Sample records for high speed tapered

  1. Static Lateral Characteristics at High Subsonic Speeds of a Complete Airplane Model with a Highly Tapered Wing having the 0.80 Chord Line Unswept and with Several Tail Configurations (United States)

    Goodson, Kenneth W.


    An investigation was made at high subsonic speeds of a complete model having a highly tapered wing and several tail configurations. The aspect-ratio-3.50 wing had a taper ratio of 0.067 and an unswept 0.80 chord line. The complete model was tested with a wing-chord-plane tail, a T-tail, and a biplane tail (combined T-tail and wing-chord-plane tail). The model was tested in the Langley high-speed 7- by 10-foot tunnel at Mach numbers from 0.60 to 0.92 over a range of angle of attack of about +/- 20 deg. and a range of sideslip of -15 deg. to 13 deg. Some data were obtained with the horizontal stabilizer deflected. A few tests were also made with the wing tips clipped to an aspect ratio of 3.00. The data show that shock-interference effects between the tail surfaces (T-tail) can have considerable influence on the directional stability and effective dihedral. For example, the T-tail configuration with horizontal-tail leading-edge overhang showed a considerable loss in directional stability as the angle of attack was reduced to zero or negative values; whereas, the T-tail with zero leading-edge overhang showed the loss to be considerably less. The directional stability of the model with the low tail was essentially constant over a range of angle of attack of +/- 50 deg. All configurations tested showed a large reduction in stability at positive and negative angles of attack larger than about 15 deg., probably because of adverse sidewash associated with wing stall. The data show that a wing-chord-plane horizontal tail (low tail) tends to give a positive pitching-moment increment with increase in sideslip angle; whereas, a high tail (T-tail) tends to give negative increments in pitching moment.

  2. Influence of Drilling Speed on Stability of Tapered Dental Implants: An Ex Vivo Experimental Study. (United States)

    Almeida, Karen P; Delgado-Ruiz, Rafael; Carneiro, Leandro G; Leiva, Alberto Bordonaba; Calvo-Guirado, Jose Luis; Gómez-Moreno, Gerardo; Malmström, Hans; Romanos, Georgios E


    The aim of this study was to evaluate whether the drilling speed used during implant site preparation influences primary stability. Eighty tapered designed implants (3.8 × 10 mm) were inserted following osteotomies created in solid rigid polyurethane foam (simulating bone type II) and cellular rigid polyurethane foam (simulating bone type IV). Half were prepared using drilling speeds of 800 rpm (low speed), and the other half were prepared using speeds of 1,500 rpm (high speed). Following insertion, implant primary stability was measured using Periotest and Osstell (resonance frequency analysis [RFA]) devices. Two-way analysis of variance (ANOVA) used for this study found that the drilling speed used to create the osteotomies appeared to have no significant impact on primary stability. The bone quality and not the osteotomy drilling speed seems to influence the implant primary stability.

  3. Effects of Sweep and Thickness on the Static Longitudinal Aerodynamic Characteristics of a Series of Thin, Low-aspect-ratio, Highly Tapered Wings at Transonic Speeds : Transonic-bump Method (United States)

    Fournier, Paul G; Few, Albert G , Jr


    An investigation by the transonic-bump technique of the static longitudinal aerodynamic characteristics of a series of thin, low-aspect-ratio, highly tapered wings has been made in the Langley high-speed 7- by 10-foot tunnel. The Mach number range extended from about 0.60 to 1.18, with corresponding Reynolds numbers ranging from about 0.75 x 10(6) to 0.95 x 10(6). The angle of attack range was from -10 degrees to approximately 32 degrees.The effects on drag and lift-drag ratio of a variation in sweep angle from -14.03 degrees to 45 degrees with respect to the quarter-chord line for wings of 3-percent-chord thickness was found to be small in comparison to the effects of a variation in thickness from 2 percent chord to 4.5 percent chord for wings with 14.03 degree sweepback. For the range of variables considered, variations in plan form were considerably more important with regard to longitudinal stability characteristics than the variations in thickness. For the series of basic wings having an aspect ratio of 4, the most hearly linear pitching-moment characteristics were obtained with 26.57 degree of sweepback of the quarter-chord line. However, for the modified series of wings (obtained by clipping the tips of the original wings parallel to the plane of symmetry to give an aspect ratio of 3 and a taper ratio of 0.143), the most nearly linear pitching-moment characteristics were obtained with 36.87 degrees of sweepback. By decreasing the thickness-to-chord ratios from 0.03 to 0.02, a large increase in lift-curve slope was obtained for both the basic and modified wings. All of the wings of both series had fairly large inward shifts of the lateral center-of-pressure location (indicative of tip stalling) with increasing lift coefficient, except those wings having minimum sweepback angles.

  4. Microdroplet-etched highly birefringent low-loss fiber tapers. (United States)

    Mikkelsen, Jared C; Poon, Joyce K S


    We use hydrofluoric acid microdroplets to directly etch highly birefringent biconical fiber tapers from standard single-mode fibers. The fiber tapers have micrometer-sized cross sections, which are controlled by the etching condition. The characteristic teardrop cross section leads to a high group birefringence of B(G)≈0.017 and insertion losses <0.7 dB over waist lengths of about 2.1 mm.

  5. High speed data converters

    CERN Document Server

    Ali, Ahmed MA


    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  6. Coherent beam combining architectures for high power tapered laser arrays (United States)

    Schimmel, G.; Janicot, S.; Hanna, M.; Decker, J.; Crump, P.; Erbert, G.; Witte, U.; Traub, M.; Georges, P.; Lucas-Leclin, G.


    Coherent beam combining (CBC) aims at increasing the spatial brightness of lasers. It consists in maintaining a constant phase relationship between different emitters, in order to combine them constructively in one single beam. We have investigated the CBC of an array of five individually-addressable high-power tapered laser diodes at λ = 976 nm, in two architectures: the first one utilizes the self-organization of the lasers in an interferometric extended-cavity, which ensures their mutual coherence; the second one relies on the injection of the emitters by a single-frequency laser diode. In both cases, the coherent combining of the phase-locked beams is ensured on the front side of the array by a transmission diffractive grating with 98% efficiency. The passive phase-locking of the laser bar is obtained up to 5 A (per emitter). An optimization algorithm is implemented to find the proper currents in the five ridge sections that ensured the maximum combined power on the front side. Under these conditions we achieve a maximum combined power of 7.5 W. In the active MOPA configuration, we can increase the currents in the tapered sections up to 6 A and get a combined power of 11.5 W, corresponding to a combining efficiency of 76%. It is limited by the beam quality of the tapered emitters and by fast phase fluctuations between emitters. Still, these results confirm the potential of CBC approaches with tapered lasers to provide a high-power and high-brightness beam, and compare with the current state-of-the-art with laser diodes.

  7. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard


    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  8. High power supercontinuum generation in tapered photonic crystal fibers

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper


    Tapering of photonic crystal fibers has proven to be an effective way of blueshifting the dispersive wavelength edge of a supercontinuum spectrum down in the deep-blue. In this contribution we will discuss the underlying mechanisms of supercontinuum generation in tapers. We show, by introducing t...... at the spectral edges of the generated supercontinuum is at a constant level independent on the pump power in both tapered and uniform fibers....

  9. High Efficiency Electron-Laser Interactions in Tapered Helical Undulators (United States)

    Duris, Joseph Patrick

    Efficient coupling of relativistic electron beams with high power radiation lies at the heart of advanced accelerator and light source research and development. The inverse free electron laser is a stable accelerator capable of harnessing very high intensity laser electric fields to efficiently transfer large powers from lasers to electron beams. In this dissertation, we first present the theoretical framework to describe the interaction, and then apply our improved understanding of the IFEL to the design and numerical study of meter-long, GeV IFELs for compact light sources. The central experimental work of the dissertation is the UCLA BNL helical inverse free electron laser experiment at the Accelerator Test Facility in Brookhaven National Laboratory which used a strongly tapered 54cm long, helical, permanent magnet undulator and a several hundred GW CO2 laser to accelerate electrons from 52 to 106MeV, setting new records for inverse free electron laser energy gain (54MeV) and average accelerating gradient (100MeV/m). The undulator design and fabrication as well as experimental diagnostics are presented. In order to improve the stability and quality of the accelerated electron beam, we redesigned the undulator for a slightly reduced output energy by modifying the magnet gap throughout the undulator, and we used this modified undulator to demonstrated capture of >25% of the injected beam without prebunching. In the study of heavily loaded GeV inverse free electron lasers, we show that a majority of the power may be transferred from a laser to the accelerated electron beam. Reversing the process to decelerate high power electron beams, a mechanism we refer to as tapering enhanced stimulated superradiant amplification, offers a clear path to high power light sources. We present studies of radiation production for a wide range of wavelengths (10mum, 13nm, and 0.3nm) using this method and discuss the design for a deceleration experiment using the same undulator used

  10. STIR-Physics: Cold Atoms and Nanocrystals in Tapered Nanofiber and High-Q Resonator Potentials (United States)


    STIR-Physics: Cold Atoms and Nanocrystals in Tapered Nanofiber and High-Q Resonator Potentials We worked on a tapered fiber in cold atomic cloud...setup. At the end of this program, we had built the vacuum system, specialized cold atom chamber and were working on the fiber epoxy mount for the...Triangle Park, NC 27709-2211 Tapered Fibers, Cold atoms , Nonlinear Optics REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR

  11. High Speed Ice Friction (United States)

    Seymour-Pierce, Alexandra; Sammonds, Peter; Lishman, Ben


    Many different tribological experiments have been run to determine the frictional behaviour of ice at high speeds, ostensibly with the intention of applying results to everyday fields such as winter tyres and sports. However, experiments have only been conducted up to linear speeds of several metres a second, with few additional subject specific studies reaching speeds comparable to these applications. Experiments were conducted in the cold rooms of the Rock and Ice Physics Laboratory, UCL, on a custom built rotational tribometer based on previous literature designs. Preliminary results from experiments run at 2m/s for ice temperatures of 271 and 263K indicate that colder ice has a higher coefficient of friction, in accordance with the literature. These results will be presented, along with data from further experiments conducted at temperatures between 259-273K (in order to cover a wide range of the temperature dependent behaviour of ice) and speeds of 2-15m/s to produce a temperature-velocity-friction map for ice. The effect of temperature, speed and slider geometry on the deformation of ice will also be investigated. These speeds are approaching those exhibited by sports such as the luge (where athletes slide downhill on an icy track), placing the tribological work in context.

  12. Widely Tunable High-Power Tapered Diode Laser at 1060 nm

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Sumpf, Bernd; Erbert, Götz


    We report a large tuning range from 1018 to 1093 nm from a InGaAs single quantum-well 1060-nm external cavity tapered diode laser. More than 2.5-W output power has been achieved. The tuning range is to our knowledge the widest obtained from a high-power InGaAs single quantum-well tapered laser...

  13. HIGH SPEED CAMERA (United States)

    Rogers, B.T. Jr.; Davis, W.C.


    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  14. High-power green light generation by second harmonic generation of single-frequency tapered diode lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Andersen, Peter E.; Sumpf, Bernd


    laser emits in excess of 9 W single-frequency output power with a good beam quality. The output from the tapered diode laser is frequency doubled using periodically poled MgO:LiNbO3. We investigate the modulation potential of the green light and improve the modulation depth from 1:4 to 1:50.......We demonstrate the generation of high power (>1.5W) and single-frequency green light by single-pass second harmonic generation of a high power tapered diode laser. The tapered diode laser consists of a DBR grating for wavelength selectivity, a ridge section and a tapered section. The DBR tapered...

  15. Gearbox Reliability Collaborative High Speed Shaft Tapered Roller Bearing Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; Guo, Y.; McNiff, B.


    The National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) is a project investigating gearbox reliability primarily through testing and modeling. Previous dynamometer testing focused upon acquiring measurements in the planetary section of the test gearbox. Prior to these tests, the strain gages installed on the planetary bearings were calibrated in a load frame.

  16. Gearbox Reliability Collaborative High-Speed Shaft Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; McNiff, B.


    Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

  17. High speed preprocessing system

    Indian Academy of Sciences (India)

    (a) Digitizing and writing the video data in the memory at HR rate, and (b) once the data are ready in the memory, reading the data and generating the LR image. Thus the execution time mainly depends on (i) processor speed, and (ii) the time taken for fetching video information/data. Figure 1. Hardware block diagram. 514.

  18. Duodenal Derotation and Extent Tapering Jejunoplasty as Primary Repair for Neonates With High Jejunal Atresia

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Luo


    Conclusion: In very proximal high atresia, the extent of tapering is limited by the proximity of the ligament of Treitz. Duodenal derotation provides better access to the high atresia. The results of this limited experience suggest that the DDETJ procedure could provide an alternative therapy in patients with high jejunal atresia.

  19. High-speed AC motors

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)


    The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

  20. Biconical-taper-assisted fiber interferometer with modes coupling enhancement for high-sensitive curvature measurement (United States)

    Wo, Jianghai; Sun, Qizhen; Li, Xiaolei; Liu, Deming; Shum, Perry Ping


    A modal interferometer based on multimode-singlemode-multimode fiber structure built with a biconical taper for fiber curvature measurement is proposed and experimentally demonstrated. Due to the tapered singlemode fiber acting as a high-efficient mode power converter to enhance the modes coupling, curvature sensor with improved sensitivity is achieved by monitoring the defined fringe visibility of the interference spectrum. The measuring range can be tuned by changing the waist diameter of the fiber taper. Meanwhile, the sensor shows an intrinsic ability to overcome the influence of temperature cross-sensitivity and the power fluctuation of light source. The advantages of easy fabrication, high-quality spectrum with improved sensitivity, and small hysteresis will provide great potential for practical applications of the sensor.

  1. High-frequency impedance of small-angle tapers and collimators

    Directory of Open Access Journals (Sweden)

    G. Stupakov


    Full Text Available Collimators and transitions in accelerator vacuum chambers often include small-angle tapering to lower the wakefields generated by the beam. While the low-frequency impedance is well described by Yokoya’s formula (for axisymmetric geometry, much less is known about the behavior of the impedance in the high-frequency limit. In this paper we develop an analytical approach to the high-frequency regime for round collimators and tapers. Our analytical results are compared with computer simulations using the code ECHO.

  2. High speed rail distribution study. (United States)


    The Texas Central Partners are in the process of developing a high speed rail line connecting : Houston and Dallas, Texas. Ultimately, plans are for 8 car trains that accommodate 200 people per : vehicle scheduled every 30 minutes. In addition, Texas...

  3. High-Speed Electrochemical Imaging. (United States)

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R


    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques.

  4. High Speed Compressor Study (United States)


    Davey G. The Design and Testing of a Stirling Cycle Domestic Freezer. Proc. of Conference on Applications for Natural Refrigerants , held in Aarhus...carried out on a relatively old design of compressor, initially developed for use with a Stirling cycle domestic freezer12, and subsequently used in a...limit’, and is suitable for high cycle fatigue. Beryllium copper has been largely superseded by stainless steel, which is more readily available

  5. High-speed photonics interconnects

    CERN Document Server

    Chrostowski, Lukas


    Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed

  6. High-speed pulse techniques

    CERN Document Server

    Coekin, J A


    High-Speed Pulse Techniques covers the many aspects of technique in digital electronics and encompass some of the more fundamental factors that apply to all digital systems. The book describes the nature of pulse signals and their deliberate or inadvertent processing in networks, transmission lines and transformers, and then examines the characteristics and transient performance of semiconductor devices and integrated circuits. Some of the problems associated with the assembly of these into viable systems operating at ultra high speed are also looked at. The book examines the transients and w

  7. High-speed OTDM switching

    DEFF Research Database (Denmark)

    Jepsen, Kim Stokholm; Mikkelsen, Benny; Clausen, Anders


    Optical TDM (OTDM) continues to be of interest both for point-point transmission and as a networking technology for both LANs and long-distance fibre transmission. Recent research has demonstrated enabling techniques for OTDM networks at high speeds. In conclusion, OTDM is emerging as an attracti...

  8. High speed cryogenic monodisperse targets (United States)

    Boukharov, A.; Vishnevkii, E.


    The basic possibility of creation of high speed cryogenic monodisperse targets is shown. According to calculations at input of thin liquid cryogenic jets with a velocity of bigger 100 m/s in vacuum the jets don’t manage to freeze at distance to 1 mm and can be broken into monodisperse drops. Drops due to evaporation are cooled and become granules. High speed cryogenic monodisperse targets have the following advantages: direct input in vacuum (there is no need for a chamber of a triple point chamber and sluices), it is possible to use the equipment of a cluster target, it is possible to receive targets with a diameter of D 100m/s), exact synchronization of the target hitting moment in a beam with the moment of sensors turning on.

  9. Novel Highly Sensitive Protein Sensors Based on Tapered Optical Fibres Modified with Au-Based Nanocoatings

    Directory of Open Access Journals (Sweden)

    Aitor Urrutia


    Full Text Available Novel protein sensors based on tapered optical fibres modified with Au coatings deposited using two different procedures are proposed. Au-based coatings are deposited onto a nonadiabatic tapered optical fibre using (i a novel facile method composed of layer-by-layer deposition consisting of polycation (poly(allylamine hydrochloride, PAH and negatively charged SiO2 nanoparticles (NPs followed by the deposition of the charged Au NPs and (ii the sputtering technique. The Au NPs and Au thin film surfaces are then modified with biotin in order to bind streptavidin (SV molecules and detect them. The sensing principle is based on the sensitivity of the transmission spectrum of the device to changes in the refractive index of the coatings induced by the SV binding to the biotin. Both sensors showed high sensitivity to SV, with the lowest measured concentration levels below 2.5 nM. The calculated binding constant for the biotin-SV pair was 2.2×10-11 M−1 when a tapered fibre modified with the LbL method was used, with a limit of detection (LoD of 271 pM. The sensor formed using sputtering had a binding constant of 1.01×10-10 M−1 with a LoD of 806 pM. These new structures and their simple fabrication technique could be used to develop other biosensors.

  10. Ultra high-speed sorting. (United States)

    Leary, James F


    Cell sorting has a history dating back approximately 40 years. The main limitation has been that, although flow cytometry is a science, cell sorting has been an art during most of this time. Recent advances in assisting technologies have helped to decrease the amount of expertise necessary to perform sorting. Droplet-based sorting is based on a controlled disturbance of a jet stream dependent on surface tension. Sorting yield and purity are highly dependent on stable jet break-off position. System pressures and orifice diameters dictate the number of droplets per second, which is the sort rate limiting step because modern electronics can more than handle the higher cell signal processing rates. Cell sorting still requires considerable expertise. Complex multicolor sorting also requires new and more sophisticated sort decisions, especially when cell subpopulations are rare and need to be extracted from background. High-speed sorting continues to pose major problems in terms of biosafety due to the aerosols generated. Cell sorting has become more stable and predictable and requires less expertise to operate. However, the problems of aerosol containment continue to make droplet-based cell sorting problematical. Fluid physics and cell viability restraints pose practical limits for high-speed sorting that have almost been reached. Over the next 5 years there may be advances in fluidic switching sorting in lab-on-a-chip microfluidic systems that could not only solve the aerosol and viability problems but also make ultra high-speed sorting possible and practical through massively parallel and exponential staging microfluidic architectures.

  11. A Broadband and High Gain Tapered Slot Antenna for W-Band Imaging Array Applications

    Directory of Open Access Journals (Sweden)

    Dong Sik Woo


    Full Text Available A broadband and high gain tapered slot antenna (TSA by utilizing a broadband microstrip- (MS- to-coplanar stripline (CPS balun has been developed for millimeter-wave imaging systems and sensors. This antenna exhibits ultrawideband performance for frequency ranges from 70 to over 110 GHz with the high antenna gain, low sidelobe levels, and narrow beamwidth. The validity of this antenna as imaging arrays is also demonstrated by analyzing mutual couplings and 4-element linear array. This antenna can be applied to mm-wave phased array, imaging array for plasma diagnostics applications.

  12. High energy supercontinuum sources using tapered photonic crystal fibers for multispectral photoacoustic microscopy

    DEFF Research Database (Denmark)

    Bondu, Magalie; Brooks, Christopher; Jakobsen, Christian


    We demonstrate a record bandwidth high energy supercontinuum source suitable for multispectral photoacoustic microscopy. The source has more than 150  nJ/10  nm150  nJ/10  nm bandwidth over a spectral range of 500 to 1600 nm. This performance is achieved using a carefully designed fiber taper...... with large-core input for improved power handling and small-core output that provides the desired spectral range of the supercontinuum source....

  13. High Efficiency Energy Extraction from a Relativistic Electron Beam in a Strongly Tapered Undulator (United States)

    Sudar, N.; Musumeci, P.; Duris, J.; Gadjev, I.; Polyanskiy, M.; Pogorelsky, I.; Fedurin, M.; Swinson, C.; Kusche, K.; Babzien, M.; Gover, A.


    We present results of an experiment where, using a 200 GW CO2 laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54-cm-long strongly tapered helical magnetic undulator, extracting over 30% of the initial electron beam energy to coherent radiation. These results, supported by simulations of the radiation field evolution, demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.

  14. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal


    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  15. High speed nanofluidic protein accumulator. (United States)

    Wu, Dapeng; Steckl, Andrew J


    Highly efficient preconcentration is a crucial prerequisite to the identification of important protein biomarkers with extremely low abundance in target biofluids. In this work, poly(dimethylsiloxane) microchips integrated with 10 nm polycarbonate nanopore membranes were utilized as high-speed protein accumulators. Double-sided injection control of electrokinetic fluid flow in the sample channel resulted in highly localized protein accumulation at a very sharp point in the channel cross point. This greatly enhanced the ability to detect very low levels of initial protein concentration. Fluorescein labeled human serum albumin solutions of 30 and 300 pM accumulated to 3 and 30 microM in only 100 s. Initial solutions as low as 0.3 and 3 pM could be concentrated within 200 s to 0.3 and 3 microM, respectively. This demonstrates a approximately 10(5)-10(6) accumulation factor, and an accumulation rate as high as 5000/sec, yielding a >10x improvement over most results reported to date.

  16. High Speed Viterbi Decoder Architecture

    DEFF Research Database (Denmark)

    Paaske, Erik; Andersen, Jakob Dahl


    The fastest commercially available Viterbi decoders for the (171,133) standard rate 1/2 code operate with a decoding speed of 40-50 Mbit/s (net data rate). In this paper we present a suitable architecture for decoders operating with decoding speeds of 150-300 Mbit/s....

  17. Wake flow characteristics at high wind speed

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.


    Wake flow characteristic at high wind speeds is the main subject of this paper. Although the wake losses decrease at high wind speeds it has been found in a recent study that for multiple wake inflow the increase in loading due to wake effects are substantial even at wind speeds well above rated ...

  18. Software Developed for Analyzing High- Speed Rolling-Element Bearings (United States)

    Fleming, David P.


    COBRA-AHS (Computer Optimized Ball & Roller Bearing Analysis--Advanced High Speed, J.V. Poplawski & Associates, Bethlehem, PA) is used for the design and analysis of rolling element bearings operating at high speeds under complex mechanical and thermal loading. The code estimates bearing fatigue life by calculating three-dimensional subsurface stress fields developed within the bearing raceways. It provides a state-of-the-art interactive design environment for bearing engineers within a single easy-to-use design-analysis package. The code analyzes flexible or rigid shaft systems containing up to five bearings acted upon by radial, thrust, and moment loads in 5 degrees of freedom. Bearing types include high-speed ball, cylindrical roller, and tapered roller bearings. COBRA-AHS is the first major upgrade in 30 years of such commercially available bearing software. The upgrade was developed under a Small Business Innovation Research contract from the NASA Glenn Research Center, and incorporates the results of 30 years of NASA and industry bearing research and technology.

  19. 16 W output power by high-efficient spectral beam combining of DBR-tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Vijayakumar, Deepak; Jensen, Ole Bjarlin


    Up to 16 W output power has been obtained using spectral beam combining of two 1063 nm DBR-tapered diode lasers. Using a reflecting volume Bragg grating, a combining efficiency as high as 93.7% is achieved, resulting in a single beam with high spatial coherence. The result represents the highest...... output power achieved by spectral beam combining of two single element tapered diode lasers. Since spectral beam combining does not affect beam propagation parameters, M2-values of 1.8 (fast axis) and 3.3 (slow axis) match the M2- values of the laser with lowest spatial coherence. The principle...... of spectral beam combining used in our experiments can be expanded to combine more than two tapered diode lasers and hence it is expected that the output power may be increased even further in the future....

  20. Influence of longitudinally tapered collimators on a high brightness electron beam

    Directory of Open Access Journals (Sweden)

    S. Di Mitri


    Full Text Available This article presents the design and operation of a longitudinally tapered collimator in a single-pass S-band linac driving a high brightness electron beam. Measurements were done for the transverse emittance growth induced by the collimator wakefield as a function of the lateral displacement of the beam inside the collimator and the energy acceptance provided by an identical collimator installed in a dispersive region. The measurements demonstrate that: (i the proposed design allows very precise and reproducible motion down to the micron level of the compact, four-hole collimator; (ii the collimator does not degrade the beam emittance in the presence of standard trajectory control; (iii the measured kick factor and energy acceptance are in agreement with the theoretical expectations. These measurements were made using 500 pC, 2.4 ps long bunches at the FERMI@Elettra free electron laser facility.

  1. Mid-infrared supercontinuum generation spanning from 1.9 to 5.7 μm in a chalcogenide fiber taper with ultra-high NA (United States)

    Wang, Yingying; Dai, Shixun; Peng, Xuefeng; Zhang, Peiqing; Wang, Xunsi; You, Chenyang


    We report a broadband supercontinuum generation in a chalcogenide fiber taper with an ultra-high numerical aperture. The chalcogenide step-index fiber consisting of As2Se3 core and As2S3 cladding was fabricated by using the isolated stacked extrusion method. The fiber taper with a core diameter of 1.75 μm was prepared by employing a homemade tapering setup. By pumping the fiber taper with a femtosecond laser pulses at 3.3 μm, a broadband supercontinuum generation spanning from 1.9 to 5.7 μm was achieved.

  2. High Speed On-Wafer Characterization Laboratory (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  3. High speed imaging - An important industrial tool (United States)

    Moore, Alton; Pinelli, Thomas E.


    High-speed photography, which is a rapid sequence of photographs that allow an event to be analyzed through the stoppage of motion or the production of slow-motion effects, is examined. In high-speed photography 16, 35, and 70 mm film and framing rates between 64-12,000 frames per second are utilized to measure such factors as angles, velocities, failure points, and deflections. The use of dual timing lamps in high-speed photography and the difficulties encountered with exposure and programming the camera and event are discussed. The application of video cameras to the recording of high-speed events is described.

  4. Comparison of Pressure Changes by Head and Neck Position between High-Volume Low-Pressure and Taper-Shaped Cuffs: A Randomized Controlled Trial. (United States)

    Komasawa, Nobuyasu; Mihara, Ryosuke; Imagawa, Kentaro; Hattori, Kazuo; Minami, Toshiaki


    The present study compared changes in cuff pressure by head and neck position between high-volume low-pressure (HVLP) and taper-shaped (taper) cuffs in a prospective randomized clinical trial. Methods. Forty patients were intubated using tracheal tubes with either HVLP (n = 20; HVLP group) or taper-shaped (n = 20; Taper group) cuffs. Initial cuff pressure was adjusted to 15, 20, or 25 cmH2O in the neutral position. Cuff pressure was evaluated after changing the head and neck positions to flexion, extension, and rotation. Results. Cuff pressure significantly increased with flexion in both HVLP and Taper groups at all initial cuff pressures. It significantly increased with extension in the HVLP group, but not in the Taper group. Cuff pressure did not significantly differ with rotation in either group and was significantly smaller in the Taper group during flexion and extension than in the HVLP group, regardless of initial cuff pressure. Conclusion. Cuff pressure changes with head and neck flexion and extension were smaller in the Taper group than in the HVLP group. Our results highlight the potential for taper cuffs to prevent excessive cuff pressure increases with positional changes in the head and neck. This trial is registered with UMIN000016119.

  5. Comparison of Pressure Changes by Head and Neck Position between High-Volume Low-Pressure and Taper-Shaped Cuffs: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Nobuyasu Komasawa


    Full Text Available The present study compared changes in cuff pressure by head and neck position between high-volume low-pressure (HVLP and taper-shaped (taper cuffs in a prospective randomized clinical trial. Methods. Forty patients were intubated using tracheal tubes with either HVLP (n=20; HVLP group or taper-shaped (n=20; Taper group cuffs. Initial cuff pressure was adjusted to 15, 20, or 25 cmH2O in the neutral position. Cuff pressure was evaluated after changing the head and neck positions to flexion, extension, and rotation. Results. Cuff pressure significantly increased with flexion in both HVLP and Taper groups at all initial cuff pressures. It significantly increased with extension in the HVLP group, but not in the Taper group. Cuff pressure did not significantly differ with rotation in either group and was significantly smaller in the Taper group during flexion and extension than in the HVLP group, regardless of initial cuff pressure. Conclusion. Cuff pressure changes with head and neck flexion and extension were smaller in the Taper group than in the HVLP group. Our results highlight the potential for taper cuffs to prevent excessive cuff pressure increases with positional changes in the head and neck. This trial is registered with UMIN000016119.

  6. High-speed imaging in fluids

    NARCIS (Netherlands)

    Versluis, Michel


    High-speed imaging is in popular demand for a broad range of experiments in fluids. It allows for a detailed visualization of the event under study by acquiring a series of image frames captured at high temporal and spatial resolution. This review covers high-speed imaging basics, by defining

  7. Highly Sensitive Refractive Index Sensor Based on Adiabatically Tapered Microfiber Long Period Gratings

    Directory of Open Access Journals (Sweden)

    Choong Leng Ng


    Full Text Available We demonstrate a refractive index sensor based on a long period grating (LPG inscribed in a special photosensitive microfiber with double-clad profile. The fiber is tapered gradually enough to ensure the adiabaticity of the fiber taper. In other words, the resulting insertion loss is sufficiently small. The boron and germanium co-doped inner cladding makes it suitable for inscribing gratings into its tapered form. The manner of wavelength shift for refractive indices (RIs differs from conventional LPG, and the refractive index detection limit is 1.67 × 10−5.

  8. High speed curving performance of rail vehicles (United States)


    On March 13, 2013, the Federal Railroad Administration (FRA) published a final rule titled Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations which amended the Track Safety Standards (49 CFR Part213) and ...

  9. Jane's high-speed marine transportation

    National Research Council Canada - National Science Library

    Phillips, S.J


    The purpose of this book is to provide a comprehensive reference yearbook covering the design, build and operation of high-speed marine transportation, worldwide, an annually updated reference book...

  10. Investigation of the Electron Acceleration by a High-Power Laser and a Density-Tapered Mixed-Gas Cell (United States)

    Kim, Jinju; Phung, Vanessa L. J.; Kim, Minseok; Hur, Min-Sup; Suk, Hyyong


    Plasma-based accelerators can generate about 1000 times stronger acceleration field compared with RF-based conventional accelerators, which can be done by high power laser and plasma. There are many issues in this research and one of them is development of a good plasma source for higher electron beam energy. For this purpose, we are investigating a special type of plasma source, which is a density-tapered gas cell with a mixed-gas for easy injection. By this type of special gas cell, we expect higher electron beam energies with easy injection in the wakefield. In this poster, some experimental results for electron beam generation with the density-tapered mixed-gas cell are presented. In addition to the experimental results, CFD (Computational-Fluid-Dynamics) and PIC (Particle-In-Cell) simulation results are also presented for comparison studies.

  11. High speed rail : challenges for the high speed rail project in Norway


    Ringstad, Vidar


    This Master Thesis has focus on parts of the public transport system in Norway. The main topic in this thesis is: What variables must be calculated for the decision concerning the construction and implementation of the Norwegian High Speed Rail project, and how are the variables calculated? High Speed Rail does not have a single standard definition. High Speed Rail definition, given in the European Union definition, Directive 96/48 is suitable for many different systems of rolling stock...

  12. Spectrum online-tunable Mach-Zehnder interferometer based on step-like tapers and its refractive index sensing characteristics (United States)

    Zhao, Yong; Chen, Mao-qing; Xia, Feng; Hu, Hai-feng


    A novel refractive index (RI) sensor based on an asymmetrical Mach-Zehnder interferometer (MZI) with two different step-like tapers is proposed. The step-like taper is fabricated by fusion splicing two half tapers with an appropriate offset. By further applying offset and discharging to the last fabricated step-like taper of MZI, influence of taper parameters on interference spectrum is investigated using only one device. This simple technique provides an on-line method to sweep parameters of step-like tapers and speeds up the optimization process of interference spectrum, meanwhile. In RI sensing experiment, the sensor has a high sensitivity of -185.79 nm/RIU (refractive index unit) in the RI range of 1.3333-1.3673.

  13. Scientific Visualization in High Speed Network Environments (United States)

    Vaziri, Arsi; Kutler, Paul (Technical Monitor)


    In several cases, new visualization techniques have vastly increased the researcher's ability to analyze and comprehend data. Similarly, the role of networks in providing an efficient supercomputing environment have become more critical and continue to grow at a faster rate than the increase in the processing capabilities of supercomputers. A close relationship between scientific visualization and high-speed networks in providing an important link to support efficient supercomputing is identified. The two technologies are driven by the increasing complexities and volume of supercomputer data. The interaction of scientific visualization and high-speed networks in a Computational Fluid Dynamics simulation/visualization environment are given. Current capabilities supported by high speed networks, supercomputers, and high-performance graphics workstations at the Numerical Aerodynamic Simulation Facility (NAS) at NASA Ames Research Center are described. Applied research in providing a supercomputer visualization environment to support future computational requirements are summarized.

  14. Aerodynamic design on high-speed trains (United States)

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li


    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  15. Brandaris ultra high-speed imaging facility

    NARCIS (Netherlands)

    Lajoinie, Guillaume; de Jong, Nico; Versluis, Michel; Tsuji, K.


    High-speed imaging is in popular demand for a broad range of scientific applications, including fluid physics, and bubble and droplet dynamics. It allows for a detailed visualization of the event under study by acquiring a series of images captured at high temporal and spatial resolution. The

  16. High Speed Digital Camera Technology Review (United States)

    Clements, Sandra D.


    A High Speed Digital Camera Technology Review (HSD Review) is being conducted to evaluate the state-of-the-shelf in this rapidly progressing industry. Five HSD cameras supplied by four camera manufacturers participated in a Field Test during the Space Shuttle Discovery STS-128 launch. Each camera was also subjected to Bench Tests in the ASRC Imaging Development Laboratory. Evaluation of the data from the Field and Bench Tests is underway. Representatives from the imaging communities at NASA / KSC and the Optical Systems Group are participating as reviewers. A High Speed Digital Video Camera Draft Specification was updated to address Shuttle engineering imagery requirements based on findings from this HSD Review. This draft specification will serve as the template for a High Speed Digital Video Camera Specification to be developed for the wider OSG imaging community under OSG Task OS-33.

  17. High Speed Wireless Signal Generation and Demodulation

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Sambaraju, Rakesh; Zibar, Darko

    We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation.......We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation....

  18. High-speed dynamic-clamp interface (United States)

    Yang, Yang; Adowski, Timothy; Ramamurthy, Bina; Neef, Andreas


    The dynamic-clamp technique is highly useful for mimicking synaptic or voltage-gated conductances. However, its use remains rare in part because there are few systems, and they can be expensive and difficult for less-experienced programmers to implement. Furthermore, some conductances (such as sodium channels) can be quite rapid or may have complex voltage sensitivity, so high speeds are necessary. To address these issues, we have developed a new interface that uses a common personal computer platform with National Instruments data acquisition and WaveMetrics IGOR to provide a simple user interface. This dynamic clamp implements leak and linear synaptic conductances as well as a voltage-dependent synaptic conductance and kinetic channel conductances based on Hodgkin-Huxley or Markov models. The speed of the system can be assayed using a testing mode, and currently speeds of >100 kHz (10 μs per cycle) are achievable with short latency and little jitter. PMID:25632075

  19. Tunable high-power narrow-spectrum external-cavity diode laser based on tapered amplifier at 668 nm

    DEFF Research Database (Denmark)

    Chi, Mingjun; Erbert, G.; Sumpf, B.


    A 668 nm tunable high-power narrow-spectrum diode laser system based on a tapered semiconductor optical amplifier in external cavity is demonstrated. The laser system is tunable from 659 to 675 nm. As high as 1.38 W output power is obtained at 668.35 nm. The emission spectral bandwidth is less than...... 0.07 nm throughout the tuning range, and the beam quality factor M2 is 2.0 with the output power of 1.27 W....

  20. FDML swept source at 1060 nm using a tapered amplifier

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang


    We present a novel frequency-swept light source working at 1060nm that utilizes a tapered amplifier as gain medium. These devices feature significantly higher saturation power than conventional semiconductor optical amplifiers and can thus improve the limited output power of swept sources...... in this wavelength range. We demonstrate that a tapered amplifier can be integrated into a fiber-based swept source and allows for high-speed FDML operation. The developed light source operates at a sweep rate of 116kHz with an effective average output power in excess of 30mW. With a total sweep range of 70 nm...

  1. High-Speed Rail & Air Transport Competition

    NARCIS (Netherlands)

    Adler, Nicole; Nash, Chris; Pels, Eric


    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers,

  2. High-speed Rail & air transport competition

    NARCIS (Netherlands)

    Adler, N; Nash, C.; Pels, E.


    This research develops a methodology to assess infrastructure investments and their effects on transport equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub-and-spoke legacy airlines and regional low-cost

  3. Crew Rostering for the High Speed Train

    NARCIS (Netherlands)

    R.M. Lentink (Ramon); M.A. Odijk; E. van Rijn


    textabstractAt the time of writing we entered the final stage of implementing the crew rostering system Harmony CDR to facilitate the planning of catering crews on board of the Thalys, the High Speed Train connecting Paris, Cologne, Brussels, Amsterdam, and Geneva. Harmony CDR optimally supports the

  4. Controllable High-Speed Rotation of Nanowires (United States)

    Fan, D. L.; Zhu, F. Q.; Cammarata, R. C.; Chien, C. L.


    We report a versatile method for executing controllable high-speed rotation of nanowires by ac voltages applied to multiple electrodes. The rotation of the nanowires can be instantly switched on or off with precisely controlled rotation speed (to at least 1800 rpm), definite chirality, and total angle of rotation. We have determined the torque due to the fluidic drag force on nanowire of different lengths. We also demonstrate a micromotor using a rotating nanowire driving a dust particle into circular motion. This method has been used to rotate magnetic and nonmagnetic nanowires as well as carbon nanotubes.

  5. High Speed SPM of Functional Materials

    Energy Technology Data Exchange (ETDEWEB)

    Huey, Bryan D. [Univ. of Connecticut, Storrs, CT (United States)


    The development and optimization of applications comprising functional materials necessitates a thorough understanding of their static and dynamic properties and performance at the nanoscale. Leveraging High Speed SPM and concepts enabled by it, efficient measurements and maps with nanoscale and nanosecond temporal resolution are uniquely feasible. This includes recent enhancements for topographic, conductivity, ferroelectric, and piezoelectric properties as originally proposed, as well as newly developed methods or improvements to AFM-based mechanical, friction, thermal, and photoconductivity measurements. The results of this work reveal fundamental mechanisms of operation, and suggest new approaches for improving the ultimate speed and/or efficiency, of data storage systems, magnetic-electric sensors, and solar cells.

  6. Potential scenarios of concern for high speed rail operations (United States)


    Currently, multiple operating authorities are proposing the : introduction of high-speed rail service in the United States. : While high-speed rail service shares a number of basic : principles with conventional-speed rail service, the operational : ...

  7. High speed, high current pulsed driver circuit (United States)

    Carlen, Christopher R.


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

  8. Hard plastic cladding fiber (HPCF) based optical components for high speed short reach optical communications (United States)

    Kim, Jun Ki; Kim, Dong Uk; Kim, Tae Young; Park, Chang Soo; Oh, Kyunghwan


    We developed the primary components applicable to HPCF links for short reach (SR) and very short reach (VSR) data communication systems. We fabricated 4x4 HPCF fused taper splitter, HPCF pigtailed VCSEL and PIN photodiode for high speed short reach communications and characterized back to back transmission performance of the link composed of these components by measuring eye diagrams and jitters. Adapting the fusion-tapering technique for glass optical fiber, we successfully fabricated a 4x4 HPCF fused taper coupler. The HPCF with a core diameter of 200μm and an outer diameter of 230μm had step refractive index of 1.45 and 1.40 for the core and the clad. The optimized fusion length and tapering waist which make minimum insertion loss of about 7dB and uniform output power splitting ratio with less than 0.5dB are 13mm and 150µm, respectively. As a light source for VSR networks, we chose a vertical cavity surface emitting laser (VCSEL) and developed a package with a HPCF pigtail. After positioning VCSEL and HPCF that made a minimum coupling loss, we glued the HPCF inside ceramic ferrule housing. In HPCF-PIN PD packaging, we added a micro polymer lens tip onto the HPCF ends to match the mode field area to the sensitive area of GaAs or InGaAs PIN PD. Coupling between a PIN PD chip and the lensed HPCF was optimized with the radius of curvature of 156µm with a low coupling loss of 0.3dB, which is compatible to conventional MMF-PD packaging. For 1.25 Gbps data rate, the eyes adequate to eye mask in gigabit Ethernet were wide open after all HPCF transmission link and no significant power penalty was observed.

  9. Radiation-Tolerant High-Speed Camera (United States)


    Radiation -Tolerant High-Speed Camera Esko Mikkola, Andrew Levy, Matt Engelman Alphacore, Inc. Tempe, AZ 85281 Abstract: As part of an... radiation -hardened CMOS image sensor and camera system. Radiation -hardened cameras with frame rates as high as 10 kfps and resolution of 1Mpixel are solution that is under development with a similar architecture. It also includes a brief description of the radiation -hardened camera that

  10. PMSM sensorless control with separate control strategies and smooth switch from low speed to high speed. (United States)

    Chen, SiYi; Luo, Ying; Pi, YouGuo


    This paper proposes a smooth switching scheme with separate control strategies on low speed mode and high speed mode for permanent magnet synchronous motor (PMSM) sensorless control to improve the overall performance in full speed range. Constant voltage/frequency tuning method is used on low speed mode because the rotor position can hardly be estimated precisely at low speed. Along with the increasing speed, the control strategy can be switched to high speed mode smoothly when current and speed meet the given requirements. In this high speed mode, the current tracking with a sliding mode observer (SMO) and speed tracking with a sliding mode controller (SMC) are handled, respectively. Experimental demonstration is presented to show the desired performance in full speed range of the PMSM sensorless control using the proposed control scheme in this paper. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. CMOS Image Sensors for High Speed Applications. (United States)

    El-Desouki, Munir; Deen, M Jamal; Fang, Qiyin; Liu, Louis; Tse, Frances; Armstrong, David


    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).

  12. CMOS Image Sensors for High Speed Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen


    Full Text Available Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps.

  13. Developing course lecture notes on high-speed rail. (United States)


    1. Introduction a. World-wide Development of High-Speed Rail (Japan, Europe, China) b. High-speed Rail in the U.S. 2. High-Speed Rail Infrastructure a. Geometric Design of High Speed Rail i. Horizontal Curve ii. Vertical Curve iii. Grade and Turnout ...

  14. Gas turbine for high speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Chenard, J.-L. [Turbomeca (France)


    This presentation will show how the gas turbine engines can be the right compromise to face the challenges raised by the demand for high speed trains through out the world. From the steam locomotive still in use in China to the TGV or ICE in Europe and Shinkensen in Japan able to run at more than 300 kms/hour, the modes of traction for trains have been greatly improved during the last fifty years. Even more faster trains are under studies for the future with the magnetic levitation system. Three main propulsion system, diesel, electric and gas turbines are actually competing in the high speed train market. They will have to comply with the new environmental regulations, better efficiency and customers` requirements for the developed countries, and with the necessity to use the existing tracks for most of the applications

  15. High-Speed Rail & Air Transport Competition


    Nicole Adler; Chris Nash; Eric Pels


    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers, maximize profit functions via prices, frequency and train/plane sizes, given infrastructure provision and costs and environmental charges. The methodology is subsequently applied to all 27 Europea...

  16. High-speed inline holographic Stokesmeter imaging. (United States)

    Liu, Xue; Heifetz, Alexander; Tseng, Shih C; Shahriar, M S


    We demonstrate a high-speed inline holographic Stokesmeter that consists of two liquid crystal retarders and a spectrally selective holographic grating. Explicit choices of angles of orientation for the components in the inline architecture are identified to yield higher measurement accuracy than the classical architecture. We show polarimetric images of an artificial scene produced by such a Stokesmeter, demonstrating the ability to identify an object not recognized by intensity-only imaging systems.

  17. All aboard for high-speed rail

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D.


    A sleek, bullet-nosed train whizzing across the countryside is a fairly common sight in many nations. Since the Train a Grande Vitesse (TGV)--the record-setting ``train with great speed``--was introduced in France in 1981, Germany, Japan, and other countries have joined the high-speed club. In addition, the Eurostar passenger train, which travels between Great Britain and France through the Channel Tunnel, can move at 186 miles per hour once it reaches French tracks. Despite the technology`s growth elsewhere, rapid rail travel has not been seen on US shores beyond a few test runs by various manufacturers. Before the end of the century, however, American train spotters will finally be able to see some very fast trains here too. In March, Washington, DC-based Amtrak announced the purchase of 18 American Flyer high-speed train sets for the Northeast Corridor, which stretches from Boston through new York to the nation`s capital. Furthermore, Florida will get its own system by 2004, and other states are now taking a look at the technology. The American Flyer--designed by Montreal-based Bombardier and TGV manufacturer GEC Alsthom Transport in Paris--should venture onto US rails by 1999. Traveling at up to 150 miles per hour, the American Flyer will cut the New York-Boston run from 4 1/2 hours to 3 hours and reduce New York-Washington trip time from 3 hours to less than 2 3/4. Amtrak hopes the new trains and better times will earn it a greater share of travelers from air shuttles and perhaps from Interstate 95. This article describes how technologies that tilt railcars and propel the world`s fastest trains will be merged into one train set for the American Flyer, Amtrak`s first trip along high-speed rails.

  18. Network Based High Speed Product Innovation

    DEFF Research Database (Denmark)

    Lindgren, Peter

    In the first decade of the 21st century, New Product Development has undergone major changes in the way NPD is managed and organised. This is due to changes in technology, market demands, and in the competencies of companies. As a result NPD organised in different forms of networks is predicted...... to be of ever-increasing importance to many different kinds of companies. This happens at the same times as the share of new products of total turnover and earnings is increasing at unprecedented speed in many firms and industries. The latter results in the need for very fast innovation and product development...... - a need that can almost only be resolved by organising NPD in some form of network configuration. The work of Peter Lindgren is on several aspects of network based high speed product innovation and contributes to a descriptive understanding of this phenomenon as well as with normative theory on how NPD...

  19. Efficient generation of 3.5W laser light at 515nm by frequency doubling a single-frequency high power DBR tapered diode laser

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Hansen, Anders Kragh; Müller, André


    More than 3.5 W of green light at 515 nm is generated by frequency doubling a single-frequency high power DBR tapered diode laser. The frequency doubling is performed in a cascade of PPMgLN and PPMgSLT crystals in order to reach high power and avoid thermal effects present in PPMgLN at high power...

  20. 14 CFR 23.253 - High speed characteristics. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High speed characteristics. 23.253 Section... Requirements § 23.253 High speed characteristics. If a maximum operating speed VMO/MMO is established under § 23.1505(c), the following speed increase and recovery characteristics must be met: (a) Operating...

  1. Joint High-Order Synchrosqueezing Transform and Multi-Taper Empirical Wavelet Transform for Fault Diagnosis of Wind Turbine Planetary Gearbox under Nonstationary Conditions. (United States)

    Hu, Yue; Tu, Xiaotong; Li, Fucai; Meng, Guang


    Wind turbines usually operate under nonstationary conditions, such as wide-range speed fluctuation and time-varying load. Its critical component, the planetary gearbox, is prone to malfunction or failure, which leads to downtime and repair costs. Therefore, fault diagnosis and condition monitoring for the planetary gearbox in wind turbines is a vital research topic. Meanwhile, the signals measured by the vibration sensors mounted in the gearbox exhibit time-varying and nonstationary features. In this study, a novel time-frequency method based on high-order synchrosqueezing transform (SST) and multi-taper empirical wavelet transform (MTEWT) is proposed for the wind turbine planetary gearbox under nonstationary conditions. The high-order SST uses accurate instantaneous frequency approximations to obtain a sharper time-frequency representation (TFR). As the acquired signal consists of many components, like the meshing and rotating components of the gear and bearing, the fault component may be masked by other unrelated components. The MTEWT is used to separate the fault feature from the masking components. A variety of experimental signals of the wind turbine planetary gearbox under nonstationary conditions have been analyzed to demonstrate the effectiveness and robustness of the proposed method. Results show that the proposed method is effective in diagnosing both gear and bearing faults.

  2. High-speed multispectral confocal biomedical imaging. (United States)

    Carver, Gary E; Locknar, Sarah A; Morrison, William A; Ramanujan, V Krishnan; Farkas, Daniel L


    A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues.

  3. Theory Of High-Speed Stereophotogrammetry (United States)

    Hongxun, Song; Junren, Chen


    The general equations of direct linear transformation (DLT) are derived according to the actual process of high-speed stereophotogrammetry. The equations are not only applicable to the ordinary photographic system, but also to the photographic system with reflectors or stereo-reflectors. The equations are also suitable to the enlarged, copied and projected measurements of photographic film. The linear and non-linear errors in photogrammetric process can be corrected. Finally, the equations of right angle intersection photogrammetry are given and the merits and demerits of this method are discussed.


    Directory of Open Access Journals (Sweden)

    S. T. Djabbarov


    Full Text Available Purpose. Studies of the effect of aerodynamic pressure on the maximum permissible speeds of a high-speed train on the existing railway infrastructure. Methodology. The study of the magnitude and direction of the aerodynamic pressure, its effect on the maximum speeds of a high-speed train was carried out on a train model composed of axisymmetric bodies with conical forms of head and tail parts. Findings. Determined the values of the aerodynamic pressure at different distances from the train are, when the high-speed train moves at a speed of 200 km/h or more. The maximum speeds of a high-speed train are determined taking into account the state of the infrastructure of the existing railway, ensuring the safe operation of a high-speed railway. Originality. Theoretical studies of aerodynamic pressure from secondary air currents formed during the movement of high-speed trains are performed on a model of a train composed of identical axisymmetric bodies with conical forms of head and tail moving in a compressible medium. The results of the research allow the regularity of the change in aerodynamic pressure during the movement of a high-speed train. Practical value. The obtained results allow to establish: 1 the maximum permissible speeds of a high-speed train taking into account the technical condition of permanent devices and structures of the existing railway infrastructure; 2 technical parameters of individual objects and structural elements of the infrastructure of high-speed iron subjected to the effect of aerodynamic pressure for a given maximum speed of high-speed trains.

  5. High-power quantum-dot tapered tunable external-cavity lasers based on chirped and unchirped structures. (United States)

    Haggett, Stephanie; Krakowski, Michel; Montrosset, Ivo; Cataluna, Maria Ana


    A high-power tunable external cavity laser configuration with a tapered quantum-dot semiconductor optical amplifier at its core is presented, enabling a record output power for a broadly tunable semiconductor laser source in the 1.2 - 1.3 µm spectral region. Two distinct optical amplifiers are investigated, using either chirped or unchirped quantum-dot structures, and their merits are compared, considering the combination of tunability and high output power generation. At 1230 nm, the chirped quantum-dot laser achieved a maximum power of 0.62 W and demonstrated nearly 100-nm tunability. The unchirped laser enabled a tunability range of 32 nm and at 1254 nm generated a maximum power of 0.97 W, representing a 22-fold increase in output power compared with similar narrow-ridge external-cavity lasers at the same current density.

  6. Study of high-speed civil transports (United States)


    A systems study to identify the economic potential for a high-speed commercial transport (HSCT) has considered technology, market characteristics, airport infrastructure, and environmental issues. Market forecasts indicate a need for HSCT service in the 2000/2010 time frame conditioned on economic viability and environmental acceptability. Design requirements focused on a 300 passenger, 3 class service, and 6500 nautical mile range based on the accelerated growth of the Pacific region. Compatibility with existing airports was an assumed requirement. Mach numbers between 2 and 25 were examined in conjunction with the appropriate propulsion systems, fuels, structural materials, and thermal management systems. Aircraft productivity was a key parameter with aircraft worth, in comparison to aircraft price, being the airline-oriented figure of merit. Aircraft screening led to determination that Mach 3.2 (TSJF) would have superior characteristics to Mach 5.0 (LNG) and the recommendation that the next generation high-speed commercial transport aircraft use a kerosene fuel. The sensitivity of aircraft performance and economics to environmental constraints (e.g., sonic boom, engine emissions, and airport/community noise) was identified together with key technologies. In all, current technology is not adequate to produce viable HSCTs for the world marketplace. Technology advancements must be accomplished to meet environmental requirements (these requirements are as yet undetermined for sonic boom and engine emissions). High priority is assigned to aircraft gross weight reduction which benefits both economics and environmental aspects. Specific technology requirements are identified and national economic benefits are projected.

  7. Laser beam welding by high-speed beam deflection; Laserstrahlschweissen durch High-Speed-Strahlbewegung

    Energy Technology Data Exchange (ETDEWEB)

    Klotzbach, A.; Morgenthal, L.; Beyer, E. [Fraunhofer-Institut fuer Werkstoff- und Strahltechnik, Dresden (Germany)


    The beam deflection system developed at Fraunhofer IWS can be used for rapid moving of a high power laser beam over the workpiece surface. Therefore it is possible to scan even rather small paths with high speed. The system contents two galvanometer scanner with specially designed lightweight mirrors in combination with a beam focusing unit. (Fig. 1). The high-speed welding of contours with small diameter is favorably done with both focusing optics and workpiece fixed (Fig. 2,3). Thus all notorius problems of conventional handling systems, as limited velocity and accuracy resulting from the inertia of the moved focusing head or workpiece, vanish. (orig.)

  8. Nonlinear Label-Free Biosensing With High Sensitivity Using As2S3 Chalcogenide Tapered Fiber

    DEFF Research Database (Denmark)

    Markos, Christos; Bang, Ole


    We demonstrate an experimentally feasible fiber design, which can act as a highly sensitive, label-free, and selective biosensor using the inherent high nonlinearity of an As2S3 chalcogenide tapered fiber. The surface immobilization of the fiber with an antigen layer can provide the possibility t...

  9. ACTS High-Speed VSAT Demonstrated (United States)

    Tran, Quang K.


    The Advanced Communication Technology Satellite (ACTS) developed by NASA has demonstrated the breakthrough technologies of Ka-band transmission, spot-beam antennas, and onboard processing. These technologies have enabled the development of very small and ultrasmall aperture terminals (VSAT s and USAT's), which have capabilities greater than have been possible with conventional satellite technologies. The ACTS High Speed VSAT (HS VSAT) is an effort at the NASA Glenn Research Center at Lewis Field to experimentally demonstrate the maximum user throughput data rate that can be achieved using the technologies developed and implemented on ACTS. This was done by operating the system uplinks as frequency division multiple access (FDMA), essentially assigning all available time division multiple access (TDMA) time slots to a single user on each of two uplink frequencies. Preliminary results show that, using a 1.2-m antenna in this mode, the High Speed VSAT can achieve between 22 and 24 Mbps of the 27.5 Mbps burst rate, for a throughput efficiency of 80 to 88 percent.

  10. Stimulated Brillouin scattering in highly birefringent multimode tapered chalcogenide photonic crystal fiber for distributed optical sensors (Retraction Notice) (United States)

    Baili, Amira; Cherif, Rim; Zghal, Mourad


    This paper, originally published on September 15, 2016, was retracted from the SPIE Digital Library on October 5, 2016, due to a high degree of similarity between specific portions of the text of the paper to the following publications: J. Tchahame, J. Beugnot, A. Kudlinski, and T. Sylvestre, "Multimode Brillouin spectrum in a long tapered birefringent photonic crystal fiber," Opt. Lett. 40, 4281-4284 (2015). doi: 10.1364/OL.40.004281 W. W. Ke, X. J. Wang and X. Tang, "Stimulated Brillouin Scattering Model in Multi-Mode Fiber Lasers," in IEEE Journal of Selected Topics in Quantum Electronics, vol. 20, no. 5, pp. 305-314, Sept.-Oct. 2014. doi: 10.1109/JSTQE.2014.2303256.

  11. High-speed analog CMOS pipeline system (United States)

    Möschen, J.; Caldwell, A.; Hervas, L.; Hosticka, B.; Kötz, U.; Sippach, B.


    We present a switched-capacitor readout system for high speed analog signals. It consists of a 10 MHz four-channel delay-line chip with 58 samples per channel and a 12 channel buffer chip with a sampling rate of 1 MHz and a depth of nine samples. In addition the buffer chip includes an analog multiplexer with 25 inputs for the buffer channels and for 13 additional unbuffered signals. Both chips have been fabricated in CMOS-technology and will be used for the readout of the ZEUS high resolution calorimeter. The circuit and chip concept will be presented and some design optimizations will be discussed. Measurements from integrated prototypes will be given including some experimental data from irradiated chips.

  12. 14 CFR 25.253 - High-speed characteristics. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High-speed characteristics. 25.253 Section...-speed characteristics. (a) Speed increase and recovery characteristics. The following speed increase and recovery characteristics must be met: (1) Operating conditions and characteristics likely to cause...

  13. Using a High-Speed Camera to Measure the Speed of Sound (United States)

    Hack, William Nathan; Baird, William H.


    The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

  14. High-speed ground transportation noise and vibration impact assessment. (United States)


    This report is the second edition of a guidance manual originally issued in 2005, which presents procedures for predicting and assessing noise and vibration impacts of high-speed ground transportation projects. Projects involving high-speed trains us...

  15. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project (United States)

    National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

  16. South Carolina southeast high speed rail corridor improvement study (United States)


    The Southeast Rail Corridor was originally designated as a high-speed corridor in Section 1010 of the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991. More specifically, it involved the high-speed grade-crossing improvement program o...

  17. High-speed and intercity passenger rail testing strategy. (United States)


    This high-speed and intercity passenger rail (HSIPR) testing strategy addresses the requirements for testing of high-speed train sets and technology before introduction to the North American railroad system. The report documents the results of a surv...

  18. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project (United States)

    National Aeronautics and Space Administration — We propose to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight, low voltage beam...

  19. High-speed electrical motor evaluation

    Energy Technology Data Exchange (ETDEWEB)


    Under this task, MTI conducted a general review of state-of-the-art high-speed motors. The purpose of this review was to assess the operating parameters, limitations and performance of existing motor designs, and to establish commercial sources for a motor compatible with the requirements of the Brayton-cycle system. After the motor requirements were established, a list of motor types, manufacturers and designs capable of achieving the requisite performance was compiled. This list was based on an in-house evaluation of designs. Following the establishment of these options, a technical evaluation of the designs selected was conducted. In parallel with their evaluations, MTI focused on the establishment of commercial sources.


    Goss, W.C.; Gilley, L.F.


    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  1. High Speed/ Low Effluent Process for Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    M. Clark Dale


    n this project, BPI demonstrated a new ethanol fermentation technology, termed the High Speed/ Low Effluent (HS/LE) process on both lab and large pilot scale as it would apply to wet mill and/or dry mill corn ethanol production. The HS/LE process allows very rapid fermentations, with 18 to 22% sugar syrups converted to 9 to 11% ethanol ‘beers’ in 6 to 12 hours using either a ‘consecutive batch’ or ‘continuous cascade’ implementation. This represents a 5 to 8X increase in fermentation speeds over conventional 72 hour batch fermentations which are the norm in the fuel ethanol industry today. The ‘consecutive batch’ technology was demonstrated on a large pilot scale (4,800 L) in a dry mill corn ethanol plant near Cedar Rapids, IA (Xethanol Biofuels). The pilot demonstrated that 12 hour fermentations can be accomplished on an industrial scale in a non-sterile industrial environment. Other objectives met in this project included development of a Low Energy (LE) Distillation process which reduces the energy requirements for distillation from about 14,000 BTU/gal steam ($0.126/gal with natural gas @ $9.00 MCF) to as low as 0.40 KW/gal electrical requirements ($0.022/gal with electricity @ $0.055/KWH). BPI also worked on the development of processes that would allow application of the HS/LE fermentation process to dry mill ethanol plants. A High-Value Corn ethanol plant concept was developed to produce 1) corn germ/oil, 2) corn bran, 3) ethanol, 4) zein protein, and 5) nutritional protein, giving multiple higher value products from the incoming corn stream.

  2. High-Speed Low-Jitter Frequency Multiplication in CMOS

    NARCIS (Netherlands)

    van de Beek, R.C.H.


    This thesis deals with high-speed Clock and Frequency Multiplication. The term `high-speedù applies to both the output and the reference frequency of the multiplier. Much emphasis is placed on analysis and optimization of the total timing inaccuracies, and on implementing a high-speed feedback

  3. Videokymography : High-speed line scanning of vocal fold vibration

    NARCIS (Netherlands)

    Svec, JG; Schutte, HK

    A digital technique for high-speed visualization of vibration, called videokymography, was developed and applied to the vocal folds. The system uses a modified video camera able to work in two modes: high-speed (nearly 8,000 images/s) and standard (50 images/s in CCIR norm). In the high-speed mode,

  4. High sensitivity stretched-abrupt-tapered Mach-Zehnder interferometer with optical attractive force for active microsensing applications (United States)

    Chen, Nan-Kuang; Yang, Tsung-Hsun; Chen, Yi-Ning; Guo, Tuan; Guan, Bai-Ou


    We demonstrate micro tapered fiber Mach-Zehnder interferometer with one of the two abrupt tapers is stretched and thinned to a diameter of 3.64 μm whereas the other one keeps its diameter of around 45 μm. The stretched and thinned abrupt taper can enlarge the optical path length difference between core and cladding modes to lead to a narrower free spectral range. The significantly exposed evanescent field can generate the optical attractive force to attract microparticles and can even substantially change the properties of external materials through photothermal effect when an optical power of up to 116 mW is launched.

  5. High-tech maintenance for high-speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Javier Rutz [Nertus Mantenimiento Ferroviario, S.A., Madrid (Spain); Hofmann, Manfred [Siemens AG, Erlangen (Germany). Mobility Div., Integrated Services


    Reliable, punctual trains cannot do without professional maintenance. Nertus S.A., a joint subsidiary of Siemens and Renfe, is responsible for providing precisely this for the Spanish high-speed train, Velaro E (AVE S103), which operates between Madrid and Barcelona. (orig.)

  6. Cleveland-Columbus-Cincinnati high-speed rail study (United States)


    In the past five years, the evaluation of different high-speed rail (HSR) studies in the Midwest has resulted in a realization that high speed rail, with speeds greater than 110 miles per hour, is too expensive in the short term to be implemented in ...

  7. Tunable high-power narrow-linewidth semiconductor laser based on an external-cavity tapered amplifier at 670 nm

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Erbert, G.


    A narrow-linewidth laser system based on a tapered semiconductor optical amplifier in external cavity is demonstrated. 800 mW output power is obtained, and the laser system is tunable from 655 to 679 nm.......A narrow-linewidth laser system based on a tapered semiconductor optical amplifier in external cavity is demonstrated. 800 mW output power is obtained, and the laser system is tunable from 655 to 679 nm....

  8. High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications (United States)

    Taveniku, Mikael


    A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

  9. Analysis of coupling between high-speed railway and common speed railway system in transportation corridor (United States)

    Zhou, Hongchang; Li, Haijun; Chen, Xiaohong; Zhu, Changfeng


    The high-speed railway and common speed railway subsystems as important components of the railway transportation system, can make railway traffic organization more orderly, when there are a rational division and balance development between them. In order to quantitatively evaluate the coordinate relations between high-speed railway subsystem and common speed railway subsystem, this paper takes the railway transportation corridor from Baoji to Lanzhou as an example. Firstly, using Logit model and grey forecasting model predict the passenger volume, passenger turnover and time value of high-speed railway and common speed railway in the Baoji-Lanzhou corridor. And then, the coupling forecast model of these two subsystems is established. Lastly, the coupling and coupling coordination of these two subsystems using are predicted and analyzed at theatrically level.

  10. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.


    Over the last decade the rapid advances in high-speed video technology, have opened up to study many multi-phase fluid phenomena, which tend to occur most rapidly on the smallest length-scales. One of these is the entrapment of a small bubble under a drop impacting onto a solid surface. Here we have gone from simply observing the presence of the bubble to detailed imaging of the formation of a lubricating air-disc under the drop center and its subsequent contraction into the bubble. Imaging the full shape-evolution of the air-disc has required μm and sub-μs space and time resolutions. Time-resolved 200 ns interferometry with monochromatic light, has allowed us to follow individual fringes to obtain absolute air-layer thicknesses, based on the eventual contact with the solid. We can follow the evolution of the dimple shape as well as the compression of the gas. The improved imaging has also revealed new levels of detail, like the nature of the first contact which produces a ring of micro-bubbles, highlighting the influence of nanometric surface roughness. Finally, for impacts of ultra-viscous drops we see gliding on ~100 nm thick rarified gas layers, followed by extreme wetting at numerous random spots.

  11. Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Jan; Guillaume, Patrick; Guo, Yi; Keller, Jonathan


    Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

  12. Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Jan; Guillaume, Patrick; Guo, Yi; Keller, Jonathan


    Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

  13. High Speed Link Radiated Emission Reduction (United States)

    Bisognin, P.; Pelissou, P.; Cissou, R.; Giniaux, M.; Vargas, O.


    To control the radiated emission of high-speed link and associated unit, the current approach is to implement overall harness shielding on cables bundles. This method is very efficient in the HF/ VHF (high frequency/ very high frequency) and UHF (ultra-high frequency) ranges when the overall harness shielding is properly bonded on EMC back-shell. Unfortunately, with the increasing frequency, the associated half wavelength matches with the size of Sub-D connector that is the case for the L band. Therefore, the unit connectors become the main source of interference emission. For the L-band and S-band, the current technology of EMC back-shell leaves thin aperture matched with the L band half wavelength and therefore, the shielding effectiveness is drastically reduced. In addition, overall harness shielding means significant increases of the harness mass.Airbus D&S Toulouse and Elancourt investigated a new solution to avoid the need of overall harness shielding. The objective is to procure EM (Electro-Magnetic) clean unit connected to cables bundles free of any overall harness shielding. The proposed solution is to implement EMC common mode filtering on signal interfaces directly on unit PCB as close as possible the unit connector.Airbus D&S Elancourt designed and manufactured eight mock-ups of LVDS (Low Voltage Differential Signaling) interface PCBs' with different solutions of filtering. After verification of the signal integrity, three mock-ups were retained (RC filter and two common mode choke coil) in addition to the reference one (without EMC filter).Airbus D&S Toulouse manufactured associated LVDS cable bundles and integrated the RX (Receiver) and TX (Transmitter) LVDS boards in shielded boxes.Then Airbus D&S performed radiated emission measurement of the LVDS links subassemblies (e.g. RX and TX boxes linked by LVDS cables) according to the standard test method. This paper presents the different tested solutions and main conclusions on the feasibility of such

  14. High speed flow cytometric separation of viable cells (United States)

    Sasaki, Dennis T.; Van den Engh, Gerrit J.; Buckie, Anne-Marie


    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  15. Simple taper: Taper equations for the field forester (United States)

    David R. Larsen


    "Simple taper" is set of linear equations that are based on stem taper rates; the intent is to provide taper equation functionality to field foresters. The equation parameters are two taper rates based on differences in diameter outside bark at two points on a tree. The simple taper equations are statistically equivalent to more complex equations. The linear...

  16. Water Containment Systems for Testing High-Speed Flywheels (United States)

    Trase, Larry; Thompson, Dennis


    Water-filled containers are used as building blocks in a new generation of containment systems for testing high-speed flywheels. Such containment systems are needed to ensure safety by trapping high-speed debris in the event of centrifugal breakup or bearing failure. Traditional containment systems for testing flywheels consist mainly of thick steel rings. The effectiveness of this approach to shielding against high-speed debris was demonstrated in a series of tests.

  17. Chicago-St. Louis high speed rail plan

    Energy Technology Data Exchange (ETDEWEB)

    Stead, M.E.


    The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team`s analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor.

  18. High-speed Stochastic Fatigue Testing

    DEFF Research Database (Denmark)

    Brincker, Rune; Sørensen, John Dalsgaard


    testing, quite unacceptable errors are introduced. Usually this problem is solved by running the tests at very low speeds and by editing the load history in order to reduce the duration of the test. In this paper a new method for control of stochastic fatigue tests is proposed. It is based on letting...

  19. High-speed rail-coming to America? (United States)

    Cameron, David Ossian


    The United States lags many parts of the world when it comes to high-speed rail. But investing in high-speed rail could help us through current problems. Funds- $8 billion-in the economic stimulus package passed by Congress are designated for high-speed rail. Other funds in the pipeline total approximately $15.5 billion. High-speed rail can relieve congestion, free up national airspace, provide reliable transportation and positive economic development, create jobs, and is more energy efficient than other modes of travel.

  20. The high-speed train and its spatial effects


    Javier Gutiérrez Puebla


    This paper analyses the high-speed train from a spatial point of view. The basic characteristics of this transportation mode,the evolution of high-speed networks in several countries and the building of a trans-European high-speed railway network are studied.The paper analyses also the process of space-time convergence and its consequences on competitivity and cohesion;the tunel effect;the impact of the high speed-train on transportation demand;and the impacts on the city.

  1. High Speed and Wide Bandwidth Delta-Sigma ADCs

    NARCIS (Netherlands)

    Bolatkale, M.


    This thesis describes the theory, design and implementation of a high-speed, high-performance continuous-time delta-sigma (CT??) ADC for applications such as medical imaging, high-definition video processing, and wireline and wireless communications. In order to achieve a GHz clocking speed, this

  2. Time optimal paths for high speed maneuvering

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Lenhart, S.M.


    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  3. Design and Analysis of a High Speed Carry Select Adder


    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel


    An optimal high-speed and low-power VLSI architecture requires an efficient arithmetic processing unit that is optimized for speed and power consumption. Adders are one of the widely used in digital integrated circuit and system design. High speed adder is the necessary component in a data path, e.g. Microprocessors and a Digital signal processor. The present paper proposes a novel high-speed adder by combining the advantages of Carry Look Ahead Adder (CLAA) and Carry Select Adder (CSA), devi...

  4. Design and Analysis of a High Speed Carry Select Adder


    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel


    An optimal high-speed and low-power VLSI architecture requires an efficient arithmetic processing unit that is optimized for speed and power consumption. Adders are one of the widely used in digital integrated circuit and system design.High speed adder is the necessary component in a data path, e.g. Microprocessors and a Digital signal processor. The present paper proposes a novel high-speed adder by combining the advantages of Carry Look Ahead Adder (CLAA) and Carry Select Adder (CSA), devis...

  5. Light beam coupling between standard single mode fibers and highly nonlinear photonic crystal fibers based on the fused biconical tapering technique. (United States)

    Liu, Jianguo; Cheng, Tee-Hiang; Yeo, Yong-Kee; Wang, Yixin; Xue, Lifang; Xu, Zhaowen; Wang, Dawei


    We propose and experimentally demonstrate light beam coupling between a single-mode fiber (SMF) and a highly nonlinear photonic crystal fiber (HN-PCF) based on the fused biconical tapering (FBT) technique. In our experiment, a standard SMF is pre-tapered to match its propagation constant to that of a HN-PCF. In order to remove the condensation in the air holes, the temperature is increased gradually to preheat the fibers. An appropriate level of hydrogen flow is administered to avoid the air-hole collapse. As a result, coupling ratio exceeding 90% between the SMF and HN-PCF is achieved. This technique avoids back Fresnel reflection, mode-field diameter (MFD) mismatch and fiber-core misalignment, bubble generation and air-hole collapse in the interface fusion splice.

  6. Florida High Speed Rail Authority - 2003 report to the legislature (United States)


    Since its last full report to the Legislature in January 2002, the Florida High Speed Rail Authority (FHSRA) has continued to fulfill the duties defined in the Florida High Speed Rail Authority Act, Section 341.8201 to 341.842, Florida Statutes. The ...

  7. Advancing high-speed rail policy in the United States. (United States)


    This report builds on a review of international experience with high-speed rail projects to develop recommendations for a High-speed rail policy framework for the United States. The international review looked at the experience of Korea, Taiwan, Chin...

  8. Optical Systems for Ultra-High-Speed TDM Networking

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Mulvad, Hans Christian Hansen


    This paper discusses key results in the field of high speed optical networking with particular focus on packet-based systems. Schemes for optical packet labeling, packet switching and packet synchronization will be discussed, along with schemes for optical clock recovery, channel identification...... and detection of ultra-high-speed optical signals....

  9. Optical Systems for Ultra-High-Speed TDM Networking

    Directory of Open Access Journals (Sweden)

    Michael Galili


    Full Text Available This paper discusses key results in the field of high speed optical networking with particular focus on packet-based systems. Schemes for optical packet labeling, packet switching and packet synchronization will be discussed, along with schemes for optical clock recovery, channel identification and detection of ultra-high-speed optical signals.

  10. Rounding Technique for High-Speed Digital Signal Processing (United States)

    Wechsler, E. R.


    Arithmetic technique facilitates high-speed rounding of 2's complement binary data. Conventional rounding of 2's complement numbers presents problems in high-speed digital circuits. Proposed technique consists of truncating K + 1 bits then attaching bit in least significant position. Mean output error is zero, eliminating introducing voltage offset at input.

  11. CMOS Image Sensors for High Speed Applications


    Jamal Deen, M.; Qiyin Fang; Louis Liu; Frances Tse; David Armstrong; Munir El-Desouki


    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm) due to ...

  12. External-cavity high-power dual-wavelength tapered amplifier with tunable THz frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael


    A tunable 800 nm high-power dual-wavelength diode laser system with double-Littrow external-cavity feedback is demonstrated. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 5.0 THz. A maximum output power of 1.54 W is achie......A tunable 800 nm high-power dual-wavelength diode laser system with double-Littrow external-cavity feedback is demonstrated. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 5.0 THz. A maximum output power of 1.54 W...... is achieved with a frequency difference of 0.86 THz, the output power is higher than 1.3 W in the 5.0 THz range of frequency difference, and the amplified spontaneous emission intensity is more than 20 dB suppressed in the range of frequency difference. The beam quality factor M2 is 1.22±0.15 at an output...

  13. Tapered structure construction

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Eric D.; Takata, Rosalind K.; Slocum, Alexander H.; Nayfeh, Samir A.


    Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

  14. High-speed OCT light sources and systems [Invited


    Klein, Thomas; Huber, Robert


    Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.

  15. High-speed OCT light sources and systems [Invited]. (United States)

    Klein, Thomas; Huber, Robert


    Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.

  16. High-speed OCT light sources and systems [Invited (United States)

    Klein, Thomas; Huber, Robert


    Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems. PMID:28270988


    Directory of Open Access Journals (Sweden)

    Dimas Endro W


    Full Text Available High speed design studies became very intense studies. One of the subject that can be explore is obtaining total resistace. A high speed ship has four stages of condition when she operates. Starting from low speed condition until developent of dinamics lift force. These four states that happened on high speed ship when she cuise on her operational speed, make a specific consideration on predicting her total resistance.  As high speed ship become more widely built and operate in Indonesia, the study of the state of art of high speed vessel  especially for obtaining total resistance has became more challenging In this paper is foccused on proposing an applicative methods for high speed resistance calculation based on savitsky method. Result which obtained form empirical study is compared to numerical software. Result of this study shows that there are no significant differences between empirical method and result form software application. Considering of sea margin would be effective to made the empirical method would be applicable. There is a 128,0812 KN of total resistance using empirical method, by considering sea margine factor, and a 128,512 KN of total resistance resulted form software calculation

  18. Parametric Optimization for High Speed FLIM Implementation

    Directory of Open Access Journals (Sweden)

    Kim Jayul


    Full Text Available FLIM (Fluorescence Lifetime Imaging Microscopy has been considered an effective technique to investigate chemical properties of the specimens, especially of biological samples. Despite of this advantageous trait, researchers in this field have had difficulties applying FLIM to their systems because acquiring an image using FLIM consumes too much time. To increase the FLIM speed, many methodologies have been developed and applied to the system. One of the recent methodologies is an analogue mean delay based FLIM using a PMT and digitizer for image reconstruction. In this system, however, imaging time is largely dependent upon several parameters such as data transfer rate, sampling rate of an A/D converter, and signal width etc. In this paper, such parametric optimization method is introduced for faster acquisition of the image.

  19. The use of high-speed imaging in education (United States)

    Kleine, H.; McNamara, G.; Rayner, J.


    Recent improvements in camera technology and the associated improved access to high-speed camera equipment have made it possible to use high-speed imaging not only in a research environment but also specifically for educational purposes. This includes high-speed sequences that are created both with and for a target audience of students in high schools and universities. The primary goal is to engage students in scientific exploration by providing them with a tool that allows them to see and measure otherwise inaccessible phenomena. High-speed imaging has the potential to stimulate students' curiosity as the results are often surprising or may contradict initial assumptions. "Live" demonstrations in class or student- run experiments are highly suitable to have a profound influence on student learning. Another aspect is the production of high-speed images for demonstration purposes. While some of the approaches known from the application of high speed imaging in a research environment can simply be transferred, additional techniques must often be developed to make the results more easily accessible for the targeted audience. This paper describes a range of student-centered activities that can be undertaken which demonstrate how student engagement and learning can be enhanced through the use of high speed imaging using readily available technologies.

  20. Next Generation Modeling Technology for High Speed Rotorcraft Project (United States)

    National Aeronautics and Space Administration — Development of a new generation of high speed rotorcraft has been hampered by both an absence of strong predictive methods for rotors operating at very high advance...

  1. Modern trends in designing high-speed trains

    Directory of Open Access Journals (Sweden)

    Golubović Snežana D.


    Full Text Available Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself. Along with increased train speed, the motion resistance is increased as well, whereby at speeds over 200 km/h the proportion of air resistance becomes the most dominant member. One of the most efficient measures for reducing air resistance, as well as other negative consequences of high-speed motion, is the development of the aerodynamic shape of the train. This paper presents some construction solutions that affect the aerodynamic properties of high-speed trains, first and foremost, the nose shape, as well as the similarities and differences of individual subsystems necessary for the functioning of modern high-speed rail systems. We analysed two approaches to solving the problem of the aerodynamic shape of the train and the appropriate infrastructure using the examples of Japan and France. Two models of high-speed trains, Shinkansen (Japan and TGV, i.e. AGV (France, have been discussed.

  2. On-line high-speed rail defect detection. (United States)


    This report presents the results of phase 2 of the project On-line high-speed rail defect detection aimed at improving the reliability and the speed of current defect detection in rails. Ultrasonic guided waves, traveling in the rail running di...

  3. High speed electromechanical response of ionic microactuators (United States)

    Maziz, Ali; Plesse, Cedric; Soyer, Caroline; Cattan, Eric; Vidal, Frederic


    This paper presents the synthesis and characterization of thin and ultra-fast conducting polymer microactuators which can operate in the open air. Compared to all previous existing electronic conducting polymer based microactuators, this approach deals with the synthesis of robust interpenetrating polymer networks (IPNs) combined with a spincoating technique in order to tune and drastically reduce the thickness of conducting IPN microactuators using a so-called "trilayer" configuration. Patterning of electroactive materials has been performed with existing technologies, such as standard photolithography and dry etching. The smallest air-operating microbeam actuator based on conducting polymer is then described with dimensions as low as 160x30x6 μm3. Under electrical stimulation the translations of small ion motion into bending deformations are used as tools to demonstrate that small ion vibrations can still occur at frequency as several hundreds of Hz. Conducting IPN microactuators are then promising candidates to develop new MEMS combining downscaling, softness, low driving voltage, and fast response speed.

  4. High speed high dynamic range high accuracy measurement system (United States)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng


    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  5. High-speed optical measurement for the drumhead vibration (United States)

    Zhang, Qican; Su, Xianyu


    In this paper, a high-speed optical measurement for the vibrating drumhead is presented and verified by experiment. A projected sinusoidal fringe pattern on the measured drumhead is dynamically deformed with the vibration of the membrane and grabbed by a high-speed camera. The shape deformation of the drumhead at each sampling instant can be recovered from this sequence of obtained fringe patterns. The vibration of the membrane of a Chinese drum has been measured with a high speed sampling rate (1,000 fps) and a standard deviation (0.075 mm). The restored vibration of the drumhead is also presented in an animation.

  6. The Paris - Strasbourg high-speed line; Hochgeschwindigkeitsstrecke Paris - Strassburg

    Energy Technology Data Exchange (ETDEWEB)

    Brux, G.


    On 10th June 2007, TGV high-speed trains operated by French state railways SNCF, and ICE high-speed trains of Deutsche Bahn, will commence operations of France's eastern highspeed line Paris - Strasbourg, running services from Paris to Luxembourg, Frankfurt am Main and Stuttgart, and also to Basel and Zurich. As from the start of the new timetable on 9th December 2007, the service will also extend to Munich. The new high-speed line will shorten rail travels on these connections by several hours. (orig.)

  7. FPGA Flash Memory High Speed Data Acquisition (United States)

    Gonzalez, April


    The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

  8. Impedance Discontinuity Reduction Between High-Speed Differential Connectors and PCB Interfaces (United States)

    Navidi, Sal; Agdinaoay, Rodell; Walter, Keith


    High-speed serial communication (i.e., Gigabit Ethernet) requires differential transmission and controlled impedances. Impedance control is essential throughout cabling, connector, and circuit board construction. An impedance discontinuity arises at the interface of a high-speed quadrax and twinax connectors and the attached printed circuit board (PCB). This discontinuity usually is lower impedance since the relative dielectric constant of the board is higher (i.e., polyimide approx. = 4) than the connector (Teflon approx. = 2.25). The discontinuity can be observed in transmit or receive eye diagrams, and can reduce the effective link margin of serial data networks. High-speed serial data network transmission improvements can be made at the connector-to-board interfaces as well as improving differential via hole impedances. The impedance discontinuity was improved by 10 percent by drilling a 20-mil (approx. = 0.5-mm) hole in between the pin of a differential connector spaced 55 mils (approx. = 1.4 mm) apart as it is attached to the PCB. The effective dielectric constant of the board can be lowered by drilling holes into the board material between the differential lines in a quadrax or twinax connector attachment points. The differential impedance is inversely proportional to the square root of the relative dielectric constant. This increases the differential impedance and thus reduces the above described impedance discontinuity. The differential via hole impedance can also be increased in the same manner. This technique can be extended to multiple smaller drilled holes as well as tapered holes (i.e., big in the middle followed by smaller ones diagonally).

  9. Method for upgrading the performance at track transitions for high-speed service : next generation high-speed rail program (United States)


    High-speed trains in the speed range of 100 to 160 mph require tracks of nearly perfect geometry and mechanical uniformity, when subjected to moving wheel loads. Therefore, this report briefly describes the remedies being used by various railroads to...

  10. Effects of High-Speed Power Training on Muscle Performance and Braking Speed in Older Adults

    Directory of Open Access Journals (Sweden)

    Stephen P. Sayers


    Full Text Available We examined whether high-speed power training (HSPT improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs were randomized to HSPT at 40% one-repetition maximum (1RM (HSPT: n=25; 3 sets of 12–14 repetitions, slow-speed strength training at 80%1RM (SSST: n=25; 3 sets of 8–10 repetitions, or control (CON: n=22; stretching 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40–90% 1RM; P<0.05 and improved braking speed (P<0.05. Work was similar between groups, but perceived exertion was lower in HSPT (P<0.05. Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.

  11. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.


    The purpose of Phase 1 of the study is to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. The systems we consider are high data rate space communication systems. Also...... components. Node synchronization performed within a Viterbi decoder is discussed, and algorithms for frame synchronization are described and analyzed. We present a list of system configurations that we find potentially useful. Further, the high level architecture of units that contain frame synchronization...

  12. Parallelism and pipelining in high-speed digital simulators (United States)

    Karplus, W. J.


    The attainment of high computing speed as measured by the computational throughput is seen as one of the most challenging requirements. It is noted that high speed is cardinal in several distinct classes of applications. These classes are then discussed; they comprise (1) the real-time simulation of dynamic systems , (2) distributed parameter systems, and (3) mixed lumped and distributed systems. From the 1950s on, the quest for high speed in digital simulators concentrated on overcoming the limitations imposed by the so-called von Neumann bottleneck. Two major architectural approaches have made ig possible to circumvent this bottleneck and attain high speeds. These are pipelining and parallelism. Supercomputers, peripheral array processors, and microcomputer networks are then discussed.

  13. Railroad Embankment Stabilization Demonstration for High-Speed Rail Corridors (United States)


    The development of high-speed railroad corridors in the United States is being considered by Congress as a fuel efficient and economical alternative to air or highway passenger travel. The exisiting infrastructure is, in many ways, suitable for freig...

  14. Promoting intermodal connectivity at California's high-speed rail stations. (United States)


    High-speed rail (HSR) has emerged as one of the most revolutionary and transformative transportation technologies, having a : profound impact on urban-regional accessibility and inter-city travel across Europe, Japan, and more recently China and othe...

  15. Florida High Speed Rail Authority - 2002 report to the legislature (United States)


    This report addresses a legislative requirement that the Authority issue a report of its actions, findings and recommendations. Previous high speed ground transportation studies were reviewed as part of the preparation of this report. Independent ana...

  16. High-speed rail turnout literature review : final report. (United States)


    High-speed rail (HSR) turnout design criteria generally address unbalanced lateral acceleration or cant deficiency (CD), cant deficiency change rate (CDCR), and entry and exit jerk. Various countries have adopted different design values for their HSR...

  17. Safety evaluation of high-speed rail bogie concepts. (United States)


    The study defines the basic design concepts required to provide a safe, reliable, high-speed bogie for the next generation PRIIA passenger locomotive. The requirements and conditions for the U.S. market create unique design challenges that currently ...

  18. High-Speed-/-Hypersonic-Weapon-Development-Tool Integration

    National Research Council Canada - National Science Library

    Duchow, Erin M; Munson, Michael J; Alonge, Jr, Frank A


    Multiple tools exist to aid in the design and evaluation of high-speed weapons. This paper documents efforts to integrate several existing tools, including the Integrated Hypersonic Aeromechanics Tool (IHAT)1-7...

  19. High speed railway track dynamics models, algorithms and applications

    CERN Document Server

    Lei, Xiaoyan


    This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.

  20. High-Speed Thermal Characterization of Cryogenic Flows Project (United States)

    National Aeronautics and Space Administration — Luna proposes to continue development on a high-speed fiber optic sensor and readout system for cryogenic temperature measurements in liquid oxygen (LOX) and liquid...

  1. Modern trends in designing high-speed trains

    National Research Council Canada - National Science Library

    Golubović, Snežana D; Rašuo, Boško P; Lučanin, Vojkan J


    Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains...

  2. Application of Beyond Bound Decoding for High Speed Optical Communications

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José


    This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB....

  3. Characterising argon-bomb balloons for high-speed photography

    CSIR Research Space (South Africa)

    Olivier, M


    Full Text Available -1 SABO 2013 TME Workshop Alkantpan Characterising Argon-bomb balloons for High-speed Photography M Olivier and FJ Mostert Landward Sciences, Defence Peace Safety and Security, CSIR, Meiring Naude Road, Pretoria, RSA. Abstract A...

  4. Engineering Data on Selected High Speed Passenger Trucks (United States)


    The purpose of this project is to compile a list of high speed truck engineering parameters for characterization in dynamic performance modeling activities. Data tabulations are supplied for trucks from France, Germany, Italy, England, Japan, U.S.S.R...

  5. Next Generation Modeling Technology for High Speed Rotorcraft Project (United States)

    National Aeronautics and Space Administration — Recent R&D associated with designing high speed rotorcraft has been greatly hampered by a lack of test data and confidence in predictions for rotors operating...

  6. Portable fiber-optic taper coupled optical microscopy platform (United States)

    Wang, Weiming; Yu, Yan; Huang, Hui; Ou, Jinping


    The optical fiber taper coupled with CMOS has advantages of high sensitivity, compact structure and low distortion in the imaging platform. So it is widely used in low light, high speed and X-ray imaging systems. In the meanwhile, the peculiarity of the coupled structure can meet the needs of the demand in microscopy imaging. Toward this end, we developed a microscopic imaging platform based on the coupling of cellphone camera module and fiber optic taper for the measurement of the human blood samples and ascaris lumbricoides. The platform, weighing 70 grams, is based on the existing camera module of the smartphone and a fiber-optic array which providing a magnification factor of 6x.The top facet of the taper, on which samples are placed, serves as an irregular sampling grid for contact imaging. The magnified images of the sample, located on the bottom facet of the fiber, are then projected onto the CMOS sensor. This paper introduces the portable medical imaging system based on the optical fiber coupling with CMOS, and theoretically analyzes the feasibility of the system. The image data and process results either can be stored on the memory or transmitted to the remote medical institutions for the telemedicine. We validate the performance of this cell-phone based microscopy platform using human blood samples and test target, achieving comparable results to a standard bench-top microscope.

  7. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu


    This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

  8. Minimum Plate Thickness in High-Speed Craft

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming


    The minimum plate thickness requirements specified by the classification societies for high-speed craft are supposed to ensure adequate resistance to impact loads such as collision with floating objects and objects falling on the deck. The paper presents analytical methods of describing such impact...... phenomena and proposes performance requirements instead of thickness requirements for hull panels in high-speed craft made of different building materials....

  9. From periphery to core: economic adjustments to high speed rail


    Ahlfeldt, Gabriel M.; Feddersen, Arne


    This paper presents evidence that high speed rail systems, by bringing economic agents closer together, sustainably promote economic activity within regions that enjoy an increase in accessibility. Our results on the one hand confirm expectations that have led to huge public investments into high speed rail all over the world. On the other hand, they confirm theoretical predictions arising from a consolidate body of (New) Economic Geography literature taking a positive, man-made and reproduci...

  10. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.


    The study has been divided into two phases. The purpose of Phase 1 of the study was to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. After selection of which specific...... potentially useful.Algorithms for frame synchronization are described and analyzed. Further, the high level architecture of units that contain frame synchronization and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder...... towards a realization in an FPGA.Node synchronization performed within a Viterbi decoder is discussed, and the high level architectures of three possible implementations of Viterbi decoders are described: The first implementation uses a number of commercially available decoders while the the two others...

  11. Nanotechnology: high-speed integrated nanowire circuits. (United States)

    Friedman, Robin S; McAlpine, Michael C; Ricketts, David S; Ham, Donhee; Lieber, Charles M


    Macroelectronic circuits made on substrates of glass or plastic could one day make computing devices ubiquitous owing to their light weight, flexibility and low cost. But these substrates deform at high temperatures so, until now, only semiconductors such as organics and amorphous silicon could be used, leading to poor performance. Here we present the use of low-temperature processes to integrate high-performance multi-nanowire transistors into logical inverters and fast ring oscillators on glass substrates. As well as potentially enabling powerful electronics to permeate all aspects of modern life, this advance could find application in devices such as low-cost radio-frequency tags and fully integrated high-refresh-rate displays.

  12. Optimization Based High-Speed Railway Train Rescheduling with Speed Restriction

    Directory of Open Access Journals (Sweden)

    Li Wang


    Full Text Available A decision support framework with four components is proposed for high-speed railway timetable rescheduling in case of speed restriction. The first module provides the speed restriction information. The capacity evaluation module is used to evaluate whether the capacity can fulfill the demand before rescheduling timetable based on deduction factor method. The bilayer rescheduling module is the key of the decision support framework. In the bilayer rescheduling module, the upper-layer objective is to make an optimal rerouting plan with selected rerouting actions. Given a specific rerouting plan, the lower-layer focuses on minimizing the total delay as well as the number of seriously impacted trains. The result assessment module is designed to invoke the rescheduling model iteratively with different settings. There are three prominent features of the framework, such as realized interaction with dispatchers, emphasized passengers’ satisfaction, and reduced computation complexity with a bilayer modeling approach. The proposed rescheduling model is simulated on the busiest part of Beijing to Shanghai high-speed railway in China. The case study shows the significance of rerouting strategy and utilization of the railway network capacity in case of speed restriction.

  13. Dual-wavelength high-power diode laser system based on an external-cavity tapered amplifier with tunable frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael


    A dual-wavelength high-power semiconductor laser system based on a tapered amplifier with double-Littrow external cavity is demonstrated around 800 nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 10.0 THz. To our...... knowledge, this is the broadest tuning range of the frequency difference from a dual-wavelength diode laser system. The spectrum, output power, and beam quality of the diode laser system are characterized. The power stability of each wavelength is measured, and the power fluctuations of the two wavelengths...

  14. High-speed quantum networking by ship. (United States)

    Devitt, Simon J; Greentree, Andrew D; Stephens, Ashley M; Van Meter, Rodney


    Networked entanglement is an essential component for a plethora of quantum computation and communication protocols. Direct transmission of quantum signals over long distances is prevented by fibre attenuation and the no-cloning theorem, motivating the development of quantum repeaters, designed to purify entanglement, extending its range. Quantum repeaters have been demonstrated over short distances, but error-corrected, global repeater networks with high bandwidth require new technology. Here we show that error corrected quantum memories installed in cargo containers and carried by ship can provide a exible connection between local networks, enabling low-latency, high-fidelity quantum communication across global distances at higher bandwidths than previously proposed. With demonstrations of technology with sufficient fidelity to enable topological error-correction, implementation of the quantum memories is within reach, and bandwidth increases with improvements in fabrication. Our approach to quantum networking avoids technological restrictions of repeater deployment, providing an alternate path to a worldwide Quantum Internet.

  15. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody


    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  16. High-speed analog-to-digital conversion

    CERN Document Server

    Demler, Michael J


    This book covers the theory and applications of high-speed analog-to-digital conversion. An analog-to-digital converter takes real-world inputs (such as visual images, temperature readings, and rates of speed) and transforms them into digital form for processing by computer. This book discusses the design and uses of such circuits, with particular emphasis on improving the speed of the conversion process and the accuracy of its output--how well the output is a corresponding digital representation of the output*b1input signal. As computers become increasingly interfaced to the outside world, ""

  17. Switching speed limitations of high power IGBT modules

    DEFF Research Database (Denmark)

    Incau, Bogdan Ioan; Trintis, Ionut; Munk-Nielsen, Stig


    In this paper the switching speed limits of high power IGBT modules are investigated. The limitation of turn-on and turn-off switching speeds of the IGBTs are experimentally detected in a pulse tester. Different dc-bus stray inductances are considered, as well as the worst case scenario for the b......In this paper the switching speed limits of high power IGBT modules are investigated. The limitation of turn-on and turn-off switching speeds of the IGBTs are experimentally detected in a pulse tester. Different dc-bus stray inductances are considered, as well as the worst case scenario...... for the blocking dc-link voltage. Switching losses are analyzed upon a considerable variation of resistor value from turn-on gate driver side. Short circuit operations are investigated along with safe operating area for entire module to validate electrical capabilities under extreme conditions....

  18. High Speed Imaging of Diesel Fuel Sprays (United States)

    Jackson, Ja'kira; Bittle, Joshua


    Fuel sprays primarily serve as methods for fuel distribution, fuel/air mixing, and atomization. In this research, a constant pressure flow rig vessel is being tested at various pressures and temperatures using n-heptane. The experiment requires two imaging techniques: color Schlieren and Mie-scatter. Schlieren captures density gradients in a spray which includes both liquid and vapor phases while Mie-scatter is only sensitive to the liquid phase of the fuel spray. Essentially, studies are mainly focused on extracting the liquid boundary from the Schlieren to possibly eliminate the need for acquiring the Mie-Scatter technique. Four test conditions (combination of low and high pressure and temperatures) are used in the application to attempt to find the liquid boundary independent of the Mie-scatter technique. In this pursuit the following methods were used: a color threshold, a value threshold, and the time variation in color. All methods provided some indication of the liquid region but none were able to capture the full liquid boundary as obtained by the Mie-scatter results. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

  19. ALICE HLT high speed tracking on GPU

    CERN Document Server

    Gorbunov, Sergey; Aamodt, Kenneth; Alt, Torsten; Appelshauser, Harald; Arend, Andreas; Bach, Matthias; Becker, Bruce; Bottger, Stefan; Breitner, Timo; Busching, Henner; Chattopadhyay, Sukalyan; Cleymans, Jean; Cicalo, Corrado; Das, Indranil; Djuvsland, Oystein; Engel, Heiko; Erdal, Hege Austrheim; Fearick, Roger; Haaland, Oystein Senneset; Hille, Per Thomas; Kalcher, Sebastian; Kanaki, Kalliopi; Kebschull, Udo Wolfgang; Kisel, Ivan; Kretz, Matthias; Lara, Camillo; Lindal, Sven; Lindenstruth, Volker; Masoodi, Arshad Ahmad; Ovrebekk, Gaute; Panse, Ralf; Peschek, Jorg; Ploskon, Mateusz; Pocheptsov, Timur; Ram, Dinesh; Rascanu, Theodor; Richter, Matthias; Rohrich, Dieter; Ronchetti, Federico; Skaali, Bernhard; Smorholm, Olav; Stokkevag, Camilla; Steinbeck, Timm Morten; Szostak, Artur; Thader, Jochen; Tveter, Trine; Ullaland, Kjetil; Vilakazi, Zeblon; Weis, Robert; Yin, Zhong-Bao; Zelnicek, Pierre


    The on-line event reconstruction in ALICE is performed by the High Level Trigger, which should process up to 2000 events per second in proton-proton collisions and up to 300 central events per second in heavy-ion collisions, corresponding to an inp ut data stream of 30 GB/s. In order to fulfill the time requirements, a fast on-line tracker has been developed. The algorithm combines a Cellular Automaton method being used for a fast pattern recognition and the Kalman Filter method for fitting of found trajectories and for the final track selection. The tracker was adapted to run on Graphics Processing Units (GPU) using the NVIDIA Compute Unified Device Architecture (CUDA) framework. The implementation of the algorithm had to be adjusted at many points to allow for an efficient usage of the graphics cards. In particular, achieving a good overall workload for many processor cores, efficient transfer to and from the GPU, as well as optimized utilization of the different memories the GPU offers turned out to be cri...

  20. The advantages of a tapered whisker.

    Directory of Open Access Journals (Sweden)

    Christopher M Williams

    Full Text Available The role of facial vibrissae (whiskers in the behavior of terrestrial mammals is principally as a supplement or substitute for short-distance vision. Each whisker in the array functions as a mechanical transducer, conveying forces applied along the shaft to mechanoreceptors in the follicle at the whisker base. Subsequent processing of mechanoreceptor output in the trigeminal nucleus and somatosensory cortex allows high accuracy discriminations of object distance, direction, and surface texture. The whiskers of terrestrial mammals are tapered and approximately circular in cross section. We characterize the taper of whiskers in nine mammal species, measure the mechanical deflection of isolated felid whiskers, and discuss the mechanics of a single whisker under static and oscillatory deflections. We argue that a tapered whisker provides some advantages for tactile perception (as compared to a hypothetical untapered whisker, and that this may explain why the taper has been preserved during the evolution of terrestrial mammals.

  1. Modern trends in designing high-speed trains


    Golubović Snežana D.; Rašuo Boško P.; Lučanin Vojkan J.


    Increased advantages of railway transportation systems over other types of transportation systems in the past sixty years have been a result of an intensive development of the new generations of high-speed trains. Not only do these types of trains comply with the need for increased speed of transportation and make the duration of the journey shorter, but they also meet the demands for increased reliability, safety and direct application of energy efficiency to the transportation system itself...

  2. Effect of tapering after a period of high-volume sprint interval training on running performance and muscular adaptations in moderately trained runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Almquist, Nicki Winfield; Kvorning, Thue


    The effect of tapering following a period of high-volume sprint interval training (SIT) and a basic volume of aerobic training on performance and muscle adaptations in moderately trained runners was examined. Eleven (8 males, 3 females) runners (maximum oxygen uptake (VO2-max): 56.8±2.9 mL·min(-1......)·kg(-1); mean±SD) conducted high-volume SIT (HV; 20 SIT sessions; 8-12 x 30-s all-out) for 40 days followed by 18 days of tapering (TAP; 4 SIT sessions; 4 x 30-s all-out). Before and after HV as well as midway through and at the end of TAP, the subjects completed a 10-km running test and a repeated...... at 60% of vVO2-max was lower (Phigh-volume SIT improved 10-km performance and running economy, and short-duration exercise capacity was better than before the high-volume SIT period together with higher expression...

  3. High-power dual-wavelength external-Cavity diode laser based on tapered amplifier with tunable terahertz frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael


    Tunable dual-wavelength operation of a diode laser system based on a tapered diode amplifier with double-Littrow external-cavity feedback is demonstrated around 800nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 5:0 THz......, this is the highest output power from a dual-wavelength diode laser system operating with tunable terahertz frequency difference. © 2011 Optical Society of America.......Tunable dual-wavelength operation of a diode laser system based on a tapered diode amplifier with double-Littrow external-cavity feedback is demonstrated around 800nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 5:0 THz....... An output power of 1:54W is achieved with a frequency difference of 0:86 THz, the output power is higher than 1:3W in the 5:0 THz range of frequency difference, and the amplified spontaneous emission intensity is more than 20 dB suppressed in the range of frequency difference. To our knowledge...

  4. Extremely high-speed imaging based on tubeless technology (United States)

    Li, Jingzhen


    This contribution focuses on the tubeless imaging, the extreme-high speed imaging. A detail discussion is presented on how and why to make them, which would be the most important in the high speed imaging field in the future. Tubeless extreme-high speed imaging can not only be used to observe the transient processes like collision, detonating, and high voltage discharge, but also to research the processes like disintegration and transfer of phonon and exacton in solid, photosynthesis primitive reaction, and electron dynamics inside atom shell. Its imaging frequency is about 107~1015fps. For this kind of imaging, the mechanism of how forming both high speed and framing would better make fine use of the light speed, the light parallelism, the parameters of light wave such as its amplitude, phase, polarization and wave length, and even quantum characteristics of photons. In the cascade connection system of electromagnetic wave and particle wave, it is able to simultaneously realize high level both the temporal resolution and the spatial resolution, and it would be possible to break through the limit of the Heisenberg uncertainty correlation of the optical frequency band.

  5. Assessment of rural soundscapes with high-speed train noise. (United States)

    Lee, Pyoung Jik; Hong, Joo Young; Jeon, Jin Yong


    In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions. © 2013.

  6. HDR {sup 192}Ir source speed measurements using a high speed video camera

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Viana, Rodrigo S. S.; Yoriyaz, Hélio [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Podesta, Mark [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Rubo, Rodrigo A.; Sales, Camila P. de [Hospital das Clínicas da Universidade de São Paulo—HC/FMUSP, São Paulo 05508-000 (Brazil); Reniers, Brigitte [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, Frank, E-mail: [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H3G 1A4 (Canada)


    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  7. Thermal Behavior of High-Speed Helical Gear Trains Investigated (United States)

    Handschuh, Robert F.


    High-speed and heavily loaded gearing are commonplace in the rotorcraft systems employed in helicopter and tiltrotor transmissions. The components are expected to deliver high power from the gas turbine engines to the high-torque, low-speed rotor, reducing the shaft rotational speed in the range of 25:1 to 100:1. These components are designed for high power-to-weight ratios, thus the components are fabricated as light as possible with the best materials and processing to transmit the required torque and carry the resultant loads without compromising the reliability of the drive system. This is a difficult task that is meticulously analyzed and thoroughly tested experimentally prior to being applied on a new or redesigned aircraft.

  8. High-energy passively Q-switched 2 μm Tm(3+)-doped double-clad fiber laser using graphene-oxide-deposited fiber taper. (United States)

    Liu, Chun; Ye, Chenchun; Luo, Zhengqian; Cheng, Huihui; Wu, Duanduan; Zheng, Yonglong; Liu, Zhen; Qu, Biao


    We have demonstrated a high-energy Q-switched double-clad thulium-doped fiber laser (TDFL) using a graphene-oxide-deposited tapered fiber (GODTF) device as a saturable absorber operating at a wavelength of 2 μm for the first time. Because of the side-interaction of the graphene-oxide with the evanescent field on the taper waist, the GODTF devices have potential for offering high laser damage threshold. Using a 788 nm laser diode as the pump source, the TDFL generated stable single transverse mode Q-switched pulses with a single pulse energy of 6.71 μJ (corresponding to an average power of 302 mW) at a wavelength of 2032 nm. This is significantly higher than the highest pulse energy/average power from any rare-earth-doped fiber lasers employing a graphene or graphene-oxide based Q-switch so far. The demonstrated TDFL in this paper represents an encouraging step towards the practical applications of graphene or graphene-oxide based Q-switched 2 μm TDFLs.

  9. Unsteady Flow Simulation of High-speed Turbopumps (United States)

    Kiris, Cetin C.; Kwak, dochan; Chan, William; Housman, Jeffrey A.


    Computation of high-speed hydrodynamics requires high-fidelity simulation to resolve flow features involving transient flow, cavitation, tip vortex and multiple scales of unsteady fluctuations. One example of this type in aerospace is related to liquid-fueled rocket turbopump. Rocket turbopumps operate under severe conditions at very high rotational speeds typically at thousands of rpm. For example, the Shuttle orbiter low-pressure-fuel-turbopump creates transient flow features associated with reverse flows, tip clearance effects, secondary flows, vortex shedding, junction flows, and cavitation effects. Flow unsteadiness originating from the orbiter Low-Pressure-Fuel-Turbopump (LPFTP) inducer is one of the major contributors to the high frequency cyclic loading that results in high cycle fatigue damage to the flow liners just upstream of the LPFTP. The reverse flow generated at the tip of the inducer blades travels upstream and interacts with the bellows cavity. Simulation procedure for this type high-speed hydrodynamic problems requires a method for quantifying multi-scale and multi-phase flow as well as an efficient high-end computing strategy. The current paper presents a high-fidelity computational procedure for unsteady hydrodynamic problems using a high-speed liquid-fueled rocket turbopump.

  10. Noise in the passenger cars of high-speed trains. (United States)

    Hong, Joo Young; Cha, Yongwon; Jeon, Jin Yong


    The aim of this study is to investigate the effects of both room acoustic conditions and spectral characteristics of noises on acoustic discomfort in a high-speed train's passenger car. Measurement of interior noises in a high-speed train was performed when the train was operating at speeds of 100 km/h and 300 km/h. Acoustic discomfort caused by interior noises was evaluated by paired comparison methods based on the variation of reverberation time (RT) in a passenger car and the spectral differences in interior noises. The effect of RT on acoustic discomfort was not significant, whereas acoustic discomfort significantly varied depending on spectral differences in noise. Acoustic discomfort increased with increment of the sound pressure level (SPL) ratio at high frequencies, and variation in high-frequency noise components were described using sharpness. Just noticeable differences of SPL with low- and high-frequency components were determined to be 3.7 and 2.9 dB, respectively. This indicates that subjects were more sensitive to differences in SPLs at the high-frequency range than differences at the low-frequency range. These results support that, for interior noises, reduction in SPLs at high frequencies would significantly contribute to improved acoustic quality in passenger cars of high-speed trains.

  11. Tactile shoe inlays for high speed pressure monitoring

    DEFF Research Database (Denmark)

    Drimus, Alin; Mátéfi-Tempfli, Stefan


    pressure sensitive cells and the use of high speed electronics and multiplexing algorithms provides frame rates of 100 Hz. The sensors tolerate overloads while showing a consistent output. The developed prototypes show a high potential not only for robotics, but also for use in sensorised human prosthetics....

  12. High-speed T-38A landing gear extension loads (United States)

    Schmitt, A. L.


    Testing of T-38A landing gear extension at high speed and high altitude is described. The mechanisms are shown together with peak hydraulic pressure data during landing gear deployment with active and inactive strut door flaps. Results of strain gage measurements of stress on various structural members are included.

  13. High energy gain of trapped electrons in a tapered, diffraction-dominated inverse-free-electron laser. (United States)

    Musumeci, P; Tochitsky, S Ya; Boucher, S; Clayton, C E; Doyuran, A; England, R J; Joshi, C; Pellegrini, C; Ralph, J E; Rosenzweig, J B; Sung, C; Tolmachev, S; Travish, G; Varfolomeev, A A; Varfolomeev, A A; Yarovoi, T; Yoder, R B


    Energy gain of trapped electrons in excess of 20 MeV has been demonstrated in an inverse-free-electron-laser (IFEL) accelerator experiment. A 14.5 MeV electron beam is copropagated with a 400 GW CO2 laser beam in a 50 cm long undulator strongly tapered in period and field amplitude. The Rayleigh range of the laser, approximately 1.8 cm, is much shorter than the undulator length yielding a diffraction-dominated interaction. Experimental results on the dependence of the acceleration on injection energy, laser focus position, and laser power are discussed. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the first half of the undulator at a gradient of 70 MeV/m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator.

  14. High Energy Gain of Trapped Electrons in a Tapered, Diffraction-Dominated Inverse-Free-Electron Laser (United States)

    Musumeci, P.; Tochitsky, S. Ya.; Boucher, S.; Clayton, C. E.; Doyuran, A.; England, R. J.; Joshi, C.; Pellegrini, C.; Ralph, J. E.; Rosenzweig, J. B.; Sung, C.; Tolmachev, S.; Travish, G.; Varfolomeev, A. A.; Varfolomeev, A. A.; Yarovoi, T.; Yoder, R. B.


    Energy gain of trapped electrons in excess of 20 MeV has been demonstrated in an inverse-free-electron-laser (IFEL) accelerator experiment. A 14.5 MeV electron beam is copropagated with a 400 GW CO2 laser beam in a 50 cm long undulator strongly tapered in period and field amplitude. The Rayleigh range of the laser, ˜1.8 cm, is much shorter than the undulator length yielding a diffraction-dominated interaction. Experimental results on the dependence of the acceleration on injection energy, laser focus position, and laser power are discussed. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the first half of the undulator at a gradient of 70 MeV/m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator.

  15. High-speed modulation of vertical cavity surface emitting lasers

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Armendariz, M.G.; Choquette, K.D.; Lear, K.L.


    This report summarizes work on the development of high-speed vertical cavity surface emitting lasers (VCSELs) for multi-gigabit per second optical data communications applications (LDRD case number 3506.010). The program resulted in VCSELs that operate with an electrical bandwidth of 20 GHz along with a simultaneous conversion efficiency (DC to light) of about 20%. To achieve the large electrical bandwidth, conventional VCSELs were appropriately modified to reduce electrical parasitics and adapted for microwave probing for high-speed operation.

  16. Method for high-speed Manchester encoded optical signal generation

    DEFF Research Database (Denmark)

    Zhang, Jianfeng; Chi, Nan; Holm-Nielsen, Pablo Villanueva


    A method for high-speed Manchester encoded optical signal generation is proposed and demonstrated with a specially configured electro-optical modulator. A 10 Gb/s Manchester encoded optical signal was generated, and its bit-error-ratio (BER) performance was evaluated.......A method for high-speed Manchester encoded optical signal generation is proposed and demonstrated with a specially configured electro-optical modulator. A 10 Gb/s Manchester encoded optical signal was generated, and its bit-error-ratio (BER) performance was evaluated....

  17. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.


    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  18. Miniature high speed compressor having embedded permanent magnet motor (United States)

    Zhou, Lei (Inventor); Zheng, Liping (Inventor); Chow, Louis (Inventor); Kapat, Jayanta S. (Inventor); Wu, Thomas X. (Inventor); Kota, Krishna M. (Inventor); Li, Xiaoyi (Inventor); Acharya, Dipjyoti (Inventor)


    A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing supports.

  19. Wind-Tunnel Investigation of the Characteristics of Blunt-Nose Ailerons on a Tapered Wing (United States)

    Toll, Thomas A.


    Characteristics are determined for various modifications of 0.155-chord blunt-nose aileron on semispan model of tapered fighter plane wing. Ailerons with 40 percent nose balance reduced high-speed stick forces. Increased balance chord increases effectiveness and reduces high-speed stick forces. Increased balance chord increases effectiveness and reduces adverse effects of gap at aileron hose. Increase of nose radii increased negative slope of curve hinge-movement coefficient plotted against deflection. Extended deflection range decreased aileron effectiveness for small deflections but increased it at large deflections. Peak pressures at noses of ailerons are relatively high at moderate deflections.

  20. Tapering Practices of Croatian Open-Class Powerlifting Champions. (United States)

    Grgic, Jozo; Mikulic, Pavle


    Grgic, J and Mikulic, P. Tapering practices of Croatian open-class powerlifting champions. J Strength Cond Res 31(9): 2371-2378, 2017-The aim of this study was to explore tapering practices among 10 Croatian open-class powerlifting champions (mean ± SD: age 29.2 ± 3.2 years; Wilks coefficient 355.1 ± 54.8). The athletes were interviewed about their tapering practices using a semi-structured interview after which the audio content was transcribed. The athletes reported decreasing training volume during the taper by 50.5 ± 11.7% using a step type or an exponential type of taper with a fast decay. Training intensity was maintained or increased during the taper, and it reached its highest values 8 ± 3 days before the competition. Training frequency was reduced or maintained during the taper. The final week included a reduction in training frequency by 47.9 ± 17.5% with the last training session performed 3 ± 1 days before the competition. The participants typically stated that the main reasons for conducting the taper were maintaining strength and reducing the amount of fatigue. They also stated that (a) the taper was structured identically for the squat, bench press, and the deadlift; (b) the training during the taper was highly specific, the assistance exercises were removed, and the same equipment was used as during competition; (c) the source of information for tapering was their coach, and training fluctuated based on the coach's feedback; and (d) nutrition, foam rolling, static stretching, and massage were all given extra attention during the taper. These results may aid athletes and coaches in strength sports in terms of the optimization of tapering variables.

  1. Effects of high sound speed confiners on ANFO detonations (United States)

    Kiyanda, Charles; Jackson, Scott; Short, Mark


    The interaction between high explosive (HE) detonations and high sound speed confiners, where the confiner sound speed exceeds the HE's detonation speed, has not been thoroughly studied. The subsonic nature of the flow in the confiner allows stress waves to travel ahead of the main detonation front and influence the upstream HE state. The interaction between the detonation wave and the confiner is also no longer a local interaction, so that the confiner thickness now plays a significant role in the detonation dynamics. We report here on larger scale experiments in which a mixture of ammonium nitrate and fuel oil (ANFO) is detonated in aluminium confiners with varying charge diameter and confiner thickness. The results of these large-scale experiments are compared with previous large-scale ANFO experiments in cardboard, as well as smaller-scale aluminium confined ANFO experiments, to characterize the effects of confiner thickness.

  2. Ultra-high-speed optical and electronic distributed devices

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.


    This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

  3. High-speed ultrafast laser machining with tertiary beam positioning (Conference Presentation) (United States)

    Yang, Chuan; Zhang, Haibin


    For an industrial laser application, high process throughput and low average cost of ownership are critical to commercial success. Benefiting from high peak power, nonlinear absorption and small-achievable spot size, ultrafast lasers offer advantages of minimal heat affected zone, great taper and sidewall quality, and small via capability that exceeds the limits of their predecessors in via drilling for electronic packaging. In the past decade, ultrafast lasers have both grown in power and reduced in cost. For example, recently, disk and fiber technology have both shown stable operation in the 50W to 200W range, mostly at high repetition rate (beyond 500 kHz) that helps avoid detrimental nonlinear effects. However, to effectively and efficiently scale the throughput with the fast-growing power capability of the ultrafast lasers while keeping the beneficial laser-material interactions is very challenging, mainly because of the bottleneck imposed by the inertia-related acceleration limit and servo gain bandwidth when only stages and galvanometers are being used. On the other side, inertia-free scanning solutions like acoustic optics and electronic optical deflectors have small scan field, and therefore not suitable for large-panel processing. Our recent system developments combine stages, galvanometers, and AODs into a coordinated tertiary architecture for high bandwidth and meanwhile large field beam positioning. Synchronized three-level movements allow extremely fast local speed and continuous motion over the whole stage travel range. We present the via drilling results from such ultrafast system with up to 3MHz pulse to pulse random access, enabling high quality low cost ultrafast machining with emerging high average power laser sources.

  4. Recent Advances in Ultra-High-Speed Optical Signal Processing

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Palushani, Evarist; Hu, Hao


    We review recent advances in the optical signal processing of ultra-high-speed serial data signals up to 1.28 Tbit/s, with focus on applications of time-domain optical Fourier transformation. Experimental methods for the generation of symbol rates up to 1.28 Tbaud are also described....

  5. A high-speed interconnect network using ternary logic

    DEFF Research Database (Denmark)

    Madsen, Jens Kargaard; Long, S. I.


    This paper describes the design and implementation of a high-speed interconnect network (ICN) for a multiprocessor system using ternary logic. By using ternary logic and a fast point-to-point communication technique called STARI (Self-Timed At Receiver's Input), the communication between...

  6. High Speed Rail (HSR) in the United States (United States)


    Magnetic Levitation (Maglev) ...............................................................................................5 High Speed Rail In...conventional steel wheel on steel rail technology, or magnetic levitation (in which superconducting magnets levitate a train above a guide rail...transported.14 Magnetic Levitation (Maglev) Maglev train technology was developed in the United States in the 1960s. It uses electromagnets to suspend

  7. Visualization of Projectile Flying at High Speed in Dusty Atmosphere (United States)

    Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro


    Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.

  8. Time-interleaved high-speed D/A converters

    NARCIS (Netherlands)

    Olieman, E.


    This thesis is on power efficient very high-speed digital-to-analog converters (DACs) in CMOS technology, intended to generate signals from DC to RF. Components in RF signal chains are nowadays often moved from the analog domain to the digital domain. This allows for more flexibility and better

  9. Bottom Raking Damage to High-Speed Craft

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup


    This paper presents a comparative study of the raking damage to high speed craft (HSC) and conventional ships. The analysis is based on a detailed theoretical model for the raking resistance of an assembled ship bottom structure and on the idea that the impact conditions for various ship types have...

  10. Research notes : high-speed rail survey results. (United States)


    The survey was conducted from April 2010 to June 2010 using both a print and a web version with identical questions. The print version of the survey was distributed at open house meetings on high-speed rail held in Eugene, Junction City, Albany, Sale...

  11. The impact of high speed rail on airport competition

    NARCIS (Netherlands)

    Terpstra, I.; Lijesen, M.G.


    We study the effects of introducing a high speed train connection on competition between airports, focusing on the new HST-link between Amsterdam and Brussels. We conduct a detailed analysis regarding the airport choice of passengers living in the Netherlands, Belgium, Luxembourg, Northern France

  12. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

    Ghani, Arfan; Usmani, S. H.; Stassen, Flemming


    Static CMOS design displays benefits such as low power consumption, dominated by dynamic power consumption. In contrast, MOS Current Mode Logic (MCML) displays static rather than dynamic power consumption. High-speed low-power design is one of the many application areas in VLSI that require...

  13. High-speed photodiodes in standard CMOS technology

    NARCIS (Netherlands)

    Radovanovic, S.


    This thesis describes high-speed photodiodes in standard CMOS technology which allow monolithic integration of optical receivers for short-haul communication. The electronics for (multiple users) long-haul communication is very expensive (InP, GaAs), but the usage is justified by the large number of

  14. Optimization and performance of a high-speed plasma position ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 62; Issue 1. Optimization and performance of a high-speed plasma position digital control system. M Emami A R Babazadeh H Rasouli. Research Articles Volume 62 Issue 1 January 2004 pp 53-60 ...

  15. Faster than "g", Revisited with High-Speed Imaging (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter


    The introduction of modern high-speed cameras in physics teaching provides a tool not only for easy visualization, but also for quantitative analysis of many simple though fast occurring phenomena. As an example, we present a very well-known demonstration experiment--sometimes also discussed in the context of falling chimneys--which is commonly…

  16. High speed ultrafast laser surface processing (Conference Presentation) (United States)

    Mincuzzi, Girolamo; Kling, Rainer; Lopez, John; Hoenninger, Clemens; Audouard, Eric; Mottay, Eric P.


    Surface functionalization is a rapidly growing application for industrial ultrafast lasers. There is an increasing interest for high throughput surface processing, especially for texturing and engraving large manufacturing tools for different industrial fields such as injection molding, embossing and printing. Hydrophobic and hydrophilic surfaces, colored or deep black metal surfaces can now be industrially produced. The engraving speed is continuously improving following improvements in beam scanning technology and high average power industrial ultrafast lasers. Several tenths of MHz for the laser repetition rate and several hundreds of meter per second for the beam speed are available. More than 100 m/s scanning speed is then possible for laser surface structuring. But these surfaces are quite hard to produce since it is necessary to have a good compromise between high removal rate and high surface quality (low roughness, burr-free, narrow heat affected zone). In this work, we apply a simple engineering model based on the two temperature description of ultra-fast ablation to estimate key processing parameters. In particular, the pulse-to-pulse overlap which depends on the scanning velocity, the spot size, and the laser repetition rate all have to be adjusted to optimize the depth and roughness, otherwise heat accumulation and heat affected zone may appear. Optimal sequences of time and spatial superposition of pulses are determined and applied with a polygonal scanner. Ablation depth and processing speed obtained are compared with experimental results.

  17. Optimization and performance of a high-speed plasma position ...

    Indian Academy of Sciences (India)

    a time domain of the order of few milliseconds. In order to achieve maximum performance it is essential to optimize the control system. In this paper plasma position measurement and the details of implementing high-speed PID controllers based on a TMS320c25 digital signal processor along with the system optimization ...

  18. Parallel and distributed processing in high speed traffic monitoring

    NARCIS (Netherlands)

    Cristea, Mihai Lucian


    This thesis presents a parallel and distributed approach for the purpose of processing network traffic at high speeds. The proposed architecture provides the processing power required to run one or more traffic processing applications at line rates by means of processing full packets at

  19. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    All these facts are the outcome of research on optical solitons in fibers in spite of the fact that the commonly used RZ format is not always called a soliton format. The overview presented here attempts to incorporate the role of soliton-based communications research in present day ultra-high speed communications.

  20. A High-Speed Train Operation Plan Inspection Simulation Model

    Directory of Open Access Journals (Sweden)

    Yang Rui


    Full Text Available We developed a train operation simulation tool to inspect a train operation plan. In applying an improved Petri Net, the train was regarded as a token, and the line and station were regarded as places, respectively, in accordance with the high-speed train operation characteristics and network function. Location change and running information transfer of the high-speed train were realized by customizing a variety of transitions. The model was built based on the concept of component combination, considering the random disturbance in the process of train running. The simulation framework can be generated quickly and the system operation can be completed according to the different test requirements and the required network data. We tested the simulation tool when used for the real-world Wuhan to Guangzhou high-speed line. The results showed that the proposed model can be developed, the simulation results basically coincide with the objective reality, and it can not only test the feasibility of the high-speed train operation plan, but also be used as a support model to develop the simulation platform with more capabilities.

  1. High-speed cinematography of compressible mixing layers (United States)

    Mahadevan, R.; Loth, Eric


    Experiments are performed using high-speed film cinematography to temporally resolve compressible planar mixing layer structures using shadowgraphs and planar light sheet visualization. The technique is relatively inexpensive and allows multiple images. The time-dependent shadowgraph and Mie scattering images are documented with a rotating mirror camera operating at approximately 350 kHz. The results show the presence of large scale structures in the mixing layer which flatten as they convect downstream. Both spatial and temporal covariances have been obtained through digital image processing which yield, on average, elliptical structures with convective speeds above the isentropic prediction, and non-isotropic streamwise and transverse scalar transport fluctuations.

  2. Investigations in high speed blanking: cutting forces and microscopic observations

    Directory of Open Access Journals (Sweden)

    Larue A.


    Full Text Available A new hopefull technique, called high speed blanking, has been investigated since few years. To understand the cutting process and how the tools have to be designed, this study is interrested in the cutting force measurement. A new cutting force measurement device has to be designed consider the industrial interest of such a study. The designed test bench induces a calibration process in order to stucy the cutting forces evolution. The paper is discussing the result that the peack load seems to decrease when the punch speed increases. Finally microscopic observations are made in order to find Adiabatic Shear Bands.

  3. Speed Acquisition Methods for High-Bandwidth Servo Drives


    Bähr, Alexander


    A servo control needs the actual values of speed and position.Usually, the latter is computed from the signals of a position encoder; its 1st derivative is smoothed by a low-pass filter and used as actual speed signal. A number of enhanced and alternative methods is experimentally investigated in this thesis. Based on an equal steady-state behavior, the controlled servo's dynamic stiffness is used as the performance measure. The used setup has a special feature: because of its rather high res...

  4. Quiet High Speed Fan II (QHSF II): Final Report (United States)

    Kontos, Karen; Weir, Don; Ross, Dave


    This report details the aerodynamic, mechanical, structural design and fabrication of a Honey Engines Quiet High Speed Fan II (lower hub/tip ratio and higher specific flow than the Baseline I fan). This fan/nacelle system incorporates features such as advanced forward sweep and an advanced integrated fan/fan exit guide vane design that provides for the following characteristics: (1) Reduced noise at supersonic tip speeds, in comparison to current state-of-the-art fan technology; (2) Improved aeroelastic stability within the anticipated operating envelope; and (3) Aerodynamic performance consistent with current state-of-the-art fan technology. This fan was fabricated by Honeywell and tested in the NASA Glenn 9- by 15-Ft Low Speed Wind Tunnel for aerodynamic, aeromechanical, and acoustic performance.

  5. Imaging acoustic sources moving at high-speed (United States)

    Bodony, Daniel; Papanicolaou, George


    In the quantification of the noise radiated by a turbulent flow the source motion is important. It is well known that moving acoustic sources radiate sound preferrentially in the direction of motion in a phenomenon termed `convective amplification.' Modern acoustic theories have utilized this behavior in their predictions. In the inverse problem the imaging of noise sources, by techniques such as beam forming, the source motion is not explicitly taken into account. In this talk we consider the imaging of acoustic sources moving at speeds on the order of the the ambient speed of sound, as typical of high-speed jets, for which the D"oppler shift approximation is not appropriate. An analysis will be presented that can be used to estimate the source motion based on the radiated acoustic field.

  6. Modeling Compressibility Effects in High-Speed Turbulent Flows (United States)

    Sarkar, S.


    Man has strived to make objects fly faster, first from subsonic to supersonic and then to hypersonic speeds. Spacecraft and high-speed missiles routinely fly at hypersonic Mach numbers, M greater than 5. In defense applications, aircraft reach hypersonic speeds at high altitude and so may civilian aircraft in the future. Hypersonic flight, while presenting opportunities, has formidable challenges that have spurred vigorous research and development, mainly by NASA and the Air Force in the USA. Although NASP, the premier hypersonic concept of the eighties and early nineties, did not lead to flight demonstration, much basic research and technology development was possible. There is renewed interest in supersonic and hypersonic flight with the HyTech program of the Air Force and the Hyper-X program at NASA being examples of current thrusts in the field. At high-subsonic to supersonic speeds, fluid compressibility becomes increasingly important in the turbulent boundary layers and shear layers associated with the flow around aerospace vehicles. Changes in thermodynamic variables: density, temperature and pressure, interact strongly with the underlying vortical, turbulent flow. The ensuing changes to the flow may be qualitative such as shocks which have no incompressible counterpart, or quantitative such as the reduction of skin friction with Mach number, large heat transfer rates due to viscous heating, and the dramatic reduction of fuel/oxidant mixing at high convective Mach number. The peculiarities of compressible turbulence, so-called compressibility effects, have been reviewed by Fernholz and Finley. Predictions of aerodynamic performance in high-speed applications require accurate computational modeling of these "compressibility effects" on turbulence. During the course of the project we have made fundamental advances in modeling the pressure-strain correlation and developed a code to evaluate alternate turbulence models in the compressible shear layer.

  7. Sound transmission loss of windows on high speed trains (United States)

    Zhang, Yumei; Xiao, Xinbiao; Thompson, David; Squicciarini, Giacomo; Wen, Zefeng; Li, Zhihui; Wu, Yue


    The window is one of the main components of the high speed train car body structure through which noise can be transmitted. To study the windows’ acoustic properties, the vibration of one window of a high speed train has been measured for a running speed of 250 km/h. The corresponding interior noise and the noise in the wheel-rail area have been measured simultaneously. The experimental results show that the window vibration velocity has a similar spectral shape to the interior noise. Interior noise source identification further indicates that the window makes a contribution to the interior noise. Improvement of the window's Sound Transmission Loss (STL) can reduce the interior noise from this transmission path. An STL model of the window is built based on wave propagation and modal superposition methods. From the theoretical results, the window's STL property is studied and several factors affecting it are investigated, which provide indications for future low noise design of high speed train windows.

  8. Spectral domain optical coherence tomography - Ultra-high speed, ultra-high resolution ophthalmic imaging

    NARCIS (Netherlands)

    Chen, T.; Cense, B.; Pierce, M. C.; Nassif, N. A.; Park, B. H.; Yun, S. H.; White, B.; Bouma, B. E.; Tearney, G. J.; de Boer, J.F.


    Objective: To introduce a new ophthalmic optical coherence tomography technology that allows unprecedented simultaneous ultra-high speed and ultra-high resolution. Methods: Using a superluminescent diode source, a clinically viable ultra-high speed, ultra-high resolution spectral domain optical

  9. High speed tracking control of ball screw drives (United States)

    Liu, Chao-Yi; Huang, Ruei-Yu; Lee, An-Chen


    This paper presents a new method to achieve the requirement of high speed and high precision for ball screw drive. First, a PI controller is adopted to increase the equivalent structural damping in the velocity loop. Next, the design of the position controller is implemented by a two-stage method. The Doubly Coprime Factorization Disturbance Observer (DCFDOB) is developed to suppress disturbance and resist modelling error in the inner loop, while the outer loop is then designed based on method to extend the system bandwidth over first resonant frequency so that high speed and high accuracy can be achieved. Finally, a feedforward controller is implemented to improve tracking performance. The experiment results showed that the proposed method has smaller tracking error and better performance for suppressing disturbance when compared to the conventional cascaded P-PI control.

  10. Ping-Pong Robotics with High-Speed Vision System

    DEFF Research Database (Denmark)

    Li, Hailing; Wu, Haiyan; Lou, Lei


    The performance of vision-based control is usually limited by the low sampling rate of the visual feedback. We address Ping-Pong robotics as a widely studied example which requires high-speed vision for highly dynamic motion control. In order to detect a flying ball accurately and robustly......, a multithreshold legmentation algorithm is applied in a stereo-vision running at 150Hz. Based on the estimated 3D ball positions, a novel two-phase trajectory prediction is exploited to determine the hitting position. Benefiting from the high-speed visual feedback, the hitting position and thus the motion planning...... of the manipulator are updated iteratively with decreasing error. Experiments are conducted on a 7 degrees of freedom humanoid robot arm. A successful Ping-Pong playing between the robot arm and human is achieved with a high successful rate of 88%....

  11. Development of Industrial High-Speed Transfer Parallel Robot

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung In; Kyung, Jin Ho; Do, Hyun Min; Jo, Sang Hyun [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)


    Parallel robots used in industry require high stiffness or high speed because of their structural characteristics. Nowadays, the importance of rapid transportation has increased in the distribution industry. In this light, an industrial parallel robot has been developed for high-speed transfer. The developed parallel robot can handle a maximum payload of 3 kg. For a payload of 0.1 kg, the trajectory cycle time is 0.3 s (come and go), and the maximum velocity is 4.5 m/s (pick amp, place work, adept cycle). In this motion, its maximum acceleration is very high and reaches approximately 13g. In this paper, the design, analysis, and performance test results of the developed parallel robot system are introduced.

  12. Assessment of potential aerodynamic effects on personnel and equipment in proximity to high-speed train operations : safety of high-speed ground transportation systems (United States)


    Amtrak is planning to provide high-speed passenger train service at speeds significantly higher than their current top speed of 125 mph, and with these higher speeds, there are concerns with safety from the aerodynamic effects created by a passing tr...

  13. Complement activation capacity in plasma before and during high-dose prednisolone treatment and tapering in exacerbations of Crohn's disease and ulcerative colitis

    Directory of Open Access Journals (Sweden)

    Baatrup Gunnar


    Full Text Available Abstract Background Ulcerative colitis (UC and Crohn's disease (CD are characterized by intestinal inflammation mainly caused by a disturbance in the balance between cytokines and increased complement (C activation. Our aim was to evaluate possible associations between C activation capacity and prednisolone treatment. Methods Plasma from patients with exacerbations of UC (n = 18 or CD (n = 18 were collected before and during high dose prednisolone treatment (1 mg/kg body weight and tapering. Friedman's two way analysis of variance, Mann-Whitney U test and Wilcoxon signed-rank sum test were used Results Before treatment, plasma from CD patients showed significant elevations in all C-mediated analyses compared to the values obtained from 38 healthy controls (p Conclusion Our findings indicate that C activation capacity is up-regulated significantly in plasma from CD patients. The decreases observed after prednisolone treatment reflect a general down-regulation in immune activation.

  14. High-speed gears for gas turbine drive

    Energy Technology Data Exchange (ETDEWEB)

    Kane, J.


    Recently, Lufkin Industries, Power Transmission Div., full-load tested a high-speed gear designed to couple a 50 Hz electric power generator to a GE LM6000 gas turbine for a power generation project in Australia. The gear is rated 52.2 MW to match the output of the LM6000 gas turbine believed to be one of the largest gear testing operations for this type and size of gear. Each gear drive manufactured by Lufkin is full-speed tested to verify its performance. Tests performed on high-speed units duplicate field conditions, as closely as possible, in order to verify critical speed analysis results and new bearing designs, if used. Lufkin also tests design techniques used in the development of new products. The finite element analysis performed to predict housing deflection in the thrust bearing area of a new extruder driveline was verified by testing of a prototype unit housing. Recently, housing structure stiffness and natural frequencies were predicted and verified on the test stand for some 50 MW vertically offset gear units. A complete data acquisition system is used to gather data from bearing, inlet and drain temperature monitoring points. The temperature monitoring system will accommodate type T,K,J, and E thermocouples and platinum and nickel RTDs.

  15. High Speed Genetic Lips Detection by Dynamic Search Domain Control (United States)

    Akashi, Takuya; Wakasa, Yuji; Tanaka, Kanya; Karungaru, Stephen; Fukumi, Minoru

    In this paper, high-speed size and orientation invariant lips detection of a talking person in an active scene using template matching and genetic algorithms is proposed. As part of the objectives, we also try to acquire numerical parameters to represent the lips. The information is very important for many applications, where high performance is required, such as audio-visual speech recognition, speaker identification systems, robot perception and personal mobile devices interfaces. The difficulty in lips detection is mainly due to deformations and geometric changes of the lips during speech and the active scene by free camera motion. In order to enhance the performance in speed and accuracy, initially, the performance is improved on a single still image, that is, the base of video processing. Our proposed system is based on template matching using genetic algorithms (GA). Only one template is prepared per experiment. The template is the closed mouth of a subject, because the application is for personal devices. In our previous study, the main problem was trade-off between search accuracy and search speed. To overcome this problem, we use two methods: scaling window and dynamic search domain control (SD-Control). We therefore focus on the population size of the GA, because it has a direct effect on search accuracy and speed. The effectiveness of the proposed system is demonstrated by performing computer simulations. We achieved a lips detection accuracy of 91.33% at an average processing time of 33.70 milliseconds per frame.

  16. Difference in muscle activation patterns during high-speed versus standard-speed yoga: A randomized sequence crossover study. (United States)

    Potiaumpai, Melanie; Martins, Maria Carolina Massoni; Wong, Claudia; Desai, Trusha; Rodriguez, Roberto; Mooney, Kiersten; Signorile, Joseph F


    To compare the difference in muscle activation between high-speed yoga and standard-speed yoga and to compare muscle activation of the transitions between poses and the held phases of a yoga pose. Randomized sequence crossover trial SETTING: A laboratory of neuromuscular research and active aging Interventions: Eight minutes of continuous Sun Salutation B was performed, at a high speed versus a standard-speed, separately. Electromyography was used to quantify normalized muscle activation patterns of eight upper and lower body muscles (pectoralis major, medial deltoids, lateral head of the triceps, middle fibers of the trapezius, vastus medialis, medial gastrocnemius, thoracic extensor spinae, and external obliques) during the high-speed and standard-speed yoga protocols. Difference in normalized muscle activation between high-speed yoga and standard-speed yoga. Normalized muscle activity signals were significantly higher in all eight muscles during the transition phases of poses compared to the held phases (pyoga across the entire session. Our results show that transitions from one held phase of a pose to another produces higher normalized muscle activity than the held phases of the poses and that overall activity is greater during highspeed yoga than standard-speed yoga. Therefore, the transition speed and associated number of poses should be considered when targeting specific improvements in performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Performance analysis of WAVE communication under high-speed driving

    Directory of Open Access Journals (Sweden)

    Bo-young Kang


    Full Text Available Although WAVE (Wireless Access in Vehicular Environments is a technology designed for the high-speed mobile environments, WAVE communication performance in a real road environment is highly dependent on the surrounding environments such as moving vehicles, road shape, and topography. In particular, when a vehicle moves at high speed, the location of the vehicle and its proximity to the road-side device are rapidly changed and thus affect communication performance. Accordingly, we build a performance evaluation system based on the WAVE-LTE network cooperative operation. We also analyzed the performance differences based on external environmental factors, such as information volume and velocity, from the data acquired through actual vehicle tests.

  18. High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips. (United States)

    Vyas, Nina; Pecheva, Emilia; Dehghani, Hamid; Sammons, Rachel L; Wang, Qianxi X; Leppinen, David M; Walmsley, A Damien


    Cavitation occurs around dental ultrasonic scalers, which are used clinically for removing dental biofilm and calculus. However it is not known if this contributes to the cleaning process. Characterisation of the cavitation around ultrasonic scalers will assist in assessing its contribution and in developing new clinical devices for removing biofilm with cavitation. The aim is to use high speed camera imaging to quantify cavitation patterns around an ultrasonic scaler. A Satelec ultrasonic scaler operating at 29 kHz with three different shaped tips has been studied at medium and high operating power using high speed imaging at 15,000, 90,000 and 250,000 frames per second. The tip displacement has been recorded using scanning laser vibrometry. Cavitation occurs at the free end of the tip and increases with power while the area and width of the cavitation cloud varies for different shaped tips. The cavitation starts at the antinodes, with little or no cavitation at the node. High speed image sequences combined with scanning laser vibrometry show individual microbubbles imploding and bubble clouds lifting and moving away from the ultrasonic scaler tip, with larger tip displacement causing more cavitation.

  19. Quantification of the uncertainties of high-speed camera measurements

    Directory of Open Access Journals (Sweden)

    Robbe C.


    Full Text Available This article proposes a combined theoretical and experimental approach to assess and quantify the global uncertainty of a high-speed camera velocity measurement. The study is divided in five sections: firstly, different sources of measurement uncertainties performed by a high-speed camera are identified and quantified. They consist of geometrical uncertainties, pixel discretisation uncertainties or optical uncertainties. Secondly, a global uncertainty factor, taking into account the previously identified sources of uncertainties, is computed. Thirdly, a sensibility study of the camera set-up parameters is performed, allowing the experimenter to optimize these parameters in order to minimize the final uncertainties. Fourthly, the theoretical computed uncertainty is compared with experimental measurements. Good concordance has been found. Finally, the velocity measurement uncertainty study is extended to continuous displacement measurements as a function of time. The purpose of this article is to propose all the mathematical tools necessary to quantify the individual and global uncertainties, to highlight the important aspects of the experimental set-up, and to give recommendations on how to improve a specific set-up in order to minimize the global uncertainty. Taking all these into account, it has been shown that highly dynamic phenomena such as a ballistic phenomenon can be measured using a high-speed camera with a global uncertainty of less than 2%.

  20. 36 CFR 1192.175 - High-speed rail cars, monorails and systems. (United States)


    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false High-speed rail cars... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to those using “maglev” or high speed...

  1. High-speed measurement of firearm primer blast waves

    CERN Document Server

    Courtney, Michael; Eng, Jonathan; Courtney, Amy


    This article describes a method and results for direct high-speed measurements of firearm primer blast waves employing a high-speed pressure transducer located at the muzzle to record the blast pressure wave produced by primer ignition. Key findings are: 1) Most of the lead styphnate based primer models tested show 5.2-11.3% standard deviation in the magnitudes of their peak pressure. 2) In contrast, lead-free diazodinitrophenol (DDNP) based primers had standard deviations of the peak blast pressure of 8.2-25.0%. 3) Combined with smaller blast waves, these large variations in peak blast pressure of DDNP-based primers led to delayed ignition and failure to fire in brief field tests.

  2. Characterizing pyrotechnic igniter output with high-speed schlieren imaging (United States)

    Skaggs, M. N.; Hargather, M. J.; Cooper, M. A.


    Small-scale pyrotechnic igniter output has been characterized using a high-speed schlieren imaging system for observing critical features of the post-combustion flow. The diagnostic, with laser illumination, was successfully applied towards the quantitative characterization of the output from Ti/KClO_4 and TiH_{1.65}/KClO_4 pyrotechnic igniters. The high-speed image sequences showed shock motion, burned gas expansion, and particle motion. A statistical-based analysis methodology for tracking the full-field shock motion enabled straightforward comparisons across the experimental parameters of pyrotechnic material and initial density. This characterization of the mechanical energy of the shock front within the post-combustion environment is a necessary addition to the large body of literature focused on pyrotechnic combustion behavior within the powder bed. Ultimately, understanding the role that the combustion behavior has on the resulting multiphase environment is required for tailored igniter development and comparative performance assessments.

  3. High-speed imaging polarimetry using liquid crystal modulators

    Directory of Open Access Journals (Sweden)

    Ambs P.


    Full Text Available This paper deals with dynamic polarimetric imaging techniques. The basics of modern polarimetry have been known for one and a half century, but no practical high-speed implementation providing the full polarization information is currently available. Various methods are reviewed which prove to be a trade-off between the complexity of the optical set-up and the amount of polarimetric information they provide (ie the number of components of the Stokes vector. Techniques using liquid crystal devices, incepted in the late 1990's, are emphasized. Optical set-ups we implemented are presented. We particularly focus on high-speed techniques (i.e. faster than 200 Hz using ferroelectric liquid crystal devices.

  4. Clinical application of high speed B mode echocardiography. (United States)

    Kambe, T; Nishimura, K; Hibi, N; Sakakibara, T; Kato, T


    This study discusses the clinical application of high speed B mode echocardiography to a wide variety of heart diseases. We used a rapid mechanical sector scan at 30 frames per second and 120 scanning lines per frame, resulting in real time observation of cardiac structures. The sector angle was relatively wide (maximum 90 degrees). The tomograms were synchronized with the electrocardiogram and recorded on ordinary 35 mm or Polaroid film in conjunction with 8 mm cinematography. Heart cross sections could be recorded even in the presence of arrhythmia. We used a flat or focused, 10 mm diameter transducer made of lead zirconate-titanate with a resonant frequency of 2 or 3 MHz at a repetition rate of 3.6 kHz. High speed B mode echocardiography is a means of observing cross sections of the heart that can contribute to the improvement of accuracy in cardiac diagnosis.

  5. HIPO: a high-speed imaging photometer for occultations (United States)

    Dunham, Edward W.; Elliot, James L.; Bida, Thomas A.; Taylor, Brian W.


    HIPO is a special purpose instrument for SOFIA, the Stratospheric Observatory For Infrared Astronomy. It is a high-speed, imaging photometer that will be used for a variety of time-resolved precise photometry observations, including stellar occultations by solar system objects and transits by extrasolar planets. HIPO has two independent CCD detectors and can also co-mount with FLITECAM, an InSb imager and spectrometer, making simultaneous photometry at three wavelengths possible. HIPO's flexible design and high-speed imaging capability make it well suited to carry out initial test observations on the completed SOFIA system, and to this end a number of additional features have been incorporated. Earlier papers have discussed the design requirements and optical design of HIPO. This paper provides an overview of the instrument, describes the instrument's features, and reviews the actual performance, in most areas, of the completed instrument.

  6. Embedded function methods for compressible high speed turbulent flow (United States)

    Walker, J. D. A.


    This is the final report on the work performed on the grant 'Embedded Function Methods for Compressible High Speed Turbulent Flow' carried out at Lehigh University during the contract period from September, 1987, to October of 1991. Work has continued at Lehigh on this project on an unfunded basis to the present. The original proposed work had two separate thrusts which were associated with developing embedded function methods in order to obviate the need to expend computational resources on turbulent wall layers in Navier Stokes and boundary-layer calculations. Previous work on the incompressible problem had indicated that this could be done successfully for two-dimensional and three-dimensional incompressible flows. The central objective here was to extend the basic approach to the high speed compressible problem.

  7. High-Speed Coherent Raman Fingerprint Imaging of Biological Tissues

    CERN Document Server

    Camp, Charles H; Heddleston, John M; Hartshorn, Christopher M; Walker, Angela R Hight; Rich, Jeremy N; Lathia, Justin D; Cicerone, Marcus T


    We have developed a coherent Raman imaging platform using broadband coherent anti-Stokes Raman scattering (BCARS) that provides an unprecedented combination of speed, sensitivity, and spectral breadth. The system utilizes a unique configuration of laser sources that probes the Raman spectrum over 3,000 cm$^{-1}$ and generates an especially strong response in the typically weak Raman "fingerprint" region through heterodyne amplification of the anti-Stokes photons with a large nonresonant background (NRB) while maintaining high spectral resolution of $<$ 13 cm$^{-1}$. For histology and pathology, this system shows promise in highlighting major tissue components in a non-destructive, label-free manner. We demonstrate high-speed chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues and interfaces between xenograft brain tumors and the surrounding healthy brain matter.

  8. Comparison of high-speed rail and maglev systems

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, F.T. [Univ. of Florida, Gainesville, FL (United States). Dept. of Civil Engineering; Nassar, F.E. [Keith and Schnars, Fort Lauderdale, FL (United States)


    European and Japanese high-speed rail (HSR) and magnetically levitated (maglev) systems were each developed to respond to specific transportation needs within local economic, social, and political constraints. Not only is maglev technology substantially different from that of HSR, but also HSR and maglev systems differ in trainset design, track characteristics, cost structure, and cost sensitivity to design changes. This paper attempts to go beyond the traditional technology comparison table and focuses on the characteristics and conditions for which existing European and Japanese systems were developed. The technologies considered are the French train a grand vitesse (TGV), the Swedish X2000, the German Intercity Express (ICE) and Transrapid, and the Japanese Shinkansen, MLU, and high-speed surface train (HSST).

  9. Optical communication equalized technique suitable for high-speed transmission (United States)

    Zhu, Yaolin; Guan, Hao


    To solve the phase distortion and high error rate in optical signal transmission, an equalized technique is proposed, which aims to improve the constant modulus algorithm (CMA). In order to correct phase rotating and reduce the error rate with 64 quadrature amplitude modulation (QAM), the method takes the mean square error as the judgment and utilizes the time-varying step size. Simulation results demonstrate that the proposed algorithm can improve the convergence speed of constellation points, make the eye opening larger, and the signal noise ratio (SNR) can be increased by 4 dB under the same bit error rate (BER), which is efficient for the recovery of information in high-speed transmission.

  10. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi


    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  11. High-speed FPGA-based phase measuring profilometry architecture. (United States)

    Zhan, Guomin; Tang, Hongwei; Zhong, Kai; Li, Zhongwei; Shi, Yusheng; Wang, Congjun


    This paper proposes a high-speed FPGA architecture for the phase measuring profilometry (PMP) algorithm. The whole PMP algorithm is designed and implemented based on the principle of full-pipeline and parallelism. The results show that the accuracy of the FPGA system is comparable with those of current top-performing software implementations. The FPGA system achieves 3D sharp reconstruction using 12 phase-shifting images and completes in 21 ms with 1024 × 768 pixel resolution. To the best of our knowledge, this is the first fully pipelined architecture for PMP systems, and this makes the PMP system very suitable for high-speed embedded 3D shape measurement applications.

  12. High-speed cell sorting: fundamentals and recent advances. (United States)

    Ibrahim, Sherrif F; van den Engh, Ger


    Cell sorters have undergone dramatic technological improvements in recent years. Driven by the increased ability to differentiate between cell types, modern advances have yielded a new generation of cytometers, known as high-speed cell sorters. These instruments are capable of higher throughput than traditional sorters and can distinguish subtler differences between particles by measuring and processing more optical parameters in parallel. These advances have expanded their use to facilitate genomic and proteomic discovery, and as vehicles for many emerging cell-based therapies. High-speed cell sorting is becoming established as an essential research tool across a broad range of scientific fields and is poised to play a pivotal role in the latest therapeutic modalities.

  13. Numerical Investigation of Aerodynamic Characteristics of High Speed Train (United States)

    Ali, J. S. Mohamed; Omar, Ashraf Ali; Ali, Muhammad ‘Atif B.; Baseair, Abdul Rahman Bin Mohd


    In this work, initially the effect of nose shape on the drag characteristics of a high speed train is studied. Then the influence of cross winds on the aerodynamics and hence the stability of such modern high speed trains is analyzed. CFD analysis was conducted using STAR-CCM+ on trains with different features and important aerodynamic coefficients such as the drag, side force and rolling moment coefficients have been calculated for yaw angles of crosswinds ranging from 0° to 90°. The results show that the modification on train nose shape can reduce the drag up to more than 50%. It was also found that, bogie faring only reduces small percentage of drag but significantly contributed to higher rolling moment and side force coefficient hence induced train instability.

  14. Robust adaptive cruise control of high speed trains. (United States)

    Faieghi, Mohammadreza; Jalali, Aliakbar; Mashhadi, Seyed Kamal-e-ddin Mousavi


    The cruise control problem of high speed trains in the presence of unknown parameters and external disturbances is considered. In particular a Lyapunov-based robust adaptive controller is presented to achieve asymptotic tracking and disturbance rejection. The system under consideration is nonlinear, MIMO and non-minimum phase. To deal with the limitations arising from the unstable zero-dynamics we do an output redefinition such that the zero-dynamics with respect to new outputs becomes stable. Rigorous stability analyses are presented which establish the boundedness of all the internal states and simultaneously asymptotic stability of the tracking error dynamics. The results are presented for two common configurations of high speed trains, i.e. the DD and PPD designs, based on the multi-body model and are verified by several numerical simulations. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  15. High speed turning of compacted graphite iron using controlled modulation (United States)

    Stalbaum, Tyler Paul

    Compacted graphite iron (CGI) is a material which emerged as a candidate material to replace cast iron (CI) in the automotive industry for engine block castings. Its thermal and mechanical properties allow the CGI-based engines to operate at higher cylinder pressures and temperatures than CI-based engines, allowing for lower fuel emissions and increased fuel economy. However, these same properties together with the thermomechanical wear mode in the CGI-CBN system result in poor machinability and inhibit CGI from seeing wide spread use in the automotive industry. In industry, machining of CGI is done only at low speeds, less than V = 200 m/min, to avoid encountering rapid wear of the cutting tools during cutting. Studies have suggested intermittent cutting operations such as milling suffer less severe tool wear than continuous cutting. Furthermore, evidence that a hard sulfide layer which forms over the cutting edge in machining CI at high speeds is absent during machining CGI is a major factor in the difference in machinability of these material systems. The present study addresses both of these issues by modification to the conventional machining process to allow intermittent continuous cutting. The application of controlled modulation superimposed onto the cutting process -- modulation-assisted machining (MAM) -- is shown to be quite effective in reducing the wear of cubic boron nitride (CBN) tools when machining CGI at high machining speeds (> 500 m/min). The tool life is at least 20 times greater than found in conventional machining of CGI. This significant reduction in wear is a consequence of reduction in the severity of the tool-work contact conditions with MAM. The propensity for thermochemical wear of CBN is thus reduced. It is found that higher cutting speed (> 700 m/min) leads to lower tool wear with MAM. The MAM configuration employing feed-direction modulation appears feasible for implementation at high speeds and offers a solution to this challenging

  16. Analysis and design technology for high-speed aircraft structures (United States)

    Starnes, James H., Jr.; Camarda, Charles J.


    Recent high-speed aircraft structures research activities at NASA Langley Research Center are described. The following topics are covered: the development of analytical and numerical solutions to global and local thermal and structural problems, experimental verification of analysis methods, identification of failure mechanisms, and the incorporation of analysis methods into design and optimization strategies. The paper describes recent NASA Langley advances in analysis and design methods, structural and thermal concepts, and test methods.

  17. Ocular Imaging Combining Ultrahigh Resolution and High Speed OCT (United States)

    Schmoll, Tilman; Leitgeb, Rainer A.

    The impact of ultrahigh-resolution and ultrahigh-speed OCT technique on corneal and retinal imaging is shown. The capabilities of advanced OCT system for imaging of the cornea and the thickness determination of the tear film, corneal epithelium, and Bowman's layer over a wide field of view are demonstrated. The high transverse and axial resolution of OCT system allowing one to image individual nerve fiber bundles, the parafoveal capillary network, and individual cone photoreceptors is described.

  18. High-speed deformation processing of a titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tamirisakandala, S.; Medeiros, S.C.; Malas, J.C. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433 (United States); Yellapregada, P.V.R.K. [Department of Metallurgy, Indian Institute of Science Bangalore, Karnataka 560 012 (India); Frazier, W.G. [NCPA Coliseum Drive, University, MS 38677 (United States); Dutta, B. [Department of Materials Science, Darmstadt University of Technology, Petersenstrasse 23, D-64287 Darmstadt (Germany)


    The deformation rate is the critical parameter for the phase transforming mechanism and subsequently the morphology of Ti-Al-V alloys, which in turn determines the feasibility of high-speed deformation. The evolution of defect-free equiaxed microstructures is due to dislocation-induced heterogeneous nucleation and growth. The Figure shows a microstructure of a Ti-6Al-4V specimen deformed at 1000 C in a backscattered SEM image. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  19. Design and specification of a high speed transport protocol


    McArthur, Robert C.


    Approved for public release; distribution is unlimited Due to the increase in data throughput potential provided by high speed (fiber optic) networks, existing transport protocols are becoming increasingly incapable of providing reli­able and timely transfer of data. Whereas in networks of the past it was the transmission medium that caused the greatest communications delay, it is the case today that the transport protocols themselves have become the bottleneck. This thesis provides de...

  20. High Speed White Dwarf Asteroseismology with the Herty Hall Cluster (United States)

    Gray, Aaron; Kim, A.


    Asteroseismology is the process of using observed oscillations of stars to infer their interior structure. In high speed asteroseismology, we complete that by quickly computing hundreds of thousands of models to match the observed period spectra. Each model on a single processor takes five to ten seconds to run. Therefore, we use a cluster of sixteen Dell Workstations with dual-core processors. The computers use the Ubuntu operating system and Apache Hadoop software to manage workloads.

  1. Study and improvement of a high speed hydraulic jack (United States)

    Garcia, M. S.; Nouillant, M.; Viot, P.


    This paper describes the control problem of a high speed hydraulic jack. We shall estimate the performances of a servo-control with a classic controlled correction of type PD (Proportional Derivate). The study will be performed from a model (servo valve + jack + load), whose simulation will be performed in the Matlab-SimulinK environment. The aim of this article is to characterize, by simulating, the interdependence between the experimental apparatus and the tested object.

  2. On the reversed Brayton cycle with high speed machinery

    Energy Technology Data Exchange (ETDEWEB)

    Backman, J.


    This work was carried out in the laboratory of Fluid Dynamics, at Lappeenranta University of Technology during the years 1991-1996. The research was a part of larger high speed technology development research. First, there was the idea of making high speed machinery applications with the Brayton cycle. There was a clear need to deepen the knowledge of the cycle itself and to make a new approach in the field of the research. Also, the removal of water from the humid air seemed very interesting. The goal of this work was to study methods of designing high speed machinery for the reversed Brayton cycle, from theoretical principles to practical applications. The reversed Brayton cycle can be employed as an air dryer, a heat pump or a refrigerating machine. In this research the use of humid air as a working fluid has an environmental advantage, as well. A new calculation method for the Brayton cycle is developed. In this method especially the expansion process in the turbine is important because of the condensation of the water vapour in the humid air. This physical phenomena can have significant effects on the level of performance of the application. Also, the influence of calculating the process with actual, achievable process equipment efficiencies is essential for the development of future machinery. The above theoretical calculations are confirmed with two different laboratory prototypes. (53 refs.)

  3. Double Helical Gear Performance Results in High Speed Gear Trains (United States)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles


    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  4. Direct Numerical Simulation of Disperse Multiphase High-Speed Flows

    Energy Technology Data Exchange (ETDEWEB)

    Nourgaliev, R R; Dinh, T N; Theofanous, T G; Koning, J M; Greenman, R M; Nakafuji, G T


    A recently introduced Level-Set-based Cartesian Grid (LSCG) Characteristics-Based Matching (CBM) method is applied for direct numerical simulation of shock-induced dispersal of solid material. The method incorporates the latest advancements in the level set technology and characteristics-based numerical methods for solution of hyperbolic conservation laws and boundary treatment. The LSCG/CBM provides unique capabilities to simulate complex fluid-solid (particulate) multiphase flows under high-speed flow conditions and taking into account particle-particle elastic and viscoelastic collisions. The particular emphasis of the present study is placed on importance of appropriate modeling of particle-particle collisions, which are demonstrated to crucially influence the global behavior of high-speed multiphase particulate flows. The results of computations reveal the richness and complexity of flow structures in compressible disperse systems, due to dynamic formation of shocks and contact discontinuities, which provide an additional long-range interaction mechanism in dispersed high-speed multiphase flows.

  5. Development of High-speed Machining Database with Case-based Reasoning

    Institute of Scientific and Technical Information of China (English)


    Applying high-speed machining technology in shop floor has many benefits, such as manufacturing more accurate parts with better surface finishes. The selection of the appropriate machining parameters plays a very important role in the implementation of high-speed machining technology. The case-based reasoning is used in the developing of high-speed machining database to overcome the shortage of available high-speed cutting parameters in machining data handbooks and shop floors. The high-speed machining data...

  6. Numerical analysis of dipole sound source around high speed trains. (United States)

    Takaishi, Takehisa; Sagawa, Akio; Nagakura, Kiyoshi; Maeda, Tatsuo


    As the maximum speed of high speed trains increases, the effect of aeroacoustic noise on the sound level on the ground becomes increasingly important. In this paper, the distribution of dipole sound sources at the bogie section of high speed trains is predicted numerically. The three-dimensional unsteady flow around a train is solved by the large eddy simulation technique. The time history of vortices shows that unstable shear layer separation at the leading edge of the bogie section sheds vortices periodically. These vortices travel downstream while growing to finally impinge upon the trailing edge of the section. The wavelength of sound produced by these vortices is large compared to the representative length of the bogie section, so that the source region can be regarded as acoustically compact. Thus a compact Green's function adapted to the shape can be used to determine the sound. By coupling the instantaneous flow properties with the compact Green's function, the distribution of dipole sources is obtained. The results reveal a strong dipole source at the trailing edge of the bogie section where the shape changes greatly and the variation of flow with time is also great. On the other hand, the bottom of the bogie section where the shape does not change, or the leading edge and boundary layer where the variation of flow with time is small, cannot generate a strong dipole source.

  7. Phoenix: Preliminary design of a high speed civil transport (United States)

    Aguilar, Joseph; Davis, Steven; Jett, Brian; Ringo, Leslie; Stob, John; Wood, Bill


    The goal of the Phoenix Design Project was to develop a second generation high speed civil transport (HSCT) that will meet the needs of the traveler and airline industry beginning in the 21st century. The primary emphasis of the HSCT is to take advantage of the growing needs of the Pacific Basin and the passengers who are involved in that growth. A passenger load of 150 persons, a mission range of 5150 nautical miles, and a cruise speed of Mach 2.5 constitutes the primary design points of this HSCT. The design concept is made possible with the use of a well designed double delta wing and four mixed flow engines. Passenger comfort, compatibility with existing airport infrastructure, and cost competitive with current subsonic aircraft make the Phoenix a viable aircraft for the future.

  8. High speed coding for velocity by archerfish retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Kretschmer Viola


    Full Text Available Abstract Background Archerfish show very short behavioural latencies in response to falling prey. This raises the question, which response parameters of retinal ganglion cells to moving stimuli are best suited for fast coding of stimulus speed and direction. Results We compared stimulus reconstruction quality based on the ganglion cell response parameters latency, first interspike interval, and rate. For stimulus reconstruction of moving stimuli using latency was superior to using the other stimulus parameters. This was true for absolute latency, with respect to stimulus onset, as well as for relative latency, with respect to population response onset. Iteratively increasing the number of cells used for reconstruction decreased the calculated error close to zero. Conclusions Latency is the fastest response parameter available to the brain. Therefore, latency coding is best suited for high speed coding of moving objects. The quantitative data of this study are in good accordance with previously published behavioural response latencies.

  9. Analog parallel processor hardware for high speed pattern recognition (United States)

    Daud, T.; Tawel, R.; Langenbacher, H.; Eberhardt, S. P.; Thakoor, A. P.


    A VLSI-based analog processor for fully parallel, associative, high-speed pattern matching is reported. The processor consists of two main components: an analog memory matrix for storage of a library of patterns, and a winner-take-all (WTA) circuit for selection of the stored pattern that best matches an input pattern. An inner product is generated between the input vector and each of the stored memories. The resulting values are applied to a WTA network for determination of the closest match. Patterns with up to 22 percent overlap are successfully classified with a WTA settling time of less than 10 microsec. Applications such as star pattern recognition and mineral classification with bounded overlap patterns have been successfully demonstrated. This architecture has a potential for an overall pattern matching speed in excess of 10 exp 9 bits per second for a large memory.

  10. High speed cutting of AZ31 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Liwei Lu


    Full Text Available Using LBR-370 numerical control lathe, high speed cutting was applied to AZ31 magnesium alloy. The influence of cutting parameters on microstructure, surface roughness and machining hardening were investigated by using the methods of single factor and orthogonal experiment. The results show that the cutting parameters have an important effect on microstructure, surface roughness and machine hardening. The depth of stress layer, roughness and hardening present a declining tendency with the increase of the cutting speed and also increase with the augment of the cutting depth and feed rate. Moreover, we established a prediction model of the roughness, which has an important guidance on actual machining process of magnesium alloy.

  11. Dynamics of High-Speed Rotors Supported in Sliding Bearings (United States)

    Šimek, J.; Svoboda, R.

    The higher the operating speed, the more serious are problems with rotor stability. Three basic groups of rotors are analyzed and some methods of suppressing instability are shown. In the first group are classical elastic rotors supported in hydrodynamic bearings. Practically all high-speed rotors now run in tilting pad bearings, which are inherently stable, but in specific conditions even tiling pad bearings may not ensure rotor stability. The second group is composed of combustion engines turbocharger rotors, which are characteristic by heavy impellers at both overhung ends of elastic shaft. These rotors are in most cases supported in floating ring bearings, which bring special features to rotor behaviour. The third group of rotors with gas bearings exhibits special features.

  12. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders


    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects......-Yo Intermittent Recovery Test level 1 (YYIRT-1) was performed and a muscle biopsy was obtained at rest. RESULTS: YYIRT-1 performance was 11.6±6.4% (mean±SD) better (2803±330 vs. 3127±383 m, P

  13. High Speed Gear Sized and Configured to Reduce Windage Loss (United States)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)


    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  14. Implementation of High Speed Distributed Data Acquisition System (United States)

    Raju, Anju P.; Sekhar, Ambika


    This paper introduces a high speed distributed data acquisition system based on a field programmable gate array (FPGA). The aim is to develop a "distributed" data acquisition interface. The development of instruments such as personal computers and engineering workstations based on "standard" platforms is the motivation behind this effort. Using standard platforms as the controlling unit allows independence in hardware from a particular vendor and hardware platform. The distributed approach also has advantages from a functional point of view: acquisition resources become available to multiple instruments; the acquisition front-end can be physically remote from the rest of the instrument. High speed data acquisition system transmits data faster to a remote computer system through Ethernet interface. The data is acquired through 16 analog input channels. The input data commands are multiplexed and digitized and then the data is stored in 1K buffer for each input channel. The main control unit in this design is the 16 bit processor implemented in the FPGA. This 16 bit processor is used to set up and initialize the data source and the Ethernet controller, as well as control the flow of data from the memory element to the NIC. Using this processor we can initialize and control the different configuration registers in the Ethernet controller in a easy manner. Then these data packets are sending to the remote PC through the Ethernet interface. The main advantages of the using FPGA as standard platform are its flexibility, low power consumption, short design duration, fast time to market, programmability and high density. The main advantages of using Ethernet controller AX88796 over others are its non PCI interface, the presence of embedded SRAM where transmit and reception buffers are located and high-performance SRAM-like interface. The paper introduces the implementation of the distributed data acquisition using FPGA by VHDL. The main advantages of this system are high

  15. High-speed and high-fidelity system and method for collecting network traffic (United States)

    Weigle, Eric H [Los Alamos, NM


    A system is provided for the high-speed and high-fidelity collection of network traffic. The system can collect traffic at gigabit-per-second (Gbps) speeds, scale to terabit-per-second (Tbps) speeds, and support additional functions such as real-time network intrusion detection. The present system uses a dedicated operating system for traffic collection to maximize efficiency, scalability, and performance. A scalable infrastructure and apparatus for the present system is provided by splitting the work performed on one host onto multiple hosts. The present system simultaneously addresses the issues of scalability, performance, cost, and adaptability with respect to network monitoring, collection, and other network tasks. In addition to high-speed and high-fidelity network collection, the present system provides a flexible infrastructure to perform virtually any function at high speeds such as real-time network intrusion detection and wide-area network emulation for research purposes.

  16. Signal Conditioning in Process of High Speed Imaging

    Directory of Open Access Journals (Sweden)

    Libor Hargas


    Full Text Available The accuracy of cinematic analysis with camera system depends on frame rate of used camera. Specific case of cinematic analysis is in medical research focusing on microscopic objects moving with high frequencies (cilia of respiratory epithelium. The signal acquired by high speed video acquisition system has very amount of data. This paper describes hardware parts, signal condition and software, which is used for image acquiring thru digital camera, intelligent illumination dimming hardware control and ROI statistic creation. All software parts are realized as virtual instruments.

  17. Design and Analysis of High Speed Capacitive Pipeline DACs


    Duong, Quoc-Tai; Dabrowski, Jerzy; Alvandpour, Atila


    Design of a high speed capacitive digital-to-analog converter (SC DAC) is presented for 65 nm CMOS technology. SC pipeline architecture is used followed by an output driver. For GHz frequency operation with output voltage swing suitable for wireless applications (300 mVpp) the DAC performance is shown to be limited by the capacitor array imperfections. While it is possible to design a highly linear output driver with HD3 < -70 dB and HD2 < -90 dB over 0.55 GHz band as we show, the maxi...

  18. High-speed optical links for UAV applications (United States)

    Chen, C.; Grier, A.; Malfa, M.; Booen, E.; Harding, H.; Xia, C.; Hunwardsen, M.; Demers, J.; Kudinov, K.; Mak, G.; Smith, B.; Sahasrabudhe, A.; Patawaran, F.; Wang, T.; Wang, A.; Zhao, C.; Leang, D.; Gin, J.; Lewis, M.; Nguyen, D.; Quirk, K.


    High speed optical backbone links between a fleet of UAVs is an integral part of the Facebook connectivity architecture. To support the architecture, the optical terminals need to provide high throughput rates (in excess of tens of Gbps) while achieving low weight and power consumption. The initial effort is to develop and demonstrate an optical terminal capable of meeting the data rate requirements and demonstrate its functions for both air-air and air-ground engagements. This paper is a summary of the effort to date.

  19. Development of FPGA-based High-Speed serial links for High Energy Physics Experiments


    Perrella, Sabrina


    High Energy Physics (HEP) experiments generate high volumes of data which need to be transferred over long distance. Then, for data read out, reliable and high-speed links are necessary. Over the years, due to their extreme high bandwidth, serial links (especially optical) have been preferred over the parallel ones. So that, now, high-speed serial links are commonly used in Trigger and Data Acquisition (TDAQ) systems of HEP experiments, not only for data transfer, but also for the distributio...

  20. Fusion: ultra-high-speed and IR image sensors (United States)

    Etoh, T. Goji; Dao, V. T. S.; Nguyen, Quang A.; Kimata, M.


    Most targets of ultra-high-speed video cameras operating at more than 1 Mfps, such as combustion, crack propagation, collision, plasma, spark discharge, an air bag at a car accident and a tire under a sudden brake, generate sudden heat. Researchers in these fields require tools to measure the high-speed motion and heat simultaneously. Ultra-high frame rate imaging is achieved by an in-situ storage image sensor. Each pixel of the sensor is equipped with multiple memory elements to record a series of image signals simultaneously at all pixels. Image signals stored in each pixel are read out after an image capturing operation. In 2002, we developed an in-situ storage image sensor operating at 1 Mfps 1). However, the fill factor of the sensor was only 15% due to a light shield covering the wide in-situ storage area. Therefore, in 2011, we developed a backside illuminated (BSI) in-situ storage image sensor to increase the sensitivity with 100% fill factor and a very high quantum efficiency 2). The sensor also achieved a much higher frame rate,16.7 Mfps, thanks to the wiring on the front side with more freedom 3). The BSI structure has another advantage that it has less difficulties in attaching an additional layer on the backside, such as scintillators. This paper proposes development of an ultra-high-speed IR image sensor in combination of advanced nano-technologies for IR imaging and the in-situ storage technology for ultra-highspeed imaging with discussion on issues in the integration.

  1. Fourier domain mode-locked swept source at 1050 nm based on a tapered amplifier

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang


    While swept source optical coherence tomography (OCT) in the 1050 nm range is promising for retinal imaging, there are certain challenges. Conventional semiconductor gain media have limited output power, and the performance of high-speed Fourier domain mode-locked (FDML) lasers suffers from...... chromatic dispersion in standard optical fiber. We developed a novel light source with a tapered amplifier as gain medium, and investigated the FDML performance comparing two fiber delay lines with different dispersion properties. We introduced an additional gain element into the resonator, and thereby...... achieved stable FDML operation, exploiting the full bandwidth of the tapered amplifier despite high dispersion. The light source operates at a repetition rate of 116 kHz with an effective average output power in excess of 30 mW. With a total sweep range of 70 nm, we achieved an axial resolution of 15 μm...

  2. AC_ICAP: A Flexible High Speed ICAP Controller

    Directory of Open Access Journals (Sweden)

    Luis Andres Cardona


    Full Text Available The Internal Configuration Access Port (ICAP is the core component of any dynamic partial reconfigurable system implemented in Xilinx SRAM-based Field Programmable Gate Arrays (FPGAs. We developed a new high speed ICAP controller, named AC_ICAP, completely implemented in hardware. In addition to similar solutions to accelerate the management of partial bitstreams and frames, AC_ICAP also supports run-time reconfiguration of LUTs without requiring precomputed partial bitstreams. This last characteristic was possible by performing reverse engineering on the bitstream. Besides, we adapted this hardware-based solution to provide IP cores accessible from the MicroBlaze processor. To this end, the controller was extended and three versions were implemented to evaluate its performance when connected to Peripheral Local Bus (PLB, Fast Simplex Link (FSL, and AXI interfaces of the processor. In consequence, the controller can exploit the flexibility that the processor offers but taking advantage of the hardware speed-up. It was implemented in both Virtex-5 and Kintex7 FPGAs. Results of reconfiguration time showed that run-time reconfiguration of single LUTs in Virtex-5 devices was performed in less than 5 μs which implies a speed-up of more than 380x compared to the Xilinx XPS_HWICAP controller.

  3. How sand grains stop a high speed intruder (United States)

    Behringer, Robert

    When a speeding intruder impacts on a granular material, it comes rapidly to rest after penetrating only a modest distance. Empirical dynamical models, dating to the 19th century (if not earlier), describe the drag on the intruder in terms of two types of depth-dependent forces: one a static force, which also includes gravity, and the other a collisional force proportional to the square of the instantaneous speed of the intruder. What processes occur in the material to so quickly decelerate the intruder? We address this question through experiments and simulations (work of Lou Kondic and collaborators). We first probe the granular response using quasi-two-dimensional granular materials consisting of photoelastic discs. When such a particle experiences a force, it appears bright under cross-polarized illumination. High speed video reveals dynamic force transmission into the material along force chains that form in response to the intruder motion. These chains are nearly normal to the intruder surface, implying that collisional rather than frictional forces dominate the momentum transfer from intruder to grains. These observations allow the formation of a collision-based model that correctly captures the collisional drag force for both 2D and 3D intruders of a variety of shapes. This talk will develop a collisional picture of impact, and also explore the change in the system response as the impact speed increases. Experimental collaborators include Abe Clark, Cacey Stevens Bester, and Alec Petersen. This work supported by DTRA, NSF Grant DMR1206351, NASA Grant NNX15AD38G, and the William M. Keck Foundation.

  4. High-sensitivity, high-speed continuous imaging system (United States)

    Watson, Scott A; Bender, III, Howard A


    A continuous imaging system for recording low levels of light typically extending over small distances with high-frame rates and with a large number of frames is described. Photodiode pixels disposed in an array having a chosen geometry, each pixel having a dedicated amplifier, analog-to-digital convertor, and memory, provide parallel operation of the system. When combined with a plurality of scintillators responsive to a selected source of radiation, in a scintillator array, the light from each scintillator being directed to a single corresponding photodiode in close proximity or lens-coupled thereto, embodiments of the present imaging system may provide images of x-ray, gamma ray, proton, and neutron sources with high efficiency.

  5. Profile parameters of wheelset detection for high speed freight train (United States)

    Yang, Kai; Ma, Li; Gao, Xiaorong; Wang, Li


    Because of freight train, in China, transports goods on railway freight line throughout the country, it does not depart from or return to engine shed during a long phase, thus we cannot monitor the quality of wheel set effectively. This paper provides a system which uses leaser and high speed camera, applies no-contact light section technology to get precise wheel set profile parameters. The paper employs clamping-track method to avoid complex railway ballast modification project. And detailed descript an improved image-tracking algorithm to extract central line from profile curve. For getting one pixel width and continuous line of the profile curve, uses local gray maximum points as direction control points to direct tracking direction. The results based on practical experiment show the system adapted to detection environment of high speed and high vibration, and it can effectively detect the wheelset geometric parameters with high accuracy. The system fills the gaps in wheel set detection for freight train in main line and has an enlightening function on monitoring the quality of wheel set.

  6. High-speed signal processing using highly nonlinear optical fibres

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen


    We review recent progress in all-optical signal processing techniques making use of conventional silica-based highly nonlinear fibres. In particular, we focus on recent demonstrations of ultra-fast processing at 640 Gbit/s and above, as well as on signal processing of novel modulation formats...... relying on the phase of the optical field. Topics covered include all-optical switching of 640 Gbit/s and 1.28 Tbit/s serial data, wavelength conversion at 640 Gbit/s, optical amplitude regeneration of differential phase shift keying (DPSK) signals, as well as midspan spectral inversion for differential 8......-state phase shift keying (D8PSK) signals....

  7. Generation of an Optimum High Speed High Accuracy Operational Amplifier. (United States)


    certainly will have gains and emitter resistances that are not identical. In mono- lithic op-amps, it is highly desirable that all of the tran- sistors on a...external resistances ( a and K . altered). In general, w and Q are functions of a and K. p .p , "It is desirable to select these values such that the...220),OMEGA(220) COMPLEX HH,S,DENOM REAL K,ANUM c THE FOLLOWING ARE CONSTANTS TO BE UTILIZED:A01=>DC GAIN OF FIRST c OPAMP ;A02=>DC GAIN OF SECOND OPAMP

  8. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi


    We overview recent trend in developing high speed wireless communication systems by exploring large bandwidth available in the THz band, and we also present our recent experimental achievements on 400 GHz wireless transmission with a data rate of up to 60 Gbit/s by using a uni-travelling carrier...... photodiode (UTC-PD) as emitter and a Schottky diode as receiver. This system is foreseen to be capable of accommodating faster data rates beyond 100 Gbit/s, and would find application in bandwidth hungry scenarios....

  9. HORNET: High-speed Onion Routing at the Network Layer


    Chen, Chen; Asoni, Daniele Enrico; Barrera, David; Danezis, George; Perrig, Adrian


    We present HORNET, a system that enables high-speed end-to-end anonymous channels by leveraging next generation network architectures. HORNET is designed as a low-latency onion routing system that operates at the network layer thus enabling a wide range of applications. Our system uses only symmetric cryptography for data forwarding yet requires no per-flow state on intermediate nodes. This design enables HORNET nodes to process anonymous traffic at over 93 Gb/s. HORNET can also scale as requ...

  10. An adaptive finite element method for high speed flows (United States)

    Peraire, J.; Morgan, K.; Peiro, J.; Zienkiewicz, O. C.


    The solution of the equations of compressible high speed flow, on unstructured triangular grids in 2D and tetrahedral grids in 3D, is considered. Solution methods based upon both Taylor-Galerkin and Runge-Kutta time-stepping techniques are presented and the incorporation of the ideas of flux corrected transport (FCT) is discussed. These methods are combined with an adaptive mesh regeneration procedure and are employed in the solution of several examples, consisting of Euler flows in both 2D and 3D and Navier-Stokes flows in 2D.

  11. Flexible, High-Speed CdSe Nanocrystal Integrated Circuits. (United States)

    Stinner, F Scott; Lai, Yuming; Straus, Daniel B; Diroll, Benjamin T; Kim, David K; Murray, Christopher B; Kagan, Cherie R


    We report large-area, flexible, high-speed analog and digital colloidal CdSe nanocrystal integrated circuits operating at low voltages. Using photolithography and a newly developed process to fabricate vertical interconnect access holes, we scale down device dimensions, reducing parasitic capacitances and increasing the frequency of circuit operation, and scale up device fabrication over 4 in. flexible substrates. We demonstrate amplifiers with ∼7 kHz bandwidth, ring oscillators with <10 μs stage delays, and NAND and NOR logic gates.

  12. 3D high-speed cinematography and its problems (United States)

    Eisfeld, Fritz


    Many fast events are three dimensional but the normal high- speed cameras are only suitable for 2-D images. Therefore it was investigated which stereoscopic methods could be used to study three dimensional processes. The choice of the optimal method is dependent on the investigated event. To record the 3-D spreading of an injection jet in a laboratory has to use other methods as to record an explosion from a smoke bomb in open air. Three methods are described and critically compared. Furthermore it is shown how from films with double pictures a cinematographic film can be made.

  13. High-Speed EMU TCMS Design and LCC Technology Research

    Directory of Open Access Journals (Sweden)

    Hongwei Zhao


    Full Text Available This paper introduces the high-speed electrical multiple unit (EMU life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system (TCMS software development platform, the TCMS testing and verification bench, the EMU driving simulation platform, and the EMU remote data transmittal and maintenance platform. All these platforms and benches combined together make up the EMU life cycle cost (LCC system. Each platform facilitates EMU LCC management and is an important part of the system.

  14. Pushbroom Stereo for High-Speed Navigation in Cluttered Environments


    Barry, Andrew J.; Tedrake, Russ


    We present a novel stereo vision algorithm that is capable of obstacle detection on a mobile ARM processor at 120 frames per second. Our system performs a subset of standard block-matching stereo processing, searching only for obstacles at a single depth. By using an onboard IMU and state-estimator, we can recover the position of obstacles at all other depths, building and updating a local depth-map at framerate. Here, we describe both the algorithm and our implementation on a high-speed, sma...

  15. Photonic Technologies for Ultra-High-Speed Information Highways

    DEFF Research Database (Denmark)

    Bouchoule, S; Lèfevre, R.; Legros, E.


    The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbeds....... This paper reviews the current status of 40 Gbit/s TDM components and subsystem technologies achieved in HIGHWAY. The results of HIGHWAY 40 Gbit/s TDM systems and field tests will be reported in a subsequent paper. (C) 1999 Academic Press....

  16. Preliminary results from the High Speed Airframe Integration Research project (United States)

    Coen, Peter G.; Sobieszczanski-Sobieski, Jaroslaw; Dollyhigh, Samuel M.


    A review is presented of the accomplishment of the near term objectives of developing an analysis system and optimization methods during the first year of the NASA Langley High Speed Airframe Integration Research (HiSAIR) project. The characteristics of a Mach 3 HSCT transport have been analyzed utilizing the newly developed process. In addition to showing more detailed information about the aerodynamic and structural coupling for this type of vehicle, this exercise aided in further refining the data requirements for the analysis process.

  17. A quick-retrieval high-speed digital framing camera


    Sato, A.H.; Yee, J; Bellan, P. M.


    A new high-speed digital framing camera is described. The design is built around a rotating polygon mirror that provides a framing rate of 24 000 frames/s. The camera electronics digitizes an image into a 32×104 grid of pixels, where the second dimension of the grid can be varied and is determined by the 8 bit computer-aided measurement and control digitizer sampling rate. Available digitizer memory provides for 314 frames at this horizontal resolution. The advantages over other available hig...

  18. High-speed digital-to-analog converter concepts (United States)

    Schmidt, Christian; Kottke, Christoph; Jungnickel, Volker; Freund, Ronald


    In today's fiber-optic communication systems, the bandwidth of the photonic components, i.e. modulators and photo diodes, is way greater than that of their electrical counterparts, i.e. digital-to-analog converters (DACs) and analog-to-digital converters (ADCs). In order to increase the transmission capacity, the bandwidth limitations need to be overcome. We review the progress and the recent results in the field of high-speed DACs, which are desirable for software-defined transmitters. Furthermore, we evaluate interleaving concepts regarding their ability to overcome the above mentioned limitations and demonstrate recent experimental results for a bandwidth interleaved DAC with 40 GHz analog electrical bandwidth.

  19. High Speed Capacitor-Inverter Based Carbon Nanotube Full Adder

    Directory of Open Access Journals (Sweden)

    Rashtian M


    Full Text Available Abstract Carbon Nanotube filed-effect transistor (CNFET is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay product in comparison to contemporary CNFET Adder Cells. Simulations were carried out using HSPICE based on CNFET model with 0.6 V VDD.

  20. The effects of modified exponential tapering technique on perceived exertion, heart rate, time trial performance, VO2max and power output among highly trained junior cyclists. (United States)

    Ishak, Asmadi; Hashim, Hairul A; Krasilshchikov, Oleksandr


    The present study investigated the effects of a 2-week modified exponential taper on physiological adaptation and time trial performance among junior cyclists. Participants (N.=27) with the mean age of 16.95±0.8 years, height of 165.6±6.1 cm and weight of 54.19±8.1 kg were matched into either modified exponential taper (N.=7), normal exponential taper (N.=7), or control (N.=7) groups using their initial VO2max values. Both experimental groups followed a 12-week progressive endurance training program and subsequently, a 2-week tapering phase. A simulated 20-km time trial performance along with VO2max, power output, heart rate and rating of perceived exertion were measured at baseline, pre and post-taper. One way ANOVA was used to analyze the difference between groups before the start of the intervention while mixed factorial ANOVA was used to analyze the difference between groups across measurement sessions. When homogeneity assumption was violated, the Greenhouse-Geisser Value was used for the corrected values of the degrees of freedom for the within subject factor the analysis. Significant interactions between experimental groups and testing sessions were found in VO2max (F=6.67, df=4, P<0.05), power output (F=5.02, df=4, P<0.05), heart rate (F=10.87, df=2.51, P<0.05) rating of perceived exertion (F=13.04, df=4, P<0.05) and 20KM time trial (F=4.64, df=2.63, P<0.05). Post-hoc analysis revealed that both types of taper exhibited positive effects compared to the non-taper condition in the measured performance markers at post-taper while no different were found between the two taper groups. It was concluded that both taper protocols successfully inducing physiological adaptations among the junior cyclists by reducing the volume and maintaining the intensity of training.

  1. Ultra-High-Speed Image Signal Accumulation Sensor

    Directory of Open Access Journals (Sweden)

    Takeharu Goji Etoh


    Full Text Available Averaging of accumulated data is a standard technique applied to processing data with low signal-to-noise ratios (SNR, such as image signals captured in ultra-high-speed imaging. The authors propose an architecture layout of an ultra-high-speed image sensor capable of on-chip signal accumulation. The very high frame rate is enabled by employing an image sensor structure with a multi-folded CCD in each pixel, which serves as an in situ image signal storage. The signal accumulation function is achieved by direct connection of the first and the last storage elements of the in situ storage CCD. It has been thought that the multi-folding is achievable only by driving electrodes with complicated and impractical layouts. Simple configurations of the driving electrodes to overcome the difficulty are presented for two-phase and four-phase transfer CCD systems. The in situ storage image sensor with the signal accumulation function is named Image Signal Accumulation Sensor (ISAS.

  2. Storage and compression design of high speed CCD (United States)

    Cai, Xichang; Zhai, LinPei


    In current field of CCD measurement, large area and high resolution CCD is used to obtain big measurement image, so that, speed and capacity of CCD requires high performance of later storage and process system. The paper discusses how to use SCSI hard disk to construct storage system and use DSPs and FPGA to realize image compression. As for storage subsystem, Because CCD is divided into multiplex output, SCSI array is used in RAID0 way. The storage system is com posed of high speed buffer, DM A controller, control M CU, SCSI protocol controller and SCSI hard disk. As for compression subsystem, according to requirement of communication and monitor system, the output is fixed resolution image and analog PA L signal. The compression means is JPEG 2000 standard, in which, 9/7 wavelets in lifting format is used. 2 DSPs and FPGA are used to com pose parallel compression system. The system is com posed of FPGA pre-processing module, DSP compression module, video decoder module, data buffer module and communication module. Firstly, discrete wavelet transform and quantization is realized in FPGA. Secondly, entropy coding and stream adaption is realized in DSPs. Last, analog PA L signal is output by Video decoder. Data buffer is realized in synchronous dual-port RAM and state of subsystem is transfer to controller. Through subjective and objective evaluation, the storage and compression system satisfies the requirement of system.

  3. High speed optical filtering using active resonant subwavelength gratings (United States)

    Gin, A. V.; Kemme, S. A.; Boye, R. R.; Peters, D. W.; Ihlefeld, J. F.; Briggs, R. D.; Wendt, J. R.; Ellis, A. R.; Marshall, L. H.; Carter, T. R.; Hunker, J. D.; Samora, S.


    In this work, we describe the most recent progress towards the device modeling, fabrication, testing and system integration of active resonant subwavelength grating (RSG) devices. Passive RSG devices have been a subject of interest in subwavelength-structured surfaces (SWS) in recent years due to their narrow spectral response and high quality filtering performance. Modulating the bias voltage of interdigitated metal electrodes over an electrooptic thin film material enables the RSG components to act as actively tunable high-speed optical filters. The filter characteristics of the device can be engineered using the geometry of the device grating and underlying materials. Using electron beam lithography and specialized etch techniques, we have fabricated interdigitated metal electrodes on an insulating layer and BaTiO3 thin film on sapphire substrate. With bias voltages of up to 100V, spectral red shifts of several nanometers are measured, as well as significant changes in the reflected and transmitted signal intensities around the 1.55um wavelength. Due to their small size and lack of moving parts, these devices are attractive for high speed spectral sensing applications. We will discuss the most recent device testing results as well as comment on the system integration aspects of this project.

  4. High speed and wide bandwidth delta-sigma ADCs

    CERN Document Server

    Bolatkale, Muhammed; Makinwa, Kofi A A


    This book describes techniques for realizing wide bandwidth (125MHz) over-sampled analog-to-digital converters (ADCs) in nanometer-CMOS processes.  The authors offer a clear and complete picture of system level challenges and practical design solutions in high-speed Delta-Sigma modulators.  Readers will be enabled to implement ADCs as continuous-time delta-sigma (CT∆Σ) modulators, offering simple resistive inputs, which do not require the use of power-hungry input buffers, as well as offering inherent anti-aliasing, which simplifies system integration. The authors focus on the design of high speed and wide-bandwidth ΔΣMs that make a step in bandwidth range which was previously only possible with Nyquist converters. More specifically, this book describes the stability, power efficiency, and linearity limits of ΔΣMs, aiming at a GHz sampling frequency.   • Provides overview of trends in Wide Bandwidth and High Dynamic Range analog-to-digital converters (ADCs); • Enables the design of a wide band...

  5. Large area high-speed metrology SPM system (United States)

    Klapetek, P.; Valtr, M.; Picco, L.; Payton, O. D.; Martinek, J.; Yacoot, A.; Miles, M.


    We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm2 regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope.

  6. Role of the eye in high-speed motion analysis (United States)

    Hyzer, William G.


    Prior to the investigation of the photographic process over 150 years ago, the analyses of rapid motions were limited by the dynamic efficacies of the human eye, which has a temporal resolution of approximately 1/10 sec and a maximum information acquisition rate estimated at 103 to 104 bits/sec. At high rates of object motion, only the simplest actions can be resolved, comprehended and retained in human memory. Advances in the field of high-speed photography drastically changed all this by providing us with the ability today to capture permanent images of transient events at acquisition rates in excess of 1012 bits/sec. As remarkable as these improvements in temporal resolution and image retention may be, the final step in correctly interpreting any image still rests largely upon the analyst's ability to process visual data. Those who enter the field of image analysis soon learn how capricious the eye can be in this task. It is incumbent upon anyone performing important image analyses to have at least a basic understanding of the eye's performance characteristics, especially its limitations and capricious anomalies. Exemplary data presented in this paper are drawn from the scientific literature and the author's forty years of experience as a researcher, author and educator in the field of high-speed imaging.

  7. Reflectively coupled waveguide photodetector for high speed optical interconnection. (United States)

    Hsu, Shih-Hsiang


    To fully utilize GaAs high drift mobility, techniques to monolithically integrate In0.53Ga0.47As p-i-n photodetectors with GaAs based optical waveguides using total internal reflection coupling are reviewed. Metal coplanar waveguides, deposited on top of the polyimide layer for the photodetector's planarization and passivation, were then uniquely connected as a bridge between the photonics and electronics to illustrate the high-speed monitoring function. The photodetectors were efficiently implemented and imposed on the echelle grating circle for wavelength division multiplexing monitoring. In optical filtering performance, the monolithically integrated photodetector channel spacing was 2 nm over the 1,520-1,550 nm wavelength range and the pass band was 1 nm at the -1 dB level. For high-speed applications the full-width half-maximum of the temporal response and 3-dB bandwidth for the reflectively coupled waveguide photodetectors were demonstrated to be 30 ps and 11 GHz, respectively. The bit error rate performance of this integrated photodetector at 10 Gbit/s with 2(7)-1 long pseudo-random bit sequence non-return to zero input data also showed error-free operation.

  8. High speed imaging of an Er,Cr:YSGG laser in a model of a root canal (United States)

    Verdaasdonk, Rudolf; Blanken, Jan; van Heeswijk, Hans; de Roode, Rowland; Klaessens, John


    Laser systems of various wavelengths and pulse characteristics have been introduced in dentistry. At present, the range of applications for the different systems is being investigated mainly differentiating between soft and hard tissue applications. For the preparation of root canals both hard and soft tissues are involved. Ideally, one would like to use one laser system for the whole treatment. In this study, we studied the characteristics of the pulsed 2,78 Er,Cr:YSGG laser (Biolase, Waterlase Millenium), in view of root canal cleaning and desinfection. The laser energy was fiber delivered with fiber tip diameters from 400 μm down to 200 μm. Special thermal and high speed imaging techniques were applied in a transparent model of a tapered root canal and slices cut from human teeth. High speed imaging revealed the dynamics of an explosive vapor bubble at the tip of the Er laser in water and the root canal model. Typically for Erbium lasers, within a time span of several hundred μs, a longitudinal bubble expanded to maximum size of 5 mm length and 2 mm diameter at 100 mJ and imploded afterwards. In the root canal, the explosive bubble created turbulent high speed water streaming which resects soft tissue from the hard tissue. Thermal imaging showed the dynamics of all lasers heating of the canal wall up to several mm depending on the wavelength and energy settings. The mechanism of smear layer removal and sterilization in the root canal, is attributed to cavitation effects induced by the pulsed laser. The heat generation into the dentine wall was minimal.

  9. Material Properties of High-Speed Steel Rolls

    Directory of Open Access Journals (Sweden)

    Shaohua Wu


    Full Text Available Recently, it has been required to improve the material properties of high-speed steel (HSS rolls, because of the low wear resistance and low mechanical properties. To improve them, several new steels have been proposed, which have high wear resistance as well as excellent mechanical properties, e.g., hardness and tensile properties, where additional elements (V, Cr and W were employed. However, their steels may have still technical issues, as the roll surfaces become roughened during the production process. The reason for this problem is found to be affected by the oxidation of the HSS surface. In this work, we have provided the suggestions to make high wear resistance of the HSS rolls

  10. Dark matter phenomenology of high-speed galaxy cluster collisions

    Energy Technology Data Exchange (ETDEWEB)

    Mishchenko, Yuriy [Izmir University of Economics, Faculty of Engineering, Izmir (Turkey); Ji, Chueng-Ryong [North Carolina State University, Department of Physics, Raleigh, NC (United States)


    We perform a general computational analysis of possible post-collision mass distributions in high-speed galaxy cluster collisions in the presence of self-interacting dark matter. Using this analysis, we show that astrophysically weakly self-interacting dark matter can impart subtle yet measurable features in the mass distributions of colliding galaxy clusters even without significant disruptions to the dark matter halos of the colliding galaxy clusters themselves. Most profound such evidence is found to reside in the tails of dark matter halos' distributions, in the space between the colliding galaxy clusters. Such features appear in our simulations as shells of scattered dark matter expanding in alignment with the outgoing original galaxy clusters, contributing significant densities to projected mass distributions at large distances from collision centers and large scattering angles of up to 90 {sup circle}. Our simulations indicate that as much as 20% of the total collision's mass may be deposited into such structures without noticeable disruptions to the main galaxy clusters. Such structures at large scattering angles are forbidden in purely gravitational high-speed galaxy cluster collisions. Convincing identification of such structures in real colliding galaxy clusters would be a clear indication of the self-interacting nature of dark matter. Our findings may offer an explanation for the ring-like dark matter feature recently identified in the long-range reconstructions of the mass distribution of the colliding galaxy cluster CL0024+017. (orig.)

  11. Investigation of a Plasma Ball using a High Speed Camera (United States)

    Laird, James; Zweben, Stewart; Raitses, Yevgeny; Zwicker, Andrew; Kaganovich, Igor


    The physics of how a plasma ball works is not clearly understood. A plasma ball is a commercial ``toy'' in which a center electrode is charged to a high voltage and lightning-like discharges fill the ball with many plasma filaments. The ball uses high voltage applied on the center electrode (˜5 kV) which is covered with glass and capacitively coupled to the plasma filaments. This voltage oscillates at a frequency of ˜26 kHz. A Nebula plasma ball from Edmund Scientific was filmed with a Phantom v7.3 camera, which can operate at speeds up to 150,000 frames per second (fps) with a limit of >=2 μsec exposure per frame. At 100,000 fps the filaments were only visible for ˜5 μsec every ˜40 μsec. When the plasma ball is first switched on, the filaments formed only after ˜800 μsec and initially had a much larger diameter with more chaotic behavior than when the ball reached its final plasma filament state at ˜30 msec. Measurements are also being made of the final filament diameter, the speed of the filament propagation, and the effect of thermal gradients on the filament density. An attempt will be made to explain these results from plasma theory and movies of these filaments will be shown. Possible theoretical models include streamer-like formation, thermal condensation instability, and dielectric barrier discharge instability.

  12. Control-Surface Instability on High-Speed Airplanes (United States)

    Phillips, William H.


    Tests of several modern airplanes indicate that control surfaces with a high degree of aerodynamic balance are likely to possess characteristics which make them unsatisfactory or dangerous in high-speed flight. Dive tests made in the spring of 1940 at the NACA on a naval fighter-type airplane illustrate one form of instability that may be encountered. During a dive at an indicated airspeed of 365 miles per hour, the ailerons suddenly overbalanced. The efforts of the pilot to bring the ailerons back to neutral resulted in a violent oscillation of the control stick from side to side. Fortunately, the force required to return the ailerons to neutral was within the pilot's capabilities. A time history of the maneuver is given in figure1 and typical frames from motion pictures of the cockpit and of the wing, taken during the maneuver, are given in figure 2. In the illustrated case, the occurrence of aerodynamic overbalance was attributed to a slight bulge, approximately 1/16 inch thick, on the lower surface of the leading edges of the ailerons, caused by the installation of additional mass balance ahead of the hinge line. A drawing showing the shape of the bulge is given in figure 3. After this slight protuberance had been eliminated, dives were successfully made at higher speeds.

  13. Preliminary design of nine high speed civil transports (United States)

    Sandlin, Doral; Vantriet, Robert; Soban, Dani; Hoang, TY


    Sixty senior design students at Cal Poly, SLO have completed a year-long project to design the next generation of High Speed Civil Transports (HSCT). The design process was divided up into three distinct phases. The first third of the project was devoted entirely to research into the special problems associated with an HSCT. These included economic viability, airport compatibility, high speed aerodynamics, sonic boom minimization, environmental impact, and structures and materials. The result of this research was the development of nine separate Requests for Proposal (RFP) that outlined reasonable yet challenging design criteria for the aircraft. All were designed to be technically feasible in the year 2015. The next phase of the project divided the sixty students into nine design groups. Each group, with its own RFP, completed a Class 1 preliminary design of an HSCT. The nine configurations varied from conventional double deltas to variable geometry wings to a pivoting oblique wing design. The final phase of the project included a more detailed Class 2 sizing as well as performance and stability and control analysis. Cal Poly, San Luis Obispo presents nine unique solutions to the same problem: that of designing an economically viable, environmentally acceptable, safe and comfortable supersonic transport.

  14. Active resonant subwavelength grating devices for high speed spectroscopic sensing (United States)

    Gin, A. V.; Kemme, S. A.; Boye, R. R.; Peters, D. W.; Ihlefeld, J. F.; Briggs, R. D.; Wendt, J. R.; Marshall, L. H.; Carter, T. R.; Samora, S.


    In this paper, we describe progress towards a multi-color spectrometer and radiometer based upon an active resonant subwavelength grating (RSG). This active RSG component acts as a tunable high-speed optical filter that allows device miniaturization and ruggedization not realizable using current sensors with conventional bulk optics. Furthermore, the geometrical characteristics of the device allow for inherently high speed operation. Because of the small critical dimensions of the RSG devices, the fabrication of these sensors can prove challenging. However, we utilize the state-of-the-art capabilities at Sandia National Laboratories to realize these subwavelength grating devices. This work also leverages previous work on passive RSG devices with greater than 98% efficiency and ~1nm FWHM. Rigorous coupled wave analysis has been utilized to design RSG devices with PLZT, PMN-PT and BaTiO3 electrooptic thin films on sapphire substrates. The simulated interdigitated electrode configuration achieves field strengths around 3×107 V/m. This translates to an increase in the refractive index of 0.05 with a 40V bias potential resulting in a 90% contrast of the modulated optical signal. We have fabricated several active RSG devices on selected electro-optic materials and we discuss the latest experimental results on these devices with variable electrostatic bias and a tunable wavelength source around 1.5μm. Finally, we present the proposed data acquisition hardware and system integration plans.

  15. High-speed stimulated Brillouin scattering spectroscopy at 780 nm

    Directory of Open Access Journals (Sweden)

    Itay Remer


    Full Text Available We demonstrate a high-speed stimulated Brillouin scattering (SBS spectroscopy system that is able to acquire stimulated Brillouin gain point-spectra in water samples and Intralipid tissue phantoms over 2 GHz within 10 ms and 100 ms, respectively, showing a 10-100 fold increase in acquisition rates over current frequency-domain SBS spectrometers. This improvement was accomplished by integrating an ultra-narrowband hot rubidium-85 vapor notch filter in a simplified frequency-domain SBS spectrometer comprising nearly counter-propagating continuous-wave pump-probe light at 780 nm and conventional single-modulation lock-in detection. The optical notch filter significantly suppressed stray pump light, enabling detection of stimulated Brillouin gain spectra with substantially improved acquisition times at adequate signal-to-noise ratios (∼25 dB in water samples and ∼15 dB in tissue phantoms. These results represent an important step towards the use of SBS spectroscopy for high-speed measurements of Brillouin gain resonances in scattering and non-scattering samples.

  16. High-speed digital fiber optic links for satellite traffic (United States)

    Daryoush, A. S.; Ackerman, E.; Saedi, R.; Kunath, R. R.; Shalkhauser, K.


    Large aperture phased array antennas operating at millimeter wave frequencies are designed for space-based communications and imaging platforms. Array elements are comprised of active T/R modules which are linked to the central processing unit through high-speed fiber-optic networks. The system architecture satisfying system requirements at millimeter wave frequency is T/R level data mixing where data and frequency reference signals are distributed independently before mixing at the T/R modules. This paper demonstrates design procedures of a low loss high-speed fiber-optic link used for transmission of data signals over 600-900 MHz bandwidth inside satellite. The fiber-optic link is characterized for transmission of analog and digital data. A dynamic range of 79 dB/MHz was measured for analog data over the bandwidth. On the other hand, for bursted SMSK satellite traffic at 220 Mbps rates, BER of 2 x 10 to the -7th was measured for E(b)/N(o) of 14.3 dB.

  17. High-speed atomic force microscopy: imaging and force spectroscopy. (United States)

    Eghiaian, Frédéric; Rico, Felix; Colom, Adai; Casuso, Ignacio; Scheuring, Simon


    Atomic force microscopy (AFM) is the type of scanning probe microscopy that is probably best adapted for imaging biological samples in physiological conditions with submolecular lateral and vertical resolution. In addition, AFM is a method of choice to study the mechanical unfolding of proteins or for cellular force spectroscopy. In spite of 28 years of successful use in biological sciences, AFM is far from enjoying the same popularity as electron and fluorescence microscopy. The advent of high-speed atomic force microscopy (HS-AFM), about 10 years ago, has provided unprecedented insights into the dynamics of membrane proteins and molecular machines from the single-molecule to the cellular level. HS-AFM imaging at nanometer-resolution and sub-second frame rate may open novel research fields depicting dynamic events at the single bio-molecule level. As such, HS-AFM is complementary to other structural and cellular biology techniques, and hopefully will gain acceptance from researchers from various fields. In this review we describe some of the most recent reports of dynamic bio-molecular imaging by HS-AFM, as well as the advent of high-speed force spectroscopy (HS-FS) for single protein unfolding. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  18. Recent high-speed rail vehicles; Kosoku tetsudo sharyo

    Energy Technology Data Exchange (ETDEWEB)

    Sone, S. [The University of Tokyo, Tokyo (Japan); Ishizu, K. [Central Japan Railway Company, Nagoya (Japan); Yoshie, N. [Nishi-Nippon Railroad Co. Ltd., Fukuoka (Japan); Hata, T. [East Japan Railway Co., Tokyo (Japan); Watanabe, T.; Hata, H. [Railway Technical Research Institute, Tokyo (Japan); Brun, D.


    This paper describes the latest progress in high speed rail vehicles. It was in 1981 when TGV has inaugurated commercial operation with a speed of 260 km/h. Japan is trying to recover from a setback by putting forward the 300-line vehicle of discrete motive force system, and the 500-line vehicle of complete discrete motive force system featured by reduced weight and a unique power collection system. Central Japan Railway is moving forward a 700-line train aimed at improving comfortability and reducing noise. The 500-line vehicle has vehicular features such as the sharpened head shape, weight reduction and adoption of vibration control, and also such features in electric circuits as centralized main circuit devices and improved monitoring devices. The vehicle`s running test verified stable run at 300 km/h. The Shinkansen vehicle designed by East Japan Railway adopted collective control on the main circuit system, and transferred to a system in which large capacity GTOs are used to drive three-phase induction motors. The Inter City Express has been put into practical use in Germany, with traction vehicles arranged on both ends of a train. Technological characteristics in TGV may be pointed out as avoidance of curves and high gradient. Exchange of electric train technologies is in progress between Japan and Europe. 19 refs., 27 figs., 6 tabs.

  19. High-speed digital video tracking system for generic applications (United States)

    Walton, James S.; Hallamasek, Karen G.


    The value of high-speed imaging for making subjective assessments is widely recognized, but the inability to acquire useful data from image sequences in a timely fashion has severely limited the use of the technology. 4DVideo has created a foundation for a generic instrument that can capture kinematic data from high-speed images. The new system has been designed to acquire (1) two-dimensional trajectories of points; (2) three-dimensional kinematics of structures or linked rigid-bodies; and (3) morphological reconstructions of boundaries. The system has been designed to work with an unlimited number of cameras configured as nodes in a network, with each camera able to acquire images at 1000 frames per second (fps) or better, with a spatial resolution of 512 X 512 or better, and an 8-bit gray scale. However, less demanding configurations are anticipated. The critical technology is contained in the custom hardware that services the cameras. This hardware optimizes the amount of information stored, and maximizes the available bandwidth. The system identifies targets using an algorithm implemented in hardware. When complete, the system software will provide all of the functionality required to capture and process video data from multiple perspectives. Thereafter it will extract, edit and analyze the motions of finite targets and boundaries.

  20. Quantitative Image Analysis Techniques with High-Speed Schlieren Photography (United States)

    Pollard, Victoria J.; Herron, Andrew J.


    Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available.

  1. High-Speed Solar Wind and Geomagnetic Activity (United States)

    Olyak, M. R.


    The impact of high-speed solar wind disturbances on the occurrence of geomagnetic storms is analyzed. The solar wind velocity values, determined from scintillation observations at the UTR-2 and URAN-2 Ukrainian decameter radio telescopes are analyzed together with the solar wind parameters at the Earth’s orbit and geomagnetic indices Ap. The solar wind velocity increase during observations was chiefly caused by the high-speed streams from coronal holes. At the time of February 2011, the X-class solar flare, accompanied by coronal mass ejections, was also observed. It was found that the geomagnetic disturbances of that period occurred at negative daily values of the interplanetary magnetic field component being perpendicular to the ecliptic plane. It was shown that the increasing solar wind velocity observed with the UTR-2 and URAN-2 within a wide range of helio- latitudes leads to increase in geomagnetic index Ap and to geomagnetic disturbance. Whereas the increase of solar wind velocity in a narrow range of helio-latitudes near to the ecliptic plane was never accompanied by geomagnetic perturbations.

  2. High-speed visual feedback for realizing high-performance robotic manipulation (United States)

    Huang, S.; Bergström, N.; Yamakawa, Y.; Senoo, T.; Ishikawa, M.


    High-speed vision sensing becomes a driving factor in developing new methods for robotic manipulation. In this paper we present two such methods in order to realize high-performance manipulation. First, we present a dynamic compensation approach which aims to achieve simultaneously fast and accurate positioning under various (from system to external environment) uncertainties. Second, a high-speed motion strategy for manipulating flexible objects is introduced to address the issue of deformation uncertainties. Both methods rely on high-speed visual feedback and are model independent, which we believe is essential to ensure good flexibility in a wide range of applications. The high-speed visual feedback tracks the relative error between the working tool and the target in image coordinates, which implies that there is no need for accurate calibrations of the vision system. Tasks for validating these methods were implemented and experimental results were provided to illustrate the effectiveness of the proposed methods.

  3. Tapered LSO arrays for small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yongfeng; James, Sara St.; Wu Yibao; Du, Huini; Qi, Jinyi; Cherry, Simon R [Department of Biomedical Engineering, University of California-Davis, One Shields Avenue, CA 95616 (United States); Farrell, Richard; Dokhale, Purushottam A; Shah, Kanai S [Radiation Monitoring Devices Inc., Watertown, MA 02172 (United States); Vaigneur, Keith [Agile Engineering, 123 Perimeter Park Rd., Ste. E, Knoxville, TN 37922 (United States)


    By using detectors with good depth encoding accuracy ({approx}2 mm), an animal PET scanner can be built with a small ring diameter and thick crystals to simultaneously obtain high spatial resolution and high sensitivity. However, there will be large wedge-shaped gaps between detector modules in such a scanner if traditional cuboid crystal arrays are used in a polygonal arrangement. The gaps can be minimized by using tapered scintillator arrays enabling the sensitivity of the scanner to be further improved. In this work, tapered lutetium oxyorthosilicate (LSO) arrays with different crystal dimensions and different combinations of inter-crystal reflector and crystal surface treatments were manufactured and their performance was evaluated. Arrays were read out from both ends by position-sensitive avalanche photodiodes (PSAPDs). In the optimal configuration, arrays consisting of 0.5 mm LSO elements could be clearly resolved and a depth of interaction resolution of 2.6 mm was obtained for a 20 mm thick array. For this tapered array, the intrinsic spatial is degraded from 0.67 to 0.75 mm compared to a standard cuboidal array with similar dimensions, while the increase in efficiency is 41%. Tapered scintillator arrays offer the prospect of improvements in sensitivity and sampling for small-bore scanners, without large increases in manufacturing complexity.

  4. Influence of “J”-Curve Spring Stiffness on Running Speeds of Segmented Legs during High-Speed Locomotion

    Directory of Open Access Journals (Sweden)

    Runxiao Wang


    Full Text Available Both the linear leg spring model and the two-segment leg model with constant spring stiffness have been broadly used as template models to investigate bouncing gaits for legged robots with compliant legs. In addition to these two models, the other stiffness leg spring models developed using inspiration from biological characteristic have the potential to improve high-speed running capacity of spring-legged robots. In this paper, we investigate the effects of “J”-curve spring stiffness inspired by biological materials on running speeds of segmented legs during high-speed locomotion. Mathematical formulation of the relationship between the virtual leg force and the virtual leg compression is established. When the SLIP model and the two-segment leg model with constant spring stiffness and with “J”-curve spring stiffness have the same dimensionless reference stiffness, the two-segment leg model with “J”-curve spring stiffness reveals that (1 both the largest tolerated range of running speeds and the tolerated maximum running speed are found and (2 at fast running speed from 25 to 40/92 m s−1 both the tolerated range of landing angle and the stability region are the largest. It is suggested that the two-segment leg model with “J”-curve spring stiffness is more advantageous for high-speed running compared with the SLIP model and with constant spring stiffness.

  5. Advanced Ultra-High Speed Motor for Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Impact Technologies LLC; University of Texas at Arlington


    Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at

  6. Ultra-high-speed Optical Signal Processing using Silicon Photonics

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

    on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show......— In supercomputers, the optical inter-connects are getting closer and closer to the processing cores. Today, a single supercomputer system has as many optical links as the whole worldwide web together, and it is envisaged that future computing chips will contain multiple electronic processor cores...... that silicon can indeed be used to control Tbit/s serial data signals [2], perform 640 Gbit/s wavelength conversion [3] 640 Gbit/s serial-to-parallel conversion [4], 160 Gbit/s packet switching as well as all-optical regeneration [5]. We will also discuss the performance limitations of crystalline silicon...

  7. High speed MSM photodetector based on Ge nanowires network (United States)

    Dhyani, Veerendra; Das, Samaresh


    This paper presents the photoresponse characteristics of a high speed Ge nanowires (NWs) network metal-semiconductor-metal photodetector. Ge NWs with different diameters (30 nm-100 nm) were grown by a vapour-liquid-solid method on SiO2/Si (100) wafers. Responsivity up to 1.75 A W-1 has been observed for a 30 nm NWs device compared to 0.5 A W-1 for a 100 nm NWs detector. A large population of surface states results in higher responsivity in a smaller diameter NWs device. The high gain in photocurrent has been explained using back-to-back Schottky junctions in a NWs network. The 30 nm NWs detector shows a fast photoresponse with a rise time of 95 μs and a fall time of 100 μs. The observed diameter-dependent time response in network NWs devices has been explained using barrier-dominant photo-conductance.

  8. Physiological consequences of military high-speed boat transits. (United States)

    Myers, Stephen D; Dobbins, Trevor D; King, Stuart; Hall, Benjamin; Ayling, Ruth M; Holmes, Sharon R; Gunston, Tom; Dyson, Rosemary


    The purpose of this study was to investigate the consequences of a high-speed boat transit on physical performance. Twenty-four Royal Marines were randomly assigned to a control (CON) or transit (TRAN) group. The CON group sat onshore for 3 h whilst the TRAN group completed a 3-h transit in open-boats running side-by-side, at 40 knots in moderate-to-rough seas, with boat deck and seat-pan acceleration recorded. Performance tests (exhaustive shuttle-run, handgrip, vertical-jump, push-up) were completed pre- and immediately post-transit/sit, with peak heart rate (HRpeak) and rating of perceived exertion (RPE) recorded. Serial blood samples (pre, 24, 36, 48, 72 h) were analyzed for creatine kinase (CK) activity. The transit was typified by frequent high shock impacts, but moderate mean heart rates (boat transits.

  9. High-Speed, Three Dimensional Object Composition Mapping Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M Y


    This document overviews an entirely new approach to determining the composition--the chemical-elemental, isotopic and molecular make-up--of complex, highly structured objects, moreover with microscopic spatial resolution in all 3 dimensions. The front cover depicts the new type of pulsed laser system at the heart of this novel technology under adjustment by Alexis Wynne, and schematically indicates two of its early uses: swiftly analyzing the 3-D composition governed structure of a transistor circuit with both optical and mass-spectrometric detectors, and of fossilized dinosaur and turtle bones high-speed probed by optical detection means. Studying the composition-cued 3-D micro-structures of advanced composite materials and the microscopic scale composition-texture of biological tissues are two near-term examples of the rich spectrum of novel applications enabled by this field-opening analytic tool-set.

  10. High Speed Water Sterilization Using One-Dimensional Nanostructures

    KAUST Repository

    Schoen, David T.


    The removal of bacteria and other organisms from water is an extremely important process, not only for drinking and sanitation but also industrially as biofouling is a commonplace and serious problem. We here present a textile based multiscale device for the high speed electrical sterilization of water using silver nanowires, carbon nanotubes, and cotton. This approach, which combines several materials spanning three very different length scales with simple dying based fabrication, makes a gravity fed device operating at 100000 L/(h m2) which can inactivate >98% of bacteria with only several seconds of total incubation time. This excellent performance is enabled by the use of an electrical mechanism rather than size exclusion, while the very high surface area of the device coupled with large electric field concentrations near the silver nanowire tips allows for effective bacterial inactivation. © 2010 American Chemical Society.

  11. The taper corrosion pattern observed for one bi-modular stem design is related to geometry-determined taper mechanics. (United States)

    Buente, Dennis; Bryant, Michael; Ward, Michael; Neville, Anne; Morlock, Michael; Huber, Gerd


    Bi-modular primary hip stems exhibit high revision rates owing to corrosion at the stem-neck taper, and are associated with local adverse tissue reactions. The aim of this study was to relate the wear patterns observed for one bi-modular design to its design-specific stem-neck taper geometry. Wear patterns and initial geometry of the taper junctions were determined for 27 retrieved bi-modular primary hip arthroplasty stems (Rejuvenate, Stryker Orthopaedics) using a tactile coordinate-measuring device. Regions of high-gradient wear patterns were additionally analyzed via optical and electron microscopy. The determined geometry of the taper junction revealed design-related engagement at its opening (angle mismatch), concentrated at the medial and lateral apexes (axes mismatch). A patch of retained topography on the proximal medial neck-piece taper apex was observed, surrounded by regions of high wear. On the patch, a deposit from the opposing female stem taper-containing Ti, Mo, Zr, and O-was observed. High stress concentrations were focused at the taper apexes owing to the specific geometry. A medial canting of the components may have augmented the inhomogeneous stress distributions in vivo. In the regions with high normal loads interfacial slip and consequently fretting was inhibited, which explains the observed pattern of wear. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. High Speed Running and Sprinting Profiles of Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Miñano-Espin Javier


    Full Text Available Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD = 536, External Defenders (ED = 491, Central Midfielders (CM = 544, External Midfielders (EM = 233, and Forwards (F = 278. Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France. A repeated measures analysis of variance (ANOVA was performed for distances covered at different intensities (sprinting (>24.0 km/h and high-speed running (21.1-24.0 km/h and the number of sprints (21.1-24.0 km/h and >24.0 km/h during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p 0.01 from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition.

  13. Propulsion challenges and opportunities for high-speed transport aircraft (United States)

    Strack, William C.


    For several years there was a growing interest in the subject of efficient sustained supersonic cruise technology applied to a high-speed transport aircraft. The major challenges confronting the propulsion community for supersonic transport (SST) applications are identified. Both past progress and future opportunities are discussed in relation to perceived technology shortfalls for an economically successful SST that satisfies environmental constraints. A very large improvement in propulsion system efficiency is needed both at supersonic and subsonic cruise conditions. Toward that end, several advanced engine concepts are being considered that, together with advanced discipline and component technologies, promise at least 40 percent better efficiency that the Concorde engine. The quest for higher productivity through higher speed is also thwarted by the lack of a conventional, low-priced fuel that is thermally stable at the higher temperatures associated with faster flight. Airport noise remains a tough challenge because previously researched concepts fall short of achieving FAR 36 Stage 3 noise levels. Innovative solutions may be necessary to reach acceptably low noise. While the technical challenges are indeed formidable, it is reasonable to assume that the current shortfalls in fuel economy and noise can be overcome through an aggressive propulsion research program.

  14. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli


    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  15. Radio Wave Propagation Scene Partitioning for High-Speed Rails

    Directory of Open Access Journals (Sweden)

    Bo Ai


    Full Text Available Radio wave propagation scene partitioning is necessary for wireless channel modeling. As far as we know, there are no standards of scene partitioning for high-speed rail (HSR scenarios, and therefore we propose the radio wave propagation scene partitioning scheme for HSR scenarios in this paper. Based on our measurements along the Wuhan-Guangzhou HSR, Zhengzhou-Xian passenger-dedicated line, Shijiazhuang-Taiyuan passenger-dedicated line, and Beijing-Tianjin intercity line in China, whose operation speeds are above 300 km/h, and based on the investigations on Beijing South Railway Station, Zhengzhou Railway Station, Wuhan Railway Station, Changsha Railway Station, Xian North Railway Station, Shijiazhuang North Railway Station, Taiyuan Railway Station, and Tianjin Railway Station, we obtain an overview of HSR propagation channels and record many valuable measurement data for HSR scenarios. On the basis of these measurements and investigations, we partitioned the HSR scene into twelve scenarios. Further work on theoretical analysis based on radio wave propagation mechanisms, such as reflection and diffraction, may lead us to develop the standard of radio wave propagation scene partitioning for HSR. Our work can also be used as a basis for the wireless channel modeling and the selection of some key techniques for HSR systems.

  16. Changes of indicators of high-speed and high-speed and power preparedness at volleyball players of 12–13 years old


    Oleg Shevchenko


    Purpose: to define changes of indicators of high-speed and high-speed and power preparedness of volleyball players of 12–13 years old. Material & Methods: the test exercises, which are recommended by the training program of CYSS on volleyball, were used for the definition of the level of development of high-speed and high-speed and power abilities of volleyball players. 25 young volleyball players from the group of the previous basic preparation took part in the experiment. Sports experie...

  17. High-speed single-pixel digital holography (United States)

    González, Humberto; Martínez-León, Lluís.; Soldevila, Fernando; Araiza-Esquivel, Ma.; Tajahuerce, Enrique; Lancis, Jesús


    The complete phase and amplitude information of biological specimens can be easily determined by phase-shifting digital holography. Spatial light modulators (SLMs) based on liquid crystal technology, with a frame-rate around 60 Hz, have been employed in digital holography. In contrast, digital micro-mirror devices (DMDs) can reach frame rates up to 22 kHz. A method proposed by Lee to design computer generated holograms (CGHs) permits the use of such binary amplitude modulators as phase-modulation devices. Single-pixel imaging techniques record images by sampling the object with a sequence of micro-structured light patterns and using a simple photodetector. Our group has reported some approaches combining single-pixel imaging and phase-shifting digital holography. In this communication, we review these techniques and present the possibility of a high-speed single-pixel phase-shifting digital holography system with phase-encoded illumination. This system is based on a Mach-Zehnder interferometer, with a DMD acting as the modulator for projecting the sampling patterns on the object and also being used for phase-shifting. The proposed sampling functions are phaseencoded Hadamard patterns generated through a Lee hologram approach. The method allows the recording of the complex amplitude distribution of an object at high speed on account of the high frame rates of the DMD. Reconstruction may take just a few seconds. Besides, the optical setup is envisaged as a true adaptive system, which is able to measure the aberration induced by the optical system in the absence of a sample object, and then to compensate the wavefront in the phasemodulation stage.

  18. High-speed cinematography of gas-metal atomization

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Jason [ALCOA Specialty Metals Division, 100 Technical Drive, Alcoa Center, PA 15069 (United States)]. E-mail:; Connor, Jeffery [Material Science Engineering Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Ridder, Stephen [Metallurgical Processing Group, NIST, 100 Bureau Dr. Stop 8556, Gaithersburg, MD 20899 (United States)


    A high-speed cinematographic footage of a 304L stainless steel gas atomization, recorded at the National Institute of Standard and Technology (NIST), was analyzed using a discrete Fourier transform (DFT) algorithm. The analysis showed the gas atomization process possesses two prominent frequency ranges of melt oscillation (pulsation). A low-frequency oscillation in the melt flow occurring between 5.41 and 123 Hz, with a dominant frequency at 9.93 Hz, was seen in the recirculation zone adjacent to the melt orifice. A high-frequency melt oscillation range was observed above 123 Hz, and was more prominent one melt-tip-diameter downstream in the melt atomization image than upstream near the melt tip. This high-frequency range may reflect the melt atomization frequency used to produce finely atomized powder. This range also included a prominent high frequency at 1273 Hz, which dominated in the image further away downstream from the melt tip. This discrete high-frequency oscillation is most probably caused by the aeroacoustic ''screech'' phenomenon, intrasound (<20 kHz), a result of the atomizing gas jets undergoing flow resonance. It is hypothesized that this discrete intrinsic aeroacoustic tone may enhance melt breakup in the atomization process with evidence of this fact in the melt images.

  19. High-speed Integrated Circuits for electrical/Optical Interfaces

    DEFF Research Database (Denmark)

    Jespersen, Christoffer Felix


    of LC-oscillators with oscillator criteria, phase noise and different topologies are given as background. The theory of PLL circuits is also presented. Guidelines and suggestions for static divider, VCO, LA and CDR design are presented using static divider, 50-100 GHz VCO and 100Gb/s LA+CDR circuits......This thesis is a continuation of the effort to increase the bandwidth of communicationnetworks. The thesis presents the results of the design of several high-speed electrical ircuits for an electrical/optical interface. These circuits have been a contribution to the ESTA project in collaboration...... circuits at the receiver interface, though VCOs are also found in the transmitter where a multitude of independent sources have to be mutually synchronized before multiplexing. The circuits are based on an InP DHBT process (VIP-2) supplied by Vitesse and made publicly available as MPW. The VIP-2 process...

  20. Simplified Dynamic Model for High-Speed Checkweigher (United States)

    Yamakawa, Yuji; Yamazaki, Takanori

    In this paper, we concern with the dynamic behaviors of a high speed mass measurement system with conveyor belt (a checkweigher). The goal of this paper is to construct a simple model of the measurement system so as to duplicate a response of the system. The checkweigher with electromagnetic force compensation can be approximated by the combined spring-mass-damper systems as the physical model, and the equation of motion is derived. The model parameters (a damping coefficient and a spring constant) can be obtained from the experimental data for open-loop system. Finally, the validity of the proposed model can be confirmed by comparison of the simulation results with the realistic responses. The simple dynamic model obtained offers practical and useful information to examine control scheme.


    Directory of Open Access Journals (Sweden)

    Benea Ciprian


    Full Text Available In this exposure we intend to make visible the situation in which global warming is given by road and air transport, how could be revitalized railways, and how high speed trains could become a preferred mode of transport. But there is manifesting an opposition to railway development, nurtured by different interests, ranking from governments themselves, to oil importing countries, oil exporting countries, oil companies with their colligate partners situated along the oil distribution chain. But, there could be identified some voices which could create themselves the possibility to speak lauder in order to promote railway transportation. The greens, NGOs, the epistemic communities, for example, could unite their force to make something in order to provide the framework for rail transportation’s development, and for road and air transport reduction, for the benefit of while humankind.

  2. Design implications of high-speed digital PPM (United States)

    Sibley, Martin J. N.


    Work in the area of digital pulse position modulation (digital PPM) has shown that this type of modulation can yield sensitivities that are typically 4 - 5 dB better than an equivalent PCM system. Recent experimental work has shown that the receiver in a digital PPM system does not need to have a wide bandwidth. Instead, the bandwidth can be very low so that the receiver is effectively impulsed by the digital PPM signal. The advent of very high speed Si digital ICs, and fast lasers, means that digital PPM can now be used to code gigabit PCM signals. This paper presents original theoretical results for a digital PPM system coding 1 Gbit/s PCM signals into 8 Gbit/s digital PPM signals. The paper also addresses the difficulties that the system designer is likely to encounter, and discusses some possible solutions.

  3. Machining Chatter Analysis for High Speed Milling Operations (United States)

    Sekar, M.; Kantharaj, I.; Amit Siddhappa, Savale


    Chatter in high speed milling is characterized by time delay differential equations (DDE). Since closed form solution exists only for simple cases, the governing non-linear DDEs of chatter problems are solved by various numerical methods. Custom codes to solve DDEs are tedious to build, implement and not error free and robust. On the other hand, software packages provide solution to DDEs, however they are not straight forward to implement. In this paper an easy way to solve DDE of chatter in milling is proposed and implemented with MATLAB. Time domain solution permits the study and model of non-linear effects of chatter vibration with ease. Time domain results are presented for various stable and unstable conditions of cut and compared with stability lobe diagrams.

  4. Premiere in high speed materials inter-operability

    Energy Technology Data Exchange (ETDEWEB)

    Brun, D.


    The Eurostar trains have been designed to meet the safety requirements of the Channel Tunnel. In particular, ti must be possible to remove the train from the tunnel in most fault scenarios. The train design is based upon an optimal capacity/price ratio. As far as the installation of electrical equipment is concerned (power supply, power conversion, motor units), the variety of track configurations is another consideration in addition to the questions of safety. The original solutions adopted give traction and braking performance that are satisfactory by comparison with the high-speed trains (TGV) in service on appropriate track, and the best possible for the British track. The trains are heavier and less powerful, but they are capable of getting out of the tunnel with only one motor out of three in service. (author). 6 figs.

  5. Towards high-speed autonomous navigation of unknown environments (United States)

    Richter, Charles; Roy, Nicholas


    In this paper, we summarize recent research enabling high-speed navigation in unknown environments for dynamic robots that perceive the world through onboard sensors. Many existing solutions to this problem guarantee safety by making the conservative assumption that any unknown portion of the map may contain an obstacle, and therefore constrain planned motions to lie entirely within known free space. In this work, we observe that safety constraints may significantly limit performance and that faster navigation is possible if the planner reasons about collision with unobserved obstacles probabilistically. Our overall approach is to use machine learning to approximate the expected costs of collision using the current state of the map and the planned trajectory. Our contribution is to demonstrate fast but safe planning using a learned function to predict future collision probabilities.

  6. Dynamic Control of High-speed Train Following Operation

    Directory of Open Access Journals (Sweden)

    Deng Pan


    Full Text Available Both safety and efficiency should be considered in high-speed train following control. The real-time calculation of dynamic safety following distance is used by the following train to understand the quality of its own following behavior. A new velocity difference control law can help the following train to adjust its own behavior from a safe and efficient steady-following state to another one if the actual following distance is greater than the safe following distance. Meanwhile, the stopping control law would work for collision avoidance when the actual following distance is less than the safe following distance. The simulation shows that the dynamic control of actual inter-train distance can be well accomplished by the behavioral adjustment of the following train, and verifies the effectiveness and feasibility of our presented methods for train following control.

  7. High-speed counters in Fibonacci numerical system (United States)

    Azarov, Olexiy; Chernyak, Olexandr; Komada, Paweł; Kozhambardiyeva, Miergul; Kalizhanova, Aliya


    Possibility of executing the carriers and borrowings by means of elementary additive transformations in the process of calculation in Fibonacci numerical system is substantiated. Methods of counting in the given numerical system, based on the usage of information redundancy are suggested. The methods consist in the fact that at every step executed all possible elementary addition transformations of code in the counter simultaneously with adding one. The suggested methods enable to construct up-, down- and up/down counters with high speed, independent on the data capacity and small hardware cost that linearly grow with the increase of the capacity. Schemes of structural organization of one digit for each of the suggested methods are given.

  8. Model Lengkung Bentuk Batang (Taper Curve Pohon Jati (Tectona Grandis

    Directory of Open Access Journals (Sweden)

    Ronggo Sadono


    Full Text Available Model of Taper Curve of Teak Stem (Tectona grandis Detailed information on tree volume for fancy wood, such as teak, is important to estimate its financial value. Therefore, a method of estimating stem volume in portion wise is developed. The objective of this study was to apply a parabolic taper curve in various tree strata. Data of stem diameter at any relative height were collected from selected felled-tree samples according to stem quality both in the state and community forests by section wise measurement. Regression analysis was applied to estimate parameter and to test the suitability level of the parabolic taper model. The results showed that parabolic taper model could be used to describe the stem curve of clear bole stem in state forest and the stem curve up to tree height with minimum diameter of ca. 10 cm. In the state forest, the parabolic taper model was fit to medium and large diameter classes or in the intermediate and dominant strata. For small diameter class or in suppressed stratum, the model was not sufficiently fit. On the other hand, the parabolic taper model was fit to all samples from community forests because the samples comprised the stem of best quality from the stand. The parabolic taper model was suitable to apply on high quality stems which were characterized with healthy, cylindrical, and straight stem, high clear bole, and straight grain.

  9. High-Speed Edge-Detecting Line Scan Smart Camera (United States)

    Prokop, Norman F.


    A high-speed edge-detecting line scan smart camera was developed. The camera is designed to operate as a component in a NASA Glenn Research Center developed inlet shock detection system. The inlet shock is detected by projecting a laser sheet through the airflow. The shock within the airflow is the densest part and refracts the laser sheet the most in its vicinity, leaving a dark spot or shadowgraph. These spots show up as a dip or negative peak within the pixel intensity profile of an image of the projected laser sheet. The smart camera acquires and processes in real-time the linear image containing the shock shadowgraph and outputting the shock location. Previously a high-speed camera and personal computer would perform the image capture and processing to determine the shock location. This innovation consists of a linear image sensor, analog signal processing circuit, and a digital circuit that provides a numerical digital output of the shock or negative edge location. The smart camera is capable of capturing and processing linear images at over 1,000 frames per second. The edges are identified as numeric pixel values within the linear array of pixels, and the edge location information can be sent out from the circuit in a variety of ways, such as by using a microcontroller and onboard or external digital interface to include serial data such as RS-232/485, USB, Ethernet, or CAN BUS; parallel digital data; or an analog signal. The smart camera system can be integrated into a small package with a relatively small number of parts, reducing size and increasing reliability over the previous imaging system..

  10. Parallel scanning laser ophthalmoscope (PSLO) for high-speed retinal imaging

    NARCIS (Netherlands)

    Vienola, K.V.; Braaf, Boy; Damodaran, Mathi; Vermeer, Koenraad A.; de Boer, Johannes F.


    Purpose High-speed imaging of the retina is crucial for obtaining high quality images in the presence of eye motion. To improve the speed of traditional scanners, a high-speed ophthalmic device is presented using a digital micro-mirror device (DMD) for confocal imaging with multiple simultaneous

  11. 49 CFR 236.1007 - Additional requirements for high-speed service. (United States)


    ... by this subpart, and which have been utilized on high-speed rail systems with similar technical and... 49 Transportation 4 2010-10-01 2010-10-01 false Additional requirements for high-speed service..., AND APPLIANCES Positive Train Control Systems § 236.1007 Additional requirements for high-speed...

  12. Dual-camera system for high-speed imaging in particle image velocimetry

    CERN Document Server

    Hashimoto, K; Hara, T; Onogi, S; Mouri, H


    Particle image velocimetry is an important technique in experimental fluid mechanics, for which it has been essential to use a specialized high-speed camera. However, the high speed is at the expense of other performances of the camera, i.e., sensitivity and image resolution. Here, we demonstrate that the high-speed imaging is also possible with a pair of still cameras.

  13. An Ultra-High Speed Whole Slide Image Viewing System

    Directory of Open Access Journals (Sweden)

    Yukako Yagi


    Full Text Available Background: One of the goals for a Whole Slide Imaging (WSI system is implementation in the clinical practice of pathology. One of the unresolved problems in accomplishing this goal is the speed of the entire process, i.e., from viewing the slides through making the final diagnosis. Most users are not satisfied with the correct viewing speeds of available systems. We have evaluated a new WSI viewing station and tool that focuses on speed.

  14. Ultra-low loss single-mode silica tapers manufactured by a microheater

    CERN Document Server

    Ding, Lu; Ducci, Sara; Leo, Giuseppe; Favero, Ivan


    Using a ceramic thermoelectric heater, we show highly reproducible fabrication of single-mode sub-wavelength silica tapers with ultra-low loss level. The reproducibility of the process is studied statistically, leading to an average taper transmission of 94%. The best tapers have a transmission superior to 99%, above common level reached by other fabrication methods. The taper profile is inspected along its length and closely follows the exponential profile predicted by the model of Birks and Li. This high degree of control over the taper shape allows a detailed analysis of the transition to the single-mode regime during tapering. As an application of this fabrication method, we present a micro-looped taper probe for evanescent coupling experiments requiring fine spatial selectivity.

  15. High-Speed, Low-Power Digitizer II (2007037) Project (United States)

    National Aeronautics and Space Administration — Future detectors and arrays for visible, IR, and submillimeter imaging and spectroscopy require much higher speed digitizers than are currently available. In...

  16. High-Speed, Low-Power Digitizer (9725) Project (United States)

    National Aeronautics and Space Administration — Future detectors and arrays for visible, IR, and submillimeter imaging and spectroscopy require much higher speed digitizers than are currently available. In...

  17. Plastic straw: future of high-speed signaling (United States)

    Song, Ha Il; Jin, Huxian; Bae, Hyeon-Min


    The ever-increasing demand for bandwidth triggered by mobile and video Internet traffic requires advanced interconnect solutions satisfying functional and economic constraints. A new interconnect called E-TUBE is proposed as a cost-and-power-effective all-electrical-domain wideband waveguide solution for high-speed high-volume short-reach communication links. The E-TUBE achieves an unprecedented level of performance in terms of bandwidth-per-carrier frequency, power, and density without requiring a precision manufacturing process unlike conventional optical/waveguide solutions. The E-TUBE exhibits a frequency-independent loss-profile of 4 dB/m and has nearly 20-GHz bandwidth over the V band. A single-sideband signal transmission enabled by the inherent frequency response of the E-TUBE renders two-times data throughput without any physical overhead compared to conventional radio frequency communication technologies. This new interconnect scheme would be attractive to parties interested in high throughput links, including but not limited to, 100/400 Gbps chip-to-chip communications.

  18. Budgerigar flight in a varying environment: flight at distinct speeds?


    Schiffner, Ingo; Srinivasan, Mandyam V.


    How do flying birds respond to changing environments? The behaviour of budgerigars, Melopsittacus undulatus, was filmed as they flew through a tapered tunnel. Unlike flying insects���which vary their speed progressively and continuously by holding constant the optic flow induced by the walls���the birds showed a tendency to fly at only two distinct, fixed speeds. They switched between a high speed in the wider section of the tunnel, and a low speed in the narrower section. The transition betw...

  19. Changes of indicators of high-speed and high-speed and power preparedness at volleyball players of 12–13 years old

    Directory of Open Access Journals (Sweden)

    Oleg Shevchenko


    Full Text Available Purpose: to define changes of indicators of high-speed and high-speed and power preparedness of volleyball players of 12–13 years old. Material & Methods: the test exercises, which are recommended by the training program of CYSS on volleyball, were used for the definition of the level of development of high-speed and high-speed and power abilities of volleyball players. 25 young volleyball players from the group of the previous basic preparation took part in the experiment. Sports experience of sportsmen is 3–4 years. The analysis of scientifically-methodical literature, pedagogical testing, pedagogical experiment, methods of mathematical statistics were carried out. Results: the analyzed level of high-speed and high-speed and power abilities of volleyball players. Conclusions: the results had reliable changes (t=2,2–2,4 at р<0,05 of the level of high-speed and high-speed and power abilities of volleyball players of 12–13years old in the experimental group at the end of the experiment, except run on 30 m that demonstrates a positive influence of application of special exercises in the educational-training process.

  20. The use of low-radius circular-cross-section helical strakes for the reduction of VIV of tapered cylinders at high Reynolds numbers

    DEFF Research Database (Denmark)

    Johansson, Jens; Christensen, Silas Sverre


    transportation. Wind tunnel experiments have been conducted with a tapered cylinder section model representing these towers, and static tests have been performed up to Re = 7.2x10^5. Dynamic tests have been performed for a setup with a critical wind velocity for vortex shedding corresponding to Re = 4.96 x10...

  1. Towards real-time feedback in high performance speed skating

    NARCIS (Netherlands)

    van der Eb, Jeroen; Zandee, Willem; van den Bogaard, Timo; Geraets, Sjoerd; Veeger, H.E.J.; Beek, Peter; Potthast, Wolfgang; Niehoff, Anja; David, Sina


    The aim of the current study is to evaluate several performance indicators to be used as real-time feedback in the coming experiments to enhance performance of elite speeds skaters. Six speed skaters, wearing one IMU per skate, collected data over one full training season to evaluate and pinpoint

  2. Fire protection for high speed line tunnels; Risk analysis and exceptional robotic application results

    NARCIS (Netherlands)

    Linde, F.W.J. van de; Gijsbers, F.B.J.; Klok, G.J.


    The Green Hart Tunnel in The Netherlands is a 7 km long high speed railway tunnel with an exterior diameter of 14.5 metres. A separation wall devides the tunnel into two single tubes. High speed trains will pass the tunnel at speeds of more than 300 kph. Inside the tunnel 200,000 m2 fire resistant

  3. Improvement of vocal pathologies diagnosis using high-speed videolaryngoscopy. (United States)

    Tsuji, Domingos Hiroshi; Hachiya, Adriana; Dajer, Maria Eugenia; Ishikawa, Camila Cristina; Takahashi, Marystella Tomoe; Montagnoli, Arlindo Neto


    Introduction The study of the dynamic properties of vocal fold vibration is important for understanding the vocal production mechanism and the impact of organic and functional changes. The advent of high-speed videolaryngoscopy (HSV) has provided the possibility of seeing the real cycle of vocal fold vibration in detail through high sampling rate of successive frames and adequate spatial resolution. Objective To describe the technique, advantages, and limitations of using HSV and digital videokymography in the diagnosis of vocal pathologies. Methods We used HSV and digital videokymography to evaluate one normophonic individual and four patients with vocal fold pathologies (nodules, unilateral paralysis of the left vocal fold, intracordal cyst, and adductor spasmodic dysphonia). The vocal fold vibration parameters (glottic closure, vibrational symmetry, periodicity, mucosal wave, amplitude, and glottal cycle phases) were assessed. Results Differences in the vocal vibration parameters were observed and correlated with the pathophysiology. Conclusion HSV is the latest diagnostic tool in visual examination of vocal behavior and has considerable potential to refine our knowledge regarding the vocal fold vibration and voice production, as well as regarding the impact of pathologic conditions have on the mechanism of phonation.

  4. Improvement of Vocal Pathologies Diagnosis Using High-Speed Videolaryngoscopy

    Directory of Open Access Journals (Sweden)

    Tsuji, Domingos Hiroshi


    Full Text Available Introduction The study of the dynamic properties of vocal fold vibration is important for understanding the vocal production mechanism and the impact of organic and functional changes. The advent of high-speed videolaryngoscopy (HSV has provided the possibility of seeing the real cycle of vocal fold vibration in detail through high sampling rate of successive frames and adequate spatial resolution. Objective To describe the technique, advantages, and limitations of using HSV and digital videokymography in the diagnosis of vocal pathologies. Methods We used HSV and digital videokymography to evaluate one normophonic individual and four patients with vocal fold pathologies (nodules, unilateral paralysis of the left vocal fold, intracordal cyst, and adductor spasmodic dysphonia. The vocal fold vibration parameters (glottic closure, vibrational symmetry, periodicity, mucosal wave, amplitude, and glottal cycle phases were assessed. Results Differences in the vocal vibration parameters were observed and correlated with the pathophysiology. Conclusion HSV is the latest diagnostic tool in visual examination of vocal behavior and has considerable potential to refine our knowledge regarding the vocal fold vibration and voice production, as well as regarding the impact of pathologic conditions have on the mechanism of phonation.

  5. Lagrangian transported MDF methods for compressible high speed flows (United States)

    Gerlinger, Peter


    This paper deals with the application of thermochemical Lagrangian MDF (mass density function) methods for compressible sub- and supersonic RANS (Reynolds Averaged Navier-Stokes) simulations. A new approach to treat molecular transport is presented. This technique on the one hand ensures numerical stability of the particle solver in laminar regions of the flow field (e.g. in the viscous sublayer) and on the other hand takes differential diffusion into account. It is shown in a detailed analysis, that the new method correctly predicts first and second-order moments on the basis of conventional modeling approaches. Moreover, a number of challenges for MDF particle methods in high speed flows is discussed, e.g. high cell aspect ratio grids close to solid walls, wall heat transfer, shock resolution, and problems from statistical noise which may cause artificial shock systems in supersonic flows. A Mach 2 supersonic mixing channel with multiple shock reflection and a model rocket combustor simulation demonstrate the eligibility of this technique to practical applications. Both test cases are simulated successfully for the first time with a hybrid finite-volume (FV)/Lagrangian particle solver (PS).

  6. Submonolayer Quantum Dots for High Speed Surface Emitting Lasers

    Directory of Open Access Journals (Sweden)

    Zakharov ND


    Full Text Available AbstractWe report on progress in growth and applications of submonolayer (SML quantum dots (QDs in high-speed vertical-cavity surface-emitting lasers (VCSELs. SML deposition enables controlled formation of high density QD arrays with good size and shape uniformity. Further increase in excitonic absorption and gain is possible with vertical stacking of SML QDs using ultrathin spacer layers. Vertically correlated, tilted or anticorrelated arrangements of the SML islands are realized and allow QD strain and wavefunction engineering. Respectively, both TE and TM polarizations of the luminescence can be achieved in the edge-emission using the same constituting materials. SML QDs provide ultrahigh modal gain, reduced temperature depletion and gain saturation effects when used in active media in laser diodes. Temperature robustness up to 100 °C for 0.98 μm range vertical-cavity surface-emitting lasers (VCSELs is realized in the continuous wave regime. An open eye 20 Gb/s operation with bit error rates better than 10−12has been achieved in a temperature range 25–85 °Cwithout current adjustment. Relaxation oscillations up to ∼30 GHz have been realized indicating feasibility of 40 Gb/s signal transmission.

  7. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.


    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  8. Prototype high speed optical delay line for stellar interferometry (United States)

    Colavita, M. M.; Hines, B. E.; Shao, M.; Klose, G. J.; Gibson, B. V.


    The long baselines of the next-generation ground-based optical stellar interferometers require optical delay lines which can maintain nm-level path-length accuracy while moving at high speeds. NASA-JPL is currently designing delay lines to meet these requirements. The design is an enhanced version of the Mark III delay line, with the following key features: hardened, large diameter wheels, rather than recirculating ball bearings, to reduce mechanical noise; a friction-drive cart which bears the cable-dragging forces, and drives the optics cart through a force connection only; a balanced PZT assembly to enable high-bandwidth path-length control; and a precision aligned flexural suspension for the optics assembly to minimize bearing noise feedthrough. The delay line is fully programmable in position and velocity, and the system is controlled with four cascaded software feedback loops. Preliminary performance is a jitter in any 5 ms window of less than 10 nm rms for delay rates of up to 28 mm/s; total jitter is less than 10 nm rms for delay rates up to 20 mm/s.

  9. The Kaye effect revisited: High speed imaging of leaping shampoo (United States)

    Versluis, Michel; Blom, Cock; van der Meer, Devaraj; van der Weele, Ko; Lohse, Detlef


    When a visco-elastic fluid such as shampoo or shower gel is poured onto a flat surface the fluid piles up forming a heap on which rather irregular combinations of fluid buckling, coiling and folding are observed. Under specific conditions a string of fluid leaps from the heap and forms a steady jet fed by the incoming stream. Momentum transfer of the incoming jet, combined with the shear-thinning properties of the fluid, lead to a spoon-like dimple in the highly viscous fluid pool in which the jet recoils. The jet can be stable for several seconds. This effect is known as the Kaye effect. In order to reveal its mechanism we analyzed leaping shampoo through high-speed imaging. We studied the jet formation, jet stability and jet disruption mechanisms. We measured the velocity of both the incoming and recoiled jet, which was found to be thicker and slower. By inclining the surface on which the fluid was poured we observed jets leaping at upto five times.

  10. Composite flywheel material design for high-speed energy storage

    Directory of Open Access Journals (Sweden)

    Michael A. Conteh


    Full Text Available Lamina and laminate mechanical properties of materials suitable for flywheel high-speed energy storage were investigated. Low density, low modulus and high strength composite material properties were implemented for the constant stress portion of the flywheel while higher density, higher modulus and strength were implemented for the constant thickness portion of the flywheel. Design and stress analysis were used to determine the maximum energy densities and shape factors for the flywheel. Analytical studies along with the use of the CADEC-online software were used to evaluate the lamina and laminate properties. This study found that a hybrid composite of M46J/epoxy–T1000G/epoxy for the flywheel exhibits a higher energy density when compared to known existing flywheel hybrid composite materials such as boron/epoxy–graphite/epoxy. Results from this study will contribute to further development of the flywheel that has recently re-emerged as a promising application for energy storage due to significant improvements in composite materials and technology.

  11. High-Speed Visualisation of Combustion in Modern Gasoline Engines (United States)

    Sauter, W.; Nauwerck, A.; Han, K.-M.; Pfeil, J.; Velji, A.; Spicher, U.


    Today research and development in the field of gasoline engines have to face a double challenge: on the one hand, fuel consumption has to be reduced, while on the other hand, ever more stringent emission standards have to be fulfilled. The development of engines with its complexity of in-cylinder processes requires modern development tools to exploit the full potential in order to reduce fuel consumption. Especially optical, non-intrusive measurement techniques will help to get a better understanding of the processes. With the presented high-speed visualisation system the electromagnetic radiation from combustion in the UV range is collected by an endoscope and transmitted to a visualisation system by 10, 000 optical fibres. The signal is projected to 1, 920 photomultipliers, which convert the optical into electric signals with a maximum temporal resolution of 200 kHz. This paper shows the systematic application of flame diagnostics in modern combustion systems. For this purpose, a single-cylinder SI engine has been modified for a spray guided combustion strategy as well as for HCCI. The characteristics of flame propagation in both combustion modes were recorded and correlated with thermodynamic analyses. In case of the spray guided GDI engine, high pressure fuel injection was applied and evaluated.

  12. Materials, structures, and devices for high-speed electronics (United States)

    Woollam, John A.; Snyder, Paul G.


    Advances in materials, devices, and instrumentation made under this grant began with ex-situ null ellipsometric measurements of simple dielectric films on bulk substrates. Today highly automated and rapid spectroscopic ellipsometers are used for ex-situ characterization of very complex multilayer epitaxial structures. Even more impressive is the in-situ capability, not only for characterization but also for the actual control of the growth and etching of epitaxial layers. Spectroscopic ellipsometry has expanded from the research lab to become an integral part of the production of materials and structures for state of the art high speed devices. Along the way, it has contributed much to our understanding of the growth characteristics and material properties. The following areas of research are summarized: Si3N4 on GaAs, null ellipsometry; diamondlike carbon films; variable angle spectroscopic ellipsometry (VASE) development; GaAs-AlGaAs heterostructures; Ta-Cu diffusion barrier films on GaAs; GaAs-AlGaAs superlattices and multiple quantum wells; superconductivity; in situ elevated temperature measurements of III-V's; optical constants of thermodynamically stable InGaAs; doping dependence of optical constants of GaAs; in situ ellipsometric studies of III-V epitaxial growth; photothermal spectroscopy; microellipsometry; and Si passivation and Si/SiGe strained-layer superlattices.

  13. New Drive Train Concept with Multiple High Speed Generator (United States)

    Barenhorst, F.; Serowy, S.; Andrei, C.; Schelenz, R.; Jacobs, G.; Hameyer, K.


    In the research project RapidWind (financed by the German Federal Ministry for Economic Affairs and Energy under Grant 0325642) an alternative 6 MW drive train configuration with six high-speed (n = 5000 rpm) permanent magnet synchronous generators for wind turbine generators (WTG) is designed. The gearbox for this drive train concept is assembled with a six fold power split spur gear stage in the first stage, followed by six individual 1 MW geared driven generators. Switchable couplings are developed to connect and disconnect individual geared generators depending on the input power. With this drive train configuration it is possible to improve the efficiency during partial load operation, increasing the energy yield about 1.15% for an exemplary low-wind site. The focus of this paper is the investigation of the dynamic behavior of this new WTG concept. Due to the high gear ratio the inertia relationship between rotor and generator differs from conventional WT concepts, possibly leading to intensified vibration behavior. Moreover there are switching procedures added, that might also lead to vibration issues.

  14. Do Stem Taper Microgrooves Influence Taper Corrosion in Total Hip Arthroplasty? A Matched Cohort Retrieval Study. (United States)

    Arnholt, Christina M; MacDonald, Daniel W; Underwood, Richard J; Guyer, Eric P; Rimnac, Clare M; Kurtz, Steven M; Mont, Michael A; Klein, Gregg R; Lee, Gwo-Chin; Chen, Antonia F; Hamlin, Brian R; Cates, Harold E; Malkani, Arthur L; Kraay, Matthew J


    Previous studies identified imprinting of the stem morphology onto the interior head bore, leading researchers to hypothesize an influence of taper topography on mechanically assisted crevice corrosion. The purpose of this study was to analyze whether microgrooved stem tapers result in greater fretting corrosion damage than smooth stem tapers. A matched cohort of 120 retrieved head-stem pairs from metal-on-polyethylene bearings was created controlling for implantation time, flexural rigidity, apparent length of engagement, and head size. There were 2 groups of 60 heads each, mated with either smooth or microgrooved stem tapers. A high-precision roundness machine was used to measure and categorize the surface morphology. Fretting corrosion damage at the head-neck junction was characterized using the Higgs-Goldberg scoring method. Fourteen of the most damaged heads were analyzed for the maximum depth of material loss and focused ion beam cross-sectioned to view oxide and base metal. Fretting corrosion damage was not different between the 2 cohorts at the femoral head (P = .14, Mann-Whitney) or stem tapers (P = .35). There was no difference in the maximum depths of material loss between the cohorts (P = .71). Cross-sectioning revealed contact damage, signs of micro-motion, and chromium-rich oxide layers in both cohorts. Microgroove imprinting did not appear to have a different effect on the fretting corrosion behavior. The results of this matched cohort retrieval study do not support the hypothesis that taper surfaces with microgrooved stems exhibit increased in vivo fretting corrosion damage or material release. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Numerical study of a high-speed miniature centrifugal compressor (United States)

    Li, Xiaoyi

    A miniature centrifugal compressor is a key component of reverse Brayton cycle cryogenic cooling system. The system is commonly used to generate a low cryogenic temperature environment for electronics to increase their efficiency, or generate, store and transport cryogenic liquids, such as liquid hydrogen and oxygen, where space limit is also an issue. Because of space limitation, the compressor is composed of a radial IGV, a radial impeller and an axial-direction diffuser (which reduces the radial size because of smaller diameter). As a result of reduction in size, rotating speed of the impeller is as high as 313,000 rpm, and Helium is used as the working fluid, in order to obtain the required static pressure ratio/rise. Two main characteristics of the compressor---miniature and high-speed, make it distinct from conventional compressors. Higher compressor efficiency is required to obtain a higher COP (coefficient of performance) system. Even though miniature centrifugal compressors start to draw researchers' attention in recent years, understanding of the performance and loss mechanism is still lacking. Since current experimental techniques are not advanced enough to capture details of flow at miniature scale, numerical methods dominate miniature turbomachinery study. This work numerically studied a high speed miniature centrifugal compressor with commercial CFD code. The overall performance of the compressor was predicted with consideration of interaction between blade rows by using sliding mesh model. The law of similarity of turbomachinery was validated for small scale machines. It was found that the specific ratio effect needs to be considered when similarity law is applied. But Reynolds number effect can be neglected. The loss mechanism of each component was analyzed. Loss due to turning bend was significant in each component. Tip leakage loss of small scale turbomachines has more impact on the impeller performance than that of large scale ones. Because the

  16. The wild tapered block bootstrap

    DEFF Research Database (Denmark)

    Hounyo, Ulrich

    -based method in terms of asymptotic accuracy of variance estimation and distribution approximation. For stationary time series, the asymptotic validity, and the favorable bias properties of the new bootstrap method are shown in two important cases: smooth functions of means, and M-estimators. The first......In this paper, a new resampling procedure, called the wild tapered block bootstrap, is introduced as a means of calculating standard errors of estimators and constructing confidence regions for parameters based on dependent heterogeneous data. The method consists in tapering each overlapping block...... of the series first, the applying the standard wild bootstrap for independent and heteroscedastic distrbuted observations to overlapping tapered blocks in an appropriate way. Its perserves the favorable bias and mean squared error properties of the tapered block bootstrap, which is the state-of-the-art block...

  17. Development and Performance of the ACTS High Speed VSAT (United States)

    Quintana, J.; Tran, Q.; Dendy, R.


    The Advanced Communication Technology Satellite (ACTS), developed by the U.S. National Aeronautics and Space Administration (NASA) has demonstrated the breakthrough technologies of Ka-band, spot beam antennas, and on-board processing. These technologies have enabled the development of very small aperture terminals (VSAT) and ultra-small aperture terminals (USAT) which have capabilities greater than were previously possible with conventional satellite technologies. However, the ACTS baseband processor (BBP) is designed using a time division multiple access (TDMA) scheme, which requires each earth station using the BBP to transmit data at a burst rate which is much higher than the user throughput data rate. This tends to mitigate the advantage of the new technologies by requiring a larger earth station antenna and/or a higher-powered uplink amplifier than would be necessary for a continuous transmission at the user data rate. Conversely, the user data rate is much less than the rate that can be supported by the antenna size and amplifier. For example, the ACTS TI VSAT operates at a burst rate of 27.5 Mbps, but the maximum user data rate is 1.792 Mbps. The throughput efficiency is slightly more than 6.5%. For an operational network, this level of overhead will greatly increase the cost of the user earth stations, and that increased cost must be repeated thousands of times, which may ultimately reduce the market for such a system. The ACTS High Speed VSAT (HS VSAT) is an effort to experimentally demonstrate the maximum user throughput data rate which can be achieved using the technologies developed and implemented on ACTS. Specifically, this was done by operating the system uplinks as frequency division multiple access (FDMA), essentially assigning all available TDMA time slots to a single user on each of two uplink frequencies. Preliminary results show that using a 1.2-m antenna in this mode, the HS VSAT can achieve between 22 and 24 Mbps out of the 27.5 Mbps burst

  18. A Novel High Dimensional and High Speed Data Streams Algorithm: HSDStream


    Irshad Ahmed; Irfan Ahmed; Waseem Shahzad


    This paper presents a novel high speed clustering scheme for high-dimensional data stream. Data stream clustering has gained importance in different applications, for example, network monitoring, intrusion detection, and real-time sensing. High dimensional stream data is inherently more complex when used for clustering because the evolving nature of the stream data and high dimensionality make it non-trivial. In order to tackle this problem, projected subspace within the high dimensions and l...

  19. Tapered undulators for SASE FELs

    CERN Document Server

    Fawley, W M; Vinokurov, N A


    We discuss the use of tapered undulators to enhance the performance of free-electron lasers (FELs) based upon self-amplified spontaneous emission, where the radiation tends to have a relatively broad bandwidth and limited temporal coherence. Using the polychromatic FEL simulation code GINGER, we numerically demonstrate the effectiveness of tapered undulators for parameters corresponding to the Argonne low-energy undulator test line FEL and the proposed linac coherent light source.

  20. Holistic design in high-speed optical interconnects (United States)

    Saeedi, Saman

    Integrated circuit scaling has enabled a huge growth in processing capability, which necessitates a corresponding increase in inter-chip communication bandwidth. As bandwidth requirements for chip-to-chip interconnection scale, deficiencies of electrical channels become more apparent. Optical links present a viable alternative due to their low frequency-dependent loss and higher bandwidth density in the form of wavelength division multiplexing. As integrated photonics and bonding technologies are maturing, commercialization of hybrid-integrated optical links are becoming a reality. Increasing silicon integration leads to better performance in optical links but necessitates a corresponding co-design strategy in both electronics and photonics. In this light, holistic design of high-speed optical links with an in-depth understanding of photonics and state-of-the-art electronics brings their performance to unprecedented levels. This thesis presents developments in high-speed optical links by co-designing and co-integrating the primary elements of an optical link: receiver, transmitter, and clocking. In the first part of this thesis a 3D-integrated CMOS/Silicon-photonic receiver will be presented. The electronic chip features a novel design that employs a low-bandwidth TIA front-end, double-sampling and equalization through dynamic offset modulation. Measured results show -14.9dBm of sensitivity and energy eciency of 170fJ/b at 25Gb/s. The same receiver front-end is also used to implement source-synchronous 4-channel WDM-based parallel optical receiver. Quadrature ILO-based clocking is employed for synchronization and a novel frequency-tracking method that exploits the dynamics of IL in a quadrature ring oscillator to increase the effective locking range. An adaptive body-biasing circuit is designed to maintain the per-bit-energy consumption constant across wide data-rates. The prototype measurements indicate a record-low power consumption of 153fJ/b at 32Gb/s. The

  1. Cadence® High High-Speed PCB Design Flow Workshop

    CERN Document Server


    Last release of Cadence High-Speed PCB Design methodology (PE142) based on Concept-HDL schematic editor, Constraint Manager, SPECCTRAQuest signal integrity analysis tool and ALLEGRO layout associated with SPECCTRA auto router tools, is now enough developed and stable to be taken into account for high-speed board designs at CERN. The implementation of this methodology, build around the new Constraint Manager program, is essential when you have to develop a board having a lot of high-speed design rules such as terminated lines, large bus structures, maximum length, timing, crosstalk etc.. that could not be under control by traditional method. On more conventional designs, formal aspect of the methodology could avoid misunderstanding between hardware and ALLEGRO layout designers, minimizing prototype iteration, development time and price. The capability to keep trace of the original digital designer intents in schematic or board layout, loading formal constraints in EDMS, could also be considered for LHC electro...

  2. High speed QWIP FPAs on InP substrates (United States)

    Eker, S. U.; Arslan, Y.; Besikci, C.


    Quantum well infrared photodetector (QWIP) technology has allowed the realization of low cost staring focal plane arrays (FPAs). However, AlGaAs/(In)GaAs QWIP FPAs suffer from low quantum and conversion efficiencies under high frame rate and/or low background conditions. We extensively discuss the effect of sensor gain on the FPA performance under various operating conditions, and highlight the superiority of the InP/InGaAs material system with respect to AlGaAs/GaAs for high speed/low background thermal imaging applications. InP/InGaAs QWIPs, providing a bias adjustable gain in a wide range, offer the flexibility of adapting the FPA to strict operating conditions. We also present an experimental comparison of large format AlGaAs/GaAs and (strained) InP/InGaAs QWIP FPAs under different operating conditions. A 640 × 512 QWIP FPA constructed with the 40-well strained InP/In 0.48Ga 0.52As material system displays a cut-off wavelength of 9.7 μm ( λ p = 8.9 μm) with a BLIP temperature higher than 65 K ( f/2), and a peak quantum efficiency as high as 12% with a broad spectral response (Δ λ/ λ p = 17%). The conversion efficiency of the FPA pixels is as high as 20% under large bias (4 V) where the detectivity is reasonably high (˜3 × 10 10 cm Hz 1/2/W, f/2, 65 K). While providing a considerably higher quantum efficiency than the pixels of a similar AlGaAs/GaAs FPA, the InP/InGaAs QWIP provides similar NETD values with much shorter integration times and, being less sensitive to the read noise, successfully operates with sub-millisecond integration times. The results clearly demonstrate that InP based material systems display high potential for single- and dual-band QWIP FPAs by overcoming the limitations of the standard GaAs based QWIPs under high frame rate and/or low background conditions.

  3. Yonjung High-Speed Railway Bridge Assessment Using Output-Only Structural Health Monitoring Measurements under Train Speed Changing

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop


    Full Text Available Yonjung Bridge is a hybrid multispan bridge that is designed to transport high-speed trains (HEMU-430X with maximum operating speed of 430 km/h. The bridge consists of simply supported prestressed concrete (PSC and composite steel girders to carry double railway tracks. The structural health monitoring system (SHM is designed and installed to investigate and assess the performance of the bridge in terms of acceleration and deformation measurements under different speeds of the passing train. The SHM measurements are investigated in both time and frequency domains; in addition, several identification models are examined to assess the performance of the bridge. The drawn conclusions show that the maximum deflection and acceleration of the bridge are within the design limits that are specified by the Korean and European codes. The parameters evaluation of the model identification depicts the quasistatic and dynamic deformations of PSC and steel girders to be different and less correlated when higher speeds of the passing trains are considered. Finally, the variation of the frequency content of the dynamic deformations of the girders is negligible when high speeds are considered.

  4. In defence of high-speed memory scanning. (United States)

    Sternberg, Saul


    This paper reviews some of the evidence that bears on the existence of a mental high-speed serial exhaustive scanning process (SES) used by humans to interrogate the active memory of a set of items to determine whether it contains a test item. First proposed in the 1960s, based on patterns of reaction times (RTs), numerous later studies supported, elaborated, extended, and limited the generality of SES, while critics claimed that SES never occurred, that predictions from SES were violated, and that other mechanisms produced the RT patterns that led to the idea. I show that some of these claims result from ignoring variations in experimental procedure that produce superficially similar but quantitatively different RT patterns and that, for the original procedures, the most frequently repeated claims that predictions are violated are false. I also discuss evidence against the generality of competing theories of active-memory interrogation, especially those that depend on discrimination of directly accessible "memory-strength". Some of this evidence has been available since the 1960s but has been ignored by some proponents of alternative theories. Other evidence presented herein is derived from results of one relevant experiment described for the first time, results of another described in more detail than heretofore, and new analyses of old data. Knowledge of brain function acquired during the past half century has increased the plausibility of SES. SES is alive and well, but many associated puzzles merit further investigation, suggestions for which are offered.

  5. Measurements of granular flow dynamics with high speed digital images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jingeol [Univ. of Florida, Gainesville, FL (United States)


    The flow of granular materials is common to many industrial processes. This dissertation suggests and validates image processing algorithms applied to high speed digital images to measure the dynamics (velocity, temperature and volume fraction) of dry granular solids flowing down an inclined chute under the action of gravity. Glass and acrylic particles have been used as granular solids in the experiment. One technique utilizes block matching for spatially averaged velocity measurements of the glass particles. This technique is compared with the velocity measurement using an optic probe which is a conventional granular flow velocity measurement device. The other technique for measuring the velocities of individual acrylic particles is developed with correspondence using a Hopfield network. This technique first locates the positions of particles with pattern recognition techniques, followed by a clustering technique, which produces point patterns. Also, several techniques are compared for particle recognition: synthetic discriminant function (SDF), minimum average correlation energy (MACE) filter, modified minimum average correlation energy (MMACE) filter and variance normalized correlation. The author proposes an MMACE filter which improves generalization of the MACE filter by adjusting the amount of averaged spectrum of training images in the spectrum whitening stages of the MACE filter. Variance normalized correlation is applied to measure the velocity and temperature of flowing glass particles down the inclined chute. The measurements are taken for the steady and wavy flow and qualitatively compared with a theoretical model of granular flow.

  6. Integrated design and manufacturing for the high speed civil transport (United States)

    Lee, Jae Moon; Gupta, Anurag; Mueller, Craig; Morrisette, Monica; Dec, John; Brewer, Jason; Donofrio, Kevin; Sturisky, Hilton; Smick, Doug; An, Meng Lin


    In June 1992, the School of Aerospace Engineering at Georgia Tech was awarded a three year NASA University Space Research Association (USRA) Advanced Design Program (ADP) grant to address issues associated with the Integrated Design and Manufacturing of High Speed Civil Transport (HSCT) configurations in its graduate Aerospace Systems Design courses. This report provides an overview of the on-going Georgia Tech initiative to address these design/manufacturing issues during the preliminary design phases of an HSCT concept. The new design methodology presented here has been incorporated in the graduate aerospace design curriculum and is based on the concept of Integrated Product and Process Development (IPPD). The selection of the HSCT as a pilot project was motivated by its potential global transportation payoffs; its technological, environmental, and economic challenges; and its impact on U.S. global competitiveness. This pilot project was the focus of each of the five design courses that form the graduate level aerospace systems design curriculum. This year's main objective was the development of a systematic approach to preliminary design and optimization and its implementation to an HSCT wing/propulsion configuration. The new methodology, based on the Taguchi Parameter Design Optimization Method (PDOM), was established and was used to carry out a parametric study where various feasible alternative configurations were evaluated. The comparison criterion selected for this evaluation was the economic impact of this aircraft, measured in terms of average yield per revenue passenger mile ($/RPM).

  7. A DSP Based POD Implementation for High Speed Multimedia Communications

    Directory of Open Access Journals (Sweden)

    Chang Nian Zhang


    Full Text Available In the cable network services, the audio/video entertainment contents should be protected from unauthorized copying, intercepting, and tampering. Point-of-deployment (POD security module, proposed by OpenCableTM, allows viewers to receive secure cable services such as premium subscription channels, impulse pay-per-view, video-on-demand as well as other interactive services. In this paper, we present a digital signal processor (DSP (TMS320C6211 based POD implementation for the real-time applications which include elliptic curve digital signature algorithm (ECDSA, elliptic curve Diffie Hellman (ECDH key exchange, elliptic curve key derivation function (ECKDF, cellular automata (CA cryptography, communication processes between POD and Host, and Host authentication. In order to get different security levels and different rates of encryption/decryption, a CA based symmetric key cryptography algorithm is used whose encryption/decryption rate can be up to 75 Mbps. The experiment results indicate that the DSP based POD implementation provides high speed and flexibility, and satisfies the requirements of real-time video data transmission.

  8. A high-speed linear algebra library with automatic parallelism (United States)

    Boucher, Michael L.


    Parallel or distributed processing is key to getting highest performance workstations. However, designing and implementing efficient parallel algorithms is difficult and error-prone. It is even more difficult to write code that is both portable to and efficient on many different computers. Finally, it is harder still to satisfy the above requirements and include the reliability and ease of use required of commercial software intended for use in a production environment. As a result, the application of parallel processing technology to commercial software has been extremely small even though there are numerous computationally demanding programs that would significantly benefit from application of parallel processing. This paper describes DSSLIB, which is a library of subroutines that perform many of the time-consuming computations in engineering and scientific software. DSSLIB combines the high efficiency and speed of parallel computation with a serial programming model that eliminates many undesirable side-effects of typical parallel code. The result is a simple way to incorporate the power of parallel processing into commercial software without compromising maintainability, reliability, or ease of use. This gives significant advantages over less powerful non-parallel entries in the market.

  9. Entrainment characteristics of fine particles under high speed airflow

    Directory of Open Access Journals (Sweden)

    Yin Shaowu


    Full Text Available Fine silicon particles (mean size of 2.7 μm are used as entrained materials, and the entrainment characteristics of fine particles are investigated in a cylindrical fluidized-bed (inner diameter of 28 mm and height of 1000 mm under high speed airflow. The effects of the volume flow of gas (Q, 1 m3/h to 2.5 m3/h, the number of holes (N, 1 to 4, the size of holes (D, 1 mm to 3 mm, and the distance between holes and the upper surface of the material layer (H, -100 mm to 200 mm on the entrainment characteristics (entrainment rate W and entrained powder-gas ratio R are experimentally studied through orthogonal experiment. The experimental results show that an increase in Q and H constantly improves the entrainment characteristics; a decrease in D enhances such characteristics, whereas the number of holes N has no significant effect on the entrainment characteristics. An optimal operating condition can result in optimal entrainment characteristics (W, 3.1 g/min and R, 0.058 g/g, which can be achieved with a Q of 2.5 m3/h, N of 1, D of 2 mm and H of 200 mm.

  10. Hardware demonstration of high-speed networks for satellite applications.

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, Jonathon W.; Lee, David S.


    This report documents the implementation results of a hardware demonstration utilizing the Serial RapidIO{trademark} and SpaceWire protocols that was funded by Sandia National Laboratories (SNL's) Laboratory Directed Research and Development (LDRD) office. This demonstration was one of the activities in the Modeling and Design of High-Speed Networks for Satellite Applications LDRD. This effort has demonstrated the transport of application layer packets across both RapidIO and SpaceWire networks to a common downlink destination using small topologies comprised of commercial-off-the-shelf and custom devices. The RapidFET and NEX-SRIO debug and verification tools were instrumental in the successful implementation of the RapidIO hardware demonstration. The SpaceWire hardware demonstration successfully demonstrated the transfer and routing of application data packets between multiple nodes and also was able reprogram remote nodes using configuration bitfiles transmitted over the network, a key feature proposed in node-based architectures (NBAs). Although a much larger network (at least 18 to 27 nodes) would be required to fully verify the design for use in a real-world application, this demonstration has shown that both RapidIO and SpaceWire are capable of routing application packets across a network to a common downlink node, illustrating their potential use in real-world NBAs.

  11. Increasing the life of high-speed steel cutting tools

    Energy Technology Data Exchange (ETDEWEB)

    Plyusnin, Y.G.


    The paper describes work on determining the rational area of use, mastering of production operations, and introduction into the plants of the industry of various methods of increasing the life of high-speed tools. Among these methods are carbonitriding, treatment of the tool by shock cooling and by application of a magnetic field, and the application of wear resistant coatings by the method of cathodic-ionic bombardment. The article briefly characterizes each method. Experience in the introduction of the carbonitriding process has shown that the greatest increase in life is obtained for relatively large cutting tools such as hubs and large diameter drills. The effectiveness of shock cooling depends to a great degree upon the original structure of the tool material and upon the requirements imposed on it in service (for stability). Experience in the magnetic treatment of drills and end mills up to 30mm in diameter has shown that the life of a magnetically treated tool with subsequent demagnetization increases by 1.2-1.4 times and without demagnetization by 1.7-2 times. The effectiveness of magnetic hardening depends not only upon the correctly selected strength of the magnetic field and time of application, but also upon the time of postmagnetic aging. Wear resistant coatings applied by the cathodic-ionic bombardment method increases by 2-5 times the life of a cutting tool. However, careful preparation of the tool surface is required as well as careful control of the temperature and thickness of the coating.

  12. An Early Evaluation of Italian High Speed Rail Projects

    Directory of Open Access Journals (Sweden)

    Paolo Beria


    Full Text Available Italy has undergone, in the last 15 years, an exceptional public financial effort to build approximately 1,000 km of high speed rail lines. Further extensions are under construction or planned, especially in the most important international relations. This network is widely considered as fundamental to comply the European vision of a continental-wide transport system.The paper analyses the past and the future of such network, where possible from a quantitative point of view. The first part of the article reviews the history of the Alta Velocità scheme, particularly focusing on the issues related to the economic regulation of the investments and the financial troubles at first and then on the present issues related to the regulation of rail services.The analysis of the supply, the time gains, the demand and the costs allows to build a simple but independent evaluation of the past projects from an ex-post perspective, pointing out the successes, but also important critical issues.The second part of the paper analyses the future expansion plans looking at the costs, the existing and expected demand and derives some policy indications and cost reduction strategies capable both to control public expenditure in a period of crisis and not to abandon the idea of a modern and effective rail network.

  13. Spiral Tube Assembly for High-Speed Countercurrent Chromatography (United States)

    Ito, Y.; Clary, R.; Powell, J.; Knight, M.; Finn, T. M.


    Optimal elution modes were determined for four typical two-phase solvent systems each with different physical parameters to achieve the best peak resolution and retention of the stationary phase by spiral tube high-speed countercurrent chromatography using a suitable set of test samples. Both retention of the stationary phase and partition efficiency are governed by an interplay between two forces, i.e., Archimedean Screw force and radial centrifugal force gradient of the spiral channel. In the polar solvent system represented by 1-butanol./acetic acid/water (4:1:5, v/v/v) with settling time of over 30 s, the effect by the radial centrifugal gradient force dominates giving the best separation of dipeptides either by pumping the lower phase from the inner terminal or the upper phase from the outer terminal of the spiral channel. In the moderately hydrophobic two-phase solvent system represented by hexane/ethyl acetate/methanol/0.1 M HCl (1:1:1:1) with settling time of 19 s, and two hydrophobic solvent systems of hexane/ethanol/water (5:4:1, v/v/v) and non-aqueous binary system of hexane/acetonitrile both having settling time of 9, the effect of the Archimedean screw force play a major role in hydrodynamic equilibrium, giving the best separations by pumping the lower phase from the head or the upper phase from the tail of the spiral channel. PMID:19343107

  14. Innovative Airbreathing Propulsion Concepts for High-speed Applications (United States)

    Whitlow, Woodrow, Jr.


    The current cost to launch payloads to low earth orbit (LEO) is approximately loo00 U.S. dollars ($) per pound ($22000 per kilogram). This high cost limits our ability to pursue space science and hinders the development of new markets and a productive space enterprise. This enterprise includes NASA's space launch needs and those of industry, universities, the military, and other U.S. government agencies. NASA's Advanced Space Transportation Program (ASTP) proposes a vision of the future where space travel is as routine as in today's commercial air transportation systems. Dramatically lower launch costs will be required to make this vision a reality. In order to provide more affordable access to space, NASA has established new goals in its Aeronautics and Space Transportation plan. These goals target a reduction in the cost of launching payloads to LEO to $lo00 per pound ($2200 per kilogram) by 2007 and to $100' per pound by 2025 while increasing safety by orders of magnitude. Several programs within NASA are addressing innovative propulsion systems that offer potential for reducing launch costs. Various air-breathing propulsion systems currently are being investigated under these programs. The NASA Aerospace Propulsion and Power Base Research and Technology Program supports long-term fundamental research and is managed at GLenn Research Center. Currently funded areas relevant to space transportation include hybrid hyperspeed propulsion (HHP) and pulse detonation engine (PDE) research. The HHP Program currently is addressing rocket-based combined cycle and turbine-based combined cycle systems. The PDE research program has the goal of demonstrating the feasibility of PDE-based hybrid-cycle and combined cycle propulsion systems that meet NASA's aviation and access-to-space goals. The ASTP also is part of the Base Research and Technology Program and is managed at the Marshall Space Flight Center. As technologies developed under the Aerospace Propulsion and Power Base

  15. Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera (United States)

    Yu, Liping; Pan, Bing


    Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

  16. Method and apparatus for high speed data acquisition and processing (United States)

    Ferron, J.R.


    A method and apparatus are disclosed for high speed digital data acquisition. The apparatus includes one or more multiplexers for receiving multiple channels of digital data at a low data rate and asserting a multiplexed data stream at a high data rate, and one or more FIFO memories for receiving data from the multiplexers and asserting the data to a real time processor. Preferably, the invention includes two multiplexers, two FIFO memories, and a 64-bit bus connecting the FIFO memories with the processor. Each multiplexer receives four channels of 14-bit digital data at a rate of up to 5 MHz per channel, and outputs a data stream to one of the FIFO memories at a rate of 20 MHz. The FIFO memories assert output data in parallel to the 64-bit bus, thus transferring 14-bit data values to the processor at a combined rate of 40 MHz. The real time processor is preferably a floating-point processor which processes 32-bit floating-point words. A set of mask bits is prestored in each 32-bit storage location of the processor memory into which a 14-bit data value is to be written. After data transfer from the FIFO memories, mask bits are concatenated with each stored 14-bit data value to define a valid 32-bit floating-point word. Preferably, a user can select any of several modes for starting and stopping direct memory transfers of data from the FIFO memories to memory within the real time processor, by setting the content of a control and status register. 15 figs.

  17. Contact freezing observed with a high speed video camera (United States)

    Hoffmann, Nadine; Koch, Michael; Kiselev, Alexei; Leisner, Thomas


    Freezing of supercooled cloud droplets on collision with ice nucleating particle (INP) has been considered as one of the most effective heterogeneous freezing mechanisms. Potentially, it could play an important role in rapid glaciation of a mixed phase cloud especially if coupled with ice multiplication mechanism active at moderate subzero temperatures. The necessary condition for such coupling would be, among others, the presence of very efficient INPs capable of inducing ice nucleation of the supercooled drizzle droplets in the temperature range of -5°C to -20°C. Some mineral dust particles (K-feldspar) and biogenic INPs (pseudomonas bacteria, birch pollen) have been recently identified as such very efficient INPs. However, if observed with a high speed video (HSV) camera, the contact nucleation induced by these two classes of INPs exhibits a very different behavior. Whereas bacterial INPs can induce freezing within a millisecond after initial contact with supercooled water, birch pollen need much more time to initiate freezing. The mineral dust particles seem to induce ice nucleation faster than birch pollen but slower than bacterial INPs. In this contribution we show the HSV records of individual supercooled droplets suspended in an electrodynamic balance and colliding with airborne INPs of various types. The HSV camera is coupled with a long-working-distance microscope, allowing us to observe the contact nucleation of ice at very high spatial and temporal resolution. The average time needed to initiate freezing has been measured depending on the INP species. This time do not necessarily correlate with the contact freezing efficiency of the ice nucleating particles. We discuss possible mechanisms explaining this behavior and potential implications for future ice nucleation research.

  18. Very High Speed Discrete Time Optical Signal Generation and Filtering (United States)

    Narayan, Vishwa

    Optical lattice filters constitute a class of devices that generate and operate upon high bandwidth optical signals. This dissertation describes the design, analysis, construction and testing of such devices. We derive elegant z-transform based filter transfer functions and develop a convenient state variable based scattering matrix filter description. A variety of filters are designed and analyzed. We also design locally optimal optical lattice filters with mirror imperfections such as losses and finite reflectivity round-off error. We conduct a quantitative sensitivity analysis of the degrading effects of these imperfections on system performance, and study the distorting effects of phase error on pulse train shape. Experimentally, we use mirror based optical lattice filters to generate 667 GHz repetition rate pulse bursts with step and ramp envelopes, and coded pulse bursts. We also demonstrate the quadrupling and octupling of the 76 MHz repetition rate of a mode-locked laser. We demonstrate the low pass filtering property of optical lattice filters by realizing a high speed discrete time optical integrator. Step functions are integrated to ramps, and ramps to quadratics, at 667 GHz. We also constructed a mechanical variable repetition rate filter with a tuning range of 2.14 to 100 GHz. We design and analyze a gain based mirror filter with active gain elements. Small signal linear constant gain tends to improve filter performance by increasing the output, and reducing fluctuations in the frequency response. We study the behavior of these filters at the stability limit, characterized by large fluctuations in the frequency response. Optical lattice filters may be used as wavelength multiplexers/demultiplexers in lightwave systems, as variable repetition rate pulse train generators for tunable repetition rate optical spectroscopy, as optical clock generators, and as discrete time/analog optical signal filters.

  19. Prediction Of Limit Rotational Speeds In A High-Speed Tool Bason FE Computed J-Integral Intensitiesed

    DEFF Research Database (Denmark)

    Hvejsel, Bjørn; Langmack, Lasse; Kristensen, Anders


    In order to obtain an estimate of the critical number of rotations for a high speed milling tool crack growth analysis has been performed. The crack growth is determined from stress intensities computed by J-integrals. The problem is solved in 3D using ANSYS. Boundary conditions arising from a co...

  20. Development of precision casting in high speed steel; Seimitsu chuzo haisu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, H.; Fujii, T. [Daido Steel Co. Ltd., Nagoya (Japan)


    As to the high speed steel manufactured by precision casting process, effect of decarbonization technology and low temperature casting, and difference between the characteristics of a steel and a high speed steel were examined. The high speed steel was cast by vacuum casing process using a mold manufactured by the lost wax process. Effect of superheating in casting on the product structure and the bending strength was examined. Decarbonization can be prevented by the vacuum casting process. By low temperature casting, the high speed steel structure becomes fine, and the bending strength or toughness is improved; 80% of the T-direction bending strength of the steel can be secured in the high speed steel. The high speed steel exceeds the steel by a little bit in abrasion resistance. When the high speed steel was applied to a spiral cutter, the high speed steel product exceeded 1.2 times the machined steel in the tool life. In the high speed steel, the cutting process is drastically reduced, and reduction of the material cost is also possible compared with the machined steel. The high speed steel is considered to show good results because of excellent abrasion resistance since the tool life depended more on abrasion than on toughness because of the machining conditions. 4 refs., 8 figs., 2 tabs.

  1. Salivary hormonal values from high-speed resistive exercise workouts. (United States)

    Caruso, John F; Lutz, Brant M; Davidson, Mark E; Wilson, Kyle; Crane, Chris S; Craig, Chrsity E; Nissen, Tim E; Mason, Melissa L; Coday, Michael A; Sheaff, Robert J; Potter, William T


    Our study purpose examined salivary hormonal responses to high-speed resistive exercise. Healthy subjects (n = 45) performed 2 elbow flexor workouts on a novel (inertial kinetic exercise; Oconomowoc, WI, USA) strength training device. Our methods included saliva sample collection at both preexercise and immediately postexercise; workouts entailed two 60-second sets separated by a 90-second rest period. The samples were analyzed in duplicate for their testosterone and cortisol concentrations ([T], [C]). Average and maximum elbow flexor torque were measured from each exercise bout; they were later analyzed with a 2(gender) × 2(workout) analysis of variance (ANOVA) with repeated measures for workout. The [T] and [C] each underwent a 2(gender) × 2(time) ANOVA with repeated measures for time. A within-subject design was used to limit error variance. Average and maximum torque each had gender (men > women; p time, but women's values were unchanged. Yet multivariate regression revealed that 3 predictor variables (body mass and average and maximum torques) did not account for a significant amount of variance associated with the rise in male [T]. Changes in [C] were not significant. In conclusion, changes in [T] concur with the results from other studies that showed significant elevations in male [T], despite the brevity of current workouts and the rather modest volume of muscle mass engaged. Practical applications imply that salivary assays may be a viable alternative to blood draws from athletes, yet coaches and others who may administer this treatment should know that our results may have produced greater pre-post hormonal changes if postexercise sample collection had occurred at a later time point.

  2. High quality yarns from high speed roller ginning of upland cotton (United States)

    The highest quality yarns from upland cotton are typically produced by using combing in the textile mill. Combing is a resource-intensive process in which short fibers are removed from cotton before spinning. The improvement in fiber length and length uniformity of upland cotton when high speed ro...

  3. Automatic in-process chatter avoidance in the high-speed milling process

    NARCIS (Netherlands)

    Dijk, N.J.M. van; Doppenberg, E.J.J.; Faassen, R.P.H.; Wouw, N. van de; Oosterling, J.A.J.; Nijmeijer, H.


    High-speed milling is often used in industry to maximize productivity of the manufacturing of high-technology components, such as aeronautical components, mold, and dies. The occurrence of chatter highly limits the efficiency and accuracy of high-speed milling operations. In this paper, two control

  4. High performance multi-channel high-speed I/O circuits

    CERN Document Server

    Oh, Taehyoun


    This book describes design techniques that can be used to mitigate crosstalk in high-speed I/O circuits. The focus of the book is in developing compact and low power integrated circuits for crosstalk cancellation, inter-symbol interference (ISI) mitigation and improved bit error rates (BER) at higher speeds. This book is one of the first to discuss in detail the problem of crosstalk and ISI mitigation encountered as data rates have continued beyond 10Gb/s. Readers will learn to avoid the data performance cliff, with circuits and design techniques described for novel, low power crosstalk cancel


    Directory of Open Access Journals (Sweden)

    Mehranpour A.B.


    Full Text Available Purpose : This study examined that effect of two types of tapering on interleukin-6(IL-6, cortisol and performance in elite male wrestler. Material : After 4 weeks of progressive training, wrestlers were randomly divided into three equal groups, 1-control group (N=10 continued performing progressive training for one week, 2-taper group 1 (N=10 continued with a 50% reduction in training volume for one week, 3-taper group 2 (N=10 continued with a 75% reduction in volume of training for one week .plasma blood IL-6 and cortisol levels were assayed from analysis obtained via standard ELISA. Also general strength of muscles was recorded as a performance test. All data were collected before and after progressive training and also after one week of tapering period. Results : There were significant reduction of IL-6 and cortisol levels in both tapering group comparing with control group (P≤0.05.There was significant reduction of IL-6 and cortisol levels among tapering 50% and tapering 75% after tapering period (P≤0.05. Also there was significant increase of general strength of muscles between tapering 75% and control group (P≤0.05. Conclusion : hence, one week tapering with 75% reduction in training volume after progressive training while the intensity kept high is effective strategy for reduction of IL-6, and cortisol levels and also increase performance. It seems that higher reduction of training volume when the intensity kept high is a good strategy for wrestler before main competition.

  6. Substructure method in high-speed monorail dynamic problems (United States)

    Ivanchenko, I. I.


    The study of actions of high-speed moving loads on bridges and elevated tracks remains a topical problem for transport. In the present study, we propose a new method for moving load analysis of elevated tracks (monorail structures or bridges), which permits studying the interaction between two strained objects consisting of rod systems and rigid bodies with viscoelastic links; one of these objects is the moving load (monorail rolling stock), and the other is the carrying structure (monorail elevated track or bridge). The methods for moving load analysis of structures were developed in numerous papers [1-15]. At the first stage, when solving the problem about a beam under the action of the simplest moving load such as a moving weight, two fundamental methods can be used; the same methods are realized for other structures and loads. The first method is based on the use of a generalized coordinate in the expansion of the deflection in the natural shapes of the beam, and the problem is reduced to solving a system of ordinary differential equations with variable coefficients [1-3]. In the second method, after the "beam-weight" system is decomposed, just as in the problem with the weight impact on the beam [4], solving the problem is reduced to solving an integral equation for the dynamic weight reaction [6, 7]. In [1-3], an increase in the number of retained forms leads to an increase in the order of the system of equations; in [6, 7], difficulties arise when solving the integral equations related to the conditional stability of the step procedures. The method proposed in [9, 14] for beams and rod systems combines the above approaches and eliminates their drawbacks, because it permits retaining any necessary number of shapes in the deflection expansion and has a resolving system of equations with an unconditionally stable integration scheme and with a minimum number of unknowns, just as in the method of integral equations [6, 7]. This method is further developed for

  7. An Alternative Approach for High Speed Railway Carrying Capacity Calculation Based on Multiagent Simulation

    Directory of Open Access Journals (Sweden)

    Mo Gao


    Full Text Available It is a multiobjective mixed integer programming problem that calculates the carrying capacity of high speed railway based on mathematical programming method. The model is complex and difficult to solve, and it is difficult to comprehensively consider the various influencing factors on the train operation. The multiagent theory is employed to calculate high speed railway carrying capacity. In accordance with real operations of high speed railway, a three-layer agent model is developed to simulate the operating process of high speed railway. In the proposed model, railway network agent, line agent, station agent, and train agent are designed, respectively. To validate the proposed model, a case study is performed for Beijing–Shanghai high speed railway by using NetLogo software. The results are consistent with the actual data, which implies that the proposed multiagent method is feasible to calculate the carrying capacity of high speed railway.

  8. Adaptive wall technology for three-dimensional models at high subsonic speeds and aerofoil testing through the speed of sound (United States)

    Lewis, M. C.; Taylor, N. J.; Goodyer, M. J.


    Adaptive wall research at the University of Southampton has been directed towards the development of testing techniques for use in nonporous test sections where two flexible walls are profiled in single curvature. This paper highlights the recent advances that have been made in the testing of 2D airfoils through the speed of sound and the testing of 3D models at high subsonic speeds. Techniques have been developed to accommodate the variety of flow regimes encountered in near sonic airfoil tests. The experimental evidence to date suggests that the new techniques coupled with established procedures allow airfoil data, free from top and bottom wall interference, to be gathered from adaptive flexible walled test sections throughout the entire subsonic, transonic and supersonic speed ranges. Techniques applicable to the testing of 3D models have evolved primarily from experience gained by testing sidewall mounted half-wings. Emphasis has been placed upon models with planforms similar to those of current transport wings. Techniques for high subsonic speeds have now been developed to the point where the residual levels of interference are low.

  9. Verifying cell loss requirements in high-speed communication networks

    Directory of Open Access Journals (Sweden)

    Kerry W. Fendick


    Full Text Available In high-speed communication networks it is common to have requirements of very small cell loss probabilities due to buffer overflow. Losses are measured to verify that the cell loss requirements are being met, but it is not clear how to interpret such measurements. We propose methods for determining whether or not cell loss requirements are being met. A key idea is to look at the stream of losses as successive clusters of losses. Often clusters of losses, rather than individual losses, should be regarded as the important “loss events”. Thus we propose modeling the cell loss process by a batch Poisson stochastic process. Successive clusters of losses are assumed to arrive according to a Poisson process. Within each cluster, cell losses do not occur at a single time, but the distance between losses within a cluster should be negligible compared to the distance between clusters. Thus, for the purpose of estimating the cell loss probability, we ignore the spaces between successive cell losses in a cluster of losses. Asymptotic theory suggests that the counting process of losses initiating clusters often should be approximately a Poisson process even though the cell arrival process is not nearly Poisson. The batch Poisson model is relatively easy to test statistically and fit; e.g., the batch-size distribution and the batch arrival rate can readily be estimated from cell loss data. Since batch (cluster sizes may be highly variable, it may be useful to focus on the number of batches instead of the number of cells in a measurement interval. We also propose a method for approximately determining the parameters of a special batch Poisson cell loss with geometric batch-size distribution from a queueing model of the buffer content. For this step, we use a reflected Brownian motion (RBM approximation of a G/D/1/C queueing model. We also use the RBM model to estimate the input burstiness given the cell loss rate. In addition, we use the RBM model to

  10. Gearbox Reliability Collaborative Investigation of Gearbox Motion and High-Speed-Shaft Loads

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jon [National Renewable Energy Lab. (NREL), Golden, CO (United States); Guo, Yi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sethuraman, Latha [National Renewable Energy Lab. (NREL), Golden, CO (United States)


    This paper extends a model-to-test validation effort to examine the effect of different constant rotor torque and moment conditions and intentional generator misalignment on the gearbox motion and high-speed-shaft loads. Fully validating gearbox motion and high-speed-shaft loads across a range of test conditions is a critical precursor to examining the bearing loads, as the gearbox motion and high-speed-shaft loads are the drivers of these bearing loads.

  11. A Review on High-Speed Machining of Titanium Alloys

    National Research Council Canada - National Science Library

    RAHMAN, Mustafizur; WANG, Zhi-Gang; WONG, Yoke-San


    .... However, it is very difficult to machine them due to their poor machinability. When machining titanium alloys with conventional tools, the tool wear rate progresses rapidly, and it is generally difficult to achieve a cutting speed of over 60m/min...

  12. Prospects of high-speed traffic development on international routes to ukraine. an experience of other countries in establishing high-speed passenger traffic

    Directory of Open Access Journals (Sweden)

    Віта Валеріївна Якименко


    Full Text Available Prospects and directions of high-speed traffic development on international railway communication, possible ways of solving the mismatch problem of the railway track width are described and analyzed in the article. An experience of other countries in addressing the issue of international high-speed passenger traffic, ways to overcome negative influences on the number of passengers and direction of their solution is analyzed and reviewed

  13. High-speed non-intrusive measurements of fuel velocity fields at high-pressure injectors (United States)

    Gürtler, Johannes; Schlüßler, Raimund; Fischer, Andreas; Czarske, Jürgen


    Using a single high-speed camera and a frequency modulated laser, a novel approach is presented for fast velocity field measurements in unsteady spray flows. The velocity range is from zero up to several 100 m/s, which requires a high measurement rate and a large dynamic. Typically, flow measurements require to seed tracer particles to the fluid. A paradigm shift to seeding-free measurements is presented. The light scattered at the phase boundaries of the fluid droplets is evaluated. In order to validate the high-speed measurement system, a detailed uncertainty analysis is performed by means of measurements as well as simulations. Thereby, variations of the scattered light intensity, which are based on the high temporal velocity gradients, are found to be the main contribution to the uncertainty. The eventually measurement results, obtained at a measurement rate of 500 kHz, exhibit spray velocities ranging from 0 m/s up to 400 m/s in less than 1 ms, and the detection of unsteady and irregular flow phenomena with a characteristic time of several μs is achieved. This demonstrates the high measurement rate, the high temporal resolution and the large measurement range of the proposed high-speed measurement system.

  14. Large motion high cycle high speed optical fibers for space based applications.

    Energy Technology Data Exchange (ETDEWEB)

    Stromberg, Peter G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tandon, Rajan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gibson, Cory S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reedlunn, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rasberry, Roger David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rohr, Garth David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    Future remote sensing applications will require higher resolution and therefore higher data rates (up to perhaps 100 gigabits per second) while achieving lower mass and cost. A current limitation to the design space is high speed high bandwidth data does not cross movable gimbals because of cabling issues. This requires the detectors to be off gimbal. The ability to get data across the gimbal would open up efficiencies in designs where the detectors and the electronics can be placed anywhere on the system. Fiber optic cables provide light weight high speed high bandwidth connections. Current options are limited to 20,000 cycles as opposed to the 1,000,000 cycles needed for future space based applications. To extend this to the million+ regime, requires a thorough understanding of the failure mechanisms and the materials, proper selection of materials (e.g., glass and jacket material) allowable geometry changes to the cable, radiation hardness, etc.

  15. Study of fish response using particle image velocimetry and high-speed, high-resolution imaging

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, M. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mueller, R. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gruensch, G. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    Fish swimming has fascinated both engineers and fish biologists for decades. Digital particle image velocimetry (DPIV) and high-speed, high-resolution digital imaging are recently developed analysis tools that can help engineers and biologists better understand how fish respond to turbulent environments. This report details studies to evaluate DPIV. The studies included a review of existing literature on DPIV, preliminary studies to test the feasibility of using DPIV conducted at our Flow Biology Laboratory in Richland, Washington September through December 2003, and applications of high-speed, high-resolution digital imaging with advanced motion analysis to investigations of fish injury mechanisms in turbulent shear flows and bead trajectories in laboratory physical models. Several conclusions were drawn based on these studies, which are summarized as recommendations for proposed research at the end of this report.

  16. High Speed and High Spatial Density Parameter Measurement Using Fiber Optic Sensing Technology (United States)

    Parker, Allen R. Jr. (Inventor); Chan, Hon Man (Inventor); Richards, William Lance (Inventor); Piazza, Anthony (Inventor); Hamory, Philip J (Inventor)


    The present invention is an improved fiber optic sensing system (FOSS) having the ability to provide both high spatial resolution and high frequency strain measurements. The inventive hybrid FOSS fiber combines sensors from high acquisition speed and low spatial resolution Wavelength-Division Multiplexing (WDM) systems and from low acquisition speed and high spatial resolution Optical Frequency Domain Reflection (OFDR) systems. Two unique light sources utilizing different wavelengths are coupled with the hybrid FOSS fiber to generate reflected data from both the WDM sensors and OFDR sensors operating on a single fiber optic cable without incurring interference from one another. The two data sets are then de-multiplexed for analysis, optionally with conventionally-available WDM and OFDR system analyzers.

  17. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high speed civil aircraft will require breakthrough developments in propulsion design, including novel techniques to optimize inlet...

  18. High-speed velocity measurements on an EFI-system (United States)

    Prinse, W. C.; van't Hof, P. G.; Cheng, L. K.; Scholtes, J. H. G.


    For the development of an Exploding Foil Initiator for Insensitive Munitions applications the following topics are of interest: the electrical circuit, the exploding foil, the velocity of the flyer, the driver explosive, the secondary flyer and the acceptor explosive. Several parameters of the EFI have influences on the velocity of the flyer. To investigate these parameters a Fabry-Perot Velocity Interferometer System (F-PVIS) has been used. The light to and from the flyer is transported by a multimode fibre terminated with a GRIN-lens. By this method the velocity of very tiny objects (0.1 mm), can be measured. The velocity of flyer can be recorded with nanosecond resolution, depending on the Fabry-Perot etalon and the streak camera. With this equipment the influence of the dimensions of the exploding foil and the flyer on the velocity and the acceleration of the flyer are investigated. Also the integrity of the flyer during flight can be analyzed. To characterize the explosive material, to be used as driver explosive in EFI's, the initiation behaviour of the explosive has been investigated by taking pictures of the explosion with a high speed framing and streak camera. From these pictures the initiation distance and the detonation behaviour of the explosive has been analyzed. Normally, the driver explosive initiates the acceptor explosive (booster) by direct contact. This booster explosive is embedded in the main charge of the munitions. The combination of initiator, booster explosive and main charge explosive is called the detonation train. In this research the possibility of initiation of the booster by an intermediate flyer is investigated. This secondary flyer can be made of different materials, like aluminium, steel and polyester with different sizes. With the aid of the F-PVIS the acceleration of the secondary flyer is investigated. This reveals the influence of the thickness and density of the flyer on the acceleration and final velocity. Under certain

  19. Transient flow characteristics of a high speed rotary valve (United States)

    Browning, Patrick H.

    were experimentally mapped as a function of valve speed, inter-cylinder pressure ratios and volume ratios and the results were compared to compressible flow theoretical models. Specifically, the transient behavior suggested a short-lived loss-mode initiation closely resembled by shock tube theory followed by a quasi-steady flow regime resembling choked flow behavior. An empirical model was then employed to determine the useful range of the CCV design as applied to a four-stroke CIBAI engine cycle modeled using a 1-D quasi-steady numerical method, with particular emphasis on the cyclic timing of the CCV opening. Finally, a brief discussion of a high-temperature version of the CCV design is presented.

  20. A New High-Speed Low Distortion Switched-Current Cell

    DEFF Research Database (Denmark)

    Shah, Peter Jivan; Toumazou, Christofer


    A new switched-current cell is presented which simultaneously offers high speed, low distortion, low gain error, and a virtual ground input. In a simulation example 0.01% distortion was achieved at 50MHz sampling rate which makes the cell very well suited for high accuracy high speed filtering...

  1. High-speed high-sensitivity infrared spectroscopy using mid-infrared swept lasers (Conference Presentation) (United States)

    Childs, David T. D.; Groom, Kristian M.; Hogg, Richard A.; Revin, Dmitry G.; Cockburn, John W.; Rehman, Ihtesham U.; Matcher, Stephen J.


    Infrared spectroscopy is a highly attractive read-out technology for compositional analysis of biomedical specimens because of its unique combination of high molecular sensitivity without the need for exogenous labels. Traditional techniques such as FTIR and Raman have suffered from comparatively low speed and sensitivity however recent innovations are challenging this situation. Direct mid-IR spectroscopy is being speeded up by innovations such as MEMS-based FTIR instruments with very high mirror speeds and supercontinuum sources producing very high sample irradiation levels. Here we explore another possible method - external cavity quantum cascade lasers (EC-QCL's) with high cavity tuning speeds (mid-IR swept lasers). Swept lasers have been heavily developed in the near-infrared where they are used for non-destructive low-coherence imaging (OCT). We adapt these concepts in two ways. Firstly by combining mid-IR quantum cascade gain chips with external cavity designs adapted from OCT we achieve spectral acquisition rates approaching 1 kHz and demonstrate potential to reach 100 kHz. Secondly we show that mid-IR swept lasers share a fundamental sensitivity advantage with near-IR OCT swept lasers. This makes them potentially able to achieve the same spectral SNR as an FTIR instrument in a time x N shorter (N being the number of spectral points) under otherwise matched conditions. This effect is demonstrated using measurements of a PDMS sample. The combination of potentially very high spectral acquisition rates, fundamental SNR advantage and the use of low-cost detector systems could make mid-IR swept lasers a powerful technology for high-throughput biomedical spectroscopy.

  2. Detecting and Blocking Network Attacks at Ultra High Speeds

    Energy Technology Data Exchange (ETDEWEB)

    Paxson, Vern


    Stateful, in-depth, in-line traffic analysis for intrusion detection and prevention has grown increasingly more difficult as the data rates of modern networks rise. One point in the design space for high-performance network analysis - pursued by a number of commercial products - is the use of sophisticated custom hardware. For very high-speed processing, such systems often cast the entire analysis process in ASICs. This project pursued a different architectural approach, which we term Shunting. Shunting marries a conceptually quite simple hardware device with an Intrusion Prevention System (IPS) running on commodity PC hardware. The overall design goal is was to keep the hardware both cheap and readily scalable to future higher speeds, yet also retain the unparalleled flexibility that running the main IPS analysis in a full general-computing environment provides. The Shunting architecture we developed uses a simple in-line hardware element that maintains several large state tables indexed by packet header fields, including IP/TCP flags, source and destination IP addresses, and connection tuples. The tables yield decision values the element makes on a packet-by-packet basis: forward the packet, drop it, or divert ('shunt') it through the IPS (the default). By manipulating table entries, the IPS can, on a fine-grained basis: (i) specify the traffic it wishes to examine, (ii) directly block malicious traffic, and (iii) 'cut through' traffic streams once it has had an opportunity to 'vet' them, or (iv) skip over large items within a stream before proceeding to further analyze it. For the Shunting architecture to yield benefits, it needs to operate in an environment for which the monitored network traffic has the property that - after proper vetting - much of it can be safely skipped. This property does not universally hold. For example, if a bank needs to examine all Web traffic involving its servers for regulatory compliance, then a

  3. High Speed Mobility Through On-Demand Aviation (United States)

    Moore, Mark D.; Goodrich, Ken; Viken, Jeff; Smith, Jeremy; Fredericks, Bill; Trani, Toni; Barraclough, Jonathan; German, Brian; Patterson, Michael


    automobiles. ?? Community Noise: Hub and smaller GA airports are facing increasing noise restrictions, and while commercial airliners have dramatically decreased their community noise footprint over the past 30 years, GA aircraft noise has essentially remained same, and moreover, is located in closer proximity to neighborhoods and businesses. ?? Operating Costs: GA operating costs have risen dramatically due to average fuel costs of over $6 per gallon, which has constrained the market over the past decade and resulted in more than 50% lower sales and 35% less yearly operations. Infusion of autonomy and electric propulsion technologies can accomplish not only a transformation of the GA market, but also provide a technology enablement bridge for both larger aircraft and the emerging civil Unmanned Aerial Systems (UAS) markets. The NASA Advanced General Aviation Transport Experiments (AGATE) project successfully used a similar approach to enable the introduction of primary composite structures and flat panel displays in the 1990s, establishing both the technology and certification standardization to permit quick adoption through partnerships with industry, academia, and the Federal Aviation Administration (FAA). Regional and airliner markets are experiencing constant pressure to achieve decreasing levels of community emissions and noise, while lowering operating costs and improving safety. But to what degree can these new technology frontiers impact aircraft safety, the environment, operations, cost, and performance? Are the benefits transformational enough to fundamentally alter aircraft competiveness and productivity to permit much greater aviation use for high speed and On-Demand Mobility (ODM)? These questions were asked in a Zip aviation system study named after the Zip Car, an emerging car-sharing business model. Zip Aviation investigates the potential to enable new emergent markets for aviation that offer "more flexibility than the existing transportation solutions

  4. Theory of tapered laser cooling

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Hiromi; Wei, J.


    A theory of tapered laser cooling for fast circulating ion beams in a storage ring is constructed. The authors describe the fundamentals of this new cooling scheme, emphasizing that it might be the most promising way to beam crystallization. The cooling rates are analytically evaluated to study the ideal operating condition. They discuss the physical implication of the tapering factor of cooling laser, and show how to determine its optimum value. Molecular dynamics method is employed to demonstrate the validity of the present theory.

  5. Slab track systems for high-speed railways.


    Michas, Georgios


    In the last 40 years an increase in train speed and axle load around the world and other challenges in the conventional ballasted track system gave birth to ballastless railway track system. This study examines in depth the various slab track systems that are being used today. Their design characteristics as well as the various requirements for efficient use are thoroughly explained. At least 34 different ballastless systems have been recorded in many railway networks throughout the world. Th...

  6. Double-reflection polygon mirror for high-speed optical coherence microscopy. (United States)

    Liu, Linbo; Chen, Nanguang; Sheppard, C J R


    We report on a high-speed, high-efficiency, high-duty-cycle, path-length-maintaining and linear beam scanner suitable for en face scanning optical coherence microscopy. Fast transverse beam scanning is achieved by use of a double-reflection polygon mirror (DRPM) rotating at a constant speed. With a motor speed of 18,000 rpm and a scanner diameter of 50 mm, the DRPM provides a line rate up to 3 kHz, +/-1.8 degrees scanning range, and 90% duty cycle. A much higher scanning speed and much larger scanning range can be readily achieved by increasing the scanner diameter.

  7. High Speed Rail System and the Tourism Market: Between Accessibility, Image and Coordination Tool


    marie delaplace; sylvie bazin; francesca pagliara; Antonio Sposaro


    the aim of this P is to propose a state-of-the-art concerning the interaction between High-Speed Rail systems and the tourism market, in order to identify the possible best practices aiming to enhance the value of the tourist activities. This question arises because there are many projects of High-Speed Rail and others are ongoing, whose economic justification is based on the benefits deriving from them. In November 2013 there were 21.472 km of High Speed Railways (i.e., whose speed is greate...

  8. Composite reinforced metallic cylinder for high speed rotation (United States)

    Pradhan, Sahadev


    The objective of the present study is to design and development of the composite reinforced thin metallic cylinder to increase the peripheral speed significantly and thereby improve the separation performance in a centrifugal gas separation processes through proper optimization of the internal parameters. According to Dirac equation (Cohen (1951)), the maximum separative work for a centrifugal gas separation process increase with 4th power of the peripheral speed. Therefore, it has been intended to reinforce the metallic cylinder with composites (carbon fibers: T-700 and T- 1000 grade with suitable epoxy resin) to increase the stiffness and hoop stress so that the peripheral speed can be increased significantly, and thereby enhance the separative output. Here, we have developed the mathematical model to investigate the elastic stresses of a laminated cylinder subjected to mechanical, thermal and thermo-mechanical loading. A detailed analysis is carried out to underline the basic hypothesis of each formulation. Further, we evaluate the steady state creep response of the rotating cylinder and analyze the stresses and strain rates in the cylinder.

  9. Algorithms for High-Speed Noninvasive Eye-Tracking System (United States)

    Talukder, Ashit; Morookian, John-Michael; Lambert, James


    Two image-data-processing algorithms are essential to the successful operation of a system of electronic hardware and software that noninvasively tracks the direction of a person s gaze in real time. The system was described in High-Speed Noninvasive Eye-Tracking System (NPO-30700) NASA Tech Briefs, Vol. 31, No. 8 (August 2007), page 51. To recapitulate from the cited article: Like prior commercial noninvasive eyetracking systems, this system is based on (1) illumination of an eye by a low-power infrared light-emitting diode (LED); (2) acquisition of video images of the pupil, iris, and cornea in the reflected infrared light; (3) digitization of the images; and (4) processing the digital image data to determine the direction of gaze from the centroids of the pupil and cornea in the images. Most of the prior commercial noninvasive eyetracking systems rely on standard video cameras, which operate at frame rates of about 30 Hz. Such systems are limited to slow, full-frame operation. The video camera in the present system includes a charge-coupled-device (CCD) image detector plus electronic circuitry capable of implementing an advanced control scheme that effects readout from a small region of interest (ROI), or subwindow, of the full image. Inasmuch as the image features of interest (the cornea and pupil) typically occupy a small part of the camera frame, this ROI capability can be exploited to determine the direction of gaze at a high frame rate by reading out from the ROI that contains the cornea and pupil (but not from the rest of the image) repeatedly. One of the present algorithms exploits the ROI capability. The algorithm takes horizontal row slices and takes advantage of the symmetry of the pupil and cornea circles and of the gray-scale contrasts of the pupil and cornea with respect to other parts of the eye. The algorithm determines which horizontal image slices contain the pupil and cornea, and, on each valid slice, the end coordinates of the pupil and cornea

  10. Design of noise barrier inspection system for high-speed railway (United States)

    Liu, Bingqian; Shao, Shuangyun; Feng, Qibo; Ma, Le; Cholryong, Kim


    The damage of noise barriers will highly reduce the transportation safety of the high-speed railway. In this paper, an online inspection system of noise barrier based on laser vision for the safety of high-speed railway is proposed. The inspection system, mainly consisted of a fast camera and a line laser, installed in the first carriage of the high-speed CIT(Composited Inspection Train).A Laser line was projected on the surface of the noise barriers and the images of the light line were received by the camera while the train is running at high speed. The distance between the inspection system and the noise barrier can be obtained based on laser triangulation principle. The results of field tests show that the proposed system can meet the need of high speed and high accuracy to get the contour distortion of the noise barriers.

  11. Environmental risks of high-speed railway in China: Public participation, perception and trust

    NARCIS (Netherlands)

    He, G.; Mol, A.P.J.; Zhang, L.; Lu, Y.


    Two decades ago China entered an era with rapid expansion of transport infrastructure. In an ambitious plan on high-speed railway development, China plans to have the longest high-speed railway network by 2020. Social concerns and anxiety with the adverse environmental and social risks and impacts

  12. Fire ventilation for the high-speed line south train tunnels

    NARCIS (Netherlands)

    Leur, P.H.E. van de; Oerle, N.J. van; Lemaire, A.D.; Molag, M.


    In The Netherlands, the High-Speed Line South project currently under development as a part of the European railway network for high speed trains. In support of a Quantitative Risk Assessment, CFD calculations provide data on the consequences of fire scenarios for escaping passengers. The paper

  13. Calibration and test capabilities of the Langley 7- by 10- foot high speed tunnel (United States)

    Fox, C. H., Jr.; Huffman, J. K.


    The results of a new subsonic calibration of the Langley 7 by 10 foot high speed tunnel with the test section in a solid wall configuration are presented. A description of the test capabilities of the 7 by 10 foot high speed tunnel is also given.

  14. L1 Adaptive Manoeuvring Control of Unmanned High-speed Water Craft

    DEFF Research Database (Denmark)

    Svendsen, Casper H.; Holck, Niels Ole; Galeazzi, Roberto


    This work addresses the issue of designing an adaptive robust control system to govern the steering of a high speed unmanned personal watercraft (PWC) maintaining equal performance across the craft’s envelope of operation. The maneuvering dynamics of a high speed PWC is presented and a strong...

  15. Tri-state high speed rail study : Chicago - Milwaukee - Twin Cities corridor (United States)


    This report, the Final Report for the Tri-State Study of High Speed Rail Service, describes the work carried out by TMS/Benesch in analyzing the potential for high speed rail in the Tri-State Corridor. Specifically, the study provides a pre-feasibili...

  16. Impact of high-speed railway accessibility on the location choices of office establishments

    NARCIS (Netherlands)

    Willigers, J.


    High-speed railways are becoming increasingly common in Europe. In the Netherlands soon the HSL-South will be opened. This high-speed railway line connects the Randstad to Brussels and Paris. A prominent aim of this new railway is to improve international competitiveness of the Netherlands. As a

  17. Developing seamless connections in the urban transit network : a look toward high-speed rail interconnectivity. (United States)


    In the past, U.S. studies on high-speed rail (HSR) have focused primarily on the economic implications of high-speed rail development. Recently, however, studies have begun evaluating multimodal connectivity of HSR stations. The ways in which differe...

  18. Evaluation of intrusion detection technologies for high speed rail grade crossings : final report. (United States)


    The rail industry is in the process of developing a prototype system for high speed rail. One of the concerns when using high speed rail is the danger of obstructions on the track. This level of danger is much higher than with traditional railway veh...

  19. Evaluation of a new device for sterilizing dental high-speed handpieces

    DEFF Research Database (Denmark)

    Larsen, T; Andersen, H K; Fiehn, N E


    Dental high-speed turbines and handpieces can take up and expel microorganisms during operation and thus need regular sterilization. This study established a method for validating devices used to sterilize high-speed turbines and handpieces. The air and water channels and turbine chambers were...

  20. Flow-Visualization Techniques Used at High Speed by Configuration Aerodynamics Wind-Tunnel-Test Team (United States)

    Lamar, John E. (Editor)


    This paper summarizes a variety of optically based flow-visualization techniques used for high-speed research by the Configuration Aerodynamics Wind-Tunnel Test Team of the High-Speed Research Program during its tenure. The work of other national experts is included for completeness. Details of each technique with applications and status in various national wind tunnels are given.

  1. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.


    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...

  2. Ultra-high-speed optical signal processing of serial data signals

    DEFF Research Database (Denmark)

    Clausen, Anders; Mulvad, Hans Christian Hansen; Palushani, Evarist


    To ensure that ultra high-speed serial data signals can be utilised in future optical communication networks, it is indispensable to have all-optical signal processing elements at our disposal. In this paper, the most recent advances in our use of non-linear materials incorporated in different...... function blocks for high-speed signal processing are reviewed....

  3. Smart Sensor Based Obstacle Detection for High-Speed Unmanned Surface Vehicle

    DEFF Research Database (Denmark)

    Hermann, Dan; Galeazzi, Roberto; Andersen, Jens Christian


    This paper describes an obstacle detection system for a high-speed and agile unmanned surface vehicle (USV), running at speeds up to 30 m/s. The aim is a real-time and high performance obstacle detection system using both radar and vision technologies to detect obstacles within a range of 175 m. ...

  4. Characterization of arbitrary fiber taper profiles with optical microscopy and image processing algorithms (United States)

    Farias, Heric D.; Sebem, Renan; Paterno, Aleksander S.


    This work reports results from the development of a software to process the parameters involved in the characterization of fiber taper profiles, while using optical microscopy, a high-definition camera and a high- precision translation stage as the moveable base on which the taper is positioned. In addition to this procedure, image processing algorithms were customized to process the acquired images. With edge detection algorithms in the stitched image, one would be able to characterize the given taper radius curve that represents the taper profile when the camera has a sufficient resolution. As a consequence, the proposed fiber taper characterization procedure is a first step towards a high-resolution characterization of fiber taper diameters with arbitrary profiles, specially this case, in which tapers are fabricated with the stepwise technique that allows the production of non- biconical profiles. The parameters of the stitched images depends on the used microscope objective and the length of the characterized tapers. A non-biconical arbitrary taper is measured as an example for the illustration of the developed software and procedure.

  5. Signal Integrity Analysis of High-Speed Interconnects

    CERN Document Server

    Oltean Karlsson, A


    LHC detectors and future experiments will produce very large amount of data that will be transferred at multi-Gigabit speeds. At such data rates, signal-integrity effects become important and traditional rules of thumb are no longer enough for the design and layout of the traces. Simulations for signal-integrity effects at board level provide a way to study and validate several scenarios before arriving at a set of optimized design rules prior to building the actual printed circuit board (PCB). This article describes some of the available tools at CERN. Two case studies will be used to highlight the capabilities of these programs.

  6. Simulation of high-speed interaction between impactor and layered-spaced design involving explosive (United States)

    Ishchenko, Aleksandr; Afanas'eva, Svetlana; Belov, Nikolai; Burkin, Viktor; Zykova, Angelica; Rogaev, Konstantin; Yugov, Nikolai


    In this paper we present calculating and experimental study of high-speed interaction between explosive content, protected by layered-spaced design, and the cermet impactor in wide speed range. An experimental technique and mathematical model of during the behavior of explosives, protected by layer-spaced design, by with high-speed impact. The process of the interaction between the cermet impactor and element of the protective design is customized and depends on the materials of the interacting bodies, the speed and angle of impact.

  7. High resolution, high speed, long working distance, large field of view confocal fluorescence microscope. (United States)

    Pacheco, Shaun; Wang, Chengliang; Chawla, Monica K; Nguyen, Minhkhoi; Baggett, Brend K; Utzinger, Urs; Barnes, Carol A; Liang, Rongguang


    Confocal fluorescence microscopy is often used in brain imaging experiments, however conventional confocal microscopes are limited in their field of view, working distance, and speed for high resolution imaging. We report here the development of a novel high resolution, high speed, long working distance, and large field of view confocal fluorescence microscope (H2L2-CFM) with the capability of multi-region and multifocal imaging. To demonstrate the concept, a 0.5 numerical aperture (NA) confocal fluorescence microscope is prototyped with a 3 mm × 3 mm field of view and 12 mm working distance, an array of 9 beams is scanned over the field of view in 9 different regions to speed up the acquisition time by a factor of 9. We test this custom designed confocal fluorescence microscope for future use with brain clarification methods to image large volumes of the brain at subcellular resolution. This multi-region and multi-spot imaging method can be used in other imaging modalities, such as multiphoton microscopes, and the field of view can be extended well beyond 12 mm × 12 mm.

  8. A simulation-based study of HighSpeed TCP and its deployment

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Evandro de [Univ. of California, Berkeley, CA (United States)


    The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simulation results showing the performance of HighSpeed TCP and the impact of its use on the present implementation of TCP are presented. Network conditions including different degrees of congestion, different levels of loss rate, different degrees of bursty traffic and two distinct router queue management policies were simulated. The performance and fairness of HighSpeed TCP were compared to the existing TCP and solutions for bulk-data transfer using parallel streams.

  9. Dynamic of Friction Coupling Independently Rotating Wheels for High Speed

    Directory of Open Access Journals (Sweden)

    Yan Shi


    Full Text Available A new lateral coupling structure with independently rotating wheels (IRW is proposed, and longitudinal creepage is obtained by replacing the gear pair with the friction pair to synchronize the rotation speed of left and right wheels. The auxiliary wheelset made up of two friction wheels can be placed either under the primary suspension or on the frame. Vehicles dynamics models with three different kinds of bogies are developed, including friction coupling bogie with independently rotating wheels (FCIRW-bogie, bogie with independently rotating wheels (IRW-bogie, and bogie with rigid wheelsets, and their guiding and resetting capability when negotiating large-radius curves are compared and analyzed. Results show that FCIRW has the advantages of both IRW and rigid wheelset. On the straight track, FCIRW has sufficient wheel-rail longitudinal creep force to assist the reset; its critical speed is much higher than that of the rigid wheelset. On the curved track, the whole vehicle wear power of FCIRW-bogie vehicle is about 2/3 of the rigid axle level.

  10. High speed image acquisition system of absolute encoder (United States)

    Liao, Jianxiang; Chen, Xin; Chen, Xindu; Zhang, Fangjian; Wang, Han


    Absolute optical encoder as a product of optical, mechanical and electronic integration has been widely used in displacement measuring fields. However, how to improve the measurement velocity and reduce the manufacturing cost of absolute optical encoder is the key problem to be solved. To improve the measurement speed, a novel absolute optical encoder image acquisition system is proposed. The proposed acquisition system includes a linear CCD sensor is applied for capturing coding pattern images, an optical magnifying system is used for enlarging the grating stripes, an analog-digital conversion(ADC) module is used for processing the CCD analogy signal, a field programmable gate array(FPGA) device and other peripherals perform driving task. An absolute position measurement experiment was set up to verify and evaluate the proposed image acquisition system. The experimental result indicates that the proposed absolute optical encoder image acquisition system has the image acquisition speed of more than 9500fp/s with well reliability and lower manufacture cost.

  11. Downforce variation dependence of angle of incidence modification for the rear wing of high speed vehicles (United States)

    Tarulescu, R.; Tarulescu, S.; Leahu, C.


    The conventional downforce devices (with fixed geometry) of high speed vehicles have parameters such as area, angle of incidence and head resistance coefficients, all with constant values. The downforce is proportional with the square of movement speed and the power consumed for the neutralization of aerodynamic road resistance is proportional with the cube of speed. The authors carried out an analytical study of downforce, adjustable/monitored by optimum incidence (modification of incidence angle of rear wing for performance improvement).

  12. Multicolor upconversion emissions in Tm 3+/Er3+ codoped tellurite photonic microwire between silica fiber tapers. (United States)

    Chen, Nan-Kuang; Kuan, Pei-Wen; Zhang, Junjie; Zhang, Liyan; Hu, Lili; Lin, Chinlon; Tong, Limin


    We report multicolor upconversion emissions including the blue-violet, green, and red lights in a Tm 3+/Er3+codoped tellurite glass photonic microwire between two silica fiber tapers. A silica fiber is tapered until its evanescent field is exposed and then angled-cleaved at the tapered center to divide the tapered fibers into two parts. A tellurite glass is melted by a gas flame to cluster into a sphere at the tip of one tapered fiber. The other angled-cleaved tapered fiber is blended into the melted tellurite glass. When the tellurite glass is melted, the two silica fiber tapers are simultaneously moving outwards to draw the tellurite glass into a microwire in between. The advantage of angled-cleaving on fiber tapers is to avoid cavity resonances in high index photonic microwire. Thus, the broadband white light can be transmitted between silica fibers and a special optical property like high intensity upconversion emission can be achieved. A cw 1064 nm Nd:YAG laser light is launched into the Tm 3+/Er3+ codoped tellurite microwire through a silica fiber taper to generate the multicolor upconversion emissions, including the blue-violet, green, and red lights, simultaneously.

  13. High-Speed Additive Manufacturing Through High-Aspect-Ratio Nozzles (United States)

    Shaw, Leon; Islam, Mashfiqul; Li, Jie; Li, Ling; Ayub, S. M. Imran


    The feasibility of layer-by-layer manufacturing through high-aspect-ratio (HAR) nozzles for microextrusion of paste to deposit planes has been investigated. Various conditions for paste extrusion, including nozzle moving speed, piston speed, extrusion rate, and distance between the nozzle tip and substrate, have been evaluated. By linking various microextrusion parameters together with the aid of a critical distance concept derived from microextrusion using circular nozzles and addressing the extrusion delay in response to the change of the piston speed and air pocket problems properly, we successfully microextruded single planes, multilayer objects, and larger planes made of multiple smaller planes side by side through HAR nozzles. It is further demonstrated that the X-Y dimensions of an extruded plane in the steady-state extrusion stage are determined by the nozzle travel distance and the length of the HAR nozzle opening if microextrusion is conducted with proper conditions. However, the height of the extruded plane is not only determined by the microextrusion conditions, but also affected by the drying shrinkage of the paste after microextrusion. This demonstration of the feasibility of using a HAR nozzle machine opens the door to manufacture of multimaterial, multilayer devices with high productivity in the near future.

  14. Measurement and Analysis of High-speed Railway Subgrade Settlement in China: A Case Study

    National Research Council Canada - National Science Library

    Qulin Tan; Leijuan Li; Senlin Wang


    .... With the rapid development of China's high-speed railway, it puts a very high requirement for track smoothness, and thus the requirements of subgrade stability and deformation control become very stringent...

  15. Estimating workforce development needs for high-speed rail in California. (United States)


    This study provides an assessment of the job creation and attendant education and training needs associated with the creation of the California High-Speed Rail (CHSR) network, scheduled to begin construction in September 2012. Given the high profile ...


    Directory of Open Access Journals (Sweden)

    Lukáš Týfa


    Full Text Available The paper first describes high speed rail generally and explains the relationship between high speed and conventional railway networks (according to the vehicle types in operation on the network. The core of the paper is comprised of the methodology for choosing the best route for a railway line and its application to the high speed railway connection Praha – Brno. The Algorithm used assumes the existence of more route proposals, which could be different in terms of the operational conception, line routing or types of vehicles used. The optimal variant is the one with the lowest daily cost, which includes infrastructure and vehicle costs; investment and operational costs. The results from applying this model confirmed the assumption, that a dedicated high speed railway line, only for high speed trains, has the same or lower investment costs than a line for both high speed and conventional trains. Furthermore, a dedicated high line also has a lower cost for infrastructure maintenance but a higher cost for buying high speed multiple units.

  17. Protective Effectiveness of Porous Shields Under the Influence of High-Speed Impact Loading

    Directory of Open Access Journals (Sweden)

    Kramshonkov E.N.


    Full Text Available The results of numerical simulations of a compact steel impactor with the aluminum porous shields under high-speed shock loading are presented. The porosity of barrier varies in wide range provided that its mass stays the same, but the impactor has always equal (identical mass. Here presented the final assessment of the barrier perforation speed depending on its porosity and initial shock speed. The range of initial impact speed varies from 1 to 10 km/s. Physical phenomena such as: destruction, melting, vaporization of a interacting objects are taken into account. The analysis of a shield porosity estimation disclosed that the protection effectiveness of porous shield reveals at the initial impact speed grater then 1.5 km/s, and it increases when initial impact speed growth.

  18. High power CO2 laser development with AOM integration for ultra high-speed pulses (United States)

    Bohrer, Markus; Vaupel, Matthias; Nirnberger, Robert; Weinberger, Bernhard; Jamalieh, Murad


    There is a 500 billion USD world market for packaging expected to grow to a trillion in 2030. Austria plays an important role world wide for high speed laser engraving applications — especially when it comes to high end solutions. Such high end solutions are fundamental for the production of print forms for the packaging and decorating industry (e. g. cans). They are additionally used for security applications (e. g. for printing banknotes), for the textile printing industry and for creating embossing forms (e. g. for the production of dashboards in the automotive industry). High speed, high precision laser engraving needs laser resonators with very stable laser beams (400 - 800W) especially in combination with AOMs. Based upon a unique carbon fiber structure - stable within the sub-micrometer range - a new resonator has been developed, accompanied by most recent thermo-mechanical FEM calculations. The resulting beam is evaluated on an automated optical bench using hexapods, allowing to optimize the complete beam path with collimators and AOM. The major steps related to laser engraving of dry offset printing plates during the full workflow from the artists design to the printed result on an aluminum can is presented in this paper as well as laser characteristics, AOM integration and correlative CLSM and SEM investigation of the results.

  19. Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Eric [Texas A & M Univ., College Station, TX (United States); Krejci, Michael [Texas A & M Univ., College Station, TX (United States); Mathieu, Olivier [Texas A & M Univ., College Station, TX (United States); Vissotski, Andrew [Texas A & M Univ., College Station, TX (United States); Ravi, Sankat [Texas A & M Univ., College Station, TX (United States); Plichta, Drew [Texas A & M Univ., College Station, TX (United States); Sikes, Travis [Texas A & M Univ., College Station, TX (United States); Levacque, Anthony [Texas A & M Univ., College Station, TX (United States); Camou, Alejandro [Texas A & M Univ., College Station, TX (United States); Aul, Christopher [Texas A & M Univ., College Station, TX (United States)


    This final report documents the technical results of the 3-year project entitled, “Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels,” funded under the NETL of DOE. The research was conducted under six main tasks: 1) program management and planning; 2) turbulent flame speed measurements of syngas mixtures; 3) laminar flame speed measurements with diluents; 4) NOx mechanism validation experiments; 5) fundamental NOx kinetics; and 6) the effect of impurities on NOx kinetics. Experiments were performed using primary constant-volume vessels for laminar and turbulent flame speeds and shock tubes for ignition delay times and species concentrations. In addition to the existing shock- tube and flame speed facilities, a new capability in measuring turbulent flame speeds was developed under this grant. Other highlights include an improved NOx kinetics mechanism; a database on syngas blends for real fuel mixtures with and without impurities; an improved hydrogen sulfide mechanism; an improved ammonia kintics mechanism; laminar flame speed data at high pressures with water addition; and the development of an inexpensive absorption spectroscopy diagnostic for shock-tube measurements of OH time histories. The Project Results for this work can be divided into 13 major sections, which form the basis of this report. These 13 topics are divided into the five areas: 1) laminar flame speeds; 2) Nitrogen Oxide and Ammonia chemical kinetics; 3) syngas impurities chemical kinetics; 4) turbulent flame speeds; and 5) OH absorption measurements for chemical kinetics.

  20. Soap-film coating: high-speed deposition of multilayer nanofilms. (United States)

    Zhang, Renyun; Andersson, Henrik A; Andersson, Mattias; Andres, Britta; Edlund, Håkan; Edström, Per; Edvardsson, Sverker; Forsberg, Sven; Hummelgård, Magnus; Johansson, Niklas; Karlsson, Kristoffer; Nilsson, Hans-Erik; Norgren, Magnus; Olsen, Martin; Uesaka, Tetsu; Ohlund, Thomas; Olin, Håkan


    The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.

  1. Aerodynamic effects of high-speed passenger trains on other trains. (United States)


    This study assesses the potential safety risks associated with aerodynamic loads produced by the Acela high-speed train when passing freight and bi-level commuter passenger cars. Acela operates at speeds up to 150 mph, on tangent tracks adjacent to n...

  2. Effect of Cutting Fluids on the Flank Wear of High Speed and ...

    African Journals Online (AJOL)

    The effect of some cutting fluids namely: Mentholated spirit, paraffin, and soluble oil on the flank wear of High-speed steel and carbide tipped tools by orthogonal cutting has been studied. Cente lathe was used for cylindrical turning operated at a speed of 370rpm and depth of cut of 1mm to machine aluminum, brass, mild ...

  3. Environmental impact statement : Chicago-St. Louis high speed rail project (United States)


    The proposed action would provide High-Speed Rail (HSR) passenger service between Chicago and St. Louis, operating at top speeds of 110 mph (180 kph) through most of the project area, except for a 29-kilometer (18-mile) segment between Lincoln and Sp...

  4. The new AGV high-speed train; Der neue Hochgeschwindigkeitszug AGV

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.


    On 5th February 2008, Alstom lifted the veil on its new AGV high speed-train. With articulated carriages like the TGV, the AGV has a distributed drive system. Designed for a commercial speed of 360 km/h, the modular architecture of the AGV enables it to be built in a variety of configurations. (orig.)

  5. High-speed rail aerodynamic assessment and mitigation report : final report. (United States)


    This report advances the current state of knowledge, as well as shared understanding and evaluation of present procedures used to : mitigate the impacts effects from high-speed trains (HST) operating at speeds between 110 mph and 250 mph. This work g...

  6. Repeated high-speed activities during youth soccer games in relation to changes in maximal sprinting and aerobic speeds. (United States)

    Buchheit, M; Simpson, B M; Mendez-Villanueva, A


    The aim of this study was to examine in highly-trained young soccer players whether substantial changes in either maximal sprinting speed (MSS) or maximal aerobic speed (as inferred from peak incremental test speed, V(Vam-Eval)) can affect repeated high-intensity running during games. Data from 33 players (14.5±1.3 years), who presented substantial changes in either MSS or V(Vam-Eval) throughout 2 consecutive testing periods (~3 months) were included in the final analysis. For each player, time-motion analyses were performed using a global positioning system (1-Hz) during 2-10 international club games played within 1-2 months from/to each testing period of interest (n for game analyzed=109, player-games=393, games per player per period=4±2). Sprint activities were defined as at least a 1-s run at intensities higher than 61% of individual MSS. Repeated-sprint sequences (RSS) were defined as a minimum of 2 consecutive sprints interspersed with a maximum of 60 s of recovery. Improvements in both MSS and V(Vam-Eval) were likely associated with a decreased RSS occurrence, but in some positions only (e. g., - 24% vs. - 3% for improvements in MSS in strikers vs. midfielders, respectively). The changes in the number of sprints per RSS were less clear but also position-dependent, e. g., +7 to +12% for full-backs and wingers, - 5 to - 7% for centre-backs and midfielders. In developing soccer players, changes in repeated-sprint activity during games do not necessarily match those in physical fitness. Game tactical and strategic requirements are likely to modulate on-field players' activity patterns independently (at least partially) of players' physical capacities. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Design of high-speed turnouts and crossings (United States)

    Raif, Lukáš; Puda, Bohuslav; Havlík, Jiří; Smolka, Marek


    Recently, the new ways to improve the railway switches and crossings have been sought, as the railway transport increases its operating speed. The expectation of these adjustments is to decrease the dynamic load, which usually increases together with velocity, and this influences the comfort of the vehicle passage, the wear of the structural parts and the cost of maintenance. These adjustments are primarily the turnout elements such as the optimized geometry of the turnout branch line by means of transition curves application, which minimizes the lateral acceleration during the vehicle passage through the track curve. The rail inclination is solved either by means of inclination in fastening system, or by machining of the rail head shape, because this ways of adjustment retain the wheel-rail interaction characteristics along the whole length of the turnout. Secondly, it is the crossing with movable part, which excludes the interruption of the running surface and optimization of the railway stiffness throughout the whole turnout length as well. We can see that the different stiffness along the turnout influences the dynamic load and it is necessary to optimize the discontinuities in the stiffness along the whole length of the turnout. For this purpose, the numeric modeling is carried out to seek the areas with the highest stiffness and subsequently, the system of stiffness optimization will be designed.

  8. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.


    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluat...... score, TS ≈ 0.37). The predicted high-speed streams show typical uncertainties in the arrival time of about 1 day and uncertainties in the speed of about 100 km/s. General advantages and disadvantages of the investigated solar wind models are diagnosed and outlined.......High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  9. High-speed Impact Modelling and Testing of Dyneema Composite


    Heru Utomo, B.D.


    Dyneema (Ultra High Molecular Weight Polyethylene – UHMW PE) is a high performance material that is used in many applications. These applications vary from leisure articles such as sails and kite wires to surgical wires and personal protection products. The reason that Dyneema outperforms many other materials is that it possesses a combination of the following properties: high strength, high stiffness and low density. Describing Dyneema, and especially Dyneema composite, is -however- challeng...

  10. High Pressure Sensing and Dynamics Using High Speed Fiber Bragg Grating Interrogation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, G. [LANL; Sandberg, R. L. [LANL; Lalone, B. M. [NSTec; Marshall, B. R. [NSTec; Grover, M. [NSTec; Stevens, G. D. [NSTec; Udd, E. [Columbia Gorge Research


    Fiber Bragg gratings (FBGs) are developing into useful sensing tools for measuring high pressure dynamics in extreme environments under shock loading conditions. Approaches using traditional diode array coupled FBG interrogation systems are often limited to readout speeds in the sub-MHz range. For shock wave physics, required detection speeds approaching 100 MHz are desired. We explore the use of two types of FBG sensing systems that are aimed at applying this technology as embedded high pressure probes for transient shock events. Both approaches measure time resolved spectral shifts in the return light from short (few mm long) uniform FBGs at 1550 nm. In the first approach, we use a fiber coupled spectrometer to demultiplex spectral channels into an array (up to 12) of single element InGaAs photoreceivers. By monitoring the detectors during a shock impact event with high speed recording, we are able to track the pressure induced spectral shifting in FBG down to a time resolution of 20 ns. In the second approach, developed at the Special Technologies Lab, a coherent mode-locked fiber laser is used to illuminate the FBG sensor. After the sensor, wavelength-to-time mapping is accomplished with a chromatic dispersive element, and entire spectra are sampled using a single detector at the modelocked laser repetition rate of 50 MHz. By sampling with a 12 GHz InGaAs detector, direct wavelength mapping in time is recorded, and the pressure induced FBG spectral shift is sampled at 50 MHz. Here, the sensing systems are used to monitor the spectral shifts of FBGs that are immersed into liquid water and shock compressed using explosives. In this configuration, the gratings survive to pressures approaching 50 kbar. We describe both approaches and present the measured spectral shifts from the shock experiments.

  11. High speed data transmission coaxial-cable in the space communication system (United States)

    Su, Haohang; Huang, Jing


    An effective method is proved based on the scattering parameter of high speed 8-core coaxial-cable measured by vector network analyzer, and the semi-physical simulation is made to receive the eye diagram at different data transmission rate. The result can be apply to analysis decay and distortion of the signal through the coaxial-cable at high frequency, and can extensively design for electromagnetic compatibility of high-speed data transmission system.

  12. Analysis of Contact Stresses in High Speed Sheet Metal Forming Processes


    Bonnen, J.; Gillard, A.; Golovashchenko, S.; Ibrahim, R.; Mamutov, A.; SMITH, L.


    In high speed metal forming, determination of contact stresses applied to forming dies is necessary in order to identify the requirements to the die material. Contact stresses greatly control the die design due to their effects on die durability. Very high contact stresses and fracture under impulsive loading have been reported in literature on contact type of high speed forming. In pulsed forming operations using electro-hydraulic forming (EHF), a work piece is often accelerat...

  13. High Speed Dim Air Target Detection Using Airborne Radar under Clutter and Jamming Effects


    A. E. Almslmany; Q. S. Cao; Wang, C.Y.


    The challenging potential problems associated with using airborne radar in detection of high Speed Maneuvering Dim Target (HSMDT) are the highly noise, jamming and clutter effects. The problem is not only how to remove clutter and jamming as well as the range migration and Doppler ambiguity estimation problems due to high relative speed between the targets and airborne radar. Some of the recently published works ignored the range migration problems, while the others ignored the Doppler ambigu...

  14. Special features of high-speed projectile interaction with barriers protected by a water layer (United States)

    Afanas'eva, S. A.; Belov, N. N.; Burkin, V. V.; D'yachkovskii, A. S.; Evtyushkin, E. V.; Zykov, E. N.; Ishchenko, A. N.; Monakhov, R. Yu.; Rodionov, A. A.; Khabibullin, M. V.; Yugov, N. T.


    The stress-strain state (SSS) of projectiles is investigated when a high-speed projectile enters water and interacts with barriers protected by a water layer. Experimental investigations are carried out using a high-speed ballistic setup. Calculations are performed within the framework of mechanics of continuous media for an elastic plastic model of a solid with allowance for fracture and hydrodynamic water model. Depending on the projectile speed, different SSS regimes are observed: from small deformed at a speed of ≈1 km/s to fractured at a speed of ≈2 km/s. Calculation technique allows distances in water to be determined at which the metal barrier can be punched for the inertial model.

  15. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda


    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  16. High speed ultrasound monitoring in the field of sports biomechanics (United States)

    Zakir Hossain, M.; Twerdowski, E.; Grill, W.


    Ultrasonic monitoring allowing the evaluation of the performance of muscles under training has been developed. The monitoring scheme is suitable to determine muscle movement and is based on the measurement of the transit time of longitudinally polarized ultrasound propagating across the observed muscle. Variations of the length of the muscle lead to variations of the lateral extension since the volume of the muscle is conserved. The corresponding variations of the observed time-of-flight result dominantly from the variation of the path length. This allows the time-resolved detection of the movement of the muscles in the path of the ultrasonic beam. In this way not only the degree of contraction or relaxation, but also the speed of these processes can be quantitatively monitored. The muscle thickness has been determined with a resolution of +/- 0.02 mm corresponding to about +/- 0.2 % of the thickness of the relaxed muscle. This resolution is already in the range of unavoidable uncertainties caused by the surface structure of the individual muscles. Similarly, the already obtained resolution in time corresponds to a fraction 1/750 of the time of the fastest known human muscle movement of 7.5 ms, observed for the full contraction of the eye lid muscle. The time of flight is measured along a line between two electro-acoustic transducers positioned on the skin on opposite sides of the monitored muscle. The transducers can be placed at any desired position but should be positioned such, that no bones or intestines are obstructing the path between them. The time-of-flight from which all other data is derived is observed with the aid of a computer-controlled arbitrary function generator and a synchronized transient recorder. Even in the demonstrated developmental state the equipment is already rather compact (lap-top size) and can be battery operated.

  17. High-Speed, High-Resolution Time-to-Digital Conversion (United States)

    Katz, Richard; Kleyner, Igor; Garcia, Rafael


    This innovation is a series of time-tag pulses from a photomultiplier tube, featuring short time interval between pulses (e.g., 2.5 ns). Using the previous art, dead time between pulses is too long, or too much hardware is required, including a very-high-speed demultiplexer. A faster method is needed. The goal of this work is to provide circuits to time-tag pulses that arrive at a high rate using the hardwired logic in an FPGA - specifically the carry chain - to create what is (in effect) an analog delay line. High-speed pulses travel down the chain in a "wave." For instance, a pulse train has been demonstrated from a 1- GHz source reliably traveling down the carry chain. The size of the carry chain is over 10 ns in the time domain. Thus, multiple pulses will travel down the carry chain in a wave simultaneously. A register clocked by a low-skew clock takes a "snapshot" of the wave. Relatively simple logic can extract the pulses from the snapshot picture by detecting the transitions between logic states. The propagation delay of CMOS (complementary metal oxide semiconductor) logic circuits will differ and/or change as a result of temperature, voltage, age, radiation, and manufacturing variances. The time-to-digital conversion circuits can be calibrated with test signals, or the changes can be nulled by a separate on-die calibration channel, in a closed loop circuit.

  18. Holographic memory for high-density data storage and high-speed pattern recognition (United States)

    Gu, Claire


    As computers and the internet become faster and faster, more and more information is transmitted, received, and stored everyday. The demand for high density and fast access time data storage is pushing scientists and engineers to explore all possible approaches including magnetic, mechanical, optical, etc. Optical data storage has already demonstrated its potential in the competition against other storage technologies. CD and DVD are showing their advantages in the computer and entertainment market. What motivated the use of optical waves to store and access information is the same as the motivation for optical communication. Light or an optical wave has an enormous capacity (or bandwidth) to carry information because of its short wavelength and parallel nature. In optical storage, there are two types of mechanism, namely localized and holographic memories. What gives the holographic data storage an advantage over localized bit storage is the natural ability to read the stored information in parallel, therefore, meeting the demand for fast access. Another unique feature that makes the holographic data storage attractive is that it is capable of performing associative recall at an incomparable speed. Therefore, volume holographic memory is particularly suitable for high-density data storage and high-speed pattern recognition. In this paper, we review previous works on volume holographic memories and discuss the challenges for this technology to become a reality.


    Directory of Open Access Journals (Sweden)

    S. T. Djabbarov


    Full Text Available Purpose. The scientific paper highlights research of aerodynamic pressure and distribution of airflow velocity field along the moving high-speed train. Methodology. The study of velocity field distribution around the moving high-speed train is produced by simulating its movement as axially symmetric body with the ogive-shaped head and tail parts in compressible (acoustic environment. Findings. The values of the absolute velocity (theoretical of air flow generated by the body movement is determined (for the case when the body moves at a constant speed (200, 250, 350, 400 km / h at a certain height from the ground, for the points located at different distances from the axis of the moving body (high-speed train. The calculations results allowed building the graphs of the air flow velocity in the acoustic environment along the moving body at different distances from it. Using the Bernoulli law (pressure change dependences on the flow velocity, the values of the overpressure generated by the air stream from the moving body were determined. Originality. This is the first theoretical study of the aerodynamics of the high-speed train as axially symmetric body with the ogive-shaped head and tail parts in compressible (acoustic environment, moving with steady speed. The research results allow us to establish the distribution of the excess air flow pressure generated along the moving high-speed train. Practical value. The obtained results allows determining of the following parameters: 1 requirements for physical-mechanical and strength characteristics of the individual elements of the railway infrastructure in the areas of high-speed train movement, subject to aerodynamic pressure; 2 minimum distance from the track safe for people location during high-speed train passage.

  20. Monitoring and data acquisition of the high speed hydrogen pellet in SPINS

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Samiran Shanti, E-mail:; Mishra, Jyotishankar; Gangradey, Ranjana; Dutta, Pramit; Rastogi, Naveen; Panchal, Paresh; Nayak, Pratik; Agarwal, Jyoti; Bairagi, Pawan; Patel, Haresh; Sharma, Hardik


    Highlights: • Pellet INjector System with monitoring and data acquisition is described. • A high speed camera was used to view pellet size, and its flight trajectory. • PXI based high speed control system is used data acquisition. • Pellets of length 2–4.8 mm and speed 250–750 m/s were obtained. - Abstract: Injection of solid hydrogen pellets is an efficient way of replenishing the spent fuel in high temperature plasmas. Aiming that, a Single Pellet INjector System (SPINS) is developed at Institute for Plasma Research (IPR), India, to initiate pellet injection related research in SST-1. The pellet injector is controlled by a PXI system based data acquisition and control (DAC) system for pellet formation, precise firing control, data collection and diagnostics. The velocity of high speed moving pellets is estimated by using two sets of light gate diagnostic. Apart from light gate, a fast framing camera is used to measure the pellet size and its speed. The pellet images are captured at a frame rate of ∼200,000 frames per second at (128 × 64) pixel resolution with an exposure time of 1 μs. Using these diagnostic, various cylindrical pellets of length ranging from 2 to 4.8 mm and speed 250–750 m/s were successfully obtained. This paper describes the control and data acquisition system of SPINS, the techniques for measurement of pellet velocity and capturing images of high speed moving pellet.

  1. Aerodynamic Effects of High-Speed Trains on People and Property at Stations in the Northeast Corridor. Safety of High-Speed Ground Transportation Systems. (United States)


    This report presents the results of a study to evaluate the aerodynamic (air velocity and pressure) effects of the new high-speed trains on the safety and comfort of people, and the impacts on physical facilities, in and around Northeast Corridor sta...

  2. Tapered stems one-third proximally coated have higher complication rates than cylindrical two-third coated stems in patients with high hip dislocation undergoing total hip arthroplasty with step-cut shortening osteotomy. (United States)

    Ozden, V Emre; Dikmen, G; Beksac, B; Tozun, I Remzi


    The results of cementless stems in total hip arthroplasty (THA) done because of congenital dislocation with step-cut osteotomy is not well known, particularly the influence of the design and the role of extent of porous coating. Therefore we performed a retrospective study to evaluate the mid to long-term results THA performed with a single type acetabular component and different geometry and fixation type stems with ceramic bearings in the setting of step-cut subtrochanteric osteotomy in high hip dislocated (HHD) patients. We asked if the stem type affect the outcomes in terms of (1) intra and postoperative complication rates (2) radiographic outcomes (3) prosthesis survival in step-cut subtrochanteric shortening osteotomy. The type of the stem, whether cylindrical or tapered does not affect the outcome if the femoral canal fit and fill is obtained and the step-cut femoral shortening osteotomy is primarily fixed. Forty-five hips in 35 patients with a mean follow up of 10 years (range, 7-14 years) were evaluated. The single type cementless cup was placed at the level of the true acetabulum, a step-cut shortening femoral osteotomy was performed and reconstruction was performed with two different types of tapered stem in twenty-two hips (Synergy™ and Image™ proximally coated, Smith and Nephew, Menphis, TN, USA) and one type of cylindrical stem (Echelon™ with 2/3 coated, Smith and Nephew, Menphis, TN, USA) in twenty-three hips. Harris hip scores (HHS) and a University of California Los Angeles (UCLA) activity scores were calculated for all patients and successive X-rays were evaluated regarding component loosening and osteolysis, along with complications related to bearing, step-cut osteotomy and stem types. Forty-one hips (91%) had good and excellent clinical outcome according to HHS. The mean UCLA activity scores improved from 3.2±0.6 points (range, 2-4) preoperatively to 6.3 points±0.5 (range, 5-7) at the latest follow-up. The mean femoral shortening was 36

  3. Permanent magnet design for high-speed superconducting bearings (United States)

    Hull, John R.; Uherka, Kenneth L.; Abdoud, Robert G.


    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

  4. High-speed Impact Modelling and Testing of Dyneema Composite

    NARCIS (Netherlands)

    Heru Utomo, B.D.


    Dyneema (Ultra High Molecular Weight Polyethylene – UHMW PE) is a high performance material that is used in many applications. These applications vary from leisure articles such as sails and kite wires to surgical wires and personal protection products. The reason that Dyneema outperforms many other

  5. High-speed photodetectors in a photonic crystal platform

    DEFF Research Database (Denmark)

    Ottaviano, Luisa; Semenova, Elizaveta; Schubert, Martin


    We demonstrate a fast photodetector (f3dB > 40GHz) integrated into a high-index contrast photonic crystal platform. Device design, fabrication and characterization are presented.......We demonstrate a fast photodetector (f3dB > 40GHz) integrated into a high-index contrast photonic crystal platform. Device design, fabrication and characterization are presented....

  6. High-speed lateral polysilicon photodiode in standard CMOS

    NARCIS (Netherlands)

    Radovanovic, S.; Annema, Anne J.; Nauta, Bram


    A high-performance lateral polysilicon photodiode was designed in standard 0.18 /spl mu/m CMOS technology. The device has a frequency bandwidth far in the GHz range: the measured bandwidth of the poly photodiode was 6 GHz, which figure was limited by the measurement equipment. The high intrinsic

  7. High-speed lateral polysilicon photodiode in standard CMOS

    NARCIS (Netherlands)

    Radovanovic, S.; Annema, Anne J.; Nauta, Bram

    A high-performance lateral polysilicon photodiode was designed in standard 0.18 μm CMOS technology. The device has a frequency bandwidth far in the GHz range: the measured bandwidth of the poly photodiode was 6 GHz, which figure was limited by the measurement equipment. The high intrinsic (physical)

  8. A New High-Speed, High-Cycle, Gear-Tooth Bending Fatigue Test Capability (United States)

    Stringer, David B.; Dykas, Brian D.; LaBerge, Kelsen E.; Zakrajsek, Andrew J.; Handschuh, Robert F.


    A new high-speed test capability for determining the high cycle bending-fatigue characteristics of gear teeth has been developed. Experiments were performed in the test facility using a standard spur gear test specimens designed for use in NASA Glenn s drive system test facilities. These tests varied in load condition and cycle-rate. The cycle-rate varied from 50 to 1000 Hz. The loads varied from high-stress, low-cycle loads to near infinite life conditions. Over 100 tests were conducted using AISI 9310 steel spur gear specimen. These results were then compared to previous data in the literature for correlation. Additionally, a cycle-rate sensitivity analysis was conducted by grouping the results according to cycle-rate and comparing the data sets. Methods used to study and verify load-path and facility dynamics are also discussed.

  9. The Tapering Practices of Strongman Athletes. (United States)

    Winwood, P W; Dudson, M K; Wilson, D; Mclaren-Harrison, J K H; Redjkins, V; Pritchard, H J; Keogh, J W L


    This study provides the first empirical evidence of how strongman athletes taper for strongman competitions. Strongman athletes (n=454) (mean ±SD: 33.2 ±8.0y, 178.1 ±10.6cm, 108.6 ±27.9kg, 12.6 ±8.9y general resistance training, 5.3 ±5.0y strongman implement training) completed a self-reported 4-page internet survey on tapering practices. Analysis by gender (male and female), age (≤ 30 and >30y), body mass (≤ 105 and >105kg) and competitive standard (local/regional amateur, national amateur and professional) was conducted. Eighty seven percent (n=396) of strongman athletes reported they used a taper. Athletes stated their typical taper length was 8.6 ±5.0 days, with the step taper the most commonly performed taper (52%). Training volume decreased during the taper by 45.5 ±12.9% and all training ceased 3.9 ±1.8 days out from competition. Typically, athletes reported training frequency and training duration stayed the same or decreased and training intensity decreased to around 50% in the last week. Athletes generally stated that; tapering was performed to achieve recovery, rest and peak performance; the deadlift, yoke walk and stone lifts/work took longer to recover from than other lifts; assistance exercises were reduced or removed in the taper; massage, foam rolling, nutritional changes and static stretching were strategies utilized in the taper; and, poor tapering occurred when athletes trained too heavy/hard or had too short a taper. This data will assist strongman athletes and coaches in the optimization of tapering variables leading to more peak performances. Future research could investigate the priming and pre-activation strategies strongman athletes utilize on competition day.

  10. [Comfort of crew and passengers and atmospheric pressure, noise, wind speed in high-speed train of Shijiazhuang-Taiyuan passenger dedicated line]. (United States)

    Zhai, Yi-biao; Huo, Wei; Liu, Qiao-ying; Chen, Bao-shan; Zhang, Jin-long; Shi, Lei


    To explore the crew and passengers' comfort on the Shijiazhuang-Taiyuan passenger dedicated line and physical factors, such as air pressure, noise, wind speed. Comfort investigation of all the crew (n = 244) and passengers (n = 377) on the Shijiazhuang-Taiyuan passenger dedicated line at speed of 250 km/h and 200 km/h and the detection of the air pressure, noise and wind speed were performed in 2011. Significantly higher ratio of comfortable feeling, lower ratio of seriously discomfortable feeling were observed in crew and passengers at 200 km/h compared with those at 250 km/h (P high-speed train passing through the tunnels. The individuals feel more comfortable at 200 km/h than 250 km/h in this line., which may be related with rapid variation of wind speed and noise when the train passes through the tunnels with high speed.

  11. High Speed and High Accuracy Control of Industrial Articulated Robot Arms with Jerk Restraint by Spline Interpolated Taught Data (United States)

    Goto, Satoru; Iwanaga, Takuya; Kyura, Nobuhiro; Nakamura, Masatoshi

    In industrial robot arms, high speed and high accurate operation is required. However in case of high speed operation, it often arises high jerk, i, e., rapid change of acceleration. Jerk causes deterioration of control performance such as vibration of a tip of a robot arm. It is, therefore, important to reduce jerk during robot arm operation. In this research, spline interpolation is used to reduce jerk under torque and speed constraints. Effectiveness of the proposed method was assured by experimental results and simulation results of an actual robot arm.

  12. The Time Lens Concept Applied to Ultra-High-Speed OTDM Signal Processing

    DEFF Research Database (Denmark)

    Clausen, Anders; Palushani, Evarist; Mulvad, Hans Christian Hansen


    This survey paper presents some of the applications where the versatile time-lens concept successfully can be applied to ultra-high-speed serial systems by offering expected needed functionalities for future optical communication networks....

  13. High Speed Railway Environment Safety Evaluation Based on Measurement Attribute Recognition Model

    Directory of Open Access Journals (Sweden)

    Qizhou Hu


    Full Text Available In order to rationally evaluate the high speed railway operation safety level, the environmental safety evaluation index system of high speed railway should be well established by means of analyzing the impact mechanism of severe weather such as raining, thundering, lightning, earthquake, winding, and snowing. In addition to that, the attribute recognition will be identified to determine the similarity between samples and their corresponding attribute classes on the multidimensional space, which is on the basis of the Mahalanobis distance measurement function in terms of Mahalanobis distance with the characteristics of noncorrelation and nondimensionless influence. On top of the assumption, the high speed railway of China environment safety situation will be well elaborated by the suggested methods. The results from the detailed analysis show that the evaluation is basically matched up with the actual situation and could lay a scientific foundation for the high speed railway operation safety.

  14. OptoCeramic-Based High Speed Fiber Multiplexer for Multimode Fiber Project (United States)

    National Aeronautics and Space Administration — A fiber-based fixed-array laser transmitter can be combined with a fiber-arrayed detector to create the next-generation NASA array LIDAR systems. High speed optical...

  15. High speed television camera system processes photographic film data for digital computer analysis (United States)

    Habbal, N. A.


    Data acquisition system translates and processes graphical information recorded on high speed photographic film. It automatically scans the film and stores the information with a minimal use of the computer memory.

  16. Analysis and improvement of calculation procedure of high-speed centrifugal pumps (United States)

    Kraeva, E. M.; Masich, I. S.


    The model of flow around a flowing part of a high-speed centrifugal pump with a semi-open impeller is presented. The calculated ratios for design of lowflow pumps are obtained and confirmed experimentally.

  17. Integrated High-Speed Digital Optical True-Time-Delay Modules for Synthetic Aperture Radars Project (United States)

    National Aeronautics and Space Administration — Crystal Research, Inc. proposes an integrated high-speed digital optical true-time-delay module for advanced synthetic aperture radars. The unique feature of this...

  18. High-Speed, Low-Power ADC for Digital Beam Forming (DBF) Systems Project (United States)

    National Aeronautics and Space Administration — In Phase 1, Ridgetop Group designed a high-speed, yet low-power silicon germanium (SiGe)-based, analog-to-digital converter (ADC) to be a key element for digital...

  19. Study on the subgrade deformation under high-speed train loading and water-soil interaction (United States)

    Han, Jian; Zhao, Guo-Tang; Sheng, Xiao-Zhen; Jin, Xue-Song


    It is important to study the subgrade characteristics of high-speed railways in consideration of the water-soil coupling dynamic problem, especially when high-speed trains operate in rainy regions. This study develops a nonlinear water-soil interaction dynamic model of slab track coupling with subgrade under high-speed train loading based on vehicle-track coupling dynamics. By using this model, the basic dynamic characteristics, including water-soil interaction and without water induced by the high-speed train loading, are studied. The main factors-the permeability coefficient and the porosity-influencing the subgrade deformation are investigated. The developed model can characterize the soil dynamic behaviour more realistically, especially when considering the influence of water-rich soil.

  20. Advanced Modular, Multi-Channel, High Speed Fiber Optic Sensing System for Acoustic Emissions Monitoring Project (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes to prove the feasibility of innovations based on ultra-light-weight, ultra-high-speed, multi-channel,...