In general. The corporate officers or officially designated representatives of each steer...

  6. 7 CFR 59.103 - Mandatory weekly reporting for steers and heifers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Mandatory weekly reporting for steers and heifers. 59... (CONTINUED) LIVESTOCK MANDATORY REPORTING Cattle Reporting § 59.103 Mandatory weekly reporting for steers and heifers. (a) In general. The corporate officers or officially designated representatives of each steer...

  7. Chromium supplementation enhances the acute phase response of steers to a lipopolysaccharide (LPS) challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Twenty crossbred steers (235±4 kg BW) received 0 ppb (Control; C) or 200 ppb chromium propionate (CHR) for 55 days. Steers were fitted with jugular catheters and rectal temperature (RT) recording...

  8. Muon front end for the neutrino factory

    NASA Astrophysics Data System (ADS)

    Rogers, C. T.; Stratakis, D.; Prior, G.; Gilardoni, S.; Neuffer, D.; Snopok, P.; Alekou, A.; Pasternak, J.

    2013-04-01

    In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

  9. Steering S-H and N-H bond activation by a stable n-heterocyclic silylene: different addition of H(2)S, NH(3), and organoamines on a silicon(II) ligand versus its Si(II)-->Ni(CO)(3) complex.

    PubMed

    Meltzer, Antje; Inoue, Shigeyoshi; Präsang, Carsten; Driess, Matthias

    2010-03-10

    The strikingly different behavior of the ylide-like, N-heterocyclic silylene LSi: (5: L = CH[(C horizontal lineCH(2))CMe(NAr)(2)]; Ar = 2,6-(i)PrC(6)H(3)) versus its LSi-->Ni(CO)(3) complex 13 to activate E-H bonds (E = S, N) of small molecules is reported. Remarkably, conversion of 5 with hydrogen sulfide leads exclusively to the first isolable silathioformamide, L'Si( horizontal lineS)H (16: L' = CH[C(Me)NAr](2); Ar = 2,6-(i)PrC(6)H(3)) with a donor-supported Si horizontal lineS double bond and four-coordinate silicon. The latter result demonstrates the unusual ambivalent reactivity of 5 by combining two modes of reactivity involving S-H bond activation and subsequent 1,4- and 1,1-addition, respectively. In addition, 5 can serve as a ligand with well-balanced sigma-donor and pi-acceptor capabilities toward transition metals. This has been demonstrated by the isolable [Ni(0)(arene)] complexes 12a-e (arene = Me(n)C(6)H(6-n), n = 0-3), which are ideal precursors for the formation of the corresponding Ni(CO)(3) complex 13. The latter activates a S-H bond in hydrogen sulfide, too, but the presence of the Ni(CO)(3) moiety governs the formation of the complex 17, bearing an unprecedented beta-diketiminate silicon(II) thiol ligand: L'Si(SH): (L' = CH[C(Me)NAr](2); Ar = 2,6-(i)PrC(6)H(3)). Likewise, the Si(II)-->Ni(CO)(3) coordination in 13 steers exclusively 1,4-addition of ammonia, isopropylamine, and phenylhydrazine onto the silylene ligand 5, leading to the corresponding beta-diketiminate silicon(II) amide or hydrazide complexes L'Si(NHR)-->Ni(CO)(3) (23a-c: R = H, (i)Pr, N(H)Ph). IR measurements reveal that the carbonyl stretching frequencies of the Ni(CO)(3) moiety in 23a-c are shifted to even lower wavenumbers in comparison to those of NHCs or phosphines. In other words, the beta-diketiminate silicon(II) amide ligands in 23a-c represent the strongest donors in the series of N-heterocyclic silylenes reported as yet. PMID:20148586

  10. Front blind spot crashes in Hong Kong.

    PubMed

    Cheng, Yuk Ki; Wong, Koon Hung; Tao, Chi Hang; Tam, Cheok Ning; Tam, Yiu Yan; Tsang, Cheuk Nam

    2016-09-01

    In 2012-2014, our laboratory had investigated a total of 9 suspected front blind spot crashes, in which the medium and heavy goods vehicles pulled away from rest and rolled over the pedestrians, who were crossing immediately in front of the vehicles. The drivers alleged that they did not see any pedestrians through the windscreens or the front blind spot mirrors. Forensic assessment of the goods vehicles revealed the existence of front blind spot zones in 3 out of these 9 accident vehicles, which were attributed to the poor mirror adjustments or even the absence of a front blind spot mirror altogether. In view of this, a small survey was devised involving 20 randomly selected volunteers and their goods vehicles and 5 out of these vehicles had blind spots at the front. Additionally, a short questionnaire was conducted on these 20 professional lorry drivers and it was shown that most of them were not aware of the hazards of blind spots immediately in front of their vehicles, and many did not use the front blind spot mirrors properly. A simple procedure for quick measurements of the coverage of front blind spot mirrors using a coloured plastic mat with dimensional grids was also introduced and described in this paper.

  11. Helices in the wake of precipitation fronts.

    PubMed

    Thomas, Shibi; Lagzi, István; Molnár, Ferenc; Rácz, Zoltán

    2013-08-01

    A theoretical study of the emergence of helices in the wake of precipitation fronts is presented. The precipitation dynamics is described by the Cahn-Hilliard equation and the fronts are obtained by quenching the system into a linearly unstable state. Confining the process onto the surface of a cylinder and using the pulled-front formalism, our analytical calculations show that there are front solutions that propagate into the unstable state and leave behind a helical structure. We find that helical patterns emerge only if the radius of the cylinder R is larger than a critical value R>R(c), in agreement with recent experiments. PMID:24032809

  12. Car Gestures - Advisory warning using additional steering wheel angles.

    PubMed

    Maag, Christian; Schneider, Norbert; Lübbeke, Thomas; Weisswange, Thomas H; Goerick, Christian

    2015-10-01

    Advisory warning systems (AWS) notify the driver about upcoming hazards. This is in contrast to the majority of currently deployed advanced driver assistance systems (ADAS) that manage emergency situations. The target of this study is to investigate the effectiveness, acceptance, and controllability of a specific kind of AWS that uses the haptic information channel for warning the driver. This could be beneficial, as alternatives for using the visual modality can help to reduce the risk of visual overload. The driving simulator study (N=24) compared an AWS based on additional steering wheel angle control (Car Gestures) with a visual warning presented in a simulated head-up display (HUD). Both types of warning were activated 3.5s before the hazard object was reached. An additional condition of unassisted driving completed the experimental design. The subjects encountered potential hazards in a variety of urban situations (e.g. a pedestrian standing on the curbs). For the investigated situations, subjective ratings show that a majority of drivers prefer visual warnings over haptic information via gestures. An analysis of driving behavior indicates that both warning approaches guide the vehicle away from the potential hazard. Whereas gestures lead to a faster lateral driving reaction (compared to HUD warnings), the visual warnings result in a greater safety benefit (measured by the minimum distance to the hazard object). A controllability study with gestures in the wrong direction (i.e. leading toward the hazard object) shows that drivers are able to cope with wrong haptic warnings and safety is not reduced compared to unassisted driving as well as compared to (correct) haptic gestures and visual warnings.

  13. The Steering of Higher Education Systems: A Public Management Perspective

    ERIC Educational Resources Information Center

    Ferlie, Ewan; Musselin, Christine; Andresani, Gianluca

    2008-01-01

    This article focuses on the steering of higher education systems in the light of political science and public management approaches. It first recalls that an important part of the existing literature on higher education is focused on public policies in terms of reforms and decision-making, while the other part is dedicated to discovering and…

  14. Analytic Steering: Inserting Context into the Information Dialog

    SciTech Connect

    Bohn, Shawn J.; Calapristi, Augustin J.; Brown, Shyretha D.; Nakamura, Grant C.

    2011-10-23

    An analyst’s intrinsic domain knowledge is a primary asset in almost any analysis task. Unstructured text analysis systems that apply un-supervised content analysis approaches can be more effective if they can leverage this domain knowledge in a manner that augments the information discovery process without obfuscating new or unexpected content. Current unsupervised approaches rely upon the prowess of the analyst to submit the right queries or observe generalized document and term relationships from ranked or visual results. We propose a new approach which allows the user to control or steer the analytic view within the unsupervised space. This process is controlled through the data characterization process via user supplied context in the form of a collection of key terms. We show that steering with an appropriate choice of key terms can provide better relevance to the analytic domain and still enable the analyst to uncover un-expected relationships; this paper discusses cases where various analytic steering approaches can provide enhanced analysis results and cases where analytic steering can have a negative impact on the analysis process.

  15. Final Report of the Steering Committee. A Learning Alberta

    ERIC Educational Resources Information Center

    Alberta Advanced Education, 2006

    2006-01-01

    This is the final report and recommendations of the Steering Committee for "A Learning Alberta": a report gleaned from a series of discussions and reports to review the Advanced Education system in Alberta. In order to foster a strong system, the committee recommended the achievement of six key goals and provided a 20 year strategic plan to…

  16. Image Processing In Laser-Beam-Steering Subsystem

    NASA Technical Reports Server (NTRS)

    Lesh, James R.; Ansari, Homayoon; Chen, Chien-Chung; Russell, Donald W.

    1996-01-01

    Conceptual design of image-processing circuitry developed for proposed tracking apparatus described in "Beam-Steering Subsystem For Laser Communication" (NPO-19069). In proposed system, desired frame rate achieved by "windowed" readout scheme in which only pixels containing and surrounding two spots read out and others skipped without being read. Image data processed rapidly and efficiently to achieve high frequency response.

  17. Linac Alignment Algorithm: Analysis on 1-to-1 Steering

    SciTech Connect

    Sun, Yipeng; Adolphsen, Chris; /SLAC

    2011-08-19

    In a linear accelerator, it is important to achieve a good alignment between all of its components (such as quadrupoles, RF cavities, beam position monitors et al.), in order to better preserve the beam quality during acceleration. After the survey of the main linac components, there are several beam-based alignment (BBA) techniques to be applied, to further optimize the beam trajectory and calculate the corresponding steering magnets strength. Among these techniques the most simple and straightforward one is the one-to-one (1-to-1) steering technique, which steers the beam from quad center to center, and removes the betatron oscillation from quad focusing. For a future linear collider such as the International Linear Collider (ILC), the initial beam emittance is very small in the vertical plane (flat beam with {gamma}{epsilon}{sub y} = 20-40nm), which means the alignment requirement is very tight. In this note, we evaluate the emittance growth with one-to-one correction algorithm employed, both analytically and numerically. Then the ILC main linac accelerator is taken as an example to compare the vertical emittance growth after 1-to-1 steering, both from analytical formulae and multi-particle tracking simulation. It is demonstrated that the estimated emittance growth from the derived formulae agrees well with the results from numerical simulation, with and without acceleration, respectively.

  18. 46 CFR 167.65-25 - Steering gear tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships... and tested by an officer of the nautical school ship within a period of not more than 12 hours...

  19. Greenhouse gas and alcohol emissions from feedlot steers and calves.

    PubMed

    Stackhouse, Kimberly R; Pan, Yuee; Zhao, Yongjing; Mitloehner, Frank M

    2011-01-01

    Livestock's contributions to climate change and smog-forming emissions are a growing public policy concern. This study quantifies greenhouse gas (GHG) and alcohol emissions from calves and feedlot steers. Carbon dioxide (CO) methane (CH), nitrous oxide (NO), ethanol (EtOH), and methanol (MeOH) were measured from a total of 45 Holstein and Angus steers and 9 Holstein calves representative of four different growth stages commonly present on calf ranches and commercial feedlots. Individuals from each animal type were randomly assigned to three equal replicate groups of nine animals per group. Steers were fed a high concentrate diet and calves a milk replacer and grain supplement. Cattle and calves were housed in groups of three animals in an environmental chamber for 24 h. The CO, NO, EtOH, and MeOH concentrations from the air inlet and outlet of the chamber were measured using an INNOVA 1412 monitor and CH using a TEI 55C methane analyzer. Emission rates (g head h) were calculated. The GHGs were mainly produced by enteric fermentation and respiration and differed across life stages of cattle. Compared with dairy cows, feedlot steers produce relatively less GHG. In general, ethanol and methanol, the most important volatile organic compound (VOC) group in the dairy sector, were below the lower limit of detection of the gas analyzer. The present data will be useful to verify models and to enhance GHG emission inventories for enteric fermentation, respiration, and fresh excreta for numerous cattle life stages across the beef industry.

  20. 46 CFR 182.610 - Main steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of moving the rudder from 35 degrees on one side to 30 degrees on the other side in not more than 28... the requirements of paragraphs (a) through (e) of this section, a vessel with a power driven main... with a power driven main steering gear must be provided with the following: (1) A visual means,...

  1. Wave front fragmentation due to ventricular geometry in a model of the rabbit heart

    NASA Astrophysics Data System (ADS)

    Rogers, Jack M.

    2002-09-01

    The role of the heart's complex shape in causing the fragmentation of activation wave fronts characteristic of ventricular fibrillation (VF) has not been well studied. We used a finite element model of cardiac propagation capable of simulating functional reentry on curved two-dimensional surfaces to test the hypothesis that uneven surface curvature can cause local propagation block leading to proliferation of reentrant wave fronts. We found that when reentry was induced on a flat sheet, it rotated in a repeatable meander pattern without breaking up. However, when a model of the rabbit ventricles was formed from the same medium, reentrant wave fronts followed complex, nonrepeating trajectories. Local propagation block often occurred when wave fronts propagated across regions where the Gaussian curvature of the surface changed rapidly. This type of block did not occur every time wave fronts crossed such a region; rather, it only occurred when the wave front was very close behind the previous wave in the cycle and was therefore propagating into relatively inexcitable tissue. Close wave front spacing resulted from nonstationary reentrant propagation. Thus, uneven surface curvature and nonstationary reentrant propagation worked in concert to produce wave front fragmentation and complex activation patterns. None of the factors previously thought to be necessary for local propagation block (e.g., heterogeneous refractory period, steep action potential duration restitution) were present. We conclude that the complex geometry of the heart may be an important determinant of VF activation patterns.

  2. Seasonal variation in carcass characteristics of korean cattle steers.

    PubMed

    Piao, M Y; Baik, M

    2015-03-01

    Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of 28.4°C and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of -4.0°C and a wind-chill temperature of -6.2°C. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated (r≥0.71; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated (r≤-0.74; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions. PMID:25656196

  3. Seasonal variation in carcass characteristics of korean cattle steers.

    PubMed

    Piao, M Y; Baik, M

    2015-03-01

    Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of 28.4°C and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of -4.0°C and a wind-chill temperature of -6.2°C. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated (r≥0.71; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated (r≤-0.74; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.

  4. Comparing Ultrasound and Mechanical Steering in a Biodiesel Production Process

    NASA Astrophysics Data System (ADS)

    Costa-Felix, Rodrigo P. B.; Ferreira, Jerusa R. L.

    The analysis of the kinetics of the transesterification reaction is crucial to compare different routes or routes with different catalysts or reaction accelerators. The use of ultrasound is considereda method for accelerating the biodiesel production. However, little effort has been done and is reported in the literature about how and under what conditions the use of ultrasound really speeds up the process, or the conditions under which its use is unnecessary or even harmful, burdening the process. Two dissimilar energy injections into a typical route were tested: ultrasound (@ 1 MHz and no heating) and mechanical steering (with heating), both applied in an 8:1 ratio of soybean oil and methanol, adding 1% of KOH as catalyzer. As results, during the first 10 minutes of reaction ultrasound showed unbearable effect on the transesterification, whilst mechanical steering and heating achieved almost 70% of conversion ratio. However, during the following 10 minutes, the mechanical steering and heating got nothing more than 80% of conversion, a considerable less efficient process than ultrasound assisted one, which achieved more than 90%. The straightforward explanation is that ultrasound continually inserts energy in a slower rate, what can result in a more stable conversion scenario. On the other hand, mechanical steering and heating provides more energy at a glance, but cannot push the final conversion rate beyond a limit, as the transesterification is a double-way chemical process. The instability mechanical steering and heating settles in the reaction medium pulls the components back to their original states more than pushes than to the converted equilibrium state of the matter.

  5. A spiral wave front beacon for underwater navigation: basic concept and modeling.

    PubMed

    Hefner, Brian T; Dzikowicz, Benjamin R

    2011-06-01

    A spiral wave front source produces an acoustic field that has a phase that is proportional to the azimuthal angle about the source. The concept of a spiral wave front beacon is developed by combining this source with a reference source that has a phase that is constant with the angle. The phase difference between these sources contains information about the receiver's azimuthal angle relative to the beacon and can be used for underwater navigation. To produce the spiral wave front, two sources are considered: a "physical-spiral" source, which produces the appropriate phase by physically deforming the active element of the source into a spiral, and a "phased-spiral" source, which uses an array of active elements, each driven with the appropriate phase, to produce the spiral wave front. Using finite element techniques, the fields produced by these sources are examined in the context of the spiral wave front beacon, and the advantages of each source are discussed.

  6. The APS beamline front end vacuum system

    SciTech Connect

    Nielsen, R.W.

    1993-10-15

    This report discusses the design of the vacuum system for the advanced photon source beamline front ends. Included in this report are discussions on: vacuum calculations, the differential pump; front end vacuum set points; cleaning methods and agents; and continuing and completed research and development.

  7. Crossbred steer temperament as yearlings and whole genome association of steer temperament as yearlings and calf temperament post-weaning.

    PubMed

    Riley, D G; Gill, C A; Boldt, C R; Funkhouser, R R; Herring, A D; Riggs, P K; Sawyer, J E; Lunt, D K; Sanders, J O

    2016-04-01

    cattle often have the reputation for a poor or dangerous temperament. Identification of genomic regions that associate with temperament of such cattle may be useful for genetic improvement strategies. The objectives of this study were to evaluate subjective temperament scores (1 to 9; higher scores indicated more unfavorable temperament) for aggressiveness, nervousness, flightiness, gregariousness, and overall temperament of one-half steers in feedlot conditions at 1 yr of age and compare those scores of those steers when evaluated approximately 1 mo postweaning, and conduct whole genome association analyses using SNP markers and the temperament traits of those steers at 1 yr of age and for temperament traits of all calves at weaning. Contemporary groups ( < 0.001) were steers born in the same year and season, and fed in the same feedlot pen. Aggressiveness of steers at 1 yr of age was not associated with aggressiveness at weaning (linear regression coefficient did not differ from 0; = 0.96), but regressions of all other yearling scores of steers on the scores at weaning were positive (coefficients ranged from 0.26 ± 0.04 to 0.32 ± 0.04; < 0.001). Estimates of Pearson correlation coefficients (using unadjusted values and residual values) of the different traits measured at 1 yr of age were large ( > 0.63; < 0.008) except for aggressiveness with nervousness, flightiness, or gregariousness, which did not differ from 0 ( > 0.1). Five SNP on BTA 1, 24, and 29 had suggestive associations (0.17 < [adjusted for FDR] < 0.24) with aggressiveness, nervousness, or flightiness at evaluation postweaning and 13 SNP on 11 chromosomes had suggestive associations (0.07 < [adjusted for FDR] < 0.24) with aggressiveness, nervousness, flightiness, or overall temperament score of steers at 1 yr of age. Genes close to these loci with roles in neural systems of various organisms included synaptotagmin 4 (BTA 24), FAT atypical cadhedrin 3 (BTA 29), tubulin tyrosine ligase-like 1 (BTA 5

  8. Acoustic startle/escape reactions in tethered flying locusts: motor patterns and wing kinematics underlying intentional steering.

    PubMed

    Dawson, J W; Leung, F-H; Robertson, R M

    2004-07-01

    We simultaneously recorded flight muscle activity and wing kinematics in tethered, flying locusts to determine the relationship between asymmetric depressor muscle activation and the kinematics of the stroke reversal at the onset of wing depression during attempted intentional steering manoeuvres. High-frequency, pulsed sounds produced bilateral asymmetries in forewing direct depressor muscles (M97, 98, 99) that were positively correlated with asymmetric forewing depression and asymmetries in stroke reversal timing. Bilateral asymmetries in hindwing depressor muscles (M127 and M128 but not M129) were positively correlated with asymmetric hindwing depression and asymmetries in the timing of the hindwing stroke reversal; M129 was negatively correlated with these shifts. Hindwing depressor asymmetries and wing kinematic changes were smaller and shifted in opposite direction than corresponding measurements of the forewings. These findings suggest that intentional steering manoeuvres employ bulk shifts in depressor muscle timing that affect the timing of the stroke reversals thereby establishing asymmetric wing depression. Finally, we found indications that locusts may actively control the timing of forewing rotation and speculate this may be a mechanism for generating steering torques. These effects would act in concert with forces generated by asymmetric wing depression and angle of attack to establish rapid changes in direction. PMID:15127218

  9. Observations of Gravity Waves at Atmospheric Fronts

    NASA Astrophysics Data System (ADS)

    Abu Samah, Azizan B. Hj.

    1990-01-01

    Available from UMI in association with The British Library. An observational study of pressure perturbations associated with the passage of atmospheric fronts over the British Isles using a triangular array of sensitive microbarographs reveals the preponderance of gravity wave activities in the vicinity of the surface cold front (SCF). Examination of the time series of these pressure perturbations in the frequency domain shows an enhancement for frequencies less than the local buoyancy frequency N after the passage of the SCF. The spectral analysis also shows two predominant frequency peaks usually located near N and N/2 s ^{-1}. Isolating these frequencies shows that there is a systematic amplitude modulation with an amplification near the SCF and at a region 2-3 hours before and after the SCF passage. The cross-correlation analysis reveals that the gravity waves in the post SCF region propagate towards the SCF. As these waves approach the SCF, the across front component of the phase speed decreases and the direction of propagation of the wave rotates in an anticlockwise manner. It is found that a consistent description of the gravity waves can only be made if first the waves are assumed to be ducted, i.e. there is a reflecting layer aloft, and second that as these waves propagate through the frontal environment, due to the inhomogeneity, they are refracted. A number of conceptual models are then developed to account for the observed wave behaviour in a frontal region. In this investigation it is shown that the stable layer associated with the frontal zone can form a good upper reflector for non-hydrostatic gravity waves. It is also argued that the slope of this layer plays an important role in the refraction of the observed gravity waves. A model of wave propagation in a wedge is then used to account for this slope. This model however predicts a clockwise rotation of the direction of propagation as the wave propagates toward the SCF. This rotation is the opposite

  10. Front end for GPS receivers

    NASA Technical Reports Server (NTRS)

    Thomas, Jr., Jess Brooks (Inventor)

    1999-01-01

    The front end in GPS receivers has the functions of amplifying, down-converting, filtering and sampling the received signals. In the preferred embodiment, only two operations, A/D conversion and a sum, bring the signal from RF to filtered quadrature baseband samples. After amplification and filtering at RF, the L1 and L2 signals are each sampled at RF at a high selected subharmonic rate. The subharmonic sample rates are approximately 900 MHz for L1 and 982 MHz for L2. With the selected subharmonic sampling, the A/D conversion effectively down-converts the signal from RF to quadrature components at baseband. The resulting sample streams for L1 and L2 are each reduced to a lower rate with a digital filter, which becomes a straight sum in the simplest embodiment. The frequency subsystem can be very simple, only requiring the generation of a single reference frequency (e.g. 20.46 MHz minus a small offset) and the simple multiplication of this reference up to the subharmonic sample rates for L1 and L2. The small offset in the reference frequency serves the dual purpose of providing an advantageous offset in the down-converted carrier frequency and in the final baseband sample rate.

  11. A BiCMOS time interval digitizer based on fully-differential, current-steering circuits

    SciTech Connect

    Loinaz, M.J.; Wooley, B.A. . Center for Integrated Systems)

    1994-06-01

    A time interval digitizer cell with a 0--16 ns input range and a nominal LSB width of 1.0 ns has been integrated in a 2-[mu]m BiCMOS technology. The circuit exhibits both integral and differential nonlinearity below 0.15 LSB and a timing error of 0.32 ns RMS. Logic gate propagation delays are used as time measurement units, and the nominal value of the delays is set by an on-chip phase-locked loop (PLL). Fully-differential, current-steering circuits with low voltage swings are used to implement the time interval digitizer so as to generate minimal switching noise. The cell is to be used in the monolithic, multi-channel realization of a high-sensitivity, mixed-signal data acquisition front-end. By virtue of the time digitization architecture used, the average power dissipation of the cell is only 19.8 mW, despite the use of circuits that dissipate static power, and the layout area is a compact 448 [mu]m x 634 [mu]m.

  12. Effect of dietary phosphorus on finishing steer performance, bone status, and carcass maturity.

    PubMed

    Erickson, G E; Klopfenstein, T J; Milton, C T; Hanson, D; Calkins, C

    1999-10-01

    Yearling crossbred steers (n = 60; 386 kg) were individually fed in a completely randomized experimental design to determine their P requirement. Treatments were in a factorial arrangement with two levels of Ca (.35 or .70% of DM) and five concentrations of P (.14, .19, .24, .29, or .34% of DM). The finishing diet consisted of 34.5% dry-rolled corn, 22.5% brewers grits, 22.5% corn bran, 7.5% ground corncobs, 5% molasses, 3% fat, and 5% supplement. Supplemental P was provided as monosodium phosphate and Ca as limestone. Ash content was determined on the first phalanx bone from the lower front legs following slaughter, and rib bone breaking strength was determined with an Instron Universal Testing Machine. Carcass maturity and shear force were also evaluated on wholesale rib cuts. Because no interactions between Ca and P levels were detected, only main effects are presented. Daily gain, DMI, and feed efficiency were not affected by dietary P concentration or P intake. Bone ash (g or g/100 kg BW) and rib bone breaking strength were also unaffected by dietary P. Feeding .7% Ca decreased (P<.06) ADG and efficiency compared with feeding .35% Ca. Neither dietary Ca nor P had a significant effect on tenderness (shear force), skeletal maturity, or overall maturity. These results indicate that the P requirement for finishing yearlings is .14% of diet DM or less and that supplementing P above levels supplied by basal ingredients in many grain-based finishing diets is not necessary.

  13. Relativistic ionization fronts in gas jets

    NASA Astrophysics Data System (ADS)

    Lemos, Nuno; Dias, J. M.; Gallacher, J. G.; Issac, R. C.; Fonseca, R. A.; Lopes, N. C.; Silva, L. O.; Mendonça, J. T.; Jaroszynski, D. A.

    2006-10-01

    A high-power ultra-short laser pulse propagating through a gas jet, ionizes the gas by tunnelling ionization, creating a relativistic plasma-gas interface. The relativistic ionization front that is created can be used to frequency up-shift electromagnetic radiation either in co-propagation or in counter-propagation configurations. In the counter-propagation configuration, ionization fronts can act as relativistic mirrors for terahertz radiation, leading to relativistic double Doppler frequency up-shift to the visible range. In this work, we identified and explored, the parameters that optimize the key features of relativistic ionization fronts for terahertz radiation reflection. The relativistic ionization front generated by a high power laser (TOPS) propagating in a supersonic gas jet generated by a Laval nozzle has been fully characterized. We have also performed detailed two-dimensional relativistic particle-in-cell simulations with Osiris 2.0 to analyze the generation and propagation of the ionization fronts.

  14. Coherent structures for front propagation in fluids

    NASA Astrophysics Data System (ADS)

    Mitchell, Kevin; Mahoney, John

    2014-03-01

    Our goal is to characterize the nature of reacting flows by identifying important ``coherent'' structures. We follow the recent work by Haller, Beron-Vera, and Farazmand which formalized the notion of lagrangian coherent structures (LCSs) in fluid flows. In this theory, LCSs were derived from the Cauchy-Green strain tensor. We adapt this perspective to analogously define coherent structures in reacting flows. By this we mean a fluid flow with a reaction front propagating through it such that the propagation does not affect the underlying flow. A reaction front might be chemical (Belousov-Zhabotinsky, flame front, etc.) or some other type of front (electromagnetic, acoustic, etc.). While the recently developed theory of burning invariant manifolds (BIMs) describes barriers to front propagation in time-periodic flows, this current work provides an important complement by extending to the aperiodic setting. Funded by NSF Grant CMMI-1201236.

  15. Thin front propagation in random shear flows.

    PubMed

    Chinappi, M; Cencini, M; Vulpiani, A

    2006-01-01

    Front propagation in time-dependent laminar flows is investigated in the limit of very fast reaction and very thin fronts--i.e., the so-called geometrical optics limit. In particular, we consider fronts stirred by random shear flows, whose time evolution is modeled in terms of Ornstein-Uhlembeck processes. We show that the ratio between the time correlation of the flow and an intrinsic time scale of the reaction dynamics (the wrinkling time tw) is crucial in determining both the front propagation speed and the front spatial patterns. The relevance of time correlation in realistic flows is briefly discussed in light of the bending phenomenon--i.e., the decrease of propagation speed observed at high flow intensities.

  16. Time of daily supplementation for steers grazing dormant intermediate wheatgrass pasture.

    PubMed

    Barton, R K; Krysl, L J; Judkins, M B; Holcombe, D W; Broesder, J T; Gunter, S A; Beam, S W

    1992-02-01

    To compare the effects of time of daily protein supplementation on grazing behavior, forage intake, digesta kinetics, ruminal fermentation, and serum hormones and metabolites, 12 ruminally cannulated Holstein steers (449 and 378 kg average initial and final BW, respectively) were allotted to three groups. Treatments consisted of CON = no supplement, AM = cottonseed meal (.25% of BW) at 0600, and PM = cottonseed meal (.25% of BW) at 1200. Steers grazed a dormant (1.1% N) intermediate wheatgrass (Thinopyrum intermedium Host) pasture. Sampling trials occurred in December, January, and February. Supplementation altered (P = .01) time spent grazing; CON steers grazed approximately 1.5 h longer than supplemented steers. Supplemented steers lost less (P = .02) BW (-40 kg) than CON steers (-75 kg) did. Supplementation did not alter (P greater than .15) forage OM intake; however, total OM intake was greater (P = .01) for supplemented steers (22.3 g/kg of BW) than for CON (18.4 g/kg of BW) steers. Supplementation did not affect (P greater than .15) digesta kinetics. Extent of in situ NDF (96 h) and rate (%/h) of disappearance for supplemented steers was greater (P = .01) than for CON steers. Across all periods, ruminal NH3 N and total VFA concentrations were lower (P = .01) for CON steers than for supplemented steers. Serum insulin (ng/mL) concentration was lower (P = .03) and concentration of serum growth hormone (ng/mL) was higher (P = .02) for CON steers than for supplemented steers. Cottonseed meal supplementation enhanced utilization of intermediate wheatgrass; however, supplementation time had minimal effects on the variables measured.

  17. Abomasal protein infusions for growing steers fed corn grain rations.

    PubMed

    Johnson, A B; Owens, F N; Mizwicki, K L

    1982-01-01

    Casein was abomasally infused into five growing 226-kg steers consuming a urea-supplemented corn grain diet ad libitum. Infusate solutions in the 5 x 5 Latin square arrangement of treatments contained 0, 20, 40, 80 and 120 g casein made isocaloric and isonitrogenous by the addition of dextrose and urea. Feed intake averaged 5.4 kg dry matter daily and was not altered significantly by abomasal infusions. Apparent digestibility of N decreased from 71.7 to 66.8% as level of casein infusion increased. N retentions (NR) were 40.5, 35.5, 42.8, 35.1 and 32.7 g/d at the five levels of infusion, respectively. A second study was conducted to determine whether level of feed intake influenced the benefit seen from postruminal protein supplementation. Four steers (306 kg) ate ad libitum or were limit-fed (2.5 kg/d) a 1% urea-supplemented corn grain diet in a 4 x 4 Latin square design. These steers were abomasally infused with 120 g casein or an isocaloric, isonitrogenous dextrose-urea mixture. Daily ad libitum feed intake averaged 4.7 kg and was not altered significantly by infusion composition. NR tended to increase with casein infusion at both levels of intake, but, as a percentage, the increase tended to be greater with limit feeding (43 vs 20%). To determine whether supplemental abomasal urea might be beneficial, a third trial was conducted with four 313 kg steers consuming the same diet ad libitum in a crossover design. Infusates consisted of 120 g dextrose or 120 g dextrose plus 42.6 g urea/d. Daily feed intakes were 4.5 and 4.8 kg/d for the steers given the dextrose and the dextrose plus urea infusions, respectively. NR tended to increase with urea infusion (20.9 vs 29.7 g/d). Results suggest that energy, total N or other nutrients, but not postruminal amino acids, limited N balance of young growing steers fed a urea-supplemented, cracked corn diet and gaining weight at .9 kg daily.

  18. Dipolarization front and current disruption

    NASA Astrophysics Data System (ADS)

    Lui, A. T. Y.

    2016-10-01

    The modification of current density on the dawn-dusk cross section of the magnetotail with the earthward approach of a dipolarization front (DF) is examined through the recently published results of a three-dimensional (3-D) particle-in-cell (PIC) simulation. It is found that the current density intensifies by 37% abruptly within 1.5 ion gyrotime as the DF approaches and shows localized regions with north-south extrusions. After reaching its peak value, it undergoes a drastic current reduction (DCR) by 65% within 2 ion gyrotime. Breakdown of the frozen-in condition occurs in the neutral sheet region in association with DCR, demonstrating the non-MHD behavior of the phenomenon. The evolution of current density from this 3-D PIC simulation bears several similarities to those observed for the current disruption (CD) phenomenon, such as explosive growth and disruption of the current density leading to a breakdown of the frozen-in condition. The evolution is also similar to those from a previous two-dimensional (2-D) PIC simulation specially designed to investigate the nonlinear evolution of the cross-field current instability for CD. One interpretation of these findings is that CD and substorm triggering can be associated with earthward intrusion of a DF into the near-Earth plasma sheet as indicated by previous Cluster and Time History of Events and Macroscale Interactions during Substorms observations. An alternative interpretation is that both DF and CD are consequences of a global evolution from an ion-tearing-like instability of the magnetotail.

  19. Life on the front lines.

    PubMed

    Hern, W M

    1994-01-01

    Warren Hern's reminiscences about his experiences as medical director of the Boulder (Colorado) Abortion Clinic and as an abortion provider in private practice provide support for his statement, "Every doctor in America who does abortions lives under a death threat." Shortly after the clinic was opened, a group of anti-abortion physicians pressured the Boulder County Medical Society to pass a resolution declaring the clinic a "clear and present danger" that should be shut down by local health boards. As the only freestanding abortion clinic in the state in the mid-1970's, the Boulder center was targeted by the Right-to-Life Committee picketers and Dr. Hern was harassed in his home and in public. When Dr. Hern left the clinic a year later to establish a private practice specializing in pregnancy termination, the picketers followed. After release of a textbook he prepared on abortion practice, the publisher was deluged with hate mail and threats of boycott, leading them to withdraw the text from its list. Violent attacks on abortion clinics accelerated after Reagan's election and bullets were fired into Hern's waiting room. Randall Terry, national head of Operation Rescue, prayed for Hern's death at a rally in front of his clinic. By the time Dr. David Gunn was assassinated by an anti-abortionist in March 1993, there had been over 1285 acts of violence against abortion facilities and more than 100 facilities had been completely destroyed. The transgression for which Dr. Gunn was murdered was that he sought to save the lives and futures of countless women and support their right to become full participants in society.

  20. Cold Fronts in Cold Dark Matter Clusters

    NASA Astrophysics Data System (ADS)

    Nagai, Daisuke; Kravtsov, Andrey V.

    2003-04-01

    Recently, high-resolution Chandra observations revealed the existence of very sharp features in the X-ray surface brightness and temperature maps of several clusters. These features, called cold fronts, are characterized by an increase in surface brightness by a factor >~2 over 10-50 kpc accompanied by a drop in temperature of a similar magnitude. The existence of such sharp gradients can be used to put interesting constraints on the physics of the intracluster medium (ICM) if their mechanism and longevity are well understood. Here, we present results of a search for cold fronts in high-resolution simulations of galaxy clusters in cold dark matter models. We show that sharp gradients with properties similar to those of observed cold fronts naturally arise in cluster mergers when the shocks heat gas surrounding the merging subcluster, while its dense core remains relatively cold. The compression induced by supersonic motions and shock heating during the merger enhance the amplitude of gas density and temperature gradients across the front. Our results indicate that cold fronts are nonequilibrium transient phenomena and can be observed for a period of less than a billion years. We show that the velocity and density fields of gas surrounding the cold front can be very irregular, which would complicate analyses aiming to put constraints on the physical conditions of the ICM in the vicinity of the front.