Experimental research on a vibration isolation platform for momentum wheel assembly

NASA Astrophysics Data System (ADS)

Zhou, Weiyong; Li, Dongxu

2013-03-01

This paper focuses on experimental research on a vibration isolation platform for momentum wheel assembly (MWA). A vibration isolation platform, consisting of four folded beams, was designed to isolate the microvibrations produced by MWA during operation. The performance of the platform was investigated with an impact test to verify the natural frequencies and damping coefficients of the system when the MWA was at rest, and with a measurement system consisting of a Kistler table and an optical tabletop to monitor the microvibrations produced when the MWA operated at stable speed. The results show that although the sixth natural frequency of the system is 26.29 Hz (1577 rev/min) when the MWA is at rest, the critical speed occurs at 2600 rev/min due to the gyroscopic effect of the flywheel, and that the platform can effectively isolate the high frequency disturbances in the 100-300 Hz range in all six degrees of freedom. Thus, the gyroscopic effect force deserves more attention in the design and analysis of vibration isolation platform for rotating wheel assembly, and the platform in this paper is particularly effective for MWA, which generally operates at high rotating speed range.

Mechanical Design Engineering Enabler Project wheel and wheel drives

NASA Technical Reports Server (NTRS)

Nutt, Richard E.; Couch, Britt K.; Holley, John L., Jr.; Garris, Eric S.; Staut, Paul V.

1992-01-01

Our group was assigned the responsibility of designing the wheel and wheel drive system for a proof-of-concept model of the lunar-based ENABLER. ENABLER is a multi-purpose, six wheeled vehicle designed to lift and transport heavy objects associated with the construction of a lunar base. The resulting design was based on the performance criteria of the ENABLER. The drive system was designed to enable the vehicle to achieve a speed of 7 mph on a level surface, climb a 30 percent grade, and surpass a one meter high object and one meter wide crevice. The wheel assemblies were designed to support the entire weight of the vehicle on two wheels. The wheels were designed to serve as the main component of the vehicle's suspension and will provide suitable traction for lunar-type surfaces. The expected performance of the drive system for the ENABLER was influenced by many mechanical factors. The expected top speed on a level sandy surface is 4 mph instead of the desired 7 mph. This is due to a lack of necessary power at the wheels. The lack of power resulted from dimension considerations that allowed only an eight horsepower engine and also from mechanical inefficiencies of the hydraulic system. However, the vehicle will be able to climb a 30 percent grade, surpass a one meter high object and one meter wide crevice. The wheel assemblies will be able to support the entire weight of the vehicle on two wheels. The wheels will also provide adequate suspension for the vehicle and sufficient traction for lunar-type surfaces.

Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

NASA Astrophysics Data System (ADS)

Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

2013-10-01

The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

Interaction between a railway track and uniformly moving tandem wheels

NASA Astrophysics Data System (ADS)

Belotserkovskiy, P. M.

2006-12-01

Interaction among loaded wheels via railway track is studied. The vertical parametric oscillations of an infinite row of identical equally spaced wheels, bearing constant load and uniformly moving over a railway track, are calculated by means of Fourier series technique. If the distance between two consecutive wheels is big enough, then one can disregard their interaction via the railway track and consider every wheel as a single one. In this case, however, the Fourier series technique represents an appropriate computation time-saving approximation to a Fourier integral transformation technique that describes the oscillations of a single moving wheel. Two schemes are considered. In the first scheme, every wheel bears the same load. In the second one, consecutive wheels bear contrarily directed loads of the same magnitude. The second scheme leads to simpler calculations and so is recommended to model the wheel-track interaction. The railway track periodicity due to sleeper spacing is taken into account. Each period is the track segment between two adjacent sleepers. A partial differential equation with constant coefficients governs the vertical oscillations of each segment. Boundary conditions bind the oscillations of two neighbour segments and provide periodicity to the track. The shear deformation in the rail cross-section strongly influences the parametric oscillations. It also causes discontinuity of the rail centre-line slope at any point, where a concentrated transverse force is applied. Therefore, Timoshenko beam properties with respect to the topic of this paper are discussed. Interaction between a railway track and a bogie moving at moderate speed is studied. The study points to influence of the bogie frame oscillations on variation in the wheel-rail contact force over the sleeper span. The simplified bogie model considered includes only the primary suspension. A static load applied to the bogie frame centre presents the vehicle body.

Rim seal for turbine wheel

DOEpatents

Glezer, Boris; Boyd, Gary L.; Norton, Paul F.

1996-01-01

A turbine wheel assembly includes a disk having a plurality of blades therearound. A ceramic ring is mounted to the housing of the turbine wheel assembly. A labyrinth rim seal mounted on the disk cooperates with the ceramic ring to seal the hot gases acting on the blades from the disk. The ceramic ring permits a tighter clearance between the labyrinth rim seal and the ceramic ring.

Bifurcations of the Self-Exciting Oscillations of a Wheeled Assembly About Straight-Line Motion

NASA Astrophysics Data System (ADS)

Vel'magina, N. A.

2013-11-01

The effect of characteristic parameters of a system describing a wheeled assembly on the oscillatory-instability domain is analyzed. The influence of the accuracy of approximation of the lateral force and the heeling moment on the behavior of self-exciting oscillations is examined. A bifurcation set that divides the plane of parameters into domains with different number of limit cycles is constructed

Tire/wheel concept

NASA Technical Reports Server (NTRS)

Harper, P. M., Sr. (Inventor)

1981-01-01

A tire and wheel assembly is disclosed in which a low profile pneumatic tire (having sidewalls which deflect inwardly under load) and a wheel (having a rim featuring a narrow central channel and extended rim flanges) form the combination. The extended rim flanges support the tire sidewalls under static and dynamic loading conditions to produce a combination particularly suited to aircraft applications.

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

PubMed

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.

Blade attachment assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, andmore » retains the blade in the adaptor member, and the assembly in the rotor wheel.« less

An improved genome assembly uncovers prolific tandem repeats in Atlantic cod.

PubMed

Tørresen, Ole K; Star, Bastiaan; Jentoft, Sissel; Reinar, William B; Grove, Harald; Miller, Jason R; Walenz, Brian P; Knight, James; Ekholm, Jenny M; Peluso, Paul; Edvardsen, Rolf B; Tooming-Klunderud, Ave; Skage, Morten; Lien, Sigbjørn; Jakobsen, Kjetill S; Nederbragt, Alexander J

2017-01-18

The first Atlantic cod (Gadus morhua) genome assembly published in 2011 was one of the early genome assemblies exclusively based on high-throughput 454 pyrosequencing. Since then, rapid advances in sequencing technologies have led to a multitude of assemblies generated for complex genomes, although many of these are of a fragmented nature with a significant fraction of bases in gaps. The development of long-read sequencing and improved software now enable the generation of more contiguous genome assemblies. By combining data from Illumina, 454 and the longer PacBio sequencing technologies, as well as integrating the results of multiple assembly programs, we have created a substantially improved version of the Atlantic cod genome assembly. The sequence contiguity of this assembly is increased fifty-fold and the proportion of gap-bases has been reduced fifteen-fold. Compared to other vertebrates, the assembly contains an unusual high density of tandem repeats (TRs). Indeed, retrospective analyses reveal that gaps in the first genome assembly were largely associated with these TRs. We show that 21% of the TRs across the assembly, 19% in the promoter regions and 12% in the coding sequences are heterozygous in the sequenced individual. The inclusion of PacBio reads combined with the use of multiple assembly programs drastically improved the Atlantic cod genome assembly by successfully resolving long TRs. The high frequency of heterozygous TRs within or in the vicinity of genes in the genome indicate a considerable standing genomic variation in Atlantic cod populations, which is likely of evolutionary importance.

NICMOS Filter Wheel Test

NASA Astrophysics Data System (ADS)

Malhotra, Sangeeta

2003-07-01

This is an engineering test to verify the aliveness, functionality, operability, and electro-mechanical calibration of the NICMOS filter wheel motors and assembly after NCS restart in August 2003. This test has been designed to obviate concerns over possible deformation or breakage of the fitter wheel "soda-straw" shafts due to excess rotational drag torque and/or bending moments which may be imparted due to changes in the dewar metrology from warm-up/cool-down. This test should be executed after the NCS {and filter wheel housing} has reached and approximately equilibrated to its nominal Cycle 11 operating temperature.

Orbiter wheel and tire certification

NASA Technical Reports Server (NTRS)

Campbell, C. C., Jr.

1985-01-01

The orbiter wheel and tire development has required a unique series of certification tests to demonstrate the ability of the hardware to meet severe performance requirements. Early tests of the main landing gear wheel using conventional slow roll testing resulted in hardware failures. This resulted in a need to conduct high velocity tests with crosswind effects for assurance that the hardware was safe for a limited number of flights. Currently, this approach and the conventional slow roll and static tests are used to certify the wheel/tire assembly for operational use.

Air actuated clutch for four wheel drive vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clohessy, K.E.

1986-12-09

A control system is described for selectively engaging and disengaging a vehicle wheel and a vehicle drive mechanism comprising; a spindle having inside and outside rotative support surfaces, the spindle adapted to be mounted to a vehicle frame, an axle portion rotatably supported on the inside support surface, and drive means for selectively and rotatively driving the axle portion relative to the spindle; a wheel hub assembly adapted to carry a vehicle wheel, the hub assembly rotatively supported on the outside support surface of the spindle; a sealed expansion chamber defined in part by the spindle, the axle portion, themore » hub assembly and a movable wall carried by the hub assembly, venting means venting the outer side of the movable wall to atmospheric pressure, the clutch ring engaged by the movable wall for movement of the clutch ring with movement of the movable wall as induced by a pressure difference generated within the chamber, and pressurizing means for selectively pressurizing and depressurizing the expansion chamber to thereby selectively shift the clutch ring between the positions of interlocking the axle portion and hub assembly and unlocking the axle portion and hub assembly.« less

75 FR 56991 - Grant of Authority for Subzone Status Michelin North America, Inc. (Tire Distribution and Wheel...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-17

... Status Michelin North America, Inc. (Tire Distribution and Wheel Assembly) Baltimore, MD Pursuant to its... warehouse/distribution and wheel assembly facility of Michelin North America, Inc., located in Elkton, MD... tire accessories warehousing and distribution and wheel assembly at the facility of Michelin North...

Development Tests of a Cryogenic Filter Wheel Assembly for the NIRCam Instrument

NASA Technical Reports Server (NTRS)

McCully, Sean; Clark, Charles; Schermerhorn, Michael; Trojanek, Filip; O'Hara, Mark; Williams, Jeff; Thatcher, John

2006-01-01

The James Webb Space Telescope is an infrared-optimized space telescope scheduled for launch in 201 3. Its 6.5-m diameter primary mirror will collect light from some of the first galaxies formed after the big bang. The Near Infrared camera (NIRCam) will detect the first light from these galaxies, provide the necessary tools for studying the formation of stars, aid in discovering planets around other stars, and adjust the wave front error on the primary mirror (Fig. 1). The instrument and its complement of mechanisms and optics will operate at a cryogenic temperature of 35 K. This paper describes tests and test results of the NIRCam Filter Wheel assembly prototype.

Multi-component lightweight gearwheels with deep-drawn wheel body for automotive applications

NASA Astrophysics Data System (ADS)

Benkert, Tim; Hiller, Maria; Volk, Wolfram

2017-09-01

Multi-component gearwheels offer great lightweight opportunities for automotive applications. An assembly of a gear ring and a wheel body joined by press fit replaces the monolithic gearwheel. To save weight, the wheel body uses lightweight design. This lightweight design influences the assembled gearwheel’s mechanical properties like stiffness, weight and torque capacity. Further, the wheel body material influences the mentioned properties as well. In this paper, the effects of the lightweight wheel body manufactured by deep-drawing on the mechanical properties of the assembled gearwheel are investigated. Three different wheel body designs are examined regarding their stiffness and weight compared to a reference gearwheel. Using the best design, the influence of five materials with increasing yield strength on the maximum torque the gearwheel can transmit is studied. All research is done virtually using Abaqus 6.12-3.

Development of a vehicle-track model assembly and numerical method for simulation of wheel-rail dynamic interaction due to unsupported sleepers

NASA Astrophysics Data System (ADS)

Zhu, Jian Jun; Ahmed, A. K. W.; Rakheja, Subhash; Khajepour, Amir

2010-12-01

In practice, it is not very uncommon to find railway track systems with unsupported sleepers due to the uneven settlement of a ballasted track system. These unsupported sleepers are among the major vibration excitations for a train and track system when a train moves forwards on a track. The vibration induced by unsupported sleepers can cause a large dynamic contact force between wheels and rails. For heavily loaded high-speed trains, the deteriorated sleeper support may lead to accelerated degradation of the railway track and vehicle components, and may thus impose safety risk to the operation. This paper presents analyses of a coupled vehicle-track assembly consisting of a roll plane vehicle model, a continuous track system model and an adaptive wheel-rail contact model. In order to improve the simulation efficiency, a numerical approach based on the central finite difference method is proposed in this investigation. The developed model assembly and proposed simulation method are utilised to simulate the vehicle-track dynamic interaction in the presence of unsupported sleepers. The dynamic response in terms of the dynamic wheel-rail interaction force due to one or multiple unsupported sleepers is studied. Important factors influencing the dynamic wheel-rail interaction force in the presence of sleeper voids are also investigated. The results show that the vehicle speed, the gap size and the number of unsupported sleepers primarily dictate the magnitude of impact load which can be significant.

Propulsion Wheel Motor for an Electric Vehicle

NASA Technical Reports Server (NTRS)

Herrera, Eduardo (Inventor); Farrell, Logan Christopher (Inventor); Guo, Raymond (Inventor); Junkin, Lucien Q. (Inventor); Bluethmann, William J. (Inventor); Vitale, Robert L. (Inventor); Weber, Steven J. (Inventor); Lee, Chunhao J. (Inventor); Eggleston, IV, Raymond Edward (Inventor); Figuered, Joshua M. (Inventor);

Multi-Spoked Wheel Assembly

NASA Technical Reports Server (NTRS)

Greer, Lawrence (Inventor); Krasowski, Michael (Inventor)

2017-01-01

A robust ground traction (drive) assembly for remotely controlled vehicles, which not only operates smoothly on surfaces that are flat, but also upon surfaces that include rugged terrain, snow, mud, and sand, is provided. The assembly includes a sun gear and a braking gear. The sun gear is configured to cause rotational force to be applied to second planetary gears through a coupling of first planetary gears. The braking gear is configured to cause the assembly (or the second planetary gears) to rotate around the braking gear when an obstacle or braking force is applied.

Lateral ring metal elastic wheel absorbs shock loading

NASA Technical Reports Server (NTRS)

Galan, L.

1966-01-01

Lateral ring metal elastic wheel absorbs practically all shock loading when operated over extremely rough terrain and delivers only a negligible shock residue to associated suspension components. The wheel consists of a rigid aluminum assembly to which lateral titanium ring flexible elements with treads are attached.

All solution-processed lead halide perovskite-BiVO4 tandem assembly for photolytic solar fuels production.

PubMed

Chen, Yong-Siou; Manser, Joseph S; Kamat, Prashant V

2015-01-21

The quest for economic, large-scale hydrogen production has motivated the search for new materials and device designs capable of splitting water using only energy from the sun. Here we introduce an all solution-processed tandem water splitting assembly composed of a BiVO4 photoanode and a single-junction CH3NH3PbI3 hybrid perovskite solar cell. This unique configuration allows efficient solar photon management, with the metal oxide photoanode selectively harvesting high energy visible photons, and the underlying perovskite solar cell capturing lower energy visible-near IR wavelengths in a single-pass excitation. Operating without external bias under standard AM 1.5G illumination, the photoanode-photovoltaic architecture, in conjunction with an earth-abundant cobalt phosphate catalyst, exhibits a solar-to-hydrogen conversion efficiency of 2.5% at neutral pH. The design of low-cost tandem water splitting assemblies employing single-junction hybrid perovskite materials establishes a potentially promising new frontier for solar water splitting research.

Assembly, Thermodynamics, and Structure of a Two-Wheeled Composite of a Dumbbell-Shaped Molecule and Cylindrical Molecules with Different Edges.

PubMed

Matsuno, Taisuke; Kamata, Sho; Sato, Sota; Yokoyama, Atsutoshi; Sarkar, Parantap; Isobe, Hiroyuki

2017-11-20

A carbonaceous dumbbell was able to spontaneously glue two tubular receptors to form a unique two-wheeled composite through van der Waals interactions, thus forcing the wheel components into contact with each other at the edges. In the present study, two tubular receptors with enantiomeric carbon networks were assembled on the dumbbell joint, and the handedness of the receptors was discriminated, thus leading to the self-sorting of homomeric receptors from a mixture of enantiomeric tubes. The crystal structures of the composites revealed the structural origins of the molecular recognition driven by van der Waals forces as well as the presence of a columnar array of C 120 molecules in a 1:1 composite. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A versatile 50 ft-lb-sec reaction wheel for TRMM and XTE missions

NASA Astrophysics Data System (ADS)

Bialke, Bill

A 50 ft-lb-sec Reaction Wheel is being manufactured by ITHACO, Inc. for NASA's X-ray Timing Explorer (XTE) and Tropical Rainfall Measuring Mission (TRMM) missions, using the same mechanical assemblies as a similar Reaction Wheel developed by ITHACO for the Air Force's Advanced Research and Global Observation Satellite (ARGOS) (P91-1) mission. The versatile design allows variation in motor torque and speed capability with no mechanical modifications. State of the art ball bearing technology is combined with flight proven materials and conventional fabrication techniques to produce a relaible and manufacturable wheel assembly. An ironless armature brushless DC motor is incorporated for high efficiency and minimum weight. Comprehensive tradeoff analyses from the Reaction Wheel development are discussed for each component, and performance characteristics are presented for design variations from a high torque Reaction Wheel used in a three axis stabilized spacecraft to a low torque Momentum Wheel used in a momentum biased attitude Control System.

Crack detection in a wheel end spindle using wave propagation via modal impacts and piezo actuation

NASA Astrophysics Data System (ADS)

Ackers, Spencer; Evans, Ronald; Johnson, Timothy; Kess, Harold; White, Jonathan; Adams, Douglas E.; Brown, Pam

2006-03-01

This research demonstrates two methodologies for detecting cracks in a metal spindle housed deep within a vehicle wheel end assembly. First, modal impacts are imposed on the hub of the wheel in the longitudinal direction to produce broadband elastic wave excitation spectra out to 7000 Hz. The response data on the flange is collected using 3000 Hz bandwidth accelerometers. It is shown using frequency response analysis that the crack produces a filter, which amplifies the elastic response of the surrounding components of the wheel assembly. Experiments on wheel assemblies mounted on the vehicle with the vehicle lifted off the ground are performed to demonstrate that the modal impact method can be used to nondestructively evaluate cracks of varying depths despite sources of variability such as the half shaft angular position relative to the non-rotating spindle. Second, an automatic piezo-stack actuator is utilized to excite the wheel hub with a swept sine signal extending from 20 kHz. Accelerometers are then utilized to measure the response on the flange. It is demonstrated using frequency response analysis that the crack filters waves traveling from the hub to the flange. A simple finite element model is used to interpret the experimental results. Challenges discussed include variability from assembly to assembly, the variability in each assembly, and the high amount of damping present in each assembly due to the transmission gearing, lubricant, and other components in the wheel end. A two-channel measurement system with a graphical user interface for detecting cracks was also developed and a procedure was created to ensure that operators properly perform the test.

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2014 CFR

2014-07-01

... means the transfer and attachment of an assembled rim wheel onto a vehicle axle hub. Removing means the... 29 Labor 5 2014-07-01 2014-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2013 CFR

2013-07-01

... means the transfer and attachment of an assembled rim wheel onto a vehicle axle hub. Removing means the... 29 Labor 5 2013-07-01 2013-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2012 CFR

2012-07-01

... means the transfer and attachment of an assembled rim wheel onto a vehicle axle hub. Removing means the... 29 Labor 5 2012-07-01 2012-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

Prototype color field sequential television lens assembly

NASA Technical Reports Server (NTRS)

1974-01-01

The design, development, and evaluation of a prototype modular lens assembly with a self-contained field sequential color wheel is presented. The design of a color wheel of maximum efficiency, the selection of spectral filters, and the design of a quiet, efficient wheel drive system are included. Design tradeoffs considered for each aspect of the modular assembly are discussed. Emphasis is placed on achieving a design which can be attached directly to an unmodified camera, thus permitting use of the assembly in evaluating various candidate camera and sensor designs. A technique is described which permits maintaining high optical efficiency with an unmodified camera. A motor synchronization system is developed which requires only the vertical synchronization signal as a reference frequency input. Equations and tradeoff curves are developed to permit optimizing the filter wheel aperture shapes for a variety of different design conditions.

Tandem Fusion of Hepatitis B Core Antigen Allows Assembly of Virus-Like Particles in Bacteria and Plants with Enhanced Capacity to Accommodate Foreign Proteins

PubMed Central

Peyret, Hadrien; Gehin, Annick; Thuenemann, Eva C.; Blond, Donatienne; El Turabi, Aadil; Beales, Lucy; Clarke, Dean; Gilbert, Robert J. C.; Fry, Elizabeth E.; Stuart, David I.; Holmes, Kris; Stonehouse, Nicola J.; Whelan, Mike; Rosenberg, William; Lomonossoff, George P.; Rowlands, David J.

2015-01-01

The core protein of the hepatitis B virus, HBcAg, assembles into highly immunogenic virus-like particles (HBc VLPs) when expressed in a variety of heterologous systems. Specifically, the major insertion region (MIR) on the HBcAg protein allows the insertion of foreign sequences, which are then exposed on the tips of surface spike structures on the outside of the assembled particle. Here, we present a novel strategy which aids the display of whole proteins on the surface of HBc particles. This strategy, named tandem core, is based on the production of the HBcAg dimer as a single polypeptide chain by tandem fusion of two HBcAg open reading frames. This allows the insertion of large heterologous sequences in only one of the two MIRs in each spike, without compromising VLP formation. We present the use of tandem core technology in both plant and bacterial expression systems. The results show that tandem core particles can be produced with unmodified MIRs, or with one MIR in each tandem dimer modified to contain the entire sequence of GFP or of a camelid nanobody. Both inserted proteins are correctly folded and the nanobody fused to the surface of the tandem core particle (which we name tandibody) retains the ability to bind to its cognate antigen. This technology paves the way for the display of natively folded proteins on the surface of HBc particles either through direct fusion or through non-covalent attachment via a nanobody. PMID:25830365

Dynamic modeling of moment wheel assemblies with nonlinear rolling bearing supports

NASA Astrophysics Data System (ADS)

Wang, Hong; Han, Qinkai; Luo, Ruizhi; Qing, Tao

2017-10-01

Moment wheel assemblies (MWA) have been widely used in spacecraft attitude control and large angle slewing maneuvers over the years. Understanding and controlling vibration of MWAs is a crucial factor to achieving the desired level of payload performance. Dynamic modeling of a MWA with nonlinear rolling bearing supports is conducted. An improved load distribution analysis is proposed to more accurately obtain the contact deformations and angles between the rolling balls and raceways. Then, the bearing restoring forces are then obtained through iteratively solving the load distribution equations at every time step. The effects of preload condition, surface waviness, Hertz contact and elastohydrodynamic lubrication could all be reflected in the nonlinear bearing forces. Considering the mass imbalances of the flywheel, flexibility of supporting structures and rolling bearing nonlinearity, the dynamic model of a typical MWA is established based upon the energy theorem. Dynamic tests are conducted to verify the nonlinear dynamic model. The influences of flywheel mass eccentricity and inner/outer waviness amplitudes on the dynamic responses are discussed in detail. The obtained results would be useful for the design and vibration control of the MWA system.

Head assembly for multiposition borehole extensometer

DOEpatents

Frank, Donald N.

1983-01-01

A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

A new family of omnidirectional and holonomic wheeled platforms for mobile robots

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1994-08-01

This paper presents the concepts for a new family of holonomic wheeled platforms that feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. The authors first present the orthogonal-wheels'' concept and the two major wheel assemblies on which these platforms are based. The authors then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. Several alternative designs are considered, and their respective characteristics with respect to rotational and translational motion control are discussed. The design and control of a prototype platform developed tomore » test and demonstrate the proposed concepts is then described, and experimental results illustrating the full omnidirectionality of the platforms with decoupled rotational and translational degrees of freedom are presented.« less

Dynamic interaction of rotating momentum wheels with spacecraft elements

NASA Astrophysics Data System (ADS)

Shankar Narayan, S.; Nair, P. S.; Ghosal, Ashitava

2008-09-01

In modern spacecraft with the requirement of increased accuracy of payloads, the on-orbit structural dynamic behavior of spacecraft is increasingly influencing the design and performance of spacecraft. During the integrated spacecraft testing of one of the satellites, a strong coupling between rotating momentum wheels and an earth sensor was detected. This resulted in corruption of the earth sensor data at certain wheel speeds. This paper deals with the dynamic coupling problem of a rotating momentum wheel with its support brackets affecting other subsystems of spacecraft. As part of this investigation, extensive modal tests and vibration tests were carried out on the momentum wheel bracket assembly with wheels in stationary and rotating conditions. It was found that the effects of gyroscopic forces arising out of rotating wheels are significant and this aspect needs to be taken into account while designing the mounting brackets. Results of analysis and tests were used to redesign the bracket leading to a significant reduction in the interaction and associated problems. A procedure for design of a support structure using a low-order mathematical model is also shown.

Parametric excitation of tire-wheel assemblies by a stiffness non-uniformity

NASA Astrophysics Data System (ADS)

Stutts, D. S.; Krousgrill, C. M.; Soedel, W.

1995-01-01

A simple model of the effect of a concentrated radial stiffness non-uniformity in a passenger car tire is presented. The model treats the tread band of the tire as a rigid ring supported on a viscoelastic foundation. The distributed radial stiffness is lumped into equivalent horizontal (fore-and-aft) and vertical stiffnesses. The concentrated radial stiffness non-uniformity is modeled by treating the tread band as fixed, and the stiffness non-uniformity as rotating around it at the nominal angular velocity of the wheel. Due to loading, the center of mass of the tread band ring model is displaced upward with respect to the wheel spindle and, therefore, the rotating stiffness non-uniformity is alternately compressed and stretched through one complete rotation. This stretching and compressing of the stiffness non-uniformity results in force transmission to the wheel spindle at twice the nominal angular velocity in frequency, and therefore, would excite a given resonance at one-half the nominal angular wheel velocity that a mass unbalance would. The forcing produced by the stiffness non-uniformity is parametric in nature, thus creating the possibility of parametric resonance. The basic theory of the parametric resonance is explained, and a parameter study using derived lumped parameters based on a typical passenger car tire is performed. This study revealed that parametric resonance in passenger car tires, although possible, is unlikely at normal highway speeds as predicted by this model unless the tire is partially deflated.

MicroRNA-triggered, cascaded and catalytic self-assembly of functional ``DNAzyme ferris wheel'' nanostructures for highly sensitive colorimetric detection of cancer cells

NASA Astrophysics Data System (ADS)

Zhou, Wenjiao; Liang, Wenbin; Li, Xin; Chai, Yaqin; Yuan, Ruo; Xiang, Yun

2015-05-01

The construction of DNA nanostructures with various sizes and shapes has significantly advanced during the past three decades, yet the application of these DNA nanostructures for solving real problems is still in the early stage. On the basis of microRNA-triggered, catalytic self-assembly formation of the functional ``DNAzyme ferris wheel'' nanostructures, we show here a new signal amplification platform for highly sensitive, label-free and non-enzyme colorimetric detection of a small number of human prostate cancer cells. The microRNA (miR-141), which is catalytically recycled and reused, triggers isothermal self-assembly of a pre-designed, G-quadruplex sequence containing hairpin DNAs into ``DNAzyme ferris wheel''-like nanostructures (in association with hemin) with horseradish peroxidase mimicking activity. These DNAzyme nanostructures catalyze an intensified color transition of the probe solution for highly sensitive detection of miR-141 down to 0.5 pM with the naked eye, and the monitoring of as low as 283 human prostate cancer cells can also, theoretically, be achieved in a colorimetric approach. The work demonstrated here thus offers new opportunities for the construction of functional DNA nanostructures and for the application of these DNA nanostructures as an effective signal amplification means in the sensitive detection of nucleic acid biomarkers.

77 FR 12812 - Steel Wheels From the People's Republic of China: Notice of Preliminary Affirmative Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... separately. These products are used with both tubed and tubeless tires. Steel wheels, whether or not attached to tires or axles, are included. However, if the steel wheels are imported as an assembly attached to tires or axles, the tire or axle is not covered by the scope. The scope includes steel wheels, discs...

Research on Standard and Automatic Judgment of Press-fit Curve of Locomotive Wheel-set Based on AAR Standard

NASA Astrophysics Data System (ADS)

Lu, Jun; Xiao, Jun; Gao, Dong Jun; Zong, Shu Yu; Li, Zhu

2018-03-01

In the production of the Association of American Railroads (AAR) locomotive wheel-set, the press-fit curve is the most important basis for the reliability of wheel-set assembly. In the past, Most of production enterprises mainly use artificial detection methods to determine the quality of assembly. There are cases of miscarriage of justice appear. For this reason, the research on the standard is carried out. And the automatic judgment of press-fit curve is analysed and designed, so as to provide guidance for the locomotive wheel-set production based on AAR standard.

Optimization of Angular-Momentum Biases of Reaction Wheels

NASA Technical Reports Server (NTRS)

Lee, Clifford; Lee, Allan

2008-01-01

RBOT [RWA Bias Optimization Tool (wherein RWA signifies Reaction Wheel Assembly )] is a computer program designed for computing angular momentum biases for reaction wheels used for providing spacecraft pointing in various directions as required for scientific observations. RBOT is currently deployed to support the Cassini mission to prevent operation of reaction wheels at unsafely high speeds while minimizing time in undesirable low-speed range, where elasto-hydrodynamic lubrication films in bearings become ineffective, leading to premature bearing failure. The problem is formulated as a constrained optimization problem in which maximum wheel speed limit is a hard constraint and a cost functional that increases as speed decreases below a low-speed threshold. The optimization problem is solved using a parametric search routine known as the Nelder-Mead simplex algorithm. To increase computational efficiency for extended operation involving large quantity of data, the algorithm is designed to (1) use large time increments during intervals when spacecraft attitudes or rates of rotation are nearly stationary, (2) use sinusoidal-approximation sampling to model repeated long periods of Earth-point rolling maneuvers to reduce computational loads, and (3) utilize an efficient equation to obtain wheel-rate profiles as functions of initial wheel biases based on conservation of angular momentum (in an inertial frame) using pre-computed terms.

Passive vibration isolation of reaction wheel disturbances using a low frequency flexible space platform

NASA Astrophysics Data System (ADS)

Kamesh, D.; Pandiyan, R.; Ghosal, Ashitava

2012-03-01

Reaction wheel assemblies (RWAs) are momentum exchange devices used in fine pointing control of spacecrafts. Even though the spinning rotor of the reaction wheel is precisely balanced to minimize emitted vibration due to static and dynamic imbalances, precision instrument payloads placed in the neighborhood can always be severely impacted by residual vibration forces emitted by reaction wheel assemblies. The reduction of the vibration level at sensitive payloads can be achieved by placing the RWA on appropriate mountings. A low frequency flexible space platform consisting of folded continuous beams has been designed to serve as a mount for isolating a disturbance source in precision payloads equipped spacecrafts. Analytical and experimental investigations have been carried out to test the usefulness of the low frequency flexible platform as a vibration isolator for RWAs. Measurements and tests have been conducted at varying wheel speeds, to quantify and characterize the amount of isolation obtained from the reaction wheel generated vibration. These tests are further extended to other variants of similar design in order to bring out the best isolation for given disturbance loads. Both time and frequency domain analysis of test data show that the flexible beam platform as a mount for reaction wheels is quite effective and can be used in spacecrafts for passive vibration control.

Development of a Two-Wheel Contingency Mode for the MAP Spacecraft

NASA Technical Reports Server (NTRS)

Starin, Scott R.; ODonnell, James R., Jr.; Bauer, Frank (Technical Monitor)

2002-01-01

The Microwave Anisotropy Probe (MAP) is a follow-on mission to the Cosmic Background Explorer (COBE), and is currently collecting data from its orbit near the second Sun-Earth libration point. Due to limited mass, power, and financial resources, a traditional reliability concept including fully redundant components was not feasible for MAP. Instead, the MAP design employs selective hardware redundancy in tandem with contingency software modes and algorithms to improve the odds of mission success. One direction for such improvement has been the development of a two-wheel backup control strategy. This strategy would allow MAP to position itself for maneuvers and collect science data should one of its three reaction wheels fail. Along with operational considerations, the strategy includes three new control algorithms. These algorithms would use the remaining attitude control actuators-thrusters and two reaction wheels-in ways that achieve control goals while minimizing adverse impacts on the functionality of other subsystems and software.

Apparatus and methods for aligning holes through wheels and spacers and stacking the wheels and spacers to form a turbine rotor

DOEpatents

Berry, Robert Randolph; Palmer, Gene David; Wilson, Ian David

2000-01-01

A gas turbine rotor stacking fixture includes upstanding bolts for reception in aligned bolt holes in superposed aft disk, wheels and spacers and upstanding alignment rods received in openings of the disk, wheels and spacers during the rotor stacking assembly. The axially registering openings enable insertion of thin-walled tubes circumferentially about the rim of the rotor, with tight tolerances to the openings to provide supply and return steam for cooling buckets. The alignment rods have radial dimensions substantially less than their dimensions in a circumferential direction to allow for radial opening misalignment due to thermal expansion, tolerance stack-up and wheel-to-spacer mismatch due to rabbet mechanical growth. The circumferential dimension of the alignment rods affords tightly toleranced alignment of the openings through which the cooling tubes are installed.

Suspension system for a wheel rolling on a flat track. [bearings for directional antennas

NASA Technical Reports Server (NTRS)

Mcginness, H. D. (Inventor)

1981-01-01

An improved suspension system for an uncrowned wheel rolling on a flat track is presented. It is characterized by a wheel frame assembly including a wheel frame and at least one uncrowned wheel connected in supporting relation with the frame. It is adapted to be seated in rolling engagement with a flat track, a load supporting bed, and a plurality of flexural struts interconnecting the bed in supported relation with the frame. Each of said struts is disposed in a plane passing through the center of the uncrowned wheel surface along a line substantially bisecting the line of contact established between the wheel surface and the flat surface of the truck and characterized by a modulus of elasticity sufficient for maintaining the axis of rotation for the wheel in substantial parallelism with the line of contact established between the surfaces of the wheel and track.

Warning system against locomotive driving wheel flaccidity

NASA Astrophysics Data System (ADS)

Luo, Peng

2014-09-01

Causes of locomotive relaxation are discussed. Alarm system against locomotive driving wheel flaccidity is designed by means of techniques of infrared temperature measurement and Hall sensor measurement. The design scheme of the system, the principle of detecting locomotive driving wheel flaccidity with temperature and Hall sensor is introduced, threshold temperature of infrared alarm is determined. The circuit system is designed by microcontroller technology and the software is designed with the assembly language. The experiment of measuring the flaccid displacement with Hall sensor measurement is simulated. The results show that the system runs well with high reliability and low cost, which has a wide prospect of application and popularization.

Composite airfoil assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia-Crespo, Andres Jose

A composite blade assembly for mounting on a turbine wheel includes a ceramic airfoil and an airfoil platform. The ceramic airfoil is formed with an airfoil portion, a blade shank portion and a blade dovetail tang. The metal platform includes a platform shank and a radially inner platform dovetail. The ceramic airfoil is captured within the metal platform, such that in use, the ceramic airfoil is held within the turbine wheel independent of the metal platform.

Green's functions for analysis of dynamic response of wheel/rail to vertical excitation

NASA Astrophysics Data System (ADS)

Mazilu, Traian

2007-09-01

An analytical model to simulate wheel/rail interaction using the Green's functions method is proposed in this paper. The model consists of a moving wheel on a discretely supported rail. Particularly for this model of rail, the bending and the longitudinal displacement are coupled due to the rail pad and a complex model of the rail pad is adopted. An efficient method for solving a time-domain analysis for wheel/rail interaction is presented. The method is based on the properties of the rail's Green functions and starting to these functions, a track's Green matrix is assembled for the numerical simulations of wheel/rail response due to three kinds of vertical excitations: the steady-state interaction, the rail corrugation and the wheel flat. The study points to influence of the worn rail—rigid contact—on variation in the wheel/rail contact force. The concept of pinned-pinned inhibitive rail pad is also presented.

Reaction wheel low-speed compensation using a dither signal

NASA Astrophysics Data System (ADS)

Stetson, John B., Jr.

1993-08-01

A method for improving low-speed reaction wheel performance on a three-axis controlled spacecraft is presented. The method combines a constant amplitude offset with an unbiased, oscillating dither to harmonically linearize rolling solid friction dynamics. The complete, nonlinear rolling solid friction dynamics using an analytic modification to the experimentally verified Dahl solid friction model were analyzed using the dual-input describing function method to assess the benefits of dither compensation. The modified analytic solid friction model was experimentally verified with a small dc servomotor actuated reaction wheel assembly. Using dither compensation abrupt static friction disturbances are eliminated and near linear behavior through zero rate can be achieved. Simulated vehicle response to a wheel rate reversal shows that when the dither and offset compensation is used, elastic modes are not significantly excited, and the uncompensated attitude error reduces by 34:1.

Grinding assembly, grinding apparatus, weld joint defect repair system, and methods

DOEpatents

Larsen, Eric D.; Watkins, Arthur D.; Bitsoi, Rodney J.; Pace, David P.

2005-09-27

A grinding assembly for grinding a weld joint of a workpiece includes a grinder apparatus, a grinder apparatus includes a grinding wheel configured to grind the weld joint, a member configured to receive the grinding wheel, the member being configured to be removably attached to the grinder apparatus, and a sensor assembly configured to detect a contact between the grinding wheel and the workpiece. The grinding assembly also includes a processing circuitry in communication with the grinder apparatus and configured to control operations of the grinder apparatus, the processing circuitry configured to receive weld defect information of the weld joint from an inspection assembly to create a contour grinding profile to grind the weld joint in a predetermined shape based on the received weld defect information, and a manipulator having an end configured to carry the grinder apparatus, the manipulator further configured to operate in multiple dimensions.

A Ferris Wheel Accident at a Movable Amusement Park.

PubMed

Cho, Young-Jin; Ji, Hong-Keun; Moon, Byung-Sun; Park, Ha-Sun; Goh, Jae-Mo; Park, Nam-Kyu; Choi, Don-Mook

2017-05-01

This study presented a Ferris wheel accident case. A Ferris wheel is composed of many parts, and the outmost ring of it is assembled using a lock pin. This accident occurred because the lock pin caught the door of a gondola and the gondola overturned. Five of the seven passengers in the gondola fell to the ground, along with the gondola's viewing window. The investigation revealed that the gondola became stuck when its door was caught by a lock pin at the Ferris wheel's three o'clock position. The contact between the door and the lock pin was due to a structural problem: There was not enough space allotted between the door and the lock pin. Therefore, if a passenger pushed on the gondola's door, the potential existed for contact between the door and the lock pin. © 2016 American Academy of Forensic Sciences.

Art on Wheels.

ERIC Educational Resources Information Center

Szekely, George

2002-01-01

Discusses the use of wheels in children's art. Focuses on collecting wheels, ideas for decorating different artworks with wheels, and objects that can move on wheels. Sees wheels as an inspiration for children's art, reflecting on the use of this object in the art classroom. (CMK)

54. VAL COUNTERWEIGHT CAR DURING CONSTRUCTION SHOWING CAR FRAME, WHEEL ...

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

54. VAL COUNTERWEIGHT CAR DURING CONSTRUCTION SHOWING CAR FRAME, WHEEL ASSEMBLIES AND METAL REINFORCING, December 19, 1947. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

Low cost attitude control system reaction wheel development

NASA Astrophysics Data System (ADS)

Bialke, William

1991-03-01

In order to satisfy a growing demand for low cost attitude control systems for small spacecraft, development of a low power and low cost Reaction Wheel Assembly was initiated. The details of the versatile design resulting from this effort are addressed. Tradeoff analyses for each of the major components are included, as well as test data from an engineering prototype of the hardware.

Low cost attitude control system reaction wheel development

NASA Technical Reports Server (NTRS)

Bialke, William

1991-01-01

In order to satisfy a growing demand for low cost attitude control systems for small spacecraft, development of a low power and low cost Reaction Wheel Assembly was initiated. The details of the versatile design resulting from this effort are addressed. Tradeoff analyses for each of the major components are included, as well as test data from an engineering prototype of the hardware.

Inertia-Wheel Vibration-Damping System

NASA Technical Reports Server (NTRS)

Fedor, Joseph V.

1990-01-01

Proposed electromechanical system would damp vibrations in large, flexible structure. In active vibration-damping system motors and reaction wheels at tips of appendages apply reaction torques in response to signals from accelerometers. Velocity signal for vibrations about one axis processes into control signal to oppose each of n vibrational modes. Various modes suppressed one at a time. Intended primarily for use in spacecraft that has large, flexible solar panels and science-instrument truss assembly, embodies principle of control interesting in its own right and adaptable to terrestrial structures, vehicles, and instrument platforms.

Mono- and multilayers of molecular spoked carbazole wheels on graphite

PubMed Central

Aggarwal, A Vikas; Kalle, Daniel; Höger, Sigurd

2014-01-01

Summary Self-assembled monolayers of a molecular spoked wheel (a shape-persistent macrocycle with an intraannular spoke/hub system) and its synthetic precursor are investigated by scanning tunneling microscopy (STM) at the liquid/solid interface of 1-octanoic acid and highly oriented pyrolytic graphite. The submolecularly resolved STM images reveal that the molecules indeed behave as more or less rigid objects of certain sizes and shapes – depending on their chemical structures. In addition, the images provide insight into the multilayer growth of the molecular spoked wheels (MSWs), where the first adlayer acts as a template for the commensurate adsorption of molecules in the second layer. PMID:25550744

Mono- and multilayers of molecular spoked carbazole wheels on graphite.

PubMed

Jester, Stefan-S; Aggarwal, A Vikas; Kalle, Daniel; Höger, Sigurd

2014-01-01

Self-assembled monolayers of a molecular spoked wheel (a shape-persistent macrocycle with an intraannular spoke/hub system) and its synthetic precursor are investigated by scanning tunneling microscopy (STM) at the liquid/solid interface of 1-octanoic acid and highly oriented pyrolytic graphite. The submolecularly resolved STM images reveal that the molecules indeed behave as more or less rigid objects of certain sizes and shapes - depending on their chemical structures. In addition, the images provide insight into the multilayer growth of the molecular spoked wheels (MSWs), where the first adlayer acts as a template for the commensurate adsorption of molecules in the second layer.

Cryogenic filter wheel design for an infrared instrument

NASA Astrophysics Data System (ADS)

Azcue, Joaquín.; Villanueva, Carlos; Sánchez, Antonio; Polo, Cristina; Reina, Manuel; Carretero, Angel; Torres, Josefina; Ramos, Gonzalo; Gonzalez, Luis M.; Sabau, Maria D.; Najarro, Francisco; Pintado, Jesús M.

2014-09-01

In the last two decades, Spain has built up a strong IR community which has successfully contributed to space instruments, reaching Co-PI level in the SPICA mission (Space Infrared Telescope for Cosmology and Astrophysics). Under the SPICA mission, INTA, focused on the SAFARI instrument requirements but highly adaptable to other missions has designed a cryogenic low dissipation filter wheel with six positions, taking as starting point the past experience of the team with the OSIRIS instrument (ROSETTA mission) filter wheels and adapting the design to work at cryogenic temperatures. One of the main goals of the mechanism is to use as much as possible commercial components and test them at cryogenic temperature. This paper is focused on the design of the filter wheel, including the material selection for each of the main components of the mechanism, the design of elastic mount for the filter assembly, a positioner device designed to provide positional accuracy and repeatability to the filter, allowing the locking of the position without dissipation. In order to know the position of the wheel on every moment a position sensor based on a Hall sensor was developed. A series of cryogenic tests have been performed in order to validate the material configuration selected, the ball bearing lubrication and the selection of the motor. A stepper motor characterization campaign was performed including heat dissipation measurements. The result is a six position filter wheel highly adaptable to different configurations and motors using commercial components. The mechanism was successfully tested at INTA facilities at 20K at breadboard level.

A new family of low cost momentum/reaction wheels

NASA Astrophysics Data System (ADS)

Bialke, Bill

In order to satisfy the tight budgets and stringent power requirements of small and medium sized satellites, a new series of momentum/reaction wheels has been developed by ITHACO, Inc. The T-WHEEL integrates state-of-the-art ball bearing technology with flight-proven materials and conventional fabrication techniques to produce a reliable and manufacturable wheel assembly. Maximum performance is attained by using an optimized ball bearing suspension system and an ironless armature brushless dc motor for low power dissipation and minimum weight. In addition to summaries of the tradeoff studies performed, the results of the development effort include the application of a low vapor pressure synthetic hydrocarbon lubricant in the ball bearing suspension system, and performance data from the ironless armature brushless dc motor and driver. The original 4 N-m-s version (Type A) has been enlarged to increase the momentum storage capacity to 19.5 N-m-s (Type B), using the same suspension system and design baseline. A 68 N-m-s version is currently under development to broaden the product family.

3-Dimensional Analysis of Deformation of Disk Wheels and Transverse Force of Wheel Bolts

NASA Astrophysics Data System (ADS)

Kagiwada, Tadao; Harada, Hiroyuki

Loosening of the wheel nuts, which fix the disk wheels of automobiles to the wheel hub, may be the cause of accidents where the wheel falls off while the automobile is running. When the transverse force of wheel bolts exceeds a certain proportion of the bolt shaft force, the wheel nut begins to loosen. Further, the force on the bolt shaft may also be influenced by the loads acting to the wheel through the moment caused by the offset of the wheel. This study determined the 3-dimensional deformation of the disk wheels and the transverse forces on the wheel bolt by 3-dimensional numerical analysis. The results established that the transverse force was influenced by the bolt shaft force caused by the bolt fastening and was superposed on that due to the load, and that it fluctuated greatly during the revolution of the wheel. This phenomenon may be a large factor in the loosening of wheel nuts.

Omnidirectional wheel

NASA Technical Reports Server (NTRS)

Blumrich, J. F. (Inventor)

1974-01-01

The apparatus consists of a wheel having a hub with radially disposed spokes which are provided with a plurality of circumferential rim segments. These rim segments carry, between the spokes, rim elements which are rigid relative to their outer support surfaces, and defined in their outer contour to form a part of the circle forming the wheel diameter. The rim segments have provided for each of the rim elements an independent drive means selectively operable when the element is in ground contact to rotatably drive the rim element in a direction of movement perpendicularly lateral to the normal plane of rotation and movement of the wheel. This affords the wheel omnidirectional movement.

A Study on Wheel Sinkage and Rolling Resistance with variations in wheel geometry for Plain and Lugged wheels on TRI -1 Soil Simulant

NASA Astrophysics Data System (ADS)

Gireesh Kumar, Pala; Jayalekshmi, S.

2018-03-01

Wheel-soil Interaction studies are gaining momentum in the field of Terramechanics, but the basis is Terzaghi’s bearing capacity equation. For the current study, on a lunar soil simulant TRI – 1, two plain rigid wheels are considered, i.e., small wheel (dia. of 210 mm and width of 50 mm) and large wheel (dia. 160 mm and width 32 mm). Also, different number of lugs (N = 8, 12, 16) with various lug heights (h = 5 mm, 10 mm, 15 mm) are used. In this paper, the variation of wheel sinkages from experiments obtained for various wheel weights are examined and presented. The parameter, Coefficient of rolling resistance (CRR) is determined for various cases. Hence, rolling resistance was determined and examined from the obtained CRR for all cases. Among the cases examined, the large wheel with weight 67.44 N for plain wheels and weight 67.85 N for lugged wheel (no. of lugs = 16, and height of lugs = 5 mm) registered better mobility. Similarly, for small wheel with weight 52.189 N for plain wheel and weight 52.481 N for lugged wheel (no. of lugs = 16, and height of lugs = 5 mm) registered better mobility, a lesser rolling resistance for these cases.

De novo protein sequencing by combining top-down and bottom-up tandem mass spectra.

PubMed

Liu, Xiaowen; Dekker, Lennard J M; Wu, Si; Vanduijn, Martijn M; Luider, Theo M; Tolić, Nikola; Kou, Qiang; Dvorkin, Mikhail; Alexandrova, Sonya; Vyatkina, Kira; Paša-Tolić, Ljiljana; Pevzner, Pavel A

2014-07-03

There are two approaches for de novo protein sequencing: Edman degradation and mass spectrometry (MS). Existing MS-based methods characterize a novel protein by assembling tandem mass spectra of overlapping peptides generated from multiple proteolytic digestions of the protein. Because each tandem mass spectrum covers only a short peptide of the target protein, the key to high coverage protein sequencing is to find spectral pairs from overlapping peptides in order to assemble tandem mass spectra to long ones. However, overlapping regions of peptides may be too short to be confidently identified. High-resolution mass spectrometers have become accessible to many laboratories. These mass spectrometers are capable of analyzing molecules of large mass values, boosting the development of top-down MS. Top-down tandem mass spectra cover whole proteins. However, top-down tandem mass spectra, even combined, rarely provide full ion fragmentation coverage of a protein. We propose an algorithm, TBNovo, for de novo protein sequencing by combining top-down and bottom-up MS. In TBNovo, a top-down tandem mass spectrum is utilized as a scaffold, and bottom-up tandem mass spectra are aligned to the scaffold to increase sequence coverage. Experiments on data sets of two proteins showed that TBNovo achieved high sequence coverage and high sequence accuracy.

Influence of polygonal wear of railway wheels on the wheel set axle stress

NASA Astrophysics Data System (ADS)

Wu, Xingwen; Chi, Maoru; Wu, Pingbo

2015-11-01

The coupled vehicle/track dynamic model with the flexible wheel set was developed to investigate the effects of polygonal wear on the dynamic stresses of the wheel set axle. In the model, the railway vehicle was modelled by the rigid multibody dynamics. The wheel set was established by the finite element method to analyse the high-frequency oscillation and dynamic stress of wheel set axle induced by the polygonal wear based on the modal stress recovery method. The slab track model was taken into account in which the rail was described by the Timoshenko beam and the three-dimensional solid finite element was employed to establish the concrete slab. Furthermore, the modal superposition method was adopted to calculate the dynamic response of the track. The wheel/rail normal forces and the tangent forces were, respectively, determined by the Hertz nonlinear contact theory and the Shen-Hedrick-Elkins model. Using the coupled vehicle/track dynamic model, the dynamic stresses of wheel set axle with consideration of the ideal polygonal wear and measured polygonal wear were investigated. The results show that the amplitude of wheel/rail normal forces and the dynamic stress of wheel set axle increase as the vehicle speeds rise. Moreover, the impact loads induced by the polygonal wear could excite the resonance of wheel set axle. In the resonance region, the amplitude of the dynamic stress for the wheel set axle would increase considerably comparing with the normal conditions.

Experimental heat and mass transfer of the separated and coupled rotating desiccant wheel and heat wheel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enteria, Napoleon; Yoshino, Hiroshi; Mochida, Akashi

The experimental evaluation of the separated and coupled rotating desiccant wheel and heat wheel is reported. The study aims to investigate the performance of the desiccant wheel and of the heat wheel both when operated separately and jointly. The performance evaluation of the desiccant wheel is based on its moisture removal capacity (MRC), moisture removal regeneration (MRR), and moisture mass balance (MMB). In addition, the study used the total energy balance (TEB), sensible coefficient of performance (COP{sub Sensible}), latent coefficient of performance (COP{sub Latent}) and, total coefficient of performance (COP{sub Total}). The performance of the heat wheel is based onmore » its effectiveness. The COP{sub Sensible}, COP{sub Latent} and, COP{sub Total} are used in the performance evaluation of the coupled desiccant wheel and heat wheel. The general results of the study show that the MRC, MRR and MMB coupled with the TEB, COP{sub Latent}, COP{sub Sensible} and COP{sub Total} predict adequately the performance of the desiccant wheel. In addition, the coupled operation of the desiccant wheel and heat wheel, contributed to the reduction of the external thermal energy requirement for the regeneration of the desiccant wheel. This study can be applied in other researches seeking evaluation of the desiccant wheel, heat wheel, and their combined operation. Moreover, the data presented here are significant for the desiccant wheel benchmarking and for evaluation of the desiccant wheel models. (author)« less

The response of a high-speed train wheel to a harmonic wheel-rail force

NASA Astrophysics Data System (ADS)

Sheng, Xiaozhen; Liu, Yuxia; Zhou, Xin

2016-09-01

The maximum speed of China's high-speed trains currently is 300km/h and expected to increase to 350-400km/h. As a wheel travels along the rail at such a high speed, it is subject to a force rotating at the same speed along its periphery. This fast moving force contains not only the axle load component, but also many components of high frequencies generated from wheel-rail interactions. Rotation of the wheel also introduces centrifugal and gyroscopic effects. How the wheel responds is fundamental to many issues, including wheel-rail contact, traction, wear and noise. In this paper, by making use of its axial symmetry, a special finite element scheme is developed for responses of a train wheel subject to a vertical and harmonic wheel-rail force. This FE scheme only requires a 2D mesh over a cross-section containing the wheel axis but includes all the effects induced by wheel rotation. Nodal displacements, as a periodic function of the cross-section angle 6, can be decomposed, using Fourier series, into a number of components at different circumferential orders. The derived FE equation is solved for each circumferential order. The sum of responses at all circumferential orders gives the actual response of the wheel.

Model Predictive Control considering Reachable Range of Wheels for Leg / Wheel Mobile Robots

NASA Astrophysics Data System (ADS)

Suzuki, Naito; Nonaka, Kenichiro; Sekiguchi, Kazuma

2016-09-01

Obstacle avoidance is one of the important tasks for mobile robots. In this paper, we study obstacle avoidance control for mobile robots equipped with four legs comprised of three DoF SCARA leg/wheel mechanism, which enables the robot to change its shape adapting to environments. Our previous method achieves obstacle avoidance by model predictive control (MPC) considering obstacle size and lateral wheel positions. However, this method does not ensure existence of joint angles which achieves reference wheel positions calculated by MPC. In this study, we propose a model predictive control considering reachable mobile ranges of wheels positions by combining multiple linear constraints, where each reachable mobile range is approximated as a convex trapezoid. Thus, we achieve to formulate a MPC as a quadratic problem with linear constraints for nonlinear problem of longitudinal and lateral wheel position control. By optimization of MPC, the reference wheel positions are calculated, while each joint angle is determined by inverse kinematics. Considering reachable mobile ranges explicitly, the optimal joint angles are calculated, which enables wheels to reach the reference wheel positions. We verify its advantages by comparing the proposed method with the previous method through numerical simulations.

Stabilizing Wheels For Rover Vehicle

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr.

1990-01-01

Proposed articulated, normally-four-wheeled vehicle holds extra pair of wheels in reserve. Deployed to lengthen wheelbase on slopes, thereby making vehicle more stable, and to aid vehicle in negotiating ledge or to right vehicle if turned upside down. Extra wheels are drive wheels mounted on arms so they pivot on axis of forward drive wheels. Both extra wheels and arms driven by chains, hydraulic motors, or electric motors. Concept promises to make remotely controlled vehicles more stable and maneuverable in such applications as firefighting, handling hazardous materials, and carrying out operations in dangerous locations.

The Cassini Reaction Wheels: Drag and Spin-Rate Trends from an Aging Interplanetary Spacecraft at Saturn

NASA Technical Reports Server (NTRS)

Brown, Todd S.

2016-01-01

The purpose of this paper is to provide a summary of the long-term trends of the estimated drag torque and spin-rates of the Cassini reaction wheel assemblies during eleven years of intensive science operations at Saturn..

High-Clearance Six-Wheel Suspension

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1992-01-01

Multilevered suspension system gives body of vehicle high clearance and allows wheels to be steered independently. Suspension linkages above wheels enable body to skim over obstacles as high as wheel. Levers and independently steered wheels enable vehicle to climb steps 1 1/2 wheel diameters high and cross gaps 1 3/4 wide. Adaptable to off-the-road recreational vehicles, military scout vehicles, and robotic emergency vehicles.

Development of a Two-Wheel Contingency Mode for the MAP Spacecraft

NASA Technical Reports Server (NTRS)

Starin, Scott R.; ODonnell, James R., Jr.; Bauer, Frank H. (Technical Monitor)

2002-01-01

In the event of a failure of one of MAP's three reaction wheel assemblies (RWAs), it is not possible to achieve three-axis, full-state attitude control using the remaining two wheels. Hence, two of the attitude control algorithms implemented on the MAP spacecraft will no longer be usable in their current forms: Inertial Mode, used for slewing to and holding inertial attitudes, and Observing Mode, which implements the nominal dual-spin science mode. This paper describes the effort to create a complete strategy for using software algorithms to cope with a RWA failure. The discussion of the design process will be divided into three main subtopics: performing orbit maneuvers to reach and maintain an orbit about the second Earth-Sun libration point in the event of a RWA failure, completing the mission using a momentum-bias two-wheel science mode, and developing a new thruster-based mode for adjusting the inertially fixed momentum bias. In this summary, the philosophies used in designing these changes is shown; the full paper will supplement these with algorithm descriptions and testing results.

A Generic Microdisturbanace Transmissibility Model For Reaction Wheels

NASA Astrophysics Data System (ADS)

Penate Castro, Jose; Seiler, Rene

2012-07-01

The increasing demand for space missions with high- precision pointing requirements for their payload instruments is underlining the importance of studying the impact of micro-level disturbances on the overall performance of spacecraft. For example, a satellite with an optical telescope taking high-resolution images might be very sensitive to perturbations, generated by moving equipment and amplified by the structure of the equipment itself as well as that of the host spacecraft that is accommodating both, the sources of mechanical disturbances and sensitive payload instruments. One of the major sources of mechanical disturbances inside a satellite may be found with reaction wheels. For investigation of their disturbance generation and propagation characteristics, a finite element model with parametric geometry definition has been developed. The model covers the main structural features of typical reaction wheel assemblies and can be used for a transmissibility representation of the equipment. With the parametric geometry definition approach, a wide range of different reaction wheel types and sizes can be analysed, without the need for (re-)defining an individual reaction wheel configuration from scratch. The reaction wheel model can be combined with a finite element model of the spacecraft structure and the payload for an end-to-end modelling and simulation of the microdisturbance generation and propagation. The finite element model has been generated in Patran® Command Language (PCL), which provides a powerful and time-efficient way to change parameters in the model, for creating a new or modifying an existing geometry, without requiring comprehensive manual interactions in the modelling pre-processor. As part of the overall modelling approach, a tailored structural model of the mechanical ball bearings has been implemented, which is one of the more complex problems to deal with, among others, due to the anisotropic stiffness and damping characteristics

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

NASA Astrophysics Data System (ADS)

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.

Leg pairs as virtual wheels

NASA Astrophysics Data System (ADS)

Howe, Russel; Duttweiler, Mark; Khanlian, Luke; Setrakian, Mark

2005-05-01

We propose the use of virtual wheels as the starting point of a new vehicle design. Each virtual wheel incorporates a pair of simple legs that, by simulating the rotary motion and ground contact of a traditional wheel, combine many of the benefits of legged and wheeled motion. We describe the use of virtual wheels in the design of a robotic mule, presenting an analysis of the mule's mobility the results of our efforts to model and build such a device.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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

Development of an Optimization Methodology for the Aluminum Alloy Wheel Casting Process

NASA Astrophysics Data System (ADS)

Duan, Jianglan; Reilly, Carl; Maijer, Daan M.; Cockcroft, Steve L.; Phillion, Andre B.

2015-08-01

An optimization methodology has been developed for the aluminum alloy wheel casting process. The methodology is focused on improving the timing of cooling processes in a die to achieve improved casting quality. This methodology utilizes (1) a casting process model, which was developed within the commercial finite element package, ABAQUS™—ABAQUS is a trademark of Dassault Systèms; (2) a Python-based results extraction procedure; and (3) a numerical optimization module from the open-source Python library, Scipy. To achieve optimal casting quality, a set of constraints have been defined to ensure directional solidification, and an objective function, based on the solidification cooling rates, has been defined to either maximize, or target a specific, cooling rate. The methodology has been applied to a series of casting and die geometries with different cooling system configurations, including a 2-D axisymmetric wheel and die assembly generated from a full-scale prototype wheel. The results show that, with properly defined constraint and objective functions, solidification conditions can be improved and optimal cooling conditions can be achieved leading to process productivity and product quality improvements.

Design and manufacture of wheels for a dual-mode (manned - automatic) lunar surface roving vehicle. Volume 2: Proposed test plan

NASA Technical Reports Server (NTRS)

1970-01-01

A developmental test plan for the wheel and wheel drive assembly of the dual-mode (manned/automated) lunar surface roving vehicle is presented. The tests cover performance, as well as critical environmental characteristics. Insofar as practical, the environmental conditions imposed will be in the sequence expected during the hardware's life from storage through the lunar mission. Test procedures are described for static load deflection and endurance tests. Soft soil tests to determine mobility characteristics including drawbar-pull and thrust vs slip, and motion resistance for various wheel loads are also discussed. Test designs for both ambient and thermal vacuum conditions are described. Facility, transducer, and instrumentation requirements are outlined.

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

PubMed Central

Davis, Claire

2014-01-01

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. PMID:24526883

49 CFR 230.114 - Wheel centers.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., following the repair, the crankpin and axle shall remain tight in the wheel. Banding of the hub is permitted... 49 Transportation 4 2013-10-01 2013-10-01 false Wheel centers. 230.114 Section 230.114... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel...

49 CFR 230.114 - Wheel centers.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., following the repair, the crankpin and axle shall remain tight in the wheel. Banding of the hub is permitted... 49 Transportation 4 2014-10-01 2014-10-01 false Wheel centers. 230.114 Section 230.114... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel...

49 CFR 230.114 - Wheel centers.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., following the repair, the crankpin and axle shall remain tight in the wheel. Banding of the hub is permitted... 49 Transportation 4 2012-10-01 2012-10-01 false Wheel centers. 230.114 Section 230.114... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel...

49 CFR 230.114 - Wheel centers.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., following the repair, the crankpin and axle shall remain tight in the wheel. Banding of the hub is permitted... 49 Transportation 4 2011-10-01 2011-10-01 false Wheel centers. 230.114 Section 230.114... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel...

49 CFR 230.114 - Wheel centers.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., following the repair, the crankpin and axle shall remain tight in the wheel. Banding of the hub is permitted... 49 Transportation 4 2010-10-01 2010-10-01 false Wheel centers. 230.114 Section 230.114... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel...

Portrait of an Aging Wheel

NASA Technical Reports Server (NTRS)

2004-01-01

This plot maps the increasing amounts of energy needed to spin Spirit's right front wheel drive, which has been showing signs of age. The wheel has now traveled six times farther than its design life. Since Spirit's 126th day on Mars, this wheel has required additional electric current to run at normal speeds, as indicated with blue diamonds on this graph. Efforts to improve the situation by redistributing the lubricant in the wheel with heat and rest were only mildly successful (pink squares). To cope with the condition, rover planners have come up with a creative solution: they will drive the rover backwards using five of six wheels. The sixth wheel will be activated only when the terrain demands it.

49 CFR 215.103 - Defective wheel.

Code of Federal Regulations, 2012 CFR

2012-10-01

... less; (d) A wheel rim, flange, plate, or hub area on the car has a crack or break; (e) A wheel on the... 49 Transportation 4 2012-10-01 2012-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange...

49 CFR 215.103 - Defective wheel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... less; (d) A wheel rim, flange, plate, or hub area on the car has a crack or break; (e) A wheel on the... 49 Transportation 4 2011-10-01 2011-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange...

49 CFR 215.103 - Defective wheel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... less; (d) A wheel rim, flange, plate, or hub area on the car has a crack or break; (e) A wheel on the... 49 Transportation 4 2010-10-01 2010-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange...

49 CFR 215.103 - Defective wheel.

Code of Federal Regulations, 2014 CFR

2014-10-01

... less; (d) A wheel rim, flange, plate, or hub area on the car has a crack or break; (e) A wheel on the... 49 Transportation 4 2014-10-01 2014-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange...

49 CFR 215.103 - Defective wheel.

Code of Federal Regulations, 2013 CFR

2013-10-01

... less; (d) A wheel rim, flange, plate, or hub area on the car has a crack or break; (e) A wheel on the... 49 Transportation 4 2013-10-01 2013-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange...

Lightweight concentrator module with 30 percent AM0 efficient GaAs/GaSb tandem cells

NASA Technical Reports Server (NTRS)

Avery, J. E.; Fraas, L. M.; Sundaram, V. S.; Mansoori, N.; Yerkes, J. W.; Brinker, D. J.; Curtis, H. B.; O'Neill, M. J.

1990-01-01

A concept is presented for an aerospace concentrator module with lightweight domed lenses and 30 percent AM0 efficient GaAs/GaSb tandem solar cell circuits. The performance of transparent GaAs cells is reviewed. NASA's high-altitude jet flight calibration data for recent GaSb cells assembled with bulk GaAs filters are reported, along with subsequent Boeing and NASA measurements of GaSb I-V performance at various light levels and temperatures. The expected performance of a basic two-terminal tandem concentrator circuit with three-to-one voltage matching is discussed. All of the necessary components being developed to assemble complete flight test coupons are shown. Straightforward interconnect and assembly techniques yield voltage matched circuits with near-optimum performance over a wide temperature range.

Prediction of Lunar Reconnaissance Orbiter Reaction Wheel Assembly Angular Momentum Using Regression Analysis

NASA Technical Reports Server (NTRS)

DeHart, Russell

2017-01-01

This study determines the feasibility of creating a tool that can accurately predict Lunar Reconnaissance Orbiter (LRO) reaction wheel assembly (RWA) angular momentum, weeks or even months into the future. LRO is a three-axis stabilized spacecraft that was launched on June 18, 2009. While typically nadir-pointing, LRO conducts many types of slews to enable novel science collection. Momentum unloads have historically been performed approximately once every two weeks with the goal of maintaining system total angular momentum below 70 Nms; however flight experience shows the models developed before launch are overly conservative, with many momentum unloads being performed before system angular momentum surpasses 50 Nms. A more accurate model of RWA angular momentum growth would improve momentum unload scheduling and decrease the frequency of these unloads. Since some LRO instruments must be deactivated during momentum unloads and in the case of one instrument, decontaminated for 24 hours there after a decrease in the frequency of unloads increases science collection. This study develops a new model to predict LRO RWA angular momentum. Regression analysis of data from October 2014 to October 2015 was used to develop relationships between solar beta angle, slew specifications, and RWA angular momentum growth. The resulting model predicts RWA angular momentum using input solar beta angle and mission schedule data. This model was used to predict RWA angular momentum from October 2013 to October 2014. Predictions agree well with telemetry; of the 23 momentum unloads performed from October 2013 to October 2014, the mean and median magnitude of the RWA total angular momentum prediction error at the time of the momentum unloads were 3.7 and 2.7 Nms, respectively. The magnitude of the largest RWA total angular momentum prediction error was 10.6 Nms. Development of a tool that uses the models presented herein is currently underway.

Running Wheel for Earthworms

PubMed Central

Wilson, W. Jeffrey; Johnson, Brandon A.

2016-01-01

We describe the construction and use of a running wheel responsive to the movement of the earthworm. The wheel employs readily available, inexpensive components and is easily constructed. Movement of the wheel can be monitored visually or via standard behavioral laboratory computer interfaces. Examples of data are presented, and possibilities for use in the teaching classroom are discussed. PMID:27385934

Wheel running in the wild.

PubMed

Meijer, Johanna H; Robbers, Yuri

2014-07-07

The importance of exercise for health and neurogenesis is becoming increasingly clear. Wheel running is often used in the laboratory for triggering enhanced activity levels, despite the common objection that this behaviour is an artefact of captivity and merely signifies neurosis or stereotypy. If wheel running is indeed caused by captive housing, wild mice are not expected to use a running wheel in nature. This however, to our knowledge, has never been tested. Here, we show that when running wheels are placed in nature, they are frequently used by wild mice, also when no extrinsic reward is provided. Bout lengths of running wheel behaviour in the wild match those for captive mice. This finding falsifies one criterion for stereotypic behaviour, and suggests that running wheel activity is an elective behaviour. In a time when lifestyle in general and lack of exercise in particular are a major cause of disease in the modern world, research into physical activity is of utmost importance. Our findings may help alleviate the main concern regarding the use of running wheels in research on exercise.

A Two-Wheel Observing Mode for the MAP Spacecraft

NASA Technical Reports Server (NTRS)

Starin, Scott R.; ODonnell, James R., Jr.

2001-01-01

The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE). Due to the MAP project's limited mass, power, and budget, a traditional reliability concept including fully redundant components was not feasible. The MAP design employs selective hardware redundancy, along with backup software modes and algorithms, to improve the odds of mission success. This paper describes the effort to develop a backup control mode, known as Observing II, that will allow the MAP science mission to continue in the event of a failure of one of its three reaction wheel assemblies. This backup science mode requires a change from MAP's nominal zero-momentum control system to a momentum-bias system. In this system, existing thruster-based control modes are used to establish a momentum bias about the sun line sufficient to spin the spacecraft up to the desired scan rate. Natural spacecraft dynamics exhibits spin and nutation similar to the nominal MAP science mode with different relative rotation rates, so the two reaction wheels are used to establish and maintain the desired nutation angle from the sun line. Detailed descriptions of the ObservingII control algorithm and simulation results will be presented, along with the operational considerations of performing the rest of MAP's necessary functions with only two wheels.

Automatic Mechetronic Wheel Light Device

DOEpatents

Khan, Mohammed John Fitzgerald

2004-09-14

A wheel lighting device for illuminating a wheel of a vehicle to increase safety and enhance aesthetics. The device produces the appearance of a "ring of light" on a vehicle's wheels as the vehicle moves. The "ring of light" can automatically change in color and/or brightness according to a vehicle's speed, acceleration, jerk, selection of transmission gears, and/or engine speed. The device provides auxiliary indicator lights by producing light in conjunction with a vehicle's turn signals, hazard lights, alarm systems, and etc. The device comprises a combination of mechanical and electronic components and can be placed on the outer or inner surface of a wheel or made integral to a wheel or wheel cover. The device can be configured for all vehicle types, and is electrically powered by a vehicle's electrical system and/or battery.

Two wheeled lunar dumptruck

NASA Technical Reports Server (NTRS)

Brus, Michael R.; Haleblain, Ray; Hernandez, Tomas L.; Jensen, Paul E.; Kraynick, Ronald L.; Langley, Stan J.; Shuman, Alan G.

1988-01-01

The design of a two wheel bulk material transport vehicle is described in detail. The design consists of a modified cylindrical bowl, two independently controlled direct drive motors, and two deformable wheels. The bowl has a carrying capacity of 2.8 m (100 ft) and is constructed of aluminum. The low speed, high HP motors are directly connected to the wheels, thus yielding only two moving parts. The wheels, specifically designed for lunar applications, utilize the chevron tread pattern for optimum traction. The vehicle is maneuvered by varying the relative angular velocities of the wheels. The bulk material being transported is unloaded by utilizing the motors to oscillate the bowl back and forth to a height at which dumping is achieved. The analytical models were tested using a scaled prototype of the lunar transport vehicle. The experimental data correlated well with theoretical predictions. Thus, the design established provides a feasible alternative for the handling of bulk material on the moon.

Broken rims in railroad wheels.

DOT National Transportation Integrated Search

2014-12-01

Broken wheels are one of the most common types of equipment-caused train accidents. The failure of rail car wheel rims, which : are usually the result of shattered rims or vertical split rims (VSR), are the leading cause of wheel-related accidents, a...

Tread buildup on railroad wheels.

DOT National Transportation Integrated Search

2015-04-01

Based on the results of wheel slide tests and an inspection of wheels, the root cause of tread buildup (TBU) was identified as : wheel slide caused by excessive brake force. During the tests, TBU accumulated to the greatest heights under dry conditio...

Robotic Two-Wheeled Vehicle

NASA Technical Reports Server (NTRS)

Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor); Matthews, Jaret B. (Inventor); Nesnas, Issa A. D. (Inventor)

2014-01-01

A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

Robotic Two-Wheeled Vehicle

NASA Technical Reports Server (NTRS)

Nesnas, Issa A. D. (Inventor); Matthews, Jaret B. (Inventor); Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor)

2013-01-01

A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

Tracked Vehicle Road Wheel Puller

DTIC Science & Technology

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

Rotating Wheel Wake

NASA Astrophysics Data System (ADS)

Lombard, Jean-Eloi; Xu, Hui; Moxey, Dave; Sherwin, Spencer

2016-11-01

For open wheel race-cars, such as Formula One, or IndyCar, the wheels are responsible for 40 % of the total drag. For road cars, drag associated to the wheels and under-carriage can represent 20 - 60 % of total drag at highway cruise speeds. Experimental observations have reported two, three or more pairs of counter rotating vortices, the relative strength of which still remains an open question. The near wake of an unsteady rotating wheel. The numerical investigation by means of direct numerical simulation at ReD =400-1000 is presented here to further the understanding of bifurcations the flow undergoes as the Reynolds number is increased. Direct numerical simulation is performed using Nektar++, the results of which are compared to those of Pirozzoli et al. (2012). Both proper orthogonal decomposition and dynamic mode decomposition, as well as spectral analysis are leveraged to gain unprecedented insight into the bifurcations and subsequent topological differences of the wake as the Reynolds number is increased.

Grinding Wheel System

DOEpatents

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.

Grinding Wheel System

DOEpatents

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

2006-01-10

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.

Wheeled and Tracked Vehicle Endurance Testing

DTIC Science & Technology

2014-10-02

Vehicle (ATV) 10 10 50 30 Fire Trucks - Crash and Rescue, Brush, Structural 49/56/50 22/16/50 - 29/28/0 a Wheeled Combat 30 40 15 15 Roboticb - 30 50... Wheeled Light W-M = Wheeled Medium W-H = Wheeled Heavy LM-TT = Light/Medium Truck H-TT = Heavy Truck Tractor/Trailer M = Motorcycle FT = Fire ...TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Test Operations Procedure (TOP) 02-2-506A Wheeled and Tracked Vehicle Endurance

Why Wheels Work.

ERIC Educational Resources Information Center

Stepp, Richard D.

1982-01-01

Discusses how the wheel works. The inherent mechanical advantage of wheel-and-axle system is that it reduced the distance the load-bearing surfaces have to slip relative to one another when the whole apparatus advances some given distance reducing (with leverage) the force needed to propel the system. (Author/JN)

Control of a Wheeled Transport Robot with Two Steerable Wheels

NASA Astrophysics Data System (ADS)

Larin, V. B.

2017-09-01

The control of a system with one actuator failed is studied. The problem of control of a wheeled transport robot with two steerable wheels of which the rear one is stuck (its drive has failed) is solved. An algorithm for controlling the system in this situation is proposed. The effectiveness of the algorithm is demonstrated by way of an example.

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

NASA Astrophysics Data System (ADS)

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.

Development and validation of a new kind of coupling element for wheel-hub motors

NASA Astrophysics Data System (ADS)

Perekopskiy, Sergey; Kasper, Roland

2018-05-01

For the automotive industry, electric powered vehicles are becoming an increasingly relevant factor in the competition against climate change. Application of one special example - a wheel-hub motor, for electric powered vehicle can support this challenge. Patented slotless air gap winding invented at the chair of mechatronics of the Otto von Guericke University Magdeburg has great application potential in constantly growing e-mobility field, especially for wheel-hub motors based on this technology due to its advantages, such as a high gravimetric power density and high efficiency. However, advantages of this technology are decreased by its sensibility to the loads out of driving maneuvers by dimensional variations of air gap consistency. This article describes the development and validation of a coupling element for the designed wheel-hub motor. To find a suitable coupling concept first the assembly structure of the motor was analyzed and developed design of the coupling element was checked. Based on the geometry of the motor and wheel a detailed design of the coupling element was generated. The analytical approach for coupling element describes a potential of the possible loads on the coupling element. The FEM simulation of critical load cases for the coupling element validated results of the analytical approach.

Three Axis Control of the Hubble Space Telescope Using Two Reaction Wheels and Magnetic Torquer Bars for Science Observations

NASA Technical Reports Server (NTRS)

Hur-Diaz, Sun; Wirzburger, John; Smith, Dan

2008-01-01

The Hubble Space Telescope (HST) is renowned for its superb pointing accuracy of less than 10 milli-arcseconds absolute pointing error. To accomplish this, the HST relies on its complement of four reaction wheel assemblies (RWAs) for attitude control and four magnetic torquer bars (MTBs) for momentum management. As with most satellites with reaction wheel control, the fourth RWA provides for fault tolerance to maintain three-axis pointing capability should a failure occur and a wheel is lost from operations. If an additional failure is encountered, the ability to maintain three-axis pointing is jeopardized. In order to prepare for this potential situation, HST Pointing Control Subsystem (PCS) Team developed a Two Reaction Wheel Science (TRS) control mode. This mode utilizes two RWAs and four magnetic torquer bars to achieve three-axis stabilization and pointing accuracy necessary for a continued science observing program. This paper presents the design of the TRS mode and operational considerations necessary to protect the spacecraft while allowing for a substantial science program.

Wheel speed management control system for spacecraft

NASA Technical Reports Server (NTRS)

Goodzeit, Neil E. (Inventor); Linder, David M. (Inventor)

1991-01-01

A spacecraft attitude control system uses at least four reaction wheels. In order to minimize reaction wheel speed and therefore power, a wheel speed management system is provided. The management system monitors the wheel speeds and generates a wheel speed error vector. The error vector is integrated, and the error vector and its integral are combined to form a correction vector. The correction vector is summed with the attitude control torque command signals for driving the reaction wheels.

Energy-Absorbing, Lightweight Wheels

NASA Technical Reports Server (NTRS)

Waydo, Peter

2003-01-01

Improved energy-absorbing wheels are under development for use on special-purpose vehicles that must traverse rough terrain under conditions (e.g., extreme cold) in which rubber pneumatic tires would fail. The designs of these wheels differ from those of prior non-pneumatic energy-absorbing wheels in ways that result in lighter weights and more effective reduction of stresses generated by ground/wheel contact forces. These wheels could be made of metals and/or composite materials to withstand the expected extreme operating conditions. As shown in the figure, a wheel according to this concept would include an isogrid tire connected to a hub via spring rods. The isogrid tire would be a stiff, lightweight structure typically made of aluminum. The isogrid aspect of the structure would both impart stiffness and act as a traction surface. The hub would be a thin-walled body of revolution having a simple or compound conical or other shape chosen for structural efficiency. The spring rods would absorb energy and partially isolate the hub and the supported vehicle from impact loads. The general spring-rod configuration shown in the figure was chosen because it would distribute contact and impact loads nearly evenly around the periphery of the hub, thereby helping to protect the hub against damage that would otherwise be caused by large loads concentrated onto small portions of the hub.

Automated array assembly, phase 2

NASA Technical Reports Server (NTRS)

Carbajal, B. G.

1979-01-01

Tasks of scaling up the tandem junction cell (TJC) from 2 cm x 2 cm to 6.2 cm and the assembly of several modules using these large area TJC's are described. The scale-up of the TJC was based on using the existing process and doing the necessary design activities to increase the cell area to an acceptably large area. The design was carried out using available device models. The design was verified and sample large area TJCs were fabricated. Mechanical and process problems occurred causing a schedule slippage that resulted in contract expiration before enough large-area TJCs were fabricated to populate the sample tandem junction modules (TJM). A TJM design was carried out in which the module interconnects served to augment the current collecting buses on the cell. No sample TJMs were assembled due to a shortage of large-area TJCs.

Tools and methods for automated assembly of miniaturized gear systems

NASA Astrophysics Data System (ADS)

Nienhaus, Matthias; Ehrfeld, Wolfgang; Berg, Udo; Schmitz, Felix; Soultan, H.

2000-10-01

The assembly of gear systems with the size of a pin head is almost beyond the bound of human tactile skills. The magic formula for series fabrication of this hybrid micro systems is the automation of the assembly process. As a contribution, this paper presents and discusses three different assembly methods comprising specifically developed tools for different types of planetary gears with outer diameters of 1.9 mm. Because of the huge importance for the complete micro assembly process, particular attention will be dedicated to the feeding and magazining of the micro gear components. Starting with metallic gear wheels as bulk good, an extremely miniaturized gear system of the Wolfram type has been automatically assembled by employing the strategy of tolerance compensation movement. As a key component, a modular tong gripper with specifically adapted gripping jaws produced by LIGA technology has been used. Further detailed investigations were spend on handling and assembly of micro injection moulded gear wheels made of POM for a three state planetary gear system. One strategy, following the idea of in situ observation, focuses on the intensive use of electronic pattern recognition. Alternatively, an unusual method based on a novel plastic wafer magazine will be discussed in detail. Hereby the exact position and orientation of injection moulded micro components will be presented from the manufacturing process up to the final micro assembly procedure. By simplifying the moulding of the micro gears as well as their handling, storing and assembly, this method has the potential to revolutionize the series fabrication of products with dimensions in the microscopic range in general.

Wheel inspection system environment.

DOT National Transportation Integrated Search

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 ...

Four-Wheel Vehicle Suspension System

NASA Technical Reports Server (NTRS)

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).

Wheel-type magnetic refrigerator

DOEpatents

Barclay, J.A.

1983-10-11

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.

Wheel-type magnetic refrigerator

DOEpatents

Barclay, John A.

1983-01-01

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

Wheel-type magnetic refrigerator

DOEpatents

Barclay, J.A.

1982-01-20

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

Wheel/Rail Noise and Vibration : Volume 1. Mechanics of Wheel Rail Noise Generation.

DOT National Transportation Integrated Search

1975-05-01

The final reports are reported of a project to develop a basic understanding of urban transit wheel/rail noise control measures. Analytical models of impedance, response, radiation efficiency, and directivity of wheels and rails are presented and com...

7. Detail of Flywheels and Drive Assembly, Looking West, Showing ...

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

7. Detail of Flywheels and Drive Assembly, Looking West, Showing (Left to Right): Brake, Pulley Wheel, and Flywheel - Heckert Oil Pumping Jack, 0.6 mile North of Connoquenessing Creek, 0.15 mile East of Powder Mill Creek, Renfrew, Butler County, PA

PowerWheel - A new look at waterwheels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisman, R.N.; Broome, K.R.; Mayo, H.A.

1995-12-31

The PowerWheel is an advanced overshot water wheel, designed to generate electric power at drop structures on canals or on overflow spillways. Unlike the wheels of the 18th and 19th century which were designed to have maximum efficiency at a single flow rate, the current applications demand a wheel that can operate efficiently over a wide range of flows. The prototype PowerWheel will have a width to diameter ratio of 3 or more, in contrast to the wheels of the 19th century, which had large diameters and narrow widths. A model PowerWheel was built of plexiglass and delivered for testingmore » to the Imbt Hydraulics Laboratory at Lehigh University. The wheel has a diameter of 3.5 ft and is 16 in wide. The wheel contains 20 buckets and the bucket depth can be varied from a shallow depth of 4 in to a mid depth of 7 in to 10 in for the deep bucket. The blades have a rather simple geometry with a 4 in radius quarter circle at the outside of the wheel and then straight to the bottom of the bucket. The flume in which the wheel was tested has a width of 18 in. A hole was cut in the head box of the flume and a delivery chute was connected to the head box. The position of the chute can readily be moved up or down in relation to the wheel; for a fixed position of the chute on the head box, the slope of the chute can be changed because the chute was attached to the head box with a piano hinge. The laboratory flow system can deliver flow up to 6 cfs through a calibrated Venturi meter. The PowerWheel was subjected to flows ranging from 0.3 to 3.5 cfs.« less

A Flight-Calibrated Methodology for Determination of Cassini Thruster On-Times for Reaction Wheel Biases

NASA Technical Reports Server (NTRS)

Sarani, Sam

2010-01-01

The Cassini spacecraft, the largest and most complex interplanetary spacecraft ever built, continues to undertake unique scientific observations of planet Saturn, Titan, Enceladus, and other moons of the ring world. In order to maintain a stable attitude during the course of its mission, this three-axis stabilized spacecraft uses two different control systems: the Reaction Control System (or RCS) and the Reaction Wheel Assembly (RWA) control system. In the course of its mission, Cassini performs numerous reaction wheel momentum biases (or unloads) using its reaction control thrusters. The use of the RCS thrusters often imparts undesired velocity changes (delta Vs) on the spacecraft and it is crucial for Cassini navigation and attitude control teams to be able to, quickly but accurately, predict the hydrazine usage and delta V vector in Earth Mean Equatorial (J2000) inertial coordinates for reaction wheel bias events, without actually having to spend time and resources simulating the event in a dynamic or hardware-in-the-loop simulation environments. The flight-calibrated methodology described in this paper, and the ground software developed thereof, are designed to provide the RCS thruster on-times, with acceptable accuracy and without any form of dynamic simulation, for reaction wheel biases, along with the hydrazine usage and the delta V in EME-2000 inertial frame.

Four-wheel dual braking for automobiles

NASA Technical Reports Server (NTRS)

Edwards, H. B.

1981-01-01

Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

Multi-disciplinary optimization of railway wheels

NASA Astrophysics Data System (ADS)

Nielsen, J. C. O.; Fredö, C. R.

2006-06-01

A numerical procedure for multi-disciplinary optimization of railway wheels, based on Design of Experiments (DOE) methodology and automated design, is presented. The target is a wheel design that meets the requirements for fatigue strength, while minimizing the unsprung mass and rolling noise. A 3-level full factorial (3LFF) DOE is used to collect data points required to set up Response Surface Models (RSM) relating design and response variables in the design space. Computationally efficient simulations are thereafter performed using the RSM to identify the solution that best fits the design target. A demonstration example, including four geometric design variables in a parametric finite element (FE) model, is presented. The design variables are wheel radius, web thickness, lateral offset between rim and hub, and radii at the transitions rim/web and hub/web, but more variables (including material properties) can be added if needed. To improve further the performance of the wheel design, a constrained layer damping (CLD) treatment is applied on the web. For a given load case, compared to a reference wheel design without CLD, a combination of wheel shape and damping optimization leads to the conclusion that a reduction in the wheel component of A-weighted rolling noise of 11 dB can be achieved if a simultaneous increase in wheel mass of 14 kg is accepted.

A Nontoxic Barlow's Wheel

NASA Astrophysics Data System (ADS)

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.

Wind wheel electric power generator

NASA Technical Reports Server (NTRS)

Kaufman, J. W. (Inventor)

1980-01-01

Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

Customer loads of two-wheeled vehicles

NASA Astrophysics Data System (ADS)

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.

Reaction wheels for kinetic energy storage

NASA Astrophysics Data System (ADS)

Studer, P. A.

1984-11-01

In contrast to all existing reaction wheel implementations, an order of magnitude increase in speed can be obtained efficiently if power to the actuators can be recovered. This allows a combined attitude control-energy storage system to be developed with structure mounted reaction wheels. The feasibility of combining reaction wheels with energy storage wwheels is demonstrated. The power required for control torques is a function of wheel speed but this energy is not dissipated; it is stored in the wheel. The I(2)R loss resulting from a given torque is shown to be constant, independent of the design speed of the motor. What remains, in order to efficiently use high speed wheels (essential for energy storage) for control purposes, is to reduce rotational losses to acceptable levels. Progress was made in permanent magnet motor design for high speed operation. Variable field motors offer more control flexibility and efficiency over a broader speed range.

Reaction wheels for kinetic energy storage

NASA Technical Reports Server (NTRS)

Studer, P. A.

1984-01-01

In contrast to all existing reaction wheel implementations, an order of magnitude increase in speed can be obtained efficiently if power to the actuators can be recovered. This allows a combined attitude control-energy storage system to be developed with structure mounted reaction wheels. The feasibility of combining reaction wheels with energy storage wwheels is demonstrated. The power required for control torques is a function of wheel speed but this energy is not dissipated; it is stored in the wheel. The I(2)R loss resulting from a given torque is shown to be constant, independent of the design speed of the motor. What remains, in order to efficiently use high speed wheels (essential for energy storage) for control purposes, is to reduce rotational losses to acceptable levels. Progress was made in permanent magnet motor design for high speed operation. Variable field motors offer more control flexibility and efficiency over a broader speed range.

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

PubMed Central

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

2017-01-01

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

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.

PubMed

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

Electron microscopic analysis of rotavirus assembly-replication intermediates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boudreaux, Crystal E.; Kelly, Deborah F.; McDonald, Sarah M., E-mail: mcdonaldsa@vtc.vt.edu

2015-03-15

Rotaviruses (RVs) replicate their segmented, double-stranded RNA genomes in tandem with early virion assembly. In this study, we sought to gain insight into the ultrastructure of RV assembly-replication intermediates (RIs) using transmission electron microscopy (EM). Specifically, we examined a replicase-competent, subcellular fraction that contains all known RV RIs. Three never-before-seen complexes were visualized in this fraction. Using in vitro reconstitution, we showed that ~15-nm doughnut-shaped proteins in strings were nonstructural protein 2 (NSP2) bound to viral RNA transcripts. Moreover, using immunoaffinity-capture EM, we revealed that ~20-nm pebble-shaped complexes contain the viral RNA polymerase (VP1) and RNA capping enzyme (VP3). Finally,more » using a gel purification method, we demonstrated that ~30–70-nm electron-dense, particle-shaped complexes represent replicase-competent core RIs, containing VP1, VP3, and NSP2 as well as capsid proteins VP2 and VP6. The results of this study raise new questions about the interactions among viral proteins and RNA during the concerted assembly–replicase process. - Highlights: • Rotaviruses replicate their genomes in tandem with early virion assembly. • Little is known about rotavirus assembly-replication intermediates. • Assembly-replication intermediates were imaged using electron microscopy.« less

Wheel Diameter and Speedometer Reading

NASA Astrophysics Data System (ADS)

Murray, Clifton

2010-09-01

Most introductory physics students have seen vehicles with nonstandard wheel diameters; some may themselves drive "low-rider" cars or "big-wheel" pickup trucks. But how does changing wheel diameter affect speedometer readout for a given speed? Deriving the answer can be followed readily by students who have been introduced to rotation, and it makes a good illustration of how reasoning in physics can lead to a result that is useful outside the classroom.

77 FR 70478 - RG Steel Wheeling, LLC, Wheeling Office, A Division Of RG Steel, LLC, Including On-Site Leased...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-81,880: TA-A-81,880A] RG Steel Wheeling, LLC, Wheeling Office, A Division Of RG Steel, LLC, Including On-Site Leased Workers From Pro Unlimited and Green Energy Initiatives LLC, Including Workers Whose Wages Were Reported Through Severstal Wheeling, Wheeling, WV: Mountain State...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2012 CFR

2012-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2012-10-01 2012-10-01 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...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2010 CFR

2010-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 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...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2014 CFR

2014-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2014-10-01 2014-10-01 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...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2013 CFR

2013-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2013-10-01 2013-10-01 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...

49 CFR 230.113 - Wheels and tire defects.

Code of Federal Regulations, 2011 CFR

2011-10-01

... crack or break in the flange, tread, rim, plate, hub or brackets. (b) Flat spots. Wheels and tires may... 49 Transportation 4 2011-10-01 2011-10-01 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...

Modelling of Dynamics of a Wheeled Mobile Robot with Mecanum Wheels with the use of Lagrange Equations of the Second Kind

NASA Astrophysics Data System (ADS)

Hendzel, Z.; Rykała, Ł.

2017-02-01

The work presents the dynamic equations of motion of a wheeled mobile robot with mecanum wheels derived with the use of Lagrange equations of the second kind. Mecanum wheels are a new type of wheels used in wheeled mobile robots and they consist of freely rotating rollers attached to the circumference of the wheels. In order to derive dynamic equations of motion of a wheeled mobile robot, the kinetic energy of the system is determined, as well as the generalised forces affecting the system. The resulting mathematical model of a wheeled mobile robot was generated with the use of Maple V software. The results of a solution of inverse and forward problems of dynamics of the discussed object are also published.

Performance of the Boeing LRV wheels in a lunar soil simulant. Report 2: Effects of speed, Wheel load, and soil

NASA Technical Reports Server (NTRS)

Melzer, K.

1971-01-01

Two nearly identical Boeing-GM wire-mesh Lunar Roving Vehicle (LRV) wheels were laboratory tested in a lunar soil simulant to determine the influence of wheel speed and acceleration, wheel load, presence of a fender, travel direction, and soil strength on the wheel performance. Constant-slip and three types of programmed-slip tests were conducted with a single-wheel dynamometer system. Test results indicated that performance of single LRV wheels in terms of pull coefficient, power number, and efficiency were not influenced by wheel speed and acceleration, travel direction, the presence of a fender, or wheel load. Of these variables, only load influenced sinkage, which increased with increasing load. For a given slip, the pull coefficient and power number increased with increasing soil strength. However, for a given pull coefficient or slope, slip was less in firmer soil; thus, the power number decreased and efficiency increased with increasing soil strength.

An Ultrasonic Wheel-Array Probe

NASA Astrophysics Data System (ADS)

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.

Mechanics of wheel-soil interaction

NASA Technical Reports Server (NTRS)

Houland, H. J.

1973-01-01

An approximate theory for wheel-soil interaction is presented which forms the basis for a practical solution to the problem. It is shown that two fundamental observations render the problem determinate: (1) The line of action of the resultant of radial stresses acting at the wheel soil interface approximately bisects the wheel-soil contact angle for all values of slip. (2) A shear stress surface can be hypothesized. The influence of soil inertia forces is also evaluated. A concept of equivalent cohesion is introduced which allows a convenient experimental comparison for both cohesive and frictional soils. This theory compares favorably with previous analyses and experimental data, and shows that soil inertia forces influencing the motion of a rolling wheel can be significant.

Electronic 4-wheel drive control device

NASA Technical Reports Server (NTRS)

Hayato, S.; Takanori, S.; Shigeru, H.; Tatsunori, S.

1984-01-01

The internal rotation torque generated during operation of a 4-wheel drive vehicle is reduced using a control device whose clutch is attached to one part of the rear-wheel drive shaft. One torque sensor senses the drive torque associated with the rear wheel drive shaft. A second sensor senses the drive torque associated with the front wheel drive shaft. Revolution count sensors sense the revolutions of each drive shaft. By means of a microcomputer, the engagement of the clutch is changed to insure that the ratio of the torque sensors remains constant.

Wheeled hopping robot

DOEpatents

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.

STS-109 MS Newman replace Reaction Wheel assembly during EVA 2

NASA Image and Video Library

2002-03-05

STS109-E-5399 (5 March 2002) --- Astronaut James H. Newman, mission specialist, moves about in the Space Shuttle Columbia's cargo bay while working in tandem with astronaut Michael J. Massimino (out of frame), mission specialist, during the STS-109 mission's second day of extravehicular activity (EVA). Inside Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the Remote Manipulator System (RMS) to assist the two in their work on the Hubble Space Telescope (HST). Part of the giant telescope's base, latched down in the payload bay, can be seen just above Newman. The image was recorded with a digital still camera.

The Planning Wheel: Value Added Performance.

ERIC Educational Resources Information Center

Murk, Peter J.; Walls, Jeffrey L.

The "Planning Wheel" is an evolution of the original Systems Approach Model (SAM) that was introduced in 1986 by Murk and Galbraith. Unlike most current planning models, which are linear in design and concept, the Planning Wheel bridges the gap between linear and nonlinear processes. The "Program Planning Wheel" is designed to…

Wheel/Rail Noise and Vibration : Volume 2. Applications to Control of Wheel/Rail Noise.

DOT National Transportation Integrated Search

1975-05-01

The final reports are reported of a project to develop a basic understanding of urban transit wheel/rail noise control measures. Analytical models of impedance, response, radiation efficiency, and directivity of wheels and rails are presented and com...

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

NASA Astrophysics Data System (ADS)

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.

Propulsion and Levitation with a Large Electrodynamic Wheel

NASA Astrophysics Data System (ADS)

Gaul, Nathan; Lane, Hannah

We constructed an electrodynamic wheel using a motorized bicycle wheel with a radius of 12 inches and 36 one-inch cube magnets attached to the rim of the wheel. The radial magnetic field on the outside of the wheel was maximized by arranging the magnets into a series of Halbach arrays which amplify the field on one side of the array and reduce it on the other side. Rotating the wheel produces a rapidly oscillating magnetic field. When a conductive metal ``track'' is placed in this area of strong magnetic flux, eddy currents are produced in the track. These eddy currents create magnetic fields that interact with the magnetic fields from the electrodynamic wheel. The interaction of the magnetic fields produces lift and drag forces on the track which were measured with force gauges. Measurements were taken at a variety of wheel speeds, and the results were compared to the theoretical prediction that there should be a linear relationship between the lift and drag forces with increasing wheel speed. Partial levitation was achieved with the current electrodynamic wheel. In the future, the wheel will be upgraded to include 72 magnets rather than 36 magnets. This will double the frequency at which the magnetic field oscillates, increasing the magnetic flux. Electrodynamic wheels have applications to the transportation industry, since multiple electrodynamic wheels could be used on a vehicle to produce a lift and propulsion force over a conductive track.

29 CFR 1915.134 - Abrasive wheels.

Code of Federal Regulations, 2012 CFR

2012-07-01

... shall be so mounted as to maintain proper alignment with the wheel, and the guard and its fastenings... safety flanges are required, they shall be used only with wheels designed to fit the flanges. Only safety... wheels shall fit freely on the spindle and shall not be forced on. The spindle nut shall be tightened...

29 CFR 1915.134 - Abrasive wheels.

Code of Federal Regulations, 2013 CFR

2013-07-01

... shall be so mounted as to maintain proper alignment with the wheel, and the guard and its fastenings... safety flanges are required, they shall be used only with wheels designed to fit the flanges. Only safety... wheels shall fit freely on the spindle and shall not be forced on. The spindle nut shall be tightened...

29 CFR 1915.134 - Abrasive wheels.

Code of Federal Regulations, 2014 CFR

2014-07-01

... shall be so mounted as to maintain proper alignment with the wheel, and the guard and its fastenings... safety flanges are required, they shall be used only with wheels designed to fit the flanges. Only safety... wheels shall fit freely on the spindle and shall not be forced on. The spindle nut shall be tightened...

OCILOW-Wheeled Platform Controls Executable Set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, John F.

2005-11-30

The OCILOW Controls Executable Set is the complete set of machine executable instructions to control the motion of wheeled platforms that incorporate Off-Centered In-Line Omni-directional Wheels (OCILOW). The controls utilize command signals for the desired motion of the platform (X, Y and Theta) and calculate and control the steering and rolling motion required of each OCILOW wheels to achieve the desired translational and rotational platform motion. The controls utilize signals from the wheel steering and rolling resolvers, and from three load cells located at each wheels, to coordinate the motion of all wheels, while respecting their non-holonomic constraints (i.e., keepingmore » internal stresses and slippage due to possible errors, uneven floors, bumps, misalignment, etc. bounded). The OCILOW Controls Executable Set, which is copyrighted here, is an embodiment of the generic OCILOW algorithms (patented separately) developed specifically for controls of the Proof-of-Principle-Transporter (POP-T) system that has been developed to demonstrate the overall OCILOW controls feasibility and capabilities.« less

Recombinant Expression of Tandem-HBc Virus-Like Particles (VLPs).

PubMed

Stephen, Sam L; Beales, Lucy; Peyret, Hadrien; Roe, Amy; Stonehouse, Nicola J; Rowlands, David J

2018-01-01

The hepatitis B virus (HBV) core protein (HBc) has formed the building block for virus-like particle (VLP) production for more than 30 years. The ease of production of the protein, the robust ability of the core monomers to dimerize and assemble into intact core particles, and the strong immune responses they elicit when presenting antigenic epitopes all demonstrate its promise for vaccine development (reviewed in Pumpens and Grens (Intervirology 44: 98-114, 2001)). HBc has been modified in a number of ways in attempts to expand its potential as a novel vaccine platform. The HBc protein is predominantly α-helical in structure and folds to form an L-shaped molecule. The structural subunit of the HBc particle is a dimer of monomeric HBc proteins which together form an inverted T-shaped structure. In the assembled HBc particle the four-helix bundle formed at each dimer interface appears at the surface as a prominent "spike." The tips of the "spikes" are the preferred sites for the insertion of foreign sequences for vaccine purposes as they are the most highly exposed regions of the assembled particles. In the tandem-core modification two copies of the HBc protein are covalently linked by a flexible amino acid sequence which allows the fused dimer to fold correctly and assemble into HBc particles. The advantage of the modified structure is that the assembly of the dimeric subunits is defined and not formed by random association. This facilitates the introduction of single, larger sequences at the tip of each surface "spike," thus overcoming the conformational clashes contingent on insertion of large structures into monomeric HBc proteins.Differences in inserted sequences influence the assembly characteristics of the modified proteins, and it is important to optimize the design of each novel construct to maximize efficiency of assembly into regular VLPs. In addition to optimization of the construct, the expression system used can also influence the ability of

Break in Raised Tread on Curiosity Wheel

NASA Image and Video Library

2017-03-21

Two of the raised treads, called grousers, on the left middle wheel of NASA's Curiosity Mars rover broke during the first quarter of 2017, including the one seen partially detached at the top of the wheel in this image from the Mars Hand Lens Imager (MAHLI) camera on the rover's arm. This image was taken on March 19, 2017, as part of a set used by rover team members to inspect the condition of the rover's six wheels during the 1,641st Martian day, or sol, of Curiosity's work on Mars. Holes and tears in the wheels worsened significantly during 2013 as Curiosity was crossing terrain studded with sharp rocks on the route from near its 2012 landing site to the base of Mount Sharp. Team members have used MAHLI systematically since then to watch for when any of the zig-zag shaped grousers begin to break. The last prior set of wheel-inspection images from before Sol 1641 was taken on Jan. 27, 2017, (Sol 1591) and revealed no broken grousers. Longevity testing with identical aluminum wheels on Earth indicates that when three grousers on a given wheel have broken, that wheel has reached about 60 percent of its useful life. Curiosity has driven well over 60 percent of the amount needed for reaching all the geological layers planned as the mission's science destinations, so the start of seeing broken grousers is not expected to affect the mission's operations. Curiosity's six aluminum wheels are about 20 inches (50 centimeters) in diameter and 16 inches (40 centimeters) wide. Each of the six wheels has its own drive motor, and the four corner wheels also have steering motors. http://photojournal.jpl.nasa.gov/catalog/PIA21486

An evaluation of reaction wheel emitted vibrations for space telescope

NASA Technical Reports Server (NTRS)

1977-01-01

Emitted forces and moments characteristics of the Space Telescope Reaction Wheel Assembly (ST RWA) were measured under room temperature and pressure, thermal extremes, and vibratory conditions. The RWA/Emitted Vibration Measurement Fixture was calibrated statically and dynamically, and background noise was measured with ST RWA not operating. A base line set of forces and moments of the ST RWA along and about three mutually perpendicular axes were recorded at room ambient. The temperature vibration sensitivites shown are those which were concluded to be a function of rotor unbalance changes and not associated with either spin motor nor rotor electronic changes.

Understanding wheel dynamics.

PubMed

Proffitt, D R; Kaiser, M K; Whelan, S M

1990-07-01

In five experiments, assessments were made of people's understandings about the dynamics of wheels. It was found that undergraduates make highly erroneous dynamical judgments about the motions of this commonplace event, both in explicit problem-solving contexts and when viewing ongoing events. These problems were also presented to bicycle racers and high-school physics teachers; both groups were found to exhibit misunderstandings similar to those of naive undergraduates. Findings were related to our account of dynamical event complexity. The essence of this account is that people encounter difficulties when evaluating the dynamics of any mechanical system that has more than one dynamically relevant object parameter. A rotating wheel is multidimensional in this respect: in addition to the motion of its center of mass, its mass distribution is also of dynamical relevance. People do not spontaneously form the essential multidimensional quantities required to adequately evaluate wheel dynamics.

Mars Pathfinder: The Wheel Abrasion Experiment

NASA Technical Reports Server (NTRS)

1996-01-01

NASA Lewis Research Center's Wheel Abrasion Experiment (WAE) will measure the amount of wear on wheel surfaces of the Mars Pathfinder rover. WAE uses thin films of Al, Ni, and Pt (ranging in thickness from 200 to 1000 angstroms) deposited on black, anodized Al strips attached to the rover wheel. As the wheel moves across the martian surface, changes in film reflectivity will be monitored by reflected sunlight. These changes, measured as output from a special photodetector mounted on the rover chassis, will be due to abrasion of the metal films by martian surface sand, dust, and clay.

47 CFR 69.111 - Tandem-switched transport and tandem charge.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Tandem-switched transport and tandem charge. 69... SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.111 Tandem-switched transport and tandem...-switched transport shall consist of two rate elements, a transmission charge and a tandem switching charge...

[Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics].

PubMed

Kauther, M D; Rummel, S; Hussmann, B; Lendemans, S; Nast-Kolb, D; Wedemeyer, C

2011-12-01

The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate. © Georg Thieme Verlag KG Stuttgart · New York.

Reimagining the Color Wheel

ERIC Educational Resources Information Center

Snyder, Jennifer

2011-01-01

Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

Fracture Resistance of Railroad Wheels

DOT National Transportation Integrated Search

1974-09-01

The effects of manufacturing method, chemical composition, heat treatment, temperature, and loading rate on the plane strain fracture toughness KIC of railroad wheels have been determined. Carbon content of the wheels is shown to be the principal fac...

Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

NASA Technical Reports Server (NTRS)

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.

Why Animals Run on Legs, Not on Wheels.

ERIC Educational Resources Information Center

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)

All-wheel drive and winter-weather safety.

DOT National Transportation Integrated Search

2013-03-01

It is frequently stated that people living in northern states, the so called Snowbelt of the United : States, benefit with respect to safety from driving all-wheel or four-wheel drive vehicles as : opposed to front or rear-wheel drive only. This stud...

Thermal fatigue performance of integrally cast automotive turbine wheels

NASA Technical Reports Server (NTRS)

Humphreys, V. E.; Hofer, K. E.

1980-01-01

Fluidized bed thermal fatigue testing was conducted on 16 integrally cast automotive turbine wheels for 1000-10,000 (600 sec total) thermal cycles at 935/50 C. The 16 wheels consisted of 14 IN-792 + 1% Hf and 2 gatorized AF2-1DA wheels; 6 of the IN-792 + Hf wheels contained crack arrest pockets inside the blade root flange. Temperature transients during the thermal cycling were measured in three calibration tests using either 18 or 30 thermocouples per wheel. Thermal cracking based on crack length versus accumulated cycles was greatest for unpocketed wheels developing cracks in 8-13 cycles compared to 75-250 cycles for unpocketed wheels. However, pocketed wheels survived up to 10,000 cycles with crack lengths less than 20 mm, whereas two unpocketed wheels developed 45 mm long cracks in 1000-2000 cycles.

Ultrasonic search wheel probe

DOEpatents

Mikesell, Charles R.

1978-01-01

A device is provided for reducing internal reflections from the tire of an ultrasonic search wheel probe or from within the material being examined. The device includes a liner with an anechoic chamber within which is an ultrasonic transducer. The liner is positioned within the wheel and includes an aperture through which the ultrasonic sound from the transducer is directed.

Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

NASA Technical Reports Server (NTRS)

Reynolds, R. G.; Markley, F. Landis

2001-01-01

Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum which 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 implementation strategies for specific wheel configurations are also considered.

Determining Wheel-Soil Interaction Loads Using a Meshfree Finite Element Approach Assisting Future Missions with Rover Wheel Design

NASA Technical Reports Server (NTRS)

Contreras, Michael T.; Peng, Chia-Yen; Wang, Dongdong; Chen, Jiun-Shyan

2012-01-01

A wheel experiencing sinkage and slippage events poses a high risk to rover missions as evidenced by recent mobility challenges on the Mars Exploration Rover (MER) project. Because several factors contribute to wheel sinkage and slippage conditions such as soil composition, large deformation soil behavior, wheel geometry, nonlinear contact forces, terrain irregularity, etc., there are significant benefits to modeling these events to a sufficient degree of complexity. For the purposes of modeling wheel sinkage and slippage at an engineering scale, meshfree finite element approaches enable simulations that capture sufficient detail of wheel-soil interaction while remaining computationally feasible. This study demonstrates some of the large deformation modeling capability of meshfree methods and the realistic solutions obtained by accounting for the soil material properties. A benchmark wheel-soil interaction problem is developed and analyzed using a specific class of meshfree methods called Reproducing Kernel Particle Method (RKPM). The benchmark problem is also analyzed using a commercially available finite element approach with Lagrangian meshing for comparison. RKPM results are comparable to classical pressure-sinkage terramechanics relationships proposed by Bekker-Wong. Pending experimental calibration by future work, the meshfree modeling technique will be a viable simulation tool for trade studies assisting rover wheel design.

Voluntary Wheel Running in Mice

PubMed Central

Goh, Jorming; Ladiges, Warren

2015-01-01

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. The basic 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 to 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. PMID:26629772

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2010 CFR

2010-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 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...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2012 CFR

2012-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2012-10-01 2012-10-01 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...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2011 CFR

2011-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2011-10-01 2011-10-01 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...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2014 CFR

2014-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2014-10-01 2014-10-01 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...

49 CFR 229.75 - Wheels and tire defects.

Code of Federal Regulations, 2013 CFR

2013-10-01

... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion welding... 49 Transportation 4 2013-10-01 2013-10-01 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...

Voluntary Wheel Running in Mice.

PubMed

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.

Peculiarities of Clutch Forming Rails and Wheel Block Construction

NASA Astrophysics Data System (ADS)

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.

Geneva mechanism. [including star wheel and driver

NASA Technical Reports Server (NTRS)

Summers, R. H.; Kenney, R. L. (Inventor)

1974-01-01

An improved Geneva mechanism is characterized by a driven star-wheel having a segmented cam-follower surface. Star-wheel driver includes a restraining cam having a segmented cam surface for engaging the cam-follower surface of the star-wheel and antifriction rollers pinned to the restraining cam for engaging the cam-follower surface.

Progress toward a performance based specification for diamond grinding wheels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, J.S.; Piscotty, M.S.; Blaedel, K.L.

1996-11-12

This work sought to improve the communication between users and makers of fine diamond grinding wheels. A promising avenue for this is to formulate a voluntary product standard that comprises performance indicators that bridge the gap between specific user requirements and the details of wheel formulations. We propose a set of performance specifiers of figures-of-merit, that might be assessed by straightforward and traceable testing methods, but do not compromise proprietary information of the wheel user of wheel maker. One such performance indicator might be wheel hardness. In addition we consider technologies that might be required to realize the benefits ofmore » optimized grinding wheels. A non-contact wheel-to- workpiece proximity sensor may provide a means of monitoring wheel wear and thus wheel position, for wheels that exhibit high wear rates in exchange for improved surface finish.« less

The Goal Wheel: Adapting Navajo Philosophy and the Medicine Wheel to Work with Adolescents

ERIC Educational Resources Information Center

Garner, Holly; Bruce, Mary Alice; Stellern, John

2011-01-01

The purpose of this article is to describe a group counseling model that is based on the indigenous medicine wheel as well as Navajo philosophy by which to help troubled adolescents restore harmony and balance in their lives, through establishing goals and sequential steps to accomplish these goals. The authors call this model the Goal Wheel. A…

Two-state dynamics of the SH3-SH2 tandem of Abl kinase and the allosteric role of the N-cap.

PubMed

Corbi-Verge, Carles; Marinelli, Fabrizio; Zafra-Ruano, Ana; Ruiz-Sanz, Javier; Luque, Irene; Faraldo-Gómez, José D

2013-09-03

The regulation and localization of signaling enzymes is often mediated by accessory modular domains, which frequently function in tandems. The ability of these tandems to adopt multiple conformations is as important for proper regulation as the individual domain specificity. A paradigmatic example is Abl, a ubiquitous tyrosine kinase of significant pharmacological interest. SH3 and SH2 domains inhibit Abl by assembling onto the catalytic domain, allosterically clamping it in an inactive state. We investigate the dynamics of this SH3-SH2 tandem, using microsecond all-atom simulations and differential scanning calorimetry. Our results indicate that the Abl tandem is a two-state switch, alternating between the conformation observed in the structure of the autoinhibited enzyme and another configuration that is consistent with existing scattering data for an activated form. Intriguingly, we find that the latter is the most probable when the tandem is disengaged from the catalytic domain. Nevertheless, an amino acid stretch preceding the SH3 domain, the so-called N-cap, reshapes the free-energy landscape of the tandem and favors the interaction of this domain with the SH2-kinase linker, an intermediate step necessary for assembly of the autoinhibited complex. This allosteric effect arises from interactions between N-cap and the SH2 domain and SH3-SH2 connector, which involve a phosphorylation site. We also show that the SH3-SH2 connector plays a determinant role in the assembly equilibrium of Abl, because mutations thereof hinder the engagement of the SH2-kinase linker. These results provide a thermodynamic rationale for the involvement of N-cap and SH3-SH2 connector in Abl regulation and expand our understanding of the principles of modular domain organization.

Tandem Repeat Proteins Inspired By Squid Ring Teeth

NASA Astrophysics Data System (ADS)

Pena-Francesch, Abdon

Proteins are large biomolecules consisting of long chains of amino acids that hierarchically assemble into complex structures, and provide a variety of building blocks for biological materials. The repetition of structural building blocks is a natural evolutionary strategy for increasing the complexity and stability of protein structures. However, the relationship between amino acid sequence, structure, and material properties of protein systems remains unclear due to the lack of control over the protein sequence and the intricacies of the assembly process. In order to investigate the repetition of protein building blocks, a recently discovered protein from squids is examined as an ideal protein system. Squid ring teeth are predatory appendages located inside the suction cups that provide a strong grasp of prey, and are solely composed of a group of proteins with tandem repetition of building blocks. The objective of this thesis is the understanding of sequence, structure and property relationship in repetitive protein materials inspired in squid ring teeth for the first time. Specifically, this work focuses on squid-inspired structural proteins with tandem repeat units in their sequence (i.e., repetition of alternating building blocks) that are physically cross-linked via beta-sheet structures. The research work presented here tests the hypothesis that, in these systems, increasing the number of building blocks in the polypeptide chain decreases the protein network defects and improves the material properties. Hence, the sequence, nanostructure, and properties (thermal, mechanical, and conducting) of tandem repeat squid-inspired protein materials are examined. Spectroscopic structural analysis, advanced materials characterization, and entropic elasticity theory are combined to elucidate the structure and material properties of these repetitive proteins. This approach is applied not only to native squid proteins but also to squid-inspired synthetic polypeptides

Cause of Thermal Fatigue Cracking in Metroliner Wheels

DOT National Transportation Integrated Search

1977-03-01

One new wheel and two used wheels (one with a thermal crack in the tread) were examined for mechanical properties, macrostructure, microstructure, and residual stresses. Similar examinations were conducted on three new wheels which were first subject...

Study of the Correlation between the Performances of Lunar Vehicle Wheels Predicted by the Nepean Wheeled Vehicle Performance Model and Test Data

NASA Technical Reports Server (NTRS)

Wong, J. Y.; Asnani, V. M.

2008-01-01

This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in Performance evaluation of wheels for lunar vehicles , Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 464 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth s gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth s gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth s gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio (P20/W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable

Constructing a Celestial Calendar Wheel.

ERIC Educational Resources Information Center

Cousineau, Sarah M.

1999-01-01

Explains how to create a paper replica of the Bighorn Medicine Wheel, an ancient timepiece thought to have been constructed by the Lakota Indians around 1700 A.D. The Bighorn Wheel uses four key seasonal stars as well as the solstice sunrise and sunset to mark the passage of time through the summer. (WRM)

Determining Spacecraft Reaction Wheel Friction Parameters

NASA Technical Reports Server (NTRS)

Sarani, Siamak

2009-01-01

Software was developed to characterize the drag in each of the Cassini spacecraft's Reaction Wheel Assemblies (RWAs) to determine the RWA friction parameters. This tool measures the drag torque of RWAs for not only the high spin rates (greater than 250 RPM), but also the low spin rates (less than 250 RPM) where there is a lack of an elastohydrodynamic boundary layer in the bearings. RWA rate and drag torque profiles as functions of time are collected via telemetry once every 4 seconds and once every 8 seconds, respectively. Intermediate processing steps single-out the coast-down regions. A nonlinear model for the drag torque as a function of RWA spin rate is incorporated in order to characterize the low spin rate regime. The tool then uses a nonlinear parameter optimization algorithm based on the Nelder-Mead simplex method to determine the viscous coefficient, the Dahl friction, and the two parameters that account for the low spin-rate behavior.

Study on design of light-weight super-abrasive wheel

NASA Astrophysics Data System (ADS)

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.

Space Art "Wheel of Optimism"

NASA Image and Video Library

2006-12-14

Artist EV Day visited the Jet Propulsion Laboratory to learn about the Mars Exploration Rovers. She so intrigued the Mars scientists that she was given a sample rover wheel to work with in creating a piece of art titled "Wheel of Optimism" for NASA. Day took the wheel and created a Martian world within it complete with organic plantlife, rocks and a Martian landscape in the background. Day poetically grapples with the age old question of whether life on Mars exists or whether it is just an figment of our science fiction imaginations. Rover Tire, mixed media, 9-1/4 (diameter)x8 (depth). 2006. Copyrighted: For more information contact Curator, NASA Art Program.

Aerodynamic analysis of an isolated vehicle wheel

NASA Astrophysics Data System (ADS)

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.

Two-state dynamics of the SH3–SH2 tandem of Abl kinase and the allosteric role of the N-cap

PubMed Central

Corbi-Verge, Carles; Marinelli, Fabrizio; Zafra-Ruano, Ana; Ruiz-Sanz, Javier; Luque, Irene; Faraldo-Gómez, José D.

2013-01-01

The regulation and localization of signaling enzymes is often mediated by accessory modular domains, which frequently function in tandems. The ability of these tandems to adopt multiple conformations is as important for proper regulation as the individual domain specificity. A paradigmatic example is Abl, a ubiquitous tyrosine kinase of significant pharmacological interest. SH3 and SH2 domains inhibit Abl by assembling onto the catalytic domain, allosterically clamping it in an inactive state. We investigate the dynamics of this SH3–SH2 tandem, using microsecond all-atom simulations and differential scanning calorimetry. Our results indicate that the Abl tandem is a two-state switch, alternating between the conformation observed in the structure of the autoinhibited enzyme and another configuration that is consistent with existing scattering data for an activated form. Intriguingly, we find that the latter is the most probable when the tandem is disengaged from the catalytic domain. Nevertheless, an amino acid stretch preceding the SH3 domain, the so-called N-cap, reshapes the free-energy landscape of the tandem and favors the interaction of this domain with the SH2-kinase linker, an intermediate step necessary for assembly of the autoinhibited complex. This allosteric effect arises from interactions between N-cap and the SH2 domain and SH3–SH2 connector, which involve a phosphorylation site. We also show that the SH3–SH2 connector plays a determinant role in the assembly equilibrium of Abl, because mutations thereof hinder the engagement of the SH2-kinase linker. These results provide a thermodynamic rationale for the involvement of N-cap and SH3–SH2 connector in Abl regulation and expand our understanding of the principles of modular domain organization. PMID:23959873

Free vibration analysis of composite railway wheels

NASA Astrophysics Data System (ADS)

Ganesan, N.; Ramesh, T. C.

1992-02-01

Composite materials have been finding increasing applications in the field of transportation. A U.S.A. patent suggesting the use of composite materials for railway wheels is the basis for this paper. In thispaper, the natural vibrations of railway wheels made of composite materials have been theoretically estimated by the finite element method and compared with those in wheels made of steel. A thick conical shell element with displacements in the axial, radial and circumferential directions has been used in the analysis. This element brings out the coupling between the different modes of vibration, and this aspect is important in the dynamic analysis of composite wheels. Three geometries of wheels and two materials (Kevlar-epoxy and graphite-epoxy) have been used in the study. For each of these materials, two fiber orientations (radial and circumferential) have been taken up and their natural frequencies determined.

STS-109 MS Massimino and Newman replace Reaction Wheel assembly during EVA 2

NASA Image and Video Library

2002-03-05

STS109-E-5401 (5 March 2002) --- With his feet secured on a platform connected to the remote manipulator system (RMS) robotic arm of the Space Shuttle Columbia, astronaut Michael J. Massimino, mission specialist, hovers over the shuttle's cargo bay while working in tandem with astronaut James H. Newman, mission specialist, during the STS-109 mission's second day of extravehicular activity (EVA). Inside Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the RMS. The image was recorded with a digital still camera.

STS-109 MS Massimino and Newman replace Reaction Wheel assembly during EVA 2

NASA Image and Video Library

2002-03-05

STS109-E-5402 (5 March 2002) --- With his feet secured on a platform connected to the remote manipulator system (RMS) robotic arm of the Space Shuttle Columbia, astronaut Michael J. Massimino, mission specialist, hovers over the shuttle's cargo bay while working in tandem with astronaut James H. Newman, mission specialist, during the STS-109 mission's second day of extravehicular activity (EVA). Inside Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the RMS. The image was recorded with a digital still camera.

Characterization of a starch based desiccant wheel dehumidifier

NASA Astrophysics Data System (ADS)

Beery, Kyle Edward

Starch, cellulose, and hemicellulose have an affinity for water, and adsorb water vapor from air. Materials made from combinations of these biobased sugar polymers also have been found to possess adsorptive properties. An interesting possible application of these starch-based adsorbents is the desiccant wheel dehumidifier. The desiccant wheel dehumidifier is used in conjunction with a standard air conditioning system. In this process, ambient air is passed through a stationary section while a wheel packed with desiccant rotates through that section. The desiccant adsorbs humidity (latent load) from the air, and the air conditioning system then cools the air (sensible load). Several starch based adsorbents were developed and tested for adsorptive capacity in a new high throughput screening system. The best formulations from the high throughput screening system, also taking into account economic considerations and structural integrity, were considered for use in the desiccant wheel dehumidifier. A suitable adsorbent was chosen and formulated into a matrix structure for the desiccant wheel system. A prototype desiccant wheel system was constructed and the performance was investigated under varying regeneration temperatures and rotation speeds. The results from the experiments showed that the starch based desiccant wheel dehumidification system does transfer moisture from the inlet process stream to the outlet regeneration stream. The DESSIM model was modified for the starch based adsorbent and compared to the experimental results. Also, the results when the wheel parameters were varied were compared to the predicted results from the model. The results given by the starch based desiccant wheel system show the desired proof of concept.

An assembly process model based on object-oriented hierarchical time Petri Nets

NASA Astrophysics Data System (ADS)

Wang, Jiapeng; Liu, Shaoli; Liu, Jianhua; Du, Zenghui

2017-04-01

In order to improve the versatility, accuracy and integrity of the assembly process model of complex products, an assembly process model based on object-oriented hierarchical time Petri Nets is presented. A complete assembly process information model including assembly resources, assembly inspection, time, structure and flexible parts is established, and this model describes the static and dynamic data involved in the assembly process. Through the analysis of three-dimensional assembly process information, the assembly information is hierarchically divided from the whole, the local to the details and the subnet model of different levels of object-oriented Petri Nets is established. The communication problem between Petri subnets is solved by using message database, and it reduces the complexity of system modeling effectively. Finally, the modeling process is presented, and a five layer Petri Nets model is established based on the hoisting process of the engine compartment of a wheeled armored vehicle.

Design of a robotic vehicle with self-contained intelligent wheels

NASA Astrophysics Data System (ADS)

Poulson, Eric A.; Jacob, John S.; Gunderson, Robert W.; Abbott, Ben A.

1998-08-01

The Center for Intelligent Systems has developed a small robotic vehicle named the Advanced Rover Chassis 3 (ARC 3) with six identical intelligent wheel units attached to a payload via a passive linkage suspension system. All wheels are steerable, so the ARC 3 can move in any direction while rotating at any rate allowed by the terrain and motors. Each intelligent wheel unit contains a drive motor, steering motor, batteries, and computer. All wheel units are identical, so manufacturing, programing, and spare replacement are greatly simplified. The intelligent wheel concept would allow the number and placement of wheels on the vehicle to be changed with no changes to the control system, except to list the position of all the wheels relative to the vehicle center. The task of controlling the ARC 3 is distributed between one master computer and the wheel computers. Tasks such as controlling the steering motors and calculating the speed of each wheel relative to the vehicle speed in a corner are dependent on the location of a wheel relative to the vehicle center and ar processed by the wheel computers. Conflicts between the wheels are eliminated by computing the vehicle velocity control in the master computer. Various approaches to this distributed control problem, and various low level control methods, have been explored.

Shock-absorbing caster wheel is simple and compact

NASA Technical Reports Server (NTRS)

Kindley, R. J.

1968-01-01

Compact shock-absorbing caster wheel mitigates or absorbs shock by a compressible tire which deforms into a cavity between its inner edge and the wheel hub. A tee-shaped annular ring embedded in the tire distributes loads more uniformly throughout both wheel and tire.

A simulation model for risk assessment of turbine wheels

NASA Technical Reports Server (NTRS)

Safie, Fayssal M.; Hage, Richard T.

1991-01-01

A simulation model has been successfully developed to evaluate the risk of the Space Shuttle auxiliary power unit (APU) turbine wheels for a specific inspection policy. Besides being an effective tool for risk/reliability evaluation, the simulation model also allows the analyst to study the trade-offs between wheel reliability, wheel life, inspection interval, and rejection crack size. For example, in the APU application, sensitivity analysis results showed that the wheel life limit has the least effect on wheel reliability when compared to the effect of the inspection interval and the rejection crack size. In summary, the simulation model developed represents a flexible tool to predict turbine wheel reliability and study the risk under different inspection policies.

A simulation model for risk assessment of turbine wheels

NASA Astrophysics Data System (ADS)

Safie, Fayssal M.; Hage, Richard T.

A simulation model has been successfully developed to evaluate the risk of the Space Shuttle auxiliary power unit (APU) turbine wheels for a specific inspection policy. Besides being an effective tool for risk/reliability evaluation, the simulation model also allows the analyst to study the trade-offs between wheel reliability, wheel life, inspection interval, and rejection crack size. For example, in the APU application, sensitivity analysis results showed that the wheel life limit has the least effect on wheel reliability when compared to the effect of the inspection interval and the rejection crack size. In summary, the simulation model developed represents a flexible tool to predict turbine wheel reliability and study the risk under different inspection policies.

Wheel/Rail Noise and Vibration Control

DOT National Transportation Integrated Search

1974-05-01

Reported here are the interim results of a program under the UMTA Urban Rail Supporting Technology Program to develop a basic understanding of urban transit wheel/rail noise generation for application to the evaluation and improvement of wheel/rail n...

29 CFR 1915.134 - Abrasive wheels.

Code of Federal Regulations, 2011 CFR

2011-07-01

... shall be kept a distance not to exceed 1/8 inch from the surface of the wheel. (c) Cup type wheels used for external grinding shall be protected by either a revolving cup guard or a band type guard in...

29 CFR 1915.134 - Abrasive wheels.

Code of Federal Regulations, 2010 CFR

2010-07-01

... shall be kept a distance not to exceed 1/8 inch from the surface of the wheel. (c) Cup type wheels used for external grinding shall be protected by either a revolving cup guard or a band type guard in...

77 FR 27249 - Certain Steel Wheels From China

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

... Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the subject... of certain steel wheels from China, provided for in subheading 8708.70 of the Harmonized Tariff... preliminary determinations by Commerce that imports of certain steel wheels from China were subsidized within...

14 CFR 29.483 - One-wheel landing conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false One-wheel landing conditions. 29.483 Section 29.483 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... One-wheel landing conditions. For the one-wheel landing condition, the rotorcraft is assumed to be in...

14 CFR 27.483 - One-wheel landing conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false One-wheel landing conditions. 27.483 Section 27.483 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... One-wheel landing conditions. For the one-wheel landing condition, the rotorcraft is assumed to be in...

14 CFR 27.483 - One-wheel landing conditions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false One-wheel landing conditions. 27.483 Section 27.483 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... One-wheel landing conditions. For the one-wheel landing condition, the rotorcraft is assumed to be in...

14 CFR 29.483 - One-wheel landing conditions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false One-wheel landing conditions. 29.483 Section 29.483 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... One-wheel landing conditions. For the one-wheel landing condition, the rotorcraft is assumed to be in...

16 CFR 1512.12 - Requirements for wheel hubs.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Requirements for wheel hubs. 1512.12 Section... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.12 Requirements for wheel hubs. All bicycles (other than sidewalk bicycles) shall meet the following requirements: (a) Locking devices. Wheels shall be...

16 CFR 1512.12 - Requirements for wheel hubs.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Requirements for wheel hubs. 1512.12 Section... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.12 Requirements for wheel hubs. All bicycles (other than sidewalk bicycles) shall meet the following requirements: (a) Locking devices. Wheels shall be...

Aircraft Wheel Life Assessment

DTIC Science & Technology

1993-07-01

L"tV. bM) ~2. REOTDAEJ M YEAN AE CVNE & T AL ND SUBTI. ,5 PU 0010125 AIRCRAFT WHEEL LIFE ASSESSMENT - 13 43105 "s TA 01 B. F. SPENCER, JR., D. J...methodology is the finite element program ANTWIL (ANalysis of Tire-Wheel Interface Loads) [Kandarpa et al ., 1991) which recovers the pressure...to deter- mine the propagation behavior of cracks in the bead seat region [Enneking, 1987; Lawler, et al ., 1989]. While the results of the effort

Phenomena of Foamed Concrete under Rolling of Aircraft Wheels

NASA Astrophysics Data System (ADS)

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.

Biomechanics of liver injury by steering wheel loading.

PubMed

Lau, I V; Horsch, J D; Viano, D C; Andrzejak, D V

1987-03-01

Abdominal injury induced by steering wheel contact at a velocity of 32 km/hr was investigated using anesthetized swine as the surrogate on a Hyge sled. The lower rim of the wheel was positioned 5 cm below the xyphoid. By varying wheel stiffness, wheel orientation, and column angle, resultant abdominal injury ranged from fatal or critical to minor or none. Wheel stiffness was found to be the primary determinant of abdominal injury severity. The mechanism of abdominal injury was identified to be the rim impacting the abdomen and exceeding a combined velocity and compression sensitive tolerance limit. Abdominal injury occurred within the initial 15 ms of wheel contact before whole body movement of the surrogate of column compression, which were initiated by hub contact with the thorax. The severity of abdominal injury correlated with the peak viscous response which can be represented by the product of the instantaneous velocity of abdominal deformation and abdominal compression. It did not correlate with spinal acceleration.

MR-Tandem: parallel X!Tandem using Hadoop MapReduce on Amazon Web Services.

PubMed

Pratt, Brian; Howbert, J Jeffry; Tasman, Natalie I; Nilsson, Erik J

2012-01-01

MR-Tandem adapts the popular X!Tandem peptide search engine to work with Hadoop MapReduce for reliable parallel execution of large searches. MR-Tandem runs on any Hadoop cluster but offers special support for Amazon Web Services for creating inexpensive on-demand Hadoop clusters, enabling search volumes that might not otherwise be feasible with the compute resources a researcher has at hand. MR-Tandem is designed to drop in wherever X!Tandem is already in use and requires no modification to existing X!Tandem parameter files, and only minimal modification to X!Tandem-based workflows. MR-Tandem is implemented as a lightly modified X!Tandem C++ executable and a Python script that drives Hadoop clusters including Amazon Web Services (AWS) Elastic Map Reduce (EMR), using the modified X!Tandem program as a Hadoop Streaming mapper and reducer. The modified X!Tandem C++ source code is Artistic licensed, supports pluggable scoring, and is available as part of the Sashimi project at http://sashimi.svn.sourceforge.net/viewvc/sashimi/trunk/trans_proteomic_pipeline/extern/xtandem/. The MR-Tandem Python script is Apache licensed and available as part of the Insilicos Cloud Army project at http://ica.svn.sourceforge.net/viewvc/ica/trunk/mr-tandem/. Full documentation and a windows installer that configures MR-Tandem, Python and all necessary packages are available at this same URL. brian.pratt@insilicos.com

Reaction Wheel Disturbance Model Extraction Software - RWDMES

NASA Technical Reports Server (NTRS)

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

Investigation of the effects of sliding on wheel tread damage

DOT National Transportation Integrated Search

2005-11-05

Wheel tread spalling is the main source of damage to wheel treads and : a primary cause for wheel removals from service. Severe frictional : heating of the wheel-rail contact patch during sliding causes the : formation of martensite, a hard, brittle ...

The Development of Wheels for the Lunar Roving Vehicle

NASA Technical Reports Server (NTRS)

Asnani, Vivake; Delap, Damon; Creager, Colin

2009-01-01

The Lunar Roving Vehicle (LRV) was developed for NASA s Apollo program so astronauts could cover a greater range on the lunar surface, carry more science instruments, and return more soil and rock samples than by foot. Because of the unique lunar environment, the creation of flexible wheels was the most challenging and time consuming aspect of the LRV development. Wheels developed for previous lunar systems were not sufficient for use with this manned vehicle; therefore, several new designs were created and tested. Based on criteria set by NASA, the choices were narrowed down to two: the wire mesh wheel developed by General Motors (GM), and the hoop spring wheel developed by the Bendix Corporation. Each of these underwent intensive mechanical, material, and terramechanical analyses, and in the end, the wire mesh wheel was chosen for the LRV. Though the wire mesh wheel was determined to be the best choice for its particular application, it may be insufficient towards achieving the objectives of future lunar missions that could require higher tractive capability, increased weight capacity, or extended life. Therefore lessons learned from the original LRV wheel development and suggestions for future Moon wheel projects are offered.

Suspension Parameter Measurements of Wheeled Military Vehicles

DTIC Science & Technology

2012-08-01

suspension through the wheel pads. The SPIdER was designed so that in the future, with a modest amount of modification , it can be upgraded to include the...AND MOBILITY (P&M) MINI-SYMPOSIUM AUGUST 14-16, MICHIGAN SUSPENSION PARAMETER MEASUREMENTS OF WHEELED MILITARY VEHICLES Dale Andreatta Gary...was built to measure the suspension parameters of any military wheeled vehicle. This is part of an ongoing effort to model and predict vehicle

Wheel brakes and their application to aircraft

NASA Technical Reports Server (NTRS)

Dowty, G H

1928-01-01

The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls.

MR-Tandem: parallel X!Tandem using Hadoop MapReduce on Amazon Web Services

PubMed Central

Pratt, Brian; Howbert, J. Jeffry; Tasman, Natalie I.; Nilsson, Erik J.

2012-01-01

Summary: MR-Tandem adapts the popular X!Tandem peptide search engine to work with Hadoop MapReduce for reliable parallel execution of large searches. MR-Tandem runs on any Hadoop cluster but offers special support for Amazon Web Services for creating inexpensive on-demand Hadoop clusters, enabling search volumes that might not otherwise be feasible with the compute resources a researcher has at hand. MR-Tandem is designed to drop in wherever X!Tandem is already in use and requires no modification to existing X!Tandem parameter files, and only minimal modification to X!Tandem-based workflows. Availability and implementation: MR-Tandem is implemented as a lightly modified X!Tandem C++ executable and a Python script that drives Hadoop clusters including Amazon Web Services (AWS) Elastic Map Reduce (EMR), using the modified X!Tandem program as a Hadoop Streaming mapper and reducer. The modified X!Tandem C++ source code is Artistic licensed, supports pluggable scoring, and is available as part of the Sashimi project at http://sashimi.svn.sourceforge.net/viewvc/sashimi/trunk/trans_proteomic_pipeline/extern/xtandem/. The MR-Tandem Python script is Apache licensed and available as part of the Insilicos Cloud Army project at http://ica.svn.sourceforge.net/viewvc/ica/trunk/mr-tandem/. Full documentation and a windows installer that configures MR-Tandem, Python and all necessary packages are available at this same URL. Contact: brian.pratt@insilicos.com PMID:22072385

Power transmission device for four wheel drive vehicle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwatsuki, T.; Kawamoto, M.; Kano, T.

This patent describes a power transmission device with an improved differential motion limiting mechanism for a four wheel drive vehicle having automatic transmission means, front wheel differential gear means, differential motion limiting means and transfer unit means including center differential gear means, comprising: a first gear mount casing having a gear adapted to mesh with an output of a transmission; a differential motion limiting device arranged together with a front wheel differential gear in the first gear mount casing. The front wheel differential gear having a first diff-carrier and the differential motion limiting device comprising a hydraulic friction clutch formore » engaging and disengaging the first gear mount casing with the first diff-carrier of the front wheel differential gear; a second gear mount casing disposed coaxially with respect to the first gear mount casing; and a transfer unit including a center differential gear arranged in the second gear mount casing, the center differential gear comprising a second diff-carrier coupled with the first gear mount casing, a first side gear coupled with the first diff-carrier of the front wheel differential gear, and a second side gear coupled with the second gear mount casing for transmitting power to the rear wheels.« less

16 CFR 1512.12 - Requirements for wheel hubs.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Requirements for wheel hubs. 1512.12 Section... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.12 Requirements for wheel hubs. All bicycles (other... hub retention test, § 1512.18(j)(3), to assure that when the locking devices are released the wheel...

16 CFR 1512.12 - Requirements for wheel hubs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for wheel hubs. 1512.12 Section... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.12 Requirements for wheel hubs. All bicycles (other... hub retention test, § 1512.18(j)(3), to assure that when the locking devices are released the wheel...

Control of wheeled mobile robot in restricted environment

NASA Astrophysics Data System (ADS)

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.

16 CFR 1507.8 - Wheel devices.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Wheel devices. 1507.8 Section 1507.8 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.8 Wheel devices. Drivers in fireworks devices commonly known as “wheels” shall be...

UT Biomedical Informatics Lab (BMIL) probability wheel

NASA Astrophysics Data System (ADS)

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.

Stabilization of the wheel running phenotype in mice.

PubMed

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

Hybrid/Tandem Laser-Arc Welding of Thick Low Carbon Martensitic Stainless Steel Plates =

NASA Astrophysics Data System (ADS)

Mirakhorli, Fatemeh

High efficiency and long-term life of hydraulic turbines and their assemblies are of utmost importance for the hydropower industry. Usually, hydroelectric turbine components are made of thick-walled low carbon martensitic stainless steels. The assembly of large hydroelectric turbine components has been a great challenge. The use of conventional welding processes involves typical large groove design and multi-pass welding to fill the groove which exposes the weld to a high heat input creating relatively large fusion zone and heat affected zone. The newly-developed hybrid/tandem laser-arc welding technique is believed to offer a highly competitive solution to improve the overall hydro-turbine performance by combining the high energy density and fast welding speed of the laser welding technology with the good gap bridging and feeding ability of the gas metal arc welding process to increase the productivity and reduce the consumable material. The main objective of this research work is to understand different challenges appearing during hybrid laser-arc welding (HLAW) of thick gauge assemblies of low carbon 13%Cr- 4%Ni martensitic stainless steel and find a practical solution by adapting and optimizing this relatively new welding process in order to reduce the number of welding passes necessary to fill the groove gap. The joint integrity was evaluated in terms of microstructure, defects and mechanical properties in both as-welded and post-welded conditions. A special focus was given to the hybrid and tandem laser-arc welding technique for the root pass. Based on the thickness of the low carbon martensitic stainless steel plates, this work is mainly focused on the following two tasks: • Single pass hybrid laser-arc welding of 10-mm thick low carbon martensitic stainless steel. • Multi-pass hybrid/tandem laser-arc welding of 25-mm thick martensitic stainless steel.

14 CFR 23.483 - One-wheel landing conditions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false One-wheel landing conditions. 23.483... Ground Loads § 23.483 One-wheel landing conditions. For the one-wheel landing condition, the airplane is assumed to be in the level attitude and to contact the ground on one side of the main landing gear. In...

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

NASA Astrophysics Data System (ADS)

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

Long-Read Single Molecule Sequencing to Resolve Tandem Gene Copies: The Mst77Y Region on the Drosophila melanogaster Y Chromosome

PubMed Central

Krsticevic, Flavia J.; Schrago, Carlos G.; Carvalho, A. Bernardo

2015-01-01

The autosomal gene Mst77F of Drosophila melanogaster is essential for male fertility. In 2010, Krsticevic et al. (Genetics 184: 295−307) found 18 Y-linked copies of Mst77F (“Mst77Y”), which collectively account for 20% of the functional Mst77F-like mRNA. The Mst77Y genes were severely misassembled in the then-available genome assembly and were identified by cloning and sequencing polymerase chain reaction products. The genomic structure of the Mst77Y region and the possible existence of additional copies remained unknown. The recent publication of two long-read assemblies of D. melanogaster prompted us to reinvestigate this challenging region of the Y chromosome. We found that the Illumina Synthetic Long Reads assembly failed in the Mst77Y region, most likely because of its tandem duplication structure. The PacBio MHAP assembly of the Mst77Y region seems to be very accurate, as revealed by comparisons with the previously found Mst77Y genes, a bacterial artificial chromosome sequence, and Illumina reads of the same strain. We found that the Mst77Y region spans 96 kb and originated from a 3.4-kb transposition from chromosome 3L to the Y chromosome, followed by tandem duplications inside the Y chromosome and invasion of transposable elements, which account for 48% of its length. Twelve of the 18 Mst77Y genes found in 2010 were confirmed in the PacBio assembly, the remaining six being polymerase chain reaction−induced artifacts. There are several identical copies of some Mst77Y genes, coincidentally bringing the total copy number to 18. Besides providing a detailed picture of the Mst77Y region, our results highlight the utility of PacBio technology in assembling difficult genomic regions such as tandemly repeated genes. PMID:25858959

Non-Circular Wheels: Reuleaux and Squares

ERIC Educational Resources Information Center

Mills, Allan

2011-01-01

Circular wheels are so familiar on vehicles of all types that it is seldom realized that alternatives do exist. This short non-mathematical article describes Reuleaux and square wheels that, rolling along appropriate tracks, can maintain a moving platform at a constant height. Easily made working models lend themselves to demonstrations at science…

The colour wheels of art, perception, science and physiology

NASA Astrophysics Data System (ADS)

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.

Research on Walking Wheel Slippage Control of Live Inspection Robot

NASA Astrophysics Data System (ADS)

Yan, Yu; Liu, Xiaqing; Guo, Hao; Li, Jinliang; Liu, Lanlan

2017-07-01

To solve the problem of walking wheel slippage of a live inspection robot during walking or climbing, this paper analyzes the climbing capacity of the robot with a statics method, designs a pressing wheel mechanism, and presents a method of indirectly identifying walking wheel slippage by reading speed of the pressing wheel due to the fact that the linear speed of the pressing wheel and the walking wheel at the contract point is the same; and finds that the slippage state can not be controlled through accurate mathematical models after identifying the slippage state, whereas slippage can be controlled with fuzzy control. The experiment results indicate that due to design of the pressing wheel mechanism, friction force of the walking wheel is increased, and the climbing capability of the robot is improved. Within the range of climbing capability of the robot, gradient is the key factor that has influence on slippage of robot, and slippage can be effectively eliminated through the fuzzy control method proposed in this paper.

C57 mice increase wheel-running behavior following stress: preliminary findings.

PubMed

Sibold, Jeremy S; Hammack, Sayamwong E; Falls, William A

2011-10-01

Exercise has been shown to reduce anxiety in both humans and animals. To date, there are few, if any studies that examine the effect of stress on self-selected exercise using an animal model. This study examined the effect of acute stress on wheel-running distance in mice. Forty 8-week-old, male C57BL/6J mice were randomly assigned to one of three groups: no stress + wheel-running experience, stress + wheel-running experience, or stress with no wheel-running experience. Stressed mice were exposed to foot shock in a brightly lit environment. Following treatment, wheel-running distances were observed for three hours. Stress significantly increased voluntary wheel-running in mice with wheel-running experience as compared to nonstressed controls and stressed mice with no wheel-running experience. These results suggest that mice familiar with wheel-running may self-select this exercise as a modality for the mitigation of accumulated anxiety.

Wheel running, voluntary ethanol consumption, and hedonic substitution.

PubMed

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.

Harsh medicine. [retail wheeling experiment in Michigan and side effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Studness, C.M.

1993-07-15

Retailing wheeling's harmful side-effects may surface in a Michigan experiment. In the final analysis, the debate over retail wheeling is about whether there will be direct price competition in the electric power industry. Retail wheeling would extend to the electric power market the same freedom of choice among customers that is present elsewhere in the economy. It would provide a mechanism through which competition could enforce an efficient allocation of resources. It also undoubtedly would eliminate most of the huge discrepancies that exist between so many neighboring service areas. It is unlikely that permitting retail wheeling would actually result inmore » much wheeling or loss of load. Utilities will no doubt meet the threat of the loss of load by cutting rates to hold their customers. Hence, the primary effect would be on the pricing of electricity, not the wheeling of power. The retail wheeling experiment under consideration in Michigan can become an important step toward making the utility industry more efficient for the nation and more equitable for ratepayers. Unfortunately, it also is potentially unfair to the utilities involved. A retail wheeling experiment in one state is likely to put those utilities at risk for competitive attack, but is unlikely to give those utilities the countervailing power to use retail wheeling elsewhere to market their power. Fairness and economic efficiency require that retail wheeling exist everywhere, and that is is accessible to utilities as well as non-utilities.« less

Experiments on a Tail-wheel Shimmy

NASA Technical Reports Server (NTRS)

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.

In-wheel hub SRM simulation and analysis

NASA Astrophysics Data System (ADS)

Sager, Milton W., III

Is it feasible to replace the conventional gasoline engine and subsequent drive system in a motorcycle with an electric switched reluctance motor (SRM) by placing the SRM inside the rear wheel, thereby removing the need for things such as a clutch, chain, transmission, gears and sprockets? The goal of this thesis is to study the theoretical aspect of prototyping and analyzing an in-wheel electric hub motor to replace the standard gasoline engine traditionally found on motorcycles. With the recent push for clean energy, electric vehicles are becoming more common. All currently produced electric motorcycles use conventional, prefabricated electric motors connected to the traditional sprocket and chain design. This greatly restricts the efficiency and range of these motorcycles. My design stands apart by turning the rear wheel into a SRM which uses electromagnets around a non-magnetic core to convert electrical energy into mechanical force driving the rear wheel. To my knowledge, there is currently no motorcycle designed with an in-wheel hub SRM. A three-phase SRM and a five-phase SRM will be simulated and analyzed using MATLAB with Simulink. Factors such as friction, weight, power, etc. will be taken into account in order to create a realistic simulation as if it were inside the rear wheel of a motorcycle. Since time and finances will not allow for a full scale build, a scaled model three-phase SRM will be attempted for demonstration purposes.

Benefits of magnesium wheels for consumer cars

NASA Astrophysics Data System (ADS)

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.

The Fatigue Life Prediction of Train Wheel Rims Containing Spherical Inclusions

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

Low-cost real-time automatic wheel classification system

NASA Astrophysics Data System (ADS)

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.

A Wavelet-Based Methodology for Grinding Wheel Condition Monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, T. W.; Ting, C.F.; Qu, Jun

2007-01-01

Grinding wheel surface condition changes as more material is removed. This paper presents a wavelet-based methodology for grinding wheel condition monitoring based on acoustic emission (AE) signals. Grinding experiments in creep feed mode were conducted to grind alumina specimens with a resinoid-bonded diamond wheel using two different conditions. During the experiments, AE signals were collected when the wheel was 'sharp' and when the wheel was 'dull'. Discriminant features were then extracted from each raw AE signal segment using the discrete wavelet decomposition procedure. An adaptive genetic clustering algorithm was finally applied to the extracted features in order to distinguish differentmore » states of grinding wheel condition. The test results indicate that the proposed methodology can achieve 97% clustering accuracy for the high material removal rate condition, 86.7% for the low material removal rate condition, and 76.7% for the combined grinding conditions if the base wavelet, the decomposition level, and the GA parameters are properly selected.« less

A Flight-Calibrated Methodology for Determination of Cassini Thruster On-Times for Reaction Wheel Biases

NASA Technical Reports Server (NTRS)

Sarani, Siamak

2010-01-01

This paper describes a methodology for accurate and flight-calibrated determination of the on-times of the Cassini spacecraft Reaction Control System (RCS) thrusters, without any form of dynamic simulation, for the reaction wheel biases. The hydrazine usage and the delta V vector in body frame are also computed from the respective thruster on-times. The Cassini spacecraft, the largest and most complex interplanetary spacecraft ever built, continues to undertake ambitious and unique scientific observations of planet Saturn, Titan, Enceladus, and other moons of Saturn. In order to maintain a stable attitude during the course of its mission, this three-axis stabilized spacecraft uses two different control systems: the RCS and the reaction wheel assembly control system. The RCS is used to execute a commanded spacecraft slew, to maintain three-axis attitude control, control spacecraft's attitude while performing science observations with coarse pointing requirements, e.g. during targeted low-altitude Titan and Enceladus flybys, bias the momentum of reaction wheels, and to perform RCS-based orbit trim maneuvers. The use of RCS often imparts undesired delta V on the spacecraft. The Cassini navigation team requires accurate predictions of the delta V in spacecraft coordinates and inertial frame resulting from slews using RCS thrusters and more importantly from reaction wheel bias events. It is crucial for the Cassini spacecraft attitude control and navigation teams to be able to, quickly but accurately, predict the hydrazine usage and delta V for various reaction wheel bias events without actually having to spend time and resources simulating the event in flight software-based dynamic simulation or hardware-in-the-loop simulation environments. The methodology described in this paper, and the ground software developed thereof, are designed to provide just that. This methodology assumes a priori knowledge of thrust magnitudes and thruster pulse rise and tail-off time

16 CFR § 1512.12 - Requirements for wheel hubs.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Requirements for wheel hubs. § 1512.12... ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.12 Requirements for wheel hubs. All bicycles (other than sidewalk bicycles) shall meet the following requirements: (a) Locking devices. Wheels...

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

PubMed

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.

Analysis of wheel rim - Material and manufacturing aspects

NASA Astrophysics Data System (ADS)

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.

Blocking of conditioned taste avoidance induced by wheel running.

PubMed

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

PubMed Central

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. PMID:27458354

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

PubMed

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.

16 CFR 1420.3 - Requirements for four-wheel ATVs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for four-wheel ATVs. 1420.3... REGULATIONS REQUIREMENTS FOR ALL TERRAIN VEHICLES § 1420.3 Requirements for four-wheel ATVs. (a) Each ATV shall comply with all applicable provisions of the American National Standard for Four Wheel All-Terrain...

Wheel-running reinforcement in free-feeding and food-deprived rats.

PubMed

Belke, Terry W; Pierce, W David

2016-03-01

Rats experiencing sessions of 30min free access to wheel running were assigned to ad-lib and food-deprived groups, and given additional sessions of free wheel activity. Subsequently, both ad-lib and deprived rats lever pressed for 60s of wheel running on fixed ratio (FR) 1, variable ratio (VR) 3, VR 5, and VR 10 schedules, and on a response-initiated variable interval (VI) 30s schedule. Finally, the ad-lib rats were switched to food deprivation and the food-deprived rats were switched to free food, as rats continued responding on the response-initiated VI 30-s schedule. Wheel running functioned as reinforcement for both ad-lib and food-deprived rats. Food-deprived rats, however, ran faster and had higher overall lever-pressing rates than free-feeding rats. On the VR schedules, wheel-running rates positively correlated with local and overall lever pressing rates for deprived, but not ad-lib rats. On the response-initiated VI 30s schedule, wheel-running rates and lever-pressing rates changed for ad-lib rats switched to food deprivation, but not for food-deprived rats switched to free-feeding. The overall pattern of results suggested different sources of control for wheel running: intrinsic motivation, contingencies of automatic reinforcement, and food-restricted wheel running. An implication is that generalizations about operant responding for wheel running in food-deprived rats may not extend to wheel running and operant responding of free-feeding animals. Copyright © 2015 Elsevier B.V. All rights reserved.

Pre-exposure to wheel running disrupts taste aversion conditioning.

PubMed

Salvy, Sarah-Jeanne; Pierce, W David; Heth, Donald C; Russell, James C

2002-05-01

When rats are given access to a running wheel after drinking a flavored solution, they subsequently drink less of that flavor solution. It has been suggested that running produces a conditioned taste aversion (CTA). This study explored whether CTA is eliminated by prior exposure to wheel running [i.e., unconditioned stimulus (UCS) pre-exposure effect]. The rats in the experimental group (UW) were allowed to wheel run for 1 h daily for seven consecutive days of pre-exposure. Rats in the two other groups had either access to locked wheels (LW group) or were maintained in their home cages (HC group) during the pre-exposure days. All rats were then exposed to four paired and four unpaired trials using a "ABBAABBA" design. Conditioning trials were composed of one flavored liquid followed by 60-min access to wheel running. For the unpaired trials, rats received a different flavor not followed by the opportunity to run. All rats were then initially tested for water consumption followed by tests of the two flavors (paired or unpaired) in a counterbalanced design. Rats in the UW group show no CTA to the liquid paired with wheel running, whereas LW and HC groups developed CTA. These results indicate that pre-exposure to wheel running (i.e., the UCS), eliminates subsequent CTA.

A Nontoxic Barlow's Wheel

ERIC Educational Resources Information Center

Daffron, John A.; Greenslade, Thomas B., Jr.

2015-01-01

Barlow's wheel has been a favorite demonstration since its invention by Peter Barlow (1776-1862) in 1822. 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…

Magnetic bearing reaction wheel. [for spacecraft attitude control

NASA Technical Reports Server (NTRS)

Sabnis, A.; Schmitt, F.; Smith, L.

1976-01-01

The results of a program for the development, fabrication and functional test of an engineering model magnetically suspended reaction wheel are described. The reaction wheel develops an angular momentum of + or - 0.5 foot-pound-second and is intended for eventual application in the attitude control of long-life interplanetary and orbiting spacecraft. A description of the wheel design and its major performance characteristics is presented. Recommendations for flight prototype development are made.

Hopping Robot with Wheels

NASA Technical Reports Server (NTRS)

Barlow, Edward; Marzwell, Nevellie; Fuller, Sawyer; Fionni, Paolo; Tretton, Andy; Burdick, Joel; Schell, Steve

2003-01-01

A small prototype mobile robot is capable of (1) hopping to move rapidly or avoid obstacles and then (2) moving relatively slowly and precisely on the ground by use of wheels in the manner of previously reported exploratory robots of the "rover" type. This robot is a descendant of a more primitive hopping robot described in "Minimally Actuated Hopping Robot" (NPO- 20911), NASA Tech Briefs, Vol. 26, No. 11 (November 2002), page 50. There are many potential applications for robots with hopping and wheeled-locomotion (roving) capabilities in diverse fields of endeavor, including agriculture, search-and-rescue operations, general military operations, removal or safe detonation of land mines, inspection, law enforcement, and scientific exploration on Earth and remote planets. The combination of hopping and roving enables this robot to move rapidly over very rugged terrain, to overcome obstacles several times its height, and then to position itself precisely next to a desired target. Before a long hop, the robot aims itself in the desired hopping azimuth and at a desired takeoff angle above horizontal. The robot approaches the target through a series of hops and short driving operations utilizing the steering wheels for precise positioning.

Performance of Boeing LRV wheels in a lunar soil simulant. Report 1: Effect of wheel design and soil

NASA Technical Reports Server (NTRS)

Green, A. J.; Melzer, K.

1971-01-01

Six versions of the wire mesh wheel were laboratory tested in a lunar soil simulant, consisting of a crushed basalt with a grainsize distribution similar to that of samples collected during Apollo 11 and 12 flights, to determine their relative performance. The consistency of the soil was varied to cover a range of cohesive and frictional properties to simulate soil conditions assumed to exist on the moon. Programmed-slip and constant-slip tests conducted with the single wheel dynamometer system showed that the performance of the wheel covered with a metal chevron tread over 50 percent of its contact surface was slightly superior to that of other tread designs.

75 FR 32806 - Notice of Issuance of Final Determination Concerning Certain Upright and Recumbent Exercise Bikes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

... assembly, are assembled in the U.S. The primary subassemblies include the wheel assembly; the leg leveler.../shaft; the drive pulley/crank hub; the idler-arm assembly; the alternator- pulley assembly; the rear.... Pressing flange bearing into wheel using arbor press; (wheel assembly) 2. Securing insert to wheel and...

Symmetry based assembly of a 2 dimensional protein lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poulos, Sandra; Agah, Sayeh; Jallah, Nikardi

2017-04-18

The design of proteins that self-assemble into higher order architectures is of great interest due to their potential application in nanotechnology. Specifically, the self-assembly of proteins into ordered lattices is of special interest to the field of structural biology. Here we designed a 2 dimensional (2D) protein lattice using a fusion of a tandem repeat of three TelSAM domains (TTT) to the Ferric uptake regulator (FUR) domain. We determined the structure of the designed (TTT-FUR) fusion protein to 2.3 Å by X-ray crystallographic methods. In agreement with the design, a 2D lattice composed of TelSAM fibers interdigitated by the FURmore » domain was observed. As expected, the fusion of a tandem repeat of three TelSAM domains formed 21 screw axis, and the self-assembly of the ordered oligomer was under pH control. We demonstrated that the fusion of TTT to a domain having a 2-fold symmetry, such as the FUR domain, can produce an ordered 2D lattice. The TTT-FUR system combines features from the rotational symmetry matching approach with the oligomer driven crystallization method. This TTT-FUR fusion was amenable to X-ray crystallographic methods, and is a promising crystallization chaperone.« less

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

PubMed

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.

Wheelchair users' perceptions of and experiences with power assist wheels.

PubMed

Giacobbi, Peter R; Levy, Charles E; Dietrich, Frederick D; Winkler, Sandra Hubbard; Tillman, Mark D; Chow, John W

2010-03-01

To assess wheelchair users' perceptions of and experiences with power assist wheels using qualitative interview methods. Qualitative evaluations were conducted in a laboratory setting with a focus on users' experiences using power assist wheel in their naturalistic environments. Participants consisted of seven women and 13 men (M(age) = 42.75, SD = 14.68) that included one African American, one Hispanic, 17 whites, and one individual from Zambia. Qualitative interviews were conducted before, during, and after use of a power assist wheel. Main outcome measures included the wheelchair users' evaluations and experiences related to the use of power assist wheels. The primary evaluations included wheeling on challenging terrains, performance of novel activities, social/family aspects, fatigue, and pain. These descriptions indicated that most participants perceived positive experiences with the power assist wheels, including access to new and different activities. Secondary evaluations indicated that the unit was cumbersome and prohibitive for some participants because of difficulties with transport in and out of a vehicle and battery life. Most participants felt that power assist wheels provided more independence and social opportunities. The power assist wheel seems to offer physical and social benefits for most wheelers. Clinicians should consider users' home environment and overall life circumstances before prescribing.

Resting Is Rusting: A Critical View on Rodent Wheel-Running Behavior.

PubMed

Richter, Sophie Helene; Gass, Peter; Fuss, Johannes

2014-08-01

Physical exercise is known to exert various beneficial effects on brain function and bodily health throughout life. In biomedical research, these effects are widely studied by introducing running wheels into the cages of laboratory rodents. Yet, although rodents start to run in the wheels immediately, and perform wheel-running excessively on a voluntary basis, the biological significance of wheel-running is still not clear. Here, we review the current literature on wheel-running and discuss potentially negative side-effects that may give cause for concern. We particularly emphasize on analogies of wheel-running with stereotypic and addictive behavior to stimulate further research on this topic. © The Author(s) 2014.

Mobility performance analysis of an innovation lunar rover with diameter-variable wheel

NASA Astrophysics Data System (ADS)

Sun, Gang; Gao, Feng; Sun, Peng; Xu, Guoyan

2007-11-01

To achieve excellent mobility performance, a four-wheel, all-wheel drive lunar rover with diameter-variable wheel was presented, the wheel can be contracted and extended by the motor equipped in the wheel hub, accompanied with wheel diameter varying from 200mm to 390mm. The wheel sinkage and drawbar pull force were predicated with terramechanics formulae and lunar regolith mechanic parameters employed, furthermore, the slope traversability was investigated through quasi-static modeling mechanic analysis, also the obstacle resistance and the maximum negotiable obstacle height for different wheel radius were derived from the equations of static equilibrium of the rover. Analysis results show that for the innovation lunar rover presented, it will bring much better slope traveling stability and obstacle climbing capability than rovers with normal wheels, these will improve the rover mobility performance and stabilize the rover's frame, smooth the motion of sensors.

Rover wheel charging on the lunar surface

NASA Astrophysics Data System (ADS)

Jackson, Telana L.; Farrell, William M.; Zimmerman, Michael I.

2015-03-01

The environment at the Moon is dynamic, with highly variable solar wind plasma conditions at the lunar dayside, terminator, and night side regions. Moving objects such as rover wheels will charge due to contact electrification with the surface, but the degree of charging is controlled by the local plasma environment. Using a dynamic charging model of a wheel, it is demonstrated herein that moving tires will tribocharge substantially when venturing into plasma-current starved regions such as polar craters or the lunar nightside. The surface regolith distribution and the overall effect on charge accumulation of grains cohesively sticking to the rover tire has been incorporated into the model. It is shown that dust sticking can limit the overall charge accumulated on the system. However charge dissipation times are greatly increased in shadowed regions and can present a potential hazard to astronauts and electrical systems performing extra-vehicular activities. We show that dissipation times change with wheel composition and overall system tribocharging is dependent upon wheel velocity.

Wheels With Sense

NASA Astrophysics Data System (ADS)

Cambridge, Dwayne; Clauss, Douglas; Hewson, Fraser; Brown, Robert; Hisrich, Robert; Taylor, Cyrus

2002-10-01

We describe a student intrapreneurial project in the Physics Entrepreneurship Program at Case Western Reserve University. At the request of a major fortune 100 company, a study has been made of the technical and marketing issues for a new business of selling sensors on commercial vehicle wheels for monitoring pressure, temperature, rotations, and vibrations, as well as providing identification. The nature of the physics involved in the choice of the appropriate device such as capacitive or piezoresistive sensors is discussed, along with the possibility of MEMS (micro-electro-mechanical systems) technology and RFID (radiofrequency identification) readout on wheels. Five options (status quo, in-house development, external business acquisition, a large business national partnership, and a small-business Cleveland consortium partnership) were studied from both technological and business perspectives to commercialize the technology. The decision making process for making a choice is explained.

21 CFR 890.3690 - Powered wheeled stretcher.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered wheeled stretcher. 890.3690 Section 890.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3690 Powered wheeled...

21 CFR 890.3690 - Powered wheeled stretcher.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered wheeled stretcher. 890.3690 Section 890.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3690 Powered wheeled...

21 CFR 890.3690 - Powered wheeled stretcher.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered wheeled stretcher. 890.3690 Section 890.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3690 Powered wheeled...

21 CFR 890.3690 - Powered wheeled stretcher.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered wheeled stretcher. 890.3690 Section 890.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3690 Powered wheeled...

21 CFR 890.3690 - Powered wheeled stretcher.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered wheeled stretcher. 890.3690 Section 890.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3690 Powered wheeled...

Retail wheeling - users, utilities and power producers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubacki, J. Jr.

1996-12-31

Information is outlined on the retail wheeling of electric power. Topics discussed include: SEL mission; average cost per kWh; retail pilot programs; retail wheeling activity; key tasks for industrials; power marketer quote; retail wheeling strategic planning; metered customer load profile; proposed ISO regions; conjunctive billing; interconnection areas; FERC order 888; open access same time information systems; transmission inferconnections; suppliers of energy and capacity; self-generation; FERC Form 714; rebundling unbundled services; key variables: load factor; energy and capacity; metering today; competitive industry configuration; power cost reduction: strategic planning; real-time pricing; prime sources of leverage; likeliness of switching utilities; and Strategic Energymore » Ltd.« less

Design and optimisation of wheel-rail profiles for adhesion improvement

NASA Astrophysics Data System (ADS)

Liu, B.; Mei, T. X.; Bruni, S.

2016-03-01

This paper describes a study for the optimisation of the wheel profile in the wheel-rail system to increase the overall level of adhesion available at the contact interface, in particular to investigate how the wheel and rail profile combination may be designed to ensure the improved delivery of tractive/braking forces even in poor contact conditions. The research focuses on the geometric combination of both wheel and rail profiles to establish how the contact interface may be optimised to increase the adhesion level, but also to investigate how the change in the property of the contact mechanics at the wheel-rail interface may also lead to changes in the vehicle dynamic behaviour.

Reinforcement value and substitutability of sucrose and wheel running: implications for activity anorexia.

PubMed

Belke, Terry W; Pierce, W David; Duncan, Ian D

2006-09-01

Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior was allocated to sucrose and more reinforcements were obtained from that alternative. Allocation of behavior to wheel running decreased, but obtained wheel-running reinforcement did not change. Overall, the results suggested that food-deprived rats were sensitive to qualitative changes in food supply (sucrose concentration) while continuing to defend a level of physical activity (wheel running). In the second study, 15 female Long Evans rats were exposed to concurrent variable ratio schedules of sucrose and wheel-running, wheel-running and wheel-running, and sucrose and sucrose reinforcement. For each pair of reinforcers, substitutability was assessed by the effect of income-compensated price changes on consumption of the two reinforcers. Results showed that, as expected, sucrose substituted for sucrose and wheel running substituted for wheel running. Wheel running, however, did not substitute for sucrose; but sucrose partially substituted for wheel running. We address the implications of the interrelationships of sucrose and wheel running for an understanding of activity anorexia.

Method for controlling a vehicle with two or more independently steered wheels

DOEpatents

Reister, D.B.; Unseren, M.A.

1995-03-28

A method is described for independently controlling each steerable drive wheel of a vehicle with two or more such wheels. An instantaneous center of rotation target and a tangential velocity target are inputs to a wheel target system which sends the velocity target and a steering angle target for each drive wheel to a pseudo-velocity target system. The pseudo-velocity target system determines a pseudo-velocity target which is compared to a current pseudo-velocity to determine a pseudo-velocity error. The steering angle targets and the steering angles are inputs to a steering angle control system which outputs to the steering angle encoders, which measure the steering angles. The pseudo-velocity error, the rate of change of the pseudo-velocity error, and the wheel slip between each pair of drive wheels are used to calculate intermediate control variables which, along with the steering angle targets are used to calculate the torque to be applied at each wheel. The current distance traveled for each wheel is then calculated. The current wheel velocities and steering angle targets are used to calculate the cumulative and instantaneous wheel slip and the current pseudo-velocity. 6 figures.

Wheel-running attenuates intravenous cocaine self-administration in rats: sex differences.

PubMed

Cosgrove, Kelly P; Hunter, Robb G; Carroll, Marilyn E

2002-10-01

This experiment examines the effect of access to a running-wheel on intravenous cocaine self-administration in male and female rats. Rats maintained at 85% of their free-feeding body weight were first exposed to the running-wheel alone during the 6-h sessions until behavior stabilized for 14 days. Intravenous cannulae were then implanted, and the rats were trained to self-administer a low dose of cocaine (0.2 mg/kg) under a fixed-ratio (FR 1) schedule during the 6-h sessions, while the wheel remained inactive and cocaine self-administration stabilized (cocaine-only condition). Next, the wheel access and cocaine self-administration were concurrently available followed by a period of cocaine-only. Behavior was allowed to stabilize for 10 days at each phase. During wheel access, cocaine infusions decreased by 21.9% in males and 70.6% in females compared to the cocaine-only condition; the effect was statistically significant in females. Infusions increased to baseline levels when wheel access was terminated. When cocaine infusions were concurrently available, wheel revolutions were reduced by 63.7% and 61.5% in males and females, respectively, compared to the wheel-only condition. This result did not differ due to sex, but it was statistically significant when data from males and females were combined. These results indicate that wheel-running activity had a greater suppressant effect on cocaine self-administration in females than in males, and in females, wheel-running and cocaine self-administration are substitutable as reinforcers.

Wheel running decreases the positive reinforcing effects of heroin.

PubMed

Smith, Mark A; Pitts, Elizabeth G

2012-01-01

The purpose of this study was to examine the effects of voluntary wheel running on the positive reinforcing effects of heroin in rats with an established history of drug self-administration. Rats were assigned to sedentary (no wheel) and exercise (wheel) conditions and trained to self-administer cocaine under positive reinforcement contingencies. Rats acquiring cocaine self-administration were then tested with various doses of heroin during daily test sessions. Sedentary rats self-administered more heroin than exercising rats, and this effect was greatest at low and moderate doses of heroin. These data suggest that voluntary wheel running decreases the positive reinforcing effects of heroin.

Habituation contributes to the decline in wheel running within wheel-running reinforcement periods.

PubMed

Belke, Terry W; McLaughlin, Ryan J

2005-02-28

Habituation appears to play a role in the decline in wheel running within an interval. Aoyama and McSweeney [Aoyama, K., McSweeney, F.K., 2001. Habituation contributes to within-session changes in free wheel running. J. Exp. Anal. Behav. 76, 289-302] showed that when a novel stimulus was presented during a 30-min interval, wheel-running rates following the stimulus increased to levels approximating those earlier in the interval. The present study sought to assess the role of habituation in the decline in running that occurs over a briefer interval. In two experiments, rats responded on fixed-interval 30-s schedules for the opportunity to run for 45 s. Forty reinforcers were completed in each session. In the first experiment, the brake and chamber lights were repeatedly activated and inactivated after 25 s of a reinforcement interval had elapsed to assess the effect on running within the remaining 20 s. Presentations of the brake/light stimulus occurred during nine randomly determined reinforcement intervals in a session. In the second experiment, a 110 dB tone was emitted after 25 s of the reinforcement interval. In both experiments, presentation of the stimulus produced an immediate decline in running that dissipated over sessions. No increase in running following the stimulus was observed in the first experiment until the stimulus-induced decline dissipated. In the second experiment, increases in running were observed following the tone in the first session as well as when data were averaged over several sessions. In general, the results concur with the assertion that habituation plays a role in the decline in wheel running that occurs within both long and short intervals. (c) 2004 Elsevier B.V. All rights reserved.

Increasing Slew Performance of Reaction Wheel Attitude Control Systems

DTIC Science & Technology

2013-09-01

vectors in any arbitrary direction creates the momentum envelope (Chapter IV). The shape of the reaction wheel momentum envelope is a polyhedron [15...performance. This procedural limitation further reduces the operable reaction wheel momentum space polyhedron to the largest inscribed sphere, which...respective plane. These minima are also the global minima, each marked in magenta. The four-wheel polyhedron is again shown in three orthogonal views in

Wheel liner design for improved sound and structural performances

NASA Astrophysics Data System (ADS)

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.

Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia

PubMed Central

Belke, Terry W; Duncan, Ian D; David Pierce, W

2006-01-01

Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior was allocated to sucrose and more reinforcements were obtained from that alternative. Allocation of behavior to wheel running decreased, but obtained wheel-running reinforcement did not change. Overall, the results suggested that food-deprived rats were sensitive to qualitative changes in food supply (sucrose concentration) while continuing to defend a level of physical activity (wheel running). In the second study, 15 female Long Evans rats were exposed to concurrent variable ratio schedules of sucrose and wheel-running, wheel-running and wheel-running, and sucrose and sucrose reinforcement. For each pair of reinforcers, substitutability was assessed by the effect of income-compensated price changes on consumption of the two reinforcers. Results showed that, as expected, sucrose substituted for sucrose and wheel running substituted for wheel running. Wheel running, however, did not substitute for sucrose; but sucrose partially substituted for wheel running. We address the implications of the interrelationships of sucrose and wheel running for an understanding of activity anorexia. PMID:17002224

Stereotypic wheel running decreases cortical activity in mice

PubMed Central

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

The Ferris Wheel and Justifications of Curvature

ERIC Educational Resources Information Center

Stevens, Irma E.; Moore, Kevin C.

2016-01-01

This report discusses the results of semi-structured clinical interviews with ten prospective secondary mathematics teachers who were provided with dynamic images of Ferris wheels. We asked the students to graph the relationship between the distance a rider traveled around the Ferris wheel and the height of the rider from the ground. We focus on…

PROGRESSIVE RESISTANCE VOLUNTARY WHEEL RUNNING IN THE mdx MOUSE

PubMed Central

Call, Jarrod A.; McKeehen, James N.; Novotny, Susan A.; Lowe, Dawn A.

2012-01-01

Exercise training has been minimally explored as a therapy to mitigate the loss of muscle strength for individuals with Duchenne muscular dystrophy (DMD). Voluntary wheel running is known to elicit beneficial adaptations in the mdx mouse model for DMD. The aim of this study was to examine progressive resistance wheel running in mdx mice by comprehensively testing muscle function before, during, and after a 12-week training period. Male mdx mice at ~4 weeks age were randomized into three groups: Sedentary, Free Wheel, and Resist Wheel. Muscle strength was assessed via in vivo dorsiflexion torque, grip strength, and whole body tension intermittently throughout the training period. Contractility of isolated soleus muscles was analyzed at the study’s conclusion. Both Free and Resist Wheel mice had greater grip strength (~22%) and soleus muscle specific tetanic force (26%) compared with Sedentary mice. This study demonstrates that two modalities of voluntary exercise are beneficial to dystrophic muscle and may help establish parameters for an exercise prescription for DMD. PMID:21104862

29 CFR 1926.303 - Abrasive wheels and tools.

Code of Federal Regulations, 2011 CFR

2011-07-01

... distance not to exceed one-eighth inch from the surface of the wheel. (3) Cup type wheels used for external grinding shall be protected by either a revolving cup guard or a band type guard in accordance with the...

29 CFR 1926.303 - Abrasive wheels and tools.

Code of Federal Regulations, 2010 CFR

2010-07-01

... distance not to exceed one-eighth inch from the surface of the wheel. (3) Cup type wheels used for external grinding shall be protected by either a revolving cup guard or a band type guard in accordance with the...

Two men with multiple disabilities carry out an assembly work activity with the support of a technology system.

PubMed

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Green, Vanessa A; Oliva, Doretta; Campodonico, Francesca

2013-10-01

To assess whether two persons with multiple disabilities could learn a work activity (i.e., assembling trolley wheels) with the support of a technology system. After an initial baseline, the study compared the effects of intervention sessions relying on the technology system (which called the participants to the different workstations and provided feedback and final stimulation) with the effects of intervention sessions carried out without technology. The two types of intervention sessions were conducted according to an alternating treatments design. Eventually, only intervention sessions relying on the technology system were used. Both participants managed to assemble wheels independently during intervention sessions relying on the technology system while they failed during sessions without the system. Their performance was strengthened during the final part of the study, in which only sessions with the system occurred. Technology may be critical in helping persons with multiple disabilities manage multi-step work activities.

Fiber optic sensor system for detecting movement or position of a rotating wheel bearing

DOEpatents

Veeser, Lynn R.; Rodriguez, Patrick J.; Forman, Peter R.; Monahan, Russell E.; Adler, Jonathan M.

1997-01-01

An improved fiber optic sensor system and integrated sensor bearing assembly for detecting movement or position of a rotating wheel bearing having a multi-pole tone ring which produces an alternating magnetic field indicative of movement and position of the rotating member. A magneto-optical material, such as a bismuth garnet iron (B.I.G.) crystal, having discrete magnetic domains is positioned in the vicinity of the tone ring so that the domains align themselves to the magnetic field generated by the tone ring. A single fiber optic cable, preferably single mode fiber, carries light generated by a source of light to the B.I.G. crystal. The light passes through the B.I.G. crystal and is refracted at domain boundaries in the crystal. The intensity of the refracted light is indicative of the amount of alignment of the domains and therefore the strength of the magnetic field. The refracted light is carried by the fiber optic cable to an optic receiver where the intensity is measured and an electrical signal is generated and sent to a controller indicating the frequency of the changes in light intensity and therefore the rotational speed of the rotating wheel bearing.

An investigation into the mechanism of the polygonal wear of metro train wheels and its effect on the dynamic behaviour of a wheel/rail system

NASA Astrophysics Data System (ADS)

Jin, Xuesong; Wu, Lei; Fang, Jianying; Zhong, Shuoqiao; Ling, Liang

2012-12-01

This paper presents a detailed investigation conducted into the mechanism of the polygonal wear of metro train wheels through extensive experiments conducted at the sites. The purpose of the experimental investigation is to determine from where the resonant frequency that causes the polygonal wear of the metro train wheels originates. The experiments include the model tests of a vehicle and its parts and the tracks, the dynamic behaviour test of the vehicle in operation and the observation test of the polygonal wear development of the wheels. The tracks tested include the viaducts and the tunnel tracks. The structure model tests show that the average passing frequency of a polygonal wheel is approximately close to the first bending resonant frequency of the wheelset that is found by the wheelset model test and verified by the finite element analysis of the wheelset. Also, the dynamic behaviour test of the vehicle in operation indicates the main frequencies of the vertical acceleration vibration of the axle boxes, which are dominant in the vertical acceleration vibration of the axle boxes and close to the passing frequency of a polygonal wheel, which shows that the first bending resonant frequency of the wheelset is very exciting in the wheelset operation. The observation test of the polygonal wear development of the wheels indicates an increase in the rate of the polygonal wear of the wheels after their re-profiling. This paper also describes the dynamic models used for the metro vehicle coupled with the ballasted track and the slab track to analyse the effect of the polygonal wear of the wheels on the wheel/rail normal forces.

Magnetic power conversion with machines containing full or porous wheel heat exchangers

NASA Astrophysics Data System (ADS)

Egolf, Peter W.; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier

2009-04-01

A first part of the article contains a thermodynamic theory describing the temperature distribution in a Curie wheel. The occurring nonlinear ordinary differential equation has an analytical solution. If a Curie wheel is stabilized by levitation, it is named Palmy wheel. These wheels show a full structure, and because of this reason, their uptake of heat from a flame (Curie wheel) or by (solar) light absorption (Palmy wheel) only on the periphery of a cylinder is very limited. To improve the method, a modification of the principle by introducing a convective heat transport into a porous wheel is discussed. By this the power conversion rate from a heat flux to mechanical and electric power is very much increased. The second part of the article presents results of a theoretical/numerical study on the efficiencies of magnetic power conversion plants operating with porous wheels. Furthermore, these efficiencies—which are promising—are compared with those of existing power conversion plants, as e.g. geothermal binary cycle power plants.

Technics study on high accuracy crush dressing and sharpening of diamond grinding wheel

NASA Astrophysics Data System (ADS)

Jia, Yunhai; Lu, Xuejun; Li, Jiangang; Zhu, Lixin; Song, Yingjie

2011-05-01

Mechanical grinding of artificial diamond grinding wheel was traditional wheel dressing process. The rotate speed and infeed depth of tool wheel were main technics parameters. The suitable technics parameters of metals-bonded diamond grinding wheel and resin-bonded diamond grinding wheel high accuracy crush dressing were obtained by a mount of experiment in super-hard material wheel dressing grind machine and by analysis of grinding force. In the same time, the effect of machine sharpening and sprinkle granule sharpening was contrasted. These analyses and lots of experiments had extent instruction significance to artificial diamond grinding wheel accuracy crush dressing.

49 CFR 230.112 - Wheels and tires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... wheels mounted on the same axle shall not vary more than 1/4 inch. (d) Tire thickness. Wheels may not have tires with a minimum thickness less than that indicated in the table in this paragraph (d). When... the minimum thickness of tires may be as much below the limits specified earlier in this paragraph (d...

Riding the Ferris Wheel: A Sinusoidal Model

ERIC Educational Resources Information Center

Mittag, Kathleen Cage; Taylor, Sharon E.

2011-01-01

When thinking of models for sinusoidal waves, examples such as tides of the ocean, daily temperatures for one year in your town, light and sound waves, and certain types of motion are used. Many textbooks [1, p. 222] also present a "Ferris wheel description problem" for students to work. This activity takes the Ferris wheel problem out of the…

Effect of short-term prefeeding and body weight on wheel running and responding reinforced by the opportunity to run in a wheel.

PubMed

Belke, Terry W; Pierce, W David; Jensen, K

2004-07-30

A biobehavioural analysis of activity anorexia suggests that the motivation for physical activity is regulated by food supply and body weight. In the present experiment, food allocation was varied within subjects by prefeeding food-deprived rats 0, 5, 10 and 15 g of food before sessions of lever pressing for wheel-running reinforcement. The experiment assessed the effects of prefeeding on rates of wheel running, lever pressing, and postreinforcement pausing. Results showed that prefeeding animals 5 g of food had no effect. Prefeeding 10 g of food reduced lever pressing for wheel running and rates of wheel running without a significant change in body weight; the effect was, however, transitory. Prefeeding 15 g of food increased the animals' body weights, resulting in a sustained decrease of wheel running and lever pressing, and an increase in postreinforcement pausing. Overall the results indicate that the motivation for physical activity is regulated by changes in local food supply, but is sustained only when there is a concomitant change in body weight.

Metagenomic assembly through the lens of validation: recent advances in assessing and improving the quality of genomes assembled from metagenomes.

PubMed

Olson, Nathan D; Treangen, Todd J; Hill, Christopher M; Cepeda-Espinoza, Victoria; Ghurye, Jay; Koren, Sergey; Pop, Mihai

2017-08-07

Metagenomic samples are snapshots of complex ecosystems at work. They comprise hundreds of known and unknown species, contain multiple strain variants and vary greatly within and across environments. Many microbes found in microbial communities are not easily grown in culture making their DNA sequence our only clue into their evolutionary history and biological function. Metagenomic assembly is a computational process aimed at reconstructing genes and genomes from metagenomic mixtures. Current methods have made significant strides in reconstructing DNA segments comprising operons, tandem gene arrays and syntenic blocks. Shorter, higher-throughput sequencing technologies have become the de facto standard in the field. Sequencers are now able to generate billions of short reads in only a few days. Multiple metagenomic assembly strategies, pipelines and assemblers have appeared in recent years. Owing to the inherent complexity of metagenome assembly, regardless of the assembly algorithm and sequencing method, metagenome assemblies contain errors. Recent developments in assembly validation tools have played a pivotal role in improving metagenomics assemblers. Here, we survey recent progress in the field of metagenomic assembly, provide an overview of key approaches for genomic and metagenomic assembly validation and demonstrate the insights that can be derived from assemblies through the use of assembly validation strategies. We also discuss the potential for impact of long-read technologies in metagenomics. We conclude with a discussion of future challenges and opportunities in the field of metagenomic assembly and validation. © The Author 2017. Published by Oxford University Press.

Opportunity Rolls Free Again (Four Wheels)

NASA Technical Reports Server (NTRS)

2006-01-01

This animated piece illustrates the recent escape of NASA's Mars Exploration Rover Opportunity from dangerous, loose material on the vast plains leading to the rover's next long-term target, 'Victoria Crater.'

A series of images from the front and rear hazard-avoidance cameras make up this brief movie chronicling the challenge Opportunity faced to free itself from the ripple dubbed 'Jammerbugt.' Each quadrant shows one of the rover's four corner wheels: left front wheel in upper left, right front wheel in upper right, rear wheels in the lower quadrants. The wheels became partially embedded in the ripple at the end of a drive on Opportunity's 833rd Martian day, or sol (May 28, 2006). The images in this clip were taken on sols 836 through 841 (May 31 through June 5, 2006).

Scientists and engineers who had been elated at the meters of progress the rover had been making in earlier drives were happy for even centimeters of advance per sol as they maneuvered their explorer through the slippery material of Jammerbugt. The wheels reached solid footing on a rock outcrop on the final sol of this sequence.

The science and engineering teams appropriately chose the ripple's informal from name the name of a bay on the north coast of Denmark. Jammerbugt, or Jammerbugten, loosely translated, means Bay of Lamentation or Bay of Wailing. The shipping route from the North Sea to the Baltic passes Jammerbugt on its way around the northern tip of Jutland. This has always been an important trade route and many ships still pass by the bay. The prevailing wind directions are typically northwest to southwest with the strongest winds and storms tending to blow from the northwest. A northwesterly wind will blow straight into the Jammerbugt, towards shore. Therefore, in the age of sail, many ships sank there during storms. The shore is sandy, but can have strong waves, so running aground was very dangerous even though there are no rocks.

Fortunately, Opportunity

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

NASA Astrophysics Data System (ADS)

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.

Sustainable Rural Energy: Traditional Water Wheels in Padang (PWW) Indonesia

NASA Astrophysics Data System (ADS)

Ibrahim, Gusri Akhyar; Haron, Che Hassan Che; Azhari, Che Husna

2010-06-01

Renewable and sustainable energy is increasingly gaining interest in current research circles due to the debates on renewable energy resources. It is essential for scientists and researchers to search for solutions in renewable energy resources, with effective technologies, and low cost in operation and maintenance. Hydro resources can be considered a potential renewable energy resource. The traditional water wheel with simple construction coupled with a basic concept of technology can be utilised as a renewable and sustainable rural energy system. This paper discusses the case of the water wheel as a renewable energy system employed in Padang, Indonesia. The Padang water wheel is constructed from hardwood material with a diameter of 300 cm and width of 40 cm. It is built on a river using water flow to generate the movement of the wheel. The water wheel application in the area showed that it is suitable to be utilised to elevate and distribute water to rice fields located at a higher level than the water level of the river. The water wheel capacity is about 100-120 liters/min. It could continuously irrigate ±5 ha. of the rice fields. One of the advantages of this water wheel type is to function as a green technology concept promising no negative effect on the environment. The traditional water wheel has also a big economic impact on the rural economy, increasing the productivity of the rice fields. The people of Padang live in a water landscape encompassing the water wheel as an ubiquitous part of their lives, hence they relate to it and the technology of fabrication as well as the utilisation, making it an amenable and effective technology, finding relevance in the modern world.

Forces on wheels and fuel consumption in cars

NASA Astrophysics Data System (ADS)

Güémez, J.; Fiolhais, M.

2013-07-01

Motivated by real classroom discussions, we analyze the forces acting on moving vehicles, specifically friction on their wheels. In typical front-wheel-drive cars when the car accelerates these forces are in the forward direction in the front wheels, but they are in the opposite direction in the rear wheels. The situation may be intriguing for students, but it may also be helpful and stimulating to clarify the role of friction forces on rolling objects. In this paper we also study the thermodynamical aspects of an accelerating car, relating the distance traveled to the amount of fuel consumed. The fuel consumption is explicitly shown to be Galilean invariant and we identify the Gibbs free energy as the relevant quantity that enters into the thermodynamical description of the accelerating car. The more realistic case of the car's motion with the dragging forces taken into account is also discussed.

Reduction of extinction and reinstatement of cocaine seeking by wheel running in female rats.

PubMed

Zlebnik, Natalie E; Anker, Justin J; Gliddon, Luke A; Carroll, Marilyn E

2010-03-01

Previous work has shown that wheel running reduced the maintenance of cocaine self-administration in rats. In the present study, the effect of wheel running on extinction and reinstatement of cocaine seeking was examined. Female rats were trained to run in a wheel during 6-h sessions, and they were then catheterized and placed in an operant conditioning chamber where they did not have access to the wheel but were allowed to self-administer iv cocaine. Subsequently, rats were divided into four groups and were tested on the extinction and reinstatement of cocaine seeking while they had varying access to a wheel in an adjoining compartment. The four groups were assigned to the following wheel access conditions: (1) wheel running during extinction and reinstatement (WER), (2) wheel running during extinction and a locked wheel during reinstatement (WE), (3) locked wheel during extinction and wheel running during reinstatement (WR), and (4) locked wheel during extinction and reinstatement (WL). WE and WR were retested later to examine the effect of one session of wheel access on cocaine-primed reinstatement. There were no group differences in wheel revolutions, in rate of acquisition of cocaine self-administration, or in responding during maintenance when there was no wheel access. However, during extinction, WE and WER responded less than WR and WL. WR and WER had lower cocaine-primed reinstatement than WE and WL. One session of wheel exposure in WE also suppressed cocaine-primed reinstatement. Wheel running immediately and effectively reduced cocaine-seeking behavior, but concurrent access to running was necessary. Thus, exercise is a useful and self-sustaining intervention to reduce cocaine-seeking behavior.

Innovative grinding wheel design for cost-effective machining of advanced ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Licht, R.H.; Kuo, P.; Liu, S.

2000-05-01

This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

Contamination of the GOES-K filter wheel cooler

NASA Astrophysics Data System (ADS)

Sanders, Jack T., Jr.; Rosecrans, Glenn P.

1998-10-01

The Geostationary Operational Environmental Satellite (GOES) Sounder instrument uses radiant coolers to reduce the operating temperature of the detectors and filter wheel. GOES resides in an equatorial orbit 36,000 kilometers above the earth, and is stationary with respect to it. During the year, all sides of the spacecraft are exposed to the sun; the filter wheel emitter and detector radiators must be shielded form it to adequately cooled these components for nominal operations.Mirror Optical Solar Reflectors are used too reject sunlight before it can strike the radiators. Molecular outgassing from the Sounder instrument cavity, the filter wheel module, and the Sounder vacuum cooler housing have been demonstrated through mass transport modeling to contaminate the filter wheel sunshield panels during the in- orbit Radiant Cooler bakeout. Excessive molecular and particulate contamination can increase solar energy scatter, increase thermal emittance, and increase solar absorptance; all of which can increase the temperature of the components they serve, thus degrading nominal operations. After the GOES-K spacecraft thermal vacuum test, a haze was observed on and around the entrance aperture, and on the inside faces the filter wheel cooler sunshield. This paper documents the inspections, testing, and analysis used to: a) locate the likely sources for the contaminants, b) predict molecular contaminant accumulation on the filter wheel sunshields during the in-orbit bakeout, c) estimate the thermal effects from molecular build-up, and d) assess proposed hardware modifications and show the selection rationale used to maintain functionality for the GOES-K Sounder instrument.

6. VIEW OF BORING MILL. Chuck action of locomotive wheel ...

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

6. VIEW OF BORING MILL. Chuck action of locomotive wheel Wheel weight 1200 pounds, 3'-0' diameter. Table 53' in diameter Wheel is 48'. Largest hole that can be bored is 9-1/2' plus (GE axle is 10'). - Juniata Shops, Erecting Shop & Machine Shop, East of Fourth Avenue, between Fourth & Fifth Streets, Altoona, Blair County, PA

76 FR 18781 - Certain Steel Wheels From China

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-05

...)] Certain Steel Wheels From China AGENCY: United States International Trade Commission. ACTION: Institution... the United States is materially retarded, by reason of imports from China of certain steel wheels... Government of China. Unless the Department of Commerce extends the time for initiation pursuant to sections...

A compact magnetic bearing for gimballed momentum wheel

NASA Technical Reports Server (NTRS)

Yabu-Uchi, K.; Inoue, M.; Akishita, S.; Murakami, C.; Okamoto, O.

1983-01-01

A three axis controlled magnetic bearing and its application to a momentum wheel are described. The four divided stators provide a momentum wheel with high reliability, low weight, large angular momentum storage capacity, and gimbal control. Those characteristics are desirable for spacecraft attitude control.

Lightweight, Self-Deployable Wheels

NASA Technical Reports Server (NTRS)

Chmielewski, Artur; Sokolowski, Witold; Rand, Peter

2003-01-01

Ultra-lightweight, self-deployable wheels made of polymer foams have been demonstrated. These wheels are an addition to the roster of cold hibernated elastic memory (CHEM) structural applications. Intended originally for use on nanorovers (very small planetary-exploration robotic vehicles), CHEM wheels could also be used for many commercial applications, such as in toys. The CHEM concept was reported in "Cold Hibernated Elastic Memory (CHEM) Expandable Structures" (NPO-20394), NASA Tech Briefs, Vol. 23, No. 2 (February 1999), page 56. To recapitulate: A CHEM structure is fabricated from a shape-memory polymer (SMP) foam. The structure is compressed to a very small volume while in its rubbery state above its glass-transition temperature (Tg). Once compressed, the structure can be cooled below Tg to its glassy state. As long as the temperature remains

77 FR 52682 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

... OTR Wheel Engineering, Inc.'s Wheel Hub Assemblies and TRBs,'' dated February 7, 2011 (finding Blackstone OTR LLC and OTR Wheel Engineering, Inc.'s wheel hub assemblies are within the scope of the order... Trend Engineering Ltd.'s Wheel Hub Assemblies,'' dated April 18, 2011 (finding New Trend Engineering...

Covalently Linked Tandem Lesions in DNA

PubMed Central

Patrzyc, Helen B.; Dawidzik, Jean B.; Budzinski, Edwin E.; Freund, Harold G.; Wilton, John H.; Box, Harold C.

2013-01-01

Reactive oxygen species (ROS) generate a type of DNA damage called tandem lesions, two adjacent nucleotides both modified. A subcategory of tandem lesions consists of adjacent nucleotides linked by a covalent bond. Covalently linked tandem lesions generate highly characteristic liquid chromotography-tandem mass spectrometry (LC-MS/MS) elution profiles. We have used this property to comprehensively survey X-irradiated DNA for covalently linked tandem lesions. A total of 15 tandem lesions were detected in DNA irradiated in deoxygenated aqueous solution, five tandem lesions were detected in DNA that was irradiated in oxygenated solution. PMID:23106212

Perspectives on energy storage wheels for space station application

NASA Technical Reports Server (NTRS)

Oglevie, R. E.

1984-01-01

Several of the issues of the workshop are addressed from the perspective of a potential Space Station developer and energy wheel user. Systems' considerations are emphasized rather than component technology. The potential of energy storage wheel (ESW) concept is discussed. The current status of the technology base is described. Justification for advanced technology development is also discussed. The study concludes that energy storage in wheels is an attractive concept for immediate technology development and future Space Station application.

Electric propulsion system for wheeled vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramos, J.A.

1981-11-03

An electric propulsion system for a wheeled vehicle has a generator and motor connected to a drive shaft and an electrical system for charging a battery during all conditions of power transfer from the wheels of the vehicle to the generator to minimize energy required for propulsion. A variable speed power coupling unit connecting the motor to the drive shaft has sprockets revolving about a belt connected sun sprocket with speed control effected by varying the rate of satellite sprocket rotation.

A mechanical model for deformable and mesh pattern wheel of lunar roving vehicle

NASA Astrophysics Data System (ADS)

Liang, Zhongchao; Wang, Yongfu; Chen, Gang (Sheng); Gao, Haibo

2015-12-01

As an indispensable tool for astronauts on lunar surface, the lunar roving vehicle (LRV) is of great significance for manned lunar exploration. An LRV moves on loose and soft lunar soil, so the mechanical property of its wheels directly affects the mobility performance. The wheels used for LRV have deformable and mesh pattern, therefore, the existing mechanical theory of vehicle wheel cannot be used directly for analyzing the property of LRV wheels. In this paper, a new mechanical model for LRV wheel is proposed. At first, a mechanical model for a rigid normal wheel is presented, which involves in multiple conventional parameters such as vertical load, tangential traction force, lateral force, and slip ratio. Secondly, six equivalent coefficients are introduced to amend the rigid normal wheel model to fit for the wheels with deformable and mesh-pattern in LRV application. Thirdly, the values of the six equivalent coefficients are identified by using experimental data obtained in an LRV's single wheel testing. Finally, the identified mechanical model for LRV's wheel with deformable and mesh pattern are further verified and validated by using additional experimental results.

Stress Measurements in Railroad Wheels Via the Barkhausen Effect

DOT National Transportation Integrated Search

1977-02-01

The feasibility of utilizing the Barkhausen Effect in ferromagnetic steels as a nondestructive means for ascertaining residual stresses in railroad wheels was investigated. Railroad wheels are generally manufactured with compressive stress distributi...

Wheel slip dump valve for railway braking system

NASA Astrophysics Data System (ADS)

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.

Bore tube assembly for steam cooling a turbine rotor

DOEpatents

DeStefano, Thomas Daniel; Wilson, Ian David

2002-01-01

An axial bore tube assembly for a turbine is provided to supply cooling steam to hot gas components of the turbine wheels and return the spent cooling steam. A pair of inner and outer tubes define a steam supply passage concentric about an inner return passage. The forward ends of the tubes communicate with an end cap assembly having sets of peripheral holes communicating with first and second sets of radial tubes whereby cooling steam from the concentric passage is supplied through the end cap holes to radial tubes for cooling the buckets and return steam from the buckets is provided through the second set of radial tubes through a second set of openings of the end cap into the coaxial return passage. A radial-to-axial flow transitioning device, including anti-swirling vanes is provided in the end cap. A strut ring adjacent the aft end of the bore tube assembly permits axial and radial thermal expansion of the inner tube relative to the outer tube.

Chiral recognition and selection during the self-assembly process of protein-mimic macroanions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Panchao; Zhang, Zhi-Ming; Lv, Hongjin

The research on chiral recognition and chiral selection is not only fundamental in resolving the puzzle of homochirality, but also instructive in chiral separation and stereoselective catalysis. Here we report the chiral recognition and chiral selection during the self-assembly process of two enantiomeric wheel-shaped macroanions, [Fe28(μ3-O)8(Tart)16(HCOO)24]20- (Tart=D- or L-tartaric acid tetra-anion). The enantiomers are observed to remain self-sorted and self-assemble into their individual assemblies in their racemic mixture solution. The addition of chiral co-anions can selectively suppress the self-assembly process of the enantiomeric macroanions, which is further used to separate the two enantiomers from their mixtures on the basis ofmore » the size difference between the monomers and the assemblies. We believe that delicate long-range electrostatic interactions could be responsible for such high-level chiral recognition and selection.« less

Modeling of traction-coupling properties of wheel propulsor

NASA Astrophysics Data System (ADS)

Sakhapov, R. L.; Nikolaeva, R. V.; Gatiyatullin, M. H.; Makhmutov, M. M.

2017-12-01

In conditions of operation of aggregates on soils with low bearing capacity, the main performance indicators of their operation are determined by the properties of retaining the functional qualities of the propulsor. Therefore, the parameters of the anti-skid device can not be calculated by only one criterion. The equipment of propellers with anti-skid devices, which allow to reduce the compaction effect of the propulsion device on the soil, seems to be a rational solution to the problem of increasing traction and coupling properties of the driving wheels. The mathematical model is based on the study of the interaction of the driving wheel with anti-skid devices and a deformable bearing surface, which takes into account the wheel diameter, skid coefficient, the parameters of the anti-skid device, the physical and mechanical properties of the soil. As a basic mathematical model that determines the dependence of the coupling properties on the wheel parameters, the model obtained as a result of integration and reflecting the process of soil deformation from the shear stress is adopted. The total value of the resistance forces will determine the force of the hitch pressure on the horizontal soil layers, and the value of its deformation is the degree of wheel slippage. When the anti-skid devices interact with the soil, the traction capacity of the wheel is composed of shear forces, soil shear and soil deformation forces with detachable hooks. As a result of the interaction of the hook with the soil, the latter presses against the walls of the hook with the force equal to the sum of the hook load and the resistance to movement. During operation, the linear dimensions of the hook will decrease, which is not taken into account by the safety factor. Abrasive wear of the thickness of the hook is approximately proportional to the work of friction caused by the movement of the hook when inserted into the soil and slipping the wheel.

Applied design methodology for lunar rover elastic wheel

NASA Astrophysics Data System (ADS)

Cardile, Diego; Viola, Nicole; Chiesa, Sergio; Rougier, Alessandro

2012-12-01

In recent years an increasing interest in the Moon surface operations has been experienced. In the future robotic and manned missions of Moon surface exploration will be fundamental in order to lay the groundwork for more ambitious space exploration programs. Surface mobility systems will be the key elements to ensure an efficient and safe Moon exploration. Future lunar rovers are likely to be heavier and able to travel longer distances than the previously developed Moon rover systems. The Lunar Roving Vehicle (LRV) is the only manned rover, which has so far been launched and used on the Moon surface. Its mobility system included flexible wheels that cannot be scaled to the heavier and longer range vehicles. Thus the previously developed wheels are likely not to be suitable for the new larger vehicles. Taking all these considerations into account, on the basis of the system requirements and assumptions, several wheel concepts have been discussed and evaluated through a trade-off analysis. Semi-empirical equations have been utilized to predict the wheel geometrical characteristics, as well as to estimate the motion resistances and the ability of the system to generate thrust. A numerical model has also been implemented, in order to define more into the details the whole wheel design, in terms of wheel geometry and physical properties. As a result of the trade-off analysis, the ellipse wheel concept has shown the best behavior in terms of stiffness, mass budget and dynamic performance. The results presented in the paper have been obtained in cooperation with Thales Alenia Space-Italy and Sicme motori, in the framework of a regional program called STEPS . STEPS-Sistemi e Tecnologie per l'EsPlorazione Spaziale is a research project co-financed by Piedmont Region and firms and universities of the Piedmont Aerospace District in the ambit of the P.O.R-F.E.S.R. 2007-2013 program.

Technological development of multispectral filter assemblies for micro bolometer

NASA Astrophysics Data System (ADS)

Le Goff, Roland; Tanguy, François; Fuss, Philippe; Etcheto, Pierre

2017-11-01

Since 2007 Sodern has successfully developed visible and near infrared multispectral filter assemblies for Earth remote sensing imagers. Filter assembly is manufactured by assembling several sliced filter elements (so-called strips), each corresponding to one spectral band. These strips are cut from wafers using a two dimensional accuracy precision process. In the frame of a 2011 R&T preparatory initiative undertaken by the French agency CNES, the filter assembly concept was adapted by Sodern to the long wave infrared spectral band taken into account the germanium substrate, the multilayer bandpass filters and the F-number of the optics. Indeed the current trend in space instrumentation toward more compact uncooled infrared radiometer leads to replace the filter wheel with a multispectral filter assembly mounted directly above the micro bolometer window. The filter assembly was customized to fit the bolometer size. For this development activity we consider a ULIS VGA LWIR micro bolometer with 640 by 480 pixels and 25 microns pixel pitch. The feasibility of the concept and the ability to withstand space environment were investigated and demonstrated by bread boarding activities. The presentation will contain a detailed description of the bolometer and filter assembly design, the stray light modeling analysis assessing the crosstalk between adjacent spectral bands and the results of the manufacturing and environmental tests (damp heat and thermal vacuum cycling).

Experimental studies of breaking of elastic tired wheel under variable normal load

NASA Astrophysics Data System (ADS)

Fedotov, A. I.; Zedgenizov, V. G.; Ovchinnikova, N. I.

2017-10-01

The paper analyzes the braking of a vehicle wheel subjected to disturbances of normal load variations. Experimental tests and methods for developing test modes as sinusoidal force disturbances of the normal wheel load were used. Measuring methods for digital and analogue signals were used as well. Stabilization of vehicle wheel braking subjected to disturbances of normal load variations is a topical issue. The paper suggests a method for analyzing wheel braking processes under disturbances of normal load variations. A method to control wheel baking processes subjected to disturbances of normal load variations was developed.

Self-Assembly of Porphyrin J-Aggregates

NASA Astrophysics Data System (ADS)

Snitka, Valentinas; Rackaitis, Mindaugas; Navickaite, Gintare

2006-03-01

The porphyrin nanotubes were built by ionic self-assembly of two oppositely charged porphyrins in aqueous solution. The porphyrins in the acid aqueous solution self-assemble into J-aggregates, wheels or other structures. The electrostatic forces between these porphyrin blocks contribute to the formation of porphyrin aggregates in the form of nanotubes, enhance the structural stability of these nanostructures. The nanotubes were composed mixing aqueous solutions of the two porphyrins - anionic Meso-tetra(4- sulfonatophrnyl)porhine dihydrochloride (TPPS4) and cationic Meso-tetra(4-pyridyl)porphine (T4MPyP). The porphyrin nanotubes obtained are hollow structures with the length of 300 nm and diameter 50 nm. Photocatalytic porphyrins are used to reduce metal complexes from aqueous solution and to control the deposition of Au from AuHCl4 and Au nanoparticles colloid solutions onto porphyrin nanotubes. Porphyrin nanotubes are shown to reduce metal complexes and deposit the metal selectively onto the inner or outer surface of the tubes, leading to nanotube-metal composite structures.

Color Wheel Windows

ERIC Educational Resources Information Center

Leonard, Stephanie

2012-01-01

In this article, the author describes a painting and drawing lesson which was inspired by the beautiful circular windows found in cathedrals and churches (also known as "rose windows"). This two-week lesson would reinforce both the concept of symmetry and students' understanding of the color wheel. (Contains 1 online resource.)

Adelphi on Wheels

ERIC Educational Resources Information Center

Levy, Lawrence C.

1976-01-01

Adelphi University has awarded 76 Masters in Business Administration degrees to people in the New York City area who attended its Classroom on Wheels, one specially equipped car on each of four commuter train lines. The program, reaching over 1000 people since 1971 is run and promoted solely on tuition. (JT)

Habituation contributes to within-session changes in free wheel running.

PubMed Central

Aoyama, K; McSweeney, F K

2001-01-01

Three experiments tested the hypothesis that habituation contributes to the regulation of wheel running. Rats ran in a wheel for 30-min sessions. Experiment 1 demonstrated spontaneous recovery. Rats ran more and the within-session decreases in running were smaller after 2 days of wheel deprivation than after 1 day. Experiment 2 demonstrated dishabituation. Running rate increased immediately after the termination of a brief extra event (application of the brake or flashing of the houselight). Experiment 3 demonstrated stimulus specificity. Rats completed the second half of the session in either the same wheel as the first half, or a different wheel. Second-half running was faster in the latter case. Within-session patterns of running were well described by equations that describe data from the habituation, motivation, and operant literatures. These results suggest that habituation contributes to the regulation of running. In fact, habituation provides a better explanation for the termination of wheel running than fatigue, the variable to which this termination is usually attributed. Overall, the present findings are consistent with the proposition that habituation and sensitization contribute to the regulation of several forms of motivated behavior. PMID:11768712

ILC TARGET WHEEL RIM FRAGMENT/GUARD PLATE IMPACT ANALYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagler, L

2008-07-17

A positron source component is needed for the International Linear Collider Project. The leading design concept for this source is a rotating titanium alloy wheel whose spokes rotate through an intense localized magnetic field. The system is composed of an electric motor, flexible motor/drive-shaft coupling, stainless steel drive-shaft, two Plumber's Block tapered roller bearings, a titanium alloy target wheel, and electromagnet. Surrounding the target wheel and magnet is a steel frame with steel guarding plates intended to contain shrapnel in case of catastrophic wheel failure. Figure 1 is a layout of this system (guard plates not shown for clarity). Thismore » report documents the FEA analyses that were performed at LLNL to help determine, on a preliminary basis, the required guard plate thickness for three potential plate steels.« less

Study on general theory of kinematics and dynamics of wheeled mobile robots

NASA Astrophysics Data System (ADS)

Tsukishima, Takahiro; Sasaki, Ken; Takano, Masaharu; Inoue, Kenji

1992-03-01

This paper proposes a general theory of kinematics and dynamics of wheeled mobile robots (WMRs). Unlike robotic manipulators which are modeled as 3-dimensional serial link mechanism, WMRs will be modeled as planar linkage mechanism with multiple links branching out from the base and/or another link. Since this model resembles a tree with branches, it will be called 'tree-structured-link'. The end of each link corresponds to the wheel which is in contact with the floor. In dynamics of WMR, equation of motion of a WMR is derived from joint input torques incorporating wheel dynamics. The wheel dynamics determines forces and moments acting on wheels as a function of slip velocity. This slippage of wheels is essential in dynamics of WMR. It will also be shown that the dynamics of WMR reduces to kinematics when slippage of wheels is neglected. Furthermore, the equation of dynamics is rewritten in velocity input form, since most of industrial motors are velocity controlled.

Design and performance tests of a distributed power-driven wheel loader

NASA Astrophysics Data System (ADS)

Jin, Xiaolin; Shi, Laide; Bian, Yongming

2010-03-01

An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

Design and performance tests of a distributed power-driven wheel loader

NASA Astrophysics Data System (ADS)

Jin, Xiaolin; Shi, Laide; Bian, Yongming

2009-12-01

An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

Automated Array Assembly, Phase 2

NASA Technical Reports Server (NTRS)

Carbajal, B. G.

1979-01-01

The Automated Array Assembly Task, Phase 2 of the Low Cost Silicon Solar Array Project is a process development task. The contract provides for the fabrication of modules from large area tandem junction cells (TJC). During this quarter, effort was focused on the design of a large area, approximately 36 sq cm, TJC and process verification runs. The large area TJC design was optimized for minimum I squared R power losses. In the TJM activity, the cell-module interfaces were defined, module substrates were formed and heat treated and clad metal interconnect strips were fabricated.

Wheel-like Ln18 Cluster Organic Frameworks for Magnetic Refrigeration and Conversion of CO2.

PubMed

Song, Tian-Qun; Dong, Jie; Yang, An-Fei; Che, Xue-Jing; Gao, Hong-Ling; Cui, Jian-Zhong; Zhao, Bin

2018-03-19

Two isostructural 2D MOFs ([Ln 7 (CDA) 6 (HCOO) 3 (μ 3 -OH) 6 (H 2 O) 8 ] n , abbreviated as 1-Gd and 2-Dy) were successfully synthesized under solvothermal conditions. The self-assembly of lanthanide(III) nitrate and 1,1'-cyclopropane-dicarboxylic acid (H 2 CDA) resulted in wheel-like Ln 18 cluster second building units (SBU), which are further linked to six neighboring wheels to generate a 2D ordered honeycomb array. Both 1-Gd and 2-Dy exhibit high thermal stability and decompose above 330 °C. Moreover, they have good solvent stability in ten common solvents and pH stability with pH values from 1 to 13. Magnetic studies reveal that 1-Gd exhibits weak antiferromagnetic coupling between adjacent Gd 3+ ions and has a large magnetocaloric effect of 47.30 J kg -1 K -1 (Δ H = 7.0 T at 2 K), while 2-Dy shows ferromagnetic interaction between adjacent Dy 3+ ions. Interestingly, 1-Gd and 2-Dy can catalyze the cycloaddition of CO 2 to epoxides under mild conditions and can be reused at least five rounds with negligible loss of catalytic performance.

Conditioned taste avoidance induced by forced and voluntary wheel running in rats.

PubMed

Forristall, J R; Hookey, B L; Grant, V L

2007-03-01

Voluntary exercise by rats running in a freely rotating wheel (free wheel) produces conditioned taste avoidance (CTA) of a flavored solution consumed before running [e.g., Lett, B.T., Grant, V.L., 1996. Wheel running induces conditioned taste aversion in rats trained while hungry and thirsty. Physiol. Behav. 59, 699-702]. Forced exercise, swimming or running, also produces CTA in rats [e.g., Masaki, T., Nakajima, S., 2006. Taste aversion induced by forced swimming, voluntary running, forced running, and lithium chloride injection treatments. Physiol. Behav. 88, 411-416]. Energy expenditure may be the critical factor in producing such CTA. If so, forced running in a motorized running wheel should produce CTA equivalent to that produced by a similar amount of voluntary running. In two experiments, we compared forced running in a motorized wheel with voluntary running in a free wheel. Mean distance run over 30 min was equated as closely as possible in the two apparatuses. Both types of exercise produced CTA relative to sedentary, locked-wheel controls. However, voluntary running produced greater CTA than forced running. We consider differences between running in the free and motorized wheels that may account for the differences in strength of CTA.

76 FR 29265 - Certain Steel Wheels From China

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-20

... Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the subject... with material injury by reason of imports from China of certain steel wheels, provided for in... United States at less than fair value (LTFV) and subsidized by the Government of China.\\2\\ \\1\\ The record...

Magnetic suspension options for spacecraft inertia-wheel applications

NASA Technical Reports Server (NTRS)

Downer, J. R.

1984-01-01

Design criteria for spacecraft inertia-wheel suspensions are listed. The advantages of magnetic suspensions over other suspension types for spacecraft inertia-wheel applications are cited along with the functions performed by magnetic suspension. The common designs for magnetic suspensions are enumerated. Materials selection of permanent magnets and core materials is considered.

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

PubMed Central

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

Review of Rail Behavior Under Wheel/Rail Impact Loading

DOT National Transportation Integrated Search

1986-04-01

The report discusses several studies involving factors that significantly affect rail life, particularly wheel impact loads. Parameters that characterize the effect of wheel impact loads on rail behavior are examined in terms of system variables such...

49 CFR 238.119 - Rim-stamped straight-plate wheels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... input to the wheel during braking. (b) A rim-stamped straight-plate wheel shall not be used as a... that is periodically tread-braked for a short duration by automatic circuitry for the sole purpose of...

Method for controlling a vehicle with two or more independently steered wheels

DOEpatents

Reister, David B.; Unseren, Michael A.

1995-01-01

A method (10) for independently controlling each steerable drive wheel (W.sub.i) of a vehicle with two or more such wheels (W.sub.i). An instantaneous center of rotation target (ICR) and a tangential velocity target (v.sup.G) are inputs to a wheel target system (30) which sends the velocity target (v.sub.i.sup.G) and a steering angle target (.theta..sub.i.sup.G) for each drive wheel (W.sub.i) to a pseudovelocity target system (32). The pseudovelocity target system (32) determines a pseudovelocity target (v.sub.P.sup.G) which is compared to a current pseudovelocity (v.sub.P.sup.m) to determine a pseudovelocity error (.epsilon.). The steering angle targets (.theta..sup.G) and the steering angles (.theta..sup.m) are inputs to a steering angle control system (34) which outputs to the steering angle encoders (36), which measure the steering angles (.theta..sup.m). The pseudovelocity error (.epsilon.), the rate of change of the pseudovelocity error ( ), and the wheel slip between each pair of drive wheels (W.sub.i) are used to calculate intermediate control variables which, along with the steering angle targets (.theta..sup.G) are used to calculate the torque to be applied at each wheel (W.sub.i). The current distance traveled for each wheel (W.sub.i) is then calculated. The current wheel velocities (v.sup.m) and steering angle targets (.theta..sup.G) are used to calculate the cumulative and instantaneous wheel slip (e, ) and the current pseudovelocity (v.sub.P.sup.m).

Wheel-Sleeper Impact Model in Rail Vehicles Analysis

NASA Astrophysics Data System (ADS)

Brabie, Dan

The current paper establishes the necessary prerequisites for studying post-derailment dynamic behavior of high-speed rail vehicles by means of multi-body system (MBS) software. A finite-element (FE) model of one rail vehicle wheel impacting a limited concrete sleeper volume is built in LS-DYNA. A novel simulation scheme is employed for obtaining the necessary wheel-sleeper impact data, transferred to the MBS code as pre-defined look-up tables of the wheel's impulse variation during impact. The FE model is tentatively validated successfully by comparing the indentation marks with one photograph from an authentic derailment for a continuous impact sequence over three subsequent sleepers. A post-derailment module is developed and implemented in the MBS simulation tool GENSYS, which detects the wheel contact with sleepers and applies valid longitudinal, lateral and vertical force resultants based on the existing impact conditions. The accuracy of the MBS code in terms of the wheels three-dimensional trajectory over 24 consecutive sleepers is successfully compared with its FE counterpart for an arbitrary impact scenario. An axle mounted brake disc is tested as an alternative substitute guidance mechanism after flange climbing derailments at 100 and 200 km/h on the Swedish high-speed tilting train X 2000. Certain combinations of brake disc geometrical parameters manage to stop the lateral deviation of the wheelsets in circular curve sections at high lateral track plane acceleration.

29 CFR 1910.215 - Abrasive wheel machinery.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and in good balance. There shall be no rough surfaces or sharp edges. (4) Uniformity of diameter. (i... Structural steel (min. tensile strength 60,000 p.s.i.) 1/2 inch or less 14,200 SFPM 1/16 1/16 3/32 3/32 1/8 1... for Straight Flanges—for Mechanical Grinders 12,500 S.F.P.M. to 16,5 S.F.P.M. 1 Wheel diameter Wheel...

29 CFR 1910.215 - Abrasive wheel machinery.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and in good balance. There shall be no rough surfaces or sharp edges. (4) Uniformity of diameter. (i... Structural steel (min. tensile strength 60,000 p.s.i.) 1/2 inch or less 14,200 SFPM 1/16 1/16 3/32 3/32 1/8 1... for Straight Flanges—for Mechanical Grinders 12,500 S.F.P.M. to 16,5 S.F.P.M. 1 Wheel diameter Wheel...

29 CFR 1910.215 - Abrasive wheel machinery.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and in good balance. There shall be no rough surfaces or sharp edges. (4) Uniformity of diameter. (i... Structural steel (min. tensile strength 60,000 p.s.i.) 1/2 inch or less 14,200 SFPM 1/16 1/16 3/32 3/32 1/8 1... for Straight Flanges—for Mechanical Grinders 12,500 S.F.P.M. to 16,5 S.F.P.M. 1 Wheel diameter Wheel...

29 CFR 1910.215 - Abrasive wheel machinery.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and in good balance. There shall be no rough surfaces or sharp edges. (4) Uniformity of diameter. (i... Structural steel (min. tensile strength 60,000 p.s.i.) 1/2 inch or less 14,200 SFPM 1/16 1/16 3/32 3/32 1/8 1... for Straight Flanges—for Mechanical Grinders 12,500 S.F.P.M. to 16,5 S.F.P.M. 1 Wheel diameter Wheel...

29 CFR 1910.215 - Abrasive wheel machinery.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and in good balance. There shall be no rough surfaces or sharp edges. (4) Uniformity of diameter. (i... Structural steel (min. tensile strength 60,000 p.s.i.) 1/2 inch or less 14,200 SFPM 1/16 1/16 3/32 3/32 1/8 1... for Straight Flanges—for Mechanical Grinders 12,500 S.F.P.M. to 16,5 S.F.P.M. 1 Wheel diameter Wheel...

Analytical study of shimmy of airplane wheels

NASA Technical Reports Server (NTRS)

Bourcier De Carbon, Christian

1952-01-01

The problem of shimmy of a castering wheel, such as the nose wheel of a tricycle gear airplane, is treated analytically. The flexibility of the tire is considered to be the primary cause of shimmy. The rather simple theory developed agrees rather well with previous experimental results. The author suggests that shimmy may be eliminated through a suitable choice of landing gear dimensions in lieu of a damper.

The Wheels of Stress Go 'Round and 'Round

ERIC Educational Resources Information Center

Brey, Rebecca A.; Clark, Susan E.

2012-01-01

"The Wheels of Stress Go Round and Round" teaching idea uses three activity wheels to reinforce stress-related content and concepts. After presenting a definition of stress, the instructor assists students in identifying stressors, and aids in formulating a list of negative, reactive behaviors and a list of positive coping mechanisms. Using…

Fluid Mechanics of a High Performance Racing Bicycle Wheel

NASA Astrophysics Data System (ADS)

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.

Dynamics of omnidirectional unmanned rescue vehicle with mecanum wheels

NASA Astrophysics Data System (ADS)

Typiak, Andrzej; Łopatka, Marian Janusz; Rykała, Łukasz; Kijek, Magdalena

2018-01-01

The work presents the dynamic equations of motion of a unmanned six-wheeled vehicle with mecanum wheels for rescue applications derived with the of Lagrange equations of the second kind with multipliers. Analysed vehicle through using mecanum wheels has three degrees of freedom and can move on a flat ground in any direction with any configuration of platform's frame. In order to derive dynamic equations of motion of mentioned object, kinetic potential of the system and generalized forces affecting the system are determined. The results of a solution of inverse dynamics problem are also published.

Judging rolling wheels: Dynamic and kinematic aspects of rotation-translation coupling

NASA Technical Reports Server (NTRS)

Hecht, Heiko

1993-01-01

Four experiments were carried out to investigate observers' abilities to judge rolling motions. The experiments were designed to assess whether two important aspects of such motions are appreciated: the kinematic coupling of rotation and translation, and the dynamic effects of gravity. Different motion contexts of rolling wheels were created using computer-generated displays. The first experiment involved wheels rolling down an inclined plane. Observers spontaneously appreciated the anomaly of wheels that failed to accelerate, but they were not able to differentiate between different acceleration functions. Moreover, their judgements were almost exclusively based on the translation component of the rolling motion, neglecting the rotation component. In a second experiment it was found that observers could accurately estimate the perimeter of various objects. Thus, their inability to consider rotation information is not attributable to misperceptions of the geometry of wheels. In a third experiment the finding that rolling wheels appear to overrotate was replicated; however, findings from this experiment also showed, together with those from a fourth experiment, that observers are able to make very accurate judgments about translation-rotation coupling in rolling wheels when information is provided about the orientation of the wheel and the texture of the surface on which it rolls.

Judging rolling wheels: dynamic and kinematic aspects of rotation-translation coupling.

PubMed

Hecht, H

1993-01-01

Four experiments were carried out to investigate observers' abilities to judge rolling motions. The experiments were designed to assess whether two important aspects of such motions are appreciated: the kinematic coupling of rotation and translation, and the dynamic effects of gravity. Different motion contexts of rolling wheels were created using computer-generated displays. The first experiment involved wheels rolling down an inclined plane. Observers spontaneously appreciated the anomaly of wheels that failed to accelerate, but they were not able to differentiate between different acceleration functions. Moreover, their judgments were almost exclusively based on the translation component of the rolling motion, neglecting the rotation component. In a second experiment it was found that observers could accurately estimate the perimeter of various objects. Thus, their inability to consider rotation information is not attributable to misperceptions of the geometry of wheels. In a third experiment the finding that rolling wheels appear to overrotate was replicated; however, findings from this experiment also showed, together with those from a fourth experiment, that observers are able to make very accurate judgments about translation-rotation coupling in rolling wheels when information is provided about the orientation of the wheel and the texture of the surface on which it rolls.

Design and evaluation of a toroidal wheel for planetary rovers

NASA Technical Reports Server (NTRS)

Koskol, J.; Yerazunis, S. W.

1977-01-01

The inverted toroidal wheel concept was perceived, mathematically quantified, and experimentally verified. The wheel design has a number of important characteristics, namely; (1) the low footprint pressures required for Mars exploration (0.5 to 1.0 psi); (2) high vehicle weight to wheel weight ratios capable of exceeding 10:1; (3) extremely long cyclic endurances tending towards infinite life; and (4) simplicity of design. The concept, in combination with appropriate materials such as titanium or composites, provides a planetary roving vehicle with a very high degree of exploratory mobility, a substantial savings in weight and a high assurity of mission success. Design equations and computation procedures necessary to formulate an inverted wheel are described in detail.

Front and Back Movement Analysis of a Triangle-Structured Three-Wheeled Omnidirectional Mobile Robot by Varying the Angles between Two Selected Wheels.

PubMed

Mohanraj, A P; Elango, A; Reddy, Mutra Chanakya

2016-01-01

Omnidirectional robots can move in all directions without steering their wheels and it can rotate clockwise and counterclockwise with reference to their axis. In this paper, we focused only on front and back movement, to analyse the square- and triangle-structured omnidirectional robot movements. An omnidirectional mobile robot shows different performances with the different number of wheels and the omnidirectional mobile robot's chassis design. Research is going on in this field to improve the accurate movement capability of omnidirectional mobile robots. This paper presents a design of a unique device of Angle Variable Chassis (AVC) for linear movement analysis of a three-wheeled omnidirectional mobile robot (TWOMR), at various angles (θ) between the wheels. Basic mobility algorithm is developed by varying the angles between the two selected omnidirectional wheels in TWOMR. The experiment is carried out by varying the angles (θ = 30°, 45°, 60°, 90°, and 120°) between the two selected omniwheels and analysing the movement of TWOMR in forward direction and reverse direction on a smooth cement surface. Respectively, it is compared to itself for various angles (θ), to get its advantages and weaknesses. The conclusion of the paper provides effective movement of TWOMR at a particular angle (θ) and also the application of TWOMR in different situations.

Curiosity Wheel During Descent

NASA Image and Video Library

2012-08-07

This color thumbnail image was obtained by NASA Curiosity rover illustrating the first appearance of the left front wheel of the Curiosity rover after deployment of the suspension system as the vehicle was about to touch down on Mars.

Three dimensional modeling and dynamic analysis of four-wheel-steering vehicles

NASA Astrophysics Data System (ADS)

Hu, Haiyan; Han, Qiang

2003-02-01

The paper presents a nonlinear dynamic model of 9 degrees of freedom for four-wheel-steering vehicles. Compared with those in previous studies, this model includes the pitch and roll of the vehicle body, the motion of 4 wheels in the accelerating or braking process, the nonlinear coupling of vehicle body and unsprung part, as well as the air drag and wind effect. As a result, the model can be used for the analysis of various maneuvers of the four-wheel-steering vehicles. In addition, the previous models can be considered as a special case of this model. The paper gives some case studies for the dynamic performance of a four-wheel-steering vehicle under step input and saw-tooth input of steering angle applied on the front wheels, respectively.

Rotor bore and turbine rotor wheel/spacer heat exchange flow circuit

DOEpatents

Caruso, Philip M.; Eldrid, Sacheverel Quentin; Ladhani, Azad A.; DeMania, Alan Richard; Palmer, Gene David; Wilson, Ian David; Rathbun, Lisa Shirley; Akin, Robert Craig

2002-01-01

In a turbine having closed-circuit steam-cooling passages about the rim of the rotor during steady-state operation, compressor discharge air is supplied to the rotor bore for passage radially outwardly into the wheel space cavities between the wheels and spacers. Communicating slots and channels in the spacers and wheels at circumferentially spaced positions enable egress of the compressor discharge air into the hot gas flow path. At turbine startup, cooling air flows through the closed-circuit steam passages to cool the outer rim of the rotor while compressor discharge air pre-warms the wheels and spacers. At steady-state, cooling steam is supplied in the closed-circuit steam-cooling passages and compressor discharge air is supplied through the bore and into the wheel space cavities to cool the rotor.

Characterizing the Performance of the Wheel Electrostatic Spectrometer

NASA Technical Reports Server (NTRS)

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

Test Report: Assembly and Structural Loading of Army Research Lab’s High Strength Low Alloy - Vanadium (HSLA - V) Bridge

DTIC Science & Technology

2010-04-28

34 to 1" drive adapter MHE ============ 15,000 lbs forklift 6,000 lbs. forklift 5,000 pallet truck Two 30,000 lbs. 6’x16’ caster wheeled carts...Suggested modifications to reduce assembly time* ================================================== Use powered torque multipliers to torque bolts

Dynamic Wheel-Rail Forces on Mismatched Joints with Ramps

DOT National Transportation Integrated Search

2016-04-12

The discontinuity between rail ends at a joint creates : dynamic wheel-rail forces (i.e. high impact forces and wheel : unloading) that can result in a range of problems including : wear, deterioration, and early failure of the track structure, its :...

The Development of Lightweight Commercial Vehicle Wheels Using Microalloying Steel

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

Inflight Performance of Cassini Reaction Wheel Bearing Drag in 1997-2013

NASA Technical Reports Server (NTRS)

Lee, Allan Y.; Wang, Eric K.

2013-01-01

As the first spacecraft to achieve orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for a first and second extended missions through September 2017. Cassini is a three-axis stabilized spacecraft. It uses reaction wheels to achieve high level of spacecraft pointing stability that is needed during imaging operations of several science instruments. The Cassini flight software makes in-flight estimates of reaction wheel bearing drag torque and made them available to the mission operations team. These telemetry data are being trended for the purpose of monitoring the long-term health of the reaction wheel bearings. Anomalous drag torque signatures observed over the past 15 years are described in this paper. One of these anomalous drag conditions is bearing cage instability that appeared (and disappeared) spontaneously and unpredictably. Cage instability is an uncontrolled vibratory motion of the bearing cage that can produce high-impact forces internal to the bearing that will cause intermittent and erratic torque transients. Characteristics of the observed cage instabilities and other drag torque "spikes" are described in this paper. In day-to-day operations, the reaction wheels' rates must be neither too high nor too low. To protect against operating the wheels in any undesirable conditions (such as prolonged low spin rate operations), a ground software tool named Reaction Wheel Bias Optimization Tool (RBOT) was developed for the management of the wheels. Disciplined and long-term use of this ground software has led to significant reduction in the daily consumption rate of the wheels' low spin rate dwell time. Flight experience on the use of this ground software tool as well as other lessons learned on the management of Cassini reaction wheels is given in this paper.

Detumbling of a rigid spacecraft via torque wheel assisted gyroscopic motion

NASA Astrophysics Data System (ADS)

Lin, Yiing-Yuh; Wang, Chin-Tzuo

2014-01-01

A time and energy efficient two-part method for detumbling a rigid spacecraft using an onboard torque wheel and a set of three-axis magnetic torquer is presented in this paper. Part-1 of the method manipulates the speed of the wheel, whose spin axis is parallel to a designated body axis of a tumbling spacecraft, and induces a desired gyroscopic-like motion to align the designated axis with its total angular momentum, H. The procedure in effect detumbles the spacecraft to rotate about the designated axis and distributes H, which is conserved during this control period, between the body and the wheel. After the alignment is achieved, Part-2 control, activated with a specified momentum transfer parameter, η, can either quickly stop the body rotation by transferring its angular momentum to the wheel or offload most of the momentum into space, using the wheel and the magnetic torquer. Convergence criteria and control laws for both parts are derived from the Lyapunov stability analysis and the method of feedback linearization. The wheel performs as a momentum storing and transferring device regulating the angular momentum between the wheel and the body. It can also provide gyroscopic stiffness to stabilize the system while the magnetic torquer is offloading the momentum. Simulation results from the included cases indicate that significantly fast detumbling of the spacecraft can be achieved with Part-1 of the proposed method. The results also show that, under the same condition, either by transferring almost all H to the wheel or dumping it, the two-part method, with a chosen η and final residual momentum condition, requires much less time and energy needed than the B-dot method does. Moreover, the stability nature of the two-part method is heuristically substantiated as the wheel torques and the dipole moment were constrained in the simulation.

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

PubMed Central

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

2011-01-01

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. PMID:21525375

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

PubMed

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.

Orthogonal tandem catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lohr, Tracy L.; Marks, Tobin J.

2015-05-20

Tandem catalysis is a growing field that is beginning to yield important scientific and technological advances toward new and more efficient catalytic processes. 'One-pot' tandem reactions, where multiple catalysts and reagents, combined in a single reaction vessel undergo a sequence of precisely staged catalytic steps, are highly attractive from the standpoint of reducing both waste and time. Orthogonal tandem catalysis is a subset of one-pot reactions in which more than one catalyst is used to promote two or more mechanistically distinct reaction steps. This Perspective summarizes and analyses some of the recent developments and successes in orthogonal tandem catalysis, withmore » particular focus on recent strategies to address catalyst incompatibility. We also highlight the concept of thermodynamic leveraging by coupling multiple catalyst cycles to effect challenging transformations not observed in single-step processes, and to encourage application of this technique to energetically unfavourable or demanding reactions.« less

The Drag of Airplane Wheels, Wheel Fairings, and Landing Gears - I

NASA Technical Reports Server (NTRS)

Herrnstein, William H; Biermann, David

1935-01-01

This report presents the results of tests made in the 7-by 10-foot wind tunnel and in the 20-foot tunnel of the National Advisory Committee for Aeronautics to determine the drag of a number of airplane wheels, wheel fairings, and landing gears designed or selected for an airplane of 3,000 pounds gross weight. All tests were made on full-size models; those in the 7-by 10-foot tunnel were made at air speeds up to 80 miles per hour and those in the 20-foot tunnel were made at air speeds up to 100 miles per hour. Although most of the landing-gear tests were made in conjunction with a fuselage and at 0 degree pitch angle, some of the tests were made in conjunction with fuselage plus wings and a radial air-cooled engine and at pitch angles from -5 degrees to 6 degrees to obtain an indication of the general effect of these various items on landing-gear drag. All tests were made in the absence of propeller slipstream.

Wheel Unloading of Rail Vehicles Due to Track Twist

DOT National Transportation Integrated Search

1986-02-01

An analysis is presented describing the effect that track twist has on the loads carried by the wheels of a rail car. Wheel unloading is determined as a function of the difference in crosslevel between the truck centers of the car. The different vehi...

Multi-scale Fatigue Damage Life Assessment of Railroad Wheels

DOT National Transportation Integrated Search

2018-01-01

This study focused on the presence of a crack in the railway wheels subsurface and how it affects the wheels fatigue life. A 3-D FE-model was constructed to simulate the stress/strain fields that take place under the rolling contact of railway ...

A comparison of two types of running wheel in terms of mouse preference, health, and welfare.

PubMed

Walker, Michael; Mason, Georgia

2018-07-01

Voluntary wheel running occurs in mice of all strains, sexes, and ages. Mice find voluntary wheel running rewarding, and it leads to numerous health benefits. For this reason wheels are used both to enhance welfare and to create models of exercise. However, many designs of running wheel are used. This makes between-study comparisons difficult, as this variability could potentially affect the amount, pattern, and/or intensity of running behaviour, and thence the wheels' effects on welfare and exercise-related changes in anatomy and physiology. This study therefore evaluated two commercially available models, chosen because safe for group-housed mice: Bio Serv®'s "fast-trac" wheel combo and Ware Manufacturing Inc.'s stainless steel mesh 5″ upright wheel. Working with a total of three hundred and fifty one female C57BL/6, DBA/2 and BALB/c mice, we assessed these wheels' relative utilization by mice when access was free; the strength of motivation for each wheel-type when access required crossing an electrified grid; and the impact each wheel had on mouse well-being (inferred from acoustic startle responses and neophobia) and exercise-related anatomical changes (BMI; heart and hind limb masses). Mice ran more on the "fast-trac" wheel regardless of whether both wheel-types were available at once, or only if one was present. In terms of motivation, subjects required to work to access a single wheel worked equally hard for both wheel-types (even if locked and thus not useable for running), but if provided with one working wheel for free and the other type of wheel (again unlocked) accessible via crossing the electrified grid, the "fast-trac" wheel emerged as more motivating, as the Maximum Price Paid for the Ware metal wheel was lower than that paid for the "fast-trac" plastic wheel, at least for C57BL/6s and DBA/2s. No deleterious consequences were noted with either wheel in terms of health and welfare, but only mice with plastic wheels developed significantly larger

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

NASA Astrophysics Data System (ADS)

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.

9. Close view of gate valves (foreground), paddle wheel guard ...

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

9. Close view of gate valves (foreground), paddle wheel guard (midground), and water wheel (background), facing southeast (downstream) from drum screen cover. - Congdon Canal, Fish Screen, Naches River, Yakima, Yakima County, WA

Design study for a magnetically supported reaction wheel

NASA Technical Reports Server (NTRS)

Stocking, G.; Dendy, J.; Sabnis, A.

1974-01-01

Results are described of a study program in which the characteristics of a magnetically supported reaction wheel are defined. Tradeoff analyses are presented for the principal components, which are then combined in several reaction wheel design concepts. A preliminary layout of the preferred configuration is presented along with calculated design and performance parameters. Recommendations are made for a prototype development program.

On the importance of a funneled energy landscape for the assembly and regulation of multidomain Src tyrosine kinases.

PubMed

Faraldo-Gómez, José D; Roux, Benoît

2007-08-21

Regulation of signaling pathways in the cell often involves multidomain allosteric enzymes that are able to adopt alternate active or inactive conformations in response to specific stimuli. It is therefore of great interest to elucidate the energetic and structural determinants that govern the conformational plasticity of these proteins. In this study, free-energy computations have been used to address this fundamental question, focusing on one important family of signaling enzymes, the Src tyrosine kinases. Inactivation of these enzymes depends on the formation of an assembly comprising a tandem of SH3 and SH2 modules alongside a catalytic domain. Activation results from the release of the SH3 and SH2 domains, which are then believed to be structurally uncoupled by virtue of a flexible peptide link. In contrast to this view, this analysis shows that inactivation depends critically on the intrinsic propensity of the SH3-SH2 tandem to adopt conformations that are conducive to the assembled inactive state, even when no interactions with the rest of the kinase are possible. This funneling of the available conformational space is encoded within the SH3-SH2 connector, which appears to have evolved to modulate the flexibility of the tandem in solution. To further substantiate this notion, we show how constitutively activating mutations in the SH3-SH2 connector shift the assembly equilibrium toward the disassembled, active state. Based on a similar analysis of several constructs of the kinase complex, we propose that assembly is characterized by the progressive optimization of the protein's conformational energy, with little or no energetic frustration.

Front and Back Movement Analysis of a Triangle-Structured Three-Wheeled Omnidirectional Mobile Robot by Varying the Angles between Two Selected Wheels

PubMed Central

Mohanraj, A. P.; Elango, A.; Reddy, Mutra Chanakya

2016-01-01

Omnidirectional robots can move in all directions without steering their wheels and it can rotate clockwise and counterclockwise with reference to their axis. In this paper, we focused only on front and back movement, to analyse the square- and triangle-structured omnidirectional robot movements. An omnidirectional mobile robot shows different performances with the different number of wheels and the omnidirectional mobile robot's chassis design. Research is going on in this field to improve the accurate movement capability of omnidirectional mobile robots. This paper presents a design of a unique device of Angle Variable Chassis (AVC) for linear movement analysis of a three-wheeled omnidirectional mobile robot (TWOMR), at various angles (θ) between the wheels. Basic mobility algorithm is developed by varying the angles between the two selected omnidirectional wheels in TWOMR. The experiment is carried out by varying the angles (θ = 30°, 45°, 60°, 90°, and 120°) between the two selected omniwheels and analysing the movement of TWOMR in forward direction and reverse direction on a smooth cement surface. Respectively, it is compared to itself for various angles (θ), to get its advantages and weaknesses. The conclusion of the paper provides effective movement of TWOMR at a particular angle (θ) and also the application of TWOMR in different situations. PMID:26981585

Mission Analysis and Orbit Control of Interferometric Wheel Formation Flying

NASA Astrophysics Data System (ADS)

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.

Development and testing of a new system for assessing wheel-running behaviour in rodents.

PubMed

Chomiak, Taylor; Block, Edward W; Brown, Andrew R; Teskey, G Campbell; Hu, Bin

2016-05-05

Wheel running is one of the most widely studied behaviours in laboratory rodents. As a result, improved approaches for the objective monitoring and gathering of more detailed information is increasingly becoming important for evaluating rodent wheel-running behaviour. Here our aim was to develop a new quantitative wheel-running system that can be used for most typical wheel-running experimental protocols. Here we devise a system that can provide a continuous waveform amenable to real-time integration with a high-speed video ideal for wheel-running experimental protocols. While quantification of wheel running behaviour has typically focused on the number of revolutions per unit time as an end point measure, the approach described here allows for more detailed information like wheel rotation fluidity, directionality, instantaneous velocity, and acceleration, in addition to total number of rotations, and the temporal pattern of wheel-running behaviour to be derived from a single trace. We further tested this system with a running-wheel behavioural paradigm that can be used for investigating the neuronal mechanisms of procedural learning and postural stability, and discuss other potentially useful applications. This system and its ability to evaluate multiple wheel-running parameters may become a useful tool for screening new potentially important therapeutic compounds related to many neurological conditions.

Space shuttle wheels and brakes

NASA Technical Reports Server (NTRS)

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.

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

PubMed

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.

Reaction Wheel Disturbance Modeling, Jitter Analysis, and Validation Tests for Solar Dynamics Observatory

NASA Technical Reports Server (NTRS)

Liu,Kuo-Chia; Maghami, Peiman; Blaurock, Carl

2008-01-01

The Solar Dynamics Observatory (SDO) aims to study the Sun's influence on the Earth by understanding the source, storage, and release of the solar energy, and the interior structure of the Sun. During science observations, the jitter stability at the instrument focal plane must be maintained to less than a fraction of an arcsecond for two of the SDO instruments. To meet these stringent requirements, a significant amount of analysis and test effort has been devoted to predicting the jitter induced from various disturbance sources. One of the largest disturbance sources onboard is the reaction wheel. This paper presents the SDO approach on reaction wheel disturbance modeling and jitter analysis. It describes the verification and calibration of the disturbance model, and ground tests performed for validating the reaction wheel jitter analysis. To mitigate the reaction wheel disturbance effects, the wheels will be limited to operate at low wheel speeds based on the current analysis. An on-orbit jitter test algorithm is also presented in the paper which will identify the true wheel speed limits in order to ensure that the wheel jitter requirements are met.

A third-order approximation method for three-dimensional wheel-rail contact

NASA Astrophysics Data System (ADS)

Negretti, Daniele

2012-03-01

Multibody train analysis is used increasingly by railway operators whenever a reliable and time-efficient method to evaluate the contact between wheel and rail is needed; particularly, the wheel-rail contact is one of the most important aspects that affects a reliable and time-efficient vehicle dynamics computation. The focus of the approach proposed here is to carry out such tasks by means of online wheel-rail elastic contact detection. In order to improve efficiency and save time, a main analytical approach is used for the definition of wheel and rail surfaces as well as for contact detection, then a final numerical evaluation is used to locate contact. The final numerical procedure consists in finding the zeros of a nonlinear function in a single variable. The overall method is based on the approximation of the wheel surface, which does not influence the contact location significantly, as shown in the paper.

A method for improved accuracy in three dimensions for determining wheel/rail contact points

NASA Astrophysics Data System (ADS)

Yang, Xinwen; Gu, Shaojie; Zhou, Shunhua; Zhou, Yu; Lian, Songliang

2015-11-01

Searching for the contact points between wheels and rails is important because these points represent the points of exerted contact forces. In order to obtain an accurate contact point and an in-depth description of the wheel/rail contact behaviours on a curved track or in a turnout, a method with improved accuracy in three dimensions is proposed to determine the contact points and the contact patches between the wheel and the rail when considering the effect of the yaw angle and the roll angle on the motion of the wheel set. The proposed method, with no need of the curve fitting of the wheel and rail profiles, can accurately, directly, and comprehensively determine the contact interface distances between the wheel and the rail. The range iteration algorithm is used to improve the computation efficiency and reduce the calculation required. The present computation method is applied for the analysis of the contact of rails of CHINA (CHN) 75 kg/m and wheel sets of wearing type tread of China's freight cars. In addition, it can be proved that the results of the proposed method are consistent with that of Kalker's program CONTACT, and the maximum deviation from the wheel/rail contact patch area of this two methods is approximately 5%. The proposed method, can also be used to investigate static wheel/rail contact. Some wheel/rail contact points and contact patch distributions are discussed and assessed, wheel and rail non-worn and worn profiles included.

Anthropometry and Standards for Wheeled Mobility: An International Comparison

ERIC Educational Resources Information Center

Steinfeld, Edward; Maisel, Jordana; Feathers, David; D'Souza, Clive

2010-01-01

Space requirements for accommodating wheeled mobility devices and their users in the built environment are key components of standards for accessible design. These requirements typically include dimensions for clear floor areas, maneuvering clearances, seat and knee clearance heights, as well as some reference dimensions on wheeled mobility device…

Estimators of wheel slip for electric vehicles using torque and encoder measurements

NASA Astrophysics Data System (ADS)

Boisvert, M.; Micheau, P.

2016-08-01

For the purpose of regenerative braking control in hybrid and electrical vehicles, recent studies have suggested controlling the slip ratio of the electric-powered wheel. A slip tracking controller requires an accurate slip estimation in the overall range of the slip ratio (from 0 to 1), contrary to the conventional slip limiter (ABS) which calls for an accurate slip estimation in the critical slip area, estimated at around 0.15 in several applications. Considering that it is not possible to directly measure the slip ratio of a wheel, the problem is to estimate the latter from available online data. To estimate the slip of a wheel, both wheel speed and vehicle speed must be known. Several studies provide algorithms that allow obtaining a good estimation of vehicle speed. On the other hand, there is no proposed algorithm for the conditioning of the wheel speed measurement. Indeed, the noise included in the wheel speed measurement reduces the accuracy of the slip estimation, a disturbance increasingly significant at low speed and low torque. Herein, two different extended Kalman observers of slip ratio were developed. The first calculates the slip ratio with data provided by an observer of vehicle speed and of propeller wheel speed. The second observer uses an original nonlinear model of the slip ratio as a function of the electric motor. A sinus tracking algorithm is included in the two observers, in order to reject harmonic disturbances of wheel speed measurement. Moreover, mass and road uncertainties can be compensated with a coefficient adapted online by an RLS. The algorithms were implemented and tested with a three-wheel recreational hybrid vehicle. Experimental results show the efficiency of both methods.

Behavioral assessment of intermittent wheel running and individual housing in mice in the laboratory.

PubMed

Pham, Therese M; Brené, Stefan; Baumans, Vera

2005-01-01

Physical cage enrichment--exercise devices for rodents in the laboratory--often includes running wheels. This study compared responses of mice in enriched physical and social conditions and in standard social conditions to wheel running, individual housing, and open-field test. The study divided into 6 groups, 48 female BALB/c mice group housed in enriched and standard conditions. On alternate days, the study exposed 2 groups to individual running wheel cages. It intermittently separated from their cage mates and housed individually 2 groups with no running wheels; 2 control groups remained in enriched or standard condition cages. There were no significant differences between enriched and standard group housed mice in alternate days' wheel running. Over time, enriched, group housed mice ran less. Both groups responded similarly to individual housing. In open-field test, mice exposed to individual housing without running wheel moved more and faster than wheel running and home cage control mice. They have lower body weights than group housed and wheel running mice. Intermittent withdrawal of individual housing affects the animals more than other commodities. Wheel running normalizes some effects of intermittent separation from the enriched, social home cage.

Rover Wheel-Actuated Tool Interface

NASA Technical Reports Server (NTRS)

Matthews, Janet; Ahmad, Norman; Wilcox, Brian

2007-01-01

A report describes an interface for utilizing some of the mobility features of a mobile robot for general-purpose manipulation of tools and other objects. The robot in question, now undergoing conceptual development for use on the Moon, is the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) rover, which is designed to roll over gentle terrain or walk over rough or steep terrain. Each leg of the robot is a six-degree-of-freedom general purpose manipulator tipped by a wheel with a motor drive. The tool interface includes a square cross-section peg, equivalent to a conventional socket-wrench drive, that rotates with the wheel. The tool interface also includes a clamp that holds a tool on the peg, and a pair of fold-out cameras that provides close-up stereoscopic images of the tool and its vicinity. The field of view of the imagers is actuated by the clamp mechanism and is specific to each tool. The motor drive can power any of a variety of tools, including rotating tools for helical fasteners, drills, and such clamping tools as pliers. With the addition of a flexible coupling, it could also power another tool or remote manipulator at a short distance. The socket drive can provide very high torque and power because it is driven by the wheel motor.

Wheel climb derailment criteria for evaluation of rail vehicle safety

DOT National Transportation Integrated Search

1984-01-01

Criteria for evaluating safety of rail vehicles with respect to wheel climb derailment are reviewed. The relationship between flanging wheel lateral to veritical force ratio at impending derailment and angle of attack, lateral velocity and longitudin...

Planter closing wheel effects on cotton emergence in a conservation tillage system

USDA-ARS?s Scientific Manuscript database

Closing wheels on a row crop planter help provide good seed-soil contact during planting and can influence emergence and crop stand. Various types of closing wheels are available to producers for use on planters. Seven closing wheel types were used on a row crop planter planting cotton in a conser...

14 CFR 23.497 - Supplementary conditions for tail wheels.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Structure Ground Loads § 23.497 Supplementary conditions for tail wheels. In determining the ground loads on the tail wheel and affected supporting structures, the following apply: (a) For the obstruction load, the limit ground reaction obtained in the tail down landing condition is assumed to act up and aft...

14 CFR 23.497 - Supplementary conditions for tail wheels.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Structure Ground Loads § 23.497 Supplementary conditions for tail wheels. In determining the ground loads on the tail wheel and affected supporting structures, the following apply: (a) For the obstruction load, the limit ground reaction obtained in the tail down landing condition is assumed to act up and aft...

Considerations on the use of elastic wheels to the urban transport vehicles

NASA Astrophysics Data System (ADS)

Sebesan, Ioan; Arsene, Sorin; Manea, Ion

2018-03-01

To minimize dynamic wheel-rail interaction efforts a condition is that the unassembled mass of the vehicle is as small as possible. The elastic wheel by its construction fulfills these conditions - she has interposed between the crown and the body of the wheel, the elastic rubber elements. In this way, it can be considered that the unsupported mass is represented only by the mass of the wheel crown. Additionally, this elasticity also has a reduction effect on rolling noise. This feature makes it suitable for use on urban transport vehicles.

Naloxone attenuates the conditioned place preference induced by wheel running in rats.

PubMed

Lett, B T; Grant, V L; Koh, M T

2001-02-01

Pairings, during which an episode of wheel running is followed by confinement in a distinctive place, produce conditioned place preference (CPP) in rats. This finding indicates that wheel running has a rewarding effect that outlasts the activity itself. In two similar experiments, we tested the hypothesis that this rewarding effect of wheel running is mediated by endogenous opioids. During a paired trial, the rats in the naloxone group were first allowed to wheel run for 2 h, then injected with naloxone (0.5 or 0.1 mg/kg in Experiments 1 and 2, respectively), and 10 min later placed in a distinctive chamber. During an unpaired trial, these rats were confined in an adjoining chamber without wheel running. Naloxone was injected before placement in both chambers, so that if naloxone-induced conditioned place aversion occurred, it would have counteracting effects on performance during the preference test. The rats in the saline group were similarly treated, except that saline was injected instead of naloxone. CPP occurred in the saline group, but not in the naloxone group. Thus, naloxone attenuated the CPP induced by wheel running. This finding supports the hypothesis that the rewarding effect of wheel running is mediated by endogenous opioids.

Fault detection method for railway wheel flat using an adaptive multiscale morphological filter

NASA Astrophysics Data System (ADS)

Li, Yifan; Zuo, Ming J.; Lin, Jianhui; Liu, Jianxin

2017-02-01

This study explores the capacity of the morphology analysis for railway wheel flat fault detection. A dynamic model of vehicle systems with 56 degrees of freedom was set up along with a wheel flat model to calculate the dynamic responses of axle box. The vehicle axle box vibration signal is complicated because it not only contains the information of wheel defect, but also includes track condition information. Thus, how to extract the influential features of wheels from strong background noise effectively is a typical key issue for railway wheel fault detection. In this paper, an algorithm for adaptive multiscale morphological filtering (AMMF) was proposed, and its effect was evaluated by a simulated signal. And then this algorithm was employed to study the axle box vibration caused by wheel flats, as well as the influence of track irregularity and vehicle running speed on diagnosis results. Finally, the effectiveness of the proposed method was verified by bench testing. Research results demonstrate that the AMMF extracts the influential characteristic of axle box vibration signals effectively and can diagnose wheel flat faults in real time.

Reciprocal inhibitory effects of intravenous d-methamphetamine self-administration and wheel activity in rats

PubMed Central

Miller, ML; Vaillancourt, BD; Wright, MJ; Aarde, SM; Vandewater, SA; Creehan, KM; Taffe, MA

2011-01-01

Background Some epidemiological and cessation studies suggest physical exercise attenuates or prevents recreational drug use in humans. Preclinical studies indicate wheel activity reduces cocaine self-administration in rats; this may, however, require the establishment of compulsive wheel activity. Methods Effects of concurrent wheel activity on intravenous d-methamphetamine (METH) self-administration were examined in male Wistar and Sprague Dawley rats with negligible prior wheel experience. Wistar rats self-administered METH (0.05 mg/kg/inf) under a fixed-ratio 1 (FR1) schedule with concurrent access to an activity wheel during sessions 1–14, 8–21 or 15–21. Control rats which did not self-administer METH had access to an activity wheel during sessions 1–14, 8–21 or 15–28. Sprague Dawley rats self-administered METH (0.1 mg/kg/inf) under FR1 for 14 sessions with either concurrent access to a locked or an unlocked activity wheel. Results METH self-administration was lower when the wheel was available concurrently from the start of self-administration training in both strains, even though Sprague Dawley rats self-administered twice as many METH infusions and ran one-sixth as much on the wheel compared to Wistar rats. Wheel access initiated after 7 or 14 days had no effect on METH self-administration in Wistar rats. Wheel activity was significantly reduced in these groups compared with the group with concurrent wheel and METH access for the first 14 sessions. Conclusions These data show METH self-administration is reduced by exercise if initiated from the start of self-administration and that prior METH self-administration experience interferes with the value of exercise as a reinforcer. PMID:21899959

Achieving 15% Tandem Polymer Solar Cells

DTIC Science & Technology

2015-06-23

solar cell structures – both polymer only and hybrid tandem cells to constantly pushing the envelope of solution processed solar cell ...performance – 11.6% polymer tandem cell , 7% transparent tandem polymer cell , and over 10% PCE hybrid tandem solar cells were achieved. In addition, AFOSR’s...final support also enabled us to explore novel hybrid perovskite solar cells in depth. For example, single junction cell efficiency

14 CFR 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CATEGORY AIRPLANES Structure Ground Loads § 23.511 Ground load; unsymmetrical loads on multiple-wheel units... coefficient of friction of 0.8 applied to the main gear and its supporting structure. (b) Unequal tire loads... distribution, to the dual wheels and tires in each dual wheel landing gear unit. (c) Deflated tire loads. For...

14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2014 CFR

2014-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2013 CFR

2013-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2012 CFR

2012-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2011 CFR

2011-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2014 CFR

2014-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2011 CFR

2011-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2012 CFR

2012-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

Code of Federal Regulations, 2013 CFR

2013-01-01

... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the... gravity; or (2) The probability of landing with initial contact on the rear wheel must be shown to be... paragraph (f)(1) of this section must be applied— (i) At the ground contact point with the wheel in the...

Allen figure and broken wheel visual acuity measurement in preschool children.

PubMed

Schmidt, P P

1992-02-01

In a masked investigation, 34 preschool children (n = 34, 19 females and 15 males) between the ages of 3 and 5 years (mean age = 4.1 years) enrolled in Project Headstart had their monocular and binocular visual acuity measured using the Broken Wheel and Allen figure methods. The results showed that 1) a greater range in acuity values was found with the Allen figure than Broken Wheel test, despite the identical Snellen equivalent acuity levels and similar probability of guessing criteria used for both Broken Wheel and Allen figure acuity measurement e.g., no strong statistical correlation (rOD = +0.22, rOS = -0.11 and rOU = +0.04; rho OD = +0.22, rho OS = -0.11, rho OU = 0.00) for the two tests was found; and 2) the Broken Wheel test appeared to discriminate between 20/30 and 20/40 acuity performance more consistently than did Allen figure and in a way not attributable to chance (p less than or equal to 0.003). In a separate evaluation, the Broken Wheel test showed consistency in the acuity measured. Broken Wheel acuity measurement, even with an average variation of +/- 5.6 percent from the corresponding Snellen standard, appears to be a valuable clinical tool to measure acuity in young children.

Structural Insights into DD-Fold Assembly and Caspase-9 Activation by the Apaf-1 Apoptosome.

PubMed

Su, Tsung-Wei; Yang, Chao-Yu; Kao, Wen-Pin; Kuo, Bai-Jiun; Lin, Shan-Meng; Lin, Jung-Yaw; Lo, Yu-Chih; Lin, Su-Chang

2017-03-07

Death domain (DD)-fold assemblies play a crucial role in regulating the signaling to cell survival or death. Here we report the crystal structure of the caspase recruitment domain (CARD)-CARD disk of the human apoptosome. The structure surprisingly reveals that three 1:1 Apaf-1:procaspase-9 CARD protomers form a novel helical DD-fold assembly on the heptameric wheel-like platform of the apoptosome. The small-angle X-ray scattering and multi-angle light scattering data also support that three protomers could form an oligomeric complex similar to the crystal structure. Interestingly, the quasi-equivalent environment of CARDs could generate different quaternary CARD assemblies. We also found that the type II interaction is conserved in all DD-fold complexes, whereas the type I interaction is found only in the helical DD-fold assemblies. This study provides crucial insights into the caspase activation mechanism, which is tightly controlled by a sophisticated and highly evolved CARD assembly on the apoptosome, and also enables better understanding of the intricate DD-fold assembly. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Tandem CARDs of NOD2: Intramolecular Interactions and Recognition of RIP2

PubMed Central

Fridh, Veronica; Rittinger, Katrin

2012-01-01

Caspase recruitment domains (CARDs) are homotypic protein interaction modules that link the stimulus-dependent assembly of large signaling platforms such as inflammasomes to the activation of downstream effectors that often include caspases and kinases and thereby play an important role in the regulation of inflammatory and apoptotic signaling pathways. NOD2 belongs to the NOD-like (NLR) family of intracellular pattern recognition receptors (PRR) and induces activation of the NF-κB pathway in response to the recognition of bacterial components. This process requires the specific recognition of the CARD of the protein kinase RIP2 by the tandem CARDs of NOD2. Here we demonstrate that the tandem CARDs of NOD2 are engaged in an intramolecular interaction that is important for the structural stability of this region. Using a combination of ITC and pull-down experiments we identify distinct surface areas that are involved in the intramolecular tandem CARD interaction and the interaction with the downstream effector RIP2. Our findings indicate that while CARDa of NOD2 might be the primary binding partner of RIP2 the two CARDs of NOD2 do not act independently of one another but may cooperate to from a binding surface that is distinct from that of single CARDs. PMID:22470564

Feasibility of Flaw Detection in Railroad Wheels Using Acoustic Signatures

DOT National Transportation Integrated Search

1976-10-01

The feasibility study on the use of acoustic signatures for detection of flaws in railway wheels was conducted with the ultimate objective of development of an intrack device for moving cars. Determinations of the natural modes of vibrating wheels un...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2011 CFR

2011-07-01

... rim wheel onto a vehicle axle hub. Removing means the opposite of installing. Mounting a tire means... 29 Labor 5 2011-07-01 2011-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2010 CFR

2010-07-01

... rim wheel onto a vehicle axle hub. Removing means the opposite of installing. Mounting a tire means... 29 Labor 5 2010-07-01 2010-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

Improved infrared-sensing running wheel systems with an effective exercise activity indicator.

PubMed

Chen, Chi-Chun; Chang, Ming-Wen; Chang, Ching-Ping; Chang, Wen-Ying; Chang, Shin-Chieh; Lin, Mao-Tsun; Yang, Chin-Lung

2015-01-01

This paper describes an infrared-sensing running wheel (ISRW) system for the quantitative measurement of effective exercise activity in rats. The ISRW system provides superior exercise training compared with commercially available traditional animal running platforms. Four infrared (IR) light-emitting diode/detector pairs embedded around the rim of the wheel detect the rat's real-time position; the acrylic wheel has a diameter of 55 cm and a thickness of 15 cm, that is, it is larger and thicker than traditional exercise wheels, and it is equipped with a rubber track. The acrylic wheel hangs virtually frictionless, and a DC motor with an axially mounted rubber wheel, which has a diameter of 10 cm, drives the acrylic wheel from the outer edge. The system can automatically train rats to run persistently. The proposed system can determine effective exercise activity (EEA), with the IR sensors (which are connected to a conventional PC) recording the rat exercise behavior. A prototype of the system was verified by a hospital research group performing ischemic stroke experiments on rats by considering middle cerebral artery occlusion. The experimental data demonstrated that the proposed system provides greater neuroprotection in an animal stroke model compared with a conventional treadmill and a motorized running wheel for a given exercise intensity. The quantitative exercise effectiveness indicator showed a 92% correlation between an increase in the EEA and a decrease in the infarct volume. This indicator can be used as a noninvasive and objective reference in clinical animal exercise experiments.

Sensor set-up for wireless measurement of automotive rim and wheel parameters in laboratory conditions

NASA Astrophysics Data System (ADS)

Borecki, M.; Prus, P.; Korwin-Pawlowski, M. L.; Rychlik, A.; Kozubel, W.

2017-08-01

Modern rims and wheels are tested at the design and production stages. Tests can be performed in laboratory conditions and on the ride. In the laboratory, complex and costly equipment is used, as for example wheel balancers and impact testers. Modern wheel balancers are equipped with electronic and electro-mechanical units that enable touch-less measurement of dimensions, including precision measurement of radial and lateral wheel run-out, automatic positioning and application of the counterweights, and vehicle wheel set monitoring - tread wear, drift angles and run-out unbalance. Those tests are performed by on-wheel axis measurements with laser distance meters. The impact tester enables dropping of weights from a defined height onto a wheel. Test criteria are the loss of pressure of the tire and generation of cracks in the wheel without direct impact of the falling weights. In the present paper, a set up composed of three accelerometers, a temperature sensor and a pressure sensor is examined as the base of a wheel tester. The sensor set-up configuration, on-line diagnostic and signal transmission are discussed.

Nocturnal to Diurnal Switches with Spontaneous Suppression of Wheel-Running Behavior in a Subterranean Rodent

PubMed Central

Tachinardi, Patricia; Tøien, Øivind; Valentinuzzi, Veronica S.; Buck, C. Loren; Oda, Gisele A.

2015-01-01

Several rodent species that are diurnal in the field become nocturnal in the lab. It has been suggested that the use of running-wheels in the lab might contribute to this timing switch. This proposition is based on studies that indicate feed-back of vigorous wheel-running on the period and phase of circadian clocks that time daily activity rhythms. Tuco-tucos (Ctenomys aff. knighti) are subterranean rodents that are diurnal in the field but are robustly nocturnal in laboratory, with or without access to running wheels. We assessed their energy metabolism by continuously and simultaneously monitoring rates of oxygen consumption, body temperature, general motor and wheel running activity for several days in the presence and absence of wheels. Surprisingly, some individuals spontaneously suppressed running-wheel activity and switched to diurnality in the respirometry chamber, whereas the remaining animals continued to be nocturnal even after wheel removal. This is the first report of timing switches that occur with spontaneous wheel-running suppression and which are not replicated by removal of the wheel. PMID:26460828

A new solution method for wheel/rail rolling contact.

PubMed

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.

Theoretical design study of the MSFC wind-wheel turbine

NASA Technical Reports Server (NTRS)

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.

Wheel Scuff Mark at Rocknest

NASA Image and Video Library

2012-10-04

NASA Mars rover Curiosity cut a wheel scuff mark into a wind-formed ripple at the Rocknest site to give researchers a better opportunity to examine the particle-size distribution of the material forming the ripple.

Model Design for Water Wheel Control System of Heumgyeonggaknu

NASA Astrophysics Data System (ADS)

Kim, Sang Hyuk; Ham, Seon Young; Lee, Yong Sam

2016-03-01

Heumgyeonggaknu (????) is powered by a water-hammering-type water wheel. The technique that maintains the constant speed of the water wheel is assumed to be the one used in the Cheonhyeong (???) apparatus in Shui Yun Yi Xiang Tai (???) made by the Northern Song (??) dynasty in the 11th century. We investigated the history of the development and characteristics of the Cheonhyeong apparatus, and we analyzed ways to transmit the power of Heumgyeonggaknu. In addition, we carried out a conceptual design to systematically examine the power control system. Based on the conceptual design, we built a model for a water wheel control system that could be used in experiments by drawing a 3D model and a basic design.

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

PubMed

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.

Cassini Attitude Control Operations - Guidelines Levied on Science to Extend Reaction Wheel Life

NASA Technical Reports Server (NTRS)

Mittelsteadt, Carson O.

2011-01-01

The Cassini spacecraft was launched on October 15, 1997 and arrived at Saturn on June 30, 2004. It has performed detailed observations and remote sensing of Saturn, its rings, and its satellites since that time. Cassini deployed the European-built Huygens probe, which descended through the Titan atmosphere (Saturn's largest moon) and landed on its surface on January 14, 2005. The Cassini mission has recently been approved by NASA to continue through September of 2017. This 7-year extension is called the Solstice mission and it presents challenges to the spacecraft operations team and its ability to maintain the health of the spacecraft. To keep the spacecraft healthy for 7 more years, the spacecraft team must carefully manage hydrazine use (about 48% of the 132 kg launch load remains as of January 2011). A vital part of conserving hydrazine is to use the reaction wheel assembly (RWA) control system for precise pointing and slews wherever possible. In any given week, the Cassini spacecraft is commanded to use RWA control about 99% of the time, with about 1% of the time requiring reaction control system (RCS) thruster control (to perform Delta V course corrections or to bias the RWA momentum). Such extensive use of the RWA hardware throughout the mission requires that the RWAs be operated in a way that minimizes degradation in the RWA electronics, DC motor, and spin bearing for each reaction wheel. Three consumables in particular have been identified for the RWAs: (1) Total number of revolutions for each RWA. (2) Time spent at very low wheel speeds. At these low speeds, good elasto-hydrodynamic (EHD) film lubrication may be compromised. (3) Total number of on/off power cycles. The second of these consumables, minimizing the time spent at very low wheel speeds, is especially important to keep the spin bearing healthy and well-lubricated. These consumables are actively managed by the attitude control operations team throughout the mission. One vital management

Wheels Shorty Award

NASA Image and Video Library

2011-03-30

A Shorty Award is seen Wednesday, March 30, 2011 at NASA Headquarters in Washington. The award was presented to NASA astronaut Doug Wheelock for an image of the moon he took and posted to his Twitter account, @Astro_Wheels, while living aboard the International Space Station last year. The awards ceremony was held at the TimesCenter in New York City on Monday, March 28. Photo Credit: (NASA/Paul E. Alers)

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

PubMed

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

PubMed Central

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

Rational design of alpha-helical tandem repeat proteins with closed architectures

PubMed Central

Doyle, Lindsey; Hallinan, Jazmine; Bolduc, Jill; Parmeggiani, Fabio; Baker, David; Stoddard, Barry L.; Bradley, Philip

2015-01-01

Tandem repeat proteins, which are formed by repetition of modular units of protein sequence and structure, play important biological roles as macromolecular binding and scaffolding domains, enzymes, and building blocks for the assembly of fibrous materials1,2. The modular nature of repeat proteins enables the rapid construction and diversification of extended binding surfaces by duplication and recombination of simple building blocks3,4. The overall architecture of tandem repeat protein structures – which is dictated by the internal geometry and local packing of the repeat building blocks – is highly diverse, ranging from extended, super-helical folds that bind peptide, DNA, and RNA partners5–9, to closed and compact conformations with internal cavities suitable for small molecule binding and catalysis10. Here we report the development and validation of computational methods for de novo design of tandem repeat protein architectures driven purely by geometric criteria defining the inter-repeat geometry, without reference to the sequences and structures of existing repeat protein families. We have applied these methods to design a series of closed alpha-solenoid11 repeat structures (alpha-toroids) in which the inter-repeat packing geometry is constrained so as to juxtapose the N- and C-termini; several of these designed structures have been validated by X-ray crystallography. Unlike previous approaches to tandem repeat protein engineering12–20, our design procedure does not rely on template sequence or structural information taken from natural repeat proteins and hence can produce structures unlike those seen in nature. As an example, we have successfully designed and validated closed alpha-solenoid repeats with a left-handed helical architecture that – to our knowledge – is not yet present in the protein structure database21. PMID:26675735

Mathematical model of rolling an elastic wheel over deformable support base

NASA Astrophysics Data System (ADS)

Volskaia, V. N.; Zhileykin, M. M.; Zakharov, A. Y.

2018-02-01

One of the main direction of economic growth in Russia remains to be a speedy development of north and northeast regions that are the constituents of the 60 percent of the country territory. The further development of these territories requires new methods and technologies for solving transport and technological problems when off-road transportation of cargoes and people is conducting. One of the fundamental methods of patency prediction is imitation modeling of wheeled vehicles movement in different operating conditions. Both deformable properties of tires and physical and mechanical properties of the ground: normal tire deflection and gauge depth; variation of contact patch area depending on the load and pressure of air in the tire; existence of hysteresis losses in the tire material which are influencing on the rolling resistance due to friction processes between tire and ground in the contact patch; existence of the tangential reaction from the ground by entire contact area influence on the tractive patency. Nowadays there are two main trends in theoretical research of interaction wheeled propulsion device with ground: analytical method involving mathematical description of explored process and finite element method based on computational modeling. Mathematical models of interaction tire with the ground are used both in processes of interaction individual wheeled propulsion device with ground and researches of mobile vehicle dynamical models operated in specific road and climate conditions. One of the most significant imperfection of these models is the description of interaction wheel with flat deformable support base whereas profile of real support base surface has essential height of unevenness which is commensurate with radius of the wheel. The description of processes taking place in the ground under influence of the wheeled propulsion device using the finite element method is relatively new but most applicable lately. The application of this method allows

49 CFR 571.129 - Standard No. 129; New non-pneumatic tires for passenger cars.

Code of Federal Regulations, 2013 CFR

2013-10-01

...-pneumatic tire assembly incorporates a wheel, supports the tire, and attaches, either integrally or... directly or through a wheel or wheel center member, the vertical load and tractive forces from the roadway... assembly means a non-pneumatic tire, alone or in combination with a wheel or wheel center member, which can...

14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

Code of Federal Regulations, 2014 CFR

2014-01-01

... (0.80 may be used); F Vmax=maximum vertical force on wheel (pounds)=n j W e, where W e and n j are... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The...

14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

Code of Federal Regulations, 2013 CFR

2013-01-01

... (0.80 may be used); F Vmax=maximum vertical force on wheel (pounds)=n j W e, where W e and n j are... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The...

14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

Code of Federal Regulations, 2011 CFR

2011-01-01

... (0.80 may be used); F Vmax=maximum vertical force on wheel (pounds)=n j W e, where W e and n j are... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The...

14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

Code of Federal Regulations, 2010 CFR

2010-01-01

... (0.80 may be used); F Vmax=maximum vertical force on wheel (pounds)=n j W e, where W e and n j are... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The...

14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

Code of Federal Regulations, 2012 CFR

2012-01-01

... (0.80 may be used); F Vmax=maximum vertical force on wheel (pounds)=n j W e, where W e and n j are... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The...

Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel

PubMed Central

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. PMID:29515651

Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel.

PubMed

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.

The effect of mountain bike wheel size on cross-country performance.

PubMed

Hurst, Howard Thomas; Sinclair, Jonathan; Atkins, Stephen; Rylands, Lee; Metcalfe, John

2017-07-01

The purpose of this study was to determine the influence of different wheel size diameters on indicators of cross-country mountain bike time trial performance. Nine competitive male mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) performed 1 lap of a 3.48 km mountain bike (MTB) course as fast as possible on 26″, 27.5″ and 29″ wheeled MTB. Time (s), mean power (W), cadence (revs · min -1 ) and velocity (km · h -1 ) were recorded for the whole lap and during ascent and descent sections. One-way repeated measure ANOVA was used to determine significant differences. Results revealed no significant main effects for any variables by wheel size during all trials, with the exception of cadence during the descent (F (2, 16)  = 8.96; P = .002; P 2  = .53). Post hoc comparisons revealed differences lay between the 26″ and 29″ wheels (P = .02). The findings indicate that wheel size does not significantly influence performance during cross-country when ridden by trained mountain bikers, and that wheel choice is likely due to personal choice or sponsorship commitments.

Impact of wheel running on chronic ethanol intake in aged Syrian hamsters.

PubMed

Brager, Allison J; Hammer, Steven B

2012-10-10

Alcohol dependence in aging populations is seen as a public health concern, most recently because of the significant proportion of heavy drinking among "Baby Boomers." Basic animal research on the effects of aging on physiological and behavioral regulation of ethanol (EtOH) intake is sparse, since most of this research is limited to younger models of alcoholism. Here, EtOH drinking and preference were measured in groups of aged Syrian hamsters. Further, because voluntary exercise (wheel-running) is a rewarding substitute for EtOH in young adult hamsters, the potential for such reward substitution was also assessed. Aged (24 month-old) male hamsters were subjected to a three-stage regimen of free-choice EtOH (20% v/v) or water and unlocked or locked running wheels to investigate the modulatory effects of voluntary wheel running on EtOH intake and preference. Levels of fluid intake and activity were recorded daily across 60 days of experimentation. Prior to wheel running, levels of EtOH intake were significantly less than levels of water intake, resulting in a low preference for EtOH (30%). Hamsters with access to an unlocked running wheel had decreased EtOH intake and preference compared with hamsters with access to a locked running wheel. These group differences in EtOH intake and preference were sustained for up to 10 days after running wheels were re-locked. These results extend upon those of our previous work in young adult hamsters, indicating that aging dampens EtOH intake and preference. Voluntary wheel running further limited EtOH intake, suggesting that exercise could offer a practical approach for managing late-life alcoholism. Copyright © 2012 Elsevier Inc. All rights reserved.

Voluntary wheel running improves adipose tissue immunometabolism in ovariectomized low-fit rats.

PubMed

Zidon, Terese M; Park, Young-Min; Welly, Rebecca J; Woodford, Makenzie L; Scroggins, Rebecca J; Britton, Steven L; Koch, Lauren G; Booth, Frank W; Padilla, Jaume; Kanaley, Jill A; Vieira-Potter, Victoria J

2018-01-02

Loss of ovarian hormones is associated with increased adiposity, white adipose tissue (WAT) inflammation, and insulin resistance (IR). Previous work demonstrated ovariectomized (OVX) rats bred for high aerobic fitness (HCR) are protected against weight gain and IR compared to rats bred for low aerobic fitness (LCR) yet wheel running prevents OVX-induced IR in LCR rats. The purpose of this study was to determine whether adipose tissue immunometabolic characteristics from female HCR and LCR rats differs before or after OVX, and whether wheel running mitigates OVX-induced adipose tissue immunometabolic changes in LCR rats. Female OVX HCR and LCR rats were all fed a high fat diet (HFD) (n = 7-8/group) and randomized to either a running wheel or remain sedentary for 11 weeks. Ovary-intact rats (n = 7-12/group) were fed a standard chow diet with no wheel. Ovary-intact LCR rats had a greater visceral WAT inflammatory profile compared to HCR. Following OVX, sedentary LCR rats had greater serum leptin (p<0.001) and WAT inflammation (p<0.05) than sedentary HCR. Wheel running normalized the elevated serum leptin and reduced both visceral (p<0.05) and subcutaneous (p<0.03) WAT inflammatory markers in the LCR rats. Paradoxically, wheel running increased some markers of WAT inflammation in OVX HCR rats (p<0.05), which correlated with observed weight gain. Taken together, HCR rats appear to have a healthier WAT immune and metabolic profile compared to LCR, even following OVX. Wheel running improves WAT health in previously sedentary LCR rats. On the other hand, increased WAT inflammation is associated with adiposity gain despite a high volume of wheel running in HCR rats.

Voluntary resistance running wheel activity pattern and skeletal muscle growth in rats.

PubMed

Legerlotz, Kirsten; Elliott, Bradley; Guillemin, Bernard; Smith, Heather K

2008-06-01

The aims of this study were to characterize the pattern of voluntary activity of young rats in response to resistance loading on running wheels and to determine the effects of the activity on the growth of six limb skeletal muscles. Male Sprague-Dawley rats (4 weeks old) were housed individually with a resistance running wheel (R-RUN, n = 7) or a conventional free-spinning running wheel (F-RUN, n = 6) or without a wheel, as non-running control animals (CON, n = 6). The torque required to move the wheel in the R-RUN group was progressively increased, and the activity (velocity, distance and duration of each bout) of the two running wheel groups was recorded continuously for 45 days. The R-RUN group performed many more, shorter and faster bouts of running than the F-RUN group, yet the mean daily distance was not different between the F-RUN (1.3 +/- 0.2 km) and R-RUN group (1.4 +/- 0.6 km). Only the R-RUN resulted in a significantly (P < 0.05) enhanced muscle wet mass, relative to the increase in body mass, of the plantaris (23%) and vastus lateralis muscle (17%), and the plantaris muscle fibre cross-sectional area, compared with CON. Both F-RUN and R-RUN led to a significantly greater wet mass relative to increase in body mass and muscle fibre cross-sectional area in the soleus muscle compared with CON. We conclude that the pattern of voluntary activity on a resistance running wheel differs from that on a free-spinning running wheel and provides a suitable model to induce physiological muscle hypertrophy in rats.

Design of a wheeled articulating land rover

NASA Technical Reports Server (NTRS)

Stauffer, Larry; Dilorenzo, Mathew; Yandle, Barbara

1994-01-01

The WALRUS is a wheeled articulating land rover that will provide Ames Research Center with a reliable, autonomous vehicle for demonstrating and evaluating advanced technologies. The vehicle is one component of the Ames Research Center's on-going Human Exploration Demonstration Project. Ames Research Center requested a system capable of traversing a broad spectrum of surface types and obstacles. In addition, this vehicle must have an autonomous navigation and control system on board and its own source of power. The resulting design is a rover that articulates in two planes of motion to allow for increased mobility and stability. The rover is driven by six conical shaped aluminum wheels, each with an independent, internally coupled motor. Mounted on the rover are two housings and a removable remote control system. In the housings, the motor controller board, tilt sensor, navigation circuitry, and QED board are mounted. Finally, the rover's motors and electronics are powered by thirty C-cell rechargeable batteries, which are located in the rover wheels and recharged by a specially designed battery charger.

The vibration behavior of railway track at high frequencies under multiple preloads and wheel interactions

PubMed

Wu; Thompson

2000-09-01

The track foundation is preloaded by multiple wheel loads due to the train weight and, as the pad and ballast are nonlinear, their stiffness depends upon the preload in them. Due to the influence of these resilient components of the track, the track vibration is affected by the wheel loads. It is also affected by the wheel/rail interactions. In this article the preloads in the pad and ballast are calculated by considering the nonlinear properties of the track foundation, and thus the preloaded pad and ballast stiffnesses are determined. The vibration properties are explored for the track under multiple wheel loads and multiple wheel/rail interactions by comparing the results from different track models with and without these effects. It is found that the point receptance of the track is reduced and the vibration decay rate is enhanced at low frequencies due to the wheel loads. The effects of the wheel/rail interactions are most significant for frequencies 400-2000 Hz. Because of the wheel/rail interactions, the point receptance fluctuates and the vibration decay is enhanced in the regions around the wheels.

TANDEM: matching proteins with tandem mass spectra.

PubMed

Craig, Robertson; Beavis, Ronald C

2004-06-12

Tandem mass spectra obtained from fragmenting peptide ions contain some peptide sequence specific information, but often there is not enough information to sequence the original peptide completely. Several proprietary software applications have been developed to attempt to match the spectra with a list of protein sequences that may contain the sequence of the peptide. The application TANDEM was written to provide the proteomics research community with a set of components that can be used to test new methods and algorithms for performing this type of sequence-to-data matching. The source code and binaries for this software are available at http://www.proteome.ca/opensource.html, for Windows, Linux and Macintosh OSX. The source code is made available under the Artistic License, from the authors.

A rational fraction polynomials model to study vertical dynamic wheel-rail interaction

NASA Astrophysics Data System (ADS)

Correa, N.; Vadillo, E. G.; Santamaria, J.; Gómez, J.

2012-04-01

This paper presents a model designed to study vertical interactions between wheel and rail when the wheel moves over a rail welding. The model focuses on the spatial domain, and is drawn up in a simple fashion from track receptances. The paper obtains the receptances from a full track model in the frequency domain already developed by the authors, which includes deformation of the rail section and propagation of bending, elongation and torsional waves along an infinite track. Transformation between domains was secured by applying a modified rational fraction polynomials method. This obtains a track model with very few degrees of freedom, and thus with minimum time consumption for integration, with a good match to the original model over a sufficiently broad range of frequencies. Wheel-rail interaction is modelled on a non-linear Hertzian spring, and consideration is given to parametric excitation caused by the wheel moving over a sleeper, since this is a moving wheel model and not a moving irregularity model. The model is used to study the dynamic loads and displacements emerging at the wheel-rail contact passing over a welding defect at different speeds.

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

USGS Publications Warehouse

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.

On the dynamic response at the wheel axle of a pneumatic tire

NASA Astrophysics Data System (ADS)

Kung, L. E.; Soedel, W.; Yang, T. Y.

1986-06-01

A method for calculating the steady state displacement response and force transmission at the wheel axle of a pneumatic tire-suspension system due to a steady state force or displacement excitation at the tire to ground contact point is developed. The method requires the frequency responses (or receptances)_of both tire-wheel and suspension units. The frequency response of the tire-wheel unit is obtained by using the modal expansion method. The natural frequencies and mode shapes of the tire-wheel unit are obtained by using a geometrically non-linear, ring type, thin shell finite element of laminate composite. The frequency response of the suspension unit is obtained analytically. These frequency responses are used to calculate the force-input and the displacement-input responses at the wheel axle. This method allows the freedom of designing a vehicle and its tires independently and still achieving optimum dynamic performance.

Wheeled and standard walkers in Parkinson's disease patients with gait freezing.

PubMed

Cubo, Esther; Moore, Charity G; Leurgans, Sue; Goetz, Christopher G

2003-10-01

Compare the efficacy of two walking assistance devices (wheeled walker and standard walker) to unassisted walking for patients with PD and gait freezing. Although numerous walking devices are used clinically, their relative effects on freezing and walking speed have never been systematically tested. Nineteen PD patients (14 non-demented) walked under three conditions in randomized order: unassisted walking, standard walker, and wheeled walker. Patients walked up to three times in each condition through a standard course that included rising from a chair, walking through a doorway, straightway walking, pivoting, and return. Total walking time, freezing time and number of freezes were compared for the three conditions using mixed models (walking time) and Friedman's test (freezing). The wheeled walker was further studied by comparing the effect of an attached laser that projected a bar of light on the floor as a visual walking cue. Use of either type of device significantly slowed walking compared to unassisted walking. Neither walker reduced any index of freezing, nor the laser attachment offered any advantage to the wheeled walker. The standard walker increased freezing, and the wheeled walker had no effect on freezing. Among the non-demented subjects (n=14), the same patterns occurred, although the walking speed was less impaired by the wheeled walker than the standard walker in this group. Though walkers may stabilize patients and increase confidence, PD patients walk more slowly when using them, without reducing freezing. Because the wheeled walker was intermediate for walking time and does not aggravate freezing, if walkers are used for these subjects, this type of walker should be favored.