Surface grinding characteristics of ferrous metals under high-speed and speed-stroke grinding conditions

International Nuclear Information System (INIS)

Ghani, A.K.; Choudhury, I.A.; Ahim, M.B.

1999-01-01

Some ferrous metals have been ground under different conditions with high-speed and speed-stroke in surface grinding operation. The paper describes experimental investigation of grinding forces in grinding some ferrous metals with the application of cutting fluids. Grinding tests have been carried out on mild steel, assab steel and stainless steel with different combinations of down feed and cross feed. The wheel speed was 27 m/sec while the table speed was maintained at the maximum possible 25 m/min. The grindability has been evaluated by measuring the grinding forces, grinding ratio, and surface finish. Grinding forces have been plotted against down feed of the grinding wheel and cross feed of the table. It has been observed that the radial and tangential grinding forces in stainless steel were higher than those in assab steel and mild steel

Profile parameters of wheelset detection for high speed freight train

Science.gov (United States)

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

2012-04-01

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

Effects of size, sex, and voluntary running speeds on costs of locomotion in lines of laboratory mice selectively bred for high wheel-running activity.

Science.gov (United States)

Rezende, Enrico L; Kelly, Scott A; Gomes, Fernando R; Chappell, Mark A; Garland, Theodore

2006-01-01

Selective breeding for over 35 generations has led to four replicate (S) lines of laboratory house mice (Mus domesticus) that run voluntarily on wheels about 170% more than four random-bred control (C) lines. We tested whether S lines have evolved higher running performance by increasing running economy (i.e., decreasing energy spent per unit of distance) as a correlated response to selection, using a recently developed method that allows for nearly continuous measurements of oxygen consumption (VO2) and running speed in freely behaving animals. We estimated slope (incremental cost of transport [COT]) and intercept for regressions of power (the dependent variable, VO2/min) on speed for 49 males and 47 females, as well as their maximum VO2 and speeds during wheel running, under conditions mimicking those that these lines face during the selection protocol. For comparison, we also measured COT and maximum aerobic capacity (VO2max) during forced exercise on a motorized treadmill. As in previous studies, the increased wheel running of S lines was mainly attributable to increased average speed, with males also showing a tendency for increased time spent running. On a whole-animal basis, combined analysis of males and females indicated that COT during voluntary wheel running was significantly lower in the S lines (one-tailed P=0.015). However, mice from S lines are significantly smaller and attain higher maximum speeds on the wheels; with either body mass or maximum speed (or both) entered as a covariate, the statistical significance of the difference in COT is lost (one-tailed P> or =0.2). Thus, both body size and behavior are key components of the reduction in COT. Several statistically significant sex differences were observed, including lower COT and higher resting metabolic rate in females. In addition, maximum voluntary running speeds were negatively correlated with COT in females but not in males. Moreover, males (but not females) from the S lines exhibited

Estimation of longitudinal force, lateral vehicle speed and yaw rate for four-wheel independent driven electric vehicles

Science.gov (United States)

Chen, Te; Xu, Xing; Chen, Long; Jiang, Haobing; Cai, Yingfeng; Li, Yong

2018-02-01

Accurate estimation of longitudinal force, lateral vehicle speed and yaw rate is of great significance to torque allocation and stability control for four-wheel independent driven electric vehicle (4WID-EVs). A fusion method is proposed to estimate the longitudinal force, lateral vehicle speed and yaw rate for 4WID-EVs. The electric driving wheel model (EDWM) is introduced into the longitudinal force estimation, the longitudinal force observer (LFO) is designed firstly based on the adaptive high-order sliding mode observer (HSMO), and the convergence of LFO is analyzed and proved. Based on the estimated longitudinal force, an estimation strategy is then presented in which the strong tracking filter (STF) is used to estimate lateral vehicle speed and yaw rate simultaneously. Finally, co-simulation via Carsim and Matlab/Simulink is carried out to demonstrate the effectiveness of the proposed method. The performance of LFO in practice is verified by the experiment on chassis dynamometer bench.

Temperature measurement of flat glass edge during grinding and effect of wheel and workpiece speeds

International Nuclear Information System (INIS)

Moussa, Tala; Garnier, Bertrand; Peerhossaini, Hassan

2017-01-01

Flat glass temperature at the vicinity of the grinding wheel during grinding can become very high and reach that of the glass transition (typically around 550–600 °C). In such cases, the mechanical strength of glass is greatly affected and the grinding process cannot be carried out properly. Hence, thermal phenomena must be managed by adjusting the machining parameters to avoid overheating. For this purpose, it is very important to be able to measure the glass temperature, especially at the grinding interface. However, measuring the interfacial glass temperature is difficult and none of the existing methods for metal grinding is adequate for glass grinding. This work shows a novel temperature method that uses constantan and copper strips on both sides of the glass plates; thermoelectric contact being provided by the metallic binder of diamond particles in the grinding wheel. This new technique allows the measurement of the glass edge temperature during the wheel displacement around the glass plate. The experimental results show an average glass edge temperature between 300 and 600 °C depending on the value of the machining parameters such as work speed, wheel speed, depth of cut and water coolant flow rate. As this new thermal instrumentation is rather intrusive, glass temperature biases were analysed using a 3D heat transfer model with a moving source. Model computations performed using finite elements show that the temperature biases are less than 70 °C, which is smaller than the standard deviation of the glass edge temperatures measured during grinding. (paper)

Changes in hippocampal theta rhythm and their correlations with speed during different phases of voluntary wheel running in rats.

Science.gov (United States)

Li, J-Y; Kuo, T B J; Hsieh, I-T; Yang, C C H

2012-06-28

Hippocampal theta rhythm (4-12 Hz) can be observed during locomotor behavior, but findings on the relationship between locomotion speed and theta frequency are inconsistent if not contradictory. The inconsistency may be because of the difficulties that previous analyses and protocols have had excluding the effects of behavior training. We recorded the first or second voluntary wheel running each day, and assumed that theta frequency and activity are correlated with speed in different running phases. By simultaneously recording electroencephalography, physical activity, and wheel running speed, this experiment explored the theta oscillations during spontaneous running of the 12-h dark period. The recording was completely wireless and allowed the animal to run freely while being recorded in the wheel. Theta frequency and theta power of middle frequency were elevated before running and theta frequency, theta power of middle frequency, physical activity, and running speed maintained persistently high levels during running. The slopes of the theta frequency and theta activity (4-9.5 Hz) during the initial running were different compared to the same values during subsequent running. During the initial running, the running speed was positively correlated with theta frequency and with theta power of middle frequency. Over the 12-h dark period, the running speed did not positively correlate with theta frequency but was significantly correlated with theta power of middle frequency. Thus, theta frequency was associated with running speed only at the initiation of running. Furthermore, theta power of middle frequency was associated with speed and with physical activity during running when chronological order was not taken into consideration. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Investigation of the Effects of Tire Inflation Pressure and Forward Speed of Driven Wheel on Horizontal Impact of Passing Rectangular Obstacle

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H Mohammadzadeh

2013-09-01

Full Text Available The tire-mechanics models have been developed for the study of wheel movement on the road or soil surface while these models are unlikely to describe the motion of wheels on uneven surfaces. Due to dynamical complexity of this phenomena and the importance of this subject for farm conditions and the wheel carrier devices, the present research aimed to investigate the effects of several parameters on the wheel passing the obstacle. The experiments were carried out using single wheel tester in soil bin condition. The results indicated a relatively linear relationship between the impact force applied on tire and forward speed of wheel and also the height of rectangular obstacle. The effect of inflation pressure was inversed in the range of complete formed tire’s body on impact force and in low levels of tire inflation pressure; tire’s body damps the maximum impact forces. The medium levels of pressure (about 150-200 kPa resulted in less horizontal force that applied on the wheel for different levels of forward speed and obstacle’s height. Tractive force for passing obstacle was increased by raising forward speed and the obstacle’s height.

Recovery tread wheel pairs of machining

Directory of Open Access Journals (Sweden)

Igor IVANOV

2013-01-01

Full Text Available The basic methods of resurfacing wheels are determined and analised. It’sshown that for raising resource of used wheels and decreasing requirements of railwaytransport for new wheels it’s reasonable to use methods of recovering not only geometricparameters of rim, but also its mechanical properties. It’s marked that use of infeedprofile high-speed grinding (VPVSh enables to intensify significantly process ofmechanical treatment of wheel rim profile both when its resurfacing in service and whenmanufacturing new wheel.

Research on the Vibration Insulation of High-Speed Train Bogies in Mid and High Frequency

Directory of Open Access Journals (Sweden)

Jia Liu

2018-01-01

Full Text Available According to a large amount of the test data, the mid and high frequency vibrations of high-speed bogies are very notable, especially in the 565~616 Hz range, which are just the passing frequencies corresponding to the 22nd to 24th polygonal wear of the wheel. In order to investigate the main cause of wheel higher-order polygon formation, a 3D flexible model of a Chinese high-speed train bogie is developed using the explicit finite element method. The results show that the couple vibration of bogie and wheelset may lead to the high-order wears of wheel. In order to reduce the coupled resonance of the wheelset and the bogie frame, the effects of the stiffness and damping of the primary suspensions, wheelset axle radius, and bogie frame strength on the vibration transmissibility are discussed carefully. The numerical results show that the resonance peaks in high frequency range can be reduced by reducing the stiffness of axle box rotary arm joint, reducing the wheelset axle radius or strengthening the bogie frame location. The related results may provide a reference for structure improvement of the existing bogies and structure design of the new high-speed bogies.

Locomotor trade-offs in mice selectively bred for high voluntary wheel running.

Science.gov (United States)

Dlugosz, Elizabeth M; Chappell, Mark A; McGillivray, David G; Syme, Douglas A; Garland, Theodore

2009-08-01

We investigated sprint performance and running economy of a unique ;mini-muscle' phenotype that evolved in response to selection for high voluntary wheel running in laboratory mice (Mus domesticus). Mice from four replicate selected (S) lines run nearly three times as far per day as four control lines. The mini-muscle phenotype, resulting from an initially rare autosomal recessive allele, has been favoured by the selection protocol, becoming fixed in one of the two S lines in which it occurred. In homozygotes, hindlimb muscle mass is halved, mass-specific muscle oxidative capacity is doubled, and the medial gastrocnemius exhibits about half the mass-specific isotonic power, less than half the mass-specific cyclic work and power, but doubled fatigue resistance. We hypothesized that mini-muscle mice would have a lower whole-animal energy cost of transport (COT), resulting from lower costs of cycling their lighter limbs, and reduced sprint speed, from reduced maximal force production. We measured sprint speed on a racetrack and slopes (incremental COT, or iCOT) and intercepts of the metabolic rate versus speed relationship during voluntary wheel running in 10 mini-muscle and 20 normal S-line females. Mini-muscle mice ran faster and farther on wheels, but for less time per day. Mini-muscle mice had significantly lower sprint speeds, indicating a functional trade-off. However, contrary to predictions, mini-muscle mice had higher COT, mainly because of higher zero-speed intercepts and postural costs (intercept-resting metabolic rate). Thus, mice with altered limb morphology after intense selection for running long distances do not necessarily run more economically.

Moessbauer spectrometry analysis of Fe78Si9B13 metallic glass prepared with different quenching wheel speed

International Nuclear Information System (INIS)

Narges Amini; Bu-Ali Sina University, Hamedan; Safdar Habibi; Dekan, Julius; Pavuk, Milan; Novak, Patrik; Miglierini, Marcel; Czech Technical University in Prague, Prague

2017-01-01

Impact of the wheel speed upon microstructure and hyperfine interactions of amorphous Fe 78 Si 9 B 13 ribbons was studied. Moessbauer spectrometry, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, atomic force microscopy, and magnetic measurements were applied. Though minor effects of wheel speed upon macroscopic magnetic properties was found, notable changes in repositioning of magnetic moments of the resonant atoms caused by modifications in the topological short-range order (SRO) were unveiled. No deviations were observed in the chemical SRO. The observed effects were enhanced after annealing at moderate temperatures. (author)

Reinventing the wheel: comparison of two wheel cage styles for assessing mouse voluntary running activity.

Science.gov (United States)

Seward, T; Harfmann, B D; Esser, K A; Schroder, E A

2018-04-01

Voluntary wheel cage assessment of mouse activity is commonly employed in exercise and behavioral research. Currently, no standardization for wheel cages exists resulting in an inability to compare results among data from different laboratories. The purpose of this study was to determine whether the distance run or average speed data differ depending on the use of two commonly used commercially available wheel cage systems. Two different wheel cages with structurally similar but functionally different wheels (electromechanical switch vs. magnetic switch) were compared side-by-side to measure wheel running data differences. Other variables, including enrichment and cage location, were also tested to assess potential impacts on the running wheel data. We found that cages with the electromechanical switch had greater inherent wheel resistance and consistently led to greater running distance per day and higher average running speed. Mice rapidly, within 1-2 days, adapted their running behavior to the type of experimental switch used, suggesting these running differences are more behavioral than due to intrinsic musculoskeletal, cardiovascular, or metabolic limits. The presence of enrichment or location of the cage had no detectable impact on voluntary wheel running. These results demonstrate that mice run differing amounts depending on the type of cage and switch mechanism used and thus investigators need to report wheel cage type/wheel resistance and use caution when interpreting distance/speed run across studies. NEW & NOTEWORTHY The results of this study highlight that mice will run different distances per day and average speed based on the inherent resistance present in the switch mechanism used to record data. Rapid changes in running behavior for the same mouse in the different cages demonstrate that a strong behavioral factor contributes to classic exercise outcomes in mice. Caution needs to be taken when interpreting mouse voluntary wheel running activity to

A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

International Nuclear Information System (INIS)

AntolIn, P; Goicolea, J M; Astiz, M A; Alonso, A

2010-01-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

Science.gov (United States)

Antolín, P.; Goicolea, J. M.; Astiz, M. A.; Alonso, A.

2010-06-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

High frequency vibration characteristics of electric wheel system under in-wheel motor torque ripple

Science.gov (United States)

Mao, Yu; Zuo, Shuguang; Wu, Xudong; Duan, Xianglei

2017-07-01

With the introduction of in-wheel motor, the electric wheel system encounters new vibration problems brought by motor torque ripple excitation. In order to analyze new vibration characteristics of electric wheel system, torque ripple of in-wheel motor based on motor module and vector control system is primarily analyzed, and frequency/order features of the torque ripple are discussed. Then quarter vehicle-electric wheel system (QV-EWS) dynamics model based on the rigid ring tire assumption is established and the main parameters of the model are identified according to tire free modal test. Modal characteristics of the model are further analyzed. The analysis indicates that torque excitation of in-wheel motor is prone to arouse horizontal vibration, in which in-phase rotational, anti-phase rotational and horizontal translational modes of electric wheel system mainly participate. Based on the model, vibration responses of the QV-EWS under torque ripple are simulated. The results show that unlike vertical low frequency (lower than 20 Hz) vibration excited by road roughness, broadband torque ripple will arouse horizontal high frequency (50-100 Hz) vibration of electric wheel system due to participation of the three aforementioned modes. To verify the theoretical analysis, the bench experiment of electric wheel system is conducted and vibration responses are acquired. The experiment demonstrates the high frequency vibration phenomenon of electric wheel system and the measured order features as well as main resonant frequencies agree with simulation results. Through theoretical modeling, analysis and experiments this paper reveals and explains the high frequency vibration characteristics of electric wheel system, providing references for the dynamic analysis, optimal design of QV-EWS.

Distributed and self-adaptive vehicle speed estimation in the composite braking case for four-wheel drive hybrid electric car

Science.gov (United States)

Zhao, Z.-G.; Zhou, L.-J.; Zhang, J.-T.; Zhu, Q.; Hedrick, J.-K.

2017-05-01

Considering the controllability and observability of the braking torques of the hub motor, Integrated Starter Generator (ISG), and hydraulic brake for four-wheel drive (4WD) hybrid electric cars, a distributed and self-adaptive vehicle speed estimation algorithm for different braking situations has been proposed by fully utilising the Electronic Stability Program (ESP) sensor signals and multiple powersource signals. Firstly, the simulation platform of a 4WD hybrid electric car was established, which integrates an electronic-hydraulic composited braking system model and its control strategy, a nonlinear seven degrees-of-freedom vehicle dynamics model, and the Burckhardt tyre model. Secondly, combining the braking torque signals with the ESP signals, self-adaptive unscented Kalman sub-filter and main-filter adaptable to the observation noise were, respectively, designed. Thirdly, the fusion rules for the sub-filters and master filter were proposed herein, and the estimation results were compared with the simulated value of a real vehicle speed. Finally, based on the hardware in-the-loop platform and by picking up the regenerative motor torque signals and wheel cylinder pressure signals, the proposed speed estimation algorithm was tested under the case of moderate braking on the highly adhesive road, and the case of Antilock Braking System (ABS) action on the slippery road, as well as the case of ABS action on the icy road. Test results show that the presented vehicle speed estimation algorithm has not only a high precision but also a strong adaptability in the composite braking case.

On the non-proportionality between wheel/rail contact forces and speed during wheelset passage over specific welds

Science.gov (United States)

Correa, Nekane; Vadillo, Ernesto G.; Santamaria, Javier; Blanco-Lorenzo, Julio

2018-01-01

This study investigates the influence on the wheel-rail contact forces of the running speed and the shape and position of weld defects along the track. For this purpose, a vertical dynamic model in the space domain is used. The model is obtained from the transformation between the domains of frequency and space using a Rational Fraction Polynomials (RFP) method, which is modified with multiobjective genetic algorithms in order to improve the fitting of track receptance and to assist integration during simulations. This produces a precise model with short calculation times, which is essential to this study. The wheel-rail contact is modelled using a non-linear Hertz spring. The contact forces are studied for several types of characteristic welds. The way in which forces vary as a function of weld position and running speed is studied for each type of weld. This paper studies some of the factors that affect the maximum forces when the vehicle moves over a rail weld, such as weld geometry, parametric excitation and contact stiffness. It is found that the maximum force in the wheel-rail contact when the vehicle moves over a weld is not always proportional to the running speed. The paper explains why it is not proportional in specific welds.

Full drive-by-wire dynamic control for four-wheel-steer all-wheel-drive vehicles

Science.gov (United States)

Fahimi, Farbod

2013-03-01

Most of the controllers introduced for four-wheel-steer (4WS) vehicles are derived with the assumption that the longitudinal speed of the vehicle is constant. However, in real applications, the longitudinal speed varies, and the longitudinal, lateral, and yaw dynamics are coupled. In this paper, the longitudinal dynamics of the vehicle as well as its lateral and yaw motions are controlled simultaneously. This way, the effect of driving/braking forces of the tires on the lateral and yaw motions of the vehicle are automatically included in the control laws. To address the dynamic parameter uncertainty of the vehicle, a chatter-free variable structure controller is introduced. Elimination of chatter is achieved by introducing a dynamically adaptive boundary layer thickness. It is shown via simulations that the proposed control approach performs more robustly than the controllers developed based on dynamic models, in which longitudinal speed is assumed to be constant, and only lateral speed and yaw rate are used as system states. Furthermore, this approach supports all-wheel-drive vehicles. Front-wheel-drive or rear-wheel-drive vehicles are also supported as special cases of an all-wheel-drive vehicle.

High-speed Maglev studies in Canada

International Nuclear Information System (INIS)

Atherton, D.L.; Eastham, A.R.

1974-01-01

This paper reports on Canadian studies of superconducting magnetic levitation and variable-speed linear synchronous motor propulsion for high-speed inter-city guided ground transport. Levitation is obtained by the interaction of vehicle-mounted superconducting magnets and the eddy currents induced in aluminium strip conductors on the guideway. Non-contact propulsion by linear synchronous motor (LSM) is obtained by using vehicle-borne superconducting magnets and powered guideway coils. A suggested guidance scheme uses a flat guideway with 'null-flux' loops overlying the LSM windings. The propulsion magnets interact with the loops and the edges of the levitation strips to provide lateral stabilization. The test facility is a 7.6m wheel, rotating with a peripheral speed of 33m/s. (author)

A Brief Opportunity to Run Does Not Function as a Reinforcer for Mice Selected for High Daily Wheel-Running Rates

Science.gov (United States)

Belke, Terry W.; Garland, Theodore, Jr.

2007-01-01

Mice from replicate lines, selectively bred based on high daily wheel-running rates, run more total revolutions and at higher average speeds than do mice from nonselected control lines. Based on this difference it was assumed that selected mice would find the opportunity to run in a wheel a more efficacious consequence. To assess this assumption…

Maximal metabolic rates during voluntary exercise, forced exercise, and cold exposure in house mice selectively bred for high wheel-running.

Science.gov (United States)

Rezende, Enrico L; Chappell, Mark A; Gomes, Fernando R; Malisch, Jessica L; Garland, Theodore

2005-06-01

Selective breeding for high wheel-running activity has generated four lines of laboratory house mice (S lines) that run about 170% more than their control counterparts (C lines) on a daily basis, mostly because they run faster. We tested whether maximum aerobic metabolic rates (V(O2max)) have evolved in concert with wheel-running, using 48 females from generation 35. Voluntary activity and metabolic rates were measured on days 5+6 of wheel access (mimicking conditions during selection), using wheels enclosed in metabolic chambers. Following this, V(O2max) was measured twice on a motorized treadmill and twice during cold-exposure in a heliox atmosphere (HeO2). Almost all measurements, except heliox V(O2max), were significantly repeatable. After accounting for differences in body mass (S running speeds on the treadmill. However, running speeds and V(O2max) during voluntary exercise were significantly higher in S lines. Nevertheless, S mice never voluntarily achieved the V(O2max) elicited during their forced treadmill trials, suggesting that aerobic capacity per se is not limiting the evolution of even higher wheel-running speeds in these lines. Our results support the hypothesis that S mice have genetically higher motivation for wheel-running and they demonstrate that behavior can sometimes evolve independently of performance capacities. We also discuss the possible importance of domestication as a confounding factor to extrapolate results from this animal model to natural populations.

Performance Evaluation of an In-Wheel Motor Cooling System in an Electric Vehicle/Hybrid Electric Vehicle

Directory of Open Access Journals (Sweden)

Dong Hyun Lim

2014-02-01

Full Text Available High power and miniaturization of motors in an in-wheel drive system, which is installed inside the wheels of a vehicle, are required for directly driving the wheels. In addition, an efficient cooling system is required to ensure high driving performance and durability. This study experimentally evaluated the heat dissipation performance of a 35-kW-class large-capacity in-wheel motor equipped with an internal-circulation-type oil-cooling system that exhibits high cooling performance and can be easily miniaturized to this motor. Temperatures of the coil and stator core of cooling systems with and without a radiator were measured in real time under in-wheel motor driving conditions. It was found that operating the cooling system at a continuous-rating maximum speed without the radiator was difficult. We confirmed that under continuous-rating base speed and continuous-rating maximum speed driving conditions, the cooling system with the radiator showed thermally stable operation. Furthermore, under maximum-rating base speed and maximum-rating maximum speed driving conditions, the cooling system with the radiator provided additional driving times of approximately 22 s and 2 s, respectively.

Pre-study on the Berlin-Budapest high-speed rail link; Hochgeschwindigkeitsverkehr: Vorstudie zur Strecke Berlin-Budapest

Energy Technology Data Exchange (ETDEWEB)

Fengler, W.; Stehle, J. [TU Dresden (Germany). Fakultaet Verkehrswissenschaften ' ' Friedrich List' ' ; Schach, R. [TU Dresden (Germany). Fakultaet Bauingenieurwesen; Stephan, A. [Inst. fuer Bahntechnik GmbH, Dresden/Berlin (Germany)

2008-07-01

In a pre-study, the Government of the State of Saxony commissioned a comparison between wheel/rail and maglev technology for high-speed operations on the northern section of the pan-European Corridor IV. From the holistic perspective of the business evaluation and the expected economic impact, it can be concluded that there is a case for establishing a guided high-speed link between Berlin and Budapest and that the plan should be pursued further. Teh pre-study showed that, taking a comprehensive view of investment and operational aspects, the Transrapid technology already stands comparison with wheel/rail technology. (orig.)

Aerodynamic design on high-speed trains

Science.gov (United States)

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

2016-04-01

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

Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm

Directory of Open Access Journals (Sweden)

Wilmar Hernandez

2006-02-01

Full Text Available Among the complete family of sensors for automotive safety, consumer andindustrial application, speed sensors stand out as one of the most important. Actually, speedsensors have the diversity to be used in a broad range of applications. In today’s automotiveindustry, such sensors are used in the antilock braking system, the traction control systemand the electronic stability program. Also, typical applications are cam and crank shaftposition/speed and wheel and turbo shaft speed measurement. In addition, they are used tocontrol a variety of functions, including fuel injection, ignition timing in engines, and so on.However, some types of speed sensors cannot respond to very low speeds for differentreasons. What is more, the main reason why such sensors are not good at detecting very lowspeeds is that they are more susceptible to noise when the speed of the target is low. In short,they suffer from noise and generally only work at medium to high speeds. This is one of thedrawbacks of the inductive (magnetic reluctance speed sensors and is the case under study.Furthermore, there are other speed sensors like the differential Hall Effect sensors that arerelatively immune to interference and noise, but they cannot detect static fields. This limitstheir operations to speeds which give a switching frequency greater than a minimumoperating frequency. In short, this research is focused on improving the performance of avariable reluctance speed sensor placed in a car under performance tests by using arecursive least-squares (RLS lattice algorithm. Such an algorithm is situated in an adaptivenoise canceller and carries out an optimal estimation of the relevant signal coming from thesensor, which is buried in a broad-band noise background where we have little knowledgeof the noise characteristics. The experimental results are satisfactory and show a significantimprovement in the signal-to-noise ratio at the system output.

Wheel liner design for improved sound and structural performances

Science.gov (United States)

Oltean, Alexandru; Diaconescu, Claudiu; Tabacu, Ştefan

2017-10-01

Vehicle noise is composed mainly of wheel-road noise and noise from the power unit. At low speeds power unit noise dominates while at high speeds wheel-road noise dominates as wheel-road noise level increases approximately logarithmically with speed. The wheel liner is designed as a component of the vehicle that has a multiple role. It has to prevent the dirt or water from the road surface that are engaged by the wheel to access the engine/front bay. Same time it has the important role to reduce perceived noised in the passenger’s compartment that comes from the wheel-road interaction. Progress in plastic injection moulding technology allowed for new structures to be developed - nonwoven materials in combination with a PP based carrier structure which benefits from a cell structure caused by MuCell injection moulding. The results are light parts with increased sound absorption performances. An adapted combination of materials and production processes can provide the solution for stiff yet soundproofing structures valued for modern vehicles. Sound absorption characteristics of materials used for wheel liners applications were reported in this study. Different polypropylene and polyester fibre-based thermally bonded nonwovens varying in weight and thickness were investigated. Having as a background the performances of the nonwoven material the microcellular structure was part of the analysis. Acoustical absorptive behaviour was explained by analysing the results obtained using the impedance tube and correlating with the knowledge of materials structure.

A novel dual motor drive system for three wheel electric vehicles

Science.gov (United States)

Panmuang, Piyapat; Thongsan, Taweesak; Suwapaet, Nuchida; Laohavanich, Juckamass; Photong, Chonlatee

2018-03-01

This paper presents a novel dual motor drive system used for three wheel electric vehicles that have one free wheel at the front and two wheels with a drive system at the end of the vehicles. A novel dual motor drive system consists of two identical DC motors that are independently controlled by its speed-torque controller. Under light load conditions, only one of the DC motors will operate around it rated whilst under hard load conditions both of the DC motors will operate. With this drive system, the motors will operate only at its high performance at rated or else no operate to retain longer lifetime. The simulated results for the Skylab three wheel electric vehicle prototype with 8kW at full load (high torque, low speed) and around 4kW at light/normal operating loads (regular speed-torque) showed that the proposed system provides better dynamic responses with faster overshoot current/voltage recovery time, has lower investment costs, has longer lifetime of the motors and allows the motors to always operate at their high performance and thus achieve more cost effective system compared to a single motor drive system with 8kW DC motors.

DESIGN OF BACKWARD SWEPT TURBINE WHEEL FOR CRYOGENIC TURBOEXPANDER

Directory of Open Access Journals (Sweden)

BALAJI K. CHOUDHURY

2014-08-01

Full Text Available With support from the Department of Atomic Energy, our institute has initiated a programme on development and study of a low capacity (20 liters/hr. turboexpander based Nitrogen liquefier. Hence a process design was carried out and a turboexpander was designed to meet the requirement of the liquefier. The turboexpander is used for lowering the temperature of the process gas (Nitrogen by the isenthalpic expansion. The efficiency of the turboexpander mainly depends on the specific speed and specific diameter of the turbine wheel. The paper explains a general methodology for the design of any type of turbine wheel (radial, backward swept and forward swept for any pressure ratio with different process gases. The design of turbine wheel includes the determination of dimensions, blade profile and velocity triangles at inlet and outlet of the turbine wheel. Generally radial turbine wheels are used but in this case to achieve the high efficiency at desired speed, backward curved blades are used to maintain the Mach number of the process gas at the nozzle exit, close to unity. If the velocity of fluid exceeds the speed of sound, the flow gets choked leading to the creation of shock waves and flow at the exit of the nozzle will be non-isentropic.

Effect of rare-earth elements and quenching wheel speed on the structure, mechanical and thermal properties of rapidly solidified AZ91 Mg melt-spun ribbons

Energy Technology Data Exchange (ETDEWEB)

Ekrami, A. [Iran University of Industries & Mines, Faculty of Engineering & High-Technology (Iran, Islamic Republic of); Shahri, F., E-mail: fshahri@irost.ir [Iranian Research Organization for Science & Technology, Department of Advanced Materials & Renewable Energy (Iran, Islamic Republic of); Mirak, A. [Iran University of Industries & Mines, Faculty of Engineering & High-Technology (Iran, Islamic Republic of)

2017-01-27

In this work, an attempt is made to study the effects of rare-earth elements as an additive (2 wt% of Ce base misch-metal) and various quenching wheel speeds (10–40 m/s) on the microstructure, thermal and mechanical properties of rapidly solidified AZ91 alloy prepared by single roller melt-spinning process. In this respect, all of the samples were studied using various techniques such as x-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC) and mechanical properties such as microhardness and tensile tests. The finding bore witness to proposed hypothesis in this study illustrating due to high affinity between Al and RE by adding 2 wt% rare-earth elements in the AZ91alloy, thermally stable Al{sub x}RE{sub y} intermetallic compounds are precipitated and the formation of β-Mg{sub 17}Al{sub 12} phases is reduced. DSC results revealed that by adding RE to AZ91 alloy, AlRE phases got stable up to 500 °C, while for the AZ91 sample, β-Mg{sub 17}Al{sub 12} phase was formed at temperature about 180 °C and then with increasing of temperature dissolved at 410 °C in the α-Mg matrix. Further it has been observed that the higher was the quenching wheel speed, the smaller was the grain size which in turn gives rise to a higher tensile properties (from 406 MPa for quenching wheel speed of 10 m/s to 510 MPa for 40 m/s) for the MM-added alloys. Tensile strength of 386 MPa was obtained for the AZ91 pure alloy which is prepared at wheel speed of 40 m/sec.

Design and experimental study of a micro-groove grinding wheel with spray cooling effect

Directory of Open Access Journals (Sweden)

Shi Chaofeng

2014-04-01

Full Text Available The effectiveness of grinding fluid supply has a crucial impact on grinding quality and efficiency in high speed grinding. In order to improve the cooling and lubrication, through in-depth research of self-inhaling internal cooling method and intermittent grinding mechanism, a new spray cooling method used in high speed grinding is proposed. By referring to the structure of bowl-shaped dispersion disk, the grinding wheel matrix with atomization ability is designed; through studying heat transfer of droplet collision and the influence of micro-groove on the boiling heat transfer, grinding segment with micro-groove is designed to enhance the heat flux of coolant and achieve maximum heat transfer between droplets and grinding contact zone. High-speed grinding experiments on GH4169 with the developed grinding wheel are carried out. The results show that with the micro-groove grinding wheel just 5.4% of pump outlet flow rate and 0.5% of spindle energy is needed to reduce the grinding temperature to 200 °C, which means the developed grinding wheel makes cooling high efficient and low energy consuming.

Effect of wheel speed and annealing temperature on microstructure and texture evolution of Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} ribbon

Energy Technology Data Exchange (ETDEWEB)

Feng, Yan, E-mail: yanfeng@nwpu.edu.cn [State Key Laboratory of Solidification Processing Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Chen, Hong [State Key Laboratory of Solidification Processing Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Gao, Li [College of Engineering Science and Technology, Shanghai Ocean University, Shanghai 201306 (China); Wang, Haibo [College of Physics and Electronic Engineering, Taizhou University, Taizhou, Zhejiang 318000 (China); Bian, Xiaohai; Gong, Mingjie [State Key Laboratory of Solidification Processing Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China)

2016-12-15

Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} magnetic shape memory alloy was successfully produced as preferentially textured ribbon by melting spinning with different wheel speed. X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) were used to study structure and texture evolution of these melt-spun ribbons. The thickness of melt-spun ribbon is 42 μm, 65 μm and 30 μm depending on wheel speed of 1 0 m/s, 15 m/s and 20 m/s, respectively. Density of α fiber texture (〈100〉//ND) vary with wheel speed changes, and is most intensive in the ribbon with wheel speed of 15 m/s. Grains of the ribbons grow after being annealed at 873 K, 973 K, 1073 K and 1173 K, recrystallization was not observed in ribbons after being annealed at 873 K but occurred in ribbons after being annealed at higher temperatures. The α fiber texture becomes weaker to some extent after annealing at different temperatures, due to new recrystallization texture formed at the process of annealing. - Highlights: •Sectional part of shape memory ribbon is firstly investigated by EBSD method. •Thickness and texture of ribbons vary with wheel speed. •Annealing temperature affect texture and microstructure evolution greatly. •Recrystallization textures were observed in ribbons after being annealed.

Optimization of wheel-rail interface friction using top-of-rail friction modifiers: State of the art

Science.gov (United States)

Khan, M. Roshan; Dasaka, Satyanarayana Murty

2018-05-01

High Speed Railways and Dedicated Freight Corridors are the need of the day for fast and efficient transportation of the ever growing population and freight across long distances of travel. With the increase in speeds and axle loads carried by these trains, wearing out of rails and train wheel sections are a common issue, which is due to the increase in friction at the wheel-rail interfaces. For the cases where the wheel-rail interface friction is less than optimum, as in case of high speed trains with very low axle loads, wheel-slips are imminent and loss of traction occurs when the trains accelerate rapidly or brake all of a sudden. These vast variety of traction problems around the wheel-rail interface friction need to be mitigated carefully, so that the contact interface friction neither ascents too high to cause material wear and need for added locomotive power, nor be on the lower side to cause wheel-slips and loss of traction at high speeds. Top-of-rail friction modifiers are engineered surface coatings applied on top of rails, to maintain an optimum frictional contact between the train wheels and the rails. Extensive research works in the area of wheel-rail tribology have revealed that the optimum frictional coefficients at wheel-rail interfaces lie at a value of around 0.35. Application of top-of-rail (TOR) friction modifiers on rail surfaces add an extra layer of material coating on top of the rails, with a surface frictional coefficient of the desired range. This study reviews the common types of rail friction modifiers, the methods for their application, issues related with the application of friction modifiers, and a guideline on selection of the right class of coating material based on site specific requirements of the railway networks.

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

Science.gov (United States)

2010-07-01

..., monorails and systems. 1192.175 Section 1192.175 Parks, Forests, and Public Property ARCHITECTURAL AND... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a... steel-wheel-on-steel-rail technology, and monorail systems operating primarily on dedicated rail (i.e...

Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm

Science.gov (United States)

Hernandez, Wilmar

2006-01-01

Among the complete family of sensors for automotive safety, consumer and industrial application, speed sensors stand out as one of the most important. Actually, speed sensors have the diversity to be used in a broad range of applications. In today's automotive industry, such sensors are used in the antilock braking system, the traction control system and the electronic stability program. Also, typical applications are cam and crank shaft position/speed and wheel and turbo shaft speed measurement. In addition, they are used to control a variety of functions, including fuel injection, ignition timing in engines, and so on. However, some types of speed sensors cannot respond to very low speeds for different reasons. What is more, the main reason why such sensors are not good at detecting very low speeds is that they are more susceptible to noise when the speed of the target is low. In short, they suffer from noise and generally only work at medium to high speeds. This is one of the drawbacks of the inductive (magnetic reluctance) speed sensors and is the case under study. Furthermore, there are other speed sensors like the differential Hall Effect sensors that are relatively immune to interference and noise, but they cannot detect static fields. This limits their operations to speeds which give a switching frequency greater than a minimum operating frequency. In short, this research is focused on improving the performance of a variable reluctance speed sensor placed in a car under performance tests by using a recursive least-squares (RLS) lattice algorithm. Such an algorithm is situated in an adaptive noise canceller and carries out an optimal estimation of the relevant signal coming from the sensor, which is buried in a broad-band noise background where we have little knowledge of the noise characteristics. The experimental results are satisfactory and show a significant improvement in the signal-to-noise ratio at the system output.

The hydraulic wheel

International Nuclear Information System (INIS)

Alvarez Cardona, A.

1985-01-01

The present article this dedicated to recover a technology that key in disuse for the appearance of other techniques. It is the hydraulic wheel with their multiple possibilities to use their energy mechanical rotational in direct form or to generate electricity directly in the fields in the place and to avoid the high cost of transport and transformation. The basic theory is described that consists in: the power of the currents of water and the hydraulic receivers. The power of the currents is determined knowing the flow and east knowing the section of the flow and its speed; they are given you formulate to know these and direct mensuration methods by means of floodgates, drains and jumps of water. The hydraulic receivers or properly this hydraulic wheels that are the machines in those that the water acts like main force and they are designed to transmit the biggest proportion possible of absolute work of the water, the hydraulic wheels of horizontal axis are the common and they are divided in: you rotate with water for under, you rotate with side water and wheels with water for above. It is analyzed each one of them, their components are described; the conditions that should complete to produce a certain power and formulate them to calculate it. There are 25 descriptive figures of the different hydraulic wheels

The Effect of First-Order Bending Resonance of Wheelset at High Speed on Wheel-Rail Contact Behavior

Directory of Open Access Journals (Sweden)

Shuoqiao Zhong

2013-01-01

Full Text Available The first-order bending deformation of wheelset is considered in the modeling vehicle/track coupling dynamic system to investigate its effect on wheel/rail contact behavior. In considering the effect of the first-order bending resonance on the rolling contact of wheel/rail, a new wheel/rail contact model is derived in detail in the modeling vehicle/track coupling dynamic system, in which the many intermediate coordinate systems and complex coordinate system transformations are used. The bending mode shape and its corresponding frequency of the wheelset are obtained through the modal analysis by using commercial software ANSYS. The modal superposition method is used to solve the differential equations of wheelset motion considering its flexible deformation due to the first-order bending resonance. In order to verify the present model and clarify the influence of the first-order bending deformation of wheelset on wheel/track contact behavior, a harmonic track irregularity with a fixed wavelength and a white-noise roughness are, respectively used as the excitations in the two models of vehicle-rail coupling dynamic system, one considers the effect of wheelset bending deformation, and the other does not. The numerical results indicate that the wheelset first-order bending deformation has an influence on wheel/rail rolling contact behavior and is easily excited under wheel/rail roughness excitation.

Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

Directory of Open Access Journals (Sweden)

Wenchuan Cai

2014-01-01

Full Text Available Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

A new solution method for wheel/rail rolling contact.

Science.gov (United States)

Yang, Jian; Song, Hua; Fu, Lihua; Wang, Meng; Li, Wei

2016-01-01

To solve the problem of wheel/rail rolling contact of nonlinear steady-state curving, a three-dimensional transient finite element (FE) model is developed by the explicit software ANSYS/LS-DYNA. To improve the solving speed and efficiency, an explicit-explicit order solution method is put forward based on analysis of the features of implicit and explicit algorithm. The solution method was first applied to calculate the pre-loading of wheel/rail rolling contact with explicit algorithm, and then the results became the initial conditions in solving the dynamic process of wheel/rail rolling contact with explicit algorithm as well. Simultaneously, the common implicit-explicit order solution method is used to solve the FE model. Results show that the explicit-explicit order solution method has faster operation speed and higher efficiency than the implicit-explicit order solution method while the solution accuracy is almost the same. Hence, the explicit-explicit order solution method is more suitable for the wheel/rail rolling contact model with large scale and high nonlinearity.

Wheel set run profile renewing method effectiveness estimation

OpenAIRE

Somov, Dmitrij; Bazaras, Žilvinas; Žukauskaite, Orinta

2010-01-01

At all the repair enterprises, despite decreased rim wear-off resistance, after every grinding only geometry wheel profile parameters are renewed. Exploit wheel rim work edge decrease tendency is noticed what induces acquiring new wheels. This is related to considerable axle load and train speed increase and also because of wheel work edge repair method imperfection.

Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

OpenAIRE

Cai, Wenchuan; Liao, Wenhao; Li, Danyong; Song, Yongduan

2014-01-01

Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST) is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate t...

Endurance capacity of mice selectively bred for high voluntary wheel running.

Science.gov (United States)

Meek, Thomas H; Lonquich, Brian P; Hannon, Robert M; Garland, Theodore

2009-09-15

Mice from four lines bred for high voluntary wheel activity run approximately 3-fold more revolutions per day and have elevated maximal oxygen consumption during forced treadmill exercise, as compared with four unselected control (C) lines. We hypothesized that these high runner (HR) lines would have greater treadmill endurance-running capacity. Ninety-six mice from generation 49 were familiarized with running on a motorized treadmill for 3 days. On days 4 and 5, mice were given an incremental speed test (starting at 20 m min(-1), increased 1.5 m min(-1) every 2 min) and endurance was measured as the total time or distance run to exhaustion. Blood samples were taken to measure glucose and lactate concentrations at rest during the photophase, during peak nightly wheel running, and immediately following the second endurance test. Individual differences in endurance time were highly repeatable between days (r=0.79), and mice tended to run longer on the second day (paired t-test, Pwheel running and treadmill endurance differed between the sexes, reinforcing previous studies that indicate sex-specific responses to selective breeding. HR mice appear to have a higher endurance capacity than reported in the literature for inbred strains of mice or transgenics intended to enhance endurance.

ANALYSIS OF FORMING TREAD WHEEL SETS

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Igor IVANOV

2017-09-01

Full Text Available This paper shows the results of a theoretical study of profile high-speed grinding (PHSG for forming tread wheel sets during repair instead of turning and mold-milling. Significant disadvantages of these methods are low capacity to adapt to the tool and inhomogeneous structure of the wheel material. This leads to understated treatment regimens and difficulties in recovering wheel sets with thermal and mechanical defects. This study carried out modeling and analysis of emerging cutting forces. Proposed algorithms describe the random occurrence of the components of the cutting forces in the restoration profile of wheel sets with an inhomogeneous structure of the material. To identify the statistical features of randomly generated structures fractal dimension and the method of random additions were used. The multifractal spectrum formed is decomposed into monofractals by wavelet transform. The proposed method allows you to create the preconditions for controlling the parameters of the treatment process.

Stabilization of the wheel running phenotype in mice.

Science.gov (United States)

Bowen, Robert S; Cates, Brittany E; Combs, Eric B; Dillard, Bryce M; Epting, Jessica T; Foster, Brittany R; Patterson, Shawnee V; Spivey, Thomas P

2016-03-01

Increased physical activity is well known to improve health and wellness by modifying the risks for many chronic diseases. Rodent wheel running behavior is a beneficial surrogate model to evaluate the biology of daily physical activity in humans. Upon initial exposure to a running wheel, individual mice differentially respond to the experience, which confounds the normal activity patterns exhibited in this otherwise repeatable phenotype. To promote phenotypic stability, a minimum seven-day (or greater) acclimation period is utilized. Although phenotypic stabilization is achieved during this 7-day period, data to support acclimation periods of this length are not currently available in the literature. The purpose of this project is to evaluate the wheel running response in C57BL/6j mice immediately following exposure to a running wheel. Twenty-eight male and thirty female C57BL/6j mice (Jackson Laboratory, Bar Harbor, ME) were acquired at eight weeks of age and were housed individually with free access to running wheels. Wheel running distance (km), duration (min), and speed (m∙min(-1)) were measured daily for fourteen days following initial housing. One-way ANOVAs were used to evaluate day-to-day differences in each wheel running character. Limits of agreement and mean difference statistics were calculated between days 1-13 (acclimating) and day 14 (acclimated) to assess day-to-day agreement between each parameter. Wheel running distance (males: F=5.653, p=2.14 × 10(-9); females: F=8.217, p=1.20 × 10(-14)), duration (males: F=2.613, p=0.001; females: F=4.529, p=3.28 × 10(-7)), and speed (males: F=7.803, p=1.22 × 10(-13); females: F=13.140, p=2.00 × 10(-16)) exhibited day-to-day differences. Tukey's HSD post-hoc testing indicated differences between early (males: days 1-3; females: days 1-6) and later (males: days >3; females: days >6) wheel running periods in distance and speed. Duration only exhibited an anomalous difference between wheel running on day 13

Benefits of magnesium wheels for consumer cars

Science.gov (United States)

Frishfelds, Vilnis; Timuhins, Andrejs; Bethers, Uldis

2018-05-01

Advantages and disadvantages of magnesium wheels are considered based on a mechanical model of a car. Magnesium wheels are usually applied to racing cars as they provide slightly better strength/weight ratio than aluminum alloys. Do they provide notable benefits also for the everyday user when the car speeds do not exceed allowed speed limit? Distinct properties of magnesium rims are discussed. Apart from lighter weight of magnesium alloys, they are also good in dissipating the energy of vibrations. The role of energy dissipation in the rim of a wheel is estimated by a quarter car model. Improvements to safety by using the magnesium wheels are considered. Braking distance and responsiveness of the car is studied both with and without using an Anti Blocking System (ABS). Influence of rim weight on various handling parameters of the car is quantitatively tested.

Study on the ultrasonic inspection method using the full matrix capture for the in service railway wheel

Energy Technology Data Exchange (ETDEWEB)

Peng, Jianping; Wang, Li; Zhang, Yu; Gao, Xiaorong; Wang, Zeyong; Peng, Chaoyong [NDT Research Center, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China)

2014-02-18

The quality of wheel is especially important for the safety of high speed railway. In this paper, a new ultrasonic array inspection method, the Full Matrix Capture (FMC) has been studied and applied to the high speed railway wheel inspection, especially in the wheel web from the tread. Firstly, the principle of FMC and TFM algorithm is discussed, and then the new optimization is applied to the standard FMC; Secondly the fundamentals of optimization is described in detail and the performance is analyzed. Finally, the experiment has been built with a standard phased array block and railway wheel, and then the testing results are discussed and analyzed. It is demonstrated that this change for the ultrasonic data acquisition and image reconstruction has higher efficiency and lower cost comparing to the FMC's procedure.

Stereotypic wheel running decreases cortical activity in mice

Science.gov (United States)

Fisher, Simon P.; Cui, Nanyi; McKillop, Laura E.; Gemignani, Jessica; Bannerman, David M.; Oliver, Peter L.; Peirson, Stuart N.; Vyazovskiy, Vladyslav V.

2016-01-01

Prolonged wakefulness is thought to gradually increase ‘sleep need' and influence subsequent sleep duration and intensity, but the role of specific waking behaviours remains unclear. Here we report the effect of voluntary wheel running during wakefulness on neuronal activity in the motor and somatosensory cortex in mice. We find that stereotypic wheel running is associated with a substantial reduction in firing rates among a large subpopulation of cortical neurons, especially at high speeds. Wheel running also has longer-term effects on spiking activity across periods of wakefulness. Specifically, cortical firing rates are significantly higher towards the end of a spontaneous prolonged waking period. However, this increase is abolished when wakefulness is dominated by running wheel activity. These findings indicate that wake-related changes in firing rates are determined not only by wake duration, but also by specific waking behaviours. PMID:27748455

A novel mouse running wheel that senses individual limb forces: biomechanical validation and in vivo testing

Science.gov (United States)

Roach, Grahm C.; Edke, Mangesh

2012-01-01

Biomechanical data provide fundamental information about changes in musculoskeletal function during development, adaptation, and disease. To facilitate the study of mouse locomotor biomechanics, we modified a standard mouse running wheel to include a force-sensitive rung capable of measuring the normal and tangential forces applied by individual paws. Force data were collected throughout the night using an automated threshold trigger algorithm that synchronized force data with wheel-angle data and a high-speed infrared video file. During the first night of wheel running, mice reached consistent running speeds within the first 40 force events, indicating a rapid habituation to wheel running, given that mice generated >2,000 force-event files/night. Average running speeds and peak normal and tangential forces were consistent throughout the first four nights of running, indicating that one night of running is sufficient to characterize the locomotor biomechanics of healthy mice. Twelve weeks of wheel running significantly increased spontaneous wheel-running speeds (16 vs. 37 m/min), lowered duty factors (ratio of foot-ground contact time to stride time; 0.71 vs. 0.58), and raised hindlimb peak normal forces (93 vs. 115% body wt) compared with inexperienced mice. Peak normal hindlimb-force magnitudes were the primary force component, which were nearly tenfold greater than peak tangential forces. Peak normal hindlimb forces exceed the vertical forces generated during overground running (50-60% body wt), suggesting that wheel running shifts weight support toward the hindlimbs. This force-instrumented running-wheel system provides a comprehensive, noninvasive screening method for monitoring gait biomechanics in mice during spontaneous locomotion. PMID:22723628

A Study of Torque Vectoring and Traction Control for an All-Wheel Drive Electric Vehicle

Directory of Open Access Journals (Sweden)

Maharun Mui’nuddin

2014-07-01

Full Text Available Common vehicle always experience energy loss during cornering manoeuver. Thus, to ensure it did not happened especially at high speed, a study of torque vectoring and traction control need to be made since it can increase the traction control of tyres during cornering at high speed. The study of torque vectoring and traction control for an all-wheel drive electric vehicle was conducted by modelling an all-wheel drive electric vehicle (EV in ADAMS/Car software. In addition, an optimal control algorithm will be developed for best performance to minimize energy losses using MATLAB/Simulink software. Furthermore, to prove the effectiveness of the all-wheel drive electric, the torque and traction control simulation of the all-wheel drive electric vehicle will be compared with uncontrolled electric vehicle model. According to the result, torque vectoring and traction control of in-wheel motor in all wheel drive EV can help to increase the performance of the electric vehicle during cornering manoeuver. In conclusion, this study of torque vectoring and traction control for an all-wheel drive electric vehicle will help researchers to improve the design of the future electric vehicle in term of the vehicle performance during cornering manoeuvre.

High-speed, low-damage grinding of advanced ceramics Phase 1. Final report

Energy Technology Data Exchange (ETDEWEB)

Kovach, J.A. [Eaton Corp., Willoughby Hills, OH (United States). Mfg. Technologies Center; Malkin, S. [Univ. of Massachusetts (United States)

1995-03-01

In manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. Most of these costs arise from the conventional multi-step grinding process with numerous grinding wheels and additional capital equipment, perishable dressing tools, and labor. In an attempt to reduce structural ceramic grinding costs, a feasibility investigation was undertaken to develop a single step, roughing-finishing process suitable for producing high-quality silicon nitride ceramic parts at high material removal rates at lower cost than traditional, multi-stage grinding. This feasibility study employed combined use of laboratory grinding tests, mathematical grinding models, and characterization of resultant material surface condition. More specifically, this Phase 1 final report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding and the conditions necessary to achieve the small grain depths of cut necessary for low damage grinding while operating at relatively high material removal rates. Particular issues addressed include determining effects of wheel speed and material removal rate on resulting mode of material removal (ductile or brittle fracture), limiting grinding forces, calculation of approximate grinding zone temperatures developed during HSLD grinding, and developing the experimental systems necessary for determining HSLD grinding energy partition relationships. In addition, practical considerations for production utilization of the HSLD process are also discussed.

Computation of wheel-rail contact force for non-mapping wheel-rail profile of Translohr tram

Science.gov (United States)

Ji, Yuanjin; Ren, Lihui; Zhou, Jinsong

2017-09-01

Translohr tram has steel wheels, in V-like arrangements, as guide wheels. These operate over the guide rails in inverted-V arrangements. However, the horizontal and vertical coordinates of the guide wheels and guide rails are not always mapped one-to-one. In this study, a simplified elastic method is proposed in order to calculate the contact points between the wheels and the rails. By transforming the coordinates, the non-mapping geometric relationship between wheel and rail is converted into a mapping relationship. Considering the Translohr tram's multi-point contact between the guide wheel and the guide rail, the elastic-contact hypothesis take into account the existence of contact patches between the bodies, and the location of the contact points is calculated using a simplified elastic method. In order to speed up the calculation, a multi-dimensional contact table is generated, enabling the use of simulation for Translohr tram running on curvatures with different radii.

Simulation and Measurement of Wheel on Rail Fatigue and Wear

OpenAIRE

Dirks, Babette

2015-01-01

The life of railway wheels and rails has been decreasing in recent years. This is mainly caused by more traffic and running at higher vehicle speed. A higher speed usually generates higher forces, unless compensated by improved track and vehicle designs, in the wheel-rail contact, resulting in more wear and rolling contact fatigue (RCF) damage to the wheels and rails. As recently as 15 years ago, RCF was not recognised as a serious problem. Nowadays it is a serious problem in many countries a...

Stocks and flows of lead-based wheel weights in the United States

Science.gov (United States)

Bleiwas, Donald I.

2006-01-01

Lead is used in many widely known applications, such as automobile batteries and radiation shielding. Another lesser known, but long-term, use of lead is in automotive vehicle wheel weights. Lead weights have been used to balance wheels since the 1930s because of its high specific gravity, low relative cost, and its malleability. Out-of-balance tires tend to 'cup' and vibrate and as a result cause excessive wear on tires and vehicle suspension components and result in compromised handling, especially at high speeds. The mass, number, and style of weights needed to balance a wheel depend on the tire's size and weight and on the type and condition of the wheels (rims) on the vehicle. This study addresses an accounting of the stocks and flows of lead contained in lead wheel weights from their manufacture, through use, dissipation, and recycling, and environmental issues associated with the use of lead.

Tilted wheel satellite attitude control with air-bearing table experimental results

Science.gov (United States)

Inumoh, Lawrence O.; Forshaw, Jason L.; Horri, Nadjim M.

2015-12-01

Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

General motors front wheel drive 2-mode hybrid transmission

Energy Technology Data Exchange (ETDEWEB)

Hendrickson, James [General Motors Corp., Pontiac, MI (United States). New Transmission Products Group.; Holmes, Alan G. [General Motors Corp., Pontiac, MI (United States). Powertrain Hybrid Architecture

2009-07-01

General Motors now expands the application of two-mode hybrid technology to front wheel drive vehicles with the development of a hybrid electric transmission packaged into essentially the same space as a conventional automatic transmission for front wheel drive. This was accomplished using a space-efficient arrangement based on two planetary gear sets and electric motor-generators with large internal diameters. A combination of damper and hydraulically-controlled clutch allow comfortable shutdown and restarting of large-displacement engines in front wheel drive vehicles. The hybrid system delivers electric low-speed urban driving, two continuously variable ranges of transmission speed ratios, four fixed transmission speed ratios, electric acceleration boosting, and regenerative braking. In the first vehicle application, the two-mode hybrid helps to reduce vehicle fuel consumption by approximately one-third. (orig.)

Design procedure for a wind-wheel with self-adjusting blade mechanism

Directory of Open Access Journals (Sweden)

Gennady A. Oborsky

2014-12-01

Full Text Available Developed is a wind-wheel design equipped with the self-adjusting blade. The blade is positioned eccentrically to the balance wheel and can freely rotate around its axis. Elaborated is the method of calculating the energy characteristics for a wind-wheel with the self-adjusting blade, considering not only the wind force but the force of air counter flow resistance to the blade’s rotation. Initially, the blade being located at an angle α = 45 to the wheel rotation plane, the air flow rotates the wheel with the maximum force. Thus, the speed of rotation increases that involves the increase in air counter flow resistance and results in blade turning with respective angle α reduction. This, consequently, reduces the torque. When the torsional force and the resistance enter into equilibrium, the blade takes a certain angle α, and the wheel speed becomes constant. This wind-wheel design including a self-adjusting blade allows increasing the air flow load ratio when compared to the wind-wheel equipped with a jammed blade.

Reaction Wheel Disturbance Model Extraction Software - RWDMES

Science.gov (United States)

Blaurock, Carl

2009-01-01

The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

The Design of a Permanent Magnet In-Wheel Motor with Dual-Stator and Dual-Field-Excitation Used in Electric Vehicles

Directory of Open Access Journals (Sweden)

Peng Gao

2018-02-01

Full Text Available The in-wheel motor has received more attention owing to its simple structure, high transmission efficiency, flexible control, and easy integration design. It is difficult to achieve high performance with conventional motors due to their dimensions and structure. This paper presents a new dual-stator and dual-field-excitation permanent-magnet in-wheel motor (DDPMIM that is based on the structure of the conventional in-wheel motor and the structure of both the radial and axial magnetic field motor. The finite element analysis (FEA model of the DDPMIM is established and compared with that of the conventional in-wheel motor. The results show that the DDPMIM achieves a higher output torque at low speeds and that the flux-weakening control strategy is not needed in the full speed range.

Out-of-round railway wheels—assessment of wheel tread irregularities in train traffic

Science.gov (United States)

Johansson, Anders

2006-06-01

Results from an extensive wheel measurement campaign performed in Sweden are given and discussed. Out-of-roundness (OOR), transverse profile and surface hardness of 99 wheels on passenger trains (X2 and intercity), freight trains, commuter trains (Regina) and underground trains (C20) were measured. Both tread and disc braked wheels were investigated. The selected wheels had travelled a distance of more than 100000 km, and the measurements were conducted when the train wagons/coaches had been taken out of traffic for maintenance, most of them due to reasons other than wheel OOR. Mechanical contact measurement methods were used. The highest roughness levels (higher than 20 dB re 1 μm for some wheels) were found on powered high-speed (X2) train wheels. The previously known polygonalization of C20 underground wheels is quantified. It is also verified that an initial irregularity is formed due to the clamping in a three-jaw chuck during profiling of new C20 wheels. Magnitudes and wavelength contents of measured wheel roughness are compared with corresponding measurements of rail roughness.

Nesting behavior of house mice (Mus domesticus) selected for increased wheel-running activity.

Science.gov (United States)

Carter, P A; Swallow, J G; Davis, S J; Garland, T

2000-03-01

Nest building was measured in "active" (housed with access to running wheels) and "sedentary" (without wheel access) mice (Mus domesticus) from four replicate lines selected for 10 generations for high voluntary wheel-running behavior, and from four randombred control lines. Based on previous studies of mice bidirectionally selected for thermoregulatory nest building, it was hypothesized that nest building would show a negative correlated response to selection on wheel-running. Such a response could constrain the evolution of high voluntary activity because nesting has also been shown to be positively genetically correlated with successful production of weaned pups. With wheel access, selected mice of both sexes built significantly smaller nests than did control mice. Without wheel access, selected females also built significantly smaller nests than did control females, but only when body mass was excluded from the statistical model, suggesting that body mass mediated this correlated response to selection. Total distance run and mean running speed on wheels was significantly higher in selected mice than in controls, but no differences in amount of time spent running were measured, indicating a complex cause of the response of nesting to selection for voluntary wheel running.

Deformation and lifetime behaviour of cyclic loaded rail and wheel steels

Energy Technology Data Exchange (ETDEWEB)

Denne, B.; Lang, K.-H.; Loehe, D. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Werkstoffkunde 1

2000-07-01

Corrugation, shelling and squats are some unexpected technical problems caused by increasing service tonnage, increasing load of the rails and increasing train speed at Deutsche Bahn AG lines since the last decades. As the complex phenomena of rolling contact fatigue in the rail / wheel system is difficult to understand extensive investigations have to be done to describe the multiaxial rolling contact fatigue processes and to develop and verify multiaxial fatigue criteria and lifetime predictions. To reach this aim a reliable fatigue data base of the utilised steels is required. To obtain such data, specimens were worked out of rails and wheels used in high speed traffic. With these specimens the lifetime behaviour and the endurance limit were estimated from push-pull tests. For the rail steel stress and total strain controlled fatigue tests were performed. The resulting lifetime behaviour is compared. In the wheel there are several regions with different microstructures due to the heat treatment at the end of the manufacturing process. Specimens were taken from the wheel rim representing these different microstructures. With these specimens stress controlled fatigue tests were performed. The influence of the different microstructures on the deformation and lifetime behaviour is showed. (orig.)

Western diet increases wheel running in mice selectively bred for high voluntary wheel running.

Science.gov (United States)

Meek, T H; Eisenmann, J C; Garland, T

2010-06-01

Mice from a long-term selective breeding experiment for high voluntary wheel running offer a unique model to examine the contributions of genetic and environmental factors in determining the aspects of behavior and metabolism relevant to body-weight regulation and obesity. Starting with generation 16 and continuing through to generation 52, mice from the four replicate high runner (HR) lines have run 2.5-3-fold more revolutions per day as compared with four non-selected control (C) lines, but the nature of this apparent selection limit is not understood. We hypothesized that it might involve the availability of dietary lipids. Wheel running, food consumption (Teklad Rodent Diet (W) 8604, 14% kJ from fat; or Harlan Teklad TD.88137 Western Diet (WD), 42% kJ from fat) and body mass were measured over 1-2-week intervals in 100 males for 2 months starting 3 days after weaning. WD was obesogenic for both HR and C, significantly increasing both body mass and retroperitoneal fat pad mass, the latter even when controlling statistically for wheel-running distance and caloric intake. The HR mice had significantly less fat than C mice, explainable statistically by their greater running distance. On adjusting for body mass, HR mice showed higher caloric intake than C mice, also explainable by their higher running. Accounting for body mass and running, WD initially caused increased caloric intake in both HR and C, but this effect was reversed during the last four weeks of the study. Western diet had little or no effect on wheel running in C mice, but increased revolutions per day by as much as 75% in HR mice, mainly through increased time spent running. The remarkable stimulation of wheel running by WD in HR mice may involve fuel usage during prolonged endurance exercise and/or direct behavioral effects on motivation. Their unique behavioral responses to WD may render HR mice an important model for understanding the control of voluntary activity levels.

Wheel slip dump valve for railway braking system

Science.gov (United States)

Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao

2017-09-01

As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

Further study on the wheel-rail impact response induced by a single wheel flat: the coupling effect of strain rate and thermal stress

Science.gov (United States)

Jing, Lin; Han, Liangliang

2017-12-01

A comprehensive dynamic finite-element simulation method was proposed to study the wheel-rail impact response induced by a single wheel flat based on a 3-D rolling contact model, where the influences of the structural inertia, strain rate effect of wheel-rail materials and thermal stress due to the wheel-rail sliding friction were considered. Four different initial conditions (i.e. pure mechanical loading plus rate-independent, pure mechanical loading plus rate-dependent, thermo-mechanical loading plus rate-independent, and thermo-mechanical loading plus rate-dependent) were involved into explore the corresponding impact responses in term of the vertical impact force, von-Mises equivalent stress, equivalent plastic strain and shear stress. Influences of train speed, flat length and axle load on the flat-induced wheel-rail impact response were discussed, respectively. The results indicate that the maximum thermal stresses are occurred on the tread of the wheel and on the top surface of the middle rail; the strain rate hardening effect contributes to elevate the von-Mises equivalent stress and restrain the plastic deformation; and the initial thermal stress due to the sliding friction will aggravate the plastic deformation of wheel and rail. Besides, the wheel-rail impact responses (i.e. impact force, von-Mises equivalent stress, equivalent plastic strain, and XY shear stress) induced by a flat are sensitive to the train speed, flat length and axle load.

Computational Model for Impact-Resisting Critical Thickness of High-Speed Machine Outer Protective Plate

Science.gov (United States)

Wu, Huaying; Wang, Li Zhong; Wang, Yantao; Yuan, Xiaolei

2018-05-01

The blade or surface grinding blade of the hypervelocity grinding wheel may be damaged due to too high rotation rate of the spindle of the machine and then fly out. Its speed as a projectile may severely endanger the field persons. Critical thickness model of the protective plate of the high-speed machine is studied in this paper. For easy analysis, the shapes of the possible impact objects flying from the high-speed machine are simplified as sharp-nose model, ball-nose model and flat-nose model. Whose front ending shape to represent point, line and surface contacting. Impact analysis based on J-C model is performed for the low-carbon steel plate with different thicknesses in this paper. One critical thickness computational model for the protective plate of high-speed machine is established according to the damage characteristics of the thin plate to get relation among plate thickness and mass, shape and size and impact speed of impact object. The air cannon is used for impact test. The model accuracy is validated. This model can guide identification of the thickness of single-layer outer protective plate of a high-speed machine.

Modeling and analysis of linearized wheel-rail contact dynamics

International Nuclear Information System (INIS)

Soomro, Z.

2014-01-01

The dynamics of the railway vehicles are nonlinear and depend upon several factors including vehicle speed, normal load and adhesion level. The presence of contaminants on the railway track makes them unpredictable too. Therefore in order to develop an effective control strategy it is important to analyze the effect of each factor on dynamic response thoroughly. In this paper a linearized model of a railway wheel-set is developed and is later analyzed by varying the speed and adhesion level by keeping the normal load constant. A wheel-set is the wheel-axle assembly of a railroad car. Patch contact is the study of the deformation of solids that touch each other at one or more points. (author)

Mice from lines selectively bred for high voluntary wheel running exhibit lower blood pressure during withdrawal from wheel access.

Science.gov (United States)

Kolb, Erik M; Kelly, Scott A; Garland, Theodore

2013-03-15

Exercise is known to be rewarding and have positive effects on mental and physical health. Excessive exercise, however, can be the result of an underlying behavioral/physiological addiction. Both humans who exercise regularly and rodent models of exercise addiction sometimes display behavioral withdrawal symptoms, including depression and anxiety, when exercise is denied. However, few studies have examined the physiological state that occurs during this withdrawal period. Alterations in blood pressure (BP) are common physiological indicators of withdrawal in a variety of addictions. In this study, we examined exercise withdrawal in four replicate lines of mice selectively bred for high voluntary wheel running (HR lines). Mice from the HR lines run almost 3-fold greater distances on wheels than those from non-selected control lines, and have altered brain activity as well as increased behavioral despair when wheel access is removed. We tested the hypothesis that male HR mice have an altered cardiovascular response (heart rate, systolic, diastolic, and mean arterial pressure [MAP]) during exercise withdrawal. Measurements using an occlusion tail-cuff system were taken during 8 days of baseline, 6 days of wheel access, and 2 days of withdrawal (wheel access blocked). During withdrawal, HR mice had significantly lower systolic BP, diastolic BP, and MAP than controls, potentially indicating a differential dependence on voluntary wheel running in HR mice. This is the first characterization of a cardiovascular withdrawal response in an animal model of high voluntary exercise. Copyright © 2013. Published by Elsevier Inc.

Integration of uniform design and quantum-behaved particle swarm optimization to the robust design for a railway vehicle suspension system under different wheel conicities and wheel rolling radii

Science.gov (United States)

Cheng, Yung-Chang; Lee, Cheng-Kang

2017-10-01

This paper proposes a systematic method, integrating the uniform design (UD) of experiments and quantum-behaved particle swarm optimization (QPSO), to solve the problem of a robust design for a railway vehicle suspension system. Based on the new nonlinear creep model derived from combining Hertz contact theory, Kalker's linear theory and a heuristic nonlinear creep model, the modeling and dynamic analysis of a 24 degree-of-freedom railway vehicle system were investigated. The Lyapunov indirect method was used to examine the effects of suspension parameters, wheel conicities and wheel rolling radii on critical hunting speeds. Generally, the critical hunting speeds of a vehicle system resulting from worn wheels with different wheel rolling radii are lower than those of a vehicle system having original wheels without different wheel rolling radii. Because of worn wheels, the critical hunting speed of a running railway vehicle substantially declines over the long term. For safety reasons, it is necessary to design the suspension system parameters to increase the robustness of the system and decrease the sensitive of wheel noises. By applying UD and QPSO, the nominal-the-best signal-to-noise ratio of the system was increased from -48.17 to -34.05 dB. The rate of improvement was 29.31%. This study has demonstrated that the integration of UD and QPSO can successfully reveal the optimal solution of suspension parameters for solving the robust design problem of a railway vehicle suspension system.

Evaluation of wheel/rail contact mechanics : roller rig concept design review.

Science.gov (United States)

2014-07-01

A need exists for a new test rig design with advanced sensing technologies that will allow the railroad industry and regulatory : agencies to better understand the wheel-rail contact dynamics and mechanics, especially as it pertains to high-speed rai...

TECHNICAL NOTE: High-speed grinding using thin abrasive disks for microcomponents

Science.gov (United States)

Yeo, S. H.; Balon, S. A. P.

2002-01-01

This paper introduces the development of a high-speed grinding device for cylindrical grinding of microcomponents made of hard and brittle materials. The study made use of an ultraprecision diamond turning machine tool as a basic platform. The novelty of the device is based on the high-speed air bearing spindle with a thin grinding wheel, similar to the dicing technology for silicon wafer fabrication. The spindle attachment is inclined at an angle to the main spindle which holds the precision fixture mechanism via the vacuum chuck. Experiments have been conducted to verify the design and implementation of the grinding methodology. A feature size as small as 31 μm in diameter and average surface roughness of 98 nm were obtained in the experimental work. It is found that the work done is capable of manufacturing miniature components, such as microcylindrical stepped shafts.

Canadian high speed magnetically levitated vehicle system

Energy Technology Data Exchange (ETDEWEB)

Atherton, D L [Queen' s Univ., Kingston, Ont.; Belanger, P R; Burke, P E; Dawson, G E; Eastham, A R; Hayes, W F; Ooi, B T; Silvester, P; Slemon, G R

1978-04-01

A technically feasible high speed (400 to 480 km/h) guided ground transportation system, based on the use of the vehicle-borne superconducting magnets for electrodynamic suspension and guidance and for linear synchronous motor propulsion was defined as a future modal option for Canadian application. Analysis and design proposals were validated by large-scale tests on a rotating wheel facility and by modelling system components and their interactions. Thirty ton vehicles carrying 100 passengers operate over a flat-topped elevated guideway, which minimizes system down-time due to ice and snow accumulation and facilitates the design of turn-outs. A clearance of up to 15 cm is produced by the electrodynamic interaction between the vehicle-borne superconducting magnets and aluminum guideway strips. Propulsion and automatic system control is provided by the superconducting linear synchronous motor which operates at good efficiency (0.74) and high power factor (0.95). The vehicle is guided primarily by the interaction between the LSM field magnet array and flat null-flux loops overlying the stator windings in the guideway. The linear synchronous motor, electrodynamic suspension as well as levitation strip joints, parasitic LSM winding losses and limitations to the use of ferromagnetic guideway reinforcement were investigated experimentally on the test wheel facility. The use of a secondary suspension assures adequate dynamic stability, and good ride quality is achieved by optimized passive components with respect to lateral modes and by an actively controlled secondary suspension with respect to vertical motion.

Development of High-Speed, Low-fixed Latency Serial Links for the Router of ATLAS NSW sTGC Detector

CERN Document Server

Hu, Xueye; The ATLAS collaboration

2014-01-01

The ATLAS experiment at the Large Hadron Collider (LHC) needs to be upgraded in order to cope with the increased luminosity and particle rates expected for the High Luminosity LHC (HL­LHC) running. Part of the phase­1 upgrade, to be done in the 2018/19 shutdown, is the replacement of the present muon forward detector (wheel) by a new detector, the so called New Small Wheel (NSW). The NSW detector consists of two detector technologies and the work here is on the small­strip Thin­Gap Chambers (sTGC). For sTGC, it requires very high­speed electronic triggering of signal events. The data must be quickly digitized, serialized, and transmitted off­detector for computer processing. The serialized data is sent to the trigger processor through a routing system that serves as a switchyard for all active signals. Design requirements on the router are low latency and stable/predictable data transfer timing with high­speed serial links (4.8 Gbps). We describe a 4.8 Gbps (maximum 6.6 Gbps) serial link structure base...

Influence of Wheel Eccentricity on Vertical Vibration of Suspended Monorail Vehicle: Experiment and Simulation

Directory of Open Access Journals (Sweden)

Kaikai Lv

2017-01-01

Full Text Available This paper investigates the influence of wheel eccentricity on vertical vibration of suspended monorail vehicle based on experiment and simulation. Two sets of tests are conducted in the first Chinese suspended monorail, and the tested acceleration is analyzed and exhibited. A multibody dynamic model of the suspended monorail vehicle is established to simulate the vertical vibration of car body excited by wheel eccentricity. The results show that there are three factors which may cause an abnormal vibration considering the track and the vehicle system. The influence of wheel eccentricity on the car body vibration was firstly analyzed. Simulated acceleration of car body has a great accordance with test. The wheel eccentricity could excite the resonance of car body at the speed of 21 km/h, and the vertical acceleration would increase considerably. Decreasing the secondary stiffness can effectively reduce the vertical vibration caused by wheel eccentricity, especially at the resonant speed. In the secondary test, the peak of car body acceleration at speed of 20 km/h is not appearing when only renewing the wheels, and the acceleration is decreasing obviously at the domain frequency. It is further determined that the abnormal vibration is mainly caused by the wheel eccentricity.

Design Optimization of Heat Wheels for Energy Recovery in HVAC Systems

Directory of Open Access Journals (Sweden)

Stefano De Antonellis

2014-11-01

Full Text Available Air to air heat exchangers play a crucial role in mechanical ventilation equipment, due to the potential primary energy savings both in case of refurbishment of existing buildings or in case of new ones. In particular, interest in heat wheels is increasing due to their low pressure drop and high effectiveness. In this paper a detailed optimization of design parameters of heat wheels is performed in order to maximize sensible effectiveness and to minimize pressure drop. The analysis is carried out through a one dimensional lumped parameters heat wheel model, which solves heat and mass transfer equations, and through appropriate correlations to estimate pressure drop. Simulation results have been compared with experimental data of a heat wheel tested in specific facilities, and good agreement is attained. The device optimization is performed through the variation of main design parameters, such as heat wheel length, channel base, height and thickness and for different operating conditions, namely the air face velocity and the revolution speed. It is shown that the best configurations are achieved with small channel thickness and, depending on the required sensible effectiveness, with appropriate values of wheel length and channel base and height.

Experimental analysis on performance of high temperature heat pump and desiccant wheel system

DEFF Research Database (Denmark)

Sheng, Ying; Zhang, Yufeng; Deng, Na

2013-01-01

In order to solve the problem of high energy consumption for regeneration of desiccant wheel in the rotary desiccant system, high temperature heat pump and desiccant wheel (HTHP&DW) system and corresponding air conditioning unit is built and tested in the extensive thermal hygrometric environment...

Peculiarities of Clutch Forming Rails and Wheel Block Construction

Science.gov (United States)

Shiler, V. V.; Galiev, I. I.; Shiler, A. V.

2018-03-01

The clutch of the wheel and rail is significantly influenced by the design features of the standard wheel pair, which are manifested in the presence of "parasitic" slipping of the wheels along the rails during its movement. The purpose of the presented work is to evaluate new design solutions for wheel sets. The research was carried out using methods of comparative simulation modelling and physical prototyping. A new design of the wheel pair (block wheel pair) is proposed, which features an independent rotation of all surfaces of the wheels in contact with the rails. The block construction of the wheel pair forms open mechanical contours with the track gauge, which completely eliminates the "parasitic" slippage. As a result, in the process of implementing traction or braking forces, the coupling coefficient of the block construction of the wheel pair is significantly higher than that of existing structures. In addition, in the run-out mode, the resistance to movement of the block wheel pair is half as much. All this will allow one to significantly reduce the energy consumption for traction of trains, wear of track elements and crew, and to increase the speed and safety of train traffic.

Design of wheel-type walking-assist device

International Nuclear Information System (INIS)

Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

2006-03-01

In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed

Dynamic Rocker-Bogie: Kinematical Analysis in a High-Speed Traversal Stability Enhancement

Directory of Open Access Journals (Sweden)

Sunxin Wang

2016-01-01

Full Text Available The rocker-bogie suspension system has robust capabilities to deal with uneven terrain because of its distributing of the payload over its six wheels uniformly, while there is one major shortcoming to high-speed traversal over the planar terrain. This paper proposes a new dynamic rocker-bogie suspension system with two modes of operation: it can expand the span of the rocker-bogie support polygon to increase travel rate when the terrain is planar; and it can switch to its original configuration to move by low speed when it is faced with rough terrain. The analysis on dynamic stability margin and kinematical simulation on the two operating modes of rocker-bogie are employed to analyze and verify the rationality and effectiveness of the modification in the structure.

Accounting of possibilities of blade oscillation emergence at the calculation of operating wheel of turbomolecular vacuum pump

International Nuclear Information System (INIS)

Pereslavlev, A.V.

1988-01-01

Possibilities of blade oscillation emergence in the operating wheel of turbomolecular vacuum pump (TVP) are considered. Permissible value of safety factor for tensile strength in the operating wheel blade root section, at which the necessary fatigue limit of a material is provided for (k=2 for aluminium alloys and k=1.5 for VT-8 titanium alloy) is determined. Methods of calculating the main dimensions of blade operating wheel on the basis of the specified maximum pumping speed, taking account of possibilities of blade oscillation emergence are presented. Results of calculating the 4S max/πD 2 2 complex, characterizing maximum speed of operating wheel pumping, depending on permissible tensipn in the blade root section (σ), are given. It is shown that (σ increase above (2.5 2.7)x10 8 Pa for aluminium alloys and above ∼ 4x10 8 Pa for VT titanium alloy don't cause increase of operating wheel maximum pumping speed. 8 refs.; 6 figs

Origami Wheel Transformer: A Variable-Diameter Wheel Drive Robot Using an Origami Structure.

Science.gov (United States)

Lee, Dae-Young; Kim, Sa-Reum; Kim, Ji-Suk; Park, Jae-Jun; Cho, Kyu-Jin

2017-06-01

A wheel drive mechanism is simple, stable, and efficient, but its mobility in unstructured terrain is seriously limited. Using a deformable wheel is one of the ways to increase the mobility of a wheel drive robot. By changing the radius of its wheels, the robot becomes able to pass over not only high steps but also narrow gaps. In this article, we propose a novel design for a variable-diameter wheel using an origami-based soft robotics design approach. By simply folding a patterned sheet into a wheel shape, a variable-diameter wheel was built without requiring lots of mechanical parts and a complex assembly process. The wheel's diameter can change from 30 to 68 mm, and it is light in weight at about 9.7 g. Although composed of soft materials (fabrics and films), the wheel can bear more than 400 times its weight. The robot was able to change the wheel's radius in response to terrain conditions, allowing it to pass over a 50-mm gap when the wheel is shrunk and a 50-mm step when the wheel is enlarged.

Experiments on a Tail-wheel Shimmy

Science.gov (United States)

Harling, R; Dietz, O

1954-01-01

Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumatic tires (scale 1:2) more accurate investigations were made on the tail wheel itself. The results of drum and road tests show good agreement with one another and with model values. Detailed investigations were made regarding the dependence of the shimmy tendency on trail, rolling speed, load, size of tires, ground friction,and inclination of the swivel axis; furthermore, regarding the influence of devices with restoring effect on the tail wheel, and the friction damping required for prevention of shimmy. Finally observations from slow-motion pictures are reported and conclusions drawn concerning the influence of tire deformation.

Mechatronic track guidance on disturbed track: the trade-off between actuator performance and wheel wear

Science.gov (United States)

Kurzeck, Bernhard; Heckmann, Andreas; Wesseler, Christoph; Rapp, Matthias

2014-05-01

Future high-speed trains are the main focus of the DLR research project Next Generation Train. One central point of the research activities is the development of mechatronic track guidance for the two-axle intermediate wagons with steerable, individually powered, independently rotating wheels. The traction motors hereby fulfil two functions; they concurrently are traction drives and steering actuators. In this paper, the influence of the track properties - line layout and track irregularities - on the performance requirements for the guidance actuator is investigated using multi-body models in SIMPACK®. In order to compromise on the design conflict between low wheel wear and low steering torque, the control parameters of the mechatronic track guidance are optimised using the DLR in-house software MOPS. Besides the track irregularities especially the increasing inclination at transition curves defines high actuator requirements due to gyroscopic effects at high speed. After introducing a limiter for the actuating variables into the control system, a good performance is achieved.

Stability Simulation of a Vehicle with Wheel Active Steering

Directory of Open Access Journals (Sweden)

Brabec Pavel

2016-01-01

Full Text Available This paper deals with the possibility of increasing the vehicle driving stability at a higher speed. One of the ways how to achieve higher stability is using the 4WS system. Mathematical description of vehicle general movement is a very complex task. For simulation, models which are aptly simplified are used. For the first approach, so-called single-truck vehicle model (often linear is usually used. For the simulation, we have chosen to extend the model into a two-truck one, which includes the possibility to input more vehicle parameters. Considering the 4WS system, it is possible to use a number of potential regulations. In our simulation model, the regulation system with compound coupling was used. This type of regulation turns the rear wheels depending on the input parameters of the system (steering angle of the front wheels and depending on the output moving quantities of the vehicle, most frequently the yaw rate. Criterion for compensation of lateral deflection centre of gravity angle is its zero value, or more precisely the zero value of its first-order derivative. Parameters and set-up of the simulation model were done in conjunction with the dSAPACE software. Reference performances of the vehicle simulation model were made through the defined manoeuvres. But the simulation results indicate that the rear-wheels steering can have a positive effect on the vehicle movement stability, especially when changing the driving direction at high speed.

An Innovative Running Wheel-based Mechanism for Improved Rat Training Performance.

Science.gov (United States)

Chen, Chi-Chun; Yang, Chin-Lung; Chang, Ching-Ping

2016-09-19

This study presents an animal mobility system, equipped with a positioning running wheel (PRW), as a way to quantify the efficacy of an exercise activity for reducing the severity of the effects of the stroke in rats. This system provides more effective animal exercise training than commercially available systems such as treadmills and motorized running wheels (MRWs). In contrast to an MRW that can only achieve speeds below 20 m/min, rats are permitted to run at a stable speed of 30 m/min on a more spacious and high-density rubber running track supported by a 15 cm wide acrylic wheel with a diameter of 55 cm in this work. Using a predefined adaptive acceleration curve, the system not only reduces the operator error but also trains the rats to run persistently until a specified intensity is reached. As a way to evaluate the exercise effectiveness, real-time position of a rat is detected by four pairs of infrared sensors deployed on the running wheel. Once an adaptive acceleration curve is initiated using a microcontroller, the data obtained by the infrared sensors are automatically recorded and analyzed in a computer. For comparison purposes, 3 week training is conducted on rats using a treadmill, an MRW and a PRW. After surgically inducing middle cerebral artery occlusion (MCAo), modified neurological severity scores (mNSS) and an inclined plane test were conducted to assess the neurological damages to the rats. PRW is experimentally validated as the most effective among such animal mobility systems. Furthermore, an exercise effectiveness measure, based on rat position analysis, showed that there is a high negative correlation between the effective exercise and the infarct volume, and can be employed to quantify a rat training in any type of brain damage reduction experiments.

High Fat High Sugar Diet Reduces Voluntary Wheel Running in Mice Independent of Sex Hormone Involvement

Science.gov (United States)

Vellers, Heather L.; Letsinger, Ayland C.; Walker, Nicholas R.; Granados, Jorge Z.; Lightfoot, J. Timothy

2017-01-01

Introduction: Indirect results in humans suggest that chronic overfeeding decreases physical activity with few suggestions regarding what mechanism(s) may link overfeeding and decreased activity. The primary sex hormones are known regulators of activity and there are reports that chronic overfeeding alters sex hormone levels. Thepurpose of this study was to determine if chronic overfeeding altered wheel running through altered sex hormone levels. Materials and Methods: C57BL/6J mice were bred and the pups were weaned at 3-weeks of age and randomly assigned to either a control (CFD) or high fat/high sugar (HFHS) diet for 9–11 weeks depending on activity analysis. Nutritional intake, body composition, sex hormone levels, and 3-day and 2-week wheel-running activity were measured. Additionally, groups of HFHS animals were supplemented with testosterone (males) and 17β-estradiol (females) to determine if sex hormone augmentation altered diet-induced changes in activity. Results: 117 mice (56♂, 61♀) were analyzed. The HFHS mice consumed significantly more calories per day than CFD mice (male: p running-wheel distance in male (p = 0.05, 70 ± 28%) and female mice (p = 0.02, 57 ± 26%). In animals that received hormone supplementation, there was no significant effect on activity levels. Two-weeks of wheel access was not sufficient to alter HFHS-induced reductions in activity or increases in body fat. Conclusion: Chronic overfeeding reduces wheel running, but is independent of the primary sex hormones. PMID:28890701

Dynamic Modeling and Vibration Analysis for the Vehicles with Rigid Wheels Based on Wheel-Terrain Interaction Mechanics

Directory of Open Access Journals (Sweden)

Jianfeng Wang

2015-01-01

Full Text Available The contact mechanics for a rigid wheel and deformable terrain are complicated owing to the rigid flexible coupling characteristics. Bekker’s equations are used as the basis to establish the equations of the sinking rolling wheel, to vertical load pressure relationship. Since vehicle movement on the Moon is a complex and on-going problem, the researcher is poised to simplify this problem of vertical loading of the wheel. In this paper, the quarter kinetic models of a manned lunar rover, which are both based on the rigid road and deformable lunar terrain, are used as the simulation models. With these kinetic models, the vibration simulations were conducted. The simulation results indicate that the quarter kinetic model based on the deformable lunar terrain accurately reflects the deformable terrain’s influence on the vibration characteristics of a manned lunar rover. Additionally, with the quarter kinetic model of the deformable terrain, the vibration simulations of a manned lunar rover were conducted, which include a parametric analysis of the wheel parameters, vehicle speed, and suspension parameters. The results show that a manned lunar rover requires a lower damping value and stiffness to achieve better vibration performance.

Modelling and simulation of dynamic wheel-rail interaction using a roller rig

International Nuclear Information System (INIS)

Anyakwo, A; Pislaru, C; Ball, A; Gu, F

2012-01-01

The interaction between the wheel and rail greatly influences the dynamic response of railway vehicles on the track. A roller rig facility can be used to study and monitor real time parameters that influence wheel-rail interaction such as wear, adhesion, friction and corrugation without actual field tests being carried out. This paper presents the development of the mathematical models for full scale roller rig and 1/5 scale roller rig and the wear prediction model based on KTH wear function. The simulated critical speed for the 1/5 scale roller rig is about one-fifth of the critical speed for the full scale model so the simulated results compare well with the theory related to wheel-rail contact and dynamics. Also the differences between the simulated rolling radii for the full scale model with and without wear function are analysed. This paper presents the initial stage of a large scale research project where the influence of wear on the wheel-rail performance will be studied in more depth.

THE PROCESS OF FORMATION OF RAILWAY WHEEL DAMAGES AND TIRES IN OPERATION

Directory of Open Access Journals (Sweden)

N. A. Grischenko

2015-01-01

Full Text Available Purpose. The dependence analysis of structural changes in the metal of railway wheels and tires from indicated influences in operation, for the further development of strategy of service reliability growth. Methodology. Test materials are the details selected from railway wheels which were taken out of operation beforehand because of various damages. Micro-structural researches were made with the use of light microscope Epiquant and electron microscope. The sizing of structural elements was done by using the methods of quantitative metallography. Findings. Over the past few decades the rapid development of industry was supported by the steady growth of intensity of using railway transport. In this case simultaneous increase of load at wheel set axle, with the increase of speed was accompanied by natural increase of the amount of cases of premature wheels and tires’ withdrawing out of operation. Railway wheel, except the formation of metal layer at rolling surface with the high defects concentration of crystal structure and first of all dislocations, falls under thermal influence from interaction with break blocks. The nature of joint influence (cold deformation and heating on the metal rim of a wheel is conditioned by the appearance of sufficiently high gradients of structural changes that can be considered as the influence on the level of internal residual stresses. In case of the rise of volume part of carbide phase at a constant ferrite grain size, it is achieved only by the increasing of dislocation nucleation sources without changing the number of annihilation positions. In this case the accumulation of dislocations at the initial stages of plastic deformation (in metal volume in front of delta arm crack will lead to the formation of cementite globes around certain interlocked dislocation density. In contrast the sharp increase of deformation hardening carbon steel parameters is observed. Originality. During the braking of locomotive the

Online measurement for geometrical parameters of wheel set based on structure light and CUDA parallel processing

Science.gov (United States)

Wu, Kaihua; Shao, Zhencheng; Chen, Nian; Wang, Wenjie

2018-01-01

The wearing degree of the wheel set tread is one of the main factors that influence the safety and stability of running train. Geometrical parameters mainly include flange thickness and flange height. Line structure laser light was projected on the wheel tread surface. The geometrical parameters can be deduced from the profile image. An online image acquisition system was designed based on asynchronous reset of CCD and CUDA parallel processing unit. The image acquisition was fulfilled by hardware interrupt mode. A high efficiency parallel segmentation algorithm based on CUDA was proposed. The algorithm firstly divides the image into smaller squares, and extracts the squares of the target by fusion of k_means and STING clustering image segmentation algorithm. Segmentation time is less than 0.97ms. A considerable acceleration ratio compared with the CPU serial calculation was obtained, which greatly improved the real-time image processing capacity. When wheel set was running in a limited speed, the system placed alone railway line can measure the geometrical parameters automatically. The maximum measuring speed is 120km/h.

A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model

International Nuclear Information System (INIS)

Chen, C.C.; Chang, M.W.; Chang, C.P.; Chan, S.C.; Chang, W.Y.; Yang, C.L.; Lin, M.T.

2014-01-01

We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05) and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use

A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model

Directory of Open Access Journals (Sweden)

C.C. Chen

2014-10-01

Full Text Available We developed a forced non-electric-shock running wheel (FNESRW system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h. An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS, an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05 and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use.

A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model.

Science.gov (United States)

Chen, C C; Chang, M W; Chang, C P; Chan, S C; Chang, W Y; Yang, C L; Lin, M T

2014-10-01

We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05) and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use.

A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model

Energy Technology Data Exchange (ETDEWEB)

Chen, C.C. [Department of Electrical Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Chang, M.W. [Department of Electrical Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Chang, C.P. [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Chan, S.C.; Chang, W.Y.; Yang, C.L. [Department of Electrical Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Lin, M.T. [Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan (China)

2014-08-15

We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05) and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use.

High speed in Portugal - metamorphosis from planning construction measures to a national railway concept; Hochgeschwindigkeit in Portugal - von der Bauplanung zu einem nationalen Eisenbahnkonzept

Energy Technology Data Exchange (ETDEWEB)

Stohler, Werner [Beratungfirma SMA und Partner AG, Zuerich (Switzerland)

2010-03-15

Portugal is planning the construction of two high-speed railway lines (using the UIC gauge of 1435 mm) between Lisbon and Madrid and between Lisbon and Porto. Integration with the country's existing Iberian-gauge network will be achieved in some places by laying three-rail tracks and in other places by running trains with adjustable wheel gauges. The adaptations to the legacy network triggered by the plants for the high-speed lines include, inter alia, a rearrangement of the networks of the regional-express services in and around Lisbon and Porto. (orig.)

A simple tool for tubing modification to improve spiral high-speed counter-current chromatography for protein purification.

Science.gov (United States)

Ito, Yoichiro; Ma, Xiaofeng; Clary, Robert

2016-01-01

A simple tool is introduced which can modify the shape of tubing to enhance the partition efficiency in high-speed countercurrent chromatography. It consists of a pair of interlocking identical gears, each coaxially holding a pressing wheel to intermittently compress plastic tubing in 0 - 10 mm length at every 1 cm interval. The performance of the processed tubing is examined in protein separation with 1.6 mm ID PTFE tubing intermittently pressed in 3 mm and 10 mm width both at 10 mm intervals at various flow rates and revolution speeds. A series of experiments was performed with a polymer phase system composed of polyethylene glycol and dibasic potassium phosphate each at 12.5% (w/w) in deionized water using three protein samples. Overall results clearly demonstrate that the compressed tubing can yield substantially higher peak resolution than the non-processed tubing. The simple tubing modifier is very useful for separation of proteins with high-speed countercurrent chromatography.

Effect of uphill and downhill walking on walking performance in geriatric patients using a wheeled walker.

Science.gov (United States)

Lindemann, Ulrich; Schwenk, Michael; Schmitt, Syn; Weyrich, Michael; Schlicht, Wolfgang; Becker, Clemens

2017-08-01

Wheeled walkers are recommended to improve walking performance in older persons and to encourage and assist participation in daily life. Nevertheless, using a wheeled walker can cause serious problems in the natural environment. This study aimed to compare uphill and downhill walking with walking level in geriatric patients using a wheeled walker. Furthermore, we investigated the effect of using a wheeled walker with respect to dual tasking when walking level. A total of 20 geriatric patients (median age 84.5 years) walked 10 m at their habitual pace along a level surface, uphill and downhill, with and without a standard wheeled walker. Gait speed, stride length and cadence were assessed by wearable sensors and the walk ratio was calculated. When using a wheeled walker while walking level the walk ratio improved (0.58 m/[steps/min] versus 0.57 m/[steps/min], p = 0.023) but gait speed decreased (1.07 m/s versus 1.12 m/s, p = 0.020) when compared to not using a wheeled walker. With respect to the walk ratio, uphill and downhill walking with a wheeled walker decreased walking performance when compared to level walking (0.54 m/[steps/min] versus 0.58 m/[steps/min], p = 0.023 and 0.55 m/[steps/min] versus 0.58 m/[steps/min], p = 0.001, respectively). At the same time, gait speed decreased (0.079 m/s versus 1.07 m/s, p walker improved the quality of level walking but the performance of uphill and downhill walking was worse compared to walking level when using a wheeled walker.

Fluid Mechanics of a High Performance Racing Bicycle Wheel

Science.gov (United States)

Mercat, Jean-Pierre; Cretoux, Brieuc; Huat, Francois-Xavier; Nordey, Benoit; Renaud, Maxime; Noca, Flavio

2013-11-01

In 2012, MAVIC released the most aerodynamic bicycle wheel on the market, the CXR 80. The french company MAVIC has been a world leader for many decades in the manufacturing of bicycle wheels for competitive events such as the Olympic Games and the Tour de France. Since 2010, MAVIC has been in a research partnership with the University of Applied Sciences in Geneva, Switzerland, for the aerodynamic development of bicycle wheels. While most of the development up to date has been performed in a classical wind tunnel, recent work has been conducted in an unusual setting, a hydrodynamic towing tank, in order to achieve low levels of turbulence and facilitate quantitative flow visualization (PIV). After a short introduction on the aerodynamics of bicycle wheels, preliminary fluid mechanics results based on this novel setup will be presented.

Finite element analysis of rail-wheel interaction

International Nuclear Information System (INIS)

Rahman, F.; Kharlamov, Y.A.; Islam, S.; Khan, A.A.

2006-01-01

Damage mechanisms such as surface cracks, plastic deformation and wear can significantly reduce the service life of railway track and rolling stock. They also have a negative impact on the rolling noise as well as: on the riding comfort. A proper understanding of these mechanisms requires a detailed knowledge of physical interaction between wheel and rail. Furthermore, demands for higher train speeds and increased axle loads implies that the consequences of larger contact. forces between wheel and rail must be thoroughly investigated. Two methods have traditionally been used to investigate the rail-wheel contact, that is the Hertz analytical method and simplified numerical method based on the boundary element (BE) method. These methods rely on a half-space assumption and a linear material model. This paper presents that to overcome these limitations, a tool for FE-based quasistatic wheel-rail contact simulations has been developed. The tool is a library of ANSYS macro routines for configuring, meshing and loading of a parametric wheel-rail model. The meshing is based on measured wheel and rail profiles. The wheel and rail materials in the contact region are treated as elastic-plastic with kinematic hardening. By controlling the values of the configuration parameters, representations of various driving cases can be generated. The quasi-static loads are obtained from train motion. Interaction phenomena such as rolling, spinning and sidling can be included. The modeling tool and a methodology are described in the presented paper. Significant differences in the calculated state between the FE solution and the traditional approaches can be observed. These differences are most significant in situations with flange contact. (author)

Wheel-running activity and energy metabolism in relation to ambient temperature in mice selected for high wheel-running activity

NARCIS (Netherlands)

Vaanholt, Lobke M.; Garland, Theodore; Daan, Serge; Visser, G. Henk; Garland Jr., Theodore; Heldmaier, G.

Interrelationships between ambient temperature, activity, and energy metabolism were explored in mice that had been selectively bred for high spontaneous wheel-running activity and their random-bred controls. Animals were exposed to three different ambient temperatures (10, 20 and 30 degrees C) and

High Fat High Sugar Diet Reduces Voluntary Wheel Running in Mice Independent of Sex Hormone Involvement

Directory of Open Access Journals (Sweden)

Heather L. Vellers

2017-08-01

Full Text Available Introduction: Indirect results in humans suggest that chronic overfeeding decreases physical activity with few suggestions regarding what mechanism(s may link overfeeding and decreased activity. The primary sex hormones are known regulators of activity and there are reports that chronic overfeeding alters sex hormone levels. Thepurpose of this study was to determine if chronic overfeeding altered wheel running through altered sex hormone levels.Materials and Methods: C57BL/6J mice were bred and the pups were weaned at 3-weeks of age and randomly assigned to either a control (CFD or high fat/high sugar (HFHS diet for 9–11 weeks depending on activity analysis. Nutritional intake, body composition, sex hormone levels, and 3-day and 2-week wheel-running activity were measured. Additionally, groups of HFHS animals were supplemented with testosterone (males and 17β-estradiol (females to determine if sex hormone augmentation altered diet-induced changes in activity.Results: 117 mice (56♂, 61♀ were analyzed. The HFHS mice consumed significantly more calories per day than CFD mice (male: p < 0.0001; female: p < 0.0001 and had significantly higher body fat (male: p < 0.0001; female: p < 0.0001. The HFHS diet did not reduce sex hormone levels, but did significantly reduce acute running-wheel distance in male (p = 0.05, 70 ± 28% and female mice (p = 0.02, 57 ± 26%. In animals that received hormone supplementation, there was no significant effect on activity levels. Two-weeks of wheel access was not sufficient to alter HFHS-induced reductions in activity or increases in body fat.Conclusion: Chronic overfeeding reduces wheel running, but is independent of the primary sex hormones.

High speed atom source

International Nuclear Information System (INIS)

Hoshino, Hitoshi.

1990-01-01

In a high speed atom source, since the speed is not identical between ions and electrons, no sufficient neutralizing effect for ionic rays due to the mixing of the ionic rays and the electron rays can be obtained failing to obtain high speed atomic rays at high density. In view of the above, a speed control means is disposed for equalizing the speed of ions forming ionic rays and the speed of electrons forming electron rays. Further, incident angle of the electron rays and/or ionic rays to a magnet or an electrode is made variable. As a result, the relative speed between the ions and the electrons to the processing direction is reduced to zero, in which the probability of association between the ions and the electrons due to the coulomb force is increased to improve the neutralizing efficiency to easily obtain fine and high density high speed electron rays. Further, by varying the incident angle, a track capable of obtaining an ideal mixing depending on the energy of the neutralized ionic rays is formed. Since the high speed electron rays has such high density, they can be irradiated easily to the minute region of the specimen. (N.H.)

Characterizing the Performance of the Wheel Electrostatic Spectrometer

Science.gov (United States)

Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Calle, C. I.; Clements, J. S.

2013-01-01

Insulators need to be discharged after each wheel revolution. Sensor responses repeatable within one standard deviation in the noise of the signal. Insulators may not need to be cleaned after each revolution. Parent Technology- Mars Environmental Compatibility Assessment/Electrometer Electrostatic sensors with dissimilar cover insulators Protruding insulators tribocharge against regolith simulant Developed for use on the scoop for the 2001 Mars Odyssey lander Wheel Electrostatic Spectrometer Embedded electrostatic sensors in prototype Martian rover wheel If successful, this technology will enable constant electrostatic testing on Mars Air ionizing fan used to neutralize the surface charge on cover insulators . WES rolled on JSClA lunar simulant Control experiment -Static elimination not conducted between trials -Capacitor discharged after each experiment Charge neutralization experiment -Static elimination conducted between trials -Capacitor discharged after each experiment. Air ionizing fan used on insulators after each wheel revolution Capacitor discharged after each trial Care was taken to roll WES with same speed/pressure Error bars represent one standard deviation in the noise of e ach sensor

Wheel running reduces high-fat diet intake, preference and mu-opioid agonist stimulated intake

Science.gov (United States)

Liang, Nu-Chu; Bello, Nicholas T.; Moran, Timothy H.

2015-01-01

The ranges of mechanisms by which exercise affects energy balance remain unclear. One potential mechanism may be that exercise reduces intake and preference for highly palatable, energy dense fatty foods. The current study used a rodent wheel running model to determine whether and how physical activity affects HF diet intake/preference and reward signaling. Experiment 1 examined whether wheel running affected the ability of intracerebroventricular (ICV) µ opioid receptor agonist D-Ala2, NMe-Phe4, Glyol5-enkephalin (DAMGO) to increase HF diet intake. Experiment 2 examined the effects of wheel running on the intake of and preference for a previously preferred HF diet. We also assessed the effects of wheel running and diet choice on mesolimbic dopaminergic and opioidergic gene expression. Experiment 1 revealed that wheel running decreased the ability of ICV DAMGO administration to stimulate HF diet intake. Experiment 2 showed that wheel running suppressed weight gain and reduced intake and preference for a previously preferred HF diet. Furthermore, the mesolimbic gene expression profile of wheel running rats was different from that of their sedentary paired-fed controls but similar to that of sedentary rats with large HF diet consumption. These data suggest that alterations in preference for palatable, energy dense foods play a role in the effects of exercise on energy homeostasis. The gene expression results also suggest that the hedonic effects of exercise may substitute for food reward to limit food intake and suppress weight gain. PMID:25668514

A development of the distributive law of points on the multi-wheeled machine wheels with electro-mechanical transmission, made under the scheme "motor-axis"

Directory of Open Access Journals (Sweden)

M. M. Jileikin

2014-01-01

Full Text Available Currently, developers of multi-wheeled vehicles (MWV show growing interest in electromechanical drive in the «motor-axis» implementation. However, in designing the traction electric drive (TED based on such approach the problems arise, primarily, from a lack of creating experience and of ready algorithmic solutions to control the traction motors. The use of methods to implement the individual TED is impossible because of the presence of cross-axle differential in the leading axle drive, which does not allow the input torque control of each wheel singly. The paper offers a law to control a traction electric drive of MWV leading axles that comprises the law to control the tractive effort torque and braking moment on the leading axles as well as algorithms of anti-lock brake and traction control systems.An analysis of simulation modeling results shows an efficiency of the developed law that allows control of the traction electric drive of MWV leading axles. The control law includes an algorithm to control the tractive effort torque and braking moment on the driving-wheels, as well as algorithms of anti-lock brake and traction systems.At stationary (constant speed rotation and non-stationary (elk test maneuvering there was no spin of vehicle wheels. Angular speeds of the wheels vary smoothly. Partial loss of vehicle stability when making maneuvers on ice may be reduced through development of algorithms for dynamic stabilization, which will improve the MWV road-holding and trajectory ability. Fullscale tests of MWV with traction electric drive implemented using a “motor-axis" approach are required to have a final answer on the performance and effectiveness of the developed control law.

Soil mechanical stresses in high wheel load agricultural field traffic: a case study

DEFF Research Database (Denmark)

Lamandé, Mathieu; Schjønning, Per

2017-01-01

highly skewed. Across tyres, the maximum stress in the contact area correlated linearly with, but was much higher than, the mean ground pressure. For each of the three soil depths, the maximum stresses under the tyres were significantly correlated with the wheel load, but not with other loading......Subsoil compaction is a serious long-term threat to soil functions. Only a few studies have quantified the mechanical stresses reaching deep subsoil layers for modern high wheel load machinery. In the present study we measured the vertical stresses in the tyre–soil contact area and at 0.3, 0...

A novel method of freeform surface grinding with a soft wheel based on industrial robots

Science.gov (United States)

Sha, Sheng-chun; Guo, Xiao-ling

2011-08-01

In order to meet the growing demand for high-quality images, optical elements of freeform surface are more and more applied to imaging system. However the fabrication of freeform surface optical elements is much more difficult than that of traditional spherical ones. Recent research on freeform surface manufacture often deals with precision machine tools which have limitations on dimensions and are always expensive. Little has been researched on industrial robots. In this paper, a new method of freeform surface grinding based on industrial robots was found. This method could be applied to both whole surface grinding as well as partial surface grinding. The diameter of lenses to be ground would not be restricted to the machine tool's size. In this method a high-speed-rotating soft wheel was used. The relation between removing amount and grinding time which could be called removing function was established and measured. The machining precision was achieved by means of controlling the grinding time instead of the machine tool or industrial robot itself. There are two main factors affecting the removing function: i).rotating speed of the soft wheel; ii).pressure between the wheel and the work piece. In this paper, two groups of experiments have been conducted. One is the removing function tested at constant rotating speed while under different pressure. The other is that tested under a certain pressure with variable speed. Tables and curves which can show the effect of speed and pressure on the removing efficiency have been obtained. Cause for inaccuracy between experiment data and calculated result according to the theory and the non-linearity in the curves was analyzed. Through these analyses the removing function could be concluded under certain condition including rotating speed and pressure. Finally several experiments were performed to verify the appropriateness of the removing function. It could also be concluded that this method was more efficient in comparison

The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels

Directory of Open Access Journals (Sweden)

Paul Molyneux-Berry

2014-01-01

Full Text Available The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing. The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

Selective Breeding and Short-Term Access to a Running Wheel Alter Stride Characteristics in House Mice.

Science.gov (United States)

Claghorn, Gerald C; Thompson, Zoe; Kay, Jarren C; Ordonez, Genesis; Hampton, Thomas G; Garland, Theodore

Postural and kinematic aspects of running may have evolved to support high runner (HR) mice to run approximately threefold farther than control mice. Mice from four replicate HR lines selectively bred for high levels of voluntary wheel running show many differences in locomotor behavior and morphology as compared with four nonselected control (C) lines. We hypothesized that HR mice would show stride alterations that have coadapted with locomotor behavior, morphology, and physiology. More specifically, we predicted that HR mice would have stride characteristics that differed from those of C mice in ways that parallel some of the adaptations seen in highly cursorial animals. For example, we predicted that limbs of HR mice would swing closer to the parasagittal plane, resulting in a two-dimensional measurement of narrowed stance width. We also expected that some differences between HR and C mice might be amplified by 6 d of wheel access, as is used to select breeders each generation. We used the DigiGait Imaging System (Mouse Specifics) to capture high-speed videos in ventral view as mice ran on a motorized treadmill across a range of speeds and then to automatically calculate several aspects of strides. Young adults of both sexes were tested both before and after 6 d of wheel access. Stride length, stride frequency, stance width, stance time, brake time, propel time, swing time, duty factor, and paw contact area were analyzed using a nested analysis of covariance, with body mass as a covariate. As expected, body mass and treadmill speed affected nearly every analyzed metric. Six days of wheel access also affected nearly every measure, indicating pervasive training effects, in both HR and C mice. As predicted, stance width was significantly narrower in HR than C mice. Paw contact area and duty factor were significantly greater in minimuscle individuals (subset of HR mice with 50%-reduced hind limb muscle mass) than in normal-muscled HR or C mice. We conclude that

Effects of setting angle on performance of fish-bionic wind wheel

Science.gov (United States)

Li, G. S.; Yang, Z. X.; Song, L.; Chen, Q.; Li, Y. B.; Chen, W.

2016-08-01

With the energy crisis and the increasing environmental pollutionmore and more efforts have been made about wind power development. In this paper, a new type of vertical axis named the fish-bionic wind wheel was proposed, and the outline of wind wheel was constructed by curve of Fourier fitting and polynomial equations. This paper attempted to research the relationship between the setting angle and the wind turbine characteristics by computational fluid dynamics (CFD) simulation. The results showed that the setting angle of the fish-bionic wind wheel has some significant effects on the efficiency of the wind turbine, Within the range of wind speed from 13m/s to 15m/s, wind wheel achieves the maximum efficiency when the setting angle is at 37 degree. The conclusion will work as a guideline for the improvement of wind turbine design.

A dynamic wheel-rail impact analysis of railway track under wheel flat by finite element analysis

Science.gov (United States)

Bian, Jian; Gu, Yuantong; Murray, Martin Howard

2013-06-01

Wheel-rail interaction is one of the most important research topics in railway engineering. It involves track impact response, track vibration and track safety. Track structure failures caused by wheel-rail impact forces can lead to significant economic loss for track owners through damage to rails and to the sleepers beneath. Wheel-rail impact forces occur because of imperfections in the wheels or rails such as wheel flats, irregular wheel profiles, rail corrugations and differences in the heights of rails connected at a welded joint. A wheel flat can cause a large dynamic impact force as well as a forced vibration with a high frequency, which can cause damage to the track structure. In the present work, a three-dimensional finite element (FE) model for the impact analysis induced by the wheel flat is developed by the use of the FE analysis (FEA) software package ANSYS and validated by another validated simulation. The effect of wheel flats on impact forces is thoroughly investigated. It is found that the presence of a wheel flat will significantly increase the dynamic impact force on both rail and sleeper. The impact force will monotonically increase with the size of wheel flats. The relationships between the impact force and the wheel flat size are explored from this FEA and they are important for track engineers to improve their understanding of the design and maintenance of the track system.

Followup Audit: DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle

Science.gov (United States)

2016-04-29

Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle A P R I L...Results in Brief Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled...and Maritime Paid Too Much for High Mobility Multipurpose Wheeled Vehicle Repair Parts,” (HMMWV) was issued on April 4, 2014. The audit

Plasma adiponectin is increased in mice selectively bred for high wheel-running activity, but not by wheel running per se

NARCIS (Netherlands)

Vaanholt, L. M.; Meerlo, P.; Garland, T.; Visser, G. H.; van Dijk, G.

2007-01-01

Mice selectively bred for high wheel-running activity (S) have decreased fat content compared to mice from randomly bred control (C) lines. We explored whether this difference was associated with alterations in levels of circulating hormones involved in regulation of food intake and energy balance,

Analysis of the distribution of temperature fields in the braked railway wheel

Directory of Open Access Journals (Sweden)

Suchánek Andrej

2018-01-01

Full Text Available The article deals with detection of reduced stress in a braked railway wheel, based on thermal transient analysis on virtual models, which influence the characteristics of the railway wheels. Structural analysis was performed by means of the ANSYS Multiphysics program system package. Thermal transient analysis deals with detection of temperature fields which are a result of braking by brake block. The applied heat flux represents the heat generated by friction of brake block. It is applied to a quarter model of the wheel to speed up the calculation. This analysis simulates two braking processes with subsequent cooling. Distribution of the equivalent stress was detected in the railway wheel cross section, at selected points. The input parameters were taken from the thermal transient analysis. These equivalent stresses result from thermal load.

High Performance Grinding and Advanced Cutting Tools

CERN Document Server

Jackson, Mark J

2013-01-01

High Performance Grinding and Advanced Cutting Tools discusses the fundamentals and advances in high performance grinding processes, and provides a complete overview of newly-developing areas in the field. Topics covered are grinding tool formulation and structure, grinding wheel design and conditioning and applications using high performance grinding wheels. Also included are heat treatment strategies for grinding tools, using grinding tools for high speed applications, laser-based and diamond dressing techniques, high-efficiency deep grinding, VIPER grinding, and new grinding wheels.

Theoretical design study of the MSFC wind-wheel turbine

Science.gov (United States)

Frost, W.; Kessel, P. A.

1982-01-01

A wind wheel turbine (WWT) is studied. Evaluation of the probable performance, possible practical applications, and economic viability as compared to other conventional wind energy systems is discussed. The WWT apparatus is essentially a bladed wheel which is directly exposed to the wind on the upper half and exposed to wind through multiple ducting on the lower half. The multiple ducts consist of a forward duct (front concentrator) and two side ducts (side concentrators). The forced rotation of the wheel is then converted to power through appropriate subsystems. Test results on two simple models, a paper model and a stainless steel model, are reported. Measured values of power coefficients over wind speeds ranging from 4 to 16 m/s are given. An analytical model of a four bladed wheel is also developed. Overall design features of the wind turbine are evaluated and discussed. Turbine sizing is specified for a 5 and 25 kW machine. Suggested improvements to the original design to increase performance and performance predictions for an improved WWT design are given.

Development of Trigger and Readout Electronics for the ATLAS New Small Wheel Detector Upgrade

CERN Document Server

Guan, Liang; The ATLAS collaboration

2017-01-01

The present small wheel muon detector at ATLAS will be replaced with a New Small Wheel (NSW) detector to handle the increase in data rates and harsh radiation environment expected at the LHC. Resistive Micromegas and small strip Thin Gap Chambers will be used to provide both trigger and tracking primitives. Muon segments found at NSW will be combined with the segments found at the Big Wheel to determine the muon transverse momentum at the first-level trigger. A new trigger and readout system is developed for the NSW detector. The new system has about 2.4 million trigger and readout channels and about 8,000 Front-End boards. The large number of input channels, short time available to prepare and transmit data, harsh radiation environment, and low power consumption all impose great challenges on the design. We will discuss the overall electronics design and studies with various ASICs and high-speed circuit board prototypes.

Non-linear vehicle-bridge-wind interaction model for running safety assessment of high-speed trains over a high-pier viaduct

Science.gov (United States)

Olmos, José M.; Astiz, Miguel Á.

2018-04-01

In order to properly study the high-speed traffic safety on a high-pier viaduct subject to episodes of lateral turbulent winds, an efficient dynamic interaction train-bridge-wind model has been developed and experimentally validated. This model considers the full wheel and rail profiles, the friction between these two bodies in contact, and the piers P-Delta effect. The model has been used to determine the critical train and wind velocities from which the trains cannot travel safely over the O'Eixo Bridge. The dynamic simulations carried out and the results obtained in the time domain show that traffic safety rates exceed the allowed limits for turbulent winds with mean velocities at the deck higher than 25 m/s.

Bucket wheel rehabilitation of ERC 1400-30/7 high-capacity excavators from lignite quarries

Science.gov (United States)

Vîlceanu, Fl; Iancu, C.

2016-11-01

The existence of bucket wheel equipment type ERC 1400-30/7 in lignite quarries with lifetime expired, or in the ultimate life period, together with high cost investments for their replacement, makes rational the efforts made to rehabilitation in order to extend their life. Rehabilitation involves checking operational safety based on relevant expertise of metal structures supporting effective resistance but also the replacement (or modernization) of subassemblies that can increase excavation process productivity, lowering energy consumption, reducing mechanical stresses. This paper proposes an analysis of constructive solution of using a part of the classical bucket wheel, on which are located 9 cutting cups and 9 chargers cups and adding a new part so that the new redesigned bucket-wheel will contain 18 cutting-chargers cups, compared to the classical model. On the CAD model of bucket wheel was performed a static and a dynamic FEA, the results being compared with the yield strength of the material of the entire structure, were checked mechanical stresses in the overall distribution map, and were verified the first 4 vibrating modes the structure compared to real loads. Thus was verified that the redesigned bucket-wheel can accomplish the proposed goals respectively increase excavation process productivity, lowering energy consumption and reducing mechanical stresses.

A novel instrumented multipeg running wheel system, Step-Wheel, for monitoring and controlling complex sequential stepping in mice.

Science.gov (United States)

Kitsukawa, Takashi; Nagata, Masatoshi; Yanagihara, Dai; Tomioka, Ryohei; Utsumi, Hideko; Kubota, Yasuo; Yagi, Takeshi; Graybiel, Ann M; Yamamori, Tetsuo

2011-07-01

Motor control is critical in daily life as well as in artistic and athletic performance and thus is the subject of intense interest in neuroscience. Mouse models of movement disorders have proven valuable for many aspects of investigation, but adequate methods for analyzing complex motor control in mouse models have not been fully established. Here, we report the development of a novel running-wheel system that can be used to evoke simple and complex stepping patterns in mice. The stepping patterns are controlled by spatially organized pegs, which serve as footholds that can be arranged in adjustable, ladder-like configurations. The mice run as they drink water from a spout, providing reward, while the wheel turns at a constant speed. The stepping patterns of the mice can thus be controlled not only spatially, but also temporally. A voltage sensor to detect paw touches is attached to each peg, allowing precise registration of footfalls. We show that this device can be used to analyze patterns of complex motor coordination in mice. We further demonstrate that it is possible to measure patterns of neural activity with chronically implanted tetrodes as the mice engage in vigorous running bouts. We suggest that this instrumented multipeg running wheel (which we name the Step-Wheel System) can serve as an important tool in analyzing motor control and motor learning in mice.

Improving Performance of Cantilevered Momentum Wheel Assemblies by Soft Suspension Support

Directory of Open Access Journals (Sweden)

Weiyong Zhou

2013-01-01

Full Text Available This paper focuses on improving the performance of the rigid support cantilevered momentum wheel assemblies (CMWA by soft suspension support. A CMWA, supported by two angular contact ball bearings, was modeled as a Jeffcott rotor. The support stiffness, before and after in series with a linear soft suspension support, were simplified as two Duffing's type springs respectively. The result shows that the rigid support CMWA produces large disturbance force at the resonance speed range. The soft suspension CMWA can effectively reduce the force on the bearing (also disturbance forces produced by the CMWA at high rotational speed, and also reduce the nonlinear characteristic of the stiffness. However, the instability of the soft suspension CMWA will limit the maximum rotational speed of the CMWA. Thus, a "proper" stiffness of the soft suspension system is a trade-off strategy between reduction of the force and extension of the speed range simultaneously.

Wheeling in Canada

International Nuclear Information System (INIS)

Fytche, E.L.

1991-01-01

The quest for economic efficiency, or lowest cost, in the electricity supply industry is furthered by trading between high and low cost utilities, one aspect being transporting or wheeling power through the transmission system of a third party. Some of the pressures and constraints limiting wheeling are discussed. A simple formula is presented for determining whether trading and wheeling are worthwhile. It is demonstrated for assumed capital and operating cost levels, the viability of nine cases where bulk power or economy energy would need to be wheeled across provincial boundaries in order to reach potential buyers. Wheeling in Canada is different from the situation in the USA, due to large distances spanned by Canadian utilities and because most are provincial crown corporations, with different territorial interests and profit motivations than investor-owned utilities. Most trading in electricity has been between contiguous neighbours, for mutual advantage. New technology allows power transmission over distances of up to 1000 miles, and the economics of Canada's electrical supply could be improved, with means including access to low cost coal of Alberta, and remote hydro in British Columbia, Manitoba, Quebec and Labrador. Nuclear plants could be located anywhere but suffer from an unfriendly public attitude. A bridge across the Prairies appears uneconomic due to cost of transmission, and also due to low valuation given to Alberta coal. 7 refs., 2 figs., 3 tabs

Selection for increased voluntary wheel-running affects behavior and brain monoamines in mice

Science.gov (United States)

Waters, R.Parrish; Pringle, R.B.; Forster, G.L.; Renner, K.J.; Malisch, J.L.; Garland, T.; Swallow, J.G.

2013-01-01

Selective-breeding of house mice for increased voluntary wheel-running has resulted in multiple physiological and behavioral changes. Characterizing these differences may lead to experimental models that can elucidate factors involved in human diseases and disorders associated with physical inactivity, or potentially treated by physical activity, such as diabetes, obesity, and depression. Herein, we present ethological data for adult males from a line of mice that has been selectively bred for high levels of voluntary wheel-running and from a non-selected control line, housed with or without wheels. Additionally, we present concentrations of central monoamines in limbic, striatal, and midbrain regions. We monitored wheel-running for 8 weeks, and observed home-cage behavior during the last 5 weeks of the study. Mice from the selected line accumulated more revolutions per day than controls due to increased speed and duration of running. Selected mice exhibited more active behaviors than controls, regardless of wheel access, and exhibited less inactivity and grooming than controls. Selective-breeding also influenced the longitudinal patterns of behavior. We found statistically significant differences in monoamine concentrations and associated metabolites in brain regions that influence exercise and motivational state. These results suggest underlying neurochemical differences between selected and control lines that may influence the observed differences in behavior. Our results bolster the argument that selected mice can provide a useful model of human psychological and physiological diseases and disorders. PMID:23352668

Newtonian liquid jet impaction on a high-speed moving surface

International Nuclear Information System (INIS)

Keshavarz, B.; Green, S.I.; Davy, M.H.; Eadie, D.T.

2011-01-01

Highlights: ► We studied experimentally the interaction of a liquid jet with a moving surface. ► Decreasing the Reynolds number reduced the incidence of splash. ► The Weber number had a much smaller impact on splash than the Reynolds number. ► The jet impingement angle had only a small effect on the splash. ► Increasing the surface roughness substantially decreased the splash threshold. - Abstract: In the railroad industry a friction modifying agent may be applied to the rail or wheel in the form of a liquid jet. In this mode of application the interaction between the high-speed liquid jet and a fast moving surface is important. Seven different Newtonian liquids with widely varying shear viscosities were tested to isolate the effect of viscosity from other fluid properties. Tests were also done on five surfaces of different roughness heights to investigate the effects of surface roughness. High-speed video imaging was employed to scrutinize the interaction between the impacting jet and the moving surface. For all surfaces, decreasing the Reynolds number reduced the incidence of splash and consequently enhanced the transfer efficiency. At the elevated Weber numbers of the testing, the Weber number had a much smaller impact on splash than the Reynolds number. The ratio of the surface velocity to the jet velocity has only a small effect on the splash, whereas increasing the roughness-height-to-jet-diameter ratio substantially decreased the splash threshold.

Physical characteristics of experienced and junior open-wheel car drivers.

Science.gov (United States)

Raschner, Christian; Platzer, Hans-Peter; Patterson, Carson

2013-01-01

Despite the popularity of open-wheel car racing, scientific literature about the physical characteristics of competitive race car drivers is scarce. The purpose of this study was to compare selected fitness parameters of experienced and junior open-wheel race car drivers. The experienced drivers consisted of five Formula One, two GP2 and two Formula 3 drivers, and the nine junior drivers drove in the Formula Master, Koenig, BMW and Renault series. The following fitness parameters were tested: multiple reactions, multiple anticipation, postural stability, isometric upper body strength, isometric leg extension strength, isometric grip strength, cyclic foot speed and jump height. The group differences were calculated using the Mann-Whitney U-test. Because of the multiple testing strategy used, the statistical significance was Bonferroni corrected and set at P < 0.004. Significant differences between the experienced and junior drivers were found only for the jump height parameter (P = 0.002). The experienced drivers tended to perform better in leg strength (P = 0.009), cyclic foot speed (P = 0.024) and grip strength (P = 0.058). None of the other variables differed between the groups. The results suggested that the experienced drivers were significantly more powerful than the junior drivers: they tended to be quicker and stronger (18% to 25%) but without statistical significance. The experienced drivers demonstrated excellent strength and power compared with other high-performance athletes.

A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2018-06-01

This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

Rotor-dynamic design aspects for a variable frequency drive based high speed cryogenic centrifugal pump in fusion devices

International Nuclear Information System (INIS)

Das, Jotirmoy; Vaghela, Hitensinh; Bhattacharya, Ritendra; Patel, Pratik; Shukla, Vinit; Shah, Nitin; Sarkar, Biswanath

2015-01-01

Superconducting magnets of large size are inevitable for fusion devices due to high magnetic field requirements. Forced flow cooling of the superconducting magnets with high mass flowrate of the order ∼3 kg/s is required to keep superconducting magnets within its safe operational boundaries during various plasma scenarios. This important requirement can be efficiently fulfilled by employing high capacity and high efficiency cryogenic centrifugal pumps. The efficiency > 70% will ensure overall lower heat load to the cryoplant. Thermo-hydraulic design of cryogenic centrifugal pump revealed that to achieve the operational regime with high efficiency, the speed should be ∼ 10,000 revolutions per minute. In this regard, the rotor-dynamic design aspect is quite critical from the operational stability point of view. The rotor shaft design of the cryogenic pump is primarily an outcome of optimization between thermal heat-in leak at cryogenic temperature level from ambient, cryogenic fluid impedance and designed rotation speed of the impeller wheel. The paper describes the basic design related to critical speed of the rotor shaft, rotor whirl and system instability prediction to explore the ideal operational range of the pump from the system stability point of view. In the rotor-dynamic analysis, the paper also describes the Campbell plots to ensure that the pump is not disturbed by any of the critical speeds, especially while operating near the nominal and enhanced operating modes. (author)

THE IMPACT OF THE CAR BODY TILT WHEN MOVING ON CURVED TRACK SECTIONS ON THE INTERACTION BETWEEN WHEELS AND RAILS

Directory of Open Access Journals (Sweden)

D. I. Yakunin

2009-08-01

Full Text Available In the article the information on calculated forces of interaction in the system "wheel-rail" is presented at movement on curve sections of a track with a speed less than 160 km/h and the change of wear of wheels is predicted.

Experimental Setup for Diamond Grinding Using Electrochemical InProcess Controlled Dressing (ECD of Grinding Wheel

Directory of Open Access Journals (Sweden)

M. A. Shavva

2014-01-01

Full Text Available The most effective method for finish machining of hard-metals and alloys is to use the diamond grinding wheels for grinding. An application of diamond wheels significantly increases the employee output, reduces costs, and raises manufacturing efficiency with achieving the high performance properties of treated surfaces.During grinding a working surface of diamond wheel wears out. It adversely affects the cutting capability of the diamond grains, and depending on the grinding conditions can occur through different mechanisms. Wear of diamond wheel causes distortion of its shape and reduces cutting properties. However, dressing of diamond wheels is a complicated and time-consuming operation in terms of manufacturing technique.Methods to make dressing of diamond grinding wheel have different types of classification. Classification of dressing methods by the type of energy used is as follows: mechanical, chemical, electrophysical, electromechanical, and electrochemical. All these methods have their advantages and disadvantages.Electrochemical method of dressing is the most productive and efficient. Electrochemical method comprises anode-mechanical dressing and electrochemical (electrolytic one. The paper presents the electrochemical in-process dressing (ECD and the electrolytic in-process dressing (ELID.The source of energy, grinding a wheel with metal bond, and an electrode are necessary for providing ELID. The ELID consists of several stages. The first stage is preliminary electrolytic dressing of diamond wheel. The electrolyte is placed into the gap between the wheel and electrode. The bond of the wheel is oxidized. An insulating layer is formed. It reduces an electrical conductivity of the wheel and controls consumption of diamond grains, as well as polishes the surface of the work piece. Further, the insulating layer is destroyed. The cycle of dressing begins anew.The ECD proceeds in the same way as ELID. However during the ECD-process there

High levels of wheel running protect against behavioral sensitization to cocaine.

Science.gov (United States)

Renteria Diaz, Laura; Siontas, Dora; Mendoza, Jose; Arvanitogiannis, Andreas

2013-01-15

Although there is no doubt that the direct action of stimulant drugs on the brain is necessary for sensitization to their behavioral stimulating effects, several experiments indicate that drug action is often not sufficient to produce sensitization. There is considerable evidence that many individual characteristics and experiential variables can modulate the behavioral and neural changes that are seen following repeated exposure to stimulant drugs. In the work presented here, we examined whether chronic wheel running would modulate behavioral sensitization to cocaine, and whether any such influence was contingent on individual differences in wheel running. We found that a 5- or 10-week experience with wheel running protects against behavioral sensitization to cocaine but only in animals with a natural tendency to run the most. Understanding the mechanism underlying the modulating effect of wheel running on behavioral sensitization may have important implications for future studies on the link between drug-induced behavioral and neural adaptations. Copyright © 2012 Elsevier B.V. All rights reserved.

Inertia coupling analysis of a self-decoupled wheel force transducer under multi-axis acceleration fields.

Directory of Open Access Journals (Sweden)

Lihang Feng

Full Text Available Wheel force transducer (WFT, which measures the three-axis forces and three-axis torques applied to the wheel, is an important instrument in the vehicle testing field and has been extremely promoted by researchers with great interests. The transducer, however, is typically mounted on the wheel of a moving vehicle, especially on a high speed car, when abruptly accelerating or braking, the mass/inertia of the transducer/wheel itself will have an extra effect on the sensor response so that the inertia/mass loads will also be detected and coupled into the signal outputs. The effect which is considered to be inertia coupling problem will decrease the sensor accuracy. In this paper, the inertia coupling of a universal WFT under multi-axis accelerations is investigated. According to the self-decoupling approach of the WFT, inertia load distribution is solved based on the principle of equivalent mass and rotary inertia, thus then inertia impact can be identified with the theoretical derivation. The verification is achieved by FEM simulation and experimental tests. Results show that strains in simulation agree well with the theoretical derivation. The relationship between the applied acceleration and inertia load for both wheel force and moment is the approximate linear, respectively. All the relative errors are less than 5% which are within acceptable and the inertia loads have the maximum impact on the signal output about 1.5% in the measurement range.

Inertia coupling analysis of a self-decoupled wheel force transducer under multi-axis acceleration fields.

Science.gov (United States)

Feng, Lihang; Lin, Guoyu; Zhang, Weigong; Dai, Dong

2015-01-01

Wheel force transducer (WFT), which measures the three-axis forces and three-axis torques applied to the wheel, is an important instrument in the vehicle testing field and has been extremely promoted by researchers with great interests. The transducer, however, is typically mounted on the wheel of a moving vehicle, especially on a high speed car, when abruptly accelerating or braking, the mass/inertia of the transducer/wheel itself will have an extra effect on the sensor response so that the inertia/mass loads will also be detected and coupled into the signal outputs. The effect which is considered to be inertia coupling problem will decrease the sensor accuracy. In this paper, the inertia coupling of a universal WFT under multi-axis accelerations is investigated. According to the self-decoupling approach of the WFT, inertia load distribution is solved based on the principle of equivalent mass and rotary inertia, thus then inertia impact can be identified with the theoretical derivation. The verification is achieved by FEM simulation and experimental tests. Results show that strains in simulation agree well with the theoretical derivation. The relationship between the applied acceleration and inertia load for both wheel force and moment is the approximate linear, respectively. All the relative errors are less than 5% which are within acceptable and the inertia loads have the maximum impact on the signal output about 1.5% in the measurement range.

Design and implementation of self-balancing coaxial two wheel robot based on HSIC

Science.gov (United States)

Hu, Tianlian; Zhang, Hua; Dai, Xin; Xia, Xianfeng; Liu, Ran; Qiu, Bo

2007-12-01

This thesis has studied the control problem concerning position and orientation control of self-balancing coaxial two wheel robot based on the human simulated intelligent control (HSIC) theory. Adopting Lagrange equation, the dynamic model of self-balancing coaxial two-wheel Robot is built up, and the Sensory-motor Intelligent Schemas (SMIS) of HSIC controller for the robot is designed by analyzing its movement and simulating the human controller. In robot's motion process, by perceiving position and orientation of the robot and using multi-mode control strategy based on characteristic identification, the HSIC controller enables the robot to control posture. Utilizing Matlab/Simulink, a simulation platform is established and a motion controller is designed and realized based on RT-Linux real-time operating system, employing high speed ARM9 processor S3C2440 as kernel of the motion controller. The effectiveness of the new design is testified by the experiment.

Wheel-running activity modulates circadian organization and the daily rhythm of eating behavior

Science.gov (United States)

Pendergast, Julie S.; Branecky, Katrina L.; Huang, Roya; Niswender, Kevin D.; Yamazaki, Shin

2014-01-01

Consumption of high-fat diet acutely alters the daily rhythm of eating behavior and circadian organization (the phase relationship between oscillators in central and peripheral tissues) in mice. Voluntary wheel-running activity counteracts the obesogenic effects of high-fat diet and also modulates circadian rhythms in mice. In this study, we sought to determine whether voluntary wheel-running activity could prevent the proximate effects of high-fat diet consumption on circadian organization and behavioral rhythms in mice. Mice were housed with locked or freely rotating running wheels and fed chow or high-fat diet for 1 week and rhythms of locomotor activity, eating behavior, and molecular timekeeping (PERIOD2::LUCIFERASE luminescence rhythms) in ex vivo tissues were measured. Wheel-running activity delayed the phase of the liver rhythm by 4 h in both chow- and high-fat diet-fed mice. The delayed liver phase was specific to wheel-running activity since an enriched environment without the running wheel did not alter the phase of the liver rhythm. In addition, wheel-running activity modulated the effect of high-fat diet consumption on the daily rhythm of eating behavior. While high-fat diet consumption caused eating events to be more evenly dispersed across the 24 h-day in both locked-wheel and wheel-running mice, the effect of high-fat diet was much less pronounced in wheel-running mice. Together these data demonstrate that wheel-running activity is a salient factor that modulates liver phase and eating behavior rhythms in both chow- and high-fat-diet fed mice. Wheel-running activity in mice is both a source of exercise and a self-motivating, rewarding behavior. Understanding the putative reward-related mechanisms whereby wheel-running activity alters circadian rhythms could have implications for human obesity since palatable food and exercise may modulate similar reward circuits. PMID:24624109

EXPERIMENTAL EVALUATION OF ARTICULATED WHEELED VEHICLES POSITION STABILITY

Directory of Open Access Journals (Sweden)

Ye. Dubinin

2015-07-01

Full Text Available With introducing a mobile measurement system with linear acceleration sensors there was experimentally determined the parameter of position stability of the articulated wheeled vehicle on the example of HTA-200 «Slobozhanets». It was determined that the position stability was provided within the entire range of operating speeds and accelerations. The obtained results can be used to enhance the traffic safety of articulated vehicles.

Assessing the influence of wheel defects of a rolling stockon railway tracks

Directory of Open Access Journals (Sweden)

Loktev Aleksey Alekseevich

2015-05-01

- slides (potholes, etc.The motion of the wheels with irregularities on the surface of the rail leads to vertical oscillation of the wheel, resulting in the forces of inertia, which is an additional load on the rail. In case of movement of the wheel with isolated roughness on the tread surface of the slide there is a strike, having a very large additional impact on the rail. Such attacks can cause kinked rails, especially in the winter months when there is increased fragility of rail steel, because of lowered temperatures. This is an abnormal phenomenon and occurs relatively rarely, at a small number of isolated irregularities on a wheel of the rolling stock. As correlations connecting the contact force and local deformation in the interaction of the wheel-rail system, we use the quasi-static Hertz’s model, linear-elastic model and two elastoplastic contact models: Alexandrov-Kadomtsev and Kil’chevsky. According to the results of Loktev’s studies ratios of the contact Hertz’s theory are quite suitable for modeling the dynamic effects of wheel and rail for speeds up to 90 km/h for engineering calculations. Since the contact surface is homogeneous and isotropic, the friction forces in the contact zone are not taken into account, the size of the pad is small compared to the dimensions of the contacting bodies and characteristic radii of curvature of the undeformed surfaces, the contacting surfaces are smooth.When train is driving, the position of the wheelset in relation to the rails varies considerably, giving rise to different combinations of the contact areas of the wheel and rail. Even assuming constant axial load the normal voltage will vary considerably because of the differences in the radii of curvature of the contacting surfaces of these zones. Thus, the proposed method allows evaluating the influence of several types of wheel defects on the condition of the rail and the prospects of its use in the upper structure of a railway track on plots with different

Costs associated with wheeling

International Nuclear Information System (INIS)

Anon.

1991-01-01

Wheeling costs are incurred by all companies that experience a change in power flows over their transmission lines during a specific transaction, whether or not the lines of that company are part of the contract path. The costs of providing wheeling service differ from one system to another and from one kind of wheeling transaction to another. While most transactions may be completed using existing capacity, others may require an increase in line. Depending on the situation, some cost components may be high, low, negative, or not incurred at all. This article discusses two general categories of costs; transactional and capital. The former are all operation, maintenance and opportunity costs incurred in completing a specific transaction assuming the existence of adequate capacity. Capital costs are the costs of major new equipment purchases and lines necessary to provide any increased level of transmission services

Systems-on-chip approach for real-time simulation of wheel-rail contact laws

Science.gov (United States)

Mei, T. X.; Zhou, Y. J.

2013-04-01

This paper presents the development of a systems-on-chip approach to speed up the simulation of wheel-rail contact laws, which can be used to reduce the requirement for high-performance computers and enable simulation in real time for the use of hardware-in-loop for experimental studies of the latest vehicle dynamic and control technologies. The wheel-rail contact laws are implemented using a field programmable gate array (FPGA) device with a design that substantially outperforms modern general-purpose PC platforms or fixed architecture digital signal processor devices in terms of processing time, configuration flexibility and cost. In order to utilise the FPGA's parallel-processing capability, the operations in the contact laws algorithms are arranged in a parallel manner and multi-contact patches are tackled simultaneously in the design. The interface between the FPGA device and the host PC is achieved by using a high-throughput and low-latency Ethernet link. The development is based on FASTSIM algorithms, although the design can be adapted and expanded for even more computationally demanding tasks.

Experimental analysis and regression prediction of desiccant wheel behavior in high temperature heat pump and desiccant wheel air-conditioning system

DEFF Research Database (Denmark)

Sheng, Ying; Zhang, Yufeng; Sun, Yuexia

2014-01-01

The objectives of this study are to evaluate the performance of desiccant wheel (DW) in the running system and obtain the useful data for practical application. The combined influences of multiple variables on the performance of desiccant wheel are investigated based on evaluating the indexes...... of moisture removal capacity, dehumidification effectiveness, dehumidification coefficient of performance and sensible energy ratio. The results show that higher effect on the dehumidification is due to the regeneration temperature and outdoor air humidity ratio rather than the outdoor air temperature...... and the ratio between regeneration and process air flow rates. A simple method based on multiple linear regression theory for predicting the performance of the wheel has been proposed. The predicted values and the experimental data are compared and good agreements are obtained. Regression models are established...

A combined multibody and finite element approach for dynamic interaction analysis of high-speed train and railway structure including post-derailment behavior during an earthquake

International Nuclear Information System (INIS)

Tanabe, M; Wakui, H; Sogabe, M; Matsumoto, N; Tanabe, Y

2010-01-01

A combined multibody and finite element approach is given to solve the dynamic interaction of a Shinkansen train (high-speed train in Japan) and the railway structure including post-derailment during an earthquake effectively. The motion of the train is expressed in multibody dynamics. Efficient mechanical models to express interactions between wheel and track structure including post-derailment are given. Rail and track elements expressed in multibody dynamics and FEM are given to solve contact problems between wheel and long railway components effectively. The motion of a railway structure is modeled with various finite elements and rail and track elements. The computer program has been developed for the dynamic interaction analysis of a Shinkansen train and railway structure including post derailment during an earthquake. Numerical examples are demonstrated.

Open-field behavior of house mice selectively bred for high voluntary wheel-running.

Science.gov (United States)

Bronikowski, A M; Carter, P A; Swallow, J G; Girard, I A; Rhodes, J S; Garland, T

2001-05-01

Open-field behavioral assays are commonly used to test both locomotor activity and emotionality in rodents. We performed open-field tests on house mice (Mus domesticus) from four replicate lines genetically selected for high voluntary wheel-running for 22 generations and from four replicate random-bred control lines. Individual mice were recorded by video camera for 3 min in a 1-m2 open-field arena on 2 consecutive days. Mice from selected lines showed no statistical differences from control mice with respect to distance traveled, defecation, time spent in the interior, or average distance from the center of the arena during the trial. Thus, we found little evidence that open-field behavior, as traditionally defined, is genetically correlated with wheel-running behavior. This result is a useful converse test of classical studies that report no increased wheel-running in mice selected for increased open-field activity. However, mice from selected lines turned less in their travel paths than did control-line mice, and females from selected lines had slower travel times (longer latencies) to reach the wall. We discuss these results in the context of the historical open-field test and newly defined measures of open-field activity.

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.

Experimental investigation into the mechanism of the polygonal wear of electric locomotive wheels

Science.gov (United States)

Tao, Gongquan; Wang, Linfeng; Wen, Zefeng; Guan, Qinghua; Jin, Xuesong

2018-06-01

Experiments were conducted at field sites to investigate the mechanism of the polygonal wear of electric locomotive wheels. The polygonal wear rule of electric locomotive wheels was obtained. Moreover, two on-track tests have been carried out to investigate the vibration characteristics of the electric locomotive's key components. The measurement results of wheels out-of-round show that most electric locomotive wheels exhibit polygonal wear. The main centre wavelength in the 1/3 octave bands is 200 mm and/or 160 mm. The test results of vibration characteristics indicate that the dominating frequency of the vertical acceleration measured on the axle box is approximately equal to the passing frequency of a polygonal wheel, and does not vary with the locomotive speed during the acceleration course. The wheelset modal analysis using the finite element method (FEM) indicates that the first bending resonant frequency of the wheelset is quite close to the main vibration frequency of the axle box. The FEM results are verified by the experimental modal analysis of the wheelset. Moreover, different plans were designed to verify whether the braking system and the locomotive's adhesion control have significant influence on the wheel polygon or not. The test results indicate that they are not responsible for the initiation of the wheel polygon. The first bending resonance of the wheelset is easy to be excited in the locomotive operation and it is the root cause of wheel polygon with centre wavelength of 200 mm in the 1/3 octave bands.

Estimating the Backup Reaction Wheel Orientation Using Reaction Wheel Spin Rates Flight Telemetry from a Spacecraft

Science.gov (United States)

Rizvi, Farheen

2013-01-01

A report describes a model that estimates the orientation of the backup reaction wheel using the reaction wheel spin rates telemetry from a spacecraft. Attitude control via the reaction wheel assembly (RWA) onboard a spacecraft uses three reaction wheels (one wheel per axis) and a backup to accommodate any wheel degradation throughout the course of the mission. The spacecraft dynamics prediction depends upon the correct knowledge of the reaction wheel orientations. Thus, it is vital to determine the actual orientation of the reaction wheels such that the correct spacecraft dynamics can be predicted. The conservation of angular momentum is used to estimate the orientation of the backup reaction wheel from the prime and backup reaction wheel spin rates data. The method is applied in estimating the orientation of the backup wheel onboard the Cassini spacecraft. The flight telemetry from the March 2011 prime and backup RWA swap activity on Cassini is used to obtain the best estimate for the backup reaction wheel orientation.

Arrangement for adapting a wind wheel to an electric power generator

Energy Technology Data Exchange (ETDEWEB)

Beusse, H

1977-08-11

The invention is concerned with a device for adapting a wind wheel to an electric power generator in such a way that the wind wheel will always be operated with a maximum performance coefficient, that another source of energy, e.g. a prime mover, can supply the power deficit if the wind power is not sufficient, and that the generator at the output of the facility is kept mains-synchronous of constant speed and constant voltage. According to the invention, the shaft power of the wind power engine is transmitted to a first generator driving an electromotor. The motor is coupled to a second generator feeding into a consumer grid. By means of an anemometer the excitation output of the motor is controled in such manner that the speed of the generator is practically constant-provided a sufficient supply of wind is available. On the shaft of the output generator a prinse mover, e.g. a Diesel engine, is mounted being controllable for contant speed by means of a controll device in such a way that the prime mover takes over the missing amount of power if the wind supply falls short of the power taken off at the generator output.

Non-Harmonic Fourier Analysis for bladed wheels damage detection

Science.gov (United States)

Neri, P.; Peeters, B.

2015-11-01

The interaction between bladed wheels and the fluid distributed by the stator vanes results in cyclic loading of the rotating components. Compressors and turbines wheels are subject to vibration and fatigue issues, especially when resonance conditions are excited. Even if resonance conditions can be often predicted and avoided, high cycle fatigue failures can occur, causing safety issues and economic loss. Rigorous maintenance programs are then needed, forcing the system to expensive shut-down. Blade crack detection methods are beneficial for condition-based maintenance. While contact measurement systems are not always usable in exercise conditions (e.g. high temperature), non-contact methods can be more suitable. One (or more) stator-fixed sensor can measure all the blades as they pass by, in order to detect the damaged ones. The main drawback in this situation is the short acquisition time available for each blade, which is shortened by the high rotational speed of the components. A traditional Discrete Fourier Transform (DFT) analysis would result in a poor frequency resolution. A Non-Harmonic Fourier Analysis (NHFA) can be executed with an arbitrary frequency resolution instead, allowing to obtain frequency information even with short-time data samples. This paper shows an analytical investigation of the NHFA method. A data processing algorithm is then proposed to obtain frequency shift information from short time samples. The performances of this algorithm are then studied by experimental and numerical tests.

Time response analysis in suspension system design of a high-speed car

Science.gov (United States)

Pagwiwoko, Cosmas Pandit

2010-03-01

A land speed record vehicle is designed to run on a flat surface like salt lake where the wheels are normally made from solid metal with a special suspension system. The suspension is designed to provide a stable platform to keep the wheel treads on tract, to insulate the car and the driver from the surface irregularities and to take part of good handling properties. The surface condition of the lake beds is basically flat without undulations but with inconsistent surface textures and ridges. Spring with nonlinear rate is used with the reason that the resistance builds up roughly proportional to the aerodynamic download for keeping the height more nearly constant. The objective of the work is to produce an efficient method for assisting the design of suspension system. At the initial step, the stiffness and the damping constants are determined based on RMS optimization by following the optimization strategy i.e. to minimize the absolute acceleration respect to the relative displacement of the suspension. Power bond graph technique is then used to model the nonlinearity of the components i.e. spring and dashpot of the suspension system. This technique also enables to incorporate the interactions of dynamic response of the vehicle's body with aerodynamic flow as a result of the base excitation of the ground to the wheels. The simulation is conducted on the platform of Simulink-MATLAB and the interactions amongst the components within the system are observed in time domain to evaluate the effectiveness of the suspension.

Jitter reduction of a reaction wheel by management of angular momentum using magnetic torquers in nano- and micro-satellites

Science.gov (United States)

Inamori, Takaya; Wang, Jihe; Saisutjarit, Phongsatorn; Nakasuka, Shinichi

2013-07-01

Nowadays, nano- and micro-satellites, which are smaller than conventional large satellites, provide access to space to many satellite developers, and they are attracting interest as an application of space development because development is possible over shorter time period at a lower cost. In most of these nano- and micro-satellite missions, the satellites generally must meet strict attitude requirements for obtaining scientific data under strict constraints of power consumption, space, and weight. In many satellite missions, the jitter of a reaction wheel degrades the performance of the mission detectors and attitude sensors; therefore, jitter should be controlled or isolated to reduce its effect on sensor devices. In conventional standard-sized satellites, tip-tilt mirrors (TTMs) and isolators are used for controlling or isolating the vibrations from reaction wheels; however, it is difficult to use these devices for nano- and micro-satellite missions under the strict power, space, and mass constraints. In this research, the jitter of reaction wheels is reduced by using accurate sensors, small reaction wheels, and slow rotation frequency reaction wheel instead of TTMs and isolators. The objective of a reaction wheel in many satellite missions is the management of the satellite's angular momentum, which increases because of attitude disturbances. If the magnitude of the disturbance is reduced in orbit or on the ground, the magnitude of the angular momentum that the reaction wheels gain from attitude disturbances in orbit becomes smaller; therefore, satellites can stabilize their attitude using only smaller reaction wheels or slow rotation speed, which cause relatively smaller vibration. In nano- and micro-satellite missions, the dominant attitude disturbance is a magnetic torque, which can be cancelled by using magnetic actuators. With the magnetic compensation, the satellite reduces the angular momentum that the reaction wheels gain, and therefore, satellites do

Umbrella Wheel - a stair-climbing and obstacle-handling wheel design concept

DEFF Research Database (Denmark)

Iversen, Simon; Jouffroy, Jerome

2017-01-01

This paper proposes a new design for stair-climbing using a wheel that can split into segments and walk up stairs or surmount other obstacles often found where humans traverse, while still being able to retain a perfectly round shape for traveling on smooth ground. Using this change of configurat......This paper proposes a new design for stair-climbing using a wheel that can split into segments and walk up stairs or surmount other obstacles often found where humans traverse, while still being able to retain a perfectly round shape for traveling on smooth ground. Using this change...... of configuration, staircases with a wide range of dimensions can be covered efficiently and safely. The design, named Umbrella Wheel, can consist of as many wheel segments as desired, and as few as two. A smaller or higher number of wheel segments has advantages and disadvantages depending on the specific...

High speed heterostructure devices

CERN Document Server

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

1994-01-01

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

Mitochondrial haplotypes are not associated with mice selectively bred for high voluntary wheel running.

Science.gov (United States)

Wone, Bernard W M; Yim, Won C; Schutz, Heidi; Meek, Thomas H; Garland, Theodore

2018-04-04

Mitochondrial haplotypes have been associated with human and rodent phenotypes, including nonshivering thermogenesis capacity, learning capability, and disease risk. Although the mammalian mitochondrial D-loop is highly polymorphic, D-loops in laboratory mice are identical, and variation occurs elsewhere mainly between nucleotides 9820 and 9830. Part of this region codes for the tRNA Arg gene and is associated with mitochondrial densities and number of mtDNA copies. We hypothesized that the capacity for high levels of voluntary wheel-running behavior would be associated with mitochondrial haplotype. Here, we analyzed the mtDNA polymorphic region in mice from each of four replicate lines selectively bred for 54 generations for high voluntary wheel running (HR) and from four control lines (Control) randomly bred for 54 generations. Sequencing the polymorphic region revealed a variable number of adenine repeats. Single nucleotide polymorphisms (SNPs) varied from 2 to 3 adenine insertions, resulting in three haplotypes. We found significant genetic differentiations between the HR and Control groups (F st  = 0.779, p ≤ 0.0001), as well as among the replicate lines of mice within groups (F sc  = 0.757, p ≤ 0.0001). Haplotypes, however, were not strongly associated with voluntary wheel running (revolutions run per day), nor with either body mass or litter size. This system provides a useful experimental model to dissect the physiological processes linking mitochondrial, genomic SNPs, epigenetics, or nuclear-mitochondrial cross-talk to exercise activity. Copyright © 2018. Published by Elsevier B.V.

Continuous Wheel Momentum Dumping Using Magnetic Torquers and Thrusters

Science.gov (United States)

Oh, Hwa-Suk; Choi, Wan-Sik; Eun, Jong-Won

1996-12-01

Two momentum management schemes using magnetic torquers and thrusters are sug-gested. The stability of the momentum dumping logic is proved at a general attitude equilibrium. Both momentum dumping control laws are implemented with Pulse-Width- Pulse-Frequency Modulated on-off control, and shown working equally well with the original continuous and variable strength control law. Thrusters are assummed to be asymmetrically configured as a contingency case. Each thruster is fired following separated control laws rather than paired thrusting. Null torque thrusting control is added on the thrust control calculated from the momentum control law for the gener-ation of positive thrusting force. Both magnetic and thrusting control laws guarantee the momentum dumping, however, the wheel inner loop control is needed for the "wheel speed" dumping, The control laws are simulated on the KOrea Multi-Purpose SATellite (KOMPSAT) model.

Design of Wheeled Mobile Robot with Tri-Star Wheel as Rescue Robot

Directory of Open Access Journals (Sweden)

Rafiuddin Syam

2014-10-01

Full Text Available This study aims to design, and analyze a mobile robot that can handle some of the obstacles, they are uneven surfaces, slopes, can also climb stairs. WMR in this study is Tristar wheel that is containing three wheels for each set. On average surface only two wheels in contact with the surface, if there is an uneven surface or obstacle then the third wheel will rotate with the rotation center of the wheel in contact with the leading obstacle then only one wheel in contact with the surface. This study uses the C language program. Furthermore, the minimum thrust to be generated torque of the motor and transmission is 9.56 kg. The results obtained by calculation and analysis of DC motors used must have a torque greater than 14.67 kg.cm. Minimum thrust to be generated motor torque and the transmission is 9.56 kg. The experimental results give good results for robot to moving forward, backward, turn left, turn right and climbing the stairs.

A full-spectrum analysis of high-speed train interior noise under multi-physical-field coupling excitations

Science.gov (United States)

Zheng, Xu; Hao, Zhiyong; Wang, Xu; Mao, Jie

2016-06-01

High-speed-railway-train interior noise at low, medium, and high frequencies could be simulated by finite element analysis (FEA) or boundary element analysis (BEA), hybrid finite element analysis-statistical energy analysis (FEA-SEA) and statistical energy analysis (SEA), respectively. First, a new method named statistical acoustic energy flow (SAEF) is proposed, which can be applied to the full-spectrum HST interior noise simulation (including low, medium, and high frequencies) with only one model. In an SAEF model, the corresponding multi-physical-field coupling excitations are firstly fully considered and coupled to excite the interior noise. The interior noise attenuated by sound insulation panels of carriage is simulated through modeling the inflow acoustic energy from the exterior excitations into the interior acoustic cavities. Rigid multi-body dynamics, fast multi-pole BEA, and large-eddy simulation with indirect boundary element analysis are first employed to extract the multi-physical-field excitations, which include the wheel-rail interaction forces/secondary suspension forces, the wheel-rail rolling noise, and aerodynamic noise, respectively. All the peak values and their frequency bands of the simulated acoustic excitations are validated with those from the noise source identification test. Besides, the measured equipment noise inside equipment compartment is used as one of the excitation sources which contribute to the interior noise. Second, a full-trimmed FE carriage model is firstly constructed, and the simulated modal shapes and frequencies agree well with the measured ones, which has validated the global FE carriage model as well as the local FE models of the aluminum alloy-trim composite panel. Thus, the sound transmission loss model of any composite panel has indirectly been validated. Finally, the SAEF model of the carriage is constructed based on the accurate FE model and stimulated by the multi-physical-field excitations. The results show

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

Science.gov (United States)

Janczur, R.

2016-09-01

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

Wheel running decreases palatable diet preference in Sprague-Dawley rats

OpenAIRE

Moody, Laura; Liang, Joy; Choi, Pique P.; Moran, Timothy H.; Liang, Nu-Chu

2015-01-01

Physical activity has beneficial effects on not only improving some disease conditions but also by preventing the development of multiple disorders. Experiments in this study examined the effects of wheel running on intakes of chow and palatable diet e.g. high fat (HF) or high sucrose (HS) diet in male and female Sprague Dawley rats. Experiment 1 demonstrated that acute wheel running results in robust HF or HS diet avoidance in male rats. Although female rats with running wheel...

A rotating target wheel system for gammasphere

International Nuclear Information System (INIS)

Greene, J. P.

1999-01-01

A description is given for a low-mass, rotating target wheel to be used within the Gammasphere target chamber. This system was developed for experiments employing high beam currents in order to extend lifetimes of targets using low-melting point target material. The design is based on a previously successful implementation of rotating target wheels for the Argonne Positron Experiment (APEX) as well as the Fragment Mass Analyser (FMA) at ATLAS (Argonne Tandem Linac Accelerator System). A brief history of these rotating target wheel systems is given as well as a discussion on target preparation and performance

14 CFR 23.253 - High speed characteristics.

Science.gov (United States)

2010-01-01

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

Design, Construction and Evaluation of an Interchangeable Digital System to Measure Slip and Ground Speed of Existing 2WD Tractors in Iran

Directory of Open Access Journals (Sweden)

M Khosravi

2012-05-01

Full Text Available The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has been designed. Furthermore, it has been assessed after construction. To measure actual and theoretical ground speed, four rotary encoders for sensing the rotation of front and rear wheels have been utilized. Slip and ground speed were measured by means of software which has been developed in an ATmega16PU microprocessor. The measured slip and speed are digitally displayed on tractor dashboard. To evaluate the performance of the system, the measured values of ground speed and slip were compared with their calculated values obtained from conventional method. The Micro-controller has been programmed in such a way that the effect of front wheel sliding on slip is eliminated. In all evaluation conditions (in field and on asphalt, the maximum difference between system measurements for slip and speed and calculated slip and speed via conventional method was 2.4% and 0.2 km h-1, respectively. With slight alteration this system can be fitted on any kind of exiting two wheel drive tractors in the country.

49 CFR 570.10 - Wheel assemblies.

Science.gov (United States)

2010-10-01

... bead through one full wheel revolution and note runout in excess of one-eighth of an inch. (c) Mounting... 49 Transportation 6 2010-10-01 2010-10-01 false Wheel assemblies. 570.10 Section 570.10... Pounds or Less § 570.10 Wheel assemblies. (a) Wheel integrity. A tire rim, wheel disc, or spider shall...

Railway bogie vibration analysis by mathematical simulation model and a scaled four-wheel railway bogie set

Science.gov (United States)

Visayataksin, Noppharat; Sooklamai, Manon

2018-01-01

The bogie is the part that connects and transfers all the load from the vehicle body onto the railway track; interestingly the interaction between wheels and rails is the critical point for derailment of the rail vehicles. However, observing or experimenting with real bogies on rail vehicles is impossible due to the operational rules and safety concerns. Therefore, this research aimed to develop a vibration analysis set for a four-wheel railway bogie by constructing a four-wheel bogie with scale of 1:4.5. The bogie structures, including wheels and axles, were made from an aluminium alloy, equipped with springs and dampers. The bogie was driven by an electric motor using 4 round wheels instead of 2 straight rails, with linear velocity between 0 to 11.22 m/s. The data collected from the vibration analysis set was compared to the mathematical simulation model to investigate the vibration behavior of the bogie, especially the hunting motion. The results showed that vibration behavior from a scaled four-wheel railway bogie set significantly agreed with the mathematical simulation model in terms of displacement and hunting frequency. The critical speed of the wheelset was found by executing the mathematical simulation model at 13 m/s.

Design of Wheeled Mobile Robot with Tri-Star Wheel as Rescue Robot

Directory of Open Access Journals (Sweden)

Rafiuddin Syam

2016-05-01

Full Text Available This study aims to design, and analyze a mobilerobot that can handle some of the obstacles, they are unevensurfaces, slopes, can also climb stairs. WMR in this study is Tristarwheel that is containing three wheels for each set. Onaverage surface only two wheels in contact with the surface, ifthere is an uneven surface or obstacle then the third wheel willrotate with the rotation center of the wheel in contact with theleading obstacle then only one wheel in contact with the surface.This study uses the C language program. Furthermore, theminimum thrust to be generated torque of the motor andtransmission is 9.56 kg. The results obtained by calculation andanalysis of DC motors used must have a torque greater than14.67 kg.cm. Minimum thrust to be generated motor torque andthe transmission is 9.56 kg. The experimental results give goodresults for robot to moving forward, backward, turn left, turnright and climbing the stairs

Ride performance of a high speed rail vehicle using controlled semi active suspension system

Science.gov (United States)

Sharma, Sunil Kumar; Kumar, Anil

2017-05-01

The rail-wheel interaction in a rail vehicle running at high speed results in large amplitude vibration of carbody that deteriorates the ride comfort of travellers. The role of suspension system is crucial to provide an acceptable level of ride performance. In this context, an existing rail vehicle is modelled in vertical, pitch and roll motions of carbody and bogies. Additionally, nonlinear stiffness and damping parameters of passive suspension system are defined based on experimental data. In the secondary vertical suspension system, a magneto-rheological (MR) damper is included to improve the ride quality and comfort. The parameters of MR damper depend on the current, amplitude and frequency of excitations. At different running speeds, three semi-active suspension strategies with MR damper are analysed for periodic track irregularity and the resulting performance indices are juxtaposed with the nonlinear passive suspension system. The disturbance rejection and force tracking damper controller algorithms are applied to control the desired force of MR damper. This study reveals that the vertical vibrations of a vehicle can be reduced significantly by using the proposed semi-active suspension strategies. Moreover, it naturally results in improved ride quality and passenger’s comfort in comparison to the existing passive system.

Study of Micro-hardness of High-Speed W9Mo4Co8 Steel Plates in Pendulum Grinding by Abrasive Wheel Periphery

OpenAIRE

Soler, Yakov Iosifovich; Nguyen, Van Canh

2017-01-01

In cutting tool assembly, grinding is the most important technological step of the finishing treatment, largely determining the workmanship. An increase of micro-hardness after grinding relative to the original one indicates the dominant role of abrasive tool force impact on the ground surface. A decrease, in contrast, evidences a significant softening under the influence of heat source. This research based on nonparametric statistics to predict the effect of wheel characteristics with abrasi...

High-Speed Photography

International Nuclear Information System (INIS)

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

1998-01-01

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

Wheel running, voluntary ethanol consumption, and hedonic substitution.

Science.gov (United States)

Ozburn, Angela Renee; Harris, R Adron; Blednov, Yuri A

2008-08-01

Few studies have examined the relationship between naturally rewarding behaviors and ethanol drinking behaviors in mice. Although natural and drug reinforcers activate similar brain circuitry, there is behavioral evidence suggesting food and drug rewards differ in perceived value. The primary goal of the present study was to investigate the relationships between naturally reinforcing stimuli and consumption of ethanol in ethanol preferring C57BL/6J mice. Mouse behaviors were observed after the following environmental manipulations: standard or enhanced environment, accessible or inaccessible wheel, and presence or absence of ethanol. Using a high-resolution volumetric drinking monitor and wheel running monitor, we evaluated whether alternating access to wheel running modified ethanol-related behaviors and whether alternating access to ethanol modified wheel running or subsequent ethanol-related behaviors. We found that ethanol consumption remains stable with alternating periods of wheel running. Wheel running increases in the absence of ethanol and decreases upon reintroduction of ethanol. Upon reintroduction of ethanol, an alcohol deprivation effect was seen. Collectively, the results support theories of hedonic substitution and suggest that female C57BL/6J mice express ethanol seeking and craving under these specific conditions.

SEAL FOR HIGH SPEED CENTRIFUGE

Science.gov (United States)

Skarstrom, C.W.

1957-12-17

A seal is described for a high speed centrifuge wherein the centrifugal force of rotation acts on the gasket to form a tight seal. The cylindrical rotating bowl of the centrifuge contains a closure member resting on a shoulder in the bowl wall having a lower surface containing bands of gasket material, parallel and adjacent to the cylinder wall. As the centrifuge speed increases, centrifugal force acts on the bands of gasket material forcing them in to a sealing contact against the cylinder wall. This arrangememt forms a simple and effective seal for high speed centrifuges, replacing more costly methods such as welding a closure in place.

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.

Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

Directory of Open Access Journals (Sweden)

Chen Zhenzhen

2014-08-01

Full Text Available For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function. However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride (CBN wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temperature, which were better than those of the vitrified one under the same grinding conditions. Compared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.

Genetic Algorithm-Based Optimization for Surface Roughness in Cylindrically Grinding Process Using Helically Grooved Wheels

Science.gov (United States)

Çaydaş, Ulaş; Çelik, Mahmut

The present work is focused on the optimization of process parameters in cylindrical surface grinding of AISI 1050 steel with grooved wheels. Response surface methodology (RSM) and genetic algorithm (GA) techniques were merged to optimize the input variable parameters of grinding. The revolution speed of workpiece, depth of cut and number of grooves on the wheel were changed to explore their experimental effects on the surface roughness of machined bars. The mathematical models were established between the input parameters and response by using RSM. Then, the developed RSM model was used as objective functions on GA to optimize the process parameters.

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

Science.gov (United States)

Shaw, Robert J.

1994-01-01

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

Modelling of a mecanum wheel taking into account the geometry of road rollers

Science.gov (United States)

Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

2017-08-01

the road rollers, is their bearings. Depending on the load, carried by the vehicle and the rotational speed of the drive wheel, the bearings themselves can greatly affect the diameter of the rollers and the whole Mecanum wheels. The solution of this problem is presented in the paper. It is illustrated with virtual models elaborated in advanced program of the CAE class.

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…

Analysing a Relationship Between Wheel Wear and Cutting Forces During Diamond Grinding

Directory of Open Access Journals (Sweden)

M. A. Shavva

2014-01-01

carbide (Т15К6 work pieces was experimentally made. Experiments were carried out on the universal flat-grinding machine 3G71M using a diamond grinding wheel 6А2 250х20х4х29х76 АС6 160/125 А1 100% М1-01 according to GOST 16170-91. When using this equipment, cutting operation conditions, namely grinding speed and longitudinal table feed were 35 m/s and 3 - 12 m/min, respectively.The work piece was clamped in a vise. Vise was set on the universal attachment. Device was installed on a three-component dynamometer brands Kistler 9257B to measure cutting forces.Grinding was carried out under the following operation conditions: traverse Strav= 3 m/min, depth of cutting t = 20 μm. Grinding used a water-based cooling emulsion. Wheel speed was 35m/s. The dynamometer was tuned to the frequency of signal equal to 250 Hz.After processing the experimental and calculated data were compared using the theoretical formulas. The maximum difference between them was 17%.Owing to the presented model it is possible to obtain data on the diamond tool wear during cutting through a change of the tangential component of the cutting force. With the definite maximum wear of diamond wheel it is possible to calculate a threshold value of the tangential component of the cutting force. When the threshold value of the tangential component of the cutting force is reached, a diamond wheel must be subjected to dressing. On-time wheel dressing allows us to avoid reducing quality of the machined surface.Control of forces in the cutting zone is difficult to organize; the procedure can be performed by power control of the grinding spindle through the current control.

33 CFR 84.24 - High-speed craft.

Science.gov (United States)

2010-07-01

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

Time-domain simulation and nonlinear analysis on ride performance of four-wheel vehicles

Energy Technology Data Exchange (ETDEWEB)

Wang, Y S; He, H; Geng, A L [School of Automobile and Traffic Engineering, Liaoning University of Technology, Jinzhou 121001 (China)], E-mail: jzwbt@163.com

2008-02-15

A nonlinear dynamic model with eight DOFs of a four-wheel vehicle is established in this paper. After detaching the nonlinear characteristics of the leaf springs and shock absorbers, the multi-step linearizing method is used to simulate the vehicle vibration in time domain, under a correlated four-wheel road roughness model. Experimental verifications suggest that the newly built vehicle model and simulation procedure are reasonable and feasible to be used in vehicle vibration analysis. Furthermore, some nonlinear factors of the leaf springs and shock absorbers, which affect the vehicle ride performance (or comfort), are investigated under different vehicle running speeds. Some substaintial rules of the nonlinear vehicle vibrations are revealed in this paper.

Time-domain simulation and nonlinear analysis on ride performance of four-wheel vehicles

International Nuclear Information System (INIS)

Wang, Y S; He, H; Geng, A L

2008-01-01

A nonlinear dynamic model with eight DOFs of a four-wheel vehicle is established in this paper. After detaching the nonlinear characteristics of the leaf springs and shock absorbers, the multi-step linearizing method is used to simulate the vehicle vibration in time domain, under a correlated four-wheel road roughness model. Experimental verifications suggest that the newly built vehicle model and simulation procedure are reasonable and feasible to be used in vehicle vibration analysis. Furthermore, some nonlinear factors of the leaf springs and shock absorbers, which affect the vehicle ride performance (or comfort), are investigated under different vehicle running speeds. Some substaintial rules of the nonlinear vehicle vibrations are revealed in this paper

Modern trends in designing high-speed trains

Directory of Open Access Journals (Sweden)

Golubović Snežana D.

2015-01-01

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

Grinding Characteristics Of Directionally Aligned SiC Whisker Wheel-Comparison With Al2O3 Fiber Wheel

Institute of Scientific and Technical Information of China (English)

魏源迁; 山口胜美; 菊泽贤二; 洞口严; 中根正喜

2003-01-01

A unique SiC whisker wheel was invented,in which the whiskers were aligned normally to the grinding wheel surface.In this paper,grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains,Al2O3 grains,as well as Al2O3 long and short fibres which were also aligned normally to the grinding wheel surface,respectively.The main research contents concern grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal volume,wheel-wear rates,integrity of the ground surfaces,grinding ratios and grinding efficiency.Furthermore,grinding wheels of whiskers and fibres have a common disadvantage:they tend to load easily.The authors have proposed a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.

Equipping an automated wheelchair with an infrared encoder wheel odometer - biomed 2011.

Science.gov (United States)

Schultz, D; Allen, M; Barrett, S F

2011-01-01

Assistive technology is a rapidly growing field that provides a degree of freedom and self-sufficiency to people of limited mobility. Smart wheelchairs are a subset of assistive technology, and are designed to be operated by people who are unable to use a traditional control system. Instead, smart wheelchairs are equipped with a combination of automated functionality and steering mechanisms specialized to meet a person’s individual needs. One feature common to the automated capabilities of smart wheelchairs is the tracking system. The wheelchair’s microcontroller needs to know how far the chair has travelled, its speed, and the rotational direction of its wheels in order to successfully navigate through an environment. The purpose of this research was to develop an odometer to track the motion of a motorized wheelchair. Due to federal regulations that prohibit changing the structure or internal mechanics of a medical device, the odometer had to be designed as a separate, removable part. The final design for the odometer consisted of two infrared sensors that measure edge transitions of a segmented black and white encoder wheel. The sensor output was then run through two comparator op amps and a high pass filter to produce a clean, crisp square wave signal output. The signal was then fed to an Atmel ATmega164P microcontroller. The microcontroller was programmed to compare the sensor signal with its internal clock, sense edge transitions, and thereby extrapolate the speed, travelled distance, and rotational direction of the wheelchair.

Tracked Vehicle Road Wheel Puller

Science.gov (United States)

2009-02-01

employed for removing smaller-size components, such as bolts and the like. U.S. Patent No. 5,410,792, issued to Freeman (3), discloses a caster wheel ...separation of the rubberized annular layer from the outer annular surface of the wheel . Figure 5 further illustrates a modification of the wheel puller...2001. 2. Rubino et al. Pulling Tool. U.S. Patent 5,479,688, 1996. 3. Freeman. Caster Wheel Axle Extraction Apparatus. U.S. Patent 5,410,792

Simulation modeling of wheeled vehicle dynamics on the stand "Roller"

Directory of Open Access Journals (Sweden)

G. O. Kotiev

2014-01-01

Full Text Available The tests are an integral part of the wheeled vehicle design, manufacturing, and operation. The need for their conducting arises from the research and experimental activities to assess the qualitative and quantitative characteristics of the vehicles in general, as well as the individual components and assemblies. It is obvious that a variety of design features of wheeled vehicles request a development of methods both for experimental studies and for creating the original bench equipment for these purposes.The main positive feature of bench tests of automotive engineering is a broad capability to control the combinations of traction loads, speed rates, and external input conditions. Here, the steady state conditions can be used for a long time, allowing all the necessary measurements to be made, including those with video and photo recording experiment.It is known that the benefits of test "M" type (using a roller dynamometer include a wide range of test modes, which do not depend on the climatic conditions, as well as a capability to use a computer-aided testing programs. At the same time, it is known that the main drawback of bench tests of full-size vehicle is that the tire rolling conditions on the drum mismatch to the real road pavements, which are difficult to simulate on the drum surface. This problem can be solved owing to wheeled vehicle tests at the benches "Roller" to be, in efficiency, the most preferable research method. The article gives a detailed presentation of developed at BMSTU approach to its solving.Problem of simulation mathematical modeling has been solved for the vehicle with the wheel formula 8 × 8, and individual wheel-drive.The simulation results have led to the conclusion that the proposed principle to simulate a vehicle rolling on a smooth non-deformable support base using a bench " Roller " by simulation modeling is efficient.

Optimal control of mode transition for four-wheel-drive hybrid electric vehicle with dry dual-clutch transmission

Science.gov (United States)

Zhao, Zhiguo; Lei, Dan; Chen, Jiayi; Li, Hangyu

2018-05-01

When the four-wheel-drive hybrid electric vehicle (HEV) equipped with a dry dual clutch transmission (DCT) is in the mode transition process from pure electrical rear wheel drive to front wheel drive with engine or hybrid drive, the problem of vehicle longitudinal jerk is prominent. A mode transition robust control algorithm which resists external disturbance and model parameter fluctuation has been developed, by taking full advantage of fast and accurate torque (or speed) response of three electrical power sources and getting the clutch of DCT fully involved in the mode transition process. Firstly, models of key components of driveline system have been established, and the model of five-degrees-of-freedom vehicle longitudinal dynamics has been built by using a Uni-Tire model. Next, a multistage optimal control method has been produced to realize the decision of engine torque and clutch-transmitted torque. The sliding-mode control strategy for measurable disturbance has been proposed at the stage of engine speed dragged up. Meanwhile, the double tracking control architecture that integrates the model calculating feedforward control with H∞ robust feedback control has been presented at the stage of speed synchronization. Finally, the results from Matlab/Simulink software and hardware-in-the-loop test both demonstrate that the proposed control strategy for mode transition can not only coordinate the torque among different power sources and clutch while minimizing vehicle longitudinal jerk, but also provide strong robustness to model uncertainties and external disturbance.

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.

Mice selectively bred for high voluntary wheel-running behavior conserve more fat despite increased exercise.

Science.gov (United States)

Hiramatsu, Layla; Garland, Theodore

2018-04-20

Physical activity is an important component of energy expenditure, and acute changes in activity can lead to energy imbalances that affect body composition, even under ad libitum food availability. One example of acute increases in physical activity is four replicate, selectively-bred High Runner (HR) lines of mice that voluntarily run ~3-fold more wheel revolutions per day over 6-day trials and are leaner, as compared with four non-selected control (C) lines. We expected that voluntary exercise would increase food consumption, build lean mass, and reduce fat mass, but that these effects would likely differ between HR and C lines or between the sexes. We compared wheel running, cage activity, food consumption, and body composition between HR and C lines for young adults of both sexes, and examined interrelationships of those traits across 6 days of wheel access. Before wheel testing, HR mice weighed less than C, primarily due to reduced lean mass, and females were lighter than males, entirely due to lower lean mass. Over 6 days of wheel access, all groups tended to gain small amounts of lean mass, but lose fat mass. HR mice lost less fat than C mice, in spite of much higher activity levels, resulting in convergence to a fat mass of ~1.7 g for all 4 groups. HR mice consumed more food than C mice (with body mass as a covariate), even accounting for their higher activity levels. No significant sex-by-linetype interactions were observed for any of the foregoing traits. Structural equation models showed that the four sex-by-linetype groups differed considerably in the complex phenotypic architecture of these traits. Interrelationships among traits differed by genetic background and sex, lending support to the idea that recommendations regarding weight management, diet, and exercise may need to be tailored to the individual level. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

High speed data acquisition

International Nuclear Information System (INIS)

Cooper, P.S.

1997-07-01

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

Effects of leptin treatment and Western diet on wheel running in selectively bred high runner mice.

Science.gov (United States)

Meek, Thomas H; Dlugosz, Elizabeth M; Vu, Kim T; Garland, Theodore

2012-05-15

The role of leptin in regulating physical activity is varied. The behavioral effects of leptin signaling depend on the type of activity and the animal's physiological state. We used mice from lines selectively bred for high voluntary wheel running to further study how leptin regulates volitional exercise. Mice from four replicate high runner (HR) lines typically run ~3-fold more revolutions per day than those from four non-selected control (C) lines. HR mice have altered dopamine function and differences from C in brain regions known to be important in leptin-mediated behavior. Furthermore, male HR mice have been found to dramatically increase running when administered Western diet, an effect possibly mediated through leptin signaling. Male mice from generation 61 (representing three HR lines and one C line) were allowed wheel access at 24 days of age and given either Western diet (high in fat and with added sucrose) or standard chow. After four weeks, Western diet significantly increased circulating leptin, insulin, C-peptide, gastric inhibitory polypeptide, and inflammatory hormone resistin concentrations in HR mice (C mice not measured). Western diet increased running in HR mice, but did not significantly affect running in C mice. During the fifth week, all mice received two days of intra-peritoneal sham injections (physiological saline) followed by three days of murine recombinant leptin injections, and then another six days of sham injections. Leptin treatment significantly decreased caloric intake (adjusted for body mass) and body mass in all groups. Wheel running significantly increased with leptin injections in HR mice (fed Western or standard diet), but was unaffected in C mice. Whether Western diet and leptin treatment stimulate wheel running in HR mice through the same physiological pathways awaits future study. These results have implications for understanding the neural and endocrine systems that control locomotor activity, food consumption, and body

Grinding Wheel System

Science.gov (United States)

Malkin, Stephen; Gao, Robert; Guo, Changsheng; Varghese, Biju; Pathare, Sumukh

2003-08-05

A grinding wheel system includes a grinding wheel with at least one embedded sensor. The system also includes an adapter disk containing electronics that process signals produced by each embedded sensor and that transmits sensor information to a data processing platform for further processing of the transmitted information.

The Development of Lightweight Commercial Vehicle Wheels Using Microalloying Steel

Science.gov (United States)

Lu, Hongzhou; Zhang, Lilong; Wang, Jiegong; Xuan, Zhaozhi; Liu, Xiandong; Guo, Aimin; Wang, Wenjun; Lu, Guimin

Lightweight wheels can reduce weight about 100kg for commercial vehicles, and it can save energy and reduce emission, what's more, it can enhance the profits for logistics companies. The development of lightweight commercial vehicle wheels is achieved by the development of new steel for rim, the process optimization of flash butt welding, and structure optimization by finite element methods. Niobium micro-alloying technology can improve hole expansion rate, weldability and fatigue performance of wheel steel, and based on Niobium micro-alloying technology, a special wheel steel has been studied whose microstructure are Ferrite and Bainite, with high formability and high fatigue performance, and stable mechanical properties. The content of Nb in this new steel is 0.025% and the hole expansion rate is ≥ 100%. At the same time, welding parameters including electric upsetting time, upset allowance, upsetting pressure and flash allowance are optimized, and by CAE analysis, an optimized structure has been attained. As a results, the weight of 22.5in×8.25in wheel is up to 31.5kg, which is most lightweight comparing the same size wheels. And its functions including bending fatigue performance and radial fatigue performance meet the application requirements of truck makers and logistics companies.

Wake flow characteristics at high wind speed

DEFF Research Database (Denmark)

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

2016-01-01

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

Effects of early-life exposure to Western diet and wheel access on metabolic syndrome profiles in mice bred for high voluntary exercise.

Science.gov (United States)

Meek, T H; Eisenmann, J C; Keeney, B K; Hannon, R M; Dlugosz, E M; Garland, T

2014-03-01

Experimental studies manipulating diet and exercise have shown varying effects on metabolic syndrome components in both humans and rodents. To examine the potential interactive effects of diet, exercise and genetic background, we studied mice from four replicate lines bred (52 generations) for high voluntary wheel running (HR lines) and four unselected control lines (C). At weaning, animals were housed for 60 days with or without wheels and fed either a standard chow or Western diet (WD, 42% kcal from fat). Four serial (three juvenile and one adult) blood samples were taken to measure fasting total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides and glucose. Western diet was obesogenic for all mice, even after accounting for the amount of wheel running and kilojoules consumed. Western diet significantly raised glucose as well as TC and HDL-C concentrations. At the level of individual variation (repeatability), there was a modest correlation (r = 0.3-0.5) of blood lipids over time, which was reduced with wheel access and/or WD. Neither genetic selection history nor wheel access had a statistically significant effect on blood lipids. However, HR and C mice had divergent ontogenetic trajectories for body mass and caloric intake. HR mice also had lower adiposity, an effect that was dependent on wheel access. The environmental factors of diet and wheel access had pronounced effects on body mass, food consumption and fasting glucose concentrations, interacting with each other and/or with genetic strain. These data underscore the importance (and often unpredictable nature) of genotype-by-environment and environment-by-environment interactions when studying body weight regulation. © 2013 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

14 CFR 25.253 - High-speed characteristics.

Science.gov (United States)

2010-01-01

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

Chicago-St. Louis high speed rail plan

International Nuclear Information System (INIS)

Stead, M.E.

1994-01-01

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

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.

Maternal exposure to Western diet affects adult body composition and voluntary wheel running in a genotype-specific manner in mice.

Science.gov (United States)

Hiramatsu, Layla; Kay, Jarren C; Thompson, Zoe; Singleton, Jennifer M; Claghorn, Gerald C; Albuquerque, Ralph L; Ho, Brittany; Ho, Brett; Sanchez, Gabriela; Garland, Theodore

2017-10-01

Some human diseases, including obesity, Type II diabetes, and numerous cancers, are thought to be influenced by environments experienced in early life, including in utero. Maternal diet during the perinatal period may be especially important for adult offspring energy balance, potentially affecting both body composition and physical activity. This effect may be mediated by the genetic background of individuals, including, for example, potential "protective" mechanisms for individuals with inherently high levels of physical activity or high basal metabolic rates. To examine some of the genetic and environmental factors that influence adult activity levels, we used an ongoing selection experiment with 4 replicate lines of mice bred for high voluntary wheel running (HR) and 4 replicate, non-selected control lines (C). Dams (half HR and half C) were fed a "Western" diet (WD, high in fat and sucrose) or a standard diet (SD) from 2weeks prior to mating until their pups could feed on solid food (14days of age). We analyzed dam and litter characteristics from birth to weaning, and offspring mass and physical activity into adulthood. One male offspring from each litter received additional metabolic and behavioral tests. Maternal WD caused pups to eat solid food significantly earlier for C litters, but not for HR litters (interaction of maternal environment and genotype). With dam mass as a covariate, mean pup mass was increased by maternal WD but litter size was unaffected. HR dams had larger litters and tended to have smaller pups than C dams. Home-cage activity of juvenile focal males was increased by maternal WD. Juvenile lean mass, fat mass, and fat percent were also increased by maternal WD, but food consumption (with body mass as a covariate) was unaffected (measured only for focal males). Behavior in an elevated plus maze, often used to indicate anxiety, was unaffected by maternal WD. Maximal aerobic capacity (VO 2 max) was also unaffected by maternal WD, but HR had

Lubrication and cooling for high speed gears

Science.gov (United States)

Townsend, D. P.

1985-01-01

The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

The use of high-speed imaging in education

Science.gov (United States)

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

2017-02-01

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

High-speed elevators controlled by inverters

Energy Technology Data Exchange (ETDEWEB)

Sakai, Yoshio; Takahashi, Hideaki; Nakamura, Kiyoshi; Kinoshita, Hiroshi

1988-10-25

The super-high-speed elevator with superiority to 300m/min of speed, requires both the large capacity power and wide range speed controls. Therefore, in order to materialize the smooth and quiet operation characteristics, by applying the inverter control, the low torque ripple control in the low frequency range and high frequency large capacity inverting for lowering the motor in noise are necessary with their being assured of reliability. To satisfy the above necessary items, together with the development of a sine wave pulse width and frequency modulation (PWM/PFM) control system, to more precisely enable the sine wave electric current control, and 3kHz switching power converter, using a 800A power transistor module, a supervoltage control circuit under the extraordinary condition was designed. As a result of commercializing a 360m/min super-high speed inverter elevator, the power source unit, due to the effect of high power factor, could be reduced by 30% in capacity and also the higher harmonic wave including ratio could be considerably lowered to the inferiority to 5%. 2 references, 7 figures, 1 table.

High - speed steel for precise cased tools

International Nuclear Information System (INIS)

Karwiarz, J.; Mazur, A.

2001-01-01

The test results of high-vanadium high - speed steel (SWV9) for precise casted tools are presented. The face -milling cutters of NFCa80A type have been tested in industrial operating conditions. An average life - time of SWV9 steel tools was 3-10 times longer compare to the conventional high - speed milling cutters. Metallography of SWB9 precise casted steel revealed beneficial for tool properties distribution of primary vanadium carbides in the steel matrix. Presented results should be a good argument for wide application of high - vanadium high - speed steel for precise casted tools. (author)

Using wheel availability to shape running behavior of the rat towards improved behavioral and neurobiological outcomes.

Science.gov (United States)

Basso, Julia C; Morrell, Joan I

2017-10-01

Though voluntary wheel running (VWR) has been used extensively to induce changes in both behavior and biology, little attention has been given to the way in which different variables influence VWR. This lack of understanding has led to an inability to utilize this behavior to its full potential, possibly blunting its effects on the endpoints of interest. We tested how running experience, sex, gonadal hormones, and wheel apparatus influence VWR in a range of wheel access "doses". VWR increases over several weeks, with females eventually running 1.5 times farther and faster than males. Limiting wheel access can be used as a tool to motivate subjects to run but restricts maximal running speeds attained by the rodents. Additionally, circulating gonadal hormones regulate wheel running behavior, but are not the sole basis of sex differences in running. Limitations from previous studies include the predominate use of males, emphasis on distance run, variable amounts of wheel availability, variable light-dark cycles, and possible food and/or water deprivation. We designed a comprehensive set of experiments to address these inconsistencies, providing data regarding the "microfeatures" of running, including distance run, time spent running, running rate, bouting behavior, and daily running patterns. By systematically altering wheel access, VWR behavior can be finely tuned - a feature that we hypothesize is due to its positive incentive salience. We demonstrate how to maximize VWR, which will allow investigators to optimize exercise-induced changes in their behavioral and/or biological endpoints of interest. Published by Elsevier B.V.

Wheel inspection system environment.

Science.gov (United States)

2008-11-18

International Electronic Machines Corporation (IEM) has developed and is now marketing a state-of-the-art Wheel Inspection System Environment (WISE). WISE provides wheel profile and dimensional measurements, i.e. rim thickness, flange height, flange ...

The prospects for retail wheeling

International Nuclear Information System (INIS)

O'Donnell, E.H.; Center, J.A.

1992-01-01

This paper as published is an outline of a presentation on retail wheeling of electric power. The topics discussed are development of increased wholesale transmission access, government regulatory policies on wholesale transmission, examples of past and present retail transmission access agreements, examples of Federal Energy Regulatory Commission jurisdiction over retail wheeling, and state policies on retail wheeling

Wheel running decreases palatable diet preference in Sprague-Dawley rats.

Science.gov (United States)

Moody, Laura; Liang, Joy; Choi, Pique P; Moran, Timothy H; Liang, Nu-Chu

2015-10-15

Physical activity has beneficial effects on not only improving some disease conditions but also by preventing the development of multiple disorders. Experiments in this study examined the effects of wheel running on intakes of chow and palatable diet e.g. high fat (HF) or high sucrose (HS) diet in male and female Sprague-Dawley rats. Experiment 1 demonstrated that acute wheel running results in robust HF or HS diet avoidance in male rats. Although female rats with running wheel access initially showed complete avoidance of the two palatable diets, the avoidance of the HS diet was transient. Experiment 2 demonstrated that male rats developed decreased HF diet preferences regardless of the order of diet and wheel running access presentation. Running associated changes in HF diet preference in females, on the other hand, depended on the testing schedule. In female rats, simultaneous presentation of the HF diet and running access resulted in transient complete HF diet avoidance whereas running experience prior to HF diet access did not affect the high preference for the HF diet. Ovariectomy in females resulted in HF diet preference patterns that were similar to those in male rats during simultaneous exposure of HF and wheel running access but similar to intact females when running occurred before HF exposure. Overall, the results demonstrated wheel running associated changes in palatable diet preferences that were in part sex dependent. Furthermore, ovarian hormones play a role in some of the sex differences. These data reveal complexity in the mechanisms underlying exercise associated changes in palatable diet preference. Published by Elsevier Inc.

Wheel running decreases palatable diet preference in Sprague-Dawley rats

Science.gov (United States)

Moody, Laura; Liang, Joy; Choi, Pique P.; Moran, Timothy H.; Liang, Nu-Chu

2015-01-01

Physical activity has beneficial effects on not only improving some disease conditions but also by preventing the development of multiple disorders. Experiments in this study examined the effects of wheel running on intakes of chow and palatable diet e.g. high fat (HF) or high sucrose (HS) diet in male and female Sprague Dawley rats. Experiment 1 demonstrated that acute wheel running results in robust HF or HS diet avoidance in male rats. Although female rats with running wheel access initially showed complete avoidance of the two palatable diets, the avoidance of the HS diet was transient. Experiment 2 demonstrated that male rats developed decreased HF diet preferences regardless of the order of diet and wheel running access presentation. Running associated changes in HF diet preference in females, on the other hand, depended on the testing schedule. In female rats, simultaneous presentation of the HF diet and running access resulted in transient complete HF diet avoidance whereas running experience prior to HF diet access did not affect the high preference for the HF diet. Ovariectomy in females resulted in HF diet preference patterns that were similar to those in male rats during simultaneous exposure of HF and wheel running access but similar to intact females when running occurred before HF exposure. Overall, the results demonstrated wheel running associated changes in palatable diet preferences that were in part sex dependent. Furthermore, ovarian hormones play a role in some of the sex differences. These data reveal complexity in the mechanisms underlying exercise associated changes in palatable diet preference. PMID:25791204

Mission Analysis and Orbit Control of Interferometric Wheel Formation Flying

Science.gov (United States)

Fourcade, J.

Flying satellite in formation requires maintaining the specific relative geometry of the spacecraft with high precision. This requirement raises new problem of orbit control. This paper presents the results of the mission analysis of a low Earth observation system, the interferometric wheel, patented by CNES. This wheel is made up of three receiving spacecraft, which follow an emitting Earth observation radar satellite. The first part of this paper presents trades off which were performed to choose orbital elements of the formation flying which fulfils all constraints. The second part presents orbit positioning strategies including reconfiguration of the wheel to change its size. The last part describes the station keeping of the formation. Two kinds of constraints are imposed by the interferometric system : a constraint on the distance between the wheel and the radar satellite, and constraints on the distance between the wheel satellites. The first constraint is fulfilled with a classical chemical station keeping strategy. The second one is fulfilled using pure passive actuators. Due to the high stability of the relative eccentricity of the formation, only the relative semi major axis had to be controlled. Differential drag due to differential attitude motion was used to control relative altitude. An autonomous orbit controller was developed and tested. The final accuracy is a relative station keeping better than few meters for a wheel size of one kilometer.

Study on the Rollover Characteristic of In-Wheel-Motor-Driven Electric Vehicles Considering Road and Electromagnetic Excitation

Directory of Open Access Journals (Sweden)

Di Tan

2016-01-01

Full Text Available For in-wheel-motor-driven electric vehicles, the motor is installed in the wheel directly. Tyre runout and uneven load can cause magnet gap deformation in the motor, which will produce electromagnetic forces that further influence the vehicle rollover characteristics. To study the rollover characteristics, a verified 16-degree-of-freedom rollover dynamic model is introduced. Next, the vehicle rollover characteristics both with and without electromagnetic force are analyzed under conditions of the Fixed Timing Fishhook steering and grade B road excitation. The results show that the electromagnetic force has a certain effect on the load transfer and can reduce the antirollover performance of the vehicle. Therefore, the effect of the electromagnetic force on the rollover characteristic should be considered in the vehicle design. To this end, extensive analysis was conducted on the effect of the road level, vehicle speed, and the road adhesion coefficient on the vehicle rollover stability. The results indicate that vehicle rollover stability worsens when the above-mentioned factors increase, the most influential factor being the road adhesion coefficient followed by vehicle speed and road level. This paper can offer certain theory basis for the design of the in-wheel-motor-driven electric vehicles.

High-speed ground transportation development outside United States

Energy Technology Data Exchange (ETDEWEB)

Eastham, T.R. [Queen`s Univ., Kingston, Ontario (United Kingdom)

1995-09-01

This paper surveys the state of high-speed (in excess of 200 km/h) ground-transportation developments outside the United States. Both high-speed rail and Maglev systems are covered. Many vehicle systems capable of providing intercity service in the speed range 200--500 km/h are or will soon be available. The current state of various technologies, their implementation, and the near-term plans of countries that are most active in high-speed ground transportation development are reported.

Four-Wheel Vehicle Suspension System

Science.gov (United States)

Bickler, Donald B.

1990-01-01

Four-wheel suspension system uses simple system of levers with no compliant components to provide three-point suspension of chassis of vehicle while maintaining four-point contact with uneven terrain. Provides stability against tipping of four-point rectangular base, without rocking contact to which rigid four-wheel frame susceptible. Similar to six-wheel suspension system described in "Articulated Suspension Without Springs" (NPO-17354).

Running in a running wheel substitutes for stereotypies in mink (Mustela vison) but does it improve their welfare?

DEFF Research Database (Denmark)

Hansen, Steffen W; Damgaard, Birthe Marie

2009-01-01

This experiment investigated whether access to a running wheel affects the development of stereotypies during restricted feeding and whether selection for high or low levels of stereotypy affects the use of the running wheel. Sixty-two female mink kept in standard cages and selected for high or low...... levels of stereotypy were used. Thirty of these females had access to a running wheel whereas thirty-two female mink had no access to running wheels. The number of turns of the running wheel, behaviour, feed consumption, body weight and the concentration of plasma cortisol were measured during the winter...... period. Mink with access to a running wheel did not perform stereotypic behaviour and mink selected for a high level of stereotypies had more turns in the running wheel than mink selected for low levels of stereotypies. Mink with access to a running wheel used the running wheel for the same amount...

The Reaction Wheel Pendulum

CERN Document Server

Block, Daniel J; Spong, Mark W

2007-01-01

This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

Propulsion Wheel Motor for an Electric Vehicle

Science.gov (United States)

Figuered, Joshua M. (Inventor); Herrera, Eduardo (Inventor); Waligora, Thomas M. (Inventor); Bluethmann, William J. (Inventor); Farrell, Logan Christopher (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Winn, Ross Briant (Inventor); Eggleston, IV, Raymond Edward (Inventor); Guo, Raymond (Inventor);

Swissmetro - high speed underground transportation system propulsion, levitation and guiding system

Energy Technology Data Exchange (ETDEWEB)

Jufer, M [Lab. of Electromechanical and Electrical Machines, Swiss Federal Inst. of Technology, Lausanne (Switzerland); Cassat, A [Lab. of Electromechanical and Electrical Machines, Swiss Federal Inst. of Technology, Lausanne (Switzerland); Macabrey, N [Lab. of Electromechanical and Electrical Machines, Swiss Federal Inst. of Technology, Lausanne (Switzerland)

1996-12-31

The idea behind Swissmetro is to move travelers underground between the main cities of Switzerland at a speed of up to 500 km/h in a tube under partial vacuum. The train, carrying 800 passengers, would travel without contact to the infrastructure through an application of linear motor technology and magnetic levitation. The energy consumption of the system will be low, due to the reduced air resistance and the absence of wheel-rail contact. This publication describes the electromechanical and electromagnetic specific devices such as: The linear, short stator motors; the levitation system with electromagnets; the guidance system with electromagnets; the energy transmission system to the vehicle by induction, using a linear transformer. After a preliminary study, the Swissmetro project started an industrial study of 4 years in order to obtain the concession license from the Swiss government. (orig.)

Fault estimation of satellite reaction wheels using covariance based adaptive unscented Kalman filter

Science.gov (United States)

Rahimi, Afshin; Kumar, Krishna Dev; Alighanbari, Hekmat

2017-05-01

Reaction wheels, as one of the most commonly used actuators in satellite attitude control systems, are prone to malfunction which could lead to catastrophic failures. Such malfunctions can be detected and addressed in time if proper analytical redundancy algorithms such as parameter estimation and control reconfiguration are employed. Major challenges in parameter estimation include speed and accuracy of the employed algorithm. This paper presents a new approach for improving parameter estimation with adaptive unscented Kalman filter. The enhancement in tracking speed of unscented Kalman filter is achieved by systematically adapting the covariance matrix to the faulty estimates using innovation and residual sequences combined with an adaptive fault annunciation scheme. The proposed approach provides the filter with the advantage of tracking sudden changes in the system non-measurable parameters accurately. Results showed successful detection of reaction wheel malfunctions without requiring a priori knowledge about system performance in the presence of abrupt, transient, intermittent, and incipient faults. Furthermore, the proposed approach resulted in superior filter performance with less mean squared errors for residuals compared to generic and adaptive unscented Kalman filters, and thus, it can be a promising method for the development of fail-safe satellites.

High Speed Exit Taxiways.

Science.gov (United States)

1981-02-01

the runway with 1800 ft. radius and no specified runout distance, was developed circa 1958 and standardized in the 19609. A considerable nur, ber of...cornerinl) . Even wi th eaync);e wheel steering, the small fraction of total weight on thle nose whoel prevents tricycle airplaines from being very...would provide more runout but would require greater clearance travel distances at both Fnds. Z2 The results of reference (a) indicated that

Wheel slide protection control using a command map and Smith predictor for the pneumatic brake system of a railway vehicle

Science.gov (United States)

Lee, Nam-Jin; Kang, Chul-Goo

2016-10-01

In railway vehicles, excessive sliding or wheel locking can occur while braking because of a temporarily degraded adhesion between the wheel and the rail caused by the contaminated or wet surface of the rail. It can damage the wheel tread and affect the performance of the brake system and the safety of the railway vehicle. To safeguard the wheelset from these phenomena, almost all railway vehicles are equipped with wheel slide protection (WSP) systems. In this study, a new WSP algorithm is proposed. The features of the proposed algorithm are the use of the target sliding speed, the determination of a command for WSP valves using command maps, and compensation for the time delay in pneumatic brake systems using the Smith predictor. The proposed WSP algorithm was verified using experiments with a hardware-in-the-loop simulation system including the hardware of the pneumatic brake system.

The mathematical model for the investigation of different influence factors on the economic and ecological indicators of a wheel tractor

Directory of Open Access Journals (Sweden)

Zakharchuk V.I.

2016-08-01

Full Text Available To solve the problem of oil deficit and reduce emissions of harmful substances from exhaust gases of vehicles alternative motor fuels, including biodiesel may by used. Most of wheel tractors are used as technological transport in agriculture, industry and municipal services. The article aims to clarify the mathematical model to determine the effect of the type of fuel used wheeled tractors on its performance. The mathematical model of the system "operator-wheel tractor-road" for the design research impact type of fuel on harmful emissions and fuel consumption wheeled tractor, is used as technological transport during its movement for driving cycle. Driving cycle showed main modes of motion there are acceleration, motion with constant speed and deceleration. The mathematical model allows to accurately consider peculiarities of the wheel tractor as the vehicle and engine describing its characteristics by polinomial dependencies. In mathematical models specified polynomial dependences that describe the fuel supply cycle indicated torque, fuel consumption and concentrations of main harmful substances in the exhaust gases of diesel during operation on diesel and biodiesel.

MATHEMATICAL MODEL OF WHEELSET OSCILLATIONS WITH INDEPENDENT WHEEL ROTATION IN THE HORIZONTAL PLANE

Directory of Open Access Journals (Sweden)

S. V. Myamlin

2016-08-01

Full Text Available Purpose. The work is devoted to the study of horizontal oscillation and the assessment of the motion stability of a single wheelset with independent wheel rotation, and to the comparison of stability indicators of the typical wheelset and the wheelset with independent wheel rotation. This is connected with the necessity to increase traffic speed of rolling stock, improve road safety and comfort of passengers. Methodology. To achieve this purpose we used the methods of mathematical simulation of railway rolling stock dynamics, as well as the linear algebra methods to assess the stability of solutions of the linear homogeneous differential equations. Findings. To solve the set task the design model of a single wheelset with independent wheel rotation was created. The wheelset is not a single solid body; each of the wheelset axles has a surplus degree of freedom. Thus, we obtained the system with 4 degrees of freedom. The design model allowed to obtain the system of linear homogeneous differential equations describing the oscillations of the represented wheelset in a horizontal plane on a straight track section. On the basis of the computer modeling were calculated the eigenvalues of the differential equation system coefficients and the asymptotic stability analysis of the wheelset motion with independent wheel rotation. The increment and the frequency of fluctuations were compared with similar indicators for the standard wheelset. The authors also discussed non-oscillatory forms of the wheelset motion and the issues of wheelset self-centering on the track. Originality. The result of the work is the mathematical model of the sinuous movement of a single wheelset, in two-dimensional formulation, with independent wheel rotation and the estimate of the dynamic indices during its motion on a straight track section without any irregularities. There were also proposed the ways to ensure the self-centering on the track of the wheelset with independent

Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

DEFF Research Database (Denmark)

Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

might induce different effects on soil physical properties. The objective of this study was to investigate the impact of vehicle traffic on soil physical properties and air permeability by systematic collection of samples in a transect running from the center to the outside of the wheel rut. A field...... catena running from center of the wheel rut to un wheeled part of the field ( 0, 20, 40, 50,60 and 400 cm horizontal distance). We measured water retention and air permeability (ka) at -30, -100 and -300 hPa matric potentials. At -100 hPa, we obtained consistently lower air filled under the wheel rut......The impact of wheel traffic on soil physical properties is usually quantified by randomly collecting soil cores at specific depths below the wheeled surface. However, modeling studies as well as few measurements indicated a non-uniform stress distribution in a catena across the wheel rut, which...

Biaxial wheel/hub test facility. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Fischer, G.; Grubisic, V. [eds.

2000-07-01

The 4{sup th} meeting aims to exchange the experience and knowledge of engineers during several presentations and discussions about new developments required for a reliable, time and cost reducing validation of the wheel/hub assembly. Tremendous development of the wheel performance, described by the ratio of the rated load (kg) versus the wheel weight (kg) had taken place during the last 5000 years. Starting from the ratio of 3 for wooden 2-piece-disc-wheels in Mesopotamia it needed nearly 1000 years to increase the ratio to approx 5 at light-weight spoke wheels for fighting carriages, found in the grave of king Tutenchamon in Egypt. Modern light alloy wheels of commercial vehicles reach values up to 160 kg/kg. Additionally the comlex design of the modern systems for cars and commercial vehicles comprising wheel, brake, hub, bearing, spindle and hub carrier, including different materials and their treatment, fasteners, press-fits, require an appropriate testing procedure. The variable loading conditions, caused by operational wheel forces, brake and torque moments including heating, may result in changing tolerances and press-fits during operation and consequently in different damage mechanisms. This can be simulated in the Biaxial Wheel Test Machine, whereby corresponding load programs are necessary. An overview about all biaxial test machines in usage at the end of 1999 is shown in the introduction. The total number is 17 for cars, 7 for commercial vehicles and 1 for trains. The six presentations of this meeting were consequently concentrated on: (a) recommendations for a standardization of load programs of the German Wheel Committee, (b) the simulation of brake and torque events and (c) the possibility for a numerical stress analyses and fatigue life assessment. (orig./AKF)

Improving Performance of Cantilevered Momentum Wheel Assemblies by Soft Suspension Support

OpenAIRE

Zhou, Weiyong; Li, Dongxu

2013-01-01

This paper focuses on improving the performance of the rigid support cantilevered momentum wheel assemblies (CMWA) by soft suspension support. A CMWA, supported by two angular contact ball bearings, was modeled as a Jeffcott rotor. The support stiffness, before and after in series with a linear soft suspension support, were simplified as two Duffing's type springs respectively. The result shows that the rigid support CMWA produces large disturbance force at the resonance speed range. The soft...

Ultrasonic test of highly stressed gear shafts

Energy Technology Data Exchange (ETDEWEB)

Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H [Siemens Power Generation (Germany)

1999-12-31

In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

Ultrasonic test of highly stressed gear shafts

Energy Technology Data Exchange (ETDEWEB)

Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

1998-12-31

In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera

Science.gov (United States)

Yu, Liping; Pan, Bing

2017-08-01

Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

A Nontoxic Barlow's Wheel

Science.gov (United States)

Daffron, John A.; Greenslade, Thomas B.

2015-01-01

Barlow's wheel has been a favorite demonstration since its invention by Peter Barlow (1776-1862) in 1822.1 In the form shown in Fig. 1, it represents the first electric motor. The interaction between the electric current passing from the axle of the wheel to the rim and the magnetic field produced by the U-magnet produces a torque that turns the wheel. The original device used mercury to provide electrical contact to the rim, and the dangers involved with the use of this heavy metal have caused the apparatus to disappear from the lecture hall.

High speed VLSI neural network for high energy physics

NARCIS (Netherlands)

Masa, P.; Masa, P.; Hoen, K.; Hoen, Klaas; Wallinga, Hans

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

Problems of locomotive wheel wear in fleet replacement

Directory of Open Access Journals (Sweden)

L.P. Lingaytis

2013-08-01

Full Text Available Purpose. To conduct a research and find out the causes of defects appearing on the wheel thread of freight locomotives 2М62 and SIEMENS ER20CF. Methodology. To find the ways to solve this problem comparing the locomotive designs and their operating conditions. Findings. After examining the nature of the wheel wear the main difference was found: in locomotives of the 2M62 line wears the wheel flange, and in the locomotives SIEMENS ER20CF – the tread surface. After installation on the 2M62 locomotive the lubrication system of flanges their wear rate significantly decreased. On the new freight locomotives SIEMENS ER20CF the flange lubrication systems of the wheel set have been already installed at the factory, however the wheel thread is wearing. As for locomotives 2M62, and on locomotives SIEMENS ER20CF most wear profile skating wheels of the first wheel set. On both locomotive lines the 2М62 and the SIEMENS ER20CF the tread profile of the first wheel set most of all is subject to the wear. After reaching the 170 000 km run, the tread surface of some wheels begins to crumble. There was a suspicion that the reason for crumb formation of the wheel surface may be insufficient or excessive wheel hardness or its chemical composition. In order to confirm or deny this suspicion the following studies were conducted: the examination of the rim surface, the study of the wheel metal hardness and the document analysis of the wheel production and their comparison with the results of wheel hardness measurement. Practical value. The technical condition of locomotives is one of the bases of safety and reliability of the rolling stock. The reduction of the wheel wear significantly reduces the operating costs of railway transport. After study completion it was found that there was no evidence to suggest that the ratio of the wheel-rail hardness could be the cause of the wheel surface crumbling.

Dynamics of a motor vehicle taking into consideration the interaction of wheels and road pavement surface

Directory of Open Access Journals (Sweden)

O. Prentkovskis

2002-12-01

Full Text Available The authors of this article focus on the simulation of the motor vehicle on a certain road and propose their specific solution of this problem. A mathematical model of the system “motor vehicle – road” is presented. The motor vehicle is simulated by concentrated masses interconnected by elastic and dissipative links. The presented model of the motor vehicle evaluates the movement of the motor vehicle body in space; the movement and turning of front and rear suspensions with respect to the body; the interaction of the wheel with the road pavement surface; the blocking of the wheel; the changing cohesive forces which influence the motor vehicle. The investigated road pavement surface is simulated by triangular finite elements, the certain height of road pavement surface roughness and the cohesion coefficients of road pavement surface and the motor vehicle wheel in the longitudinal and transverse directions of the wheel are selected in each finite element nodal point. The presented results illustrate: the motor vehicle movement trajectories braking at various initial conditions and on a certain pavement surface of the road section under investigation and the motor vehicle driving on the speed reduction bump (“sleeping policeman”.

Customer loads of two-wheeled vehicles

Science.gov (United States)

Gorges, C.; Öztürk, K.; Liebich, R.

2017-12-01

Customer usage profiles are the most unknown influences in vehicle design targets and they play an important role in durability analysis. This publication presents a customer load acquisition system for two-wheeled vehicles that utilises the vehicle's onboard signals. A road slope estimator was developed to reveal the unknown slope resistance force with the help of a linear Kalman filter. Furthermore, an automated mass estimator was developed to consider the correct vehicle loading. The mass estimation is performed by an extended Kalman filter. Finally, a model-based wheel force calculation was derived, which is based on the superposition of forces calculated from measured onboard signals. The calculated wheel forces were validated by measurements with wheel-load transducers through the comparison of rainflow matrices. The calculated wheel forces correspond with the measured wheel forces in terms of both quality and quantity. The proposed methods can be used to gather field data for improved vehicle design loads.

Space shuttle wheels and brakes

Science.gov (United States)

Carsley, R. B.

1985-01-01

The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

Assessment of a Boat Fractured Steering Wheel

Directory of Open Access Journals (Sweden)

Vukelic Goran

2016-09-01

Full Text Available During regular use of the steering wheel mounted on a boat, two cracks emanating from a fastener hole were noticed which, consequently, caused final fracture of the wheel. To determine the behavior of a boat steering wheel with cracks present, assessment of a fractured wheel was performed. Torque moments of the fasteners were measured prior to removing the steering wheel from the boat. Visual and dye penetrant inspection followed along with the material detection. Besides using experimental procedures, assessment of the fractured wheel was performed using finite element analysis, i.e. stress intensity factor values were numerically determined. Variation of stress intensity factor with crack length is presented. Possible causes of crack occurrence are given and they include excessive values of fastener torque moments coupled with fretting between fastener and fastener hole that was poorly machined. Results obtained by this assessment can be taken for predicting fracture behavior of a cracked steering wheel and as a reference in the design, mounting and exploitation process of steering wheels improving that way their safety in transportation environment.

Multiroller Traction Drive Speed Reducer. Evaluation for Automotive Gas Turbine Engine

Science.gov (United States)

1982-06-01

Speed is deLermined by a magnetic pickup on a toothed wheel . Gas turbine engine instrumunelLtiouu i -designed 1f0r measurement of specific fuel...buffer seal and the fluid--film bearing measured a maximum total runout of 0.038 mm (0.0015 in.) at low speed. At higher speeds, above 8000 rpm, the...maximum was 0.025 mm (0.001 in.) except near 10 000 rpm, where the oscilloscope indicated an excursion of 0.045 mm (0.0018 in.). This runout was within

A High-Speed Design of Montgomery Multiplier

Science.gov (United States)

Fan, Yibo; Ikenaga, Takeshi; Goto, Satoshi

With the increase of key length used in public cryptographic algorithms such as RSA and ECC, the speed of Montgomery multiplication becomes a bottleneck. This paper proposes a high speed design of Montgomery multiplier. Firstly, a modified scalable high-radix Montgomery algorithm is proposed to reduce critical path. Secondly, a high-radix clock-saving dataflow is proposed to support high-radix operation and one clock cycle delay in dataflow. Finally, a hardware-reused architecture is proposed to reduce the hardware cost and a parallel radix-16 design of data path is proposed to accelerate the speed. By using HHNEC 0.25μm standard cell library, the implementation results show that the total cost of Montgomery multiplier is 130 KGates, the clock frequency is 180MHz and the throughput of 1024-bit RSA encryption is 352kbps. This design is suitable to be used in high speed RSA or ECC encryption/decryption. As a scalable design, it supports any key-length encryption/decryption up to the size of on-chip memory.

Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

Science.gov (United States)

Zhao, Youqun; Zhu, Mingmin; Lin, Fen; Xiao, Zhen; Li, Haiqing; Deng, Yaoji

2018-01-01

A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

Bladed wheels damage detection through Non-Harmonic Fourier Analysis improved algorithm

Science.gov (United States)

Neri, P.

2017-05-01

Recent papers introduced the Non-Harmonic Fourier Analysis for bladed wheels damage detection. This technique showed its potential in estimating the frequency of sinusoidal signals even when the acquisition time is short with respect to the vibration period, provided that some hypothesis are fulfilled. Anyway, previously proposed algorithms showed severe limitations in cracks detection at their early stage. The present paper proposes an improved algorithm which allows to detect a blade vibration frequency shift due to a crack whose size is really small compared to the blade width. Such a technique could be implemented for condition-based maintenance, allowing to use non-contact methods for vibration measurements. A stator-fixed laser sensor could monitor all the blades as they pass in front of the spot, giving precious information about the wheel health. This configuration determines an acquisition time for each blade which become shorter as the machine rotational speed increases. In this situation, traditional Discrete Fourier Transform analysis results in poor frequency resolution, being not suitable for small frequency shift detection. Non-Harmonic Fourier Analysis instead showed high reliability in vibration frequency estimation even with data samples collected in a short time range. A description of the improved algorithm is provided in the paper, along with a comparison with the previous one. Finally, a validation of the method is presented, based on finite element simulations results.

An Ultrasonic Wheel-Array Probe

Science.gov (United States)

Drinkwater, B. W.; Brotherhood, C. J.; Freemantle, R. J.

2004-02-01

This paper describes the development and modeling of an ultrasonic array wheel probe scanning system. The system operates at 10 MHz using a 64 element array transducer which is 50 mm in length and located in a fluid filled wheel. The wheel is coupled to the test structure dry, or with a small amount of liquid couplant. When the wheel is rolled over the surface of the test structure a defect map (C-Scan) is generated in real-time. The tyre is made from a soft, durable polymer which has very little acoustic loss. Two application studies are presented; the inspection of sealant layers in an aluminum aircraft wing structure and the detection of embedded defects in a thick section carbon composite sample.

Circulating levels of endocannabinoids respond acutely to voluntary exercise, are altered in mice selectively bred for high voluntary wheel running, and differ between the sexes.

Science.gov (United States)

Thompson, Zoe; Argueta, Donovan; Garland, Theodore; DiPatrizio, Nicholas

2017-03-01

The endocannabinoid system serves many physiological roles, including in the regulation of energy balance, food reward, and voluntary locomotion. Signaling at the cannabinoid type 1 receptor has been specifically implicated in motivation for rodent voluntary exercise on wheels. We studied four replicate lines of high runner (HR) mice that have been selectively bred for 81 generations based on average number of wheel revolutions on days five and six of a six-day period of wheel access. Four additional replicate lines are bred without regard to wheel running, and serve as controls (C) for random genetic effects that may cause divergence among lines. On average, mice from HR lines voluntarily run on wheels three times more than C mice on a daily basis. We tested the general hypothesis that circulating levels of endocannabinoids (i.e., 2-arachidonoylglycerol [2-AG] and anandamide [AEA]) differ between HR and C mice in a sex-specific manner. Fifty male and 50 female mice were allowed access to wheels for six days, while another 50 males and 50 females were kept without access to wheels (half HR, half C for all groups). Blood was collected by cardiac puncture during the time of peak running on the sixth night of wheel access or no wheel access, and later analyzed for 2-AG and AEA content by ultra-performance liquid chromatography coupled to tandem mass spectrometry. We observed a significant three-way interaction among sex, linetype, and wheel access for 2-AG concentrations, with females generally having lower levels than males and wheel access lowering 2-AG levels in some but not all subgroups. The number of wheel revolutions in the minutes or hours immediately prior to sampling did not quantitatively predict plasma 2-AG levels within groups. We also observed a trend for a linetype-by-wheel access interaction for AEA levels, with wheel access lowering plasma concentrations of AEA in HR mice, while raising them in C mice. In addition, females tended to have higher AEA

Wheeled hopping robot

Science.gov (United States)

Fischer, Gary J [Albuquerque, NM

2010-08-17

The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

49 CFR 229.73 - Wheel sets.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Wheel sets. 229.73 Section 229.73 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.73 Wheel sets. (a...) when applied or turned. (b) The maximum variation in the diameter between any two wheel sets in a three...

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

Science.gov (United States)

Weigle, Eric H [Los Alamos, NM

2010-08-24

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

Reduced metabolic disease risk profile by voluntary wheel running accompanying juvenile Western diet in rats bred for high and low voluntary exercise.

Science.gov (United States)

Ruegsegger, Gregory N; Toedebusch, Ryan G; Braselton, Joshua F; Roberts, Christian K; Booth, Frank W

2015-12-01

Metabolic disease risk is influenced by genetics and modifiable factors, such as physical activity and diet. Beginning at 6 weeks of age, rats selectively bred for high (HVR) versus low voluntary running distance (LVR) behaviors were housed in a complex design with or without voluntary running wheels being fed either a standard or Western (WD, 42% kcal from fat and added sucrose) diet for 8 weeks. Upon intervention completion, percent body fat, leptin, insulin, and mediobasal hypothalamic mRNAs related to appetite control were assessed. Wheel access led to differences in body weight, food intake, and serum leptin and insulin. Intriguingly, percent body fat, leptin, and insulin did not differ between HVR and LVR lines in response to the two levels of voluntary running, regardless of diet, after the 8 wk. experiment despite HVR eating more calories than LVR regardless of diet and voluntarily running 5-7 times further in wheels than LVR. In response to WD, we observed increases in Cart and Lepr mediobasal hypothalamic mRNA in HVR, but no differences in LVR. Npy mRNA was intrinsically greater in LVR than HVR, while wheel access led to greater Pomc and Cart mRNA in LVR versus HVR. These data suggest that despite greater consumption of WD, HVR animals respond similarly to WD as LVR as a result, in part, of their increased wheel running behavior. Furthermore, high physical activity in HVR may offset the deleterious effects of a WD on adiposity despite greater energy intake in this group. Copyright © 2015 Elsevier Inc. All rights reserved.

Potential scenarios of concern for high speed rail operations

Science.gov (United States)

2011-03-16

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

Three omni-directional wheels control on a mobile robot

OpenAIRE

Ribeiro, António Fernando; Moutinho, Ivo; Silva, Pedro; Fraga, Carlos; Pereira, Nino

2004-01-01

Traditional two wheels differential drive normally used on mobile robots have manoeuvrability limitations and take time to sort out. Most teams use two driving wheels (with one or two cast wheels), four driving wheels and even three driving wheels. A three wheel drive with omni-directional wheel has been tried with success, and was implemented on fast moving autonomous mobile robots. This paper deals with the mathematical kinematics description of such mobile platform, it describes the advant...

On minimizing mechanical stresses of the rail way wheels

International Nuclear Information System (INIS)

Moosavi, H.; Esfahanian, M.

2000-01-01

The purpose of this paper is to study the behavior of elastic-plastic stresses under severe drag braking. A railway wheel performs three tasks, aiding in trian movement, supporting the car load, and acting as a brake drum. Finite element computer programs are developed for elasto-plastic stress analysis. An attempt is made here to find an improved fillet profile of the wheel with the intention of minimizing high tensile mechanical stresses. Three new fillet profiles for the wheel are tested. A penalty function is used as a criterion for comparison of stresses between the new designs and the old design. The design with the least penalty is chosen to be the improved one

Fuzzy model for predicting the number of deformed wheels

Directory of Open Access Journals (Sweden)

Ž. Đorđević

2015-10-01

Full Text Available Deformation of the wheels damage cars and rails and affect on vehicle stability and safety. Repair and replacement cause high costs and lack of wagons. Planning of maintenance of wagons can not be done without estimates of the number of wheels that will be replaced due to wear and deformation in a given period of time. There are many influencing factors, the most important are: weather conditions, quality of materials, operating conditions, and distance between the two replacements. The fuzzy logic model uses the collected data as input variables to predict the output variable - number of deformed wheels for a certain type of vehicle in the defined period at a particular section of the railway.

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

Directory of Open Access Journals (Sweden)

Vadym Zayets

2017-01-01

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

High speed laser tomography system

Science.gov (United States)

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

2008-03-01

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

A Historical Review of High Speed Metal Forming

OpenAIRE

Zittel, G.

2010-01-01

This paper will present a Historical Review of High Speed Metal Forming beginning with the first thought of forming metal by using an electromagnetic impulse to today, whereby High Speed Metal Forming is an accepted production process. Although this paper will briefly cover the basic physics of the process, it will not dwell on it. It will rather show how the industrial acceptance of High Speed Metal Forming is tightly connected to the knowledge acquired from many applications studies. These ...

Minisatellite Attitude Guidance Using Reaction Wheels

Directory of Open Access Journals (Sweden)

Ion STROE

2015-06-01

Full Text Available In a previous paper [2], the active torques needed for the minisatellite attitude guidance from one fixed attitude posture to another fixed attitude posture were determined using an inverse dynamics method. But when considering reaction/momentum wheels, instead of this active torques computation, the purpose is to compute the angular velocities of the three reaction wheels which ensure the minisatellite to rotate from the initial to the final attitude. This paper presents this computation of reaction wheels angular velocities using a similar inverse dynamics method based on inverting Euler’s equations of motion for a rigid body with one fixed point, written in the framework of the x-y-z sequence of rotations parameterization. For the particular case A=B not equal C of an axisymmetric minisatellite, the two computations are compared: the active torques computation versus the computation of reaction wheels angular velocities ̇x , ̇y and ̇z. An interesting observation comes out from this numerical study: if the three reaction wheels are identical (with Iw the moment of inertia of one reaction wheel with respect to its central axis, then the evolutions in time of the products between Iw and the derivatives of the reaction wheels angular velocities, i.e. ̇ , ̇ and ̇ remain the same and do not depend on the moment of inertia Iw.

High-speed photography. Technique and evolution

International Nuclear Information System (INIS)

Sanchez-Tembleque, R.

1981-01-01

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

Review of High-Speed Fiber Optic Grating Sensors Systems

Energy Technology Data Exchange (ETDEWEB)

Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

2010-03-24

Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

Numerical Modelling of the Dynamic Response of High-Speed Railway Bridges Considering Vehicle-Structure and Structure-Soil-Structure Interaction

DEFF Research Database (Denmark)

Bucinskas, Paulius; Agapii, L.; Sneideris, J.

2015-01-01

is idealized as a multi-degree-of-freedom system, modelled with two layers of spring-dashpot suspension systems. Coupling the vehicle system and railway track is realized through interaction forces between the wheels and the rail, where the irregularities of the track are implemented as a random stationary......The aim of this paper is the dynamic analysis of a multi-support bridge structure exposed to high-speed railway traffic. The proposed computational model has a unified approach for simultaneously accounting for the bridge structure response, soil response and forces induced by the vehicle....... The bridge structure is modelled in three dimensions based on the finite element method using two-noded three-dimensional beam elements. The track structure is composed of three layers: rail, sleepers and deck which are connected through spring-dashpot systems. The vehicle travelling along a bridge...

Design of high-speed turnouts and crossings

Science.gov (United States)

Raif, Lukáš; Puda, Bohuslav; Havlík, Jiří; Smolka, Marek

2017-09-01

Recently, the new ways to improve the railway switches and crossings have been sought, as the railway transport increases its operating speed. The expectation of these adjustments is to decrease the dynamic load, which usually increases together with velocity, and this influences the comfort of the vehicle passage, the wear of the structural parts and the cost of maintenance. These adjustments are primarily the turnout elements such as the optimized geometry of the turnout branch line by means of transition curves application, which minimizes the lateral acceleration during the vehicle passage through the track curve. The rail inclination is solved either by means of inclination in fastening system, or by machining of the rail head shape, because this ways of adjustment retain the wheel-rail interaction characteristics along the whole length of the turnout. Secondly, it is the crossing with movable part, which excludes the interruption of the running surface and optimization of the railway stiffness throughout the whole turnout length as well. We can see that the different stiffness along the turnout influences the dynamic load and it is necessary to optimize the discontinuities in the stiffness along the whole length of the turnout. For this purpose, the numeric modeling is carried out to seek the areas with the highest stiffness and subsequently, the system of stiffness optimization will be designed.

Cross-stream ejection in the inter-wheel region of aircraft landing gears

Science.gov (United States)

McCarthy, Philip; Ekmekci, Alis

2014-11-01

The reduction of aircraft noise is an important challenge currently faced by aircraft manufacturers. During approach and landing, the landing gears contribute a significant proportion of the aircraft generated noise. It is therefore critical that the key noise sources be identified and understood in order for effective mitigation methods to be developed. For a simplified two-wheel nose landing gear, a strong cross stream flow ejection phenomena has been observed to occur in the inter-wheel region in presence of wheel wells. The location and orientation of these flow ejections causes highly unsteady, three dimensional flow between the wheels that may impinge on other landing gear components, thereby potentially acting as a significant noise generator. The effects of changing the inter-wheel geometry (inter-wheel spacing, the wheel well depth and main strut geometry) upon the cross-stream ejection behaviour has been experimentally investigated using both qualitative flow visualisation and quantitative PIV techniques. A summary of the key results will be presented for the three main geometrical parameters under examination and the application of these findings to real life landing gears will be discussed. Thanks to Messier-Bugatti-Dowty and NSERC for their support for this project.

High-Speed Videography Instrumentation And Procedures

Science.gov (United States)

Miller, C. E.

1982-02-01

High-speed videography has been an electronic analog of low-speed film cameras, but having the advantages of instant-replay and simplicity of operation. Recent advances have pushed frame-rates into the realm of the rotating prism camera. Some characteristics of videography systems are discussed in conjunction with applications in sports analysis, and with sports equipment testing.

Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

Science.gov (United States)

Markley, F. Landis; Reynolds, Reid G.; Liu, Frank X.; Lebsock, Kenneth L.

2009-01-01

Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum that the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical strategies for distributing a prescribed torque or momentum among the n wheels are presented, with special emphasis on configurations of four, five, and six wheels.

Rotary Speed Sensor for Antilocking Brakes

Science.gov (United States)

Berdahl, C. M.

1986-01-01

Sensor based on fluidic principles produces negative pressure approximately proportional to rotational speed. Sensor developed as part of antilocking brake system for motorcycles. Uses inlet pressure rather than outlet pressure as braking-control signal, eliminating pressure pulsations caused by pump vanes and ensuring low-noise signal. Sensor is centrifugal air pump turned by one of motorcycle wheels. Air enters pump through orifice plates, and suction taken off through port in pump inlet plenum.

Nonlinear dynamics modeling and simulation of two-wheeled self-balancing vehicle

Directory of Open Access Journals (Sweden)

Yunping Liu

2016-11-01

Full Text Available Two-wheeled self-balancing vehicle system is a kind of naturally unstable underactuated system with high-rank unstable multivariable strongly coupling complicated dynamic nonlinear property. Nonlinear dynamics modeling and simulation, as a basis of two-wheeled self-balancing vehicle dynamics research, has the guiding effect for system design of the project demonstration and design phase. Dynamics model of the two-wheeled self-balancing vehicle is established by importing a TSi ProPac package to the Mathematica software (version 8.0, which analyzes the stability and calculates the Lyapunov exponents of the system. The relationship between external force and stability of the system is analyzed by the phase trajectory. Proportional–integral–derivative control is added to the system in order to improve the stability of the two-wheeled self-balancing vehicle. From the research, Lyapunov exponent can be used to research the stability of hyperchaos system. The stability of the two-wheeled self-balancing vehicle is better by inputting the proportional–integral–derivative control. The Lyapunov exponent and phase trajectory can help us analyze the stability of a system better and lay the foundation for the analysis and control of the two-wheeled self-balancing vehicle system.

Why Animals Run on Legs, Not on Wheels.

Science.gov (United States)

Diamond, Jared

1983-01-01

Speculates why animals have not developed wheels in place of inefficient legs. One study cited suggests three reasons why animals are better off without wheels: wheels are efficient only on hard surfaces, limitation of wheeled motion due to vertical obstructions, and the problem of turning in spaces cluttered with obstacles. (JN)

Integrated computer network high-speed parallel interface

International Nuclear Information System (INIS)

Frank, R.B.

1979-03-01

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

High-speed and intercity passenger rail testing strategy.

Science.gov (United States)

2013-05-01

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

Application of high-speed photography to hydrodynamic instability research

International Nuclear Information System (INIS)

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

2012-01-01

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

Development of high-speed video cameras

Science.gov (United States)

Etoh, Takeharu G.; Takehara, Kohsei; Okinaka, Tomoo; Takano, Yasuhide; Ruckelshausen, Arno; Poggemann, Dirk

2001-04-01

Presented in this paper is an outline of the R and D activities on high-speed video cameras, which have been done in Kinki University since more than ten years ago, and are currently proceeded as an international cooperative project with University of Applied Sciences Osnabruck and other organizations. Extensive marketing researches have been done, (1) on user's requirements on high-speed multi-framing and video cameras by questionnaires and hearings, and (2) on current availability of the cameras of this sort by search of journals and websites. Both of them support necessity of development of a high-speed video camera of more than 1 million fps. A video camera of 4,500 fps with parallel readout was developed in 1991. A video camera with triple sensors was developed in 1996. The sensor is the same one as developed for the previous camera. The frame rate is 50 million fps for triple-framing and 4,500 fps for triple-light-wave framing, including color image capturing. Idea on a video camera of 1 million fps with an ISIS, In-situ Storage Image Sensor, was proposed in 1993 at first, and has been continuously improved. A test sensor was developed in early 2000, and successfully captured images at 62,500 fps. Currently, design of a prototype ISIS is going on, and, hopefully, will be fabricated in near future. Epoch-making cameras in history of development of high-speed video cameras by other persons are also briefly reviewed.

AT89S52 Microcontroller Based A Speed Restraint Equipment for Motorcycle

Directory of Open Access Journals (Sweden)

Ikhsan hidayat

2009-08-01

Full Text Available Security riding is very important in the aspects of traffic. One of the main factors of traffic accidents is high speed. Therefore, it is required a speed restraint equipment for pressing the number of accidents. The car speed restraint system is available in the market, but on a motorcycle is not available yet. This paper presents a design of speed restraint equipment for motorcycle that safe for users, and is expected to reduce traffic accident. The Main idea this speed restriction is cutting off the flow of electrical signals from the pulser (the time ignition trigger sensor to the CDI for 1 second. The cutting Signal with mechanical relays controlled by microcontroller AT89S52 using the on-off algorithm. Speed sensor use optocoupler is used to detect the number of rounds wheel motorcycle. If a result of measurement is more than the speed setpoint, microcontroler make a decission to cut motorcycle ignition signal. Results of this research is a prototype speed restraint shown that it able to process data from the measurement of the speed limit on the speed of a motorcycle. This prototype safe for all users and accordance with the set value and the level of success is above 90% for speed of 10 km/hr to 40 km/hr.

High-speed AFM of human chromosomes in liquid

Energy Technology Data Exchange (ETDEWEB)

Picco, L M; Dunton, P G; Ulcinas, A; Engledew, D J; Miles, M J [H H Wills Physics Laboratory and IRC in Nanotechnology, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Hoshi, O; Ushiki, T [Division of Microscopic Anatomy and Bio-Imaging, Department of Cellular Function, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi-Dori 1, Niigata, 951-8150 (Japan)], E-mail: m.j.miles@bristol.ac.uk

2008-09-24

Further developments of the previously reported high-speed contact-mode AFM are described. The technique is applied to the imaging of human chromosomes at video rate both in air and in water. These are the largest structures to have been imaged with high-speed AFM and the first imaging in liquid to be reported. A possible mechanism that allows such high-speed contact-mode imaging without significant damage to the sample is discussed in the context of the velocity dependence of the measured lateral force on the AFM tip.

Characterizing speed-independence of high-level designs

DEFF Research Database (Denmark)

Kishinevsky, Michael; Staunstrup, Jørgen

1994-01-01

This paper characterizes the speed-independence of high-level designs. The characterization is a condition on the design description ensuring that the behavior of the design is independent of the speeds of its components. The behavior of a circuit is modeled as a transition system, that allows data...... types, and internal as well as external non-determinism. This makes it possible to verify the speed-independence of a design without providing an explicit realization of the environment. The verification can be done mechanically. A number of experimental designs have been verified including a speed-independent...

Development of ultra high speed photographic system using high repetition rate visible laser

International Nuclear Information System (INIS)

Lee, Jong Min; Cha, Byung Hun; Kim, Sung Ho; Kim, Jung Bog; Lim, Chang Hwan; Cha, Hyung Ki; Song, Kyu Seok; Lee, Byung Deok; Rhi, Jong Hoon; Baik, Dae Hyun; Han, Jae Min; Rho, Si Pyo; Lee, Byung Cheol; Jeong, Do Yung; Choi, An Seong; Jeong, Chan Ik; Park, Dae Ung; Jeong, Sung Min; Lee, Sang Kil; Kim, Heon Jun; Jang, Rae gak; Jo, Do Hun; Park, Min Young

1992-12-01

The goal of this project is to develop and commercialize a high speed photographic system equipped with a high repetition rate visible laser. The developed system provides the characteristics of high time resolution and large number of frames. The system consists of 10 W air cooled CVL or a 30 W water cooled CVL, a rotating drum-type high speed camera with the framing rate of 35,000 fps, and a automatic control device. The system has the performance of 10 nsec time resolution, 35,000 fps framing rate, and 250 picture frames. The high speed photographic systems are widely applied to the fields such as high-efficient engine development, high-speed vibration analysis, shock wave propagation study, flow visualization analysis, weapon development, etc. (Author)

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....

The large scale and long term evolution of the solar wind speed distribution and high speed streams

International Nuclear Information System (INIS)

Intriligator, D.S.

1977-01-01

The spatial and temporal evolution of the solar wind speed distribution and of high speed streams in the solar wind are examined. Comparisons of the solar wind streaming speeds measured at Earth, Pioneer 11, and Pioneer 10 indicate that between 1 AU and 6.4 AU the solar wind speed distributions are narrower (i.e. the 95% value minus the 5% value of the solar wind streaming speed is less) at extended heliocentric distances. These observations are consistent with one exchange of momentum in the solar wind between high speed streams and low speed streams as they propagate outward from the Sun. Analyses of solar wind observations at 1 AU from mid 1964 through 1973 confirm the earlier results reported by Intriligator (1974) that there are statistically significant variations in the solar wind in 1968 and 1969, years of solar maximum. High speed stream parameters show that the number of high speed streams in the solar wind in 1968 and 1969 is considerably more than the predicted yearly average, and in 1965 and 1972 less. Histograms of solar wind speed from 1964 through 1973 indicate that in 1968 there was the highest percentage of elevated solar wind speeds and in 1965 and 1972 the lowest. Studies by others also confirm these results although the respective authors did not indicate this fact. The duration of the streams and the histograms for 1973 imply a shifting in the primary stream source. (Auth.)

A Four-Wheel-Rhombus-Arranged Mobility System for a New Lunar Robotic Rover

Directory of Open Access Journals (Sweden)

Guilin Wen

2013-10-01

Full Text Available Different from traditional ground vehicles, planetary robotic rovers with limited weight and power need to travel in unfamiliar and extremely arduous environments. In this paper, a newly developed four-wheel-rhombus-arranged (FWRA mobility system is presented as a lunar robotic rover with high mobility and a low-weight structure. The mobility system integrates independent active suspensions with a passive rotary link structure. The active suspension with swing arms improves the rover's capacity to escape from a trapped environment whereas the passive rotary link structure guarantees continuous contact between the four wheels and the terrain. The four-wheel-three-axis rhombus configuration of the mobility system gives a high degree of lightweight structure because it has a simple mechanism with the minimum number of wheels among wheeled rovers with three-axis off-road mobility. The performance evaluation of the lightweight nature of the structure, manoeuvrability and the mobility required in a planetary exploring environment are illustrated by theoretical analysis and partly shown by experiments on the developed rover prototype.

49 CFR 230.113 - Wheels and tire defects.

Science.gov (United States)

2010-10-01

... tires may not have a seam running lengthwise that is within 33/4 inches of the flange. (g) Worn flanges... 49 Transportation 4 2010-10-01 2010-10-01 false Wheels and tire defects. 230.113 Section 230.113... Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

Electronic differential control of 2WD electric vehicle considering steering stability

Science.gov (United States)

Hua, Yiding; Jiang, Haobin; Geng, Guoqing

2017-03-01

Aiming at the steering wheel differential steering control technology of rear wheel independent driving electric wheel, considering the assisting effect of electronic differential control on vehicle steering, based on the high speed steering characteristic of electric wheel car, the electronic differential speed of auxiliary wheel steering is also studied. A yaw moment control strategy is applied to the vehicle at high speed. Based on the vehicle stability reference value, yaw rate is used to design the fuzzy controller to distribute the driving wheel torque. The simulation results show that the basic electronic differential speed function is realized based on the yaw moment control strategy, while the vehicle stability control is improved and the driving safety is enhanced. On the other hand, the torque control strategy can also assist steering of vehicle.

Rat muscle blood flows during high-speed locomotion

International Nuclear Information System (INIS)

Armstrong, R.B.; Laughlin, M.H.

1985-01-01

We previously studied blood flow distribution within and among rat muscles as a function of speed from walking (15 m/min) through galloping (75 m/min) on a motor-driven treadmill. The results showed that muscle blood flows continued to increase as a function of speed through 75 m/min. The purpose of the present study was to have rats run up to maximal treadmill speeds to determine if blood flows in the muscles reach a plateau as a function of running speed over the animals normal range of locomotory speeds. Muscle blood flows were measured with radiolabeled microspheres at 1 min of running at 75, 90, and 105 m/min in male Sprague-Dawley rats. The data indicate that even at these relatively high treadmill speeds there was still no clear evidence of a plateau in blood flow in most of the hindlimb muscles. Flows in most muscles continued to increase as a function of speed. These observed patterns of blood flow vs. running speed may have resulted from the rigorous selection of rats that were capable of performing the high-intensity exercise and thus only be representative of a highly specific population of animals. On the other hand, the data could be interpreted to indicate that the cardiovascular potential during exercise is considerably higher in laboratory rats than has normally been assumed and that inadequate blood flow delivery to the muscles does not serve as a major limitation to their locomotory performance

Analysis of self-oscillations of the wheeled vehicle model when driving on a straight-line segment of the overpass

Directory of Open Access Journals (Sweden)

Sakhno V.P.

2016-08-01

Full Text Available There is the problem of traffic congestion of large cities of Ukraine. The introduction of the monorail will solve this problem. To ensure the comfort and safety of the transport of passengers it is proposed to investigate the lateral stability of this type of transportation, namely, to consider the question of self-oscillations. An approximate analysis of the amplitudes of oscillation of the model "one-wheeled" vehicle when driving on a straight-line segment of the overpass was performed. The diagram of the amplitudes of the oscillation system, which is received when changing the longitudinal speed of the crew allows us to estimate the influence of structural parameters of the system on the boundary of oscillatory instability and the amplitude of oscillation occurring. Rational selection of parameters of the transverse stiffness of the guide wheel module according to this method is consistent with the previously obtained research results. On the basis of the offered analytically-numerical method it is proved that rational choice of design parameters of systems that enable sustainable movement in the range operating speed (the maximum constructional speed of V = 140 km/h, moreover, security buckling when exceeding this speed. The amplitude of oscillation in excess of a critical value of the velocity parameter increases monotonically and does not exceed 3°, with V = 280 km/h.

High-Speed Photo-Polarimetry of Magnetic Cataclysmic Variables

Directory of Open Access Journals (Sweden)

S. B. Potter

2015-02-01

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

Preliminary experimental evaluation of a four wheel motors, batteries plus ultracapacitors and series hybrid powertrain

Energy Technology Data Exchange (ETDEWEB)

Rambaldi, Lorenzo [Interuniversity Research Center on Sustainable Development, Sapienza University of Rome, Rome (Italy); Bocci, Enrico [Department of Mechanics and Aeronautics, Sapienza University of Rome, Rome (Italy); Orecchini, Fabio [Guglielmo Marconi University, Rome (Italy)

2011-02-15

This paper reports the preliminary experimental evaluation of a four wheel motors series hybrid prototype equipped with an internal combustion engine coupled to a generator and an energy recovery system (batteries plus ultracapacitors). The paper analyses global efficiency (energy dissipated to overcome the dissipative forces on energy dissipated in fuel), autonomy in electric configuration, and the efficiency of the regenerative braking system. The tests were carried out in a test cell equipped with a chassis dynamometer. The tests were performed according to the current regulated procedures. A constant speed test was performed in order to evaluate the autonomy of the vehicle in the electric configuration. The results show that the real tank to wheels efficiency is about 30% for HOST as a series hybrid and 79% for HOST as an electric vehicle. (author)

A dead reckoning localization system for mobile robots using inertial sensors and wheel revolution encoding

Energy Technology Data Exchange (ETDEWEB)

Cho, Bong Su; Moon, Woo Sung; Seo, Woo Jin; Baek, Kwang Ryul [Pusan National University, Busan (Korea, Republic of)

2011-11-15

Inertial navigation systems (INS) are composed of inertial sensors, such as accelerometers and gyroscopes. An INS updates its orientation and position automatically; it has an acceptable stability over the short term, however this stability deteriorates over time. Odometry, used to estimate the position of a mobile robot, employs encoders attached to the robot's wheels. However, errors occur caused by the integrative nature of the rotating speed and the slippage between the wheel and the ground. In this paper, we discuss mobile robot position estimation without using external signals in indoor environments. In order to achieve optimal solutions, a Kalman filter that estimates the orientation and velocity of mobile robots has been designed. The proposed system combines INS and odometry and delivers more accurate position information than standalone odometry.

Trend on High-speed Power Line Communication Technology

Science.gov (United States)

Ogawa, Osamu

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

A high speed digital noise generator

Science.gov (United States)

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

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

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 an extensive discussion of the various approaches used in predicting both free shear and wall bounded flows is presented. Experimental measurement techniques common to the compressible flow regime are introduced with particular emphasis on the unique challenges presented by high speed flows. Both experimental and numerical simulation work is supplied throughout to provide the reader with an overall perspective of current tre...

Design and jump phenomenon analysis of an eccentric ring energy harvester

International Nuclear Information System (INIS)

Wang, Yu-Jen; Chen, Chung-De

2013-01-01

This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318–442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers. (paper)

Design and jump phenomenon analysis of an eccentric ring energy harvester

Science.gov (United States)

Wang, Yu-Jen; Chen, Chung-De

2013-10-01

This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318-442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers.

High-speed solar wind flow parameters at 1 AU

International Nuclear Information System (INIS)

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

1976-01-01

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

Four-wheeled walker related injuries in older adults in the Netherlands.

Science.gov (United States)

van Riel, K M M; Hartholt, K A; Panneman, M J M; Patka, P; van Beeck, E F; van der Cammen, T J M

2014-02-01

With ageing populations worldwide, mobility devices are used more than ever. In the current literature there is no consensus whether the available mobility devices safely improve the mobility of their users. Also, evidence is lacking concerning the risks and types of injuries sustained while using a four-wheeled walker. To assess injury risks and injury patterns in older adults (≥65 years) who presented at Emergency Departments (ED) in the Netherlands with an injury due to using a four-wheeled walker. In this study, the Dutch Injury Surveillance System was used to obtain a national representative sample of annual ED visits in the Netherlands in the adult population (≥65 years) sustaining an injury while using a four-wheeled walker. The numbers of four-wheeled walker users in the Netherlands were obtained from the national insurance board. The numbers of ED visits were divided by the numbers of four-wheeled walker users to calculate age- and sex-specific injury risks. Annually 1869 older adults visited an ED after sustaining an injury while using a four-wheeled walker. Falls were the main cause of injury (96%). The injury risk was 3.1 per 100 users of four-wheeled walkers. Women (3.5 per 100 users) had a higher risk than men (2.0 per 100 users). Injury risk was the highest in women aged 85 years and older (6.2 per 100 users). The majority of injuries were fractures (60%) with hip fracture (25%) being the most common injury. Nearly half of all four-wheeled walker related injuries required hospitalisation, mostly due to hip fractures. Healthcare costs per injury were approximately €12 000. This study presents evidence that older adults experiencing a fall while using a four-wheeled walker are at high risk to suffer severe injuries.

California statewide model for high-speed rail

OpenAIRE

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

2010-01-01

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

Voluntary Wheel Running in Mice.

Science.gov (United States)

Goh, Jorming; Ladiges, Warren

2015-12-02

Voluntary wheel running in the mouse is used to assess physical performance and endurance and to model exercise training as a way to enhance health. Wheel running is a voluntary activity in contrast to other experimental exercise models in mice, which rely on aversive stimuli to force active movement. This protocol consists of allowing mice to run freely on the open surface of a slanted, plastic saucer-shaped wheel placed inside a standard mouse cage. Rotations are electronically transmitted to a USB hub so that frequency and rate of running can be captured via a software program for data storage and analysis for variable time periods. Mice are individually housed so that accurate recordings can be made for each animal. Factors such as mouse strain, gender, age, and individual motivation, which affect running activity, must be considered in the design of experiments using voluntary wheel running. Copyright © 2015 John Wiley & Sons, Inc.

Modelling and mitigation of wheel squeal noise amplitude

Science.gov (United States)

Meehan, Paul A.; Liu, Xiaogang

2018-01-01

The prediction of vibration amplitude and sound pressure level of wheel squeal noise is investigated using a concise mathematical model that is verified with measurements from both a rolling contact two disk test rig and a field case study. The model is used to perform an energy-based analysis to determine a closed form solution to the steady state limit cycle amplitude of creep and vibration oscillations during squealing. The analytical solution compares well with a numerical solution using an experimentally tuned creep curve with full nonlinear shape. The predicted squeal sound level trend also compares well with that recorded at various crabbing velocities (proportional to angle of attack) for the test rig at different rolling speeds. In addition, further verification is performed against many field recordings of wheel squeal on a sharp curve of 300 m. A comparison with a simplified modified result from Rudd [1] is also provided and highlights the accuracy and advantages of the present efficient model. The analytical solution provides insight into why the sound pressure level of squeal noise increases with crabbing velocity (or angle of attack) as well as how the amplitude is affected by the critical squeal parameters including a detailed investigation of modal damping. Finally, the efficient model is used to perform a parametric investigation into means of achieving a 6 dB decrease in squeal noise. The results highlight the primary importance of crabbing velocity (and angle of attack) as well as the creep curve parameters that may be controlled using third body control (ie friction modifiers). The results concur with experimental and field observations and provide important theoretical insight into the useful mechanisms of mitigating wheel squeal and quantifying their relative merits.

Effectiveness Testing of a Piezoelectric Energy Harvester for an Automobile Wheel Using Stochastic Resonance

Directory of Open Access Journals (Sweden)

Yunshun Zhang

2016-10-01

Full Text Available The collection of clean power from ambient vibrations is considered a promising method for energy harvesting. For the case of wheel rotation, the present study investigates the effectiveness of a piezoelectric energy harvester, with the application of stochastic resonance to optimize the efficiency of energy harvesting. It is hypothesized that when the wheel rotates at variable speeds, the energy harvester is subjected to on-road noise as ambient excitations and a tangentially acting gravity force as a periodic modulation force, which can stimulate stochastic resonance. The energy harvester was miniaturized with a bistable cantilever structure, and the on-road noise was measured for the implementation of a vibrator in an experimental setting. A validation experiment revealed that the harvesting system was optimized to capture power that was approximately 12 times that captured under only on-road noise excitation and 50 times that captured under only the periodic gravity force. Moreover, the investigation of up-sweep excitations with increasing rotational frequency confirmed that stochastic resonance is effective in optimizing the performance of the energy harvester, with a certain bandwidth of vehicle speeds. An actual-vehicle experiment validates that the prototype harvester using stochastic resonance is capable of improving power generation performance for practical tire application.

29 CFR 1910.215 - Abrasive wheel machinery.

Science.gov (United States)

2010-07-01

... be securely fastened to the spindle and the bearing surface shall run true. When more than one wheel... 29 Labor 5 2010-07-01 2010-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a...

Research on Aerodynamic Noise Reduction for High-Speed Trains

OpenAIRE

Zhang, Yadong; Zhang, Jiye; Li, Tian; Zhang, Liang; Zhang, Weihua

2016-01-01

A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H)...

Module-based structure design of wheeled mobile robot

Directory of Open Access Journals (Sweden)

Z. Luo

2018-02-01

Full Text Available This paper proposes an innovative and systematic approach for synthesizing mechanical structures of wheeled mobile robots. The principle and terminologies used for the proposed synthesis method are presented by adopting the concept of modular design, isomorphic and non-isomorphic, and set theory with its associated combinatorial mathematics. The modular-based innovative synthesis and design of wheeled robots were conducted at two levels. Firstly at the module level, by creative design and analysing the structures of classic wheeled robots, a wheel module set containing four types of wheel mechanisms, a suspension module set consisting of five types of suspension frames and a chassis module set composed of five types of rigid or articulated chassis were designed and generalized. Secondly at the synthesis level, two kinds of structure synthesis modes, namely the isomorphic-combination mode and the non-isomorphic combination mode were proposed to synthesize mechanical structures of wheeled robots; which led to 241 structures for wheeled mobile robots including 236 novel ones. Further, mathematical models and a software platform were developed to provide appropriate and intuitive tools for simulating and evaluating performance of the wheeled robots that were proposed in this paper. Eventually, physical prototypes of sample wheeled robots/rovers were developed and tested so as to prove and validate the principle and methodology presented in this paper.

Comparison between two braking control methods integrating energy recovery for a two-wheel front driven electric vehicle

International Nuclear Information System (INIS)

Itani, Khaled; De Bernardinis, Alexandre; Khatir, Zoubir; Jammal, Ahmad

2016-01-01

Highlights: • Comparison between two braking methods for an EV maximizing the energy recovery. • Wheels slip ratio control based on robust sliding mode and ECE R13 control methods. • Regenerative braking control strategy. • Energy recovery of a HESS with respect to road surface type and road condition. - Abstract: This paper presents the comparison between two braking methods for a two-wheel front driven Electric Vehicle maximizing the energy recovery on the Hybrid Energy Storage System. The first method consists in controlling the wheels slip ratio while braking using a robust sliding mode controller. The second method will be based on ECE R13H constraints for an M1 passenger vehicle. The vehicle model used for simulation is a simplified five degrees of freedom model. It is driven by two 30 kW permanent magnet synchronous motor (PMSM) recovering energy during braking phases. Several simulation results for extreme braking conditions will be performed and compared on various road type surfaces using Matlab/Simulink®. For an initial speed of 80 km/h, simulation results demonstrate that the difference of energy recovery efficiency between the two control braking methods is beneficial to the ECE constraints control method and it can vary from 3.7% for high friction road type to 11.2% for medium friction road type. At low friction road type, the difference attains 6.6% due to different reasons treated in the paper. The stability deceleration is also discussed and detailed.

Recognition of diamond grains on surface of fine diamond grinding wheel

Institute of Scientific and Technical Information of China (English)

Fengwei HUO; Zhuji JIN; Renke KANG; Dongming GUO; Chun YANG

2008-01-01

The accurate evaluation of grinding wheel sur-face topography, which is necessary for the investigation of the grinding principle, optimism, modeling, and simu-lation of a grinding process, significantly depends on the accurate recognition of abrasive grains from the measured wheel surface. A detailed analysis of the grain size distri-bution characteristics and grain profile wavelength of the fine diamond grinding wheel used for ultra-precision grinding is presented. The requirements of the spatial sampling interval and sampling area for instruments to measure the surface topography of a diamond grinding wheel are discussed. To recognize diamond grains, digital filtering is used to eliminate the high frequency disturb-ance from the measured 3D digital surface of the grinding wheel, the geometric features of diamond grains are then extracted from the filtered 3D digital surface, and a method based on the grain profile frequency characteris-tics, diamond grain curvature, and distance between two adjacent diamond grains is proposed. A 3D surface pro-filer based on scanning white light interferometry is used to measure the 3D surface topography of a #3000 mesh resin bonded diamond grinding wheel, and the diamond grains are then recognized from the 3D digital surface. The experimental result shows that the proposed method is reasonable and effective.

Nugget Structure Evolution with Rotation Speed for High-Rotation-Speed Friction-Stir-Welded 6061 Aluminum Alloy

Science.gov (United States)

Zhang, H. J.; Wang, M.; Zhu, Z.; Zhang, X.; Yu, T.; Wu, Z. Q.

2018-03-01

High-rotation-speed friction stir welding (HRS-FSW) is a promising technique to reduce the welding loads during FSW and thus facilitates the application of FSW for in situ fabrication and repair. In this study, 6061 aluminum alloy was friction stir welded at high-rotation speeds ranging from 3000 to 7000 rpm at a fixed welding speed of 50 mm/min, and the effects of rotation speed on the nugget zone macro- and microstructures were investigated in detail in order to illuminate the process features. Temperature measurements during HRS-FSW indicated that the peak temperature did not increase consistently with rotation speed; instead, it dropped remarkably at 5000 rpm because of the lowering of material shear stress. The nugget size first increased with rotation speed until 5000 rpm and then decreased due to the change of the dominant tool/workpiece contact condition from sticking to sliding. At the rotation speed of 5000 rpm, where the weld material experienced weaker thermal effect and higher-strain-rate plastic deformation, the nugget exhibited relatively small grain size, large textural intensity, and high dislocation density. Consequently, the joint showed superior nugget hardness and simultaneously a slightly low tensile ductility.

Balancing High-Speed Rotors at Low Speed

Science.gov (United States)

Giordano, J.; Zorzi, E.

1986-01-01

Flexible balancing reduces vibrations at operating speeds. Highspeed rotors in turbomachines dynamically balanced at fraction of operating rotor speed. New method takes into account rotor flexible rather than rigid.

High-speed holographic camera

International Nuclear Information System (INIS)

Novaro, Marc

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

Recent progress on high-speed optical transmission

Directory of Open Access Journals (Sweden)

Jianjun Yu

2016-05-01

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

Single-Photon Tracking for High-Speed Vision

Directory of Open Access Journals (Sweden)

Istvan Gyongy

2018-01-01

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

A high-speed interface for multi-channel analyzer

International Nuclear Information System (INIS)

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

2003-01-01

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

Exercise training effects on hypoxic and hypercapnic ventilatory responses in mice selected for increased voluntary wheel running.

Science.gov (United States)

Kelly, Scott A; Rezende, Enrico L; Chappell, Mark A; Gomes, Fernando R; Kolb, Erik M; Malisch, Jessica L; Rhodes, Justin S; Mitchell, Gordon S; Garland, Theodore

2014-02-01

What is the central question of this study? We used experimental evolution to determine how selective breeding for high voluntary wheel running and exercise training (7-11 weeks) affect ventilatory chemoreflexes of laboratory mice at rest. What is the main finding and its importance? Selective breeding, although significantly affecting some traits, did not systematically alter ventilation across gas concentrations. As with most human studies, our findings support the idea that endurance training attenuates resting ventilation. However, little evidence was found for a correlation between ventilatory chemoreflexes and the amount of individual voluntary wheel running. We conclude that exercise 'training' alters respiratory behaviours, but these changes may not be necessary to achieve high levels of wheel running. Ventilatory control is affected by genetics, the environment and gene-environment and gene-gene interactions. Here, we used an experimental evolution approach to test whether 37 generations of selective breeding for high voluntary wheel running (genetic effects) and/or long-term (7-11 weeks) wheel access (training effects) alter acute respiratory behaviour of mice resting in normoxic, hypoxic and hypercapnic conditions. As the four replicate high-runner (HR) lines run much more than the four non-selected control (C) lines, we also examined whether the amount of exercise among individual mice was a quantitative predictor of ventilatory chemoreflexes at rest. Selective breeding and/or wheel access significantly affected several traits. In normoxia, HR mice tended to have lower mass-adjusted rates of oxygen consumption and carbon dioxide production. Chronic wheel access increased oxygen consumption and carbon dioxide production in both HR and C mice during hypercapnia. Breathing frequency and minute ventilation were significantly reduced by chronic wheel access in both HR and C mice during hypoxia. Selection history, while significantly affecting some traits

High-speed readout of high-Z pixel detectors with the LAMBDA detector

International Nuclear Information System (INIS)

Pennicard, D.; Smoljanin, S.; Sheviakov, I.; Xia, Q.; Rothkirch, A.; Yu, Y.; Struth, B.; Hirsemann, H.; Graafsma, H.

2014-01-01

High-frame-rate X-ray pixel detectors make it possible to perform time-resolved experiments at synchrotron beamlines, and to make better use of these sources by shortening experiment times. LAMBDA is a photon-counting hybrid pixel detector based on the Medipix3 chip, designed to combine a small pixel size of 55 μm, a large tileable module design, high speed, and compatibility with ''high-Z'' sensors for hard X-ray detection. This technical paper focuses on LAMBDA's high-speed-readout functionality, which allows a frame rate of 2000 frames per second with no deadtime between successive images. This takes advantage of the Medipix3 chip's ''continuous read-write'' function and highly parallelised readout. The readout electronics serialise this data and send it back to a server PC over two 10 Gigabit Ethernet links. The server PC controls the detector and receives, processes and stores the data using software designed for the Tango control system. As a demonstration of high-speed readout of a high-Z sensor, a GaAs LAMBDA detector was used to make a high-speed X-ray video of a computer fan

High Speed Magnetostrictive MEMS Actuated Mirror Deflectors, Phase II

Data.gov (United States)

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

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...

High-speed LWR transients simulation for optimizing emergency response

International Nuclear Information System (INIS)

Wulff, W.; Cheng, H.S.; Lekach, S.V.; Mallen, A.N.; Stritar, A.

1984-01-01

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

Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel.

Science.gov (United States)

Zhang, Zhihong; Wang, Xiaoyang; Tong, Jin; Stephen, Carr

2018-01-01

A highly efficient soil-burrowing dung beetle possesses an intricate outer contour curve on its foreleg end-tooth. This study was carried out based on evidence that this special outer contour curve has the potential of reducing soil penetration resistance and could enhance soil-burrowing efficiency. A toothed wheel is a typical agricultural implement for soil imprinting, to increase its working efficiency; the approach of the bionic geometrical structure was utilized to optimize the innovative shape of imprinting toothed wheel. Characteristics in the dung beetle's foreleg end-tooth were extracted and studied by the edge detection technique. Then, this special outer contour curve was modeled by a nine-order polynomial function and used for the innovative design of imprinting the tooth's cutting edge. Both the conventional and bionic teeth were manufactured, and traction tests in a soil bin were conducted. Taking required draft force and volume of imprinted microbasin as the evaluating indexes, operating efficiency and quality of different toothed wheels were compared and investigated. Results indicate that compared with the conventional toothed wheel, a bionic toothed wheel possesses a better forward resistance reduction property against soil and, meanwhile, can enhance the quality of soil imprinting by increasing the volume of the created micro-basin.

Mathematical Modeling of the Braking System of Wheeled Mainline Aircraft

Directory of Open Access Journals (Sweden)

I. S. Shumilov

2016-01-01

the aircraft braking mode with a slight increase in weight and complexity of the system.Mathematical modeling of the WBCS is intended to provide the possibility for studying the effect of various parameters on the braking process, choice of a rational law of the anti-skid automatics and minimization of the brake way on the runway in designing the WBCS, and its certification for compliance with AP25 under normal operation and in appearing of credible failures. The article presents differential equations of motion of the braking system of the aircraft landing gear wheel, which is an electro-hydraulic actuator to form the braking torque Мт, depending on the control signal Uу. The actuator comprises a remote control system of pressure and multi-disc friction brake. This mathematical model of the braking system of aircraft landing gear wheel allows us to study the braking process in a wide variation range of different parameters both of the braking system itself and its components, and of the aircraft parameters, runway conditions, and anti-skid system parameters, i.e. it provides an optimized braking process in conditions of changing a large number of different parameters the most important of which are: RFC, lifting force and aircraft weight; speed of the aircraft; parameters of the WBCS hydraulic units, etc.

Temperature calculations of heat loads in rotating target wheels exposed to high beam currents

International Nuclear Information System (INIS)

Greene, John P.; Gabor, Rachel; Neubauer, Janelle

2001-01-01

In heavy-ion physics, high beam currents can eventually melt or destroy the target. Tightly focused beams on stationary targets of modest melting point will exhibit short lifetimes. Defocused or 'wobbled' beams are employed to enhance target survival. Rotating targets using large diameter wheels can help overcome target melting and allow for higher beam currents to be used in experiments. The purpose of the calculations in this work is to try and predict the safe maximum beam currents which produce heat loads below the melting point of the target material

Temperature calculations of heat loads in rotating target wheels exposed to high beam currents

International Nuclear Information System (INIS)

Greene, J. P.; Gabor, R.; Neubauer, J.

2000-01-01

In heavy-ion physics, high beam currents can eventually melt or destroy the target. Tightly focused beams on stationary targets of modest melting point will exhibit short lifetimes. Defocused or wobbled beams are employed to enhance target survival. Rotating targets using large diameter wheels can help overcome target melting and allow for higher beam currents to be used in experiments. The purpose of the calculations in this work is to try and predict the safe maximum beam currents which produce heat loads below the melting point of the target material

Eating meals before wheel-running exercise attenuate high fat diet-driven obesity in mice under two meals per day schedule.

Science.gov (United States)

Sasaki, Hiroyuki; Hattori, Yuta; Ikeda, Yuko; Kamagata, Mayo; Shibata, Shigenobu

2015-06-01

Mice that exercise after meals gain less body weight and visceral fat compared to those that exercised before meals under a one meal/exercise time per day schedule. Humans generally eat two or three meals per day, and rarely have only one meal. To extend our previous observations, we examined here whether a "two meals, two exercise sessions per day" schedule was optimal in terms of maintaining a healthy body weight. In this experiment, "morning" refers to the beginning of the active phase (the "morning" for nocturnal animals). We found that 2-h feeding before 2-h exercise in the morning and evening (F-Ex/F-Ex) resulted in greater attenuation of high fat diet (HFD)-induced weight gain compared to other combinations of feeding and exercise under two daily meals and two daily exercise periods. There were no significant differences in total food intake and total wheel counts, but feeding before exercise in the morning groups (F-Ex/F-Ex and F-Ex/Ex-F) increased the morning wheel counts. These results suggest that habitual exercise after feeding in the morning and evening is more effective for preventing HFD-induced weight gain. We also determined whether there were any correlations between food intake, wheel rotation, visceral fat volume and skeletal muscle volumes. We found positive associations between gastrocnemius muscle volumes and morning wheel counts, as well as negative associations between morning food intake volumes/body weight and morning wheel counts. These results suggest that morning exercise-induced increase of muscle volume may refer to anti-obesity. Evening exercise is negatively associated with fat volume increases, suggesting that this practice may counteract fat deposition. Our multifactorial analysis revealed that morning food intake helps to increase exercise, and that evening exercise reduced fat volumes. Thus, exercise in the morning or evening is important for preventing the onset of obesity.

Body weight manipulation, reinforcement value and choice between sucrose and wheel running: a behavioral economic analysis.

Science.gov (United States)

Belke, Terry W; Pierce, W David

2009-02-01

Twelve female Long-Evans rats were exposed to concurrent variable (VR) ratio schedules of sucrose and wheel-running reinforcement (Sucrose VR 10 Wheel VR 10; Sucrose VR 5 Wheel VR 20; Sucrose VR 20 Wheel VR 5) with predetermined budgets (number of responses). The allocation of lever pressing to the sucrose and wheel-running alternatives was assessed at high and low body weights. Results showed that wheel-running rate and lever-pressing rates for sucrose and wheel running increased, but the choice of wheel running decreased at the low body weight. A regression analysis of relative consumption as a function of relative price showed that consumption shifted toward sucrose and interacted with price differences in a manner consistent with increased substitutability. Demand curves showed that demand for sucrose became less elastic while demand for wheel running became more elastic at the low body weight. These findings reflect an increase in the difference in relative value of sucrose and wheel running as body weight decreased. Discussion focuses on the limitations of response rates as measures of reinforcement value. In addition, we address the commonalities between matching and demand curve equations for the analysis of changes in relative reinforcement value.

Cutting force model for high speed machining process

International Nuclear Information System (INIS)

Haber, R. E.; Jimenez, J. E.; Jimenez, A.; Lopez-Coronado, J.

2004-01-01

This paper presents cutting force-based models able to describe a high speed machining process. The model considers the cutting force as output variable, essential for the physical processes that are taking place in high speed machining. Moreover, this paper shows the mathematical development to derive the integral-differential equations, and the algorithms implemented in MATLAB to predict the cutting force in real time MATLAB is a software tool for doing numerical computations with matrices and vectors. It can also display information graphically and includes many toolboxes for several research and applications areas. Two end mill shapes are considered (i. e. cylindrical and ball end mill) for real-time implementation of the developed algorithms. the developed models are validated in slot milling operations. The results corroborate the importance of the cutting force variable for predicting tool wear in high speed machining operations. The developed models are the starting point for future work related with vibration analysis, process stability and dimensional surface finish in high speed machining processes. (Author) 19 refs

Study on design of light-weight super-abrasive wheel

Science.gov (United States)

Nohara, K.; Yanagihara, K.; Ogawa, M.

2018-01-01

Fixed-abrasive tool, also called a grinding wheel, is produced by furnacing abrasive compound which contains abrasive grains and binding powder such as vitrified materials or resins. Fixed-abrasive tool is installed on spindle of grinding machine. And it is given 1,800-2,000 min-1 of spindle rotation for the usage. The centrifugal fracture of the compound of fixed- abrasive tool is one of the careful respects in designing. In recent years, however, super-abrasive wheel as a fixed-abrasive tool has been developed and applied widely. One of the most characteristic respects is that metal is applied for the body of grinding-wheel. The strength to hold abrasive grain and the rigidity of wheel become stronger than those of general grinding wheel, also the lifespan of fixed-abrasive tool becomes longer. The weight of fixed-abrasive tool, however, becomes heavier. Therefore, when the super-abrasive wheel is used, the power consumption of spindle motor becomes larger. It also becomes difficult for the grinding-wheel to respond to sudden acceleration or deceleration. Thus, in order to reduce power consumption in grinding and to obtain quicker frequency response of super-abrasive wheel, the new wheel design is proposed. The design accomplishes 46% weight reduction. Acceleration that is one second quicker than that of conventional grinding wheel is obtained.

Voluntary wheel running in dystrophin-deficient (mdx) mice: Relationships between exercise parameters and exacerbation of the dystrophic phenotype

OpenAIRE

Smythe, Gayle M; White, Jason D

2012-01-01

Voluntary wheel running can potentially be used to exacerbate the disease phenotype in dystrophin-deficient mdx mice. While it has been established that voluntary wheel running is highly variable between individuals, the key parameters of wheel running that impact the most on muscle pathology have not been examined in detail. We conducted a 2-week test of voluntary wheel running by mdx mice and the impact of wheel running on disease pathology. There was significant individual variation in the...

Aerodynamic analysis of an isolated vehicle wheel

Science.gov (United States)

Leśniewicz, P.; Kulak, M.; Karczewski, M.

2014-08-01

Increasing fuel prices force the manufacturers to look into all aspects of car aerodynamics including wheels, tyres and rims in order to minimize their drag. By diminishing the aerodynamic drag of vehicle the fuel consumption will decrease, while driving safety and comfort will improve. In order to properly illustrate the impact of a rotating wheel aerodynamics on the car body, precise analysis of an isolated wheel should be performed beforehand. In order to represent wheel rotation in contact with the ground, presented CFD simulations included Moving Wall boundary as well as Multiple Reference Frame should be performed. Sliding mesh approach is favoured but too costly at the moment. Global and local flow quantities obtained during simulations were compared to an experiment in order to assess the validity of the numerical model. Results of investigation illustrates dependency between type of simulation and coefficients (drag and lift). MRF approach proved to be a better solution giving result closer to experiment. Investigation of the model with contact area between the wheel and the ground helps to illustrate the impact of rotating wheel aerodynamics on the car body.

Aerodynamic analysis of an isolated vehicle wheel

International Nuclear Information System (INIS)

Leśniewicz, P; Kulak, M; Karczewski, M

2014-01-01

Increasing fuel prices force the manufacturers to look into all aspects of car aerodynamics including wheels, tyres and rims in order to minimize their drag. By diminishing the aerodynamic drag of vehicle the fuel consumption will decrease, while driving safety and comfort will improve. In order to properly illustrate the impact of a rotating wheel aerodynamics on the car body, precise analysis of an isolated wheel should be performed beforehand. In order to represent wheel rotation in contact with the ground, presented CFD simulations included Moving Wall boundary as well as Multiple Reference Frame should be performed. Sliding mesh approach is favoured but too costly at the moment. Global and local flow quantities obtained during simulations were compared to an experiment in order to assess the validity of the numerical model. Results of investigation illustrates dependency between type of simulation and coefficients (drag and lift). MRF approach proved to be a better solution giving result closer to experiment. Investigation of the model with contact area between the wheel and the ground helps to illustrate the impact of rotating wheel aerodynamics on the car body.

Research on the tool holder mode in high speed machining

Science.gov (United States)

Zhenyu, Zhao; Yongquan, Zhou; Houming, Zhou; Xiaomei, Xu; Haibin, Xiao

2018-03-01

High speed machining technology can improve the processing efficiency and precision, but also reduce the processing cost. Therefore, the technology is widely regarded in the industry. With the extensive application of high-speed machining technology, high-speed tool system has higher and higher requirements on the tool chuck. At present, in high speed precision machining, several new kinds of clip heads are as long as there are heat shrinkage tool-holder, high-precision spring chuck, hydraulic tool-holder, and the three-rib deformation chuck. Among them, the heat shrinkage tool-holder has the advantages of high precision, high clamping force, high bending rigidity and dynamic balance, etc., which are widely used. Therefore, it is of great significance to research the new requirements of the machining tool system. In order to adapt to the requirement of high speed machining precision machining technology, this paper expounds the common tool holder technology of high precision machining, and proposes how to select correctly tool clamping system in practice. The characteristics and existing problems are analyzed in the tool clamping system.

High-speed photodetectors in optical communication system

Science.gov (United States)

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

2017-12-01

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

Analysis and topology optimization design of high-speed driving spindle

Science.gov (United States)

Wang, Zhilin; Yang, Hai

2018-04-01

The three-dimensional model of high-speed driving spindle is established by using SOLIDWORKS. The model is imported through the interface of ABAQUS, A finite element analysis model of high-speed driving spindle was established by using spring element to simulate bearing boundary condition. High-speed driving spindle for the static analysis, the spindle of the stress, strain and displacement nephogram, and on the basis of the results of the analysis on spindle for topology optimization, completed the lightweight design of high-speed driving spindle. The design scheme provides guidance for the design of axial parts of similar structures.

HIGH SPEED RAILWAY LINES – FUTURE PART OF CZECH RAILWAY NETWORK?

Directory of Open Access Journals (Sweden)

Lukáš Týfa

2017-08-01

Full Text Available The paper first describes high speed rail generally and explains the relationship between high speed and conventional railway networks (according to the vehicle types in operation on the network. The core of the paper is comprised of the methodology for choosing the best route for a railway line and its application to the high speed railway connection Praha – Brno. The Algorithm used assumes the existence of more route proposals, which could be different in terms of the operational conception, line routing or types of vehicles used. The optimal variant is the one with the lowest daily cost, which includes infrastructure and vehicle costs; investment and operational costs. The results from applying this model confirmed the assumption, that a dedicated high speed railway line, only for high speed trains, has the same or lower investment costs than a line for both high speed and conventional trains. Furthermore, a dedicated high line also has a lower cost for infrastructure maintenance but a higher cost for buying high speed multiple units.

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Application of Fabry-Perot velocimeter to high-speed experiments

International Nuclear Information System (INIS)

Chaw, H.H.; McMillan, C.F.; Osher, J.E.

1988-01-01

The Fabry-Perot (F-P) velocimeter is a useful instrument for measuring the velocity of objects at speeds ranging from fractions of a kilometer per second to a few tens of kilometers per second and up. Because of its immunity to electromagnetic interference and its velocity resolution, it has become the prime diagnostic tool in our electric-gun facility. Examples of its application to high speed experiments are discussed, including: electric-gun flyer studies, spallation of materials under high-speed impact, momentum-transfer studies, pressure pulse created by high-velocity impact, and detonation-wave studies in high-explosive experiments

First Wheel of the Hadronic EndCap Calorimeter Completed

CERN Multimedia

Oram, C.J.

2002-01-01

With the LAr calorimeters well advanced in module production, the attention is turning to Batiment 180 where the calorimeter modules are formed into complete detectors and inserted into their respective cryostats. For the Hadronic End Cap (HEC) Group the task in B180 is to assemble the wheels, rotate them into their final orientation, and put them onto the cradle in front of the End Cap Cryostat. These tasks have been completed for the first HEC wheel in the B180 End Cap Clean Room. Given that this wheel weighs 70 tons the group is very relieved to have established that these gymnastics with the wheel proceed in a routine fashion. To assemble a wheel we take modules that have already been cold tested, do the final electrical testing and locate them onto the HEC wheel assembly table. Four wheels are required in total, each consisting of 32 modules. Wheel assembly is done in the horizontal position, creating a doughnut-like object sitting on the HEC table. The first picture shows the last module being added ...

Wheel-running in a transgenic mouse model of Alzheimer's disease: protection or symptom?

Science.gov (United States)

Richter, Helene; Ambrée, Oliver; Lewejohann, Lars; Herring, Arne; Keyvani, Kathy; Paulus, Werner; Palme, Rupert; Touma, Chadi; Schäbitz, Wolf-Rüdiger; Sachser, Norbert

2008-06-26

Several studies on both humans and animals reveal benefits of physical exercise on brain function and health. A previous study on TgCRND8 mice, a transgenic model of Alzheimer's disease, reported beneficial effects of premorbid onset of long-term access to a running wheel on spatial learning and plaque deposition. Our study investigated the effects of access to a running wheel after the onset of Abeta pathology on behavioural, endocrinological, and neuropathological parameters. From day 80 of age, the time when Abeta deposition becomes apparent, TgCRND8 and wildtype mice were kept with or without running wheel. Home cage behaviour was analysed and cognitive abilities regarding object recognition memory and spatial learning in the Barnes maze were assessed. Our results show that, in comparison to Wt mice, Tg mice were characterised by impaired object recognition memory and spatial learning, increased glucocorticoid levels, hyperactivity in the home cage and high levels of stereotypic behaviour. Access to a running wheel had no effects on cognitive or neuropathological parameters, but reduced the amount of stereotypic behaviour in transgenics significantly. Furthermore, wheel-running was inversely correlated with stereotypic behaviour, suggesting that wheel-running may have stereotypic qualities. In addition, wheel-running positively correlated with plaque burden. Thus, in a phase when plaques are already present in the brain, it may be symptomatic of brain pathology, rather than protective. Whether or not access to a running wheel has beneficial effects on Alzheimer-like pathology and symptoms may therefore strongly depend on the exact time when the wheel is provided during development of the disease.

Application of polarization in high speed, high contrast inspection

Science.gov (United States)

Novak, Matthew J.

2017-08-01

Industrial optical inspection often requires high speed and high throughput of materials. Engineers use a variety of techniques to handle these inspection needs. Some examples include line scan cameras, high speed multi-spectral and laser-based systems. High-volume manufacturing presents different challenges for inspection engineers. For example, manufacturers produce some components in quantities of millions per month, per week or even per day. Quality control of so many parts requires creativity to achieve the measurement needs. At times, traditional vision systems lack the contrast to provide the data required. In this paper, we show how dynamic polarization imaging captures high contrast images. These images are useful for engineers to perform inspection tasks in some cases where optical contrast is low. We will cover basic theory of polarization. We show how to exploit polarization as a contrast enhancement technique. We also show results of modeling for a polarization inspection application. Specifically, we explore polarization techniques for inspection of adhesives on glass.

High speed network sampling

OpenAIRE

Rindalsholt, Ole Arild

2005-01-01

Master i nettverks- og systemadministrasjon Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

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...

Project considerations and design of systems for wheeling cogenerated power

Energy Technology Data Exchange (ETDEWEB)

Tessmer, R.G. Jr.; Boyle, J.R.; Fish, J.H. III; Martin, W.A.

1994-08-01

Wheeling electric power, the transmission of electricity not owned by an electric utility over its transmission lines, is a term not generally recognized outside the electric utility industry. Investigation of the term`s origin is intriguing. For centuries, wheel has been used to describe an entire machine, not just individual wheels within a machine. Thus we have waterwheel, spinning wheel, potter`s wheel and, for an automobile, wheels. Wheel as a verb connotes transmission or modification of forces and motion in machinery. With the advent of an understanding of electricity, use of the word wheel was extended to be transmission of electric power as well as mechanical power. Today, use of the term wheeling electric power is restricted to utility transmission of power that it doesn`t own. Cogeneration refers to simultaneous production of electric and thermal power from an energy source. This is more efficient than separate production of electricity and thermal power and, in many instances, less expensive.

High-speed nonvolatile CMOS/MNOS RAM

International Nuclear Information System (INIS)

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

1979-01-01

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

Phenomena of Foamed Concrete under Rolling of Aircraft Wheels

Science.gov (United States)

Jiang, Chun-shui; Yao, Hong-yu; Xiao, Xian-bo; Kong, Xiang-jun; Shi, Ya-jie

2014-04-01

Engineered Material Arresting System (EMAS) is an effective technique to reduce hazards associated with aircraft overrunning runway. In order to ascertain phenomena of the foamed concrete used for EMAS under rolling of aircraft wheel, a specially designed experimental setup was built which employed Boeing 737 aircraft wheels bearing actual vertical loads to roll through the foamed concrete. A number of experiments were conducted upon this setup. It is discovered that the wheel rolls the concrete in a pure rolling manner and crushes the concrete downwards, instead of crushing it forward, as long as the concrete is not higher than the wheel axle. The concrete is compressed into powder in-situ by the wheel and then is brought to bottom of the wheel. The powder under the wheel is loose and thus is not able to sustain wheel braking. It is also found that after being rolled by the wheel the concrete exhibits either of two states, i.e. either 'crushed through' whole thickness of the concrete or 'crushed halfway', depending on combination of strength of the concrete, thickness of the concrete, vertical load the wheel carries, tire dimension and tire pressure. A new EMAS design concept is developed that if an EMAS design results in the 'crushed through' state for the main gears while the 'crushed halfway' state for the nose gear, the arresting bed would be optimal to accommodate the large difference in strength between the nose gear and the main gear of an aircraft.

Evaluation of pavement skid resistance using high speed texture measurement

Directory of Open Access Journals (Sweden)

Jay N. Meegoda

2015-12-01

Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

High-speed cryptography and cryptanalysis

NARCIS (Netherlands)

Schwabe, P.

2011-01-01

Modern digital communication relies heavily on cryptographic protection to ensure data integrity and privacy. In order to deploy state-of-the art cryptographic primitives and protocols in real-world scenarios, one needs to highly optimize software for both speed and security. This requires careful

Advancing high-speed rail policy in the United States.

Science.gov (United States)

2012-06-01

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

Design and applications of a pneumatic accelerator for high speed punching

International Nuclear Information System (INIS)

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

2007-01-01

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

Assessment of rural soundscapes with high-speed train noise.

Science.gov (United States)

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

2014-06-01

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

High-speed imaging of explosive eruptions: applications and perspectives

Science.gov (United States)

Taddeucci, Jacopo; Scarlato, Piergiorgio; Gaudin, Damien; Capponi, Antonio; Alatorre-Ibarguengoitia, Miguel-Angel; Moroni, Monica

2013-04-01

Explosive eruptions, being by definition highly dynamic over short time scales, necessarily call for observational systems capable of relatively high sampling rates. "Traditional" tools, like as seismic and acoustic networks, have recently been joined by Doppler radar and electric sensors. Recent developments in high-speed camera systems now allow direct visual information of eruptions to be obtained with a spatial and temporal resolution suitable for the analysis of several key eruption processes. Here we summarize the methods employed to gather and process high-speed videos of explosive eruptions, and provide an overview of the several applications of these new type of data in understanding different aspects of explosive volcanism. Our most recent set up for high-speed imaging of explosive eruptions (FAMoUS - FAst, MUltiparametric Set-up,) includes: 1) a monochrome high speed camera, capable of 500 frames per second (fps) at high-definition (1280x1024 pixel) resolution and up to 200000 fps at reduced resolution; 2) a thermal camera capable of 50-200 fps at 480-120x640 pixel resolution; and 3) two acoustic to infrasonic sensors. All instruments are time-synchronized via a data logging system, a hand- or software-operated trigger, and via GPS, allowing signals from other instruments or networks to be directly recorded by the same logging unit or to be readily synchronized for comparison. FAMoUS weights less than 20 kg, easily fits into four, hand-luggage-sized backpacks, and can be deployed in less than 20' (and removed in less than 2', if needed). So far, explosive eruptions have been recorded in high-speed at several active volcanoes, including Fuego and Santiaguito (Guatemala), Stromboli (Italy), Yasur (Vanuatu), and Eyjafiallajokull (Iceland). Image processing and analysis from these eruptions helped illuminate several eruptive processes, including: 1) Pyroclasts ejection. High-speed videos reveal multiple, discrete ejection pulses within a single Strombolian

Real Time Speed Measure while Automobile Braking on Soft Sensing Technique

Energy Technology Data Exchange (ETDEWEB)

Zhu, W B; Li, D S; Lu, Y [China Jiliang University, Hangzhou, Zhejiang province, 310018 (China)

2006-10-15

Because the braking performance of automobile has close relationship to traffic safety, it is important to detect that. Focusing on the problem that the real time speed is difficult to obtain in detection process, soft sensing technique is introduced in this paper. According to analyzing the relationship of the dynamics equation of a moving automobile, a module of real time speed of braking is set up. By using imitation method with experiment data to get the pressure function of cylinder and analyzing the relationship between the trigging moment of a wheel and the pressure function of brake cylinder, the real time speed is confirmed in good precision. The maximal measurement error of real time speed is 8.7% and the precision can satisfy engineering request.

Real Time Speed Measure while Automobile Braking on Soft Sensing Technique

International Nuclear Information System (INIS)

Zhu, W B; Li, D S; Lu, Y

2006-01-01

Because the braking performance of automobile has close relationship to traffic safety, it is important to detect that. Focusing on the problem that the real time speed is difficult to obtain in detection process, soft sensing technique is introduced in this paper. According to analyzing the relationship of the dynamics equation of a moving automobile, a module of real time speed of braking is set up. By using imitation method with experiment data to get the pressure function of cylinder and analyzing the relationship between the trigging moment of a wheel and the pressure function of brake cylinder, the real time speed is confirmed in good precision. The maximal measurement error of real time speed is 8.7% and the precision can satisfy engineering request

High-speed microjet generation using laser-induced vapor bubbles

Science.gov (United States)

Oudalov, Nikolai; Tagawa, Yoshiyuki; Peters, Ivo; Visser, Claas-Willem; van der Meer, Devaraj; Prosperetti, Andrea; Sun, Chao; Lohse, Detlef

2011-11-01

The generation and evolution of microjets are studied both experimentally and numerically. The jets are generated by focusing a laser pulse into a microscopic capillary tube (~50 μm) filled with water-based red dye. A vapor bubble is created instantly after shooting the laser (<1 μs), sending out a shockwave towards the curved free surface at which the high-speed microjet forms. The process of jet formation is captured using high-speed recordings at 1.0 × 106 fps. The velocity of the microjets can reach speeds of ~850 m/s while maintaining a very sharp geometry. The high-speed recordings enable us to study the effect of several parameters on the jet velocity, e.g. the absorbed energy and the distance between the laser spot and the free surface.The results show a clear dependence on these variables, even for supersonic speeds. Comparisons with numerical simulations confirm the nature of these dependencies.

Damages and resource of locomotive wheels used under the north operating conditions

Directory of Open Access Journals (Sweden)

A. V. Grigorev

2014-01-01

Full Text Available In operating railway equipment, in particular the elements, such as a wheel and a rail there is damage accumulation of any kind, causing a premature equipment failure. Thus, an analysis of the mechanisms and modeling of damage accumulation and fracture both on the surface and in the bulk material remain a challenge.Data on the defective wheel sets to be subjected to facing has been collected and analyzed to assess the locomotive wheel sets damage of the locomotive fleet company of AK «Yakutia Railways», city of Aldan, The Republic of Sakha (Yakutia. For this purpose, three main locomotives have been examined.The object of research carried out in this paper, is a locomotive wheels tire, which is subjected to cyclic impact (dynamic loads during operation. In this regard, the need arises to determine both the strength of material in response to such shock loads and the quantitative calculation of damage accumulated therein.The accumulated fatigue damage has been attributed to one radial cross section of the wheel coming into contact with the rail once per revolution of the wheel. Consequently, in one revolution a wheel is under one loading cycle. As stated, the average mileage of locomotives to have the unacceptable damages formed on the tread surface is 12 thousand km.Test results establish that along with the high-cycle loading the shock-contact action on rail joints significantly affects the accumulation of damage in the locomotive wheels tire. The number of cycles to failure due to the formation of unacceptable damage in the locomotive wheels tire is N = 2,4×106 and 6×105 cycles, respectively, for fatigue and shock-contact loading.In general, we can say that the problem of higher intensity to form the surface damage is directly related to the operation of the locomotive wheel tire under abnormally low climatic temperatures. With decreasing ambient temperature, this element material rapidly looses its plastic properties, thereby accelerating

A fully omnidirectional wheeled assembly for robotic vehicles

International Nuclear Information System (INIS)

Killough, S.M.; Pin, F.G.

1990-01-01

A large number of wheeled or tracked platform mechanisms have been studied and developed to provide their mobility capability to teleoperated and autonomous robot vehicles. This paper presents an original wheeled platform based on an orthogonal wheel assembly that provides a full (three-degrees-of-freedom) omnidirectionality of the platform without wheel slippage and with the capability for simultaneous motions in rotation and translation (including sideways movements). A schematic of the basic wheel assembly is shown. The motion of the assembly is unconstrained (freewheeling) in the direction parallel to the main assembly shaft, while it is constrained in the direction perpendicular to the shaft, being driven in this direction by rotation of the shaft. A prototype platform was constructed to demonstrate the feasibility of this new concept

High speed railway track dynamics models, algorithms and applications

CERN Document Server

Lei, Xiaoyan

2017-01-01

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

Plasma-Assisted Chemistry in High-Speed Flow

International Nuclear Information System (INIS)

Leonov, Sergey B.; Yarantsev, Dmitry A.; Napartovich, Anatoly P.; Kochetov, Igor V.

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

Thermomechanical simulations and experimental validation for high speed incremental forming

Science.gov (United States)

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

2016-10-01

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

High Speed Photomicrography

Science.gov (United States)

Hyzer, William G.

1983-03-01

One of the most challenging areas in applying high-speed photography and videography in the plant and laboratory is in the recording of rapid events at macro and microscopic scales. Depth of field, exposure efficiency, working distance, and required exposure time are all reduced as optical magnification is increased, which severely taxes the skill and ingenuity of workers interested in recording any fast moving phenomena through the microscope or with magnifying lenses. This paper defines the problems inherent in photographing within macro and microscopic ranges and offers a systematic approach to optimizing the selection of equipment and choice of applicable techniques.

Material requirements for the High Speed Civil Transport

Science.gov (United States)

Stephens, Joseph R.; Hecht, Ralph J.; Johnson, Andrew M.

1993-01-01

Under NASA-sponsored High Speed Research (HSR) programs, the materials and processing requirements have been identified for overcoming the environmental and economic barriers of the next generation High Speed Civil Transport (HSCT) propulsion system. The long (2 to 5 hours) supersonic cruise portion of the HSCT cycle will place additional durability requirements on all hot section engine components. Low emissions combustor designs will require high temperature ceramic matrix composite liners to meet an emission goal of less than 5g NO(x) per Kg fuel burned. Large axisymmetric and two-dimensional exhaust nozzle designs are now under development to meet or exceed FAR 36 Stage III noise requirements, and will require lightweight, high temperature metallic, intermetallic, and ceramic matrix composites to reduce nozzle weight and meet structural and acoustic component performance goals. This paper describes and discusses the turbomachinery, combustor, and exhaust nozzle requirements of the High Speed Civil Transport propulsion system.

High-Speed Sealift Technology Development Plan

National Research Council Canada - National Science Library

2002-01-01

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

Control of wheeled mobile robot in restricted environment

Science.gov (United States)

Ali, Mohammed A. H.; En, Chang Yong

2018-03-01

This paper presents a simulation and practical control system for wheeled mobile robot in restricted environment. A wheeled mobile robot with 3 wheels is fabricated and controlled by proportional derivative active force control (PD-AFC) to move in a pre-planned restricted environment to maintain the tracking errors at zero level. A control system with two loops, outer by PD controller and inner loop by Active Force Control, are designed to control the wheeled mobile robot. Fuzzy logic controller is implemented in the Active force Control to estimate the inertia matrix that will be used to calculate the actual torque applied on the wheeled mobile robot. The mobile robot is tested in two different trajectories, namely are circular and straight path. The actual path and desired path are compared.

Nonlinear analysis of the GFRP material wheel hub

Directory of Open Access Journals (Sweden)

Dong Yun-Feng

2015-01-01

Full Text Available In this paper, the current bicycle wheel was replaced by the ones which composed by the wheel hub with Glassfiber Reinforced Plastic (alkali free thin-walled cylinder material, hereinafter referred to as GFRP material and the protective components made up of rubber outer pneumatic pad. With the help of the basic theory of elastic-plastic mechanics, the finite element “Nonlinear buckling” analysis of the wheel was carried out. The results show that the maximum elastic deformation of the wheel hub and the critical value of buckling failure load were restricted by the elasticity under the condition of external loads. Considering with the tensile strength and elastic modulus of the GFRP value of the material, it is demonstrated that the material is feasible to be used for wheel hub.

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Meals on Wheels Association of America

Science.gov (United States)

... Meals About Meals on Wheels Get Started The Issue The Problem & Our Solution Meals on Wheels Health Facts & Resources Senior Facts Map State Fact Sheets Research More Than a Meal Pilot Research Study Medicare Claims Analyses Policy Myths Hunger in Older Adults Take Action Volunteer Advocate #SAVELUNCH ...

Optimal design of high-speed loading spindle based on ABAQUS

Science.gov (United States)

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

2017-12-01

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

Development of Diamond-like Carbon Fibre Wheel

Institute of Scientific and Technical Information of China (English)

魏源迁; 山口勝美; 洞口巌; 竹内雅之

2004-01-01

A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned normally to the grinding wheel surface by laminating Al sheets together with DLC fibres. In this paper, the formation process of DLC fibres and the fabrication process of a DLC fibre wheel were investigated. Many grinding experiments were also carried out on a precision NC plane milling machine using a newly developed DLC wheel. Grinding of specimens of silicon wafers, optical glasses, quartz, granites and hardened die steel SKD11 demonstrated the capabilities of nanometer surface finish. A smooth surface with a roughness value of Ra2.5nm (Ry26nm) was achieved.

UT Biomedical Informatics Lab (BMIL) probability wheel

Science.gov (United States)

Huang, Sheng-Cheng; Lee, Sara; Wang, Allen; Cantor, Scott B.; Sun, Clement; Fan, Kaili; Reece, Gregory P.; Kim, Min Soon; Markey, Mia K.

A probability wheel app is intended to facilitate communication between two people, an "investigator" and a "participant", about uncertainties inherent in decision-making. Traditionally, a probability wheel is a mechanical prop with two colored slices. A user adjusts the sizes of the slices to indicate the relative value of the probabilities assigned to them. A probability wheel can improve the adjustment process and attenuate the effect of anchoring bias when it is used to estimate or communicate probabilities of outcomes. The goal of this work was to develop a mobile application of the probability wheel that is portable, easily available, and more versatile. We provide a motivating example from medical decision-making, but the tool is widely applicable for researchers in the decision sciences.

Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity.

Science.gov (United States)

Claghorn, Gerald C; Thompson, Zoe; Wi, Kristianna; Van, Lindsay; Garland, Theodore

2017-03-01

The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO 2 max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO 2

Comprehensive surface treatment of high-speed steel tool

Science.gov (United States)

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

2018-03-01

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

Performance Studies of Micromegas Chambers for the New Small Wheel Upgrade Project

Directory of Open Access Journals (Sweden)

Leontsinis S.

2016-01-01

Full Text Available The ATLAS collaboration has chosen the Micromegas technology along with the small-strip Thin Gap Chambers for the upgrade of the inner muon station in the high-rapidity region, the so called New Small Wheel upgrade project. It will employ eight layers of Micromegas and eight layers of small-strip Thin Gap Chambers per wheel. The New Small Wheel project requires fully efficient Micromegas chambers, able to cope with the maximum expected rate of 15 kHz/cm2 featuring single plane spatial resolution better than 100 μm. The Micromegas detectors will cover a total active area of ~ 1200 m2 and will be operated in a moderate magnetic field (≤ 0.3 T. Moreover, together with their precise tracking capability the New Small Wheel Micromegas chambers will contribute to the ATLAS Level-1 trigger system. Several studies have been performed on small (10 × 10 cm2 and medium (1 × 0.5 m2 size prototypes using medium (1 − 5 GeV/c and high momentum (120 – 150 GeV/c hadron beams at CERN. A brief overview of the results obtained is presented.

High-speed railway signal trackside equipment patrol inspection system

Science.gov (United States)

Wu, Nan

2018-03-01

High-speed railway signal trackside equipment patrol inspection system comprehensively applies TDI (time delay integration), high-speed and highly responsive CMOS architecture, low illumination photosensitive technique, image data compression technique, machine vision technique and so on, installed on high-speed railway inspection train, and achieves the collection, management and analysis of the images of signal trackside equipment appearance while the train is running. The system will automatically filter out the signal trackside equipment images from a large number of the background image, and identify of the equipment changes by comparing the original image data. Combining with ledger data and train location information, the system accurately locate the trackside equipment, conscientiously guiding maintenance.

Wheeling rates evaluation using optimal power flows

International Nuclear Information System (INIS)

Muchayi, M.; El-Hawary, M. E.

1998-01-01

Wheeling is the transmission of electrical power and reactive power from a seller to a buyer through a transmission network owned by a third party. The wheeling rates are then the prices charged by the third party for the use of its network. This paper proposes and evaluates a strategy for pricing wheeling power using a pricing algorithm that in addition to the fuel cost for generation incorporates the optimal allocation of the transmission system operating cost, based on time-of-use pricing. The algorithm is implemented for the IEEE standard 14 and 30 bus system which involves solving a modified optimal power flow problem iteratively. The base of the proposed algorithm is the hourly spot price. The analysis spans a total time period of 24 hours. Unlike other algorithms that use DC models, the proposed model captures wheeling rates of both real and reactive power. Based on the evaluation, it was concluded that the model has the potential for wide application in calculating wheeling rates in a deregulated competitive power transmission environment. 9 refs., 3 tabs

49 CFR 229.75 - Wheels and tire defects.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Wheels and tire defects. 229.75 Section 229.75....75 Wheels and tire defects. Wheels and tires may not have any of the following conditions: (a) A... two adjoining spots that are each two or more inches in length. (e) A seam running lengthwise that is...

Wheel slip control with torque blending using linear and nonlinear model predictive control

Science.gov (United States)

Basrah, M. Sofian; Siampis, Efstathios; Velenis, Efstathios; Cao, Dongpu; Longo, Stefano

2017-11-01

Modern hybrid electric vehicles employ electric braking to recuperate energy during deceleration. However, currently anti-lock braking system (ABS) functionality is delivered solely by friction brakes. Hence regenerative braking is typically deactivated at a low deceleration threshold in case high slip develops at the wheels and ABS activation is required. If blending of friction and electric braking can be achieved during ABS events, there would be no need to impose conservative thresholds for deactivation of regenerative braking and the recuperation capacity of the vehicle would increase significantly. In addition, electric actuators are typically significantly faster responding and would deliver better control of wheel slip than friction brakes. In this work we present a control strategy for ABS on a fully electric vehicle with each wheel independently driven by an electric machine and friction brake independently applied at each wheel. In particular we develop linear and nonlinear model predictive control strategies for optimal performance and enforcement of critical control and state constraints. The capability for real-time implementation of these controllers is assessed and their performance is validated in high fidelity simulation.

Pulse-burst PIV in a high-speed wind tunnel

International Nuclear Information System (INIS)

Beresh, Steven; Kearney, Sean; Wagner, Justin; Guildenbecher, Daniel; Henfling, John; Spillers, Russell; Pruett, Brian; Jiang, Naibo; Slipchenko, Mikhail; Mance, Jason; Roy, Sukesh

2015-01-01

Time-resolved particle image velocimetry (TR-PIV) has been achieved in a high-speed wind tunnel, providing velocity field movies of compressible turbulence events. The requirements of high-speed flows demand greater energy at faster pulse rates than possible with the TR-PIV systems developed for low-speed flows. This has been realized using a pulse-burst laser to obtain movies at up to 50 kHz, with higher speeds possible at the cost of spatial resolution. The constraints imposed by use of a pulse-burst laser are limited burst duration of 10.2 ms and a low duty cycle for data acquisition. Pulse-burst PIV has been demonstrated in a supersonic jet exhausting into a transonic crossflow and in transonic flow over a rectangular cavity. The velocity field sequences reveal the passage of turbulent structures and can be used to find velocity power spectra at every point in the field, providing spatial distributions of acoustic modes. The present work represents the first use of TR-PIV in a high-speed ground-test facility. (paper)

To the question of modeling of wheels and rails wear processes

Directory of Open Access Journals (Sweden)

S.V. Myamlin

2013-06-01

Full Text Available Purpose. There is a need of wear process modeling in the wheel-rail system. This is related to the fact that the wear processes in this system are absolutely different in the initial and final stages. The profile change of rail and, especially, of the wheels caused by the wear significantly affects the rolling stock dynamics, traffic safety and the resource of the wheels and rails. Wear modeling and the traffic safety evaluation requires the accounting of the low frequency component forces (including the modeling of transitional areas affecting the wheel on the side of the rail and carriage in motion of rolling stock, so the statistical analysis is not possible. Methodology. The method of mathematical modeling of the wheel set and the rail interaction was used during the research conducting. Findings. As a result of the modeling of the wheel set motion on the rail track, the mathematic model with 19 freedom degrees was obtained. This model takes into account the axle torque and studies wheels constructions as the components of the mechanical systems, consisting of a hub and tire. Originality. The mathematic model allows evaluating the wear degree of the wheels and rails when using on the rolling stock not only all-metal wheel sets, but also compound ones with the use of spring wheels and independent rotation of semi-axes with the wheels. Practical value. The development of the improved mathematical model of freight car wheel set motion with differential rotation of the wheels and compound axles allows studying the wear processes of wheels and rails.

Identifying factors affecting the safety of mid-block bicycle lanes considering mixed 2-wheeled traffic flow.

Science.gov (United States)

Bai, Lu; Chan, Ching-Yao; Liu, Pan; Xu, Chengcheng

2017-10-03

Electric bikes (e-bikes) have been one of the fastest growing trip modes in Southeast Asia over the past 2 decades. The increasing popularity of e-bikes raised some safety concerns regarding urban transport systems. The primary objective of this study was to identify whether and how the generalized linear regression model (GLM) could be used to relate cyclists' safety with various contributing factors when riding in a mid-block bike lane. The types of 2-wheeled vehicles in the study included bicycle-style electric bicycles (BSEBs), scooter-style electric bicycles (SSEBs), and regular bicycles (RBs). Traffic conflict technology was applied as a surrogate measure to evaluate the safety of 2-wheeled vehicles. The safety performance model was developed by adopting a generalized linear regression model for relating the frequency of rear-end conflicts between e-bikes and regular bikes to the operating speeds of BSEBs, SSEBs, and RBs in mid-block bike lanes. The frequency of rear-end conflicts between e-bikes and bikes increased with an increase in the operating speeds of e-bikes and the volume of e-bikes and bikes and decreased with an increase in the width of bike lanes. The large speed difference between e-bikes and bikes increased the frequency of rear-end conflicts between e-bikes and bikes in mid-block bike lanes. A 1% increase in the average operating speed of e-bikes would increase the expected number of rear-end conflicts between e-bikes and bikes by 1.48%. A 1% increase in the speed difference between e-bikes and bikes would increase the expected number of rear-end conflicts between e-bikes/bikes by 0.16%. The conflict frequency in mid-block bike lanes can be modeled using generalized linear regression models. The factors that significantly affected the frequency of rear-end conflicts included the operating speeds of e-bikes, the speed difference between e-bikes and regular bikes, the volume of e-bikes, the volume of bikes, and the width of bike lanes. The

Development of Trigger and Readout Electronics for the ATLAS New Small Wheel Detector Upgrade

CERN Document Server

Zhu, Junjie; The ATLAS collaboration

2017-01-01

The planned Phase-I and Phase-II upgrades of the LHC accelerator drastically impacts the ATLAS trigger and trigger rates. A replacement of the ATLAS innermost endcap muon station with a new small wheel (NSW) detector is planned for the second long shutdown period of 2019 - 2020. This upgrade will allow us to maintain a low pT threshold for single muon and excellent tracking capability even after the High-Luminosity LHC upgrade. The NSW detector will feature two new detector technologies, Resistive Micromegas and small-strip Thin Gap Chambers. Both detector technologies will provide trigger and tracking primitives. The total number of trigger and readout channels is about 2.4 millions, and the overall power consumption is expected to be about 75 kW. The electronics design will be implemented in some 8000 front-end boards including the design of four custom front-end ASICs capable to drive trigger and tracking primitives with high speed sterilizers to drive trigger candidates to the backend trigger processor sy...

The effect of wheel eccentricity and run-out on grinding forces, waviness, wheel wear and chatter

OpenAIRE

O'DONNELL, GARRET; MURPHY, STUART

2011-01-01

PUBLISHED The effect of grinding-wheel eccentricity on grinding forces, wheel wear and final waviness height was studied. Eccentricity was evident in force oscillations and acceleration and audio measurements. A model was developed to predict final scallop-profile shape from grinding parameters and eccentricity. Recommendations are given on detecting eccentricity and determining when eccentricity is tolerable.

29 CFR 1915.134 - Abrasive wheels.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... wheels shall fit freely on the spindle and shall not be forced on. The spindle nut shall be tightened...

Miniature Reaction Wheel for Small Satellite Control, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The overall goal of this project is to design, develop, demonstrate, and deliver a miniature, high torque, low-vibration reaction wheel for use on small satellites....

The influence of friction coefficient and wheel/rail profiles on energy dissipation in the wheel/rail contact

NARCIS (Netherlands)

Idarraga Alarcon, G.A.; Burgelman, N.D.M.; Meza Meza, J.; Toro, A.; Li, Z.

2015-01-01

This work investigates the energy dissipation in a wheel/rail system through friction work modeling. In order to identify the effect of the friction coefficient on the energy dissipation in the wheel/rail contact, several simulations were performed using a 3D multibody model of a railway vehicle

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

Science.gov (United States)

2010-10-01

... 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, including... monorail systems operating primarily on dedicated rail (i.e., not used by freight trains) or guideway, in...

Noise in the passenger cars of high-speed trains.

Science.gov (United States)

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

2015-12-01

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

High Speed Rail (HSR) in the United States

Science.gov (United States)

2009-12-08

announced that it will expand the capacity on its aging high speed line between Tokyo and Osaka, the most heavily traveled intercity rail segment in the...United States, in most of these countries intercity rail travel (including both conventional and high speed rail) represents less than 10% of all...that is sometimes mentioned by its advocates. Intercity passenger rail transport is relatively safe, at least compared with highway travel . And HSR in

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....

Modeling of the motion of automobile elastic wheel in real-time for creation of wheeled vehicles motion control electronic systems

Science.gov (United States)

Balakina, E. V.; Zotov, N. M.; Fedin, A. P.

2018-02-01

Modeling of the motion of the elastic wheel of the vehicle in real-time is used in the tasks of constructing different models in the creation of wheeled vehicles motion control electronic systems, in the creation of automobile stand-simulators etc. The accuracy and the reliability of simulation of the parameters of the wheel motion in real-time when rolling with a slip within the given road conditions are determined not only by the choice of the model, but also by the inaccuracy and instability of the numerical calculation. It is established that the inaccuracy and instability of the calculation depend on the size of the step of integration and the numerical method being used. The analysis of these inaccuracy and instability when wheel rolling with a slip was made and recommendations for reducing them were developed. It is established that the total allowable range of steps of integration is 0.001.0.005 s; the strongest instability is manifested in the calculation of the angular and linear accelerations of the wheel; the weakest instability is manifested in the calculation of the translational velocity of the wheel and moving of the center of the wheel; the instability is less at large values of slip angle and on more slippery surfaces. A new method of the average acceleration is suggested, which allows to significantly reduce (up to 100%) the manifesting of instability of the solution in the calculation of all parameters of motion of the elastic wheel for different braking conditions and for the entire range of steps of integration. The results of research can be applied to the selection of control algorithms in vehicles motion control electronic systems and in the testing stand-simulators

Altered fibre types in gastrocnemius muscle of high wheel-running selected mice with mini-muscle phenotypes.

Science.gov (United States)

Guderley, Helga; Joanisse, Denis R; Mokas, Sophie; Bilodeau, Geneviève M; Garland, Theodore

2008-03-01

Selective breeding of mice for high voluntary wheel running has favoured characteristics that facilitate sustained, aerobically supported activity, including a "mini-muscle" phenotype with markedly reduced hind limb muscle mass, increased mass-specific activities of oxidative enzymes, decreased % myosin heavy chain IIb, and, in the medial gastrocnemius, reduced twitch speed, reduced mass-specific isotonic power, and increased fatigue resistance. To evaluate whether selection has altered fibre type expression in mice with either "mini" or normal muscle phenotypes, we examined fibre types of red and white gastrocnemius. In both the medial and lateral gastrocnemius, the mini-phenotype increased activities of oxidative enzymes and decreased activities of glycolytic enzymes. In red muscle samples, the mini-phenotype markedly changed fibre types, with the % type I and type IIA fibres and the surface area of type IIA fibres increasing; in addition, mice from selected lines in general had an increased % type IIA fibres and larger type I fibres as compared with mice from control lines. White muscle samples from mini-mice showed dramatic structural alterations, with an atypical distribution of extremely small, unidentifiable fibres surrounded by larger, more oxidative fibres than normally present in white muscle. The increased proportion of oxidative fibres and these atypical small fibres together may explain the reduced mass and increased mitochondrial enzyme activities in mini-muscles. These and previous results demonstrate that extension of selective breeding beyond the time when the response of the selected trait (i.e. distance run) has levelled off can still modify the mechanistic underpinnings of this behaviour.

DC Brushless Motor Control Design and Preliminary Testing for Independent 4-Wheel Drive Rev-11 Robotic Platform

Directory of Open Access Journals (Sweden)

Roni Permana Saputra

2012-03-01

Full Text Available This paper discusses the design of control system for brushless DC motor using microcontroller ATMega 16 that will be applied to an independent 4-wheel drive Mobile Robot LIPI version 2 (REV-11. The control system consists of two parts which are brushless DC motor control module and supervisory control module that coordinates the desired command to the motor control module. To control the REV-11 platform, supervisory control transmit the reference data of speed and direction of motor to control the speed and direction of each actuator on the platform REV-11. From the test results it is concluded that the designed control system work properly to coordinate and control the speed and direction of motion of the actuator motor REV-11 platform. 

High-speed parallel counter

International Nuclear Information System (INIS)

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

1985-01-01

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

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

Directory of Open Access Journals (Sweden)

Runxiao Wang

2016-01-01

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

The colour wheels of art, perception, science and physiology

Science.gov (United States)

Harkness, Nick

2006-06-01

Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

High speed rotary drum

Energy Technology Data Exchange (ETDEWEB)

Sagara, H

1970-03-25

A high speed rotary drum is disclosed in which the rotor vessel is a double-wall structure comprising an inner wave-shaped pipe inserted coaxially within an outer straight pipe, the object being to provide a strengthened composite light-weight structure. Since force induced axial deformation of the straight pipe and radial deformation of the corrugated pipe are small, the composite effectively resists external forces and, if the waves of the inner pipe are given a sufficient amplitude, the thickness of both pipes may be reduced to lower the overall weight. Thus high angular velocities can be obtained to separate U/sup 235/ from gaseous UF/sub 6/.

Coronal holes and high-speed wind streams

International Nuclear Information System (INIS)

Zirker, J.B.

1977-01-01

Coronal holes low have been identified as Bartel's M regions, i.e., sources of high-speed wind streams that produce recurrent geomagnetic variations. Throughout the Skylab period the polar caps of the Sun were coronal holes, and at lower latitudes the most persistent and recurrent holes were equatorial extensions of the polar caps. The holes rotated 'rigidly' at the equatorial synodic rate. They formed in regions of unipolar photospheric magnetic field, and their internal magnetic fields diverged rapidly with increasing distance from the sun. The geometry of the magnetic field in the inner corona seems to control both the physical properties of the holes and the global distribution of high-speed wind streams in the heliosphere. The latitude variation of the divergence of the coronal magnetic field lines produces corresponding variations in wind speed.During the years of declining solar activity the global field of the corona approximates a perturbed dipole. The divergence of field lines in each hemisphere produces a high-speed wind near the poles and low-speed wind in a narrow belt that coincides with the magnetic neutral sheet. The analysis of electron density measurements within a polar hole indicates that solar wind is accelerated principally in the region between 2 and 5 R/sub s/ and that mechanical wave pressure (possibly Alfven wave) may be responsible for the accleration of the wind. Phenomenological models for the birth and decay of coronal holes have been proposed. Attempts to explain the birth and rigid rotation of holes through dynamo action have been only partially successful. The 11-year variation of cosmic ray intensities at the earth may result from cyclic variation of open field regions associated with coronal holes

Characterizing Wheel-Soil Interaction Loads Using Meshfree Finite Element Methods: A Sensitivity Analysis for Design Trade Studies

Science.gov (United States)

Contreras, Michael T.; Trease, Brian P.; Bojanowski, Cezary; Kulakx, Ronald F.

2013-01-01

A wheel experiencing sinkage and slippage events poses a high risk to planetary rover missions as evidenced by the mobility challenges endured by the Mars Exploration Rover (MER) project. Current wheel design practice utilizes loads derived from a series of events in the life cycle of the rover which do not include (1) failure metrics related to wheel sinkage and slippage and (2) performance trade-offs based on grouser placement/orientation. Wheel designs are rigorously tested experimentally through a variety of drive scenarios and simulated soil environments; however, a robust simulation capability is still in development due to myriad of complex interaction phenomena that contribute to wheel sinkage and slippage conditions such as soil composition, large deformation soil behavior, wheel geometry, nonlinear contact forces, terrain irregularity, etc. For the purposes of modeling wheel sinkage and slippage at an engineering scale, meshfree nite element approaches enable simulations that capture su cient detail of wheel-soil interaction while remaining computationally feasible. This study implements the JPL wheel-soil benchmark problem in the commercial code environment utilizing the large deformation modeling capability of Smooth Particle Hydrodynamics (SPH) meshfree methods. The nominal, benchmark wheel-soil interaction model that produces numerically stable and physically realistic results is presented and simulations are shown for both wheel traverse and wheel sinkage cases. A sensitivity analysis developing the capability and framework for future ight applications is conducted to illustrate the importance of perturbations to critical material properties and parameters. Implementation of the proposed soil-wheel interaction simulation capability and associated sensitivity framework has the potential to reduce experimentation cost and improve the early stage wheel design proce

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

Networked Control System for the Guidance of a Four-Wheel Steering Agricultural Robotic Platform

Directory of Open Access Journals (Sweden)

Eduardo Paciência Godoy

2012-01-01

Full Text Available A current trend in the agricultural area is the development of mobile robots and autonomous vehicles for precision agriculture (PA. One of the major challenges in the design of these robots is the development of the electronic architecture for the control of the devices. In a joint project among research institutions and a private company in Brazil a multifunctional robotic platform for information acquisition in PA is being designed. This platform has as main characteristics four-wheel propulsion and independent steering, adjustable width, span of 1,80 m in height, diesel engine, hydraulic system, and a CAN-based networked control system (NCS. This paper presents a NCS solution for the platform guidance by the four-wheel hydraulic steering distributed control. The control strategy, centered on the robot manipulators control theory, is based on the difference between the desired and actual position and considering the angular speed of the wheels. The results demonstrate that the NCS was simple and efficient, providing suitable steering performance for the platform guidance. Even though the simplicity of the NCS solution developed, it also overcame some verified control challenges in the robot guidance system design such as the hydraulic system delay, nonlinearities in the steering actuators, and inertia in the steering system due the friction of different terrains.

Study on the Attitude Control of Spacecraft Using Reaction Wheels

Directory of Open Access Journals (Sweden)

Ju-Young Du

1998-06-01

Full Text Available Attitude determination and control of satellite is important component which determines the accomplish satellite missions. In this study, attitude control using reaction wheels and momentum dumping of wheels are considered. Attitude control law is designed by Sliding control and LQR. Attitude maneuver control law is obtained by Shooting method. Wheels momentum dumping control law is designed by Bang-Bang control. Four reaction wheels are configurated for minimized the electric power consumption. Wheels control torque and magnetic moment of magnetic torquer are limited.

High-speed motion neutron radiography

International Nuclear Information System (INIS)

Bossi, R.H.; Barton, J.P.; Robinson, A.H.

1982-01-01

A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames. Synchronization has provided high-speed motion neutron radiographs for evaluation of the firing cycles of 7.62-mm munition rounds within a thick steel rifle barrel. The system has also been used to demonstrate its ability to produce neutron radiographic movies of two-phase flow. The equipment includes a TRIGA reactor capable of pulsing to a peak power of 3000 MW, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16-mm high-speed movie camera. The peak neutron flux incident at the object position is about 4 X 10 11 n/cm 2 X s with a pulse, full-width at half-maximum, of 9 ms. Modulation transfer function techniques have been used to assist optimization of the system performance. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on information availability

Effects of genetic background and environmental novelty on wheel running as a rewarding behaviour in mice.

Science.gov (United States)

de Visser, Leonie; van den Bos, Ruud; Stoker, Astrid K; Kas, Martien J H; Spruijt, Berry M

2007-02-27

Recent studies suggest running wheel activity to be naturally rewarding and reinforcing; considering the shared neuro-behavioural characteristics with drug-induced reward situations, wheel running behaviour gains interest as a tool to study mechanisms underlying reward-sensitivity. Previously, we showed that wheel running has the potential to disrupt the daily organization of home cage behaviour in female C57BL/6 [de Visser L, van den Bos R, Spruijt BM. Automated home cage observations as a tool to measure the effects of wheel running on cage floor locomotion. Behav Brain Res 2005;160:382-8]. In the present study, we investigated the effects of novelty-induced stress on wheel running and its impact on home cage behaviour in male C57BL/6 and DBA/2 mice. Our aim was to determine whether wheel running may be used as a tool to study both genetic and environmentally induced differences in sensitivity to rewarding behaviour in mice. One group of male mice was placed in an automated home cage observation system for 2 weeks with a wheel integrated in the cage. A second group of mice was allowed to habituate to this cage for 1 week before a running wheel was introduced. Results showed a pronounced sensitising effect of novelty on the level of wheel running in C57Bl/6 mice but not in DBA mice. Overall levels of wheel running were higher in DBA/2 mice. Furthermore, wheel running affected circadian rhythmicity in DBA/2 mice but not in C57BL/6 mice. From these findings we tentatively suggest that wheel running behaviour could serve as a tool to study the interaction between genetic and environmental factors in sensitivity to rewarding behaviour in mice. As it is displayed spontaneously and easy to monitor, wheel running may be well suitable to be included in high-throughput phenotyping assays.

Development and evaluation of a gyroscope-based wheel rotation monitor for manual wheelchair users.

Science.gov (United States)

Hiremath, Shivayogi V; Ding, Dan; Cooper, Rory A

2013-07-01

To develop and evaluate a wireless gyroscope-based wheel rotation monitor (G-WRM) that can estimate speeds and distances traveled by wheelchair users during regular wheelchair propulsion as well as wheelchair sports such as handcycling, and provide users with real-time feedback through a smartphone application. The speeds and the distances estimated by the G-WRM were compared with the criterion measures by calculating absolute difference, mean difference, and percentage errors during a series of laboratory-based tests. Intraclass correlations (ICC) and the Bland-Altman plots were also used to assess the agreements between the G-WRM and the criterion measures. In addition, battery life and wireless data transmission tests under a number of usage conditions were performed. The percentage errors for the angular velocities, speeds, and distances obtained from three prototype G-WRMs were less than 3% for all the test trials. The high ICC values (ICC (3,1) > 0.94) and the Bland-Altman plots indicate excellent agreement between the estimated speeds and distances by the G-WRMs and the criterion measures. The battery life tests showed that the device could last for 35 hours in wireless mode and 139 hours in secure digital card mode. The wireless data transmission tests indicated less than 0.3% of data loss. The results indicate that the G-WRM is an appropriate tool for tracking a spectrum of wheelchair-related activities from regular wheelchair propulsion to wheelchair sports such as handcycling. The real-time feedback provided by the G-WRM can help wheelchair users self-monitor their everyday activities.

A High-Speed Train Operation Plan Inspection Simulation Model

Directory of Open Access Journals (Sweden)

Yang Rui

2018-01-01

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

High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing.

Science.gov (United States)

Kuang, Xiao; Zhao, Zeang; Chen, Kaijuan; Fang, Daining; Kang, Guozheng; Qi, Hang Jerry

2018-04-01

Design and direct fabrication of high-performance thermosets and composites via 3D printing are highly desirable in engineering applications. Most 3D printed thermosetting polymers to date suffer from poor mechanical properties and low printing speed. Here, a novel ink for high-speed 3D printing of high-performance epoxy thermosets via a two-stage curing approach is presented. The ink containing photocurable resin and thermally curable epoxy resin is used for the digital light processing (DLP) 3D printing. After printing, the part is thermally cured at elevated temperature to yield an interpenetrating polymer network epoxy composite, whose mechanical properties are comparable to engineering epoxy. The printing speed is accelerated by the continuous liquid interface production assisted DLP 3D printing method, achieving a printing speed as high as 216 mm h -1 . It is also demonstrated that 3D printing structural electronics can be achieved by combining the 3D printed epoxy composites with infilled silver ink in the hollow channels. The new 3D printing method via two-stage curing combines the attributes of outstanding printing speed, high resolution, low volume shrinkage, and excellent mechanical properties, and provides a new avenue to fabricate 3D thermosetting composites with excellent mechanical properties and high efficiency toward high-performance and functional applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-speed imaging of blood splatter patterns

Energy Technology Data Exchange (ETDEWEB)

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

1993-01-01

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

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.

The Fatigue Life Prediction of Train Wheel Rims Containing Spherical Inclusions

Science.gov (United States)

Li, Yajie; Chen, Huanguo; Cai, Li; Chen, Pei; Qian, Jiacheng; Wu, Jianwei

2018-03-01

It is a common phenomenon that fatigue crack initiation occurs frequently in the inclusions of wheel rims. Research on the fatigue life of wheel rims with spherical inclusions is of great significance on the reliability of wheels. To find the danger point and working condition of a wheel, the stress state of the wheel rim with spherical inclusions was analyzed using the finite element method. Results revealed that curve conditions are dangerous. The critical plane method, based on the cumulative fatigue damage theory, was used to predict the fatigue life of the wheel rim and whether it contained spherical inclusions or not under curve conditions. It was found that the fatigue life of the wheel rim is significantly shorter when the wheel rim contains spherical inclusions. Analysis of the results can provide a theoretical basis and technical support for train operations and maintenance.

Low-cost real-time automatic wheel classification system

Science.gov (United States)

Shabestari, Behrouz N.; Miller, John W. V.; Wedding, Victoria

1992-11-01

This paper describes the design and implementation of a low-cost machine vision system for identifying various types of automotive wheels which are manufactured in several styles and sizes. In this application, a variety of wheels travel on a conveyor in random order through a number of processing steps. One of these processes requires the identification of the wheel type which was performed manually by an operator. A vision system was designed to provide the required identification. The system consisted of an annular illumination source, a CCD TV camera, frame grabber, and 386-compatible computer. Statistical pattern recognition techniques were used to provide robust classification as well as a simple means for adding new wheel designs to the system. Maintenance of the system can be performed by plant personnel with minimal training. The basic steps for identification include image acquisition, segmentation of the regions of interest, extraction of selected features, and classification. The vision system has been installed in a plant and has proven to be extremely effective. The system properly identifies the wheels correctly up to 30 wheels per minute regardless of rotational orientation in the camera's field of view. Correct classification can even be achieved if a portion of the wheel is blocked off from the camera. Significant cost savings have been achieved by a reduction in scrap associated with incorrect manual classification as well as a reduction of labor in a tedious task.

OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

Directory of Open Access Journals (Sweden)

Soňa Benešová

2013-09-01

Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

Directory of Open Access Journals (Sweden)

Sona Benesova

2013-05-01

Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

High performance multi-channel high-speed I/O circuits

CERN Document Server

Oh, Taehyoun

2013-01-01

This book describes design techniques that can be used to mitigate crosstalk in high-speed I/O circuits. The focus of the book is in developing compact and low power integrated circuits for crosstalk cancellation, inter-symbol interference (ISI) mitigation and improved bit error rates (BER) at higher speeds. This book is one of the first to discuss in detail the problem of crosstalk and ISI mitigation encountered as data rates have continued beyond 10Gb/s. Readers will learn to avoid the data performance cliff, with circuits and design techniques described for novel, low power crosstalk cancel

High-speed photography of light beams transmitted through pinhole targets

International Nuclear Information System (INIS)

Yaonan, D.; Haien, He.; Lian, C.; Huifang, Z.; Zhijian, Z.

1988-01-01

A method of high speed photography is presented. It was designed and performed in order to study temporal behaviors of plasma closure effects of pinhole targets in laser plasma experiments. A series of high speed photographs were taken for the laser beam transmitted through the pinhole targets. Spatially resolved and integrated temporal histories of closure effects were observed, respectively. Some physical information about closure effect and closure speed have been studied

Analysis of wheel rim - Material and manufacturing aspects

Science.gov (United States)

Misra, Sheelam; Singh, Abhiraaj; James, Eldhose

2018-05-01

The tire in an automobile is supported by the rim of the wheel and its shape and dimensions should be adjusted to accommodate a specified tire. In this study, a tire of car wheel rim belonging to the disc wheel category is considered. Design is an important industrial operation used to define and specify the quality of the product. The design and modelling reduces the risk of damage involved in the manufacturing process. The design performed on this wheel rim is done on modelling software. After designing the model, it is imported for analysis purposes. The analysis software is used to calculate the different types of force, stresses, torque, and pressures acting upon the rim of the wheel and it reduces the time spent by a human for mathematical calculations. The analysis carried out considers two different materials namely structural steel and aluminium. Both materials are analyzed and their performance is noted.

A high sensitivity 20Mfps CMOS image sensor with readout speed of 1Tpixel/sec for visualization of ultra-high speed phenomena

Science.gov (United States)

Kuroda, R.; Sugawa, S.

2017-02-01

Ultra-high speed (UHS) CMOS image sensors with on-chop analog memories placed on the periphery of pixel array for the visualization of UHS phenomena are overviewed in this paper. The developed UHS CMOS image sensors consist of 400H×256V pixels and 128 memories/pixel, and the readout speed of 1Tpixel/sec is obtained, leading to 10 Mfps full resolution video capturing with consecutive 128 frames, and 20 Mfps half resolution video capturing with consecutive 256 frames. The first development model has been employed in the high speed video camera and put in practical use in 2012. By the development of dedicated process technologies, photosensitivity improvement and power consumption reduction were simultaneously achieved, and the performance improved version has been utilized in the commercialized high-speed video camera since 2015 that offers 10 Mfps with ISO16,000 photosensitivity. Due to the improved photosensitivity, clear images can be captured and analyzed even under low light condition, such as under a microscope as well as capturing of UHS light emission phenomena.

Blocking of conditioned taste avoidance induced by wheel running.

Science.gov (United States)

Pierce, W David; Heth, C Donald

2010-01-01

In Experiment 1, compared to non-reinforced presentation of a food stimulus (A-->no US), the association of a food stimulus with wheel running (A-->US) blocked subsequent avoidance of a distinctive flavor (X), when both the food and flavor were followed by wheel running (AX-->US). Experiment 2 replicated and extended the blocking effect, demonstrating that the amount of avoidance of X after AX-->wheel training depended on the correlation between A-alone trials and wheel running-the predictiveness of the A stimulus. The present study is the first to demonstrate associative blocking of conditioned taste avoidance (CTA) induced by wheel running and strongly implicates associative learning as the basis for this kind of avoidance. 2009 Elsevier B.V. All rights reserved.

The Running Wheel Enhances Food Anticipatory Activity: An Exploratory Study.

Science.gov (United States)

Flôres, Danilo E F L; Bettilyon, Crystal N; Jia, Lori; Yamazaki, Shin

2016-01-01

Rodents anticipate rewarding stimuli such as daily meals, mates, and stimulant drugs. When a single meal is provided daily at a fixed time of day, an increase in activity, known as food anticipatory activity (FAA), occurs several hours before feeding time. The factors affecting the expression of FAA have not been well-studied. Understanding these factors may provide clues to the undiscovered anatomical substrates of food entrainment. In this study we determined whether wheel-running activity, which is also rewarding to rodents, modulated the robustness of FAA. We found that access to a freely rotating wheel enhanced the robustness of FAA. This enhancement was lost when the wheel was removed. In addition, while prior exposure to a running wheel alone did not enhance FAA, the presence of a locked wheel did enhance FAA as long as mice had previously run in the wheel. Together, these data suggest that FAA, like wheel-running activity, is influenced by reward signaling.

Solidification at the High and Low Rate Extreme

Energy Technology Data Exchange (ETDEWEB)

Meco, Halim [Iowa State Univ., Ames, IA (United States)

2004-12-19

The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

Simulation of the ATLAS New Small Wheel Trigger Sysmtem

CERN Document Server

Saito, Tomoyuki; The ATLAS collaboration

2017-01-01

The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the original design value to explore higher energy scale. In order to benefit from the expected high luminosity performance, the first station of the ATLAS muon end-cap Small Wheel system will be replaced by a New Small Wheel (NSW) detector. The NSW provide precise track segment information to the muon Level-1 trigger to reduce fake triggers. This contribution will summarize a detail of the NSW trigger decision system, track reconstruction algorithm implemented into the trigger processor and results of performance studies on the trigger system.

Vibration characteristics of dental high-speed turbines and speed-increasing handpieces.

Science.gov (United States)

Poole, Ruth L; Lea, Simon C; Dyson, John E; Shortall, Adrian C C; Walmsley, A Damien

2008-07-01

Vibrations of dental handpieces may contribute to symptoms of hand-arm vibration syndrome in dental personnel and iatrogenic enamel cracking in teeth. However, methods for measuring dental handpiece vibrations have previously been limited and information about vibration characteristics is sparse. This preliminary study aimed to use a novel approach to assess the vibrations of unloaded high-speed handpieces in vitro. Maximum vibration displacement amplitudes of five air turbines and two speed-increasing handpieces were recorded whilst they were operated with and without a rotary cutting instrument (RCI) using a scanning laser vibrometer (SLV). RCI rotation speeds, calculated from frequency peaks, were consistent with expected values. ANOVA statistical analysis indicated significant differences in vibrations between handpiece models (p0.11). Operating handpieces with a RCI resulted in greater vibrations than with no RCI (pmeasurement exceeded 4 microm for the handpieces in the current test setup (implying that these vibrations may be unlikely to cause adverse effects), this study has formed the basis for future work which will include handpiece vibration measurements whilst cutting under clinically representative loads.

Liquid metal current collectors for high-speed rotating machinery

International Nuclear Information System (INIS)

Carr, S.L.

1976-01-01

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

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...

Development and application of resilient wheels in urban rail transit vehicle

Directory of Open Access Journals (Sweden)

Juan WEN

Full Text Available Urban rail transit vehicles have been more and more attractive to people as a kind of fast, comfortable, energy-saving, environmental protection and safe transportation. But because of the vehicle noise and vibration, urban rail vehicles also face severe challenges. The research of resilient wheels has been continuously developed and improved. Based on the review of development background and structure sorts of resilient wheels, the advantages of resilient wheels are described, and the research status of noise and vibration reducing, infinite element strength analysis, vehicle dynamic analysis and the wheel-rail wear of resilient wheels are discussed. Taking the low-floor LRVs (light rail vehicles in domestic and overseas as example, the development and application of the resilient wheels in city rail transit is described, and the application prospects of the resilient wheels in LRVs in domestic and the future research direction of elastic wheel are discussed.

MATHEMATICAL MODEL OF ATTITUDE CONTROL BUCKET‐WHEEL EXCAVATOR