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Sample records for spiral tube high-speed

  1. An improved design of spiral tube assembly for separation of proteins by high-speed counter-current chromatography.

    Science.gov (United States)

    Dasarathy, Dhweeja; Ito, Yoichiro

    2015-10-30

    A new spiral tube assembly was designed to improve the column capacity and partition efficiency for protein separation. This spiral tube assembly has greater column capacity than the original tubing because of an increase in radial grooves from 4 to 12 to accommodate more spiral layers and 12 narrow spots instead of 4 in each circular loop to interrupt the laminar flow that causes sample band broadening. Standard PTFE tubing (1.6mm ID) and the modified flat-twisted tubing were used as the separation column. The performances of both assemblies were compared for separating three stable test proteins including cytochrome c, myoglobin, and lysozyme using a two phase aqueous-aqueous solvent system composed of polyethylene glycol 1000 (12.5% w/w) and dibasic potassium phosphate (12.5% w/w). All samples were run at 1, 2, 3, and 5mL/min at both 800rpm and 1000rpm. The separation of these three protein samples produced high stationary phase retentions at 1, 2, and 3mL/min, yet separated efficiently at 5mL/min in 40min. After comparing the separation efficiency in terms of the peak resolutions, theoretical plate numbers, and separation times, it was determined that the flat-twisted tubing was more effective in separating these protein samples. In order to validate the efficacy of this novel assembly, a mixture of five protein samples (cytochrome c, myoglobin, ovalbumin, lysozyme, and hemoglobin) were separated, under the optimal conditions established with these three protein samples, at 1mL/min with a revolution speed of 1000rpm. There were high stationary phase retentions of around 60%, with effective separations, demonstrating the efficiency of the flat-twisted spiral tube assembly. The separation time of 6h was a limitation but can potentially be shortened by improving the strength of the column that will permit an increase in revolution speed and flow rate. This novel spiral separation column will allow rapid and efficient separation of mixtures with high yield of the

  2. Proposal of a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography

    International Nuclear Information System (INIS)

    Hattori, Hitoshi; Fukushima, Harunobu; Yoshii, Yasuo; Nakamuta, Hironori; Iwase, Mitsuo; Kitade, Koichi

    2009-01-01

    In this paper, a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography is proposed. In order to obtain both the stability and the high load carrying capacity, the hydrodynamic bearing lubricated by liquid metal (Gallium alloy), named as the hybrid hydrodynamic bearing generates the lubricating film by wedge effect on the plane region between the spiral grooves under high loading condition. The parallelism between the bearing and the rotating body can be secured by optimizing the rigidity distribution of stationary shaft in the proposed rotating mechanism. By carrying out the fundamental design by numerical analyses, it has been made clear that the hybrid hydrodynamic bearing and the rotating mechanism are suitable for the X-ray tube used in the CT with ever-increasingly scanning speed. (author)

  3. High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller

    International Nuclear Information System (INIS)

    Habibullah, H.; Pota, H. R.; Petersen, I. R.

    2014-01-01

    This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM’s piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method

  4. High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller.

    Science.gov (United States)

    Habibullah, H; Pota, H R; Petersen, I R

    2014-03-01

    This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM's piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method.

  5. Analysis of High Speed Jets Produced by a Servo Tube Driven Liquid Jet Injector

    Science.gov (United States)

    Portaro, Rocco; Ng, Hoi Dick

    2017-11-01

    In today's healthcare environment many types of medication must be administered through the use of hypodermic needles. Although this practice has been in use for many years, drawbacks such as accidental needle stick injuries, transmission of deadly viruses and bio-hazardous waste are still present. This study focuses on improving a needle free technology known as liquid jet injection, through the implementation of a linear servo tube actuator for the construction of a fully closed loop liquid jet injection system. This device has the ability to deliver both micro- and macro- molecules, high viscosity fluids whilst providing real time control of the jet pressure profile for accurate depth and dispersion control. The experiments are conducted using a prototype that consists of a 3 kW servo tube actuator, coupled to a specially designed injection head allowing nozzle size and injection volume to be varied. The device is controlled via a high speed servo amplifier and FPGA. The high speed jets emanating from the injector are assessed via high speed photography and through the use of a force transducer. Preliminary results indicate that the system allows for accurate shaping of the jet pressure profile, making it possible to target different tissue depths/types accurately.

  6. SPIRAL COUNTER-CURRENT CHROMATOGRAPHY OF SMALL MOLECULES, PEPTIDES AND PROTEINS USING THE SPIRAL TUBING SUPPORT ROTOR

    OpenAIRE

    Knight, Martha; Finn, Thomas M.; Zehmer, John; Clayton, Adam; Pilon, Aprile

    2011-01-01

    An important advance in countercurrent chromatography (CCC) carried out in open flow-tubing coils, rotated in planetary centrifuges, is the new design to spread out the tubing in spirals. More spacing between the tubing was found to significantly increase the stationary phase retention, such that now all types of two-phase solvent systems can be used for liquid-liquid partition chromatography in the J-type planetary centrifuges. A spiral tubing support (STS) frame with circular channels was c...

  7. Chemical milling of zircaloy tubing to produce integral OD spiral finned tubes. AWBA development program

    Science.gov (United States)

    Horwood, W. A.

    1982-02-01

    A detailed process description is provided for producing integral spiral fins on the outside surface of Zircaloy nuclear fuel cladding tubes by masking with pressure sensitive tape strips and then chemical milling (pickling) the tube wall between the tape strips to leave the fins in relief. Fins up to 0.020 inch high by 0.05 to 0.12 inch wide were consistently produced on tubes having wall thickness of 0.008 inch or greater after fin pickling. Wall thickness uniformity was excellent. Information is provided on tube surface preparation to maximize tape mask adhesion time during pickling, acid chemistry control to prevent local tube wall thinning near the fin, and pickling techniques to promote uniform material removal. Simple fixture designs are described for quickly and conveniently applying the tape strips to the tube wall in an accurate spiral.

  8. High-Speed Measurement of the Internal Diameter of Tubes: A Comparison of Methods

    DEFF Research Database (Denmark)

    Gundtoft, Hans Erik; Agerup, C.C.; Nielsen, N.

    1974-01-01

    The authors have compared various methods of tube measurement and have made the striking conclusion that the continuous measurement of the internal diameter of precision tubes with an air gauge is often useless in practice. The methods selected for experiment were all contactless and so included...

  9. Heat transfer enhancement in two-start spirally corrugated tube

    Directory of Open Access Journals (Sweden)

    Zaid S. Kareem

    2015-09-01

    Full Text Available Various techniques have been tested on heat transfer enhancement to upgrade the involving equipment, mainly in thermal transport devices. These techniques unveiled significant effects when utilized in heat exchangers. One of the most essential techniques used is the passive heat transfer technique. Corrugations represent a passive technique. In addition, it provides effective heat transfer enhancement because it combined the features of extended surfaces, turbulators and artificial roughness. Therefore, A Computational Fluid Dynamics was employed for water flowing at low Reynolds number in spiral corrugated tubes. This article aimed for the determination of the thermal performance of unique smooth corrugation profile. The Performance Evaluation Criteria were calculated for corrugated tubes, and the simulation results of both Nusselt number and friction factor were compared with those of standard plain and corrugated tubes for validation purposes. Results showed the best thermal performance range of 1.8–2.3 for the tube which has the severity of 45.455 × 10−3 for Reynolds number range of 100–700. The heat transfer enhancement range was 21.684%–60.5402% with friction factor increase of 19.2–36.4%. This indicated that this creative corrugation can improve the heat transfer significantly with appreciably increasing friction factor.

  10. Strain-based design procedures for spiral-welded steel tubes in combined walls

    NARCIS (Netherlands)

    Gresnigt, A.M.; van Es, S.H.J.; Vasilikis, D; Karamanos, SA; Dubina, D.; Ungureanu, V.

    2016-01-01

    To investigate the structural behaviour of large-diameter spiral-welded steel tubes under bending, a full scale experimental program has been performed, consisting of thirteen 42-inch diameter, spiral-welded steel tubes with D/t ratios ranging between 65 and 120. Additionally, numerical studies have

  11. Organic high ionic strength aqueous two-phase solvent system series for separation of ultra-polar compounds by spiral high-speed counter-current chromatography

    Science.gov (United States)

    Zeng, Yun; Liu, Gang; Ma, Ying; Chen, Xiaoyuan; Ito, Yoichiro

    2011-01-01

    Existing two-phase solvent systems for high-speed countercurrent chromatography cover the separation of hydrophobic to moderately polar compounds, but often fail to provide suitable partition coefficient values for highly polar compounds such as sulfonic acids, catecholamines and zwitter ions. The present paper introduces a new solvent series which can be applied for the separation of these polar compounds. It is composed of 1-butanol, ethanol, saturated ammonium sulfate and water at various volume ratios and consists of a series of 10 steps which are arranged according to the polarity of the solvent system so that the two-phase solvent system with suitable K values for the target compound(s) can be found in a few steps. Each solvent system gives proper volume ratio and high density difference between the two phases to provide a satisfactory level of retention of the stationary phase in the spiral column assembly. The method is validated by partition coefficient measurement of four typical polar compounds including methyl green (basic dye), tartrazine (sulfonic acid), tyrosine (zwitter ion) and epinephrine (a catecholamine), all of which show low partition coefficient values in the polar 1-butanol-water system. The capability of the method is demonstrated by separation of three catecholamines. PMID:22033108

  12. Spiral Countercurrent Chromatography

    Science.gov (United States)

    Ito, Yoichiro; Knight, Martha; Finn, Thomas M.

    2013-01-01

    For many years, high-speed countercurrent chromatography conducted in open tubing coils has been widely used for the separation of natural and synthetic compounds. In this method, the retention of the stationary phase is solely provided by the Archimedean screw effect by rotating the coiled column in the centrifugal force field. However, the system fails to retain enough of the stationary phase for polar solvent systems such as the aqueous–aqueous polymer phase systems. To address this problem, the geometry of the coiled channel was modified to a spiral configuration so that the system could utilize the radially acting centrifugal force. This successfully improved the retention of the stationary phase. Two different types of spiral columns were fabricated: the spiral disk assembly, made by stacking multiple plastic disks with single or four interwoven spiral channels connected in series, and the spiral tube assembly, made by inserting the tetrafluoroethylene tubing into a spiral frame (spiral tube support). The capabilities of these column assemblies were successfully demonstrated by separations of peptides and proteins with polar two-phase solvent systems whose stationary phases had not been well retained in the earlier multilayer coil separation column for high-speed countercurrent chromatography. PMID:23833207

  13. Preparative separation of two subsidiary colors of FD&C Yellow No. 5 (Tartrazine) using spiral high-speed counter-current chromatography.

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D; Roque, Jose A; Mazzola, Eugene P; Ito, Yoichiro

    2014-05-23

    Specifications in the U.S. Code of Federal Regulations for the color additive FD&C Yellow No. 5 (Color Index No. 19140) limit the level of the tetrasodium salt of 4-[(4',5-disulfo[1,1'-biphenyl]-2-yl)hydrazono]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid and that of the trisodium salt of 4,4'-[4,5-dihydro-5-oxo-4-[(4-sulfophenyl)hydrazono]-1H-pyrazol-1,3-diyl]bis[benzenesulfonic acid], which are subsidiary colors abbreviated as Pk5 and Pk7, respectively. Small amounts of Pk5 and Pk7 are needed by the U.S. Food and Drug Administration for confirmatory analyses and for development of analytical methods. The present study describes the use of spiral high-speed counter-current chromatography (HSCCC) to separate the closely related minor components Pk5 and Pk7 from a sample of FD&C Yellow No. 5 containing ∼3.5% Pk5 and ∼0.7% Pk7. The separations were performed with highly polar organic/high-ionic strength aqueous two-phase solvent systems that were chosen by applying the recently introduced method known as graphic optimization of partition coefficients (Zeng et al., 2013). Multiple ∼1.0g portions of FD&C Yellow No. 5 (totaling 6.4g dye) were separated, using the upper phase of the solvent system 1-butanol/abs. ethanol/saturated ammonium sulfate/water, 1.7:0.3:1:1, v/v/v/v, as the mobile phase. After removing the ammonium sulfate from the HSCCC-collected fractions, these separations resulted in an enriched dye mixture (∼160mg) of which Pk5 represented ∼46% and Pk7, ∼21%. Separation of the enriched mixture, this time using the lower phase of that solvent system as the mobile phase, resulted in ∼61mg of Pk5 collected in fractions whose purity ranged from 88.0% to 92.7%. Pk7 (20.7mg, ∼83% purity) was recovered from the upper phase of the column contents. Application of this procedure also resulted in purifying the major component of FD&C Yellow No. 5 to >99% purity. The separated compounds were characterized by high-resolution mass

  14. Preparative separation of two subsidiary colors of FD&C Yellow No. 5 (Tartrazine) using spiral high-speed counter-current chromatography◊

    Science.gov (United States)

    Roque, Jose A.; Mazzola, Eugene P.; Ito, Yoichiro

    2014-01-01

    Specifications in the U.S. Code of Federal Regulations for the color additive FD&C Yellow No. 5 (Colour Index No. 19140) limit the level of the tetrasodium salt of 4-[(4',5-disulfo[1,1'-biphenyl]-2-yl)hydrazono]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid and that of the trisodium salt of 4,4'-[4,5-dihydro-5-oxo-4-[(4-sulfophenyl)hydrazono]-1H-pyrazol-1,3-diyl]bis[benzenesulfonic acid], which are subsidiary colors abbreviated as Pk5 and Pk7, respectively. Small amounts of Pk5 and Pk7 are needed by the U.S. Food and Drug Administration for confirmatory analyses and for development of analytical methods. The present study describes the use of spiral high-speed counter-current chromatography (HSCCC) with the recently introduced highly polar organic/high-ionic strength aqueous solvent systems to separate Pk5 and Pk7 from a sample of FD&C Yellow No. 5 containing ~3.5% Pk5 and ~0.7% Pk7. Multiple ~1.0 g portions of FD&C Yellow No. 5 (totaling 6.4 g dye) were separated, using the upper phase of the solvent system 1-BuOH/EtOHabs/saturated ammonium sulfate/water, 1.7:0.3:1:1, v/v/v/v, as the mobile phase. After applying a specially developed method for removing the ammonium sulfate from the HSCCC-collected fractions, these separations resulted in an enriched mixture (~160 mg) of Pk5 and Pk7 (~46% and ~21%, respectively). Separation of the enriched mixture, this time using the lower phase of that solvent system as the mobile phase, resulted in ~ 61 mg of Pk5 collected in fractions whose purity ranged from 88.0% to 92.7% (by HPLC at 254 nm). Pk7 (20.7 mg, ~83% purity) was recovered from the upper phase of the column content. Application of this procedure also resulted in purifying the major component of FD&C Yellow No. 5 to >99% purity. The separated compounds were characterized by high-resolution mass spectrometry and several 1H and 13C nuclear magnetic resonance spectroscopic techniques (COSY, NOESY, HSQC, and HMBC). PMID:24755184

  15. Impact of Cutting Forces and Chip Microstructure in High Speed Machining of Carbon Fiber – Epoxy Composite Tube

    Directory of Open Access Journals (Sweden)

    Roy Y. Allwin

    2017-09-01

    Full Text Available Carbon fiber reinforced polymeric (CFRP composite materials are widely used in aerospace, automobile and biomedical industries due to their high strength to weight ratio, corrosion resistance and durability. High speed machining (HSM of CFRP material is needed to study the impact of cutting parameters on cutting forces and chip microstructure which offer vital inputs to the machinability and deformation characteristics of the material. In this work, the orthogonal machining of CFRP was conducted by varying the cutting parameters such as cutting speed and feed rate at high cutting speed/feed rate ranges up to 346 m/min/ 0.446 mm/rev. The impact of the cutting parameters on cutting forces (principal cutting, feed and thrust forces and chip microstructure were analyzed. A significant impact on thrust forces and chip segmentation pattern was seen at higher feed rates and low cutting speeds.

  16. Application of spiral nasointestinal tube in enteral nutrition support for patients with extensive burn

    Directory of Open Access Journals (Sweden)

    Lai-Ping Wang

    2016-09-01

    Full Text Available Objective: To observe the effect of spiral nasointestinal tube on enteral nutrition support in patients with extensive burn. Methods: A total of 60 patients with extensive burn who were admitted in our hospital from January, 2014 to June, 2015 were included in the study and divided into the observation group and the control group with 30 cases in each group according to different catheter indwelling methods. The patients in the observation group were given spiral nasointestinal tube for enteral nutrition support, while the patients in the control group were given routine gastric tube for enteral nutrition support. The nutrition status and the occurrence rate of complications before catheter indwelling, 3, 6, and 10 d after catheter indwelling in the two groups were recorded. Results: The levels of ALB, HB, PA, and Scr 6, 10 d after catheter indwelling in the observation group were significantly higher than those in the control group (P<0.05. The occurrence rate of complications during the treatment period in the observation group was significantly lower than that in the control group (P<0.05. Conclusions: The spiral nasointestinal tube can provide the patients with extensive burn a better effective enteral nutrition support and improve the nutrition support, with a lower occurrence rate of complications, which is beneficial for the patients’ rehabilitation.

  17. EXPERIMENTAL INVESTIGATION OF THE CONVECTIVE HEAT TRANSFER IN A SPIRALLY COILED CORRUGATED TUBE WITH RADIANT HEATING

    Directory of Open Access Journals (Sweden)

    Milan Đorđević

    2017-12-01

    Full Text Available The Archimedean spiral coil made of a transversely corrugated tube was exposed to radiant heating in order to represent a heat absorber of the parabolic dish solar concentrator. The main advantage of the considered innovative design solution is a coupling effect of the two passive methods for heat transfer enhancement - coiling of the flow channel and changes in surface roughness. The curvature ratio of the spiral coil varies from 0.029 to 0.234, while water and a mixture of propylene glycol and water are used as heat transfer fluids. The unique focus of this study is on specific boundary conditions since the heat flux upon the tube external surfaces varies not only in the circumferential direction, but in the axial direction as well. Instrumentation of the laboratory model of the heat absorber mounted in the radiation field includes measurement of inlet fluid flow rate, pressure drop, inlet and outlet fluid temperature and 35 type K thermocouples welded to the coil surface. A thermal analysis of the experimentally obtained data implies taking into consideration the externally applied radiation field, convective and radiative heat losses, conduction through the tube wall and convection to the internal fluid. The experimental results have shown significant enhancement of the heat transfer rate compared to spirally coiled smooth tubes, up to 240% in the turbulent flow regime.

  18. CFD investigation of flow and heat transfer of nanofluids in isoflux spirally fluted tubes

    KAUST Repository

    Salama, Amgad

    2012-01-01

    In this work, the problem of flow and heat transfer of nanofluids in spirally fluted tubes is investigated numerically using the CFD code Fluent. The tube investigated in this work is characterized by the existence of helical ridging which is usually obtained by embossing a smooth tube. A tube of diameter of 15 mm, 1.5 mm groove depth and a single helix with pitch of 64 mm is chosen for simulation. This geometry has been chosen for simulation because it has been investigated experimentally for pure fluids and would, therefore, provide a verification framework with our CFD model. The result of our CFD investigation compares very well with the experimental work conducted on this tube geometry. Interesting patterns are highlighted and investigated including the existence of flow swirl as a result of the existence of the spirally enhanced ridges. This swirl flow enhances heat transfer characteristics of this system as reported in the literatures. This study also shows that further enhancement is achieved if small amount of nanoparticles are introduced to the fluid. These nanoparticles (metallic-based nanoparticles) when introduced to the fluid enhances its heat transfer characteristics.

  19. Spiral multiple-effect diffusion solar still coupled with vacuum-tube collector and heat pipe

    KAUST Repository

    Huang, Bin-Juine

    2015-04-01

    © 2015 Elsevier B.V. A novel solar still with spiral-shape multiple-effect diffusion unit is developed in the present study. The test results of a 14-effect unit coupled with vacuum-tube solar collector (absorber area 1.08m2) show that the highest daily pure water production is 40.6kgd-1. The measured highest productivity based on the area of glass cover, solar absorber, and evaporating surface is 34.7, 40.6, and 7.96kgm-2d-1, respectively, which are much higher than the published results. The measured solar distillation efficiency is 2.0-3.5. The performance enhancement results mainly from the lateral diffusion process in the spiraled still cell. The vapor flow generated by heat input can flow freely and laterally through the spiral channel down to the end when solar heat input is high. Besides, the larger evaporating and condensing area at the outer cell may increase heat and mass transfer at the outer cell.

  20. Preparative separation and identification of novel subsidiary colors of the color additive D&C Red No. 33 (Acid Red 33) using spiral high-speed counter-current chromatography.

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D; Mazzola, Eugene P; Ito, Yoichiro

    2015-02-06

    Three low-level subsidiary color impurities (A, B, and C) often present in batches of the color additive D&C Red No. 33 (R33, Acid Red 33, Colour Index No. 17200) were separated from a portion of R33 by spiral high-speed counter-current chromatography (HSCCC). The separation involved use of a very polar solvent system, 1-BuOH/5mM aq. (NH4)2SO4. Addition of ammonium sulfate to the lower phase forced partition of the components into the upper phase, thereby eliminating the need to add a hydrophobic counterion as was previously required for separations of components from sulfonated dyes. The very polar solvent system used would not have been retained in a conventional multi-layer coil HSCCC instrument, but the spiral configuration enabled retention of the stationary phase, and thus, the separation was possible. A 1g portion of R33 enriched in A, B, and C was separated using the upper phase of the solvent system as the mobile phase. The retention of the stationary phase was 38.1%, and the separation resulted in 4.8 mg of A of >90% purity, 18.3mg of B of >85% purity, and 91 mg of C of 65-72% purity. A second separation of a portion of the C mixture resulted in 7 mg of C of >94% purity. The separated impurities were identified by high-resolution mass spectrometry and NMR spectroscopic techniques as follows: 5-amino-3-biphenyl-3-ylazo-4-hydroxy-naphthalene-2,7-disulfonic acid, A; 5-amino-4-hydroxy-6-phenyl-3-phenylazo-naphthalene-2,7-disulfonic acid, B; and 5-amino-4-hydroxy-3,6-bis-phenylazo-naphthalene-2,7-disulfonic acid, C. The isomers A and B are compounds reported for the first time. Application of the spiral HSCCC method resulted in the additional benefit of yielding 930 mg of the main component of R33, 5-amino-4-hydroxy-3-phenylazo-naphthalene-2,7-disulfonic acid, of >97% purity. Published by Elsevier B.V.

  1. Preparative separation and identification of novel subsidiary colors of the color additive D&C Red No. 33 (Acid Red 33) using spiral high-speed counter-current chromatography☆

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D.; Mazzola, Eugene P.; Ito, Yoichiro

    2015-01-01

    Three low-level subsidiary color impurities (A, B, and C) often present in batches of the color additive D&C Red No. 33 (R33, Acid Red 33, Colour Index No. 17200) were separated from a portion of R33 by spiral high-speed counter-current chromatography (HSCCC). The separation involved use of a very polar solvent system, 1-BuOH/5 mM aq. (NH4)2SO4. Addition of ammonium sulfate to the lower phase forced partition of the components into the upper phase, thereby eliminating the need to add a hydrophobic counterion as was previously required for separations of components from sulfonated dyes. The very polar solvent system used would not have been retained in a conventional multi-layer coil HSCCC instrument, but the spiral configuration enabled retention of the stationary phase, and thus, the separation was possible. A 1 g portion of R33 enriched in A, B, and C was separated using the upper phase of the solvent system as the mobile phase. The retention of the stationary phase was 38.1%, and the separation resulted in 4.8 mg of A of >90% purity, 18.3 mg of B of >85% purity, and 91 mg of C of 65–72% purity. A second separation of a portion of the C mixture resulted in 7 mg of C of >94% purity. The separated impurities were identified by high-resolution mass spectrometry and NMR spectroscopic techniques as follows: 5-amino-3-biphenyl-3-ylazo-4-hydroxy-naphthalene-2,7-disulfonic acid, A; 5-amino-4-hydroxy-6-phenyl-3-phenylazo-naphthalene-2,7-disulfonic acid, B; and 5-amino-4-hydroxy-3,6-bis-phenylazo-naphthalene-2,7-disulfonic acid, C. The isomers A and B are compounds reported for the first time. Application of the spiral HSCCC method resulted in the additional benefit of yielding 930 mg of the main component of R33, 5-amino-4-hydroxy-3-phenylazo-naphthalene-2,7-disulfonic acid, of >97% purity. PMID:25591404

  2. Numerical Investigation of the Fully-Developed Periodic Flow Field for Optimal Heat Transfer in Spirally Corrugated Tubes

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Condra, Thomas Joseph; Sørensen, Kim

    Even though the corrugated tube is a widely used technique to enhance transfer heat, the exact heat transfer enhancing mechanism remains relatively un-documented. Most studies attribute the favourable heat transfer characteristics to a swirling flow being present at higher corrugation....... In this study, a systematic approach relying on Computational Fluid Dynamics (CFD) is used to study and compare the heat transfer characteristics with the detailed flow field in the spirally corrugated tubes. By comparing the flow in 12 different spirally corrugated tubes at a fixed Reynolds number of 5000......, this study compares the flow field with the surface averaged Nusselt number to gain valuable insight into which flow phenomena causes favourable heat transfer characteristics. While the flow at low corrugations approximates the non-corrugated tube, higher corrugations of h/D creates a significant tangential...

  3. The usefulness of levin tube inserted drip infusion spiral CT: comparison with conventional method in subtotal gastrectomy patients

    International Nuclear Information System (INIS)

    Park, Young Jin; Kim, Young Hwan; Yoon, Jung Hee; Cha, Soon Joo; Kim, Jeong Sook; Kim, Sung Rok; Hur, Gham; Rhim, Hyun Chul

    1998-01-01

    The purpose of this study is to access the usefulness of newly designed Levin tube inserted drip infusion spiral CT for the evaluation of remnant stomach and anastomosis site in patients who have undergone subtotal gastrectomy for stomach cancer. A new technique named Levin tube inserted drip infusion spiral CT was used to prospectively study 23 patients. A 16Fr Levin tube was inserted into the remnant stomach; 500 ml of tap water was drip infused just before CT scanning and an additional 500 ml of water was infused during IV contrast injection. Water was infused by gravity, using a water bottle suspended at a height of 90 cm (Group A). The 31 patients who underwent conventional spiral CT scanning immediately after the divided ingestion of 900 ml diluted gastrografin were selected as a control group (Group B). The anatomic delineation of the anastomosis site was graded by two radiologists as excellent (3), good(2), fair (1) or poor (0). To evaluate the degree of distension, the maximal diameters of remnant stomach and the anastomosis site, and the thickness of the stomach wall, were also measured. In patients who had undergone subtobal gastrectomy, Levin tube inserted drip infusion spiral CT showed excellent anatomic delineation of the site of anastomosis and remnant stomach. We found that because it increases the distension of remnant stomach and the anastomosis site, this technique is effective for the evaluation of postoperative stomach. (author). 10 refs., 2 tabs., 3 figs

  4. Parabolic solar cooker: Cooking with heat pipe vs direct spiral copper tubes

    Science.gov (United States)

    Craig, Omotoyosi O.; Dobson, Robert T.

    2016-05-01

    Cooking with solar energy has been seen by many researchers as a solution to the challenges of poverty and hunger in the world. This is no exception in Africa, as solar coking is viewed as an avenue to eliminate the problem of food insecurity, insufficient energy supply for household and industrial cooking. There are several types of solar cookers that have been manufactured and highlighted in literature. The parabolic types of solar cookers are known to reach higher temperatures and therefore cook faster. These cookers are currently being developed for indoor cooking. This technology has however suffered low cooking efficiency and thus leads to underutilization of the high heat energy captured from the sun in the cooking. This has made parabolic solar cookers unable to compete with other conventional types of cookers. Several methods to maximize heat from the sun for indirect cooking has been developed, and the need to improve on them of utmost urgency. This paper investigates how to optimize the heat collected from the concentrating types of cookers by proposing and comparing two types of cooking sections: the spiral hot plate copper tube and the heat pipe plate. The system uses the concentrating solar parabolic dish technology to focus the sun on a conical cavity of copper tubes and the heat is stored inside an insulated tank which acts both as storage and cooking plate. The use of heat pipes to transfer heat between the oil storage and the cooking pot was compared to the use of a direct natural syphon principle which is achieved using copper tubes in spiral form like electric stove. An accurate theoretical analysis for the heat pipe cooker was achieved by solving the boiling and vaporization in the evaporator side and then balancing it with the condensation and liquid-vapour interaction in the condenser part while correct heat transfer, pressure and height balancing was calculated in the second experiment. The results show and compare the cooking time, boiling

  5. High-Speed Photography

    International Nuclear Information System (INIS)

    Paisley, D.L.; Schelev, M.Y.

    1998-01-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) copyright 1998 Society of Photo-Optical Instrumentation Engineers

  6. High speed data acquisition

    International Nuclear Information System (INIS)

    Cooper, P.S.

    1997-07-01

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

  7. High speed heterostructure devices

    CERN Document Server

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

    1994-01-01

    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. Magnitudes of gluteus medius muscle activation during standing hip joint movements in spiral-diagonal patterns using elastic tubing resistance.

    Science.gov (United States)

    Youdas, James W; Adams, Kady E; Bertucci, John E; Brooks, Koel J; Steiner, Meghan M; Hollman, John H

    2015-01-01

    The aim of this study was to simultaneously quantify electromyographic (EMG) activation levels (% maximum voluntary isometric contraction [MVIC]) within the gluteus medius muscles on both moving and stance limbs across the performance of four proprioceptive neuromuscular facilitation (PNF) spiral-diagonal patterns in standing using resistance provided by elastic tubing. Differential EMG activity was recorded from the gluteus medius muscle of 26 healthy participants. EMG signals were collected with surface electrodes at a sampling frequency of 1000 Hz during three consecutive repetitions of each spiral-diagonal movement pattern. Significant differences existed among the four-spiral-diagonal movement patterns (F3,75 = 19.8; p gluteus medius muscle recruitment (50 SD 29.3% MVIC) than any of the other three patterns and the diagonal one extension [D1E] (39 SD 37% MVIC) and diagonal two extension [D2E] (35 SD 29% MVIC) patterns generated more gluteus medius muscle recruitment than diagonal one flexion [D1F] (22 SD 21% MVIC). From a clinical efficiency standpoint, a fitness professional using the spiral-diagonal movement pattern of D2F and elastic tubing with an average peak tension of about 9% body mass may be able to concurrently strengthen the gluteus medius muscle on both stance and moving lower limbs.

  9. Strength of Short Concrete Filled Steel Tube Columns with Spiral Reinforcement

    Science.gov (United States)

    Krishan, A. L.; Troshkina, E. A.; Astafyeva, M. A.

    2017-11-01

    To further increase the bearing capacity and survivability of reinforced concrete filled steel tube (RCFT) columns, it is offered to supply their concrete core with additional spiral reinforcement. Such reinforcement also has a positive effect on the fire resistance of the columns. The practical use of compressed RCFT elements is restrained by the absence of procedures for determining their bearing capacity. A calculation procedure for determining the strength of short centrally compressed RCFT columns is offered. It is rather easy in terms of application and it allows one to take into account the main features of power resistance of such columns. The results of comparison of the calculated strength with experimental data are presented. The analysis of these results testifies that the accuracy of calculation of RCFT columns strength is sufficient for practice. The offered calculation procedure allows to provide the wider use of RCFT columns in construction practice as heavy loaded bearing elements of buildings and structures. It is recommended to use high-strength longitudinal reinforcement for further increase of the efficiency of these columns.

  10. High speed computer assisted tomography

    International Nuclear Information System (INIS)

    Maydan, D.; Shepp, L.A.

    1980-01-01

    X-ray generation and detection apparatus for use in a computer assisted tomography system which permits relatively high speed scanning. A large x-ray tube having a circular anode (3) surrounds the patient area. A movable electron gun (8) orbits adjacent to the anode. The anode directs into the patient area xrays which are delimited into a fan beam by a pair of collimating rings (21). After passing through the patient, x-rays are detected by an array (22) of movable detectors. Detector subarrays (23) are synchronously movable out of the x-ray plane to permit the passage of the fan beam

  11. High speed computer assisted tomography

    International Nuclear Information System (INIS)

    Maydan, D.; Shepp, L.A.

    1980-01-01

    X-ray generation and detection apparatus for use in a computer assisted tomography system which permits relatively high speed scanning. A large X-ray tube having an annular anode surrounds the patient area. A movable electron gun orbits adjacent to the anode. The anode directs X-rays through the patient area towards an array of movable detectors. Detector subarrays are synchronously movable out of the X-ray plane to permit passage of the X-ray beam as it rotates within a plane in which the detector array is disposed. (author)

  12. LMTD Design Methodology Assessment of Spiral Tube Heat Exchanger under the S-CO2 cycle operating condition

    International Nuclear Information System (INIS)

    Jung, Hwa Young; Lee, Jeong Ik; Ahn, Yoon Han

    2013-01-01

    The advantages of PCHE are compact high pressure difference endurance high temperature operation. However, PCHE is quite expensive and the resistance to the fast thermal cycling is questionable. In order to overcome this problem, the Korea Advanced Institute of Science and Technology (KAIST) research team is considering an alternative for the PCHE. Currently KAIST research team is using a Spiral Tube Heat Exchanger (STHE) of Sentry Equipment Corp. as a pre cooler in the SCO 2 PE facility. A STHE is relatively cheap but the operating pressure and temperature are acceptable for utilizing it as a pre cooler. A STHE is consisted of spiral shaped tubes (hot side i.e. S-CO 2 ) immersed in a shell (cold side i.e. water). This study is aimed at whether the logarithmic mean temperature difference (LMTD) heat exchanger design methodology is acceptable for designing the S-CO 2 cycle pre cooler. This is because the LMTD method usually assumes a constant specific heat, but the pre cooler in the S-CO 2 cycle operates at the nearest point to the critical point where a dramatic change in properties is expected. Experimentally obtained data are compared to the vendor provided technical specification based on the LMTD method. The detailed specifications provided by the vendor are listed in Table 1

  13. Designing high speed diagnostics

    Science.gov (United States)

    Veliz Carrillo, Gerardo; Martinez, Adam; Mula, Swathi; Prestridge, Kathy; Extreme Fluids Team Team

    2017-11-01

    Timing and firing for shock-driven flows is complex because of jitter in the shock tube mechanical drivers. Consequently, experiments require dynamic triggering of diagnostics from pressure transducers. We explain the design process and criteria for setting up re-shock experiments at the Los Alamos Vertical Shock Tube facility, and the requirements for particle image velocimetry and planar laser induced fluorescence measurements necessary for calculating Richtmeyer-Meshkov variable density turbulent statistics. Dynamic triggering of diagnostics allows for further investigation of the development of the Richtemeyer-Meshkov instability at both initial shock and re-shock. Thanks to the Los Alamos National Laboratory for funding our project.

  14. High Speed Ice Friction

    Science.gov (United States)

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

    2014-05-01

    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.

  15. Discharge characteristics of a high speed fuel injection system

    Science.gov (United States)

    Matthews, Robertson

    1925-01-01

    Discussed here are some discharge characteristics of a fuel injection system intended primarily for high speed service. The system consisted of a cam actuated fuel pump, a spring loaded automatic injection valve, and a connecting tube.

  16. High Speed Smoke Flow Visualization.

    Science.gov (United States)

    1981-03-01

    releasable to the National Technical Information Service (NTIS). At NTIS, it will be available to the general public, including foreign nations. This... information . 9 The initial work focused on the evaluation of the flow field within the high speed flow visualization tunnels and the optical and...with the high speed flow visuLl iza tion; it waIs used to take simul taneous smoke/Schlieren photographs. Siice it allowed for this unique method of

  17. High-speed photonics interconnects

    CERN Document Server

    Chrostowski, Lukas

    2013-01-01

    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

  18. High-speed pulse techniques

    CERN Document Server

    Coekin, J A

    1975-01-01

    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

  19. High-speed holographic camera

    International Nuclear Information System (INIS)

    Novaro, Marc

    The high-speed holographic camera is a disgnostic instrument using holography as an information storing support. It allows us to take 10 holograms, of an object, with exposures times of 1,5ns, separated in time by 1 or 2ns. In order to get these results easily, no mobile part is used in the set-up [fr

  20. High speed cryogenic monodisperse targets

    Science.gov (United States)

    Boukharov, A.; Vishnevkii, E.

    2017-11-01

    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.

  1. High-speed parallel counter

    International Nuclear Information System (INIS)

    Gus'kov, B.N.; Kalinnikov, V.A.; Krastev, V.R.; Maksimov, A.N.; Nikityuk, N.M.

    1985-01-01

    This paper describes a high-speed parallel counter that contains 31 inputs and 15 outputs and is implemented by integrated circuits of series 500. The counter is designed for fast sampling of events according to the number of particles that pass simultaneously through the hodoscopic plane of the detector. The minimum delay of the output signals relative to the input is 43 nsec. The duration of the output signals can be varied from 75 to 120 nsec

  2. High-speed AC motors

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.

  3. Application Of High Speed Photography In Science And Technology

    Science.gov (United States)

    Wu Ji-Zong, Wu; Yu-Ju, Lin

    1983-03-01

    The service works in high-speed photography carried out by the Department of Precision Instruments, Tianjin University are described in this paper. A compensation type high-speed camera was used in these works. The photographic methods adopted and better results achieved in the studies of several technical fields, such as velocity field of flow of overflow surface of high dam, combustion process of internal combustion engine, metal cutting, electrical are welding, experiment of piling of steel tube piles for supporting the marine platforms and characteristics of motion of wrist watch escape mechanism and so on are illustrated in more detail. As the extension of human visual organs and for increasing the abi-lities of observing and studying the high-speed processes, high-speed photography plays a very important role. In order to promote the application and development on high-speed photography, we have carried out the consultative and service works inside and outside Tianjin Uni-versity. The Pentazet 35 compensation type high-speed camera, made in East Germany, was used to record the high-speed events in various kinds of technical investigations and necessary results have been ob-tained. 1. Measurement of flow velocity on the overflow surface of high dam. In the design of a key water control project with high head, it is extremely necessary to determinate various characteristics of flow velocity field on the overflow surface of high dam. Since the water flow on the surface of high overflow dam possesses the features of large flow velocity and shallow water depth, therefore it is difficult to use the conventional current meters such as pilot tube, miniature cur-rent meter or electrical measuring methods of non-electrical quantities for studying this problem. Adopting the high-speed photographic method to study analogously the characteristics of flow velocity field on the overflow surface of high dam is a kind of new measuring method. People

  4. Flexible high-speed CODEC

    Science.gov (United States)

    Segallis, Greg P.; Wernlund, Jim V.; Corry, Glen

    1993-01-01

    This report is prepared by Harris Government Communication Systems Division for NASA Lewis Research Center under contract NAS3-25087. It is written in accordance with SOW section 4.0 (d) as detailed in section 2.6. The purpose of this document is to provide a summary of the program, performance results and analysis, and a technical assessment. The purpose of this program was to develop a flexible, high-speed CODEC that provides substantial coding gain while maintaining bandwidth efficiency for use in both continuous and bursted data environments for a variety of applications.

  5. Enantioseparation of DL-tryptophan by spiral tube assembly counter-current chromatography and evaluation of mass transfer rate for enantiomers

    Science.gov (United States)

    Tong, Shengqiang; Ito, Yoichiro; Ma, Ying

    2014-01-01

    Spiral tube assembly counter-current chromatography was successfully applied in enantioseparation of DL-tryptophan using bovine serum albumin as chiral selector. An improved biphasic aqueous-aqueous solvent system 12.0% (w/w) polyethyleneglycol 8000–9.0% (w/w) dibasic potassium phosphate-0.1% ammonia-78.9% water was used as the solvent system for counter-current chromatography, in which bovine serum albumin was predominantly distributed in the lower phase of the two-phase aqueous system. The aqueous-aqueous solvent system gave a very high enantioselectivity for D- and L-tryptophan at α=2.605 along with distribution ratio DD=1.200 and DL=0.461. High peak resolution was obtained for enantioseparation of 2.0 mg of DL-tryptophan by spiral tube assembly counter-current chromatography under room temperature. It was found that 0.1% ammonia added in the aqueous-aqueous solvent system greatly improved the enantioseparations. An unusual extremely broad peak for L-tryptophan was observed during enantioseparations. In order to give an explanation, mass transfer rates of D- and L-enantiomers through the interface between the two phases were measured. It was found that L-tryptophan showed lower mass transfer rate than D-tryptophan. Further discussions were proposed for possible reasons for mass transfer rate difference between the enantiomers. PMID:25476690

  6. High speed laser tomography system

    Science.gov (United States)

    Samsonov, D.; Elsaesser, A.; Edwards, A.; Thomas, H. M.; Morfill, G. E.

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120000slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

  7. Small Scale High Speed Turbomachinery

    Science.gov (United States)

    London, Adam P. (Inventor); Droppers, Lloyd J. (Inventor); Lehman, Matthew K. (Inventor); Mehra, Amitav (Inventor)

    2015-01-01

    A small scale, high speed turbomachine is described, as well as a process for manufacturing the turbomachine. The turbomachine is manufactured by diffusion bonding stacked sheets of metal foil, each of which has been pre-formed to correspond to a cross section of the turbomachine structure. The turbomachines include rotating elements as well as static structures. Using this process, turbomachines may be manufactured with rotating elements that have outer diameters of less than four inches in size, and/or blading heights of less than 0.1 inches. The rotating elements of the turbomachines are capable of rotating at speeds in excess of 150 feet per second. In addition, cooling features may be added internally to blading to facilitate cooling in high temperature operations.

  8. Application of high-speed photography to hydrodynamic instability research

    International Nuclear Information System (INIS)

    Chang Lihua; Li Zuoyou; Xiao Zhengfei; Zou Liyong; Liu Jinhong; Xiong Xueshi

    2012-01-01

    High-speed photography is used to study the Rayleigh-Taylor instability of air-water interface driven by high- pressure exploding gas. Clear images illustrating the instability are obtained, along with the air bubble peak speed and turbulent mixing speed. The RM (Richtmyer-Meshkov) instability of air/SF 6 interface driven by shock wave is also researched by using high-speed Schlieren technique on the horizontal shock tube and primary experimental results are obtained, which show the change of the turbulent mixing region clearly. (authors)

  9. Multimode polymer waveguides for high-speed optical interconnects

    Science.gov (United States)

    Bamiedakis, N.; Ingham, J. D.; Penty, R. V.; White, I. H.; DeGroot, J. V.; Clapp, T. V.

    2017-11-01

    Polymeric multimode waveguides are of particular interest for optical interconnections in short-reach data links. In some applications, for example in space-borne systems, the use of advanced materials with outstanding performance in extreme environments is required (temperature and radiation). In this paper therefore, we present novel siloxane polymers suitable for these applications. The materials are used to form straight, 90° bent and spiral polymer waveguides by low-cost conventional photolithographic techniques on FR4 substrates. The samples have been tested to investigate their propagation characteristics and demonstrate their potential for high-speed data links. Overall, there is strong evidence that these multimode waveguides can be successfully employed as high-speed short-reach data links. Their excellent thermal properties, their low cost and the simple fabrication process indicate their suitability for a wide range of space applications.

  10. 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)

    1997-07-25

    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.

  11. The influence of mechanical clearance reduction between plug (m1- m.e. version) and tube sheet simulator, at its experimental installation using a high speed plastic deformation technique

    International Nuclear Information System (INIS)

    Gyongyosi, T.; Panaitescu, V. N.; Prisecaru, I.

    2013-01-01

    The steam generator has to keep its structural integrity during entire operation lifetime. The isolation at both ends of the defective tube, from the primary heat transport system, is made of special shape plugs, using a plastic deformation technique. In the paper, after a brief introduction, are presented the technique developed experimentally for plugging of the steam generator defective tubes followed by a description of the tests performed, the results analysis get and conclusions. The paper is dedicated to the specialists working in the research and technological engineering. (authors)

  12. High speed imager test station

    Science.gov (United States)

    Yates, George J.; Albright, Kevin L.; Turko, Bojan T.

    1995-01-01

    A test station enables the performance of a solid state imager (herein called a focal plane array or FPA) to be determined at high image frame rates. A programmable waveform generator is adapted to generate clock pulses at determinable rates for clock light-induced charges from a FPA. The FPA is mounted on an imager header board for placing the imager in operable proximity to level shifters for receiving the clock pulses and outputting pulses effective to clock charge from the pixels forming the FPA. Each of the clock level shifters is driven by leading and trailing edge portions of the clock pulses to reduce power dissipation in the FPA. Analog circuits receive output charge pulses clocked from the FPA pixels. The analog circuits condition the charge pulses to cancel noise in the pulses and to determine and hold a peak value of the charge for digitizing. A high speed digitizer receives the peak signal value and outputs a digital representation of each one of the charge pulses. A video system then displays an image associated with the digital representation of the output charge pulses clocked from the FPA. In one embodiment, the FPA image is formatted to a standard video format for display on conventional video equipment.

  13. Experimental results for an experimental condensation heat exchanger with a spiral minichanel tube. Comparison to numerical imulations

    Directory of Open Access Journals (Sweden)

    Hrubý J.

    2013-04-01

    Full Text Available The paper describes new results for an experimental heat exchanger equipped with a single corrugated capillary tube, basic information about the measurements and the experimental setup. Some of the results were compared with numerical simulations.

  14. High-speed digital system design

    CERN Document Server

    Davis, Justin

    2006-01-01

    High-Speed Digital System Design bridges the gap from theory to implementation in the real world. Systems with clock speeds in low megahertz range qualify for high-speed. Proper design results in quality digital transmissions and lowers the chance for errors. This book is for computer and electrical engineers who may or may not have learned electromagnetic theory. The presentation style allows readers to quickly begin designing their own high-speed systems and diagnosing existing designs for errors.

  15. High Speed On-Wafer Characterization Laboratory

    Data.gov (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...

  16. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

    Energy Technology Data Exchange (ETDEWEB)

    May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany); Deak, Paul; Kalender, Willi A. [University of Erlangen, Department of Medical Physics, Erlangen (Germany); Keller, Andrea K.; Haeberle, Lothar [University of Erlangen, Department of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Achenbach, Stephan; Seltmann, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany)

    2012-03-15

    To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 {+-} 2.1 mSv/100 mAs for TCM and 12.5 {+-} 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR ({<=}60 bpm) was highest (49 {+-} 5%) compared to intermediate (60-70 bpm, 33 {+-} 12%) and high HR (>70 bpm, 29 {+-} 12%). However lowest ED is achieved at high HR (5.2 {+-} 1.5 mSv/100 mAs), compared with intermediate (6.7 {+-} 1.6 mSv/100 mAs) and low (8.3 {+-} 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

  17. Intra-individual diagnostic image quality and organ-specific-radiation dose comparison between spiral cCT with iterative image reconstruction and z-axis automated tube current modulation and sequential cCT

    International Nuclear Information System (INIS)

    Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Gawlitza, Joshua; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Groden, Christoph; Henzler, Thomas

    2016-01-01

    •Superiority of spiral versus sequential cCT in image quality and organ-specific-radiation dose.•Spiral cCT: lower organ-specific-radiation-dose in eye lense compared to tilted sequential cCT.•State-of-the-art IR spiral cCT techniques has significant advantages over sequential cCT techniques. Superiority of spiral versus sequential cCT in image quality and organ-specific-radiation dose. Spiral cCT: lower organ-specific-radiation-dose in eye lense compared to tilted sequential cCT. State-of-the-art IR spiral cCT techniques has significant advantages over sequential cCT techniques. To prospectively evaluate image quality and organ-specific-radiation dose of spiral cranial CT (cCT) combined with automated tube current modulation (ATCM) and iterative image reconstruction (IR) in comparison to sequential tilted cCT reconstructed with filtered back projection (FBP) without ATCM. 31 patients with a previous performed tilted non-contrast enhanced sequential cCT aquisition on a 4-slice CT system with only FBP reconstruction and no ATCM were prospectively enrolled in this study for a clinical indicated cCT scan. All spiral cCT examinations were performed on a 3rd generation dual-source CT system using ATCM in z-axis direction. Images were reconstructed using both, FBP and IR (level 1–5). A Monte-Carlo-simulation-based analysis was used to compare organ-specific-radiation dose. Subjective image quality for various anatomic structures was evaluated using a 4-point Likert-scale and objective image quality was evaluated by comparing signal-to-noise ratios (SNR). Spiral cCT led to a significantly lower (p < 0.05) organ-specific-radiation dose in all targets including eye lense. Subjective image quality of spiral cCT datasets with an IR reconstruction level 5 was rated significantly higher compared to the sequential cCT acquisitions (p < 0.0001). Consecutive mean SNR was significantly higher in all spiral datasets (FBP, IR 1–5) when compared to sequential cCT with a mean

  18. High-speed imaging in fluids

    NARCIS (Netherlands)

    Versluis, Michel

    2013-01-01

    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

  19. Reducing Heating In High-Speed Cinematography

    Science.gov (United States)

    Slater, Howard A.

    1989-01-01

    Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

  20. Logarithmic Spiral

    Indian Academy of Sciences (India)

    anti-clockwise direction and we get a right-handed spiral. (Figure 2). We know that the derivative of eX is also eX. Various properties of logarithmic spiral depend on this property of eX. Properties of Logarithmic Spiral. 1. The most important property of a logarithmic spiral is that r (i.e. the distance from the origin) increases.

  1. On the Fully-Developed Heat Transfer Enhancing Flow Field in Sinusoidally, Spirally Corrugated Tubes Using Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Sørensen, Kim; Condra, Thomas Joseph

    2017-01-01

    in the ranges 0–0.16 and 0–2.0 respectively. The 3D Unsteady Reynolds-averaged Navier–Stokes (URANS) equations combined with the transition SST turbulence model are solved using the finite volume method to obtain the fully-developed flow field in a repeatable section of the heat exchangers at a constant wall...... loss. To assess the performance as a heat exchanger, the ratio of enhanced Nusselt number to enhanced friction factor η=(Nu/Nu_s)/(f/f_s)^(1/3) compared to the non-corrugated tube is used. Using this parameter, the simulations show a decrease in performance at higher corrugation heights. To link...... the detailed flow fields to the performance as a heat exchanger, non-dimensional correlations for heat transfer, pressure loss, and performance parameter are given....

  2. High speed curving performance of rail vehicles

    Science.gov (United States)

    2015-03-23

    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 ...

  3. High-Speed Sealift Technology Development Plan

    National Research Council Canada - National Science Library

    2002-01-01

    .... The purpose of the project was to define the technology investments required to enable development of the high-speed commercial and military ships needed to provide realistic future mission capabilities...

  4. High Speed Linear Induction Motor Efficiency Optimization

    Science.gov (United States)

    2005-06-01

    John Wiley and Sons, 1972. [7] Old Dominion University Maglev Train News Report, "Glitches Postpone Debut of Maglev ," October 10, 2002, http...High speed trains and monorails as well as EMALS are just a few of the recent designs using linear motors [7]. 15 In high-speed applications, there is...to the short primary DSLIM and its effect on rapid transit trains with respect to efficiency [6], [14]. As the primary field of the short primary

  5. Gas Jets in Granular Matter : Observed by a High Speed X-ray Tomography System

    NARCIS (Netherlands)

    Yang, X.

    2015-01-01

    High speed X-ray tomography is a promising tool to visualize the time-resolved gas distribution for fluidized beds. The tomography unit at Delft University of Technology is composed of three X-ray tubes and three double-layer detector arrays. The X-ray tubes are places at 120? around the fluidized

  6. Heat transfer and critical heat flux in a spiral flow in an asymmetrical heated tube; Transfert thermique et flux critique dans un ecoulement helicoidal en tube chauffe asymetriquement

    Energy Technology Data Exchange (ETDEWEB)

    Boscary, J. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Direction des Sciences de la Matiere]|[Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1997-03-01

    The design of plasma facing components is crucial for plasma performance in next fusion reactors. These elements will be submitted to very high heat flux. They will be actively water-cooled by swirl tubes in the subcooled boiling regime. High heat flux experiments were conducted in order to analyse the heat transfer and to evaluate the critical heat flux. Water-cooled mock-ups were one-side heated by an electron beam gun for different thermal-hydraulic conditions. The critical heat flux was detected by an original method based on the isotherm modification on the heated surface. The wall heat transfer law including forced convection and subcooled boiling regimes was established. Numerical calculations of the material heat transfer conduction allowed the non-homogeneous distribution of the wall temperature and of the wall heat flux to be evaluated. The critical heat flux value was defined as the wall maximum heat flux. A critical heat flux model based on the liquid sublayer dryout under a vapor blanket was established. A good agreement with test results was found. (author) 197 refs.

  7. Spiral symmetry

    CERN Document Server

    Hargittai, Istvan

    1992-01-01

    From the tiny twisted biological molecules to the gargantuan curling arms of many galaxies, the physical world contains a startling repetition of spiral patterns. Today, researchers have a keen interest in identifying, measuring, and defining these patterns in scientific terms. Spirals play an important role in the growth processes of many biological forms and organisms. Also, through time, humans have imitated spiral motifs in their art forms, and invented new and unusual spirals which have no counterparts in the natural world. Therefore, one goal of this multiauthored book is to stress the c

  8. Turbulence modeling for high speed flows

    Science.gov (United States)

    Coakley, T. J.; Huang, P. G.

    1992-01-01

    An investigation of turbulence models for high speed flows is presented. The flows consist of simple 2D flows over flat plates and complex shock-wave boundary-layer interaction flows over ramps and wedges. The flows are typical of those encountered by high speed vehicles such as the NASP. The turbulence models investigated include various two-equation models which, as a class, are considered to be well suited to the design of high speed vehicles. A description and discussion of the specific models is given and includes both baseline or uncorrected models, and model corrections which are needed to improve predictions of complex flows. It is found that most of the models studied are able to give good predictions of the flat plate flows, and some of the models are able to predict some of the complex flows, but none of them are able to accurately predict all of the complex flows. Recommendations for future model improvements are discussed.

  9. High Speed Video Applications In The Pharmaceutical Industry

    Science.gov (United States)

    Stapley, David

    1985-02-01

    The pursuit of quality is essential in the development and production of drugs. The pursuit of excellence is relentless, a never ending search. In the pharmaceutical industry, we all know and apply wide-ranging techniques to assure quality production. We all know that in reality none of these techniques are perfect for all situations. We have all experienced, the damaged foil, blister or tube, the missing leaflet, the 'hard to read' batch code. We are all aware of the need to supplement the traditional techniques of fault finding. This paper shows how high speed video systems can be applied to fully automated filling and packaging operations as a tool to aid the company's drive for high quality and productivity. The range of products involved totals some 350 in approximately 3,000 pack variants, encompassing creams, ointments, lotions, capsules, tablets, parenteral and sterile antibiotics. Pharmaceutical production demands diligence at all stages, with optimum use of the techniques offered by the latest technology. Figure 1 shows typical stages of pharmaceutical production in which quality must be assured, and highlights those stages where the use of high speed video systems have proved of value to date. The use of high speed video systems begins with the very first use of machine and materials: commissioning and validation, (the term used for determining that a process is capable of consistently producing the requisite quality) and continues to support inprocess monitoring, throughout the life of the plant. The activity of validation in the packaging environment is particularly in need of a tool to see the nature of high speed faults, no matter how infrequently they occur, so that informed changes can be made precisely and rapidly. The prime use of this tool is to ensure that machines are less sensitive to minor variations in component characteristics.

  10. Congestion control of high-speed networks

    Science.gov (United States)

    1993-06-01

    We report on four areas of activity in the past six months. These areas include the following: (1) work on the control of integrated video and image traffic, both at the access to a network and within a high-speed network; (2) more general/game theoretic models for flow control in networks; (3) work on fault management for high-speed heterogeneous networks to improve survivability; and (4) work on all-optical (lightwave) networks of the future, designed to take advantage of the enormous bandwidth capability available at optical frequencies.

  11. Aerodynamics of High-Speed Trains

    Science.gov (United States)

    Schetz, Joseph A.

    This review highlights the differences between the aerodynamics of high-speed trains and other types of transportation vehicles. The emphasis is on modern, high-speed trains, including magnetic levitation (Maglev) trains. Some of the key differences are derived from the fact that trains operate near the ground or a track, have much greater length-to-diameter ratios than other vehicles, pass close to each other and to trackside structures, are more subject to crosswinds, and operate in tunnels with entry and exit events. The coverage includes experimental techniques and results and analytical and numerical methods, concentrating on the most recent information available.

  12. High Speed and Slow Motion: The Technology of Modern High Speed Cameras

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2011-01-01

    The enormous progress in the fields of microsystem technology, microelectronics and computer science has led to the development of powerful high speed cameras. Recently a number of such cameras became available as low cost consumer products which can also be used for the teaching of physics. The technology of high speed cameras is discussed,…

  13. 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....

  14. Plastic straw: future of high-speed signaling

    Science.gov (United States)

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

    2015-11-01

    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.

  15. High-speed massively parallel scanning

    Science.gov (United States)

    Decker, Derek E [Byron, CA

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  16. Copper infiltrated high speed steels based composites

    International Nuclear Information System (INIS)

    Madej, M.; Lezanski, J.

    2003-01-01

    High hardness, mechanical strength, heat resistance and wear resistance of M3/2 high speed steel (HSS) make it an attractive material. Since technological and economical considerations are equally important, infiltration of high-speed steel skeleton with liquid cooper has proved to be a suitable technique whereby fully dense material is produced at low cost. Attempts have been made to describe the influence of the production process parameters and alloying additives, such as tungsten carbide on the microstructure and mechanical properties of copper infiltrated HSS based composites. The compositions of powder mixtures are 100% M3/2, M3/2+10% Wc, M3/2=30% WC. The powders were uniaxially cold compacted in a cylindrical die at 800 MPa. The green compacts were sintered in vacuum at 1150 o C for 60 minutes. Thereby obtained porous skeletons were subsequently infiltrated with cooper, by gravity method, in vacuum furnace at 1150 o C for 15 minutes. (author)

  17. A high speed digital noise generator

    Science.gov (United States)

    Obrien, J.; Gaffney, B.; Liu, B.

    In testing of digital signal processing hardware, a high speed pseudo-random noise generator is often required to simulate an input noise source to the hardware. This allows the hardware to be exercised in a manner analogous to actual operating conditions. In certain radar and communication environments, a noise generator operating at speeds in excess of 60 MHz may be required. In this paper, a method of generating high speed pseudo-random numbers from an arbitrarily specified distribution (Gaussian, Log-Normal, etc.) using a transformation from a uniform noise source is described. A noise generator operating at 80 MHz has been constructed. Different distributions can be readily obtained by simply changing the ROM set. The hardware and test results will be described. Using this approach, the generation of pseudo-random sequences with arbitrary distributions at word rates in excess of 200 MHz can be readily achieved.

  18. High speed printing with polygon scan heads

    Science.gov (United States)

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  19. Data Capture Technique for High Speed Signaling

    Science.gov (United States)

    Barrett, Wayne Melvin; Chen, Dong; Coteus, Paul William; Gara, Alan Gene; Jackson, Rory; Kopcsay, Gerard Vincent; Nathanson, Ben Jesse; Vranas, Paylos Michael; Takken, Todd E.

    2008-08-26

    A data capture technique for high speed signaling to allow for optimal sampling of an asynchronous data stream. This technique allows for extremely high data rates and does not require that a clock be sent with the data as is done in source synchronous systems. The present invention also provides a hardware mechanism for automatically adjusting transmission delays for optimal two-bit simultaneous bi-directional (SiBiDi) signaling.

  20. Developing course lecture notes on high-speed rail.

    Science.gov (United States)

    2017-07-15

    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 ...

  1. Proceedings of the 18th international congress on high speed photography and photonics

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    The subjects addressed at the conference presented in this book include image converter and intensifier cameras; opto-mechanical high speed cameras; X-ray generator and radiography; and Holography and interferometry. The papers include Flash x-ray cineradiography; New picosecond synchroscan streak image tube; and Streak camera CCD readout system

  2. Properties of spiral resonators

    International Nuclear Information System (INIS)

    Haeuser, J.

    1989-10-01

    The present thesis deals with the calculation and the study of the application possibilities of single and double spiral resonators. The main aim was the development and the construction of reliable and effective high-power spiral resonators for the UNILAC of the GSI in Darmstadt and the H - -injector for the storage ring HERA of DESY in Hamburg. After the presentation of the construction and the properties of spiral resonators and their description by oscillating-circuit models the theoretical foundations of the bunching are presented and some examples of a rebuncher and debuncher and their influence on the longitudinal particle dynamics are shown. After the description of the characteristic accelerator quantities by means of an oscillating-circuit model and the theory of an inhomogeneous λ/4 line it is shown, how the resonance frequency and the efficiency of single and double spiral resonators can be calculated from the geometrical quantities of the structure. In the following the dependence of the maximal reachable resonator voltage in dependence on the gap width and the surface of the drift tubes is studied. Furthermore the high-power resonators are presented, which were built for the different applications for the GSI in Darmstadt, DESY in Hamburg, and for the FOM Institute in Amsterdam. (orig./HSI) [de

  3. High speed UNIBUS-VME interface

    International Nuclear Information System (INIS)

    Olmos, P.

    1987-01-01

    An interface between VME an the UNIBUS of PDP or VAX computer is presented. The system supports high speed parallel communication (up to 1MB/S) and is composed of two modules. One of these is a commercial DR11M board which performs DMA transfers between UNIBUS and the external word. The other is a VME module specifically developed for this application. The interface has been tested under VMS operating system in VAX and VALET-PLUS system for the VME Bus. We describe in detail the VME module and its connection with the DR11M. Software, both in WMS and VALET, is also described. (Author) 7 refs

  4. High-speed photography. Technique and evolution

    International Nuclear Information System (INIS)

    Sanchez-Tembleque, R.

    1981-01-01

    It is intended to present some general considerations about ''Higg-speed photography'' as a tool of work common in mos research laboratories in the world. ''High-speed photography'' relies on the principles of photography of actions, that change rapidly with the time. The evolution of this technique goes along with the discovering of new phenomena in wich higher speeds are involved. At present is normal to deal with changing rates involving picoseconds times (10 -12 s) and new developments on the field of femtosecond (10 -15 s) theoretically are contemplated. (author)

  5. High Speed SPM of Functional Materials

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-14

    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. Wave resistance for high-speed catamarans

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, H.B. [Para University, CEP (Brazil); Vasconcellos, J.M. [Federal University of Rio de Janeiro (Brazil). Naval Architecture Department; Latorre, R.G. [University of New Orleans, LA (United States)

    2004-12-01

    The object of this study was to investigate the wave resistance component for high-speed catamarans. Two methods were applied: the slender-body theory proposed by Michell [Philos. Mag. 45(5) (1898) 106] and a 3D method used by Shipflow{sup TM} (FLOWTECH, Shipflow{sup TM} 2.4, User Manual, 1988) software. Results were obtained for different types of twin hulls and attention was given to the effects of catamaran hull spacing. The study also included the effect of shallow water on the wave resistance component. Special attention was given to the height of waves generated by the craft to ascertain effect on river banks. (author)

  7. High speed PVD thermal barrier coatings

    International Nuclear Information System (INIS)

    Beele, W.; Eschendorff, G.

    2006-01-01

    The high speed PVD process (HS-PVD) combines gas phase coating synthesis with high deposition rates. The process has been demonstrated for high purity YSZ deposited as a chemically bonded top thermal barrier with columnar structure of EB-PVD features. The process can manufacture EB-PVD like coatings that match in regards to their TGO-formation and columnar structure. Coatings with a columnar structure formed by individual columns of 1/4 of the diameter of a classical EB-PVD type TBC have been deposited. These coatings have the potential to prove a significant reduction in thermal conductivity and in erosion performance. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  8. High-speed civil transport study. Summary

    Science.gov (United States)

    1989-01-01

    A system of study of the potential for a high speed commercial transport aircraft addressed technology, economic, and environmental constraints. Market projections indicated a need for fleets of transport with supersonic or greater cruise speeds by the years 2000 to 2005. The associated design requirements called for a vehicle to carry 250 to 300 passengers over a range of 5000 to 6000 nautical miles. The study was initially unconstrained in terms of vehicle characteristics, such as cruise speed, propulsion systems, fuels, or structural materials. Analyses led to a focus on the most promising vehicle concepts. These were concepts that used a kerosene type fuel and cruised at Mach numbers between 2.0 to 3.2. Further systems study identified the impact of environmental constraints (for community noise, sonic boom, and engine emissions) on economic attractiveness and technological needs. Results showed that current technology cannot produce a viable high speed civil transport. Significant advances are needed to take off gross weight and allow for both economic attractiveness and environment acceptability. Specific technological requirements were identified to meet these needs.

  9. High-speed civil transport study

    Science.gov (United States)

    1989-01-01

    A system study of the potential for a high-speed commercial transport has addressed technological, economic, and environmental constraints. Market projections indicate a need for fleets of transports with supersonic or greater cruise speeds by the year 2000 to 2005. The associated design requirements called for a vehicle to carry 250 to 300 passengers over a range of 5,000 to 6,000 nautical miles. The study was initially unconstrained in terms of vehicle characteristic, such as cruise speed, propulsion systems, fuels, or structural materials. Analyses led to a focus on the most promising vehicle concepts. These were concepts that used a kerosene-type fuel and cruised at Mach numbers between 2.0 to 3.2. Further systems study identified the impact of environmental constraints (for community noise, sonic boom, and engine emissions) on economic attractiveness and technological needs. Results showed that current technology cannot produce a viable high-speed civil transport; significant advances are required to reduce takeoff gross weight and allow for both economic attractiveness and environmental accepatability. Specific technological requirements were identified to meet these needs.

  10. ACTS High-Speed VSAT Demonstrated

    Science.gov (United States)

    Tran, Quang K.

    1999-01-01

    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.

  11. High-speed cineradiographies acquisition and processing

    International Nuclear Information System (INIS)

    Kahn, E.; Nourrissat, Yves; Viguier, Philippe

    A high-speed cineradiography installation provides dimensional informations recorded either on a film, or on a magnetic tape. In the event of the film, the imperfection of our visual sense leads us to look for a method of measurement which allows us to extract the information from a noisy image; the association of an optical flying spot scanner with a computer is adapted to this use and allows us, for instance, to determine the inside and outside diameters of a sphere during its implosion. On the other hand, the radiographic recording on magnetic tape is processed, after numerisation by the computer, in the same way as the numeric tape generated after the optical scanner. We compare the results achieved by the two recording methods [fr

  12. Network Based High Speed Product Innovation

    DEFF Research Database (Denmark)

    Lindgren, Peter

    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......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...... - 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...

  13. High-speed electrical motor evaluation

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-03

    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.

  14. High-speed spatial scanning pyrometer

    Science.gov (United States)

    Cezairliyan, A.; Chang, R. F.; Foley, G. M.; Miller, A. P.

    1993-01-01

    A high-speed spatial scanning pyrometer has been designed and developed to measure spectral radiance temperatures at multiple target points along the length of a rapidly heating/cooling specimen in dynamic thermophysical experiments at high temperatures (above about 1800 K). The design, which is based on a self-scanning linear silicon array containing 1024 elements, enables the pyrometer to measure spectral radiance temperatures (nominally at 650 nm) at 1024 equally spaced points along a 25-mm target length. The elements of the array are sampled consecutively every 1 microsec, thereby permitting one cycle of measurements to be completed in approximately 1 msec. Procedures for calibration and temperature measurement as well as the characteristics and performance of the pyrometer are described. The details of sources and estimated magnitudes of possible errors are given. An example of measurements of radiance temperatures along the length of a tungsten rod, during its cooling following rapid resistive pulse heating, is presented.

  15. BLOSTREAM: A HIGH SPEED STREAM CIPHER

    Directory of Open Access Journals (Sweden)

    ALI H. KASHMAR

    2017-04-01

    Full Text Available Although stream ciphers are widely utilized to encrypt sensitive data at fast speeds, security concerns have led to a shift from stream to block ciphers, judging that the current technology in stream cipher is inferior to the technology of block ciphers. This paper presents the design of an improved efficient and secure stream cipher called Blostream, which is more secure than conventional stream ciphers that use XOR for mixing. The proposed cipher comprises two major components: the Pseudo Random Number Generator (PRNG using the Rabbit algorithm and a nonlinear invertible round function (combiner for encryption and decryption. We evaluate its performance in terms of implementation and security, presenting advantages and disadvantages, comparison of the proposed cipher with similar systems and a statistical test for randomness. The analysis shows that the proposed cipher is more efficient, high speed, and secure than current conventional stream ciphers.

  16. Tomosynthesis using high speed CT scanning system

    International Nuclear Information System (INIS)

    Boyd, D.P.; Rutt, B.K.

    1988-01-01

    In a high-speed CT scanning system in which fan beams of radiation are generated by sweeping an electron beam along a target and collimated X-rays emitted by the target are received by an array of detectors after passing through a patient area between the target and the array of detectors, a method of obtaining a tomograph of a patient is described comprising the steps of sweeping the electron beam along the target, measuring radiation received at detector positions as the electron beam is swept along the target; moving the patient past the collimated X-rays, and combining measurements at the detector positions as correlated in time to positions of the patient and tomosynthesizing the tomograph from data for lines in the desired plane for the positions of the patient

  17. High-speed dynamic-clamp interface

    Science.gov (United States)

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

    2015-01-01

    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

  18. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors, Phase II

    Data.gov (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,...

  19. High-speed and intercity passenger rail testing strategy.

    Science.gov (United States)

    2013-05-01

    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...

  20. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors, Phase I

    Data.gov (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...

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

    NARCIS (Netherlands)

    van de Beek, R.C.H.

    2004-01-01

    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

  2. Design of very high speed electric generators

    International Nuclear Information System (INIS)

    Labollita, Santiago

    2008-01-01

    This work approaches the design process of an electric generator suitable for running efficiently at high speed, driven by a turbo shaft.The axial flux concept was used.For the mechanical design of the prototype, cooling capacity and mounting method were considered, looking for simplicity of the parts evolved. Neodymium-iron-boron permanent magnets were used as magnetic source.For the electrical design, a calculation tool was developed in order to predict the prototype electrical parameters and optimize its geometry.The goal was to obtain 1 kW of electric power at a speed of 100,000 rpm.The efficiency and electrical behaviour of the prototype were characterized at speeds between 2,000 rpm and 30,000 rpm and then the behaviour at the design condition was predicted by obtaining an equivalent electric circuit.The estimated load voltage was 237 V as well as an electrical efficiency of 95%.Eddy current effects were not recognized. Increase of the internal resistance and decree of inductance were observed while raising the electric frequency.Finally, an electronic system was developed in order to use the prototype as a c.c. motor. Global performance was measured according to different supply characteristic. An optimum supply voltage was found.A maximum efficiency of 63% was reached. [es

  3. High-speed Civil Transport Aircraft Emissions

    Science.gov (United States)

    Miake-Lye, Richard C.; Matulaitis, J. A.; Krause, F. H.; Dodds, Willard J.; Albers, Martin; Hourmouziadis, J.; Hasel, K. L.; Lohmann, R. P.; Stander, C.; Gerstle, John H.

    1992-01-01

    Estimates are given for the emissions from a proposed high speed civil transport (HSCT). This advanced technology supersonic aircraft would fly in the lower stratosphere at a speed of roughly Mach 1.6 to 3.2 (470 to 950 m/sec or 920 to 1850 knots). Because it would fly in the stratosphere at an altitude in the range of 15 to 23 km commensurate with its design speed, its exhaust effluents could perturb the chemical balance in the upper atmosphere. The first step in determining the nature and magnitude of any chemical changes in the atmosphere resulting from these proposed aircraft is to identify and quantify the chemically important species they emit. Relevant earlier work is summarized, dating back to the Climatic Impact Assessment Program of the early 1970s and current propulsion research efforts. Estimates are provided of the chemical composition of an HSCT's exhaust, and these emission indices are presented. Other aircraft emissions that are not due to combustion processes are also summarized; these emissions are found to be much smaller than the exhaust emissions. Future advances in propulsion technology, in experimental measurement techniques, and in understanding upper atmospheric chemistry may affect these estimates of the amounts of trace exhaust species or their relative importance.

  4. Material constraints on high-speed design

    Science.gov (United States)

    Bucur, Diana; Militaru, Nicolae

    2015-02-01

    Current high-speed circuit designs with signal rates up to 100Gbps and above are implying constraints for dielectric and conductive materials and their dependence of frequency, for component elements and for production processes. The purpose of this paper is to highlight through various simulation results the frequency dependence of specific parameters like insertion and return loss, eye diagrams, group delay that are part of signal integrity analyses type. In low-power environment designs become more complex as the operation frequency increases. The need for new materials with spatial uniformity for dielectric constant is a need for higher data rates circuits. The fiber weave effect (FWE) will be analyzed through the eye diagram results for various dielectric materials in a differential signaling scheme given the fact that the FWE is a phenomenon that affects randomly the performance of the circuit on balanced/differential transmission lines which are typically characterized through the above mentioned approaches. Crosstalk between traces is also of concern due to propagated signals that have tight rise and fall times or due to high density of the boards. Criteria should be considered to achieve maximum performance of the designed system requiring critical electronic properties.

  5. Sensor study for high speed autonomous operations

    Science.gov (United States)

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  6. High Speed Fibre Optic Backbone LAN

    Science.gov (United States)

    Tanimoto, Masaaki; Hara, Shingo; Kajita, Yuji; Kashu, Fumitoshi; Ikeuchi, Masaru; Hagihara, Satoshi; Tsuzuki, Shinji

    1987-09-01

    Our firm has developed the SUMINET-4100 series, a fibre optic local area network (LAN), to serve the communications system trunk line needs for facilities, such as steel refineries, automobile plants and university campuses, that require large transmission capacity, and for the backbone networks used in intelligent building systems. The SUMINET-4100 series is already in service in various fields of application. Of the networks available in this series, the SUMINET-4150 has a trunk line speed of 128 Mbps and the multiplexer used for time division multiplexing (TDM) was enabled by designing an ECL-TTL gate array (3000 gates) based custom LSI. The synchronous, full-duplex V.24 and V.3.5 interfaces (SUMINET-2100) are provided for use with general purpose lines. And the IBM token ring network, the SUMINET-3200, designed for heterogeneous PCs and the Ethernet can all be connected to sub loops. Further, the IBM 3270 TCA and 5080 CADAM can be connected in the local mode. Interfaces are also provided for the NTT high-speed digital service, the digital PBX systems, and the Video CODEC system. The built-in loop monitor (LM) and network supervisory processor (NSP) provide management of loop utilization and send loop status signals to the host CPU's network configuration and control facility (NCCF). These built-in functions allow both the computer system and LAN to be managed from a single source at the host. This paper outlines features of the SUMINET-4150 and provides an example of its installation.

  7. High speed homology search with FPGAs.

    Science.gov (United States)

    Yamaguchi, Yoshiki; Maruyama, Tsutomu; Konagaya, Akihiko

    2002-01-01

    We will introduce a way how we can achieve high speed homology search by only adding one off-the-shelf PCI board with one Field Programmable Gate Array (FPGA) to a Pentium based computer system in use. FPGA is a reconfigurable device, and any kind of circuits, such as pattern matching program, can be realized in a moment. The performance is almost proportional to the size of FPGA which is used in the system, and FPGAs are becoming larger and larger following Moore's law. We can easily obtain latest/larger FPGAs in the form off-the-shelf PCI boards with FPGAs, at low costs. The result which we obtained is as follows. The performance is most comparable with small to middle class dedicated hardware systems when we use a board with one of the latest FPGAs and the performance can be furthermore accelerated by using more number of FPGA boards. The time for comparing a query sequence of 2,048 elements with a database sequence of 64 million elements by the Smith-Waterman algorithm is about 34 sec, which is about 330 times faster than a desktop computer with a 1 GHz Pentium III. We can also accelerate the performance of a laptop computer using a PC card with one smaller FPGA. The time for comparing a query sequence (1,024) with the database sequence (64 million) is about 185 sec, which is about 30 times faster than the desktop computer.

  8. High-speed CCD camera at NAOC

    Science.gov (United States)

    Zhao, Zhaowang; Wang, Wei; Liu, Yangbin

    2006-06-01

    A high speed CCD camera has been completed at the National Astronomical Observatories of China (NAOC). A Kodak CCD was used in the camera. Two output ports are used to read out CCD data and total speed achieved 60M pixels per second. The Kodak KAI-4021 image sensor is a high-performance 2Kx2K-pixel interline transfer device. The 7.4μ square pixels with micro lenses provide high sensitivity and the large full well capacity results in high dynamic range. The inter-line transfer structure provides high quality image and enables electronic shuttering for precise exposure control. The electronic shutter provides a method of precisely controlling the image exposure time without any mechanical components. The camera is controlled by a NIOS II family of embedded processors, which is Altera's second-generation soft-core embedded processor for FPGAs. The powerful embedded processors make the camera with splendid features to satisfy continuously appearing new observational requirements. This camera is very flexible and is easy to implement new special functions. Since FPGA and other peripheral logic signals are triggered by a single master clock, the whole system is perfectly synchronized. By using this technique the camera cuts off the noise dramatically.

  9. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.

    2017-08-31

    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.

  10. The high speed civil transport and NASA's High Speed Research (HSR) program

    Science.gov (United States)

    Shaw, Robert J.

    1994-01-01

    Ongoing studies being conducted not only in this country but in Europe and Asia suggest that a second generation supersonic transport, or High-Speed Civil Transport (HSCT), could become an important part of the 21st century international air transportation system. However, major environmental compatibility and economic viability issues must be resolved if the HSCT is to become a reality. This talk will overview the NASA High-Speed Research (HSR) program which is aimed at providing the U.S. industry with a technology base to allow them to consider launching an HSCT program early in the next century. The talk will also discuss some of the comparable activities going on within Europe and Japan.

  11. High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

    Science.gov (United States)

    Taveniku, Mikael

    2013-01-01

    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.

  12. High speed photography, videography, and photonics III; Proceedings of the Meeting, San Diego, CA, August 22, 23, 1985

    Science.gov (United States)

    Ponseggi, B. G. (Editor); Johnson, H. C. (Editor)

    1985-01-01

    Papers are presented on the picosecond electronic framing camera, photogrammetric techniques using high-speed cineradiography, picosecond semiconductor lasers for characterizing high-speed image shutters, the measurement of dynamic strain by high-speed moire photography, the fast framing camera with independent frame adjustments, design considerations for a data recording system, and nanosecond optical shutters. Consideration is given to boundary-layer transition detectors, holographic imaging, laser holographic interferometry in wind tunnels, heterodyne holographic interferometry, a multispectral video imaging and analysis system, a gated intensified camera, a charge-injection-device profile camera, a gated silicon-intensified-target streak tube and nanosecond-gated photoemissive shutter tubes. Topics discussed include high time-space resolved photography of lasers, time-resolved X-ray spectrographic instrumentation for laser studies, a time-resolving X-ray spectrometer, a femtosecond streak camera, streak tubes and cameras, and a short pulse X-ray diagnostic development facility.

  13. High Speed/ Low Effluent Process for Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    M. Clark Dale

    2006-10-30

    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.

  14. The spiral

    DEFF Research Database (Denmark)

    Bibace, Roger; Kharlamov, Nikita

    2013-01-01

    ’s work with Bernard Kaplan on symbol formation is a primer on this idea. This paper examines the idea of spirality and develops the notion of dynamic coexistence that can clarify the issue of directionality of development; that is, what is the general trajectory or ground plan that development assumes....... Directionality is discussed in terms of the organism-in-environment unfolding over time as the unit of developmental analysis. Thinking on this issue has proceeded from the nature–nurture debates, to recognition of the interaction of external and internal processes, to transactions between the organism...

  15. Multi-actuation and PI control: A simple recipe for high-speed and large-range atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Soltani Bozchalooi, I., E-mail: isoltani@mit.edu; Youcef-Toumi, K.

    2014-11-15

    High speed atomic force microscopy enables observation of dynamic nano-scale processes. However, maintaining a minimal interaction force between the sample and the probe is challenging at high speed specially when using conventional piezo-tubes. While rigid AFM scanners are operational at high speeds with the drawback of reduced tracking range, multi-actuation schemes have shown potential for high-speed and large-range imaging. Here we present a method to seamlessly incorporate additional actuators into conventional AFMs. The equivalent behavior of the resulting multi-actuated setup resembles that of a single high-speed and large-range actuator with maximally flat frequency response. To achieve this, the dynamics of the individual actuators and their couplings are treated through a simple control scheme. Upon the implementation of the proposed technique, commonly used PI controllers are able to meet the requirements of high-speed imaging. This forms an ideal platform for retroactive enhancement of existing AFMs with minimal cost and without compromise on the tracking range. A conventional AFM with tube scanner is retroactively enhanced through the proposed method and shows an order of magnitude improvement in closed loop bandwidth performance while maintaining large range. The effectiveness of the method is demonstrated on various types of samples imaged in contact and tapping modes, in air and in liquid. - Highlights: • We present a novel method to incorporate extra actuators into conventional AFMs. • A maximally flat frequency response is achieved for the out of plane piezo-motion. • Commonly used PI or PID control is enabled to handle high speed AFM imaging. • An order of magnitude improvement in closed loop bandwidth performance is obtained. • High speed imaging is achieved on a large range piezo-tube.

  16. High Speed Link Radiated Emission Reduction

    Science.gov (United States)

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

    2016-05-01

    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

  17. High resolution, high speed ultrahigh vacuum microscopy

    International Nuclear Information System (INIS)

    Poppa, Helmut

    2004-01-01

    The history and future of transmission electron microscopy (TEM) is discussed as it refers to the eventual development of instruments and techniques applicable to the real time in situ investigation of surface processes with high resolution. To reach this objective, it was necessary to transform conventional high resolution instruments so that an ultrahigh vacuum (UHV) environment at the sample site was created, that access to the sample by various in situ sample modification procedures was provided, and that in situ sample exchanges with other integrated surface analytical systems became possible. Furthermore, high resolution image acquisition systems had to be developed to take advantage of the high speed imaging capabilities of projection imaging microscopes. These changes to conventional electron microscopy and its uses were slowly realized in a few international laboratories over a period of almost 40 years by a relatively small number of researchers crucially interested in advancing the state of the art of electron microscopy and its applications to diverse areas of interest; often concentrating on the nucleation, growth, and properties of thin films on well defined material surfaces. A part of this review is dedicated to the recognition of the major contributions to surface and thin film science by these pioneers. Finally, some of the important current developments in aberration corrected electron optics and eventual adaptations to in situ UHV microscopy are discussed. As a result of all the path breaking developments that have led to today's highly sophisticated UHV-TEM systems, integrated fundamental studies are now possible that combine many traditional surface science approaches. Combined investigations to date have involved in situ and ex situ surface microscopies such as scanning tunneling microscopy/atomic force microscopy, scanning Auger microscopy, and photoemission electron microscopy, and area-integrating techniques such as x-ray photoelectron

  18. Chicago-St. Louis high speed rail plan

    Energy Technology Data Exchange (ETDEWEB)

    Stead, M.E.

    1994-12-31

    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.

  19. High-speed railway embankments : a comparison of different regulation

    OpenAIRE

    Alamaa, Angelica

    2016-01-01

    Swedish transport administration initiated this Master Thesis project and the aim was to compare regulations for the design of high-speed railways from three European countries: France, Germany and Spain. The reason why this is of interest for the Swedish transport administration is the design of the first Swedish high-speed railway, called Ostlänken. Therefore, a literature study of the regulations and other literature regarding high-speed railway has been carried out. A basic description of...

  20. 33 CFR 84.24 - High-speed craft.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false High-speed craft. 84.24 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.24 High-speed craft. (a) The masthead light of high-speed craft with a length to breadth ratio of less than 3.0 may be placed at a...

  1. Spiral tectonics

    Science.gov (United States)

    Hassan Asadiyan, Mohammad

    2014-05-01

    Spiral Tectonics (ST) is a new window to global tectonics introduced as alternative model for Plate Tectonics (PT). ST based upon Dahw(rolling) and Tahw(spreading) dynamics. Analogues to electric and magnetic components in the electromagnetic theory we could consider Dahw and Tahw as components of geodynamics, when one component increases the other decreases and vice versa. They are changed to each other during geological history. D-component represents continental crust and T-component represents oceanic crust. D and T are two arm of spiral-cell. T-arm 180 degree lags behind D-arm so named Retard-arm with respect to D or Forward-arm. It seems primary cell injected several billions years ago from Earth's center therefore the Earth's core was built up first then mantel and finally the crust was build up. Crust building initiate from Arabia (Mecca). As the universe extended gravitation wave swirled the earth fractaly along cycloid path from big to small scale. In global scale (order-0) ST collect continents in one side and abandoned Pacific Ocean in the other side. Recent researches also show two mantels upwelling in opposite side of the Earth: one under Africa (tectonic pose) and the other under Pacific Ocean (tectonic tail). In higher order (order-1) ST build up Africa in one side and S.America in the other side therefore left Atlantic Ocean meandered in between. In order-n e.g. Khoor Musa and Bandar-Deylam bay are seen meandered easterly in the Iranian part but Khoor Abdullah and Kuwait bay meandered westerly in the Arabian part, they are distributed symmetrically with respect to axis of Persian Gulf(PG), these two are fractal components of easterly Caspian-wing and westerly Black Sea-wing which split up from Anatoly. Caspian Sea and Black Sea make two legs of Y-like structure, this shape completely fitted with GPS-velocity map which start from PG and split up in the Catastrophic Point(Anatoly). We could consider PG as remnants of Ancient Ocean which spent up

  2. Synchronized high speed scanning infrared spectrometer.

    Science.gov (United States)

    Camm, J C; Taylor, R L; Lynch, R

    1967-05-01

    A spectrometer which scans a wavelength band of 0.6 micro in 30 microsec and is useful from 2-6 micro is described. The instrument can be synchronized with a pulsed source with a minimum triggering delay of 15microsec. The instrument is basically an Ebert spectrometer equipped with an indium antimonide detector at the exit slit, an aluminum scanning mirror placed 5 cm before the exit slit, and a wavelength calibration signal generator. The scanning mirror, which is supported on pivots inside a helical coil, deflects the spectrum through an angle of approximately 90 degrees onto the exit slit. When a capacitor is discharged through the coil, the resulting magnetic field spins the aluminum mirror causing the spectrum to move across the exit slit. The wavelength calibration signal generator produces a series of electrical pulses as the scanning mirror turns, permitting wavelength calibration when the pulses are displayed below the spectrometer signal on a dual beam oscilloscope. Using this instrument on a shock tube, data have bee obtained on the absolute spectral radiation intensity of air, nitrogen, neon, and argon heated by reflected shocks to equilibrium temperatures in the range of 6000 degrees K to 10,000 degrees K. In this temperature region with these gases, an important source of continuum radiation is neutral Bremsstrahlung caused by the inelastic scattering of electrons from neutral atoms and molecules. By employing the scanning ir spectrometer it has been possible to separate the continuum radiation from contributions owing to lines and bands and determine the cross section for the neutral Bremsstrahlung.

  3. A high-speed interface for multi-channel analyzer

    International Nuclear Information System (INIS)

    Shen Ji; Zheng Zhong; Qiao Chong; Chen Ziyu; Ye Yunxiu; Ye Zhenyu

    2003-01-01

    This paper presents a high-speed computer interface for multi-channel analyzer based on DMA technique. Its essential principle and operating procedure are introduced. By the detecting of γ spectrum of 137 Cs with the interface, it's proved that the interface can meet the requirements of high-speed data acquisition

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

    Directory of Open Access Journals (Sweden)

    Michael Galili

    2014-04-01

    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.

  5. Multi-channel data high speed acquisition and processing system

    International Nuclear Information System (INIS)

    Ni Qizhi; Tang Jiajun; Zhao Zhihong

    2001-01-01

    A kind of multi-channel data acquisition and process system is described emphasized on the cardinal technical capability, main structure and its working mode, including the design of preamplifier, A/D converter, data buffer memory (FIFO), digital signal processing etc. This system can be widely used in apparatus which needs high-speed data acquisition and high-speed digital signal processing

  6. 14 CFR 23.253 - High speed characteristics.

    Science.gov (United States)

    2010-01-01

    ... 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...

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

    Science.gov (United States)

    2012-06-01

    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. The Advantages of ISDN for High-Speed Remote Access.

    Science.gov (United States)

    Galvin, Mark; Hauf, Al

    1997-01-01

    Explains why ISDN (integrated services digital network) is the most practical solution for high-speed remote access, including reliability, cost, flexibility, scaleability, standards, and manageability. Other data transmission options are discussed, including asymmetric digital subscriber lines (ADSL), high-speed digital subscriber lines (HDSL),…

  9. High-Speed Photo-Polarimetry of Magnetic Cataclysmic Variables

    Directory of Open Access Journals (Sweden)

    S. B. Potter

    2015-02-01

    Full Text Available I review recent highlights of the SAAO High-speed Photo-POlarimeter (HIPPO on the study of magnetic Cataclysmic Variables. Its high-speed capabilities are demonstrated with example observations made of the intermediate polar NY Lup and the polar IGRJ14536-5522.

  10. Trend on High-speed Power Line Communication Technology

    Science.gov (United States)

    Ogawa, Osamu

    High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

  11. Thermomechanical simulations and experimental validation for high speed incremental forming

    Science.gov (United States)

    Ambrogio, Giuseppina; Gagliardi, Francesco; Filice, Luigino; Romero, Natalia

    2016-10-01

    Incremental sheet forming (ISF) consists in deforming only a small region of the workspace through a punch driven by a NC machine. The drawback of this process is its slowness. In this study, a high speed variant has been investigated from both numerical and experimental points of view. The aim has been the design of a FEM model able to perform the material behavior during the high speed process by defining a thermomechanical model. An experimental campaign has been performed by a CNC lathe with high speed to test process feasibility. The first results have shown how the material presents the same performance than in conventional speed ISF and, in some cases, better material behavior due to the temperature increment. An accurate numerical simulation has been performed to investigate the material behavior during the high speed process confirming substantially experimental evidence.

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

    National Research Council Canada - National Science Library

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

    2006-01-01

    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...

  13. Next Generation Modeling Technology for High Speed Rotorcraft Project

    Data.gov (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...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    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....

  15. Progress in the development of niobium alloyed high speed steel

    International Nuclear Information System (INIS)

    Guimaraes, J.R.C.

    1987-01-01

    The development of economy-grades of niobium alloyed high speed steel is described. Both the metallurgical concepts behind the steel design and the results of performance tests are presented. (Author) [pt

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

    CERN Document Server

    Lei, Xiaoyan

    2017-01-01

    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.

  17. Next Generation Modeling Technology for High Speed Rotorcraft Project

    Data.gov (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...

  18. High-Speed Thermal Characterization of Cryogenic Flows, Phase II

    Data.gov (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...

  19. Novel high speed fiber-optic pressure sensor systems.

    Science.gov (United States)

    2014-03-01

    The goal of this project is to develop a complete test of this technology for high-speed, high-accuracy applications, specifically cost-effective data acquisition techniques and practical mounting methods tailored for the subject environment. The sec...

  20. Preloading Piezoelectric Stack Actuator in High-speed Nanopositioning Systems

    Directory of Open Access Journals (Sweden)

    Yuen Yong

    2016-10-01

    Full Text Available Recent development in high-speed nanotechnology applications such as scanning probe microscopy and nanofabrication has increased interest on the advancement of high-bandwidth flexure-guided nanopositioning systems. These systems are capable of providing motions with sub-nanometer resolution over a positioning bandwidth of a few kilohertz or more. High-speed nanopositioning devices are commonly driven by compact and stiff piezoelectric stack actuators. However, these actuators are highly sensitive to tensile and lateral forces. During high-speed operations, excessive inertia force due to the effective mass of nanopositioning system could potentially damage the actuator. To protect the piezoelectric actuator, preload is often applied to compensate for these inertial forces. This article surveys key challenges in existing preload techniques in the context of high-speed nanopositioning designs, and explores how these challenges can be overcome.

  1. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu

    2015-01-01

    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....

  2. California statewide model for high-speed rail

    OpenAIRE

    Outwater, Maren; Tierney, Kevin; Bradley, Mark; Sall, Elizabeth; Kuppam, Arun; Modugala, Vamsee

    2010-01-01

    The California High Speed Rail Authority (CHSRA) and the Metropolitan Transportation Commission (MTC) have developed a new statewide model to support evaluation of high-speed rail alternatives in the State of California. This statewide model will also support future planning activities of the California Department of Transportation (Caltrans). The approach to this statewide model explicitly recognizes the unique characteristics of intraregional travel demand and interregional travel demand. A...

  3. Research related to vibrations from high speed railway traffic

    OpenAIRE

    Goicolea Ruigómez, José María; Gabaldón Castillo, Felipe

    2008-01-01

    We discuss here recent results from several research programmes related to dynamic aspects and vibrations induced by high speed railway traffic, developed at the computational mechanics group, within the “Escuela de Ingenieros de Caminos” of the Technical University of Madrid. The first part of this work concerns the dynamic response of railway bridges and structures under high speed traffic. The study of vertical dynamic effects in bridges has lead recently to improved understanding and...

  4. Integrated computer network high-speed parallel interface

    International Nuclear Information System (INIS)

    Frank, R.B.

    1979-03-01

    As the number and variety of computers within Los Alamos Scientific Laboratory's Central Computer Facility grows, the need for a standard, high-speed intercomputer interface has become more apparent. This report details the development of a High-Speed Parallel Interface from conceptual through implementation stages to meet current and future needs for large-scle network computing within the Integrated Computer Network. 4 figures

  5. Deflection system of a high-speed streak camera in the form of a delay line

    International Nuclear Information System (INIS)

    Korzhenevich, I.M.; Fel'dman, G.G.

    1993-01-01

    This paper presents an analysis of the operation of a meander deflection system, well-known in oscillography, when it is used to scan the image in a streak-camera tube. Effects that are specific to high-speed photography are considered. It is shown that such a deflection system imposes reduced requirements both on the steepness and on the duration of the linear leading edges of the pulses of the spark gaps that generate the sweep voltage. An example of the design of a meander deflection system whose sensitivity is a factor of two higher than for a conventional system is considered. 5 refs., 3 figs

  6. The Spiral of Euroscepticism

    DEFF Research Database (Denmark)

    Galpin, Charlotte; Trenz, Hans-Jörg

    2017-01-01

    Media scholars have increasingly examined the effects of a negativity bias that applies to political news. In the ‘spiral of cynicism’, journalist preferences for negative news correspond to public demands for sensational news. We argue that this spiral of cynicism in EU news results in a ‘spiral...

  7. High-speed solar wind flow parameters at 1 AU

    International Nuclear Information System (INIS)

    Feldman, W.C.; Asbridge, J.R.; Bame, S.J.; Gosling, J.T.

    1976-01-01

    To develop a set of constraints for theories of solar wind high-speed streams, a detailed study was made of the fastest streams observed at 1 AU during the time period spanning March 1971 through July 1974. Streams were accepted for study only if (1) the maximum speed exceeded 650 km s -1 ; (2) effects of stream-stream dynamical interaction on the flow parameters could be safely separated from the intrinsic characteristics of the high-speed regions; (3) the full width at half maximum (FWHM) of the stream when mapped back to 20 solar radii by using a constant speed approximation was greater than 45degree in Carrington longitude; and (4) there were no obvious solar-activity-induced contaminating effects. Nineteen streams during this time interval satisfied these criteria. Average parameters at 1 AU for those portions of these streams above V=650 km s -1 are given.Not only is it not presently known why electrons are significantly cooler than the protons within high-speed regions, but also observed particle fluxes and convected energy fluxes for speed greater than 650 km s -1 are substantially larger than those values predicted by any of the existing theories of solar wind high-speed streams. More work is therefore needed in refining present solar wind models to see whether suitable modifications and/or combinations of existing theories based on reasonable coronal conditions can accommodate the above high-speed flow parameters

  8. Assessment of rural soundscapes with high-speed train noise.

    Science.gov (United States)

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

    2014-06-01

    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.

  9. Fracture analysis of composites in high-speed tension

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Chiping; Cao, Li; Zou, Zhenzhu; Wang, Duo; Yao, Zhongkai (Harbin Institute of Technology (China))

    1989-12-01

    The fracture mechanism of composites in high-speed tension is investigated using a simplified theoretical model and results of a high-speed tension experiment on a sample of SiC-whisker-reinforced Al composite. Particular attention is given to the influence of microcracks and faults which may exist along the interfaces between the matrix and reinforcers of the composite on the strength of the composite. Results of the experimental observations show that, in high-speed tension (at 500 mm/min tensile rate), the effect of microcracks and faults along the interfaces on the composite's strength decreases in comparison with samples under conventional tension (i.e., at 0.5 mm/min tensile rate), and thus, the fracture strength of composites increases. 5 refs.

  10. High-speed photodetectors in optical communication system

    Science.gov (United States)

    Zhao, Zeping; Liu, Jianguo; Liu, Yu; Zhu, Ninghua

    2017-12-01

    This paper presents a review and discussion for high-speed photodetectors and their applications on optical communications and microwave photonics. A detailed and comprehensive demonstration of high-speed photodetectors from development history, research hotspots to packaging technologies is provided to the best of our knowledge. A few typical applications based on photodetectors are also illustrated, such as free-space optical communications, radio over fiber and millimeter terahertz signal generation systems. Project supported by the Preeminence Youth Fund of China (No. 61625504).

  11. Magneto-optical system for high speed real time imaging

    Science.gov (United States)

    Baziljevich, M.; Barness, D.; Sinvani, M.; Perel, E.; Shaulov, A.; Yeshurun, Y.

    2012-08-01

    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated.

  12. Single-Photon Tracking for High-Speed Vision

    Directory of Open Access Journals (Sweden)

    Istvan Gyongy

    2018-01-01

    Full Text Available Quanta Imager Sensors provide photon detections at high frame rates, with negligible read-out noise, making them ideal for high-speed optical tracking. At the basic level of bit-planes or binary maps of photon detections, objects may present limited detail. However, through motion estimation and spatial reassignment of photon detections, the objects can be reconstructed with minimal motion artefacts. We here present the first demonstration of high-speed two-dimensional (2D tracking and reconstruction of rigid, planar objects with a Quanta Image Sensor, including a demonstration of depth-resolved tracking.

  13. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1999-03-01

    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.

  14. Recent progress on high-speed optical transmission

    Directory of Open Access Journals (Sweden)

    Jianjun Yu

    2016-05-01

    Full Text Available The recently reported high spectral efficiency (SE and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP. DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

  15. A superconducting high-speed flywheel energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, R. de; Ferreira, A.C.; Sotelo, G.G.; Suemitsu, W.I.; Rolim, L.G.B.; Silva Neto, J.L.; Neves, M.A.; Santos, V.A. dos; Costa, G.C. da; Rosario, M.; Stephan, R.; Nicolsky, R

    2004-08-01

    High-speed flywheel systems have been studied as compensators of voltage sags and momentary interruptions of energy. Besides the complexity of these systems, the main concerns are bearing losses. This work is part of the development of a superconducting high-speed flywheel energy storage prototype. In order to minimize the bearing losses, this system uses a superconducting axial thrust magnetic bearing in a vacuum chamber, which guarantees low friction losses, and a switched reluctance motor-generator to drive the flywheel system. Dynamic simulations made for this prototype, connected to the electric power network, show the viability of use it as a compensator.

  16. Fast spiral-scan atomic force microscopy

    International Nuclear Information System (INIS)

    Mahmood, I A; Reza Moheimani, S O

    2009-01-01

    In this paper, we describe a new scanning technique for fast atomic force microscopy. In this method, the sample is scanned in a spiral pattern instead of the well established raster pattern. A spiral scan can be produced by applying single frequency cosine and sine signals with slowly varying amplitudes to the x-axis and y-axis of an atomic force microscope (AFM) scanner respectively. The use of the single tone input signals allows the scanner to move at high speeds without exciting the mechanical resonance of the device and with relatively small control efforts. Experimental results obtained by implementing this technique on a commercial AFM indicate that high-quality images can be generated at scan frequencies well beyond the raster scans.

  17. A stable high-speed rotational transmission system based on nanotubes

    International Nuclear Information System (INIS)

    Cai, Kun; Yin, Hang; Wei, Ning; Chen, Zhen; Shi, Jiao

    2015-01-01

    A stable rotational transmission system is designed with a single-walled carbon nanotube (SWCNT)-based motor and double-walled carbon nanotubes (DWCNTs)-based bearing. The system response is investigated using molecular dynamics (MD) simulation. It is found that the rotating motor can actuate the rotation of the inner tube in bearing because of the attraction between the two adjacent coaxial ends of motor and rotor (the inner tube in bearing). To have a stable nanostructure, each carbon atom on the adjacent ends of motor and rotor is bonded with a hydrogen atom. To obtain a stable high-speed rotational transmission system, both an armchair and a zigzag model are used in MD simulation. In each model, the motor with different diameters and rotational speeds is employed to examine the rotational transmission of corresponding DWCNTs. It is demonstrated that the long range van der Waals interaction between the adjacent ends of motor and rotor leads to a stable configuration of the adjacent ends, and further leads to a stable rotation of rotor when driven by a high-speed motor. As compared with the armchair model, the rotor in the zigzag model could reach a stable rotation mode much easier

  18. High-Speed Smart Camera with High Resolution

    Directory of Open Access Journals (Sweden)

    J. Dubois

    2007-02-01

    Full Text Available High-speed video cameras are powerful tools for investigating for instance the biomechanics analysis or the movements of mechanical parts in manufacturing processes. In the past years, the use of CMOS sensors instead of CCDs has enabled the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. In this paper, we propose a high-speed smart camera based on a CMOS sensor with embedded processing. Two types of algorithms have been implemented. A compression algorithm, specific to high-speed imaging constraints, has been implemented. This implementation allows to reduce the large data flow (6.55 Gbps and to propose a transfer on a serial output link (USB 2.0. The second type of algorithm is dedicated to feature extraction such as edge detection, markers extraction, or image analysis, wavelet analysis, and object tracking. These image processing algorithms have been implemented into an FPGA embedded inside the camera. These implementations are low-cost in terms of hardware resources. This FPGA technology allows us to process in real time 500 images per second with a 1280×1024 resolution. This camera system is a reconfigurable platform, other image processing algorithms can be implemented.

  19. High-Speed Smart Camera with High Resolution

    Directory of Open Access Journals (Sweden)

    Mosqueron R

    2007-01-01

    Full Text Available High-speed video cameras are powerful tools for investigating for instance the biomechanics analysis or the movements of mechanical parts in manufacturing processes. In the past years, the use of CMOS sensors instead of CCDs has enabled the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. In this paper, we propose a high-speed smart camera based on a CMOS sensor with embedded processing. Two types of algorithms have been implemented. A compression algorithm, specific to high-speed imaging constraints, has been implemented. This implementation allows to reduce the large data flow (6.55 Gbps and to propose a transfer on a serial output link (USB 2.0. The second type of algorithm is dedicated to feature extraction such as edge detection, markers extraction, or image analysis, wavelet analysis, and object tracking. These image processing algorithms have been implemented into an FPGA embedded inside the camera. These implementations are low-cost in terms of hardware resources. This FPGA technology allows us to process in real time 500 images per second with a 1280×1024 resolution. This camera system is a reconfigurable platform, other image processing algorithms can be implemented.

  20. Minimum Plate Thickness in High-Speed Craft

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    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...

  1. High-speed photography application to pulsed hot plasma investigation

    International Nuclear Information System (INIS)

    Borov'etskij, M.; Koz'yarkevich, V.; Skrzhechanovskij, V.; Socha, R.

    1986-01-01

    Plasma focus is investigated using an electron-optical chamber for high-speed photography (KSK-1). Experimental devices for studying dynamics and structure of a plasma layer in the chosen interval, recording plasma spectra with time resolution as well as for studying the dynamics and structure of a plasma layer by Schlieren- and shadow methods are briefly described. Experimental results are presented

  2. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    evolution of information and introduction of optical soliton solution as the stable nonlinear solution. The paper ... aged solitons will be presented to demonstrate the effectiveness of dispersion management techniques both .... Most high speed transmission systems at present use an all optical scheme with loss compensated ...

  3. CSIR National Laser Centre develops a high speed OCT system

    CSIR Research Space (South Africa)

    Sharma, Ameeth

    2016-11-01

    Full Text Available -axis scanner. Signal acquisition is made possible through a high-speed analogue-to-digital converter capable of speeds greater than 1GS/s. The system has demonstrated the ability to capture live fingerprints making it a viable alternative for high security...

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

    CSIR Research Space (South Africa)

    Olivier, M

    2013-08-01

    Full Text Available A method to optimise the geometry, explosive charge mass and volume of an argon bomb for specific lighting requirements has been proposed. The method is specifically aimed at applications that require photographic diagnostics with ultra-high speed...

  5. Evaluating safety and operation of high-speed intersections.

    Science.gov (United States)

    2010-03-01

    This Final Report reviews a research effort to evaluate the safety and operations of high-speed intersections in the State of : Oregon. In particular, this research effort focuses on four-leg, signalized intersections with speed limits of 45 mph or :...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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....

  7. The impact of high speed rail on airport competition

    NARCIS (Netherlands)

    Terpstra, I.; Lijesen, M.G.

    2015-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Yang Rui

    2018-01-01

    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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...

  10. Modeling of high speed micro rotors in moderate flow confinement

    NARCIS (Netherlands)

    Dikmen, E.; van der Hoogt, Peter; Aarts, Ronald G.K.M.; Sas, P.; Bergen, B.

    2008-01-01

    The recent developments in high speed micro rotating machinery lead to the need for multiphysical modeling of the rotor and the surrounding medium. In this study, thermal and flow induced effects on rotor dynamics of geometries with moderate flow confinement are studied. The structure is modeled via

  11. 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.

  12. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    Multi-terabit/s, ultra-high speed optical transmissions over several thousands kilometers on fibers are becoming a reality. Most use RZ (Return to Zero) format in dispersion-managed fibers. This format is the only stable waveform in the presence of fiber Kerr nonlinearity and dispersion in all optical transmission lines with ...

  13. Novel Applications of High Speed Optical-Injection Locked Lasers

    Science.gov (United States)

    2010-07-31

    modulated vertical-cavity surface-emitting laser (VCSELs) are attractive candidates as cost-effective optical transmitters for metro -area networks (MANs...local area networks (LANs) and high-speed Ethernet applications. A directly modulated VCSEL is desirable because it is compact, cost-effective and

  14. Research in high speed fiber optics local area networks

    Science.gov (United States)

    Tobagi, F. A.

    1986-01-01

    The design of high speed local area networks (HSLAN) for communication among distributed devices requires solving problems in three areas: the network medium and its topology, the medium access control, and the network interface. Considerable progress was already made in the first two areas. Accomplishments are divided into two groups according to their theoretical or experimental nature. A brief summary is given.

  15. 14 CFR 25.253 - High-speed characteristics.

    Science.gov (United States)

    2010-01-01

    ... 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...

  16. High-Speed Data Rate Controller Using Verilog

    OpenAIRE

    K. Harikishore; B.K.V.Prasad; G.V. Ravi Kumar

    2011-01-01

    DDR SDRAM (Double Data Rate Synchronously Dynamic RAM) controller is discussed in this paper. The principle and commands of FPGA-based DDR SDRAM controller are detailed. The R/W control of DDR SDRAM is realized through Verilog HDL, and this controller is applied into 580MHz single channel high-speed, high-precision and large-capacity data acquisition board

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    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 testbed...

  18. Performance of LTE in High Speed Railway Scenarios

    DEFF Research Database (Denmark)

    Sniady, Aleksander; Soler, José

    2013-01-01

    , alternative technologies, such as LTE, have to be considered as a future railway communication technology. This paper presents an analysis of transfer delay and data integrity of European Train Control System (ETCS) messages transmitted over LTE network. The analysis is made using OPNET models of a high speed...... railway line and LTE systems....

  19. A high-speed interconnect network using ternary logic

    DEFF Research Database (Denmark)

    Madsen, Jens Kargaard; Long, S. I.

    1995-01-01

    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...

  20. Research notes : high-speed rail survey results.

    Science.gov (United States)

    2010-08-01

    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...

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

    NARCIS (Netherlands)

    Olieman, E.

    2016-01-01

    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

  2. Comprehensive surface treatment of high-speed steel tool

    Science.gov (United States)

    Fedorov, Sergey V.; Aleshin, Sergey V.; Swe, Min Htet; Abdirova, Raushan D.; Kapitanov, Alexey V.; Egorov, Sergey B.

    2018-03-01

    One of the promising directions of hardening of high-speed steel tool is the creation on their surface of the layered structures with the gradient of physic-chemical properties between the wear-resistant coatings to the base material. Among the methods of such surface modification, a special process takes place based on the use of pulsed high-intensity charged particle beams. The high speed of heating and cooling allows structural-phase transformations in the surface layer, which cannot be realized in a stationary mode. The treatment was conducted in a RITM-SP unit, which constitutes a combination of a source of low-energy high-current electron beams "RITM" and two magnetron spraying systems on a single vacuum chamber. The unit enables deposition of films on the surface of the desired product and subsequent liquid-phase mixing of materials of the film and the substrate by an intense pulse electron beam. The article discusses features of the structure of the subsurface layer of high-speed steel M2, modified by surface alloying of a low-energy high-current electron beam, and its effect on the wear resistance of the tool when dry cutting hard to machine Nickel alloy. A significant decrease of intensity of wear of high-speed steel with combined treatment happens due to the displacement of the zone of wear and decrease the radius of rounding of the cutting edge because of changes in conditions of interaction with the material being treated.

  3. The Lag Model Applied to High Speed Flows

    Science.gov (United States)

    Olsen, Michael E.; Coakley, Thomas J.; Lillard, Randolph P.

    2005-01-01

    The Lag model has shown great promise in prediction of low speed and transonic separations. The predictions of the model, along with other models (Spalart-Allmaras and Menter SST) are assessed for various high speed flowfields. In addition to skin friction and separation predictions, the prediction of heat transfer are compared among these models, and some fundamental building block flowfields, are investigated.

  4. Intelligent Tool Condition Monitoring In High-Speed Turning Of ...

    African Journals Online (AJOL)

    In this paper, a Multi-Layered Perceptron (MLP) neural net-work model has been developed for on-line condition monitoring of tool wear in high-speed turning of Titanium-based alloy (Ti-6Al-4V). Machining trials were ... The neural network model was designed using Matlab® neural toolbox. Accuracy of model for the ...

  5. The high speed interconnect system architecture and operation

    Science.gov (United States)

    Anderson, Steven C.

    The design and operation of a fiber-optic high-speed interconnect system (HSIS) being developed to meet the requirements of future avionics and flight-control hardware with distributed-system architectures are discussed. The HSIS is intended for 100-Mb/s operation of a local-area network with up to 256 stations. It comprises a bus transmission system (passive star couplers and linear media linked by active elements) and network interface units (NIUs). Each NIU is designed to perform the physical, data link, network, and transport functions defined by the ISO OSI Basic Reference Model (1982 and 1983) and incorporates a fiber-optic transceiver, a high-speed protocol based on the SAE AE-9B linear token-passing data bus (1986), and a specialized application interface unit. The operating modes and capabilities of HSIS are described in detail and illustrated with diagrams.

  6. 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)

    2013-08-15

    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.

  7. Development of Industrial High-Speed Transfer Parallel Robot

    International Nuclear Information System (INIS)

    Kim, Byung In; Kyung, Jin Ho; Do, Hyun Min; Jo, Sang Hyun

    2013-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Bo-young Kang

    2017-12-01

    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.

  9. High-speed image processing and viewing system

    International Nuclear Information System (INIS)

    Saito, K.; Yamagishi, I.; Nomura, S.; Abe, T.; Smith, C.R.

    1986-01-01

    The authors achieved high-speed image processing using the computation power of 100 million arithmetic operations per second of a processor that is mainly used for CT image reconstruction from raw data. Image processing can be done in parallel with image reconstruction by time-sharing. The viewing system without frame buffer can directly access a 32-megabyte-wide main memory, and high-speed cine-display is easily achieved because image data transmission is not involved. These technical features allow real-time multiplanar image reconstruction which generates sagittal, coronal, or oblique images from axial images after a trackball-controlled cursor operation. There is no response delay, and the technique has proved effective for observing complex three-dimensional structures instantaneously. The processor is a general purpose one and can perform many other image processing routines

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

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    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 imaging polarimetry using liquid crystal modulators

    Directory of Open Access Journals (Sweden)

    Ambs P.

    2010-06-01

    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.

  12. Characterizing pyrotechnic igniter output with high-speed schlieren imaging

    Science.gov (United States)

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

    2017-01-01

    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.

  13. Ultra high speed image processing techniques. [electronic packaging techniques

    Science.gov (United States)

    Anthony, T.; Hoeschele, D. F.; Connery, R.; Ehland, J.; Billings, J.

    1981-01-01

    Packaging techniques for ultra high speed image processing were developed. These techniques involve the development of a signal feedthrough technique through LSI/VLSI sapphire substrates. This allows the stacking of LSI/VLSI circuit substrates in a 3 dimensional package with greatly reduced length of interconnecting lines between the LSI/VLSI circuits. The reduced parasitic capacitances results in higher LSI/VLSI computational speeds at significantly reduced power consumption levels.

  14. Noise factor of a high-speed cinematography system

    International Nuclear Information System (INIS)

    Secroun, A.

    2000-01-01

    Inertial confinement fusion simulates in a laboratory the thermodynamic state of the center of stars, thus leading to the determination of stellar parameters. In order to reach that aim, high-speed cinematography brings up instruments specifically adapted to picosecond measurement, for which it is necessary to know the final precision. A model of the noise factor of the instruments under study is introduced and confronted to the experimental results obtained. (authors)

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

    Science.gov (United States)

    Klein, Thomas; Huber, Robert

    2017-01-01

    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

  16. High-speed Laser Micromachining with Copper Bromide Laser

    OpenAIRE

    Balchev, Ivaylo I.; Minkovski, Nikolai I.; Kostadinov, Ivan K.; Sabotinov, Nikola V.

    2006-01-01

    The application of the copper bromide (CuBr) laser as an attractive tool in the micro-machining of different materials has been demonstrated. High-quality drilling by trepanning and precision cutting was established on several materials with a negligible heat-affected zone (HAZ). That good performance was a result of the combination of high power visible radiation, short pulses, and close to the diffraction-limited laser beam quality with high-speed galvo scanner beam steering.

  17. High Speed Downlink Packet Access in UMTS Network

    Directory of Open Access Journals (Sweden)

    Vladimir Psenak

    2005-01-01

    Full Text Available High speed downlink packet access added to UMTS network provides to users data speed up to 10 Mbit/s. The achievement of high data speed is possible due to new link management and link control, and also due to change from power adaptation to modulation and coding adaptation. The most important benefit is an accessing of data services, which request big downlink data flow.

  18. Computer programs for helicopter high speed flight analysis

    OpenAIRE

    Carmona, Waldo F.

    1983-01-01

    Approved for Public Release, Distribution Unlimited This report gives the user of HP41-CV handheld programmable calculator or the IBM 3033 calculator, a blade element method for calculating the total power required in forward, straight and level high speed flight for an isolated rotor. The computer programs consist of a main program which calculates the necessary dynamic parameters of the main rotor and several subroutines which calculate power required as well as maximum...

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

    Science.gov (United States)

    2009-12-08

    maglev train in 2003. Because of the greater costs, and relatively minor benefits,11 of operating at extremely high speeds, the top operating speed...transported.14 Magnetic Levitation ( Maglev ) Maglev train technology was developed in the United States in the 1960s. It uses electromagnets to suspend... maglev trains can go very fast, and the trains and tracks are expected to experience less wear and tear, thus reducing maintenance costs, though

  20. High speed motion-picture photography. Instrumentation and application

    International Nuclear Information System (INIS)

    Bertin-Maghit, G.; Delli, C.; Falgayrettes, M.

    1981-01-01

    Filming technology at 5,000 frames/second is presented in this paper for the determination of the volume and the expension speed of a gas bubble in water. The high speed 16 mm movie camera, fitted with ultra-wide angle lenses, is placed in front of a side light facing the bubble. Ten 60 ms fast flashes, released in succession, illuminate the bubble [fr

  1. High speed photographic study of hot wire dynamic behavior

    Science.gov (United States)

    Sernas, V.; Murphy, A. J.

    1974-01-01

    Investigation of hot wire dynamic behavior under high-current heating aimed at a better understanding of the ignition process, using high-speed photographic techniques for visual observation of the bridgewire itself during high current heating. Tests were conducted with Tophet A bridgewires in an air environment, as well as in a cell of distilled water at room temperature, and with a boron-potassium perchlorate-Viton pyrotechnic against the bridgewire behind a Plexiglas window.

  2. Gearbox Reliability Collaborative High-Speed Shaft Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; McNiff, B.

    2014-09-01

    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.

  3. Study on Electromagnetic Interference of high-speed railway EMU

    OpenAIRE

    CHENG Qiang; LIU Jin-jiang; CHENG Ning

    2013-01-01

    Electromagnetic radiation generated by pantograph-catenaries detachment is one of the inevitable problems with the development of high-speed railway this paper is focusing on the generating mechanism and characteristics of electromagnetic noise caused by pantograph-catenaries system. Based on previous research, we build an integrated model of catenaries and locomotive system, and study the electromagnetic disturbance characteristics using software FEKO. The simulation experiment results in th...

  4. Different approaches of high speed data transmission standards

    OpenAIRE

    M. Ehlert

    2004-01-01

    A number of standards addresses the problem of high-speed data transmission on serial or serial-parallel data lines. Serial-parallel data transmission means the transmitted information is distributed on parallel data lines. Even though several standards exist, there are only a few basic techniques used in most of these standards. This paper is giving an overview of these different basic techniques used in the physical layer of today’s data transmission standards, for exam...

  5. High Speed Iris Detection Method for Man-Machine Interface

    Science.gov (United States)

    Kashima, Hideki; Hongo, Hitoshi; Kato, Kunihito; Yamamoto, Kazuhiko

    We propose a high speed iris detection method for man-machine interface. In order to communicate between humans and computers comfortably, it is required that high speed processing and adapting the changes of the face direction and the individual variation of the face. Our iris detection method consists of a face detection function, a facial parts extraction function and an iris detection function. The face detection function adapts to individual variation or a light condition by using standard skin color method which decides the standard skin color by a color histogram every frame. The facial parts extraction function adapts to changes of face direction and the individual variation in order to by using the hybrid template matching which consists the four directional features field and the color different features. The iris detection function performs high speed and stable detection by segmentation of iris region using color information and the Hough transform. We conducted the comparison experiment with our past method which uses the least approximation method. By this result, processing time of our method realized equivalent to our past method. In addition, accuracy rate of iris detection with our method improved.

  6. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. (Los Alamos National Lab., NM (United States)); Levine, G.F. (California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services)

    1993-01-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  7. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  8. On the reversed Brayton cycle with high speed machinery

    Energy Technology Data Exchange (ETDEWEB)

    Backman, J.

    1996-12-31

    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.)

  9. Numerical computation of compressible, turbulent high-speed flows

    Science.gov (United States)

    Suzen, Yildirim Bora

    Separated flows and subsequent formation of shear layers are important fluid processes which play a dominant role in numerous engineering applications. Accurate prediction of this fluid process is an important element in the design and analysis of high speed vehicles and, ultimately, in performance and trajectory analysis. In this study, a two-dimensional/axisymmetric Navier-Stokes flow solver using Steger-Warming flux vector splitting technique is developed for the accurate simulation of high speed turbulent flows. Computations are performed for an underexpanded, supersonic, turbulent, axisymmetric jet and a two-stream supersonic turbulent wake flowfield behind a two-dimensional thick base as representative of high speed, compressible shear flows. Baldwin-Barth and Spalart-Allmaras one-equation turbulence models and Baseline version of Menter's zonal k - omega/k - varepsilon two-equation turbulence models are used to investigate their performance for the applications considered. Modifications to these models are incorporated in order to improve their prediction capabilities for the types of flows considered. For two-equation models, modifications to include compressibility correction terms are considered and a modeled version of Menter's models including compressible dissipation and pressure dilatation terms is developed. Axisymmetric correction is incorporated to all models by means of coefficient changes. The computational results are compared to available experimental data. Results show that the modifications improve the computed solutions for all models.

  10. Triangular spiral tilings

    International Nuclear Information System (INIS)

    Sushida, Takamichi; Hizume, Akio; Yamagishi, Yoshikazu

    2012-01-01

    The topology of spiral tilings is intimately related to phyllotaxis theory and continued fractions. A quadrilateral spiral tiling is determined by a suitable chosen triple (ζ, m, n), where ζ element of D/R, and m and n are relatively prime integers. We give a simple characterization when (ζ, m, n) produce a triangular spiral tiling. When m and n are fixed, the admissible generators ζ form a curve in the unit disk. The family of triangular spiral tilings with opposed parastichy pairs (m, n) is parameterized by the divergence angle arg (ζ), while triangular spiral tilings with non-opposed parastichy pairs are parameterized by the plastochrone ratio 1/|ζ|. The generators for triangular spiral tilings with opposed parastichy pairs are not dense in the complex parameter space, while those with non-opposed parastichy pairs are dense. The proofs will be given in a general setting of spiral multiple tilings. We present paper-folding (origami) sheets that build spiral towers whose top-down views are triangular tilings. (paper)

  11. High-Speed, High-Resolution Time-to-Digital Conversion

    Science.gov (United States)

    Katz, Richard; Kleyner, Igor; Garcia, Rafael

    2013-01-01

    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.

  12. Control Strategy for a High Speed SRM Fed from a Photovoltaic Source

    OpenAIRE

    Ahmed Said Oshaba

    2013-01-01

    High speed Switched Reluctance Motors (SRMs) have recently been gaining attention as contenders in many variable speed drive applications. This has also been stimulated by recent advances in power electronic technology which enables this drive system for many applications such as high speed water pump and space and military applications. This study presents the design and control of high speed four phases SRM suitable for high speed water pumping and other high speed variable load application...

  13. Development of a high-speed single-photon pixellated detector for visible wavelengths

    CERN Document Server

    Mac Raighne, Aaron; Mathot, Serge; McPhate, Jason; Vallerga, John; Jarron, Pierre; Brownlee, Colin; O’Shea, Val

    2009-01-01

    We present the development of a high-speed, single-photon counting, Hybrid Photo Detector (HPD). The HPD consists of a vacuum tube, containing the detector assembly, sealed with a transparent optical input window. Photons incident on the photocathode eject a photoelectron into a large electric field, which accelerates the incident electron onto a silicon detector. The silicon detector is bump bonded to a Medipix readout chip. This set-up allows for the detection and readout of low incident photon intensities at rates that are otherwise unattainable with current camera technology. Reported is the fabrication of the camera that brings together a range of sophisticated design and fabrication techniques and the expected theoretical imaging performance. Applications to cellular and molecular microscopy are also described in which single-photon-counting abilities at high frame rates are crucial

  14. Lung studies with spiral CT. pitch 1 versus pitch 2

    International Nuclear Information System (INIS)

    Sartoni Galloni, S.; Miceli, M.; Lipparino, M.; Burzi, M.; Gigli, F.; Rossi, M.S.; Santoli, G.; Guidarelli, G.

    1999-01-01

    In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality [it

  15. High speed motion neutron radiography of two-phase flow

    International Nuclear Information System (INIS)

    Robinson, A.H.; Wang, S.L.

    1983-01-01

    Current research in the area of two-phase flow utilizes a wide variety of sensing devices, but some limitations exist on the information which can be obtained. Neutron radiography is a feasible alternative to ''see'' the two-phase flow. A system to perform neutron radiographic analysis of dynamic events which occur on the order of several milliseconds has been developed at Oregon State University. Two different methods have been used to radiograph the simulated two-phase flow. These are pulsed, or ''flash'' radiography, and high speed movie neutron radiography. The pulsed method serves as a ''snap-shot'' with an exposure time ranging from 10 to 20 milliseconds. In high speed movie radiography, a scintillator is used to convert neutrons into light which is enhanced by an optical intensifier and then photographed by a high speed camera. Both types of radiography utilize the pulsing capability of the OSU TRIGA reactor. The principle difficulty with this type of neutron radiography is the fogging of the image due to the large amount of scattering in the water. This difficulty can be overcome by using thin regions for the two-phase flow or using heavy water instead of light water. The results obtained in this paper demonstrate the feasibility of using neutron radiography to obtain data in two-phase flow situations. Both movies and flash radiographs have been obtained of air bubbles in water and boiling from a heater element. The neutron radiographs of the boiling element show both nucleate boiling and film boiling. (Auth.)

  16. Liquid metal current collectors for high-speed rotating machinery

    International Nuclear Information System (INIS)

    Carr, S.L.

    1976-01-01

    Recent interest in superconducting motors and generators has created a renewed interest in homopolar machinery. Homopolar machine designs have always been limited by the need for compact, high-current, low-voltage, sliding electrical curent collectors. Conventional graphite-based solid brushes are inadequate for use in homopolar machines. Liquid metals, under certain conditions of relative sliding velocities, electrical currents, and magnetic fields are known to be capable of performing well in homopolar machines. An effort to explore the capabilities and limits of a tongue-and-groove style current collector, utilizing sodium-potassium eutectic alloy (NaK) as the working fluid in high sliding speed operation is reported here. A double current collector generator model with a 14.5-cm maximum rotor diameter, 20,000 rpm rotational capability, and electrical current carrying ability was constructed and operated successfully at a peripheral velocity of 125 m/s. The limiting factor in these experiments was a high-speed fluid-flow instability resulting in the ejection of the working fluid from the operating portions of the collectors. The effects of collector size and geometry, working fluid (NaK or water), and cover gas pressure are reported. Hydrodynamic frictional torque-speed curves are given for the two fluids and for several geometries. Electrical resistances as a function of peripheral velocity at 60 amperes are reported, and the phenomenology of the high-speed fluid-flow instabilities is discussed. The possibility of long-term high-speed operation of current collectors of the tongue-and-groove type, along with experimental and theoretical hydrodynamic friction losses at high peripheral velocities, is considered

  17. Implementation of High Speed Distributed Data Acquisition System

    Science.gov (United States)

    Raju, Anju P.; Sekhar, Ambika

    2012-09-01

    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

  18. Electron characteristics in the high speed solar wind

    International Nuclear Information System (INIS)

    Feldman, W.C.

    1978-01-01

    Experimental work done since 1976 on the physics of electrons in the high speed solar wind is reviewed. The main new results are most electron parameters are uniform in the high speed solar wind indicating that it is a well defined, structure-free state of the coronal expansion. The higher energy unbound part of electron velocity distributions (the halo) is consistent with nearly collisionless propagation to 1AU from some heliocentric distance in the range between about 10 and 30 solar radii. The low energy bound electron (core) component appears to be strongly coupled to the protons as well as to one another through Coulomb and wave electron collisions. The first measured radial profile of the core-electron temperature in the high speed solar wind is best characterized in terms of two separate power laws applicable in the distance ranges between 0.47 and 0.62 AU and between 0.62 and 1.0 AU respectively. The best estimate for the power law indices in the inner and outer regions are α 1 = -1.14 +-0.24 and α 0 = +0.28 +-0.13, respectively. A relations of the form Q = γN/sub c/kT/sub c/U/(1 + βγ/sub sigma11 γcp) with = 10.7 and β = 4.2 may be useful in closing the Vlasov moment equations describing general solar wind flows in interplanetary space. The quantity Q is the total heat flux, N/sub c/ and T/sub c/ are the core-electron density and temperature respectively, k is Boltzmann's constant, U is the proton bulk speed in the solar corotating reference frame, /sub tsigma/ is the bounce period of a typical core electron and /+ sub tcp/ is the average core electron-proton Coulomb deflection time. 16 refs

  19. High-speed AFM for Studying Dynamic Biomolecular Processes

    Science.gov (United States)

    Ando, Toshio

    2008-03-01

    Biological molecules show their vital activities only in aqueous solutions. It had been one of dreams in biological sciences to directly observe biological macromolecules (protein, DNA) at work under a physiological condition because such observation is straightforward to understanding their dynamic behaviors and functional mechanisms. Optical microscopy has no sufficient spatial resolution and electron microscopy is not applicable to in-liquid samples. Atomic force microscopy (AFM) can visualize molecules in liquids at high resolution but its imaging rate was too low to capture dynamic biological processes. This slow imaging rate is because AFM employs mechanical probes (cantilevers) and mechanical scanners to detect the sample height at each pixel. It is quite difficult to quickly move a mechanical device of macroscopic size with sub-nanometer accuracy without producing unwanted vibrations. It is also difficult to maintain the delicate contact between a probe tip and fragile samples. Two key techniques are required to realize high-speed AFM for biological research; fast feedback control to maintain a weak tip-sample interaction force and a technique to suppress mechanical vibrations of the scanner. Various efforts have been carried out in the past decade to materialize high-speed AFM. The current high-speed AFM can capture images on video at 30-60 frames/s for a scan range of 250nm and 100 scan lines, without significantly disturbing week biomolecular interaction. Our recent studies demonstrated that this new microscope can reveal biomolecular processes such as myosin V walking along actin tracks and association/dissociation dynamics of chaperonin GroEL-GroES that occurs in a negatively cooperative manner. The capacity of nanometer-scale visualization of dynamic processes in liquids will innovate on biological research. In addition, it will open a new way to study dynamic chemical/physical processes of various phenomena that occur at the liquid-solid interfaces.

  20. A CMOS high speed imaging system design based on FPGA

    Science.gov (United States)

    Tang, Hong; Wang, Huawei; Cao, Jianzhong; Qiao, Mingrui

    2015-10-01

    CMOS sensors have more advantages than traditional CCD sensors. The imaging system based on CMOS has become a hot spot in research and development. In order to achieve the real-time data acquisition and high-speed transmission, we design a high-speed CMOS imaging system on account of FPGA. The core control chip of this system is XC6SL75T and we take advantages of CameraLink interface and AM41V4 CMOS image sensors to transmit and acquire image data. AM41V4 is a 4 Megapixel High speed 500 frames per second CMOS image sensor with global shutter and 4/3" optical format. The sensor uses column parallel A/D converters to digitize the images. The CameraLink interface adopts DS90CR287 and it can convert 28 bits of LVCMOS/LVTTL data into four LVDS data stream. The reflected light of objects is photographed by the CMOS detectors. CMOS sensors convert the light to electronic signals and then send them to FPGA. FPGA processes data it received and transmits them to upper computer which has acquisition cards through CameraLink interface configured as full models. Then PC will store, visualize and process images later. The structure and principle of the system are both explained in this paper and this paper introduces the hardware and software design of the system. FPGA introduces the driven clock of CMOS. The data in CMOS is converted to LVDS signals and then transmitted to the data acquisition cards. After simulation, the paper presents a row transfer timing sequence of CMOS. The system realized real-time image acquisition and external controls.

  1. Modular high speed counter employing edge-triggered code

    Science.gov (United States)

    Vanstraelen, G.F.

    1993-06-29

    A high speed modular counter (100) utilizing a novel counting method in which the first bit changes with the frequency of the driving clock, and changes in the higher order bits are initiated one clock pulse after a 0'' to 1'' transition of the next lower order bit. This allows all carries to be known one clock period in advance of a bit change. The present counter is modular and utilizes two types of standard counter cells. A first counter cell determines the zero bit. The second counter cell determines any other higher order bit. Additional second counter cells are added to the counter to accommodate any count length without affecting speed.

  2. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi

    2016-01-01

    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....

  3. The Effects of Gouge Accumulation on High Speed Rock Friction

    Science.gov (United States)

    Barbery, M. R.; Chester, F. M.; Chester, J. S.; Saber, O.

    2016-12-01

    Previous experiments demonstrate that a significant reduction in the coefficient of sliding friction typically occurs as sliding velocity approaches seismic slip rates and that weakening may reflect flash heating of surface contacts. Experiments also show differences in the weakening behavior of bare rock and gouge-lined surfaces across different rock types. We conducted high-speed velocity-step (VS) experiments on ground surfaces of granite (Westerly) and quartzite (Sioux) using a double-direct shear (DDS) configuration, with a sliding area of 75cm2, to investigate the effects of gouge generation and accumulation on frictional weakening behavior. Sliding surface temperatures were measured using a high-speed infrared camera. Experiments were conducted at 7-9 MPa normal stress and achieved VS from 1 mm/s up to 1 m/s at high acceleration (100g) over a small distance ( 2 mm), and with sustained high-speed sliding for 30 mm. Successive experiments were run without disassembling the blocks or disturbing the sliding surfaces to generate and accumulate gouge for cumulative displacements up to 0.5 m. Locally high temperatures were observed correlating to corrugated structures within the gouge. For VS tests on bare granite, we observed an abrupt decrease in the coefficient of friction from 0.7 at quasi-static slip rates to 0.5 at m/s slip rates, and a typical weakening distance, dc, of 3 mm. This observation is consistent with rotary shear experiments conducted at similar displacements, accelerations, and sliding velocities. With the accumulation of gouge along the sliding surface, dc progressively increases to 2 cm. In contrast, VS tests on bare quartzite produce an abrupt increase in friction, from 0.65 to 0.7 within 1 mm of slip, followed by gradual weakening for the duration of high-speed sliding. With the accumulation of quartz gouge, similar behavior is observed, but with a slightly greater magnitude of strengthening. The results for quartzite are unlike those

  4. Miniature high speed compressor having embedded permanent magnet motor

    Science.gov (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)

    2011-01-01

    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.

  5. Signal Conditioning in Process of High Speed Imaging

    Directory of Open Access Journals (Sweden)

    Libor Hargas

    2015-01-01

    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.

  6. High-speed photography of microscale blast wave phenomena

    Science.gov (United States)

    Dewey, John M.; Kleine, Harald

    2005-03-01

    High-speed photography has been a primary tool for the study of blast wave phenomena, dating from the work of Toepler, even before the invention of the camera! High-speed photography was used extensively for the study of blast waves produced by nuclear explosions for which, because of the large scale, cameras running at a few hundred frames per second were adequate to obtain sharp images of the supersonic shock fronts. For the study of the blast waves produced by smaller explosive sources, ever-increasing framing rates were required. As a rough guide, for every three orders of magnitude decrease in charge size a ten-fold increase of framing rate was needed. This severely limited the use of photography for the study of blast waves from laboratory-scale charges. There are many techniques for taking single photographs of explosive phenomena, but the strongly time-dependent development of a blast wave, requires the ability to record a high-speed sequence of photographs of a single event. At ICHSPP25, Kondo et al of Shimadzu Corporation demonstrated a 1 M fps video camera that provides a sequence of up to 100 high-resolution frames. This was subsequently used at the Shock Wave Research Center of Tohoku University to record the blast waves generated by an extensive series of silver azide charges ranging in size from 10 to 0.5mg. The resulting images were measured to provide radius-time histories of the primary and secondary shocks. These were analyzed with techniques similar to those used for the study of explosions from charges with masses ranging from 500 kg to 5 kt. The analyses showed the cube-root scaling laws to be valid for the very small charges, and provided a detailed record of the peak hydrostatic pressure as a function of radius for a unit charge of silver azide, over a wide range of scaled distances. The pressure-radius variation was compared to that from a unit charge of TNT and this permitted a detailed determination of the TNT equivalence of silver azide

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

    Directory of Open Access Journals (Sweden)

    Hongwei Zhao

    2017-02-01

    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.

  8. High capacity, high speed histogramming data acquisition memory

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, A.; Boulin, C. [European Molecular Biology Lab., Heidelberg (Germany). Cell Biophysics Programme

    1996-02-01

    A double width CAMAC DRAM store module was developed for use as a histogramming memory in fast time-resolved synchrotron radiation applications to molecular biology. High speed direct memory modify (3 MHz) is accomplished by using a discrete DRAM controller and fast page mode access. The module can be configured using standard SIMMs to sizes of up to 64M-words. The word width is 16 bit and the module can handle overflows by storing the overflow addresses in a dedicated FIFO. Simultaneous front panel DMM/DMI access and CAMAC readout of the overflow addresses is supported.

  9. High speed fiber optics local area networks: Design and implementation

    Science.gov (United States)

    Tobagi, Fouad A.

    1988-01-01

    The design of high speed local area networks (HSLAN) for communication among distributed devices requires solving problems in three areas: (1) the network medium and its topology; (2) the medium access control; and (3) the network interface. Considerable progress has been made in all areas. Accomplishments are divided into two groups according to their theoretical or experimental nature. A brief summary is given in Section 2, including references to papers which appeared in the literature, as well as to Ph.D. dissertations and technical reports published at Stanford University.

  10. High speed capacitor-inverter based carbon nanotube full adder.

    Science.gov (United States)

    Navi, K; Rashtian, M; Khatir, A; Keshavarzian, P; Hashemipour, O

    2010-03-18

    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.

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

    Directory of Open Access Journals (Sweden)

    Rashtian M

    2010-01-01

    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.

  12. OMNET - high speed data communications for PDP-11 computers

    International Nuclear Information System (INIS)

    Parkman, C.F.; Lee, J.G.

    1979-12-01

    Omnet is a high speed data communications network designed at CERN for PDP-11 computers. It has grown from a link multiplexor system built for a CII 10070 computer into a full multi-point network, to which some fifty computers are now connected. It provides communications facilities for several large experimental installations as well as many smaller systems and has connections to all parts of the CERN site. The transmission protocol is discussed and brief details are given of the hardware and software used in its implementation. Also described is the gateway interface to the CERN packet switching network, 'Cernet'. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Larue A.

    2010-06-01

    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.

  14. Bottom Raking Damage to High-Speed Craft

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    certain similarities. Thus, damage statistics for one ship type can be scaled to another ship type.The result of a raking damage calculation is sensitive to various uncertain parameters, such as the impact velocity and the rock height and shape. Conveniently, the paper shows that the damage scaling factor......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...

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

    DEFF Research Database (Denmark)

    Li, Hailing; Wu, Haiyan; Lou, Lei

    2012-01-01

    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...... 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%....

  16. Time resolution performance studies of contemporary high speed photomultipliers

    International Nuclear Information System (INIS)

    Leskovar, B.; Lo, C.C.

    1977-01-01

    The time resolution capabilities of prototype microchannel plate and static crossed-field photomultipliers have been investigated. Measurements were made of electron transit time, rise time, time response, single photoelectron time spread and multiphotoelectron time spread for LEP HR350 proximity focused high gain curved microchannel plate and VPM-154A/1.6L static crossed-field photomultipliers. The experimental data have been compared with results obtained with conventionally designed RCS 8850 and C31024 high speed photomultipliers. Descriptions are given of both the measuring techniques and the measuring systems

  17. CERNET - A high-speed packet-switching network

    International Nuclear Information System (INIS)

    Gerard, J.M.

    1981-01-01

    A general mesh-structured high-speed computer network has been designed and built. This network provides communication between any pair of connected user computers over distances of upto 6 km and at line speeds of 1 to 5 Mbit/second. The network is composed of a communication subnet providing a datagram service, complemented by tasks in the connected machines to implement an end-to-end logical link protocol. Details are given of the overall structure as well as the specific modules of which the system is composed. (orig.)

  18. Production of intermediate energy beams by high speed rotors

    International Nuclear Information System (INIS)

    Nutt, C.W.; Bale, T.J.; Cosgrove, P.; Kirby, M.J.

    1975-01-01

    A rotor apparatus intended for the study of gas/surface interaction processes is presently nearing completion. The carbon fiber rotors under consideration are constructed with shapes derived from long thin cylindrical rods oriented with the longest axis in a horizontal plane, and spun in a horizontal plane about an axis which is perpendicular to the long axis and passes through the mid-point of the cylinder. The beam formation processes are discussed and rotor diagrams presented. Performance of these types of high speed rotor show them to have a very important future as sources of intermediate energy molecular beams

  19. Spiral finned crucible pot

    Science.gov (United States)

    Soemowidagdo, Arianto Leman; Tiwan, Widarto, Ardian, Aan

    2018-02-01

    Innovation on a crucible furnace to increase its efficiency in aluminum melting has been done. The innovation was a spiral finned crucible pot. The inclination of the spiral finned was vary of 5, 10, 15, and 20 degrees. The spiral finned effects was determined from the performance test result. A crucible pot without fin was also tested as a control. The crucible pot was examined at the same process condition. The crucible pot with the inclined fin of 10 degrees gives an optimum performance. It gives effective heating rate so that more efficient in LPG consumption. Therefore it saves energy in the aluminum melting process.

  20. High-speed gears for gas turbine drive

    Energy Technology Data Exchange (ETDEWEB)

    Kane, J.

    1995-06-01

    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.

  1. Jitter analysis utilizing a high speed FM tape recorder.

    Science.gov (United States)

    Nazliel, B; Kuruoğlu, R

    2000-09-01

    Jitter analysis in single fiber EMG (SFEMG) is usually done on-line during recording. However, this technique frequently prolongs the study and makes re-analysis impossible. We attempted to measure jitter with a high speed FM tape recorder and compare the results with the previously published values. SFEMG data, acquired with voluntary activation on extensor digitorum communis muscle of 25 healthy relatives of children with myasthenia gravis were retrospectively analyzed. Fiber density (FD) was estimated on-line. Five to 18 single fiber action potential (SFAP) pairs were studied in each subject. The wow of the tape recorder was 6 microseconds. Mean (SD) (upper 95th percentile) FD, individual jitter, highest jitter, mean jitter and interspike interval were 1.60 (0.18) (1.90), 25.30 (11.20) (57.00) microseconds, 31.24 (6.87) (47.00) microseconds, 25.08 (5.04) (43.00) microseconds, and 0.67 (0.11) (0.91) ms respectively. Mean jitter in the pooled SFAP pairs and mean MCD were found to be lower than the published values of the Ad Hoc Committee of the AAEM Special Interest Group on Single Fiber EMG. A high speed FM tape recorder can be reliably used for the off-line analysis of jitter.

  2. Novel High-Speed Photopolarimeter Based on a Metallic Grating

    International Nuclear Information System (INIS)

    Du, X L; Dai, J M; Sun, X G

    2006-01-01

    A novel high-speed photopolarimeter is presented in this paper, which is composed by the optical system, electronics system and PC. This instrument uses a metallic grating that can produce both reflective diffraction and transmission diffraction as a beam splitter to divide the incident light into many components, and the light fluxes of the four 1st order diffracted beams are converted linearly into four electrical signals by four photodiodes. After going through a signal conditioning circuit, these electrical signals are converted into digital values by high-speed A/D converters that can implement synchronous multi-channels sampling, and then the data sampled are high-speedily transmitted into the PC via a USB2.0 interface. The electrical signal vector I composed by the four electrical signals possesses the linear relationship with the incident light Stokes vector S. The nonsingular instrument matrix A of this instrument can be obtained by the calibration, and then the unknown Stokes vector S of the incidence light can be obtained from the equation S = A -1 I. The testing results show that the mean deviations of the measured Stokes parameters compared with the predicted values are less than 1% at 632.8nm. It is compact and easy to be installed, and can be used as a polarization state detector in real-time polarimetry and ellipsometry

  3. Physiological consequences of military high-speed boat transits.

    Science.gov (United States)

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

    2011-09-01

    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 (Forces/naval/police/rescue services carrying out demanding, high-risk physical tasks during and immediately after high-speed boat transits.

  4. Application Of CO2 Lasers To High Speed Blanking

    Science.gov (United States)

    Grenier, L. E.

    1986-11-01

    While laser cutting of sheetmetal has attained wide acceptance in the automotive industry for the purposes of prototyping and very limited preproduction work, the production rates possible with currently available systems have precluded the use of this technique in a production environment. The device design to be described embodies a high speed X-Y positioner carrying a cutting head with limited Z-axis capability. This approach confers two main benefits, first, production rate is limited only by laser power, since the positioner technology selected will permit movement at rates up to 1.5 m/s (60 in/s), second, the use of a high speed non-contact surface follower to control the Z-axis movement reduces the need to clamp the workpiece rigidly to a precision reference surface. The realized reduction of the clamping requirement permits some latitude in the feed methods that can be employed, allowing the use of coil or sheet feeding as appropriate. The author will provide estimated production rates for the proposed design and demonstrate that a suitable choice of laser source and material feed will permit the production of parts at a rate and cost comparable to conventional blanking with the advantage of much greater flexibility and reduced retooling time.

  5. High-speed digital fiber optic links for satellite traffic

    Science.gov (United States)

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

    1989-01-01

    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.

  6. Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

    Science.gov (United States)

    Pollard, Victoria J.; Herron, Andrew J.

    2017-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Itay Remer

    2016-09-01

    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.

  8. Multiscale modeling of composites subjected to high speed impact

    Science.gov (United States)

    Lee, Minhyung; Cha, Myung S.; Shang, Shu; Kim, Nam H.

    2015-06-01

    The simulation of high speed impact into composite panels is a challenging task. This is partly due to the fact macro-scale simulation requires integrating the local response at various locations, i.e. integration points. If a huge number of integration points exist for enhanced accuracy, it is often suggested to calculate the micro-scale simulation using massive parallel processing. In this paper, multiscale modeling methodology has been applied to simulate the relatively thick composite panels subjected to high speed local impact loading. Instead of massive parallel processing, we propose to use surrogate modeling to bridge micro-scale and macro-scale. Multiscale modeling of fracture phenomena of composite materials will consist of (1) micro-scale modeling of fiber-matrix structure using the unit-volume-element technique; (2) macro-scale simulation of composite panels under high strain-rate impact using material response calculated from micro-scale modeling; and (3) surrogate modeling to integrate the two scales. In order to validate the predictions, first we did the material level lab experiment such as tension test. And later we also did the field test of bullet impact into composite panels made of 4 ply and 8 ply fibers. The impact velocity ranges from 300 ~ 600 m/s. Special Thanks to grants (UD120053GD).

  9. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    Science.gov (United States)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  10. Technology of high-speed combined machining with brush electrode

    Science.gov (United States)

    Kirillov, O. N.; Smolentsev, V. P.; Yukhnevich, S. S.

    2018-03-01

    The new method was proposed for high-precision dimensional machining with a brush electrode when the true position of bundles of metal wire is adjusted by means of creating controlled centrifugal forces appeared due to the increased frequency of rotation of a tool. There are the ultimate values of circumferential velocity at which the bundles are pressed against a machined area of a workpiece in a stable manner despite the profile of the machined surface and variable stock of the workpiece. The special aspects of design of processing procedures for finishing standard parts, including components of products with low rigidity, are disclosed. The methodology of calculation and selection of processing modes which allow one to produce high-precision details and to provide corresponding surface roughness required to perform finishing operations (including the preparation of a surface for metal deposition) is presented. The production experience concerned with the use of high-speed combined machining with an unshaped tool electrode in knowledge-intensive branches of the machine-building industry for different types of production is analyzed. It is shown that the implementation of high-speed dimensional machining with an unshaped brush electrode allows one to expand the field of use of the considered process due to the application of a multipurpose tool in the form of a metal brush, as well as to obtain stable results of finishing and to provide the opportunities for long-term operation of the equipment without its changeover and readjustment.

  11. 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)

    2017-08-15

    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.)

  12. A large capacity, high-speed multiparameter multichannel analysis system

    International Nuclear Information System (INIS)

    Hendricks, R.W.; Suehiro, S.; Seeger, P.A.; Scheer, J.W.

    1982-01-01

    A data acquisition system for recording multiparameter digital data into a large memory array at over 2.5 MHz is described. The system consists of a MOSTEK MK 8600 2048 K x 24-bit memory system, I/O ports to various external devices including the CAMAC dataway, a memory incrementer/adder and a daisy-chain of experiment-specific modules which calculate the memory address which is to be incremented. The design of the daisy-chain permits multiple modules and provides for easy modification as experimental needs change. The system has been designed for use in multiparameter, multichannel analysis of high-speed data gathered by position-sensitive detectors at conventional and synchrotron X-ray sources as well as for fixed energy and time-of-flight diffraction at continuous and pulsed neutron sources. Modules which have been developed to date include a buffer for two-dimensional position-sensitive detectors, a mapper for high-speed coordinate transformations, a buffered time-of-flight clock, a time-correlator for synchronized diffraction experiments, and a display unit for data bus diagnostics. (orig.)

  13. High speed auto-charging system for condenser bank

    International Nuclear Information System (INIS)

    Mizuno, Yasunori; Bito, Fumio; Fujita, Kazuhiko; Sometani, Taro

    1987-01-01

    A current-control type high-speed charging system, which is intended for auto-charging of the condenser bank, is developed. Moreover, the system can also serve to compensate the current leakage from the condenser bank so that the charged voltage can be kept constant. The system consists of a sequence circuit, a charging current control circuit (or auto-charging circuit) and a charging circuit. The auto-charging circuit is characterized by the use of a triac to control the current. The current, controlled by the circuit, is supplied to the condenser bank through a step-up transformer and voltage doubler rectifier circuit. It is demonstrated that the use of the high-speed auto-charging circuit can largely decrease the required charging time, compared to constant voltage charging. In addition, the compensation function is shown to serve effectively for maintaining a constant voltage after the completion of charging. The required charging time is decreases as the charging current increases. The maximum charging current is decided by the rating of the traic and the current rating of the rectifier diode in the secondary circuit. Major components of these circuits have decreased impedances to minimize the effect of noise, so that the possibility of an accident can be eliminated. Other various improvements are made in the grounding circuit and the charging protection circuit in order to ensure safety. (Nogami, K.)

  14. Analysis of high-speed digital phonoscopy pediatric images

    Science.gov (United States)

    Unnikrishnan, Harikrishnan; Donohue, Kevin D.; Patel, Rita R.

    2012-02-01

    The quantitative characterization of vocal fold (VF) motion can greatly enhance the diagnosis and treatment of speech pathologies. The recent availability of high-speed systems has created new opportunities to understand VF dynamics. This paper presents quantitative methods for analyzing VF dynamics with high-speed digital phonoscopy, with a focus on expected VF changes during childhood. A robust method for automatic VF edge tracking during phonation is introduced and evaluated against 4 expert human observers. Results from 100 test frames show a subpixel difference between the VF edges selected by algorithm and expert observers. Waveforms created from the VF edge displacement are used to created motion features with limited sensitivity to variations of camera resolution on the imaging plane. New features are introduced based on acceleration ratios of critical points over each phonation cycle, which have the potential for studying issues related to impact stress. A novel denoising and hybrid interpolation/extrapolation scheme is also introduced to reduce the impact of quantization errors and large sampling intervals relative to the phonation cycle. Features extracted from groups of 4 adults and 5 children show large differences for features related to asymmetry between the right and left fold and consistent differences for impact acceleration ratio.

  15. High-speed VCSEL-based optical interconnects

    Science.gov (United States)

    Ishak, Waguih S.

    2001-11-01

    Vertical Cavity Surface Emitting Lasers (VCSEL) have made significant inroads into commercial realization especially in the area of data communications. Single VCSEL devices are key components in Gb Ethernet Transceivers. A multi-element VCSEL array is the key enabling technology for high-speed multi Gb/s parallel optical interconnect modules. In 1996, several companies introduced a new generation of fiber optic products based VCSEL technology such as multimode fiber transceivers for the ANSI Fiber Channel and Gigabit Ethernet IEEE 802.3 standards. VCSELs offer unique advantages over its edge-emitting counterparts in several areas. These include low-cost (LED-like) manufacturability, low current operation and array integrability. As data rates continue to increase, VCSELs offer the advantage of being able to provide the highest modulation bandwidth per milliamp of modulation current. Currently, most of the VCSEL-based products use short (780 - 980 nm) wavelength lasers. However, significant research efforts are taking place at universities and industrial research labs around the world to develop reliable, manufacturable and high-power long (1300 - 1550 nm) wavelength VCSELs. These lasers will allow longer (several km) transmission distances and will help alleviate some of the eye-safety issues. Perhaps, the most important advantage of VCSELs is the ability to form two-dimensional arrays much easier than in the case of edge-emitting lasers. These arrays (single and two-dimensional) will allow a whole new family of applications, specifically in very high-speed computer and switch interconnects.

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

    International Nuclear Information System (INIS)

    Mishchenko, Yuriy; Ji, Chueng-Ryong

    2017-01-01

    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 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.)

  17. A high speed digitizing photomultiplier tube base for the KTeV CsI calorimeter

    International Nuclear Information System (INIS)

    Whitmore, J.

    1994-11-01

    A circuit has been designed to digitize PMT signals over an 18-bit dynamic range with 8-bits of resolution. The crucial element of the circuit is the custom charge integrating and encoding (QIE) ASIC. This chip is designed to operate at rates up to 53 MHz, and, in conjunction with an 8-bit FADC, generates 12-bit floating point output. Bench tests of a 17-bit version of the digital base demonstrated excellent noise performance, linearity and pedestal and gain stability. Twenty-five channels of digitizing PMT bases have been built and used for readout of a CsI array in a test beam at CERN. Performance of these devices in a beam environment is discussed

  18. Using an ultra-high speed camera to capture a tube expansion test

    CSIR Research Space (South Africa)

    Snyman, Izak M

    2016-09-01

    Full Text Available .7 - - - 5.81 15.2 14.2 13.4 12.7 - - 6.78 16.1 15.4 14.6 13.4 12.7 - 7.75 16.8 16.0 15.2 14.5 13.5 12.7 8.72 17.6 16.8 16.1 15.2 14.4 13.5 9.69 19.1 18.0 17.0 16.3 15.6 14.4 10.66 19.2 18.0 17.2 16.2 15.2 14.2 11.63 19.3 18.6 17.6 16.8 15.8 15.0 12... the pixel count. Symposium 2016 of the South African Ballistic Organization Cape Town, South Africa 27-29 September 2016 12 6 REFERENCES M Conneely, HO Rolfsness, C Main, D McGloin, PA Campbell, (2011a), On the accuracy of framing...

  19. Spiral 2 Week

    International Nuclear Information System (INIS)

    2007-01-01

    The main goal of this meeting is to present and discuss the current status of the Spiral-2 project at GANIL in front of a large community of scientists and engineers. Different issues have been tackled particularly the equipment around Spiral-2 like injectors, cryo-modules or beam diagnostics, a workshop was devoted to other facilities dedicated to radioactive ion beam production. This document gathers only the slides of the presentations

  20. Spiral 2 Week

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The main goal of this meeting is to present and discuss the current status of the Spiral-2 project at GANIL in front of a large community of scientists and engineers. Different issues have been tackled particularly the equipment around Spiral-2 like injectors, cryo-modules or beam diagnostics, a workshop was devoted to other facilities dedicated to radioactive ion beam production. This document gathers only the slides of the presentations.

  1. Flow Analysis By High Speed Photography And Pictures

    Science.gov (United States)

    Werle, H.

    1985-02-01

    At the ONERA hydrodynamic visualization laboratory, high-speed photography and cinematography are used for analysing flow-phenomena around fixed or mobile models in the test section of three vertical water tunnels, operating by gravity draining. These studies in water are based on the hydraulic analogy of aerodynamic incompressible flows. Flow visualization is archieved by liquid tracers (dye emissions) or gaseous tracers (fine air bubbles in suspension in water). In many cases, the pictures at normal speed or long exposure time are insufficient, for they do not permit to distinguish all the details of the phenomena, due to an averaging or motion effect. Furthermore they must be completed with high speed pictures. This is illustrated by a few visua-lization examples recently obtained on following themes - two dimensional flow around a fixed cylinder, first at the start of the flow (symmetrical vortex), then in steady regime (periodic vortex street) ; - laminar-turbulent transition in a boundary layer along a cylindrical body at zero angle of attack ; - flow separation around a sphere and wake in steady regime at small and high Reynolds numbers; - flow separation around a profile, first with fixed incidence, then with harmonic oscillations in pitch ; - core structure of a longitudinal vortex issued from a wing first organized, then disintegrated under the effect of a lengthwise pressure gradient (vortex breakdown) ; - mixing zone around a turbulent axisymmetric jet, characterized by the formation of large vortex struc-tures ; - hovering tests of an helicopter rotor, first at the start of the rotation, then in established regime, finally in cruise flight ; - case of a complete helicopter model in cruise-flight, with air-intake simulation, gas exhaust and tail rotor ; - flow around a complete delta-wing aircraft model at mean or high angle of attack, first in steady regime, then with harmonic oscillations in yaw or pitch. These results illustrate the contribution of

  2. Observation of the dynamic movement of fragmentations by high-speed camera and high-speed video

    Science.gov (United States)

    Suk, Chul-Gi; Ogata, Yuji; Wada, Yuji; Katsuyama, Kunihisa

    1995-05-01

    The experiments of blastings using mortal concrete blocks and model concrete columns were carried out in order to obtain technical information on fragmentation caused by the blasting demolition. The dimensions of mortal concrete blocks were 1,000 X 1,000 X 1,000 mm. Six kinds of experimental blastings were carried out using mortal concrete blocks. In these experiments precision detonators and No. 6 electric detonators with 10 cm detonating fuse were used and discussed the control of fragmentation. As the results of experiment it was clear that the flying distance of fragmentation can be controlled using a precise blasting system. The reinforced concrete model columns for typical apartment houses in Japan were applied to the experiments. The dimension of concrete test column was 800 X 800 X 2400 mm and buried 400 mm in the ground. The specified design strength of the concrete was 210 kgf/cm2. These columns were exploded by the blasting with internal loading of dynamite. The fragmentation were observed by two kinds of high speed camera with 500 and 2000 FPS and a high speed video with 400 FPS. As one of the results in the experiments, the velocity of fragmentation, blasted 330 g of explosive with the minimum resisting length of 0.32 m, was measured as much as about 40 m/s.

  3. High-speed instrumentation complex for car crash testing

    Science.gov (United States)

    Baranov, S. V.; Gorin, I. M.; Drozhbin, Yu. A.; Kuznetsov, A. A.; Ponomaryov, A. M.; Semyonov, V. B.; Udalov, V. V.

    1993-01-01

    One of the most important car checking problems consists in safety testing which includes trials for different types of collision, e.g., frontal and lateral. This allows us to study deformations of the automobile and its parts during the impact. To obtain reliable data on overloading, acceleration, deformation, force load on the car's body as well as on the anthropomorphic dummies inside it, use is made of rather a great number of different techniques. Highly informative among them is high-speed cine recording which allows us to register variations that occur during a fraction of a second, and then to reproduce with variable rate the frame images obtained. This makes it possible to study the impact parameters variations much more accurately.

  4. Unwinding of a carbon nanoscroll due to high speed rotation

    Directory of Open Access Journals (Sweden)

    Hang Yin

    2015-10-01

    Full Text Available A carbon nanoscroll (CNS can be formed easily by rolling a graphene sheet around a carbon nanotube (CNT [Zhang and Li, 2010, APL, 97, 081909]. When the CNS is driven by the rotary CNT to rotate at a high speed, the attractive interaction within the CNS or between the CNS and CNT is crippled by the centrifugal force on the CNS. The unwinding of CNS is triggered when the kinetic energy increment approaches to the variation of interaction energy of the system during CNS formation. Numerical experiments also indicate that the unwinding of CNS happens earlier when the CNT has a higher rotational speed or the system is at a higher temperature.

  5. Towards high-speed autonomous navigation of unknown environments

    Science.gov (United States)

    Richter, Charles; Roy, Nicholas

    2015-05-01

    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. Material Properties of High-Speed Steel Rolls

    Directory of Open Access Journals (Sweden)

    Shaohua Wu

    2017-03-01

    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

  7. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

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

    2004-01-01

    consideration. In this work, delay and power metrics for both MCML and CMOS have been studied and a broader analysis of MCML is presented. Near minimum sized transistors are used and power consumption is measured for a wide variety of circuit blocks. The most important goal of this project is to evaluate......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...... the appropriate domains of performance and power requirements in which MCML presents benefits over standard CMOS. An optimized cell library is designed and implemented in both CMOS and MCML in order to make a comparison with reference to speed and power. Much more time is spent in order to nderstand...

  8. High speed automated microtomography of nuclear emulsions and recent application

    Energy Technology Data Exchange (ETDEWEB)

    Tioukov, V.; Aleksandrov, A.; Consiglio, L. [INFN Napoli (Italy); De Lellis, G. [Universita di Napoli (Italy); Vladymyrov, M. [LPI Moscow (Russian Federation)

    2015-12-31

    The development of high-speed automatic scanning systems was the key-factor for massive and successful emulsions application for big neutrino experiments like OPERA. The emulsion detector simplicity, the unprecedented sub-micron spatial resolution and the unique ability to provide intrinsically 3-dimensional spatial information make it a perfect device for short-living particles study, where the event topology should be precisely reconstructed in a 10-100 um scale vertex region. Recently the exceptional technological progress in image processing and automation together with intensive R&D done by Italian and Japanese microscopy groups permit to increase the scanning speed to unbelievable few years ago m{sup 2}/day scale and so greatly extend the range of the possible applications for emulsion-based detectors to other fields like: medical imaging, directional dark matter search, nuclear physics, geological and industrial applications.

  9. High Speed Water Sterilization Using One-Dimensional Nanostructures

    KAUST Repository

    Schoen, David T.

    2010-09-08

    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.

  10. High-speed real-time holographic interferometry

    Science.gov (United States)

    Yamamoto, Yoshitaka

    1999-06-01

    The principle of holography was invented by Dr. Gabor in 1948 before the invention of the laser. In 1962, after the invention of laser (in 1960: the first demonstration of laser oscillation by Maiman was achieved using a ruby cubic crystal), the off-axis reference beam holography was developed by Prof. Leith and Mr. Upatnieks. One of the most useful measuring techniques of the holography is a holographic interferometry. Holography enable to storage signal wave fronts and reconstruct it at later time, then the interference between the reconstructed signal wave fronts and the wave fronts come from the object to be able to generate an interference fringes. Real-time holographic interferometry can measure real-time phase-change of phenomena. Therefore, this method has the performance of continuously measuring phase change by coupling with high-speed cameras.

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

    DEFF Research Database (Denmark)

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

    with a photonic layer on top to interconnect them. For such systems, silicon is an attractive candidate enabling both electronic and photonic control. For some network scenarios, it may be beneficial to use optical on-chip packet switching, and for high data-density environments one may take advantage...... of the ultra-fast nonlinear response of silicon photonic waveguides. These chips offer ultra-broadband wavelength operation, ultra-high timing resolution and ultra-fast response, and when used appropriately offer energy-efficient switching. In this presentation we review some all-optical functionalities based...... 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...

  12. Analog parallel processor hardware for high speed pattern recognition

    Science.gov (United States)

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

    1990-01-01

    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.

  13. [Development of high speed UV-Vis spectrophotometer].

    Science.gov (United States)

    Huang, Mei-zhen; Ni, Yi; Lin, Feng; Yuan, Bo; Dou, Xiao-ming; Zhao, Hai-ying; Huang, Wei-shi

    2005-06-01

    A high speed spectrophotometer based on a linear CCD was developed. The function and structure of the hardware and the software for the instrument were discussed. The elementary performance was tested as follows: wavelength range 200-820 nm, full spectrum scan time < 0.1 s, spectral bandwidth 0.7 nm, wavelength accuracy +/-1 nm, photometric accuracy +/- 0.005 AU, baseline flatness < 0.001 AU (rms), and stray light < 0.1%. Results showed that this instrument is easy to use, fast and with high analytical performance. In addition, it has internet function of remote control and remote access. With the powerful data processing and spectrum analyzing software, it will provide a strong tool for routine analysis and the research on dynamic reaction in chemistry and biology fields.

  14. Thermometry of a high temperature high speed micro heater.

    Science.gov (United States)

    Xu, M; Slovin, G; Paramesh, J; Schlesinger, T E; Bain, J A

    2016-02-01

    A high temperature high-speed tungsten micro heater was fabricated and tested for application in phase change switches to indirectly heat and transform phase change material. Time domain transmissometry was used to measure heater temperature transients for given electrical inputs. Finite element modeling results on heater temperature transients show a good consistency between experiments and simulations with 0.2% mismatch in the best case and 13.1% in the worst case. The heater described in this work can reliably reach 1664 K at a rate of 1.67 × 10(10) K/s and quench to room temperature with a thermal RC time constant (time for T to fall by a factor of e) of less than 40 ns.

  15. Dynamic response of high speed centrifuge for reprocessing plant

    International Nuclear Information System (INIS)

    Rajput, Gaurav; Satish Kumar, V.; Selvaraj, T.; Ananda Rao, S.M.; Ravisankar, A.

    2012-01-01

    The standard for balancing the rotating bowl describes only the details about the selection of balance quality grade and the permissible residual unbalance for different operating speeds. This paper presents the effects of unbalance on the rotating bowl of high speed centrifuge used in reprocessing of spent nuclear fuel. In this study, the residual unbalance is evaluated for different recommended balancing grades in accordance with the ISO 1940. This unbalance mass generates dynamic force which acts on the rotor. The dynamic response of the rotor like displacements and stresses under this dynamic force are studied by numerical simulation. Finally, the effect of residual unbalance on the rotating bowl performance for different balancing grades is discussed. The experimental measurements are also carried out for the case of G 1.0 grade balanced rotating bowl to validate the resonance frequency as well as vibration amplitudes. (author)

  16. Ultra High-Speed CMOS Circuits Beyond 100 GHz

    CERN Document Server

    Gharavi, Sam

    2012-01-01

    The book covers the CMOS-based millimeter wave circuits and devices and presents methods and design techniques to use CMOS technology for circuits operating beyond 100 GHz.� Coverage includes a detailed description of both active and passive devices, including modeling techniques and performance optimization. Various mm-wave circuit blocks are discussed, emphasizing their design distinctions from low-frequency design methodologies. This book also covers a device-oriented circuit design technique that is essential for ultra high speed circuits and gives some examples of device/circuit co-design that can be used for mm-wave technology. Offers a detailed description of high frequency device modeling from a circuit designer perspective; Presents a set of techniques for optimizing the performance of CMOS for mm-wave technology, including noise and low noise design for mm-wave; Introduces circuit/device co-design techniques. �

  17. Machining Chatter Analysis for High Speed Milling Operations

    Science.gov (United States)

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

    2017-10-01

    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.

  18. High-speed nonvolatile CMOS/MNOS RAM

    International Nuclear Information System (INIS)

    Derbenwick, G.F.; Dodson, W.D.; Sokel, R.J.

    1979-01-01

    A bulk silicon technology for a high-speed static CMOS/MNOS RAM has been developed. Radiation-hardened, high voltage CMOS circuits have been fabricated for the memory array driving circuits and the enhancement-mode p-channel MNOS memory transistors have been fabricated using a native tunneling oxide with a 45 nm CVD Si 3 N 4 insulator deposited at 750 0 C. Read cycle times less than 350 ns and write cycle times of 1 μs are projected for the final 1Kx1 design. The CMOS circuits provide adequate speed for the write and read cycles and minimize the standby power dissipation. Retention times well in excess of 30 min are projected

  19. Large capacity, high-speed multiparameter multichannel analysis system

    International Nuclear Information System (INIS)

    Hendricks, R.W.; Seeger, P.A.; Scheer, J.W.; Suehiro, S.

    1980-01-01

    A data acquisition system for recording multiparameter digital data into a large memory array at over 2.5 MHz is described. The system consists of a MOSTEK MK8600 2048K x 24-bit memory system, I/O ports to various external devices including the CAMAC dataway, a memory incrementer/adder and a daisy-chain of experiment-specific modules which calculate the memory address which is to be incremented. The design of the daisy-chain permits multiple modules and provides for easy modification as experimental needs change. The system has been designed for use in multiparameter, multichannel analysis of high-speed data gathered by position-sensitive detectors at conventional and synchrotron x-ray sources as well as for fixed energy and time-of-flight diffraction at continuous and pulsed neutron sources

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

    Directory of Open Access Journals (Sweden)

    Kretschmer Viola

    2012-06-01

    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.

  1. Compact system for high-speed velocimetry using heterodyne techniques

    International Nuclear Information System (INIS)

    Strand, O. T.; Goosman, D. R.; Martinez, C.; Whitworth, T. L.; Kuhlow, W. W.

    2006-01-01

    We have built a high-speed velocimeter that has proven to be compact, simple to operate, and fairly inexpensive. This diagnostic is assembled using off-the-shelf components developed for the telecommunications industry. The main components are fiber lasers, high-bandwidth high-sample-rate digitizers, and fiber optic circulators. The laser is a 2 W cw fiber laser operating at 1550 nm. The digitizers have 8 GHz bandwidth and can digitize four channels simultaneously at 20 GS/s. The maximum velocity of this system is ∼5000 m/s and is limited by the bandwidth of the electrical components. For most applications, the recorded beat frequency is analyzed using Fourier transform methods, which determine the time response of the final velocity time history. Using the Fourier transform method of analysis allows multiple velocities to be observed simultaneously. We have obtained high-quality data on many experiments such as explosively driven surfaces and gas gun assemblies

  2. High speed cutting of AZ31 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Liwei Lu

    2016-06-01

    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.

  3. Dynamic Control of High-speed Train Following Operation

    Directory of Open Access Journals (Sweden)

    Deng Pan

    2014-08-01

    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.

  4. AGAINTS AND FOR THE HIGH SPEED TRAINS’ MULTIMPLICATION

    Directory of Open Access Journals (Sweden)

    Benea Ciprian

    2008-05-01

    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.

  5. Miniaturized High-Speed Modulated X-Ray Source

    Science.gov (United States)

    Gendreau, Keith C. (Inventor); Arzoumanian, Zaven (Inventor); Kenyon, Steven J. (Inventor); Spartana, Nick Salvatore (Inventor)

    2015-01-01

    A miniaturized high-speed modulated X-ray source (MXS) device and a method for rapidly and arbitrarily varying with time the output X-ray photon intensities and energies. The MXS device includes an ultraviolet emitter that emits ultraviolet light, a photocathode operably coupled to the ultraviolet light-emitting diode that emits electrons, an electron multiplier operably coupled to the photocathode that multiplies incident electrons, and an anode operably coupled to the electron multiplier that is configured to produce X-rays. The method for modulating MXS includes modulating an intensity of an ultraviolet emitter to emit ultraviolet light, generating electrons in response to the ultraviolet light, multiplying the electrons to become more electrons, and producing X-rays by an anode that includes a target material configured to produce X-rays in response to impact of the more electrons.

  6. Application of Nanophotonic Devices in High Speed Optical Communications

    DEFF Research Database (Denmark)

    Vukovic, Dragana

    -rate independent operation, enabling transparent networking. To confirm this, wavelength conversion of high speed WDM polarizationmultiplexed QPSK signals has been demonstrated using a polarization diversity circuit fully integrated on a silicon platform. Data signals in a transmission system are suffering from......All-optical signal processing has attracted a significant research interest in the past decade as it might become competitive with electronics in terms of compactness, energy consumption, and reliability. Furthermore it might solve the current bandwidth mismatch between optical transmission...... and electronic components in the physical layer and maintain high data rates, transparency and efficiency in optical networks. The remarkable advance, maturity, and cost reduction of optical components has therefore intensified research for the realization and exploitation of all-optical signal processing...

  7. High-speed single-pixel digital holography

    Science.gov (United States)

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

    2017-06-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Miñano-Espin Javier

    2017-08-01

    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.

  9. High-speed multispectral infrared imaging and data processing method

    Science.gov (United States)

    Rhee, Kyung T.

    1995-05-01

    The new imaging system developed in our laboratory facilitates the solutions of problems otherwise difficult to remedy. In this lecture, the progressive steps taken for building our new diagnostic tool are explained, followed by a description of the system and our data processing methods. Some of the results obtained by using the device are presented. The system design was directed to incorporation of off-the- shelf components with several newly fabricated units in order to overcome limitations in existing infrared (IR) imaging systems. In the new IR imaging system which recently became operational, four high-speed IR camera units are lined up to a single (reflective) optical unit having three spectral beam splitters. This permits simultaneous framing of four geometrically (pixel-to-pixel) identical images of the same object in respective spectral bands. The multispectral imaging by the camera is activated either by the internal clock (at a rate over 1,800 frames/sec) or an external signal such as pulses generated by an encoder. Unique features incorporated in the system include: independent variation of the framing rate and the exposure period in terms of time period (as short as 30 microsecond(s) ec) or the number of external pulses; control of the total number of images to be obtained per event from successive cyclic processes. The new device is applied to 'quantitative imaging' of rapidly reacting events/objects, e.g. determination of temporal and spatial variations of the thermochemical characteristics. Thermal objects, which typically involve a reactor wall and a gaseous mixture in front, are studied by obtaining the high-speed digital readout from the corresponding pixels of: two wall images in separate wavebands and two mixture images in other bands, i.e., total of four matrices of digital output at a time. The results are processed by the conventional two-color method and a new dual-band spectrometric algorithm.

  10. High-Speed Edge-Detecting Line Scan Smart Camera

    Science.gov (United States)

    Prokop, Norman F.

    2012-01-01

    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..

  11. Numerical study on wake characteristics of high-speed trains

    Science.gov (United States)

    Yao, Shuan-Bao; Sun, Zhen-Xu; Guo, Di-Long; Chen, Da-Wei; Yang, Guo-Wei

    2013-12-01

    Intensive turbulence exists in the wakes of high speed trains, and the aerodynamic performance of the trailing car could deteriorate rapidly due to complicated features of the vortices in the wake zone. As a result, the safety and amenity of high speed trains would face a great challenge. This paper considers mainly the mechanism of vortex formation and evolution in the train flow field. A real CRH2 model is studied, with a leading car, a middle car and a trailing car included. Different running speeds and cross wind conditions are considered, and the approaches of unsteady Reynold-averaged Navier-Stokes (URANS) and detached eddy simulation (DES) are utilized, respectively. Results reveal that DES has better capability of capturing small eddies compared to URANS. However, for large eddies, the effects of two approaches are almost the same. In conditions without cross winds, two large vortex streets stretch from the train nose and interact strongly with each other in the wake zone. With the reinforcement of the ground, a complicated wake vortex system generates and becomes strengthened as the running speed increases. However, the locations of flow separations on the train surface and the separation mechanism keep unchanged. In conditions with cross winds, three large vortices develop along the leeward side of the train, among which the weakest one has no obvious influence on the wake flow while the other two stretch to the tail of the train and combine with the helical vortices in the train wake. Thus, optimization of the aerodynamic performance of the trailing car should be aiming at reducing the intensity of the wake vortex system.

  12. The development of high-speed 100 fps CCD camera

    International Nuclear Information System (INIS)

    Hoffberg, M.; Laird, R.; Lenkzsus, F.; Liu, C.; Rodricks, B.

    1997-01-01

    This paper describes the development of a high-speed CCD digital camera system. The system has been designed to use CCDs from various manufacturers with minimal modifications. The first camera built on this design utilizes a Thomson 512 x 512 pixel CCD as its sensor, which is read out from two parallel outputs at a speed of 15 MHz/pixel/output. The data undergo correlated double sampling after which it is digitized into 12 bits. The throughput of the system translates into 60 MB/second, which is either stored directly in a PC or transferred to a custom-designed VXI module. The PC data acquisition version of the camera can collect sustained data in real time that is limited to the memory installed in the PC. The VXI version of the camera, also controlled by a PC, stores 512 MB of real-time data before it must be read out to the PC disk storage. The uncooled CCD can be used either with lenses for visible light imaging or with a phosphor screen for X-ray imaging. This camera has been tested with a phosphor screen coupled to a fiber-optic face plate for high-resolution, high-speed X-ray imaging. The camera is controlled through a custom event-driven user-friendly Windows package. The pixel clock speed can be changed from 1 to 15 MHz. The noise was measured to be 1.05 bits at a 13.3 MHz pixel clock. This paper will describe the electronics, software, and characterizations that have been performed using both visible and X-ray photons. (orig.)

  13. High-speed detection of DNA translocation in nanopipettes

    Science.gov (United States)

    Fraccari, Raquel L.; Ciccarella, Pietro; Bahrami, Azadeh; Carminati, Marco; Ferrari, Giorgio; Albrecht, Tim

    2016-03-01

    We present a high-speed electrical detection scheme based on a custom-designed CMOS amplifier which allows the analysis of DNA translocation in glass nanopipettes on a microsecond timescale. Translocation of different DNA lengths in KCl electrolyte provides a scaling factor of the DNA translocation time equal to p = 1.22, which is different from values observed previously with nanopipettes in LiCl electrolyte or with nanopores. Based on a theoretical model involving electrophoresis, hydrodynamics and surface friction, we show that the experimentally observed range of p-values may be the result of, or at least be affected by DNA adsorption and friction between the DNA and the substrate surface.We present a high-speed electrical detection scheme based on a custom-designed CMOS amplifier which allows the analysis of DNA translocation in glass nanopipettes on a microsecond timescale. Translocation of different DNA lengths in KCl electrolyte provides a scaling factor of the DNA translocation time equal to p = 1.22, which is different from values observed previously with nanopipettes in LiCl electrolyte or with nanopores. Based on a theoretical model involving electrophoresis, hydrodynamics and surface friction, we show that the experimentally observed range of p-values may be the result of, or at least be affected by DNA adsorption and friction between the DNA and the substrate surface. Electronic supplementary information (ESI) available: Gel electrophoresis confirming lengths and purity of DNA samples, comparison between Axopatch 200B and custom-built setup, comprehensive low-noise amplifier characterization, representative I-V curves of nanopipettes used, typical scatter plots of τ vs. peak amplitude for the four LDNA's used, table of most probable τ values, a comparison between different fitting models for the DNA translocation time distribution, further details on the stochastic numerical simulation of the scaling statistics and the derivation of the extended

  14. A high-speed photographic system for flow visualization in a steam turbine

    Science.gov (United States)

    Barna, G. J.

    1973-01-01

    A photographic system was designed to visualize the moisture flow in a steam turbine. Good performance of the system was verified using dry turbine mockups in which an aerosol spray simulated, in a rough way, the moisture flow in the turbine. Borescopes and fiber-optic light tubes were selected as the general instrumentation approach. High speed motion-picture photographs of the liquid flow over the stator blade surfaces were taken using stroboscopic lighting. Good visualization of the liquid flow was obtained. Still photographs of drops in flight were made using short duration flash sources. Drops with diameters as small as 30 micrometers (0.0012 in.) could be resolved. In addition, motion pictures of a spray of water simulating the spray off the rotor blades and shrouds were taken at normal framing rates. Specially constructed light tubes containing small tungsten-halogen lamps were used. Sixteen millimeter photography was used in all cases. Two potential problems resulting from the two-phase turbine flow (attenuation and scattering of light by the fog present and liquid accumulation on the borescope mirrors) were taken into account in the photographic system design but not evaluated experimentally.

  15. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Science.gov (United States)

    2010-07-01

    ...) All cars for high-speed rail systems, including but not limited to those using “maglev” or high speed...., not used by freight trains) or guideway, in which stations are constructed in accordance with subpart...

  16. 49 CFR 236.1007 - Additional requirements for high-speed service.

    Science.gov (United States)

    2010-10-01

    ... 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... by this subpart, and which have been utilized on high-speed rail systems with similar technical and...

  17. Plasma Generator Using Spiral Conductors

    Science.gov (United States)

    Szatkowski, George N. (Inventor); Dudley, Kenneth L. (Inventor); Ticatch, Larry A. (Inventor); Smith, Laura J. (Inventor); Koppen, Sandra V. (Inventor); Nguyen, Truong X. (Inventor); Ely, Jay J. (Inventor)

    2016-01-01

    A plasma generator includes a pair of identical spiraled electrical conductors separated by dielectric material. Both spiraled conductors have inductance and capacitance wherein, in the presence of a time-varying electromagnetic field, the spiraled conductors resonate to generate a harmonic electromagnetic field response. The spiraled conductors lie in parallel planes and partially overlap one another in a direction perpendicular to the parallel planes. The geometric centers of the spiraled conductors define endpoints of a line that is non-perpendicular with respect to the parallel planes. A voltage source coupled across the spiraled conductors applies a voltage sufficient to generate a plasma in at least a portion of the dielectric material.

  18. An evaluation on the antimicrobical properties of two disinfectants on dental high-speed instruments

    Directory of Open Access Journals (Sweden)

    Nejatidanesh F

    2003-08-01

    Full Text Available Statement of Problem: Rotary dental instruments (i-e. iow speed and high speed handpieces, due to"ninfection spread high potentiality, should be sterilized between dental visits for each patient. When a high"nspeed rotary instrument pauses at a high velocity, contaminated fluids like blood and saliva will be"nsucked into its tubes."nPurpose: The aim of this study was to compare the bactericidal effects ofDeconex 53 plus solution and"nthe solarsept spray on dental high- speed instruments."nMaterials and Methods: In this experimental study, one hundred and twenty (120 dental high- speed"nturbines, sterilized by autoclave, were divided into 6 groups. The turbines were contaminated with"nbacterial suspension. Streptococcus mutans, Staphilococcus aureus and Neisseria SP were the first"nmicrobial groups. Pseudomonas aruginosa was the second microbial group and Bacillus subtilis spore"nwas the third microbial group. After 5 minutes, three contaminated groups were placed in Deconex53"nplus 2% solution for 15 minutes. Three other groups after contamination were sprayed with Deconex"nsoiar sept spray for 2 minutes. Then the samples were placed in TSB culture and after 24 hours"nincubation at 37°, the samples were transmitted on blood agar solid culture for bacterial viability"nobservation. The results were observed after 24 hours incubation. Proportional test with normal"ndistribution was used for data analysis."nResults: The Deconex 53 plus had 85% disinfectant activity on the first microbial group, 10% on the"nsecond microbial group and 100% on the third microbial group. Also the solarsept spray had 30%"ndisinfectant activity on the first microbial group and 15% on the third micribial group . The solarsept"nspray had no bactericidal effect on turbines contaminated by the second microbial group. The results"nproved that the disinfectant effects of Deconex 53 plus solution for 15 minutes were significantly better"nthan the solarsept spray for 10 minutes

  19. Aeromechanics of a High Speed Coaxial Helicopter Rotor

    Science.gov (United States)

    Schmaus, Joseph Henry

    The current work seeks to understand the aeromechanics of lift offset coaxial rotors in high speeds. Future rotorcraft will need to travel significantly faster that modern rotorcraft do while maintaining hovering efficiency and low speed maneuverability. The lift offset coaxial rotor has been shown to have those capabilities. A majority of existing coaxial research is focused on hovering performance, and few studies examine the forward flight performance of a coaxial rotor with lift offset. There are even fewer studies of a single rotor with lift offset. The current study used comprehensive analysis and a new set of wind tunnel experiments to explore the aeromechanics of a lift offset coaxial rotor in high speed forward flight. The simulation was expanded from UMARC to simultaneously solve multiple rotors with coupled aerodynamics. It also had several modifications to improve the aerodynamics of the near-wake model in reverse flow and improve the modeling of blade passages. Existing coaxial hovering tests and flight test data from the XH-59A were used to validate the steady performance and blade loads of the comprehensive analysis. It was used to design the structural layout of the blades used in the wind tunnel experiment as well as the test envelope and testing procedure. The wind tunnel test of a model rotor developed by the University of Texas at Austin and the University of Maryland was performed in the Glenn L Martin Wind Tunnel. The test envelope included advance ratios 0.21-0.53, collectives 4°- 8°, and lift offsets 0%-20% for both rotors tested in isolation and as a coaxial system operating at 900 RPM. Rotating frame hub loads, pushrod loads, and pitch angle were recorded independently for each rotor. Additional studies were performed at 1200 RPM to isolate Reynold effects and with varying rotor-to-rotor phase to help quantify aerodynamic interactions. Lift offset fundamentally changes the lift distribution around the rotor disk, doing so increases the

  20. Development and Performance of the ACTS High Speed VSAT

    Science.gov (United States)

    Quintana, J.; Tran, Q.; Dendy, R.

    1999-01-01

    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

  1. 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

    2016-04-01

    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.

  2. The spinning ball spiral

    Science.gov (United States)

    Dupeux, Guillaume; Le Goff, Anne; Quéré, David; Clanet, Christophe

    2010-09-01

    We discuss the trajectory of a fast revolving solid ball moving in a fluid of comparable density. As the ball slows down owing to drag, its trajectory follows an exponential spiral as long as the rotation speed remains constant: at the characteristic distance L where the ball speed is significantly affected by the drag, the bending of the trajectory increases, surprisingly. Later, the rotation speed decreases, which makes the ball follow a second kind of spiral, also described in the paper. Finally, the use of these highly curved trajectories is shown to be relevant to sports.

  3. Quarkyonic Chiral Spirals

    International Nuclear Information System (INIS)

    Toru, Kojo; Hidaka, Y.; Pisarski, R.; McLerran, L.

    2010-01-01

    We argue the properties of confining dense quark matter, 'quarkyonic' matter, from the viewpoint of both bulk properties and excitation modes. After a brief review of confining aspects, the chiral breaking/restoration will be discussed. We argue that the strong infrared correlations induce the chiral spiral, i.e., the spatial modulation of the chiral condensate which breaks the chiral symmetry locally but restore it globally. The effective dimensional reduction takes place, allowing us to analyzing the system as 2D model in which several exact results can be explicitly derived. We also discuss the excitation spectra, both mesonic and baryonic ones, on the chiral spiral. (author)

  4. NbN nanowire optical detectors for high speed applications

    International Nuclear Information System (INIS)

    Quaranta, O; Pagano, S; Ejrnaes, M; Nappi, C; Pessina, E; Fontana, F

    2008-01-01

    We have developed a novel geometry for single photon optical detectors (SSPD) based on NbN nanowires. Traditionally the SSPD are realized in a meander structure in order to realize a reasonable (few square microns) collecting area. This has the disadvantage of generating a large detector inductance, mostly of kinetic origin, that strongly limits the detector operation in high speed applications, such as telecommunication. Moreover the extreme aspect ratio of the detector (a nanowire a fraction of mm long and 100 nm wide) puts strong requirements on the nanofabrication processes, with negative effects on the production yield. Our novel proposed geometry is based on a parallel stripes configuration designed in such a way that the light induced switching of a single stripe generates the switching of all the other through a cascade mechanism. The net result is an SSPD device that has a much lower intrinsic inductance, and consequently a much wider bandwidth (up to 10 GHz range). Moreover the signal amplitude generated is much larger than that of traditional SSPD, due to the contribution of all the parallel stripe. We present here the design and results of numerical simulation of the response of this novel type of SSPD. In particular we discuss of the design solutions that allow the cascade operation of the detector, by realizing a very fast and synchronous switching of all the parallel lines. Key issues, such as the optimal number of parallel lines, with respect to fabrication and operation constraints of the detectors are also discussed

  5. High-Speed Visualisation of Combustion in Modern Gasoline Engines

    Science.gov (United States)

    Sauter, W.; Nauwerck, A.; Han, K.-M.; Pfeil, J.; Velji, A.; Spicher, U.

    2006-07-01

    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.

  6. An Early Evaluation of Italian High Speed Rail Projects

    Directory of Open Access Journals (Sweden)

    Paolo Beria

    2011-10-01

    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.

  7. Lagrangian transported MDF methods for compressible high speed flows

    Science.gov (United States)

    Gerlinger, Peter

    2017-06-01

    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).

  8. 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: jason.ting@alcoa.com; 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)

    2005-01-15

    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.

  9. High-speed cinematography of gas-metal atomization

    International Nuclear Information System (INIS)

    Ting, Jason; Connor, Jeffery; Ridder, Stephen

    2005-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Bo Ai

    2012-01-01

    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.

  11. Data security in high-speed optical links

    Science.gov (United States)

    Kartalopoulos, Stamatios V.

    2005-05-01

    Wavelength Division Multiplexing (WDM) is a photonic technology capable to transport over a single fiber more than a Tbit/s aggregate traffic. Currently, WDM is the only deployed method in transcontinental and transoceanic applications. In the optical network, each fiber link consists of segments, each several kilometers long, the connecting points of which are amenable to tapping. When a small amount of optical signal is extracted from a tap, when the signal is properly amplified it can be monitored by unauthorized personnel thus threatening communications and land-security. Since each WDM channel carries traffic from one customer, it is not difficult for the connoisseur to demultiplex a specific channel, isolate a specific payload and break the encrypted datagram. Therefore, in addition to data encryption, high-speed communications security should also rely on securing the optical links. In this paper, we present a WDM link security method that, even if fiber is tapped, constitutes channel monitoring and information decrypting by an eavesdropper or unauthorized personnel virtually impossible. In addition, we describe the circuit building blocks behind the method that makes eavesdropping impossible.

  12. High speed friction microscopy and nanoscale friction coefficient mapping

    International Nuclear Information System (INIS)

    Bosse, James L; Lee, Sungjun; Huey, Bryan D; Andersen, Andreas Sø; Sutherland, Duncan S

    2014-01-01

    As mechanical devices in the nano/micro length scale are increasingly employed, it is crucial to understand nanoscale friction and wear especially at technically relevant sliding velocities. Accordingly, a novel technique has been developed for friction coefficient mapping (FCM), leveraging recent advances in high speed AFM. The technique efficiently acquires friction versus force curves based on a sequence of images at a single location, each with incrementally lower loads. As a result, true maps of the coefficient of friction can be uniquely calculated for heterogeneous surfaces. These parameters are determined at a scan velocity as fast as 2 mm s −1 for microfabricated SiO 2 mesas and Au coated pits, yielding results that are identical to traditional speed measurements despite being ∼1000 times faster. To demonstrate the upper limit of sliding velocity for the custom setup, the friction properties of mica are reported from 200 µm s −1 up to 2 cm s −1 . While FCM is applicable to any AFM and scanning speed, quantitative nanotribology investigations of heterogeneous sliding or rolling components are therefore uniquely possible, even at realistic velocities for devices such as MEMS, biological implants, or data storage systems. (paper)

  13. Highball: A high speed, reserved-access, wide area network

    Science.gov (United States)

    Mills, David L.; Boncelet, Charles G.; Elias, John G.; Schragger, Paul A.; Jackson, Alden W.

    1990-01-01

    A network architecture called Highball and a preliminary design for a prototype, wide-area data network designed to operate at speeds of 1 Gbps and beyond are described. It is intended for applications requiring high speed burst transmissions where some latency between requesting a transmission and granting the request can be anticipated and tolerated. Examples include real-time video and disk-disk transfers, national filestore access, remote sensing, and similar applications. The network nodes include an intelligent crossbar switch, but have no buffering capabilities; thus, data must be queued at the end nodes. There are no restrictions on the network topology, link speeds, or end-end protocols. The end system, nodes, and links can operate at any speed up to the limits imposed by the physical facilities. An overview of an initial design approach is presented and is intended as a benchmark upon which a detailed design can be developed. It describes the network architecture and proposed access protocols, as well as functional descriptions of the hardware and software components that could be used in a prototype implementation. It concludes with a discussion of additional issues to be resolved in continuing stages of this project.

  14. Ultra High-Speed Radio Frequency Switch Based on Photonics.

    Science.gov (United States)

    Ge, Jia; Fok, Mable P

    2015-11-26

    Microwave switches, or Radio Frequency (RF) switches have been intensively used in microwave systems for signal routing. Compared with the fast development of microwave and wireless systems, RF switches have been underdeveloped particularly in terms of switching speed and operating bandwidth. In this paper, we propose a photonics based RF switch that is capable of switching at tens of picoseconds speed, which is hundreds of times faster than any existing RF switch technologies. The high-speed switching property is achieved with the use of a rapidly tunable microwave photonic filter with tens of gigahertz frequency tuning speed, where the tuning mechanism is based on the ultra-fast electro-optics Pockels effect. The RF switch has a wide operation bandwidth of 12 GHz and can go up to 40 GHz, depending on the bandwidth of the modulator used in the scheme. The proposed RF switch can either work as an ON/OFF switch or a two-channel switch, tens of picoseconds switching speed is experimentally observed for both type of switches.

  15. Measurements of granular flow dynamics with high speed digital images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jingeol [Univ. of Florida, Gainesville, FL (United States)

    1994-01-01

    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.

  16. A DSP Based POD Implementation for High Speed Multimedia Communications

    Directory of Open Access Journals (Sweden)

    Chang Nian Zhang

    2002-09-01

    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.

  17. High-Speed Operation of Interband Cascade Lasers

    Science.gov (United States)

    Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Wright, Malcom W.; Farr, William H.; Yang, Rui Q.; Liu, H. C.

    2010-01-01

    Optical sources operating in the atmospheric window of 3-5 microns are of particular interest for the development of free-space optical communication link. It is more advantageous to operate the free-space optical communication link in 3-5-microns atmospheric transmission window than at the telecom wavelength of 1.5 m due to lower optical scattering, scintillation, and background radiation. However, the realization of optical communications at the longer wavelength has encountered significant difficulties due to lack of adequate optical sources and detectors operating in the desirable wavelength regions. Interband Cascade (IC) lasers are novel semiconductor lasers that have a great potential for the realization of high-power, room-temperature optical sources in the 3-5-microns wavelength region, yet no experimental work, until this one, was done on high-speed direct modulation of IC lasers. Here, highspeed interband cascade laser, operating at wavelength 3.0 m, has been developed and the first direct measurement of the laser modulation bandwidth has been performed using a unique, highspeed quantum well infrared photodetector (QWIP). The developed laser has modulation bandwidth exceeding 3 GHz. This constitutes a significant increase of the IC laser modulation bandwidth over currently existing devices. This result has demonstrated suitability of IC lasers as a mid-IR light source for multi-GHz free-space optical communications links

  18. FASTBUS Readout Controller card for high speed data acquisition

    International Nuclear Information System (INIS)

    Zimmermann, S.

    1991-10-01

    This article describes a FASTBUS Readout Controller (FRC) for high speed data acquisition in FASTBUS based systems. The controller has two main interfaces: to FASTBUS and to a Readout Port. The FASTBUS interface performs FASTBUS master and slave operations at a maximum transfer rate exceeding 40 MBytes/s. The Readout Port can be adapted for a variety of protocols. Currently, it will be interfaced to a VME bus based processor with a VSB port. The on-board LR33000 embedded processor controls the readout, executing a list of operations download into its memory. It scans the FASTBUS modules and stores the data in a triple port DRAM (TPDRAM), through one of the Serial Access Memory (SAM) ports of the (TPDRAM). Later, it transfers this data to the readout port using the other SAM. The FRC also supports serial communication via RS232 and Ethernet interfaces. This device is intended for use in the data acquisition system at the Collider Detector at Fermilab. 5 refs., 3 figs

  19. High Speed Imaging of Edge Turbulence in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S.J. Zweben; R. Maqueda; D.P. Stotler; A. Keesee; J. Boedo; C. Bush; S. Kaye; B. LeBlanc; J. Lowrance; V. Mastrocola; R. Maingi; N. Nishino; G. Renda; D. Swain; J. Wilgen; the NSTX Team

    2003-03-01

    The two-dimensional radial versus poloidal structure and motion of edge turbulence in NSTX (National Spherical Torus Experiment) were measured by using high-speed imaging of the visible light emission from a localized neutral gas puff. Edge turbulence images are shown and analyzed for Ohmic, L-mode (low-confinement mode) and H-mode (high-confinement mode) plasma conditions. Typical edge turbulence poloidal correlation lengths as measured using this technique are = 4 {+-} 1 cm and autocorrelation times are 40 {+-} 20 {micro}sec in all three regimes. The relative fluctuation level is typically smaller in H-mode than in L-mode, and transitions from H- to L-mode and can occur remarkably quickly (=30 {micro}sec). The two-dimensional images often show localized regions of strong light emission which move both poloidally and radially through the observed region at a typical speed of =10{sup 5} cm/sec, and sometimes show spatially coherent modes.

  20. Systematics of atom-atom collision strengths at high speeds

    International Nuclear Information System (INIS)

    Gillespie, G.H.; Inokuti, M.

    1980-01-01

    The collision strengths for atom-atom collisions at high speeds are calculated in the first Born approximation. We studied four classes of collisions, distinguished depending upon whether each of the collision partners becomes excited or not. The results of numerical calculations of the collision strengths are presented for all neutral atoms with Z< or =18. The calculations are based on atomic form factors and incoherent scattering functions found in the literature. The relative contribution of each class of collision processes to the total collision cross section is examined in detail. In general, inelastic processes dominate for low-Z atoms, while elastic scattering is more important for large Z. Other systematics of the collision strengths are comprehensively discussed. The relevant experimental literature has been surveyed and the results of this work for the three collision systems H-He, He-He, and H-Ar are compared with the data for electron-loss processes. Finally, suggestions are made for future work in measurements of atom-atom and ion-atom collision cross sections

  1. High speed digital interfacing for a neural data acquisition system

    Directory of Open Access Journals (Sweden)

    Bahr Andreas

    2016-09-01

    Full Text Available Diseases like schizophrenia and genetic epilepsy are supposed to be caused by disorders in the early development of the brain. For the further investigation of these relationships a custom designed application specific integrated circuit (ASIC was developed that is optimized for the recording from neonatal mice [Bahr A, Abu-Saleh L, Schroeder D, Krautschneider W. 16 Channel Neural Recording Integrated Circuit with SPI Interface and Error Correction Coding. Proc. 9th BIOSTEC 2016. Biodevices: Rome, Italy, 2016; 1: 263; Bahr A, Abu-Saleh L, Schroeder D, Krautschneider W. Development of a neural recording mixed signal integrated circuit for biomedical signal acquisition. Biomed Eng Biomed Tech Abstracts 2015; 60(S1: 298–299; Bahr A, Abu-Saleh L, Schroeder D, Krautschneider WH. 16 Channel Neural Recording Mixed Signal ASIC. CDNLive EMEA 2015 Conference Proceedings, 2015.]. To enable the live display of the neural signals a multichannel neural data acquisition system with live display functionality is presented. It implements a high speed data transmission from the ASIC to a computer with a live display functionality. The system has been successfully implemented and was used in a neural recording of a head-fixed mouse.

  2. Development of a Large Scale, High Speed Wheel Test Facility

    Science.gov (United States)

    Kondoleon, Anthony; Seltzer, Donald; Thornton, Richard; Thompson, Marc

    1996-01-01

    Draper Laboratory, with its internal research and development budget, has for the past two years been funding a joint effort with the Massachusetts Institute of Technology (MIT) for the development of a large scale, high speed wheel test facility. This facility was developed to perform experiments and carry out evaluations on levitation and propulsion designs for MagLev systems currently under consideration. The facility was developed to rotate a large (2 meter) wheel which could operate with peripheral speeds of greater than 100 meters/second. The rim of the wheel was constructed of a non-magnetic, non-conductive composite material to avoid the generation of errors from spurious forces. A sensor package containing a multi-axis force and torque sensor mounted to the base of the station, provides a signal of the lift and drag forces on the package being tested. Position tables mounted on the station allow for the introduction of errors in real time. A computer controlled data acquisition system was developed around a Macintosh IIfx to record the test data and control the speed of the wheel. This paper describes the development of this test facility. A detailed description of the major components is presented. Recently completed tests carried out on a novel Electrodynamic (EDS) suspension system, developed by MIT as part of this joint effort are described and presented. Adaptation of this facility for linear motor and other propulsion and levitation testing is described.

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

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    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.

  4. Scalable Multiprocessor for High-Speed Computing in Space

    Science.gov (United States)

    Lux, James; Lang, Minh; Nishimoto, Kouji; Clark, Douglas; Stosic, Dorothy; Bachmann, Alex; Wilkinson, William; Steffke, Richard

    2004-01-01

    A report discusses the continuing development of a scalable multiprocessor computing system for hard real-time applications aboard a spacecraft. "Hard realtime applications" signifies applications, like real-time radar signal processing, in which the data to be processed are generated at "hundreds" of pulses per second, each pulse "requiring" millions of arithmetic operations. In these applications, the digital processors must be tightly integrated with analog instrumentation (e.g., radar equipment), and data input/output must be synchronized with analog instrumentation, controlled to within fractions of a microsecond. The scalable multiprocessor is a cluster of identical commercial-off-the-shelf generic DSP (digital-signal-processing) computers plus generic interface circuits, including analog-to-digital converters, all controlled by software. The processors are computers interconnected by high-speed serial links. Performance can be increased by adding hardware modules and correspondingly modifying the software. Work is distributed among the processors in a parallel or pipeline fashion by means of a flexible master/slave control and timing scheme. Each processor operates under its own local clock; synchronization is achieved by broadcasting master time signals to all the processors, which compute offsets between the master clock and their local clocks.

  5. Stability control for high speed tracked unmanned vehicles

    Science.gov (United States)

    Pape, Olivier; Morillon, Joel G.; Houbloup, Philippe; Leveque, Stephane; Fialaire, Cecile; Gauthier, Thierry; Ropars, Patrice

    2005-05-01

    The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales as the prime contractor, focuses on about 15 robotic themes which can provide an immediate "operational add-on value". The paper details the "automatic speed adjustment" behavior (named SYR4), developed by Giat Industries Company, which main goal is to secure the teleoperated mobility of high speed tracked vehicles on rough grounds; more precisely, the validated low level behavior continuously adjusts the vehicle speed taking into account the teleperator wish AND the maximum speed that the vehicle can manage safely according to the commanded radius of curvature. The algorithm is based on a realistic physical model of the ground-tracks relation, taking into account many vehicle and ground parameters (such as ground adherence and dynamic specificities of tracked vehicles). It also deals with the teleoperator-machine interface, providing a balanced strategy between both extreme behaviors: a) maximum speed reduction before initiating the commanded curve; b) executing the minimum possible radius without decreasing the commanded speed. The paper presents the results got from the military acceptance tests performed on tracked SYRANO vehicle (French Operational Demonstrator).

  6. High-speed counter-current chromatographic separation of phytosterols.

    Science.gov (United States)

    Schröder, Markus; Vetter, Walter

    2011-07-01

    Phytosterols are bioactive compounds which occur in low concentrations in plant oils. Due to their beneficial effects on human health, phytosterols have already been supplemented to food. Commercial phytosterol standards show insufficient purity and/or are very expensive. In this study, we developed a high-speed counter-current chromatography (HSCCC) method for the fractionation and analysis of a commercial crude β-sitosterol standard (purity ∼60% according to supplier). Different solvent systems were tested in shake-flask experiments, and the system n-hexane/methanol/aqueous silver nitrate solution (34/24/1, v/v/v) was finally used for HSCCC fractionation. About 50 mg phytosterols was injected and distributed into 57 fractions. Selected fractions were condensed and re-injected into the HSCCC system. This measure provided pure sitostanol (>99%) and β-sitosterol (∼99%), as well as a mixture of campesterol and stigmasterol without further phytosterols. An enriched HSCCC fraction facilitated the mass spectrometric analysis of further 11 minor phytosterols (after trimethylsilylation). It was also shown that the commercial product contained about 0.3% carotinoids which eluted without delay into an early HSCCC fraction and which were separated from the phytosterols.

  7. Results from a high speed pyrometer measuring detonating explosive

    Science.gov (United States)

    Richley, James; Ferguson, James

    2017-06-01

    High speed pyrometry has been deployed on two series of cylinder test experiments in order to investigate its ability to measure the temperature of a detonating explosive. The pyrometer fielded on the first series of cylinder tests consisted of two, three channel systems fed by optical fibres. The optical fibres were placed such that they observed the exposed explosive at the end of the cylinder (through a lithium fluoride window). In addition an optical emission spectrometer was used to capture the emission spectrum from the same area of the explosive. The pyrometer design was then modified to produce a six-channel system, which incorporated detectors with rise times on the order of 1 ns, this was tested on a second series of cylinder tests. Half of the cylinder tests in the second series were performed without a LiF window. Results from the second series of experiments are reported and compared with those from the first series. Initial analysis suggests that the temperature observed was at least 3700 K.

  8. Submonolayer Quantum Dots for High Speed Surface Emitting Lasers

    Directory of Open Access Journals (Sweden)

    Zakharov ND

    2007-01-01

    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.

  9. New Drive Train Concept with Multiple High Speed Generator

    Science.gov (United States)

    Barenhorst, F.; Serowy, S.; Andrei, C.; Schelenz, R.; Jacobs, G.; Hameyer, K.

    2016-09-01

    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.

  10. Hardware demonstration of high-speed networks for satellite applications.

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, Jonathon W.; Lee, David S.

    2008-09-01

    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. Dynamics of face seals for high speed turbomachinery

    Science.gov (United States)

    Leefe, Simon

    1993-10-01

    Face seals in rocket engine fuel and oxidizer turbopumps have been the subject of intense investigation for over 25 years. While advances have been made in the understanding of thin film lubrication between seal faces, valuable data has been produced on the friction and wear of material pairs in cryogenic environments; pioneering work has been done on the effect of lubricant phase change in seals, and many improvements have been made in mechanical seal design. Relatively superficial attention has been given to the vibrational dynamics of face seals in high-speed turbomachinery. BHR Group Ltd. (formerly BHRA) has recently completed the first stage of a study, commissioned by the European Space Agency, to investigate this area. This has involved the development of a two-dimensional adiabatic, turbulent lubrication model for thick gas film applications, the production of an integrated mathematical model of gas seal vibrational dynamics for thin film applications, implementation in software, the undertaking of an experimental program to validate software against variations in operating conditions and design variables, and suggestions for improved seal design.

  12. A Reliability Assessment Method for High Speed Train Electromagnetic Relays

    Directory of Open Access Journals (Sweden)

    Jianqiang Liu

    2018-03-01

    Full Text Available The condition of electromagnetic relays is crucial to the safe and normal operation of the high-speed train (HST. At present, there are no proper testing and assessment methods for the condition of electromagnetic relays. Electromagnetic relays experience aging and failure over their service time, which causes many potential security problems. To solve these problems, the failure mechanisms of electromagnetic relays are analyzed. The Fick diffusion theory and the Larson–Miller method are used to deduce the degradation models for contact resistance and closing time. Based on these models, an approach to calculate relay life is proposed. To verify the effectiveness of the proposed method, a test platform was designed and built. The accelerated life test was carried out by using Siemens 3TH electromagnetic relays (3TH4244-OLF4, Siemens, Suzhou, China. Contact resistance and closing time were measured using a test platform. The least squares fitting was used to calculate the residual sum of squares and the unknown parameters in the degradation models with the test data. The optimal degradation model was chosen according to the fitting results. Relay life at four temperature stress levels was predicted by the optimal degradation model and failure threshold of the relays. The result indicates that the life of the electromagnetic relays at ambient temperature is 11,874 days and prediction error is about 5%, which provides important guidance for the maintenance of electromagnetic relays.

  13. Tube with helical grooves for heat transfer and its fabrication process

    International Nuclear Information System (INIS)

    Yampolsky, J.S.

    1977-01-01

    The invention suggests a thermal transfer tube for use in a heat exchanger. The wall of the tube includes a certain number of spiral or helical, internal and external, grooves for the flow of the heat exchange fluids along the tube. The grooves extend for the full length of the tube. They are uniform in design and mark the internal and external spiral hollows and crests. A process for the manufacture of the heat transfer tube is also included in the invention [fr

  14. Tracking Target and Spiral Waves

    DEFF Research Database (Denmark)

    Jensen, Flemming G.; Sporring, Jon; Nielsen, Mads

    2002-01-01

    A new algorithm for analyzing the evolution of patterns of spiral and target waves in large aspect ratio chemical systems is introduced. The algorithm does not depend on finding the spiral tip but locates the center of the pattern by a new concept, called the spiral focus, which is defined by the...

  15. Are spiral galaxies heavy smokers?

    International Nuclear Information System (INIS)

    Davies, J.; Disney, M.; Phillipps, S

    1990-01-01

    The dustiness of spiral galaxies is discussed. Starburst galaxies and the shortage of truly bright spiral galaxies is cited as evidence that spiral galaxies are far dustier than has been thought. The possibility is considered that the dust may be hiding missing mass

  16. Spiraling into Transformative Learning

    Science.gov (United States)

    Cranton, Patricia

    2010-01-01

    This article explores how technical and vocational learning may spiral into transformative learning. Transformative learning theory is reviewed and the learning tasks of critical theory are used to integrate various approaches to transformative learning. With this as a foundation, the article explores how transformative learning can be fostered in…

  17. Archimedean Voronoi spiral tilings

    Science.gov (United States)

    Yamagishi, Yoshikazu; Sushida, Takamichi

    2018-01-01

    We study the transition of the number of spirals (called parastichy in the theory of phyllotaxis) within a Voronoi tiling for Archimedean spiral lattices. The transition of local parastichy numbers within a tiling is regarded as a transition at the base site point in a continuous family of tilings. This gives a natural description of the quasiperiodic structure of the grain boundaries. It is proved that the number of tiles in the grain boundaries are denominators of rational approximations of the argument (called the divergence angle) of the generator. The local parastichy numbers are non-decreasing functions of the plastochron parameter. The bifurcation diagram of local parastichy numbers has a Farey tree structure. We also prove Richards’ formula of spiral phyllotaxis in the case of Archimedean Voronoi spiral tilings, and show that, if the divergence angle is a quadratic irrational number, then the shapes of tiles in the grain boundaries are close to rectangles. If the divergence angle is linearly equivalent to the golden section, then the shape of tiles in the grain boundaries is close to square.

  18. Ultra-high-speed pumping of an optical parametric oscillator (OPO) for high-speed laser-induced fluorescence measurements

    Science.gov (United States)

    Sjöholm, Johan; Kristensson, Elias; Richter, Mattias; Aldén, Marcus; Göritz, Guido; Knebel, Kai

    2009-02-01

    The feasibility of pumping an optical parametric oscillator (OPO) with an ultra-high repetition rate multi:YAG laser system, producing a burst of up to eight high-energy pulses, has been investigated. For this investigation an OPO with a bandwidth around 5 cm-1, together with a frequency doubling crystal, was selected. In some laser-induced fluorescence measurements the large linewidth from the OPO can be advantageous as several lines can be excited simultaneously avoiding the saturation effects of individual lines. The energy output from the OPO as a function of pulse separation was measured down to pulse separations of 400 ns and was found to be completely independent of the pulse separation. The efficiency of the OPO unit, when optimized for single-pulse operation, was measured to be around 25% for all pulses, giving over 80 mJ at 585 nm output when pumped with ~350 mJ at 355 nm. This is similar to the specified efficiency for the OPO. The system was found to give a slightly lower efficiency when double pulsing the Nd:YAG lasers. This is attributed to a somewhat elongated pulse length from the Nd:YAG lasers giving a lower pump energy density. The system was applied for measuring high-speed planar laser-induced fluorescence images of OH radicals in a Bunsen burner.

  19. Contact freezing observed with a high speed video camera

    Science.gov (United States)

    Hoffmann, Nadine; Koch, Michael; Kiselev, Alexei; Leisner, Thomas

    2017-04-01

    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.

  20. High Speed Deformation of the Poly(Ethylene Terephthalate)

    Science.gov (United States)

    Ladouce, L.; Perez, J.; Vassoille, R.

    1996-01-01

    Mechanical behaviour of amorphous and semi-crystalline polyethylene terephthalate films is studied over five decades of strain rates, at temperatures below and above the glass transition. The data were obtained by combining measurements from conventional Instron machine with data from a high-speed tensile machine. The activation parameters are determined and compared with the activation process of the β relaxation. Different modes of failure have been identified and the occurrence of an intermediate mode between ductile and brittle failure is shown. The brittle-ductile transition is estimated for each testing conditions and compared to the adiabatic-isothermal transition. Le comportement mécanique du Poly(éthylène téréphthalate) amorphe et semi-cristallin est étudié sur plus de cinq ordres de grandeurs de vitesse de déformation, de part et d'autre de la température de transition vitreuse. Les mesures expérimentales sont réalisées à l'aide d'une machine de traction Instron, pour les faibles vitesses de déformation, et d'une machine servo-hydraulique pour les grandes vitesses. Les paramètres d'activation sont déterminés et comparés à ceux de la relaxation secondaire basse température β. Différents modes de rupture sont identifiés; entre une rupture typiquement ductile et une rupture fragile, un mode de rupture intermédiaire est mis en évidence. La transition ductile-fragile est estimée pour chaque condition d'essai, et comparée à la transition isotherme-adiabatique.

  1. High speed machining of aluminium gear box without temperature stabilization

    Directory of Open Access Journals (Sweden)

    Abilio P. SILVA

    2010-01-01

    Full Text Available At the present time both clutch and mechanism housings, which are the main components from automotive gear boxes, are made of special aluminium alloys. These alloys are extremely light when compared with steel, making them a perfect choice to mitigate the cars weight and machining costs. Nonetheless they possess a high thermal expansion coefficient, which can be considered a major disadvantage since it makes necessary to pay extraordinary attention to dimensional variations during the production cycle due to temperature deviations. High speed machining of precision components made of aluminium requests thus their temperature to become previously stable. This procedure is the only way to force dimensions to stay inside its tolerance intervals. The main purpose of the present work was to assess the possibility to avoid the use of special ovens to make the clutch housing temperature become stable prior to machining. The dimensional stabilization of 40 sample parts, pre-heated at three temperature levels, was accomplished through the use of this system. The achieved results were made possible by analysing the part’s temperature at the machine’s entrance, the machine’s interior temperature, 35 measured dimensions and their tolerance intervals as well as the average temperature deviations of each of the five considered batches. By analysing the obtained results in detail it was possible to determine which dimensions show high sensitiveness to temperature (high correlation between dimension’s variation and temperature. Among these dimensions we can point out the ones related with depth, since they display the highest deviations due to temperature. Being a work with practical application it was possible to confirm the benefit of using this methodology by achieving significant enhancements on production efficiency, energy savings and reduction on maintenance costs, through the application of small adjustments to the machining sequence and by

  2. How sand grains stop a high speed intruder

    Science.gov (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.

  3. Holistic design in high-speed optical interconnects

    Science.gov (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

  4. Experiments on helium refrigerant at high speed of rotation

    International Nuclear Information System (INIS)

    Haseler, L.E.; Ball, A.; Scurlock, R.G.

    1976-01-01

    Electrical machines with superconducting field windings can require helium refrigeration in a rotating system. Heat transfer measurements have been made on helium in a rotating open thermosyphon. Various heater surfaces have been used at the end of a 25 mm tube full of helium at a radial distance of 0.22 mm from the rotation axis for speeds up to 37 Hsub(z), for both boiling heat transfer in subcritical helium, and convective heat transfer in sub and supercritical helium. A larger rotor of 0.44 m radius, to rotate up to 60 Hz, has been constructed to extend the range of the experiments. (author)

  5. High speed decision electronics combined to a beam Cherenkov counter

    International Nuclear Information System (INIS)

    Sghaier, H.

    1993-01-01

    The Hypolit detector for identification of particles in high energy physics using the Cherenkov radiation, is based on an intensifier tube coupled to photomultipliers via a fiber-optic matrix. Cherenkov photons are focused into a ring; particle identification consists in calculating the ring radius. A fast and high level electronic system is associated to Hypolit. Besides deriving the radius, it allows a background rejection and achieves a momentum correction. This on line tagging contributes to build the WA89 trigger. Tuning is controlled with a micro-computer which makes the access to the heart of the system friendly-user

  6. High-speed charge-to-time converter ASIC for the Super-Kamiokande detector

    International Nuclear Information System (INIS)

    Nishino, H.; Awai, K.; Hayato, Y.; Nakayama, S.; Okumura, K.; Shiozawa, M.; Takeda, A.; Ishikawa, K.; Minegishi, A.; Arai, Y.

    2009-01-01

    A new application-specific integrated circuit (ASIC), the high-speed charge-to-time converter (QTC) IWATSU CLC101, provides three channels, each consisting of preamplifier, discriminator, low-pass filter, and charge integration circuitry, optimized for the waveform of a photomultiplier tube (PMT). This ASIC detects PMT signals using individual built-in discriminators and drives output timing signals whose width represents the integrated charge of the PMT signal. Combined with external input circuits composed of passive elements, the QTC provides full analog signal processing for the detector's PMTs, ready for further processing by time-to-digital converters (TDCs). High-rate (>1MHz) signal processing is achieved by short-charge-conversion-time and baseline-restoration circuits. Wide-range charge measurements are enabled by offering three gain ranges while maintaining a short cycle time. QTC chip test results show good analog performance, with efficient detection for a single photoelectron signal, four orders of magnitude dynamic range (0.3mV∼3V; 0.2∼2500pC), 1% charge linearity, 0.2 pC charge resolution, and 0.1 ns timing resolution. Test results on ambient temperature dependence, channel isolation, and rate dependence also meet specifications.

  7. Verifying cell loss requirements in high-speed communication networks

    Directory of Open Access Journals (Sweden)

    Kerry W. Fendick

    1998-01-01

    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

  8. High-speed velocity measurements on an EFI-system

    Science.gov (United States)

    Prinse, W. C.; van't Hof, P. G.; Cheng, L. K.; Scholtes, J. H. G.

    2007-01-01

    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

  9. 78 FR 19981 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

    Science.gov (United States)

    2013-04-03

    ...; Flight Envelope Protection: High Speed Limiting AGENCY: Federal Aviation Administration (FAA), DOT... 11562). The document issued special conditions pertaining flight envelope protection: high speed...

  10. High Speed Mobility Through On-Demand Aviation

    Science.gov (United States)

    Moore, Mark D.; Goodrich, Ken; Viken, Jeff; Smith, Jeremy; Fredericks, Bill; Trani, Toni; Barraclough, Jonathan; German, Brian; Patterson, Michael

    2013-01-01

    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

  11. Design optimization of high speed gamma-ray tomography

    International Nuclear Information System (INIS)

    Maad, Rachid

    2009-01-01

    This thesis concerns research and development of efficient gamma-ray systems for high speed tomographic imaging of hydrocarbon flow dynamics with a particular focus on gas liquid imaging. The Bergen HSGT (High Speed Gamma-ray Tomograph) based on instant imaging with a fixed source-detector geometry setup, has been thoroughly characterized with a variety of image reconstruction algorithms and flow conditions. Experiments in flow loops have been carried out for reliable characterization and error analysis, static flow phantoms have been applied for the majority of experiments to provide accurate imaging references. A semi-empirical model has been developed for estimation of the contribution of scattered radiation to each HSGT detector and further for correction of this contribution prior to data reconstruction. The Bergen FGGT (Flexible Geometry Gamma-ray Tomograph) has been further developed, particularly on the software side. The system emulates any fan beam tomography. Based on user input of geometry and other conditions, the new software perform scanning, data acquisition and storage, and also weight matrix calculation and image reconstruction with the desired method. The FGGT has been used for experiments supporting those carried out with the HSGT, and in addition for research on other fan beam geometries suitable for hydrocarbon flow imaging applications. An instant no-scanning tomograph like the HSGT has no flexibility with respect to change of geometry, which usually is necessary when applying the tomograph for a new application. A computer controlled FGGT has been designed and built at the UoB. The software developed for the FGGT controls the scanning procedure, the data acquisition, calculates the weight matrix necessary for the image reconstruction, reconstructs the image using standard reconstruction algorithms, and calculates the error of the reconstructed image. The performance of the geometry has been investigated using a 100 mCi 241 Am disk source, a

  12. Texas should require homeland security standards for high-speed rail

    OpenAIRE

    Polunsky, Steven M.

    2015-01-01

    Approved for public release; distribution is unlimited A private corporation is proposing a high-speed intercity passenger train system to operate between Dallas and Houston usingJapanese technology and methods. This project brings with it an array of unique and unprecedented homeland security issues. Train bombings in Madrid and London and attacks on high-speed trains elsewhere raise questions about the security of such transportation. A modern high-speed rail system is a network of poten...

  13. 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)

    2016-03-18

    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.

  14. Theory of spiral structure

    International Nuclear Information System (INIS)

    Lin, C.C.

    1977-01-01

    The density wave theory of galactic spirals has now developed into a form suitable for consideration by experts in Applied Mechanics. On the one hand, comparison of theoretical deductions with observational data has convinced astrophysicists of the validity of the basic physical picture and the calculated results. On the other hand, the dynamical problems of a stellar system, such as those concerning the origin of spiral structure in galaxies, have not been completely solved. This paper reviews the current status of such developments, including a brief summary of comparison with observations. A particularly important mechanism, currently called the mechanism of energy exchange, is described in some detail. The mathematical problems and the physical processes involved are similar to those occurring in certain instability mechanisms in the 'magnetic bottle' designed for plasma containment. Speculations are given on the future developments of the theory and on observational programs. (Auth.)

  15. Spiral 2 workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The accelerator and experimental facilities at GANIL will be transformed over the next 5-10 years. The centerpiece of the additions to the accelerator complex will be Spiral-2. This is the first phase of a new radioactive beam facility based on the ISOL principle. The main aim of Spiral-2 will be to produce intense, high quality beams of neutron-rich nuclei created in neutron-induced fission of heavy elements and accelerated by the existing CIME cyclotron. The principal aims of this workshop will be a) to publicize the new facilities, b) to discuss and define the science which might be carried out with them, c) to discuss the instrumentation and infrastructure required to exploit the new facilities and d) to help form collaborations of scientists wishing to design and construct the equipment needed to undertake the science programme. This document gathers most of the slides presented in the workshop.

  16. Revolutionize Propulsion Test Facility High-Speed Video Imaging with Disruptive Computational Photography Enabling Technology

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced rocket propulsion testing requires high-speed video recording that can capture essential information for NASA during rocket engine flight certification...

  17. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project

    Data.gov (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. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design, Phase I

    Data.gov (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...

  19. Advanced Ultra-High Speed Motor for Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Impact Technologies LLC; University of Texas at Arlington

    2007-03-31

    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

  20. Spirality: A Noval Way to Measure Spiral Arm Pitch Angle

    Science.gov (United States)

    Shields, Douglas W.; Boe, Benjamin; Henderson, Casey L.; Hartley, Matthew; Davis, Benjamin L.; Pour Imani, Hamed; Kennefick, Daniel; Kennefick, Julia D.

    2015-01-01

    We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. For a given pitch angle template, the mean pixel value is found along each of typically 1000 spiral axes. The fitting function, which shows a local maximum at the best-fit pitch angle, is the variance of these means. Error bars are found by varying the inner radius of the measurement annulus and finding the standard deviation of the best-fit pitches. Computation time is typically on the order of 2 minutes per galaxy, assuming at least 8 GB of working memory. We tested the code using 128 synthetic spiral images of known pitch. These spirals varied in the number of spiral arms, pitch angle, degree of logarithmicity, radius, SNR, inclination angle, bar length, and bulge radius. A correct result is defined as a result that matches the true pitch within the error bars, with error bars no greater than ±7°. For the non-logarithmic spiral sample, the correct answer is similarly defined, with the mean pitch as function of radius in place of the true pitch. For all synthetic spirals, correct results were obtained so long as SNR > 0.25, the bar length was no more than 60% of the spiral's diameter (when the bar was included in the measurement), the input center of the spiral was no more than 6% of the spiral radius away from the true center, and the inclination angle was no more than 30°. The synthetic spirals were not deprojected prior to measurement. The code produced the correct result for all barred spirals when the measurement annulus was placed outside the bar. Additionally, we compared the code's results against 2DFFT results for 203 visually selected spiral galaxies in GOODS North and South. Among the entire sample, Spirality's error bars overlapped 2DFFT's error bars 64% of the time. For those galaxies in which Source code is available by email request from the primary author.

  1. Band-notched spiral antenna

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jae; Chang, John

    2018-03-13

    A band-notched spiral antenna having one or more spiral arms extending from a radially inner end to a radially outer end for transmitting or receiving electromagnetic radiation over a frequency range, and one or more resonance structures positioned adjacent one or more segments of the spiral arm associated with a notch frequency band or bands of the frequency range so as to resonate and suppress the transmission or reception of electromagnetic radiation over said notch frequency band or bands.

  2. Impact of high-speed railway accessibility on the location choices of office establishments

    NARCIS (Netherlands)

    Willigers, J.

    2006-01-01

    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

  3. Ultra-high-speed optical signal processing of serial data signals

    DEFF Research Database (Denmark)

    Clausen, Anders; Mulvad, Hans Christian Hansen; Palushani, Evarist

    2012-01-01

    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....

  4. Calibration and test capabilities of the Langley 7- by 10- foot high speed tunnel

    Science.gov (United States)

    Fox, C. H., Jr.; Huffman, J. K.

    1977-01-01

    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.

  5. Laryngeal High-Speed Videoendoscopy: Rationale and Recommendation for Accurate and Consistent Terminology

    Science.gov (United States)

    Deliyski, Dimitar D.; Hillman, Robert E.; Mehta, Daryush D.

    2015-01-01

    Purpose: The authors discuss the rationale behind the term "laryngeal high-speed videoendoscopy" to describe the application of high-speed endoscopic imaging techniques to the visualization of vocal fold vibration. Method: Commentary on the advantages of using accurate and consistent terminology in the field of voice research is…

  6. Numerical Study of the High-Speed Leg of a Wind Tunnel

    Science.gov (United States)

    Nayani, Sudheer; Sellers, William L., III; Brynildsen, Scott E.; Everhart, Joel L.

    2015-01-01

    The paper describes the numerical study of the high-speed leg of the NASA Langley 14 by 22-foot Low Speed Wind Tunnel. The high-speed leg consists of the Settling Chamber, Contraction, Test Section, and First Diffuser. Results are shown comparing two different exit boundary conditions and two different methods of determining the surface geometry.

  7. Clusters of PCS for high-speed computation for modelling of the climate

    International Nuclear Information System (INIS)

    Pabon C, Jose Daniel; Eslava R, Jesus Antonio; Montoya G, Gerardo de Jesus

    2001-01-01

    In order to create high speed computing capability, the Program of Post grade in Meteorology of the Department of Geosciences, National University of Colombia installed a cluster of 8 PCs for parallel processing. This high-speed processing machine was tested with the Climate Community Model (CCM3). In this paper, the results related to the performance of this machine are presented

  8. 76 FR 57924 - Transportation for Individuals With Disabilities at Intercity, Commuter, and High Speed Passenger...

    Science.gov (United States)

    2011-09-19

    ... that a bus or paratransit vehicle lift will safely accommodate an 800-pound wheelchair/passenger... Transportation for Individuals With Disabilities at Intercity, Commuter, and High Speed Passenger Railroad...) regulations to require intercity, commuter, and high-speed passenger railroads to ensure, at new and altered...

  9. 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.

    2015-01-01

    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

  10. 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.

    2010-01-01

    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

  11. Three phase spiral liver Scanning

    International Nuclear Information System (INIS)

    Kanyanja, T.A.

    2006-01-01

    The ability to perform rapid back-to-back spiral acquisitions is an important recent technical advantage of spiral CT. this allows imaging of the upper abdomen (liver) during peak arterial enhancement (arterial phase) and during peak hepatic parenchymal enhancement (portal venous phase). Breatheld spiral CT has completely replaced dynamic incremental CT for evaluation of the liver. in selected patients with hyper vascular metastasis (hepatoma, neuroendocrine tumors, renal cell carcinoma, etc.) a biphasic examination is performed with one spiral acquisition obtained during the hepatic arterial phase and a second acquisition during the portal venous phase

  12. Finned Tube With Vortex Generators For A Heat Exchanger.

    Science.gov (United States)

    Sohal, Monohar S.; O'Brien, James E.

    2004-09-14

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at least one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  13. 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)

    2003-05-01

    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.

  14. Effect of bow spray strips and Ω-type freeboard on high-speed boats

    Directory of Open Access Journals (Sweden)

    WEI Chengzhu

    2017-01-01

    Full Text Available A high-speed boat may encounter severe wave-making at the bow and become wetter at high speed. Some measures can be taken to overcome these disadvantages. In order to compare the effect of bow spray strips and Ω-type freeboards on a high-speed boat, hull wetness, resistance, hull motion, stability and the restoring moment of the heel at high speed of models with these two kinds of auxiliaries were calculated and measured. CFD methods and model tests were adopted. Both of these two auxiliaries can reduce hull wetness, and the model with a Ω-type freeboard has a better initial stability and larger restoring moment of the heel at high speed. A free running model test also indicates that the Ω-type freeboard has a fine performance.

  15. Design and applications of a pneumatic accelerator for high speed punching

    International Nuclear Information System (INIS)

    Yaldiz, Sueleyman; Saglam, Haci; Unsacar, Faruk; Isik, Hakan

    2007-01-01

    High speed forming is an important production method that requires specially designed HERF (high energy rate forming) machines. Most of the HERF machines are devices that consist of a system in which energy is stored and a differential piston mechanism is used to release the energy at high rate. In order to eliminate the usage of specially designed HERF machines and to obtain the high speed forming benefits, the accelerator which can be adapted easily onto conventional presses has been designed and manufactured in this study. The designed energy accelerator can be incorporated into mechanical press to convert the low speed operation into high-speed operation of a hammer. Expectations from this work are reduced distortion rates, increased surface quality and precise dimensions in metal forming operations. From the performance test, the accelerator is able to achieve high speed and energy which require for high speed blanking of thick sheet metals

  16. Accuracy Assessment for the Three-Dimensional Coordinates by High-Speed Videogrammetric Measurement

    Directory of Open Access Journals (Sweden)

    Xianglei Liu

    2018-01-01

    Full Text Available High-speed CMOS camera is a new kind of transducer to make the videogrammetric measurement for monitoring the displacement of high-speed shaking table structure. The purpose of this paper is to validate the three-dimensional coordinate accuracy of the shaking table structure acquired from the presented high-speed videogrammetric measuring system. In the paper, all of the key intermediate links are discussed, including the high-speed CMOS videogrammetric measurement system, the layout of the control network, the elliptical target detection, and the accuracy validation of final 3D spatial results. Through the accuracy analysis, the submillimeter accuracy can be made for the final the three-dimensional spatial coordinates which certify that the proposed high-speed videogrammetric technique is a better alternative technique which can replace the traditional transducer technique for monitoring the dynamic response for the shaking table structure.

  17. The subtropical nutrient spiral

    Science.gov (United States)

    Jenkins, William J.; Doney, Scott C.

    2003-12-01

    We present an extended series of observations and more comprehensive analysis of a tracer-based measure of new production in the Sargasso Sea near Bermuda using the 3He flux gauge technique. The estimated annually averaged nitrate flux of 0.84 ± 0.26 mol m-2 yr-1 constitutes only that nitrate physically transported to the euphotic zone, not nitrogen from biological sources (e.g., nitrogen fixation or zooplankton migration). We show that the flux estimate is quantitatively consistent with other observations, including decade timescale evolution of the 3H + 3He inventory in the main thermocline and export production estimates. However, we argue that the flux cannot be supplied in the long term by local diapycnal or isopycnal processes. These considerations lead us to propose a three-dimensional pathway whereby nutrients remineralized within the main thermocline are returned to the seasonally accessible layers within the subtropical gyre. We describe this mechanism, which we call "the nutrient spiral," as a sequence of steps where (1) nutrient-rich thermocline waters are entrained into the Gulf Stream, (2) enhanced diapycnal mixing moves nutrients upward onto lighter densities, (3) detrainment and enhanced isopycnal mixing injects these waters into the seasonally accessible layer of the gyre recirculation region, and (4) the nutrients become available to biota via eddy heaving and wintertime convection. The spiral is closed when nutrients are utilized, exported, and then remineralized within the thermocline. We present evidence regarding the characteristics of the spiral and discuss some implications of its operation within the biogeochemical cycle of the subtropical ocean.

  18. Flow visualization of bubble behavior under two-phase natural circulation flow conditions using high speed digital camera

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail: wlemos@con.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Faccini, Jose L.H., E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2013-07-01

    The The present work aims at identifying flow patterns and measuring interfacial parameters in two-phase natural circulation by using visualization technique with high-speed digital camera. The experiments were conducted in the Natural Circulation Circuit (CCN), installed at Nuclear Engineering Institute/CNEN. The thermo-hydraulic circuit comprises heater, heat exchanger, expansion tank, the pressure relief valve and pipes to interconnect the components. A glass tube is installed at the midpoint of the riser connected to the heater outlet. The natural circulation circuit is complemented by acquisition system of values of temperatures, flow and graphic interface. The instrumentation has thermocouples, volumetric flow meter, rotameter and high-speed digital camera. The experimental study is performed through analysis of information from measurements of temperatures at strategic points along the hydraulic circuit, besides natural circulation flow rates. The comparisons between analytical and experimental values are validated by viewing, recording and processing of the images for the flows patterns. Variables involved in the process of identification of flow regimes, dimensionless parameters, the phase velocity of the flow, initial boiling point, the phenomenon of 'flashing' pre-slug flow type were obtained experimentally. (author)

  19. Transient flow characteristics of a high speed rotary valve

    Science.gov (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. Development of high sensitivity and high speed large size blank inspection system LBIS

    Science.gov (United States)

    Ohara, Shinobu; Yoshida, Akinori; Hirai, Mitsuo; Kato, Takenori; Moriizumi, Koichi; Kusunose, Haruhiko

    2017-07-01

    The production of high-resolution flat panel displays (FPDs) for mobile phones today requires the use of high-quality large-size photomasks (LSPMs). Organic light emitting diode (OLED) displays use several transistors on each pixel for precise current control and, as such, the mask patterns for OLED displays are denser and finer than the patterns for the previous generation displays throughout the entire mask surface. It is therefore strongly demanded that mask patterns be produced with high fidelity and free of defect. To enable the production of a high quality LSPM in a short lead time, the manufacturers need a high-sensitivity high-speed mask blank inspection system that meets the requirement of advanced LSPMs. Lasertec has developed a large-size blank inspection system called LBIS, which achieves high sensitivity based on a laser-scattering technique. LBIS employs a high power laser as its inspection light source. LBIS's delivery optics, including a scanner and F-Theta scan lens, focus the light from the source linearly on the surface of the blank. Its specially-designed optics collect the light scattered by particles and defects generated during the manufacturing process, such as scratches, on the surface and guide it to photo multiplier tubes (PMTs) with high efficiency. Multiple PMTs are used on LBIS for the stable detection of scattered light, which may be distributed at various angles due to irregular shapes of defects. LBIS captures 0.3mμ PSL at a detection rate of over 99.5% with uniform sensitivity. Its inspection time is 20 minutes for a G8 blank and 35 minutes for G10. The differential interference contrast (DIC) microscope on the inspection head of LBIS captures high-contrast review images after inspection. The images are classified automatically.

  1. Study of jet fluctuations in DC plasma torch using high speed camera

    International Nuclear Information System (INIS)

    Tiwari, Nirupama; Sahasrabudhe, S N; Joshi, N K; Das, A K

    2010-01-01

    The power supplies used for the plasma torches are usually SCR controlled and have a large ripple factor. This is due to the fact that the currents in the torch are of the order of hundreds of amperes which prohibit effective filtering of the ripple. The voltage and current vary as per the ripple in the power supply and causes plasma jet to fluctuate. To record these fluctuations, the jet coming out from a D.C. plasma torch operating at atmospheric pressure was imaged using high speed camera at the rate of 3000 frame per second. Light emitted from a well defined zone in the plume was collected using an optical fibre and a Photo Multiplier Tube. Current, voltage and PMT signals were recorded simultaneously using a digital storage oscilloscope (DSO). The fast camera recorded the images for 25 ms and the starting pulse from the camera was used to trigger the DSO for recording voltage, current and optical signals. Each image of the plume recorded by the fast camera was correlated with the magnitude of the instantaneous voltage, current and optical signal. It was observed that the luminosity and length of the plume varies as per the product of instantaneous voltage and current i.e. electrical power fed to plasma torch. The experimental runs were taken with different gas flow rates and electrical powers. The images were analyzed using image processing software and constant intensity contours of images were determined. Further analysis of the images can provide a great deal of information about dynamics of the jet.

  2. Experimental analysis of high-speed gamma-ray tomography performance

    Science.gov (United States)

    Maad, R.; Johansen, G. A.

    2008-08-01

    High-speed gamma-ray tomography (HSGT) based on multiple fan-beam collimated radioisotope sources has proved to be an efficient and fast method for cross sectional imaging of the dynamics in different industrial processes. The objective of the tomography system described here is to identify the flow regime of gas/liquid pipe flows. The performance of such systems is characterized by the spatial resolution, the speed of response and the measurement resolution of the attenuation coefficient. The work presented here is an experimental analysis of how the measurement geometry and the reconstruction method affect the error of the reconstructed pixel values. These relationships are well established for medical x-ray tomography where high intensity x-ray tubes are used as sources. For radioisotope sources, however, the radiation intensity is limited, which causes the measurement uncertainty, i.e. the Poisson noise, to be considerably higher. In addition, the influence of scattered radiation is more severe in a multiple source radioisotope system compared to that of x-ray systems. A computer-controlled flexible geometry gamma-ray tomograph has been developed to acquire experimental data for different fan-beam measurement geometries, and these data have subsequently been used for image reconstruction using seven different iterative image reconstruction algorithms. The results show that the reconstruction algorithms perform cross sectional images with different quality and that there is virtually nothing to be gained by using more than seven sources for flow regime classification of multiphase pipe flow consisting of gas, oil and water.

  3. X-Ray Visualisation Of High Speed Phenomena: Application To The Behavior Of Materials Under High Explosives Loading

    Science.gov (United States)

    Hauducoeur, A.; Fischer, D.; Guix, R.

    1983-08-01

    Flash Radiography and Cineradiography allow the visualisation of high speed phenomena and the stop motion effect with recording on film of qualitative and quantitative data on the dynamic state of the matter under very intense shock waves. In this paper, we present a set of experimental devices and results obtained with a large range of flash X-ray generators : - small generators made with Marx discharge circuits coupled to void X-ray tubes, working up to 2.5 MV, - a big flash machine, GREC (presented at this conference (ref.1))used with very absor-bing materials. The presented applications illustrate a large field of experiments in the field of shock waves, interaction of 2 shock or detonation waves, flow visualisation of detonation, Taylor instabilities/metal jetting, spalling in iron...

  4. Diagnostics of high-speed streams and coronal holes using geomagnetic pulsations

    International Nuclear Information System (INIS)

    Bol'shakova, O.V.; Troitskaya, V.A.

    1980-01-01

    In order to study the relations of high-speed solar wind streams and coronal holes analyzed are the parameters of geomagnetic pulsations of the Rs3 type and of high-speed streams at the decrease branch and in the minimum of solar activity. On the basis of the analysis of exciting pulsation regime determined are the differences in characteristics of high-speed stream properties. Presented are the graphical distributions of a number of occurrances of high-speed streams, coronal holes and pure regimes of Rs3R pulsations in several sections of 1973 in the Sun rotations of N1903-1919 and of the change of solar wind velocity while passing through the high-speed streams. It is found that Rs3R occurrance can serve an indicator of the high-speed flux connection with the large equatorial coronal hole. On the basis of the analysis of exciting pulsation properties determined are the differences in the stream characteristics. However the preliminary estimates permit to adopt neither the first nor the second of the existing hypotheses on the sourse of formation of high-speed streams

  5. Assessment of left ventricular hemodynamics by Gd-DTPA enhanced high speed cine MRI

    International Nuclear Information System (INIS)

    Matsumura, Kentaro; Nakase, Emiko; Kawai, Ichiro

    1992-01-01

    To assess the validity of Gd-DTPA enhanced high speed cine MRI in left ventricular (LV) volumes and ejection fraction (EF), high speed cine MRI was compared with intra-venous digital subtraction left ventriculography (IV-DSA) in 14 patients. All patients underwent conventional cine MRI and Gd-DTPA enhanced high speed MRI, simultaneously. The pulse sequences of high speed MRI were TR 8 ms (TR 6 ms plus rewind pulse 2 ms), TE 3.2 ms, matrix 128, phase encode 8 or 6 and NEX 1. Comparison with LV-volume showed a high correlation (y = 0.854x + 1,699, r = 0.985) between high speed cine MRI and VI-DSA. To make left ventricular volume curve by area-length method in cine MRI, manual tracing of LV-cavity was more difficult in conventional cine MRI-method than enhanced high speed cine MRI-method. In conclusion, first pass-Gd-DTPA enhanced high speed cine MRI, using the horizontal long axis approach and the multiphase study, is a highly, accurate reproducible method of evaluating LV-volumetry. (author)

  6. The perfect shape spiral stories

    CERN Document Server

    Hammer, Øyvind

    2016-01-01

    This book uses the spiral shape as a key to a multitude of strange and seemingly disparate stories about art, nature, science, mathematics, and the human endeavour. In a way, the book is itself organized as a spiral, with almost disconnected chapters circling around and closing in on the common theme. A particular strength of the book is its extremely cross-disciplinary nature - everything is fun, and everything is connected! At the same time, the author puts great emphasis on mathematical and scientific correctness, in contrast, perhaps, with some earlier books on spirals. Subjects include the mathematical properties of spirals, sea shells, sun flowers, Greek architecture, air ships, the history of mathematics, spiral galaxies, the anatomy of the human hand, the art of prehistoric Europe, Alfred Hitchcock, and spider webs, to name a few.

  7. The Long-Term Settlement Deformation Automatic Monitoring System for the Chinese High-Speed Railway

    OpenAIRE

    Xu Wang; Liangqin Wu; Yi Zhou; Yanru Wang

    2015-01-01

    The Beijing-Shanghai high-speed railway is one of the milestones of China’s high-speed railway development and its security plays a significant role in China’s economic and social development. However, the evaluation methods used for large-scale security operations and important infrastructure systems, such as the high-speed railways, are discrete and nonlinear; thus they cannot issue emergency warnings in a timely manner. The emergence of optical fiber sensing technology can solve this probl...

  8. High-Speed Non-Volatile Optical Memory: Achievements and Challenges

    Directory of Open Access Journals (Sweden)

    Vadym Zayets

    2017-01-01

    Full Text Available We have proposed, fabricated, and studied a new design of a high-speed optical non-volatile memory. The recoding mechanism of the proposed memory utilizes a magnetization reversal of a nanomagnet by a spin-polarized photocurrent. It was shown experimentally that the operational speed of this memory may be extremely fast above 1 TBit/s. The challenges to realize both a high-speed recording and a high-speed reading are discussed. The memory is compact, integratable, and compatible with present semiconductor technology. If realized, it will advance data processing and computing technology towards a faster operation speed.

  9. Real time data compactor (sparsifier) and 8 megabyte high speed FIFO for HEP

    International Nuclear Information System (INIS)

    Baumbaugh, A.E.; Knickerbocker, K.L.; Wegner, C.R.; Baumbaugh, B.W.; Ruchti, R.

    1985-10-01

    A Video-Data-Acquisition-System (VDAS) has been developed to record image data from a scintillating glass fiber-optic target developed for High Energy Physics. The major components of the VDAS are a flash ADC, a ''real time'' high speed data compactor, and high speed 8 megabyte FIFO memory. The data rates through the system are in excess of 30 megabytes/second. The compactor is capable of reducing the amount of data needed to reconstruct typical images by as much as a factor of 20. The FIFO uses only standard NMOS DRAMS and TTL components to achieve its large size and high speed at relatively low power and cost

  10. Optical characterization of high speed microscanners based on static slit profiling method

    Science.gov (United States)

    Alaa Elhady, A.; Sabry, Yasser M.; Khalil, Diaa

    2017-01-01

    Optical characterization of high-speed microscanners is a challenging task that usually requires special high speed, extremely expensive camera systems. This paper presents a novel simple method to characterize the scanned beam spot profile and size in high-speed optical scanners under operation. It allows measuring the beam profile and the spot sizes at different scanning angles. The method is analyzed theoretically and applied experimentally on the characterization of a Micro Electro Mechanical MEMS scanner operating at 2.6 kHz. The variation of the spot size versus the scanning angle, up to ±15°, is extracted and the dynamic bending curvature effect of the micromirror is predicted.

  11. Infrared emission and tidal interactions of spiral galaxies

    International Nuclear Information System (INIS)

    Byrd, G.G.

    1987-01-01

    Computer simulations of tidal interactions of spiral galaxies are used to attempt to understand recent discoveries about infrared (IR) emitting galaxies. It is found that the stronger tidal perturbation by a companion the more disk gas clouds are thrown into nucleus crossing orbits and the greater the velocity jumps crossing spiral arms. Both these tidally created characteristics would create more IR emission by high speed cloud collisions and more IR via effects of recently formed stars. This expectation at greater tidal perturbation matches the observation of greater IR emission for spiral galaxies with closer and/or more massive companions. The greater collision velocities found at stronger perturbations on the models will also result in higher dust temperature in the colliding clouds. In the IR pairs examined, most have only one member, the larger, detected and when both are detected, the larger is always the more luminous. In simulations and in a simple analytic description of the strong distance dependence of the tidal force, it is found that the big galaxy of a pair is more strongly affected than the small

  12. Ultra-precision turning of complex spiral optical delay line

    Science.gov (United States)

    Zhang, Xiaodong; Li, Po; Fang, Fengzhou; Wang, Qichang

    2011-11-01

    Optical delay line (ODL) implements the vertical or depth scanning of optical coherence tomography, which is the most important factor affecting the scanning resolution and speed. The spinning spiral mirror is found as an excellent optical delay device because of the high-speed and high-repetition-rate. However, it is one difficult task to machine the mirror due to the special shape and precision requirement. In this paper, the spiral mirror with titled parabolic generatrix is proposed, and the ultra-precision turning method is studied for its machining using the spiral mathematic model. Another type of ODL with the segmental shape is also introduced and machined to make rotation balance for the mass equalization when scanning. The efficiency improvement is considered in details, including the rough cutting with the 5- axis milling machine, the machining coordinates unification, and the selection of layer direction in turning. The onmachine measuring method based on stylus gauge is designed to analyze the shape deviation. The air bearing is used as the measuring staff and the laser interferometer sensor as the position sensor, whose repeatability accuracy is proved up to 10nm and the stable feature keeps well. With this method developed, the complex mirror with nanometric finish of 10.7nm in Ra and the form error within 1um are achieved.

  13. Hurricane Spiral Bands.

    Science.gov (United States)

    Guinn, Thomas A.; Schubert, Wayne H.

    1993-10-01

    The spiral bands that occur in tropical cyclones can be conveniently divided into two classes-outer bands and inner bands. Evidence is presented here that the outer bands form as the result of nonlinear effects during the breakdown of the intertropical convergence zone (ITCZ) through barotropic instability. In this process a zonal strip of high potential vorticity (the ITCZ shear zone or monsoon trough) begins to distort in a varicose fashion, with the potential vorticity (PV) becoming pooled in local regions that are connected by filaments of high PV. As the pooled regions become more axisymmetric, the filaments become thinner and begin to wrap around the PV centers.It is argued that inner bands form in a different manner. As a tropical cyclone intensifies due to latent heat release, the PV field becomes nearly circular with the highest values of PV in the cyclone center. The radial gradient of PV provides a state on which PV waves (the generalization of Rossby waves) can propagate. The nonlinear breaking of PV waves then leads to an irreversible distortion of the PV contours and a downgradient flux of PV. The continuation of this proem tends to erode the high PV core of the tropical cyclone, to produce a surrounding surf zone, and hence to spread the PV horizontally. In a similar fashion, inner bands can also form by the merger of a vortex with a patch of relatively high PV air. As the merger proem occurs the patch of PV is quickly elongated and wrapped around the vortex. The resulting vortex is generally larger in horizontal extent and exhibits a spiral band of PV.When the formation of outer and inner bands is interpreted in the context of a normal-mode spectral model, they emerge as slow manifold phenomena; that is, they have both rotational and (balanced or slaved) gravitational mode aspects. In this sense, regarding them as simply gravity waves leads to an incomplete dynamical picture.

  14. High Speed Vessels to Market : Comparative Case Studies in the Passenger Trade

    Science.gov (United States)

    2001-08-01

    The Volpe Center chose to study several existing catamarans and high speed monohulls in comparison to representative SWATH family craft, including the SLICE 400 (passenger) and SLICE 600 (passenger/90 car) variants, the former similar in size and per...

  15. High-speed surface transportation corridor : a conceptual framework, final report.

    Science.gov (United States)

    2009-10-08

    Efficient transportation is indispensable for economic growth and prosperity. In this study we propose the development of a high-speed surface corridor and compatible vehicles. We present a conceptual framework for this corridor and vehicle. This pro...

  16. Rail infrastructure charges and competitiveness of high speed services; Trassenpreise und Wettbewerbsfaehigkeit des Eisenbahn-Hochgeschwindigkeitsverkehrs

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Borras, Marta [Univ. Politechnica de Catalunya (UPC) (ES). Center for Innovation in Transport (CENIT); Lopez-Pita, Andres [Univ. Politechnica de Catalunya (UPC) (Spain)

    2011-07-01

    The optimal use of the Trans-European high speed network, which is meant to promote sustainable development by allowing a modal shift from airways to railways, will require taking careful consideration of the level of infrastructure charges to be paid by trains running on them. Short-run social marginal costs (SRSMC) of the infrastructure of high-speed lines do not appear to be above 2 Euro/train-km. The optimal level of charges should not exceed 6.4 Euro/train-km. The article presents the results of calculations made to analyze the impact of infrastructure charges on the competitiveness of the high speed passenger services. Between 20% and 60% of the potential traffic is lost for high speed rail due to too high mark-ups above the marginal infrastructure costs. (orig.)

  17. Advances on Propulsion Technology for High-Speed Aircraft. Volume 2

    National Research Council Canada - National Science Library

    2007-01-01

    .... The demand for supersonic vehicles is believed to boost in the incoming years. This VKI/RTO lecture series will review the current state of the art of high speed propulsion for both airplanes and space launchers...

  18. Advances on Propulsion Technology for High-Speed Aircraft. Volume 1

    National Research Council Canada - National Science Library

    2007-01-01

    .... The demand for supersonic vehicles is believed to boost in the incoming years. This VKI/RTO lecture series will review the current state of the art of high speed propulsion for both airplanes and space launchers...

  19. High-Speed Rail and Local Land Development : Case Studies in London and Las Vegas

    Science.gov (United States)

    2017-11-01

    The efficacy of a high-speed rail system depends, in part, upon locating rail stations close to urban centers and integrating them into broader transportation networks and the urban realm. In addition, through economies of agglomeration, successful h...

  20. The Time Lens Concept Applied to Ultra-High-Speed OTDM Signal Processing

    DEFF Research Database (Denmark)

    Clausen, Anders; Palushani, Evarist; Mulvad, Hans Christian Hansen

    2013-01-01

    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....

  1. Estimating workforce development needs for high-speed rail in California.

    Science.gov (United States)

    2012-03-01

    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 ...

  2. Pseudophakodonesis and corneal endothelial contact: direct observations by high-speed cinematography.

    Science.gov (United States)

    Jacobs, P M; Cheng, H; Price, N C

    1983-10-01

    High-speed cinematography was used to observe the movement of Federov type I lens implants within the anterior chamber. Our measurements suggest that in most patients contact between the lens implant and corneal endothelium does not occur.

  3. High-speed photographic observation of plasma-limiter interactions in ISX-B

    International Nuclear Information System (INIS)

    Clausing, R.E.; Emerson, L.C.; Heatherly, L.

    1981-01-01

    High-speed motion pictures confirm that arcing occurs during periods of plasma instability in ISX-B. Various types of plasma-limiter interactions are described and illustrated. Arcing and other visible phenomena are correlated to plasma parameters

  4. Integrated High-Speed Torque Control System for a Robotic Joint

    Science.gov (United States)

    Davis, Donald R. (Inventor); Radford, Nicolaus A. (Inventor); Permenter, Frank Noble (Inventor); Valvo, Michael C. (Inventor); Askew, R. Scott (Inventor)

    2013-01-01

    A control system for achieving high-speed torque for a joint of a robot includes a printed circuit board assembly (PCBA) having a collocated joint processor and high-speed communication bus. The PCBA may also include a power inverter module (PIM) and local sensor conditioning electronics (SCE) for processing sensor data from one or more motor position sensors. Torque control of a motor of the joint is provided via the PCBA as a high-speed torque loop. Each joint processor may be embedded within or collocated with the robotic joint being controlled. Collocation of the joint processor, PIM, and high-speed bus may increase noise immunity of the control system, and the localized processing of sensor data from the joint motor at the joint level may minimize bus cabling to and from each control node. The joint processor may include a field programmable gate array (FPGA).

  5. Turbulent Scalar Transport Model Validation for High Speed Propulsive Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort entails the validation of a RANS turbulent scalar transport model (SFM) for high speed propulsive flows, using new experimental data sets and...

  6. Sequential multi-channel OCT in the retina using high-speed fiber optic switches

    Science.gov (United States)

    Wartak, Andreas; Augustin, Marco; Beer, Florian; Haindl, Richard; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K.

    2017-07-01

    A sequential multi-channel OCT prototype featuring high-speed fiber optical switches to enable inter A-scan (A-scan rate: 100 kHz) sample arm switching was developed and human retinal image data is presented.

  7. Formulating a strategy for securing high-speed rail in the United States.

    Science.gov (United States)

    2013-03-01

    This report presents an analysis of information relating to attacks, attempted attacks, and plots against high-speed rail (HSR) : systems. It draws upon empirical data from MTIs Database of Terrorist and Serious Criminal Attacks Against Public Sur...

  8. High-Speed Fiber Optic Micromultiplexer for Space and Airborne Lidar, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Science Division need for high-speed fiber optic multiplexers for next generation lidar systems, Luminit proposes to develop a new Fiber...

  9. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high-speed civil aircraft will require breakthrough developments in propulsion systems, including novel techniques to optimize inlet...

  10. High-Speed, Low-Power ADC for Digital Beam Forming (DBF) Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will design a high-speed, low-power silicon germanium (SiGe)-based, analog-to-digital converter (ADC) to be a key element for digital beam forming...

  11. High-Speed, Low-Power ADC for Digital Beam Forming (DBF) Systems Project

    Data.gov (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...

  12. Study on the subgrade deformation under high-speed train loading and water-soil interaction

    Science.gov (United States)

    Han, Jian; Zhao, Guo-Tang; Sheng, Xiao-Zhen; Jin, Xue-Song

    2016-04-01

    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.

  13. Some design aspects of high-speed vertical-axis wind turbines

    National Research Council Canada - National Science Library

    Templin, R. J; South, P

    1977-01-01

    ... (rotor height to diameter ratio, solidity, number of blades, etc.) for high-speed vertical-axis wind turbines from kilowatt to megawatt sizes and shows that very large turbines are theoretically feasible...

  14. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high-speed civil aircraft will require breakthrough developments in propulsion systems, including novel techniques to optimize inlet...

  15. High-Speed, Low-Power ADC for Digital Beam Forming (DBF) Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will design a high-speed, low-power silicon germanium (SiGe)-based, analog-to-digital converter (ADC) to be a key element for digital beam forming...

  16. Carbon Dioxide Mitigation Benefit of High-Speed Railway in Terms of Carbon Tax

    Directory of Open Access Journals (Sweden)

    Fu Yanbing

    2013-01-01

    Full Text Available This paper calculates the carbon dioxide mitigation benefit of high-speed railway based on the carbon dioxide tax policy. We define the carbon dioxide emission system boundary for high-speed railway in its whole life cycle and estimate the life cycle carbon dioxide inventories during its construction, application, and recovery stages. And then we establish a theoretical model to calculate the life cycle carbon dioxide mitigation quantity for high-speed railway when compared with road transport and then calculate its carbon dioxide mitigation benefit. The numerical example shows that the carbon dioxide mitigation benefit of high-speed railway is better than that of road transport from the whole life cycle perspective.

  17. 49 CFR 38.175 - High-speed rail cars, monorails and systems.

    Science.gov (United States)

    2010-10-01

    ... but not limited to those using “maglev” or high speed steel-wheel-on-steel rail technology, and monorail systems operating primarily on dedicated rail (i.e., not used by freight trains) or guideway, in...

  18. Multicamera High Dynamic Range High-Speed Video of Rocket Engine Tests and Launches

    Data.gov (United States)

    National Aeronautics and Space Administration — High-speed video recording of rocket engine tests has several challenges. The scenes that are imaged have both bright and dark regions associated with plume emission...

  19. Experimental and Simulation Performance Results of TCP/IP over High-Speed ATM over ACTS

    National Research Council Canada - National Science Library

    Charalambos, Charalambous

    1997-01-01

    To assist in the design and understanding of future global networks, this paper describes the practical and simulation experiences gained from a TCP/IP on ATM network over a high speed satellite link...

  20. Safety of High Speed Guided Ground Transportation Systems: Work Breakdown Structure

    Science.gov (United States)

    1994-11-30

    This report provides a systems approach to the assessment, evaluation and application of high-speed guided ground transportation (HSGGT) safety criteria and : presents one potential methodology by combining a work breakdown structure (WBS) : approach...

  1. Modeling and simulation of high-speed passenger train movements in the rail line

    Science.gov (United States)

    Cao, Cheng-Xuan; Xu, Yan; Li, Ke-Ping

    2013-06-01

    In this paper, we propose a new formula of the real-time minimum safety headway based on the relative velocity of consecutive trains and present a dynamic model of high-speed passenger train movements in the rail line based on the proposed formula of the minimum safety headway. Moreover, we provide the control strategies of the high-speed passenger train operations based on the proposed formula of the real-time minimum safety headway and the dynamic model of high-speed passenger train movements. The simulation results demonstrate that the proposed control strategies of the passenger train operations can greatly reduce the delay propagation in the high-speed rail line when a random delay occurs.

  2. High Speed Railway Environment Safety Evaluation Based on Measurement Attribute Recognition Model

    Directory of Open Access Journals (Sweden)

    Qizhou Hu

    2014-01-01

    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.

  3. High-speed visual feedback for realizing high-performance robotic manipulation

    Science.gov (United States)

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

    2017-02-01

    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.

  4. High Speed Railway Environment Safety Evaluation Based on Measurement Attribute Recognition Model

    Science.gov (United States)

    Hu, Qizhou; Zhang, Bing

    2014-01-01

    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. PMID:25435866

  5. Mode Transition Variable Geometry for High Speed Inlets for Hypersonic Aircraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Hypersonic propulsion research has been a focus of the NASA aeronautics program for years. Previous high-speed cruise and space access programs have examined the...

  6. Turbulent Scalar Transport Model Validation for High Speed Propulsive Flows Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort entails the validation of a RANS turbulent scalar transport model (SFM) for high speed propulsive flows, using new experimental data sets and...

  7. High-Speed Prediction for Real-Time Debris Risk Assessment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our innovation is a high-speed method for the prediction of aerodynamic debris fields that employs an extensive database of generalized empirical equations coupled...

  8. High-Speed, Low-Power ADC for Digital Beam Forming (DBF) Systems, Phase II

    Data.gov (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...

  9. Analysis and improvement of calculation procedure of high-speed centrifugal pumps

    Science.gov (United States)

    Kraeva, E. M.; Masich, I. S.

    2017-10-01

    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.

  10. OptoCeramic-Based High Speed Fiber Multiplexer for Multimode Fiber, Phase I

    Data.gov (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...

  11. Optimal design of high-speed loading spindle based on ABAQUS

    Science.gov (United States)

    Yang, Xudong; Dong, Yu; Ge, Qingkuan; Yang, Hai

    2017-12-01

    The three-dimensional model of high-speed loading spindle is established by using ABAQUS’s modeling module. A finite element analysis model of high-speed loading spindle was established by using spring element to simulate bearing boundary condition. The static and dynamic performance of the spindle structure with different specifications of the rectangular spline and the different diameter neck of axle are studied in depth, and the influence of different spindle span on the static and dynamic performance of the high-speed loading spindle is studied. Finally, the optimal structure of the high-speed loading spindle is obtained. The results provide a theoretical basis for improving the overall performance of the test-bed

  12. Shock Mitigation for the Human on High Speed Craft: Development of an Impact Injury Design Rule

    National Research Council Canada - National Science Library

    Peterson, Ron; Pierce, Eric; Price, Brian; Bass, Cameron

    2004-01-01

    Occupants of U.S. Special Operations high speed craft are exposed to severe and repeated shock loads during operation in heavy seas, leading to an alarming incidence of reported chronic and acute musculoskeletal injuries...

  13. Evaluation and Selection of Technology Concepts for a Hypersonic High Speed Standoff Missile

    National Research Council Canada - National Science Library

    Roth, Bryce

    1999-01-01

    This paper describes the application of a method for technology concept selection to the design of a hypersonic high-speed standoff missile capable of achieving pin-point strike of long-range targets...

  14. Characterization of tool wear in high-speed milling of hardened powder metallurgical steels

    OpenAIRE

    Klocke, Fritz; Arntz, Kristian; Cabral, Gustavo Francisco; Stolorz, Martin; Busch, Marc

    2011-01-01

    In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC) and the high speed steel HS 6-5-3 PM (S790...

  15. High speed data transmission coaxial-cable in the space communication system

    Science.gov (United States)

    Su, Haohang; Huang, Jing

    2018-01-01

    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.

  16. Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure

    OpenAIRE

    Ding, You-Liang; Wang, Gao-Xin; Sun, Peng; Wu, Lai-Yi; Yue, Qing

    2015-01-01

    Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM) system has been implemented on this bridge by the application of modern techniques in sens...

  17. Ultra-High Speed Switching Functionalities using none-linear fibres

    DEFF Research Database (Denmark)

    Galili, Michael

    2007-01-01

    This thesis deals with optical signal processing of high-speed optical data signals at 160-640 Gbit/s. By exploiting non-linear effects in optical fibres several signal processing functionalities are implemented. This includes wavelength conversion of intensity modulated and phase modulated data...... signals, conversion between intensity and phase modulation, clock recovery for synchronising a receiver to an incoming data signal and finally reduction of timing sensitivity in such high-speed systems....

  18. TECHNICAL APPROACH TO THE EFFICIENCY DETERMINATION OF HIGH-SPEED TRAINS

    Directory of Open Access Journals (Sweden)

    A. V. Momot

    2013-11-01

    Full Text Available Purpose. The aim of this article is to develop an approach and formulate arrangements concerning the definition of the economic appropriateness of high-speed movement implementation in Ukraine. Methodology. The economic feasibility for appropriateness of high-speed movement organization in Ukraine is an investment project, which involves step-by-step money investment into the construction. It will let get an annual profits from the passenger carriage. To solve such problems we use net present value, which UZ or newly created companies can get during the project realization and after its completion. Findings. Obtained studies can state the fact that the technical approach for full effectiveness definition of a construction and high-speed passenger trains service taking into account the cost of infrastructure, rolling stock, the impact of environmental factors, etc. was determined. Originality. We propose a scientific approach to determine the economic effectiveness of the construction and high-speed main lines service. It includes improved principles of defining the passenger traffic, the cost of high-speed rails construction, the number of rolling stock; optimizes income and expenditure calculations in the context of competitive advantages and the external factors impact on the company. A technical approach for the calculation of future traffic volumes along the high-speed line was improved. It differs essentially from the European one proposed by the French firm «SYSTRA», as it allows taking into account additional transit traffic through Ukraine. It helps to distribute the passengers on separate sections proportionally to the number of cities population, which are combined by high-speed main line, subject to the average population mobility, travel time and the coefficient that takes into account the frequency of additional passenger trips on a given section, depending on the purpose (business trip, transfer to a plane, recreation, etc

  19. Assessment of modern methods in numerical simulations of high speed flows

    Science.gov (United States)

    Pindera, M. Z.; Yang, H. Q.; Przekwas, A. J.; Tucker, K.

    1992-01-01

    Results of extensive studies on CFD algorithms for 2D inviscid flows in Cartesian and body fitted coordinates geometries are reviewed. These studies represent part of an ongoing investigation of combustion instabilities involving the interactions of high-speed nonlinear acoustic waves. Four numerical methods for the treatment of high speed flows are compared, namely, Roe-Sweby TVD, Yee symmetric TVD; Osher-Chakravarthy TVD; and the Colella's multi-dimensional Godunov method.

  20. New high-speed line Nuremberg - Ingolstadt - Electrical engineering equipment; Neubaustrecke (NBS) Nuernberg - Ingolstadt - Technische Ausruestung

    Energy Technology Data Exchange (ETDEWEB)

    Krems, S. [Balfour Beatty Rail GmbH, Berlin (Germany); Matthes, U. [DB Projektbau GmbH, Nuernberg (Germany)

    2007-07-01

    The Bavarian fast railway line Nuremberg - Ingolstadt is equipped with most recent railway infrastructure for a 300 km/h fast high-speed traffic. The electrical engineering installations were implemented within a seven years period. Since December 2006 the line has been integrated into scheduled services and operated with high-speed trains. So far, the installations complied fully with all the requirements. (orig.)

  1. High Speed PAM -8 Optical Interconnects with Digital Equalization based on Neural Network

    DEFF Research Database (Denmark)

    Gaiarin, Simone; Pang, Xiaodan; Ozolins, Oskars

    2016-01-01

    We experimentally evaluate a high-speed optical interconnection link with neural network equalization. Enhanced equalization performances are shown comparing to standard linear FFE for an EML-based 32 GBd PAM-8 signal after 4-km SMF transmission.......We experimentally evaluate a high-speed optical interconnection link with neural network equalization. Enhanced equalization performances are shown comparing to standard linear FFE for an EML-based 32 GBd PAM-8 signal after 4-km SMF transmission....

  2. Dynamic Range Enhancement of High-Speed Electrical Signal Data via Non-Linear Compression

    Science.gov (United States)

    Laun, Matthew C. (Inventor)

    2016-01-01

    Systems and methods for high-speed compression of dynamic electrical signal waveforms to extend the measuring capabilities of conventional measuring devices such as oscilloscopes and high-speed data acquisition systems are discussed. Transfer function components and algorithmic transfer functions can be used to accurately measure signals that are within the frequency bandwidth but beyond the voltage range and voltage resolution capabilities of the measuring device.

  3. Case Analysis Of The Joint High Speed Vessel Program: Defense Acquisition

    Science.gov (United States)

    2016-09-01

    Surveillance and Reconnaissance (C4ISR), Joint High- Speed Vessel (JHSV), Global War on Terrorism (GWOT), Civilian Mariners (CIVMAR), Contract Mariners (CONMAR...on Terrorism HSV High-Speed Vessel ILS Integrated Logistics Support IPT Integrated Product Team JCIDS Joint Capabilities Integration and...Watson, for her support and patience. The late nights of studying and preparation for class presentations and projects, to include this one, tend to

  4. Research on high-speed railway's vibration analysis checking based on intelligent mobile terminal

    Science.gov (United States)

    Li, Peigang; Xie, Shulin; Zhao, Xuefeng

    2017-04-01

    Recently, the development of high-speed railway meets the requirement of society booming and it has gradually become the first choice for long-length journey. Since ensuring the safety and stable operation are of great importance to high-speed trains owing to its unique features, vibration analysis checking is one of main means to be adopted. Due to the popularization of Smartphone, in this research, a novel public-participating method to achieve high-speed railway's vibration analysis checking based on smartphone and an inspection application of high-speed railway line built in the intelligent mobile terminal were proposed. Utilizing the accelerometer, gyroscope, GPS and other high-performance sensors which were integrated in smartphone, the application can obtain multiple parameters like acceleration, angle, etc and pinpoint the location. Therefore, through analyzing the acceleration data in time domain and frequency domain using fast Fourier transform, the research compared much of data from monitoring tests under different measure conditions and measuring points. Furthermore, an idea of establishing a system about analysis checking was outlined in paper. It has been validated that the smartphone-based high-speed railway line inspection system is reliable and feasible on the high-speed railway lines. And it has more advantages, such as convenience, low cost and being widely used. Obviously, the research has important practical significance and broad application prospects.

  5. The Long-Term Settlement Deformation Automatic Monitoring System for the Chinese High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Xu Wang

    2015-01-01

    Full Text Available The Beijing-Shanghai high-speed railway is one of the milestones of China’s high-speed railway development and its security plays a significant role in China’s economic and social development. However, the evaluation methods used for large-scale security operations and important infrastructure systems, such as the high-speed railways, are discrete and nonlinear; thus they cannot issue emergency warnings in a timely manner. The emergence of optical fiber sensing technology can solve this problem. This technology has progressed rapidly in its application to the monitoring of railway security and it has attracted much attention within the industry. This study considers the newly built passenger railway line between Shijiazhuang and Jinan as an example. The web-based, all-in-one fiber Bragg grating static level is described as well as a set of online monitoring systems, which is automated, real-time, remote, visual, and adaptable to the standards of the Beijing-Shanghai high-speed railway. According to our theoretical analysis, the planned automated monitoring of settlement deformation for the Beijing-Shanghai high-speed railway and the real-time analysis and calculation of monitoring data can ensure the operational security of this section of China’s high-speed railway system.

  6. High-Speed Photography and Digital Optical Measurement Techniques for Geomaterials: Fundamentals and Applications

    Science.gov (United States)

    Xing, H. Z.; Zhang, Q. B.; Braithwaite, C. H.; Pan, B.; Zhao, J.

    2017-06-01

    Geomaterials (i.e. rock, sand, soil and concrete) are increasingly being encountered and used in extreme environments, in terms of the pressure magnitude and the loading rate. Advancing the understanding of the mechanical response of materials to impact loading relies heavily on having suitable high-speed diagnostics. One such diagnostic is high-speed photography, which combined with a variety of digital optical measurement techniques can provide detailed insights into phenomena including fracture, impact, fragmentation and penetration in geological materials. This review begins with a brief history of high-speed imaging. Section 2 discusses of the current state of the art of high-speed cameras, which includes a comparison between charge-coupled device and complementary metal-oxide semiconductor sensors. The application of high-speed photography to geomechanical experiments is summarized in Sect. 3. Section 4 is concerned with digital optical measurement techniques including photoelastic coating, Moiré, caustics, holographic interferometry, particle image velocimetry, digital image correlation and infrared thermography, in combination with high-speed photography to capture transient phenomena. The last section provides a brief summary and discussion of future directions in the field.

  7. Electron accelerating unit for streak image tubes

    Indian Academy of Sciences (India)

    Keywords. High-speed photography; streak camera; Monte Carlo; electro-optical devices. 1. Introduction. Streak cameras are among the most valuable instruments for recording ultrafast phenomena in laser-driven inertial confinement fusion (ICF) experiments, and streak image tubes (SITs) are a core part of streak cameras.

  8. Investigating technical challenges and research needs related to shared corridors for high speed passenger and railroad freight operations.

    Science.gov (United States)

    2013-05-01

    The development of both incremental and dedicated high-speed rail lines in the United States poses a number of questions. Despite nearly 50 years of international experience in planning, designing, building and operating high-speed passenger infrastr...

  9. Measuring with the spiral reader

    CERN Multimedia

    1974-01-01

    The spiral reader shown here was at the time, together with the Shivamatic scanning system, the basic equipment used for measuring bubble chamber pictures. Anne Anton sits at the table. (See Photo Archive 7408343.)

  10. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine

    2015-08-20

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body is configured to receive water and a disinfectant at the inlet such that the water is exposed to the disinfectant as the water flows through the spiral flow path. Also disclosed are processes for disinfecting water in such disinfection reactors.

  11. Spiral inlets for steam turbines

    Science.gov (United States)

    Škach, Radek; Uher, Jan

    2017-09-01

    This paper deals with the design process of special nozzle blades for spiral inlets. Spiral inlets are used for the first stages of high pressure and intermediate pressure steam turbines with both reaction and impulse blades when throttling or sliding pressure control is applied. They improve the steam flow uniformity from the inlet pipe and thus decrease the aerodynamic losses. The proposed evaluation of the inlet angle is based on the free vortex law.

  12. INVESTIGATION OF AERODYNAMIC PRESSURE DURING THE HIGH-SPEED TRAIN PASSAGE

    Directory of Open Access Journals (Sweden)

    S. T. Djabbarov

    2016-10-01

    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.

  13. High-speed image analysis reveals chaotic vibratory behaviors of pathological vocal folds

    International Nuclear Information System (INIS)

    Zhang Yu; Shao Jun; Krausert, Christopher R.; Zhang Sai; Jiang, Jack J.

    2011-01-01

    Research highlights: → Low-dimensional human glottal area data. → Evidence of chaos in human laryngeal activity from high-speed digital imaging. → Traditional perturbation analysis should be cautiously applied to aperiodic high speed image signals. → Nonlinear dynamic analysis may be helpful for understanding disordered behaviors in pathological laryngeal systems. - Abstract: Laryngeal pathology is usually associated with irregular dynamics of laryngeal activity. High-speed imaging facilitates direct observation and measurement of vocal fold vibrations. However, chaotic dynamic characteristics of aperiodic high-speed image data have not yet been investigated in previous studies. In this paper, we will apply nonlinear dynamic analysis and traditional perturbation methods to quantify high-speed image data from normal subjects and patients with various laryngeal pathologies including vocal fold nodules, polyps, bleeding, and polypoid degeneration. The results reveal the low-dimensional dynamic characteristics of human glottal area data. In comparison to periodic glottal area series from a normal subject, aperiodic glottal area series from pathological subjects show complex reconstructed phase space, fractal dimension, and positive Lyapunov exponents. The estimated positive Lyapunov exponents provide the direct evidence of chaos in pathological human vocal folds from high-speed digital imaging. Furthermore, significant differences between the normal and pathological groups are investigated for nonlinear dynamic and perturbation analyses. Jitter in the pathological group is significantly higher than in the normal group, but shimmer does not show such a difference. This finding suggests that the traditional perturbation analysis should be cautiously applied to high speed image signals. However, the correlation dimension and the maximal Lyapunov exponent reveal a statistically significant difference between normal and pathological groups. Nonlinear dynamic

  14. Impact of Increased Football Field Width on Player High-Speed Collision Rate.

    Science.gov (United States)

    Joseph, Jacob R; Khalsa, Siri S; Smith, Brandon W; Park, Paul

    2017-07-01

    High-acceleration head impact is a known risk for mild traumatic brain injury (mTBI) based on studies using helmet accelerometry. In football, offensive and defensive players are at higher risk of mTBI due to increased speed of play. Other collision sport studies suggest that increased playing surface size may contribute to reductions in high-speed collisions. We hypothesized that wider football fields lead to a decreased rate of high-speed collisions. Computer football game simulation was developed using MATLAB. Four wide receivers were matched against 7 defensive players. Each offensive player was randomized to one of 5 typical routes on each play. The ball was thrown 3 seconds into play; ball flight time was 2 seconds. Defensive players were delayed 0.5 second before reacting to ball release. A high-speed collision was defined as the receiver converging with a defensive player within 0.5 second of catching the ball. The simulation counted high-speed collisions for 1 team/season (65 plays/game for 16 games/season = 1040 plays/season) averaged during 10 seasons, and was validated against existing data using standard field width (53.3 yards). Field width was increased in 1-yard intervals up to 58.3 yards. Using standard field width, 188 ± 4 high-speed collisions were seen per team per season (18% of plays). When field width increased by 3 yards, high-speed collision rate decreased to 135 ± 3 per team per season (28% decrease; P football field width can lead to substantial decline in high-speed collisions, with potential for reducing instances of mTBI in football players. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Analyzing the United States Department of Transportation's Implementation Strategy for High Speed Rail: Three Case Studies

    Science.gov (United States)

    Robinson, Ryan

    High-speed rail (HSR) has become a major contributor to the transportation sector with a strong push by the Obama Administration and the Department of Transportation to implement high-speed rail in the United States. High-speed rail is a costly transportation alternative that has the potential displace some car and airport travel while increase energy security and environmental sustainability. This thesis will examine the United States high-speed rail implementation strategy by comparing it to the implementation strategies of France, Japan, and Germany in a multiple case study under four main criteria of success: economic profitability, reliability, safety, and ridership. Analysis will conclude with lessons to be taken away from the case studies and applied to the United States strategy. It is important to understand that this project has not been established to create a comprehensive implementation plan for high-speed rail in the United States; rather, this project is intended to observe the depth and quality of the current United States implementation strategy and make additional recommendations by comparing it with France, Japan, and Germany.

  16. Mechanical analysis on magnesium alloy rotating mirror for ultra-high-speed camera

    Science.gov (United States)

    Li, Chunbo; Liu, Minqiu; Ren, Xikui; Du, Chenlin; Huang, Hongbin; Ruan, Shuangchen

    2018-03-01

    Rotating mirror is not only as an imaging element in optical path of ultra-high speed camera, where imaging quality is affected by surface quality and plane deformation of the rotating mirror, but also as an element to implement ultra-high speed, because performances of the ultra-high-speed camera system are mainly dependent on the static and dynamic mechanical properties of the rotating mirror. In this paper, the static and dynamic properties of magnesium alloy rotating mirror with equilateral-triangle cross-sections were investigated by theoretically and numerically method. At the speed of 2×105 rpm, the maximum lateral deformations of the mirror facet with width 17.32 mm and length 40 mm is 2.476 μm. The maximum von Mises stress is 35.1 MPa. The deformation and stress are less than that of aluminum alloy rotating mirror, which has been successfully applied in many types of RM for ultra-high speed cameras. The first three frequencies of magnesium alloy rotating mirror are 9,539.9 Hz, 9,540.9 Hz and 12,726.0 Hz, respectively. While the first three frequencies of aluminium alloy rotating-mirror are 9,683.9 Hz, 9,685.2 Hz and 11,016.0 Hz. From which it is preliminarily shown that a magnesium alloy rotating mirror can be used as replacement for an aluminium alloy rotating mirror in ultra-high-speed camera.

  17. Combined High-Speed 3D Scalar and Velocity Reconstruction of Hairpin Vortex

    Science.gov (United States)

    Sabatino, Daniel; Rossmann, Tobias; Zhu, Xuanyu; Thorsen, Mary

    2017-11-01

    The combination of 3D scanning stereoscopic particle image velocimetry (PIV) and 3D Planar Laser Induced Fluorescence (PLIF) is used to create high-speed three-dimensional reconstructions of the scalar and velocity fields of a developing hairpin vortex. The complete description of the regenerating hairpin vortex is needed as transitional boundary layers and turbulent spots are both comprised of and influenced by these vortices. A new high-speed, high power, laser-based imaging system is used which enables both high-speed 3D scanning stereo PIV and PLIF measurements. The experimental system uses a 250 Hz scanning mirror, two high-speed cameras with a 10 kHz frame rate, and a 40 kHz pulsed laser. Individual stereoscopic PIV images and scalar PLIF images are then reconstructed into time-resolved volumetric velocity and scalar data. The results from the volumetric velocity and scalar fields are compared to previous low-speed tomographic PIV data and scalar visualizations to determine the accuracy and fidelity of the high-speed diagnostics. Comparisons between the velocity and scalar field during hairpin development and regeneration are also discussed. Supported by the National Science Foundation under Grant CBET-1531475, Lafayette College,and the McCutcheon Foundation.

  18. Real-time simulation based on a high-speed signal processing system VHS-ADC

    Science.gov (United States)

    Fu, Zhihong; Ma, Jing; Sun, Rui

    2006-11-01

    Real-time simulation for power electronics needs high-speed data processing and sampling, but most real-time simulation systems, such as dSPACE, can't meet the high-speed demands. Lyrtech's VHS-ADC, a high-speed signal processing system based on FPGA, is configured with multi-channels A/D, D/A and GPIO port, seamless interoperability with MATLAB, which has been applied widely in communication, audio, video and radar high-speed signal processing fields. However, VHS-ADC doesn't support real-time controller modeling. By constructing real-time control models including PI, PWM, Limiter and Reset-integrator model, this paper constructs a high-speed real-time simulation platform suitable for power electronics field. Further, the PWM-based Boost converter experiments prove the feasibility of real-time simulation by the rebuilt system, with Boost's switching frequency 100 kHz and its cycle 10μs. At frequency 100MHz, the corresponding simulation cycle is no more than 300ns, much less than switching cycle. Compared with TL494's waveform, it is proved that, as a novel way, VHS-ADC can support flexibly modeling process in real-time simulations with significant performance.

  19. Preknock Vibrations in a Spark-Ignition Engine Cylinder as Revealed by High-Speed Photography

    Science.gov (United States)

    Miller, Cearcy D; Logan, Walter O , Jr

    1944-01-01

    The high-speed photographic investigation of the mechanics of spark-ignition engine knock recorded in three previous reports has been extended with use of the NACA high-speed camera and combustion apparatus with a piezoelectric pressure pickup in the combustion chamber. The motion pictures of knocking combustion were taken at the rate of 40,000 frames per second. Existence of the preknock vibrations in the engine cylinder suggested in Technical Report no.727 has been definitely proved and the vibrations have been analyzed both in the high-speed motion pictures and the pressure traces. Data are also included to show that the preknock vibrations do not progressively build up to cause knock. The effect of tetraethyl lead on the preknock vibrations has been studied and results of the tests are presented. Photographs are presented which in some cases clearly show evidence of autoignition in the end zone a considerable length of time before knock occurs.

  20. High-speed photography and holography of laser induced breakdown in liquids

    International Nuclear Information System (INIS)

    Lauterborn, W.

    1979-01-01

    Optical breakdown phenomena in liquids due to focused ruby laser light are investigated by high-speed photography and holography. Special attention is given the dynamics of the cavities produced in the liquid upon breakdown as they can be expected to become a powerful research tool in cavitation physics. To this end the production of three-dimensional breakdown configurations would be desirable as well as their investigation by high-speed holographic means. Both problems are presently under study. To achieve multiple breakdown at preselected points in the liquid a grating-lens assembly and digital holograms in photoresist are used. To film the motion of the cavities high-speed holocinematographic methods are developed. By now four to eight holograms can be taken at a rate of 10 to 20 kHz. (author)

  1. Experimental High Speed Milling of the Selected Thin-Walled Component

    Directory of Open Access Journals (Sweden)

    Jozef Zajac

    2017-11-01

    Full Text Available In a technical practice, it is possible to meet thin-walled parts more and more often. These parts are most commonly used in the automotive industry or aircraft industry to reduce the weight of different design part of cars or aircraft. Presented article is focused on experimental high speed milling of selected thin-walled component. The introduction of this article presents description of high speed machining and specification of thin – walled parts. The experiments were carried out using a CNC machine Pinnacle VMC 650S and C45 material - plain carbon steel for automotive components and mechanical engineering. In the last part of the article, described are the arrangements to reduction of deformation of thin-walled component during the experimental high speed milling.

  2. High-speed X-ray phase tomography with Talbot interferometer and fringe scanning method

    International Nuclear Information System (INIS)

    Kibayashi, Shunsuke; Harasse, Sébastien; Yashiro, Wataru; Momose, Atsushi

    2012-01-01

    High-speed X-ray phase tomography based on the Fourier-transform method has been demonstrated with an X-ray Talbot interferometer using white synchrotron radiation. We report the experimental results of high-speed X-ray phase tomography with fringe-scanning method instead of Fourier-transform method to improve spatial resolution without a considerable increase of scan time. To apply fringe-scanning method to high speed tomography, we tested a scan that is a synchronous combination of one-way continuous movements of the sample rotation and the grating displacement. When this scanning method was combined with X-ray phase tomography, we were able to obtain a scan time of 5 s. A comparison of the image quality derived with the conventional approach and with the proposed approach using the fringe-scanning method showed that the latter had better spatial resolution.

  3. On The Export Control Of High Speed Imaging For Nuclear Weapons Applications

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott Avery [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Altherr, Michael Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-15

    Since the Manhattan Project, the use of high-speed photography, and its cousins flash radiography1 and schieleren photography have been a technological proliferation concern. Indeed, like the supercomputer, the development of high-speed photography as we now know it essentially grew out of the nuclear weapons program at Los Alamos2,3,4. Naturally, during the course of the last 75 years the technology associated with computers and cameras has been export controlled by the United States and others to prevent both proliferation among non-P5-nations and technological parity among potential adversaries among P5 nations. Here we revisit these issues as they relate to high-speed photographic technologies and make recommendations about how future restrictions, if any, should be guided.

  4. Embedded systems design for high-speed data acquisition and control

    CERN Document Server

    Di Paolo Emilio, Maurizio

    2015-01-01

    This book serves as a practical guide for practicing engineers who need to design embedded systems for high-speed data acquisition and control systems. A minimum amount of theory is presented, along with a review of analog and digital electronics, followed by detailed explanations of essential topics in hardware design and software development. The discussion of hardware focuses on microcontroller design (ARM microcontrollers and FPGAs), techniques of embedded design, high speed data acquisition (DAQ) and control systems. Coverage of software development includes main programming techniques, culminating in the study of real-time operating systems. All concepts are introduced in a manner to be highly-accessible to practicing engineers and lead to the practical implementation of an embedded board that can be used in various industrial fields as a control system and high speed data acquisition system.   • Describes fundamentals of embedded systems design in an accessible manner; • Takes a problem-solving ...

  5. High-speed and high-fidelity system and method for collecting network traffic

    Science.gov (United States)

    Weigle, Eric H [Los Alamos, NM

    2010-08-24

    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.

  6. A study on high speed coupling design for wind turbine using a finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyoung Woo; Kang, Jong Hun [Dept. of Mechatronics Engineering, Jungwon University, Geosan (Korea, Republic of); Han, Jeong Young [Pusan Educational Center for Computer Aided Machine Design, Pusan University, Busan (Korea, Republic of)

    2016-08-15

    The purpose of this study is to design a high speed coupling for 3 MW wind turbines and evaluate its structural stability. A basic analysis was performed to assess the structural stability of two materials, SPS6 steel plate and a composite material (Glass7628, Glass/Epoxy), in relation to misalignment in the axial and radial directions. The entire model was analyzed for a high speed coupling based on the SPS6 steel plate, which was found to have higher stability among the two materials, and safety factors were estimated for various levels of power delivery. To test the proposed high speed coupling design, a performance test was carried out to verify the stability of the final product.

  7. Monolithic integration of high-speed Ge photo-detectors on SOI-based WDM receivers

    Science.gov (United States)

    Qian, Wei; Feng, Dazeng; Liang, Hong; Zhou, Joe; Liu, Yong; Liao, Shirong; Kung, Cheng-Chih; Fong, Joan; Luff, B. Jonathan; Shafiiha, Roshanak; Lee, Daniel; White, Wayne; Asghari, Mehdi

    2012-06-01

    We report a novel, compact design of high speed Ge photo detector integrated with an echelle demultiplexer on a large cross-section SOI platform with low insertion loss and low fiber coupling loss. A narrow Ge photo detector waveguide is directly butt-coupled to a Si waveguide to ensure low loss and high speed operation. With a Ge detector size of only 0.8×15 μm2, the device achieves greater than 30 GHz modulation speed. The results indicate that the device speed is transit time limited and that the detector performance benefits from the high electron and hole drift velocity of germanium. The dark current of the detector is less than 0.5μA at -1V. This small footprint high speed Si-based WDM receiver can be fabricated using CMOS processes and used for multichannel terabit data transmission with low manufacturing cost.

  8. The Next Generation of High-Speed Dynamic Stability Wind Tunnel Testing (Invited)

    Science.gov (United States)

    Tomek, Deborah M.; Sewall, William G.; Mason, Stan E.; Szchur, Bill W. A.

    2006-01-01

    Throughout industry, accurate measurement and modeling of dynamic derivative data at high-speed conditions has been an ongoing challenge. The expansion of flight envelopes and non-conventional vehicle design has greatly increased the demand for accurate prediction and modeling of vehicle dynamic behavior. With these issues in mind, NASA Langley Research Center (LaRC) embarked on the development and shakedown of a high-speed dynamic stability test technique that addresses the longstanding problem of accurately measuring dynamic derivatives outside the low-speed regime. The new test technique was built upon legacy technology, replacing an antiquated forced oscillation system, and greatly expanding the capabilities beyond classic forced oscillation testing at both low and high speeds. The modern system is capable of providing a snapshot of dynamic behavior over a periodic cycle for varying frequencies, not just a damping derivative term at a single frequency.

  9. Energy Efficient Control of High Speed IPMSM Drives - A Generalized PSO Approach

    Directory of Open Access Journals (Sweden)

    GECIC, M.

    2016-02-01

    Full Text Available In this paper, a generalized particle swarm optimization (GPSO algorithm was applied to the problems of optimal control of high speed low cost interior permanent magnet motor (IPMSM drives. In order to minimize the total controllable electrical losses and to increase the efficiency, the optimum current vector references are calculated offline based on GPSO for the wide speed range and for different load conditions. The voltage and current limits of the drive system and the variation of stator inductances are all included in the optimization method. The stored optimal current vector references are used during the real time control and the proposed algorithm is compared with the conventional high speed control algorithm, which is mostly voltage limit based. The computer simulations and experimental results on 1 kW low cost high speed IPMSM drive are discussed in details.

  10. Real time data compactor (sparsifier) and 8 megabyte high speed FIFO for HEP

    Energy Technology Data Exchange (ETDEWEB)

    Baumbaugh, A.E.; Knickerbocker, K.L.; Wegner, C.R.; Baumbaugh, B.W.; Ruchti, R.

    1985-10-01

    A Video-Data-Acquisition-System (VDAS) has been developed to record image data from a scintillating glass fiber-optic target developed for High Energy Physics. The major components of the VDAS are a flash ADC, a ''real time'' high speed data compactor, and high speed 8 megabyte FIFO memory. The data rates through the system are in excess of 30 megabytes/second. The compactor is capable of reducing the amount of data needed to reconstruct typical images by as much as a factor of 20. The FIFO uses only standard NMOS DRAMS and TTL components to achieve its large size and high speed at relatively low power and cost.

  11. All-optical ultra-high-speed OFDM to Nyquist-WDM conversion

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

    2015-01-01

    We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER <10−9 performance for all channels.......We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER

  12. Modeling and numerical techniques for high-speed digital simulation of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, W.; Cheng, H.S.; Mallen, A.N.

    1987-01-01

    Conventional computing methods are contrasted with newly developed high-speed and low-cost computing techniques for simulating normal and accidental transients in nuclear power plants. Six principles are formulated for cost-effective high-fidelity simulation with emphasis on modeling of transient two-phase flow coolant dynamics in nuclear reactors. Available computing architectures are characterized. It is shown that the combination of the newly developed modeling and computing principles with the use of existing special-purpose peripheral processors is capable of achieving low-cost and high-speed simulation with high-fidelity and outstanding user convenience, suitable for detailed reactor plant response analyses.

  13. Propulsion challenges for a 21st century economically viable, environmentally compatible High-Speed Civil Transport

    Science.gov (United States)

    Shaw, Robert J.

    1991-01-01

    Recent NASA funded studies suggest an opportunity exists for a 21st Century High Speed Civil Transport (HSCT) to become part of the international air transportation system. However, before this opportunity for high speed travel can be realized, certain environmental and economic barrier issues must be overcome. These challenges are outlined. Research activities which NASA has planned to address these barrier issues and provide a technology base to allow the U.S. manufacturers to make an informed go/no go decision on developing an HSCT are discussed.

  14. Engine technology challenges for a 21st century high speed civil transport

    Science.gov (United States)

    Shaw, Robert J.

    1991-01-01

    Recent NASA funded studies by Boeing and Douglas suggest an opportunity exists for a 21st Century High Speed Civil Transport (HSCT) to become part of the international air transportation system. However, before this opportunity for high speed travel can be realized, certain environmental and and economic barrier issues must be overcome. These challenges are outlined. Research activities which NASA has planned to address these barrier issues and to provide a technology base to allow U.S. manufacturers to make an informed go/no go decision on developing the HSCT are discussed.

  15. The development of an open architecture control system for CBN high speed grinding

    OpenAIRE

    Silva, E. Jannone da; Biffi, M.; Oliveira, J. F. G. de

    2004-01-01

    The aim of this project is the development of an open architecture controlling (OAC) system to be applied in the high speed grinding process using CBN tools. Besides other features, the system will allow a new monitoring and controlling strategy, by the adoption of open architecture CNC combined with multi-sensors, a PC and third-party software. The OAC system will be implemented in a high speed CBN grinding machine, which is being developed in a partnership between the University of São Paul...

  16. CMOS analog integrated circuits high-speed and power-efficient design

    CERN Document Server

    Ndjountche, Tertulien

    2011-01-01

    High-speed, power-efficient analog integrated circuits can be used as standalone devices or to interface modern digital signal processors and micro-controllers in various applications, including multimedia, communication, instrumentation, and control systems. New architectures and low device geometry of complementary metaloxidesemiconductor (CMOS) technologies have accelerated the movement toward system on a chip design, which merges analog circuits with digital, and radio-frequency components. CMOS: Analog Integrated Circuits: High-Speed and Power-Efficient Design describes the important tren

  17. Influence on the rectifiers of rotor losses in high-speed permanent magnet synchronous alternator

    Science.gov (United States)

    Jang, Seok-Myeong; Cho, Han-Wook; Jeong, Yeon-Ho

    2006-04-01

    This article deals with the rotor losses in the high-speed permanent magnet (PM) synchronous alternator for distributed power generation system. Specifically, the influence of rectifiers on the rotor losses is investigated. On the basis of analytical field analysis and two-dimensional finite element analysis, this article predicts the flux harmonics and rotor losses in the PM alternator considering the rectifier load. The prototype machine with the rectifier load has been fabricated and tested. Moreover, the difference of rotor losses between the high-speed alternator with and without the rectifier is made quantitatively clear in this work.

  18. A high speed dual-gain preamplifier system with multiple channels

    International Nuclear Information System (INIS)

    Zhao Lei; Liu Shubin; Xian Ze; An Qi

    2008-01-01

    In this paper, a multiple-channel high speed preamplifier module with dual-gain is presented, together with its design principle, test methods and performance parameter. By proper choice of the chips and careful circuit design, the preamplifier accomplishes a fine performance in high speed analog signal processing. The 3 dB bandwidth is above 440 MHz for gain factor of 2 and 280 MHz for gain factor of 8, with the leading edge time of less than 2 ns. The preamplifier module has been used in the research project of β-delayed neutron emission of radionuclides in neutron-rich region. (authors)

  19. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains.

    Directory of Open Access Journals (Sweden)

    Boliang Lin

    Full Text Available This paper presents a 0-1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China's high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers.

  20. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains.

    Science.gov (United States)

    Lin, Boliang; Wang, Jiaxi; Wang, Huasheng; Wang, Zhongkai; Li, Jian; Lin, Ruixi; Xiao, Jie; Wu, Jianping

    2017-01-01

    This paper presents a 0-1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China's high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers.

  1. System Design of a Cheetah Robot Toward Ultra-high Speed

    OpenAIRE

    Mantian Li; Xin Wang; Wei Guo; Pengfei Wang; Lining Sun

    2014-01-01

    High-speed legged locomotion pushes the limits of the most challenging problems of design and development of the mechanism, also the control and the perception method. The cheetah is an existence proof of concept of what we imitate for high-speed running, and provides us lots of inspiration on design. In this paper, a new model of a cheetah-like robot is developed using anatomical analysis and design. Inspired by a biological neural mechanism, we propose a novel control method for controlling...

  2. Electrification of the Wuhan - Guangzhou high-speed line; Elektrifizierung der Hochgeschwindigkeitsstrecke Wuhan - Guangzhou

    Energy Technology Data Exchange (ETDEWEB)

    Zimmert, Gerhard; Solka, Martin [Balfour Beatty Rail GmbH, Wuhan - Guangzhou Passenger Dedicated Line Electrification, Wuhan (China)

    2009-07-01

    The Chinese Railways have started to build up their planned high-speed railway network. After the first section from Beijing to Tianjin had been taken into service on the occasion of the 2008 Olympic Games, activities are now focussed on the implementation of the world's largest high-speed railway project between Wuhan and Guangzhou. In both projects the German industry is involved with extensive supplies and the transfer of know-how. The Wuhan - Guangzhou project is presently in the phase of equipment installation and is scheduled to be finished by the end of 2009. (orig.)

  3. Twenty years of high-speed lines in Spain; Zwanzig Jahre Hochgeschwindigkeitsstrecken in Spanien

    Energy Technology Data Exchange (ETDEWEB)

    Vega Vega, Tomas [ADIF, Madrid (Spain); Gil Ortiz, Jose Miguel [Balfour Beatty Rail Iberica, Alcobendas (Spain)

    2012-07-15

    In April 1992, i.e. 20 years ago, fast train services started in Spain when high-speed trains were put into operation on the almost 500 km long Madrid-Cordoba-Sevilla railway line. Both the 1,435 mm UIC standard gauge and the 1 AC 25 kV 50 Hz overhead line voltage level meant a big step in the development. Today the Spanish high-speed network covers some 2,200 km of railway line, and more lines are planned or already under construction. (orig.)

  4. High-Speed Computation using FPGA for Excellent Performance of Direct Torque Control of Induction Machines

    Directory of Open Access Journals (Sweden)

    Tole Sutikno

    2016-03-01

    Full Text Available The major problems in hysteresis-based DTC are high torque ripple and variable switching frequency. In order to minimize the torque ripple, high sampling time and fast digital realization should be applied. The high sampling and fast digital realization time can be achieved by utilizing high-speed processor where the operation of the discrete hysteresis regulator is becoming similar to the operation of analog-based comparator. This can be achieved by utilizing field programmable gate array (FPGA which can perform a sampling at a very high speed, compared to the fact that developing an ASIC chip is expensive and laborious.

  5. Radiated Sound of a High-Speed Water-Jet-Propelled Transportation Vessel.

    Science.gov (United States)

    Rudd, Alexis B; Richlen, Michael F; Stimpert, Alison K; Au, Whitlow W L

    2016-01-01

    The radiated noise from a high-speed water-jet-propelled catamaran was measured for catamaran speeds of 12, 24, and 37 kn. The radiated noise increased with catamaran speed, although the shape of the noise spectrum was similar for all speeds and measuring hydrophone depth. The spectra peaked at ~200 Hz and dropped off continuously at higher frequencies. The radiated noise was 10-20 dB lower than noise from propeller-driven ships at comparable speeds. The combination of low radiated noise and high speed could be a factor in the detection and avoidance of water-jet-propelled ships by baleen whales.

  6. Modeling and numerical techniques for high-speed digital simulation of nuclear power plants

    International Nuclear Information System (INIS)

    Conventional computing methods are contrasted with newly developed high-speed and low-cost computing techniques for simulating normal and accidental transients in nuclear power plants. Six principles are formulated for cost-effective high-fidelity simulation with emphasis on modeling of transient two-phase flow coolant dynamics in nuclear reactors. Available computing architectures are characterized. It is shown that the combination of the newly developed modeling and computing principles with the use of existing special-purpose peripheral processors is capable of achieving low-cost and high-speed simulation with high-fidelity and outstanding user convenience, suitable for detailed reactor plant response analyses

  7. Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

  8. Tribological resistance of high speed steel HS 6-5-2 remelted with electric arc

    Directory of Open Access Journals (Sweden)

    A. Dziedzic

    2009-07-01

    Full Text Available The intensity of tribological wear of the high speed steel HS 6-5-2 remelted with the GTAW method has been compared to the heat treatment steel in a conventional way. Moreover, the types of the wear appeared during the friction. The tribiological research, were done in the technically dry friction conditions on a testing machine of the pin-on-disc T-01M. The smallest intensity of wear was shown by the high speed steel remelted with the parameters leading to obtain the biggest speed of cooling of the molten metal. The main wear type appearing during the research, was the abrasion and adhesive wear.

  9. Application of oblique plane microscopy to high speed live cell imaging

    Science.gov (United States)

    Kumar, Sunil; Wilding, Dean; Sikkel, Markus B.; Lyon, Alexander R.; MacLeod, Ken T.; Dunsby, Chris

    2011-07-01

    Oblique Plane Microscopy (OPM) is a light sheet microscopy technique that combines oblique illumination with correction optics that tilt the focal plane of the collection system. OPM can be used to image conventionally mounted specimens on coverslips or tissue culture dishes and has low out-of-plane photobleaching and phototoxicity. No moving parts are required to achieve an optically sectioned image and so high speed optically sectioned imaging is possible. We present high speed 2D and 3D optically sectioned OPM imaging of live cells using a high NA water immersion lens.

  10. Positivity-preserving space-time CE/SE scheme for high speed flows

    KAUST Repository

    Shen, Hua

    2017-03-02

    We develop a space-time conservation element and solution element (CE/SE) scheme using a simple slope limiter to preserve the positivity of the density and pressure in computations of inviscid and viscous high-speed flows. In general, the limiter works with all existing CE/SE schemes. Here, we test the limiter on a central Courant number insensitive (CNI) CE/SE scheme implemented on hybrid unstructured meshes. Numerical examples show that the proposed limiter preserves the positivity of the density and pressure without disrupting the conservation law; it also improves robustness without losing accuracy in solving high-speed flows.

  11. Usage of super high speed computer for clarification of complex phenomena

    International Nuclear Information System (INIS)

    Sekiguchi, Tomotsugu; Sato, Mitsuhisa; Nakata, Hideki; Tatebe, Osami; Takagi, Hiromitsu

    1999-01-01

    This study aims at construction of an efficient super high speed computer system application environment in response to parallel distributed system with easy transplantation to different computer system and different number by conducting research and development on super high speed computer application technology required for elucidation of complicated phenomenon in elucidation of complicated phenomenon of nuclear power field due to computed scientific method. In order to realize such environment, the Electrotechnical Laboratory has conducted development on Ninf, a network numerical information library. This Ninf system can supply a global network infrastructure for worldwide computing with high performance on further wide range distributed network (G.K.)

  12. A High-Speed Detector System for X-ray Fluorescence Microprobes.

    Energy Technology Data Exchange (ETDEWEB)

    Siddons,P.D.; Dragone, A.; De Geronimo, g.; Kuczewski, A.; Kuczewski, J.; O

    2006-10-29

    We have developed a high-speed system for collecting x-ray fluorescence microprobe data, based on ASICs developed at BNL and high-speed processors developed by CSIRO. The system can collect fluorescence data in a continuous raster scan mode, and present elemental images in real time using Ryan's Dynamic Analysis algorithm. We will present results from a 32-element prototype array illustrating the concept. The final instrument will have 384 elements arranged in a square array around a central hole.

  13. High-speed photography of dynamic photoelastic experiment with a highly accurate blasting machine

    Science.gov (United States)

    Katsuyama, Kunihisa; Ogata, Yuji; Wada, Yuji; Hashizume, K.

    1995-05-01

    A high accurate blasting machine which could control 1 microsecond(s) was developed. At first, explosion of a bridge wire in an electric detonator was observed and next the detonations of caps were observed with a high speed camera. It is well known that a compressed stress wave reflects at the free face, it propagates to the backward as a tensile stress wave, and cracks grow when the tensile stress becomes the dynamic tensile strength. The behavior of these cracks has been discussed through the observation of the dynamic photoelastic high speed photography and the three dimensional dynamic stress analysis.

  14. Feeding Tubes

    Science.gov (United States)

    ... the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via the nose, ... portion of the small intestine Naso – nose NG – Nasogastric Tube -ostomy – new opening Percutaneous – through the skin PEJ – ...

  15. High-Speed Schlieren and 10-Hz Kr PLIF for the new AFRL Mach-6 Ludwieg Tube Hypersonic Wind Tunnel

    Science.gov (United States)

    2017-11-01

    50 American Institute of Aeronautics and Astronautics DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 4 fan ...arrival of the expansion fan reflected from the driver endwall, followed by another 100-ms quasi-steady period. This trend was also observed in the

  16. Spiral Inflector For Compact Cyclotron

    CERN Document Server

    Karamysheva, G A

    2004-01-01

    Compact cyclotron for explosives detection by nuclear resonance absorption of γ-rays in nitrogen is under development [1] Cyclotron will be equipped with the external ion source. The injection system consists of a double-drift beam bunching system, a spiral inflector, beam diagnostics, focusing and adjustment elements [2]. The spiral inflector for ion bending from axial to median plane is used. Computer model of spiral inflector for the Customs cyclotron is developed. 3D electrostatic field calculations of the designed inflector are performed. Calculated electric field map and magnetic field map of the cyclotron [3] are used for beam dynamic simulations. Numeric simulations are carried out for 500 particles using code for calculation of particle dynamics by integration of differential equations in Cartesian coordinate system written in MATLAB. Direct Coulomb particle-to-particle method is used to take into account space-charge effects.

  17. 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.

    2016-01-01

    and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat...

  18. BER Reduction for mQAM High-Speed Tranmission in Optical Fiber ...

    African Journals Online (AJOL)

    The mQAM digital modulations interest lies in the fact that they are now being used as subchannel modulation techniques in other advanced modulations such as Othogonal Frenquency Division Multiplexing (OFDM). Indeed, OFDM using mQAM modulation seems to be a good candidate in high speed networks. This allows ...

  19. Wavelet-OFDM Signal Transmission Characteristics with High-Speed PLC Modem

    Science.gov (United States)

    Nakagawa, Kenichi; Tokuda, Masamitsu; Igata, Yuji

    In this paper, we measured the interference immunity characteristics of high-speed PLC system using Wavelet-OFDM when the narrowband conducted interference wave signal was injected. As the results, it was clear that (1) measured PHY rate at the all frequency band hardly decreased in C/I (Carrier to Interference ratio) of above 20dB, but began to decrease rapidly in C/I of below 0dB when the interference signal was injected in the frequency band of high-speed PLC signal, (2) when C/I became from 0dB to -20dB, the measured PHY rate at the frequency existing the notch band were improved around 10Mbps than that at the frequency not existing the notch band, (3) when the narrowband interference wave was injected outside of frequency band of high-speed PLC signal, the measured PHY rate did not decrease than that in each notch band. Therefore, it was revealed that high-speed PLC system using Wavelet-OFDM had good interference immunity characteristics.

  20. 76 FR 14443 - High-Speed Intercity Passenger Rail (HSIPR) Program

    Science.gov (United States)

    2011-03-16

    ... of the project and the ability to expend the original and additional funds in the near term. 3.5... completed engineering work to assess and manage/mitigate the proposed project's engineering and...: Notice of funding availability for high-speed and intercity passenger rail projects. SUMMARY: This notice...