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Sample records for aisi m2 high-speed

  1. Machining tools in AISI M2 high-speed steel obtained by spray forming process; Ferramentas de usinagem em aco rapido AISI M2 obtido por conformacao por 'spray'

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Edilson Rosa Barbosa de. E-mail: erbjesus@usp.br

    2004-07-01

    The aim of the present work was the obtention of AISI M2 high-speed steel by spray forming technique and the material evaluation when used as machining tool. The obtained material was hot rolled at 50% and 72% reduction ratios, and from which it was manufactured inserts for machining tests. The performance of inserts made of the spray formed material was compared to inserts obtained from conventional and powder metallurgy (MP) processed materials. The spray formed material was chemical, physical, mechanical and microstructural characterised. For further characterisation, the materials were submitted to machining tests for performance evaluation under real work condition. The results of material characterisation highlight the potential of the spray forming technique, in the obtention of materials with good characteristics and properties. Under the current processing, hot rolling and heat treatments condition, the analysis of the results of the machining tests revealed a very similar behaviour among the tested materials. Proceeding a criterious analysis of the machining results tests, it was verified that the performance presented by the powder metallurgy material (MP) was slight superior, followed by conventional obtained material (MConv), which presented a insignificant advantage over the spray formed and hot rolled (72% reduction ratio) material. The worst result was encountered for the spray forming and hot rolled (50% reduction ratio) material that presented the highest wear values. (author)

  2. Study of the solidification of M2 high speed steel Laser Cladding coatings

    Directory of Open Access Journals (Sweden)

    Candel, J. J.

    2013-10-01

    Full Text Available High speed steel laser cladding coatings are complex because cracks appear and the hardness is lower than expected. In this paper AISI M2 tool steel coatings on medium carbon AISI 1045 steel substrate have been manufactured and after Laser Cladding (LC processing it has been applied a tempering heat treatment to reduce the amount of retained austenite and to precipitate secondary carbides. The study of metallurgical transformations by Scanning Electron Microscopy (SEM and Electron Back Scattered Diffraction (EBSD shows that the microstructure is extremely fine and complex, with eutectic transformations and MC, M2C and M6C precipitation. Therefore, after the laser coating is necessary to use post-weld heat treatments.Los recubrimientos de acero rápido por Laser Cladding (LC son complejos porque aparecen fisuras y la dureza es menor a la esperada. En este trabajo se han fabricado recubrimientos de acero AISI M2 sobre acero al carbono AISI 1045 y tras el procesado por láser, se han revenido para reducir la cantidad de austenita retenida y precipitar carburos secundarios. El estudio de las transformaciones metalúrgicas con Microscopía Electrónica de Barrido (MEB y Difracción de Electrones Retrodispersados (EBSD muestra que la microestructura es extremadamente fina y compleja, presenta transformaciones eutécticas y precipitación de carburos MC, M2C y M6C. Por tanto, tras el recubrimiento por láser es necesario recurrir a tratamientos térmicos post-soldeo.

  3. Solidification microstructure of M2 high speed steel by different casting technologies

    Directory of Open Access Journals (Sweden)

    Zhou Xuefeng

    2011-08-01

    Full Text Available The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks, which were greatly refined in the ingot made by continuous casting process, compared with that by the iron mould casting process. M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods. In the ingot by iron mould casting, they have a plate-like morphology and grow anisotropically. However, in the ingot made by continuous casting, the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth. It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated, as a result, the carbides refined remarkably, compared with the case of plate-like carbides in the iron mould casting ingot.

  4. A preliminary investigation on selective laser melting of M2 high speed steel

    OpenAIRE

    Liu, Zhonghong; Chua, Chee Kai; Leong, Kah Fai; Kempen, Karolien; Thijs, Lore; Yasa, Evren; Van Humbeeck, Jan; Kruth, Jean-Pierre

    2012-01-01

    Selective Laser Melting (SLM) is an Additive Manufacturing (AM) technique that is able to process both metallic and ceramic materials in powder form. The main attraction of SLM is the ability to produce near fully dense functional parts with high geometrical complexity. Parts can be fabricated with features and designs conventional manufacturing methods cannot achieve. In this study, the feasibility of processing M2 High Speed Steel (HSS) with the SLM technique is investigated. The main focus...

  5. Comparative study of AISI M3:2 high speed steel produced through different techniques of manufacturing

    International Nuclear Information System (INIS)

    In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the addition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vacuum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstructure and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic microscopy (SEM) was used to evaluate the microstructure and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels. (author)

  6. Effect of RE-Al-N on Structures and Properties of M2 Cast High Speed Steel

    Institute of Scientific and Technical Information of China (English)

    符寒光; 杜建铭; 蒋志强; 邢建东

    2003-01-01

    M2 cast high speed steel was inoculated by addition of rare earth(RE)-Al-N, network eutectic carbides were eliminated, matrix microstructures were refined and the segregation of tungsten and molybdenum elements was relieved. In the condition that the hardness does not decrease, impact toughness obviously increases. Quenching at 1180 ℃ and three-times tempering at 560 ℃, the hardness of M2 cast high speed steel is 65~66 HRC, and impact toughness reaches 21.3 J*cm- 2. Modified M2 cast high speed steel has excellent thermal fatigue resistance and high temperature wear resistance. Roller made in modified M2 cast high speed steel has excellent service effect when it is used in slit rolling mill of hot rolling bar mill.

  7. Comparative study of AISI M3:2 high speed steel produced through different techniques of manufacturing; Estudo comparativo de acos rapidos AISI M3:2 produzidos por diferentes processos de fabricacao

    Energy Technology Data Exchange (ETDEWEB)

    Araujo Filho, Oscar Olimpio de

    2006-07-01

    In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the addition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vacuum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstructure and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic microscopy (SEM) was used to evaluate the microstructure and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels. (author)

  8. Finite Element Modelling of the effect of tool rake angle on tool temperature and cutting force during high speed machining of AISI 4340 steel

    Science.gov (United States)

    Sulaiman, S.; Roshan, A.; Ariffin, M. K. A.

    2013-12-01

    In this paper, a Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material model was used to simulate cutting force and tool temperature during high speed machining (HSM) of AISI 4340 steel. In this simulation work, a tool rake angle ranging from 0° to 20° and a range of cutting speeds between 300 to 550 m/min was investigated. The purpose of this simulation analysis was to find optimum tool rake angle where cutting force is smallest as well as tool temperature is lowest during high speed machining. It was found that cutting forces to have a decreasing trend as rake angle increased to positive direction. The optimum rake angle observed between 10° and 18° due to decrease of cutting force as 20% for all simulated cutting speeds. In addition, increasing cutting tool rake angle over its optimum value had negative influence on tool's performance and led to an increase in cutting temperature. The results give a better understanding and recognition of the cutting tool design for high speed machining processes.

  9. Characterisation of Pristine and Recoated electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings on AISI M2 steel and WC-Co substrates

    International Nuclear Information System (INIS)

    This paper is focussed on the characterisation of electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings deposited on AISI M2 steel and hardmetal (K10) substrates in two different conditions: Pristine (i.e., coated) and Recoated (i.e., stripped and recoated). Analytical methods, including X-ray diffraction (XRD), scanning electron microscopy, scratch adhesion and pin-on-disc tests were used to evaluate several coating properties. XRD analyses indicated that both Pristine and Recoated coatings consisted of a mixture of hexagonal Cr2N and cubic CrN, regardless of substrate type. For the M2 steel substrate, only small differences were found in terms of coating phases, microstructure, adhesion, friction and wear coefficients between Pristine and Recoated. Recoated on WC-Co (K10) exhibited a less dense microstructure and significant inferior adhesion compared to Pristine on WC-Co (K10). The wear coefficient of Recoated on WC-Co was 100 times higher than those exhibited by all other specimens. The results obtained confirm that the stripping process did not adversely affect the Cr-N properties when this coating was deposited onto M2 steel substrates, but it is clear from the unsatisfactory tribological performance of Recoated on WC-Co that the stripping process is unsuitable for hardmetal substrates

  10. Tribological behaviors of spot-textured TiN coatings on M2 high-speed steel under boundary lubricated conditions

    Institute of Scientific and Technical Information of China (English)

    Guangneng Dong; Meng Hua; Jian Li; Hing-Yin Ma; Youbai Xie

    2007-01-01

    The effect of sliding duration on the tribological behaviors of spot patterned coatings was investigated. Two patterns based on physical vapor deposition (PVD) TiN coatings were used, such as, in-lined (IN) and staggered (ST) spots. The tribological behaviors were evaluated by using a Cameron-Plint wear test rig. The M2 steel discs deposited TiN coatings with IN and ST patterns slid against the ASSAB 17 tool steel pins at a speed of 0.23 m/s, in Shell Tellus T32 lubricant and were loaded with 900 N. The testing results on disc specimens with two types of PVD TiN spot patterns, all coated with a bias voltage of- 180 V and slid for 4, 8 and 11 h respectively,were presented. The results revealed that the in-lined coatings possessed relatively better wear behaviors than the staggered pattern coatings. Mechanisms for such superiority and for the cause of peeling were discussed. A relevant design approach was suggested for the application of such patterned coatings.

  11. Resistencia a la corrosión de recubrimientos de nitruros metálicos depositados sobre acero AISI M2

    Directory of Open Access Journals (Sweden)

    Jhon Jairo Olaya Florez

    2012-01-01

    Full Text Available En este trabajo se estudia el comportamiento frente a la corrosión de películas de nitruro de zirconio (ZrN, nitruro de titanio (TiN, nitruro de cromo (CrN, nitruro de niobio (NbN y nitruro de tantalio (TaN depositadas sobre acero para herramientas AISI M2 mediante la técnica de sputtering con magnetrón desbalanceado (UBM. La resistencia a la corrosión fue evaluada con ensayos de espectroscopía de impedancia electroquímica (EIS en una solución al 3% de NaCl variando el tiempo de ensayo desde 1 h hasta 7 d. En general, los mejores resultados de resistencia a la corrosión se presentaron en las películas de ZrN y NbN cuando son producidas en la configuración de menor bombardeo iónico en un sistema UBM. Los recubrimientos muestran degradación en el tiempo de ensayo debido a los defectos presentes en su microestructura, que se convierten en canales de difusión por los que la solución corrosiva llega a la superficie del sustrato. Los mecanismos de corrosión para los recubrimientos producidos son discutidos en esta investigación.

  12. Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC = Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder

    Directory of Open Access Journals (Sweden)

    Jean Robert Pereira Rodrigues

    2008-07-01

    to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2, during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presentedsignificant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.

  13. High Speed Economy

    OpenAIRE

    Vadim Dumitrascu; Roxana Arabela Dumitrascu

    2013-01-01

    The use of knowledge in business opens vast possibilities for the spectacular intensification of the rhythms of the processes of economic value creation. High speeds are a fundamental feature of the knowledge economy. The sources of high speeds in business are certain economic, technological and commercial processes with the nature of some positive feedbacks. What generates it is the organization of knowledge in the form of networks. The organizations competitiveness is marked by the ability ...

  14. High speed door assembly

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.

    1991-12-31

    This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  15. HIGH SPEED CAMERA

    Science.gov (United States)

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

    1957-12-17

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

  16. The Regulating Research on Relationship Between Laser Melting Strengthening Layer of M2 High Speed Steel Shaper Cutters and Hardness of the Blade%M2高速钢插齿刀激光熔凝强化层与刀刃显微硬度关系的调控研究

    Institute of Scientific and Technical Information of China (English)

    金坤文; 胡西云; 徐娟; 张金学

    2014-01-01

    研究了M2(W6Mo5 Cr4V2)高速钢经激光熔凝淬火和570℃一次回火处理前后的强化层硬度变化和表面粗糙度,并对M2高速钢插齿刀的激光熔凝淬火加工部位进行了分析优化,讨论了刀具经激光强化及精加工后刀刃部位的显微硬度变化规律.试验研究表明:经过不同工艺参数组合的激光熔凝淬火后,试样得到不同的表面硬度,再经过一次回火后,试样表面具有明显的二次强化效应,且粗糙度值较稳定;插齿刀前刀面刀刃部位显微硬度变化规律具有工程适用性,为优选出最佳激光工艺参数及工艺方法提供了实验依据.

  17. Spray forming high speed steel - properties and processing

    International Nuclear Information System (INIS)

    The potential of spray forming (SF) for microstructural refining can be attractive to the production of high speed steels. The refined as-cast structure may lead to important improvements of material properties, compared to conventionally cast materials. The present work aimed to compare the properties of AISI M3:2 high speed steel produced through spray forming and conventional casting. Also, the processing of SF billet is considered, specifically the hot working conditions and its relation to carbide size. A round 400 mm diameter SF billet was produced using a twin atomiser. Characterisation was performed in the as-cast structure and after hot working to 116 mm squared bars and 11 mm diameter round bars. The results show that, compared to conventionally cast high speed steel, the SF material has higher isotropy in toughness due to its less oriented carbide distribution. Regarding processing procedures, time and temperature employed in heating before hot working also affect the microstructure of SF material

  18. Spray forming high speed steel - properties and processing

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Rafael Agnelli; Barbosa, Celso Antonio

    2004-10-10

    The potential of spray forming (SF) for microstructural refining can be attractive to the production of high speed steels. The refined as-cast structure may lead to important improvements of material properties, compared to conventionally cast materials. The present work aimed to compare the properties of AISI M3:2 high speed steel produced through spray forming and conventional casting. Also, the processing of SF billet is considered, specifically the hot working conditions and its relation to carbide size. A round 400 mm diameter SF billet was produced using a twin atomiser. Characterisation was performed in the as-cast structure and after hot working to 116 mm squared bars and 11 mm diameter round bars. The results show that, compared to conventionally cast high speed steel, the SF material has higher isotropy in toughness due to its less oriented carbide distribution. Regarding processing procedures, time and temperature employed in heating before hot working also affect the microstructure of SF material.

  19. High-Speed Photography 101

    Science.gov (United States)

    Davidhazy, Andrew

    1997-05-01

    This paper describes the contents of a unique introductory, applications oriented, high speed photography course offered to Imaging and Photographic Technology majors at the Rochester Institute of Technology. The course covers the theory and practice of photographic systems designed to permit analysis of events of very short duration. Included are operational characteristics of intermittent and rotating prism cameras, rotating mirror and drum cameras, synchronization systems and timing controls and high speed flash and stroboscopic systems, and high speed video recording. Students gain basic experience not only in the use of fundamental equipment but also in proper planning, set-up and introductory data reduction techniques through a series of practical experiments.

  20. Performance evaluation of high speed compressors for high speed multipliers

    Directory of Open Access Journals (Sweden)

    Nirlakalla Ravi

    2011-01-01

    Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.

  1. 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

  2. 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

  3. High-speed OTDM switching

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  4. 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.

  5. High-speed data search

    Science.gov (United States)

    Driscoll, James N.

    1994-01-01

    The high-speed data search system developed for KSC incorporates existing and emerging information retrieval technology to help a user intelligently and rapidly locate information found in large textual databases. This technology includes: natural language input; statistical ranking of retrieved information; an artificial intelligence concept called semantics, where 'surface level' knowledge found in text is used to improve the ranking of retrieved information; and relevance feedback, where user judgements about viewed information are used to automatically modify the search for further information. Semantics and relevance feedback are features of the system which are not available commercially. The system further demonstrates focus on paragraphs of information to decide relevance; and it can be used (without modification) to intelligently search all kinds of document collections, such as collections of legal documents medical documents, news stories, patents, and so forth. The purpose of this paper is to demonstrate the usefulness of statistical ranking, our semantic improvement, and relevance feedback.

  6. High speed bus technology development

    Science.gov (United States)

    Modrow, Marlan B.; Hatfield, Donald W.

    1989-09-01

    The development and demonstration of the High Speed Data Bus system, a 50 Million bits per second (Mbps) local data network intended for avionics applications in advanced military aircraft is described. The Advanced System Avionics (ASA)/PAVE PILLAR program provided the avionics architecture concept and basic requirements. Designs for wire and fiber optic media were produced and hardware demonstrations were performed. An efficient, robust token-passing protocol was developed and partially demonstrated. The requirements specifications, the trade-offs made, and the resulting designs for both a coaxial wire media system and a fiber optics design are examined. Also, the development of a message-oriented media access protocol is described, from requirements definition through analysis, simulation and experimentation. Finally, the testing and demonstrations conducted on the breadboard and brassboard hardware is presented.

  7. Exploring of Chinese High-speed Railways

    Institute of Scientific and Technical Information of China (English)

    liuYoumei

    2004-01-01

    Based ion experiences of high-speed railways in foreign countries,the speed-raise situation of the Chinese railways,the research & development and test of high-speed transportation carries,as well as the prospective of high-speed railway in China are introduced.

  8. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal

    2013-01-01

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

  9. Performance of High-Speed Grease Lubricated Hybrid Ceramic Ball Bearing

    Institute of Scientific and Technical Information of China (English)

    李秀娟; 王黎钦; 古乐

    2004-01-01

    To simplify the lubricating system for high-speed bearings and improve its reliability, grease lubricated high-speed hybrid ceramic bearings were theoretically and experimentally researched.Bearings with an outer race of 62 mm and eleven 9.525-mm balls were investigated.Traction coefficient and flash temperature between the bearing races and the balls were calculated and the results show that the traction coefficient of Si3N4 hybrid ceramic bearings is 74% that of the steel AISI 440B ones at 30 000 r/min and 1750 N, and the flash temperature of the hybrid bearings is 49% that of steel ones.Simulating the high-speed bearing rotational conditions, the grease lubricated hybrid ceramic ball bearings were tested and the results show that the power consumption of hybrid ceramic bearing lubricated by grease D at 24 000 r/min and axial load 1750 N is 80% that of steel ones.

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  11. Cutting tool materials for high speed machining

    Institute of Scientific and Technical Information of China (English)

    LIU Zhanqiang; AI Xing

    2005-01-01

    High speed machining (HSM) is one of the emerging cutting processes, which is machining at a speed significantlyhigher than the speed commonly in use on the shop floor. In the last twenty years, high speed machining has received great attentions as a technological solution for high productivity in manufacturing. This article reviews the developments of tool materials in high speed machining operations, and the properties, applications and prospective developments of tool materials in HSM are also presented.

  12. Review of high speed communications photomultiplier detectors

    Science.gov (United States)

    Enck, R. S.; Abraham, W. G.

    1978-01-01

    Four types of newly developed high speed photomultipliers are discussed: all electrostatic; static crossed field; dynamic crossed field; and hybrid (EBS). Design, construction, and performance parameters of each class are presented along with limitations of each class of device and prognosis for its future in high speed light detection. The particular advantage of these devices lies in high speed applications using low photon flux, large cathode areas, and broadband optical detection.

  13. Towards high-speed scanning tunneling microscopy

    OpenAIRE

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices is shown using finite-element simulations, combined with measurements of their resonance frequency and actuation range. Tip deposition was done using EBID (Electron-Beam Induced Deposition) which a...

  14. 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...

  15. Comparison of High Speed Congestion Control Protocols

    Directory of Open Access Journals (Sweden)

    Jawhar Ben Abed

    2012-10-01

    Full Text Available Congestion control limits the quantity of information input at a rate less important than that of thetransmission one to ensure good performance as well as protect against overload and blocking of thenetwork. Researchers have done a great deal of work on improving congestion control protocols,especially on high speed networks.In this paper, we will be studying the congestion control alongside low and high speed congestion controlprotocols. We will be also simulating, evaluating, and comparing eight of high speed congestion controlprotocols : Bic TCP, Cubic TCP, Hamilton TCP, HighSpeed TCP, Illinois TCP, Scalable TCP,Compound TCP and YeAH TCP, with multiple flows.

  16. High-Speed Ring Bus

    Science.gov (United States)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  17. 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.

  18. Residual stress in a M3:2 PM high speed steel; effect of mechanical loading

    DEFF Research Database (Denmark)

    Højerslev, Christian; Odén, Magnus; Carstensen, Jesper V.;

    2001-01-01

    X-ray lattice strains were investigated in an AISI M3:2 PM high-speed steel in the as heat treated condition and after exposure to alternating mechanical load. The volume changes during heat treatment were monitored with dilatometry. Hardened and tempered AISI M3:2 steel consists of tempered lath...... martensite and the carbides M6C,V8C7 and M23C6. In the as heat treated condition the stress state is triaxial. The primary carbides M6C and V8C7 experience a compressive state of stress. Exposure to an alternating mechanical load, changes the states of stress of V8C7 and tempered martensite, but does...

  19. Designing for High-Speed Ships

    OpenAIRE

    Røed, Bjarte Knappen

    2007-01-01

    Fast patrol boats are high-speed vessels operated by the Royal Norwegian Navy (RNoN). These ships are 36,5 meters long, have a beam of 6,2 meters and operate at high speed (32 knots – 16,5 meters per second) in very restricted waters. The fast patrol boats are war ships and navigation tasks performed by the crews are different from those in civilian high-speed craft. A team of five persons navigate the fast patrol boats, and navigation is based on traditional means such as visual observations...

  20. FINITE ELEMENT ANALYSIS FOR CHIP FORMATION IN HIGH SPEED TURNING OPERATIONS BY ARBITRARY LAGRANGIAN EULERIAN METHOD

    Institute of Scientific and Technical Information of China (English)

    USAMA Umer; XIE Lijing; WANG Xibin

    2006-01-01

    A two-dimensional finite element (FE) model for the high speed turning operations when orthogonally machining AISI H13 tool steel at 49HRC using poly crystalline cubic boron nitride(PCBN) is described. An arbitrary Lagrangian Eulerian (ALE) method has been adopted which does not need any chip separation criteria as opposed to the traditional Lagrangian approach. Through FE simulations temperature and stresses distributions are presented that could be helpful in predicting tool life and improving process parameters. The results show that high temperatures are generated along the tool rake face as compared to the shear zone temperatures due to high thermal conductivity of PCBN tools.

  1. On China's High-Speed Railway Technology

    Institute of Scientific and Technical Information of China (English)

    You-tong FANG

    2011-01-01

    Energy and environmental issues have become increasingly prominent in matters of transportation.Compared with road,air,and sea transportation,railway transportation has the advantages of a large transmission capacity,with rapid,safe,and on-time travel,requiring less land resources,with lower energy consumption,less environmental pollution,and the capacity to operate under most weather conditions.In particular,high-speed railway technology has been growing rapidly.Since the world's first high-speed railway was built in Japan in 1964,more than ten countries and regions have developed high-speed railways,operating over a total of more than 10000 km.High-speed railways not only provide the public with a new type of rapid,convenient,safe,and comfortable travel,but also greatly boost the socio-economic development of the country.

  2. Damping Bearings In High-Speed Turbomachines

    Science.gov (United States)

    Von Pragenau, George L.

    1994-01-01

    Paper presents comparison of damping bearings with traditional ball, roller, and hydrostatic bearings in high-speed cryogenic turbopumps. Concept of damping bearings described in "Damping Seals and Bearings for a Turbomachine" (MFS-28345).

  3. High Speed Wireless Signal Generation and Demodulation

    DEFF Research Database (Denmark)

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

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

  4. 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,…

  5. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  6. High-Speed Rail & Air Transport Competition

    NARCIS (Netherlands)

    Adler, Nicole; Nash, Chris; Pels, Eric

    2008-01-01

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

  7. High-speed massively parallel scanning

    Science.gov (United States)

    Decker, Derek E.

    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.

  8. High-Speed Granular Chute Flows

    Science.gov (United States)

    McElwaine, J.

    2014-12-01

    Accurate models for high speed granular flows are critical for understanding long runout landslides and rockfalls. However reproducible experimental data is extremely limited and is mostly only available for steady state flows on moderate inclinations. We report on experiments over a much greater range of slope angles 30-50 degrees and flow depths 4-130 particle diameters with upto 20kg/s of sand flowing steadily. The data suggests that friction can be much larger than the μ(I)mu(I) rheology or kinetic theories predict and suggest and that there may be constant velocity states above the angle of vanishing hstop. We show similar high speed steady flows at angles up to 50 degress in Discrete Element Simuations and discuss how these can be understood theoretically.

  9. Nanometer lapping technology at high speed

    Institute of Scientific and Technical Information of China (English)

    YANG JianDong; TIAN ChunLin; WANG ChangXing

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abrasives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  10. Nanometer lapping technology at high speed

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abra-sives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  11. Pulse Detonation Engines for High Speed Flight

    Science.gov (United States)

    Povinelli, Louis A.

    2002-01-01

    Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

  12. High speed functional magnetic resonance imaging

    CERN Document Server

    Gibson, A M

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated by reference, within the Magnetic Resonance Centre at the University of Nottingham during the period from October 1998 to October 2001. This thesis documents the implementation and application of a novel high-speed imaging technique, the multi-slice, echo shifted, echo planar imaging technique. This was implemented on the Nottingham 3 T imaging system, for functional magnetic resonance imaging. The technique uses echo shifting over the slices in a multi-slice echo planar imaging acquisition scheme, making the echo time longer than the repetition time per slice. This allows for rapid volumar sampling of the blood oxygen level dependent effect in the human brain. The new high-speed technique was used to investigate the variability of measuring the timing differences between haemodynamic responses, at the same cortical location, to simple cued motor tasks. The technique was also used in an investigation into motor cortex functional connect...

  13. 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.

  14. High-speed milling of light metals

    OpenAIRE

    F. Cus; U. Zuperl; V. Gecevska

    2007-01-01

    Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operati...

  15. Intrusion Detection in High-Speed Networks

    OpenAIRE

    Riegel, Martin; Walsø, Claes Lyth

    2007-01-01

    This thesis investigates methods for implementing an intrusion detection system (IDS) in a high-speed backbone network. The work presented in this report is run in cooperation with Kripos and Uninett. The popular IDS software, Snort, is deployed and tested in Uninett's backbone network. In addition, the monitoring API (MAPI) is considered as a possible IDS implementation in the same environment. The experiments conducted in this report make use of the programmable DAG card, which is a passive...

  16. Compressibility, turbulence and high speed flow

    CERN Document Server

    Gatski, Thomas B

    2013-01-01

    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  17. A High-Speed Information Retrieval System

    Institute of Scientific and Technical Information of China (English)

    SHI Shu-dong; LI Zhi-tang

    2004-01-01

    We cleveloped a high-speed information retrieval system. The system hased on the IXP 2800 is one of the dedicute device. The velocily of the information retrieval is 6.8 Gb/s. The protocol support Telnet, FTP, SMTP, POP3 etc. various networks protocols. The information retrieval supports the key word and the natural language process. This paper explains the hardware system, software system and the index of the performance.

  18. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  19. Architectures and applications of high-speed vision

    Science.gov (United States)

    Watanabe, Yoshihiro; Oku, Hiromasa; Ishikawa, Masatoshi

    2014-11-01

    With the progress made in high-speed imaging technology, image processing systems that can process images at high frame rates, as well as their applications, are expected. In this article, we examine architectures for high-speed vision systems, and also dynamic image control, which can realize high-speed active optical systems. In addition, we also give an overview of some applications in which high-speed vision is used, including man-machine interfaces, image sensing, interactive displays, high-speed three-dimensional sensing, high-speed digital archiving, microvisual feedback, and high-speed intelligent robots.

  20. High-speed milling of light metals

    Directory of Open Access Journals (Sweden)

    F. Cus

    2007-09-01

    Full Text Available Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operations, increase of the surface quality and longer service life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/min require modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in the automobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also the achievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficient machining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling can be compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and more frequently used in practice. This result is high quality of the surface and shorter machining times. In some cases when machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum and magnesium alloying materials are machined.

  1. 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...... - 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...

  2. Accident Safety Design for High Speed Elevator

    Directory of Open Access Journals (Sweden)

    Tawiwat Veeraklaew

    2012-12-01

    Full Text Available There have been many elevators exist in buildings for such a long time; however, an accident might happen as a free fall due to lacks of maintenance or some other accident such as firing. Although this situation is rarely occurred, many people are still concerned about it. The question here is how to make passengers to feel safe and confident when they are using an elevator, especially, high speed elevator. This problem is studied here in this paper as a free fall spring-mass-damper system with the stiffness and damping coefficient can be computed as minimum jerk of the system with given constraints on trajectories.

  3. 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.

  4. Initial performance of the High Speed Photometer

    Science.gov (United States)

    Richards, Evan; Percival, Jeff; Nelson, Matt; Hatter, ED; Fitch, John; White, Rick

    1991-01-01

    The Hubble Space Telescope High Speed Photometer has four image dissector tubes, two with UV sensitive photocathodes, two sensitive to the near UV and to visual light, and a single red sensitive photomultiplier tube. The HSP is capable of photometric measurements from 1200 to 7500 A with time resolution of 11 microseconds and has no moving parts. An initial analysis of the on-orbit engineering performance of the HSP is presented with changes in operating procedures resulting from the primary mirror spherical aberration and experience gained during the verification period.

  5. Surface Treatment of High Speed Steel Tools

    OpenAIRE

    タカハシ, ヒサオ; Hisao, TAKAHAASHI

    1997-01-01

    This paper reveals to cutting performance on 3 kinds of high speed steels throw away tips (including made by powder metallurgical process), which are compared surface treated tips by means of the coating process PVD-TiN (physical vapor deposition by the arc ion plating method) with untreated conventional tips. The results are as follows: "X"tips by name have the highest hardness and performance on continuous cutting than the others, but they have the lowest toughness and larger chipping on in...

  6. High speed UNIBUS-VME interface

    International Nuclear Information System (INIS)

    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

  7. 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.

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

    Science.gov (United States)

    Tioukov, V.; Aleksandrov, A.; Consiglio, L.; De Lellis, G.; Vladymyrov, M.

    2015-12-01

    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 m2/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 optogenetic circuit mapping

    Science.gov (United States)

    Augustine, George J.; Chen, Susu; Gill, Harin; Katarya, Malvika; Kim, Jinsook; Kudolo, John; Lee, Li M.; Lee, Hyunjeong; Lo, Shun Qiang; Nakajima, Ryuichi; Park, Min-Yoon; Tan, Gregory; Tang, Yanxia; Teo, Peggy; Tsuda, Sachiko; Wen, Lei; Yoon, Su-In

    2013-03-01

    Scanning small spots of laser light allows mapping of synaptic circuits in brain slices from transgenic mice expressing channelrhodopsin-2 (ChR2). These light spots photostimulate presynaptic neurons expressing ChR2, while postsynaptic responses can be monitored in neurons that do not express ChR2. Correlating the location of the light spot with the amplitude of the postsynaptic response elicited at that location yields maps of the spatial organization of the synaptic circuits. This approach yields maps within minutes, which is several orders of magnitude faster than can be achieved with conventional paired electrophysiological methods. We have applied this high-speed technique to map local circuits in many brain regions. In cerebral cortex, we observed that maps of excitatory inputs to pyramidal cells were qualitatively different from those measured for interneurons within the same layers of the cortex. In cerebellum, we have used this approach to quantify the convergence of molecular layer interneurons on to Purkinje cells. The number of converging interneurons is reduced by treatment with gap junction blockers, indicating that electrical synapses between interneurons contribute substantially to the spatial convergence. Remarkably, gap junction blockers affect convergence in sagittal cerebellar slices but not in coronal slices, indicating sagittal polarization of electrical coupling between interneurons. By measuring limb movement or other forms of behavioral output, this approach also can be used in vivo to map brain circuits non-invasively. In summary, ChR2-mediated high-speed mapping promises to revolutionize our understanding of brain circuitry.

  10. Temperature distribution of high speed tool steel rod during high speed hot rolling procedure

    International Nuclear Information System (INIS)

    The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod

  11. A high-speed avalanche photodiode

    International Nuclear Information System (INIS)

    High-speed avalanche photodiodes are widely used in optical communication systems. Nowadays, separate absorption charge and multiplication structure is widely adopted. In this article, a structure with higher speed than separate absorption charge and multiplication structure is reported. Besides the traditional absorption layer, charge layer and multiplication layer, this structure introduces an additional charge layer and transit layer and thus can be referred to as separate absorption, charge, multiplication, charge and transit structure. The introduction of the new charge layer and transit layer brings additional freedom in device structure design. The benefit of this structure is that the carrier transit time and device capacitance can be reduced independently, thus the 3 dB bandwidth could be improved by more than 50% in contrast to the separate absorption charge and multiplication structure with the same size. (semiconductor devices)

  12. Merging of high speed argon plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Case, A.; Messer, S.; Brockington, S.; Wu, L.; Witherspoon, F. D. [HyperV Technologies Corp., Chantilly, Virginia 22180 (United States); Elton, R. [University of Maryland, College Park, Maryland 20742 (United States)

    2013-01-15

    Formation of an imploding plasma liner for the plasma liner experiment (PLX) requires individual plasma jets to merge into a quasi-spherical shell of plasma converging on the origin. Understanding dynamics of the merging process requires knowledge of the plasma phenomena involved. We present results from the study of the merging of three plasma jets in three dimensional geometry. The experiments were performed using HyperV Technologies Corp. 1 cm Minirailguns with a preionized argon plasma armature. The vacuum chamber partially reproduces the port geometry of the PLX chamber. Diagnostics include fast imaging, spectroscopy, interferometry, fast pressure probes, B-dot probes, and high speed spatially resolved photodiodes, permitting measurements of plasma density, temperature, velocity, stagnation pressure, magnetic field, and density gradients. These experimental results are compared with simulation results from the LSP 3D hybrid PIC code.

  13. The high speed bus technology development program

    Science.gov (United States)

    Ludvigson, M. T.; Modrow, M. B.; Goldman, P. C.

    The current development status of a high-speed data bus to link MIL-STD-1750A computers in avionics applications is reviewed and illustrated with diagrams and photographs. The bus requirements include data rate 50 Mb/s, a linear token-passing scheme permitting both electronic and fiber-optic implementation, up to 64-terminal capacity, maximum terminal separation 300 ft, latency control via token-rotation-timer priority, self-test and bus-loop test capability, and automatic clock synchronization. The design concept and performance of a breadboard wire bus tested in July 1986 are discussed in detail, with particular attention to the redundancy manager, the output controller, the input controller, the ringmaster topology manager, and typical initial-placement problems.

  14. High-speed multichannel optical switching

    Energy Technology Data Exchange (ETDEWEB)

    Mikaelian, A.L.; Salakhutdinov, V.K. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Optical Neural Technologies

    1994-12-31

    The programmable interconnection between N input and N output channels based on a matrix of microholograms is considered. Such a system can be used for optical switching having high speed, about gigabits-per-second. An example of such a system using bacteriorhodopsin film is investigated both theoretically and experimentally. The thickness of bacteriorhodopsin was 50 {micro}m and the cell size 3cmx2cm. To maintain interconnects each microhologram was regenerated by means of a routing system composed of a He-Ne laser, deflectors and optical elements. Experimentally, 20 channels were used. The diameter of the microhologram was 1 mm, and the diffraction efficiency was about 2%. The tests and calculations show the possibility of arranging 10{sup 4} switching channels with speed about 1 gigabit per second.

  15. The Silicon Photomultiplier for High Speed Photometry

    Science.gov (United States)

    Vander Haagen, Gary A.

    2011-05-01

    The Silicon Photomultiplier (SPM) offers sensitivity comparable to conventional photomultipliers with the added advantage of small size, low operating voltages, and robust tolerance to excess/ambient light. A Peltier cooled SPM running at -30°C was used in conjunction with wideband electronics and a 17-inch Astrograph to collect photometric data without a reference star. High speed photometric trials were conducted on eclipsing binary AW UMa demonstrating fast data rate capability. Data shows the SPM exhibits excellent sensitivity, acceptable signal to noise, and bandwidth with sampling times as short as 1 millisecond for brighter targets. Automated digital data acquisition is discussed along with digital signal processing techniques for noise reduction, spectral analysis, and data mining. The SPM demonstrated acceptable signal to noise for fast photometric studies for 8-10th magnitude targets depending on scintillation and background conditions. Future SPM study topics are also discussed.

  16. HIGH SPEED KERR CELL FRAMING CAMERA

    Science.gov (United States)

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

    1964-01-01

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

  17. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    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,...

  18. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    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...

  19. 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.

  20. High-Speed RaPToRS

    Science.gov (United States)

    Henchen, Robert; Esham, Benjamin; Becker, William; Pogozelski, Edward; Padalino, Stephen; Sangster, Thomas; Glebov, Vladimir

    2008-11-01

    The High-Speed Rapid Pneumatic Transport of Radioactive Samples (HS-RaPToRS) system, designed to quickly and safely move radioactive materials, was assembled and tested at the Mercury facility of the Naval Research Laboratory (NRL) in Washington D.C. A sample, which is placed inside a four-inch-diameter carrier, is activated before being transported through a PVC tube via airflow. The carrier travels from the reaction chamber to the end station where it pneumatically brakes prior to the gate. A magnetic latch releases the gate when the carrier arrives and comes to rest. The airflow, optical carrier-monitoring devices, and end gate are controlled manually or automatically with LabView software. The installation and testing of the RaPToRS system at NRL was successfully completed with transport times of less than 3 seconds. The speed of the carrier averaged 16 m/s. Prospective facilities for similar systems include the Laboratory for Laser Energetics and the National Ignition Facility.

  1. Design of very high speed electric generators

    International Nuclear Information System (INIS)

    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.

  2. Modeling of high-speed electronic devices

    Directory of Open Access Journals (Sweden)

    V. G. Kudrya

    2013-09-01

    Full Text Available Introduction. The theme of this publication is the modeling of electronic tools that operate in the frequency range from zero to terahertz and higher. Application of new concepts and technologies, including biotechnology and nanotechnology in the development of monolithic integrated circuits led to a backlog of technologies of projecting from technologies and experimental research and manufacturing. The aim of this work is to develop algorithms for analysis, reflecting not only topological as well as morphological properties of the object, that is designing within the framework of accounting EMI communicational  transmission of energy and information in the volume of the monolithic integrated circuit. Basic steps for constructing the algorithm. The object of design is presented in the form of basic elements, which can be combined with a communication structure. The object of design is presented in the form of basic elements, which can be combined with a communication structure. There are three types of matrix equations: component; component - communication structure; communication structure. Systems of equations are reduced to standardized descriptors of mathematical model by which to understand current of poles and voltage arcs whole set of basic elements. In this way obtained mathematical model that can be implemented in CAD nano and micro technology electronics. Conclusions. Mathematical models of analysis of high-speed digital and analog electronic means. The algorithm allows morphological optimization is to minimize the adverse effects outside the system of electromagnetic interaction between the components and communicator.

  3. CMOS Image Sensors for High Speed Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2009-01-01

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

  4. Exhaust emissions from high speed passenger ferries

    Science.gov (United States)

    Cooper, D. A.

    Exhaust emission measurements have been carried out on-board three high-speed passenger ferries (A, B and C) during normal service routes. Ship A was powered by conventional, medium-speed, marine diesel engines, Ship B by gas turbine engines and Ship C conventional, medium-speed, marine diesel engines equipped with selective catalytic reduction (SCR) systems for NO x abatement. All ships had similar auxiliary engines (marine diesels) for generating electric power on-board. Real-world emission factors of NOx, SO2, CO, CO 2, NMVOC, CH4, N2O, NH3, PM and PAH at steady-state engine loads and for complete voyages were determined together with an estimate of annual emissions. In general, Ship B using gas turbines showed favourable NO x, PM and PAH emissions but at the expense of higher fuel consumption and CO 2 emissions. Ship C with the SCR had the lowest NO x emissions but highest NH 3 emissions especially during harbour approaches and stops. The greatest PM and PAH specific emissions were measured from auxiliary engines operating at low engine loads during harbour stops. Since all ships used a low-sulphur gas oil, SO 2 emissions were relatively low in all cases.

  5. 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.

  6. Photodetector having high speed and sensitivity

    Science.gov (United States)

    Morse, Jeffrey D.; Mariella, Jr., Raymond P.

    1991-01-01

    The present invention provides a photodetector having an advantageous combination of sensitivity and speed; it has a high sensitivity while retaining high speed. In a preferred embodiment, visible light is detected, but in some embodiments, x-rays can be detected, and in other embodiments infrared can be detected. The present invention comprises a photodetector having an active layer, and a recombination layer. The active layer has a surface exposed to light to be detected, and comprises a semiconductor, having a bandgap graded so that carriers formed due to interaction of the active layer with the incident radiation tend to be swept away from the exposed surface. The graded semiconductor material in the active layer preferably comprises Al.sub.1-x Ga.sub.x As. An additional sub-layer of graded In.sub.1-y Ga.sub.y As may be included between the Al.sub.1-x Ga.sub.x As layer and the recombination layer. The recombination layer comprises a semiconductor material having a short recombination time such as a defective GaAs layer grown in a low temperature process. The recombination layer is positioned adjacent to the active layer so that carriers from the active layer tend to be swept into the recombination layer. In an embodiment, the photodetector may comprise one or more additional layers stacked below the active and recombination layers. These additional layers may include another active layer and another recombination layer to absorb radiation not absorbed while passing through the first layers. A photodetector having a stacked configuration may have enhanced sensitivity and responsiveness at selected wavelengths such as infrared.

  7. 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.

  8. 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.

  9. 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...

  10. High-speed rail-coming to America?

    Science.gov (United States)

    Cameron, David Ossian

    2009-01-01

    The United States lags many parts of the world when it comes to high-speed rail. But investing in high-speed rail could help us through current problems. Funds- $8 billion-in the economic stimulus package passed by Congress are designated for high-speed rail. Other funds in the pipeline total approximately $15.5 billion. High-speed rail can relieve congestion, free up national airspace, provide reliable transportation and positive economic development, create jobs, and is more energy efficient than other modes of travel. PMID:19608527

  11. Design of A Novel High Speed Dynamic Comparator with Low Power Dissipation for High Speed ADCs

    Directory of Open Access Journals (Sweden)

    Sougata Ghosh

    2013-01-01

    Full Text Available A new CMOS dynamic comparator using dual input single output differential amplifier as latch stage suitable for high speed analog-to-digital converters with High Speed, low power dissipation and immune to noise than the previous reported work is proposed. Back to-back inverter in the latch stage is replaced with dual-input single output differential amplifier. This topology completely removes the noise that is present in the input. The structure shows lower power dissipation and higher speed than the conventional comparators. The circuit is simulated with 1V DC supply voltage and 250 MHz clock frequency. The proposed topology is based on two cross coupled differential pairs positive feedback and switchable current sources, has a lower power dissipation, higher speed, less area, and it is shown to be very robust against transistor mismatch, noise immunity. Previous reported comparators are designed and simulated their DC response and Transient response in Cadence®Virtuoso Analog Design Environment using GPDK 90nm technology. Layouts of the proposed comparator have been done in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS has been checked and compared with the corresponding circuits and RC extracted diagram has been generated. After that post layout simulation with 1V supply voltage has been done and compared the speed, power dissipation, Area, delay with the results before layout and the superior features of the proposed comparator are established

  12. High-speed, room-temperature quantum cascade detectors at 4.3 μm

    Science.gov (United States)

    Zhou, Yuhong; Zhai, Shenqiang; Wang, Fengjiao; Liu, Junqi; Liu, Fengqi; Liu, Shuman; Zhang, Jinchuan; Zhuo, Ning; Wang, Lijun; Wang, ZhanGuo

    2016-03-01

    We present high-speed, room-temperature operated 4.3 μm quantum cascade detectors. The devices are processed as square mesas with 50 Ω coplanar access line and air-bridge connector. The high frequency features are explored using microwave rectification technique and a RLC circuit model. The -3 dB cutoff frequency is experimentally 9 GHz and 4 GHz for 20×20 μm2 and 50×50 μm2 detectors, respectively. The equivalent circuit analysis shows that a second order filter feature governs the devices. Higher cutoff frequency can be achieved by eliminate the parasitics further.

  13. High-speed, room-temperature quantum cascade detectors at 4.3 μm

    Directory of Open Access Journals (Sweden)

    Yuhong Zhou

    2016-03-01

    Full Text Available We present high-speed, room-temperature operated 4.3 μm quantum cascade detectors. The devices are processed as square mesas with 50 Ω coplanar access line and air-bridge connector. The high frequency features are explored using microwave rectification technique and a RLC circuit model. The -3 dB cutoff frequency is experimentally 9 GHz and 4 GHz for 20×20 μm2 and 50×50 μm2 detectors, respectively. The equivalent circuit analysis shows that a second order filter feature governs the devices. Higher cutoff frequency can be achieved by eliminate the parasitics further.

  14. Structural vulnerability and intervention of high speed railway networks

    Science.gov (United States)

    Zhang, Jianhua; Hu, Funian; Wang, Shuliang; Dai, Yang; Wang, Yixing

    2016-11-01

    This paper employs complex network theory to assess the structural vulnerability of high speed railway networks subjected to two different malicious attacks. Chinese, US and Japanese high speed railway networks are used to discuss the vulnerable characteristics of systems. We find that high speed railway networks are very fragile when suffering serious disturbances and two attack rules can cause analogous damages to one high speed railway network, which illustrates that the station with large degree possesses high betweenness, vice versa. Meanwhile, we discover that Japanese high speed railway network has the best global connectivity, but Chinese high speed railway network has the best local connectivity and possesses the largest transport capacity. Moreover, we find that there exist several redundant paths in Chinese high speed railway network and discover the critical stations of three HSRNs. Furthermore, the nearest-link method is adopted to implement topological interventions and to improve the connectivity and reliability of high speed railway networks. In addition, the feasibility and effectiveness of topological interventions are shown by simulations.

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

    OpenAIRE

    Michael Galili; Hao Hu; Hans Christian Hansen Mulvad; Ashenafi Kiros Medhin; Anders Clausen; Leif Katsuo Oxenløwe

    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 and detection of ultra-high-speed optical signals.

  16. 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)...

  17. High-Speed Video Analysis of Damped Harmonic Motion

    Science.gov (United States)

    Poonyawatpornkul, J.; Wattanakasiwich, P.

    2013-01-01

    In this paper, we acquire and analyse high-speed videos of a spring-mass system oscillating in glycerin at different temperatures. Three cases of damped harmonic oscillation are investigated and analysed by using high-speed video at a rate of 120 frames s[superscript -1] and Tracker Video Analysis (Tracker) software. We present empirical data for…

  18. Intelligent high-speed cutting database system development

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,the components of a high-speed cutting system are analyzed firstly.The component variables of the high-speed cutting system are classified into four types:uncontrolled variables,process variables,control variables,and output variables.The relationships and interactions of these variables are discussed.Then,by analyzing and comparing intelligent reasoning methods frequently used,the hybrid reasoning is employed to build the high-speed cutting database system.Then,the data structures of high-speed cutting case base and databases are determined.Finally,the component parts and working process of the high-speed cutting database system on the basis of hybrid reasoning are presented.

  19. Heterotic M2-branes

    Directory of Open Access Journals (Sweden)

    Neil Lambert

    2015-10-01

    Full Text Available We construct the action for N M2-branes on S1/Z2. The resulting theory has a gauge anomaly but this can be cancelled if the two fixed point planes each support 8 chiral Fermions in the fundamental of U(N. Taking the low energy limit leads to the worldsheet theory of N free heterotic strings whose quantization induces an E8 spacetime gauge symmetry on each fixed point plane. Thus this paper presents a non-abelian worldvolume analogue of the classic Hořava–Witten analysis.

  20. Kajian Sub – Permukaan Baja Paduan Kekerasan Tinggi AISI 4140 Hasil Pembubutan Laju Tinggi Dan Kering Menggunakan Pahat CBN

    OpenAIRE

    Siahaan, Enzo Wiranta Battra

    2012-01-01

    The integrity of the sub - surface plays an important role in product quality. In this study, the impact of rate cuts, feed motion, depth of cut, cutting tool wear and tear on the sub - surface machining of steel AISI 4140 on the end for high speed machining, hard machining and dry machining studied experimentally using CBN cutting tool material. Four test parameters with three levels of cutting speed is low, medium and high. Conducted the data analysis of quantitative and qualitative. Quanti...

  1. High temperature oxidation behavior of AISI 304 and AISI 430 stainless steels

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Reis de Carvalho

    2006-12-01

    Full Text Available The oxidation behavior of AISI 304 and AISI 430 stainless steels was investigated from 1100 °C up to 1200 °C. Mössbauer spectroscopy and x ray diffraction were used to access the phase composition of the formed scales. The main crystalline phases found in the oxidized materials at temperatures above 1100 °C were hematite and magnetite for AISI 430 steel, and hematite and a spinel-like phase for AISI 304 steel. Hematite was found to be the dominant oxide at lower temperatures, whereas magnetite preferentially forms at higher temperatures. The activation energy for oxidation is smaller for AISI 430 steel in relation to AISI 304 steel in the range of studied temperatures, and therefore the AISI 430 steel is less resistant towards oxidation at high temperatures.

  2. Effect of niobium on the microstructure and properties of spray-formed M3:2 high speed steel%铌对喷射成形M3:2型高速钢组织和性能的影响

    Institute of Scientific and Technical Information of China (English)

    卢林; 黄进峰; 侯陇刚; 张金祥; 王和斌; 崔华; 张济山

    2014-01-01

    AISI M3:2 high speed steels with or without niobium addition were prepared via spray forming, then subjected to forging processes. The effects of Nb on the microstructure and properties of the high speed steels were investigated by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. It is found that Nb addition can refine the microstructure of the as-deposited steels and decrease the size of M2 C eutectic carbides. The amount of MC carbides in the as-deposited steels increases with increasing Nb content. The tempering resistance and second hardening ability of the high speed steel are improved by Nb addition. With a 1% Nb addition, lots of bulk Nb-rich primary MC carbides can form, which becomes the main cause of the reduction in bending strength and impact toughness of the high speed steel. However, the best mechanical properties can be achieved in the presence of 0. 5% Nb.%采用喷射成形工艺制备了含铌和不含铌M3:2型高速钢,然后进行锻造加工.利用扫描电子显微镜、X射线能谱仪、X射线衍射仪等研究了铌对喷射成形M3:2型高速钢组织和性能的影响.铌的加入细化了沉积态的组织,减小了M2 C共晶碳化物尺寸,而对M2 C的成分影响不明显.沉积态中MC碳化物的数量随铌含量提高而增多,且其成分变化显著.铌的加入可以提高喷射成形M3:2型高速钢的抗回火软化性和二次硬化能力.但是,当铌质量分数为1%时,组织中形成数量较多且难以破碎的以铌为主的块状MC碳化物,导致钢的弯曲强度和冲击韧性下降.铌质量分数为0.5%的喷射成形M3:2型高速钢可以获得最佳的硬度、弯曲强度和冲击韧性.

  3. HULL GESTURE AND RESISTANCE PREDICTION OF HIGH-SPEED VESSELS*

    Institute of Scientific and Technical Information of China (English)

    NI Chong-ben; ZHU Ren-chuan; MIAO Guo-ping; FAN Ju

    2011-01-01

    Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during voyage. It is necessary to take the influence of hull gesture into account for oredicting the resistance of high-speed ship. In the present work the resistance problem of high speed ship is treated with the viscous flow theory, and the dynamic mesh technique is adopted to coincide with variation of hull gesture of high speed vessel on voyage. The simulation of the models of S60 ship and a trimaran moving in towing tank with high speed are conducted by using the above theory and technique. The corresponding numerical results are in good agreement with the experimental data. It indicates that the resistance prediction for high speed vessels should take hull gesture into consideration and the dynamic mesh method proposed here is effective in calculating the resistance of high speed vessels.

  4. High-speed bipolar phototransistors in a 180 nm CMOS process.

    Science.gov (United States)

    Kostov, P; Gaberl, W; Zimmermann, H

    2013-03-01

    Several high-speed pnp phototransistors built in a standard 180 nm CMOS process are presented. The phototransistors were implemented in sizes of 40×40 μm(2) and 100×100 μm(2). Different base and emitter areas lead to different characteristics of the phototransistors. As starting material a p(+) wafer with a p(-) epitaxial layer on top was used. The phototransistors were optically characterized at wavelengths of 410, 675 and 850 nm. Bandwidths up to 92 MHz and dynamic responsivities up to 2.95 A/W were achieved. Evaluating the results, we can say that the presented phototransistors are well suited for high speed photosensitive optical applications where inherent amplification is needed. Further on, the standard silicon CMOS implementation opens the possibility for cheap integration of integrated optoelectronic circuits. Possible applications for the presented phototransistors are low cost high speed image sensors, opto-couplers, etc. PMID:23847388

  5. AN ANALYSIS METHOD FOR HIGH-SPEED CIRCUIT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method for analyzing high-speed circuit systems is presented. The method adds transmission line end currents to the circuit variables of the classical modified nodal approach. Then the matrix equation describing high-speed circuit system can be formulated directly and analyzed conveniently for its normative form. A time-domain analysis method for transmission lines is also introduced. The two methods are combined together to efficiently analyze high-speed circuit systems having general transmission lines. Numerical experiment is presented and the results are compared with that calculated by Hspice.

  6. Homogeneous M2 duals

    CERN Document Server

    Figueroa-O'Farrill, José

    2015-01-01

    Motivated by the search for new gravity duals to M2 branes with $N>4$ supersymmetry --- equivalently, M-theory backgrounds with Killing superalgebra $\\mathfrak{osp}(N|4)$ for $N>4$ --- we classify (except for a small gap) homogeneous M-theory backgrounds with symmetry Lie algebra $\\mathfrak{so}(n) \\oplus \\mathfrak{so}(3,2)$ for $n=5,6,7$. We find that there are no new backgrounds with $n=6,7$ but we do find a number of new (to us) backgrounds with $n=5$. All backgrounds are metrically products of the form $\\operatorname{AdS}_4 \\times P^7$, with $P$ riemannian and homogeneous under the action of $\\operatorname{SO}(5)$, or $S^4 \\times Q^7$ with $Q$ lorentzian and homogeneous under the action of $\\operatorname{SO}(3,2)$. At least one of the new backgrounds is supersymmetric (albeit with only $N=2$) and we show that it can be constructed from a supersymmetric Freund--Rubin background via a Wick rotation. Two of the new backgrounds have only been approximated numerically.

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

    OpenAIRE

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José; Zibar, Darko; Tafur Monroy, Idelfonso

    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.

  8. 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...

  9. High-Speed Thermal Characterization of Cryogenic Flows Project

    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...

  10. 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...

  11. Environmental impact evaluation for high-speed railway

    Institute of Scientific and Technical Information of China (English)

    宋晓东; 付延冰; 陈治亚; 刘恒斌

    2014-01-01

    Environmental impact evaluation system boundary of high-speed railway was defined based on the total life cycle theory, and the index system to evaluate the environmental impact of high-speed railway was established with the fuzzy analytic hierarchy method, and the matter-element evaluation model was established on the basis of the extension theory. By calculating its comprehensive interrelatedness, the evaluation rank of environment impacts of high-speed railway was determined. The numerical example shows that the model has vast prospect, which can not only expand the application areas of extension theory, but also change the traditional evaluation methods and provide new ideas and means for environmental impact evaluation of high-speed railway.

  12. 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.......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....

  13. 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....

  14. 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

  15. 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...... phenomena and proposes performance requirements instead of thickness requirements for hull panels in high-speed craft made of different building materials....

  16. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    OpenAIRE

    Jamaliah Idris; Chukwuekezie Christian; Eyu Gaius

    2013-01-01

    Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC) and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis par...

  17. From Periphery to Core: Economic Adjustments to High Speed Rail

    OpenAIRE

    Ahlfeldt, Gabriel M.; Feddersen, Arne

    2010-01-01

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

  18. Contributions to understanding the high speed machining effects on aeronautic part surface integrity

    Science.gov (United States)

    Jomaa, Walid

    To remain competitive, the aeronautic industry has increasing requirements for mechanical components and parts with high functional performance and longer in-service life. The improvement of the in-service life of components can be achieved by mastering and optimizing the surface integrity of the manufactured parts. Thus, the present study attempted to investigate, experimentally and theoretically, the tool/work material interactions on part surface integrity during the machining of aluminium alloys and hardened materials (low alloy steels) using orthogonal machining tests data. The studied materials are two aluminum alloys (6061-T6 and 7075-T651) and AISI 4340 steel. The AISI 4340 steel was machined after been induction heat treated to 58-60 HRC. These materials were selected in an attempt to provide a comprehensive study for the machining of metals with different behaviours (ductile and hard material). The proposed approach is built on three steps. First, we proposed a design of experiment (DOE) to analyse, experimentally, the chip formation and the resulting surface integrity during the high speed machining under dry condition. The orthogonal cutting mode, adopted in these experiments, allowed to explore, theoretically, the effects of technological (cutting speed and feed) and physical (cutting forces, temperature, shear angle, friction angle, and length Contact tool/chip) parameters on the chip formation mechanisms and the machined surface characteristics (residual stress, plastic deformation, phase transformation, etc.). The cutting conditions were chosen while maintaining a central composite design (CCD) with two factors (cutting speed and feed per revolution). For the aluminum 7075-T651, the results showed that the formation of BUE and the interaction between the tool edge and the iron-rich intermetallic particles are the main causes of the machined surface damage. The BUE formation increases with the cutting feed while the increase of the cutting speed

  19. Analysis of external noise spectrum of high-speed railway

    Institute of Scientific and Technical Information of China (English)

    邓永权; 肖新标; 何宾; 金学松

    2014-01-01

    A schematic to make the spectra of the exterior noise of high speed railway was put forward. The exterior noise spectrum was defined based on the characteristics of the high-speed train exterior noise. Its characteristics considered here include identifying the exterior main sources and their locations, their frequency components including the Doppler effect due to the noise sources moving at high speed, the sound field intensity around the train in high-speed operation, the sound radiation path out of the train, and the pressure level and frequency components of the noise at the measuring points specified by the International Organization for Standardization(ISO). The characteristics of the high-speed train exterior noise of the high speed railways in operation were introduced. The advanced measuring systems and their principles for clearly indentifying the exterior noise sources were discussed in detail. Based on the concerned noise results measured at sites, a prediction model was developed to calculate the sound level and the characteristics of the exterior noise at any point where it is difficult to measure and to help to make the exterior noise spectrums. This model was also verified with the test results. The verification shows that there is a good agreement between the theoretical and experimental results.

  20. Review of actuators for high speed active flow control

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO ZhenBing; XIA ZhiXun; LIU Bing; DENG Xiong

    2012-01-01

    Actuators are one of the key points for the development of active flow control technology.Efficient methods of high speed flow control can provide enhanced propulsive efficiency and at the same time enable safe and maneuverable high speed flight.The development of high speed flight technology promotes the emergence of novel and robust actuators.This review introduces the state of the art in the development of actuators that can be used in high speed active flow control.The classification and different operation criteria of the actuators are discussed.The specifications,mechanisms and applications of various popular actuator types including fluidic,mechanical,and plasma actuators are described.Based on the realistic need of high speed flow control and the existing results of actuators,a new actuator design method is proposed.At last,the merits and drawbacks of the actuators are summarized and some suggestions on the development of active flow control technology are put forward.

  1. High-speed deformation of aluminum by cold rolling

    International Nuclear Information System (INIS)

    High-speed deformation of aluminum was carried out by use of a high-speed rolling machine, and the results were compared with those of impact compression. The rolled specimens were electro-polished and observed under an electron microscope. As compared with the microstructures observed in the impact compression specimens, the microstructures observed in the rolled specimens showed almost the same tendency as impact compression for vacancy loop formation, but a different tendency for dislocation cell formations. The difference in the results is explained by the variation in strain rate during deformation in rolling. The results indicate that in high-speed rolling, vacancies and dislocations are produced independently during different periods. Specifically, in the high-strain period, during which dislocations are not generated, deformation proceeds without dislocations

  2. High-speed signal sampling technique in lidar application

    Science.gov (United States)

    Zhang, Yong; Zhao, Yuan; Liu, Feng; Su, Jian-zhong

    2013-09-01

    Common lidar systems sets the standard using only one sample data from the laser echo signal, while information from signal waveform is ignored, constraining further enhancement of range resolution and accuracy. By employing high-speed signal sampling technique, we make full use of the echo signal, and achieved large improvement on range resolution and accuracy. Moreover, the digital signal processing algorithm can be adopted for different targets, which provides better versatility of the lidar system. This paper reviewed high speed signal sampling technique and its application in lidar system. The HT high-speed DAQ developed in our group was used in both FMCW lidar and pulse laser radar. Over fourfold increase in range accuracy, comparing to that of traditional method, is demonstrated.

  3. High-speed LWR transients simulation for optimizing emergency response

    International Nuclear Information System (INIS)

    The purpose of computer-assisted emergency response in nuclear power plants, and the requirements for achieving such a response, are presented. An important requirement is the attainment of realistic high-speed plant simulations at the reactor site. Currently pursued development programs for plant simulations are reviewed. Five modeling principles are established and a criterion is presented for selecting numerical procedures and efficient computer hardware to achieve high-speed simulations. A newly developed technology for high-speed power plant simulation is described and results are presented. It is shown that simulation speeds ten times greater than real-time process-speeds are possible, and that plant instrumentation can be made part of the computational loop in a small, on-site minicomputer. Additional technical issues are presented which must still be resolved before the newly developed technology can be implemented in a nuclear power plant

  4. High-speed measurement of firearm primer blast waves

    OpenAIRE

    Courtney, Michael; Daviscourt, Joshua; Eng, Jonathan; Courtney, Amy

    2012-01-01

    This article describes a method and results for direct high-speed measurements of firearm primer blast waves employing a high-speed pressure transducer located at the muzzle to record the blast pressure wave produced by primer ignition. Key findings are: 1) Most of the lead styphnate based primer models tested show 5.2-11.3% standard deviation in the magnitudes of their peak pressure. 2) In contrast, lead-free diazodinitrophenol (DDNP) based primers had standard deviations of the peak blast p...

  5. 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.

  6. Supersonic stall flutter of high-speed fans

    Science.gov (United States)

    Adamczyk, J. J.; Stevans, W.; Jutras, R.

    1981-01-01

    An analytical model is proposed for predicting the onset of supersonic stall bending flutter in high-speed rotors. The analysis is based on a modified two-dimensional, compressible, unsteady actuator disk theory. The stability boundary predicted by the analysis is shown to be in good agreement with the measured boundary of a high speed fan. The prediction that the flutter mode would be a forward traveling wave sensitive to wheel speed and aerodynamic loading is confirmed by experimental measurements. In addition, the analysis shows that reduced frequency and dynamic head also play a significant role in establishing the supersonic stall bending flutter boundary of an unshrouded fan.

  7. 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.

  8. 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 the proc......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...

  9. Compact Models and Measurement Techniques for High-Speed Interconnects

    CERN Document Server

    Sharma, Rohit

    2012-01-01

    Compact Models and Measurement Techniques for High-Speed Interconnects provides detailed analysis of issues related to high-speed interconnects from the perspective of modeling approaches and measurement techniques. Particular focus is laid on the unified approach (variational method combined with the transverse transmission line technique) to develop efficient compact models for planar interconnects. This book will give a qualitative summary of the various reported modeling techniques and approaches and will help researchers and graduate students with deeper insights into interconnect models in particular and interconnect in general. Time domain and frequency domain measurement techniques and simulation methodology are also explained in this book.

  10. Plasma-Assisted Chemistry in High-Speed Flow

    Institute of Scientific and Technical Information of China (English)

    Sergey B.LEONOV; Dmitry A.YARANTSEV; Anatoly P.NAPARTOVICH; Igor V.KOCHETOV

    2007-01-01

    Fundamental problems related to the high-speed combustion are analyzed. The result of plasma-chemical modeling is presented as a motivation of experimental activity.Numerical simulations of the effect of uniform non-equilibrium discharge on the premixed hydrogen and ethylene-air mixture in supersonic flow demonstrate an advantage of such a technique over a heating.Experimental results on multi-electrode non-uniform discharge maintenance behind wallstep and in cavity of supersonic flow are presented.The model test on hydrogen and ethylene ignition is demonstrated at direct fuel injection to low-temperature high-speed airflow.

  11. Improvement of die life in high speed injection die casting

    Institute of Scientific and Technical Information of China (English)

    Yasuhiro Arisuda; Akihito Hasuno; Junji Yoshida; Kazunari Tanii

    2008-01-01

    High-speed injection die casting is an efficient manufacturing technology for upgrading aluminum die-cast products. However, deficiencies (such as die damage in eady period) due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die temperature analysis, flow analysis and thermal stress analysis). The potential countermeasures to solve the above problems were also proposed.

  12. Comparative study of high temperature oxidation behaviour in AISI 304 and AISI 439 stainless steels

    Directory of Open Access Journals (Sweden)

    Antônio Claret Soares Sabioni

    2003-06-01

    Full Text Available This work deals with a comparison of high temperature oxidation behaviour in AISI 304 austenitic and AISI 439 ferritic stainless steels. The oxidation experiments were performed between 850 and 950 °C, in oxygen and Ar (100 vpm H2. In most cases, it was formed a Cr2O3 protective scale, whose growth kinetics follows a parabolic law. The exception was for the the AISI 304 steel, at 950 °C, in oxygen atmosphere, which forms an iron oxide external layer. The oxidation resistance of the AISI 439 does not depend on the atmosphere. The AISI 304 has the same oxidation resistance in both atmospheres, at 850 °C, but at higher temperatures, its oxidation rate strongly increases in oxygen atmosphere. Concerning the performance of these steels under oxidation, our results show that the AISI 439 steel has higher oxidation resistance in oxidizing atmosphere, above 850 °C, while, in low pO2 atmosphere, the AISI 304 steel has higher oxidation resistance than the AISI 439, in all the temperature range investigated.

  13. Size Reduction of Tunable Micromachined Filters for High Speed Operations

    Institute of Scientific and Technical Information of China (English)

    Tomoyuki; Hino; Takeru; Amano; Wiganes; Janto; Fumio; Koyama

    2003-01-01

    The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever of 45 urn, exhibiting fast response of below 3 us.

  14. Faster than "g", Revisited with High-Speed Imaging

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2012-01-01

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

  15. Ultra-high-speed serial optical communications: Enabling technologies

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen;

    2008-01-01

    This paper will present recently identified and demonstrated key technologies for ultra-high-speed serial communications. Certain key components such as stabilised highly non-linear fibre switches, periodically poled Lithium Niobate devices and semiconductor optical amplifiers will be described w...

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  17. 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. 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....

  19. A high current, high speed pulser using avalanche transistors

    International Nuclear Information System (INIS)

    A high current, high speed pulser for the beam pulsing of a linear accelerator is described. It uses seven avalanche transistors in cascade. Design of a trigger circuit to obtain fast rise time is discussed. The characteristics of the pulser are : (a) Rise time = 0.9 ns (FWHM) and (d) Life time asymptotically equals 2000 -- 3000 hr (at 50 Hz). (author)

  20. 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...

  1. High speed VLSI neural network for high-energy physics

    NARCIS (Netherlands)

    Masa, P.; Hoen, K.; Wallinga, H.

    1994-01-01

    A CMOS neural network IC is discussed which was designed for very high speed applications. The parallel architecture, analog computing and digital weight storage provides unprecedented computing speed combined with ease of use. The circuit classifies up to 70 dimensional vectors within 20 nanosecond

  2. Research and practice: The European High Speed Station

    NARCIS (Netherlands)

    Triggianese, M.

    2014-01-01

    The practices of planning and architecture are undergoing considerable transformation especially for urban developments asso-ciated to infrastructural changes. This paper considers the proliferation of high-speed railways in Europe as a research opportunity to better understand the practice of compl

  3. High-tech maintenance for high-speed trains

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  4. High-speed camera characterization of voluntary eye blinking kinematics.

    Science.gov (United States)

    Kwon, Kyung-Ah; Shipley, Rebecca J; Edirisinghe, Mohan; Ezra, Daniel G; Rose, Geoff; Best, Serena M; Cameron, Ruth E

    2013-08-01

    Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.

  5. High-speed pulse-shape generator, pulse multiplexer

    Science.gov (United States)

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  6. Effects of the relative content tungsten/niobium on the solidification and the morphology of a modified M2 steel

    International Nuclear Information System (INIS)

    The cooling curves for two AISI type M2 steels modified with niobium, were obtained and samples of these steels were quenched at convenient temperatures, in order to correlate microstructure with solidification reactions as well as with W/Nb ratio. Increasing W/Nb ratios resulted in a higher fraction of austenite and complex carbide eutectics. (Author)

  7. Comportamiento del desgaste del flanco en el torneado en seco de alta velocidad del acero AISI 316L//Flank wear behavior in the dry high‐speed turning of AISI 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Yoandrys Morales-Tamayo

    2013-09-01

    Full Text Available El presente estudio experimental se centra en investigar los efectos de los parámetros corte en el desgaste de flanco con dos insertos recubiertos durante el torneado de acabado en seco a altas velocidades del acero inoxidable AISI 316L. Los efectos de los parámetros de corte fueron determinados utilizando un análisis de varianza y de regresión simple. Como principal resultado se obtuvo el efectosignificativo del avance y del tiempo de maquinado en el desgaste del flanco. El inserto de tres capas no sobrepasó el criterio de fin de vida del desgaste, mientras que el inserto de una capa sufrió un desgaste catastrófico para la mayor velocidad de corte. El desgaste del flanco tuvo mejor comportamiento para el avance de 0,08 mm/rev en todas las velocidades empleadas en este estudio.Palabras claves: torneado de alta velocidad, desgaste de flanco, acero inoxidable AISI 316L, estudio experimental, análisis de varianza y regresión.______________________________________________________________________________AbstractThe current experimental study is focused on investigating the effects of cutting parameters on flank wear in two coated carbide inserts during dry high speed finish turning of AISI 316L stainless steel. The effects of cutting parameters were determinate using analysis of variance and simple regression. As a main resulta significant effect of cutting feed and the machining time on flank wear was found. The three coating layers insert did not exceed the criterion of end of life of wear while the insert with one layer suffered a catastrophic wear at the highest cutting speed. The flank wear showed the best performance for the cuttingfeed of 0,08 mm/rev at all the speeds used in the study.Key words: high speed turning; flank wear; AISI 316L stainless steel, experimental study; analysis of variance and regression.

  8. Design Estimation of Aerodynamic Angles of High Speed Cars

    Directory of Open Access Journals (Sweden)

    Debojyoti Mitra

    2010-05-01

    Full Text Available The study of aerodynamic design of high-speed cars is mainly based on the wind-tunnel experiments and computational methods till date. In this particular study three car models of 100,200,300 pitch angles and 500,600,700 yaw angles are employed, and by wind-tunnel experiments we obtain pressure distributions over them. Now the correlations between drag-coefficient, lift-coefficient, pitch-angle and yaw-angle with Reynolds number are obtained by regression analysis of experimental data using MATLAB software. After plotting graphs it can be concluded that for minimum aerodynamic drag the optimized value of pitch and yaw angle should be 300 and 500. This type of study is expected to give a fair idea of aerodynamic angle design of high-speed cars.

  9. Investigation of fullerenes for high speed low latency, photonic switching

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. W. H; Shelton, R.N. [California Univ., Davis, CA (United States)

    1997-02-13

    The components in high-speed, all-optical photonic systems must satisfy two essential requirements: (1) high switching speeds in the range of Tbit/s, and (2) low latency, where the latency is the amount of time that the optical signal remains in the device. An important problem precluding the practical implementation of high-speed, all- optical switching is the lack of a material with appropriate nonlinear optical properties needed to effect the switching. Numerous material systems have been studied in the past, but none have met all the necessary requirements. Development of such a material and its incorporation into photonic devices would advance the field tremendously. This Lab-wide LDRD project resolved this critical problem.

  10. 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.

  11. High speed single- and dual-stage vertical positioners

    Science.gov (United States)

    Yong, Yuen K.; Wadikhaye, Sachin P.; Fleming, Andrew J.

    2016-08-01

    This article presents a high-speed single- and dual-stage vertical positioners for applications in optical systems. Each positioner employs a unique end-constraint method with orthogonal flexures to preload a piezoelectric stack actuator. This end-constraint method also significantly increases the first mechanical resonance frequency. The single-stage positioner has a displacement range of 7.6 μm and a first resonance frequency of 46.8 kHz. The dual-stage design consists of a long-range slow-stage and a short-range fast-stage. An inertial counterbalance technique was implemented on the fast-stage to cancel inertial forces resulting from high-speed motion. The dual-stage positioner has a combined travel range of approximately 10 μm and a first evident resonance frequency of 130 kHz.

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

    Science.gov (United States)

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

    2016-03-01

    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. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    Directory of Open Access Journals (Sweden)

    Jamaliah Idris

    2013-01-01

    Full Text Available Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis parameters, such as cathodic current density and temperature at constant pH, on electrodeposition and microstructure of Ni-Co alloys were examined. A homogeneous surface morphology was obtained at all current densities of the plated samples, and it was evident that the current density and temperature affect the coating thickness of Ni-Co alloy coatings.

  14. 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.

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

    DEFF Research Database (Denmark)

    Jespersen, Christoffer Felix

    2008-01-01

    This thesis is a continuation of the effort to increase the bandwidth of communicationnetworks. The thesis presents the results of the design of several high-speed electrical ircuits for an electrical/optical interface. These circuits have been a contribution to the ESTA project in collaboration...... circuits at the receiver interface, though VCOs are also found in the transmitter where a multitude of independent sources have to be mutually synchronized before multiplexing. The circuits are based on an InP DHBT process (VIP-2) supplied by Vitesse and made publicly available as MPW. The VIP-2 process...... represents the avant-garde of InP technology, with ft and fmax well above 300 GHz. Principles of high speed design are presented and described as a useful background before proceeding to circuits. A static divider is used as an example to illustrate many of the design principles. Theory and fundamentals...

  16. 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.

  17. Development of Industrial High-Speed Transfer Parallel Robot

    International Nuclear Information System (INIS)

    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

  18. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    Akira Hasegawa

    2001-11-01

    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 loss compensated by periodic amplifications. The nonlinear Schrödinger equation assisted by the split step numerical solutions is commonly used as the master equation to describe the information transfer in optical fibers. 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.

  19. 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......, a multithreshold legmentation algorithm is applied in a stereo-vision running at 150Hz. Based on the estimated 3D ball positions, a novel two-phase trajectory prediction is exploited to determine the hitting position. Benefiting from the high-speed visual feedback, the hitting position and thus the motion planning...... of the manipulator are updated iteratively with decreasing error. Experiments are conducted on a 7 degrees of freedom humanoid robot arm. A successful Ping-Pong playing between the robot arm and human is achieved with a high successful rate of 88%....

  20. 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.

  1. Analysis of OFDM Applied to Powerline High Speed Digital Communication

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Jian; YANG Gong-xu

    2003-01-01

    The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline channel is very complicated because it is an open net. This article analysed the character of the powerline channel,introduced the basics of OFDM(Orthogonal Frequency Division Multiplexing), and studied the OFDM applied into powerline high speed digital communication.

  2. NASA/GE Collaboration on Open Rotors - High Speed Testing

    Science.gov (United States)

    VanZante, Dale E.

    2011-01-01

    A low-noise open rotor system is being tested in collaboration with General Electric and CFM International, a 50/50 joint company between Snecmaand GE. Candidate technologies for lower noise will be investigated as well as installation effects such as pylon integration. Current test status for the 8x6 SWT high speed testing is presented as well as future scheduled testing which includes the FAA/CLEEN test entry. The tunnel blockage and propeller thrust calibration configurations are shown.

  3. High speed preprocessing in real time telemetry systems

    Science.gov (United States)

    Strock, O. J.; O'Brien, Michael

    A versatile high-speed preprocessor, the EMR 8715, is described which is used as a closed-coupled input device for the host computer in a telemetry system. Much of the data and time merging, number conversion, floating-point processing, and data distribution are performed by the system, reducing the host load. The EMR 8715 allows a choice of serial processing, parallel processing, or a combination of the two, on a measurement-by-measurement basis.

  4. Overall optimization of high-speed semiconductor laser modules

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; CHEN ShuoFu; WANG Xin; YUAN HaiQing; XIE Liang; ZHU NingHua

    2009-01-01

    Based on the high frequency techniques such as frequency response measurement, equivalent circuit modeling and packaging parasitics compensation, a comprehensive optimization method for packag-ing high-speed semiconductor laser module is presented in this paper. The experiments show that the small-signal magnitude frequency response of the TO packaged laser module is superior to that of laser diode in frequencies, and the in-band flatness and the phase-frequency linearity are also im-proved significantly.

  5. 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...

  6. Numerical Simulation of High-Speed Turbulent Reacting Flows

    Science.gov (United States)

    Givi, P.; Taulbee, D. B.; Madnia, C. K.; Jaberi, F. A.; Colucci, P. J.; Gicquel, L. Y. M.; Adumitroaie, V.; James, S.

    1999-01-01

    The objectives of this research are: (1) to develop and implement a new methodology for large eddy simulation of (LES) of high-speed reacting turbulent flows. (2) To develop algebraic turbulence closures for statistical description of chemically reacting turbulent flows. We have just completed the third year of Phase III of this research. This is the Final Report of our activities on this research sponsored by the NASA LaRC.

  7. Beijing-Tianjin Intercity High-speed Line

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Ever since 2003, under the guidance of the scientific development concept and in line with the decisions and deployments made by the Party Central Committee and the State Council, China Railways has eagerly taken the golden opportunity for development, to facilitate the implementation of the Mid-term and Long-term Railway Network Development Program, and so it has achieved bumper significant accomplishments in the modernization progress, with Beijing-Tianjin Intercity High-speed Line as one of the exemplary representatives.

  8. Broadband Wireless Channel measurements for high speed trains

    OpenAIRE

    Kaltenberger, Florian; BYIRINGIRO, Auguste; Arvanitakis, George; GHADDAB, Ryad; NUSSBAUM, Dominique; Knopp, Raymond; Berbineau, Marion; Cocheril, Yann; Philippe, Henri

    2014-01-01

    We describe a channel sounding measurement campaign for cellular broadband wireless communications with high speed trains that was carried out in the context of the project CORRIDOR. The campaign combines MIMO and carrier aggregation to achieve very highth roughputs. We compare two different scenarios, the first one reflects a cellular deployment, where the base station is about 1 km away from the railway line. The second scenario corresponds to a railway deployed network, where the base stat...

  9. High Speed White Dwarf Asteroseismology with the Herty Hall Cluster

    Science.gov (United States)

    Gray, Aaron; Kim, A.

    2012-01-01

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

  10. Analysis and design technology for high-speed aircraft structures

    Science.gov (United States)

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

    1992-01-01

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

  11. Potential ecological impacts analysis of California high speed rail

    OpenAIRE

    Cameron, Dick; White, Mike; Stallcup, Jerre Ann; Penrod, Kristeen

    2005-01-01

    The Nature Conservancy and the Conservation Biology Institute conducted an analysis of the potential environmental impacts of the proposed California High Speed Rail project as detailed in the 2004 Draft Programmatic Environmental Impact Report. The analysis intended to match the scale of the programmatic EIR in order to inform comments and to create a synoptic view of the project with select focal examples of potential impact areas for non-governmental organization partners and funders. An i...

  12. High Speed, Low Weight Momentum/Reaction Wheels

    OpenAIRE

    Wilhide, Larry; Brothers, Louis; Breyer, Eugene

    1999-01-01

    Advancements in several critical areas have made possible lightweight, strong and highly reliable momentum / reaction wheels. The development of reliable bearings with design features that allow high speed operation for space flight applications has significantly altered the weight / speed / wheel design considerations. Current designs typically operate at speeds at or below 6,000 RPM The new retainerless can achieve speeds 10 times that and meet or improve all other significant bearing opera...

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

    OpenAIRE

    Jia Ge; Fok, Mable P.

    2015-01-01

    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...

  14. Giga bit per second Differential Scheme for High Speed Interconnect

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Narula

    2012-02-01

    Full Text Available The performance of many digital systems today is limited by the interconnection bandwidth between chips. Although the processing performance of a single chip has increased dramatically since the inception of the integrated circuit technology, the communication bandwidth between chips has not enjoyed as much benefit. Most CMOS chips, when communicating off-chip, drive un terminated lines with full-swing CMOS drivers. Such full-swing CMOS interconnect ring-up the line, and hence has a bandwidth that is limited by the length of the line rather than the performance of the semiconductor technology. Thus, as VLSI technology scales, the pin bandwidth does not improve with the technology, but rather remains limited by board and cable geometry, making off-chip bandwidth an even more critical bottleneck. In order to increase the I/O Bandwidth, some efficient high speed signaling standard must be used which considers the line termination, signal integrity, power dissipation, noise immunity etc In this work, a transmitter has been developed for high speed off chip communication. It consists of low speed input buffer, serializer which converts parallel input data into serial data and a current mode driver which converts the voltage mode input signals into current over the transmission line. Output of 32 low speed input buffers is fed to two serializer, each serializer converting 16 bit parallel data into serial data stream. Output of two serializers is fed to LVDS current mode driver. The serial link technique used in this work is the time division multiplex (TDM and point-to-point technique. It means that the low-speed parallel signals are transferred to the high-speed serial signal at the transmitter end and the high-speed serial signal is transferred to the low-speed parallel signals at the receiver end. Serial link is the design of choice in any application where the cost of the communication channel is high and duplicating the links in large numbers is

  15. Giga bit per second Differential Scheme for High Speed Interconnect

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Narula

    2012-03-01

    Full Text Available The performance of many digital systems today is limited by the interconnection bandwidth between chips. Although the processing performance of a single chip has increased dramatically since the inception of the integrated circuit technology, the communication bandwidth between chips has not enjoyed as much benefit. Most CMOS chips, when communicating off-chip, drive unterminated lines with full-swing CMOS drivers. Such full-swing CMOS interconnect ring-up the line, and hence has a bandwidth that is limited by the length of the line rather than the performance of the semiconductor technology. Thus, as VLSI technology scales, the pin bandwidth does not improve with the technology, but rather remains limited by board and cable geometry, making off-chip bandwidth an even more critical bottleneck. In order to increase the I/O Bandwidth, some efficient high speed signaling standard must be used which considers the line termination, signal integrity, power dissipation, noise immunity etc In this work, a transmitter has been developed for high speed offchip communication. It consists of low speed input buffer, serializer which converts parallel input data into serial data and a current mode driver which converts the voltage mode input signals into current over the transmission line. Output of 32 low speed input buffers is fed to two serializer, each serializer converting 16 bit parallel data into serial data stream. Output of two serializers is fed to LVDS current mode driver. The serial link technique used in this work is the time division multiplex (TDM and point-to-point technique. It means that the low-speed parallel signals are transferred to the high-speed serial signal at the transmitter end and the high-speed serial signal is transferred to the low-speed parallel signals at the receiver end. Serial link is the design of choice in any application where the cost of the communication channel is high and duplicating the links in large numbers is

  16. Power Input of High-Speed Rotary Impellers

    OpenAIRE

    K. R. Beshay; J. Kratěna; I. Fořt; O. Brůha

    2001-01-01

    This paper presents the results of an experimental investigation of the power input of pitched blade impellers and standard Rushton turbine impellers in a cylindrical vessel provided with four radial baffles at its wall under a turbulent regime of flow of an agitated liquid. The influence of the geometry of the pitched blade impellers (pitch angle, number of blades) and the off-bottom impeller clearance of both high-speed impellers tested on the impeller power input is determined in two sizes...

  17. High Speed Friction Microscopy and Nanoscale Friction Coefficient Mapping

    OpenAIRE

    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...

  18. High-speed Laser Micromachining with Copper Bromide Laser

    CERN Document Server

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

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

    International Nuclear Information System (INIS)

    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

  20. VCA Direct-Drive High Speed and Precision XY Table

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xingyu; FENG Xiaomei; ZHANG Dawei

    2007-01-01

    In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA)direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system, the dynamic equations of the mechanical sys-tem and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the Icop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results val-idated the correctness of the model and the theory. Compared with traditional XY table, the tablehas higher speed, acceleration and positioning accuracy.

  1. High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips.

    Directory of Open Access Journals (Sweden)

    Nina Vyas

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

  2. Software Developed for Analyzing High- Speed Rolling-Element Bearings

    Science.gov (United States)

    Fleming, David P.

    2005-01-01

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

  3. Grooved roll for a high speed twin roll caster

    Directory of Open Access Journals (Sweden)

    T. Haga

    2008-04-01

    Full Text Available Purpose: Purpose of this paper is investigation of the effect of roll-surface on the strip-surface. Improvement ofsmall cracks on the strip-surface was tried and effect of groove at the roll surface on the strip surface was shown.Design/methodology/approach: Method used in the present study was high speed twin roll caster withgrooved roll. Two kinds of grooves were used: one was parallel groove and the other was cross groove machinedby knurling and bite attached to a lathe.Findings: Findings of this research are that grooved roll was effective to eliminate the small cracks on the stripsurface. The contact condition between the roll and the melt became uniform by the small groove on the rollsurface. Contact area became small, and heat transfer between the melt and roll became small, too. As the result,chill structure did not become columnar, and crack did not occur. Groove pattern on the strip surface could beerased by the cold rolling.Research limitations/implications: Research limitation is that groove life could not be investigated.Practical implications: Practical implications are as below. The roll load was small and strip was not hot-rolledin a high speed twin roll caster. The grooved roll made strip-surface sound. Grooved 600mm width roll was tested,and usefulness of the grooved roll was shown.Originality/value: In the present study effect of the grooved roll on a high speed twin roll caster was investigated.

  4. Flat belt continuously variable high speed drive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley ``turbine`` (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the ``turbine`` corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the ``turbine`` belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  5. High Speed Imaging of Cavitation around Dental Ultrasonic Scaler Tips.

    Science.gov (United States)

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

    2016-01-01

    Cavitation occurs around dental ultrasonic scalers, which are used clinically for removing dental biofilm and calculus. However it is not known if this contributes to the cleaning process. Characterisation of the cavitation around ultrasonic scalers will assist in assessing its contribution and in developing new clinical devices for removing biofilm with cavitation. The aim is to use high speed camera imaging to quantify cavitation patterns around an ultrasonic scaler. A Satelec ultrasonic scaler operating at 29 kHz with three different shaped tips has been studied at medium and high operating power using high speed imaging at 15,000, 90,000 and 250,000 frames per second. The tip displacement has been recorded using scanning laser vibrometry. Cavitation occurs at the free end of the tip and increases with power while the area and width of the cavitation cloud varies for different shaped tips. The cavitation starts at the antinodes, with little or no cavitation at the node. High speed image sequences combined with scanning laser vibrometry show individual microbubbles imploding and bubble clouds lifting and moving away from the ultrasonic scaler tip, with larger tip displacement causing more cavitation. PMID:26934340

  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

    1993-05-01

    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.

  7. Numerical Simulation of Flow Instabilities in High Speed Multistage Compressors

    Institute of Scientific and Technical Information of China (English)

    JunHu; ThomasPeters; 等

    1999-01-01

    In the present paper,a nonlinear multi“actuator disk” model is proposed to analyze the dynamic behavior of flow instabilities,including rotating stall and surge,in high speed multistage axial compressors.The model describes the duct flow fields using two dimensional,compressible and unsteady Euler equations,and accounts for the influences of downstream plenum and throttle in the system as well.It replaces each blade row of multistage compressore with a disk.For numerical calculations,the time marching procedure,using MacCormack two steps scheme,is used.The main pupose of this paper is to predict the mechanism of two dimensional short wavelength rotating stall inception and the interation between blade rows in high speed multistage compressors.It has been demonstrated that the model has the ability to predict those phenomena,and the results show that some system parameters have a strong effect on the stall features as well.Results for a five stage high speed compressor are analyzed in detail,and comparison with the experimental data demonstrates that the model and calculating results are reliable.

  8. Numerical Simulation of a Planing Vessel at High Speed

    Institute of Scientific and Technical Information of China (English)

    Yumin Su; Qingtong Chen; Hailong Shen; Wei Lu

    2012-01-01

    Planing vessels are applied widely in civil and military situations.Due to their high speed,the motion of planning vessels is complex.In order to predict the motion of planning vessels,it is important to analyze the hydrodynamic performance of planning vessels at high speeds.The computational fluid dynamic method (CFD) has been proposed to calculate hydrodynamic performance of planning vessels.However,in most traditional CFD approaches,model tests or empirical formulas are needed to obtain the running attitude of the planing vessels before calculation.This paper presents a new CFD method to calculate hydrodynamic forces of planing vessels.The numerical method was based on Reynolds-Averaged Navier-Stokes (RANS)equations.The volume of fluid (VOF) method and the six-degrees-of-freedom equation were applied.An effective process was introduced to solve the numerical divergence problem in numerical simulation.Compared with experimental results,numerical simulation results indicate that both the running attitude and hydrodynamic performance can be predicted well at high speeds.

  9. High speed turbulent reacting flows: DNS and LES

    Science.gov (United States)

    Givi, Peyman

    1990-01-01

    Work on understanding the mechanisms of mixing and reaction in high speed turbulent reacting flows was continued. Efforts, in particular, were concentrated on taking advantage of modern computational methods to simulate high speed turbulent flows. In doing so, two methodologies were used: large eddy simulations (LES) and direct numerical simulations (DNS). In the work related with LES the objective is to study the behavior of the probability density functions (pdfs) of scalar properties within the subgrid in reacting turbulent flows. The data base obtained by DNS for a detailed study of the pdf characteristics within the subgrid was used. Simulations are performed for flows under various initializations to include the effects of compressibility on mixing and chemical reactions. In the work related with DNS, a two-dimensional temporally developing high speed mixing layer under the influence of a second-order non-equilibrium chemical reaction of the type A + B yields products + heat was considered. Simulations were performed with different magnitudes of the convective Mach numbers and with different chemical kinetic parameters for the purpose of examining the isolated effects of the compressibility and the heat released by the chemical reactions on the structure of the layer. A full compressible code was developed and utilized, so that the coupling between mixing and chemical reactions is captured in a realistic manner.

  10. Research of inverse mathematical model to high-speed trains

    Institute of Scientific and Technical Information of China (English)

    朱涛; 肖守讷; 马卫华; 阳光武

    2014-01-01

    Operation safety and stability of the train mainly depend on the interaction between the wheel and rail. Knowledge of wheel/rail contact force is important for vehicle control systems that aim to enhance vehicle stability and passenger safety. Since wheel/rail contact forces of high-speed train are very difficult to measure directly, a new estimation process for wheel/rail contact forces was introduced in this work. Based on the state space equation, dynamic programming methods and the Bellman principle of optimality, the main theoretical derivation of the inversion mathematical model was given. The new method overcomes the weakness of large fluctuations which exist in current inverse techniques. High-speed vehicle was chosen as the research object, accelerations of axle box as input conditions, 10 degrees of freedom vertical vibration model and 17 degrees of freedom lateral vibration model were established, respectively. Under 250 km/h, the vertical and lateral wheel/rail forces were identified. From the time domain and frequency domain, the comparison of the results between inverse and SIMPACK models were given. The results show that the inverse mathematical model has high precision for inversing the wheel/rail contact forces of an operation high-speed vehicle.

  11. The Effects of Austenitizing Conditions on the Microstructure and Wear Resistance of a Centrifugally Cast High-Speed Steel Roll

    Science.gov (United States)

    Kang, Minwoo; Lee, Young-Kook

    2016-07-01

    The influences of austenitizing conditions on the microstructure and wear resistance of a centrifugally cast high-speed steel roll were investigated through thermodynamic calculation, microstructural analysis, and high-temperature wear tests. When the austenitizing temperature was between 1323 K and 1423 K (1050 °C and 1150 °C), coarse eutectic M2C plates were decomposed into a mixture of MC and M6C particles. However, at 1473 K (1200 °C), the M2C plates were first replaced by both new austenite grains and MC particles without M6C particles, and then remaining M2C particles were dissolved during the growth of MC particles. The wear resistance of the HSS roll was improved with increasing austenitizing temperature up to 1473 K (1200 °C) because the coarse eutectic M2C plates, which are vulnerable to crack propagation, changed to disconnected hard M6C and MC particles.

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  13. Monitoring and analysis of thermal deformation waves with a high-speed phase measurement system.

    Science.gov (United States)

    Taylor, Lucas; Talghader, Joseph

    2015-10-20

    Thermal effects in optical substrates are vitally important in determining laser damage resistance in long-pulse and continuous-wave laser systems. Thermal deformation waves in a soda-lime-silica glass substrate have been measured using high-speed interferometry during a series of laser pulses incident on the surface. Two-dimensional images of the thermal waves were captured at a rate of up to six frames per thermal event using a quantitative phase measurement method. The system comprised a Mach-Zehnder interferometer, along with a high-speed camera capable of up to 20,000 frames-per-second. The sample was placed in the interferometer and irradiated with 100 ns, 2 kHz Q-switched pulses from a high-power Nd:YAG laser operating at 1064 nm. Phase measurements were converted to temperature using known values of thermal expansion and temperature-dependent refractive index for glass. The thermal decay at the center of the thermal wave was fit to a function derived from first principles with excellent agreement. Additionally, the spread of the thermal distribution over time was fit to the same function. Both the temporal decay fit and the spatial fit produced a thermal diffusivity of 5×10-7  m2/s.

  14. Monitoring and analysis of thermal deformation waves with a high-speed phase measurement system.

    Science.gov (United States)

    Taylor, Lucas; Talghader, Joseph

    2015-10-20

    Thermal effects in optical substrates are vitally important in determining laser damage resistance in long-pulse and continuous-wave laser systems. Thermal deformation waves in a soda-lime-silica glass substrate have been measured using high-speed interferometry during a series of laser pulses incident on the surface. Two-dimensional images of the thermal waves were captured at a rate of up to six frames per thermal event using a quantitative phase measurement method. The system comprised a Mach-Zehnder interferometer, along with a high-speed camera capable of up to 20,000 frames-per-second. The sample was placed in the interferometer and irradiated with 100 ns, 2 kHz Q-switched pulses from a high-power Nd:YAG laser operating at 1064 nm. Phase measurements were converted to temperature using known values of thermal expansion and temperature-dependent refractive index for glass. The thermal decay at the center of the thermal wave was fit to a function derived from first principles with excellent agreement. Additionally, the spread of the thermal distribution over time was fit to the same function. Both the temporal decay fit and the spatial fit produced a thermal diffusivity of 5×10-7  m2/s. PMID:26560391

  15. 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.

  16. 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

  17. Development of centrifugal casting high speed steel rolls

    Institute of Scientific and Technical Information of China (English)

    Hanguang Fu; Aimin Zhao; Jiandong Xing

    2003-01-01

    The present study aims at developing the high speed steel (HSS) as roll materials to replace the traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy. The HSS roll billet was formed by centrifugal casting, and the billet was rough machined after soften annealing heat treatment, then it was quenched and tempered to get suitable hardness and toughness. After that the HSS roll was finish machined to the final dimension of φ285 mm in the outer diameter, φ160 mm in the inner diameter and 120 mm in width and its surface hardness was tested. Finally the HSS roll was used in high speed wire rod mill. The test results show that a high and homogeneous hardness can obtain on the work surface of HSS rolls, the surface hardness is 63-65HRC and its variation is smaller than 2HRC. The impact toughness of this kind of HSS is about 16 J/cra2. The results of on-line service investigation in high speed wire rod mill indicate that the HSS rolls have excellent wear resistance, the steel rolling quantity per mm of HSS rolls is 3120 t, the service life-span of HSS rolls is 4 times longer than that of high chromium cast iron rolls and it is close to that of the PM hard alloy rolls. The manufacturing burden of HSS rolls is obviously lower than that of the PM hard alloy rolls, it is only 25% of that of the PM hard alloy rolls.

  18. Fusion: ultra-high-speed and IR image sensors

    Science.gov (United States)

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

    2015-08-01

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

  19. Bottom Raking Damage to High-Speed Craft

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    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...... is insensitive to these uncertainties.The result of the analysis suggests that the normalised raking damage (damage length/ship length) to HSC can be expected to be 3-4 times longer than that to conventional ships. This implies that a significant part of HSC grounding accidents will produce tears in the full...

  20. Performance comparison of high speed microchannel plate photomultiplier tubes

    Science.gov (United States)

    Varghese, Thomas; Selden, Michael; Oldham, Thomas

    1993-01-01

    The transit time spread characteristics of high speed microchannel photomultipliers has improved since the upgrade of the NASA CDSLR network to MCP-PMT's in the mid-1980's. The improvement comes from the incorporation of 6 micron (pore size) microchannels and offers significant improvement to the satellite ranging precision. To examine the impact on ranging precision, two microchannel plate photomultiplier tubes (MCP-PMT) were evaluated for output pulse characteristics and temporal jitter. These were a Hamamatsu R 2566 U-7 MCP-PMT (6 micron) and an ITT 4129f MCP-PMT (12 micron).

  1. Magnetic Bearing Controller Improvements for High Speed Flywheel System

    Science.gov (United States)

    Dever, Timothy P.; Brown, Gerald V.; Jansen, Ralph H.; Kascak, Peter E.; Provenza, Andrew J.

    2003-01-01

    A magnetic bearing control system for a high-speed flywheel system is described. The flywheel utilizes a five axis active magnetic bearing system, using eddy current sensors for position feedback to the bearing controller. Magnetic bearing controller features designed to improve flywheel operation and testing are described. Operational improvements include feed forward control to compensate for rotor imbalance, moving notch filtering to compensate for synchronous and harmonic rotational noise, and fixed notching to prevent rotor bending mode excitation. Testing improvements include adding safe gain, bearing current hold, bearing current zero, and excitation input features. Performance and testing improvements provided by these features are measured and discussed.

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

    Directory of Open Access Journals (Sweden)

    CHENG Qiang

    2013-07-01

    Full Text Available 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 the end can not only provide accurate data, but also give a more intuitive understanding of electromagnetic field distribution and attenuation characteristics generated by pantograph detachment.    

  3. The Impact of High Speed Machining on Computing and Automation

    Institute of Scientific and Technical Information of China (English)

    KKB Hon; BT Hang Tuah Baharudin

    2006-01-01

    Machine tool technologies, especially Computer Numerical Control (CNC) High Speed Machining (HSM) have emerged as effective mechanisms for Rapid Tooling and Manufacturing applications. These new technologies are attractive for competitive manufacturing because of their technical advantages, i.e. a significant reduction in lead-time, high product accuracy, and good surface finish. However, HSM not only stimulates advancements in cutting tools and materials, it also demands increasingly sophisticated CAD/CAM software, and powerful CNC controllers that require more support technologies. This paper explores the computational requirement and impact of HSM on CNC controller, wear detection,look ahead programming, simulation, and tool management.

  4. Insect wing deformation measurements using high speed digital holographic interferometry.

    Science.gov (United States)

    Aguayo, Daniel D; Mendoza Santoyo, Fernando; De la Torre-I, Manuel H; Salas-Araiza, Manuel D; Caloca-Mendez, Cristian; Gutierrez Hernandez, David Asael

    2010-03-15

    An out-of-plane digital holographic interferometry system is used to detect and measure insect's wing micro deformations. The in-vivo phenomenon of the flapping is registered using a high power cw laser and a high speed camera. A series of digital holograms with the deformation encoded are obtained. Full field deformation maps are presented for an eastern tiger swallowtail butterfly (Pterourus multicaudata). Results show no uniform or symmetrical deformations between wings. These deformations are in the order of hundreds of nanometers over the entire surface. Out-of-plane deformation maps are presented using the unwrapped phase maps. PMID:20389581

  5. New technique for high-speed microjet breakup analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vago, N. [Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest (Hungary); Synova SA, Ch. Dent d' Oche, 1024 Ecublens (Switzerland); Spiegel, A. [Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest (Hungary); Couty, P. [Institute of Imaging and Applied Optics, Swiss Federal Institute of Technology, Lausanne, BM, 1015, Lausanne (Switzerland); Wagner, F.R.; Richerzhagen, B. [Synova SA, Ch. Dent d' Oche, 1024 Ecublens (Switzerland)

    2003-10-01

    In this paper we introduce a new technique for visualizing the breakup of thin high-speed liquid jets. Focused light of a He-Ne laser is coupled into a water jet, which behaves as a cylindrical waveguide until the point where the amplitude of surface waves is large enough to scatter out the light from the jet. Observing the jet from a direction perpendicular to its axis, the light that appears indicates the location of breakup. Real-time examination and also statistical analysis of the jet disruption is possible with this method. A ray tracing method was developed to demonstrate the light scattering process. (orig.)

  6. High Speed, Low Power Current Comparators with Hysteresis

    Directory of Open Access Journals (Sweden)

    Neeraj K. Chasta

    2012-02-01

    Full Text Available This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis, where comparator gives high accuracy (less than 50nA and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180 nm CMOS process technology for a supply voltage of 3V.

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

  9. High Speed Optical Tomography System for Imaging Dynamic Transparent Media

    Science.gov (United States)

    McMackin, Lenore; Hugo, Ronald J.; Pierson, R. E.; Truman, C. R.

    1997-11-01

    We describe the design and operation of a high speed optical tomography system for measuring two-dimensional images of a dynamic phase object at a rate of 5 kHz. Data from a set of eight Hartmann wavefront sensors is back-projected to produce phase images showing the details of the inner structure of a heated air flow. The tomographic reconstructions have a spatial resolution of approximately 2.0 mm and can measure temperature variations across the flow with an accuracy of about 0.7 C. Series of animated reconstructions at different downstream locations illustrate the development of flow structure and the effect of acoustic flow forcing.

  10. Synchronizing Photography For High-Speed-Engine Research

    Science.gov (United States)

    Chun, K. S.

    1989-01-01

    Light flashes when shaft reaches predetermined angle. Synchronization system facilitates visualization of flow in high-speed internal-combustion engines. Designed for cinematography and holographic interferometry, system synchronizes camera and light source with predetermined rotational angle of engine shaft. 10-bit resolution of absolute optical shaft encoder adapted, and 2 to tenth power combinations of 10-bit binary data computed to corresponding angle values. Pre-computed angle values programmed into EPROM's (erasable programmable read-only memories) to use as angle lookup table. Resolves shaft angle to within 0.35 degree at rotational speeds up to 73,240 revolutions per minute.

  11. Research of high speed optical switch based on compound semiconductor

    Institute of Scientific and Technical Information of China (English)

    WANG MingHua; QI Wei; YU Hui; JIANG XiaoQing; YANG JianYi

    2009-01-01

    High-speed optical switch and its array are the crucial components of all-optical switching system. This paper presents the analytical model of a total-internal-reflection (TIR) optical switch. By employing the carrier injection effect in GaAs and the GaAs/AlGaAs double heterojunction structure, the X-junction TIR switch and the Mach-Zehnder interference (MZI) switch are demonstrated at 1.55 IJm. The measured results show that the extinction ratio of both switches exceeds 20 dB. The switching speed reaches the scale of 10 ns.

  12. Study on High-Speed Magnitude Approximation for Complex Vectors

    Institute of Scientific and Technical Information of China (English)

    陈建春; 杨万海; 许少英

    2003-01-01

    High-speed magnitude approximation algorithms for complex vectors are discussed intensively. The performance and the convergence speed of these approximation algorithms are analyzed. For the polygon fitting algorithms, the approximation formula under the least mean square error criterion is derived. For the iterative algorithms, a modified CORDIC (coordinate rotation digital computer) algorithm is developed. This modified CORDIC algorithm is proved to be with a maximum relative error about one half that of the original CORDIC algorithm. Finally, the effects of the finite register length on these algorithms are also concerned, which shows that 9 to 12-bit coefficients are sufficient for practical applications.

  13. MOTION VELOCITY SMOOTH LINK IN HIGH SPEED MACHINING

    Institute of Scientific and Technical Information of China (English)

    REN Kun; FU Jianzhong; CHEN Zichen

    2007-01-01

    To deal with over-shooting and gouging in high speed machining, a novel approach for velocity smooth link is proposed. Considering discrete tool path, cubic spline curve fitting is used to find dangerous points, and according to spatial geometric properties of tool path and the kinematics theory, maximum optimal velocities at dangerous points are obtained. Based on method of velocity control characteristics stored in control system, a fast algorithm for velocity smooth link is analyzed and formulated. On-line implementation results show that the proposed approach makes velocity changing more smoothly compared with traditional velocity control methods and improves productivity greatly.

  14. High Speed, Low Power Current Comparators with Hysteresis

    Directory of Open Access Journals (Sweden)

    Neeraj K. Chasta

    2012-03-01

    Full Text Available This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis, where comparator gives high accuracy (less than 50nA and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180nm CMOS process technology for a supply voltage of 3V.

  15. Design of a high speed rotating mechanical shutter

    Energy Technology Data Exchange (ETDEWEB)

    Stowers, I.F.; Merritt, B.T.; McFann, C.B.

    1979-11-06

    A high-speed rotating shutter was designed to operate in a 10/sup -6/ Torr vacuum at the optical focus of a laser spatial filter. The shutter is basically a wheel, with a single 3 x 10-mm slot at the perimeter, which rotates with a peripheral speed of 1 km/s. The motor to drive the rotating wheel is magnetically suspended and synchronously wound. The wheel achieves a 4 ..mu..s opening time and a timing accuracy of better than 0.2 ..mu..s. (MOW)

  16. Mixing layer resonance under high-speed stream forcing

    Science.gov (United States)

    Thomassin, Jean; Mureithi, Njuki; Vo, Huu Duc

    2014-12-01

    In the majority of fluid-structure interaction problems, the biggest challenge lies in the fundamental understanding of the flow physics. Forced mixing layers is an important phenomenon found in many cases of flow-induced vibrations and acoustics. The response of a mixing layer to high-speed stream acoustic forcing is investigated with a theoretical and experimental approach. Two different experiments demonstrating the fluid mechanic phenomenon are presented. The first experiment consists of a circular jet impinging on a vibrating plate. The second experiment demonstrates the mixing layer resonance in the context of a fluidelastic instability causing high-amplitude vibrations in gas turbine high-pressure compressor rotor blades. Both the plate and the adjacent blade vibration induce an acoustic feedback that propagates within the jet and blade tip clearance flow, respectively. The resonance was found to occur when the feedback wavelength matched either the jet-to-plate or the inter-blade distance. In both experimental cases, the resonance condition has been simply modeled by the coincidence of a 1D feedback wave, which propagates upstream at reduced velocity by the high-speed flow. The coupling between the jet induced mixing layer and the feedback wave is assumed to naturally occur when one of the wave crests reaches the separation edge. The objective of this study is to improve the understanding of the coupling mechanism between an emanating shear layer and the acoustic forcing originating within a fast flow stream. The study is based on a simplified analytical model in order to enlarge the current understanding of the mixing layer receptivity to the more specific case of its response to high-speed stream forcing. To identify the mixing layer resonant modes, an analytical resonance condition is proposed. It is found that the mixing layer response becomes spatially resonant for specific source locations downstream in the high-speed flow. The study also provides an

  17. High-speed analog-to-digital conversion

    CERN Document Server

    Demler, Michael J

    1991-01-01

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

  18. Mechanochemical Reactions of Fullerenes under High-Speed Vibration Milling

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ting-Hu; LI Yu-Jin; PENG Ru-Fang; LU Ping; CHEN Zhong-Xiu; WANG Guan-Wu

    2003-01-01

    @@ Since a novel technique called "high-speed vibration milling" (HSVM) was first applied to the Reformatskytype reaction of C60 in 1996, [1] this technique has been applied to various kinds of fullerene functionalizations including the preparation of C120. [2] Most recent reactions of fullerenes under HSVM conditions will be discussed: (1)reaction of C60/C70 with N-alkylglycines and aldehydes (Scheme 1); (2) reaction of C60 with active methylene compounds in the presence of bases (Scheme 2); (3) reaction of C6o with diazo compounds (Scheme 3); (4) reaction of C6o with anthracene derivatives (Scheme 4).

  19. Ultra High Speed InP Heterojunction Bipolar Transistors

    OpenAIRE

    Dahlström, Mattias

    2003-01-01

    This thesis deals with the development of high speed InPmesa HBT’s with power gain cut—off frequencies up toand above 300 GHz, with high current density and low collectordischarging times. Key developments are Pd—based base ohmics yielding basecontact resistances as low as 10 Ωµm2, base—collector grades to enable to use ofInP in the collector, and an increase in the maximum currentdensity through collector design and thermal optimization.HBT’s with a linear doping gradient in the base are for...

  20. High-speed laser welding of plastic films

    Science.gov (United States)

    Coelho, J. P.; Abreu, M. A.; Pires, M. C.

    2000-10-01

    Laser welding of plastic materials has a large field of applications in the packaging industry provided that it can compete, in quality and productivity, with currently used industrial methods. Welding of white and transparent thin films of polypropylene and polyethylene of low and high density at high speeds of 20 m s -1 using a CO 2 laser has been studied experimentally.` The weld process has been characterised by the specific energy required for each thickness, kind of plastic and the resistance of the weld seam. The influence of the dimensions of the laser beam spot on weld strength has also been analysed.

  1. High speed fiber-based clock enhancement of NRZ data

    Institute of Scientific and Technical Information of China (English)

    Tong Wu; Kun Qiu

    2005-01-01

    A scheme for all-fiber clock enhancement of non-return-to-zero (NRZ) data based on cross-phase modulation (XPM) effect in nonlinear fibers is proposed and demonstrated in simulation. The simulation results indicate that the clock-to-data ratio of NRZ signals at 64 Gb/s can be increased to 22.94 dB by using this scheme, and the pattern effect in clock enhanced signals is very weak. The ability of high speed operation up to 140 Gb/s of this scheme is also proved in our simulation.

  2. High Speed, Low Power Current Comparators with Hysteresis

    CERN Document Server

    Chasta, Neeraj K

    2012-01-01

    This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis), where comparator gives high accuracy (less than 50nA) and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180nm CMOS process technology for a supply voltage of 3V.

  3. HIGH-SPEED 5-AXIS MACHINING FOR TOOLING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Saxer, M.

    2012-11-01

    Full Text Available In the modern metalworking industry, production moulds often have complex geometry, with undercut regions, small corner radii, sharp edges, deep cavities, or large cores. Conventional manufacturing process chains to machine these complex features are often lengthy and inefficient due to multiple steps. This article presents current results obtained through industry projects and experimental work using 5-axis high-speed machining with high-end CAD/CAM systems to improve process efficiency. Cost optimisation and lead time shortening can be clearly shown. This is of particular importance for South African manufacturing companies, where multi-axis HSC technology although not totally unknown is significantly under-used.

  4. Design criteria for light high speed desert air cushion vehicles

    Science.gov (United States)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  5. Improvements on computations of high speed propeller unsteady aerodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bousquet, J.M.; Gardarein, P. [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    2003-09-01

    This paper presents the application of the CANARI flow solver to the computation of unsteady effects in the aerodynamic interaction of a high speed propeller with the aircraft. The method is first validated on the APIAN isolated propeller test case by comparison with experiment at M = 0.7. The method is then applied to the time accurate 3D Euler computation of a generic transport aircraft at M = 0.68. Analysis of the results shows significant unsteady effects both on the propeller forces and on the wing aerodynamic flows, by comparison with steady computations. (authors)

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

    OpenAIRE

    Li, Hailing; Wu, Haiyan; Lou, Lei; Kühnlenz, Kolja; Ravn, Ole

    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. Inorder to detect a flying ball accurately and robustly, a multithreshold legmentation algorithm is applied in a stereo-vision running at 150Hz. Based on the estimated 3D ball positions, a novel two-phase trajectory prediction is exploited to determine the hittin...

  7. 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.

  8. High Speed Video Measurements of a Magneto-optical Trap

    Science.gov (United States)

    Horstman, Luke; Graber, Curtis; Erickson, Seth; Slattery, Anna; Hoyt, Chad

    2016-05-01

    We present a video method to observe the mechanical properties of a lithium magneto-optical trap. A sinusoidally amplitude-modulated laser beam perturbed a collection of trapped ce7 Li atoms and the oscillatory response was recorded with a NAC Memrecam GX-8 high speed camera at 10,000 frames per second. We characterized the trap by modeling the oscillating cold atoms as a damped, driven, harmonic oscillator. Matlab scripts tracked the atomic cloud movement and relative phase directly from the captured high speed video frames. The trap spring constant, with magnetic field gradient bz = 36 G/cm, was measured to be 4 . 5 +/- . 5 ×10-19 N/m, which implies a trap resonant frequency of 988 +/- 55 Hz. Additionally, at bz = 27 G/cm the spring constant was measured to be 2 . 3 +/- . 2 ×10-19 N/m, which corresponds to a resonant frequency of 707 +/- 30 Hz. These properties at bz = 18 G/cm were found to be 8 . 8 +/- . 5 ×10-20 N/m, and 438 +/- 13 Hz. NSF #1245573.

  9. Parametric analysis of wheel wear in high-speed vehicles

    Institute of Scientific and Technical Information of China (English)

    Na Wu; Jing Zeng

    2014-01-01

    In order to reduce the wheel profile wear of high-speed trains and extend the service life of wheels, a dynamic model for a high-speed vehicle was set up, in which the wheelset was regarded as flexible body, and the actual mea-sured track irregularities and line conditions were considered. The wear depth of the wheel profile was calculated by the well-known Archard wear law. Through this model, the influence of the wheel profile, primary suspension stiffness, track gage, and rail cant on the wear of wheel profile were studied through multiple iterative calculations. Numerical simulation results show that the type XP55 wheel profile has the smallest cumulative wear depth, and the type LM wheel profile has the largest wear depth. To reduce the wear of the wheel profile, the equivalent conicity of the wheel should not be too large or too small. On the other hand, a small primary vertical stiffness, a track gage around 1,435-1,438 mm, and a rail cant around 1:35-1:40 are beneficial for dynamic per-formance improvement and wheel wear alleviation.

  10. COMPARATIVE STUDY OF NEXT GENERATION HIGH SPEED WIRELESS NETWORK

    Directory of Open Access Journals (Sweden)

    RAHUL MALHOTRA

    2011-06-01

    Full Text Available Advances in mobile communication theory have enabled the development of different wireless access technologies. Alongside the revolutionary progress in wireless access technologies, advances in wireless access devices such as laptops, palmtops, and cell phones and mobile middleware have paved the way for the deliveryof beyond-voice-type services while on the move. This sets the platform for high-speed mobile communications that provide high-speed data and both real and non-real time multimedia to mobile users. Today's wireless world uses several communication infrastructures such as Bluetooth for personal area, IEEE 802.11 for local area,Universal Mobile Telecommunication System (UMTS for wide area, and Satellite networks for global networking other hand, since these wireless networks are complementary to each other, their integration and coordinated operation can provide ubiquitous “always best connection" quality mobile communications to the users. This paper discusses the different architectures of wireless networks and the different factors to be considered while designing a hybrid wireless network. The different factors to be considered for design of ahybrid wireless network and the different networks have been explored in this paper.

  11. Reflectively Coupled Waveguide Photodetector for High Speed Optical Interconnection

    Directory of Open Access Journals (Sweden)

    Shih-Hsiang Hsu

    2010-12-01

    Full Text Available To fully utilize GaAs high drift mobility, techniques to monolithically integrate In0.53Ga0.47As p-i-n photodetectors with GaAs based optical waveguides using total internal reflection coupling are reviewed. Metal coplanar waveguides, deposited on top of the polyimide layer for the photodetector’s planarization and passivation, were then uniquely connected as a bridge between the photonics and electronics to illustrate the high-speed monitoring function. The photodetectors were efficiently implemented and imposed on the echelle grating circle for wavelength division multiplexing monitoring. In optical filtering performance, the monolithically integrated photodetector channel spacing was 2 nm over the 1,520–1,550 nm wavelength range and the pass band was 1 nm at the −1 dB level. For high-speed applications the full-width half-maximum of the temporal response and 3-dB bandwidth for the reflectively coupled waveguide photodetectors were demonstrated to be 30 ps and 11 GHz, respectively. The bit error rate performance of this integrated photodetector at 10 Gbit/s with 27-1 long pseudo-random bit sequence non-return to zero input data also showed error-free operation.

  12. Role of the eye in high-speed motion analysis

    Science.gov (United States)

    Hyzer, William G.

    1997-05-01

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

  13. High-speed digital phonoscopy images analyzed by Nyquist plots

    Science.gov (United States)

    Yan, Yuling

    2012-02-01

    Vocal-fold vibration is a key dynamic event in voice production, and the vibratory characteristics of the vocal fold correlate closely with voice quality and health condition. Laryngeal imaging provides direct means to observe the vocal fold vibration; in the past, however, available modalities were either too slow or impractical to resolve the actual vocal fold vibrations. This limitation has now been overcome by high-speed digital imaging (HSDI) (or high-speed digital phonoscopy), which records images of the vibrating vocal folds at a rate of 2000 frames per second or higher- fast enough to resolve a specific, sustained phonatory vocal fold vibration. The subsequent image-based functional analysis of voice is essential to better understanding the mechanism underlying voice production, as well as assisting the clinical diagnosis of voice disorders. Our primary objective is to develop a comprehensive analytical platform for voice analysis using the HSDI recordings. So far, we have developed various analytical approaches for the HSDI-based voice analyses. These include Nyquist plots and associated analysese that are used along with FFT and Spectrogram in the analysis of the HSDI data representing normal voice and specific voice pathologies.

  14. Fast service discovery mechanism through high speed multimedia network

    Science.gov (United States)

    Takagi, A.; Koita, T.; Sato, K.

    2005-12-01

    In the environment that a lot of control equipments are connected discretely to offer those equipments additional flexibility, the network is required to be high speed, high reliability, and real-time responsibility. IEEE 1394 1-3 is preferable as the underlying data transport technology to meet such requirements. IEEE 1394 is an interface that can support Plug and Play between the control equipments without a host device, and guarantee real-time stream and data transmission. Using the technology as a backbone network is suitable for control network due to its characteristics. However, in the current IEEE 1394 specification, there are some issues: band shortage when a lot of devices are connected and the reliability decrease in the communication when the network topology changes. By using the new technology, the bus bridge for IEEE 1394, some of the problems can be handled. Nevertheless, some issues still remain even if the bus bridge technology is applied. In this paper, to address these issues, we have proposed the message-type service discovery method. The message-type service discovery can achieve the efficiency of forwarding communication by transmitting service information of the equipment as a set of messages. The proposed method enables to transmit service information of the equipments at high speed. Then, we actually measured the time required for the service discovery of the proposed method and discussed about the basic characteristics.

  15. ECONOMIC REASONING MAXIMUM SLOPE IN DESIGN HIGH-SPEED LINES

    Directory of Open Access Journals (Sweden)

    CHERNYSHOVA O. S.

    2016-04-01

    Full Text Available Raising of problem The worldwide design standards high-speed lines are somewhat different. This is due to several reasons: different levels of design speed, differences of characteristics of rolling stock and, in particular, the features of the design plan and longitudinal profile, that are associated primarily with the conditions of the relief. In the design of high-speed railways in Ukraine should take into account these features and determine what the maximum slope values can be used in difficult conditions, as well as how it will affect the operational and capital costs. Purpose. To determine the optimal design parameters of the longitudinal profile. Conclusion. The results are based not only on technical, but also economic indicators and allow the assessment of the necessary capital expenditures and expected cost of the railway in the future. Analytical dependences, to predict the expected operating costs of the railway, depending on the maximum slope, its length and the total length of the section.

  16. A High Speed Autofocusing System for Micro System Applications

    Institute of Scientific and Technical Information of China (English)

    Phuchong Sripolsaen; Pradit Mittrapiyanuruk; Pakorn Keawtrakulpong

    2016-01-01

    In this paper, we present a high speed autofocus system for micro system applications and design a look-up-table based autofocusing algorithm for applications when a target object is always visible, e.g., manufacturing parts with alignment fiducials. We perform an evaluation of 24 focus measures to verify that which focus measure is the best for the look-up-table based method. From the evaluation, we find that the Chebyshev moments-based focus measure (CHEB) is the most suitable. Furthermore, we also develop a look-up-table based autofocus system that uses CHEB as the focus measure. In training phase, we offline construct a table from training images of an object that are captured at several lens distances. Each entry of table consists of focus measure computed from image and lens distance. In working phase, given an input image, the algorithm first computes the focus measure and then finds the best match focus measure from the table and looks up the corresponding lens position for moving it into the in-focus position. Our algorithm can perform autofocusing within only 2 steps of lens moving. The experiment shows that the system can perform high speed autofocusing of micro objects.

  17. High speed and wide bandwidth delta-sigma ADCs

    CERN Document Server

    Bolatkale, Muhammed; Makinwa, Kofi A A

    2014-01-01

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

  18. Ultra-High-Speed Image Signal Accumulation Sensor

    Directory of Open Access Journals (Sweden)

    Takeharu Goji Etoh

    2010-04-01

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

  19. High speed digital holographic interferometry for hypersonic flow visualization

    Science.gov (United States)

    Hegde, G. M.; Jagdeesh, G.; Reddy, K. P. J.

    2013-06-01

    Optical imaging techniques have played a major role in understanding the flow dynamics of varieties of fluid flows, particularly in the study of hypersonic flows. Schlieren and shadowgraph techniques have been the flow diagnostic tools for the investigation of compressible flows since more than a century. However these techniques provide only the qualitative information about the flow field. Other optical techniques such as holographic interferometry and laser induced fluorescence (LIF) have been used extensively for extracting quantitative information about the high speed flows. In this paper we present the application of digital holographic interferometry (DHI) technique integrated with short duration hypersonic shock tunnel facility having 1 ms test time, for quantitative flow visualization. Dynamics of the flow fields in hypersonic/supersonic speeds around different test models is visualized with DHI using a high-speed digital camera (0.2 million fps). These visualization results are compared with schlieren visualization and CFD simulation results. Fringe analysis is carried out to estimate the density of the flow field.

  20. A study on centrifugal casting of high speed steel roll

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    High speed steel (HSS) rolls can replace traditional rolls such as alloyed cast iron rolls and powder metallurgical (PM) hard alloy rolls. The main reasons for the replacement are that the wear resistance of low-cost alloyed cast iron rolls is poor and the cost of high-quality PM hard alloy rolls is very high. By means of centrifugal casting, HSS rolls having excellent wear resistance have been manufactured. The hardness of the HSS roll is 65~ 67 HRC, the range of variation is smaller than 2 HRC and its impact toughness is 15 J/cm2. The wear rate of HSS rolls used in the pre-finishing stands of high-speed hot wire-rod rolling mill reaches 2.5 × 10-4 mm per ton steel. Furthermore, the manufacturing cost of HSS rolls is significantly lower than that of PM hard alloy rolls; it is only 30 percent of that of PM hard alloy rolls.

  1. The magnitude of blood lactate increases from high speed workouts.

    Science.gov (United States)

    Caruso, J F; Kucera, S; Jackson, T; Hari, P; Olson, N; McLagan, J; Taylor, S T; Shepherd, C

    2011-05-01

    To examine blood lactate concentrations from high-speed exercise resistive exercise, subjects performed workouts on an inertial kinetic exercise (Oconomowoc, WI) device. Workouts entailed two 60-s sets of elbow flexor (curling) repetitions. Pre- and post-exercise blood lactate concentrations were measured, via a fingertip blood drop, with an analyzer. From workouts the average acceleration, maximum force and total torque were derived. Blood lactate concentrations were analyzed with a 2 (gender)×2 (time) ANOVA, with repeated measures for time. Average acceleration, maximum force and total torque were analyzed with one-way (gender) ANOVAs. With an α=0.05, blood lactate concentrations had a time (prewomen) effects. Current blood lactate concentrations were commensurate with other studies that used a modest level of resistance and engaged a small muscle mass. Given the current workout protocol and muscle mass engaged, as well as parallels to other results, our study appears to offer a valid portrayal of subsequent changes in blood lactate concentrations from high-speed resistive exercise. PMID:21380973

  2. High speed TV-towing system for exploration manganese nodules

    International Nuclear Information System (INIS)

    For the oceanographic, special for the manganese nodules exploration in the deep sea a high speed-TV-towing system is to design on base of existing TV-towing systems to get better efficiency during the exploration phase. It is planned to increase to towing speed at the time of 2 knots up to 6-8 knots. The essential points of developments in this direction are 1) to decrease the hydrodynamical drag of the long towing cable with fairings. 2) To seperate to towing system into two units the passiv controlled towing cable end point 'SEP' with negativ buoyancy (weight) and the activ controlled TV-fish. With this separation it is possible to tow the TV-fish within a defined accuracy parallel to the sea floor without an influence to the overall system. 3) To adapt the TV- and photo stobe light unit for these towing conditions (high speed). 4) To design the control concept, the operating equipment, the energy and data transmission system, the towed body concept, the hydrodynamical calculation of towing phase and the other towed components. The results of this study is the definition of a two body towing system which is able towed by a research vessel to make continously TV-observation of the sea floor in depth down to 6,000 meters. (orig.)

  3. Optimisation and simulation of high speed production system

    Directory of Open Access Journals (Sweden)

    J.P.T. Mo

    2008-12-01

    Full Text Available Purpose: This paper describes the project of developing the model of a high speed production system.Design/methodology/approach: High speed production systems involve significant investment and aresensitive to change. It is important to have a plan before changing the facility to minimize risks. To achieve thisgoal, it is necessary to develop a simulation model of the manufacturing process so that the system efficiencyunder different conditions can be evaluated.Findings: The investigation included evaluation of optimal system performance based on machine specificationsand values obtained over a period of observation.Practical implications: These values were used to generate a simulation model and tested under differentconditions. Four of the six recommendations were immediately accepted by the management while the tworemaining recommendations were further investigated to clarify anticipated benefits.Originality/value: This model is simulated in a discrete simulation environment and is based on values obtainedfrom the actual production process. The effect of changing the conditions and compatibility of the system toincreased work and reduced waste can be visualized.

  4. Research into the propeller strut for high speed outboard motor

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Takashi; Sunayama, Yoshihiko

    1995-12-31

    For better performance of outboard motors for high speed craft, improvement in the performance of the propeller strut located ahead of the propeller is indispensable in addition to ameliorating the performance of the screw propeller itself. Thus, it is extremely important to reduce the drag of the propeller strut, which accounts for the predominant portion of the submerged parts of the motor and hull when the craft is running at high speed and to improve the propeller efficiency in the wake of the propeller strut. This paper, taking up two different shapes of the propeller strut, compares the performances of the propeller placed in the wake of the propeller strut in tank tests, and discusses the drag of the propeller strut. The two propeller strut shapes are that of a 70% scaled down model of the propeller strut Suzuki`s 200 PS outboard motor and its improved version. The propeller used in the experiment is one having super cavitating blades with the Pseudo-Kirchhoff nose, whose performance the authors have been analyzing systematically. Detailed comparison was further made of the drags of the differently shaped propeller struts by means of computational fluid dynamics.

  5. 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.

  6. Scratch behavior of high speed steels for hot rolls

    Institute of Scientific and Technical Information of China (English)

    Li Zhou; Dale Sun; Changsheng Liu; Chunguang Li; Lisong Yao

    2008-01-01

    The scratch behaviors of two high speed steels (HSS) for hot rolls were studied by a Micro-combi Tester, and the emphasis was placed on researching the relations between the microstructure and the scratch resistance property of different HSS. The experimental results indicate that during the scratch process, the carbides are embedded into the matrix, the penetration depth of different HSS is closely related with the matrix hardness, i.e., the higher the matrix hardness, the better the scratch resistance property; and in the matrix, the fine, dispersive carbides are beneficial to form steady friction between the indenter and the scratched materials, but the coarser carbides are easier to fall into pieces.

  7. 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...

  8. High-Speed Civil Transport Will Revolutionize Air Travel

    Science.gov (United States)

    1998-01-01

    NASA is developing advanced technologies that will allow industry to build a high-speed civil transport that will revolutionize overseas air travel. The technology challenges include developing low-cost materials and structural concepts as well as supersonic engines that can meet stringent noise and emissions standards. NASA's goal is to provide enabling technologies that will reduce the travel time to the Far East by 50 percent within 25 years, and do so at today's subsonic ticket prices. This research is part of NASA's Aeronautics and Space Transportation Technology (ASTT) Enterprise's strategy to sustain U.S. leadership in aeronautics and space. The Enterprise has set bold goals that are grouped into Three Pillars: Global Civil Aviation, Revolutionary Technology Leaps and Access to Space.

  9. Flow Characterization of a Piezo-Electric High Speed Valve

    Directory of Open Access Journals (Sweden)

    T. Takiya

    2012-03-01

    Full Text Available Injecting a gas into fusion reactors or semiconductor manufacturing systems, one has to quickly control the flow rate by a piezoelectric valve. In order to construct a gas injection system with high speed valves in the future, performance tests have been conducted on a commercial piezoelectric valve. An orifice flowmeter for measuring time average flowrate and a hot wire anemometer for instantaneous flowrate were manufactured. The total flow coefficient of the orifice flowmeter was obtained experimentally under a low pressure of a 10-2 Pa and a low flowrate of a few mg/s, although they are smaller than the values specified by Japanese Industrial Standards. It is found that the hot wire anemometer installed downstream in the vicinity of the valve is suitable for detecting the change in flowrate with the response time of less than 1 ms.

  10. Parallel algorithms for high-speed SAR processing

    Science.gov (United States)

    Mallorqui, Jordi J.; Bara, Marc; Broquetas, Antoni; Wis, Mariano; Martinez, Antonio; Nogueira, Leonardo; Moreno, Victoriano

    1998-11-01

    The mass production of SAR products and its usage on monitoring emergency situations (oil spill detection, floods, etc.) requires high-speed SAR processors. Two different parallel strategies for near real time SAR processing based on a multiblock version of the Chirp Scaling Algorithm (CSA) have been studied. The first one is useful for small companies that would like to reduce computation times with no extra investment. It uses a cluster of heterogeneous UNIX workstations as a parallel computer. The second one is oriented to institutions, which have to process large amounts of data in short times and can afford the cost of large parallel computers. The parallel programming has reduced in both cases the computational times when compared with the sequential versions.

  11. Marshall Space Flight Center High Speed Turbopump Bearing Test Rig

    Science.gov (United States)

    Gibson, Howard; Moore, Chip; Thom, Robert

    2000-01-01

    The Marshall Space Flight Center has a unique test rig that is used to test and develop rolling element bearings used in high-speed cryogenic turbopumps. The tester is unique in that it uses liquid hydrogen as the coolant for the bearings. This test rig can simulate speeds and loads experienced in the Space Shuttle Main Engine turbopumps. With internal modifications, the tester can be used for evaluating fluid film, hydrostatic, and foil bearing designs. At the present time, the test rig is configured to run two ball bearings or a ball and roller bearing, both with a hydrostatic bearing. The rig is being used to evaluate the lifetimes of hybrid bearings with silicon nitride rolling elements and steel races.

  12. High-speed polysilicon CMOS photodetector for telecom and datacom

    Science.gov (United States)

    Atabaki, Amir H.; Meng, Huaiyu; Alloatti, Luca; Mehta, Karan K.; Ram, Rajeev J.

    2016-09-01

    Absorption by mid-bandgap states in polysilicon or heavily implanted silicon has been previously utilized to implement guided-wave infrared photodetectors in CMOS compatible photonic platforms. Here, we demonstrate a resonant guided-wave photodetector based on the polysilicon layer that is used for the transistor gate in a microelectronic SOI CMOS process without any change to the foundry process flow ("zero-change" CMOS). Through a combination of doping mask layers, a lateral pn junction diode in the polysilicon is demonstrated with a strong electric field to enable efficient photo-carrier extraction and high-speed operation. This photodetector has a responsivity of more than 0.14 A/W from 1300 to 1600 nm, a 10 GHz bandwidth, and 80 nA dark current at 15 V reverse bias.

  13. CW-HSTCP: Fair TCP in high-speed networks

    Institute of Scientific and Technical Information of China (English)

    PAN Xue-zeng; SU Fan-jun; L(U) Yong; PING Ling-di

    2006-01-01

    The congestion control mechanisms of the current standard TCP constrain the congestion windows that can be achieved by TCP in high-speed networks, which leads to low link utilization. HSTCP is one solution to solve this problem by modifying the congestion control mechanism to have the characteristics of TCP friendliness in high loss rate environment and high scalability in low loss rate environment. However, experiments revealed that HSTCP has severe RTT unfairness. After analyzing the RTT unfairness in HSTCP with a model, we proposed CW-HSTCP, which added a fair factor to decrease the difference of congestion window caused by different RTT. Fair factor of long RTT flows can cause a sharp window increment that is easy to cause a bursty traffic, so a method called block-pacing was adopted. Simulation results showed that our new proposal could alleviate the RTT unfairness while keeping advantages of HSTCP.

  14. 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.

  15. Optimization and Performance Analysis of High Speed Mobile Access Networks

    CERN Document Server

    Weerawardane, Thushara

    2012-01-01

    The design and development of cost-effective mobile broadband wireless access networks is a key challenge for many mobile network operators. The over-dimensioning or under-dimensioning of an access network results in both additional costs and customer dissatisfaction.   Thushara Weerawardane introduces new transport technologies and features for High Speed Packet Access (HSPA) and Long-Term Evolution (LTE) networks. Using advanced scientific methods, he proposes new adaptive flow control and enhanced congestion control algorithms, then defends them with highly-developed analytical models derived from Markov chains. For faster analysis, compared to long-lasting detailed simulations, these models provide optimum network performance and ensure reliable quality standards for end users during transport network congestion. Further, the author investigates and analyzes LTE transport network performance by introducing novel traffic differentiation models and buffer management techniques during intra-LTE handovers.

  16. DAC for High Speed and Low Power Applications Using Abacus

    Directory of Open Access Journals (Sweden)

    Shankarayya G. Kambalimath

    2014-02-01

    Full Text Available This paper proposes a Chinese Abacus Digital-to-Ana log Converter (DAC for high speed and low power applications like audio and video applica tions. This circuit of DAC uses resister strings to get a good analog output. The designed D AC uses the algorithm of abacus. Instead of using binary code, here we use abacus code to contr ol the switches. So the complexity and the area will be reduced automatically. The 8-bit D AC is comprised of 12 resistors and 24 NMOS switches. The 8-bit Abacus resistor DAC requires 12 resistors and 24 switches. The 8-bit resistor-string DAC requires 255 resistors and 256 switches. The most important advantages are that the numbers of both resistors and switches are all reduced effectively. The simulation environment uses 1 μ m process technology

  17. Simplified Dynamic Model for High-Speed Checkweigher

    Science.gov (United States)

    Yamakawa, Yuji; Yamazaki, Takanori

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

  18. High Speed Crystal Growth by Q-switched Laser Melting

    Science.gov (United States)

    Cullis, A. G.

    1984-01-01

    The modification of the structural and electrical properties of semiconductors short radiation pulses obtained from Q-switched lasers is described. These modifications are accomplished by high heating and cooling rates. This processing revealed novel crystal growth and high speed resolidification phenomena. The behavior of semiconductor Si is analyzed. The annealing process typically employs short pulses of radiation in or near the visible region of the spectrum. The Q-switched ruby and Nd-YAG lasers are commonly used and these are sometimes mode locked to reduce the pulse length still further. Material to be annealed can be processed with a single large area radiation spot. Alternatively, a small radiation spot size can be used and a large sample area is covered by overlapping irradiated regions.

  19. Classically entangled optical beams for high-speed kinematic sensing

    CERN Document Server

    Berg-Johansen, Stefan; Stiller, Birgit; Banzer, Peter; Ornigotti, Marco; Giacobino, Elisabeth; Leuchs, Gerd; Aiello, Andrea; Marquardt, Christoph

    2015-01-01

    Tracking the kinematics of fast-moving objects is an important diagnostic tool for science and engineering. Existing optical methods include high-speed CCD/CMOS imaging, streak cameras, lidar, serial time-encoded imaging and sequentially timed all-optical mapping. Here, we demonstrate an entirely new approach to positional and directional sensing based on the concept of classical entanglement in vector beams of light. The measurement principle relies on the intrinsic correlations existing in such beams between transverse spatial modes and polarization. The latter can be determined from intensity measurements with only a few fast photodiodes, greatly outperforming the bandwidth of current CCD/CMOS devices. In this way, our setup enables two-dimensional real-time sensing with temporal resolution in the GHz range. We expect the concept to open up new directions in photonics-based metrology and sensing.

  20. A novel optical burst switching architecture for high speed networks

    Institute of Scientific and Technical Information of China (English)

    Amit Kumar Garg; R. S. Kaler

    2008-01-01

    A novel optical burst switching (OBS) high speed network architecture has been proposed. To verify its feasibility and evaluate its performance, just-enough-time (JET) signaling has been considered as a high performance protocol. In the proposed architecture, to avoid burst losses, firstly, a short-priorconfirrnation-packet (SPCP) is sent over the control channel that simulates the events that the actual packet will experience. Once SPCP detects a drop at any of the intermediate nodes, the actual packet is not sent but the process repeats. In order to increase network utilization, cost effectiveness and to overcome some limitations of conventional OBS, inherent codes (e.g., orthogonal optical codes (OOC)),which are codified only in intensity, has been used. Through simulations, it shows that a decrease in burst loss probability, cost effectiveness and a gain in processing time are obtained when optical label processing is used as compared with electronic processing.

  1. Dynamics of High-Speed Rotors Supported in Sliding Bearings

    Science.gov (United States)

    Šimek, J.; Svoboda, R.

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

  2. 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.

  3. 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.

  4. Numerical Simulation for Ventilated Supercavitation High Speed Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    YANG Wu-gang; YANG Zhen-cai; CHU Yan; DENG Qiu-xia; LI Ya-rong; ZHANG Yu-wen

    2009-01-01

    Supercavitation is a revolutionary technique to achieve high drag reduction for underwater vehicle. It can help us to break through the conventional speed barrier. This article presents a numerical algorithm for ventilated supercavitation flow field based on mixture multiphase flow model, briefs the calculation results and compares them with that tested in high-speed water tunnel and towing tank. The mathematical model, its numerical calculation method, computational region and boundary conditions are discussed in detail. Some pertinent nondimensional parameters about the ventilated supercavitation, such as geometrical configuration of supercavity, drag coefficient and ventilation rate are investigated. Reynolds number is selected to predict gas ventilation rate instead of Froude number. Finally, based on the test and simulation results, a semi-empirical formula of the ventilation rate estimation suitable for different conical angle caritators is proposed.

  5. High-speed spectral tuning CARS microscopy using AOTF laser

    Science.gov (United States)

    Hashimoto, Mamoru; Iwatsuka, Junichi; Niioka, Hirohiko; Araki, Tsutomu

    2012-03-01

    We have developed a high speed spectral tuning CARS microscopy system using a mode-locked Ti:Sapphire laser with an acousto-optic tunable filter (AOTF) in the cavity. Since the wavelength of the laser is tunable with the applied radio frequency to the AOTF, the wavelength is electrically tunable.The pulse duration of the laser is about 10 ps, tunable range is 800 nm to 930 nm, and the tuning speed is ms order. The laser is synchronized with another mode-locked Ti:Sapphire laser laser our own method using a balance cross-correlator and phase lock loop technique. The synchronized lasers are used for light source of multi-focus CARS microscopy system using a microlens array scanner, and the hyperspectral imaging of adipocyte cells is demonstrated.

  6. Tool Failure Analysis in High Speed Milling of Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiuxu; MEYER Kevin; HE Rui; YU Cindy; NI Jun

    2006-01-01

    In high speed milling of titanium alloys the high rate of tool failure is the main reason for its high manufacturing cost. In this study, fractured tools which were used in a titanium alloys 5-axis milling process have been observed both in the macro scale using a PG-1000 light microscope and in the micro scale using a Scanning Electron Microscope (SEM) respectively. These observations indicate that most of these tool fractures are the result of tool chipping. Further analysis of each chipping event has shown that beachmarks emanate from points on the cutting edge. This visual evidence indicates that the cutting edge is failing in fatigue due to cyclical mechanical and/or thermal stresses. Initial analyses explaining some of the outlying conditions for this phenomenon are discussed. Future analysis regarding determining the underlying causes of the fatigue phenomenon is then outlined.

  7. Titanium Alloys and Processing for High Speed Aircraft

    Science.gov (United States)

    Brewer, William D.; Bird, R. Keith; Wallace, Terryl A.

    1996-01-01

    Commercially available titanium alloys as well as emerging titanium alloys with limited or no production experience are being considered for a variety of applications to high speed commercial aircraft structures. A number of government and industry programs are underway to improve the performance of promising alloys by chemistry and/or processing modifications and to identify appropriate alloys and processes for specific aircraft structural applications. This paper discusses some of the results on the effects of heat treatment, service temperatures from - 54 C to +177 C, and selected processing on the mechanical properties of several candidate beta and alpha-beta titanium alloys. Included are beta alloys Timetal 21S, LCB, Beta C, Beta CEZ, and Ti-10-2-3 and alpha-beta alloys Ti-62222, Ti-6242S, Timetal 550, Ti-62S, SP-700, and Corona-X. The emphasis is on properties of rolled sheet product form and on the superplastic properties and processing of the materials.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M Y

    2001-02-14

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

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

    CERN Document Server

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

    2014-01-01

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

  10. Multimode nondestructive detecting method for high-speed rail defects

    Science.gov (United States)

    Sun, Mingjian; Cheng, Xingzhen; Wan, Guangnan; Liu, Ting; Fu, Ying; Wang, Yan

    2015-11-01

    It is very important to detect the surface defects of the high-speed rail for security concerns. A multimode detecting method, which integrates high resolution of optical image, high precision of photoacoustic detection and strong penetration of ultrasound detecting, is proposed for the rail defect detection. Utilizing the surface defect characteristics obtained from optical signal, the photoacoustic and ultrasound scanning region could be determined, and rail shallow and internal defect characteristics can be acquired subsequently. Eventually, fusing three modal signals mentioned above, the information of the entire rail defect, including type, extension trend and depth can be detected. It has been proved that the multimode method can improve the detecting efficiency, and enlarge the detection range in the meantime.

  11. High speed sub-micrometric microscopy using optical polymer microlens

    Institute of Scientific and Technical Information of China (English)

    X.H.Zeng; J.Plain; S.Jradi; P.Renaud Goud; R.Deturche; P.Royer; R.Bachelot

    2009-01-01

    We report the high speed scanning submicronic microscopy (SSM) using a low cost polymer microlens integrated at the extremity of an optical fiber.These microlenses are fabricated by a free-radical photopolymerization method.Using a polymer microlens with a radius of curvature of 250 nm,a sub-micrometric gold pattern is imaged experimentally by SSM.Different distances between the tip and the sample are used with a high scanning speed of 200 cm/s.In particular,metallic absorption contrasts are described with an optical spatial resolution of 250 nm at the wavelength of 532 nm.Moreover,finite-difference time-domain (FDTD) simulations concerning the focal lengths of microlenses with different geometries and heights support the experimental data.

  12. 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..

  13. An integrated optimum design approach for high speed prop rotors

    Science.gov (United States)

    Chattopadhyay, Aditi; Mccarthy, Thomas R.

    1995-01-01

    The objective is to develop an optimization procedure for high-speed and civil tilt-rotors by coupling all of the necessary disciplines within a closed-loop optimization procedure. Both simplified and comprehensive analysis codes are used for the aerodynamic analyses. The structural properties are calculated using in-house developed algorithms for both isotropic and composite box beam sections. There are four major objectives of this study. (1) Aerodynamic optimization: The effects of blade aerodynamic characteristics on cruise and hover performance of prop-rotor aircraft are investigated using the classical blade element momentum approach with corrections for the high lift capability of rotors/propellers. (2) Coupled aerodynamic/structures optimization: A multilevel hybrid optimization technique is developed for the design of prop-rotor aircraft. The design problem is decomposed into a level for improved aerodynamics with continuous design variables and a level with discrete variables to investigate composite tailoring. The aerodynamic analysis is based on that developed in objective 1 and the structural analysis is performed using an in-house code which models a composite box beam. The results are compared to both a reference rotor and the optimum rotor found in the purely aerodynamic formulation. (3) Multipoint optimization: The multilevel optimization procedure of objective 2 is extended to a multipoint design problem. Hover, cruise, and take-off are the three flight conditions simultaneously maximized. (4) Coupled rotor/wing optimization: Using the comprehensive rotary wing code CAMRAD, an optimization procedure is developed for the coupled rotor/wing performance in high speed tilt-rotor aircraft. The developed procedure contains design variables which define the rotor and wing planforms.

  14. An investigation on weldability of AISI 304 and AISI 1040 steels on friction welding; Untersuchung der Schweisseignung von AISI 304 und AISI 1040 mittels Reibschweissen

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Sare; Ay, Irfan [Balikesir Univ., Cagis Campus (Turkey). Mechanical Eng. Dept.; Dinc, Dincer [General Directorate of Highways, Canakkale (Turkey); Yaman, Ramazan [Balikesir Univ., Cagis Campus (Turkey). Industrial Eng. Dept.

    2010-04-15

    In welding technology, joining processes of different materials, which have dissimilar crystal structures are difficult. Welding of different materials becomes very important to reduce costs. Furthermore, the friction welding method is processed in lower temperature than the melting temperature. Especially, this is a big advantage to overcome difficulties that occur in the heat affected zone during usage of conventional methods. In this study, the weldability of AISI 304 stainless steel and AISI 1040 carbon steel by friction welding is studied. During the welding process, temperature variations in the welding zones were measured with an infrared temperature measurement device. After welding of the samples, tensile and hardness experiments were carried out. For metallographic investigations, optical microscope and scanning electron microscope (SEM) pictures were taken. Energy dispersive spectroscopy (EDS) analysis was carried out for composition investigations on welding and heat affected zones. As a result, these two steels could be joined by friction welding for industrial usage.

  15. State on AISI 304 Stainless Steel

    Directory of Open Access Journals (Sweden)

    A. Fattah-alhosseini

    2011-01-01

    Full Text Available The passivity and protective nature of the passive films are essentially related to ionic and electronic transport processes, which are controlled by the optical and electronic properties of passive films. In this study, the electrochemical behavior of passive films anodically formed on AISI 304 stainless steel in sulfuric acid solution has been examined using electrochemical impedance spectroscopy. AISI 304 in sulphuric acid solution is characterized by high interfacial impedance, thereby illustrating its high corrosion resistance. Results showed that the interfacial impedance and the polarization resistance (pol initially increase with applied potential, within the low potential passive. However, at a sufficiently high potential passive (>0.4 V, the interfacial impedance and the polarization resistance decrease with increasing potential. An electrical equivalent circuit based on the impedance analysis, which describes the behavior of the passive film on stainless steel more satisfactorily than the proposed models, is presented.

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

    CERN Document Server

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

    2012-01-01

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

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

    Science.gov (United States)

    2010-10-01

    .... Vertical alignment may be accomplished by car air suspension or other suitable means of meeting the... 49 Transportation 1 2010-10-01 2010-10-01 false High-speed rail cars, monorails and systems. 38....175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems,...

  18. 75 FR 16564 - High-Speed Intercity Passenger Rail (HSIPR) Program

    Science.gov (United States)

    2010-04-01

    ... Federal Railroad Administration High-Speed Intercity Passenger Rail (HSIPR) Program AGENCY: Federal... procedures for obtaining funding for high- speed rail planning activities under the Department of... of Pub. L. 111-117, December 16, 2009), under the title ``Capital Assistance for High Speed...

  19. 76 FR 57924 - Transportation for Individuals With Disabilities at Intercity, Commuter, and High Speed Passenger...

    Science.gov (United States)

    2011-09-19

    ... station-based lifts. On commuter, intercity, or high-speed rail lines or systems in which track passing... serves new or altered stations on the line or system. For example, if a new commuter or high-speed rail..., Commuter, and High Speed Passenger Railroad Station Platforms; Miscellaneous Amendments AGENCY: Office...

  20. 76 FR 14443 - High-Speed Intercity Passenger Rail (HSIPR) Program

    Science.gov (United States)

    2011-03-16

    ... Federal Railroad Administration High-Speed Intercity Passenger Rail (HSIPR) Program AGENCY: Federal... for high-speed and intercity passenger rail projects. SUMMARY: This notice details the application requirements and procedures for obtaining funding under FRA's High-Speed Intercity Passenger Rail...

  1. 75 FR 16552 - High-Speed Intercity Passenger Rail (HSIPR) Program

    Science.gov (United States)

    2010-04-01

    ... Federal Railroad Administration High-Speed Intercity Passenger Rail (HSIPR) Program AGENCY: Federal... remaining FY 2009 funds. FRA has concurrently issued a solicitation for high-speed rail planning activities... for FRA's High-Speed Intercity Passenger Rail (HSIPR) Program. These funds were authorized...

  2. Characterization of AISI 4140 borided steels

    International Nuclear Information System (INIS)

    The present study characterizes the surface of AISI 4140 steels exposed to the paste-boriding process. The formation of Fe2B hard coatings was obtained in the temperature range 1123-1273 K with different exposure times, using a 4 mm thick layer of boron carbide paste over the material surface. First, the growth kinetics of boride layers at the surface of AISI 4140 steels was evaluated. Second, the presence and distribution of alloying elements on the Fe2B phase was measured using the Glow Discharge Optical Emission Spectrometry (GDOES) technique. Further, thermal residual stresses produced on the borided phase were evaluated by X-ray diffraction (XRD) analysis. The fracture toughness of the iron boride layer of the AISI 4140 borided steels was estimated using a Vickers microindentation induced-fracture testing at a constant distance of 25 μm from the surface. The force criterion of fracture toughness was determined from the extent of brittle cracks, both parallel and perpendicular to the surface, originating at the tips of an indenter impression. The fracture toughness values obtained by the Palmqvist crack model are expressed in the form KC(π/2) > KC > KC(0) for the different applied loads and experimental parameters of the boriding process.

  3. FSK Modulation Scheme for High-Speed Optical Transmission

    Institute of Scientific and Technical Information of China (English)

    Nan Chi; Wuliang Fang; Yufeng Shao; Junwen Zhang; Li Tao

    2012-01-01

    In this paper, we describe the generation, detection, and performance of frequency-shift keying (FSK) for high-speed optical transmission and label switching. A non-return-to-zero (NRZ) FSK signal is generated by using two continuous-wave (CW) lasers, one Mach-Zehnder modulator (MZM), and one Mach-Zehnder delay interferometer (MZDI). An RZ-FSK signal is generated by cascading a dual-arm MZM, which is driven by a sinusoidal voltage at half the bit rate. Demodulation can be achieved on 1 bit rate through one MZDI or an array waveguide grating (AWG) demultiplexer with balanced detection. We perform numerical simulation on two types of frequency modulation schemes using MZM or PM, and we determine the effect of frequency tone spacing (FTS) on the generated FSK signal. In the proposed scheme, a novel frequency modulation format has transmission advantages compared with traditional modulation formats such as RZ and differential phase-shift keying (DPSK), under varying dispersion management. The performance of an RZ-FSK signal in a 4 x 40 Gb/s WDM transmission system is discussed. We experiment on transparent wavelength conversion based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) and in a highly nonlinear dispersion shifted fiber (HNDSF) for a 40 Gb/s RZ-FSK signal. The feasibility of all-optical signal processing of a high-speed RZ-FSK signal is confirmed. We also determine the receiver power penalty for the RZ-FSK signal after a 100 km standard single-mode fiber (SMF) transmission link with matching dispersion compensating fiber (DCF), under the post-compensation management scheme. Because the frequency modulation format is orthogonal to intensity modulation and vector modulation (polarization shift keying), it can be used in the context of the combined modulation format to decrease the data rate or enhance the symbol rate. It can also be used in orthogonal label-switching as the modulation format for the payload or the label. As an example, we

  4. Integrated design and manufacturing for the high speed civil transport

    Science.gov (United States)

    1993-01-01

    In June 1992, Georgia Tech's School of Aerospace Engineering was awarded a NASA University Space Research Association (USRA) Advanced Design Program (ADP) to address 'Integrated Design and Manufacturing for the High Speed Civil Transport (HSCT)' in its graduate aerospace systems design courses. This report summarizes the results of the five courses incorporated into the Georgia Tech's USRA ADP program. It covers AE8113: Introduction to Concurrent Engineering, AE4360: Introduction to CAE/CAD, AE4353: Design for Life Cycle Cost, AE6351: Aerospace Systems Design One, and AE6352: Aerospace Systems Design Two. AE8113: Introduction to Concurrent Engineering was an introductory course addressing the basic principles of concurrent engineering (CE) or integrated product development (IPD). The design of a total system was not the objective of this course. The goal was to understand and define the 'up-front' customer requirements, their decomposition, and determine the value objectives for a complex product, such as the high speed civil transport (HSCT). A generic CE methodology developed at Georgia Tech was used for this purpose. AE4353: Design for Life Cycle Cost addressed the basic economic issues for an HSCT using a robust design technique, Taguchi's parameter design optimization method (PDOM). An HSCT economic sensitivity assessment was conducted using a Taguchi PDOM approach to address the robustness of the basic HSCT design. AE4360: Introduction to CAE/CAD permitted students to develop and utilize CAE/CAD/CAM knowledge and skills using CATIA and CADAM as the basic geometric tools. AE6351: Aerospace Systems Design One focused on the conceptual design refinement of a baseline HSCT configuration as defined by Boeing, Douglas, and NASA in their system studies. It required the use of NASA's synthesis codes FLOPS and ACSYNT. A criterion called the productivity index (P.I.) was used to evaluate disciplinary sensitivities and provide refinements of the baseline HSCT

  5. 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.

  6. HIGH-SPEED FLOW EROSION ON A NEW ROLLER COMPACTED CONCRETE DAM DURING CONSTRUCTION

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; LUO Shao-ze; HU Ya-an; YUAN Qiang; WANG He-sheng; ZHAO Lan-hao

    2012-01-01

    A new roller compacted concrete dam of Fengman Hydropower Station is to be built in the toe of the old dam,which was identified as a dangerous dam.The new dam during construction would be influenced by the high-speed flow discharged from the old dam,which is an important problem to be considered for the first time in China,and which would affect the construction of the whole project.Therefore,a series of erosion experiments were conducted in this article.A high-speed flow erosion test apparatus was developed for the erosion experiments of the new dam materials.The maximum jet velocity goes up to 40 m/s and the section area of the nozzle is 0.0025 m2.In the process of experiments,the equipment shows a good performance.Erosive wear tests for two types of materials used in the new dam,a roller compacted concrete and a distorted concrete with four kinds of ages were carried out with the flow velocity in the range of 30 m/s-35 m/s.Erosion parameters and erosion laws for the two types of concretes with different ages were determined,and a general relationship between the erosion rate and the flow velocity is obtained as:N =cvP,with the velocity exponent P between 3.33 and 3.93.It is concluded that the erosion resistance of the distorted concrete is better than that of the roller compacted concrete and the mechanical properties of the concretes of over 14 d age are influenced slightly by the water impact.The test results might serve as a practical technique guide for the safety of this project during its construction in the flood season.

  7. Plasma nitriding process by direct current glow discharge at low temperature increasing the thermal diffusivity of AISI 304 stainless steel

    International Nuclear Information System (INIS)

    This work reports for the first time on the use of the open photoacoustic cell technique operating at very low frequencies and at room temperature to experimentally determine the thermal diffusivity parameter of commercial AISI304 stainless steel and AISI304 stainless steel nitrided samples. Complementary measurements of X-ray diffraction and scanning electron microscopy were also performed. The results show that in standard AISI 304 stainless steel samples the thermal diffusivity is (4.0 ± 0.3) × 10−6 m2/s. After the nitriding process, the thermal diffusivity increases to the value (7.1 ± 0.5) × 10−6 m2/s. The results are being associated to the diffusion process of nitrogen into the surface of the sample. Carrying out subsequent thermal treatment at 500 °C, the thermal diffusivity increases up to (12.0 ± 2) × 10−6 m2/s. Now the observed growing in the thermal diffusivity must be related to the change in the phases contained in the nitrided layer.

  8. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

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

  9. High-speed particle image velocimetry near surfaces.

    Science.gov (United States)

    Lu, Louise; Sick, Volker

    2013-06-24

    Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The complex nature of these flows may be studied using particle image velocimetry (PIV), a laser-based imaging technique for optically accessible flows. Though many forms of PIV exist that extend the technique beyond the original planar two-component velocity measurement capabilities, the basic PIV system consists of a light source (laser), a camera, tracer particles, and analysis algorithms. The imaging and recording parameters, the light source, and the algorithms are adjusted to optimize the recording for the flow of interest and obtain valid velocity data. Common PIV investigations measure two-component velocities in a plane at a few frames per second. However, recent developments in instrumentation have facilitated high-frame rate (>1 kHz) measurements capable of resolving transient flows with high temporal resolution. Therefore, high-frame rate measurements have enabled investigations on the evolution of the structure and dynamics of highly transient flows. These investigations play a critical role in understanding the fundamental physics of complex flows. A detailed description for performing high-resolution, high-speed planar PIV to study a transient flow near the surface of a flat plate is presented here. Details for adjusting the parameter constraints such as image and recording properties, the laser sheet properties, and processing algorithms to adapt PIV for any flow of interest are included.

  10. 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.

  11. Construction management through bot:Taiwan high speed rall case

    Institute of Scientific and Technical Information of China (English)

    CHANG Luh-maan; CHEN Po-han

    2004-01-01

    One of the key elements in real estate management is streamlining the construction process. Thus,the facilities can be built on a faster, cheaper, and higher quality base. Consequently, it will enhance the owner's competitiveness. Due to the high cost and lengthy duration of mega-construction projects in recent years,Build-Operate-Transfer (BOT) contracts are getting popular in delivering constructed projects in the public sector. With BOT, the public owners are able to focus on the effectiveness of fair resource allocation as well as bring the efficiency of private enterprise into governmental operations.This paper uses Taiwan High Speed Rail project to exemplify the BOT method in executing the constructed projects in the chain of real estate management processes. The paper explains the reasons for building HSR and adopting BOT approach.The detail of the HSR project and the feasibility analysis of the project will be presented in this paper. The feasibility analysis comprises the comparisons of different transportation means, the financial analysis, and other benefits from HSR. Finally, conclusions will be drawn.

  12. Application of DSP Blackfin in data acquisition of high speed

    Science.gov (United States)

    Tang, Chao

    2015-12-01

    In the traditional digital collection, the use of FIFO and MCU is usually used. Traditional data acquisition systems are expensive and slow, When the input is a fast changing signal, the output will have a large distortion, which makes the whole system performance degradation, and not suitable for large amounts of data. In this paper, a new method of high speed data acquisition based on Blackfin DSP is presented, The analog signal is processed by the signal processing circuit, so that the amplitude of the signal is limited to the input range of the A/D converter. The whole collection system is determined by the data acquisition and control circuit. In order to further improve the speed of data transmission, DSP Blackfin uses advanced DMA technology. In the algorithm, the system is mainly used in the same sampling points for the average value of the method. Experimental results show, Using the traditional system, it will lose a lot of details, the destruction of the integrity of the signal. Using this system can well reconstruct the analog signal input, Especially in the large amount of data, it shows the incomparable advantages.

  13. 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.

  14. 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

  15. 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.

  16. High-speed low-current-density 850 nm VCSELs

    Science.gov (United States)

    Larsson, Anders; Westbergh, Petter; Gustavsson, Johan; Haglund, Åsa

    2010-02-01

    The design of an oxide confined 850 nm VCSEL has been engineered for high speed operation at low current density. Strained InGaAs/AlGaAs QWs, with a careful choice of In and Al concentrations based on rigorous band structure and gain calculations, were used to increase differential gain and reduce threshold carrier density. Various measures, including multiple oxide layers and a binary compound in the lower distributed Bragg reflector, were implemented for reducing capacitance and thermal impedance. Modulation bandwidths > 20 GHz at 25°C and > 15 GHz at 85°C were obtained. At room temperature, the bandwidth was found to be limited primarily by the still relatively large oxide capacitance, while at 85°C the bandwidth was also limited by the thermal saturation of the resonance frequency. Transmission up to 32 Gb/s (on-off keying) over multimode fiber was successfully demonstrated with the VCSEL biased at a current density of only 11 kA/cm2. In addition, using a more spectrally efficient modulation format (16 QAM subcarrier multiplexing), transmission at 40 Gb/s over 200 m multimode fiber was demonstrated.

  17. 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).

  18. Thermal Conductance Engineering for High-Speed TES Microcalorimeters

    Science.gov (United States)

    Hays-Wehle, J. P.; Schmidt, D. R.; Ullom, J. N.; Swetz, D. S.

    2016-07-01

    Many current and future applications for superconducting transition-edge sensor (TES) microcalorimeters require significantly faster pulse response than is currently available. X-ray spectroscopy experiments at next-generation synchrotron light sources need to successfully capture very large fluxes of photons, while detectors at free-electron laser facilities need pulse response fast enough to match repetition rates of the source. Additionally, neutrino endpoint experiments such as HOLMES need enormous statistics, yet are extremely sensitive to pile-up effects that can distort spectra. These issues can be mitigated only by fast rising and falling edges. To address these needs, we have designed high-speed TES detectors with novel geometric enhancements to increase the thermal conductance of pixels suspended on silicon nitride membranes. This paper shows that the thermal conductivity can be precisely engineered to values spanning over an order of magnitude to achieve fast thermal relaxation times tailored to the relevant applications. Using these pixel prototypes, we demonstrate decay time constants faster than 100 μ s, while still maintaining spectral resolution of 3 eV FWHM at 1.5 keV. This paper also discusses the trade-offs inherent in reducing the pixel time constant, such as increased bias current leading to degradation in energy resolution, and potential modifications to improve performance.

  19. High speed operation of the heterostructure field effect optical modulator

    Energy Technology Data Exchange (ETDEWEB)

    Vang, T.A.; Evaldsson, P.A.; Kiely, P.A.; Taylor, G.W. [AT and T Bell Labs., Holmdel, NJ (United States); Cooke, P.W. [GEO Center Inc., Tinton Falls, NJ (United States). Fort Monmouth Operations

    1994-12-31

    The use of optical modulators in transmission systems can offer speed and chirp advantages over directly modulated semiconductor lasers. The Heterostructure Field Effect Optical Modulator (HFEOM) is a waveguide modulator that operates via band filling of quantum wells using charge transfer from an adjacent n{sup +} charge sheet. The control of this charge transfer is with a gate electrode as in a field effect transistor. The band filling of the quantum wells produces a blue-shift of the absorption edge that is used to modulate the incident light. This device is compatible in both growth and processing with the associated in-plane laser and field effect transistor. Here the authors present the initial high speed results of HFEOMs in the InGaAs/GaAs material system using a double quantum well active region. This structure has demonstrated a 35:1 extinction ratio for a 2 volt swing ({minus}1 V to + V) on a 300 {micro}m long device along with excellent wavelength compatibility with a 400 {micro}m in-plane laser fabricated from the same wafer. Capacitance limited modulation bandwidths of 1.2 GHz and 1.6 GHz are measured for 5 {micro}m and 2 {micro}m rib widths respectively.

  20. Thermographic measurements of high-speed metal cutting

    Science.gov (United States)

    Mueller, Bernhard; Renz, Ulrich

    2002-03-01

    Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

  1. High-speed Flight in an Ergodic Forest

    CERN Document Server

    Karaman, Sertac

    2012-01-01

    Inspired by birds flying through cluttered environments such as dense forests, this paper studies the theoretical foundations of a novel motion planning problem: high-speed navigation through a randomly-generated obstacle field when only the statistics of the obstacle generating process are known a priori. Resembling a planar forest environment, the obstacle generating process is assumed to determine the locations and sizes of disk-shaped obstacles. When this process is ergodic, and under mild technical conditions on the dynamics of the bird, it is shown that the existence of an infinite collision-free trajectory through the forest exhibits a phase transition. On one hand, if the bird flies faster than a certain critical speed, then, with probability one, there is no infinite collision-free trajectory, i.e., the bird will eventually collide with some tree, almost surely, regardless of the planning algorithm governing the bird's motion. On the other hand, if the bird flies slower than this critical speed, then...

  2. 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.

  3. 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.

  4. Improvement of vocal pathologies diagnosis using high-speed videolaryngoscopy.

    Science.gov (United States)

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

    2014-07-01

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

  5. 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.

  6. Mixed material integration for high-speed applications

    Science.gov (United States)

    Krishnamurthy, Nicole Andrea

    A great demand for portable and highly integrated high speed electronic components and systems has recently surfaced as a result of the vast expansion of personal communications and other wireless applications. As more and more applications in personal communications require frequencies between 1 and 100 GHz, a reduction in the cost of III-V technology is necessary for a wide distribution of wireless products in the consumer market. III-V technology provides improved and unique functionality compared with silicon CMOS integrated circuit (IC) technology, yet current III-V technologies cannot meet all the demands of low cost, high levels of integration, low power, and performance because of high material costs and low yield compared with the current silicon technology. In this thesis, thin film mixed material integration is investigated as a method to increase functionality at lower cost. InP active devices are removed from the growth substrate and integrated onto other host substrates such as silicon via substrate removal. Characterization of these devices is performed. Also, thin film passive components via deposition on free standing polyimide are evaluated for lower cost and increased design freedom. By optimizing the passives and III-V active components separately and then integrating the two opens a new realm in mixed material integration.

  7. High-Speed Acquisition of Free Vortex Formation

    CERN Document Server

    Falahatpisheh, Ahmad

    2012-01-01

    The formation of a free-vortex has been captured by using a high-speed camera (Y3, IDTVision, Inc.). The experiment is conducted using a rectangular tank, which is filled with tap water. The water free surface is open to atmospheric pressure and is at room temperature, 25\\textcelsius. Water occupies a volume of $25\\times 25\\times 10$cm$^3$. By using a stirring-spoon, the stagnant water is forced to rotate at a rate of $2\\pi$/sec. Once all the points in the water is rotating, it will be drained from a ball valve, with a diameter of 5mm, from the bottom of the tank and the acquisition starts. The formation of the vortex is captured with a resolution of $352\\times 824$ pixels at 200 frames per seconds (fps) and is exported at 5fps and with a resolution of $1280\\times 720$ in a "fluid dynamics video". The duration of the video in real time is 3.9 seconds. The slow motion video is 160 seconds. The height of the water remains almost unchanged while acquiring the images.

  8. Flow structure around high-speed train in open air

    Institute of Scientific and Technical Information of China (English)

    田红旗; 黄莎; 杨明智

    2015-01-01

    According to the analysis of the turbulent intensity level around the high-speed train, the maximum turbulent intensity ranges from 0.2 to 0.5 which belongs to high turbulent flow. The flow field distribution law was studied and eight types of flow regions were proposed. They are high pressure with air stagnant region, pressure decreasing with air accelerating region, low pressure with high air flow velocity region I, turbulent region, steady flow region, low pressure with high air flow velocity region II, pressure increasing with air decelerating region and wake region. The analysis of the vortex structure around the train shows that the vortex is mainly induced by structures with complex mutation and large curvature change. The head and rear of train, the underbody structure, the carriage connection section and the wake region are the main vortex generating sources while the train body with even cross-section has rare vortexes. The wake structure development law studied lays foundation for the train drag reduction.

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

    Science.gov (United States)

    Ge, Jia; Fok, Mable P.

    2015-11-01

    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.

  10. Salivary hormonal values from high-speed resistive exercise workouts.

    Science.gov (United States)

    Caruso, John F; Lutz, Brant M; Davidson, Mark E; Wilson, Kyle; Crane, Chris S; Craig, Chrsity E; Nissen, Tim E; Mason, Melissa L; Coday, Michael A; Sheaff, Robert J; Potter, William T

    2012-03-01

    Our study purpose examined salivary hormonal responses to high-speed resistive exercise. Healthy subjects (n = 45) performed 2 elbow flexor workouts on a novel (inertial kinetic exercise; Oconomowoc, WI, USA) strength training device. Our methods included saliva sample collection at both preexercise and immediately postexercise; workouts entailed two 60-second sets separated by a 90-second rest period. The samples were analyzed in duplicate for their testosterone and cortisol concentrations ([T], [C]). Average and maximum elbow flexor torque were measured from each exercise bout; they were later analyzed with a 2(gender) × 2(workout) analysis of variance (ANOVA) with repeated measures for workout. The [T] and [C] each underwent a 2(gender) × 2(time) ANOVA with repeated measures for time. A within-subject design was used to limit error variance. Average and maximum torque each had gender (men > women; p workouts and the rather modest volume of muscle mass engaged. Practical applications imply that salivary assays may be a viable alternative to blood draws from athletes, yet coaches and others who may administer this treatment should know that our results may have produced greater pre-post hormonal changes if postexercise sample collection had occurred at a later time point. PMID:22310520

  11. High speed friction microscopy and nanoscale friction coefficient mapping

    International Nuclear Information System (INIS)

    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 SiO2 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)

  12. High-speed tip-enhanced Raman imaging (Presentation Recording)

    Science.gov (United States)

    Chaigneau, Marc; Krayez, Andrey V.; Lancry, Ophélie; Saunin, Sergey A.

    2015-10-01

    Tip Enhanced Raman Scattering (TERS), a technique that provides molecular information on the nanometer scale, has been a subject of great scientific interest for 15 years. But regardless of the recent achievements and applications of TERS, ranging from material science and nanotechnology, strain measurement in semiconductors, to cell biological applications, the TERS technique has been hampered by extremely long acquisition times, measured in hours, required for collection of reasonably high pixel density TERS maps. In this talk, specifics of the TERS setup that enable fast, high pixel density nano-Raman imaging will be discussed: The innovative integration of technologies brings high-throughput optics and high-resolution scanning for high-speed imaging without interferences between the techniques. The latest developments in near-field optical probes also provide reliable solutions for academic and industrial researchers alike to easily get started with nanoscale Raman spectroscopy. Thanks to those latest instrumental developments, we will present the nanoscale imaging of chemical and physical properties of graphene, carbone nanotubes and self-assembled monolayers of organic molecules, with a spatial resolution routinely obtained in TERS maps in the 15 - 20 nm range and a best resolution achieved being of 7 nm

  13. 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.

  14. The Kaye effect revisited: High speed imaging of leaping shampoo

    Science.gov (United States)

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

    2003-11-01

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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Dynamic High-speed Knotting of a Rope by a Manipulator

    Directory of Open Access Journals (Sweden)

    Yuji Yamakawa

    2013-10-01

    Full Text Available In this paper we suggest an entirely new strategy for the dexterous manipulation of a linear flexible object, such as rope or a cable, with a high-speed manipulator. We deal with a flexible rope as one example of the linear flexible object. The strategy involves manipulating the object at high-speed. By moving the robot at high-speed, we can assume that the dynamic behaviour of the flexible rope can be obtained by performing algebraic calculations of the high- speed robot motion. Based on this assumption, we derive a dynamic deformation model of the flexible rope and confirm the validity of the proposed model. Then we perform a simulation of dynamic, high-speed knotting based on the proposed model. We also discuss the possibility of forming the knot based on a simple analysis model. Finally, we show experimental results demonstrating dynamic, high-speed knotting with a high-speed manipulator.

  20. Corrosion of AISI 316 and AISI 304 stainless steel with iodine vapor

    International Nuclear Information System (INIS)

    The weight loss of stainless steel in corrosion with iodine vapor was studied at 500 to 10000C and an iodine vapor pressure range of 0.05 to 0.5 mm Hg, using a thermobalance. In the initial stage of corrosion, the weight loss rate is largely influenced by solution treatment or surface treatment; the induction period, observed for solution-treated samples, is shortened or eliminated by fission-fragment irradiation, ion-bombardment or mechanical polishing, and in some cases corrosion is even accelerated by the surface treatments. A constant weight loss region follows the initial stage of corrosion. In this region, the weight loss rate is not dependent on treatment to the samples, and has a linear relationship with the vapor pressure of iodine. The rate is the largest at about 800 and 7500C for AISI 316 s. s. and AISI 304 s. s. The rates in general are larger for AISI 304 s. s. than for AISI 316 s. s. below 7000C but almost the same above 8000C. Corrosion product layer is observed on the surface of the sample below 7000C. Based on these findings, the corrosion process is discussed. The deposition of corrosion product in a temperature gradient tube is also described

  1. Numerical study of a high-speed miniature centrifugal compressor

    Science.gov (United States)

    Li, Xiaoyi

    A miniature centrifugal compressor is a key component of reverse Brayton cycle cryogenic cooling system. The system is commonly used to generate a low cryogenic temperature environment for electronics to increase their efficiency, or generate, store and transport cryogenic liquids, such as liquid hydrogen and oxygen, where space limit is also an issue. Because of space limitation, the compressor is composed of a radial IGV, a radial impeller and an axial-direction diffuser (which reduces the radial size because of smaller diameter). As a result of reduction in size, rotating speed of the impeller is as high as 313,000 rpm, and Helium is used as the working fluid, in order to obtain the required static pressure ratio/rise. Two main characteristics of the compressor---miniature and high-speed, make it distinct from conventional compressors. Higher compressor efficiency is required to obtain a higher COP (coefficient of performance) system. Even though miniature centrifugal compressors start to draw researchers' attention in recent years, understanding of the performance and loss mechanism is still lacking. Since current experimental techniques are not advanced enough to capture details of flow at miniature scale, numerical methods dominate miniature turbomachinery study. This work numerically studied a high speed miniature centrifugal compressor with commercial CFD code. The overall performance of the compressor was predicted with consideration of interaction between blade rows by using sliding mesh model. The law of similarity of turbomachinery was validated for small scale machines. It was found that the specific ratio effect needs to be considered when similarity law is applied. But Reynolds number effect can be neglected. The loss mechanism of each component was analyzed. Loss due to turning bend was significant in each component. Tip leakage loss of small scale turbomachines has more impact on the impeller performance than that of large scale ones. Because the

  2. 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

  3. Supersonic Stall Flutter of High Speed Fans. [in turbofan engines

    Science.gov (United States)

    Adamczyk, J. J.; Stevens, W.; Jutras, R.

    1981-01-01

    An analytical model is developed for predicting the onset of supersonic stall bending flutter in axial flow compressors. The analysis is based on a modified two dimensional, compressible, unsteady actuator disk theory. It is applied to a rotor blade row by considering a cascade of airfoils whose geometry and dynamic response coincide with those of a rotor blade element at 85 percent of the span height (measured from the hub). The rotor blades are assumed to be unshrouded (i.e., free standing) and to vibrate in their first flexural mode. The effects of shock waves and flow separation are included in the model through quasi-steady, empirical, rotor total-pressure-loss and deviation-angle correlations. The actuator disk model predicts the unsteady aerodynamic force acting on the cascade blading as a function of the steady flow field entering the cascade and the geometry and dynamic response of the cascade. Calculations show that the present model predicts the existence of a bending flutter mode at supersonic inlet Mach numbers. This flutter mode is suppressed by increasing the reduced frequency of the system or by reducing the steady state aerodynamic loading on the cascade. The validity of the model for predicting flutter is demonstrated by correlating the measured flutter boundary of a high speed fan stage with its predicted boundary. This correlation uses a level of damping for the blade row (i.e., the log decrement of the rotor system) that is estimated from the experimental flutter data. The predicted flutter boundary is shown to be in good agreement with the measured boundary.

  4. High-speed video recording with the TDAS

    Science.gov (United States)

    Liu, Daniel W.; Griesheimer, Eric D.; Kesler, Lynn O.

    1990-08-01

    The Tracker Data Acquisition System, TDAS is a system architecture for a high speed data recording and analysis system. The device utilizes dual Direct Memory Access (DMA), parallel Small Computer System Interface (SCSI) interface channels and multiple SCSI hard drives. Video rate data capture and storage is accomplished on 16 bit digital data at video rates to 15 Megahertz. The average data rate is approximately 1 Megabyte per second to the current hard disk drives, with instantaneous rates to 5 Megabytes per second. Message protocol enables symbology and frame data to be stored concurrently with the windowed image data. Dual parallel image buffers store 512 Kilobytes of raw image data for each frame and pass windowed data to the storage drives via the SCSI interfaces. Microcomputer control of DMA, Counter Input/Output, Serial Communications Controller and FIFO's is accomplished with a 16 bit processor which efficiently stores the video and ancillary data. Off-line storage is accomplished on 60 Megabyte streaming tape units for image and data dumps. Current applications mclude real-time multimode tracker performance recording as well as statistical post processing of system parameters. Data retrieval is driven by a separate microcomputer, providing laboratory frame-by-frame analysis of the video images and symbology. The TDAS can support 80 Megabytes of on-line storage presently, but can be simply expanded to 400 Megabytes. Phase 2 of the TDAS will include real-time playback of video images to recreate recorded scenarios. This paper describes the system architecture and implementation of the Tracker Data Acquisition system (TDAS), with current applications.

  5. Alert System for High Speed Vehicles to Avoid Wildlife Accidents

    Directory of Open Access Journals (Sweden)

    Rana Biswas

    2016-01-01

    Full Text Available “Alert System for High Speed Vehicles to Avoid Wildlife Accidents” is an alert system used to safeguard our wildlife. We often hear of various accidents of wild animals like elephant, nilgai etc., who are trying to cross the railway track. So, an intelligent electronics system is necessary which can be affixed to avoid the possibilities of accidents. Regarding this, in our project we are using a Passive Infrared Sensor (PIR sensor which is an electronic sensor that measures infrared (IR light radiating from objects in its field of view and switches ON any electrical/electronic device to which it is connected to. The key component of the sensor module is the pyroelectric element. All objects with a temperature above absolute zero emit heat energy in the form of radiation. Usually this radiation is invisible to the human eye because it is radiated at infrared wavelengths, but it is detected by this PIR sensor. This sensor does not radiate any energy for detection purposes and thus, it has no harmful effects on living beings. In our project the PIR sensor is used as a part of a burglar alarm and the electronic in the PIR typically control a small relay. This relay completes the circuit across a pair of electrical contacts connected to a detection input zone of the burglar alarm control panel. The system is usually designed such that if no living creature is being detected, the relay contact is closed- a „normally closed‟ (NC relay. If energy emitted from any nearby creature is detected, the relay opens, triggering the alarm, a signal will be directly sent to the driver‟s chamber and it will create a message in the LED screen of his chamber also an alarm will be heard which we have implemented using an ultrasonic sensor hc-sr04.

  6. Power Input of High-Speed Rotary Impellers

    Directory of Open Access Journals (Sweden)

    K. R. Beshay

    2001-01-01

    Full Text Available This paper presents the results of an experimental investigation of the power input of pitched blade impellers and standard Rushton turbine impellers in a cylindrical vessel provided with four radial baffles at its wall under a turbulent regime of flow of an agitated liquid. The influence of the geometry of the pitched blade impellers (pitch angle, number of blades and the off-bottom impeller clearance of both high-speed impellers tested on the impeller power input is determined in two sizes of the cylindrical vessel (0.3 m and 0.8 m diameter of vessel. A strain gauge torquemeter is used in the small vessel and a phase shift mechanical torquemeter is used in the large vessel. All results of the experiments correspond to the condition that the Reynolds number modified for the impeller exceeds ten thousand. The results of this study show that the significant influence of the separating disk thickness of the turbine impeller corresponds fairly well to the empirical equations presented in the literature. Both the influence of the number of impeller blades and the blade pitch angle of the pitched blade impeller were expressed quantitatively by means of the power dependence of the recently published correlations: the higher the pitch angle and the number of blades, the higher the values of the impeller power input. Finally, it follows from results of this study that the impeller off-bottom clearance has a weak influence on the power input of the Rushton turbine impeller, but with decreasing impeller off-bottom clearance the power input of the pitched blade impeller increases significantly.

  7. Advanced waveform decomposition for high-speed videoendoscopy analysis.

    Science.gov (United States)

    Ikuma, Takeshi; Kunduk, Melda; McWhorter, Andrew J

    2013-05-01

    This article presents a novel approach to analyze nonperiodic vocal fold behavior of high-speed videoendoscopy (HSV) data. Although HSV can capture true vibrational motions of the vocal folds, its clinical advantage over the videostroboscopy has not widely been accepted. One of the key advantages of the HSV over the videostroboscopy is its ability to capture vocal folds' nonperiodic behavior, which is more prominent in pathological vocal folds. However, such nonperiodicity in the HSV data has not been fully explored quantitatively beyond simple perturbation analysis. This article presents an advanced waveform modeling and decomposition technique for HSV-based waveforms. Waveforms are modeled to have three components: harmonic signal, deterministic nonharmonic signal, and random nonharmonic signal. This decomposition is motivated by the fact that voice disorders introduce signal content that is nonharmonic but carries deterministic quality such as subharmonic or modulating content. The proposed model is aimed to isolate such disordered behaviors as deterministic nonharmonic signal and quantify them. In addition to the model, the article outlines model parameter estimation procedures and a family of harmonics-to-noise ratio (HNR) parameters. The proposed HNR parameters include harmonics-to-deterministic-noise ratio (HDNR) and harmonics-to-random-noise ratio. A preliminary study demonstrates the effectiveness of the extended model and its HNR parameters. Vocal folds with and without benign lesions (Nwith = 13; Nwithout = 20) were studied with HSV glottal area waveforms. All three HNR parameters significantly distinguished the disordered condition, and the HDNR reported the largest effect size (Cohen's d = 2.04).

  8. Advances In High-Speed Photography 1972-1983

    Science.gov (United States)

    Courtney-Pratt, J. S.

    1984-01-01

    The variety, range and precision of methods available for photographic recording of fast phenomena have been increasing steadily. The capabilities of some of the newer techniques will be described. At the lower end of the speed range, the advances have been mainly in improvements in resolution, and in the introduction of video techniques. At the highest speeds the advances have included increases in dynamic range, a wider acceptance of image tubes, and a more careful analysis and characterization of their limitations. The variety, range and precision of methods available for photographic recording of fast phenomena have been increasing steadily. The capabilities of the newer techniques are considered, classifying the methods by the kind of record obtained. Descriptions of experimental techniques and apparatus, and illustrations, are given in an earlier article entitled, "A Review of the Methods of High-Speed Photography," published in Reports on Progress in Physics in 1957;[1 and in "Advances in High Speed Photography 1957-1972" published in the Proceedings of the Tenth Internatiopal Cngress on High Speed Photography (HSP10) [116 and also in JSMPTE 82 167-175 (1973). L117o This present paper is in the nature of a survey of the limits to which the various techniques have been pressed as compared to the limits attained, or reported in the open literature, at the date of the reviews 10 and 25 years ago. There are a number of recent books and articles which also provide excellent surveys and impressive bibliographies:129 -138 Streak records with drum cameras can give a time resolution of 5 x 10-9 s.[2,3] Rotating mirror streak cameras with a single reflection[15] at present approach 10-9 s and may with multiple reflections achieve 10-10 s. The Schardin limit[ 4] for presently available rotor materials is 0.25 x 10-9 s, but this is predicated upon a single reflection of the light beam from the rotor and can be surpassed if the camera is designed to take advantage of

  9. Experimental characterization of high speed centrifugal compressor aerodynamic forcing functions

    Science.gov (United States)

    Gallier, Kirk

    The most common and costly unexpected post-development gas turbine engine reliability issue is blade failure due to High Cycle Fatigue (HCF). HCF in centrifugal compressors is a coupled nonlinear fluid-structure problem for which understanding of the phenomenological root causes is incomplete. The complex physics of this problem provides significant challenges for Computational Fluid Dynamics (CFD) techniques. Furthermore, the available literature fails to address the flow field associated with the diffuser potential field, a primary cause of forced impeller vibration. Because of the serious nature of HCF, the inadequacy of current design approaches to predict HCF, and the fundamental lack of benchmark experiments to advance the design practices, there exists a need to build a database of information specific to the nature of the diffuser generated forcing function as a foundation for understanding flow induced blade vibratory failure. The specific aim of this research is to address the fundamental nature of the unsteady aerodynamic interaction phenomena inherent in high-speed centrifugal compressors wherein the impeller exit flow field is dynamically modulated by the vaned diffuser potential field or shock structure. The understanding of this unsteady aerodynamic interaction is fundamental to characterizing the impeller forcing function. Unsteady static pressure measurement at several radial and circumferential locations in the vaneless space offer a depiction of pressure field radial decay, circumferential variation and temporal fluctuation. These pressure measurements are coupled with high density, full field measurement of the velocity field within the diffuser vaneless space at multiple spanwise positions. The velocity field and unsteady pressure field are shown to be intimately linked. A strong momentum gradient exiting the impeller is shown to extend well across the vaneless space and interact with the diffuser vane leading edge. The deterministic unsteady

  10. Acoustics of dual-stream high-speed jets

    Science.gov (United States)

    Debiasi, Marco Tullio

    2000-10-01

    This work presents the results of noise measurements in high-speed, round jets whose Mach number and velocity simulate the conditions of jet engines at take-off. The Mach number of the jet potential core ranged from 1.27 to 1.77 and the velocity ranged from 550 m/s to 1010 m/s. Most of the jets were silenced with a coflow that prevented the formation of Mach waves, a dominant contribution to supersonic jet noise. This method, called Mach Wave Elimination, relies on the shielding effect of the coflow which makes the motion of the eddies subsonic with respect to the surrounding streams, thus impeding the creation of Mach waves. Schlieren photography and pitot probe surveys were used to detect the principal features and the growth rate of the jets. Microphone measurements were performed inside an anechoic chamber at many positions around the jet exit. The results were corrected for the microphone response and for the effect of human sensitivity to sound. Equal-thrust comparison of different experimental results shows that elimination of Mach waves is very effective in reducing noise in the direction of strongest emission. Except for localized shock-associated components, noise emission was found to be insensitive to nozzle exit pressure and to depend principally on the values of fully-expanded Mach number and velocity in the jet potential core. Jets with a shorter Mach wave emitting region exhibited better noise suppression. Best results were obtained with an eccentric coflow that allows the shear layer of the upper part of the jet to grow naturally while silencing the jet in the downward direction. Coflows are capable of reducing the near-field screech peaks by up to 10 dB in imperfectly-expanded jets. Scaling the experimental results to a fall-size engine shows that eccentric coflows reduce the noise perceived in the direction of peak emission by up to 11 dB. Preliminary analysis of the application of this silencing technique to engine design indicates that Mach

  11. 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

  12. Surface evolution of perfluoropolyether film at high speed quasi-contact conditions

    Science.gov (United States)

    Chen, Yung-Kan; Peng, Jih-Ping; Bogy, David B.

    2016-05-01

    Nanoscale analysis characterized by microscopy with atomic resolution demand that the targeted surface remains nearly static. Therefore, the interaction between two fast moving surfaces requires a unique methodology to capture its dynamics when contacts are of nominal area on the order of 100 μm2 but only a few angstroms in depth. We present a contact study of the head-disk interface in hard disk drives, which consists of a disk surface coated with a molecularly thin perfluoropolyether lubricant and a slider surface moving slightly separated from it with a relative velocity of 20 m/s and with 10 nm spacing. By investigating the slider dynamics and lubricant topography in-situ, we disclose that high-speed contact initiates when the slider shears the top surface of the lubricant. Such contact can pile up molecules a few angstroms high as "moguls" or annihilate existing ones through a 5-10 Å interference. The transitional spacing regime of mogul evolution is defined as "quasi-contact," and it is the initial contact in the fast sliding interface.

  13. Combustion performance of flame-ignited high-speed train seats via full-scale tests

    OpenAIRE

    Jie Zhu; Xiao Ju Li; Cheng Feng Mie

    2015-01-01

    Determining the combustion characteristics of combustibles in high-speed trains is the foundation of evaluating the fire hazard on high-speed trains scientifically, and establishing effective active and passive fire precautions. In this study, the double seats in the compartments of CRH1 high-speed trains were used as the main research object. Under different test conditions, including the power of ignition sources and ventilation rates, full-scale furniture calorimeter tests were conducted t...

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. Algorithms for High-Speed Noninvasive Eye-Tracking System

    Science.gov (United States)

    Talukder, Ashit; Morookian, John-Michael; Lambert, James

    2010-01-01

    Two image-data-processing algorithms are essential to the successful operation of a system of electronic hardware and software that noninvasively tracks the direction of a person s gaze in real time. The system was described in High-Speed Noninvasive Eye-Tracking System (NPO-30700) NASA Tech Briefs, Vol. 31, No. 8 (August 2007), page 51. To recapitulate from the cited article: Like prior commercial noninvasive eyetracking systems, this system is based on (1) illumination of an eye by a low-power infrared light-emitting diode (LED); (2) acquisition of video images of the pupil, iris, and cornea in the reflected infrared light; (3) digitization of the images; and (4) processing the digital image data to determine the direction of gaze from the centroids of the pupil and cornea in the images. Most of the prior commercial noninvasive eyetracking systems rely on standard video cameras, which operate at frame rates of about 30 Hz. Such systems are limited to slow, full-frame operation. The video camera in the present system includes a charge-coupled-device (CCD) image detector plus electronic circuitry capable of implementing an advanced control scheme that effects readout from a small region of interest (ROI), or subwindow, of the full image. Inasmuch as the image features of interest (the cornea and pupil) typically occupy a small part of the camera frame, this ROI capability can be exploited to determine the direction of gaze at a high frame rate by reading out from the ROI that contains the cornea and pupil (but not from the rest of the image) repeatedly. One of the present algorithms exploits the ROI capability. The algorithm takes horizontal row slices and takes advantage of the symmetry of the pupil and cornea circles and of the gray-scale contrasts of the pupil and cornea with respect to other parts of the eye. The algorithm determines which horizontal image slices contain the pupil and cornea, and, on each valid slice, the end coordinates of the pupil and cornea

  19. Mechanical and Microstructural Properties of Friction Welded AISI 304 Stainless Steel to AISI 1060 Steel AISI 1060

    Directory of Open Access Journals (Sweden)

    Ates H.

    2014-10-01

    Full Text Available Rotary Friction welding is one of the most popular methods of joining similar and dissimilar materials. It is widely used with metals and thermoplastics in a wide variety of aviation, transport and aerospace industrial component designs. This study investigates the influence of friction and upsetting pressures on the hardness, tensile properties and microstructure of the welds. The experimental results showed that as the friction and upsetting pressures increased, the hardness and tensile strength values increased, as well. The tensile fracture of welded joint occurred in the AISI 1060 side. The friction processed joints were evaluated for their integrity and quality aspects by optical and scanning electron microscopy. For the perfect interfacial bonding, sufficient upsetting and friction pressures are necessary to reach the optimal temperature and severe plastic deformation to bring these materials within the attraction range.

  20. Detecting and Blocking Network Attacks at Ultra High Speeds

    Energy Technology Data Exchange (ETDEWEB)

    Paxson, Vern

    2010-11-29

    Stateful, in-depth, in-line traffic analysis for intrusion detection and prevention has grown increasingly more difficult as the data rates of modern networks rise. One point in the design space for high-performance network analysis - pursued by a number of commercial products - is the use of sophisticated custom hardware. For very high-speed processing, such systems often cast the entire analysis process in ASICs. This project pursued a different architectural approach, which we term Shunting. Shunting marries a conceptually quite simple hardware device with an Intrusion Prevention System (IPS) running on commodity PC hardware. The overall design goal is was to keep the hardware both cheap and readily scalable to future higher speeds, yet also retain the unparalleled flexibility that running the main IPS analysis in a full general-computing environment provides. The Shunting architecture we developed uses a simple in-line hardware element that maintains several large state tables indexed by packet header fields, including IP/TCP flags, source and destination IP addresses, and connection tuples. The tables yield decision values the element makes on a packet-by-packet basis: forward the packet, drop it, or divert ('shunt') it through the IPS (the default). By manipulating table entries, the IPS can, on a fine-grained basis: (i) specify the traffic it wishes to examine, (ii) directly block malicious traffic, and (iii) 'cut through' traffic streams once it has had an opportunity to 'vet' them, or (iv) skip over large items within a stream before proceeding to further analyze it. For the Shunting architecture to yield benefits, it needs to operate in an environment for which the monitored network traffic has the property that - after proper vetting - much of it can be safely skipped. This property does not universally hold. For example, if a bank needs to examine all Web traffic involving its servers for regulatory compliance, then a

  1. Characterizing Vibratory Kinematics in Children and Adults with High-Speed Digital Imaging

    Science.gov (United States)

    Patel, Rita; Dubrovskiy, Denis; Döllinger, Michael

    2014-01-01

    Purpose: The aim of this study is to quantify and identify characteristic vibratory motion in typically developing prepubertal children and young adults using high-speed digital imaging. Method: The vibrations of the vocal folds were recorded from 27 children (ages 5-9 years) and 35 adults (ages 21-45 years), with high speed at 4,000 frames per…

  2. Recent Progress in Silicon Electro-optic Modulators for High Speed Applications

    Institute of Scientific and Technical Information of China (English)

    XIAO Xi; YU Jin-zhong

    2008-01-01

    Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in silicon, reviewed are some recent progresses in high-speed silicon modulators, and analyzed are advantages and shortages of the silicon modulators of different types.

  3. Design and application on experimental platform for high-speed bearing with grease lubrication

    Directory of Open Access Journals (Sweden)

    He Qiang

    2015-12-01

    Full Text Available The experimental platform for high-speed grease is an important tool for research and development of high-speed motorized spindle with grease lubrication. In this article, the experimental platform for high-speed grease is designed and manufactured which consists of the drive system, the test portion, the loading system, the lubrication system, the control system, and so on. In the meantime, the high-speed angular contact ceramic ball bearings B7005C/HQ1P4 as the research object are tested and contrasted in the grease lubrication and oil mist lubrication. The experimental platform performance is validated by contrast experiment, and the high-speed lubricated bearing performance is also studied especially in the relationship among the rotating speed,load and temperature rise. The results show that the experimental platform works steadily, accurate, and reliable in the experimental testing. And the grease lubrication ceramic ball bearings B7005C/HQ1P4 can be used in high-speed motorized spindle in the circular water cooling conditions when the rotating speed is lower than 40,000 r/min or the DN value (the value of the bearing diameter times the rotating speed is lower than the 1.44 × 106 mm r/min. Grease lubrication instead of oil mist lubrication under high-speed rotating will simplify the structure design of the high-speed motorized spindle and reduce the pollution to the environment.

  4. 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....

  5. A New High-Speed Low Distortion Switched-Current Cell

    DEFF Research Database (Denmark)

    Shah, Peter Jivan; Toumazou, Christofer

    1996-01-01

    A new switched-current cell is presented which simultaneously offers high speed, low distortion, low gain error, and a virtual ground input. In a simulation example 0.01% distortion was achieved at 50MHz sampling rate which makes the cell very well suited for high accuracy high speed filtering...

  6. L1 Adaptive Manoeuvring Control of Unmanned High-speed Water Craft

    DEFF Research Database (Denmark)

    Svendsen, Casper H.; Holck, Niels Ole; Galeazzi, Roberto;

    2012-01-01

    This work addresses the issue of designing an adaptive robust control system to govern the steering of a high speed unmanned personal watercraft (PWC) maintaining equal performance across the craft’s envelope of operation. The maneuvering dynamics of a high speed PWC is presented and a strong var...

  7. 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 sid

  8. Evaluation of a new device for sterilizing dental high-speed handpieces

    DEFF Research Database (Denmark)

    Larsen, T; Andersen, H K; Fiehn, N E

    1997-01-01

    Dental high-speed turbines and handpieces can take up and expel microorganisms during operation and thus need regular sterilization. This study established a method for validating devices used to sterilize high-speed turbines and handpieces. The air and water channels and turbine chambers were co...

  9. Use of nitrogen gas in high-speed milling of Ti-6Al-4V

    Institute of Scientific and Technical Information of China (English)

    KE Ying-lin; DONG Hui-yue; LIU Gang; ZHANG Ming

    2009-01-01

    To inhibit chips burning in the high-speed cutting of Ti-6Al-4V, nitrogen gas with 0.7 MPa pressure was ejected at the milling zone. The high speed flowing of nitrogen gas speeds up the chips leaving, and prevents the chips from burning at the same time. By this method the cutting force is reduced. Especially, the temperature increment of the finished surface is smaller than 5 ℃. This prevents the increase of hardness, improves the roughness of the finished surface, and reduces the tools wear. Comparing and analyzing the morphology and color of chips, which are obtained from the high-speed machining of Ti-6Al-4V with and without nitrogen gas ejection, show the action mechanism of nitrogen gas during the high-speed machining of titanium alloy, and it is concluded that nitrogen gas can be used to realize the proper high-speed milling of Ti-6Al-4V titanium alloy.

  10. RESEARCH ON ABRASION OF DEBRIS FLOW TO HIGH-SPEED DRAINAGE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    陈洪凯; 唐红梅; 吴四飞

    2004-01-01

    As one weak topic in research of debris flow, abrasion of debris flow shortens obviously application life of control structure composed of concrete. High-speed drainage structure, one of the most effective techniques to control giant debris flow disaster, has shortened one-third application life due to abrasion by debris flow. Based on velocity calculation method founded by two-phase theory, research of abrasion mechanism of debris flow to high-speed drainage structure was made. The mechanism includes both abrasion mechanism of homogeneous sizing and shearing mechanism of particle of debris flow to high-speed drainage trough structure. Further abrasion equations of both sizing and particle were established by Newton movement theory of debris flow. And abrasion amount formula of the high-speed drainage trough structure is set up by dimensional analysis. Amount to calculating in the formula is consistent with testing data in-situ, which is valuable in design of high-speed drainage structure.

  11. Sensor network architecture for intelligent high-speed train on-board monitoring

    Institute of Scientific and Technical Information of China (English)

    Xiao-fan WU; Chun CHEN; Jia-jun BU; Gang CHEN

    2011-01-01

    The China's high-speed railway is experiencing a rapid growth.Its operating mileage and the number of operating trains will exceed 45000 km and 1500 trains by 2015,respectively.During the long range and constant high-speed operation,the high-speed trains have extremely complex and varied work conditions.Such a situation creates a huge demand for high-speed train on-board monitoring.In this paper,architecture for high-speed train on-board monitoring sensor network is proposed.This architecture is designed to achieve the goals of reliable sensing,scalable data transporting,and easy management.The three design goals are realized separately.The reliable sensing is achieved by deploying redundant sensor nodes in the same components.Then a hierarchal transporting scheme is involved to meet the second goal.Finally,an electronic-tag based addressing method is introduced to solve the management problem.

  12. A simulation-based study of HighSpeed TCP and its deployment

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Evandro de

    2003-04-29

    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.

  13. Effect of temperature on the level of corrosion caused by heavy petroleum on AISI 304 and AISI 444 stainless steel

    OpenAIRE

    João Paulo Sampaio Eufrásio Machado; Cleiton Carvalho Silva; Ana Vládia Cabral Sobral-Santiago; Hosiberto Batista de Sant'Ana; Jesualdo Pereira Farias

    2006-01-01

    This work presents a study on the influence of national heavy petroleum in the corrosion of the AISI 444 and AISI 304 stainless steels in simulated refining operation conditions. The petroleum was first characterized through physicochemical analysis (density, fluidity point, viscosity, sulfur concentration). In an attempt to understand the corrosion effect of temperature and of the type of heating the referred types of steel thermal treatments were carried out at three levels of temperature (...

  14. Separation Analysis in a High-Speed Rotating Cylinder for a Binary Gas Mixture

    Science.gov (United States)

    Pradhan, Sahadev; Kumaran, Viswanathan

    2015-11-01

    The solutions of the species balance equations linked with the generalized Onsager model for the secondary gas flow in a high-speed rotating cylinder are compared with the direct simulation Monte Carlo (DSMC) simulations for a binary gas mixture. The concentration fields are obtained three different types of driving mechanism. These are: (a) wall thermal forcing, (b) inflow/outflow of gas along the axis, and (c) momentum source/sink inside the flow domain, for the stratification parameter (A) in the range (0.707- 3.535), and Reynolds number (Re) in the range (102 - 106 with aspect ratio (length / diameter) = 2, 4, 8. Two different types of cases have been considered, (a) no mass difference (ɛa = (2 Δm/(m1 + m2)) = 0), and (b) with mass difference (ɛa = 0.2 and 0.5) while calculating the secondary flow field in the analytical solution. Here, the stratification prameter A = √((mavΩ2 R2)/(2 kB T)), and the Reynolds number Re = ρw Ω R2)/ μ, where m is the molecular mass, Ω and R are the angular velocity and radius of the cylinder, ρw is the wall density, μ is the gas viscosity and T is the gas temperature. The comparison between numerical and analytical solution reveals that the boundary conditions in the numerical simulations and analytical model have to be matched with care. The commonly used ``diffuse reflection'' boundary conditions at the solid walls in DSMC simulations result in a non-zero slip velocity as well as a ``temperature slip'' (gas temperature at the wall is different from wall temperature).

  15. What is $\\Delta m^2_{ee}$ ?

    CERN Document Server

    Parke, Stephen

    2016-01-01

    The current short baseline reactor experiments, Daya Bay and RENO (Double Chooz) have measured (or are capable of measuring) an effective $\\Delta m^2$ associated with the atmospheric oscillation scale of 0.5 km/MeV in electron anti-neutrino disappearance. In this paper, I compare and contrast the different definitions of such an effective $\\Delta m^2$ and argue that the simple, L/E independent, definition given by $\\Delta m^2_{ee} \\equiv \\cos^2 \\theta_{12} \\Delta m^2_{31}+ \\sin^2 \\theta_{12} \\Delta m^2_{32}$, i.e. "the $\

  16. Optimal V/f control of super high-speed PMSM and its application

    Science.gov (United States)

    Bian, Chunyuan; Ren, Shuangyan; Yan, Shijie; Man, Yongkui; Wang, Zhiqiang

    2006-11-01

    Due to the features such as high efficiency, small volume and high power density, super high-speed permanent magnet synchronous motor (PMSM) are becoming attractive in many fields such as high-speed micro-turbine generators, centrifugal compressors and pumps. V/f control is flexible and easy to be realized, moreover, voltage utilization ratio of SVPWM modulation is high, so the plan combined with V/f control and SVPWM modulation can be adopted for PMSM. The effects of the stator resistance and the dead-time on the control are generally neglected in traditional V/f control, which leads to that the low-speed performance is poor and the system is not stable at high speed. Based on considering the effects of stator resistance and dead-time, an optimal V/f control of the super high-speed PMSM is presented. Combined with the optimal V/f control and SVPWM modulation, soft starting and operating experiments for PMSM generator (105Kw, 61000rpm) are successfully implemented in the designed system of super high-speed gas micro-turbine based on DSP 320F2407A. The experiment results shows that this optimal V/f control is virtual and feasible for super high-speed PMSM. The proposed scheme provided dynamic stability and high performance of the super high-speed PMSM with an open-loop control.

  17. NASA-UVA Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft

    Science.gov (United States)

    Starke, E. A., Jr.

    1997-01-01

    This is the final report of the study "Aluminum-Based Materials for High Speed Aircraft" which had the objectives (1) to identify the most promising aluminum-based materials with respect to major structural use on the HSCT and to further develop those materials and (2) to assess the materials through detailed trade and evaluation studies with respect to their structural efficiency on the HSCT. The research team consisted of ALCOA, Allied-Signal, Boeing, McDonnell Douglas, Reynolds Metals and the University of Virginia. Four classes of aluminum alloys were investigated: (1) I/M 2XXX containing Li and I/M 2XXX without Li, (2) I/M 6XXX, (3) two P/M 2XXX alloys, and (4) two different aluminum-based metal matrix composites (MMC). The I/M alloys were targeted for a Mach 2.0 aircraft and the P/M and MMC alloys were targeted for a Mach 2.4 aircraft. Design studies were conducted using several different concepts including skin/stiffener (baseline), honeycomb sandwich, integrally stiffened and hybrid adaptations (conventionally stiffened thin-sandwich skins). Alloy development included fundamental studies of coarsening behavior, the effect of stress on nucleation and growth of precipitates, and fracture toughness as a function of temperature were an integral part of this program. The details of all phases of the research are described in this final report.

  18. Microstructure and Eutectic Carbide Morphology of the High Speed Steel Strips Produced by Twin Roll Strip Casting Process

    Institute of Scientific and Technical Information of China (English)

    Hongshuang DI; Xiaoming ZHANG; Guodong WANG; Xianghua LIU

    2003-01-01

    The M2 high-speed steel strip was produced by using the laboratory scale twin roll strip caster. The microstructureand eutectic carbide morphology of thus produced products were observed and analyzed, and the comparison ofthose with conventional products was carried out. The effects of the processing parameters such as the meltingtemperature, the pouring temperature, rolling speed and separating force on the microstructure and eutectic carbidemorphology and their distribution were analyzed. The spheroidizing process of the strips in the annealing process wasinvestigated. The relations between the growth and spheroidizing of the eutectic carbide and the annealing technologywere obtained, and the mechanism of the twin roll strip casting process improving the eutectic carbide spheroidizingwas discussed. The theoretical instruction for determining the subsequent treatment process was provided.

  19. Closed-loop high-speed 3D thermal probe nanolithography

    Science.gov (United States)

    Knoll, A. W.; Zientek, M.; Cheong, L. L.; Rawlings, C.; Paul, P.; Holzner, F.; Hedrick, J. L.; Coady, D. J.; Allen, R.; Dürig, U.

    2014-03-01

    Thermal Scanning Probe Lithography (tSPL) is an AFM based patterning technique, which uses heated tips to locally evaporate organic resists such as molecular glasses [1] or thermally sensitive polymers.[2][3] Organic resists offer the versatility of the lithography process known from the CMOS environment and simultaneously ensure a highly stable and low wear tip-sample contact due to the soft nature of the resists. Patterning quality is excellent up to a resolution of sub 15 nm,[1] at linear speeds of up to 20 mm/s and pixel rates of up to 500 kHz.[4] The patterning depth is proportional to the applied force which allows for the creation of 3-D profiles in a single patterning run.[2] In addition, non-destructive imaging can be done at pixel rates of more than 500 kHz.[4] If the thermal stimulus for writing the pattern is switched off the same tip can be used to record the written topography with Angstrom depth resolution. We utilize this unique feature of SPL to implement an efficient control system for reliable patterning at high speed and high resolution. We combine the writing and imaging process in a single raster scan of the surface. In this closed loop lithography (CLL) approach, we use the acquired data to optimize the writing parameters on the fly. Excellent control is in particular important for an accurate reproduction of complex 3D patterns. These novel patterning capabilities are equally important for a high quality transfer of two-dimensional patterns into the underlying substrate. We utilize an only 3-4 nm thick SiOx hardmask to amplify the 8±0.5 nm deep patterns created by tSPL into a 50 nm thick transfer polymer. The structures in the transfer polymer can be used to create metallic lines by a lift-off process or to further process the pattern into the substrate. Here we demonstrate the fabrication of 27 nm wide lines and trenches 60 nm deep into the Silicon substrate.[5] In addition, the combined read and write approach ensures that the lateral

  20. A direct digital frequency synthesizer with high-speed current-steering DAC

    Institute of Scientific and Technical Information of China (English)

    Yu Jinshan; Fu Dongbing; Li Ruzhang; Yao Yafeng; Yan Gang; Liu Jun; Zhang Ruitao; Yu Zhou; Li Tun

    2009-01-01

    A high-speed SiGe BiCMOS direct digital frequency synthesizer (DDS) is presented. The design in tegrates a high-speed digital DDS core, a high-speed differential current-steering mode 10-bit D/A converter, a serial/parallel interface, and clock control logic. The DDS design is processed in 0.35 μm SiGe BiCMOS standard process technology and worked at 1 GHz system frequency. The measured results show that the DDS is capable of generating a frequency-agile analog output sine wave up to 400+ MHz.

  1. Pressure Distribution Characters of Flow Field around High-Speed Train

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on incompressible viscous fluid Navier-Stokes equation and k-ε 2-equationsturbulent model, an investigation on 3D turbulent flow field around four kinds of train models has been made by finite element method. From the calculation, the pressure distribution characters of flow field around high-speed trains have been obtained. It is significant for strength design of the high-speed train body, for resisting wind design of the facilities beside the high-speed railways and for determining the aerodynamic force of induced air to the human body near the railways.

  2. Research on Control System of Spindle Drive for High Speed Spinning Machine

    Institute of Scientific and Technical Information of China (English)

    魏建

    2001-01-01

    Through analyzing the principle of spindle drive of winding mechanism for high speed spinning machine,the article not only describes a kind of mode of spindle drive for take-up motion on the basis of control method of constant velocity winding, but also introduces the design technique of software and hardware for the control system of mechatronics of spindle drive mode for take- up motion on the basis of constant velocity winding for high speed spinning machine with single-chip microcomputer. The mathematical model to describe the spindle rotating speed is established. It is an important technology for high speed spinning machine and provides a feasible application way.

  3. Influence of the Magnetic High-speed Steel Cutting Tool on Cutting Capability

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The high-speed steel cutting tool has advantaged i n modern cutting tool for its preferable synthetical performance, especially, in a pplication of complicated cutting tools. Therefore, the study of the high-speed steel cutting tools that occupied half of cutting tools has become an importa nt way of studying on modern cutting technology. The cutting performance of hi gh speed-steel cutting tools will be improved by magnetization treating method. Microstructure of high-speed steel will be changed as a ...

  4. 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

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  5. ADAPTIVE FINITE ELEMENT METHOD FOR HIGH-SPEED FLOW-STRUCTURE INTERACTION

    Institute of Scientific and Technical Information of China (English)

    Wiroj LIMTRAKARN; Pramote DECHAUMPHAI

    2004-01-01

    An adaptive finite element method for high-speed flow-structure interaction is presented. The cell-centered finite element method is combined with an adaptive meshing technique to solve the Navier-Stokes equations for high-speed compressible flow behavior. The energy equation and the quasi-static structural equations for aerodynamically heated structures are solved by applying the Galerkin finite element method. The finite element formulation and computational procedure are described. Interactions between the high-speed flow, structural heat transfer, and deformation are studied by two applications of Mach 10 flow over an inclined plate, and Mach 4 flow in a channel.

  6. Study of Quintic Spline Interpolation and Generated Velocity Profile for High Speed Machining

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jinxing; ZHANG Mingjun; MENG Qingxin

    2006-01-01

    Modern high speed machining (HSM) machine tools often operates at high speed and high feedrate with high accelerations, in order to deliver the rapid feed motion. This paper presents an interpolation algorithm to generate continuous quintic spline toolpaths, with a constant travel increment at each step, while the smoother accelerations and jerks of two-order curve are obtained. Then an approach for reducing the feedrate fluctuation in high speed spline interpolation is presented. The presented approach has been validated to quickly, reliably and effective with the simulation.

  7. High speed railway promoting development of low-carbon economy in China%High speed railway promoting development of low-carbon economy in China

    Institute of Scientific and Technical Information of China (English)

    Zhou Xinjun

    2011-01-01

    Low-carbon Economy is a kind of economic developing mode which takes low energy consumption, low pollution and low discharge as its foundation. It is another important revolution of the human society after the agriculture civilization and industry civilization. It deals with various fields including low-carbon energy, low-carbon agriculture, lowcarbon industry, low-carbon transportation and low-carbon life, etc. Among those, low-carbon transportation is one of the important contents. Since high speed railway uses electricity as driving force, it runs without discharging waste gas, and it is a kind of clean and green transportation with little dust and smoke black. Therefore, the study of the relationship between the high speed railway and low-carbon economy is becoming one of the important frontier problems that confronting the theoretic circle. With demonstration analysis and comparative analysis, this paper discusses the comparative advantages of high speed railway in terms of energy saving and environment protection, treatment of sound pollution, land saving and reduction of external cost ( mainly pollution treatment cost), etc. compared with the other transportation modes and ordinary railway. Taking Beijing~Tianjin Intercity Railway as an example, the paper further demonstrates the distinctive advantages in respect of energy conservation and emission reduction. Besides, the paper also predicates the low-carbon effects after several high speed railways is put into operation in a few years. It is concluded that the development of high speed railways will meet the need of low-carbon economy and is significant for sustainable and steady development of economy and society.

  8. High-Speed Fiber Optic Micromultiplexer for Space and Airborne Lidar Project

    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. 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...

  10. High speed television camera system processes photographic film data for digital computer analysis

    Science.gov (United States)

    Habbal, N. A.

    1970-01-01

    Data acquisition system translates and processes graphical information recorded on high speed photographic film. It automatically scans the film and stores the information with a minimal use of the computer memory.

  11. Integrated High-Speed Digital Optical True-Time-Delay Modules for Synthetic Aperture Radars Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Crystal Research, Inc. proposes an integrated high-speed digital optical true-time-delay module for advanced synthetic aperture radars. The unique feature of this...

  12. Numerical simulation of high-speed turbulent water jets in air

    CERN Document Server

    Guha, Anirban; Balachandar, Ram

    2010-01-01

    Numerical simulation of high-speed turbulent water jets in air and its validation with experimental data has not been reported in the literature. It is therefore aimed to simulate the physics of these high-speed water jets and compare the results with the existing experimental works. High-speed water jets diffuse in the surrounding atmosphere by the processes of mass and momentum transfer. Air is entrained into the jet stream and the entire process contributes to jet spreading and subsequent pressure decay. Hence the physical problem is in the category of multiphase flows, for which mass and momentum transfer is to be determined to simulate the problem. Using the Eulerian multiphase and the k-\\epsilon turbulence models, plus a novel numerical model for mass and momentum transfer, the simulation was achieved. The results reasonably predict the flow physics of high-speed water jets in air.

  13. 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...

  14. Advanced Modular, Multi-Channel, High Speed Fiber Optic Sensing System for Acoustic Emissions Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes to prove the feasibility of innovations based on ultra-light-weight, ultra-high-speed, multi-channel,...

  15. 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....

  16. 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...

  17. 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.

  18. High speed railway environment safety evaluation based on measurement attribute recognition model.

    Science.gov (United States)

    Hu, Qizhou; Gao, Ningbo; 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.

  19. Research on high-speed TDICCD remote sensing camera video signal processing

    Institute of Scientific and Technical Information of China (English)

    ZHANG Da; XU Shu-yan; MENG Qing-ju

    2009-01-01

    Video signal processing needs high signal-to-noise ratio (SNR) in high-speed time delay and integration charge coupled devices (TDICCD). To solve this problem, this article first analyzes the characteristics of the output video signal of a new type of high-speed TDICCD and its operation principle. Then it studies the correlation double sample (CDS) method of reducing noise. Following that a synthesized processing method is proposed, including correlation double sample, programmable gain control, line calibration and digital offset control, etc. Among the methods, XRD98L59 is a video signal processor for the charge coupled device (CCD). Application of this processor to one kind of high-speed TDICCD with eight output ports achieves perfect video images. The experiment result indicates that the SNR of the images reaches about 50 riB. The video signal processing for high-speed multi-channel TDICCD is implemented, which meets the required project index.

  20. Simulation Analysis Module of High-speed Rail Bearings Based on Secondary Development in ADAMS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YE Jun; XU Juan; LUO Yi-chao

    2013-01-01

    This paper develops a strong secondary development based on ADAMS feature which creates high-speed rail bearings for simulation analysis module. This thesis is in the case of non-circular pattern instructions of how to achieve rapid roller modeling, with analysis of functions and parameters required for the design of the simulation module of the high-speed rail bearing , as well as the design of dialog boxes, the environment and file structure. The specific modules is based on the secondary development language provided by ADAMS/View. Through the menus, dialog boxes which input parameters, it can achieve high iron bearing automatic modeling, dynamic analysis and post-processing to simplify the analysis of high-speed rail bearing operations, as well as improving the high-speed rail bearing development efficiency.

  1. 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...

  2. High-Speed Optical Local Access Network System Using Bi-Directional Polarization Multiplexing

    Institute of Scientific and Technical Information of China (English)

    Mitsuru Miyauchi; Yanjun Sun

    2003-01-01

    A high-speed and economical optical local access network system is proposed where bi-directional polarization multiplexing is applied to a bi-directional transmission. Experimental results using a prototype system confirmlow optical loss and environmental stabilities.

  3. High-Speed Optical Local Access Network System Using Bi-Directional Polarization Multiplexing

    Institute of Scientific and Technical Information of China (English)

    Mitsuru; Miyauchi; Yanjun; Sun

    2003-01-01

    A high-speed and economical optical local access network system is proposed where bi-directional polarization multiplexing is applied to a bi-directional transmission. Experimental results using a prototype system confirm low optical loss and environmental stabilities.

  4. OptoCeramic-Based High Speed Fiber Multiplexer for Multimode Fiber Project

    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...

  5. 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.

  6. Research on High-Speed Drilling Performances of Austenitic Stainless Steels

    Institute of Scientific and Technical Information of China (English)

    J.W.Zhong; Y.P.Ma; F.H.Sun; M.Chen

    2004-01-01

    Due to specific properties arising from their structure (high ductility, high toughness,strong tenacious and low heat conductivity), the stainless steels have poor machinability. The drilling of the stainless steels becomes the machining difficulty for their serious work-hardening and abrasion of tools. In this paper, the austenitic stainless steel is used as the work-piece to perform the contrastive experiments with the TiN coated and TiAlN-coated high-speed steel drills. The cutting force, torque, cutting temperature, and the abrasion of drills and tool life are tested and analyzed in the process of high-speed drilling. Experiment results show the effect of drilling speed on cutting force, cutting temperature, and drill wear. TiAlN-coated drills demonstrate better performances in high speed drilling. The research results will be of great benefit in the selection of drills and in the control of tool wear in high speed drilling of stainless steels.

  7. 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...

  8. Mode Transition Variable Geometry for High Speed Inlets for Hypersonic Aircraft Project

    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...

  9. Technologies for Compensation or Mitigation of Transmission Impairments in Future High-Speed Optical Networks

    Institute of Scientific and Technical Information of China (English)

    W.Weiershausen; S.Vorbeck

    2003-01-01

    The presentation will give an overview over different classes of signal impairments in ultra-long-haul and high-speed optical WDM transmission systems and adequate approaches for suppression, mitigation or compensation are discussed.

  10. 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.

  11. 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....

  12. Applications of highly nonlinear dispersion tailored lead silicate fibres for high speed optical communications

    OpenAIRE

    Parmigiani F.; Camerlingo A.; Feng X; Poletti F.; Ponzo G.M.; Slavik R.; Horak P.; Petrovich M.N.; Loh W.H.; Petropoulos P.

    2010-01-01

    Recent advances in optical fibre technology, most notably in the area of microstructured optical fibres (MOFs), offer a host of new opportunities within future high speed communication systems. Herein we review how our recent progress on the implementation of lead silicate fibre designs, allowing both flexible dispersion control and a high effective nonlinearity, can be integrated into various all-optical signal processing devices for high speed optical communication systems. Highly nonlinear...

  13. Higher-order modulation formats for spectral-efficient high-speed metro systems

    Science.gov (United States)

    Freund, R.; Nölle, M.; Seimetz, M.; Hilt, J.; Fischer, J.; Ludwig, R.; Schubert, C.; Bach, H.-G.; Velthaus, K.-O.; Schell, M.

    2011-01-01

    Worldwide, higher-order modulation formats are intensively investigated to further increase the spectral efficiency for building the next generation of high-speed metro systems. IQ-modulators, coherent receivers and electronic equalizers are hereby discussed as key devices. We report on system design issues as well as on HHI's latest achievements in developing InP based high-speed modulators and coherent receiver frontends.

  14. Performance Analysis of DRA Based OFDM Data Transmission With Respect to Novel High Speed RS Decoding

    OpenAIRE

    Dr. S.V.A.V. Prasad; Anshu Thakur

    2015-01-01

    In this paper, we have analyzed the performance characteristics of OFDM data transmission with regard to a new high speed RS decoding algorithm. The various characteristics identified are mainly speed and accuracy of the transmission irrespective of channel behaviour. We consider two cases viz. data transmission without error control and data transmission with error control. Each of these cases are duly analyzed and it is proven that high speed RS decoding algorithms can actually ...

  15. Semiconductor optical amplifier-based all-optical gates for high-speed optical processing

    DEFF Research Database (Denmark)

    Stubkjær, Kristian

    2000-01-01

    Semiconductor optical amplifiers are useful building blocks for all-optical gates as wavelength converters and OTDM demultiplexers. The paper reviews the progress from simple gates using cross-gain modulation and four-wave mixing to the integrated interferometric gates using cross-phase modulation....... These gates are very efficient for high-speed signal processing and open up interesting new areas, such as all-optical regeneration and high-speed all-optical logic functions...

  16. Investigation of insulation layer dynamic characteristics for high-speed railway

    Institute of Scientific and Technical Information of China (English)

    HongYe Yan; GuoTang Zhao; DeGou Cai; QianLi Zhang; JianPing Yao; AiJun Cheng

    2015-01-01

    Dynamic performance of insulation is one of the key parameters during the insulation application for high-speed railway subgrade. This paper conducted laboratory and field tests for the materials and dynamic load, especially for thermal performance, elastic deformation, and accumulated deformation of insulation materials. Experiment results show that mechanical properties of insulation layer structure are stable, which satisfies the requirements of the high speed railway.

  17. 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.)

  18. Design and implementation of 1 GHz high speed data acquisition system

    Institute of Scientific and Technical Information of China (English)

    Zou Lin; Wang Xuegang; Qian Lu

    2009-01-01

    With the development of current electronic technology, numerous high-speed data acquisition systems provide a variety of potential benefits. This article describes a high-speed data acquisition system which consists of ECL logic and TTL logic devices, samples and stores data with a 1 GHz clock. This system is accomplished easily and works stably. A performance test of this system has been undertaken and the results show that the effective number of bits (ENOB) is more than 6.5 bits.

  19. 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

  20. Effects of honing treatment on AIP-TiN and TiAlN coated end-mill for high speed machining

    Institute of Scientific and Technical Information of China (English)

    Jae-Young HEO; Sung-Hak CHO; Tae-Jin JE; Kwang-Ho KIM; Hyung-Woo LEE; Myung-Chang KANG

    2011-01-01

    The objective of this work is to compare the tool performance of TiN and TiAIN coated carbides end-mills deposited by an arc ion plating (ALP) method, using honing treatment to polish the cutting edge surface sleekly. The curve of surface roughness versus honing time showed a rapid improvement initially and thereafter became steady, manifesting a saturation effect. The optimal honing time related to surface roughness was determined to be approximately 20 s. As the surface roughness increased, the critical loads reduced. At an average surface roughness (Ra) of 0.028 μm, the highest critical loads of TiN and TiAIN coating layers were 98 and 114 N. respectively. Tool performances of uncoated and coated tools were conducted under high speed machining (HSM) of AISI D2 cold-worked die steel (62 HRC). Consequently, the TiAIN coated end-mill using honing treatment showed excellent tool life under HSM conditions.

  1. A special issue on High.Speed Optical Transmission and Processing

    Institute of Scientific and Technical Information of China (English)

    Jian WANG

    2013-01-01

    The rapid growth in network capacity and traffic rates raises the significance of high-speed optical transmission and processing. Recent progress in optical communication systems in relation to multiplexing technologies in different degrees of freedom, advanced multi-level modulation formats, coherent detection and digital signal processing has facilitated dramatic increases in transmission capacity. To be compatible with high-speed optical transmission, high- speed optical processing has gained increased interest to enable fast data manipulation in the optical domain and avoid cumbersome optical-electrical-optical conversions at network nodes. Recent progress in nonlinear-optical devices has led to enhanced efficiency, flexibility and functionality of ultrafast nonlinear-optical signal processing. It is expected that these advances in high-speed optical transmission and processing will pave the way to achieve superior performance of high-speed optical networks. It is our intention to bring the research community's attention to these hot topics in optical communication systems and networks. In this "Special Issue on High-Speed Optical Transmission and Processing", 8 review articles and 2 research articles focusing on relevant subjects by internationally active groups in the field are specially presented.

  2. 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.

  3. Fretting fatigue in AISI 1015 steel

    Indian Academy of Sciences (India)

    R Gnanamoorthy; R Rosi Reddy

    2002-04-01

    A small osillatory movement between two contacting surfaces is termed as fretting and on many occasions it acts as the crack initiation site leading to catastrophic failure of the overall structure. The occurrence of fretting is observed in many engineering structures such as shaft flanges, gas turbines, steel ropes etc. An experimental facility, which can simulate the fretting fatigue in many engineering applications, is the primary requirement of the research program. A laboratory fretting fatigue test facility capable of varying many influencing parameters of fretting fatigue such as slip amplitutde, frequency, contact pressure, etc is designed and developed. Preliminary investigations on plain and fretting fatigue behaviour of AISI 1015 structural steel are reported in this paper. A strength reduction factor of about 1.30 was obtained due to fretting for the test material under the present experimental conditions. Influence of contact load on fretting was also studied. Increasing fretting contact load decreased the fatigue life in the range investigated. Failure analysis showed typical stage I oblique crack growth followed by stage II straight crack perpedicular to the fretting zone.

  4. Investigations on Surface Milling of Hardened AISI 4140 Steel with Pulse Jet MQL Applicator

    Science.gov (United States)

    Bashir, Mahmood Al; Mia, Mozammel; Dhar, Nikhil Ranjan

    2016-06-01

    In this article, an experimental investigation was performed in milling hardened AISI 4140 steel of hardness 40 HRC. The machining was performed in both dry and minimal quantity lubricant (MQL) conditions, as part of neat machining, to make a strong comparison of the undertaken machining environments. The MQL was impinged int the form of pulse jet, by using the specially developed pulse-jet-attachment, to ensure that the cutting fluid can be applied in different timed pulses and quantities at critical zones. The tool wear, cutting force and surface roughness were taken as the quality responses while cutting speed, table feed rate and flow rate of the pulse were considered as influential factors. The depth of cut was kept constant at 1.50 mm because of its less significant effects and the straight oil was adopted as cutting fluid in pulse-jet-MQL. The effects of different factors, on the quality responses, are analyzed using ANOVA. It is observed that MQL applicator system exhibits overall better performance when compared to dry milling by reducing surface roughness, cutting force and prolonging tool life but a flow rate of 150 ml/h has tremendous effects on the responses. This investigation and afterward results are expected to aid the industrial practitioner and researcher to adopt the pulse-MQL in high speed milling to prolong tool life, reduce tool wear, diminish cutting force generation and promote better surface finish.

  5. FATIGUE LIFE PREDICTION BASED ON MACROSCOPIC PLASTIC ZONE ON FRACTURE SURFACE OF AISI-SAE 1018 STEEL

    Directory of Open Access Journals (Sweden)

    G.M. Domínguez Almaraz

    2010-06-01

    Full Text Available This paper deals with rotating bending fatigue tests at high speed (150 Hz carried out on AISI-SAE 1018 steel with a high content of impurities (non metallic inclusions, for which the high experimental stress inside the specimen is close to the elastic limit of the material. Simulations of rotating loading are obtained by Visual NASTRAN software in order to determine the numerical stresse and strain distributions inside a hypothetical homogeneous specimen; later, this information is used for the experimental set up. A general description of experimental test machine and experimental conditions are developed and then, the experimental results are presented and discussed according the observed failure origin related to the non metallic inclusions and the associated high stress zones. Finally, a simple model is proposed to predict the fatigue life for this non homogeneous steel under high speed rotating bending fatigue tests close to the elastic limit, based on the rate between the visual macro-plastic deformation zone at fracture surface and the total fracture surface, together with the crack initiation inclusion (or inclusions located at this zone.

  6. Research on the Economic Benefits of High-speed Railway Enterprise Based on Activity Based Costing Method

    OpenAIRE

    Yang Zhengze; Gou Juanqiong

    2015-01-01

    The economic benefits are the basis for survival and development of the enterprises. Although the high-speed railway enterprise has many professions with exquisite division of labor, enormous organizations, complex calculation of economic benefits and other features, studying the economic benefits calculation for the high-speed railway enterprises, analyzing the operation costs and income conditions of high-speed railway and clarifying the economic benefits of high-speed railway enterprises a...

  7. World record in high speed laser surface microstructuring of polymer and steel using direct laser interference patterning

    Science.gov (United States)

    Lang, Valentin; Roch, Teja; Lasagni, Andrés. F.

    2016-03-01

    Periodic surfaces structures with micrometer or submicrometer resolution produced on the surface of components can be used to improve their mechanical, biological or optical properties. In particular, these surfaces can control the tribological performance of parts, for instance in the automotive industry. In the last years, substantial efforts have been made to develop new technologies capable to produce functionalized surfaces. One of these technologies is the Direct Laser Interference Patterning (DLIP) technology, which permits to combine high fabrication speed with high resolution even in the sub-micrometer range. In DLIP, a laser beam is split into two or more coherent beams which are guided to interfere on the work piece surface. This causes modulated laser intensities over the component's surface, enabling the direct fabrication of a periodic pattern based on selective laser ablation or melting. Depending on the angle between the laser beams and the wavelength of the laser, the pattern's spatial period can be perfectly controlled. In this study, we introduce new modular DLIP optical heads, developed at the Fraunhofer IWS and the Technische Universität Dresden for high-speed surface laser patterning of polymers and metals. For the first time it is shown that effective patterning speeds of up to 0.90 m2/min and 0.36 m2/min are possible on polymer and metals, respectively. Line- and dot-like surface architectures with spatial periods between 7 μm and 22 μm are shown.

  8. Influence of rare earth elements on solidification behavior of a high speed steel for roll using differential scanning calorimetry

    Institute of Scientific and Technical Information of China (English)

    WANG Mingjia; CHEN Lei; WANG Zixi; BAO Er

    2011-01-01

    The influence of rare earths (RE) on solidification behavior of a high speed steel for roll was investigated by using differential scanning calorimetry (DSC) in combination of microstructure analysis.It was found that the sequence of solidification was L→γ,L→γ+MC,L→γ+M2C,L→γ+M6C,respectively.The start temperature and the latent heat liberated by unit mass of L→γ and L→γ+MC increased with increase of RE addition,indicating that RE could trigger the crystallization of the primary γ and the MC carbide more effectively.The promoting effect of RE on the heterogeneous nucleation was believed to be an important cause of this effect.Grain refinement,discontinuous network of eutectic carbides and disperse and finer MC were observed in the samples with RE addition,moreover,RES could act as the heterogeneous nucleus of the MC.RE addition was favorable for stable M6C at the expense of the metastable M2C.

  9. 78 FR 28940 - Environmental Impact Statement for the Atlanta to Charlotte Portion of the Southeast High Speed...

    Science.gov (United States)

    2013-05-16

    ... Southeast High Speed Rail Corridor AGENCY: Federal Rail Administration (FRA), DOT. ACTION: Notice of Intent... between Atlanta, GA and Charlotte, NC, along the Southeast High-Speed Rail Corridor (SEHSR) as designated by the USDOT. The Study is being advanced consistent with the federal High-Speed Intercity...

  10. 77 FR 64183 - Notice of Availability of a Final General Conformity Determination for the California High-Speed...

    Science.gov (United States)

    2012-10-18

    ... California High-Speed Train System Merced to Fresno Section AGENCY: Federal Railroad Administration (FRA... Section of the California High-Speed Train (HST) System on September 18, 2012. FRA is the lead Federal... General Conformity requirements. The California High Speed Rail Authority (Authority), as the...

  11. 78 FR 78507 - California High-Speed Rail Authority-Construction Exemption-In Fresno, Kings, Tulare, and Kern...

    Science.gov (United States)

    2013-12-26

    ... Surface Transportation Board California High-Speed Rail Authority--Construction Exemption--In Fresno, Kings, Tulare, and Kern Counties, CA By petition filed on September 26, 2013, California High-Speed Rail... June 13, 2013, in California High-Speed Rail Authority--Construction Exemption--in Merced,...

  12. 75 FR 32240 - Draft Tier II Environmental Impact Statement: Southeast High Speed Rail Corridor-Richmond, VA...

    Science.gov (United States)

    2010-06-07

    ... Federal Railroad Administration Draft Tier II Environmental Impact Statement: Southeast High Speed Rail... Draft Environmental Impact Statement and public hearings for the Southeast High Speed Rail, Richmond, VA... availability of the Southeast High Speed Rail, Richmond, VA to Raleigh, NC Project Draft Tier II...

  13. 78 FR 24309 - California High-Speed Rail Authority-Construction Exemption-in Merced, Madera and Fresno Counties...

    Science.gov (United States)

    2013-04-24

    ... Surface Transportation Board California High-Speed Rail Authority--Construction Exemption--in Merced, Madera and Fresno Counties, Cal On March 27, 2013, California High-Speed Rail Authority (Authority), a... California High- Speed Rail Authority to know the reasons we reached this finding, but also to inform...

  14. 78 FR 73921 - California High-Speed Rail Authority-Construction Exemption-In Fresno, Kings, Tulare, and Kern...

    Science.gov (United States)

    2013-12-09

    ... Surface Transportation Board California High-Speed Rail Authority--Construction Exemption--In Fresno... approximately 114-mile high-speed passenger rail line between Fresno and Bakersfield, Cal. (the Line). The Line... would, when completed, provide high-speed intercity passenger rail service over more than 800 miles...

  15. 75 FR 51331 - Draft Tier II Environmental Impact Statement: Southeast High Speed Rail Corridor-Richmond, VA...

    Science.gov (United States)

    2010-08-19

    ... Federal Railroad Administration Draft Tier II Environmental Impact Statement: Southeast High Speed Rail... the Tier II Draft Environmental Impact Statement for the Southeast High Speed Rail, Richmond, VA to... the Draft Tier II Environmental Impact Statement for the Southeast High Speed Rail, Richmond, VA...

  16. 78 FR 22031 - California High-Speed Rail Authority-Construction Exemption-In Merced, Madera and Fresno Counties...

    Science.gov (United States)

    2013-04-12

    ... Surface Transportation Board California High-Speed Rail Authority--Construction Exemption--In Merced... Administration (FRA) and California High-Speed Rail Authority (Authority). This Final EIS is titled ``California... of the planned California HST system, which would provide intercity, high-speed passenger...

  17. Serum Stability and Affinity Optimization of an M2 Macrophage-Targeting Peptide (M2pep).

    Science.gov (United States)

    Ngambenjawong, Chayanon; Gustafson, Heather H; Pineda, Julio M; Kacherovsky, Nataly A; Cieslewicz, Maryelise; Pun, Suzie H

    2016-01-01

    Tumor associated macrophages (TAMs) are a major stromal component of the tumor microenvironment in several cancers. TAMs are a potential target for adjuvant cancer therapies due to their established roles in promoting proliferation of cancer cells, angiogenesis, and metastasis. We previously discovered an M2 macrophage-targeting peptide (M2pep) which was successfully used to target and deliver a pro-apoptotic KLA peptide to M2-like TAMs in a CT-26 colon carcinoma model. However, the effectiveness of in vivo TAM-targeting using M2pep is limited by its poor serum stability and low binding affinity. In this study, we synthesized M2pep derivatives with the goals of increasing serum stability and binding affinity. Serum stability evaluation of M2pepBiotin confirmed its rapid degradation attributed to exolytic cleavage from the N-terminus and endolytic cleavages at the W10/W11 and S16/K17 sites. N-terminal acetylation of M2pepBiotin protected the peptide against the exolytic degradation while W10w and K(17,18,19)k substitutions were able to effectively protect endolytic degradation at their respective cleavage sites. However, no tested amino acid changes at the W10 position resulted in both protease resistance at that site and retention of binding activity. Therefore, cyclization of M2pep was investigated. Cyclized M2pep better resisted serum degradation without compromising binding activity to M2 macrophages. During the serum stability optimization process, we also discovered that K9R and W10Y substitutions significantly enhanced binding affinity of M2pep. In an in vitro binding study of different M2pep analogs pre-incubated in mouse serum, cyclic M2pep with K9R and W10Y modifications (cyclic M2pep(RY)) retained the highest binding activity to M2 macrophages over time due to its improved serum stability. Finally, we evaluated the in vivo accumulation of sulfo-Cy5-labeled M2pep and cyclic M2pep(RY) in both the CT-26 and 4T1 breast carcinoma models. Cyclic M2pep

  18. Development of High Speed Inverter Rotary Compressor for the Air-conditioning System

    Science.gov (United States)

    Kang, Seoung-Min; Yang, Eun-soo; Shin, Jin-Ung; Park, Joon-Hong; Lee, Se-Dong; Ha, Jong-Hun; Son, Young-Boo; Lee, Byeong-Chul

    2015-08-01

    In order to meet the various operating loads of an air-conditioning system, an inverter compressor with a wide operational range is necessary. One of the ways to achieve a wide operation range is to drive a small capacity compressor at high speed. Moreover, it is possible to maximize the efficiency in part-load operation condition close to actual operating conditions and to reduce the cost by compact design of a small capacity compressor. In addition, the shortage of maximum capacity, due to the small rated capacity, is covered through high speed operation. However, in general, if the compressor operates at high speed, problems occurs such as reduced efficiency due to friction, increased noise, increased amount of oil discharge and decreased durability of the main components. In order to solve these problems the following have been investigated: optimized dimension parameters of the compression chamber, enhanced shaft design and the structure for the reduction of oil discharge and noise at high speed operation. Finally the high speed inverter rotary compressor with high efficiency and more compact size has been developed as compared with the conventional rotary compressor.

  19. Verification of high-speed solar wind stream forecasts using operational solar wind models

    Science.gov (United States)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.; Nikolic, Ljubomir; Vennerstrom, Susanne; Schöngassner, Florian; Hofmeister, Stefan J.

    2016-07-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation between the coronal hole area observed in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images and solar wind properties at the near-Earth environment, the WSA model establishes a link between properties of the open magnetic field lines extending from the photosphere to the corona 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 score, TS ≈ 0.37). The predicted high-speed streams show typical uncertainties in the arrival time of about 1 day and uncertainties in the speed of about 100 km/s. General advantages and disadvantages of the investigated solar wind models are diagnosed and outlined.

  20. NUMERICAL AND EXPERIMENTAL INVESTIGATION OF WAVE DYNAMIC PROCESSES IN HIGH-SPEED TRAIN/TUNNELS

    Institute of Scientific and Technical Information of China (English)

    姜宗林; K.Matsuoka; A.Sasoh; K.Takayama

    2002-01-01

    Numerical and experimental investigation on wave dynamic processes induced by high-speed trains entering railway tunnels are presented. Experiments were conducted by using a 1:250 scaled train-tunnel simulator. Numerical simulations were carried out by solving the axisymmetric Euler equations with the dispersioncontrolled scheme implemented with moving boundary conditions. Pressure histories at various positions inside the train-tunnel simulator at different distance measured from the entrance of the simulator are recorded both numerically and experimentally,and then compared with each other for two train speeds. After the validation of nonlinear wave phenomena, detailed numerical simulations were then conducted to account for the generation of compression waves near the entrance, the propagation of these waves along the train tunnel, and their gradual development into a weak shock wave. Four wave dynamic processes observed are interpreted by combining numerical results with experiments. They are: high-speed trains moving over a free terrain before entering railway tunnels; the abrupt-entering of high-speed trains into railway tunnels; the abrupt-entering of the tail of high-speed trains into railway tunnels; and the interaction of compression and expansion waves ahead of high-speed trains. The effects of train-tunnel configurations, such as the train length and the train-tunnel blockage ratio, on these wave processes have been investigated as well.

  1. Precise color images a high-speed color video camera system with three intensified sensors

    Science.gov (United States)

    Oki, Sachio; Yamakawa, Masafumi; Gohda, Susumu; Etoh, Takeharu G.

    1999-06-01

    High speed imaging systems have been used in a large field of science and engineering. Although the high speed camera systems have been improved to high performance, most of their applications are only to get high speed motion pictures. However, in some fields of science and technology, it is useful to get some other information, such as temperature of combustion flame, thermal plasma and molten materials. Recent digital high speed video imaging technology should be able to get such information from those objects. For this purpose, we have already developed a high speed video camera system with three-intensified-sensors and cubic prism image splitter. The maximum frame rate is 40,500 pps (picture per second) at 64 X 64 pixels and 4,500 pps at 256 X 256 pixels with 256 (8 bit) intensity resolution for each pixel. The camera system can store more than 1,000 pictures continuously in solid state memory. In order to get the precise color images from this camera system, we need to develop a digital technique, which consists of a computer program and ancillary instruments, to adjust displacement of images taken from two or three image sensors and to calibrate relationship between incident light intensity and corresponding digital output signals. In this paper, the digital technique for pixel-based displacement adjustment are proposed. Although the displacement of the corresponding circle was more than 8 pixels in original image, the displacement was adjusted within 0.2 pixels at most by this method.

  2. Development of a super high speed motor-generator and controller

    International Nuclear Information System (INIS)

    To develop a super high speed motor-generator, it is essential to deal with magnetic analysis, dynamic analysis, and experimental evaluation of the heart of the MTG (Microturbine Generator) system, the motor-generator. An amorphous core is applied to a stator core for reduction of iron loss at high speed, and the motor-generator is analyzed with considerations focused on magnetic losses and the statistical optimum design. The performance of the amorphous core is validated by the analysis and experiment by back-to-back tests considering the AC load. Rotor dynamics is performed for dynamic stability at high speed using transient analysis orbit diagrams and compared with the experimental results. The simulation results of the generator are compared with the experiment. Also a super high speed controller of the MTG system is developed using a sensorless algorithm, power stack, gate driver, digital signal processing, analog circuit, and radiation heat design. Based on these results, a high speed motor-generator and controller are successfully developed

  3. Development of a super high speed motor-generator and controller

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Do-Kwan, E-mail: dkhong@keri.re.kr; Ahn, Min-Hyuk; Joo, Dae-Suk; Woo, Byung-Chul; Koo, Dae-Hyun [Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of)

    2014-05-07

    To develop a super high speed motor-generator, it is essential to deal with magnetic analysis, dynamic analysis, and experimental evaluation of the heart of the MTG (Microturbine Generator) system, the motor-generator. An amorphous core is applied to a stator core for reduction of iron loss at high speed, and the motor-generator is analyzed with considerations focused on magnetic losses and the statistical optimum design. The performance of the amorphous core is validated by the analysis and experiment by back-to-back tests considering the AC load. Rotor dynamics is performed for dynamic stability at high speed using transient analysis orbit diagrams and compared with the experimental results. The simulation results of the generator are compared with the experiment. Also a super high speed controller of the MTG system is developed using a sensorless algorithm, power stack, gate driver, digital signal processing, analog circuit, and radiation heat design. Based on these results, a high speed motor-generator and controller are successfully developed.

  4. Development of a super high speed motor-generator and controller

    Science.gov (United States)

    Hong, Do-Kwan; Ahn, Min-Hyuk; Joo, Dae-Suk; Woo, Byung-Chul; Koo, Dae-Hyun

    2014-05-01

    To develop a super high speed motor-generator, it is essential to deal with magnetic analysis, dynamic analysis, and experimental evaluation of the heart of the MTG (Microturbine Generator) system, the motor-generator. An amorphous core is applied to a stator core for reduction of iron loss at high speed, and the motor-generator is analyzed with considerations focused on magnetic losses and the statistical optimum design. The performance of the amorphous core is validated by the analysis and experiment by back-to-back tests considering the AC load. Rotor dynamics is performed for dynamic stability at high speed using transient analysis orbit diagrams and compared with the experimental results. The simulation results of the generator are compared with the experiment. Also a super high speed controller of the MTG system is developed using a sensorless algorithm, power stack, gate driver, digital signal processing, analog circuit, and radiation heat design. Based on these results, a high speed motor-generator and controller are successfully developed.

  5. Breakdown and Evolution of the Protective Oxide Scales of AISI 304 and AISI 316 Stainless Steels under High-Temperature Oxidation

    Directory of Open Access Journals (Sweden)

    K. A. Habib

    2011-01-01

    Full Text Available The failure of the protective oxide scales of AISI 304 and AISI 316 stainless steels has been studied and compared at 1,000°C in synthetic air. First, the isothermal thermogravimetric curves of both stainless steels were plotted to determine the time needed to reach the breakdown point. The different resistance of each stainless steel was interpreted on the basis of the nature of the crystalline phases formed, the morphology, and the surface structure as well as the cross-section structure of the oxidation products. The weight gain of AISI 304 stainless steel was about 8 times greater than that of AISI 316 stainless steel, and AISI 316 stainless steel reached the breakdown point about 40 times more slowly than AISI 304 stainless steel. In both stainless steels, reaching the breakdown point meant the loss of the protective oxide scale of Cr2O3, but whereas in AISI 304 stainless steel the Cr2O3 scale totally disappeared and exclusively Fe2O3 was formed, in AISI 316 stainless steel some Cr2O3 persisted and Fe3O4 was mainly formed, which means that AISI 316 stainless steel is more resistant to oxidation after the breakdown.

  6. The study on the properties of AISI 4140 and AISI 1040 steel rods welded by friction welding

    OpenAIRE

    Thanee Toomprasen; Chawalit Thinvongpituk; Sukangkana Talangkun

    2014-01-01

    This paper is aimed to investigate the properties of joint between AISI 4140 and AISI 1040 welded by friction welding. The specimens were prepared in round shape of 13 mm diameter and 100 mm long. They were welded by friction welding method under the following conditions; friction pressure of 183 MPa, friction time of 12 sec, upset pressure of 428 MPa, upset time of 7 sec. and rotational speed of 1400 rpm. The strength and hardness were tested on the welded area. The result showed finer grain...

  7. High-speed testing of tandem-Banyan network switch component

    Science.gov (United States)

    Terai, Hirotaka; Kameda, Yoshio; Yorozu, Shinichi; Kawakami, Akira; Yoshikawa, Nobuyuki; Wang, Zhen

    2003-10-01

    We present the high-speed test results of a tandem-Banyan network switch (TBNS) component based on superconductor single-flux-quantum technology. The tested circuit is called a transmission checker (TMC) and is one component of the TBNS. The circuit was designed by using the CONNECT SFQ cell library developed for NEC standard fabrication technology. To perform the high-speed test, an on-chip test system composed of shift resisters and a high-speed clock generator were integrated together with the TMC circuit. The total number of Josephson junctions, including the on-chip test system, was 1545. We observed correct output waveforms at up to 40 GHz. The bias margin of the TMC circuit was ±6.1% up to 27 GHz and ±1.7% at 40 GHz.

  8. Method and Implementation of High-speed Digital Sampling Technology Based on Impulse Radar Signal

    Directory of Open Access Journals (Sweden)

    Shen Shao-xiang

    2012-06-01

    Full Text Available A High-speed digital sampling technology suitable for periodical impulse radar signal is proposed in this paper. One bit high-speed quantize is constructed by differential comparator in FPGA. Time-interleaved digital sampling and buffer encoding are used to one bit stream based on the internal multi-phase clock of FPGA, to achieve sampling rate higher than 1 GHz. High speed digital sampling is realized by the accumulation of one bit sampling data with different comparison levels. An 8 bit, 1.6 GHz ADC based on the proposed method is realized on XC2V3000 Xilinx’s FPGA, which is successfully applied in GPR. The proposed method has the advantages of low cost and power consumption as compared with real sampling, and exhibits higher efficiency as compared with equivalent sampling.

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

    Science.gov (United States)

    Weigle, Eric H.

    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.

  10. Cadence® High-Speed PCB Layout Flow Workshop

    CERN Document Server

    2003-01-01

    Last release of Cadence High-Speed PCB Design methodology (PE142) based on Concept-HDL schematic editor, Constraint Manager, SPECCTRAQuest signal integrity analysis tool and ALLEGRO layout associated with SPECCTRA auto router tools, is now enough developed and stable to be taken into account for high-speed board designs at CERN. The implementation of this methodology, build around the new Constraint Manager program, is essential when you have to develop a board having a lot of high-speed design rules such as terminated lines, large bus structures, maximum length, timing, crosstalk etc.. that could not be under control by traditional method. On more conventional designs, formal aspect of the methodology could avoid misunderstanding between hardware and ALLEGRO layout designers, minimizing prototype iteration, development time and price. The capability to keep trace of the original digital designer intents in schematic or board layout, loading formal constraints in EDMS, could also be considered for LHC electro...

  11. Cadence® High High-Speed PCB Design Flow Workshop

    CERN Document Server

    2006-01-01

    Last release of Cadence High-Speed PCB Design methodology (PE142) based on Concept-HDL schematic editor, Constraint Manager, SPECCTRAQuest signal integrity analysis tool and ALLEGRO layout associated with SPECCTRA auto router tools, is now enough developed and stable to be taken into account for high-speed board designs at CERN. The implementation of this methodology, build around the new Constraint Manager program, is essential when you have to develop a board having a lot of high-speed design rules such as terminated lines, large bus structures, maximum length, timing, crosstalk etc.. that could not be under control by traditional method. On more conventional designs, formal aspect of the methodology could avoid misunderstanding between hardware and ALLEGRO layout designers, minimizing prototype iteration, development time and price. The capability to keep trace of the original digital designer intents in schematic or board layout, loading formal constraints in EDMS, could also be considered for LHC electro...

  12. TEST METHOD OF HIGH-SPEED ON-OFF VALVE DYNAMIC CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    According to the valve port features of high speed on-offvalve and its actions, the valve port can be simplified into an a-type half bridge construction. A method that tests the dynamic characteristics of the high speed on-off valve by the output pressure signal of the a-type half bridge is proposed. Having analyzed the factors related to the dynamic characteristics of an a-type half bridge, a rule for designing the outlet chamber's volume is worked out. According to the rule, a test stand is built to test the self-developed high-speed on-off valve. From the test results, it can be seen that with the outlet chamber's volume controlled by the rule the rise time of the pressure signals driven by signals with different frequencies changes very little. The test results conform to the simulation results, which proves the correctness of the method.

  13. High-speed testing of tandem-Banyan network switch component

    International Nuclear Information System (INIS)

    We present the high-speed test results of a tandem-Banyan network switch (TBNS) component based on superconductor single-flux-quantum technology. The tested circuit is called a transmission checker (TMC) and is one component of the TBNS. The circuit was designed by using the CONNECT SFQ cell library developed for NEC standard fabrication technology. To perform the high-speed test, an on-chip test system composed of shift resisters and a high-speed clock generator were integrated together with the TMC circuit. The total number of Josephson junctions, including the on-chip test system, was 1545. We observed correct output waveforms at up to 40 GHz. The bias margin of the TMC circuit was ±6.1% up to 27 GHz and ±1.7% at 40 GHz

  14. The impact of personality on driving safety among Chinese high-speed railway drivers.

    Science.gov (United States)

    Guo, Ming; Wei, Wei; Liao, Ganli; Chu, Fulei

    2016-07-01

    This study explored the impact of personality traits on driving safety in high-speed railway drivers. A sample of high-speed railway drivers in Beijing (N=214) completed a questionnaire, including information on personality traits and background variables. The NEO Five Factor Inventory (NEO-FFI) was administered to characterize participants based on five personality traits: Neuroticism, Extraversion, Agreeableness, Openness to Experience, and Conscientiousness. The survey data were combined with naturalistic data of accident involvement and risky driving behavior in China. Poisson regression results show that drivers with high Conscientiousness and Extraversion caused fewer accidents. Higher Conscientiousness and lower Agreeableness were related to less frequent risky driving behavior. Education level and age negatively moderated the relation between certain personality traits and driving safety. The findings suggest that personality traits should be considered when selecting and training high-speed railway drivers.

  15. Research Progress of Key Technology of High-Speed and High Precision Motorized Spindles

    Institute of Scientific and Technical Information of China (English)

    XIONG Wan-li; MI Hai-qing; HUANG Hon-gwu

    2005-01-01

    High speed machining and high precision machining are two tendencies of the manufacturing technology worldwide. The motorized spindle is the core component of the machine tools for achieving the high speed and high precise machining, which affects the general development level of the machine tools to a great extent. Progress of the key techniques is reviewed in this paper, in which the high speed and high precision spindle bearings, the dynamical and thermal characteristics of spindles, the design technique of the high frequency motors and the drivers, the anti-electromagnetic damage technique of the motors, and the machining and assembling technique are involved. Finally, tha development tendencies of the motorized spindles are presented.

  16. Design and VHDL simulation of a special high speed spaceborne bus controller

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The application of high speed data bus on the satellites having several remote sensors could not only satisfy the demand of high speed data transfer,but also could reuse the equipment at both the com-ponent and subsystem levels for other space missions,thus reducing the costs of on-board processing system integration.In this article,a special high speed data bus with simple interfaces is chosen for transferring the data produced by remote sensors and other instrumentations.First,the function and the structure of the data bus are discussed carefully.And then,the bus controller,which is a key mod-ule of the data bus,is designed.At last,the function and performance of the bus controller are verified by VHDL simulation.

  17. 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.

  18. Research on cubic polynomial acceleration and deceleration control model for high speed NC machining

    Institute of Scientific and Technical Information of China (English)

    Hong-bin LENG; Yi-jie WU; Xiao-hong PAN

    2008-01-01

    To satisfy the need of high speed NC (numerical control) machining, an acceleration and deceleration (aec/dec) control model is proposed, and the speed curve is also constructed by the cubic polynomial. The proposed control model provides continuity of acceleration, which avoids the intense vibration in high speed NC machining. Based on the discrete characteristic of the data sampling interpolation, the acc/dec control discrete mathematical model is also set up and the discrete expression of the theoretical deceleration length is obtained furthermore. Aiming at the question of hardly predetermining the deceleration point in acc/dec control before interpolation, the adaptive acc/dec control algorithm is deduced from the expressions of the theoretical deceleration length. The experimental result proves that the acc/dec control model has the characteristic of easy implementation, stable movement and low impact. The model has been applied in multi-axes high speed micro fabrication machining successfully.

  19. Impact of Loss Synchronization on Reliable High Speed Networks: A Model Based Simulation

    Directory of Open Access Journals (Sweden)

    Suman Kumar

    2014-01-01

    Full Text Available Contemporary nature of network evolution demands for simulation models which are flexible, scalable, and easily implementable. In this paper, we propose a fluid based model for performance analysis of reliable high speed networks. In particular, this paper aims to study the dynamic relationship between congestion control algorithms and queue management schemes, in order to develop a better understanding of the causal linkages between the two. We propose a loss synchronization module which is user configurable. We validate our model through simulations under controlled settings. Also, we present a performance analysis to provide insights into two important issues concerning 10 Gbps high speed networks: (i impact of bottleneck buffer size on the performance of 10 Gbps high speed network and (ii impact of level of loss synchronization on link utilization-fairness tradeoffs. The practical impact of the proposed work is to provide design guidelines along with a powerful simulation tool to protocol designers and network developers.

  20. FPGA based High Speed Data Acquisition System for High Energy Physics Application

    CERN Document Server

    Mandal, Swagata; Chakrabarti, Amlan; Chattopadhyay, Subhasis

    2015-01-01

    In high energy physics experiments (HEP), high speed and fault resilient data communication is needed between detectors/sensors and the host PC. Transient faults can occur in the communication hardware due to various external effects like presence of charged particles, noise in the environment or radiation effects in HEP experiments and that leads to single/multiple bit error. In order to keep the communication system functional in such a radiation environment where direct intervention of human is not possible, a high speed data acquisition (DAQ) architecture is necessary which supports error recovery. This design presents an efficient implementation of field programmable gate array (FPGA) based high speed DAQ system with optical communication link supported by multi-bit error correcting model. The design has been implemented on Xilinx Kintex-7 board and is tested for board to board communication as well as for PC communication using PCI (Peripheral Component Interconnect express). Data communication speed up...

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

    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 highspeed 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. Case modifying of high-speed cutting database based on CSP and similarity theory

    Institute of Scientific and Technical Information of China (English)

    Kejun XIANG; Zhanqiang LIU; Xing AI

    2009-01-01

    By analyzing the reasoning of a high-speed cutting database system, a case modifying method is put forward. According to the variables' difference of the solution part in a case, a constraint satisfaction problem (CSP) and similarity calculation are used to modify a case. The constraint relationship of discrete variables is described by establishing a rule knowledge base. The algorithm of CSP is used to solve the discrete variable constraint problem. On the basis of the high-speed cutting theory, a similarity calculation formula is deduced to calculate the consecutive variables. The CSP and similarity calculation are applied to case modifying, which is possible to automatically modify cases in the high-speed cutting database system.

  3. Recent standardization directions for high-speed client and line side components

    Science.gov (United States)

    Isono, Hideki

    2016-03-01

    Triggered by the recent vast demands of the information bandwidth, high speed transmission networking system, such as 100G/400G, have been developed and installed with extremely high speed. In order to lead the proper concept/design of the leading edge optical components which is applied for these high speed networking equipment, de-fact standardization bodies such as IEEE802.3/OIF have made important roles in the industry. The demands of the bandwidth will still continue to increase with endless degree, and therefore the future migration towards higher speed transceivers such as 1T class, and also towards the smaller form factor transceivers is absolutely inevitable, and to be examined.

  4. Application of High-speed Solenoid Valve to the Semi-active Control of Landing Gear

    Institute of Scientific and Technical Information of China (English)

    Liu Hui; Gu Hongbin; Chen Dawei

    2008-01-01

    To select or develop an appropriate actuator is one of the key and difficult issues in the study of semi-active controlled landing gear.Performance of the actuator may directly affect the effectiveness of semi-active control.In this article,parallel high-speed solenoid valves are chosen to be the actuators for the semi-active controlled landing gear and being studied.A nonlinear high-speed solenoid valve model is developed with the consideration of magnctic saturation characteristics and verified by test.According to the design rule of keeping the peak load as small as possible while absorbing the specified shock energy,a fuzzy PD control rule is designed.By the rule,controller parameters can be self-regulated.The simulation results indicate that the semi-active control based on high-speed solenoid valve can effectively improve the control performance and reduce impact load during landing.

  5. The impact of personality on driving safety among Chinese high-speed railway drivers.

    Science.gov (United States)

    Guo, Ming; Wei, Wei; Liao, Ganli; Chu, Fulei

    2016-07-01

    This study explored the impact of personality traits on driving safety in high-speed railway drivers. A sample of high-speed railway drivers in Beijing (N=214) completed a questionnaire, including information on personality traits and background variables. The NEO Five Factor Inventory (NEO-FFI) was administered to characterize participants based on five personality traits: Neuroticism, Extraversion, Agreeableness, Openness to Experience, and Conscientiousness. The survey data were combined with naturalistic data of accident involvement and risky driving behavior in China. Poisson regression results show that drivers with high Conscientiousness and Extraversion caused fewer accidents. Higher Conscientiousness and lower Agreeableness were related to less frequent risky driving behavior. Education level and age negatively moderated the relation between certain personality traits and driving safety. The findings suggest that personality traits should be considered when selecting and training high-speed railway drivers. PMID:27035394

  6. Dynamics of high speed wheel/rail system and its modelling

    Institute of Scientific and Technical Information of China (English)

    ZHANG ShuGuang; ZHANG WeiHua; JIN XueSong

    2007-01-01

    With the fast increasing of train speed the interactions among the train, the track, and the power catenary system become very strong. Such interactions are also strongly coupled with the action of high speed airflow due to the high speed running. Hence, the existing research methods and numerical algorithms of railway vehicle/track systems are not fully available for characterizing the transient dynamic and long-term behaviors of train/track at higher speed. The present paper reviews the existing studies on coupling dynamics of railway vehicle/track, and clarifies their advantages and disadvantages and then puts forward an innovation stratagem for high speed railway based on rolling contact of wheel/rail systems. In the innovation stratagem, a comprehensive dynamic model of wheels/rails systems is developed to simultaneously consider the track system, the train, the rolling contact of wheel/rail, the catenary/pantograph system, and the high speed airflow with the train. The motion equations of the subsystems and their coupling boundaries are given and discussed. For the reliability and safety of the high speed train in service, the long-term behavior of the structures of the train and the track is considered in the comprehensive model. Moreover, a generalized failure model, considering the structures and the materials and working in the comprehensive dynamic model of wheels/rails system, as well as the simulation system of structure failure of the high speed train/track is established.Consequently, the present studies on the dynamics of the coupled vehicle/track will be further and largely extended.

  7. Combustion performance of flame-ignited high-speed train seats via full-scale tests

    Directory of Open Access Journals (Sweden)

    Jie Zhu

    2015-10-01

    Full Text Available Determining the combustion characteristics of combustibles in high-speed trains is the foundation of evaluating the fire hazard on high-speed trains scientifically, and establishing effective active and passive fire precautions. In this study, the double seats in the compartments of CRH1 high-speed trains were used as the main research object. Under different test conditions, including the power of ignition sources and ventilation rates, full-scale furniture calorimeter tests were conducted to study important fire combustion characteristics such as the ignition characteristics of seats, heat release rate, mass loss rate, total heat release, temperature variation, and smoke release rate. The relationships among these parameters were analyzed and summarized into combustion behavior and characteristics, thus providing fundamental data and reference for the development of fire precautions and safety design of high-speed trains. The results in this test are as follows: (i The double seats of high-speed trains are relatively easy to ignite and susceptible to the fire ground environment. (ii The combustion temperature in the test apparatus exceeded 600 °C in only 2 min for the larger ignition source. (iii The heat release rate exceeded 800 kW. (iv The total heat release resulted mainly from flame combustion. (v The final mass loss rate was ∼30%. (vi The lowest light transmittance was <25%. (vii The change process of temperature with time has the same trend as the change process of heat release rate. (viii Suppressing flame combustion and controlling the smoke generated from the seat materials themselves played key roles in retarding the combustion of high-speed train seats.

  8. High-speed imaging of sound using parallel phase-shifting interferometry.

    Science.gov (United States)

    Ishikawa, Kenji; Yatabe, Kohei; Chitanont, Nachanant; Ikeda, Yusuke; Oikawa, Yasuhiro; Onuma, Takashi; Niwa, Hayato; Yoshii, Minoru

    2016-06-13

    Sound-field imaging, the visualization of spatial and temporal distribution of acoustical properties such as sound pressure, is useful for understanding acoustical phenomena. This study investigated the use of parallel phase-shifting interferometry (PPSI) with a high-speed polarization camera for imaging a sound field, particularly high-speed imaging of propagating sound waves. The experimental results showed that the instantaneous sound field, which was generated by ultrasonic transducers driven by a pure tone of 40 kHz, was quantitatively imaged. Hence, PPSI can be used in acoustical applications requiring spatial information of sound pressure. PMID:27410311

  9. 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. PMID:26611054

  10. Advances in high-speed communications on and off the Internet

    CERN Document Server

    Carpenter, Brian E

    1998-01-01

    The lectures will review some of the basics of data communication and some of the underlying constraints on effective high speed transmission. With this background, several current developments in practical high speed data transmission will be reviewed, including Gigabit Ethernet. Real-world limits on achieved throughput on all scales up to that of the world-wide Internet will be discussed, along with new techniques being developed to cope with massive traffic scaling on the Internet. Finally, we will look at what may lie ahead in all-optical data networks.

  11. High speed short range optical wireless ground-to-train communications

    OpenAIRE

    Paudel, Rupak; Le Minh, Hoa; Ghassemlooy, Zabih; Rajbhandari, Sujan

    2010-01-01

    There is a huge demand for seamless high-speed communications in fast moving trains. People want broadband services while on board as in their home or in the workplace. This demand drives the motivation for a high speed dedicated optical wireless link. Here we propose a free space optical ground-to-train communications system which consists of optical transceivers placed on the train and along the railway track. A mathematical model for three different scenarios when the train is moving has b...

  12. Performance Analysis of DRA Based OFDM Data Transmission With Respect to Novel High Speed RS Decoding

    Directory of Open Access Journals (Sweden)

    Dr. S. V. A. V Prasad

    2015-02-01

    Full Text Available In this paper, we have analyzed the performance characteristics of OFDM data transmission with regard to a new high speed RS decoding algorithm. The various characteristics identified are mainly speed and accuracy of the transmission irrespective of channel behaviour. We consider two cases viz. data transmission without error control and data transmission with error control. Each of these cases are duly analyzed and it is proven that high speed RS decoding algorithms can actually benefit OFDM data transmission for advanced communication systems only if implemented at the hardware (VLSI level because of significant processing overhead involved in software based implementation even though the algorithm may have lower computational complexity.

  13. EXPERIMENTAL STUDY ON HIGH-SPEED CENTRIFUGAL PUMPS WITH DIFFERENT IMPELLERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The experimental study is carded out on high-speed centrifugal pumps with three different impellers. The ex-perimental results and analysis show that high-speed centrifugal pumps with a closed complex impeller can achieve thehighest efficiency and the lowest head coefficient followed by those with half-open impeller and open-impeller, and canobtain much easily stable head-capacity characrastic curve, while those with a half-open complex impeller can't. Thecharacteristic curve with a open impeller is almost constant horizontal line before dropping sharply. The results also showthat the axial clearance between pump casing and impeller can influence greatly on the performance of centrifugal pumps.

  14. Study on High-Speed Centrifugal-Regenerative Pump with an Inducer

    Institute of Scientific and Technical Information of China (English)

    朱祖超; 陈鹰; 金庆明; 黄敦回

    2002-01-01

    The study on high-speed centrifugal-regenerative pumps with an inducer (HCRP) is carried out. Thecombined structure of inducer, centrifugal impeller, and regenerative impeller is presented, and a theoretical parallelcombinatorial hydraulic design method is investigated. The comparative experimental results show that efficiency insmaller capacity region, head coefficient and efficiency in larger capacity region of HCRPs is few lower, much higherand lower than those of high-speed centrifugal pumps, respectively, anci that the suction performance of HCRPs isdetermined only by inducer. HCRPs can be more suitably applied to deliver small-capacity high-head liquids inchemical and petrochemical industries.

  15. System design of the traction power supply for the high-speed line Beijing - Tianjin

    Energy Technology Data Exchange (ETDEWEB)

    Altmann, Martin; Fischer, Andreas; Tornow, Torsten [Siemens AG, Erlangen (Germany)

    2011-11-15

    The high-speed line Beijing - Tianjin connecting the Capital Beijing with the harbour city Tianjin is the first high-speed line in China dedicated only to passenger traffic and is operated at 300 km/h. The commercial service started in due time for the Olympic games in 2008. For the system design and a reliable traction power supply the simulation software Sitras {sup registered} Sidytrac was used. The program incorporates all modules necessary for the overall system design and relating detailed investigations. Measurements during system integration test validated the simulation results. (orig.)

  16. 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.)

  17. High Speed Multiple Valued Logic Full Adder Using Carbon Nano Field Effect Transistor

    Directory of Open Access Journals (Sweden)

    Ashkan Khatir

    2011-03-01

    Full Text Available High speed Full-Adder (FA module is a critical element in designing high performance arithmeticcircuits. In this paper, we propose a new high speed multiple-valued logic FA module. The proposed FAis constructed by 14 transistors and 3 capacitors, using carbon nano-tube field effect transistor (CNFETtechnology. Furthermore, our proposed technique has been examined in different voltages (i.e., 0.65v and0.9v. The observed results reveal power consumption and power delay product (PDP improvementscompared to existing FA counterparts.

  18. Experimental study on hydrodynamic behaviors of high-speed gas jets in still water

    Institute of Scientific and Technical Information of China (English)

    Zhenqing Dai; Boyi Wang; Longxi Qi; Honghui Shi

    2006-01-01

    The present paper describes experimental investigation on the flow pattern and hydrodynamic effect of underwater gas jets from supersonic and sonic nozzles operated in correct- and imperfect expansion conditions. The flow visualizations show that jetting is the flow regime for the submerged gas injection at a high speed in the parameter range under consideration. The obtained results indicate that high-speed gas jets in still water induce large pressure pulsations upstream of the nozzle exit and the presence of shock-cell structure in the over-and under-expanded jets leads to an increase in the intensity of the jet-induced hydrodynamic pressure.

  19. An engineer's guide to automated testing of high-speed interfaces

    CERN Document Server

    Moreira, Jose

    2010-01-01

    Providing a complete introduction to the state-of-the-art in high-speed digital testing with automated test equipment (ATE), this practical resource is the first book focus exclusively on this increasingly important topic. Featuring clear examples, this one-stop reference covers all critical aspects of the subject, from high-speed digital basics, ATE instrumentation for digital applications, and test and measurements, to production testing, support instrumentation and text fixture design. This in-depth volume also discusses at advanced ATE topics, such as multiplexing of ATE pin channels and t

  20. Signal waveform design to detect an underwater high-speed small target

    Institute of Scientific and Technical Information of China (English)

    YANG Chonglin; YAO Lan

    2002-01-01

    The problem of sonar signal waveform design to detect a high-speed small target in an underwater environment is discussed. From theoretical analysis, time-frequency hop signal is regarded as the most suitable signal waveform in this application. To get precise target parameter estimation ability, the signal should have high range-Doppler resolution performance.The results of signal analysis show that hop signal with frequency serial coding as Costas array has sharp ambiguity characteristic, so it can be used in an active sonar system to detect a high speed small target. A scheme of frequency coding is also presented.

  1. 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

  2. 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

  3. Analysis and Simulations of Inertia Force in Ultra High Speed Stamping Machine

    Directory of Open Access Journals (Sweden)

    Jianyu Bai

    2010-12-01

    Full Text Available Based on analysis and simulations, it is found that extremely high inertia forces will be generated in stamping machine when stroke speed falls in range for ultra high speed stamping machine if a regular crank-slider mechanism is used. This paper presents a design method to lower the inertia forces by using balancing structure. The effectiveness of the proposed structure is validated through simulations. An analytical method to evaluate performance of balancing structure is also presented. This work paves the way to develop ultra high speed stamping machine.

  4. Investigation of monitoring system for high-speed railway subgrade frost heave

    Institute of Scientific and Technical Information of China (English)

    GuoTao Yang; ZaiTian Ke; DeGou Cai; HongYe Yan; JianPing Yao; Feng Chen

    2015-01-01

    This paper presents methods for monitoring frost heave, device requirements, testing principals, and data analysis re-quirements, such as manual leveling observation, automatic monitoring (frost heave, frost depth, and moisture), track dynamic detection, and track status detection. We focused on the requirements of subgrade frost heave monitoring for high speed railways, and the relationship of different monitoring methods during different phases of the railway. The com-prehensive monitoring system of high speed railway subgrade frost heave provided the technical support for dynamic design during construction and safe operation of the rail system.

  5. High-speed countercurrent chromatography for purification of single-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Ying Cai; Zhi Hong Yan; Ying Chun Lv; Min Zi; Li Ming Yuan

    2008-01-01

    A new chromatographic purification of single-walled carbon nanotubes using high-speed countercurrent chromatography is reported.The purification was accomplished on the basis of experiment that dispersed the single-walled carbon nanotubes with sodium dodecyl sulfate,and the result mixture was separated using the two phase system composed of n-butanol/water=1/1 (v/v).The sizes of SWNTs separated were observed by scanning electron microscopy.The results demonstrated that the high-speed countercurrent chromatography possessed a good efficency for purification of single-walled carbon nanotubes.

  6. Colloquium on Large Scale Improvement: Implications for AISI

    Science.gov (United States)

    McEwen, Nelly, Ed.

    2008-01-01

    The Alberta Initiative for School Improvement (AISI) is a province-wide partnership program whose goal is to improve student learning and performance by fostering initiatives that reflect the unique needs and circumstances of each school authority. It is currently ending its third cycle and ninth year of implementation. "The Colloquium on Large…

  7. Influence of oil and water media on fretting behaviour of AISI 52100 steel rubbing against AISI 1045 steel

    Institute of Scientific and Technical Information of China (English)

    REN Ping-di; CHEN Guang-xiong; ZHU Min-hao; ZHOU Zhong-rong

    2004-01-01

    A series of fretting test were carried out using a DELTA PLINT testing system to study the influence of hydraulic oil and water on fretting behaviour of AISI 52100 steel rubbing against AISI 1045 steel. The test result shows that media hydraulic oil and water have a distinct influence on fretting behaviour of the tested materials. Medium water can lead to shifting of the partial slip regime in the fretting map from a larger displacement amplitude toward a smaller one and enlargement of the mixed slip regime, in comparison with that in ambient atmosphere. While medium hydraulic oil can result in shifting of the partial slip regime from a smaller displacement amplitude toward a larger one. In the gross slip regime, hydraulic oil and water play a positive role as lubrication media. They can clearly decrease the fretting friction coefficient between AISI 52100 and AISI 1045. The test result also demonstrates that this lubrication effect will get better with increasing displacement amplitude and that hydraulic oil is better than water for lubrication. SEM observation of the wear scars displays that the fretting wear mainly results from abrasive wear and delamination of the fretted materials when using these two kinds of substances as lubrication media.

  8. The study on the properties of AISI 4140 and AISI 1040 steel rods welded by friction welding

    Directory of Open Access Journals (Sweden)

    Thanee Toomprasen

    2014-06-01

    Full Text Available This paper is aimed to investigate the properties of joint between AISI 4140 and AISI 1040 welded by friction welding. The specimens were prepared in round shape of 13 mm diameter and 100 mm long. They were welded by friction welding method under the following conditions; friction pressure of 183 MPa, friction time of 12 sec, upset pressure of 428 MPa, upset time of 7 sec. and rotational speed of 1400 rpm. The strength and hardness were tested on the welded area. The result showed finer grains. in the welded area. This is the result of friction pressure and upset pressure in the welding process. In addition, the observation result indicated some changes of Ferrite and Pearlite in welded zone. This phase change resulted in the increment of hardness in AISI 4140 at the contact area and adjacent. In part of AISI 1040, the portion of Pearlite and Ferrite are not significantly changed, therefore the value of hardness is almost constant.

  9. A comparative study of mechanical and tribological properties of AISI-304 and AISI-316 submitted to glow discharge nitriding

    Directory of Open Access Journals (Sweden)

    Fabiana Cristina Nascimento

    2009-06-01

    Full Text Available Mechanical and tribological properties os AISI 304 and AISI 316 stainless steels submited to glow discharge ion nitriding are reported.The atmosphere was 20:80 - N2:H2 with substrate temperatures ranging from 300 to 500 °C. Treatment at 300 °C produced expanded austenite (γN in both steels. Increasing the temperature, the phases γ´-Fe4N and - Fe2+xN were present and the latter is the major phase for AISI 304. At 500 °C, the CrN phase was also identified in both steels. Hardnesses of about 13-14 GPa at near surface regions were obtained in both steels. Moreover, AISI 316 nitrided at 500 °C has the deepest hard layer. Tribological tests showed that wear can be reduced by up to a factor of six after the nitriding processes, even for a working temperature of 300 °C. The profiles during and after nanoscratch tests did not reveal significant differences after nitriding processes in both steels.

  10. Multiple M2-Branes and Plane Waves

    OpenAIRE

    Blau, Matthias; O'Loughlin, Martin

    2008-01-01

    We propose a natural generalisation of the BLG multiple M2-brane action to membranes in curved plane wave backgrounds, and verify in two different ways that the action correctly captures the non-trivial space-time geometry. We show that the M2 to D2 reduction of the theory along a non-trivial direction in field space is equivalent to the D2-brane world-volume Yang-Mills theory with a non-trivial (null-time dependent) dilaton in the corresponding IIA background geometry. As another consistency...

  11. Bitumen/Water Emulsions as Fuels for High-Speed Ci Engines Preliminary Investigations

    DEFF Research Database (Denmark)

    Schramm, Jesper; Sigvardsen, R.; Forman, M.

    2003-01-01

    Mixtures of bitumen and water, are cheap fuel alternatives for combustion engines. There are, however, several problems that have to be solved before these fuels can be applied in high-speed diesel engines. These are: - emulsion break up due to high temperature or high shear stress in the injecti...

  12. Serum induced degradation of 3D DNA box origami observed by high speed atomic force microscope

    DEFF Research Database (Denmark)

    Jiang, Zaixing; Zhang, Shuai; Yang, Chuanxu;

    2015-01-01

    DNA box origami in serum using high-speed atomic force microscope optimized for imaging 3D DNA origami in real time. The time resolution allows characterizing the stages of serum effects on individual 3D DNA box origami with nanometer resolution. Our results indicate that the whole digest process...

  13. Trim, Control, and Performance Effects in Variable-Complexity High-Speed Civil transport Design

    OpenAIRE

    MacMillin, Peter Edward

    1996-01-01

    Numerous trim, control requirements and mission generalizations have been made to our previous multidisciplinary design methodology for a high speed civil transport. We optimize the design for minimum take off gross weight, including both aerodynamics and structures to find the wing planform and thickness distribution, fuselage shape, engine placement and thrust, using 29 design variables. While adding trim and c...

  14. HIGH SPEED STEEL TOOL WEAR AFTER WOOD MILLING IN THE PRESENCE OF HIGH TEMPERATURE TRIBOCHEMICAL REACTIONS

    Directory of Open Access Journals (Sweden)

    B. Porankiewicz

    2008-08-01

    Full Text Available Wear patterns were analyzed for High Speed Steel (HSS SKH51 cutting tools after milling wood of four wood species having very different High Temperature Tribochemical Reactions (HTTR, wood density and very low hard mineral contamination (HMC. The experimental results showed that the HTTR can be an important factor influencing acceleration of cutting tool wear.

  15. High-speed spinning of ultra-high molecular weight polyethylene fibres

    NARCIS (Netherlands)

    Roukema, Mees

    1991-01-01

    This thesis deals with the spinning of ultra-high molecular weight polyethylene ( UHMWPE ) fibres at high speeds, and the effects of the spinning parameters on the fibre properties. Polyethylene fibres with strengths up to 7.2 GPa can be produced in a gel-spinning and hot-drawing procedure. In this

  16. Fiber and yarn properties from high-speed roller ginning of upland cotton

    Science.gov (United States)

    Selective breeding has improved upland cotton fiber properties. New high-speed roller ginning technology has advanced to the point that processing capacities have approached that of saw ginning. Producers seeking a better price for their upland cotton are interested in fiber property and textile m...

  17. High-speed multiple-channel analog to digital data-acquisition module for microprocessor systems

    International Nuclear Information System (INIS)

    Intelligent data acquisition and instrumentation systems established by the incorporation of microprocessor technology require high-speed analog to digital conversion of multiple-channel input signals. Sophisticated data systems or subsystems are enabled by the microprocessor software flexibility to establish adaptive input data procedures. These adaptive procedures are enhanced by versatile interface circuitry which is software controlled

  18. Using a High-Speed Camera to Measure the Speed of Sound

    Science.gov (United States)

    Hack, William Nathan; Baird, William H.

    2012-01-01

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

  19. High speed product development in the Danish electronics industry. A theorethical framework and some empirical evidence

    DEFF Research Database (Denmark)

    Bjarnø, Ole-Christian

    1992-01-01

    This paper deals with an investigation of high speed product development. The idea has been to create a basis for practical procedures for management of fast-responding organisations, and the work here is a part of this target. The investigation starts with a review of the literature. Based...

  20. Limits, modeling and design of high-speed permanent magnet machines

    NARCIS (Netherlands)

    Borisavljevic, A.

    2011-01-01

    There is a growing number of applications that require fast-rotating machines; motivation for this thesis comes from a project in which downsized spindles for micro-machining have been researched (TU Delft Microfactory project). The thesis focuses on analysis and design of high-speed PM machines and

  1. Reliability analysis of the fire protection lining in the high speed train tunnel 'Groene Hart'

    NARCIS (Netherlands)

    Krom, A.H.M.; Wit, S. de

    2006-01-01

    Sprayed fire protection linings in bored. high speed train tunnels are a new lield ol application. Questions çere raised on lhe failure probability of the lining during the sen,ice life of the Groene Hart tunnel. The fire protection Iining is reinforced with a wire mcsh fixed to the tunnel lining, A

  2. Fuzzy Constrained Predictive Optimal Control of High Speed Train with Actuator Dynamics

    Directory of Open Access Journals (Sweden)

    Xi Wang

    2016-01-01

    Full Text Available We investigate the problem of fuzzy constrained predictive optimal control of high speed train considering the effect of actuator dynamics. The dynamics feature of the high speed train is modeled as a cascade of cars connected by flexible couplers, and the formulation is mathematically transformed into a Takagi-Sugeno (T-S fuzzy model. The goal of this study is to design a state feedback control law at each decision step to enhance safety, comfort, and energy efficiency of high speed train subject to safety constraints on the control input. Based on Lyapunov stability theory, the problem of optimizing an upper bound on the cruise control cost function subject to input constraints is reduced to a convex optimization problem involving linear matrix inequalities (LMIs. Furthermore, we analyze the influences of second-order actuator dynamics on the fuzzy constrained predictive controller, which shows risk of potentially deteriorating the overall system. Employing backstepping method, an actuator compensator is proposed to accommodate for the influence of the actuator dynamics. The experimental results show that with the proposed approach high speed train can track the desired speed, the relative coupler displacement between the neighbouring cars is stable at the equilibrium state, and the influence of actuator dynamics is reduced, which demonstrate the validity and effectiveness of the proposed approaches.

  3. High-speed kymography identifies the immediate effects of voiced vibration in healthy vocal folds

    Directory of Open Access Journals (Sweden)

    Pimenta, Regina Aparecida

    2013-01-01

    Full Text Available Introduction: The effects of voiced vibration technique can be assessed by laryngeal imaging. Kymographic images derived from high-speed videoendoscopy allow actual visualization of vocal folds vibration. Purpose: The aim of this study is to identify the immediate effects of the voiced vibration technique in healthy vocal folds using high-speed digital laryngeal imaging. Methods: Samples were obtained from 15 healthy subjects with no history of voice disorders (6 men and 9 women aged 21 to 43 years. High-speed videoendoscopy recordings were performed before and after the voiced vibration technique. Kymographic images were obtained using high-speed videoendoscopy. The vocal folds were examined in their open and closed positions and the characteristics of the opening and closing phases were determined. A customize computational routine was used quantify these parameters. The closing, opening, and speed quotients were also calculated. Results: In this study, women displayed statistically significant differences in opened phase (P= 0.05*, closed phase (P= 0.046*, and closing phase (P= 0.026* phase characteristics. Men displayed the highest difference rate in opening time characteristics (P= 0.06. The closing and opening quotients for the female group showed significant differences (P= 0.029* and P= 0.049*, respectively. The speed quotient exhibited statistically significant differences in the male group (P= 0.048*. Conclusion: The kymographic images indicated that the immediate effect of the voiced vibration technique was smooth contact in healthy vocal fold vibration.

  4. USB-based high-speed multi-channel pulse analysis system

    International Nuclear Information System (INIS)

    It introduces a 4096 channels high-speed multi-channel pulse analyzer, which consists of micro controller as the core, pulse peak sampler, low-power A/D converter and dual-port RAM. The system shortened the analyzer response time and improves the measurement accuracy. Interface with the computer using USB data communication, characterized by transmission speed and versatility. (authors)

  5. Pose Measurement Method and Experiments for High-Speed Rolling Targets in a Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Zhenyuan Jia

    2014-12-01

    Full Text Available High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  6. Reconfigurable Forward Error Correction Decoder for Beyond 100 Gbps High Speed Optical Links

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Zibar, Darko;

    2015-01-01

    In this paper we propose a reconfigurable forward error correction decoder for beyond 100 Gbps high speed optical links. The decoders for product codes can be configured to support the applications at a rate of a multiple of 100 Gbps, which provides the flexibility and scalability....

  7. Programs for high-speed Fourier, Mellin and Fourier-Bessel transforms

    Science.gov (United States)

    Ikhabisimov, D. K.; Debabov, A. S.; Kolosov, B. I.; Usikov, D. A.

    1979-01-01

    Several FORTRAN program modules for performing one-dimensional and two-dimensional discrete Fourier transforms, Mellin, and Fourier-Bessel transforms are described along with programs that realize the algebra of high speed Fourier transforms on a computer. The programs can perform numerical harmonic analysis of functions, synthesize complex optical filters on a computer, and model holographic image processing methods.

  8. Modeling of dislocation generation and interaction during high-speed deformation of metals

    DEFF Research Database (Denmark)

    Schiøtz, J.; Leffers, T.; Singh, B.N.

    2002-01-01

    at very high strain rates. We have used molecular-dynamics simulations to investigate high-speed deformation of copper crystals. Even though no pre-existing dislocation sources are present in the initial system, dislocations are quickly nucleated and a very high dislocation density is reached during...

  9. 3D organization of high-speed compressible jets by tomographic PIV

    NARCIS (Netherlands)

    Violato, D.; Ceglia, G.; Tuinstra, M.; Scarano, F.

    2013-01-01

    This work investigates the three dimensional organization of compressible jets at high-speed regime by tomographic particle image velocimetry (TOMO PIV). Experiments are conducted at Mach numbers 0.3, 0.9 and 1.1 (underexpanded regime) across the end of the potential core within a large cylindrica

  10. Nanostructured tracers for laser-based diagnostics in high-speed flows

    NARCIS (Netherlands)

    Ghaemi, S.; Schmidt-Ott, A.; Scarano, F.

    2010-01-01

    The potential application of aggregates of nanoparticles for high-speed flow diagnostics is investigated. Aluminum nanoparticles around 10 nm in diameter are produced by spark discharge in argon gas. Through rapid coagulation and oxidation, aggregates of small effective density are formed. They are

  11. Evaluation of Dynamic Load Factors for a High-Speed Railway Truss Arch Bridge

    Directory of Open Access Journals (Sweden)

    Ding Youliang

    2016-01-01

    Full Text Available Studies on dynamic impact of high-speed trains on long-span bridges are important for the design and evaluation of high-speed railway bridges. The use of the dynamic load factor (DLF to account for the impact effect has been widely accepted in bridge engineering. Although the field monitoring studies are the most dependable way to study the actual DLF of the bridge, according to previous studies there are few field monitoring data on high-speed railway truss arch bridges. This paper presents an evaluation of DLF based on field monitoring and finite element simulation of Nanjing DaShengGuan Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The DLFs in different members of steel truss arch are measured using monitoring data and simulated using finite element model, respectively. The effects of lane position, number of train carriages, and speed of trains on DLF are further investigated. By using the accumulative probability function of the Generalized Extreme Value Distribution, the probability distribution model of DLF is proposed, based on which the standard value of DLF within 50-year return period is evaluated and compared with different bridge design codes.

  12. Fatigue resistance of welded joints in aluminium high-speed craft: A total stress concept

    NARCIS (Netherlands)

    Den Besten, J.H.

    2015-01-01

    Crew transfers, surveillance duties and {security, rescue, interception} operations at sea typically require high-speed craft. Aluminium is quite often selected as hull structure material because of its weight save potential in comparison to steel. The fatigue strength, however, may become a point o

  13. High-speed repetitive pellet injector prototype for magnetic confinement fusion devices

    International Nuclear Information System (INIS)

    The design of a test facility aimed at demonstrating the feasibility of high-speed repetitive acceleration of solid D2 pellets for fusion applications, developed in a collaboration between Oak Ridge National Laboratory and ENEA Frascati, is presented. The results of tests performed at the CNPM/CNR on the piston wear in a repetitively operating two-stage gun are also reported

  14. Hardware-based image processing for high-speed inspection of grains

    Science.gov (United States)

    A high-speed, low-cost, image-based sorting device was developed to detect and separate grains with slight color differences and small defects on grains The device directly combines a complementary metal–oxide–semiconductor (CMOS) color image sensor with a field-programmable gate array (FPGA) which...

  15. Textile processing improvements due to high speed roller ginning of upland cotton

    Science.gov (United States)

    Selective breeding has improved upland cotton fiber properties. Processing capacities of new high-speed roller ginning technology approach that of saw ginning. Spinning mills are interested in mill performance data comparing new upland cultivars processed by both saw and roller ginning. Four dive...

  16. Smart Sensor Based Obstacle Detection for High-Speed Unmanned Surface Vehicle

    DEFF Research Database (Denmark)

    Hermann, Dan; Galeazzi, Roberto; Andersen, Jens Christian;

    2015-01-01

    This paper describes an obstacle detection system for a high-speed and agile unmanned surface vehicle (USV), running at speeds up to 30 m/s. The aim is a real-time and high performance obstacle detection system using both radar and vision technologies to detect obstacles within a range of 175 m. ...

  17. A Control Simulation Method of High-Speed Trains on Railway Network with Irregular Influence

    Institute of Scientific and Technical Information of China (English)

    杨立兴; 李想; 李克平

    2011-01-01

    Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains' movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.

  18. Robustness of Multiple High Speed TCP CUBIC Connections Under Severe Operating Conditions

    DEFF Research Database (Denmark)

    Pilimon, Artur; Ruepp, Sarah Renée; Berger, Michael Stübert

    2015-01-01

    We study the adaptation capabilities and robustness of the high-speed TCP CUBIC algorithm. For this purpose we consider a network environment with variable and high random packet loss and a large Bandwidth-Delay product, shared by multiple heterogeneous TCP connections. The analysis is based...

  19. Critical assessment of computational thermodynamics in the alloy design of PM high speed steels

    Energy Technology Data Exchange (ETDEWEB)

    Trabadelo, V. [CEIT, Po Manuel Lardizabal 15, 20018 San Sebastian (Spain); Gimenez, S. [K.U. Leuven, Kasteelpark Arenberg 44, B3001 Heverlee (Belgium); Gomez-Acebo, T. [TECNUN, Po Manuel Lardizabal 15, 20018 San Sebastian (Spain); Iturriza, I. [CEIT, Po Manuel Lardizabal 15, 20018 San Sebastian (Spain)]. E-mail: iiturriza@ceit.es

    2005-08-15

    The experimental powder M42HVIG is used to illustrate how the adequate selection of the constituent phases involved in the calculation of multicomponent phase diagrams is a key factor for success in the computer-aided alloy design of highly sinterable high speed steel compositions.

  20. High speed bending of 2nd level interconnects on printed circuit boards for automotive electronics

    NARCIS (Netherlands)

    Kouters, M.H.M.; Ubachs, R.; Wiel, H.J. van de; Waal, A. van der; Veer, J. van der

    2011-01-01

    Standard drop tests for portable electronics are not representative for the qualification of automotive electronics. High-frequency vibrations are more dominant than abrupt shocks during normal operation. In this work a high speed board bending (HSB) method is developed to mimic the constant cyclic